US1916197A - Refrigerating apparatus - Google Patents

Description

July 4, 1933- E. s. H. BAARS REFRIGERATING APPARATUS Filed Sept. 4, 1951 2 Sheets-Sheet l INVENTOR.

A TTORNEY.

July 4, 1933. E S. H, BAARS 1,916,197

REFRIGERATING APPARATUS Filed Sept. 4, 1951 2 Sheecs-Sheet 2 A TT ORNE Y.

Patented July 4, 1933 UNITED STATES PATENT OFFICE ERNST S. H. BAARS, OF MILWAUKEE, WISCONSIN, AS'SIGNOR T0 THE VILTER MANU- FACTURING COMPANY, OF MILWAUKEE, WISCONSIN, A CORPORATION OF WIS- CONSIN REERIGERATVING APPARATUS Applicaton led September 4, 1931. Serial No. 561,147.

' 'lhe present invention relates in general to improvements in the art of refrigeration, and relates more specifically to improvements in the construction and operation of controlv mechanisms for refrigerating systems utilizing liquid refrigerant and ordinarily comprising a compressor, an evaporator, and a condenser constituting a confin-` ing circuit for the liquid,

An object of the invention is to provide an improved control mechanism for refrigerating systems or the like,.which is simple in construction and efficient in operation.-

Another object of the invention is to provide an improved refrigerant feed valve which will( permit most economical and kefcient operation of the system with which the valve is associated. p

A further object of the invention is to provide a simple valve structure which will permit effective delivery of liquid'refrigerant torooling coils and other surfaces disposed.

above the valve structure.

Still another object of theA invention is to provide an improved feeding device which Will force liquid refrigerant to the most desirable points of a system, from anoperatingview.

Another object of the invention is to provide an improved feeder for delivering refrigerant to a number of independent'systems, through a common valve structure.

A further object of the invention is to provide a'feed valve for refrigerating systems, whichwill prevent flash gas and liquid slugs Afrom creating disturbances in the system utilizing the valve.

vStill another object of the invention is to provide an improved feed control which permits effective control of the refrigerant, and which does not permit undesirable overfeeding of refrigerant as in the so-called high pressure float feed systems heretofore proposed.

Another object of the invention is to provide an improved float control wherein a relatively small float may be employed to effectively control large capacity valves.

A further object of theinvention is `to provide a feed regulator which will operate vfloat controlled equally well at'variable temperatures, and which will not ordinarily be affected by congealing of oil due to shutting down ofthe system utilizing the regulator.

Still another object of the invention is to provide lmproved control valve structures which will eliminate undesirable variations 1n pressure in a system, such as might tend to produce objectionable irregularities in evaporation of the refrigerant.

Another object of theinvention is to provide an improved float controlled valve which may be conveniently manufactured, assembled and installed, and which is automatic in operation.

These and other objects and advantages will be apparent from the following detailed description. 't

A clear conception of'a number offembodi ments of the invention'and of the construction and mode of operating feed valves and cooling systems built in accordance with the improvement, may be had by referring to the drawings accompanying and forming a part of this specification in which like reference characters designate the same or similar parts in 'the various views:

Fig-1 is a longitudinal central vertical section through one of the improved float controlled liquid feedvalves; Y Fig. 2 is an end view of the feed valve casing; l

Fig. 3 is anopposite end view of the feed valve casing; v

Fig. 4 is a diagram of one ty e of refrigeratingsystem having one of t e improved feed valves incorporated therein; i

Fig. 5 is an end view of the upper coil of the. evaporator used in the systemof Fig. 4, a section having been taken through the coil along the line 5-5 of Fig. 4; v

Fig. 6 is a diagram of a portion of a milk orother liquid cooling system utilizing one of the. improved float controlled `regulating valves;

Fig..7 is a 4diagram of a portion of a Fig. is a sectional diagram of a special cooling coil or evaporator adapted for cooperation with the improved valve;

Fig. 9 is an enlarged transversel section through the coil of Fig. 8, the section being taken on the line 9-9 of Fig. 8;

Fig. 10 is a Adiagram of a portion of a simple form of milk and water cooler showing the application of one of the improved valves; and

Fig. 11 is a diagram of a refrigerating system embodying one of the improved valves, wherein the refrigerant from the valve is discharged below lthe level of the flow past the needle valve 18.

face of the plunger 17 adjacent to the needlechamber 20; a float 21 disposed within the chamber 20 and swingably supported upon the member 14 by means of a pivot 22; a bent lever 23 attached to the float stem and extending upwardly across and forwardly over the bore 15 a link 24 pivotally connecting the lever 23 with the end of the plunger 17 remote from the valve 18; a weight 25 adjust-- ably associated with forward extension of the lever 23 within the chamber 20; and suitable pipe connections communicating with the port 16 and chamber 2O through the member 14 an'd easing 19.

,f The supporting member 14 is preferably formed of a metal casting, while the casing 19 may be formed of a section of standard pipe having a dished sheet metal head attached thereto by welding or otherwise, and also having thimbles similarly attached thereto for the convenient connection of the piping. The joint between the member 14 and easing 19 should be absolutely tight so asto insure hermetic sealing of the chamber 20 which is ordinarily supplied with liquid refrigerant sufficient to raise the float 21. The plunger 17 besides snugly fitting the bore 15, may'also be provided with a series of sealing grooves as shown in Fig. 1, in order to prevent passage of liquid from the port 16 through the bore 15 to the chamber 20. The Weight 25 may be positioned at any desired point along the forward extension of the lever 23, so as to counter-balance the Weight and buoyancy of the float 21 to any desired extent, thus providing for very sensitive regulation of the The end survalve 18 is also. exposed to the pressure at the discharge side of the needle-valve, which preure also tends to counter-act the forward pressure upon the plunger 15 due to the float 21 and any fluid pressure which may exist Within the chamber 20.

Referring specifically to the diagram of Figs. 4 and 5, the refrigerator system therein illustrated comprises, a. pump or compressor 26, a condenser 27, a receiver 28, an accumulator 29, an upper evaporator or cooling coil 30, a lower evaporator or cooling coil 31, one of the improved float actuated control valves, and'suitable conduits or pipes connecting these elements of the system. The liquid refrigerant discharged int-o the receiver 28 from the condenser 27, is delivered to the port 16 of the control valve through a pipe 32, and after passing the needle valve 18 the refrigerant is delivered to the upper coil 30 through the pipe 33. The gases generated in the upper coil 30 due to evaporation, together with the excess liquid, escape from the upper coil 30 through a pipe 34 or a pipe 34 to the upper portion of the accumulator' 29. The surplus liquid refrigerant within the accumulator 29 passes into the lower coil through a pipe 35. and the gases from this coil 31 may also enter the accumulator through the pipe 34. The gases collecting in the yuppermost portion of the accumulator 29 escape through a pipe 36 to the compressor 26 from whence the compressed gases are delivered through a pipe 37 to the condenser 27 wherein theyare condensed for subsequent recirculation through the system.

A liquid refrigerant supply pipe 38 connects the lowermost portion of the float chamber 20 with the accumulator 29 below the normal level of the liquid refrigerant in the latter, and a gas escape pipe 39 connects the4 uppermost portion ofthe chamber 20 with the accumulator 29 above the normal liquid level. The float chamber 20 may also be provided with drain connection 40 as shown in Figs. 1 and 2. In order to insure efficient distribution of the refrigerant in the upper coil 30, this coil may be provided with upper and lower headers 41, 42 as shown in Fig. 5. The headers 41, 42 besides being in- I terconnected by the several coil sections,I are also joined by risers 43, 44, the former of which communicates directly with the pipe 33 and extends above the bottom of the header 41, and the latter of which is flush with the bottom of the header 41 but extends below the top of the header 42. The gas discharge pipe 34 communicates with the uppermost portion of theupper header 41, thus preventing escape of excessive quantities of liquid refrigerant from the cooling coil 30 to the accumulator 29. The normal operation of the system shown in' Figs. 4 and 5 should be apparent from the foregoing detailed de- `scription of the system.

,Fig 6, the milk cooler has a lower ammonia section 45 provided with a cooling coil 46, and also has a water section 47 superimposed over the lower section 45. The float actuated control valve of this cooling system is connected to the accumulator 29 by means of supply and exhaust pipes 38, 39 exactly as iny the system of Fig. 4, and liquidrefrigerant is delivered to the needle valve chamber from the receiver, through a pipe 32 and past a liquid stop valve 48 of standard construcltion. The discharge pipe 33 of the ocontrol valve, communicates with the lower end of the coil 46, and this end of the coil may also be directly connected to the lower portion of the accumulator 29 by means of a pipev 49. A by-pass connection 50having an expansion valve 5l therein, may also be provided between the pipe 32 and the pipe 33 for the purpose of permitting delivery of refrigerant from the receiver to rthe coil 46 without passing through the control valve. The upper end of the coil 46 is connected to the upper portion of the accumulator 29 by means of a pipe 34, and the suction pipe 36 leading from the top of the accumulator 29 may be provided with special automatic controlvalves 52, 53 and with an ordinary suction stop valve 54. The control valve 52 is operable by suction pressure to control the suction flow, while the valve 53 is solenoid actuated, being controlled by the quantity vor weight of milk or other liquid enteringl the water section 47 and acting upon a switch .54. This control may. also be effected thermostatically or otherwise in order to prevent excessive coding of the milk to freezing temperatures;` The valves 52, 53 form no part of the present invention, but it is to be noted that in the cooling system of Fig. 6, the float operated control valve is disposed above the cooling coil `in order to provide a liquld head for forcing the refrigerant through the coolinfi coils and connections.

In the diagram of Fig. 7 the single float actuated control valve regulates the delivery of liquid refrigerant directly from a receiver through pipes 32, 33 to the upper end of a cooling coil 55, the lower end of which communicates with a header 56 disposed on the same lever as the oat chamber' 20,

.through a'pipe 57. A second cooling coil 58 has its upper end connected directly to the header 56 and has its lower end connected to a reservoir 59 which is in turn connected to the 'header 56 above the liquid level therein, by means of a vertical pipe 60. The uppermost portion of theshead'er 56 is connected to the suction of thecompressor by means of a pipe 61, and the supply and exhaust pipes 38, 39 of the control valve, are connected respectively to the pipes 60, 61. In this system,

the use of an accumulator is dispensed with, and the singlecontrol valve regulates the de- Figs. 8 and 9, the fioatoperated control valve regulates the delivery of liquid refrigerant from the pipe 32 through the pipe 33 to the upper pipe or section 62 of an evaporator. The upper section 62 has a special overiow arrangement as shown in Fig. 9, consisting of a vertical tube 63 having an open upper end communicating with the gas space within the section 62, and an overiow elbow 64 disposed within the tube 63 and having a V-notch 65 at its upper end for establishing a definite normal level of liquid within the section 62. The pipe 33- discharges liquid refrigerant into the end of the section 62 remote from the overflow, and a gas exhaust pipe 66 connects the upper portion of the opposite end of the section 62 with a header 67 which communicates with the pipes 39, 36 of the 'systemthe latter of which leads to the compressor. The evaporator comprises other sections 68, 69, 70, 71 disposed in series beneath the upper section 62 and likewise interconnected by means of tubes 63. and overflow elbows 64, but the elbows of the lower overfiow connections need not have the V- notches therein and overflow only at their uppermost ends. The lowermost section 71 communicates at its liquid discharge end, with the supply pipe 38 for the float chamber 2() and the oat valve is disposed in the horizontal plane of the section 71 so as to maintain substantially the same liquid level in the chamber 20 and within the section 71. With this construction of evaporator, the successive sections 62, 68, 69, 70, 71 will contain a basin of liquid refrigerant, but the gases will be free to rise through the tubes 63 and to eventu'ally escape through the exhaust pipe 66. This system likewise avoids necessity of utilizing an accumulator.

lIn the liquid cooling system of Fig. 10 thc improved ioat actuated regulating valve is adapted to control the flow of liquid refrigerant from the pipe32 through the pipe 33 to a pipe 72 disposed centrally within the upper section of a coil 7 3. The lower end of the coil 73 communicates directly with the lower portion of an accumulator 29, and a gas discharge pipe 74 connects the upper end of the coil 73 with the upper end of the accumulator. The supply and exhaust pipes 38, 39 of the control valve communicate with the accumulator, respectively below and above the normal liquid level therein, and the accumulator has a gasdelivery pipe 36 communicating with the extreme upper portion thereof the same as in Figs. 4 and 6. Liquid may be admitted to a .receptacle 5 disposed adjacent to the coil 73, and the float cham- 1 ber` 2O of the control valve is disposed in the 72. When this system is in operation, it is desirable due to the fact that the operation is ordinarily intermittent, to maintain the liquid level low since considerable boiling action takes place after cooling stops. The liquid will eventually boil down to such an extent that the control valve will act to feed fresh liquid, and this fresh supply will run `along the coil surfaces and will evaporate.

The flash gas will dry in the portion of the coil 73 between the discharge end of the pipe 72 and the discharge pipe 74.

In the system shown in Fig. 11, it is desider to discharge the liquid refrigerant from the control valve below the liquid level in the accumulator 29 in order to prevent formation of excessive flash gas. Asv in Fig. 4, the system comprises a compressor 26, a condenser 27, a receiver 28, a float actuated control valve, a cooling coil 76, and pipes connecting the various elements of the system. The compressor 26 has a suction pipe 36 communicating with the upper end of the accumulator 29, and has a discharge pipe 37 connected to the condenser 27. The receiver 28 communicates with the control valve through a pipe 32 and the discharge pipe 33 of this valve communicates with the accumulator 29 below the normal liquid level therein. The coil 76 communicates at its lower end with the lower portion of the accumulator 29, and communicates vat its upper end with the upper gas chamber of the accumulator. The supply and exhaust pipes 38, 39 of the float chamber 20, communicate with the accumulator 29 respectively below and above the liquid level, and may be designated as equalizing lines since they function to equalize the pressures in the accumulator and ioat chambers. This system obviously differs from the others in that the control valve discharges liqquid refrigerant as required, directly to the accumulator 29 instead of to the evaporator or cooling coils. 't

From the description of these various diagrams and systems, it will be obvious that the improved float actuated control valve is adapted to be used. in conjunction with various typesof evaporators of either the Hooded or 'direct expansion type and regardless of whether or not an accumulator is employed in the system. The needle lvalve 1.8 is at all times exposed to liquid refrigerant, and the weight 25 maybe readily adjusted to produce any desired conditions of operation of the valve 18 by the float 21.

It will be apparent that in eachof the several systems illustrated, the liquid level within the float chamber 20 is established by au accumulator -29 or substitute device which receives liquid refrigerant from the charge end of an evaporator or cooling coil. The operation of the float control valve is not directly therefore affected by variations in the conditions at the inlet of the evaporator.

The improved float actuated control valve'is adapted to accurately regulate the flow of refrigerant regardless of variations in pressure in the source of supply or at the inlet of the evaporator, and this is true regardless of lwhether the evaporator inlet is located above,

below, or at the level of the liquid in the float chamber 20. The special construction of cooling coil or evaporator shown in Figs. 8 and 9, is especially adapted for cooperation with the improved float controlled regulating valve, and in this embodiment of the invention the lower section 71 of the evaporator may be utilized as an accumulator for establishing the desired liquid level within the float chamber 20. It will be apparent from the foregoing description that all of the objects set forth in the introduction to this specification are effectively attained with the use. of the improved float controlled regulating valve, and that this valve has special tom of the adjacent upper section, overflow elbows within the upward extensions of said riser pipes terminating below the tops thereof, and a float controlled valve operable by variations in the level of refrigerant in the lower of said sections for delivering refrigerant only to an upper of said sections.

2. .In combination, an evaporator compris- ,ing a series of superimposed tubular sections and riser pipes extending from the top of each lower section into and above the bottom of the adjacent upper section, overiow elbows within the upward extensions of said riser pipes terminating below the tops thereof, one of said elbows having a V-notch in the overow edge thereof, and a float controlled valve operable by variations in the level of refrigerant in the lower of said sections for delivering refrigerant to an upper of said sections.

3. In combination, an evaporator comprising super-imposed horizontal tubes and a riser pipe extending from the top of the lower tube into and above the bottom of th(l upper tube, and an overfiow elbow within the upward extension of said pipe, said elbow having an inlet at the bottom of said extension and having a V-notch constituting an overflow edge located beneath the top of said extension.

4. Iyncombination. an evaporator comprising a series of superimposed and interconnected tubular sections, a valve located below the upper of said sections for delivering refrigerant to said evaporator, and a float for controlling the o eration of said valve, said float being operable by variations in the level of refrigerant in a lower of said coils.

5. In combination, an evaporator comprising a series of superimposed and interconnected tubular sections, an accumulator receiving liquid refrigerant from a lower of said sections, a valve for delivering refrigerant directly to an upper of said sections, and a fioat for controlling the operationof said valve, said float being operable by variations in the level of refrigerant in said accumulator.

6. In combination, an upper evaporator, a lower evaporator disposed below said upper evaporator, a header interposed between the outlet of said upper evaporator and the inlet of said lower evaporator, conduit means connecting the outlet of said lower evapora- 'variations in level of the liquid refrigerant in said upper header for controlling delivery of refrigerant directly to the inlet of said upper evaporator, and means for effecting discharge of gaseous refrigerant from the upper portion of said upper header.

` In testimony whereof, I aflix my signature.

ERNST S. H. BAARS.

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