US1734349A - Control mechanism for refrigerating systems - Google Patents

Description

Nov. 5, 1929. A. c. SCHICKLER 1,734,349

CONTROL MECHANISM FOR REFRTGERATING SYSTEMS Filed Sept. 15, 1927 2 Sheets-Sheet 1 27 4 4M MM 8% WP Nov. 5, 1929. A. c. SCHICKLER ,7

CONTROL MECHANISM FOR REYRIGEHATING SYSTEMS Filed Sept. 1927 2 Sheets-Sheet 2 @kw Q w -WWW Patented Nov. 5, 1929 UNITED STATES PATENT OFFICE ALBERT C. SCHICKLER, OF CLEVELAND, OHIO, ASSIGNOR TO EDMUND E. ALLYNE, OF

' CLEVELAND, OHIO 4' Application filed September 15, 1927. Serial No. 219,690.

This invention relates to control mechanism for refrigerating systems and particularly to gas heated systems of the intermittent cyclic absorption type.

The object of the invention is to provide an improved safety shut off for such a system in which under any conditions in which the pilot flame for the'boiler heater is extinguished the main gas supply to the burner is shut off, thereby to avoid waste of gas or asph xiation by continued gas supply without ame or upon resumption of the supply after it has been turned ofl'.

A further object of the invention is to pro vide control mechanism in "which the mechanism or device for turning on the gas supply to initiate the boiling operation is energized or actuated by or in accordance with heat roduced by the gas flame and particularly y the pilot valve in such manner as to pre vent turning on the gas when the pilot light is out and to turn it off when the pilot light is extinguished,

A further object of the invention is to- 2 provide automatic control mechanism actuated by variations in temperature in different parts of the refrigeratingsystem, such as at the evaporator and still, with a proper correlation and organization of the parts to function according to the necessary scheme of these systems.

Further objects of the invention are in part obvious and in part will appear more in detail hereinafter.

In the drawings, which represent one suitable embodiment of the invention, Fig. 1 is a detail elevation of the control devices; Fig. 2 is an end elevation from the right in Fig. 1; Fig. 3 is a plan view; and Fig. 4 is a schematic diagram illustrating one form of absorption refrigerating system to which the invention may be applied.

The invention may be utilized in. connection with any refrigerating system involving a still or boiler which is intermittently heated to produce a boiling operation, but for purposes of. illustration andnot in any sense of limitation, the invention has been shown applied to an intermittent cyclic absorption system'such as disclosed more in detail in,

' which water may be circulated by the pipes 4, 5. Beneath the boiler is a suitable gas burner 6 supplied from a main 7 by way of a valve 8, control of which valve starts and stops the heater.

During the boiling operation a suitable refrigerant, such as ammonia, distilled from a suitable absorbing agent in the. boiler, such as water, passes off by way of a pipe 9 through the water cooled rectifier 10, thence over a high loop 11 and down to a trap 12, which may be a mercury trap of any suitable form, such as described in prior applications filed by me, for example, application Ser. No. 148,501, filed November 15, 1926.

From the trap 12 the gas is conducted through a pipe 13 to and through the condenser coil 14 immersed in the cooling water in tank 3 and thence by way of pipe 15 to the top of the evaporator, which includes a storage vessel 16 delivering refrigerant to one or more cooling or freezing coils 17, 18 connected at their lower ends to a header 19 draining into a mercury trap 20 connected by pipe 21 to the pipe 15. As described in my prior applications referred to, said. trap 20 maintains a head of liquid in the evaporator, but permits any weak liquor which finds its way to the evaporator to return to the boiler.

The boiling operation is carried on with a flow of gasified refrigerantby the path described to the condenser, where it is condensed to liquid form and from which it flows to the evaporator until a sufiicient charge is collected therein, whereupon the heat is turned off and the refrigerating or evaporating cycle begins.

During evaporation the gas leaves the top of the evaporator by Way of pipe 15 and returns through the condenser to the trap 12, where it finds opposition to return to theboiler through pipe 11, due to the mercury in the trap, and returns by way of a high referred to in the main gas supply for the burner 6. Any suitable valve may be employed for the purpose but the drawings show:

a small tapered valve having a through port or passage 23 and held to its seat by a spring 24. Said valve is rotated to open and close the gas line by rotation of its plug, which is provided for this purpose with two arms, one of which, marked 25, is adapted for operation or control bymechanism sensitive to conditions in the refrigerating system, such as variations in temperature therein, while the other arm, marked 26 is controlled or actuated by the source of heat and specifically by the pilot flame. The latter comes from a small burner 27 fed through a pipe .28 from the main or supply line side of valve 8, said pilot burner being mounted in such position as to ignite the main burner when the gas is supplied thereto and also in such position that the pilot flame plays upon a i-metal strip 29 which flexes back and forth with variations in temperature and is coupled to the valve arm 26 for operating the same. The arrangement is such that when the pilot flame is ignited, bi-metal strip 29 bends or flexes to the left or to the full line position Fig. 1, tending to move valve 8 to on po sition, but when the pilot) flame is extinguished the bi-metal strip flexes to the right or to the dotted line position Fig. 1, thereby turning the gas valve to off position. Consequently the apparatus inherently is safeguarded by its tendency to turn ofi the gas supply to the main burner whenever the pilot flame is extinguished.

The normal control mechanism shown in the drawings includes two motor means, such as expanding bellows 30, 31 mounted in a frame 32 by rigid connection of one end of each of said bellows to said'frame, their opposite'ends being provided with movable plungers 33, 34 respectively.

Bellows 30 is connected by a small tube 35 to a capsule or hollow bulb 36 located in a .re-entrant recess or well 37 of the boiler.

Bellows 31 is connected by a small tube 38 to a capsule or hollow bulb 39 located in a re-entrant well or re'cess40 init'he evaporator at, approximately the bottom of the storage tank 16thereof.

. Bulb 36, tube 35 and bellows 30 form a sealed system, the bulb 36 containing a suit able quantity of water and the tube and bel lows a heavy oil or like material capable of transmitting pressure, so that when the temperature of the still at the end of the boiling period reaches the proper degree the water in the bulb 36 is vaporized or becomes steam and thereby expands and produces expansion of bellows 30.

The bulb 39 likewisecontains a quantity of water adapted to freeze when the temperature of the evaporator drops below the freezing point, the expansion produced by the change of this water into ice beingtransmitted through tube 38 to expand bellows 31, and the ice in bulb 39 permitting said bellows to contract. a

Plunger 33 of the steam bellows 30 lies just beneath a shoulder or abutment on a lever 41 pivoted at 42 on the frame 32 and having its free end provided with a link 43 having a shoulder 44 beneath the valve arm 25. Assuming that the pilot and main burners are ignited and that the parts are in the position shown in Fig. 1 during a boiling operation, then when the boiling operation is positive rotation of valve 8 against the ten dency of the flexed bi-metal strip 29 to move to the left in Fig. 1 and turn the gas on.

When lever 41 rises fully and completely turns off the gas, it is latched in its upper position by a spring pressed primary latch 46, of bell crank form energized by a tension spring 47 and a shoulder 48 of which latch snaps beneath a shoulder or lateral extension 49 of the lever. The lever and valve are thereby latched or held in off position.

The refrigerating cycle now begins with the vaporization of gas in the evaporator and its return to and absorption in the absorbing agent in the boiler. As the boiler-liquor cools,

the steam or vapor in bulb 36 condenses and bellows 30 contacts, but without effect upon the valve or lever. Refrigeration goes on until finally the temperature in the evaporator at bulb 39 drops to a point where the water in Fig. 1, produced by expansion of bellows 30 produces two results. 1 First, its cam 52 engages the arm of primary latch 46 and moves the same ,way from the shoulder 49, but before said shoulder can drop off from holding the gas valve lever 41 in its upper position. Here it will remain so long as the ice remains frozen in bulb 39 or until the refrigerating operation has proceeded to a point where the loss of refrigerant from the storage tank 60 has permitted its temperature to rise adjacent to the bulb 39 and permit the ice in said bulb to melt. This occurs while the coils 17, 18 remain practically full of refrigerant.

When the ice in bulb 39 melts, as described, bellows 3'1 contracts and moves the second latch lever counterclockwise in Fig. 1, releasing the lever shoulder 49 and permitting said lever to be moved downward in Fig. l by its spring 45. The shoulder 44 of link 43 also moves downwardly and the bi-metal strip 29 becomes effective and flexes to the left in Fig. 1, thereby turning on the main gas valve and initiating a new boiling operation which is terminated by expanson of bellows 30, with a repetition of the cycle.

The lost motion between valve arm 25 and link 43 is advantageous because even with the lever 41 in its lower position as the result of lack of refrigeration at the evaporator, thebi-metal strip 29 can move the valve to closed position if the pilot flame is extinguished, during which movement arm 25 moves away from shoulder 44.

This arrangement safeguards the system against failure of the pilot valve and moreover utilizes the heat energy of the fuel for energizing the valve opening device.

What I claim is:

1. Refrigerating apparatus, comprising connected stillabsorber and evaporator mem bers, a gas burner for heating the still, a valve therefor, a pilot burner, a flexing bimetal device located in the zone of the pilot flame, whereby it is flexed in one direction by the heat of the flame and is flexed oppositely when permitted to cool, an operating connection between said device and valve whereby the valve is operated back and forth by the device and is opened by its movement when heated, operating means also connected to said valve to move it toward closed position, and normal control means for said operating means actuated by changing conditionsin said members, whereby'valve opening move-. ment is produced by the heat of the pilot flame and is normally controlled by said members and said valve invariably closes when the pilot flame is extinguished.

2. Refrigerating apparatus, comprising connected still-absorber and evaporator members, a gas burner for heating the still, a valve therefor, a pilot burner, a flex-ing bimetal device located in the zone of the pilot flame, whereby it is flexed in one direction by the heat of the flame and is flexed oppositely when permitted to cool, an operating connection between said device and valve whereby the. valve is operated back and forth by the device and is opened by its movement when heated, operating means also connected to said valve to move it toward closed position, means actuated by rise in temperature atthe still-absorber for moving said operat ing means to close said valve, latching means for maintaining the operating means in valve closed position, and means actuated by rise in temperature at the evaporator for releasing said latching means, whereby valve opening movement is produced by the heat of the pilot flame and is normally controlled by temperature changes at the still-absorber and evaporator and said valve invariably closes when the pilot flame is extinguished.

In testimony whereof I hereby aflix my signature.

' ALBERT C. SCHIGKLER.

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