US1425267A - Refrigerating machine - Google Patents

Description

Patented Aug. 8, 1922.

3 SHEETS SHEET E A. T. MARSSHALL.

REFRIGERATING MACHKNE- APPucATwN FILED JULY xx, 1920 Patented Aug. 8, 1922,

3 SHEETS-SHEET 2.

BYV &

Ali/W NEYS A T MARSHALL REFHIGERATWG MACHINE.

APPLICAHON FILE?) mu! 31.1920.

L w I a; s H L T m NR? WWQ T m M A. T. MARSHALL.

REFBIGERATING momma.

APPLICATION FILED SULY 31,1920. 1 25,267, Patented Au". 8, 1922.

I5 of Connecticut,

to construction mmvr T. MARSHALL, or namronn. connnencur, ASSIGNOR T AUTOMATIC REFRIGERATTNG COMPANY. 01! OF NEW JERSEY.

HARTFORD, CONNECTICUT, A. CORPORATION Bnrmenmcrmo igmcnmn Specification of Letters Patent.

l'aitnted' Aug. 8, 1-922.

Application filed July 31, 1920. Serial No. 400,455.

I '0 all whom it may concern:

Be it known that I, ALBERT T. MARSHALL, a citizen of the United States, residing at Hartford, countof Hartford and State ave invented certain new and useful Improvements in Refrigerating Machines, of which the following is a ful and clear specification.

"This invention relates to refrigerating 0 machines in which a suitable fluid is caused to travel in a circuit in which it is first ex- PQSfd t0 the active cooling efi'ects of a re frigersnt such as ammonia and afterwards conveyed to a room or refrigerating coil by 15 means of which predetermined temperature conditions-are maintained.

In systems of this character, the refrigei aptis alternately compressed to the condition 0-fa fluid and expanded to the condition it) ofdtgas for extracting the heat from the former circulating Hind. As usually embodied, the interchange of heat between the 'twocirculating systems is accomplished in ndoublc pipe cooler, the ammonia, for example, being expanded toits gaseous condi' tion mun outer pipe which surroumls an inner pipe through which the brine, for ex ample. is circulated. The primary object of this invention is [0 provide an improved and arraugcun-ut of parts whereby the temperature in thc brinc-cir cnhtting system will be limited brtu'ecu prcdctermm'ed high and low tcnuwraturcs in such a way as, to prevent freezing the brine.

l2) 0H8 the objects of this ilH'cnlion is to provide improved means for i 'mlllullillg the compressor in the ammonia cirruil by the temperature of the ammonia in the expansion-coil which contains the brine pipe cooled thereby. Another obp'rt is to oper- Iitethe compressor at a higi suction pressure, whereby the capacity and cilicicnry of the compressor may be increased. and whereby the refrigerating machine may be operated; at low 610st for the refrigeration valve under the control of the temperature in thebrine circuit for controlling the admission'of the ammonia to its expansion coil. Another object is to provide improved means for controlling the operation of the 65 compressor in the ammonia circuit by stopping it only when certain minimum temperatures have been established in all of a plurality of refrigerating units or rooms and for starting said compressor when a, piedetermined maxi-mum temperature is produced in any one of said units or rooms.

Figure 1 represents diagrammatically ageneral plan view of a preferred embodimentof my invention; i 1

Figure 2 represents a side elevation and vertical section of one of the motor-operated valves hereinafter referred to;

Figure 3 is a transverse section of the upper portion of Figure 2, showing a wiring diagram to be hereinafter referred tor Figu re 4 is an enlarged side elevation of a modified form of the heat interchanging coils adapted more es eeially to the. purpose of cooling water for rinki'ng purposes:

Figure 5 is a side elevation of another embodimcnt of my invention;

Figure 6' is a side elevation of another modification of the same; j

Figure 7 is awil'ingdiagran1 for the embodiment shown ism are t;

Figure 8 is a side'e' lrlgerating machine according to Figure 4; am

Figure 9. is a'perspertive view of thelth'en eviition of a water-re mostat shown in the refrigerating chambers of Figure 1. I

R ferring first to Figure 1 of the (new iugs. a motor repent-.95 on a belt .2 to drive lhc larger pulley 3 on a jack shaft 4. The smaller pulley :"r on said, jack shaft onerates through a belt 6 to drive a fly-wheel T on a shaft H which drives a piston (not shown) in the compressor cylinder 5!. Leading from the cylinder 9 is a pipe 10 which discharges into a condenser 11 said condenser 11 discharl ing the. liquid am} monia into a reservoir 12. Leading from the reservoir 12 is a pipe 13 which connects with a valve housing 14 of a motor-opcrated valve. A pipe ['5 connects the valve housing, 1-1 to an expansion \alvc housing In. For water cooling. this expansion ralwis preferably made to UIll'lilt. under a ii\|li sllltlflll pressurisci high at about pounds. Extending from vthe last-men tioned valve is a. pipe section 17 which leadsto a thermostat chamber 18 which is connected by a short'section' 19 with the expansion coil 20 which is connected at its upper end through a low ammonia pressure cut out 21 to a return pipe 22 which leads to the compressor cylinder 9. Referring to Figure 2'of the drawings, a plunger 23 1s provided with a cross-head 24 which slides within the bore of the pipe 13. The other end of said plunger 23 carries a head 25 which is pressed upon by a spring 26 which is into sed between the head 25 and a fixed spider 27 at the inner end of pipe 13. The pressure of spring 26 tends to hold a ball valve 281:0 its seat. An eccentric 29 carried by a. spindle 30 is adapted to assume successive positions 180 degrees apart. In the position shown, said eccentric permits the bal 28 to become seated. When rotated 180 degrees, said eccentric forces the valve 28-into open position, whichpermits a flow of liquid ammonia through the valve chamber 31 and into the pipe 15. Suitable means for rotating the spindle 3O intermittently may be provided as follows:

On the upper section 32 of the housin which contains the hereinafter described mechanism, (see Figure 2), is mounted a binding st 33 to whichis connected a wire 34 (see Figure 3), leading to a field winding 35 an a brush 36 which has running contact with the armature of a'motor 37. The other brush 38 is connected by a wire 39 toa binding post 40 on the outer wall of the section 32 of said housing, a wire 41 leading from the binding post 40 to a switch contact 42 which is adapted to be moved by a thermostatic device which is subject to the temperature of the brine in the brine circuit, as indicated in Figure 1. A fixed contact 43 is connected by a wire 44 to' a binding post 45, a wire 46 within-the housing section 32, connecting the binding post with a fixed contact 47. A link 48 is con- .nected up with the motor 37 in such a manner that it is revolved at the same angular velocity as the eccentric 29. Said link 48 is thus adapted to assume the position shown in Figure 3 when the eccentric 29 assumes the position shown in Figure 2. lly the time the eccentric 29 has rotated I80 degrees to open the valve 28, the link 48 will have revolved 180 degrees. In the position shown in Figure 3, the link 48 constitutes a bridge contact arranged between the fixed contact 47 and a contact ring 4!) which is connected by a wire 50 with a binding post 51. ire 52 leads from the brush 38 to an outer fixed ring contact- 58 which is adopted to be connected up in circuit with the switch contact 42 by means of 11 fixed contact 54 whicl1 is i-onncctcd by a wire 5.? to a binding post 56 on the outer wall of section 32 of the contact 49 and the fixed contact 58. The 7 operation of this device will now be understood, assuming the parts to bei'n the position shown in Figures 2 and 3, and the switch contact 42 to be moved over onto the fixed contact 43 under certain conditions wi i be hereinafter pointed out. The circuit is completed to include binding post 33,- wire 34, winding 35, brush 36, motor 37, brush 38, wire 39, binding post 40, wire 41, switch 42, contact 43, wire 44, binding post 45, wire 46, contact 47, link 48, ring 49, wire50 and binding post 51. Motor 37 is thus energized and begins to rotate the eccentric 29 and to revolve the link 48. As the link 48 moves into contact with the outer ring 53, the switch 42 is cut out-of the circuit and the energization of the motor 37 maintained through the wire 52, ring 53, link 48, ring 49 and wire 50; As soon as the link 48 comes into contact with the fixed contact 58, the motor operating circuit is broken,.until suchtime as the switch contact 42 is moved onto fixed contact 54 when the motor energizing circuit is again established through the switch contact 42, fixed contact 54, wire 55, binding. 58, link 48, inner ring 49 and wire 50, the eccentric 29 being in consequence returned to the position shown in Figure 2, As shown in Figure 1, the switch contact 42 is pivotall connected iy a link 60 with a pressure tube (ll. which is connected by a tube 62 to a thermostatic bulb 63, which is exposed within a fitting (34 to the temperature of the brine in the Said brine circuluting system comprises in the preferred embodiment shown on the drawings, an inner coil within'the ammonia post 56, wire 57, fixed contact I mounted.on a pin 59 which is brine-circulating system. 7

coil 20, the lower end of said innercoiLbe' ing connected by a pipe 65 to the fitting 64. A pipe 66 conmwts the fitting 64 to a britie-circulating pump 67 from which leads a pipe 68 provided with a. pressure tube (l9 which is adapted to control the operation of the compressor, in the manner to be hereinafter pointed out. Thepipe 68 connects to the lower end of a refrigerating coil 70, the other end of said coil being connected by a down-comer 71 leading to a common return pipe 72. Branching from the pipe 68 is a line pipe 73 which is connected at different points to the lower ends of other refrigerating coils 74 and 75. As illustrated in Figure 1, the refrigerating coils 70, 74 and 75 may be operated to maintain differ-cut temperature conditions. For example. in some cases there may be a room in which it is not desirable to let the temperature go below a certain point, such as one for storing eggs. In other cases, it may be important not to let a freezer go above a certain temperature and it is obvious that a similar arrangement may be used for this purpose.

In order to provide suitable and eflicient means for controlling: the operation of the ammonia compressor by means of the temperature 'of the low pressure ammonia, thermostatic bulb 76 is preferably mounted with in the fitting 18 adjacent the inlet end of the ammonia expansion coil 20. from the bulb 76 is a tube 77 which is connected to one end of a pressure tube 78. The bulb 76, tube 77, and pressure tube 78 being filled with suitable expansion fluid such as mercury, the outer end of the pressure tube 78 is moved to and fro b the temperature changes in the bulb 76. I link 79 connects the outer end of pressure tube 78 to a switch so which is pivoted at 81 and carries switch blades 82 and $43 for covering contacts 84 and R5 respedtirely. Referring now to Figure 7 the controlling circuits for the binbodiment shown in Figure 1 will be understood A main switch provided with a handle 86 is adapted to connect a positive main 87 to a wire 88. Said wire 88 is provided with a branch having a plurality of gaps or breaks which may be bridged or closed by switches 89, 90 and 91 under the control of overload or high pressure cut-off or similar control devices. Leading from the switch 91, is a wire92 which is connected to a fixed contact 93 which is covered by a contact 94 carried by pressure tube 69 when the pressure in the brine or water circuit is raised sufficiently. A wire 95 extends from the movable contact 94 toa'resistance coil 96. A solenoid- 97 is connected at one end to the coil 96, it's other,end being connected by a wire 98 to a fixed, contact which may be covered by a movable contact 100 forxbridging the gap between the contact 99 and a contact 101 which is connected to a wire 102 which leads to the negative main 1011. The main motor operating circuit o mpriscs the positive main 87, wire H8 leading to u lixed contact 104 which is adapted to be overed by a movable contact 105 for bridging: the gap between the contact 104 and a contact 106, a Wire 107, motor terminal his. motor 1, motor terminal 109, wire 110, wire 1112. and negative main 103. The bridge contacts 100 and 105 are connected by an insulating stem 111 and moved togeth er by a solenoid plunger 112 within the solenoid 517. Leading from the wire 98 is a wire 1121 having a branch 114 for connecting; it with the swit h blaii co..tact 11:: of the low ammonia pressure cut out 21, said blade I17, being oscillated by a variation of a|nmonia pressure in the return pipe 22. When- Extending ever the pressure in pipe 22 rises sulliciently, switch blade 115 is moved downwardly onto a contact-116 which is connected b a wire 117 to the contact 82 on the switch lock 80. Leading from the fixed contact 84, is a wire 118 which is connected to the movable thermostat blade contact 119 which under certain conditions to be hereinafter pointed out, is adapted to cover a fixed contact 120. Said contact 120 is connected by a wire 121 toa second movable thermostatic contact 122 which is adapted to cover a fixed contact 123 from which extends a wire 124 to a third movable thermostatic contact 125. Arranged to be covered by the contact 125. is a fixed contact 126 to which is connected the wire 102 which leads to the negative main 103. A resistance coil 127 which is of lower resistance than the solenoid 97 has one end conriected to the wire which extends between the coils 96 and 97. The other end of coil 127 is connected by a wire 128 to a connecting wire 12!) which serves to connect the fixed contact 85 with each of a series of fixed thermostatic contacts mo. 1210, 1210. Each of the fixed contacts is arranged to be covered by a movable thermostatic contact 131, all of said movable contacts 13L I31, 131, being connected by a common wire 132. A wire 17-33 extends from the contact blade 83 on switch block 80, the. above referred-to wire 113 being connected to the wire 133. As actually constructed, each .of the movable thermostatic contacts 131 is, mounted on a strip 134 of suitable insulating material such as gutta percha and each of the movable contacts 119, 122, 125 is mounted on thesame strip 134 as shown in Figure 9. A wire 13:) connects the positive. feed wire 107 to the blndina post 31-1 of the motor valve described above. A wire 136 connects the other binding post 51 of said motor valve to the negative feed wire 110 of motor 1. Three modi fied adaptations of the principles of my invention are shown in Figures 4, 5 and 6. In the embodiment shown in Figure 4, a. pipe 137 is provided with a low pressure cut-out 138 which is adapted to interrupt thecompressor in the ammonia system. whenever the pressure of the water or brine circuit falls below a. predetermined minimum. Pipe 137 conveys the fluid to be cooled within the inner coil 139 which tcrminatt-s in a fitting 140. \Vithin the fitting Hll is a thermostatic bulb containing mercury or other expausible fluid, said fluid also lilhn; a tube 141 which projects outwardly from the fitting 14" and is provided at its outer extremity with a thermostatic switch 142 which is provided with suitablc contacts which may be adjustcd to break the energizing circuit for the Motor which drives the ammonia comprcs sor, whcncvcr the temperature of the water or brine iu the fitting 140 reaches a predetermined miuimum. A pipe 143 leading From whic the fitting 140, conveys the cooling fluid to any desired points from which the fluid returns through the pipe 137 to the coil 139.

The high pressure ammonia which is conveyed by-a pipe 114 is permitted to expand through a valve 145, said valve being preferably-a fixed suction pressure expansion valve set at high premure for water. cooling, say

fifty pounds. From the expansion valve 145, the low pressure fluid is conveyed by a pipe 146 to a fitting 147 which contains a bulb 148 (shown in dotted lines). Said bulb and a tube 149 connected thereto, are filledw1th heat expansible flu-id which transmits a variable pressure to the thermostatic switch 150 of substantially similar construction to that shown at 142. It will be understood that as soon as the temperature in the fitting 147 reaches a predetermined minimum, the thermostatic switch 150 willinterru'pt the ener izing circuit which drives the motor by i the ammonia "compressor is driver On the-other hand, when the compressor is at rest, and the low pressure ammonia entering the fitting 147 is of'a temperaturehigher than a predetermined maximum, the thermostatic switch 150 will re-establish the motor energizin circuit as far as it is controlled by the evice. The fitting 147 has piping connection with the outer coil 151 through which the inner coil 139 extends. A return ammonia pipe 152 leads from the outer coil 151 as shown in Figure 8 which illustrates this embodiment of m invention in an ada tation to a water-coo inlg system for provi ing drinking water. ipe 152 conveys the ex ended ammonia to the compressor cylini er 153 which discharges through a pipe 154 into a condenser 15!) from which the condensed fluid passes to arecciver 156, the high pressure ammonia bein drawn from the receiver 156 through the pipe 144 which conveys it back to the outer coil 151. In the embodiment of my invem tion shown in Figure 5, the pipe 157 prr vided with a low water pressure cut-out 158 is connected to an inner coil 159, the other cnd of said coil being connected to a fitting Hill which contains a thermostatic bulb (not shown), which, by means of a tube 161 is adaptml to operate the thermostatic switch 162 which starts and stops the ammonia compressor as the temperature of thebrine in the fitting 16tl rises-to'a predetermined maximum or falls to a redetermined minimum. A pipe 163 leading from the fitting 16o, conveys the cooling fluid to the spaces to he refrigerated from whence they are returned to the coil 159 through the pipe 157. In this embodiment of my invention, the high pressure ammonia which is conveyed through a pipe 164, is cxpandcd through a rulvc [65 preferably under a fixed suction prcssurc (lifty pounds for water cooling) at which prcssure the ammonia is admitted to an outer coil 166. A return ammonia pipe 167 is provided with a low ammonia pressure cut-out 168 which is similar in construction to that shown at 21 in Figure 1. The last mentioned valve is adapted to interrupt the ammonia compressor when the pressure in the pipe 167 reaches a redetermined minimum. In the embodiment of my invention shown in Figure 6, the return pipe 169 of a weak brine or water circuit is provided with a low pressure device 170 which iriterrupts the operation of the ammonia compressor. Pipe 169 c'onnects with one end of aninner coil 171, theother end of said coil being connected'to a fitting 172 which contains a. thermostatic bulb (not shown)-havin a tube 173 leading to a thermostatic switc 174 for controlling the 0 ening and closing of a motor valve 175 w ich is similar in co'nstructionand operation to that shown at 14 in Figure 1. A high pressure ammonia pipe 176 leads to the motor .yalve 175 which is in turn connected to an expansion valve 177 (preferably a fixed suction pressure valve which for water cooling is set at high pressure,-say about 50 pounds). A fitting 178 which is connected to the ex ansion valve 177 contains a tller mostatic ulb 179 provided with a tube 180 which connects to a thermostatic switch 181, for interrupting the operation of the ammonia compressor at a predetermined minimum temperature and starting said compre'ssure at a predetermined maximum temperature in the fitting 178. said fitting being connected to an outer coil 182. A return pipe 183 leading from the upper end of the outer coil 182 15 provided with a low ammonia pressure cut-out 184 for interrupting the operation of the ammonia compressor when the pressure in the tube 183 reaches a predetermined minimum and for starting said'comprcssor when the pressure in'the tube 183 reaches a redetermined maximum. The operation of tlie refrigerating machine in the embodiment shown in Figures 1 and 7 is as follows: 7 Whenjhecirculating pump for the water or weak brinecircuit is workin properly, the pressure in the pipe 68 for t 1e water or weak brine will be sullicient to cause the pressure device 69 to move the contact 94 into engagement with the fixed contact 93. The hand switch 86 having been closed and the switches 89, 90 and 91 being closed 199 under normal conditions. let it be understood that the ressure in the return ammonla pipe 22 is above the predetermined maximum which will cause the sv. itch blade 115 to cover the fixed contact 116, At the 125 same time, the temperature in fitting 18 is sufficiently high to have cause the pressure device 78 to throw the 0 at? 8:5 onto the contact H4. Undcr these conditions, the following circuit will be eomplcted, namely, 139

the lixcil contact 185.

. curred.

18 fall to a predctermlncd minimum, prcs- -main 87, .wire 88, bra'nch wire 92., contacts 93, 94, wire 95, resistance 96, solenoid 97, wire 98, wire 113, wire 114, switch blade 115, contact 116, wire 117, contacts 82, 84, wire 118, thermostat blade 119 which covers contact 120 when the refrigerated space amund the coil has a temperature greater than the predetermined maximum. Wire 121, thermostat 122, 123, wire 124, thermostat 1'25, 126, wire 102, and negative main 103. Solenoid 97 being energized, the plunger 112 is drawn upwardly until the bridge contact bridges the gap between the fixed contacts 99 and 101. This action provides a short circuit from the solenoid 97 by way of contacts 99, 100, 101 and return wire 102, thus cutting out the low ammonia pressure cut-out and the other controlling devices enumerated above. As the contact bridges the gap between the fixed contacts 104 and 106. the motor operating circuit is completed and comprises positive main 87, wire 88, contacts 104, 105, 106, wire 107., terminals 108, 109, wire and return wire 102. The motor 1 being set in operation, the refrigerating action proceeds until such time as one of the thermostatic contacts 131 is caused to cover its corresponding fixed contact 130, this condition being caused by the temperature surrounding one of the refrigerating coils 75 74 or T5. reaching a predetermined minimum. It being remembered that the resistance 127 is of lower resistance than the solenoid 9?, the solenoid 97. is short-circuited as follows:

Wires $8, 92, contacts 93, 94, wire 95, re sistance 96, resistance 127, wire 128, w-ire 129, contacts 130, 131, wire 132, wire 133, wire 113, contacts 99, 100, 101 and return wire 102. a Solenoid 97 being denergizeth plunger 112 drops and contact 105 breaks the motor operating circuit. On the other hand, should the predetermined temperature referred to in com ecti'on with coils 73, 74 and 75, not have been produced, it may happen that the low pressure ammonia in pipe 22 has reached a predetermined minimum and caused the contact switch blade to cover This condition shortcircuits solenoid 97 through resistance 12?, wire 128, contacts 185, 1.15, wire 114, con tarts 99. 100, 101 and return wire 102. The

operutiim of the compressor may thus be in"- terruptcd. Furthernmrc. let it be supposed that neither of these interruptions has 0c- Should the temperature in fitting surc device '78 is caused to operate tothrow the switch blocl; 80 on its pivot 81 in such manner as to move the contact 82 from the contact 81 while at the same time moving the contact 83 onto the contact 85. Solenoid 9? thus short-circuited through resistance 12?;wi1 128. contacts, 83, wire 113. con- E5 tarts P9. 100. 101 and return wire 102. The

motor circuit is thus interrupted. In those embodiments of my invention iuwhich a motor valve 14 is arranged in the high pres sure ammonia pipe 15, as shown in Figure 1. said motor valve is opened or closed according to the temperature of the water or weak brine passed through the fitting 64. Thus, by means of the circuits described above in connection with Figures 1, 2 and 3, the energizing circuit for Operating the motor 37 is completed when the contact 42 is made to cover the contacts 43. On the other hand, when the contact 42 is made to cover the fixed contact 54, the motor is again operated to close the valve 28. As described above, the valve operating eccentric 29 remains in the position to which it has been moved .until'the opposite temperature conditions are established. The operation of the water cooling system shown in Figure 8 will be obvious from the above description.

What I claim is 1. Automatic refrigerating apparatus comprising in combination a mechanically operated refrigerant system, a system for circulating fluid to be refrigerated by said pressure in the return pipe of said refrigerant circuit for starting and stopping said compressor when said thermostatic means is in starting position.

3. In a refrigerating apparatus, a refrigerant circuit including a compressor and a thermostat, a circuit for fluid to be refrigerated/by said refrigerant circuit and ineluding a device responsive to pressure, means for circulating said fluid, and means under the conjoint control of said thermostat and said pressure responsive device for starting and stopping said compressor.

4. In a refrigerating apparatus, a refrigerating coil, an expansion valve, connections arranged between said coil and valve, said connections including a thermostat chamber, a compressor connected up with said coil and valve, a motor for driving said coinpressor, lil energizing circuit for saidmotor provided with a switch, and a thermostat in. said thermostat chamber for controlling said switch. a

5. In an automatic refrigerating apparatus, a refrigerant circuit including a refrigerating coil, an expansion valve connected to said refrigerating coil, a thermostat arranged within the refrigerant circuit 7 between said expansion valve and said re- 6 frigeratin coil, a compressor, means under tbecontro of said thermostat for stopping and starting said compressor, pressure-operated means in the return pipe of said refrigerant circut for starting and stopping said 10 compressor, and a circuit for fluid to be refrigerated including a pressure responsive device for starting and stopping said compressor.

.6. In an automatic refrigerating ratus, a refrigerant circuit including a motor-operated shut-off valve, a refrigerating scoil an expansion valve connected thereto,

a thermostat arranged within the refrigerant circuit between said expansion valve and refri crating coil, a compressogi, means under t e control of said thermostat for starting and stopping said compressor, pressureoperated means in the return: pipe of said refrigerant circuit for starting and stopping said compressor, a circuit for fluid to; be refrigerated including a pressure responsive device for starting and stopping said comappafluid to be refrigerated for controlling the operation of said compressor.

8. An automatic refrigerating apparatus comprising a refrigerant circuit, a compressor in said refrigerant circuit, a circuit for fluid to be refrigerated, means for circulating said fluid, a motor for driving said compressor, an energizing circuit for said motor provided with a switch, a coil for operating said switch, an energizing circuit for said coil including a switch, and means responsive to the pressure in said circuit for fluid to be refrigerated for operating said lastnamed switch;

ALBERT T. MARSHALL.

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