Note: Descriptions are shown in the official language in which they were submitted.
This invention relates to an electro-chemical system
of filtering filtration, and more particularly, to a method
and apparatus for electro-chemical filtration of water and
other liquids for solids removal, decontamination, and
general purification purposes.
G ERAL NATURE OF INVENTION
This invention is concerned with an electro-chemical
system of filtering water and other liquids, whereln physical
properties and/or electrical characteristics are provided by
the filter implements involved that, when coupled with the
conductive properties of the filtrant to be cleaned or
purified, establishes a reliable and controllable liquid
electro-chemical filtration and purification action. The
invention contem~Iates that sub-microscopic contaminates,
dissolved and suspended solids, foreign particulate material,
undesirable ions, and the like, will be removed from the
liquid being treated at a predic-table high rate, such as the
1 micron absolute particle size filtration level that is a
major objective of the present invention. The invention
is basically concerned with providing an economical, compact~
light weight, regenerative, high rate filtration system that
in practice will efect, for instance, nearly 100 per-
cent removal o toxic organics, scale or waste solids, and
il
-- 1 -- ;,
6~
biological or~anism contaminants ~rom, for instance, coo]ant
waters and oils, marine hatchery waters, food processing waters,
industrial waste waters, and potable drinking water.
PRIOR A.RT B~CKGROUND
The art of filtration, broadly speaking, is generally
represented by various hydro-mechanical or chemically oriented
apparatus and procedures whereby impuxities are removed from a
~low of liquid, usually water. The basic types of filtration
arrangements and devices of the prior art, and their accompanying
problems and limitations, may be categorized, generally as
follows:
1. Non-regeneration modular filters are one
time, short use, devices of inexpensive cartridge design that
haye low flow~high head loss limitations of which the filter
material involved is packed cellulose or fibronous textile
material that at the optimum best will provide no better than
5-10 micron absolute particle size filtration results. Minor
recognizeable suspended solids in the fibrant will quickly clog
the filter material within the cartridge and render the filter
system involved inoperable. Where moderate and high flow rate
is involved, replacement costs and down time are inordinantly
burdensome.
2. Regenerative membrane (rotary and stationary
types) filters are relatively expensive, and while they may
involve filtered water backwash desi~n, they are limited to
tertiary or polishing water filtration wherein suspended solids
contamination is relatively li~ht and can be removed at the 10-
15 part per million level. These fil~ers are generally not
~2~
efficient in removing solids debris below the 5-10 micron
particle size level, and they exhibit low flow filtrat.ion
characteristics (below 100 gallons per minute) even when ef-
fective in the l-S micron particle range. Membrane filters
foul readily with biological growth inherent to the passing
liquid flow, and often become inoperative or highly restrictive
to the flow of the filtrant therethrough.
3. Pressurized pre-coated filters are filters
of the pressure vessel type that are heavy, bulky, and expen-
sive, and are characterized with costly filtered coa-tings in
the form of diatomaceous earth, fly ash, or the like for
filtering and entrapping the suspended solid debris from the
passing liquid flow. While precoated filter aids of the type
indicated can effectively filter down to the 1 micron particle
size level at low filtrant flo~ rates, at higher, more desirable
output flows of 150 gallons per minute (GPM) they tend to
become plugged with solids and/or start to dissolve rapidly.
As these filter aid precoat materials cannot be regenerated and
filter life is short, disposal of contaminated precoat aids
presents serious disposal problems that frequently yiolate the
EPA Hazardous Waste definition.
~ Hi~h rate sand filtration pressure vessel
flters accommodate ~iltration of relatively large volumes of
~ater t500-1,000 ~PM), with revers~ filtration wa-ter flow along
with compressed air providing ~ackwash regeneration of the sand
~ilter material. However, the backwash waste water volume is
su~stantial~ as is the cost of the basic system involved~
Whi~le appropriate selection of sand grain size as filter material
3 D
will allow volume removal of suspended solid debris down to the
5 micron particle size, this is not adequately close to the
micro size level where at least half of the impuri~ies will be
found, namely the 1-5 micron particle size, and the dissolved
solids particle size range below 1 micron. High rate sand
filtration is known to be ineffective for removal of minute
particle siæe debris, and the large volume of backwash water
involved in these systems often makes economical disposal
impossible.
5. Ion-exchange filters involve filtration
systems based on known water chemistry criteria that dissolved
contaminating solids are composed of electrically charged
molecules and ions. In the filter devices involved, the filter
containers are packed with resin material having active site
electrical ionic polarity positions therein. A moderate low
(200 GPM) ion exchange filter system represents a complex
plumbing network involving unwieldy resin filter containers and
large installation space requirements. Regenera-tion of the
filter resin becomes complicated and often incomplete due to
the plugging of the resin pore spaces by the larger particle
size suspended solids of the filtrant. The systems have
substantial limitations limiting their practicality for general
purpose use because filtration is available for only very
select waste waters that must possess very little suspended
solids contamination and cannot exceed narrow limits of dissolved
~hemical contaminants, as well as high cost.
6. Reverse osmosis filters require costly high
pressure pumping equipment for moderate outflow apparatus with
initial investment, and operating electrical and pressure
system maintenance economics that are operationally prohibitive
from a pract.ical standpoint. The backwash brine flow required
to remove solids from the membrane filter involved periodically
causes partial contamination of the filte.r water flow and
reduces the quality of the water filtrate. Reverse osmosis
backwash flow volumes often represent 30 to ~0 per cent of the
throu~h-put filtration flow, and therefore the systems provide
only a relative low yield of filtered water per unit of capital
investment cost, and then only for very select water stream
filtration. These systems become inefficient when a multiplicity
of contaminating dissolved solids (ions) and .suspended particulate
contaminants are present that cause membrane fouling.
A principal object of the present invention is to
provide a recirculating filtration system for filtering liquids
that will effect removal from the filtrant submicroscopic
contaminating dissolved solids (in ion form) and suspended
parficulate solids that may be in the form of foreign matter
particulate material that are of either or~anic or inorganic
origin at a predictable particle size approximating 1 micron,
while at the same time providing a compact, li~ht weight,
re~enerative, and economical apparatus or device for that
purpose.
pr-~c~Pq
Another ~ ~1 object of the invention is to provide
a method and apparatus of electro-chemical filtration of
liquids in which basically the same filtration apparatus or
device may be employed for both oils and waters, and in which
the practice of the invention provides removal of toxic organics,
~2~
scale and waste solids, biological organism contaminants and
other foreign matter from the liquid, with efficiencies approach-
ing 100 per cent.
~ nother principal object of the invention is to
provide an electro-chemical filtration system that is oriented
toward taking advantage o~ the conductive properties of the
liquids to be filtered, such as natural particle debris is
water, that effects undesirable ion and colloidal particle
removal by way of coagulation, agglomeration, or flocculation
of same into larger particle size for entrapment in a two stage
polarized filter medium, with efficient regeneration of the
filter units involved being provided for by way of backwash
procedures that may be built into the system for automatic
operation.
~ nother important object of the invention is to
provide an electro-chemical system of filtration, and specifically
~ethods and devices or apparatus arranged in accordance with
said~system, that is economical of manufacture, compact, light
in weight, uncomplicated, and safe in design, that is adaptable
~for application to a wide variety of liquid filtration needs
and requirements, and that is lony lived, efficient, and easy
to use in operation~
In accordance with the invention, a basic electro-
chemical liquid filtration device is provided comprisin~ a
cani$ter in cylindrical form that has a bore extending longi-
tudinally thereof and in use îs adapted to be vertically
position oriented when installed ~or operatin~ purposes. The
can~ster at it$ upper end is adapted for connection to the-
6.
source of the liquid filtrant, and the lower end of the canisteris closed to seal same off but provide for periodic removal of
foreign materials collecting at the lower en~ of the canister.
The canister adjacent its lower end has a cross tube extending
crosswi.se through same and fixed to same that has a width tha-t
is less than the width of the bore on the order of 25 per cen-t,
with the cross tube being centered on the longitudinal axis oE
the canister and having its external ~a~.~-ng- in sealed relation
thereabout with the canister at either end of the cross tube.
Centered within the cross t~be is a tubular mandrel that
extends substantially coextensive with the cross tube, w.ith the
portions of the cross tube and mandrel that are disposed
wi.thin the canister ~ach b~ing formed to define multiple liquid
pas.sing apertures or orifices thereabout, with the aperture or
orifice area total of the cross tube apertures being greater
than the corresponding total area of the mandrel tube total
orifice or aperture areas by about 25 per cent. Interposed
between the cross tube and the mandrel is an elongate composite
~;lter sheeting tightly convoluted about the mandrel and in
close fittin~ relatiGn in the space between the mandrel and the
cross tube, with the convoluted composite filter sheeting
comprising a pair of foraminous electrically conductive corrosion
free sheets that e~ch may be in ~he form of stainless steel
wire mesh, separated by a sheet of fibrous material of such
iber size (diameter and density) that the pore spaces or
interstices defined thereby have a size in the range of from
about 1 to about 5 microns.
~ second, coarser filter unit is disposed across
the bore of the canister and located between the upper end
of same and the cross tube, and is in the form of a pair of
foraminous, electrically conductive, non-corrosive sheets,
that may be stainless steel or mesh, separated by layers of
fibrous material that may comprise one or more discs of
fibers of a suitable diameter and density to provide pore
spaces therein that have a size in the range of from approxi-
mately 15 to approximately 25 microns as average open space.
In each of these filter units of the canister, the
filter units are polarized by connecting the respective sets
of foraminous sheets anode-cathode fashion to a low voltage
low amp source of direct current, such as a 12 volt 50 amp
D.C. power supply system.
The general arrangement involved is arranged to
interact with the electrical properties of dispersed ion and
solid particulate material, whether dissolved or suspended,
that might be considered contaminating or otherwise undesir-
able matter, with filtration removal being accomplished by
, .
the passage of the filtrant through the polarized filter
units, with the upstream filter unit being of a relatively
coarse fiber type to filter out the larger solid particles,
and the downstream cross filter unit comprising a relatively
fine fiber filter for minute solids and ion removal. Withln
the two filter units, under the polariæation of both units,
the solids effect a precoating of the fibers by physical
attraction thereto, with the solids becoming alectrically
charged and attracting other charged solids thereto for
coagulation, coalescing,
lcm/ J~ -8-
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~zo~
and agglomerating of same into larger particle size within the
two filter units. The solids tend to form linear molecular
chain clusters tha~ become entrapped within the fibrous material
involved, with ions being electrically held by the pol~rization
involved within the filter units.
~ n the general arrangement involved, the filter
system canister has its cross tube filter unit arranged for
filtrate discharge at either end of same through the mandrel
bore, under the control of two three way off-on valves one at
either end of the cross tube filter unit, with the entry of the
filtrant into the canister being similarly controlled by a
similar three way of~-on valve. Pursuant ~o the basic system
involved, these three valves are simultaneously controlled for
full filtration flow in one position, and for backwash, filter
unit regeneration, flow through the canister, in an opposite
position, preferably arranged for automatic operation when the
psi of the filtrant entering the canister exceeds a predetermined
amount, with automatic return to full filtrant flow position
after a predetermined time of backwash operation.
The basic recirculating filter system provides for,
in conjunction with the discharge of the filtrate from the
cross tube filter unit, the injection of ambient air and/or
Oxidizing gases that for ~iltration flow purposes may provide
ior additional oxidation-coagulation of contaminant dissolved
solids or other treatment of the effluent, and for backwash
purposes provide for gas or air scrubbing o~ the filtration
units as part of the procedure of regenerating same.
Also dis~losed is a special gas or air injector
device specifically adapted for use in connection with the
filtration device or apparatus of this system, that provides
dispersed solution gas réquired for backwashing or for coagulating
solids into larger filtrable particle size.
Other objects, uses, and advantages will be obvious
or become apparent from a consideration of the following detailed
description in conjunction ~ith the application drawi.ngs, in
which like reference numerals are employed to indicate like
parts throughout the several views.
In the drawings:
Figure 1 is a diagrammatic side elevational view of
a electro-chemical filter module arranged in accordance with
the present invention, as adapted for incorporation as a unit
in a typical en~ineering industrial system, such as that diagram-
matically illustrated in Figure 6;
Figure 2 is a vertical sectional view through the
filter assembly itself, taken substantially along lines 2--2 of
F~ure 1, but on an enlarged scale;
Figure 3 is a vertical sectional YieW through the
~iltex assembly, taken substantially a].ong line 3--3 of Figure
2;
Fi~ure ~ is an exploded perspectiye view dia~rammati-
cally illustrating the components of the filter assembly of
this invention;
Fi~ure ~A is a fragmental perspective view diagrQmmati~
cally illustrating the convoluted arrangement of the composite
~ilter sheeting forming a part of the fine filter unit at the
cross tube portion of the filter assembly of Figures 1 - 4;
10 .
~2~ L6~)
Figure 5 is a diagrammatic and partially schematic
view illustrating the electro-chemical filter module of Figure
1 and associated electrical circuitry for operating the module
in accordance with the present invention;
Figure 6 is a diagram illustrati.ng the layout of a
typical engineering indus-trial water handling system in which
the filter module of this invention may be incorporated;
Figure 7 is a view taken along section line 3--3 of
Fi~ure 2, but illustrating on an enlar~ed scale the gas injector
device shown to the right of the filter assembly of Figures 1
and 5, with parts being shown in elevation and the liquid flow
being illustrated diagrammatically to bring out the special
nature of the injector device;
Figure 8 is an elevational view of the discharge end
o~ the injector, taken substantially alony line 8--8 of Figu.re
7; and
Figure 9 is an exploded perspective view illustrating
the basic components o~ the injector.
However, it is to be distinctly understood that the
specific drawin~ illustrations provided have been supplied
primarily to comply with the requirements of the Patent Laws,
and that the inventivn is susceptible of modi~ications and
variations that will be obvious to those skilled in the art,
and that are lntended to be covered by the appended claims~
G~N~RAL DESCRIPTION
Reference numeral 10 of Figures 1 and 5 ~enerally
indicates electro-chemical filter module arran~ed in accordance
with the present invention for application to typical industrial
11 .
or commercial water system arrangements for d~contaminating and
purifying the water, such as -the system 11 diagrammatically
illustrated in Figure 6.
The electro-chemical filter module 10 comprises
filter assembly 12, a pair of gas injector assemblies 14 and 16
disposed on either side of the filter assembly 12, and three
three way valve assemblies 18, 20 and 22 that are disposed at
the three inflow and outflow sites of the module 10 for liquid
directional flow control purposes.
The liquid directional flow control valves 18, 20 and
22 are arranged in the manner diagrammatically illustrated in
Figure 5 for simultaneous actuation between coordinated positions
whereby the filtrant is passed through the module 10, resulting
in an effluent filtrate havin~ the quality contemplated by this
invention, and a second set of coordinated oppositely disposed
positions in which the module 10 is set for backwash liquid
flow purposes for re~enerating the filter asse~bly 12.
The fi.lter assembly 12 is illustrated in detail in
Figures 2 - 4A, and comprises a canis*er 26 in the form of
cylinder 28 defining cylindrical bore 30. The canister 26 when
in its operative position is vertically disposed and has its
upper end 32 provided with fittin~ device 34 for connecting
same to the source of the liquid to be filtered as well as to
serye as the point o~ discharge ~rom the assembly 12 of backwash
~ater. The canister -~ at its lower end 36 is provided with a
suitable end closure device 38, that is to be equipped for
sealing off ~his end of the canister during use and periodic
clean out of the canister end 36.
12.
The canister bore 30 defines a liquid flow chamber 40
haviny mounted adjacen-t -the upper end of same a coarse filter
uni~ 42 that in the form shown comprises a pair of spaced apart
foraminous yri.ds 4~ and 46, that are preferably formed from
stainless steel wire screeniny, which have disposed therebetween
one or more discs 4~, that are preferably formed from resiliently
compressible fibrous sheeting material, such as polyester or
nylon fibers, which are sized and compacted or densified to
pro~ide pore space or interstice open areas within the pad like
discs that have a size in the range of from abou-t 15 to about
25 microns, on the average.
The canister 26, spaced below the coarse filter unit
42, has cross tube 50 extending thereacross and therethrough.
Cross tube 50 extends perpendicularly of the central axis 51 of
cylinder 2~ and is centered with respect to same such that its
own central axis 53 intersects the cylinder longitudinal axis
51 as indicated in Figure 2. It is a feature of the invention
that the external di.ameter of the cross tube 50 is approximately
25 per cent less than the internal diameter of the bore 30, so
that the chamber 40 has a 360 de~ree relationship with the
portipn of the cross tube 50 that is disposed within bore 30,
with unimpeded flow passage space between the cylinder and the
cross tube side wall 57, as shown in Fiyure 2.
Centered within cross tube 50 is tubular mandrel 52
defined by circumambient side wall 59 defininy bore 55. As
shown in Figures 2, 3 and 4, the porti.ons of -the cross tube 50
~P~ . ~,f~,~ 26
and the mandrel 52 disposed ~i-~ canister -~ are each formed
with multiple liquid passing apertures or orifices thereahout,
~L2~ 6~
those of -the cross tube 50 being indicated by reference numeral
c~r ~
5~, while those of the mandrel 52 ~e~*~ indicated by reference
numeral 56. The liquid passing aper-tures 54 and 56 are formed
in rows along the respective members 50 and 52, and specifically,
their side walls 57 and 59, with alterna-te rows being offset,
as indica~ed in Figure 4. A feature of the invention is that
the orifices or aper~ures 54 define an overall orifice area for
the cross tube 50 is approximately 25 per cent greater than the
composite or total orifice area defined by the orifices 56 of
the mandrel 52.
Interposed between the cross tube 50 and the mandrel
52 is fine filter unit 60 that is diagrammatically illustrated
in Figures 2 - 4A, which comprises in accordance with the in-
vention an elongate composite filter sheeting 62 tightly
conyoluted about the mandrel 52 and being in close fitting
relation between the mandrel 52 and the cross tube 50 in the
assembled relation of same, as indicated by Figures 2 and 3.
The sheeting 62 in accordance with the invention compri.ses a
pair of foraminous electrically conductive sheets 64 and 66
that may be in the form of stainless steel wire screening,
which have interposed or sandwiched therebetween resiliently
compressible fibrous sheet 68 that is preferably formed from a
suitable fibrous material, such as nylon or polyester and
~ensified o.r compressed to define pore or interstice open space
areas that avera~e in the ran~e of ~rom about 1 to about 5
microns in size. Iron o~ide ~ rock wool or iron oxide
sla~ wool fibers of the type normally used for insulation are
also appropriate for specific applications, as will be disclosed
hereinafter.
The cross tube 50 comprises cylinder member 70
in which the apertures 54 are formed, and which has opposite
end partions 72 and 74 (see Figure 3) projecting exteriorly
of the canister 26, with the joint between the cylinders 28
and 70 at the position of the cross member 50 being suitably
sealed by employing suitable bonding or sealing material.
The ends 72 and 74 of cross tube 50 have applied to them
suitable fitting devices 76 and 78, respectively, for
application thereto of the respective injector assemblies
14 and 16, which in turn have applied to them the respective
valve devices 20 and 22. The end fitting 34 of the canister
26 is operably connected to the valve device 18. As in-
dicated in Figure l, the valve device 18 is connected at one
end to filtrant lnflow pipe or conduit 80, and at the
opposed end to backwash outflow pipe or conduit 82. The
valve device 20 is connected at one end to filtrate outflow
pipe or conduite 84 and at the opposite end to backwash
inflow pipe or conduit 86. Likewise, the valve device 22
has filtrate outflow pipe or conduit 88 suitably connected
to one end!thereof), and at the opposite end backwash in-
flow pipe or conduit 90 is suitably connected~thereto~.
The three way valves 18, 20 and 22 in and of
themselves and as associated with the conduiting indicated
are conventional three way directional flow valves, with
such valves, when in their positions of Figure 1 (as in-
dicated by the three way valve indicating symbols employed),
accommodating flow of the filtrant into the module 10 vla
pipe or conduit 80, and ouflow :Erom the module 10 via the
piping or conduits 8~ and 88. When
lcm/J~ -15-
..~
~L2~
the positions of the valves 18 r 20 and 22 are reversed in
accordance w.ith the invention, filtrant flow into the module 10
ceases, as does filtrate flow therefrom, and instead backwash
flow enters the module 10 at piping or conduits ~6 and 90 and
leaves the module via piping or conduit 82.
Further in accordance with the inventi.on, the grids
or sheets ~ and 46 of filter unit 42 are electrically connected
to a suitable source of direct current energy anode-cathode
fashion for polarizin~ the unit 42, and the foraminous sheets
64 and 66 are similarly electrically connected to a suitable
source of direct current energy anode-cathode fashion to polarize
the filter unit 60. For this purpose the anode of filter unit
42, for instance, grid 44, and the anode of filter unit 60, for
instance, sheet 6~, are connected in parallel to, for instance,
a conventional 12 volt 50 am~ source of direct current power,
which source is indicated in diagrammatic Figure 5 by reference
numeral 100, while the grid 46 of filter unit 42 and the sheet
66 of the filter unit 60 are connected in parallel cathode
fashion to the same source in any suitable mannerj such as tha~
dia~rammatically illustrated in Fi~ure 5. The direct current
source 100 preferably provides D.C. volta~e in the range of
from about 12 to about 2~ volts at an amperage in the range of
from about five ~o about fifty amps.
In the module 10, the canister forming cyl.inder 26,
cross tube 50, and mandrel 52 are formed from suitable inert
materials~ such as poly~inyl chloride tubin~. In a successful
embodiment of the inYention proYidin~ a filtrate outflow of 150
~allons per mtnute with the conventional filtration pressure of
16.
6~
50 psl at the filtrant intake end of canister 1~, the cylinder
28 orming canis-~er 26 is 12 inch diame-ter pol~vinyl piping
while the cross tube 50 is 8 inch diameter polyvinyl piping and
mandrel 52 is 3 inch diameter polyvinyl piping; -the piping
preferably is of the Schedule 80C (high temperature) polyvinyl
commercial plastic piping. The grids or shèets ~ and ~i6 of
the filter unit ~2 and the grids or sheets 6~ and 66 filter
unit 60 are formed from stainless steel wire screening with
grids 4~ and 4~ having a mesh of ~, and grids or sheets 6~ and
66 having a mesh of 40. It is intended that all parts disposed
internally of the canister 12 and module 10 be formed from non-
corrosive or inert materials.
Referrin~ -to Figure 7, the gas injector assemblies 1~
and 16 each comprise suitable three way ~itting 110 that may be
$ormed from the indicated polyvinyl chloride material that is
ioined at its opposite ends to the respective connecting fittings
involved in any suitable manner. Closure disc 112 is fi~ed
across the fitting upper end 114 in any suitable manner and
mounts in upright position standpipe 116 that has applied to
sa~e a suitable conYentional check valve 118 that may be one of
the common ball types. Mounted on the lower end of the standpipe
116 is gas injector device 120 that will be described in detail
hereinafter, and which receives from under pressure a suitable
source air or other oxidizin~ and/or solids coagulation inducting
~as for injection into the moving stream passing through the
$itting 110, with the ~as involyed depending on the application
to which the module 10 is being put. The injector device 1~ is
the same as injector device 16, as indicated by corresponding
~2~316~
re~erence numerals. The check valves 118 prohibit backflow
into the piping or conduiting 136 of the filtrate being treated
by the injector devices 14 and 16. The gas should be supplied
to devices 120 a~ a psi pressure which exceeds by approximately
25 psi the psi pressure of the filtrant at the intake end of
canister 26.
In operation/ assuming that the module 10 is operably
connected to liquid flow piping or conduiting for liquid direction-
al flow purposes in the manner diagrammatically illustrated in
Figures 1 and 5, with a module 10 resting on suitable support
f--amework 130, and assuming that the filter units 42 and 60
have been polarized by electrical connection, in anode-cathode
$ashion, of the electrically conductive screening components
i`nyolved in each filter unit in the manner suggested, the valve
de~ices 18, 20 and 22 when positioned as indicated in Figure 1
accommodate filtrant flow through the module 10 in the direction
indicated by the full line arrows to effect the filtration and
water purification objectives of this invention insofar as the
~iltrate emerging from same is concerne~. /
A basic feature of the present invention is that the
~iltrate insofar as the ~o filter units are concerned is to
pass through polarized, fibrous material equipped, filter
units, with the arranqement being de~ised to take advantage of
the conductive properties that are inherent in liquids that
have contaminants and the like to be removed. These materials
may be in ion form if dissolved, and are thus inherently electrically
charged, or in colloidal form, as well as perhaps comprising
solids of the -~oxic or~anic, scale and waste, and biological
18.
~z~
organism types, all of which have been found to be responsive
to electrically polarized environment.
soth the filter units 42 and 60 effect filtration on
similar principles, in accordance with the invention, which
contemplates that as -the filtrant initially passes through the
respective units, the fibers of the fibrous components of same
become precoated with the filtrant solids due to the natural
physical attraction of such solids to the fibers, and the
charging or polariza-tion of the respective filter units effects
a charging of the fiber solid coatings which attracts thereto
further solids and ions tha-t are passing into the respective
filter units.
The solids involved as filtration proceeds/ have been
found to continuously orient electrical charge fashion, coagulate,
coalesce and ~ into larger filtrant particle size, by
way of becoming positive-negative linear molecular chain clusters,
whereby their enlarged particle size physically entraps them
within fibrous sheeting of the respectiye polarized filter
units, with the charging of such units also electrically holding
$uch solids and ionic matter within the respective ilter
units. Further, the peripheral electrical charge that is
naturally involved in each susperlded solid particle seems to
tend to prevent the return of sueh solids back into the passing
l~uid flow, as the char~e of the respective anode and cathode
components with respect to the filter units seems to condition
these particles for capture by electrical attraction to form
the larger size particles involved.
With regard to the canister 26, as the filtrant enters
the canister 26, it meets and enters filter unit 42, with the
liquid flow involved completing the circuit between the grids
44 and 46, whereby the dissolved impurities in the form of
ions are responsive to the charging involved to cause the
ions to adhere to the positive or negative grid 44 or 46, as
the case may be, and the solids to ~uild up within the pores
or interstices deined by the fibrous material involved.
Filter unit 42 functions to remove from the filtrant the larger
particle materials therein which as a matter of practice would
have a size in the range of from about 1 micron to about 5 and
larger, as well as bacteria.
The filtrant leaving the filter unit 42 moves down-
wardIy and then is applied about the cross tube 50 in 360 degree
relation thereabout for entry through cross tube apertures 54,
passing through the convoluted and thus multiple layers of the
filter unit 60, and thence through the apertures 56 of mandrel
52, into its bore 55.
During the passage of the filtrant through the filter
unit 60, the aorementioned charging and positive-negative -
orientation of the particles takes place with the resulting
coagulation, coaescence, and agglomeration into the indicated
positive to negative linear molecular chain clusters whereby
:~ they become physically and electrically entrapped within the
filter unit. The filter unit 60 is arranged to take out
particle sizes down to 0.5 to 1 micron size range. Unit 60 in
acting in accordance with the invention electrically coagulates,
coalesces, and agglomerates particles of submicron size where
20 -
,,~;
~2~
they are dissolved or in the colloidal state, and even undesirable
materials in solution ion form, into an agyre~ate of adhered
multiple particle-ion combinations that agglomerate into a
larger particle si~e forming a multiple particle-ion structural
matrix throughout the filter unit 60 and about the filter
chamber 6]. defined by cross tube 5 and the mandrel 54. The
resulting matrix that has electrically developed by agglomeration
or flocculation within the pore spaces or interstices of the
filter 62 permits the resulting filtrate to be the result of
substantially 100 per cent removal of the various toxic organics,
scale and waste solids, biological organism contaminants, and
the like that will be ~ by water to bè filter treated.
Similar results are achie~ed filtering oils.
In the area of the in~ection assemblies 14 and 16,
the injection devices 120 provide for in-line pressurized
dispersement of gases into the filtrate for treating purposes,
such as the injection of ozone or singlet molecular oxygen for
disinfectant and coagulation purposes.
Further in accordance with the invention, the module
10 is arranged for backwash purposes when the pressure of the
filtrant at the intake end of the canister ~ e~ceeds a predeter-
mined amount, such as 75 psi where the conventional 50 psi
~iltrant flow pressure is employed. ~or this purposes, a
suitable pressure switch 130 of any conventional make is
employed in communication with the conduit 80 or head end of
~ 6
the canister ~ to effect electrically reversal of the positioning
o~ ~he valve devices 18, 20 and 22 to the positions already
indicated, whereby the flow of the filtrant through the module
L6~
10 ceases, and instead bac~wash liquid, such as city main
water, is passed therethrough in a reverse flow pattern with
entry at the conduits 8~ and 90, passage through the injector
assemblies 1~ and 16, and entry into the mandrel 52 for passage
through the filter unit 60 into filter chamber 40 and through
filter unit ~2 for discharge via conduit 82 into a suitable
waste drain, or sump where recovery of some of the removed
materials is desired. It is preferable that the backwash
functioning of the apparatus be automatic during operation of
the module 10, for instance, for a specific selected time of
backwash that may be up to three minutes. A one minute backwash
cycle is contemplated for the embodiment illustrated once the
switch 130 brings this operation of the module 10 into play, by
way of the diagrammatically illustrated circuitry 132 of Figure
5, whereby the circuitry 132 incorporates a conventional double
pole double throw 60 second self reversing 115 volt 15 amp
timer indicated at 134. However, manual actuation of the means
to switch valves 18, 20 and 22 to their backwash modes may
optionally be employed.
While the module 10 is in its backwash mode, the
reverse liquid flow through the filter assembly 12 washes the
solid particle-ion structural matrix that has been built up,
from the respective filter units. The gas in~ection of the
injector assemblies 1~ and 16 continues to operate whereby the
injected gas, for instance ozone or ambient air, and backwash
water effect a vigorous agitation type scouring action on the
~ibrous filter materials, in passing through the respective
~ilter units in a reverse flow direction, effecting Eull release
~ 2.
~2~?~iL6~
of the entrapped solids. It has been found that the gas injected
by the injector devices 120, which may be partiall~ or wholly
dissolved in the backwash water, provides on entr~ into the
filter units an increased pressure, saturated gas scouring
vibration-agitation action within both filter units 42 and ~
The dissolved gas involved seems to provide a hydraulic pulsation
which expands the ~iber materials of the respective filter
units and this agitation of the filter material involved is
caused by and results in the breaking away and washing therefrom
of the contaminant solids and the like that are entrapped
therein, to.the backwash drain off flow.
It is preferred that the backwa~h liquid supplied to
the module 10 be at a pressure that exceeds that of the normal
50 psi filtrant supply pressure to the module 10; appro~imately
75 psi is preferred, assuming the normal 50 psi filtrant supply
pressure, with the backwash pressure being roughly in the same
~roportion greater when other filtrant supply pressures are
employed. The gas supplied to injector devices 120 should be
under pressure of approximately 25 psi above the filtrant
sup~ly pressure, as already indicated. As the backwash liquid
enters and passes through consecutively the respective filter
units 60 and ~ , reduced presswres are encountered whereby the
~ases carried by the liquid, whether..in dissolved relation or
not tend to be released in an effervescent manner; further, as
the backwash liqui.d and gas act on the resiliently compressible
fibrous materials involved in each filter unit, the solid in
breaking away in a random piece by piece manner are immediately
displaced by the liquid, causing a hydraulic jolting or hammering
23.
~2~}~3L6~
action that pulsates as the replacement of the solids proceeds.
This overall action seems to be responsible for the air scouring,
vibration, and agitation action that is provided on the filter
media on both filter units 60 and 42, with the fibrous layers
of same expanding under the reduced pressures and the
effervescing gas pressure they experience. After a predetermined
time of backwash, the module is returned to its filtering mode.
This operation of the mode may be effected electrically either
manually or automatically, with the circuitry 132 being arranged
for automatic switch back by way of tlmer device 134.
SPECIFIC DESCRIPTION
Referring back to Figures 1 - 4A, the fitting device 34
of canister 26 comprises collar 150 that may be formed of the
same polyvinyl chloride material as canister 26 which is bonded
to canister 26 in leak free relation thereto by employing a suit-
able standard plumbers bonding solvent for that purpose. Collar
150 defined annular flange 154 on which is mountedF as by employ-
ing suitable stainless steel screws 156, stainless steel fitting
plate 158 that is formed with a suitable internally threaded hub
164 for appropriate connection to the conduiting o the valve
mechanism 18, with suitable elastomeric seal 161 being interposed
between plate 158 and flange 154.
Filter unit 42 rests on four stainless steel studs 162
spaced 90 degrees apart about the circumference of the canister
26 and held in place by suitable stainless steel screws 164.
Interposed between the fitting plate 158 and the upper grid
sheet 44 are a plurality of compression springs 166~ which in
the form shown are formed from stainless steel wire
- 24 -
;~
~ Z(~8160
1/8th of an inch in diameter and are shaped to have coils that
are approximately 2 inches in diameter. Springs 166 bias the
filter unit 42 against the studs 162, and hold the unit 42
components together against that action of fackwasy flow.
The discs or layers 48 making up the fibrous components
of the filter unit 42 may be of several different fibrous
makeups. One recommended composition of the discs is polyester
fibers of 100 denier diameter compressed to a density of 60
ounces per quare yard or alternately 25 denier diameter fibers
at 12 ounces per square yard.
A further alternate fibrous material is 15 denier
polyesther fibers at 14 ounces per square yard. Another satis-
factory fibrous material is a 50-50 combination of nylon and
polyester fibers of 6.5 denier diameter and a density of 8
ounces per square yard.
Where it is desired to enhance the polarized characteris-
tics of the filter unit, one or more of the fibrous discs may
be formed from andl8 ~ percent iron ~e slag wool having a
density of 16 pounds per cubic foot, which may be of the commerci-
ally available type slag wool glassified insulation material
that is commercially available from 48 Insulation Company of
North Aurora, Illinois.
The disc 48 may be in the form of pads of the materials
indicated that are one-quarter inch in thickness.
The end fitting devices 76 and 78 for the cross tube
50 are identical in construction, and each comprises a collar
170 from the aforementioned polyvinyl chloride plastic material
and bonded to the cross tube 50, as by using the aforementioned
standard plumber solvent. bonding material. Affixed to the
respective collars 170 are fitting plates 172 likewise formed
from the same polyvinyl chloride plastic material that are
flanged as at 17~ to receive suitable securement bolts 176 that
a.re suitably threaded into the respec-tive collar 170 to make
fitting plates 172 ~ast -thereagainst and against suitable
elas-tomeric sealing discs 178 tha-t are compressed thereagainst
as well as several s~aling fibrous discs 180, formed from
polyester fibers or the like, that are interposed therebetween
at the respective ends 182 and 184 of the filter unit 60.
Fitting plates 172 define suitable hub portions 185 that are
adapted for fixed connection to the respective polyvinyl chloride
conduit sections 186 and 188 that connect the bore 55 of mandrel
50 with the respective injector fittings 110, with these parts
bein~ bonded together as by employing the indicated standard
plumbers polyYinyl chloride solvent for cementing purposes in
the usual leak free relation.
Valve 197 may be of the ball valye type, and when
closed, effects closing off of canister 26. It is provided to
permit occasional removal of solids, as needed, from canister
26. The canister end closure device 30 comprises a collar 187
similar to collar 150 and similarly bonded to cylinder 28 and
formed with flange 189 to which staînless steel fitting plate
191 is secured by stainless steel screws 193. Plate 191 de~ines
i.nternally threaded hub 195 to which suitable normally closed
drain valve 197 is suitably applied to close canister 260
As indicated in Figure 5, for the ~ilter unit 42 the
an~de ~ead 190 is connected to the lower grid disc or sheet 46
26.
by way of connection to one of the supporting screws 164. The
cathode connector lead 194 is electrically connected to fitting
plate 158 with springs 166 being in electrical conducting
relation between the plate 158 and the upper grid sheet or disc
~4.
As to the filter unit 60, the anode connector 190
includes branch 196 suitably connected to the electrically
conductive foraminous sheets 64, as through fitting plate 172,
while the cathode connector includes connector branch 198
suitably connected to foraminous sheet 66, as through the other
fitting plate 172 and associated parts, as diagrammatically
illustrated in Figures 3, ~A and 5. The anode connector 1~0 in
the diagrammatic illustration of Figure 5 leads to the indicated
c~nventional and preferred 12 volt 50 amp source of D.C. power
supply for module 10, which has lead 200 extending from same to
suitable conventional automatic backwash control device 202
that is diagrammatically illustrated in terms o~ circuitry in
~igure 5, in which the usual outlet plug 204 fits into a socket
supplying the familiar 115 volt alternating ~.urrent power
source, with the plug 20~ being suitably connected to supply
lines 206 and 208 and neutral or common line 210, the pressure
switch ha~ing a suitable switch arm and contacts for breaking
line 208 as indicated in the circuit portion of Figure 5.
The fibrous layer 68 of sheating 62 may be a sheeting
o~ 15 denier nylon fibers compressed to a density of 7.5 ounces
per square ~ard; alternates are a 5Q-50 per cent combinati.on
nylon-polyester fibex sheeting of 3.75 denier nylon fibers and
5 denier pol~ester fibers at a density of 6 ounces per square
o
yard, and where polarity enhancement is desired o~e per cent
iron oxide basault rock wool filter material having a density
of four pounds per cubic ~oot, or two per cent iron oxide slag
wool having a density of four pounds per cubic foot, both the
latter being commercial insulation material availahle from 48
Insulation Company, o~ North Aurora, Illinois.
The polyester fiber and nylon fiber materlals herein
referred to are comrnercially available ~rom Moldan Filbration
Corporation of North Carolina.
The sheeting 58 and pads 48 are preferably about one-
quarter inch in thickness.
The valve devices 18, 20 and 22 are identical in
construction and comprise self reversing gear driven motor
actuated valve positioning devices that are commercially
ayailable from, for instance~ Asahi/America, of Medford,
Massachusetts, with each such device haying the three connec-
tions indicated for the Yalve device 20 as il]ustrate~ in
Fi~ure 5, with connectors 212, 214, and 216 extending from
the device 202 to the appropriate locations of the valve
device 20 for forward and reverse movement of same. The
valve devices 18 and 22 are similarly arranged and connected
in parallel to the power supply device 202, which is also
arran~ed to electrically interrupt the cathode leads by
connection to the power source 100 where indicated at 220,
when the timer 13~ reverses to the backwash position so th~t
the fil~er units o$ assembly 12 are depolarized durin~
backwash. Valve units 18 and 22, as indicated, are similarly
arranged and are connected in parallel for simultaneous
operation in the same manner as illustrated for valye deYic~
~0. In the normal opera~ing posi-tion for filterin~, devices
18, 20 and 22 are posi-tioned as shown in Figures 1 and 5 and
pressure switch 130 is closed; switch 130 may be of the type
represente~ by the Penn-Baso pressure switch (Model P
6lAG -1) oEferred by Johnson Controls Corp., COntrOl Products
Div. of Oakbrook, Illinois. When the pressure switch 130 is
opened by the indicated pressure increase level at the
intake end of the module 10, timer 13~ xeverses (by way of
its conventional arrangement) to turn the valve device 18,
20 and 22 into their reverse flow modes, with -the circuit of
the cathode being in~errupted where indicated at 220. Timer
134, which may be of any conventional automatically operating
type, such as the Agastat self reversing timer, Model No.
7024 AE, available from Amerace Corp., Control Products
Div., Union, New Jersey, again reverses, after being disposed
in its backwash cycle position, 60 seconds for the illustrated
embodiment, to return the valve devices 18, 20 and 22 to
their normal filtering modes and closing the cathode circuit
ts f~ O
for filter ~e-~i~s 42 and ~
THE GAS IN~ECTOR DEVICE
Referring now to Fi~ures 7, 8 and 9, the device
120 comprises elbow pipe element 230 suitably fixed to the
depending end 232 of the standpipe 116, as by both oE the5e
components being formed from the aforeindicated polyvinyl
chloride piping and bonded together at connection 234 in
leak free relation, as by employing the aforementioned
standard plumbers bonding solvent to bond pipe end 232 to
elbow collar 235. Elbow 230 is formed to define threaded
end portion 236 to which is applied the injector device
mixer head assembl~ 238, the component parts of which are
best diagrammatically illustrated in Fi~ure 9. Thus, the
~r~ "' mixer head assembly 238 comprises ~ ~r disc 240 that is
,~?, ~
29.
seated within collar 242 that is lnterna~y threaded as a-t
244 and formed with abutment flange 246 against which the
diffuser disc is seated, the diffuser disc 240 being bonded in
place against the flange 246 of collar 242, The diffuser
disc is formed with a plurality of apertures or orifices 248 for
passage of the gas or air supply to the device 120 therethrough;
as indicated in Figures 8 and 9, the apertures or orifices 248
are evenly distributed across the diameter of disc 240 and may
be l/32nd inch in diameter for gas or air feed therethrough, it
being desired that they be equally spaced. Diffuser cone 250,
which is formed from the stainless steel and is actually frusto-
conical in configuration, has its narrow end 252 anchored to
diffuser disc 240 on its discharge side by screw 254 extending
through washer 256, the end 252 of the diffuser cone, the central
opening 258 of the diffuser disc, and washer 260, for threaded
engagement with nut 262, with the nut 262 being turned onto the
screw 254 to bring its head 264 against the washer 256 to firmly
seat the latter within the diffuser tube with the cone end 252
bearing firmly against the diffuser disc-240 about the aperture
258. ~
The resulting diffuser disc, cone, and collar
subassembly 270 are then applied to the threaded end 236 of
the elbow 230, with the internal threading 244 of the collar
242 being threaded on the elbow end 236 for this purpose
sufficiently to hold the subassembly 270 in Eirm operating
position.
Cooperating with subassembly 270 is the injector shroud
272 which comprises a plate of stainless steel shaped to the
cylindrical configuration indicated, with the overlapping
- 30 ~
....
~8~
ends being spot welded together where indicated at 274. The
shroud thus is shaped to the form of cylindrical sleeve 275
havi.ng an internal diameter that exceeds the external di~meter
of the collar 242 by a relatively small dimension, as indicated
in Figure 8 with the collar being formed to define a plurality
of spacer lugs 278 that are spaced apart about the collar
periphery and are proportioned for force fit application within
the shroud 272. The shroud 272 defines filtrate intake end 280
and filtrate discharge end 282, with the end 280 of the shroud
272 being force fit onto collar 242 and ori.ented so that its
anchoring tab 284 is aligned with and disposed adjacent aperture
286 of the elbow collar 235 so that self tapping screw 290 may
be applied throu~h the tab aperture 292 and to the elbow aperture
286 to ~ix the shroud 272 in place. Self tapping screw 296
applied through the underside of the shroud 272 into collar 242
completes the assembly of the device 120.
The filtrate water flow pattern passed and through
device 120 is indicated by the lines and arrows of Figure 7
wherein it will be seen that the device 120, the filtrate
li~uid flow and the ~rrangement of the mixer head assembly and
shroud 272 produce four distinct hydraulic flow pressure zones.
Exteriorily of the shroud the water flows to the right of
Fi~ure 7 exteriorily of the shroud 272 in a thin relatively
~uiescent zone 300. Within the shroud 272, the water flows
past the collar 242 in a relatively thin film, subdivided by
the spacer lu~s 278, in a relatively quiescent zone 302. At
a/i J~45 ~r
7~ t~e face of the ~f-~ser disc 240, the air or gas being injected
,~56 ~' J~s e ~
into the water enters a void space upstream of the ~u~r cone
31.
~Z~ 6C~
250 at a turbulent mixing zone 304. Downstream of the
diffuser cone about the margin of its larger end 253 is
a homogenizina liauid gas mix zone of annular configuration.
During the filtration mode of operation of device
120, an annular fraction of the in-line water flow past
device 120 enters into zone 302, which represents a lower
pressure thin film zone. The injected gas or air, which
enters under pressure, mi~es turbulently with the thin
water film leaving zone 302 and entering mixing zone 304,
which produces a relatively high pressure turbulent mixing
zone 304. The larger end 253 of the diffuser cone, which
is spaced from the internal surface of the shroud 272 in
relatively small annular spacing 309, approximating 3/8ths
inch, provides for a funneling through such spacing 309 of
the liquid and gaseous components emerging from the high
pressure turbulence zone 304 to effect complete dispersion
and homogenization of the injected gas or air to the passing
liquid fluid. The liauid flow passing around and
exteriorly of the shroud 272 tends to create a partial
vacuum or low pressure area immediately in front of the
zone 306 and the flow emerging from between the diffuser
cone 250 and the shroud 272 swirls up into this low
pressure area thus producing a turbulent molecular
saturation of the injected yas and air into the water
flow~
The shroud 272, diffuser cone 250, washers 256
and 260, screw 264, and nut 262, as well as screws 290
and 296 are all preferably formed from stainless steel,
- 32 -
with the other components of device 120 being formed from
the aforementioned polyvinyl chloride.
When the module 10 is in its hackwash mode, the
direction of water flow is the reverse of that shown :~
in Figure 7, with the injected gas or air effect.ing the
aforementioned scouring action of the filtering units
62 and 42.
The fittings 110 of devices 14 and 16 are suitablv
connected to the respective valve devices 20 and 22 by
suitable polyvinyl chloride sleeves 315, and suitable
couplings, etc. that are indicated at 317 and 319.
EXAMPLE OF APPLICATION
OF THE ELECTRO-C~EMICAL FILTERING MODULE
The system 11 diagrammatically illustrates the
application of the module 10 in a typical recirculating
closed loop cooling tower water treatment type of
industrial water handling piping system~ In the system
11, conduiting 320 conveys coolant water or other liquid
that has been heated b,,v the operation of industrial
or machining equipment at an industrial installation 322
and conveys it to a conventional heat exchanger 324 where
the heat is absorbed and the heat depleted coolant is
returned by conduit 326 to the installation 322~ From
the heat exchanger 32~ heat bearing water is conveved
by conduiting 328 to a hot water sump 330 where the
water may be~ for instance 80 degrees F.~ from which it
is supplied by a suitable pump 332 through conduit 334 to
a conventional cooling tower 336 which may involve, for
- 33 -
~'~ '
-.~ .,
~2~ lL6~
instance, coil tubing through which the heated water
passes that is exposed for forced air flow produced by
fans to dissipate the heat involved. The heat depleted
water returns through conduiting 338 and 340 to cool
water -sump 342 that may have a temperature
- 33a ~
, ,,r
", !
o
on the order oE 6~ degrees F., from which the cool water is
supplied by suitable pump 344 through conduit 346 to heat
exchanger 324 in a continuously circulating system in which the
,~^ operation of the pumps 332 and-~ i5 timed to maintain adequate
r
water levels in the respective sumps 330 and 342. Make up
water may be supplied -to sump 330 from a city water main via
conduit 356.
The module 10 is appropriately mounted in and incorpor-
ated in the piping comprising the system 11 of Figure 6 to
continuously treat the water that is supplied to the cooling
tower in accordance with the indicated concepts of the invention.
The module 10 as shown in Figure 6 bears reference numerals
corresponding to those of Figures 1 and 5, from which it will
be seen that the module filtrant infeed conduit 80 is connected
to conduit 346 by suitable off-on valve 350, which may be set
to admit a predetermined liquid flow to the module 10 for
~iltration treatment purposes. The gas or air supply lines or
conduits 116 are connected to a suitable source of air or
oxident gas under pressure, as desired, while the filtrate
outflow conduits 8~ and 88 are connected to conduit 390 for
communicating the filtrate to sump 342. Backwash intake conduits
26 and 90 are connected to conduit 354 that is connected through
suitable of$-on valve 355 to the city water main for supplyin~
the backwash water when module 10 is in its backwash modeO
The backwash dischar~e conduit 82 is connected to, for instance,
a suitable drain.
O~ course, any pumps needed to insure the f iltration
and backwash pressures indicated may be incorporated in conduits
80 and 354.
3~.
~z~
With module 10 interconnected as to the system ll and
operated in the manner that has been described, the water
- 7~o ~v e ~-
supply to and from the coolin~-e~r 336 is maintained in a
continuing excellent state of purity and freedom from solids
debris and foreign particulate matter.
Canisters 26 equipped with only filter unit 42 may be
employed where the objective is primarily to filter ouk heavy
and relatively large solid particulate material having little
or only minor objectionable ion content. Canisters not needing
~ilter unit 42 and providing only filter unit 60 may be employed
where minor particulate solids matter of relative small size is
to be removed, and the major objective is the removal of ionic
atter, as in the des~lting of sea water. In such cases,
backwash equipment and effectuation is the same as herein
described and illustrated.
The gas supplied to module 10 by injector assemblies
l~ and 16 will basically depend on the application, but ozone, c,,,c/
sin~let molecular oxygen are preferred for disinfectant purposes
as to biological materials, thou~h air serve~ the same purposes
to a limited degree and is very effective for the backwash
mode. These ~ases also h.a~e coagulation inductin~ characteristics
AS to the solids involved by reason of the combination of
OX y5~e~7c~0r~
molecules during ~y~n, and thus the gases to be injected
serye coagulation purposes as well as oxygenation and disinfectant
purposes.
The foregoin~ description and the drawings are given
merely to explain and illustrate the invention and the invention
is not to be limited thereto, except insofar as the appended
35.
claims are so limited, since those skilled in the art who have
the disclosure before them wlll be able to make modif.ications
and variations the.rein without departing from the scope of the
invention.
36.
