US2531315A

US2531315A - Liquid cooling apparatus

Info

Publication number: US2531315A
Application number: US689249A
Authority: US
Inventors: Margaret B Wyllie
Original assignee: Temprite Products Corp
Current assignee: Temprite Products Corp
Priority date: 1946-08-08
Filing date: 1946-08-08
Publication date: 1950-11-21
Anticipated expiration: 1967-11-21

Description

Nov. 21, 1950 Filed Aug. 8, 1946 J. WYLLIE, JR

uqumcoouuc urmms 2 Sheets-Sheen 1 Nov. 21, 1950 J. WYLLIE, JR 2,531,315,

LIQUID COOLING APPARATUS Filed Aug. 8, 1946 2 Shoets-Shoot 2 Patented Nov. 21, i950 UNITED STATES PATENT OFFICE LIQUID COOLING APPARATUS John Wyllie, Jr., deceased, late of Detroit, Micln,

- by Margaret B. Wyllie, exeentrix, Detroit, Mich,

assignor to Temprite Products Corporation, Detroit,-Mich., a corporation of Michigan Application August '8, 1946, Serial No. 689,249

Claims. 1

The invention relates to liquid cooling apparatus suitable for use in the dispensing of draft beverages (as, for example, by coin-controlled beverage vending machines) or in the cooling of other liquids under similar conditions of intermittent service.

For such cooling purposesit is desirable, in order to secure effective cooling and close temperature regulation under the varying load conditions, to use an instantaneous type of cooler, that is, one having conduit means providing a definite path for the flow of liquid to be cooled and a refrigerant expansion chamber associated with the conduit means with a metal wall separating the interiors of the conduit means and exv pansion chamber and forming a heat flow path between said interiors. It is, however, desirable also that the apparatus have the characteristics of a storage type cooler to permit cooling of stored liquid during reduced load on the apparatus and the use of a condensing unit of moderate size to serve the entire apparatus.

The production and operational control of such a system having such combined characteristics presents a problem that has not heretofore had a satisfactory solution and it is the primary object of the present invention to provide a combined instantaneous and storage type liquid cooling apparatus having relatively simple automatic control means by virtue of. which the apparatus attains a maximum output of cooled liquid for as an entirety a conventional motor-driven reirigerant condensing unit comprising a compressor 2, an electric motor 3, condenser l and, preferably, liquid refrigerant receiver 5.

Associated with the condensing unit is a precooler of storage type designated as an entirety by the numeral 6 and comprising a suitably heatinsulated tank I which may be supplied with water to be cooled in any desired manner. In the case of beverage vending machines a source of water under pressure may not be readily available and the tank will then be filled periodically by the person supervising the apparatus. when such a water source is available the tank I can be fitted as shown with a float-operated supply valve 8 adapted to be connected with the source of water supply. The side wall of the metal tank I is fitted with a refrigerant expansion coil 9 in close metal-to-metal contact with tank 1 so as to extract heat from the tank and its contents, The numeral Ill designates as an entirety an instantaneous liquid cooler comprising a helical coil I2 formed of larger diameter tubing than a given power capacity with relatively close temcidental or ancillary objects in view the invention consists in certain forms, arrangements and combinations of parts hereinafter explained in connection with the accompanying drawin s and definitely pointed out in the appended claims.

In the drawings,

Fig. 1 is a view, more or less diagrammatic, showing partly in e evation and partly in vertical section, an embodment of the invention as applied to cooling and carbonating apparatus for a beverage dispen ing system.

Fig. 2 is a vertical section. also more or less diagrammatic, showing a modified form of the instantaneous and precooler units of the apparatus shown in Fig. 1.

Referr ng in detail to the form of apparatus is the coil I i so as to form an expansion chamber between the walls of the two coils.

Arranged within the coils of the cooler in is a carbonator designated as an entirety by the numeral l3 and comprising a suitably heat-insulated metal tank It. the side wall of which has intimate contact with the refrigerant coil ii of the cooler Ill. The tank It is fitted with a spray nozzle ill for the introduction of water to be carbonated and with a discharge conduit it having its open inlet end near the bottom of the tank chamber. For the introduction of CO2 gas the tank is fitted with an inlet pipe I! which discharges into the tank chamber through a porous stone element It or other suitable gas diffusing device.

The lower part of the tank 1 of the precooler 6 is connected by a conduit l9 to a liquid pump 20 having an electric driving motor 2!, and the pump in turn is connected through a conduit 22 with the liquid inlet to the instantaneous cooler Ill at the upper end of its liquid coil Ii. The lower, discharge end of the coil ii is connected by conduit 23 with the spray nozzle it.

The pump motor M, as well as the condenser motor 3, is energized by current'from a supply line 24. To effect automatic control of the carbonator it is provided with high level and low level electrodes 25,15 which are connected in the pump motor circuit, together with a suitable illustrated in Fig. 1, the numeral I designates as relay switch device 26. These electrode and reassure serve to startmotor 2| when the liquid level in the carbonatcr falls below the lower end of electrode 25' and to stop said motor when the liquid level in the carbonator rises to the lower end of electrode 25.

A conduit 21 serves to connect the receiver I of unit I with the refrigerant inlet of the instantaneous cooler I at the lower end of its coil l2. The conduit is fitted with an expansion valve 28 adapted to respond to changes in temperature within the expansion chamber formed between the coils H and I2; Preferably valve 28 .is of the automatic type responsive to the pressure within the said-expansion chamber. Between the valve 20 and the coil l2 the conduit 21 is given several turns around container 29 to indicate provision forcooling flavoring extracts suitable for mixture with the carbonated water of the apparatus.- Such container, of course, constitutes a quite small heat load. w

The upper, outlet end of the coil 82 of the instantaneous cocler is connected by conduit 20 with the lower end of the coil 9 of the precooler while the upper outlet end of coil 9 is in-turn connected by conduit 3| "with the intake of the compressor 2 of the condensingunit. The op eration of the condensing unit is automatically controlled by a thermostatic switch 32 which may v be connected as shown into one branch of the circuit connecting motor 3 to the electric supply line 24 previously referred to. Switch 32, which also is diagrammatically shown, comprises a movable element 33 arranged to cooperate with terminals 3t, 35, when actuated-by the lever 36 which in turn is moved by the bellows 31 connected to the thermostatic bulb 38 through capillary tube'39. The connection between element 33 and lever 36 should have a lost motion action and this is conveniently aflorded by the conventional spring-biased toggle linkage shown in the drawing, The bulb 38 is arranged in a suitable well of'the carbonator so as to respond to temperature changes of the liquid therein. -When the temperature rises the bellows 31 is expanded and switch 32 is closed. To effect the openingof the switch in the normal, operation of the apparatus a lever 40 is arranged to engage the lever 38 and under the action of tension spring 4| moves the lever-36 and switch element 33 in a direction to open the switch. Such action of the lever 40 and spring 4| is subject to the control of a bellows 42 which is actuated by a thermostatic bulb 43 operatively connected to the bellows by conduit 44. The bulb 43 is arranged to contact the conduit 3| adjacent the discharge end of the coil 9 of the precooler 6 so that the actuation of the bellows 42 is responsive to the temperaturev the thermostatic switch 32 is adjusted to cut in at say 42 and to cut out at 35, and that the atmosphere surrounding the apparatus is above 42 F. In starting operation of the apparatus, as by closing a manual switch (not shown) in the supply line 24, if the carbonator is empty and the precooler tank has just been filled with-water at a temperature of, say, about 90 F., warm water 4 will beforced-thrmigh the instantaneous cooler, and simultaneously the refrigerating eiiect will be applied in part to the reduction of the temperature of the water in the low temperature. In initially starting the appsratus from a warm state the first water entering the carbonator may not be properly carbonated andaccordinglyitwillbedesirabletowastcthe first liquid drawn from the carbonator. Thereafter, if the draft of carbonated beverage is such as to place sufiicient load on the instantaneous cooler and the carbonator. the entire refrigerating effect of the compressor will be absorbed by them if the compressor is of the moderate capacitypreierred in carrying out the invention.

Let it be assumed, now, that either no drinks are being drawn from the carbonate: or else that they are being drawn at a low rate, so that the cooling requirements of the instantaneous cooler and carbonator now are less than the capacity of the compressor. Notwithstanding this surplus compressor capacity the instantaneous cooler will not freeze up because the temperature in it cannot go below 35 F. provided fo by the automatic expansion valve setting. What will happen under the stated conditions is that unevaporated liquid refrigerant willpass out of the instantaneous cooler to the expansion coil 5 of the precooler. Here, subject to the high tam-'- perature of the water in the prez'ooler tank, the refrigerant still in the liquid state will be evaporated and cooling of the water in the tank will result. Thus although the demand of the instantaneous cooler may have been satisfied, the condensing lmit continues to operate for the purpose of reducing the temperature of the water in the storage. tank. If during the cooling of the storage tank and its contents any demand is placed upon the instantaneous cooler, whether by reason of heat leakage or by the drawing of pensing rate of the apparatus when the precooler storage tank is filled with warm water. Thus the size or the condensing unit preferably-would be determined on the assumption that the water in the precooler tank will be kept at a temperature not higher than a normal maximum of, say for example. 65 F. to enable the compressor and the instantaneous cooler properly to cool the water at the normal maximum dispensing rate: and

further the refrigerant coil 9 of the precooler preferably should be constructed to absorb the full capacity oi" the compressor only when' the water in the precooler tank may be above such normal maximum of 1''. Under these conditi lls the condensing unit, once started, would stantaneous cooler had been met andalso until duced tea-65 I". At this point the heat load on the systemwiil drop below the potential refrigcrating capacity of the amount of'the refrigerant being circulated, and some unevaporated refrigerant will leave the cooling coil and pass into the suction line SI and in doing so will chill the thermostatic bulb l3 and cause the switch 32' to open and stop the condensing unit.

It has been specified that the thermostatic switch 32 be set for a cut-out temperature of 35 1". and that the expansion valve ll be set for a low side pressure at the carbonator correspending to a temperature of about 35 F.

Since there is a certain amount of pressure drop in the instantaneous cooler and in the precooler from the pressure maintained in the entrance of the cooler coil by the automatic expansion valve II, under normal operating conditions the refrigerant reachingthe point in the system adjacent than that corresponding to 35 F. This action arises from the variation in temperature of the water in the pre-cooler tank I. As long as that temperature is sufilciently high in relation to the temperature of the refrigerant in coil 9, the resulting heat transfer between the tank and coil causes a more or less super-heated state of the vaporized refrigerant in the discharge end of the coil adjacent bulb 43; but as the water temperature in tank I is lowered by operation of the compressor, a point is reached where there is insuflicient heat transfer to completely vaporise the liquid refrigerant in coil 8. This liquid refrigerant, entering coil lia at a pressure somewhat lower than that maintained at the entrance to coil if by expansion valve 28, affects bulb l3 and causes the cut-out of the thermostatic switch already noted. I

As soon as the compressor stops operating, the suction line M will rapidly rise above the cut-in temperature of 42 F., but this will not cause the switch 82 to cut in because the bulb 43 can actuate the switch only in the cut-out direction. However. if from either heat leakage into the carbonator or draft of beverage therefrom the carbonator warms up to 42 F. this will cause the thermostatic bulb 38 to actuate the switch 32 in the closing direction and the cycle which has already been described will be repeated. In other words, the requirements of the instantaneous cooler and carbonator will be met first, and then the liquid refrigerant will pass over to the precooler where it may still further reduce the temperature of the storage water. Generally speaking, the size of the precooler tank I will determine the length of the operating cycle of the compressor and it is apparent that the combination with the instantaneous cooler of the storage type precooler not only in effect increases the wor capacity of the instantaneous cooler but serves also to extend the working cycle of the apparatus to a tolerable length and prevent "short cycling."

it will be noted in the drawingthat the refrigerant suction line H after passing the thermostatic bulb M is again brought into heat exchange relation with the storace tank I at point Ma. Thus if the operation of the thermostatic switch should tend to be somewhat sluggish at cut-out this arrangement will dry out any refrigerant which may have passed the bulb 48 prior to opening of the switch 32. With such a construccontinue tooperate unwise demands 01mm the contents of the-precooler tank had been re- 8 tion it is obvious that the part of conduit 8| contacted by bulb ll should not be indirect heat I exchange relation with the tank I.

with respect to the operationof the thermostatic switch 32, while, as has been stated, the thermostatic bulb it serves only to close the switch in the normal operation of the apparatus, it may be observed that under abnormal conditions causing unduly low temperatures in the carbonator resultant contraction of the bellows .31 might serve also to open the switch.

In the modified construction shown in Fig. 2 of the drawing the precooler 46 comprises a closed tank 41 fitted with a manual air relief valve 48 and provided with an open inlet conduit 4! adapted to be connected to a water main or other suitable source of water under pressure so as the bulb 43 will be at a somewhat lower pressure tomaintain the tank filled with water. As in the first construction the tank is fitted with a refrigerant cooling coil 50.

In the modified construction the instantaneous cooler 8| consists of a liquid cooling coil 52 threaded through a refrigerant coil 53, the upper inlet end of coil 52 being connected by conduit It with the lower part of the interior chamber of the storage tank 41 of the precooler while the lower discharge end of coil 52 is connected with conduit 55 which may lead to any desired point of draft. Also, as in the first construction, the lower inlet end of the refrigerant coil 53 connects with conduit 21' leading. asin the case of conduit 21 in Fig. l, to the expansion valve and thence to the discharge of the condensing unit; and the upper discharge end of the refrigerant coil 53 is connected by conduit 30' to the inlet end of the expansion coil 50 of the precooler,

while the outlet end of coil 50 is connected by conduit H with the intake of the condenser unit.

The control devices for the modified construction comprise thermostatic bulb 38' responsive to the liquid discharge temperature of the instantaneous cooler and bulb 43' responsive to the temperature of the discharge refrigerant of the precooler, these thermostatic bulbs being connected with switch mechanism which is like that shown in Fig. 1 and need not, therefore, be further described.

in the modified construction, as will be apparent, the flow of the liquid to be cooled is unobstructed from the inlet conduit 49 into the precooler tank, thence through conduit 54 and the instantaneous cooler, and need be subject to control only at the point of draft from the liquid discharge conduit 55. The thermostatic control of the operation of the modified construction is substantially the same as that of the first described construction and therefore the description need not be repeated.

To those familiar with liquid cooling apparatus and the various kinds of cooling applications it will be apparent that the apparatus which has been described has distinct advantages and is susceptible of various applications or uses. In particular, the improved apparatus is especially adapted to meet the requirements of automatic beverage vending machines where the power capacity of the refrigerant compressor is necessarily quite limited. Under such conditions it has all the advantages of an instantaneous coole;- but without its usual disadvantages under those conditions. and at the same time it has the advantage of a storage cooler without the latter's lack of close temperature control. The construction of the apparatus both with respect to assume bodiments of the invention which have been shown and described may be modified in'various ways within the bounds of the invention as de-- fined in the appended claims.

What is claimed is:

1.'In liquid cooling apparatus. the combination of a liquid precooler comprising a liquid chamber and a refrigerant expansion chamber in heat-absorbing relation thereto; an instantaneous type liquid cooler comprising conduit means providing a definite path for the flow of liquid to be cooled and a refrigerant expansion chamber associated with the conduit means; means for conducting liquidfrom the precooler to the instantaneous cooler to replace liquid drawn from the latter; a motor-driven refrigerant condensing unit; refrigerant conduit means for conducting liquid refrigerant from the discharge of the condensing unit to the refrigerant chamber. of

the instantaneous cooler; means for controlling the passage of refrigerant through the said con- 3.- Liquid cooling apparatus as claimed in claim 1 in which the capacity of the refrigerant condensing-imit is sufficient only to carry the maximum heat load imposed Jon the instantaneous cooler;

3. Liquid cooling apparatus as claimed in claim 1 in which the precooler is of the storage type having a liquid-holding capacity largely in exc'ess of that of the instantaneous cooler.

Q. In liquid cooling and carbonating apparatus, the combination of a liquid prec'ooler comprising a liquid chamber and,a refrigerant expansion chamber in heat-absorbing relation thereto; liquid carbonating means comprising a carbonating chamber; an instantaneous type liquid cooler comprisingconduit means forming a definite path for the flow of liquid to be cooled and a refrigerant expansion chamber in heat-' absorbing relation to said conduit means and to the carbonating chamber; means for conducting liquid from the outlet of the precooler to the inlet of the instantaneous cooler and from the outg let of the latter into the carbonating chamber; a motor-driven refrigerant-liquefying means; refrigerant conduit means for conducting liquid refrigerant from the liquefyingmeans to. the refrigerant chamber of the instantaneous cooler;

cooler and from the latter chamber to the liquedischarged from the precooler to stop the lique-' fying means.

5. A liquid cooling and carbonating apparatus as claimed in claim 4 in which the carbonating chamber has a liquid-holding capacity substantially in excess of that of the instantaneous cooler.

' MARGARET B. WYILIE,

Ezecutria: of the Last Will and Testament of John Wyllz'e, Jr., deceased.

REFERENCES crran The following references are of record in the file of this patent:

onrrsn s'ra'rns PATENTS Number Name Date 2,278,225 Taylor Mar. 31, 1942 2,278,226 Taylor Mar. 31, 1942