Humidifier liner

A water-impervious liner for use in a humidifier having a rotatable drum provided with an evaporator medium and a liquid-holding chamber through which the drum is rotated, said liner being conformed to the shape of the chamber. In one of the embodiments having a single liner, the liner is divided into two chambers by means of a dividing wall having an aperture for the flow of liquid between the chambers. According to an embodiment having a plurality of liners, there is provided a water-impervious liner assembly for use in a humidifier having at least two chambers for holding liquid, wherein the humidifier liner assembly includes a first and a second water-impervious liner and a conduit means interconnecting the two chambers, and the conduit means is attached to the first liner and to the second liner in a watertight manner.

BACKGROUND OF THE INVENTION 
The present invention relates to humidifiers, and in particular to a 
disposable, water-impervious liner for liquid reservoir chambers in the 
lower case of a humidifer, such as a drum-type humidifier connected to the 
air flow system of a furnace. 
In the prior art drum-type humidifiers, such as disclosed in Stiles U.S. 
Pat. No. 3,476,673, a chamber is provided for holding tap water or other 
liquid which is applied to an evaporator medium of a rotating drum. The 
liquid is evaporated from the evaporator medium into a hot air stream of a 
furnace to humidify the air stream. Humidifiers are also known in the art 
to be used with air streams other than hot air streams of furnaces. Such a 
humidifier is disclosed in Remick U.S. Pat. No. 3,756,579. 
A typical disadvantage of a drum-type humidifier utilizing a liquid 
reservoir chamber filled with tap water is that dirt, dust, lime and other 
mineral deposits accumulate in the chamber and must be periodically 
removed to prevent interference with rotation of the drum during operation 
of the humidifier. Furthermore, particular deposits such as lime or other 
minerals not only accumulate, but also adhere to surfaces of the chamber. 
In the prior art apparatus, removal of accumulated and adhering deposits 
of foreign matter is generally accomplished by obtaining access to the 
liquid reservoir chamber and scraping, chipping or otherwise removing the 
deposits from the chamber surfaces, and then removing the deposits from 
the chamber. Depending upon the ease of access to the liquid reservoir 
chamber and the ease of removal of the chamber for immersion in a cleaning 
solution, the task of removing accumulated deposits may present merely a 
bothersome chore or may be quite difficult. 
Other prior art apparatus flow water through a humidifier chamber during 
humidifier operation to reduce mineral accumulation and algae and bacteria 
growth. Gallons of water are circulated and discarded during every hour of 
such humidifier operation, making such an apparatus unsuited for areas in 
which water conservation is desirable. 
Moreover, if the humidifier has a plurality of liquid holding chambers, and 
means interconnecting the chambers for passage of liquid therethrough, not 
only is the number of surfaces which accumulate mineral and other deposits 
increased, but also the interconnecting means may be clogged or the flow 
of liquid therethrough otherwise reduced by the accumulation and adherence 
of mineral deposits to surfaces of the chambers and the interconnecting 
means. 
SUMMARY OF THE INVENTION 
According to the present invention, a liner for drum-type humidifiers is 
provided which overcomes the disadvantages of the prior art by eliminating 
the need for scraping, chipping or otherwise removing accumulated and 
adhering dirt, dust, lime or other mineral deposits from a surface of a 
humidifier chamber. The liner itself is water-impervious, relatively thin, 
and inexpensive, so that when accumulation of deposits reaches a level 
requiring removal, the liner is removed and disposed. A replacement liner 
is them inserted into the chamber. 
For use in humidifiers including more than one liquid-holding chamber a 
humidifier liner assembly is provided which includes a plurality of 
humidifier liners, and conduit means interconnecting the liners so that 
watertight seals are created between the conduit means and the liners for 
the passage of liquid from one liner to the next without leakage of liquid 
into the space between the liners and their respective chambers. The 
liners are provided with at least one lip on an upper liner edge to assist 
in positioning of the liners within their respective chambers and to 
stiffen a liner wall to prevent buckling of the wall. 
If a humidifier case is used in which separate chambers are not 
structurally defined, a humidifier liner is provided which includes a 
dividing wall to define chambers. The dividing wall additionally includes 
an aperture for the flow of liquid between the chambers. 
The apparatus of the present invention provides many advantages. Removal of 
accumulated and adhering deposits, such as lime and other minerals, from 
the humidifier system is easily accomplished by removal of the humidifier 
liner. Because the liner is disposable, the present invention overcomes 
the disadvantages of having to chip, scrape or otherwise physically remove 
deposits from a surface to which the deposits have adhered. Damage to the 
surfaces of the humidifier chambers by such an abrasive or gouging type of 
cleaning action is thereby eliminated. Furthermore, the amount of tap 
water or liquid required in the apparatus of the present invention is not 
greater in comparison with humidifiers without liners in the prior art, 
and is much less than the amount of water used in humidifiers which 
circulate water to reduce mineral accumulation. 
Accordingly, it is the primary object of this invention to provide an 
inexpensive, disposable liner for a humidifier chamber to eliminate the 
need for chipping, scraping, or other removal of mineral deposits from a 
surface of a humidifier liquid-holding chamber. 
Another object of this invention is to provide a humidifier liner apparatus 
which presents minimal interference with operation of the humidifier 
because the liner is conformed to the shape of the chamber into which it 
is inserted. 
A further object of this invention is to provide a humidifier liner 
assembly which includes a plurality of liners interconnected in a 
watertight manner by means of a conduit which permits the passage of 
liquid from one chamber to another and also assists in properly 
positioning the liners. 
Other objects, features, and advantages of the invention will become 
apparent upon reading the following detailed description in conjunction 
with the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to the drawings, and more particularly to FIG. 1, there is 
illustrated a liner assembly for drum-type humidifiers indicated generally 
by the reference numeral 10. The illustrated humidifier liner assembly as 
herein described is particularly suited for use with a drum-type furnace 
humidifier such as the one described in the Homart Furnace Humidifier 
Instruction Manual No. F642-952 for Model 303.93831, published by Sears, 
Roebuck and Co., incorporated by reference herein. Such a drum-type 
humidifier generally employs a cylindrical sleeve of an open pore material 
such as polyurethane foam as an evaporator medium. The sleeve is partially 
immersed in a liquid-containing chamber and is constantly rotated at a 
slow speed while air is forced about the sleeve to add moisture to the 
air. The liquid in the chamber is typically tap water and the level of the 
water is generally maintained at a substantially constant level by means 
of a float arm assembly operatively connected to a tap water supply. The 
humidifier is typically mounted on or near a hot air furnace system, and 
appropriate duct work is provided so that the air circulated by the 
furnace passes through the humidifier to humidify the air. 
One type of furnace humidifier, for which the liner assembly apparatus of 
the present invention is particularly suited, includes a lower case 12 
which is separated into four chambers: a first chamber 22 accommodates an 
evaporator medium drum 26 and also retains liquid 14 to be evaporated; a 
second chamber 34 contains a reservoir of liquid 14; a third chamber 42 
contains a blower fan, and a fourth chamber 52 contains a motor to drive 
the blower fan. This drum-type humidifier typically uses a supply of tap 
water which is continuously replenished by a water supply tube 16 in 
operable relationship with an automatic float arm assembly 18. While using 
tap water as the liquid to be evaporated has the advantage of generally 
being cheaper than using distilled water in the humidifier system, various 
impurities, particularly lime and other minerals, are typically found in 
tap water, often referred to as "hard water," and tend to precipitate from 
the water solution and adhere to various chambers of the humidifier 
assembly. 
According to the present invention, as illustrated in FIGS. 1, 2, and 3, 
there are included within the water-containing chambers, i.e., the first 
chamber 22 and the second chamber 32, a first liner 24 and a second liner 
34, respectively. The adjacent chambers 22 and 32 have a common wall 29. 
The liners 24 and 34 are pre-formed of a relatively thin material to 
conform to the shape of the chambers 22 and 32 and rest within the 
chambers. These pre-formed humidifier liners 24 and 34 are each provided 
with a lip such as lip 27 as shown in FIG. 1 and lip 36 as shown in FIG. 
2, on at least one upper edge of each of the liners 24 and 34. By means of 
this lip conformed to be positioned against an upper surface of a wall of 
the chambers 22 and 32, the liners 24 and 34 are easily aligned within 
their respective chambers 22 and 32. Moreover, each lip 27 and 36 stiffens 
the liner wall to which it is connected in order to prevent buckling of 
the wall. 
A means interconnecting the chambers 22 and 32 is provided by an opening in 
the common wall 29 into which a hollow conduit plug 62 is inserted. 
Without the liners 24 and 34, the opening located in the common wall 29 
would be adequate to allow the passage of liquid to be evaporated between 
the first chamber 22 and the second chamber 32. However, the conduit plug 
62 is included in the preferred embodiment to prevent water from 
infiltrating between either of the liners 24 and 34 and their respective 
chambers 22 and 32. Such infiltration of water would cause the liners 24 
and 34 to float above a surface of the chambers 22 and 32, thereby 
allowing mineral deposits to form underneath each of the liners 24 and 34 
so that the problems and disadvantages of mineral deposits adhering to 
chamber surfaces as in the prior art would not be overcome. 
To prevent leakage of water into the area between the liners 24 and 34, and 
their respective chambers 22 and 32, the conduit plug 62 is inserted into 
the opening and is press-fitted into a first aperture 25 within the first 
liner 24, and into a second aperture 35 within the second liner 34. As 
shown in FIG. 3, both the apertures 25 and 35 are aligned with the 
interconnecting opening in the common wall 29 for the passage of liquid 
from the second liner 34 to the first liner 24 through the conduit plug 
62. The outer surface of the conduit plug 62 is in frictional engagement 
with the periphery of each aperture 25 and 35 to effect watertight seals. 
Furthermore, the plug 62 has a retaining lip 64 at one end to assist in 
positioning the plug 62 axially within the apertures 25 and 35. 
In the preferred embodiment shown in FIGS. 1, 2, and 3, the conduit plug 62 
is constructed from a water-impervious material which expands upon 
exposure to water so that the desired watertight seal is easily and 
properly achieved. Such a suitable material is nylon, which typically 
swells slightly when immersed in water. 
In addition to maintaining a watertight conduit for transfer of water 
between the first chamber 22 and the second chamber 32, the conduit plug 
62 also holds each liner 24 and 34 in desired relationship with respect to 
each chamber 22 and 32 to prevent shifting of the liners 24 and 34 due to 
manufacturing tolerances whereby the liners 24 and 34 may rub against 
either the float arm assembly 18 or the evaporator medium drum 26. 
According to another embodiment of the present invention illustrated in 
FIG. 4, there is provided a humidifier liner for use in a drum-type 
humidifier having a single chamber for accommodating a rotating evaporator 
medium drum, and wherein a chamber water level control is remote to the 
single chamber. The humidifier liner assembly is indicated generally by 
reference numeral 70. An evaporator medium drum 26' is accommodated within 
a water reservoir chamber 72 in the lower case of the humidifier. In this 
embodiment, the reservoir chamber liner 74 is a thin, flexible material, 
such as a plastic sheet, which is draped to fit the shape of the reservoir 
chamber 72 so that the liner 74 need not be pre-formed to the shape of the 
reservoir chamber 72. The liner 74 conforms to the shape of the chamber 72 
due the force of the weight of liquid within the chamber 72. The liner 74 
is held against peripheral walls of the chamber 72 to insure proper 
alignment and retention of the liner within the chamber 72 by means of an 
elastic band 76 fitted around the peripheral walls. Although in this 
embodiment the reservoir chamber 74 is illustrated as a plastic sheet 
draped within the chamber, the liner may alternatively be constructed to 
fit within the chamber, in a fashion similar to the liners 24 and 34 of 
the embodiment shown in FIGS. 1, 2, and 3. 
In the further embodiment of the present invention illustrated in FIG. 5, 
there is provided a humidifier liner for use in a drum type humidifier 
having a single chamber in a lower case 12' large enough to accommodate 
both a rotating evaporator medium drum 26 and a chamber water level 
control 18. The dual-chamber liner 80 has a dividing wall 82 within the 
liner 80 so that two chambers are provided: a first chamber 84 for the 
medium drum 26 and a second chamber 86 for the water level control 18. The 
dual-chamber liner 80 is pre-formed to the shape of the single chamber of 
the lower case 12' in which it rests. The dividing wall 82 is provided 
with an aperture 88 which permits fluid to flow between the chambers 84 
and 86. This embodiment does not use a conduit plug because the dual 
chamber liner 80 is a single unit. The liner 80 is fully removable, 
disposable, and replaceable. 
The liners 24 and 34, the flexible sheet liner 74, and the dual-chamber 
liner 80 are constructed from any suitable water-impervious material. 
Because the liners are meant to be disposable, an inexpensive material 
such as plastic is desirable. For the pre-formed liners 24, 34, and 80 any 
suitable thermoplastic or thermosetting resin may be used. Thermoplastic 
resin is typically less expensive and more easily formable at law heat, 
and therefore such thermoplastics as high impact polystyrene, 
polyethylene, and ABS, are particularly suitable in the present invention. 
This thermoplastic resin is vacuum-formed in the shape of the inside 
contour of the chamber into which it will be inserted. In the embodiment 
of the present invention depicted in FIG. 4, the liner 74 is preferably a 
thin plastic sheet such as a very flexible polyethylene. 
The preferred embodiments of the apparatus of the present invention thus 
provide an inexpensive and relatively easy means for removing accumulated 
and adhering mineral deposits from chambers of drum-type humidifiers by 
means of a thin liner which is conformed to the shape of the chamber in 
which it rests. Though the embodiments hereinbefore described are 
preferred, many modifications and refinements which do not depart from the 
true spirit and scope of the invention may be conceived by those skilled 
in the art. For instance, the present invention may also be used with 
portable humidifiers which are not directly connected to a hot air furnace 
system, but which do use tap water or other liquid containing impurities 
such as lime or other minerals. It is intended that all such modifications 
and refinements be covered by the following claims.