U.S. patent number 3,664,324 [Application Number 05/140,599] was granted by the patent office on 1972-05-23 for humidifier.
Invention is credited to Herbert W. Radtke.
United States Patent |
3,664,324 |
Radtke |
May 23, 1972 |
HUMIDIFIER
Abstract
A portable humidifier including an evaporator pan adapted to be
mounted in the plenum of a furnace, a heating element in the
evaporator pan connected to the furnace motor circuit, a reservoir
mounted at a point remote from the evaporator pan and at the same
level, a conduit connecting the reservoir to the evaporator, a
source of water connected to the reservoir through a restricted
conduit, a solenoid actuated control valve connected to control the
flow of water through the restricted conduit and a double acting
mercury switch mounted on a float in the reservoir to control the
operation of the solenoid valve and to disable the heating element
when the water in the evaporator pan drops below the heating
element.
Inventors: |
Radtke; Herbert W. (Milwaukee,
WI) |
Family
ID: |
22491964 |
Appl.
No.: |
05/140,599 |
Filed: |
May 5, 1971 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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5628 |
Jan 26, 1970 |
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868501 |
Oct 22, 1969 |
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Current U.S.
Class: |
126/113;
392/402 |
Current CPC
Class: |
F24H
1/00 (20130101) |
Current International
Class: |
F24H
1/00 (20060101); F24f 003/14 () |
Field of
Search: |
;126/113 ;219/272 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Myhre; Charles J.
Parent Case Text
RELATED APPLICATION
This application is a continuation of application Ser. No. 5,628
filed Jan. 26, 1970 which in turn is a continuation-in-part of
application Ser. No. 868,501 filed Oct. 22, 1969, and both being
now abandoned.
Claims
I claim:
1. A humidifier for a central hot air system having a plenum
chamber, said humidifier comprising, an evaporator pan mounted in
the plenum chamber, a reservoir amounted at the same level as said
evaporator pan, a conduit connecting said reservoir to said
evaporator pan, means including a solenoid valve connecting said
reservoir to a source of water, a float mounted to respond to the
level of water in said reservoir, a mercury switch mounted on said
float and electrically connected to said solenoid valve to energize
and open said solenoid valve when the water level in the reservoir
drops below a predetermined low water level and to de-energize and
close said solenoid valve when the water in said reservoir reaches
a predetermined high level.
2. A humidifier adapted to be connected to an electric power source
and mounted in a plenum chamber for a hot air heating system, said
humidifier comprising an evaporator pan, means for mounting said
pan in the plenum of the furnace, means for evaporating water in
said pan, a reservoir mounted at a point remote from said pan and
at substantially the same level, a conduit having a restricted
orifice connecting said reservoir to said evaporating pan, means
including an electrically actuated solenoid valve for supplying
water to said reservoir, and means responsive to the level of water
in said reservoir for controlling said supplying means, said
controlling means including mercury switch having a first set of
contacts connected to an electric power source and to said solenoid
valve to energize said solenoid valve whenever the water in the
reservoir drops below a predetermined minimum and to deenergize
said solenoid valve when the water reaches a predetermined high
water level and a second set of contacts connected to the electric
power source and to said evaporating means to disable said
evaporating means when the water level in the reservoir drops below
a predetermined low water level.
3. The humidifier according to claim 2 wherein said evaporating
means comprises a heating element in the bottom of said evaporator
pan.
4. The humidifier according to claim 2 including a transformer
having a primary winding connected to the electric power source
independently of said first set of contacts and a secondary winding
connected to said second set of contacts, and an electrically
actuated relay switch connected to control said heating element and
controlled by said secondary winding.
5. The humidifier according to claim 2 including a first electric
circuit connecting said primary winding to the electric power
source and a second circuit connecting said solenoid valve to the
electric power source whereby said solenoid valve is actuated
independent of said evaporating means.
6. A humidifier for a central hot air heating system having a
plenum chamber, said humidifier comprising an evaporator pan
positioned in said plenum chamber,
electric means for sensing high and low water levels in said
pan,
an electric heater positioned to evaporate water in said pan,
means including a solenoid valve for supplying water to said
evaporator pan,
a switch having a first set of contacts connected to power source
for controlling said solenoid valve and a second set of contacts
for controlling said heater, linkage means for actuating said
switch, means including an armature operatively connected to said
linkage means and a coil electrically connected to said sensing
means for actuating said switch,
a transformer having a primary winding connected to the electrical
power source independent of said first set of contacts, and a
secondary winding, an electrically actuated relay switch connected
to control said heating element and a low current circuit connected
to said secondary winding, relay switch and second set of contacts
whereby
when said water reaches a predetermined low level, said coil will
be de-energized and said armature will move said switch to a
position to close said first set of contacts and energize said
solenoid valve to supply water to said pan and open said second set
of contacts to de-energize said heater, and when said water in said
pan reaches a predetermined high level, said coil will be energized
and said armature will move said switch to a position to open said
first set of contacts and deenergize said solenoid valve and close
said second set of contacts to energize said relay switch.
7. The humidifier according to claim 6 wherein said switch
comprises a mercury switch.
8. The humidifier according to claim 6 wherein said switch
actuating means comprises a second solenoid.
Description
BACKGROUND OF THE INVENTION
Humidifiers for central hot air systems generally are permanently
installed in the plenum of the furnace. All of the operating parts
of the humidifier are combined into a single unit and all of the
electrical and water connections are made directly to the furnace.
This type of a system requires constant cleaning due to liming of
the operating parts of the system. The water level of the system is
generally controlled by a float which opens the water line whenever
the water level drops below the predetermined high water level.
These floats due to their location within the plenum become
corroded as a result of the liming in the evaporation of the
water.
SUMMARY OF THE INVENTION
The humidifier disclosed herein is readily adaptable to the plenum
of any central hot air heating system and is not affected by the
accumulation of deposits or liming which normally occurs in the
evaporating system. This is accomplished by mounting only the
evaporating pan in the plenum of the furnace. Evaporation of water
is enhanced by a heating element mounted within the pan. A water
level control assembly is mounted at a point remote from the
furnace and includes a reservoir mounted at a the same level as the
evaporator pan. The level of water in the reservoir is controlled
by a double throw mercury switch mounted on a float in the
reservoir. The mercury switch responds to the movement of the float
to control the circuit to the heating element and the circuit to a
solenoid actuated water valve. The mercury switch causes a delay in
the refilling of the reservoir by allowing the water in the
reservoir to drop to a predetermined low water level before
actuating the solenoid controlled valve. Water is then admitted to
the reservoir until it rises to the high water level before closing
the water valve. Water noise is thereby eliminated or reduced since
water only flows when the pan is being refilled and not continually
as in prior systems.
In an alternate embodiment of the invention the double throw
mercury switch is controlled by a water level sensor located in the
evaporating pan. The signal from the sensor is used to control the
position of the mercury switch by a solenoid mechanically linked to
the mercury switch. This arrangement also provides for a delay in
refilling the evaporator pan and thereby eliminates continuous
water noise.
Other objects and advantages will become apparent from the
following description when read in connection with the accompanying
drawing.
THE DRAWINGS
FIG. 1 is a perspective view of the humidifier of this invention
including a schematic showing of the electric circuit for operating
the humidifier;
FIG. 2 is a view of the control assembly for the humidifier showing
the mercury switch in the high water level position;
FIG. 3 is a view of the control assembly for the humidifier showing
the mercury switch in the low water level position;
FIG. 4 is a perspective view of an alternate embodiment of the
present invention including a schematic showing of the electric
circuit;
FIG. 5 is a view of the mercury switch in the high water level
position; and
FIG. 6 is a view of the mercury switch in the low water level
position.
DESCRIPTION OF THE INVENTION
Although the disclosure herein is detailed and exact to enable
those skilled in the art to practice the invention, the physical
embodiments herein disclosed merely exemplify the invention which
may be embodied in other specific structures.
The humidifier of this invention includes an evaporator pan 10
which is adapted to be mounted in a plenum chamber for a furnace
and includes a heating element 12. A control assembly 14 is mounted
at a point remote from the furnace and includes a reservoir 16
which is mounted at the same level as the evaporator pan 10. The
control assembly maintains the level of the water in the reservoir
at a predetermined level and disables the heating element 12 when
the water in the evaporating pan drops below the heating
element.
Means are provided for mounting the evaporating pan 10 at any angle
in the plenum. Such means is in the form of a mounting plate 15
which can be readily connected to either side of the evaporating
pan 10 or to the end of the evaporating pan. The mounting plate 15
can be secured to the evaporating pan 10 by any appropriate means
such as welding or riveting.
Water is supplied to the humidifier from a common water source 18
connected to the reservoir by a first conduit 20 and to the
evaporator pan 10 by a second conduit 22 connected between the
reservoir 16 and the evaporating pan 10. Water that enters the
reservoir 16 is free to flow through conduit 22 to the evaporating
pan 10. The water level in the evaporating pan 10 will always be
substantially the same as the water level in the reservoir 16. The
flow of water to the reservoir 16 is controlled by means of an
electrically actuated solenoid 24 which is normally closed.
Means are provided for indicating the water level in the reservoir
16 in the form of a float 26 mounted on a rod 28. Float 26 can be
made of any buoyant material such as foamed plastic. The rod 28 is
pivotally connected by means of a pivot pin 32 to a pair of
brackets 30 secured to the reservoir 16.
In accordance with the invention, means are provided on the float
26 for controlling the solenoid valve 24 and for disabling the
heating element 12. Such means is in the form of a double throw
mercury switch 34 which is mounted on the float 26 and includes a
generally horizontally disposed tube 36 mounted on a post 38. A
first set of contacts 42 are provided at the other end of the tube
36. One or the other sets of contacts 40 and 42 will be closed by a
drop of mercury 44 which is free to move from one end of the tube
36 to the other end depending on the angular position of the float
26.
Water is supplied to the reservoir whenever the water level reaches
a predetermined low water level by opening the solenoid valve 24
which is connected to the contacts 40 in the mercury switch 34.
More particularly, the water control valve 24 and the contacts 40
are connected in series across electric lines G (ground) and
H.sub.2 (hot line) from an electric power source by means of
electric lines 46, 48 and 50. Whenever the mercury switch is tilted
at an angle sufficient for the drop of mercury 44 to move to the
right, as seen in FIG. 3, closing the circuit across contacts 40,
the solenoid valve 24 will be energized opening the water line to
the reservoir. This normally occurs when the tube 36 is moved to an
angle of approximately 15.degree. to the horizontal. The valve will
remain open and water will continue to flow until the water level
reaches a predetermined high water level moving the float upward
high enough to cause the drop of mercury 44 to move to the left in
the tube 36 as seen in FIG. 2. This opens the circuit across
contacts 40 de-energizing the solenoid valve 24 and closing the
water line 20.
Means are provided for protecting the heating element 12 from
overheating whenever the water level in the evaporating pan 10
drops below a predetermined low water level. Such means includes
the electric contacts 42 which are connected in series with a relay
switch 56 and the secondary winding 57 of a transformer 58 by
electric lines 60, 62 and 64. The primary winding 59 of the
transformer 58 is connected across the electric lines G (ground)
and H.sub.1 (hot line) by lines 66 and 68. The transformer 58 is
used to provide a low current circuit for the relay which is
normally energized to close switch 56. The relay switch 56 is
connected in series with the heating element 12 and across the
electric lines G.sub.1 and H.sub.2 by lines 52 and 54.
The heating element 12 is normally energized whenever the fan motor
for the furnace is energized by means of a switch 70 provided in
the electric line H.sub.1 which is connected to control the primary
circuit 59 for the transformer 58. The switch 70 is closed whenever
the fan motor is energized so that the heating element 12 is
energized whenever the furnace fan is operating.
The rate of evaporation of water is controlled by means of an
adjustment cycling timer bimetal switch 74 provided in line 54.
This type of a switch is normally controlled by a cam to vary the
time intervals of operation and can be locked on to energize the
heating element 12 whenever the fan motor switch 70 is closed.
It should be noted that the electric circuit has been adapted for
use as a plug in type unit for use with a 115 V supply. The hot
line has been divided into a first circuit or hot line H.sub.1 and
a second circuit or hot line H.sub.2. The primary winding 59 for
the transformer 58 is connected across the ground G and first
circuit H.sub.1 and is controlled by the fan switch 70 so that
heating element 12 cannot be energized unless the fan motor switch
70 is closed. The solenoid valve 24 is connected across the ground
line G and second current circuit or hot line H.sub.2 and is
therefore operated independently of the heating element. The
solenoid valve can be opened whenever the water level in the
reservoir is too low.
Means can also be provided for controlling the heating element 12
in response to humidity. Such means is in the form of a
conventional humidity controlled switch 72 provided in the low
current circuit line 60. If this switch is open, the relay switch
56 will be opened.
Water noise caused by the flow of water to the reservoir and water
hammer caused by the closing of solenoid valve 24 can be reduced by
using a restricted conduit in place of conduit 20. A slow steady
flow of water will be allowed to enter the reservoir without the
normal water noise generally heard when water under pressure is
admitted into an open pan.
In the alternate embodiment of the invention shown in FIGS. 4, 5
and 6, the reservoir pan has been eliminated and the solenoid 24
connected directly to the evaporator pan 10 by means of the conduit
20. The water level in the evaporator pan is maintained between
predetermined limits by means of a water level sensor 80 which is
mounted on the mounting plate 15. The signal from the water level
sensor 80 is used to control the mercury switch 34 by means of a
solenoid 82 mechanically linked to the mercury switch 34.
In this last regard, the solenoid 81 includes a coil 83 and an
armature 94. The armature 94 is connected to the mercury switch 34
by means of a linkage 84 which includes a bell crank 86 pivotally
mounted on a fixed pin 88 and having one leg connected to the
mercury switch 34. An "L" bracket 90 is pivotally connected to the
other leg of bell crank 86 by a pin 92 and to the armature 94 of
the solenoid 82. The armature 94 is biased by means of a spring 96
to pivot the mercury switch 34 to the low water level position.
Although a mercury switch is shown, the circuit of this embodiment
could also be controlled by means of a double throw double pole
switch.
The water level sensor 80 includes a high water level contact 97
connected to the solenoid coil 83 by a line 98 and a low water
level contact 99 connected to the solenoid coil 83 by a line 100. A
ground contact 101 is connected to ground by a line 102. The
circuit through the solenoid coil 83 is completed by a line 104
connected to the line 50.
It should be noted that the evaporator coil 12 in this embodiment
of the invention is embedded within the base of the evaporator pan
10 so that it will not be affected by the deposit of calcium in the
pan due to evaporation of the water.
In operation, when the water level in the evaporator pan 10 drops
below the ground contact 101, the circuit to the solenoid coil 83
will be opened and the armature 94 will be biased outward from the
solenoid coil 83 by means of the spring 96 tilting the mercury
switch 34 to the position shown in FIG. 6. The drop of mercury 44
will close the circuit across contacts 40, energizing the water
control valve solenoid 24 and opening the valve to allow water to
flow into the evaporator pan through conduit 20. The water will
rise in the evaporator pan 10 until it covers the ground contact
101 and the high water level contact 97. The water will initially
complete the circuit across the low water level contact 99 and the
ground contact 101 energizing the solenoid coil 83. However, the
force of the coil 83 will not be sufficient to pull the armature 94
into the coil 83 due to the bias of the spring 96. When the water
completes the circuit from the ground contact 101 to the high water
level contact 97, the force of the coil will then be sufficient to
pull the armature 94 into the coil 83. The mercury switch 34 will
be tilted to the position shown in FIG. 5 opening the circuit
across contact 40 and de-energizing the solenoid valve 24. The flow
of water into the evaporator pan will then stop. The drop of
mercury 44 will close the circuit across contacts 42 energizing the
low current circuit through lines 60 and 62 to the solenoid switch
56.
As the water evaporates, the circuit across high water contact 97
and the ground contact 101 will again open. The circuit across the
ground contact 101 and the low water level contact 99 will remain
closed, providing sufficient energy to the solenoid coil 83 to hold
the armature 94 within the coil until the water drops below the
ground contact 101. When the water drops below the ground contact
101, both circuits to the solenoid coil 83 will be opened and the
armature 84 will drop due to the spring 96 opening the low current
circuit and again closing the circuit to the solenoid. In the
preferred embodiment, approximately a 1/2 inch water level
difference is provided by means of the location of the high and low
water level contacts. The primary advantage of this embodiment of
the invention is the ability to put the control mechanism at any
position with respect to the evaporator pan. That is, it is no
longer necessary to mount the control at the same level as the
evaporator pan.
Various of the features of this invention are set forth in the
following claims:
* * * * *