Note: Descriptions are shown in the official language in which they were submitted.
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STEAM HUMIDIFIER
FIELD OF THE INVENTION
The present invention relates to humidifiers and more specifically to steam
humidifiers typically connected to a building furnace air duct system, or the
like.
BACKGROUND OF THE INVENTION
It is well know to have steam humidifiers that boil water and let the
generated
steam reach the building furnace air duct system to humidify the air flowing
therein. However, these humidifiers suffer numerous drawbacks related to their
mode of operation, the regular maintenance or even the repair thereof
whenever required.
In fact, during normal operation, these existing steam humidifiers or steamers
keep their water reservoir filled with water when they are turned off such
that all
the non-evaporating particles of limestone or the like accumulate or get
deposited on the inner walls thereof as well as on the heating element,
especially when the water gets cooler. After a predetermined period of time of
operation (which typically depends on the water purity), one needs to either
clean-up the inside of the reservoir or simply to replace that reservoir, or
at least
the bottom section thereof. The removal of the reservoir for such maintenance
operation requires the person, typically a specialized technician, to
disconnect
few electrical wires with temporary removal of main electrical components
and/or steam diffuser connection and/or the water drain running through the
removable section (generally bottom section) of the reservoir, and the
reconnection thereof upon reinstallation of the cleaned or new reservoir.
Furthermore, in the case the water is drained out just before shut down of the
humidifier, the amount of water left after drainage is not negligible thus
allowing
fair amount of particle deposition at the bottom of the reservoir.
Accordingly, there is a need for an improved steam humidifier.
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SUMMARY OF THE INVENTION
It is therefore a general object of the present invention to provide an
improved
steam humidifier.
An advantage of the present invention is that particle deposits in the steam
humidifier are reduced, with most particles being automatically drained
therefrom.
Another advantage of the present invention is that the steam humidifier
provided
thereby requires little maintenance.
Still another advantage of the present invention is that the steam humidifier
provided thereby is easily disassembled, by removing the bottom of the water
tank, free of operating component connection, from its top cover.
Another advantage of the present invention is that the steam humidifier is
periodically self-cleaning.
A further advantage of the present invention is that the steam humidifier has
all
its operating components connected to a single element, typically the top
cover,
of a water tank therefore, the remaining portion of the water tank being
thereby
easily removable.
Still another advantage of the present invention is that the steam humidifier
nearly empties the water tank at the end of humidifying operation to eliminate
most of the particulates accumulating into the water and to enable the
following
restart with as mush fresh water as possible.
According to an aspect of the present invention a first aspect of the present
invention there is provided a steam humidifier comprising a tank having a
reservoir section and a cover removably and sealingly secured thereto, the
tank
containing water during a humidifying operation in which the humidifier
humidifies an indoor environment, the cover having a heating element mounted
thereon and extending therefrom into the reservoir section and a steam outlet
assembly mounted thereon and extending therethrough into the tank, the
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heating element evaporating at least a portion of the water during the
humidifying operation into steam output through the steam outlet assembly to
humidify the indoor environment.
Other objects and advantages of the present invention will become apparent
from a careful reading of the detailed description provided herein, with
appropriate reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Further aspects and advantages of the present invention will become better
understood with reference to the description in association with the following
Figures, in which similar references used in different Figures denote similar
components, wherein:
Figure 1 is a simplified exploded top perspective view of a steamer humidifier
in
accordance with an embodiment of the present invention, showing the front
cover detached from housing;
Figure 2 is a simplified enlarged side view of the tank of the embodiment of
Figure 1, showing the inside of the reservoir, the latter being in dotted
lines for
clarity purposes;
Figure 3 is a simplified exploded bottom perspective view of the tank of the
embodiment of Figure 1;
Figure 4 is a simplified enlarged broken perspective view taken along line 4
of
Figure 2;
Figure 4a is a simplified broken section view taken along line 4a-4a of Figure
4;
Figure 5 is a simplified broken section view taken along line 5-5 of Figure 2;
and
Figure 6 is a schematic front view of the embodiment of Figure 1 in operating
connection with the building fumace air duct system.
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the annexed drawings a preferred embodiment of the present
invention will be herein described for indicative purpose and by no means as
of
limitation.
Referring first to Figure 1 there is shown a steam humidifier, shown generally
as
10, in accordance with an embodiment of the present invention, with the
removable front cover 14 detached from the housing 12 generally mounted on a
wall 200 of a building. The cover 14 is releasably secured to the housing 12
via
quarter-turn captive mounting screws 15 or the like. The housing 12 typically
includes a rear mounting wall 16, a vertical separating wall 18 extending from
the rear mounting wall 16 and which separates the control and power side 20
from the steamer side 22 with an access opening 24 extending there through for
access to the different electrical wires 26. The housing 12 also includes a
rear
top wall 28 through which the steam pipe 30 extends. On the steamer side 22,
the removable bottom pan 32 has conventional mounting vertical slot hole 34
and horizontal slot opening 34' being engageable by respective screws 36,
rivets or the like protrusions, mounted on the separating wall 18. Although
not
shown, the pan 32 could also be similarly mounted on the rear mounting wall
16. The pan 32 typically has a sloping floor wall 38, which slopes downwardly
from the separating wall 18 when the pan 32 is connected thereto, and which
directs any water eventually falling into the pan 32 toward a drainage opening
40 connected to a pan drain pipe 41 having its downstream end typically freely
connecting to a water drain, schematically illustrated by reference 43, for
disposal of water. The water drain 43 is further adapted to freely receive the
outlet end 206 of the typically flexible water exhaust pipe 42 therein without
preventing water from the pan drain pipe 41 to simultaneously get through the
water drain 43, as shown in Figure 2. Typically, the water exhaust pipe 42
runs
downwardly along the tank 50 and out of the housing 12 through an opening
formed by a cutout corner section 33 of the pan 32.
Now referring more specifically to Figures 2 and 3, there is shown the steamer
assembly 44 located on the steamer side 22, with the top cover section 46 and
the bottom reservoir section 48 of the water tank 50 releasably and sealably
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connected to one another by a circular flange V-clamp 52 all shown broken in
Figure 2 to better illustrate the inside thereof. The cover 46 is typically
secured
to the housing 12 via a tank holder 53 attached thereto and shown in dotted
lines in Figure 1 for clarity purposes. The assembly 44 includes a water inlet
5 assembly 54, a steam outlet assembly 208, a heating element 56, a siphon
drain assembly 58, first 60 and second 62 water level sensors, and a thermal
cut-out switch 64 all mounted on the cover 46. Accordingly, the bottom
reservoir section 48 is free to be detached from the cover 46 when the clamp
52
is released, as shown in Figure 3, as long as the pan 32 has previously been
removed from the housing 12. Generally speaking, the reservoir section 48 has
a reservoir floor 68 from which one or more reservoir walls 212 extend
vertically
upwardly away therefrom, the reservoir floor 68 and reservoir walls 212
generally defining the reservoir section 48.
The siphon drain assembly 58 includes a water exhaust pipe 42, which forms
part of an outlet section 72 of the siphon drain assembly 58, and an internal
drain pipe 80 connected thereto through the cover 46 of the tank 50.
Typically,
the siphon drain assembly 58 allows drainage of a sufficient amount of water
from the tank 50 to eliminate most of the solid particles in suspension into
the
water when the humidifier is in standby non-operation state to ensure that the
following restart occurs with as much fresh water as possible. Accordingly,
water intake openings 66, of reasonable size to allow small particles in
suspension into the water to flow there through, of the siphon drain assembly
58
are typically located below the heating element 56 adjacent the bottom of the
reservoir floor 68 of the reservoir section 48, as shown in Figure 2. The
outlet
section 72 of the siphon drain assembly 58 is typically releasably and
sealably
(via an 0-ring seal 74) connected to the side wall 76 of cover 46 such that
the
siphon drain assembly 58 can eventually be easily replaced because of possible
particle depositions thereon after extensive use in draining water full of
particles
there through. More specifically, the water exhaust pipe 42 extends, from a
threaded connection end 220 thereof, connected to side wall 76 of cover 46,
outside of the tank 50 to an outlet end 206 of the water exhaust pipe 42, the
connection end 220 preferably extending through the side wall 76 into the tank
50. The internal drain pipe 80 extends from the side wall and has an 0-ring
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seal 74 mounted on a respective drain pipe threaded first end 216, and the
water intake openings 66 on a respective drain pipe second end 218 thereof
(the axial end 218 of the internal drain pipe 80 is typically closed off to
prevent
insertion of large particles in suspension in the water therein that could
eventually at least partially obstruct the pipe thus affecting the draining
efficiency thereof). The first end 216 of the internal drain pipe 80 and the
connection end 220 of the exhaust pipe 42, being threaded, are releasably
connected to one another through the side wall 76 with the 0-ring 74 sealingly
abutting the side wall 76 inside the tank 50. Thus, the internal drain pipe 80
is
sealingly connected to the side wall 76 within the tank 50 and to the exhaust
pipe 42. Alternatively, although not shown, the outlet section 72 could be
integral with the internal drain pipe 80 and be welded to an opening of the
cover
side wall 76. Accordingly, water may be received from the water drainage
openings 66 during siphoning thereof and siphoned through the internal drain
pipe 80 into the water exhaust pipe 42 and carried by the siphoning to the
outlet
end 206 for disposal in the water drain 43 for disposal thereof. To ensure
sufficient siphoning action at all time, the outlet end 206 and the water
drain 43
are typically positioned at least about 12 inches (30 cm) below the reservoir
floor 68 of the tank or the pan 32 level.
The outlet section 72 is connected to side wall 76 since it needs to be below
the
highest curved section 78 of the typically rigid internal drain pipe 80 to
allow
water siphoning to occur whenever required. The top wall 82 of cover 46 has
water inlet opening and steam outlet opening with respective water inlet pipe
84
and steam outlet pipe 86 extending there through and sealably secured thereto
with welding or the like. The water inlet assembly 54 includes a water inlet
pipe
84, a solenoid valve 88 or the like, and a flexible water inlet hose 90. The
water
inlet pipe 84, having water inlet openings 85 at the internal opening thereof,
is
connected to the water source typically via the controlled solenoid valve 88,
which is connected to the controller 112 and to a flexible water inlet hose
90, the
Flexible inlet hose 90 being directly connected to the water source. At the
end
region of the water hose 90 close to the valve 88, a water hammer absorber 91,
also part of the water inlet assembly 54, is typically provided to attenuate
any
pressure shock waves generated by the instant closings of the valve 88. The
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steam outlet assembly, shown generally as 208, includes the steam outlet pipe
86 and the flexible steam pipe 30, to which the steam outlet pipe 86 is
typically
directly connected. The first and second water level sensors 60, 62, mounted
on the cover 46 and extending into the tank 50 are respectively used to detect
draining and minimum refill water levels to ensure, respectively, and are
connected to controller 112. The normal minimum water level when refill is
required is typically below the seal line between the cover 46 and reservoir
section 48 of the tank 50. The first water level sensor 60, situated at the
draining water level, is positioned in the tank 50 at an elevation at least
substantially to the highest curved section 78, i.e. the part of the siphon
drain
assembly 58 having the highest elevation and thereby at which water is
automatically drained by siphoning through the siphon drain assembly 58. The
second water level sensor 62 is used to control the water level in the tank 50
during boiling operation of the steamer assembly 44. Because the second
water level sensor 62 is much more solicited than the first one, its sensing
tip is
typically removable to allow its cleaning and/or replacement maintenance due
to
degradation over time. Accordingly, the tip of the second water level sensor
62
is typically formed of a plated nut cap 63 or the like screwably mounting on
an
internal threaded end portion of the second sensor stem 62'.
The clamp 52 is typically permanently movably attached to the cover 46 via a
clamp mounting assembly 240, as shown in Figures 2, 3 and 4, to allow rapid
release and tightening thereof via lever 92. The clamp mounting assembly 240
allows the clamp 52 to at least radially move relative to the cover 46, and
typically includes a main clamp attachment 242 positioned typically
diametrically
opposite the lever 92, and preferably secondary clamp attachments 242' located
typically halfway between the main attachment 242 and the lever 92. As shown
in Figure 4a and illustrated by the arrows A, the V-clamp 52 squeezes an 0-
ring
94, between the cover and reservoir flanges 96, 98 extending respectively
outwardly around the cover 46 and reservoir section 48, upon tightening. The
0-ring 94 is typically, but not compulsorily, carried by the reservoir section
48 in
the reservoir flange 98. Thus, the V-clamp 52 securely holds the flanges 96,
98
in proximity to one another with the 0-ring 94 sealingly disposed
therebetween,
thereby sealaingly and removably connecting the cover 46 and reservoir section
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48, when the V-clamp 52 is tightened with the lever 92. The reservoir section
48 is removable when the V-clamp 52 is released, i.e. untightened, using lever
92. In order to allow the reservoir section 48 to remain partially secured to
the
cover 46 when the clamp 52 is released, until a force is applied thereon, the
reservoir section 48 typically has its free edge 100 with a plurality (at
least two
opposite) dimples 101 protruding radially outwardly which frictionally and
abuttingly engage the edge of the inner face the opening of the cover 46.
As shown in Figure 4, a region hidden in Figures 1 through 3, the main clamp
attachment 242 typically includes a pin 244 or the like member secured to the
cover 46 and extending radially (all references being made relative to the
axis of
the tank 50) outwardly therefrom that radially slidably engages a through bore
248 of a plate 246 extending axially and circumferentially (or tangentially)
from
the clamp 52. A biasing means, such as compressive coil spring 250 or the like
member located around the pin 244, between the cover 46 and the plate 246,
typically urges or biases the plate 246 and the clamp 52 away from the cover
46, in direction B of Figure 4a. A plate stopper 252, such as a pin head or
the
like, locally limits the outward radial displacement of the plate 246 and
clamp 52
relative to the cover 46, under the force of the coil spring 250, by a
distance
sufficient to allow the clamp 52 to clear the contained radial protrusion D of
the
reservoir flange 98 thus the vertical removal of the reservoir section 48 from
the
cover 46, in the released configuration of the clamp relative to the tightened
configuration, shown in dotted and solid lines respectively in Figure 4a.
Similarly, the secondary clamp attachments 242' includes a circumferential
slotted through hole 248' to radially and circumferentially (or tangentially)
slidably receive the corresponding pin 244 there through for proper local
displacement of the clamp 52 between the released and tightened
configurations.
Figure 5 illustrates an overflow valve 102, also part of the water inlet
assembly
54, that prevents water to get back into the inlet vaive 88 in case of water
back
flow under pressure or the like, while closing off the radial gap between the
water inlet pipe 84 and the inlet valve 88 against possible particle insertion
into
the tank 50. The overflow valve 102 includes an inlet pipe plug 104 slidably
and
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sealably mounted on the inlet valve outlet 106 and maintained in abutment
against the external opening of the water inlet pipe 84 by a compressive
spring
108. Upon high water back pressure occurring inside the water pipe 84, the
pressure pushes the plug 104 upwardly along the valve outlet 106 against the
spring force to let water, notably any excess portion thereof, escape through
the
axial opening created between the plug 104 and the water pipe 84.
To reduce deposits of solid particles from water, which are often left in tank
50
after evaporation of the water, the assembly 44 of steam humidifier 10
preferably includes a motorized rotor blade assembly 230, also mounted on the
cover 46 and which extends into tank 50. The motorized blade assembly 50
has a motor 236 mounted on the cover 46 and connected to the controller 12,
as well as at least one rotor blade 232 disposed within, i.e. extending into,
the
tank 50, preferably in the reservoir section 48 in proximity to the reservoir
floor
68. The rotor blade 232 is also connected to motor 236, by an axle 234
connected to the motor 236 and blade 232 and upon which the blade 232 is
rotatable thereby, when the motor 236 is actuated by the controller 112. The
rotor blade 232, when rotated by the motor 58, cuts solid particles in the
water
into smaller particles which may freely pass through the siphon drain assembly
58. The blades 232 preferably have sharpened edges 242, preferably disposed
perpendicular to the axle 234, for facilitating cutting of the particles, as
well as
optional blade protrusions protruding away radially therefrom, preferably in
axial
alignment with the axle 234. The motor 236 may be actuated by controller 112
during evaporation of the water to immediately break up any particles
deposited
with blades 232. Additionally, the motor 236 may be actuated whenever the
controller 112 initiates siphon draining by enabling passage of water through
the
water inlet assembly 54 until the draining water level is attained, i.e.
detected by
first water level sensor 60. In this case, the motor 236 may keep the motor
actuated 236 during the process of filling the tank 50 to the draining water
level
to cut the particles as the tank 50 is filled, disabling the motor 236 once
the
water is at the draining water level and siphoning through the siphoning
assembly 58 commences or when the siphoning is complete. Alternatively, the
controller 112 may be configured to actuate the motor 236 only when the water
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reaches the first water level, i.e. when siphoning through the siphoning
assembly 58 commences.
In operation, as schematically illustrated in Figure 6, when a humidity sensor
110 situated in the indoor environment 202 and operatively connected to the
5 controller 112 (see Figure 1) of the humidifier detects a low humidity level
inside
an indoor environment 202, such as a building, to be humidified thereby, the
controller 112 starts humidifying operation of the humidifier 10 during which
the
indoor environment 202 is humidified. In order to adjust the comfortable
inside
humidity level depending on the outdoor temperature to prevent water
10 condensation in building windows during cold outdoor weather condition, the
humidity sensor typically includes an outdoor temperature sensor 111
connected thereto which senses the temperature of an outdoor environment
204 generally adjacent the indoor environment 202. Typically, when the steam
humidifier 10 is used in conjunction with a building intermittent ventilation
system, the controller 112 first sends a turn-on command to the fan 122 of the
building furnace air duct system 114 to ensure it is operating and then
detects if
air is flowing through the system 114 or the like via a vacuum detector 116
(see
Figure 1) connected to the air duct 118 via an air pressure hose 120. In the
case the system 114 is a continuously operating ventilation system, the turn-
on
command is simply ignored. Upon presence of air flow, the controller 112
opens the inlet valve 88, thereby enabling passage of water through the water
inlet assembly 54, and lets water fill the tank 50 until a predetermined
amount of
time lapses after the second water level sensor 62 detects water has reached
its minimum level. After the pre-determined period of time, the passage of the
water through the water inlet assembly 54 is disabled by closure of the valve
88
by the controller 112. The predetermined amount of time typically ensures that
a sufficient amount of water, such as a boiling level typically around the
seal line
between the cover 46 and reservoir section 48 of the tank 50, that may
slightly
vary from time-to-time without affecting operation of the humidifier, enters
the
tank 50 for proper operation of the humidifier, and usuaily considers a water
supply pressure average. Then the heater element 56 is actuated by the
controller 112 to evaporate, i.e. boil, water and generate steam that will
flow into
the air duct via the steam pipe 30, having a steam diffuser 124 at the end
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thereof, to humidify the air inside the indoor environment 202. When
comfortable humidity level is detected by the humidity sensor 110, the
controller
112 removes power, i.e. deactuates the heater element 56 and opens the inlet
valve 88, again enabling passage of water through the water inlet assembly 54,
until the first water level sensor 60 detects water, meaning that siphoning is
about to start through the siphon drain assembly 58, and slightly beyond to
ensure draining has started, and then closes valve 88 to stop operation of the
humidifier 10. Typically, the components of the siphon drain assembly 58 are
sized to provide a draining flowrate larger than the filling flowrate to
always
ensure proper drainage of water even though there would be a malfunctioning
of the inlet valve 88 (in which case the controller 112 should detect the
unusual
opening state of the inlet valve 88 in the absence of water detection from the
first water level sensor 60). Since the outlet end 206 of the water exhaust
pipe
42 is below the floor wall 68 of the reservoir section 48, essentially all the
water
inside the tank 50 is drained out until air enters the siphon intake openings
66.
The controller 112 may actuate the motor 236, and thereby the blades 232,
either during filling of the tank 50 for humidifying, and during humidifying,
or
during filling of the tank 50 for drainage and during draining of the tank 50,
as
described above.
Obviously, during operation of the humidifier 10, when the second water level
sensor 62 stops detecting water (meaning that the water level is below its
minimum required level), the controller reopens the inlet valve 88 for the
above
pre-determined amount of time until proper boiling level is essentially
reached.
Although the humidifier 10 could be programmed to perform self-cleaning water
drainage after a predetermined amount of minutes of continuous operation, an
operator can always stop normal operation of the humidifier and force for a
water drainage to be performed simply by pressing a predetermined button 222
on the controller display interface 125 accessible via a display opening 126
(see
Figure 1) of the front panel cover 14. When the pre-determined button 222 is
pushed, the controller 112 enables passage, by siphoning, of water through the
siphon drain assembly 58, by enabling flow of water through the water inlet
assembly 54 until first water level sensor 60 detects water at the draining
water
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level. The controller 112 then disables flow of water through the water inlet
assembly 54 and the water is drained from the tank 50 by siphoning through the
siphon drain assembly 58.
Whenever maintenance is required, the operator simply needs to ensure that
water is drained out from the tank 50 before disconnecting power from the
humidifier 10. Then, the front cover 14 is removed from the housing 12 via
mounting screws 15, followed by the bottom pan 32. Then, the clamp 52 is
released to allow the reservoir section 48 to be detached from the cover 46
and
removed downwardly for easy maintenance of any part or component of the
humidifier 10. The reverse sequence needs to be performed before reactivation
of the humidifier 10.
Although the present invention has been described with a certain degree of
particularity, it is to be understood that the disclosure has been made by way
of
example only and that the present invention is not limited to the features of
the
embodiments described and illustrated herein, but includes all variations and
modifications within the scope and spirit of the invention as hereinafter
claimed.
