US2044482A - Refrigeration apparatus - Google Patents

Description

jmm as, 1936. G. MUFFLY ammgz REFRIGERAT ION APPARATUS Filed Nov. 5, 1932 3 Sheets-Sheet 1 VII/IA m .k

INVENTOR (77am Hafiz? Jud BY ATTORN EYS June 16, 1936. G. 'MUFFLY 2,044,482

REFRIGERAT ION APPARATUS Filed Nov. '5, 1932 5 Sheets-Sheet 2 ATTORNEYS June 16, W36.

G. MUFFLY REFRIGERATION APPARATUS J2 INVENTOR g ylaw? Maj ig 4 D fl/M ATTORNEYS Patented June, 16, 1936' UNITED. STATES PATENT, OFFIXCE 2,044,482 anrnrcraa'rron mmros Glenn Muflly, Scarsdale, N. Y.

Application November 5, 1932, Serial No. 641,352 I 30 Claims. (!.62-4) This earlier invention of mine was designed to cause a refrigeration system to operate for one long running period each twenty-four hours, storing' up refrigeration in the form of ice to last over the remaining major portion of the twenty-four hours.

The present invention is designed to accomplish certain additional desirable results such as provision for continuation of refrigeration at a somewhat higher temperature range in the event of the stoppage of the clock; to provide a definite stopping time just ahead of the desiredfoff period so as to more surely escape the peak-load period of the central station; to provide a single 5 adjusting means for the thermostatic control so arranged that the entire range of adjustment is available for manual setting without interior adjustments; and to provide for thermostatic cyclic operation at all times intermediate of the time 0 controlled operation.

In addition, the present invention provides correlated means for insuring the starting of the system prior to the termination of a clock-controlled oif period in the event of an unusual tem- 5 perature rise that requires such earlier starting to insure against the spoilage of materials in storage. It further provides for manual starting of a running period when required to obtain quick freezing without disturbing the adjustment of the 40 control means, thus insuring that after the freezing is finished, the system wm automatically return to its normal cyclic operation without the necessity for re-setting the control.

utilize the greater latent heat absorbing qualities of a frozen eutectic solution in cooperation with the off-peak system and thus. maintain a more uniform low temperature during the clock-controlled oif periods.

with these and other objects in view I shall describe my invention with reference to the accompanying drawings, in which:

Figure 1 is a "plan view of a refrigerator 55 equipped with an electric driven compression type A still further object of this invention is to,

refrigerating system embodying my new control method; .7

Fig. 2 is a side elevation of the same cabinet and system shown partially in section;

Fig. 3 is a sectional view of Fig. 2 on the line 5 3-3, showing a rear view of the control apparatus with the combined thermal, time and manual actuating means; I

Fig. 4 is a front elevation of the upper portion of the cabinet; j 10 Fig. 5 is an enlarged detail view of the adjusting mechanism for the control, partially in section, on line 5-5 of Fig. 1;

Fig. 6 is an enlarged detail view of the control mechanism, partially in section, as seen from the i5 rear;

Fig. '7 is an enlarged detail, sectional view of the adjusting mechanism on the line '|'l of Fig. 5,

Fig. 9 is a graphic representation of operating cycles typical of the operation of a system as illustrated by previous views.

Referring to Fig. 1, the high pressure side of. the refrigerating system is seen mounted in a cabinet above the cold storage space. This portion of the system includes the motor-compressor unit I, the condenser 2, and associated con-' trolmeans mounted on top of the unit base}, which is removably installed in the cabinet 4, as later described herein.

The refrigerant vapor, such as methyl chloride, is compressed by the unit I and passes into the condenser 2 where it is liquefied, and i then passes in liquid form through the pressure reducing device shown in Figure 2 as the capillary tube 5. The liquid refrigerant then passes into the expansion coil 6 within the brine tank I, where it vaporizes under the effect of heat picked up from the eutectic brine solution 8 contained in the tank I. There are many eutectic solutions suitv able for this use, one being a 23% solutionof barium chloride in water.

The refrigerant vapor then returns through the suction tube 9 to the intake of the compressor of unit' I. I

The operation of the motor-compressor unit i is controlled by the switch 20 which makes and breaks the circuit supplying electric currentto it. 0

The switch 20'may be amercury bulb,'as shown,- or any suitable type of switch. As shown in Fig. '3, the switch'2il is in the closed position with a mercury 2| contacting both of the terminals 22 and 23.

aoeasea A study of the foregoing description reveals considerable period. This period is normally long enough to bridge over the peak-load period of any power plant supplying a residential district. The cam 40 is provided with one or more notches t2, 82a, etc., as required for a given'loc'ation' on a power line.

The regular clock actuated stopping of the system at one or more pre-selected times each day, provides a very desirable type of load from the power company's standpoint, yet the user is privileged, when occasion arises, to cause the system to operate during any normally of! period.-

In my Patent No. 1,787,209 covering oil-peak types of refrigerating systems, I have provided for a clock-driven switch to insure the starting of a. refrigerating system at definite times, but

- in this application I have added several improvecally. For temperatures applicable to refrigera-.

ments, among which is the means for insuring the automatic starting of the system during an ofl period of the clock mechanism whenever this I automatic starting is made desirable by an unusual thermal condition. g

A graphic representation of cycles of operating resulting from the use of the apparatus herein described will be seen in Fig. 9, where time is plotted horizontally and temperatures vertition the scale at the left will serve toidentify the temperatures represented by the horizontal lines while the time in hours of the day is marked at three hour intervals with a vertical line for each hour.

The curve made by solid line 65 shows ternperature in that part of the system containing the freezing solution, or in other words the temperatures affecting the thermostatic control. Theheavy horizontal line 66 is broken during two periods of time to represent the periods during which spring. is in one of the notches t2 'and 62a. The heavy horizontal line 61 is broken to represent periods of time during which the switch 20 isactually open and the system idle. It will be noted that in general the line 65 is failing while the system is operating and is rising while the system is idle, but there are important exceptions to this rule which result. from the previously described features in tion of this type of system.

starting at midnight at the 'left end of the chart we can follow the-solid line 65 which stays on the 18 degree line for three hours and then breaks away gradually at three A. M. and then falls quite rapidly to the 11 degree line, which it reaches at six A. M. This indicates that the temperature is at first constant while the system is in operation as indicated by line 61. The refrigerating efiectis being absorbed in the main by the freezing solution which is now being frozen. This line would be falling more or less rapidly if thematerial being frozenwere other than a eutectic, but apeculiarity of eutectics-is that they freeze and melt at substantially constant temperatures, a particular temperature or the construcnarrow range of temperatures for each eutectic solution. In this case we are assuming the use of a eutectic solution such as the one mentioned earlier herein, which has a freezing and melting temperature (eutectic point) of 18 degrees F.

The pull-down of temperature after three A. M. is the result of refrigeration being continued after the eutectic freezing solution had finished freezing at three A. M. This drop of temperature affects the control bulb 30 (Fig. 2) and through it the switch 20, which opens at six A. M., as indicated by the break in the line 61 and by the fact that line 65 has stopped falling and starts up again.

This graph assumes that the standard temperature setting of the thermostat seen in Fig. 8

is to cut out at 11 degrees F. and in at 16 degrees F. -We, therefore, see that the switch 20 was opened thermostatically at 11 degrees, which temperature is shown as having been reached at six A. M. The temperature of the freezing solution 8 and tank 8, being without artificial refrigeration, rises along the curve 65 until about 6:45 A. M., at whichtime the cut-in" temperature of 16 degrees is attained and the switch recloses; 1

The running period thus initiated starts pulling the temperature down again, but this pulldown is arrested at seven A. M. when the spring 3.5 snaps into the notch 62 (the smaller notch on cam dB). The temperature now rises above the 16 degree line where the system; was restarted for its last previous run, because ,the setting of the thermostat has been modified by the change in deflection of spring 35. This change is here assumed to be such that the switch will close at approximately 20 degrees and open at 15 degrees} The rise of temperature is, however, arrested by the eryohydrate (frozen eutectic solution) atrthe eutectic temperature of 18 degrees and the temperature will remain nearly constant at about this point for several hours if nothing interferes.

At about 9:25 A. M. the cam til will have moved the cut-in temperature of the control down to the 18 degree line and the switch will be closed, restarting thesystem as indicated by the line 611-.-

The temperature indicated by line 65 does not begin to fall at once, asv some of the eutectic solution has been melted and this must be refrozen before the temperature will drop appreciably. It does start to drop at about ten A. M., after the cam has restored the original adjustment of the thermostat, and hence it falls all of the way to the 11 degree line before cutting out thermostatically at about 11:15 A. M.

The cycles indicated by lines 65 and 61 between this time and 5 P. M. are normal thermostatic .cycles such as are'common-to many types of the 15 degree line (cut-out temperature of the modified setting ofthe thermostat) the thermostatic switch 20 opens at once and the system stops. The temperature rises to the 18 degree eutectic point and stays substantially constant for several hours while themachine is idle,/r starting shortly after ten P. M.; slightly ahead of the full restoration to normal setting as it, 7'

did at 9:25 in the morning. As the machine has been idle for several hours it will now take several hours tocatch up eutectic solution, which itwlll do by about three,

cycles shown by line nd refreeze all ofthe A. M. as shown at the beginning of the chart.

In the event that a severe load were placed in the refrigerator between five and ten P. M. in the form of an extra amount of warm food, the requirement to freeze a dessert, leaving the door open, or a severe rise of room temperature, the eutectic solution fore the cam restores the normal adjustment. In such an event the temperature will rise above the 18 degree eutectic point on a curve such as that indicated by the heavy dottedline 68. This rise will cause the thermostat to reclose at 20 degrees or slightly lower, depending upon how far the cam has moved in restoring the standard setting of the control.

In case the clock ll accidentally stops immediately-after the spring 35 has snapped into one of the notches the system will stand idle until all or practically all of the eutectic solution has melted and the temperature rises to 20 degrees, at which point the control will cut in and restart the system regardless of the idle clock. In this case and with no abnormal load on the refrigerator the upward curve 68 will start later than shown, but in time to save the materials stored in the refrigerator from spoilage.

In theevent 'of a stopped clock with the spring 35 resti at the bottom of one of the notches incim 6 the machine will run in long cycles,

stopping indicated by heavy dotted line 69, warming up to the eutectic line and following it for several idle hours, then warming up onickly to'. 20 degrass "as shown by line 68, and then-restarting to pulldown quickly to 20* degrees for a long freezing period of the eutectic and another short pull-down to the 15 degree cut-out temperature.

Theemergency cycles just described are similar experienced with a system to those ordinarily employing a simple thermostatic control and a eutectic freezing solution for holdover. The 65 from eleven A. M. to flve P. M. aresimilar to perienced with a system employing ing-brine for hold-over.

This system'has two types of cycles, the compound cycle shown for twenty-four hours by line 65 and the emergency simple long cycle indicated by the dotted lines 68 and 69 as above described. This system of latent heat hold-over and automatic control may be described with reference to heating instead of to refrigeration by reference to the scale of temperatures shown at the right of Fig. 9 and taking the upwardly inclined portions of the curve 65 as the operating periods. The melting temperature of the material used for heat storage will in this case be about '120 degrees instead of 18 degrees and thereserve will be latent heat of the liquid instead of the latent heat absorbing capacity of the solid freezing solution.

a non-freez- .While the invention has been illustrated in.

a heat exchange system for the withdrawal of be obvious that the principles apply equally to the addition or heat in a heat exchange'system.

Whereas one or more embodiments of the invention have been described for the purpose of illustration, it should be understood that many tions may be made by those skilled in the art without departing from the spirit of the invention.

might be. fully melted b at 15 degrees after a short pull-down as those ordinarily ex- 'and time-controlled means acting periodically 1. In a refrigerating system; an evaporator having associated therewith a quantity of eutectic solution, thermostatic means controlling ;the

starting and stopping of said system at maximum and minimum temperatures above and belowthe freezing point of said solution, time controlled means for stopping said system, and means acting under the combined influence of said thermostatic means and said time controlled means for restarting said system at the end of the idle period initiated by said time controlled means; I

2. In a refrigerating system, temperature-responsive means for starting ,the operation of said system when a predetermined maximum temperature is reached, and time-controlled means for periodically effecting a substantial change upward of said maximum temperature as controlled by said temperature responsive means and for automatically restoring the original maximum 20 temperature setting sive means after the lapse of time.

3. In a refrigerating system, temperature-responsive means for starting the operation of said system when a predetermined maximum temperature is reached, and time-controlled means for periodically effecting a substantial change upward of the maximum temperature at which of said temperature-respona fixed. period or said temperature responsive means will start -said 30 operation'and for gradually restoring the original maximum temperaturesetting of said temperatureresponsive means during the lapse of a fixed period of time.

4. In a refrigerating system, thermostatic means for controlling the starting and stopping of said system at definite maximum and minimum temperatures, and time-controlled .means acting periodically over predetermined lengths of time to vary the temperatures of said system at which cyclic operations of said system are controlled by said thermostatic means.

5. In a refrigerating system, a condensing'unit, an evaporator having associated therewith a quantity of freezing. solution having its eutectic point within the operating range of temperatures of saidsystem, thermostatic means for controlling the startng and stopping of said system at definite maximum and minimum temperatures,

over predetermined lengths of time to modify the maximum and minimum temperatures at which the thermostatic cyclic operation of said system is controlled. I

- 6. A refrigerating system comprising a condensing unit, an evaporating unit, and a thermostatic controlfor starting and stopping the operation of said system, said evaporating unit having 'associatedtherewith a quantity of eutectic freezing solution so arranged with respect to the evenorating unit that the freezing of said solution will occur progressively from the bottom upward, said thermostatic control being arranged to stop the operation of said system in response to a drop of temperature near the top of said eutectic freezing solution, time-controlled means for stopping said system, and means acting under the combined influence of said thermostatic means and said time-controlled means for re-starting said system at the end of the said time-controlled means.

7. In a refrigerating system, a condensing unit, an evaporator having associated therewith a quantity of freezing solution having its eutectic point wtihin the operating range of temperatures falling respectively 5 idle period initiated by To v 2,044,482 of said evaporator and temperature-responsive l 8. A refrigerating system, temperature-responsive means for starting the operation of said sys-- tezn when a predetermined maximum tempera ture is reached and for stopping said system when a predetermined minimum temperature is '15 reached, and time-controlled means for periodically acting upon said temperature responsive means to efiect a substantial change upward of said maximum and minimum temperatures controlled thereby and for restoring the original temperatures ofoperation of said temperature responsive means after the lapse of 'a fixed'period of time.

9. In a refrigerating system, a condensing unit, an evaporator having associated therewith a 2 quantity-of freezing solution having its eutectic point Within the operating range of temperatures of said evaporator', temperature-responsive means for starting the operation of said system when a predetermined maximum temperature is reached and for stopping said system when a predetermined minimum temperature .is reached, and time-controlled means for periodically acting upon said temperature responsive means to effect a substantial change upward of said maximum and minimum temperatures controlled thereby and for establishing normal temperatures of operation of said temperature-responsive means after the lapse of a fixed period of time.

10. In a refrigerating system operated from a source of electrical energy, latent heat storage means comprising material which has a'melting range substantially below that of water and arranged to cause said system to start and stop within temperature l? .iits such that a substantial portion of said heat storage material will remain frozen, and other control means arranged to periodically cause said systemto remain idle while a greater portion of said heat storage material than is normally melted during the thermostatically controlled cycles melts.

11. In a refrigerating system, latent heat storage means comprising material having a melting range substantially below that of water and arranged to be refrigerated bysaid system, control means arranged to cause said system to start and stop within'temperature limitssuch that a substantial portionof said heat storage material will remain frozen'during suchcycling of said system, and secondary control means arranged to period-- ically effect a change in the cycling of said system and cause it 'to remain idle while a greater- L-than-normal portion of said heat storage material melts.

12. In a refrigerating system, in combination, an evaporator, a compressor, a motor fordrivingsaid compressor, thermostatic means responsive to variations of temperature in said system for controlling the starting and stopping of said motor, and means operable at predetermined in mum and temperatures in said system at which said motor is started and stopped as induced by said evaporator and as otherwise controlled by said thermostatic means.

T 13. In a refrigerating system, in combination,

tion of the first mentioned means when said pretervals of time for alternately varying the maxi 5- an evaporator, a compressor, a' motor for driving said compressor, means operable at predetermined time intervals to alternately stopand start said motor for the purpose of normally maintaining the temperature of said system as induced 5 by said evaporator between predetermined maxi- ;muin and minimum values, and means responsive to temperature variations in said system for starting said motor regardless of the operative posi- --d etermined maximum value is materially exceeded and for stopping saidmotor regardless of the operative position of said first mentioned means when said predetermined minimum value is materially lowered. 5

14. In a refrigerating system, a condensing unit, an evaporator having associated therewith a quantity of freezing'solution having its eutectic point within the operating range of temperatures of said evaporator, time controlled means for go automatically starting-and stopping the operation of said system, and means responsive to operative conditions of said system for stopping and starting operation of said system independently of said time controlled means between the time 25 controlled idle periods and withintemperature limits below a temperature at which a major portion of said freezing solution will have melted.

15. In a refrigerating system, a condensing unit, a cooling unit, a quantity of fre'ezablematerial contained in said cooling unit, thermostatic control means designed to stop said condensing unitwhen a large percentage of said freezable material is frozen and to restart said condensing unit in response to a relatively small rise of temperature, time control-led means for causing said condensing unit to stop at a predetermined time and to remain idle until a greater temperature rise has taken place, such greater temperature rise being sufilcient to melt a greater portion of said freezable material than is melted during the above mentioned relatively small rise of temperature, aridmeans for automatically starting said condensing after the same has been stopped by said time controlled means.

16, In a. refrigerating system, a condensing unit, a cooling a quantity of material having its freezing temperature range below 32 degrees F. permanently contained in said cooling unit, thermostatic control means designed to stop 50 said condensing unit when substantially all of said freezable material is frozen and to restart said condensing unit in response to a relatively. small rise of temperature, and time controlled means for causing said condensing unit to stop at a predetermined time and to remain idle until automatically started when a greater temperature rise has occurred, such greater temperature rise beingsufiicient to allow a substantial portion of said freezable material to melt but. not so great 60 as to allow said material to warm up to a temperature higher than ten degrees F. above' its melting temperature.

- 17. In a refrigerating system, a condensing unit, a cooling unit, a quantity of material hav-- 65 ing'its freezing temperature below 32 degrees F.

contained in said cooling unit, thermostatic con- 1 'trol means-designed to stop said condensing unit when the said material is substantially all frozen" been running and. to preventit from starting i 7 ture rise than normal has taken place, suchgreater-temperature rise being suflicie'nt to melt a greater portion of said material than is melted during such an idle period as first described and being terminated by the combined action of said thermostatic means and said time controlled means. 18. In a refrigerating system, a condensing unit, a thermostat, and time controlled means for causing the condensing unit to remain idle from a predetermined time until it is started by said thermostat,.the thermostat being capable of starting said unit in response to a maximum temperature rise in the event of failure of said time controlled means and of starting said unit at progressively lesser temperature rises as said time controlled means restores the original starting temperature adjustment of said thermostat. 19. In a refrigeratingsystem, an evaporator, a condensing unit, a thermostat, a container of freezing material associated with said evaporator in a manner tobe frozen thereby in a temperature range below 32 degrees F., and time con-.

trolled means interconnected with said thermostat for causing said system to remain idle 'during a period of time starting at a substantially definite predetermined time in the twenty-four hours of a day and ending when the said period of time has elapsed, the interconnection between said time controlled means and said thermostat being so constructed and arranged that in the event of a failure of said time controlled means 35 or in the event of an abnormal rise of temperature during said period of time said thermostat will start the system at a temperature which is reached after substantially all of sai'dfreezing material has melted, said temperature being 40 higher than theusual starting temperature at which said thermostat will normally start the system and said usual starting temperature being such that the start occurs when a substantial portion of said freezing material is still frozen.

20. In a refrigerating system, a condensing unit, an evaporator having associated therewith a quantity of material having its freezing temperature within the operating range of said evaporator and lower than 32 degrees F., :thermostatic means for starting and stopping saidsystem, and time controlled means for modifying the cycles produced by said thermostatic means so constructed and arranged that during acertain period of time the thermostatic means will be caused to operate within temperature limits that maintain said freezing material in a substantially frozen condition and during another period of time said thermostatic means will operate to allow said system to remain idle until a large part of said freezing material has melted. 21. In a refrigerating system, an evaporator,

a condensing unit, automatic control'means for starting and stopping said condensing unit, a

5 quantity of material having a freezing range below 32 degrees F. associated with said evaporator in such manner that it will I be substantially frozen at the lowest stopping point of said automatic control means, said control means com- 0 prising temperature responsive means and time controlled means for modifying the temperature range of the temperature responsive means, said control means being so constructed and.- arranged that during certain periods of time the 75 system will operate on thermostatic cycles that keep a substantial portion of said freezing materialfrozen and at other times the system will not be started until a considerable portion of said freezing material has melted.

' 22. In a refrigerating system, a condensing 5 unit, an evaporator, a quantity of material associated with said evaporator and capable of be ing frozen'by the operation of said system within a range of freezing temperatures below 32 degrees F., thermostatic means for starting said 10 system at a, maximum temperature attained when substantially all of said material is melted and stopping said system at a lower temperature, and time controlled means cooperating with said thermostatic means for modifying the action 15 thereof so that the starting'will occur at a temperature which insures that a substantial portion of said material is still frozen and the stopping will occur at a temperature below the last mentioned temperature. 20 23. In a refrigerating system, in combination, a a condensing unit, an evaporator unit, a quantity of freezable material associated in heat exchange relation with said evaporator unit, thermostatic control means so constructed and ar- 25 ranged that it starts said condensing unit at a temperature above the freezing range of said. freezable material and stops said condensing unit at a temperature below the freezing range "of said freezable'material and other means op- 30 eratively connected with the said thermostatic control means so constructed and arranged as to periodically act upon said control means to. a change the temperature responsiveness of the thermostatic control means tocause it to start 35 said condensing unit at a temperature below the freezing range of said freezable material and to stop it at a lower temperature.

24. In combination," a refrigerating system,

lcontrol means for starting and stopping the oper- 4o 'trol means normally causing cyclic operation of said system between temperature limits which 50 prevent the melting of any majorportion of said freezable material, and.mea'ns acting in conjunction with said control means to cause said' system to operate cyclically during pre-selected periods of each day between temperature limits 55 which allow a majorportion of said freezable material to melt and freeze during each cycle.

26.'In a refrigerating system, a condensing unit, an evaporating unit, a quantity of freezable material associated with said evaporating unit, 60

thermostatic control means for said system, normally causing said system to operate between one set of temperature limits and time controlled means for modifying the cycles of said system as controlled by said thermostati: control means to cause said system to operate within dif-- ferent temperature limits during pre-selected periods of each day, one set of temperature limits having its upper limit above and its lower limit below a temperature range in which a major portion of said freezable material freezes and melts.

27. In a refrigerating system, ,latent heat storage means comprising material which has a melting range substantially below that of water.

control means arranged to cause said system to l I 2,044,492 and stop within temperature limits such major portion of -its latent heat, and automatic.

means modifying a temperature adjustment of said thermostatic means during certain periods 0! each day.

29. In a refrigerating system, thermostatic means for starting and stoppingsaid system, and automatically actuated means for efiecting a temperature adjustment or said thermostatic means rlduring pre-selected periods of each day.

30. In a refrigerating system, an evaporating unit, a condensing unit, a. quantity of material freezable within a temperature range below 32 degrees F. associated with said evaporating unit so as to be capable of being frozen thereby, therinostatic means for controlling the operation of said system between pre-selected temperature, limits, and means for changing one of said ternperature limits during pre-selected periods of each day. r

- GLENN MUFFLY.)

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