Note: Descriptions are shown in the official language in which they were submitted.
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LIQUID FILLING DEVICE
Field of the Invention
This invention relates to devices that are used to fill one or more
electrolytic cells of an
electrolyte battery with water and, more particularly, to a liquid filling
device adapted to fill one
or more electrolytic cells of an electrolyte battery with water without the
use of moving parts,
and without the need for circulating battery electrolyte from the cells.
Background of the Invention
Batteries that comprise liquid electrolyte, such as lead acid batteries or the
like used in
deep cycle or other applications, require for optimum performance that the
liquid electrolyte
contained within each electrolytic cell be maintained at a specific
electrolyte level. The desired
electrolyte level generally corresponds to the volume of electrolyte that is
needed to completely
submerge the battery electrode plates contained within the electrolytic cell.
Completely
submerging the electrode plates of the battery with electrolyte promotes
optimal battery
operation, as it provides a maximum degree of electrolyte to electrode plate
contact, and thereby
promotes a maximum degree of electricity generating electrochemical reaction
within each
electrolytic cell of the battery.
To maintain an optimal level of battery performance, and to maximize battery
service life,
the battery electrolyte level must be checked regularly and replenished in the
event that it is
below a desired level. The electrolyte level in the electrolytic cells of a
battery is not static, but
is dynamic due to the effects of evaporation, leakage or spillage, and due to
outgassing that
occurs during overcharge in the charging process. To obtain maximum results
during battery
charging it is desired that the battery electrolyte level be checked and
adjusted during and after
the charging operation, to thereby ensure a maximum degree of electrolyte to
electrode interface
during the charging process.
An electrolyte battery typically comprises a number of electrolytic cells. For
example,
a conventional 12 volt electrolyte battery comprises six two-volt electrolytic
cells. Different
battery applications call for different overall battery voltages and,
therefore, different battery
configurations. Such battery applications typically require that the battery
be stored onboard the
battery-powered device or vehicle at a location that does not always permit
easy access to each
electrolytic cell, making electrolyte level inspection and electrolyte
replenishment difficult and
time consuming.
Devices have been constructed in an attempt to address such difficulties
associated with
electrolyte level checking and electrolyte replenishing in such applications.
To reduce or
eliminate the risk of environmental hazard or health danger during the
electrolyte replenishment
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operation, it is desired that only water be used or circulated to fill the
electrolytic cells.
Devices known in the art that have been developed to facilitate electrolyte
leveling and
replenishment include so called "pass-through" devices that are adapted for
installation into each
electrolytic cell of the battery. Such pass-through devices typically include
an inlet port and an
outlet port that are positioned within the cell to permit flow-through passage
of electrolyte from
the cell when a determined electrolyte level in that cell is achieved. The
pass-through devices
are installed into each electrolytic cell of the battery and are hydraulically
connected together
to permit the serial circulation of electrolyte through each electrolytic
cell, filling each cell to a
determined electrolyte level, and finally out of the battery for collection.
Electrolyte replenishment or filling is accomplished using such a pass-through
device by
routing water from a water source to a first device, that is disposed in a
first electrolytic cell,
until the electrolyte level reaches a determined level. While water addition
to the first filled cell
is continued, water mixed with electrolyte from the filled cell is routed
through its respective
device to another device that is installed in a different cell. This chain of
electrolyte transfer
continues until the determined electrolyte level in a final battery cell is
achieved and electrolyte
is routed away from the battery and the water flow is discontinued.
A disadvantage of the pass-through device is that it requires electrolyte,
rather than only
water, to be transferred through the electrolytic cells and eventually away
from the battery,
where it can pose an environmental or health risk. Additionally, when
connected in series with
a number of other such devices, the device is unable to provide a desired
concentration of
electrolyte in each cell. Rather, as mixed water and electrolyte is circulated
through each cell
the electrolyte concentration in each cell become progressively more diluted
than the next cell
in the series, thereby causing the electrolyte concentration in each cell to
vary.
Another device designed to facilitate electrolyte leveling and replenishment
is a
mechanical "float-type" device that is configured to fit into an electrolyte
fill opening of an
electrolytic cell. The device comprises a body that is engaged into the fill
opening. A plunger
extends from the body into the cell and includes a float that is designed to
float in the electrolyte.
The body includes a valve mechanism which is located outside of the
electrolytic cell and is
designed to open and close the flow of water through a water inlet in the body
to the cell,
depending on the position of the plunger and float.
When the electrolyte level in a cell is low, and the plunger and float extend
downwardly
into the cell a determined distance, the valve in the body is opened to permit
water flow into the
cell. Once a desired electrolyte level is achieved, and the plunger and float
rises in the cell to
a determined point, the valve is closed, causing water flow to the cell to
cease. The device also
includes a vent passage in the body that allows air being displaced by the
water entering the cel I
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to be routed from the cell through the body and to the atmosphere. These
devices, when installed
in respective cells, are hydraulically connected to a water source in parallel
so that as the
electrolyte level in each particular cell is achieved the water flow to that
cell is shut off.
Embodiments of the above-described float-type device are designed to permit
the filling
of more than one electrolytic cell from a single location. In such an
embodiment, each device
additionally comprises a water outlet that permits the passage of water
through its body either
during or after the determined electrolyte level, for the particular cell
within which the device
is installed, is achieved. The device is placed into each electrolytic cell
and is hydraulically
connected, with piping or tubing and the like, to permit electrolyte filling
of each cell with water
from a single point. The use of such device allows the electrolyte level in
each cell to be
replenished without circulating electrolyte between cells and away from the
battery
Although such a device permits circulation of water from a water source
through each
device without allowing electrolyte to leave the battery, it does so using
mechanically moving
parts, e.g., the plunger and valve arrangement. The use of a device having
moving parts in an
electrolyte battery cell service is not desired because of the likelihood that
such mechanism will
fail, or its operation will become impaired or unpredictable, due to its
exposure to the highly
corrosive environment of the electrolytic cell, e.g., its exposure to sulfuric
acid, sulfuric acid
vapors and the like. Sulfuric acid vapors, nascent oxygen, and hydrogen
produced during
operation or charging of the battery are allowed to escape from each cell via
a passage through
the device body, thereby placing the moving parts in direct exposure to such
corrosive and highly
aggressive vapors. It is known that prolonged exposure to such vapors
eventually reduces the
operating life of the device due to part failure.
Additionally, plastics and rubbers that are used in conjunction with the
device and/or
device-to-cell seal are known to decompose after being exposed to such
corrosive liquid and/or
vapor. The products of such decomposing material enter the device and are
known to interfere
with the movement of the parts, e.g., causing the valve to stick in an open or
closed position and,
thereby rendering the device inoperative. Additionally, the decomposition
products of such
plastic and rubber parts are known to enter the electrolytic cell, interfering
with the efficiency
of electrochemical reaction occurring therein.
U.5. Patent No. 4,754,777 discloses another device for replenishing the
electrolyte level
in electrolyte battery cells. The device comprises a body that fitted into the
fill opening of an
electrolytic cell. The body has no moving parts, but provides water flow into
the cell from a
water inlet via a water trap arrangement. The water trap is designed so that
water from the water
inlet is directed through the trap at a particular supply pressure and into
the electrolytic cell. The
water flow through the trap and into the cell terminates when the pressure of
air trapped within
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the device equals the water supply pressure, causing the supply water to
bypass the trap and be
routed from the device via a water outlet to the next serially connected such
device an another
battery cell.
The water pressure inside the trap when water flow through the trap ceases is
related to
the water supply pressure, which is regulated by a pressure control valve
installed between a
water inlet of the device and a water source. Because the shut-off water
pressure in the trap is
a function of the inlet water pressure, the electrolyte level that is provided
by the device is
pressure sensitive, i.e., the electrolyte level in each electrolytic cell
varies depending on the inlet
water pressure that the device sees. For this reason ii is necessary that the
pressure control valve
be used to fix the inlet water pressure to a desired constant value that
provides a desired
electrolyte level.
U.K. Patent No. 1,041,629 discloses another "trap-type" device that is very
similar to the
trap-type device described above, in that the device makes use of a water trap
to control the
dispensement of water into an electrolytic cell. The device operates using the
same principles
of operation as the other trap-type device and is constructed to provide an
electrolyte level within
the cell that is sensitive to the water supply pressure.
The above-described trap-type devices are adapted to be hydraulically
connected in series
with identical such devices that are installed in other electrolytic cells to
provide serial battery
leveling and replenishment. However, because the inlet water pressure to each
device
determines electrolyte level in each cell, the pressure losses that occur
through the series
arrangement of devices can cause the electrolyte level to be progressively
lower in each
sequentially arranged cell, making accurate electrolyte leveling in each cell
difficult.
Additionally, such trap-type devices are constructed so that once the desired
cell electrolyte level
is achieved, and gas that is produced within the cell is prohibited from
exiting the cell, thereby
creating a potential explosion hazard.
Although the above-described trap-type devices do permit electrolyte leveling
and
replenishment without circulating electrolyte between electrolytic cells and
away from the
battery, and without the use of moving parts, the ability of such devices to
do so is dependent on
the inlet pressure of the water, thereby making such devices unsuited for use
in applications
where precise water pressure regulation is not available and/or practical.
Additionally, the described trap-type devices are not capable of operating
under vacuum
conditions, e.g., where a differential pressure through the device is created
under vacuum rather
that positive pressure operating conditions. The ability to perform
electrolyte leveling and
replenishment using a vacuum induced differential pressure through the device
is desirable
because it eliminates the possibility of water leakage occurring outside of
the battery, which may
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be caused by leaking connection tubing or the like.
It is seen, therefore, that a need exists for a device which has some of the
following
characteristics: it permits electrolyte leveling and electrolyte replenishment
for electrolytic cells
of an electrolyte battery from a single point, i.e., from a single connection
point with a water
source; it is capable of both replenishing an electrolytic cell with water to
a determined
electrolyte level and circulating water, not electrolyte, through the device
to one or more other
devices that are installed in respective cells once its own cell is filled; it
has no moving parts and
can provide electrolyte leveling and replenishment independent of variations
in the differential
pressure within the device; and it can be used in either positive pressure or
vacuum operating
conditions.
Summary of the Invention
This invention addresses and fulfills the needs identified above. It does so
economically,
simply, efficiently and reliably.
Generally speaking, this invention comprises a device that permits the
replenishment of
one or more electrolytic cells of an electrolyte battery with water to a
determined electrolyte
level without the use of moving parts, without the need for electrolyte
circulation outside of the
battery, in a manner that is independent of water supply pressure, by creating
a pressure
differential within the device by either pressure or vacuum operating
conditions. An exemplary
embodiment of the device comprises a body having a chamber therein, and having
first and
second water ports that extend through the body into the chamber. The first
and second water
ports can be used interchangeably as either water inlet or water outlet ports.
The device body also includes first and second water passages that are
independent of one
another that extend axially in the annular chamber, that are in hydraulic
connection with
respective first and second water ports, and that have lower ends in the
cavity below the ports.
Water entering the device via one of the water ports travels axially in the
device via a respective
water passage.
A trap is disposed within the device body and has an inlet bowl at a position
below the
lower ends of the first and second water passages. Water passing through one
of the water
passages passes into the trap. The trap includes first and second weirs
disposed therein. A bell
chamber is disposed within the body adjacent an outlet of the trap. Water
passing the weirs of
the trap enters the bell chamber and is passed therethrough out of an open end
of the bell
chamber and into the electrolytic cell.
The trap and bell chamber are defined to trap a volume of air therein when the
surface of
the electrolyte in the electrolytic cell meets the bell chamber open end. As
water continues to
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pass through the device and into the electrolytic cell, the trapped air
becomes pressurized by
electrolyte rising in the bell chamber. The flow rate of water through the
trap is reduced as
pressi;u-e of trapped air begins to approach the head pressure of water in the
device caused by the
level of water therein. The trap and bell chamber are designed so that water
flow through the
trap to the electrolytic cell terminates, and the determined electrolyte level
within the cell is
achieved, at the point where the pressure of trapped air at least equals t:he
head pressure of water
in the bowl. The device may be configured to include a gas vent for releasing
gas pressure from
the electrolytic cell to the atmosphere, or to collection for further
treatment, after the watering
cycle.
The device is operated by imposing a pressure differential between water inlet
and outlet
passages of sufficient amount to effect water flow into the device from a
water source connected
to the device. The pressure differential can be imposed by either positive
pressure or vacuum
operating conditions. The device can be embodied to either fit within an
electrolyte fill opening
in an electrolytic cell, to facilitate retrofit application with an existing
electrolyte battery. or as
an intesgral part of a new battery construction.
Liquid filling devices of this invention can be hydraulically connected
together for use
in an electrolyte replenishment and leveling system for filling a respective
number of electrolytic
cells. ,An advantage of using such device in such system is that it simplifies
the replenishment
and leveling of multiple electrolytic cells by allowing such operation to be
conducted from a
single location, i.e., a single connection with a water source, without the
need to gain physical
access to each cell.
Broadly stated, a structural embodiment of the invention can comprise a body
that defines
first and second water flow ports, and a trap that has a bowl located below
the water pons. The
body also includes first and second water passages that separately connect
respective ports to the
bowl for ingress and egress of water to and from the bowl. The trap has a
discharge weir lip
between the bowl and an outlet from the trap located below the lip at a
location a selected
distance below a desired liquid level to be established in a chamber to which
the outlet is
connectable. The trap has an outlet that is located vertically relative to the
lip and the lower end
of the one of the first and second passages. The volume distribution between
such one passage
lower end and the trap outlet being defined to cause water flow through the
trap to cease after
immersion of the trap outlet and after water in the bowl rises to at least the
level of the lower end
of such. one passage.
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Accordingly, the present invention provides a device for leveling and
replenishing an
electrolytic cell with water., comprising: a body defining first and second
water flow ports;
a trap having a bowl located below the water flow ports, wherein the trap
includes an
upwardly directed weir and a dowrrwardly directed weir to contain a volume of
air within the
trap for regulating water flow therethrough, wherein the trap includes an
outlet positioned a
selected distance below a lip of the upwardly direct weir and below a bowl
floor from which
the upwardly directed weir projects to provide a desired liquid level to be
established in a
chamber to which the outlet is connectable; and
first and second water passages separately connecting respective ports to the
bowl for
ingress and egress of water to and from the bowl, wherein the trap outlet
location is vertically
relative to the lip and the lower end of the onc: of the first and second
passages and the volume
distribution between such one passage lower end and the trap outlet being
defined to cause
water flow through the trap to cease after imrnersoon of the trap outlet and
after a volume of air
within the trap reaches a sufficient pressure to cause water in the bowl to
rise to at least the
level of the lower end of such one passage.
T:he present invention also provides a device for leveling and replenishing an
electrolytic cell with water comprising: first and second water ports;
first and second water passages that are independent of one another, that
communicate
to respective water ports, and that have lower ends below the respective water
ports;
a trap disposed below the first and second water passages to receive water
from one of
the first or second water passages, wherein the trap includes a bowl extending
above the lower
end of the other of the passages and at least one weir positioned within the
trap to contain a
volume of air therein for regulating water flow therethrough; and
a bell chamber disposed adjacent an outlet of the trap and having an open end
adapted
to direct water passing through the trap into an electrolytic cell, wherein
the open end of the
bell chamber is disposed a distance below the trap to provide a desired
electrolyte level within
the cell, and wherein the bell chamber is adapted to trap a volume of air
therein with the trap
during a leveling and replenishing operation;
wherein the device terminates water flow into the electrolytic cell
independent of water
supply pressure when the pressure of trapped air within the trap and bell
chamber is at least
equal to a pressure head of~water within the trap caused by the level of water
in the trap, and
thereafter bypasses water flow through the device without passing electrolyte
through the
device.
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The present invention also provides a device for filling an electrolytic cell
with
water and providing a determined electrolyte level within the cell, the device
comprising:
a body;
first and second water ports that open into the body, and connected therein to
respective first and second water passages that are independent of one another
and that
extend downwardly in the body;
a trap disposed within the body below the first and second water passages, the
trap having a weir arrangement between an inlet positioned to receive water
from one of
the passages and a trap outlet; and
a bell chamber disposed adjacent the trap outlet and Laving an open end
adapted
to direct water passing through the trap into an electrolytic cell, wherein
the trap and bell
chamber are adapted to trap a volume of air therein during a filling
operation;
wherein the device :is adapted to cease water flow into 'the electrolytic cell
independent of water supply pressure when the pressure of trapped air within
the trap
and bell chamber is at least edual to a pressure head of water within the trap
caused by
the level of water in the trap; and
wherein the trap and bell chamber are designed to prevent the passage of
electrolyte from the electrolyte cell into the trap during a filling operation
and after a
desired electrolyte level has beeil achieved.
The present invention also provides a device for filling an electrolytic cell
with
water and providing a dete;nnined electrolyte level within the cell without
passing
electrolyte from the cell through the device, the device comprising:
a body, first and second water ports that extend into the body at an upper end
thereof, and first and second water passages that are independent of one
another and that
extend d.ownwardly in the body from respective ports axially through the body,
and
including; mounting means for nnot rating the body within an electrolyte fill
opening of an
electrolyte battery;
a trap having an inlet bowl disposed within the body below the first and
second
water passages and including a. first downwardly directed weir and a second
upwardly
directed weir, the trap being located to receive water from one of the water
passages to
pass the water under the first weir and over the second weir; and
a bell chamber disposed adjacent an outlet of the trap and having an open end
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adapted to direct water passing through the trap into an electrolytic cell,
the trap and
bell chamber being adapted to trap a volume of air therein during a filling
operation to
both regulate water flow through the trap and to prevent electrolyte flow from
the cell
into the trap, at least a portion of the trap and bc;ll chamber being disposed
below the
mounting; means within a herd space of an electrolytic cell when the device is
mounted
within an electrolyte fill opening;
wherein the device is adapted to cease water flow into the electrolytic cell
independent of water supply pressure to the body when the pressure of trapped
air
within the trap and bell chamber is at least equal to a pressure head of water
within the
trap caused by the level of water in the bowl.
The present invention also provides a watering apparatus retrofittable to a
cell of
a lead-acid battery for adding water to the cell to establish in the cell a
desired level of
acid electrolyte, the apparatus cc>nrprising:
a tubular body having exterior features by which the body is mountable in a
cell
filling opening with an upper end of the body located outside the cell and a
lower end of
the body located in the cell a selected distance below a desired electrolyte
level;
a pair of water flow ports extending to an interior of the body at the upper
end of
the body, the body defining internally thereof a water flow passage between
the ports
that has a lower portion located below the ports, the body also defining
internally thereof
a water flow trap having an inlet communicating to the passage lower portion
and an
outlet at the body lower end, the relative vertical locations of the trap
elements and the
passage lower portion being cooperatively defined in combination with the
volume
distribution of the passage lower portion and the trap elements to cause a
volume of air
to be contained within the trap and to cause the passage lower portion to be
flooded by
water flowing through one of the ports into the body when the level of
electrolyte in the
cell has been raised to the desired Level by water passing through the trap to
pressurize
the volume of air a desired amount to cause the trap then to cease to pass
water to the
cell, wherein the volume of air also prevents passage of electrolyte from the
cell into the
trap during a filling operation and after a desired electrolyte level has been
achieved.
In broad terms, a procedural embodiment of the invention can include the steps
of
creating a pressure differential between a water inlet passage and water
outlet passage of
a liquid filling device, and causing water to pass through a water inlet
passage of the
device, through a trap of the device, through a bell chamber of~ the device,
and into an
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electrolytic cell. A volume of trapped air is formed within the bell chamber
and trap
when the level of electrolyte within the cell reaches an open end of the bell
chamber.
The volume of trapped air in the device is pressurized by continued passage of
water to
the electrolytic cell until the pressure of the trapped air at least equals a
head pressure of
water in the device caused by the level of water in the device. The passage of
water into
the electrolytic cell is terminated to achieve a determined electrolyte level
when the
pressure of the trapped air a.t least equals a head pressure of water in the
device. The
determined electrolyte level is achieved independent of the pressure of water
entering
the device. The volume of trapped air prevents electrolyte from passing into
the trap
during a replenishing operation and after a desired electrolyte level has been
achieved.
In a further aspect the present invention provides a method for replenishing
multiple
electrolytic cell of an electrolyte battery with water to a determined
electrolyte level
comprising the steps of:
providing in each cell a liquid tilling device having separate water inlet and
outlet
passages therein and a trap which discharges to a bell chamber;
creating a pressure differential between the water inlet and outlet passages
of a first
liquid filling device to cause water to pass through a water inlet passal;e of
the first device,
through its trap, through its bell chamber, and into ~~ first electrolytic
cell;
forming a volume of trapped air within the bell chamber and trap of the first
device
when the level of electrolyte within the first cell reaches an open end of the
bell chamber;
pressurizing the volume of trapped air in the first device by continued
passage of
water to t:he first electrolytic cell;
terminating the passage of water into the first electrolytic: cell to achieve
a
determined electrolyte level 'when the pressure of the trapped air at least
equals a head
pressure of water in the device, wherein the determined electrolyte level is
achieved
independent of pressure conditions outside; and
circulating water entering the first device through its water outlet passages
to a
hydraulically connected next device for electrolyte replenishment and leveling
of a
respective next electrolytic cell, and continuing to circulate water through
hydraulically
connected devices until a determined electrolyte level for each electrolytic
cell is achieved.
The present invention also provides a device for leveling ;end replenishing an
electrolytic cell with water comprising:
first and second water parts;
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first and second water passages that are independent o f one another, that
communicate to respective water ports, and that have lower ends below the
respective water
ports;
a trap disposed below the first and second water passages to receive water
from one
of the first or second water passages, the trap including a pair of weirs
disposed therein;
a bell chamber disposed adjacent an outlet of the trap and having an open end
adapted to direct water passing through the trap into an electrolytic <;e11,
wherein the trap
weirs arf: positioned within the trap to act with the hell chamber to trap a
volume of air
therein during a leveling and replenishing operation to prevent electrolyte in
the cell from
entering i:he trap;
a heat transfer element projecting downwardly f-rom a portion of the device in
contact
with water entering the device from one of the passages, the heat transfer
element being
adapted to enter electrolyte within a cell to transfer thermal energy frorrr
the water within the
trap to the electrolyte;
wherein the device terminates water flow into the electrolytic. cell
independent of
water supply pressure when the pressure of trapped air within the trap and
bell chamber
is at least equal to a pressure head of water within the trap caused by the
level of water
in the trap, and thereafter bypasses water flow through the device.
The present invention also provides a method for replenishing an electrolytic
cell with
water to a determined electrolyte lcvel and thermally conditioning electrolyte
within the cell,
the method comprising the steps of:
creating a pressure differential between a water inlet passage and water
outlet passage
of a liquid filling device, causing water to pass through a water inlet
passage of the device,
through a. trap of the device, through a bell chamber of the device, and into
an electrolytic cell;
thermally conditioning electrolyte within the cell by immersing a heat
transfer element
projectin;; from the device into electrolyte within the cell, the passage of
water into the device
causing thermal energy to be conductively transferred between the water
entering the device
and the electrolyte;
forming a volume of trapped air within the bell chamber and trap when the
level of
electrolyte within the cell reaches an open end of the bell chamber tc~
regulate water flow
through the trap and to prevent electrolyte in the cell from entering the
cell;
pressurizing the volume o1' trapped air in the device by continued passage of
water to
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the electrolytic cell until the pressure of the trapped air at least equals a
head pressure of
water in the device caused by the level of water in the device; and term-
mating the passage of
water into the electrolytic cell tc achieve a determined electrolyte level
when the pressure of
the trapped air at least equals a head pressure of water in the device,
wherein the determined
electrolyte level is achieved independent of the pressure of water enterin~;
the device.
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Brief Description of the Drawings
The above-mentioned and other features of this invention are set forth in the
following
detailed description of the presently preferred and other embodiments of the
invention, which
description is presented with reference to the accompanying drawings wherein:
FIGS. 1-9 are sequential, cross-sectional elevation, schematic views of a
simplified
exemplary watering device, illustrating principles of this invention, at
successive stages in
practice of the procedural aspects of this invention; more specifically,
FIG. I illustrates placement of a watering device within a head space of an
electrolytic
cell having a less than full electrolyte level and at time before commencement
of an electrolyte
replenishment operation;
FIG. 2 illustrates commencement of the electrolyte replenishment operation
where water
is introduced into the device and is passed to a trap bowl of the device;
FIG. 3 illustrates the filling of the bowl to a water level equal to a lip
height of an exit
weir of the device;
FIG. 4 illustrates the passage of water from the bowl, over the exit weir lip,
through a bell
of the device, and into the electrolytic cell;
FIG. 5 illustrates passage of water through the trap into the electrolytic
cell at a time when
the electrolyte level in the cell is raised to a mouth of the bell, forming an
air pocket within the
bell;
FIG. 6 illustrates further passage of water into the electrolytic cell,
causing the electrolyte
level to be raised above the bell mouth and increasing the pressure of air
trapped within the air
pocket;
FIG. 7 illustrates the continued filling of the bowl and passage of water into
the
electrolytic cell, causing water in the bowl to be raised to an open end of a
water outlet passage
of the device for flow from the device;
FIG. 8 illustrates the continued filling of the bowl and rising of the
electrolyte level in the
cell to a point where a determined electrolyte level is achieved, water flow
into the cell is
terminated, and water entering the bowl is passed from the bowl through the
water outlet
passage;
FIG. 9 illustrates completion of the electrolyte replenishment operation after
the
determined electrolyte level is achieved, and after a purging process is
completed;
FIG. 10 is a cross-sectional elevation view of a first embodiment of the
device,
constructed according to principles of this invention, adapted for attachment
within an electrolyte
fill opening in an electrolytic cell;
FIG. 11 is a sectional view the device of FIG. 10 taken along line I 1-11 in
FIG. I 0;
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FIG. 12 is a sectional view taken along line 12-12 in FIG. 10;
FIG. 13 is a sectional view taken alone line 13-13 in FIG. 10;
FIG. 14 is a cross-sectional elevation view of the device of FIG. 10 rotated
by 90 degrees,
i.e., a view taken along line 14-14 in FIG. 11;
F1G. 15 is a section plan view of the device taken across section 15-15 in
FIG. 14;
FIG. 16 is a cross-sectional elevation view of a device similar to that of
FIG. 14,
comprising a checked vent cap arrangement;
FIG. 17 is a perspective view of a second embodiment of the device
constructed,
according to principles of this invention, as an integral member of the
battery cover; and
FIG. 18 is a schematic view of an electrolyte leveling and replenishment
system
comprising a number of the devices shown in FIGS. I O-15 or F1G. I G installed
in electrolytic
cells of an electrolyte battery and hydraulically connected in series;
FIG. 19 is a cross-sectional plan view depicting the device shown in FIGS. 10-
15 as
mounted in a water fill port of a battery; and
FIG. 20 is a view similar to FIG. 8 illustrating use of a watering device for
thermal
management of cell electrolyte within an electrolyte battery.
25
35
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Detailed Description
Liquid filling devices (LFDs) of this invention operate under principles of
hydraulic
pressure differentials to provide electrolyte leveling and electrolyte
replenishment for one or
more electrolytic cells in an electrolyte battery. Generally speaking, LFDs of
this invention are
disposed within a head space of an electrolytic cell and provide electrolyte
leveling and
replenishment without circulation of battery electrolyte, without the use of
moving parts and in
a manner that produces a determined electrolyte level that is independent of
the pressure or
vacuum conditions that are used to create a pressure differential in the LFD
for introducing water
into the device and into the adjacent cell.
FIG. 1 illustrates in schematic form the fundamental structural features of
LFDs 10
constructed according to principles of this invention. It is to be understood
that the LFD
illustrated in FIGS. 1-9 is presented in simplified form for purposes of
clearly illustrating the
1 S operating principles of LFDs constructed according to principles of this
invention. LFDs of this
invention are installed within a head space of an electrolytic cell 12 of an
electrolyte battery, i.e.,
above the electrolyte surface and below an electrolytic cell cover. The LFD
illustrated in FIGS.
1-9 is shown disposed completely within the electrolytic cell for purposes of
simplicity. An LFD
ofthis invention can be constructed to fit through an electrolyte fill opening
in the cell cover of
an existing electrolyte battery, or it can be constructed as an integral part
of the battery, e.g.,
constructed as a part of the cell cover itself.
The LFD comprises a water inlet passage 14 that extends through the LFD body
or battery
cell cover, whichever the case may be, depending on whether the LFD is
configured as a device
adapted for retrofit use with existing electrolytic cells, or whether the LFD
is configured as an
integral member of the electrolytic cell of a new battery, as will be better
described below. A
water outlet passage 16 extends through the LFD body or battery cover. The
water inlet passage
14 has a downward leg in the cell to an outlet end 18 that is directed to a
bowl 20 of the device
that is disposed both above the electrode plates (not shown) of the
electrolytic cell, and
essentially above the desired level of electrolyte 22 in the cell. The outlet
passage 16 has an
upward leg in the cell from an inlet end 44 (see FIGS. I and 6) located within
the height of bowl
20.
The bowl 20 includes a mouth 24 near a top of the device, and a floor 26 near
a bottom
of the device. The bowl includes and connects to a trap that is defined by a
first weir 27 that
extends vertically downwardly from the mouth 24 to form a first bowl passage
28 between a first
weir lip 30 and the bowl floor 26. As will be discussed below, the placement
of the first weir
lip 30 within the bowl contributes to the hydraulic operation of the LFD in
replenishing
electrolyte to a determined level within the cell.
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The bowl trap includes a second weir 32 that extends upwardly from the bowl
floor 26
and is positioned adjacent the first weir 27. A second bowl passage 29 extends
within the bowl
from the first weir 27, and is hydraulically connected to a bell chamber 3 3.
The second bowl
passage is defined along its top portion by a ceiling 34, and along its bottom
portion by a second
weir lip 36. As will be discussed below, the placement of the second weir lip
36 contributes to
the hydraulic operation of the LFD in replenishing electrolyte to a determined
level Wlthlll the
cell. A bell chamber 33 extends downwardly away from weir lip 36 and the LFD
body into the
electrolytic cell and includes a mouth 38 at an open end opposite the body
that is positioned at
a desired position in the cell and relative to the other structure of the LFD.
The remaining features of LFDs of this invention are better explained and
understood with
reference to FIGS. 1-9, which illustrate the simplified embodiment of a LFD of
this invention
at different times during leveling and replenishing electrolyte in an
electrolytic cell.
FIG. I illustrates the LFD 10 disposed within a head space of an electrolytic
cell 12 that
contains battery electrolyte 22 at a less than desired level. In a lead-acid
battery, e.g.. the low
electrolyte level can be the consequence of loss of water from the acid
electrolyte. In FIG. 2,
water 40 from a suitable water source is introduced into the water inlet
passage 14, and is
directed therethrough to the LFD bowl 20. The water is introduced into the LFD
by a pressure
differential that is created between the water inlet and water outlet passages
14 and 16. The
pressure differential can be imposed by either positive pressure (e.g.,
pumping the water through
passage 14 at any desired convenient pressure) or vacuum operating conditions
(e.g., connecting
passage 16 to a source of vacuum) without affecting the leveling and
replenishment performance
of the LFD. The water that initially enters the bowl is contained therein due
to the placement
of the second weir 32 within the bowl, preventing the water from being fillly
emptied into the
bell chamber 33.
In FIG. 3, the flow of water from the water source, through the water inlet
passage 14, and
into the bowl 20 is continued, causing the water level within the bowl to rise
to a level equal to
the edge of the second weir lip 36. As long as the water level in the bowl is
below the edge of
the second weir lip 36, the water in the bowl will not pass into the
electrolytic cell via the bell
chamber. in FIG. 4, the flow of water from the water source, through the water
inlet passage 14,
and to the bowl is continued, causing the water level in the bowl to rise to a
level higher than the
second weir lip 36. As soon as the water level in the bowl exceeds the height
of the second weir
lip 36, water is allowed to pass through the second bowl passage 29, into the
bell chamber 33.
through the bell chamber mouth 38, and into the electrolytic cell 12. The
water exiting the bell
chamber and entering the electrolytic cell mixes with the electrolyte 22 in
the cell and causes the
electrolyte level in the cell to rise.
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In FIG. 5, the flow of water from the water source, through the water inlet
passage 14,
through the bowl 20, through the bell chamber 33, and into the electrolytic
cell is continued,
causing the electrolyte level within the cell to rise to the same level as the
mouth 38 of the bell
chamber 33. Once the electrolyte level in the cell rises to the bell chamber
mouth 38, air 42 that
exists within the bell chamber 33 and second bowl passage 29 is trapped
therein by the water
surface within the second bowl passage 29, at one end, and by the electrolyte
surface at the bell
chamber mouth 38, at an opposite end. 'hhe air 42 that is trapped within the
device at the point
in time when the electrolyte surface contacts the bell chamber mouth typically
is at the same
pressure as the internal cell pressure. This is so because the air being
displaced within the
electrolytic cell during replenishment, by introduction of the water, is
allowed to escape from
the cell via the water outlet passage 16.
In FIG. 6, the flow of water from the water source, through the water inlet
passage I 4.
I S through the bowl 20, through the bell chamber 33, and into the
electrolytic cell is continued,
causing the level of the electrolyte in the cell to rise above the mouth 38 of
the bell chamber 33.
As the electrolyte level in both the cell and the bell chamber rises above the
mouth 38, the
pressure of the trapped air 42 within the bell chamber 33 increases, imposing
a pressure on the
surface of the water in the second bowl passage 29. The pressure imposed on
the surface of the
water in the second bowl passage causes the water level therein to be lowered
towards the lip 36
of the second weir 32, thereby reducing the rate of water passage to the bell
chamber 33. This
is so because the pressure of the trapped air 42 within bell chamber begins to
approach the head
pressure associated with the water level in the bowl. It is important to note
that the water
pressure within the bowl is produced by the level of water within the bowl.
and is independent
of the supply pressure of water entering the LFD. As the pressure of the
trapped air rises, the
water level in the bowl also begins to rise toward an open end 44 of the water
outlet passage 16.
In FIG. 7, the flow of water from the water source, through the water inlet
passage 14,
through the bowl 20, through the bell chamber 33, and into the electrolytic
cell is continued.
causing both the electrolyte level in the cell to rise and the water level in
the bowl 20 to rise to
the point where the water surface contacts the open end 44 of the water outlet
passage 16. While
the open end 44 of the water outlet passage 16 is shown in FIGS. 1-9 as being
below an open end
of the water inlet passage 14 for purposes of simplicity and of illustration,
it is to be understood
that the open ends of the water inlet and outlet passages can be positioned at
equal levels within
the device in the bowl without affecting the leveling and replenishment
operation of the LFD.
What occurs once the water level in the bowl reaches the open end 44 of the
water outlet
passage 16 depends on whether the pressure differential within the LFD is
created by pressure
or vacuum operating conditions. Under vacuum operating conditions, the water
inlet passage
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14 is connected at an inlet end 46 to a non-pressurized water source (not
shown). 'fhe water
outlet passage 16 is connected at an outlet end 48 to a vacuum source (not
shown), and a vacuum
is imposed on the water outlet passage. As the air in the cell 12 is
evacuated, water 40 is drawn
through the water inlet passage 14 and into the cell in the manner described
above. Once the
water level in the bowl 20 reaches the open end 44 of the water outlet passage
16 it is picked up
by the vacuum in the passage and is drawn thcrethrough. As water movement
through the water
outlet passage 16 continues, water continues to enter the cell via the water
inlet passage 14. and
water continues to enter the cell via flow through the bell chamber 33.
The LFD is designed to stop water flow from the bowl 20 into the cell 12 after
a
determined or desired electrolyte level is achieved. Specifically, the first
and second weir lips
30 and 36 and the open end 44 of the water outlet passage 16 are located
within the bowl 20 so
that, when the determined level of electrolyte in the cell is reached, the
trapped air 42 is
pressurized by an amount sufficient to impose an equalization pressure on the
surface of the
water in the second bowl passage 29. The LFD is designed so that the
equalization pressure
causes both the water level within the second bowl passage 29 to be moved to a
location at or
below the second weir lip 36, thereby terminating further water passage from
the howl ?U
through the bell chamber 33, and causing the water level in the bowl to rise
to the open end 44
of the water outlet passage 16, thereby allowing water still entering the bowl
to be removed from
the LFD 10, i.e., to flow through the LFD without entering into the
electrolyte space of the cell.
Once the LFD reaches its equalization pressure, i.e., the desired cell
electrolyte level is achieved.
the flow rates of water passing into and out from the LFD reach equilibrium,
and the LFD
performs a water circulating rather than an electrolyte replenishing function.
Under positive pressure operating conditions, the water inlet passage 14 is
connected at
its inlet end 46 to a pressurized water source. The outlet end 48 of the water
outlet passage 16
is at atmospheric pressure. As water enters the LFD, it tills the bowl 20 and
electrolytic cell 12
with water as described above. Once the water level in the bowl 20 reaches the
open end 44 of
the water outlet passage 16, the water level in the bowl continues to rise
until the pressure of the
trapped air 42 reaches the equalization pressure, where the water in the
second bowl passage 29
is moved below the second weir lip 36. At this point, the water level in the
bowl is sufficient to
effect water passage from the bowl through the outlet water passage 16. Like
the vacuum
operated system, once the LFD reaches its equalization pressure the desired
cell electrolyte level
is achieved, the flow rates of water passing into and out from the LFD reaches
equilibrium, and
the LFD performs a water circulating rather than an electrolyte replenishing
function.
A feature of LFDs of this invention is that they are designed to provide a
desired
electrolyte level within the cell by either a pressure or vacuum induced
pressure differential, and
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are designed provide such electrolyte level independent of the particular
operating pressure or
vacuum conditions that are used.
Referring to FIG. 8, the LFD 10 is illustrated at a point where the
equalization pressure
between the pressure of the trapped air 42 and the head pressure of the water
in the bowl has
been achieved, and the pressure of the trapped air 42 in the second bowl
passage 29 and the bell
chamber 33 has caused the water level in the second bowl passage to be moved
sufficiently
relative to the second weir lip 36 to terminate water passage into the bell
chamber 33.
Equilibrium has also been achieved in the bowl 20 so that the rate of water
entering the bowl is
equal to the rate of water routed from the LFD via the outlet water passage I
6. At this point, the
electrolyte leveling and replenishment is complete.
Depending on the particular application, the LFD may be used to fill a single
electrolytic
cell, in which case the water routed from the cell can be collected in a water
reservoir or the like,
and the water flow into the cell can be terminated after water flow is
detected from the outlet
water passage 16. LFDs constructed according to principles of this invention,
can be used to fill
a number or plurality of electrolytic cells in an electrolyte battery. In such
application, one LFD
is installed into each electrolytic cell and the water inlet and outlet
passages of each LFD are
hydraulically connected to permit leveling and replenishment of multiple
electrolytic cells in
series and/or parallel. An exemplary system for leveling and replenishing
electrolyte in multiple
electrolytic cells is better described below with reference to FIG. 17.
Referring to FIG. 9, after the process of electrolyte leveling and
replenishment is
completed and the introduction of water into the LFD is terminated, it may
desired that the water
inlet passage I4 and water outlet passage 16 be cleared of any remaining
liquid, e.g., water
trapped within the water inlet and outlet passages that extend between
hydraulically connected
LFDs. Purging water from the water inlet and outlet passages is desired
because it prevents the
passage of water between the electrolytic cells and ultimately from the
battery during battery
discharge or charging due to pressure being built up within each cell. Gas
pressure within each
cell is known to increase during the charging process due to the liberation of
gas (hydrogen and
oxygen), i.e., outgassing from the electrolyte, which can cause liquid
disposed within the water
inlet and outlet passages to travel through hydraulically connected
electrolytic cells, and
ultimately out of the battery.
The water inlet and outlet passages 14 and 16 are purged by either: ( 1 )
passing air through
the water inlet passage 14, causing liquid contained in each water outlet
passage to be passed
therethrough until the water level in the bowl 20 moves below the open end 44
and air is passed
therethrough; (2) passing air through the water outlet passage 16, causing
liquid contained
therein to be reverse purged into the bowl 20 until air passes therethrough;
(3) inducing a
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vacuum on the water inlet passage 14, causing water contained within the water
outlet passage
to be reversed purged into the bowl; or (4) inducing a vacuum on the water
outlet passage 16,
causing the water contained therein to be pulled therethrough until the water
level in the bowl
20 moves below its open end 44 and air is passed therethrough.
Referring to FIGS. 10-15, a presently preferred LFD 54, constructed according
to
principles of this invention, generally comprises the same structural features
described above for
the simplified LFD 10 illustrated in FIGS. 1-9, and has been configured to
enable its placement
(see FIG. 19) within an electrolyte fill opening of an electrolytic cell. LFD
54 is formed trom
a mufti-piece construction comprising, moving fiom an uppermost end of the
device downward:
a LFD cap 56; a LFD upper body part 58 disposed below the cap 54 and attached
thereto at an
open top end 60 of part 58; a lower body part 62 attached to a bottom open end
64 of part 58;
and a trap and bell chamber body 66 attached to a bottom end 68 of body part
58. Elements 56,
58, 62 and 66 are generally round, are coaxially aligned, and are
interconnected at their rims.
The overall configuration of LFD 54, except for the duct connection nipples
which
preferably extends laterally from the LFD and which define passage ports 70
and 72. is circularly
cylindrical with appropriate external features that enable it to be secured in
a water fill port of
an existing battery, such as a lead-acid battery.
Generally speaking, water enters the LFD upper body 58 through either one of
two water
ports 70 and 72 and is routed through the LFD body 58, through a trap formed
by body part 62
and bell chamber body 66, and into the electrolytic cell. The LFD is
constructed to provide
electrolyte leveling and replenishment according to the hydraulic principles
described above and
illustrated in FIGS. 1-9. LFD 54 is designed to accommodate water flow through
either one of
its water ports 70 and 72, thereby simplifying its hydraulic connection.
Referring to FIGS. 10 and 1 l, the LFD 54 is generally cylindrical in shape to
pem~it
installation within an electrolyte fill opening of an electrolytic cell. The
upper body 58 includes
a water chamber 74 extending therethrough from its first (top) open end 60 to
its second (bottom)
end 64, and water ports 70 and 72 positioned adjacent the first end 60 that
each extend radially
outwardly therefrom. Water ports 70 and 72 preferably extend from the LFD body
58 at
diametrically opposed locations. Two vertical spaced water baffles 76 are
disposed within the
chamber and are each oriented having a front side surface 78 perpendicular to
a respective water
port. Each water baffle 76 is connected along its lengthwise edges to an
interior wall surface of
the upper body part 58, forming a pair of diametrically opposed vertical water
passages 80 that
are each disposed between a baffle front side surface 78 and an adjacent body
wall surface. Each
water passage 80 extends downwardly from a respective water port 7U or 72 to
the (lower)
second end 64 of the upper body.
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As FIG. 10 illustrates, the LFD body 58 is symmetric in cross section about a
vertical
central axis. As will be discussed below, with reference to FIG. 14, the LFD
58 also includes
vertical gas baffles 112 that are positioned within the chamber 74
perpendicular to the water
baffles 76.
The LFD 54 includes means for providing releasible attachment with an
electrolyte fill
opening of an electrolyte battery. In a preferred embodiment, such means is in
the form of a
collar 82 that is disposed circumferentially around the LFD body 58, and that
extends axially
along the body between the water ports 70 and 72 and the LFD body second end
64. An O-ring
seal 83 is disposed circumferentially around an outside surface of the LFD
body 58 and is
interposed between the collar 82 and the LFD body to form a gas and liquid-
tight seal
therebetween. The collar 82 can either be attached around the LFD body by
interference fit or
by other connection means, such as by adhesive bonding, ultrasonic bonding, or
the like; it is
1 S preferred, however, that the body be rotatably carried in the collar.
In the preferred arrangement shown, the LFD 54 is disposed coaxially through
the collar
82 and is both sealed and held in place inside of the collar by a tight fit
provided by the O-ring
seal 83. Attaching the LFD 54 to the collar in this manner permits the LFD to
be rotated within
the collar, to accommodate routing of any external plumbing and the like,
without upsetting the
attachment and seal formed between the collar and the cell fill opening. As
will be discussed in
greater detail below, the assembled LFD 54 is inserted into the collar 82
after the collar has been
engaged within an electrolyte fill opening of an electrolytic cell.
The collar 82 is adapted to facilitate releasible attachment with an
electrolyte fill opening
of an electrolytic cell, and includes a first flange 84 that extends radially
away from the one axial
end of the collar and is positioned adjacent the water ports 70 and 72. The
first flange 84 is sized
to have a diameter greater than that of the electrol5rte fill opening to limit
an insertion depth of
the LFD into the electrolytic cell. Additionally, the first flange can have an
external shape
designed to fit a hand or other type of tool conventionally used for rotating
a member.
Configured in this manner, the first flange accommodates the use of such tool
to install and rotate
the collar into place within the electrolytic cell opening.
The collar 82 also includes two lower second flanges 86 that extend radially
away from
an opposite axial end of the collar adjacent the second end 64 of upper body
58. The second
flanges 86 are located at diametrically opposed locations on the collar and
extend partially
(preferably about 90 degrees) about the circumference of the collar, and are
sized for installation
within the electrolyte fill opening. The upper surface 88 of each flange 86 is
helically sloped in
a way that is designed to provide a releasible interlocking fit with a
complementary helically
sloped surface defined on the bottom surface of a ledge 170 which extends from
the outer
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diameter of an electrolyte fill opening 171 defined in a battery cover 172;
see FIG. I 9. These
are two diametrically opposed ledges at the fill opening and each extends
partially (preferably
about 90 degrees) about the opening. The collar 82 is designed to provide a
releasible
interlocking fit within the electrolyte fill opening by inserting the second
flange 86 therein so
that the first flange 84 is placed against a top surface of the battery cell,
e.g., the battery cover,
and rotating the LFD 54 within the opening a determined amount (preferably 90
degrees) to
cause a camming (threading) cooperation between flanges 86 and the fill
opening ledges 170
which cause upper circumferential collar flange 84 to seat and seal against
the battery cover
surface about the electrolyte fill opening.
The collar also preferably includes two movable members 89 (one such member
can be
used) in the form of a tab that is integral with a side wall portion of the
collar, as illustrated in
FIG. 14. The tab is designed having an outer surface that is planar with an
outside diameter of
the collar, and having an inside surface that extends radially inwardly from
an inside diameter
of the collar, when the LFD 54 is not disposed within the collar. Upon
insertion of the LFD 54
into the collar 82, the tab is forced by cam action to move radially outward
so that its outer
surface projects a distance away from the collar outside diameter.
The tab is positioned along the collar so that, when the LFD 54 is installed
within the
collar which has been mounted in a battery fill opening, the tab projects into
the fill opening
tongue and groove arrangement to abut against an adjacent end of the fill
opening ledge to lock
the collar into its fully rotated position within the fill opening. Such
locking engagement of the
collar within the opening is important to prevent the collar from being
rotatably moved and
loosened within the fill opening, thereby ensuring that a gas- and liquid-
tight seal between the
collar and fill opening is maintained. Such a seal is important for allowing
watering under
vacuum operating conditions. In a preferred embodiment, the collar comprises
two tabs 89 that
are positioned diametrically opposed from one another to engage diametrically
opposed
complementary portions of the fill opening, as shown in FIG. I 9.
The collar may include one or more washers (not shown) disposed
circumferentially
therearound between the first and second flanges to facilitate achieving a gas
and liquid-tight seal
against the outside surface of the battery cover.
Although a particular means for providing releasible interlocking LFD
attachment with
an electrolyte fill opening of an electrolytic cell has been described and
illustrated, it is to be
understood that other attaching means known in the art for accomplishing the
same can be used
and are intended to be within the scope of this invention.
The LFD lower body part 62 (also referred to as a weir body because it defines
a structure
which corresponds to a first weir lip 30 shown in FIGS. I-9) is attached to
the second end 64 of,
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and has the same outside diameter as, the LFD upper body 58. Referring to
FIGS. 10 and 12,
the weir body 62 includes a pair of solid sections 90 that each extend in a
horizontal direction
radially across the diameter of the weir body from diametrically opposed body
edges, wherein
the solid sections 90 each form a floor portion for a respective water passage
80 through the
LFD. Stated differently, solid sections 90 of the lower body part form the
floor of a bowl which
extends in the LFD upwardly to parts 70 and 72, and passages 80 extend
downwardly from those
parts into the bowl. The body 62 includes a centrally located passage 92 that
extends axially
therethrough a distance downwardly from the solid sections 90. The passage 92
is defined
vertically by wall surfaces 94 that form a first weir 95. In an exemplary
embodiment, the weir
body passage 92 has a rectangular cross sectional shape, as best seen in FIGS.
12 and 13. The
first weir 95 includes a first weir lip 96 at its open end that extends a
determined distance into
a central passage 97 in an upper portion of the bell chamber body 66.
Referring to FIGS. 10 and 13, the bell chamber body 66 is generally
cylindrical and has
a diameter that preferably is approximately egual to that of the LFD body
parts 58 and 62. The
bell chamber body 66 has a passage 97 that extends axially therethrough from a
first body end
98, attached to weir body 62, to a second lower open end or mouth 100. For
purposes of
reference, the bell chamber annular passage 97 shall be referred to as the
bell chamber. The be! l
chamber 97 includes a water reservoir 102 disposed therein that is defined
vertically by a pair
of diametrically opposed side walls 104, that each extend axially along the
bell chamber a
determined length, and that are attached along lengthwise edges to a wall
surface of the bell
chamber body. The side walls 104 have upper ends 110 located below solid
sections 90 of body
part 62 to form a second weir 105; compare second weir wall 32 shown in FIG.
1. The reservoir
is defined horizontally by a floor 106 that extends between the lower ends of
the side walls 104,
and that has lengthwise edges that are attached thereto. The floor 106 has
widthwise edges that
are attached to the wall surface of the bell chamber 96.
The water reservoir 102 is designed to accommodate placement of the weir body
passage
92 therein, so that the first weir lip 96 is positioned a determined distance
above the reservoir
floor 106, and so a second weir lip 110 (defined at the top edges of walls
104) is disposed a
determined distance below the weir body solid sections 90, and a determined
distance above the
first weir lip 96. Together, the first weir 95 and the second weir 105 form a
trap disposed within
the LFD 54 in the bottom of the bowl below ports 70 and 72. The water
reservoir floor 106 is
disposed a determined distance above the bell chamber mouth 100 to produce a
desired volume
of trapped air therein during electrolyte leveling and replenishment operation
of the device.
The LFD 54 is constructed to permit unidirectional water flow therethrough
using either
water port 70 or 72 as the water inlet. Water is introduced into the LFD 54 by
a creating a
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differential pressure between the water ports 70 and 72, by either pressure or
vacuum operating
conditions. Water entering the LFD passes from the inlet port through a
respective vertical water
passage 80 in the LFD body chamber 74, into the LFD trap, through the weir
body central water
passage 92, past the first weir lip 96, and is directed upwards by the second
weir 1 O5. The water
passes over the second weir lip 110, through the bell chamber 97, and into the
electrolytic cell
where it mixes with and replenishes the existing electrolyte.
The LFD 54 functions in the same manner as that previously described above for
the
simplified arrangement illustrated in FIGS. I-9. When a determined electrolyte
level within the
cell is achieved, the pressure of air trapped within the bell chamber and trap
imposes an
equalization pressure onto the surface of the water disposed between the first
and second weirs
that is equal to or greater than the head pressure of water within the LFD
body 58 associated with
the water level in the bowl of the LFD. Pressurizing the air trapped within
the bell chamber
causes the water disposed between the first and second weirs to be at or below
the second weir
lip 110. Once the pressure of the trapped air is at or above the pressure head
of water in the LFD
body, water flow to the cell is terminated.
In the LFDs described and shown, water cannot flow out of the device without
flowing
into the bowl. The only path for the flow of water from the device into its
outlet is via the bowl
with which the trap is located. That path has a downwardly excursion between
its inlet and
outlet ports, and the bowl is a part of that flow path in that excursion. The
trap functions as a
valve which has no moving parts and which responds to the level of electrolyte
in the adjacent
battery cell to regulate whether inlet water flows only to the cell, or to the
cell and also out of
the LFD, or only out of the LFD.
FIG. 14 shows the LFD 54 of FIG. 10 in a section plane which is perpendicular
to the
section plane used in FIG. 10. FIG. 14 shows the gas distribution structure of
LFD 54. A pair
of gas baffles 112 are disposed axially within the LFD chamber 74 and extend
from a position
adjacent to and slightly below the LFD upper body first end 60 to the weir
body 62. Walls 112
have continuations 112' in lower body part 62 which extend those walls to
solid sections 90, i.e.,
to the bottom of the water bowl in the LFD. Referring to FIGS. 14 and 15, the
gas baffles 112
are positioned perpendicular to, and are attached along lengthwise edges
between, the water
baffles 76; see FIG. 11. A pair of gas passages 114 are each formed within the
chamber 74
between a front side surface 116 of each gas baffle 112 and a respective
adjacent chamber wall
surface. A central passage 118 is formed along the central axis of chamber 74
between the inner
(back) surfaces of both the water baffles 76 and the gas baffles I 12.
The weir body 62 includes one or more vent openings 120 that extend through
the walls
of the weir body into gas passages 114. In an exemplary embodiment, the weir
body 62 includes
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a pair of vent openings 120 that are diametrically opposed from one another
and are fornled
through the cylindrical wall of the body above body sections 90, which form
the floor of the
bowl of the LFD. Once the LFD is installed within the electrolyte fill opening
of the electrolytic
cell, air or gas pressure that is developed within the cell enters into the
LFD 54 via the vent
openings 120. The entering gas travels from the vent openings 120 upwardly
through the gas
passages 114 toward the top of the LFD body passage, where the gas travels
over top edges 123
of the gas baffles 112 and into the central chamber 118. As will be discussed
below, gas entering
the central chamber can be routed therethrough and into the water passage 80,
where it is vented
from the LFD 54.
The LFD cap 56 is generally in the form of a disk. The cap 56 has a diameter
that is
similar to that of the LFD upper body 58, and is attached along its
circumferential edge to the
open end 60 of the LFD upper body 58. Gas that has entered the central chamber
118 passes
downwardly through the chamber where it passes under the bottom edges 125 of
the water
baffles 76 and enters one or both of the water passages 80 for removal from
the LFD 54 via a
water port 72 being used to remove water from the LFD. For example, during a
water filling
operation that is conducted under either vacuum or positive pressure operating
conditions, gas
within the central chamber exits the LFD 54 via a water passage 80 that is
used to transport water
from the LFD 54. Configured in this manner, the LFD prevents pressure from
both being built
up in the cell during the electrolyte replenishment operation, due to the
displacement of air in
the cell, and during discharge and charging operations (provided that the
water outlet port is not
blocked in and is vented to either the atmosphere or to a gas collection
unit), which buildup of
pressure could cause an explosion hazard when the buildup pressure is caused
by liberation of
gas from the water component of the electrolyte.
FIG. 16 illustrates another preferred embodiment of LFD I 24 that is similar
to the LFD
54 described above and illustrated in FIGS. 10-15, except that in LFD 124 a
valve carrier 125
is interposed between cap 56 and upper LFD body part 58. LFD 124 is configured
to allow gas
that enters the LFD to be vented therefrom. Valve carrier 125 has a circular
disk-shaped
configuration and is attached about its circumferential edge to the open end
60 of the LFD upper
body 58. The valve carrier has a transverse bottom wall 130 through which are
formed a central
valve mounting opening 126 in the center of a pattern of gas vent holes 131.
The valve carrier
also has a side wall that extends around its circumferential edge and in which
at least one vent
opening 132 is formed. Check valve means 127 is disposed within the central
opening 126 to
provide a one-way passage of gas from the central chamber 74 through the
carrier and to prevent
the passage of air from the atmosphere into the LFD. Such checked or one-way
gas venting from
the LFD is desired to permit use of the device under vacuum operating
conditions. ,
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In an exemplary embodiment, the check valve means 127 is in the form of a
resilient
check valve member or stopper that is disposed above and around the vent holes
131. It is
mounted in via a central mounting stem 128. It has a second flared end 129
that cooperates with
the top of wall 130 outwardly of the vent holes. The stopper 127 is adapted to
provide one-way
flow of air or gas from the LFD central gas chamber 118 through vent holes
131, and into the
carrier and to prevent the passage of air from the atmosphere, through the
carrier and into the
central chamber I 18.
I 0 Gas that has entered the LFD central gas chamber 118 passes through the
vent holes 13 I ,
past the stopper 127, and through the vent openings 132 to the atmosphere or,
alternatively, is
collected for further processing and/or eventual routing to the atmosphere.
Configured in this
manner, the LFD 124 prevents pressure from both being built up in the cell
during battery
charging or discharging in situations where the water ports to the LFD are
blocked and, thus gas
is otherwise unable to exit the LFD via the water passages. For example, an
LFD comprising
such a gas venting cap arrangement can be used to advantage in a battery
watering system for
a battery-powered golf cart where an off board reservoir is used and the water
inlet and outlet
conduits to the battery LFDs have check valves which close when the conduits
are disconnected
from the water source, thereby to prevent water leakage when the conduits or
hoses are
disconnected from a watering station.
The above-identified members forming LFDs 54 and 124 can be made from any
structurally suitable material that is adapted to withstand the hostile
environment of battery
service. For example, the LFD may be made from suitable polymeric or
fluoropolymer materials
that are known to exhibit a good degree of structural rigidity and that
provide a good degree of
good corrosion and/or chemical resistance, including resistance to nascent
oxygen. The
members that are used to form the LFDs can be either machined or molded. In an
exemplary
embodiment, the LFD upper body 58, LFD cap 56, carrier 133, weir body 62, bell
chamber body
66, and collar 82 are each molded from a rigid battery grade polypropylene,
and are attached
together using conventional attachment methods. The valve stopper 127 and O-
ring 83 are each
formed from a material that both possesses the desired elastomeric properties
that are called for
in the particular application, and that is adapted to withstand the hostile
environment of battery
service. In a preferred embodiment, the stopper and O-ring are formed from
EPDM rubber.
FIG. 17 schematically illustrates another LFD I 33 of this invention that is
configured as
an integral part of the battery structure itself, rather than as a device that
is designed for
attachment within an electrolyte fill opening of an existing electrolyte
battery. For purposes of
simplicity and illustration, the simplified form of LFD illustrated in FIGS. 1-
9 has been shown
in FIG. 16 as an integral member of the battery structure; namely, the battery
cover. It is,
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however, to be understood that the LFDs 54 described above and illustrated in
FIGS. 10-I 6 may
also be constructed as an integral member of the battery structure.
LFDs 133 are incorporated in a battery cover 134 that fits over and seals the
electrolytic
cells 136 of an electrolyte battery 140. The number of LFDs 133 formed in the
cover 134 equals
the number of electrolytic cells 136, and each LFD is oriented within the
battery cover so that
it is disposed within a head space of a respective cell. The cover 134
includes a water inlet port
142 that is in hydraulic connection with the water inlet passage 144 of a
first LFD. The LFDs
are hydraulically connected to one another in series between their water inlet
and water outlet
passages 144 and 146 via water transport passages 148 disposed within the
battery cover. The
cover 134 includes a water outlet port 150 that is hydraulically connected to
a water outlet
passage 146 of a terminal (last) LFD. LFDs 133 also include vent ports 152
disposed within the
battery cover to allow for built-up pressure from the cell to be removed
therefrom via the LFD,
as described above for LFD 43., e.g.
It is to be understood that the arrangement of three cells illustrated in FIG.
17 has been
selected for purposes of simplicity of illustration and reference, and that
LFDs of this invention
can be configured as integral components of a battery having any number of
electrolytic cells.
It is also to be understood that the particular construction of the LFDs as
being integral with the
battery cover is but one method of making the LFDs as part of the battery, and
that other
constructions, e.g., making the LFD integral with the electrolytic cell wall,
are intended to be
within the scope of this invention.
LFDs constructed as integral members of an electrolyte battery, rather than as
separate
devices that are adapted for retrofit through the electrolyte fill openings of
an electrolyte battery,
are desired because only one water source coupling and water outlet coupling
is needed to effect
electrolyte leveling and electrolyte replenishment for all of the battery
cells, thereby further
simplifying the electrolyte leveling and replenishment operation. Also,
avoiding the need to
retrofit LFDs into each electrolytic cell both eliminates having to fabricate
and maintain external
plumbing between the LFDs, thereby easing battery maintenance and avoiding
potential sources
of water leakage outside of the battery, and avoids any spatial concerns that
may be associated
with using add-on LFDs with existing batteries in certain space-tight
applications.
A feature of LFDs of this invention is that, when installed into each
electrolytic cell of the
battery and when hydraulically connected together, the process of electrolyte
leveling and
replenishment is reduced to a simple act of making a single connection with a
water source,
creating a pressure differential within LFDs, and waiting until water passes
from the terminal
LFD. Using LFDs of this invention avoids the need to gain physical access to
each cell for
electrolyte leveling and replenishment, and avoids the need to circulate
electrolyte outside of the
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battery, thereby eliminating a potential source of property damage or health
risk.
Another feature of LFDs of this invention is that the operation of electrolyte
leveling and
replenishment is accomplished without the use of moving parts in or at a
battery. The use of
moving parts in battery service is not desired due to the hostile environment
with which the parts
may come into contact. The use of moving parts in such a hostile environment
is known to result
in the failure of the parts and/or the improper operation of such parts, in
either case impairing
the proper operation of the device.
A further feature of LFDs of this invention is that they permit electrolyte
leveling and
replenishment under a wide range of differential pressure conditions that can
be imposed under
either pressure or vacuum operating modes. Because LFDs of this invention are
designed to
provide a determined electrolyte level within a cell, based on the equalizing
pressure between
the trapped air within the bell chamber and the pressure head associated with
the water level in
the bowl inside the LFD body, independent of the particular pressure or vacuum
operating
conditions, their use minimizes or eliminates altogether any effects that
inconsistent pressure or
vacuum operating conditions could have on the LFDs ability to consistently
provide the
determined electrolyte level in each battery cell. By using LFDs of this
invention, a person
carrying out the electrolyte leveling and replenis111nent operation can be
confident that the
electrolyte in each cell is replenished to the determined level without having
to worry about the
specific pressure or vacuum operating condition. Such feature of the invention
also makes the
leveling process easily adaptable to a variety of different pressure or vacuum
sources.
The amount of differential pressure needed to operate LFDs of the invention
depends on
the particular LFD application and size. For example, LFDs configured and
sized to be used with
an automobile or golf cart battery could be operated using a smaller
differential pressure than
that associated with a LFD which has been configured and sized for use with a
submarine
battery. In an exemplary embodiment, where the LFD is sized for use in an
automobile or golf
cart application (i.e., where the LFD is in the form of that illustrated in
FIGS. 10-16, having a
body diameter of less than about one inch to facilitate installation within
the electrolytic cell
opening) it will enable electrolyte leveling and replenishment under
differential pressure
conditions (absolute) in the range of from about 0.1 to 20 Psia, without
affecting the desired
electrolyte level that is provided by the LFD in the cell. It is, however, to
be understood that the
LFD can be configured and sized to operate under different differential
pressure conditions
depending on the particular application.
Additionally, if desired, and as depicted in FIG. 20 for simplicity of
illustration, LFDs of
this invention can be constructed and used to perform electrolyte thermal
conditioning in
addition to filling and leveling. For example, the LFD 10 can be designed
having one or more
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heat transfer elements 170 that projects downwardly from the bowl bottom or
floor 26 a distance
from the bell chamber so that each such element 170 is immersed into the
electrolyte a desired
depth. The heat transfer elements 170 are connected to the LFD 10 at a
position that permits
conductive heat transfer from the water entering and circulating through the
LFD to the
electrolyte. The heat transfer elements can be made of from a material having
good thermal
conductivity properties, such as metal or the like (e.g., stainless steel). A
LFD comprising such
heat transfer elements may be desirable in applications where heating or
cooling the electrolyte
is desired for optimum battery performance and/or service life. In such
applications, the
electrolyte in each cell can be heated by circulating heated water through
each LFD, or can be
cooled by circulating cooled water through each LFD.
FIG. 18 illustrates a liquid filling system (LFS) I 54 comprising a number of
LFDs 54 that
are described above and illustrated in FIGS. 10-16, and that are each disposed
in a respective
electrolytic cell 158 of an electrolyte battery 160. The LFDs 54 are
hydraulically cormected to
each other in series via water transport passages 162 that are each interposed
between respective
water ports 164 of adjacent LFDs.
The LFS illustrated in FIG. 18 is adapted to provide electrolyte leveling, and
replenishment when a differential pressure is imposed between the water ports
164 of each LFD
54 by either
vacuum or pressure operating conditions. The water port I 64 of a first LFD 54
is connected to
a water supply line 166 that is connected to water source (not shown). In the
event that the
differential pressure through each LFD is imposed by pressure conditions, the
water supply line
166 is connected to a water supply source that is adapted to provide water at
a suitable pressure
and flow rate, e.g., water at line pressure and the like. In the event that
the differential pressure
through each LFD is imposed by vacuum conditions, the water supply line 166 is
connected to
a water source that is adapted to supply water at atmospheric pressure, e.g.,
from a water
reservoir and the like.
FIG. 18 affords an opportunity to note that the bodies of LFDs 54 are
rotatable in their
mounting collars, so that the angular position of an LFD can be adjusted to
efficiently implement
any desired scheme for interconnecting the LFD in a multi-cell LFS.
The water port 164 of a terminal LFD 54 is connected to a water drain line
168. If
desired, an outlet end of the water drain line may be connected to a water
reservoir or the like
(not shown) to capture water exiting the LFS after the leveling and
replenishment operation is
completed.
If desired, a quick-connect type fitting attachment (not shown) can be used to
provide a
single location connection point for both the water supply line 166 and the
water drain line 168.
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Such fitting attachment may preferably be configured to provide a releasible
interlocking water-
tight fit between respective ends of the water supply and drain line. It is
additionally desired that
such fttting attachment include a check valve or the like at each connecting
end that is adapted
to both permit flow through the coupled line ends when connected, and prevent
flow though the
uncoupled line ends when disconnected. The use of a fitting attachment
configured in this
manner is desired because it reduces the steps required to initiate
electrolyte leveling and
replenishing to two; namely, activating the supply source, and connecting the
fitting attachment.
LFS 154 is operated by activating the pressure or vacuum supply source to
provide a
desired differential pressure within each LFD 54, causing water to be routed
to into the first LFD
54. As the water enters the first LFD it passes through the LFD to the
electrolytic cell in the
same manner described above and illustrated in FIGS. I-9. Specifically. as the
water enters the
first LFD 54 and is directed through it via its internal water passages, the
electrolyte level in the
1 S first cell rises until the pressure of the trapped air in the bell chamber
reaches the equalization
pressure, causing the water passage into the cell to cease, and causing the
water level in the LFD
to rise until it reaches the mouth of the empty water passage and is passed
therethrough out of
the LFD. Water that is circulated through the first LFD is routed via the
water transport passage
162 to the water port 164 of the next LFD in the series, where the process
repeats itself. Water
is circulated between each LFD in the series until the desired electrolyte
level in a terminal cell
158 is achieved and water is routed from a respective terminal LFD via its
water port I 64. Once
water is observed to exit from the water drain line 168, the water flow from
the water source is
terminated by deactivating either the pressure or vacuum supply source.
The water ports 164, water passages within the LFDs, and water transport
passages 162
hydraulically connecting the LFDs are purged of water contained therein by one
of the four
methods described above. Refernng to FIG. 18, in an exemplary embodiment, the
water can be
purged by passing pressurized air through the interconnected electrolytic
cells in either direction
using line 166 or line 168 as the air input line. Once air is observed to exit
from the other line,
the air pressure source is disconnected and the electrolyte leveling and
replenishment operation
is complete.
If desired, the electrolyte leveling and replenishing operation can take place
before, after
or during the process of charging the battery; during and/or after being
preferred.
Although an exemplary LFS has been specifically described above and
illustrated in FIG.
18 that makes use of LFDs of FIGS. 10-16, it is to be understood that LFSs of
this invention may
alternatively make use of other LFDs of this invention, and that such use is
intended to be within
the scope of this invention.
The foregoing description of presently preferred and other aspects of this
invention has
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been presented by way of illustration and example. It does not present, nor is
it intended to
present, an exhaustive catalog of all structural and procedural forms by which
the invention can
be embodied or practiced. Variations upon and alterations of the described
structures and
procedtu~es can be pursued without departing from the fair substance and scope
of the invention
consistent with the foregoing descriptions, and the following claims are to be
read and
interpreted liberally in the context of the state of the art from which this
invention has advanced.
15
25
35
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