US2136813A

US2136813A - Liquid cooler control

Info

Publication number: US2136813A
Application number: US40238A
Authority: US
Inventors: Dewey H Dolison
Original assignee: Individual
Current assignee: Individual
Priority date: 1935-09-12
Filing date: 1935-09-12
Publication date: 1938-11-15
Anticipated expiration: 1955-11-15

Description

Noy. 15, 193 8. D. H. DCLISQNi 2,136,813

" LIQUID COOLER CONTROL Filed Sept. 12, 1955 III A I 'I INVENTOR.

Ev! BY A TTORNEY.

. refrigeration in the cooling coil.

Patented Nov. 15, 1938 UNITED STATES" PATENT OFFICE LIQUID COOLER CONTROL Dewey H. Dolison, Mount Vernon, Ohio Application September 12, 1935 Serial No. 40.238

' 10 Claims.

serve drinks cold occasionally or continuously.

Up to the present, difficulty has been experienced in such systems in obtaining such flexibility of performance. If the control is set to maintain a steady cold flow of liquid, then at light loads there is apt to be serious frostbacks and even freezing of the beverage. On the other hand if the control is. set for light loads, a heavy continuous flow of beverage will result in such a severe overload as to prevent proper refrigeration. Reliance is placed upon the cessation of beverage flow between successive glasses to obtain proper But it frequently happens that a large container of beverage is drawn or even successive glasses without any interruption'to the flow. In such a case, the difficulties mentioned above militate against satisfactory performance of a direct expansion system.

An object of this invention is to devise a liquid cooler control for a direct expansion system which will obviate the above difficulties and will permit the cooling coil to supply a continuous fiow or an occasional dribble of beverage properly refrigerated.

s A further object is to devise a liquid cooler coil and control which will be flexible enough to function satisfactorily from no load to full load continuous operation in a direct expansion system.

An additional object is to devise a liquid cooler and control which will be simple, cheap, positive in operation and capable of use with difierent sizes of installations.

An additional object'is to devise a liquid cooler control which is responsive to one or more beverage temperatures\ and to supply as much refrigeration as the load demands.

Other and additional objects will become apparent as the description proceeds.

Referring to the drawing, I

Fig. 1 shows a complete liquid cooler system with my control applied thereto.

,Figs. 2 to 5 inclusive show modified forms of liquid cooler coils and control.

Referring to Fig. 1, an electric motor is connected by a belt 2 to a compressor Compressed refrigerant isdelivered through pipe 4 and condensed in a receiver 5. Liquefied refrigerant is delivered by a pipe 6 from receiver 5 tain a suitable pressure in the cooler coil.

to a control valve 1 to be later described .in detail. Valve 1 is provided with an outlet 8 which is adapted to feed liquefied refrigerant through a pipe 9 to a liquid cooling conduit or coil I0.

Cooling conduit or c'oil l0 comprises a plurality of nested conduits such as an inner pipe H adapted to have any beverage therein and a surrounding telescoped. pipe l2 adapted to contain the refrigerant. Supply. pipe 9 leads to a suitable fitting l5 at one endof the conduit or coil l0 permitting refrigerant to flow into outer pipe l2 and permitting beverage pipe I I to extend beyond coil l0. .Coil l0 is-extended for any suitable length and may be coiled, as shown, or straight or disposed in any desirable manner. It may for example be the connecting pipe between beer kegs in a cellar and faucets in a bar fixture. The other end of coil l0 terminates in a fitting l6 similar to l5. From fitting 16 a pipe I! conducts the volatilized refrigerant to a back pressure valve [8 and thence by suction line l9 back to compressor 3. Valve [8 functions as a valve to main- Such pressure would be substantially equivalent to that at which the particular refrigerant employed in the system boils when the temperature thereof is about that to which it is desired to cool the beverage in pipe II.

The entire refrigerating system is provided with the customary low pressure control comprising a pipe 20 leading from suction line l9 to a pressure control switch 2| set to operate between two pressure limits. Inasmuch as such control systems are old, no further description is necessary. When enough, refrigerant in the entire system has volatilized to raise the pressure in suction line I9 to the critical value, motor I is switched in and the compressor is driven. Finally when suflicient refrigerant has been transferred from the suction line to the receiver and liquefied to reduce the pressure in suction line I9 to the critical value, then the motor stops. This control however is supervisory only and does not function to control the amount of refrigeration applied to the beverage. This control is merely to insure a reservoir of liquefied refrigerant upon which the cooling coil and its own control can operate.

Itwill, be noted that the beverage in pipe ll comes in at fitting l6 and its flow is counter to that of the refrigerant through the cooling conbulb or receptacle is a sleeve over inner pipe H and within outer pipe II. This sleeve has its ends 25 and 21 crimped down to pipe II and suitably soldered thereto to form a gas tight chamber. A pipe or capillary tube 28 leads from bulb 25 to valve 1 through cover plate 30. This cover plate with a flexible diaphragm 3| forms an expansible chamber 32 in gaseous communication with bulb 25. A suitable expansible fluid such as methyl chloride may be disposed within bulb 25.

Cover plate 30 is attached to valve body 33. Within valve body 33 is 'a push rod 34 attached to a head 35 disposed in proximity to diaphragm 3|. The bottom of rod 34 rests upon a ball valve 35 pressed upwardly against its seat 31 by a spring 38 and cup-shaped retainer 33. Pipe 5 communicates with chamber 40 within the lower part 4| of the valve body while pipe 5 communicates with the outlet portion of valve 1. Upon expansion of gas within bulb 25 and chamber 32, diaphragm 3! is sprung downwardly to force ball 35 away from its seat and open valve 'I. Befrigerant in liquid. form and under pressure is thereupon forced into cooler coil l0. While I have described valve 1 in detail, it is understood of course that any other suitable valve mechanism may be used.

Assuming receiver 5 has suflicient refrigerant in liquid form therein, coil or conduit I0 will operate as follows: Under no load conditions. the column of beverage will be at a temperature of approximately 45 F. for example. Under these conditions, conduit i5 willhave a portion thereof .filled with liquefled refrigerant to a point near the receptacle or bulb 25. If a glass of beverage is drawn, the entire beverage liquid column will advance in inner pipe ll downward as seen in Fig. 1. Some warm beverage will come into contact with bulb 25 and cause the pressure therein to increase. This will result in valve I opening and permit liquid refrigerant to rush into outer pipe l2. Liquid refrigerant will advance to contact the receptacle or bulb 25 which will be chilled and valve 1 closed. The liquid refrigerant will gradually recede or be forced back by vaporization thereof effected through the absorption of heat. As long as the temperature of the receptacle or bulb 25 is substantially equal to the temperature of the liquefied refrigerant, nothing will happen. As soon, however, as the temperature of the bulb 25 rises above the pressure temperature value, which value is determined by the setting of back pressure valve It, then valve 1 will be opened. This rise in temperature of the bulb 25 and thermally responsive fluid or vapor contained therein may be due to heat leak or warm beverage flowing in the conduit III or both. If a heavy draught of beverage is taken off, a correspondingly heavy charge ofrefrigerant will be introduced into the conduit or coil Ill. By proper design it is possible to have a continuous flow of beverage and a continuous flow of refrigerant which is substantially completely evaporated before reaching bulb 25. The length of the conduit or coil ID from bulb 25 to fitting I5 is in the nature of a drying coil to insure against frost back on. line H under extreme conditions.

There is always a column of refrigerated beverage in the conduit or coil l5 ready for instant use and this column will always remain cold.

In practice, the coil l0 may be severed at the bulb center and the parts built up and soldered in place. I

In Fig. 2, bulb or receptacle 225 is shown on the outside of the coil. Within bulb 225, is a pipe M2 for refrigerant and within that is a pipe 2 for beverage. This construction may be used where the beverage, as beer, is stored in a refrigerated container and its temperature effect on bulb 225 is unnecessary. In such a case, bulb 225 is responsive only to the refrigerant medium directly. Indirectly of course, beverage in pipe 2, if warm, will cause refrigerant to vaporize in that region and warm up the receptacle or bulb 225. Such a construction is cheaper than that disclosed in Fig. 1 and may advantageously be used in certain cases.

Fig. 3 shows outer pipe "2 for refrigerant enclosing bulb 325 as in Fig. 1. Within bulb 325, however, are two pipes 3H! and 3H for beverages. In this case, bulb 325 will respond to the warmest of the two beverages. Along the length of. the entire coil, the temperature of the two beverages will be equalized so that if one is drawn heavily and the other lightly, the lightly drawn beverage column will tend to cool the other beverage column.

In Fig. 4 an outer pipe 430 is provided for one beverage. Within that is a refrigerant pipe 43L Inside of pipe 43l, is bulb 425 with one side touching pipe 43l. Within bulb 425 is a second beverage pipe 432. By having bulb 425 in intimate contact along one side with 43l at point 433, bulb 425 is made more responsive to conditions in the outer beverage line 430. Conditions within beverage line 432 will affect bulb 425 indirectly as in Fig. 2.

Fig. 5 is similar to Fig. 3 except that the two beverage pipes 5| II and 5 are separate pipes instead of-one having a dividing wall. Otherwise refrigerant line M2 and bulb 525 function as in Fig, 3.

It will further be noted that in all the flgures, the beverage conduit presents a smooth and unbroken surface to the beverage flow. This is important for several reasons. Sincemany beverages are carbonated, there is a tendency for gas to bubble out at sharp corners and projections and cause excessive foaming. Then in cleaning, a cleaning solution will function more effectively along a smooth surface.

The present invention provides a novel control for beverage cooling systems and the like in which the cooling of the liquid is effected by direct heat interchange from a volatile refrigerant to the liquid to be cooled. The positioning of the bulb or receptacle 25 containing the expansible fluid which governs the refrigerant inlet valve. so that the expansible liquid is subjected predominantly to only the heating or cooling effects of the liquid to be cooled and the refrigerant, promotes a rapid response of the refrigerant inlet valve to a demand for refrigerant. A body of the fluid which is responsive to temperature changes is thus housed in a receptacle having one wall positioned to be traversed by substantially all of the refrigerant flowing through the refrigerant passageway and having another wall to be traversed by substantially all of the liquid flowing through the liquid passageway. In this manner the body of thermally responsive fluid is subjected substantially solely to the temperatures of the liquid being cooled and the refrigerant to cool the liquid while the said liquid and refrigerant are flowing through their respective courses. Heating sources or cooling eifects outside of the cooling conduit do not directly influence the expansible fluid in the thermostatic receptacle. Such effect as outside heat or cold has on the control of the inlet valve is transmitted indirectly to the receptacle or bulb cooled liquid discharged. On account of the extreme sensitiveness of the novel thermostatic device for controlling the admis ion of refrigerant to the cooling conduit ther is avoidance of lag or delay in the supplying of fresh quantitles of liquid refrigerant to cool a sudden or continued influx of warm liquid.

Other means of utilizing the principles of. the present invention are contemplated, change being made in the particular details of procedure and construction set forth as required, it being understood that the embodiments shown are I given for purposes of explanation and illustration. 1

Having described the invention, what is claimed is: i

1. A liquid cooler comprising an outer conduit having an inlet end and an outlet end, pipe means arranged within said conduit and extending through the same substantially from end to end and having outlet means at the inlet end of said conduit, and a thermostatic control device arranged within said conduit; said device comprising a sleeve substantially enveloping a portion of said pipe means and cooperating therewith to form a fluidtight chamber having one wall subjected to the temperature of fluid passing through said conduit, and a capillary tube communicating with the interior of said chamber and passing through said conduit to the exterior thereof;

2. A liquid cooler, comprising a conduit having a plurality of passageways extending in parallelism therethrough, one of said passageways arranged to carry a refrigerant and another passageway arranged to carry a liquid to be cooled, a pressure valve to regulate the withdrawal of refrigerant from the conduit and maintain a predetermined pressure in the refrigerant passageway, an inlet valve associated with the refrigerant passageway to regulate the admission of refrigerant thereto, and means responsive to temperature changes to open and close the inlet valve, said means including a receptacle positioned for direct heat exchange with the passageways and intermediate the ends of the conduit, said receptacle being located within the said conduit in position to be traversed by substantially all of the refrigerant flowing through said refrigerant passageway and by substantially all of the liquid flowing through the second mentioned passageway.

3. A liquid cooler, comprising a conduit having a plurality of passageways therethrough, one of the refrigerant passageway to regulate the admis-, sion of refrigerant thereto, and means responsive to temperature changes to open and close the inlet valve, said means including a receptacle positioned for direct heat exchangewith the passageways and intermediate the ends of the conduit, said receptacle being located within the said conduit in position to be traversed by substanvtially all of the refrigerant flowing through said refrigerant passageway and by substantially all of the liquid flowing through the second mentionedv passageway.

4. A liquid cooler, comprising a conduit having a plurality of passageways extending in parallelvalve associated with the refrigerant passageway to regulate the admission of refrigerant thereto, and means responsive to temperature changes to open and close the inlet valve, said means including a receptacle positioned for direct heat exchange with the passageways and intermediate the ends of the conduit, said receptacle being 10- cated withinv the said conduit" in position to be traversed by substantially, all of the refrigerant flowing through said refrigerant passageway and by substantially all of the liquid flowing through the second mentioned passageway.

5. A liquid cooler, comprising a conduit and one or more parallel pipes passing through the interior of said conduit and cooperating therewith to form passageways extending longitudinally through the conduit, an inlet valve to regulate the admission of liquid refrigerant to one of the pas sageways, means to control the operation of said valve, said means including a receptacle located within said conduit in position to be subjected directely to temperature changes in each of the passageways at a region intermediate the ends of the conduit, and a pressure valve to regulate the withdrawal of refrigerant from the refrigerant passageway, said pressure valve arranged to permit the flow of refrigerant out. of the refrigerant passageway when the pressure therein exceeds a predetermined value and to prevent such flow when the pressure therein is less than a predetermined Value 6. A liquid cooler comprising a plurality of passageways extending in substantially side by side parallel relation,'one of said passageways having an inlet and an outlet and arranged to carry a volatile refrigerant, another of said passageways arranged to carry a liquid, means for supplying refrigerant to the refrigerant passageway, a pressure valve to regulate the withdrawal of refrigerant from the refrigerant passageway and maintain a substantially uniform predetermined pressure therein, an inlet valve associated with the inlet end of the refrigerant passageway to regulate the admission of liquid refrigerant, and means responsive to temperature changes to open and close the inlet valve, said means including a receptacle for an expanslble fluid positioned between the passageways and having one wall in common with the refrigerant passageway to be traversed by substantially all of the refrigerant flowing through the refrigerant passageway, and

another wall in common with the liquid passageway to be traversed by substantially all the liquid flowing through the said liquid passageway, and

the receptacle arranged to be alternately subjected to substantially predominantly liquid re-' frigerant and to substantially predominantly gaseous refrigerant as the effective level of liquid refrigerant advances and recedes in the refrigerant passageway.

7. The method of cooling a liquid which comprises passing the liquid over a course traversing one side of a body of fluid responsive to temperature changes, passing a volatile refrigerant over a course paralleling the; course of the liquid to be cooled and in direct heat-exchanging relation therewith and over another side of the said body of fluid, maintaining a substantially constant pressure on the refrigerant in the refrigerant course, subjecting said body of fluid solely to the temperatures of said liquid and said refrigerant in said courses, and controlling the admission of refrigerant to the refrigerant course solely in response to changes in temperature of said body of fluid.

8. The method of cooling a liquid which comprises passing the liquid over a course traversing one side of a body of fluid responsive to temperature changes, passing a volatile refrigerant first a refrigerant course solelyin response .to changes in temperature of said body of fluid. 8. The method of cooling a liquid which comprises passing the liquid over a-course which flrst traverses a body of fluid responsive to temperature changes and then parallels a refrigerant course, passing a volatile refrigerant over a cours which first parallels the liquid course in heatexchanging relation therewith and then traverses another side of said body of fluid, maintaining a substantially constant pressure on the refrigerant in the refrigerant course throughout substantially the entire length thereof, subjecting said body of fluid solely to the temperatures of said liquid and said refrigerant in said courses, and controlling the admission of refrigerant to the refrigerant course solely in response to changes in temperature of said body of fluid.

10. The method of cooling a liquid which comprises passing the liquid over a generally descending course which first traverses a body of fluid responsive to temperature changes and then parallels a refrigerant course, passing a. volatile refrigerant in a generally ascending direction over a course which flrst parallels the said liquid course in heat-exchanging relation therewith and then traverses another side of the said body of fluid, maintaining a substantially constant pressure on the refrigerant in the refrigerant course throughout substantially the entire length thereof, subjecting said body of fluid solely to the temperatures of said liquid and said refrigerant in said courses, and controlling the admission of refrigerant to the refrigerant course solely in response to changes in temperature of said body of fluid.

DEWEY H. DOLISON.