CA1082477A

CA1082477A - Laundry installation with clothes dryers incorporating a water heater

Info

Publication number: CA1082477A
Application number: CA265,414A
Authority: CA
Inventors: Ion L. Wendel
Original assignee: Individual
Current assignee: Individual
Priority date: 1976-02-23
Filing date: 1976-11-12
Publication date: 1980-07-29
Also published as: DE2650190A1; JPS52101869A

Abstract

ABSTRACT OF THE DISCLOSURE
A laundry dryer source of heat for providing warm gas to dry laundry is utilized to heat water for laundry washer use, and is particularly suited for coin operated laundries.
In the illustrated embodiment each dryer has a gas burner and a water coil is in the flame area of the burner, the coils be-ing connected in circuit between a cool water outlet and a heated water inlet of a typical automatic water heater tank. A
water circulating system includes a pump or pumps for circulat-ing cool water from the tank through coils and returning heated water from the coils to the tank whenever any of the dryers are in operation. One embodiment of the circulating system assures continuous water flow through the plurality of dryer water coils during heating operation by providing a substantially equal pressure differential between the cold water inlet and the hot water outlet of each of the coils. A cross-over between hot and cold water headers may be provided intermediate the series of dryer coils for increasing the temperature of the hot water delivered to the hot water tank. Since most laundry is promptly placed in a dryer after washing, during high or low capacity operation of the laundry the quantity of heated water is auto-matically regulated by dryer operation to the overall demand for hot water by the washers, the automatic water heater tank providing heated water during sudden surges in washer operation before the dryers are in operation sufficiently to supply the hot water.

Description

10~4~7 This invention relates to laundry installations par-ticularly those in which means are provided for conserving energy required to provide the necessary hot water supply for washers by utilizing a dryer heat source.
During low or normal capacity washer usage the auto-matic water heater provides adequate hot water for the washers in a laundry, but upon continuous heavy usage o~ the washers the water heater may prove to be inadequate and as a result the wsshers will be provided with lukewarm if not cold water.
In typical coin operated laundries, one dryer i8 usually pro-vided for two washers, with about ninety-five percent of the washed laundry generally being dried in the dryers. A system for preheating water for an automatic water heater is shown in Unlted States Patent No. 3,771,238, in which a portion of the cold water normally supplied to the water heater is preheated bg pas~ing it through coils exposed to the warm vent gases re-clrculated through the dryer. However, since the vent gas tem-perature 18 relatively low, this prior system can do no more than preheat water ~or the automatic water heater, it cannot heat the water to normal water supply temperatures, Addition-ally, this system is control~ed responsive to water tempera-ture ln the automatic water heater rather than responsive to operation of one or more of the dryers. U.S. Patent ~o.
3,o50,867 discloses a similar system but uses water heating coils in the indivldual vent flues of the dryer. Further, th~ latter system is controlled responsive to flue gas tem-perature rather than to the temperature of water in an auto-matic water heater as in the ~irst mentioned prior system U.S.
Patent No. 1,731,290, which uses also shows a system wa~te heat of a laundry environment for heating water.
The present invention is directed tQ a laundry in- ~ -stallation comprising, washer means for receiving laundry to be washed and for receiving wash water at a sufficiently high temperature for ~ormal hot washing of the laundry, dryer means for receiving the washed laundry and operable for heating the washed laundry to a normal elevated temperature for drying the laundry, and heating means reducing the normal overall energy requirement for operation of the washer and dryer means, said heating mean~ receiving at least a portion of said heat gener-ated by said dryer means and re~ponsive thereto heating said wash water to said high temperature.
One advantage of this invention is the provision of a new and useful laundry hot water supply system which effec-tlvely reduce~ the energy requirements of the laundry. Fur-thermore, this new sy~tem may be easily and economically in-stalled in existing laundries.
These and other obJect~ and advantages of the in-vention wlll be apparent from the following description of preferred embodlments of the inventlon taken together with the accompanying drawlngs in which:
Flgure 1 is a schematlc, fragmentary plan view of a portlon of a coin operated laundry;
Figure 2 1B an enlarged, fragmentary, schematic ele-vatl~nal view of laundry dryer~, as lndicated generally by the lin~ ~-2 in Figure l, with a top panel of one of the dryers } re~oved to show the heating portion of the dryer, and with parts ~roken away and removed for clearer illu~tration;
Figure 3 ls an enlarged, fragmentary, schematic sec-,. .
~ tional elevatlonal view taken generally along the llne 3-3 in $ Flgure 2, wlth parts broken away and removed for clearer 11-lustratlon; and Figure 4 is a schematic fragmentàry plan view ~ milar ~C~8'~477 to a portion of Figure 1 but illustrating a second preferred embodiment ~f a water circulating system.
Figure 1 of the drawing schematically illustrates a portion of a typical coin operated laundry having a plurality of coin operated washers 12 which receive hot water from an automatic water heater 14, including a storage tank, by means ~f a hot water supply pipe 16 connected through branch pipes 18 with the washers 12. The washers 12 are provided with cold water from a mai~ supply pipe 20 through a cold water supply pipe 22 connected by branches 24 with the washers 12. The main supply pipe 20 also suppliea the water heater 14 with cold water through pipe 26.
With continuing reference to Figure 1, a plurality of typical laundry dryers 30, such as a Huebsch dryer, Model 37A, each have the usual door 32 for insertion and removal of laundry from a perforated cylinder 34 or chamber (dashed lines, Flgure 2). Durlng drylng operatlon the cyllnder 34 18 rotated ln typlcal manner by a suitable electric motor and drlve as-sembly 36 on the rear of the dryer and this assembly also operates an exhaust blower (not shown) in the bottom portion of the dryer to exhaust the drying gas th;rough a suitable vent or flue 38, the vents usually being connected with an exhaust duct (not shown).
With reference tb Figures 2 and 3, a partition 39 is u~ually provlded.atop the front of the row of dryers 30 to i conceal the piplng, as 90-96. The upper portlon of each dryer ,~ j . .
is provided w1th a drying system including a heater, usually o~ the combustion type, such as a gas burner unit 40 within a casing 42. Each burner unit 40 provides a com~ustion area 43, ,~ ~
;~ 30 lncluding a flame area, of relatively intense heat. Each .-~ burner unlt 40 has the usual burner supply line and controls .. - --3--. .

~V~ 77 44, and is concealed by a removable panel 45. The casing 42 provides opposed inlets 46 for air which mixes with the hot gases developed by the burner flames, the resultant warm gas pa~sing downwardly through a duct 48 (Fi~ure 2) opening toward the laundry chamber 34.
With continuing reference to Figure 2, a co~n ~eter 54, upon insertion of a coin and turning of an actuator knob, initiates operation of a timer to provide a predetermined per-iod of drying for each coin inserted and causes the motor drive assembly 36 to be turned on and gas to be provided through the supply line 44 to the burner unit 40 which i8 ig-nlted by a'pilot light 56 between the burners. The dryer 30 also ha~ a temperature selection lever 58.
As illustrated in Figures 2 and 3, the hot water supply system comprises water heatlng apparatus 60 including the burner unit 40 and a water holder such as a coil 62 posi-tioned immediately above the burner unit 40 in the ~lame area thereof and well up~tream of the cyllnder 34 relative to the ~low of warm gas from the burner unlt 40 through the duct 48.
' - 20 The casi,ng 42 include~ a top wall 70 connected by " suitable support~ 72 with opposite side walls 74 and 76, with the air inlet~ 46 between each side wall and the top wall 70.
The side wall 74, along with a center wall 78, deflne sidés of ~ ' ,~ the duct 48, and a front wall 80 and a rear wall 82 o~ the ~, casing 42 prqvide front and rear closures of the duct 48.
:'~ Burner,unit 40 ls supported by cr~ss members 84 se-' cured to the ~ide wall 76 and the center wall 78, and the coil 62 is supported by cross members 86 receiv~ng upper tube runs ;~ o~ the c~'~l and having inverted U-shaped ends seated on the top '~ 30 edge of the side wall 76 and the center wall 78. The bottom tube runs of the coil 62 are pre~erably about two inches ab~ve . -4-''`~; -, , . .

~0 ~ 7 the burner gas orifices 83, and the front of the coil 62 is spaced rearwardly of the pilot 56 so that the water in the coil is not overheated by the pilot flame, thus avoiding the possibility ~f the water being appreciably heated when it is not circulating through the coils. If desired, the coil can be exposed to the pilot flame when water is being circulated 24 hours a day, to provide hot water during ~hut-down of the æystem aæ at night. With 10 dryers, the 10 pilot flames will heat the water in a 100 gallon storage tank from approximately 100F. to 125aP. in approximately 10 hours. In a Huebsch Model 37A dryer, approximately eighteen feet of copper tubing of one-half or three-quarter inch inside diameter is formed -~-~
into five convolutions with the coil being approximately six-teen inches long, nine inches wide, and approximately two and one-hal~ inches h~gh so that it may be installed through the burner access opening in the front wall 80 of the casing 42.
A~ may be noted best in F~gures 2 and 3, a water ci~culatlng ~y~tem i9 provided as follows: The front of each coil 62 has an inlet 89 and an outlet (not visible), the inlet connected with a cool water branch pipe 90 from a conduit de-fined by a cool water supply header or pipe 92 (Figure 1) and the outlet connected with a heated water branch pipe 94 to a . conduit de~ined by a heated water return header or pipe 96 (Figure 1). Branch pipes 90 and 94 may be seated on the casing top 70 to recei~e heat from the top and may be secured t~ the ~ top by pipe ~traps 97 (~igure 2). The pipes 92 and 96 are ~: preferably connected into the bottom portion of the storage tank of the automatio water heater 14, and Q motor driven pump : 98 is provided in the cool water supply pipe 92 to circulate the water and is operated by a suitable control system (not . shown) when any of the dryers 30 are turned on by insertion of .~ 5 ~8;~477 a coin and operati~n of the actuator knob of the coin-meter 54. Pressure relief valves 100 (Figure 2) are preferably pro-v~ded in each of the heated water branches 94 and preferably open into the drain lines 102.
In operation, cool water from the automatic water heater 14 is passed by this circulatin~ system to the coils 62, the water being provided at a substantially constant ~res-sure dif~erential between the inlet 89 and outlet of each of the coils 62 of the dryers 30. The resultant heated water is returned to the water heater 14 sufficiently hot for use by the washers 12, particularly during peak periods of la~ndry operation when the supply of hot water may otherwise become inadequate. The apparatus and ~ystem of the invention is par-ticularly suited for use in coin operated laundries since, in a practical senseJ the number of drying periods for a given load of wet laundry is the same with or without use of the sub~ect water heating system and apparatus.
Wlth reference to the embodiment o~ Figure 4, refer-ence numerals primed, as 92', refer to the same or similar parts as tho~e indicated by the same unprimed reference numer-als in the embodiment of Flgures 1-3, and will not necessarily ~e again described. In Figure 4 a water circulating system ;; comprises the cool water supply pipe 92' including a pipe 108 extending from the water heater 14' to a return portion 110 past the dryer farthest from the water heater 14', and then has a header 112 which returns along the series of dryers for con-~ection with the cool water ~ranch Pipes 90' to each of the coils and terminates at the last branch pipe 90'. The heated water return header or pipe 96' is connected to the heated 3~ water branch pipes 94' from the coils as in the prior embodi-ment. In this water circulating system, the cool water in the .~

. . .

:~0~;~47'7 -:

cool water header 112 and the heated water in the heated water header 96' flows in the same direction in the areas to which the branch pipes 90' and 94' are connected so that the pres-sure differential between the inlets and outlets of each of the coils is substantially the same, assuring substantially the same rate of water flow through each of the coils and ef-fectively eliminating a lack of water in any of the coils which might result in burning out of that coil.
A water circulating pump 98' is shown in ~igure 4 in the cool water supply pipe 92'~ as in the prior embodiment, and a second water circulating pump 114 is also provided in the heated water return header 96'. While two pumps as 98' and 114, are preferred in order to provide a push-pull effect on the water being circulated and assure more positive circu- -lation of the water and steam which might be present, a single pump may be provided in the system ~n only the heated water return header 96' as shown by the:pump 114. A pump having a capacity of one gallon per minute per coil i~ adequate but under some circumstances it may be desirable to provide a pump with much greater capacity, for example, eight gallons per minute per coil in which event a far greater quantity of water is circulated per minute through the coils with the heated water returning to the water heater l4' at a lower temperature.
These pump capacities, as well as thq use of a ~ingle pump ln . either the supply pipe 92' or return header 96', or a separate .~ pump in each, is e~ually appl~cable to the embodiment of Fig-.~ .
: ures 1-3.
: In Figure 4 the pressure relief valves (100 not shown) are connected with the drain lines 102' in the cool 3~ water branch pipes 90' rather than in the heated water branch pipes 94' of each of the coils 62'. If the heated water tem-iO8i~477 perature from the coils is desired at a higher tempera~urs, itis preferable to provide the relief valves in the cool water branch pipes 90' ln order to avoid possible overheating of these valves.
Increase in the delivered temperature of the heated water may be provided by a cross-over connection 116, as shown by phantom lines in Figure 4, between the header 112 of the cool water supply pipe 92' and the heated water return header 96'. The cross-over connection 116 is intermediate the series 10 of dryers 30' BO that a portion of the heated water in the re-turn header 96' may be by-passed into the header 112 of the cool water supply pipe 92', whereupon the dryer coils 62' down-~ stream of the cross-over connection receive cool water at a substantially elevated temperature over that normally provided ~ and the temperature of the water delivered to the heated ~ water branch pipes 94' i8 therefare at a substantially higher -~ temperature .before pa~sing into thq heated water header 96'.
~ The cross-over connect.lon 116 ls provided with a ehutoff valve ~ 118, and a plurallty of cross-~ver connectlo~s, as 116, may be spaced along the headers, as required.
In the previously mentioned commercial dryer, each gas burner unit 40 develops approxlmately 142,000 BTU per hour and wlll develop heated water to a temperature of at least . 13~F~ With cool water in the bottom Or an 80 gallon tank of : water heater 14 at 60DF, and with only ~ne dryer 30 in the ~:
ystem, and the heater of the automatic water heater 14 off, in three minutes the water temperature in the heated water re-~ s ~
turn pipe 96 rose to 68F., after thirty minutes of operation to 138F. and after forty minutes of operation to 142F., with 30 no hot water being withdrawn through the hot water supply pipe ~.
~i 16. Thus, b~ positioning the coil 62 closely proximate the ,~ .

~08'~77 burner units 40, water may be heated to adequate temperature for washing purposes. Any suitable flow rate of the pump 98 may be provided to keep the water circulating during dryer operation.
Since most coin operated laundries have two washers 12 for each dryer 30, during extended peak periods the hot water supply system of this invention assures a continual sup-ply of hot water to the washers, and in the event of a sudden peak load, rather than the nor~al gradual peaking, the hot water heater 14 is ~ually able to supply adequate hot water until the laundry loads are transferred from the washers to the dryers, whereupon the dryers provide ample hot water for continued laundry operations.
While this invention has been described and lllus-trated with reference to particular embodlments in a partlcu-lar envlronment, varioua changes may be apparent to one skilled in the art and the lnvention is therefore not to be llmlted to such embodiments or envirPnment~ except as set forth in the appended claims.
` .
~ .

Claims

The embodiments of the invention in which an exclu-sive property or privilege is claimed are defined as follows:

1. A laundry system comprising: a hot water storage tank; a plurality of clothes washers having associated conduit means interconnecting the clothes washers to the storage tank for supplying hot water to the clothes washers for washing clothes; a plurality of clothes dryers each including a laundry chamber for receiving laundry to be dried, a heating chamber having therein heating means for heating gases such as air in the heating chamber for delivery to the laundry chamber for dry-ing laundry therein, a water conduit in the heating chamber located adjacent said heating means such that water in the con-duit is heated by said heating means while said heating means is heating air for delivery to the laundry chamber, said water con-duit having an inlet and an outlet, said heating means having sufficient heating capacity for heating the water in the asso-ciated water conduit to a substantially normal temperature for washing laundry and simultaneously heating a sufficient quantity of air for delivery to the associated laundry chamber at a nor-mal temperature for drying laundry; a circulating system inter-connecting the hot water storage tank and the water conduits in the dryers including a cool water header connected to each inlet of said water conduits in said dryers at a plurality of loca-tions spaced along the cool water header for delivering water from the storage tank into the water conduits in said dryers, and a heated water header connected to each of the outlets of said water conduits in the dryers at a plurality of locations spaced along the heated water header for delivering heated water to the storage tank at water washing temperature from the water conduits in the dryers.

2. The system defined in claim 1 wherein said cir-culating system includes a crossover conduit between said cool water header and said heated water header in an intermediate location along said water conduits in the dryers.

3. The system defined in claim 2 wherein said cross-over conduit has therein a valve means for regulating the flow of water from the cool water header to the heated water header.

4. The system defined in claim 1 wherein said circulat-ing system includes means for maintaining substantially the same pressure differential between the inlet and the outlet of each of said water conduits in the dryers.

5. The system defined in claim 4 wherein said circulating system is such that the water flowing in said cold water header and heated water header flows in the same direction approximate the connection with said inlets and outlets of the water conduits.

6. The system defined in claim 1 wherein said circulat-ing system includes a pump responsive to operation of any of the dryers for moving water through the header conduits.

7. The system defined in claim 6 wherein said pump is located in the cool water header.

8. The system defined in claim 1 wherein said water conduits in the dryers are coils.

9. The system defined in claim 8 wherein said coils each includes a plurality of upper runs and a plurality of lower runs with the upper and lower runs lying in generally parallel horizontal planes and being interconnected at their ends.

10. The system defined in claim 9 wherein the heating means of each of said dryers has a capacity of approximately 142,000 btu per hour.

11. The system defined in claim 10 wherein said heating means includes a gas burner and wherein the lower runs of each of said coils are positioned approximately two inches above the associated burners and wherein the coils are made from heat con-ducting material having an inside diameter of approximately one-half to three-quarters of an inch.

12. The system defined in claim 1 further including pres-sure relief means associated with each of said water conduits in the dryers.

13. The system defined in claim 1, wherein said dryers are coin operated.

14. The system defined in claim 1, wherein said heating means includes a gas burner and a pilot and wherein said pilot is spaced from the water conduit in the dryer to avoid undue heating by a pilot flame.

15. The system defined in claim 2, wherein said circu-lating system includes means for maintaining substantially the same pressure differential between the inlet and the outlet of each of said water conduits in the dryers.