US2210613A - Refrigeration - Google Patents

Description

6, 1940- s. w. E. ANDERSSON 2.210.613

' REFRIGERATION Filed Oct. 11, 1957 4 Sheets-Sheet 2 {{ggwr INVEN 1 OR.

jmwimdwm g- 6, 1940- s. w. E. ANDERSSON v 2.210.613

REFRIGERATION Filed. Oct. 11, 193-1 4 Sheets-Sheet 3 fir 'l um v INVENTOR. MUlSfl/MW fll A omav.

8- 6, 1940- I s. w. E. ANDERSSQN 2, ,613

REFRIGERATION Filed Oct. 11, 1937 4 Sheets-Sheet 4 mummy! 2- 1N VENT OR.

BY 3M MW wm WTTORNEY.

Patented Aug. 6 1940 REFRIGERATION Sven W. E. Andersson, Evansville, Ind., assignor to Servel, Inc., New York, N. Y., a corporation of Delaware Application October 11, 1937, Serial No. 168,321

11 Claims.

My invention relates to refrigeration, and more particularly to a control device for refrigeration apparatus.

It is an object of my invention to provide an 5 improved control device which is sensitive and reliable in operation for controlling the energy supply of refrigeration apparatus. More particularly, it is an object of my invention to provide an improved control device for controlling the 10 energy supply of refrigeration apparatus whereby a temperature range within which a cooling element is maintained may be widened or diminished at will. I accomplish this by providing a control device whereby a low temperature at 16 which the energy supply to the refrigeration apparatus is reduced or shut off may be raised or lowered at will and independently of a higher temperature at which the energy supply is increased or again instigated after a shut-off period. In ada dition to widening or diminishing the tempera ture range within which the cooling element may be maintained, the control device is adjustable whereby the temperature range of the cooling I element may be raised or lowered.

25 Another object of my invention is to provide an improvement in refrigeration apparatus having a main burner and a pilot burner, whereby a valve of a control device for the main burner is also utilized as a safety valve to automatically shut 30 off the supply of fuel to the main burner when the flame of the pilot burner is extinguished. I accomplish this by connecting the pilot burner to a control device for the main burner which is so constructed and arranged that it operates in 35 response to fluid pressure to automatically shut oif flow of fuel to the main burner if for any reason the flame of the pilot burner is extinguished.

The novel features which I believe to be characteristic of my invention are set forth with par- 40 ticularity in the claims. The invention,'both as to organization and method, together with the above and further objects and advantages thereof, will be better understood as I next describe my improved control in connection with absorp- 45 tion refrigeration apparatus like that described in application Serial No. 107,852 of Albert R. Thomas, flied October 27, 1936.

In the drawings, Fig. 1 diagrammatically illustrates refrigeration apparatus of an absorption 50 type provided with a control device and pilot flame burner embodying my invention;

Fig. 2 is an enlarged vertical sectional view taken on line 2-2 of Fig. 3 to illustrate more clearly the control device shown in Fig. 1;

' Fig. 3 is a sectional view taken on line 3-3 of Fig. 2 with the top cover plate removed and some of the internal parts omitted from the casing;

Figs. 4 and 5 are fragmentary sectional views taken on lines 4-4 and 5-4,, respectively, of Fig.

2 to illustrate more clearly parts of the control device;

Fig. 6 is a fragmentary sectional view taken on line 6-6 of Fig. 2;

Figs. '7 and 8 are fragmentary sectional views taken on lines 'l1 and 8-8, respectively, of Fig. 3 to illustrate more clearly the flow of gas in the passages in the control device;

Fig. 9 is a fragmentary sectional view taken on line 99 of Fig. 3;

Fig. 10 is an enlarged vertical sectional view of the pilot burner shown in Fig. 1; and

Figs. 11 and 12 are vertical sectional views illustrating modifications of the pilot burner shown in Fig. 10.

Referring to Fig. 1, I have showna cooling coil I0 arranged in a thermally insulated storage compartment II. The cooling coil l0 forms part of a secondary cooling system including conduits l2 and I3 and a coil I. The secondary cooling system contains a fluid, such as brine, for ex ample, which is circulated in the system by a pump l 5 driven by an electric motor IS. The coil I4 is arranged in thermal exchange relation with a cooling element II of refrigeration apparatus.

The refrigerating effect produced in cooling element I1 is utilized to cool fluid in coil I which flows to cooling coil ill to produce cold in storage compartment ll.

The cooling element l'l forms part of absorption refrigeration apparatus of a uniform pressure type and like that described in the above application of Albert R. Thomas. In such apparatus a refrigerant is introduced into the cooling element ll through a conduit l8. In cooling ele- 40 ment I1 the refrigerant, such as ammonia, evaporates and diffuses into an inert gas, such as hydrogen, to produce a refrigerating efl'ect to cool fluid in coil I4. The resulting gas mixture of inert gas and refrigerant flows from the lower part of cooling element I! through conduit l9, outer passage of a gas heat exchanger 20, and conduit 2| into an absorber 22.

In absorber 22 refrigerant gas is absorbed by a suitable liquid absorbent, such as water, which enters through conduit 23. The inert gas, which is practically insoluble and weak in refrigerant,

. is returned to cooling element I! through conduit 24, a plurality of tubes forming the inner passage of gas heat exchanger 20, and conduit 25; and

the enriched absorption liquid is conducted from absorber 22 through the outer passage of the liquid heat exchanger 26, vessel 21, conduit 28, generator 29, and conduit 38 to a coil 3|.

The coil 3| is heated by a burner 32 whereby liquid is raised by vapor-lift action through conduit 33 into a vessel 34 in which refrigerant vapor and absorption liquid are separated. Liberated refrigerant vapor flows downward through conduit 35 into generator 29. This vapor, together with refrigerant vapor expelled out of solution in generator 29 due to heating thereof by burner 32,- fiows through conduit 28 into vessel 21. From vessel 21 refrigerant vapor flows upward through conduit 36 and a liquid cooled rectifier 31 into a condenser 38 in which the refrigerant is liquefied. The liquefied refrigerant flows from condenser 38 through conduits 39 and 40 into rectifier. 31, whereby any absorption liquid vapor accompanying the refrigerant vapor is condensed and drains back through conduit 36 into vessel 21. From rectifier 31 liquid refrigerant is returned to cooling element |1 through conduit 4|, coil 42, and conduit l8 to complete the refrigerating cycle. In coil 42 liquid refrigerant is pre-cooled by evaporation thereof into enriched gas which flows from and to the gas heat exchanger 29 through conduits 43 and 44.

The weakened absorption liquid from which refrigerant has separated flows from vessel 34 through conduit 45, the inner passage of liquid heat exchanger 26, and conduit 23 into the upper part of absorber 22. The heat liberated with absorption of refrigerant vapor in absorber 22 is transferred to a cooling medium which flows upward through a coil 46. The coil 46 may be connected to a conduit 41 which extends through condenser 38 whereby the latter is cooled by the same cooling medium as the absorber 22.

A vessel 48 having an opening 49 in the bottom thereof is arranged in absorber 22. The upper part of vessel 48 is connected by a conduit 59 to the upper part of conduit 48, so that any inert gas which may pass into condenser 38 can flow into the gas circuit. Any refrigerant vapor not liquefled in condenser 38 flows through conduit 59 to displace gas in vessel 48 and force such gas .into the gas, circuit through opening 49, thereby increasing the total pressure in the system. With such increase in pressure in the system, an adequate condensing pressure is obtained to insure condensation of refrigerant vapor in condenser In accordance with my invention the flow of gas to burner 32 is controlled by a control device 5|. The control device 5| embodies the control mechanism for refrigeration apparatus which is described in my application Serial No. 113,152,

filed November 28, 1936. Referring to Figs. 1 and 2, the control device 5| comprises a casing 52 having inlet and outlet openings 53 and 54 to which are connected conduits 55 and 56, respectively. The casing 52 is formed with a partition 51 having an opening within which is fixed a short cylindrical sleeve 58. The sleeve 58 is provided with a central hub 59 which is connected to the sleeve by spaced radial arms 69. The lower and upper ends of sleeve 58 serve as seats for valves 6| and 62 which are disposed in chambers 63 and 64, respectively, formed on opposite sides of the partition 51. The valves 6| and 62. are formed of any suitable material, such as artificial rubber commercially known as Du Prene or Thioko for example, which is not affected by contact with gas.

The valve 6| may be termed a high temperature safety valve and controls the flow of gas to the burner 32 in response to a thermal element arranged at the lower end of the casing 52. This thermal element comprises a resilient diaphragm 65 and a plate 66 which are secured between the lower end of casing 52 and a cover plate 51. To the plate 66 at an opening therein is secured one end of a tube 61 which extends through an opening in the cover plate 61 and is connected at its other end to a thermal bulb 69. The bulb 69 is arranged in thermal contact with the liquid cooled rectifier 31, as shown in Fig. 1.

The resilient diaphragm 65 and plate 66, tube 58, and bulb 69 are charged with a suitable volatile fluid and constitute an expansible fluid thermostat. The resilient diaphragm 65 is adapted to bear against the lower end of a c-shaped spring 19 which is secured at its upper end to the valve 6|. A spiral spring 1| is retained in position between the hub 59 and valve 6| to urge the latter to its normally open position.

If for any reason the temperature of the liquid cooled rectifier 31 becomes relatively high, due to failure of the cooling medium to circulate through the condenser 36, for example, the expansible fluid thermostat becomes effective to urge the valve 6| to its closed position against the tension of spiral spring 1|. With the high temperature safety valve 6| moved to its closed position, the supply of gas to burner 32 is shut ofi completely, whereby heat is no longer applied to the refrigeration apparatus.

The main valve 82 is directly connected or mounted on a diaphragm 12 which, with the partition 51, defines the chamber 64 communicating with the outlet 54. The valve 62 and diaphragm 12 are loaded or weighted by metal plates 13 fixed to both sides of the diaphragm. As will be described hereinafter, the valve 62 controls the flow of gas to the burner 32 in response to a thermal element 14 which is located in a chamber 15 formed above the diaphragm 12.

In order to maintain a pilot flame for the burner 32 when either of the valves 6| or 62 is closed, I provide a small burner 16 to which gas is conducted through a conduit 11 connected to a by-pass formed in the casing 52. As shown in Figs. 3, '1, and 8, gas flows from chamber 63 through a by-pass including an inclined passage 18, a horizontal passage 19, and a vertical passage 89 to the lower end of which is connected conduit 11. The quantity of 'gas flowing through the by-pass from chamber 63 to the small burner 16 is controlled by a plug valve 8| in horizontal passage 19. The plug valve 8| is provided with a threaded screw head 82 which is movable in a slightly larger passage 83 formed in a boss 84 at the exterior of casing 52. By turning screw 82 from the exterior of casing 52 after removing an outer screw 85, the plug valve 8| can be positioned in passage 19 to regulate the flow of gas to the small burner 16. A coil spring 86 is provided in horizontal passage 19 to permit accurate adjustment of plug valve 8| and prevent undesirable movement thereof.

The thermal element 14 is in the form of an expansible diaphragm and is secured to and in communication with a hollow hub member 81.

To the hub member '81 is connected one end of a tube 88 which extends through an opening in a cover plate 89 and is connected to a thermal bulb 90. The bulb 90 is arranged in thermal contact with conduit I3 of the secondary cooling system of the refrigeration apparatus, as shown in Fig. 1. The hub member 87 is fixed to a resilient diaphragm 9I which is secured between the upper end of casing 52 and cover plate 89. The cover plate 89 is provided with a temperature adjustment knob 92 for adjusting the position of resilient diaphragm 9I and hence the operating position of thermal element I4. The knob or control member 92 is provided with a pointer 92' which moves about a dial or scale 89' which may be formed on cover plate 89.

The thermal element I4, tube 88, and bulb are also charged with a suitable volatile fluid and constitute an expansible fluid thermostat. The thermal element I4 expands and contracts with an increase and decrease of temperature, respectively, and these movements are transmitted to bleeder valves 93 and 94 to effect control of main valve 82. The inlet valve 93 cooperates with the upper end of a passage 95 having the lower end thereof communicating with chamber 63 near the inlet 53'. The passage 95'permits the flow of gas from inlet 53 into chamber I5, and, in order to transmit the velocity pressure of the gas stream in this passage, a conical-shaped ring 96 is inserted in chamber 63, as shown in Fig. 2.

'The inlet valve 93 is guided and urged to its open position by a small spiral spring 91 which is located in the vertical portion of passage 95 formed in an inward extending part 98 of casing 52. The outlet valve 94 cooperates with the upper end of passage 80, as shown most clearly in Fig. 7, and permits gas to flow from chamber I5 through conduit TI to the small burner I6. The outlet bleeder valve 94 is guided and urged to its open position by a small spiral spring 99 which is located in the vertical portion of passage 80 formed in the upper inward extending part I00 of casing 52.

To insure a close fit of bleeder valves 93 and 94, the upper ends of passages 95 and 80 are enlarged to receive valve inserts IOI and I02, as shown most clearly in Figs. 4/and 5. The valve inserts IM and I02 are ring-shaped and project above and below the surfaces of parts 98 and I00, respectively, of the casing 52. Valve retaining members I03 and I04 are secured to the parts 98 and I00 to limit the extent to which bleeder valves 93 and 94 can be opened.

The structure in chamber I5 for transmitting movements of thermal element I4 to bleeder valves 93 and 94 includes a lever I05 having a knob or protuberance I06 which bears against thermal element I4. As shown in Fig. 3, the lever I05 is relatively wide and provided with narrow reduced ends. The right hand end of lever I05 is adapted to bear against inlet valve 93, and the left-hand end is provided with an opening in alignment with outlet valve 94. To the underside of lever I05 is secured a flat spring I0I having an abutment I08 fixed thereto which extends through the opening in lever I05 and is adapted to bear against outlet valve 94.

The lever I05 is provided with downward extending sides I09 which are pivotally connected to a pin I I0 fixed to the sides or tabs III formed on the outer end of a flat main spring H2. The inner end of main spring H2 is located about the part 98 of casing 52 and provided with spaced arms II3 which are secured to the underside of part 98, as shown in Figs. 3 and 5.

A differential adjustment screw H4 is located in a h w vertical boss II5 formed at the upper part 0%, casing 52. The lower threaded portion of screw II 4 extends through a threaded'opening in the inward extending part I00 of the casing and is adapted to contact the extreme lefthand end of lever I05. The upper unthreaded portion of screw H4 is enlarged and fits snugly in vertical passage II 6 formed in the boss I I5. A packing II! is provided in passage II6 about the unthreaded reduced portion of screw H4. The packing II! is retained in position by a washer I I8 against which bears the upper end of a coil spring II9 located in passage H6. The coil spring II 9 compresses the packing II! to efiectively seal the passage H6 and also prevents undesirable axial movement of adjustment screw I I4, whereby the latter may be accurately adjusted.

To the upper enlarged end of adjustment screw H4 is secured a control knob I20 having a plurality of notches thereof, as shown most clearly in Fig. 6. A spring I22 secured to the upper part of casing 52 is formed with a vertically extending curved portion which is adapted to engage the notches I2I and frictionally hold the knob I 20 to the position to which it is adjusted. The control knob I20 is provided with a stop I23 to limit the turning movement thereof to one revolution.

The structure located in the upper chamber I5 and just described is capable of operating the bleeder valves 93 and 94 and hence control the valve 62 and flow of gas to burner 32, whereby the cooling element ll of the refrigeration apparatus will be capable of maintaining storage compartment II in a desired low temperature range. The pin IIO exerts an upward force on lever I05 which is derived from main spring I I2. If the point at which knob I06 contacts thermal element I4 for the moment is considered the pivoting point of lever I05, the upward force exerted by pin II 0 will urge the left-hand end of lever I 05 upward and the right hand end downward to move bleeder valves 93 and 94 toward their closed positions. The fiat spring I0! to which the abutment I08 is fixed is sufliciently strong to overcome the spiral spring 99 and effect closing of outlet valve 94 without deviating from its position shown in Fig. 2. The main spring I I2 is sufficiently strong to overcome the combined moments of, flat spring I01 and spiral spring 97, and also provide the closing force for inlet valve 93.

The operation of the control device is substantially as follows: Let us assume that main valve 62 is in its closed position and that the supply of gas to burner 32 is shut ofi. Under these conditions inlet bleeder valve 93 is open and outlet bleeder valve 94 is closed. When the temperature of storage compartment II, and hence the temperature of cooling fluid in conduit I3, tends to rise above a predetermined temperature, the thermal element I4 expands a definite amount. With such expansion of thermal element I4, the lever I05 pivots about the region which bears against the inlet valve '93, whereby the left-hand end thereof moves downward. The spiral spring 99 cooperating with outlet valve 94 urges the latter to move to its open position when the lefthand end of lever I05 moves downward. With inlet valve 93 closed and outlet valve 94 opened, chamber I5 is in communication with passage 80 to which is connected the delivery conduit 11 of small pilot flame burner I6. Since the gas flowing into vertical passage 80 from chamber 63 is adjusted to a low pressure by plug valve 8|, the pressure in chamber 15 will become relatively low and slightly above atmospheric pressure,

I2I formed about the periphery While the pressure in chamber 15 is relatively low, the pressure in chamber 63 is that of the gas pressure in supply conduit 55. The plates 13 fixed to diaphragm 12 are of such size that the combined weight of the plates, diaphragm, and main valve 62 will exert a downward force which is less than the force exerted on the underside of valve 62 by gas under pressure in sleeve 58. Since the downward force on diaphragm 12 is less than the force exerted by gas in chamber 63 on the underside of the diaphragm at the relatively small portion covering the sleeve 58', main valve 62 will move upward from its seated position shown in Fig. 2. When main valve 62 cracks open, the gas pressure starts building up in chamber 64, whereby an upward force is exerted on the entire underside of the diaphragm 12 and main valve 62 will remain in its full open position.

The gas now flows to main burner 32 and is ignited by the pilot flame produced by small burner 16, and heat is applied to the refrigeration apparatus whereby refrigeration is produced by cooling element I1. The cooling fluid circulating in the secondary cooling system immediately becomes effective to increase the refrigeration produced instorage compartment II.

When the temperature of storage compartment II, and hence the temperature of cooling fluid in conduit I3, tends to fall below a predetermined low temperature, the thermal element 14 contracts a definite amount. With such contraction of thermal element 14, the left-hand end of lever I05 moves upward whereby abutment I08 closes bleeder valve 94, due to the fact that flat spring I01 is stronger than spiral spring 99. When thermal element 14 first contracts, inlet bleeder valve 93 remains in its closed position due to the action of main spring I I2. With further contraction of. thermal element 14 and when the extreme lefthand end of lever I05 contacts adjustment screw H4, bleeder valve 94 remains in its closed position even with continued upward movement of lever I05, due to the provision of flat spring I01. Under such conditions the flat spring I01 is bent and flexes away from the underside of lever I05. When lever I05 contacts the adjustment screw H4 and further contraction of thermal element 14 takes place, the lever pivots about its left-hand end whereby the right hand end moves upward and permits spiral spring 91 to move inlet bleeder valve 93 to its open position.

With inlet valve 93 open and outlet valve 94 closed, gas flows through passage 95 from lower chamber 64 or inlet 53 into the upper chamber 15. When the gas pressure in chambers 15 and 64 are substantially equal, the diaphragm 12 and main valve 62 will move downward due to the fact that the diaphragm is loaded by the plates 13. The valve 62 will effectively remain in its closed position when it is seated at the upper end of sleeve 58, because the gas under pressure in chamber 15 exerts a downward force over the entire area of diaphragm 12 while the gas under pressure in chamber 63 and sleeve 58 only exerts an upward force on the portion of the diaphragm covering the upper end of sleeve 58.

With the valve 62 in its closed position, heat is no longer applied to the refrigeration apparatus and the refrigerating effect produced by cooling element I1 is reduced. When the storage compartment II tends to rise above the predetermined temperature, the thermal element 14 will again expand sufiiciently to close inlet valve 93 and open outlet valve 94, as described above. When this occurs the pressure in upper chamber 15 is relieved and the gas from this chamber flows through vertical passage and conduit 11 to small burner 16, whereby the size of the pilot flame is momentarily increased. This coincides with the opening of main valve 62 and insures reliable operation of the small burner 10. The amount of gas discharged from chamber 15 each time main valve 62 opens is equal to the volume of gas contained in this chamber,

In view of the foregoing, it will now be understood that control device 5| operates with a temperature differential and that thermal element 14 is operative to cause main valve 62 to close at a low temperature and to open at a higher temperature. By moving temperature adjustment knob 92 on cover plate 89, the operating position of thermal element 14 may be moved to raise or lower the temperature range in which main valve 62 is opened and closed. The temperature range in which the control device operates may be so adjusted that during the periods when no heat is supplied to the refrigeration apparatus, the cooling element I1 can rise above the freezin temperature, so that defrosting of the cooling element will occur.

The differential adjustment screw H4, which will hereinafter be referred to as an adjustment screw, provides for independent adjustment of the temperature at which the supply of heat to the refrigeration apparatus is shut off. Thus. after the temperature control knob 92 is adjusted to determine the higher temperature at which heat is again delivered to burner 32 after a shutoff period, the adjustment screw H4 can be moved to increase or decrease the temperature differential and vary at will the low temperature at which the supply of heat is shut oil, When the adjustment screw H4 is raised or moved upward, more contraction of thermal element 14 is necessary to 'close outlet valve 94 and open inlet valve 93 to effect closing of main valve 62. The amount of contraction of thermal element 14 that is required to effect closing of main valve 62, of course, determines the low temperature at which the supply of heat to the refrigeration apparatus is shut off;

The control device 5I may be operated manually, if desired, to start heating of the refrigeration apparatus when main valve 52 is closed. This may be accomplished by moving adjustment screw H4 downward so that the latter presses the left-hand end of lever I05 but a slight amount to barely open outlet valve 94. This relieves the gas pressure in upper chamber 15 and permits main valve 82 to open, as described above. When the storage compartment II tends to fall below the predetermined low temperature and thermal element 14 has contracted sufliciently, lever I05 will pivot about adjustment screw H4 to close outlet valve 94 and open inlet valve 93, whereby main valve 62- is caused to move to its closed position.

The manual operation just described is very sensitive and the movement of adjustment screw H4 is very critical. If adjustment screw H4 is moved downward too far, the outlet valve 94 will remain open after the right hand end of lever I05 has moved upward to permit the inlet valve 93 to open. With both bleeder valves 93 and 94 open, gas flows through chamber 15 to the small burner 16. This condition is easily recognized by a flaring of the pilot flame produced by small burner 16. I make use of this critical condition toinitially adjust the position of adjustment screw H4.

; burner 32 so that the pilot flame produced at This may be accomplished by turning temperature adjustment knob 92 back and forth while bulb 90 is at a definite temperature, such as room temperature, for example, until thermal element 14 is at such a position that inlet valve 93 is closed and outlet valve 94 is open, whereby main valve 62 is caused to open. The position of pointer 92 on scale 89 is noted andcontrol knob 92 is moved to raise thermal element 14, so that inlet valve 93 opens and outlet valve 94 closes. The pointer 92' .of control knob 92 is then returned to a position on scale 89' which is close to theposition previously noted. In this position of the pointer 92' both bleeder valves 93 and 94 are closed, and only a small movement of control knob 92 would be necessary to move thermal .element 14 downward to open outlet valve 94. With the pointer 92' of knob 92 in this position, the adjustment screw H4 is moved downward sufflciently to press down on the left-hand end of lever I to open outlet valve 94. This will be indicated by an increase of the size of the pilot flame produced by small burner 16. With outlet valve 94 open and inlet valve 93 closed, the main valve 62 will move to its open position. The screw II4 may then be moved upward a small distance from this critical condition and knob I20 secured to screw I I4, so that stop I23 is in such a position that adjustment screw II 4 cannot be moved downward beyond the position to which it has been adjusted. When adjustment screw H4 is raised from this adjusted position, the temperature at which thermal element 14 becomes effective to cause main valve 62 to close is lowered, whereby the temperature differential is increased. The lower shut-ofi temperature may be varied at will, therefore, and independently of the higher temperature atwhich main valve 62 is caused to open and again supply heat to the refrigeration apparatus. After temperature adjustment knob 92 is moved to a definite position, the higher temperature at which main valve 62 opens remains substantially the same irrespective of any adjustment of screw II4 to vary the lower temperature at which valve 62 closes.

In accordance with my invention the small burner 16 is constructed and arranged so that main valve 62 of control device 5| is utilized as a safety valve, if for' any reason the pilot flame is extinguished. As shown in Fig. 10, the small burner 16 includes a valve body comprising a part I24 threadedly secured to a part I25. The part I25 is provided with an inlet opening to which is connected the outer end of conduit 11. The part I 24 is formed with a valve seat which cooperates with a valve I26. The valve I26 is connected to a valve stem I21 which extends through an opening in part I24 and is secured to a snap-acting thermostatic diaphragm I28 which is secured between the open end of a diaphragm housing I29 and a curved outer metallic disc I30.

A passage I3I formed in part I24 communicates with an inclined passage I32 formed in part I25. At the outer end of passage I32 is secured a nozzle I33 to provide a jet pilot flame for main burner 32. A heat conductor I 34 is secured to housing I29 and provided with an extension which is adapted to be heated by the pilot flame. When the burner 16 is lighted, heat is conducted by heat conductor I34 to the thermostatic diaphragm I 28.

The small burner 16 is located adjacent to main valve nozzle I33 will be effective to ignite the gas delivered to burner 32. The burner 16 is provided with a small hood I35 which surrounds the nozzle I33 and heat conductor I34, so that the likelihood of the, pilot flame being extinguished by sudden air draft is avoided.

The pilot burner 16 is provided with a lighter tube I36 which terminates in the vicinity of disk I30 and heat conductor I34. As shown in Fig. 1, lighter tube I36 is connected to a part I31 secured to the lower part of casing 52. Combustible gas is delivered from inlet 53 through a by-pass in casing 52 to lighter tube I36. As shown in Fig. 9, the lighter tube I36 is connected to the lower end of a vertical passage I30 which terminates in a small chamber I 39. The small chamber I39 in turn communicates witha passage I40-which communicates with the inlet 53. Within chamher I39 is located a valve I M having a stem I42 which is secured to a push-button I43 operable from the exterior of part I31. The push-button I43 is normally urged outward by a helical spring I44 whereby valve I4I remains in its closed position.

When it is desired to provide a flame at the outer end of lighter tube I36 to start burner 16, push-button I43 is pressed inward whereby valve I M is opened and combustible gas is delivered to the outer end of lighter tube I36. A small screw I45 extending into passage I38 is provided to adjust the size of a lighter tube flame. The lighter tube flame is applied to disk I30 and heat conductor I 34, and the heat is conducted to thermostatic diaphragm I28. When diaphragm I28 is heated sufliciently it snaps toward the right to open valve I 26 and permit flow of combustible gas from conduit 11 to nozzle I 33. The gas discharged from nozzle I33 is ignited by the lighter tube flame to provide the pilot flame. By providing valve I26 in conduit 11, the main valve 62 is urged to its closed position or re-. mains in its closed position if for any reason the jet pilot flame is extinguished. Normally the pressure in conduit 11 is relatively low so that the gas pressure in upper chamber 15 is efi'ectively relieved when inlet bleeder valve 93 closes and outlet bleeder valve 94 opens. This causes main valve 62 to open and permits gas to be delivered to burner 32 to start a heating period. If the jet pilot flame is extinguished, heat is no longer delivered by heat conductor I 34 to 'diaphragm I28 and the latter cools and snaps toward the left to close valve I26. If the main valve 62 should be closed when this occurs and the thermal element 14 subsequently expands to close pilot inlet bleeder valve 93 and open outlet bleeder valve 94, the gas pressure in upper chamber 15 cannot be relieved. Since gas continues to flow through the by-pass from chamber 63 into passage 80 and conduit 11, the pressure in conduit 11 increases due to the fact that valve I26 is closed. Although outlet bleedervalve 94 is open, therefore, the gas pressure in upper chamber 15 is not relieved and main valve 62 will remain in its closed position, thereby acting as a safety The same result occurs when main valve 62 is open and the gas pressure in upper chamber 15 is relatively low. If the pilot flame is extinguished under these conditions, the closing of valve I26 causes the pilot gas to back up through passage 80 into upper chamber 15. The gas pressure in chamber 15 fills up due to the fiow of gas through the by-pass, and, when the gas pressures in chambers 15 and 64 are substantially equal, the main valve 62 moves to its closed position to shut off the flow of gas to main bumer 32.

In Fig. 10 Ihave shown a modification of the pilot burner I6 just described and illustrated in Fig. 10. The pilot burner 16a in Fig. 11 includes a valve body I25a having a passage 53m to which is connected the conduit TI. The fiow of gas through passage I3Ia is controlled by a valve I280; which is fixed to snap-acting thermostatic diaphragm I28a. secured between the open end of a diaphragm housing I29a and a curved disk I3Ila. The diaphragm I280. and disk I30a are provided with openings I46 and I41, respectively, with the pilot flame being produced at the regions of openings I41. A sleeve I34a is secured to housing I29a. to protect the burner flame as well as assist disk I300. in conducting heat to diaphragm I28a. 'I'he lighter tube I36 terminates in the vicinity of housing I291; to heat diaphragm I281; and start operation of burner 16a.

When the pilot flame is burning diaphragm I 280 is flexed toward the left and valve I26a. is open. If for any reason the pilot flame is extinguished the diaphragm I28a snaps toward the right to close valve I26a. This prevents gas from being relieved from upper chamber 15 of control device -5I, as described above, whereby main valve 62 is urged to its closed position to shut off the fiow of gas to generator burner 32.

In Fig. 12 I have diagrammatically shown a further modification of a pilot burner which does not require a lighter tube to start the operation of the burner. The burner 16b in Fig. 12 includes a U-shaped bracket I48 which is secured in any suitable manner to main burner 32. To the lefthand end of bracket I48 is secured a plunger I49 having a conical-shaped end I50 which serves as a valve. A sleeve I5I connected to conduit I1 extends through an opening in the right-hand arm of bracket I48 and is arranged to slide on plunger I49. The burner flame is maintained at a plurality of openings I52 formed in the enlarged portion of sleeve I5I, and the shoulder I53 formed in the sleeve serves as a seat for valve I50. An inverted U-shaped bi-metallic strip I54 is secured to bracket I48 and the, left-hand end thereof is adapted to engage the end of sleeve I5I. A spring I55 is provided about a reduced portion of sleeve I5I to urge the latter toward the left when the strip I54 moves upward to release the lefthand end of sleeve I 5.

During operation of burner 15b the parts of the burner are in the position shown in Fig. 12, with the pilot flame heating the bimetallic strip I54. If for any reasonthe burner flame is extinguished, the strip I54 is cooled and flexes upward whereby spring I55 becomes effective to move sleeve I5I toward the left. This moves shoulder I53 against valve I50 to shut off the flow of gas to the burner, and, as described above 'inconnec-.

tion with Fig. 10, the main valve 62 is urged to its closed position.

When it is desired to re-ligrit-burner"I61;conduit I1 is pulled outward or'toward the right so that shoulder I53is moved away from valve I50. After the gas is ignited at the openings I52, conduit 11. is held for an interval of time sufficient for bi-metallic strip I54 to become heated. When strip I54 is heated sufficiently it flexes downward and engages the left-hand end of sleeve I5I, whereby conduit Il may be released.

Although I have shown my improved control device in connection with a particular type of refrlgeration apparatus, I do not wish to be limited to the particular arrangement set forth. It will be obvious to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. I therefore aim in the following claims to cover all such modifications and changes as fall within the true spirit and scope of the invention.

What is claimed is:

1. In absorption refrigeration apparatus including a cooling element, a generator, and a burner for heating said generator, a control device including a diaphragm operated valve to control flow of gas to the burner, structure to permit said gas to exert force on both sides of said diaphragm, mechanism to effect operation of said valve and including an element responsive to temperature or pressure to control the gas capable of exerting force on one side of said diaphragm, means to bodily move said element to regulate the operation of said valve, and means independent of bodily movement of said element to further regulate the operation of said valve.

2. In an absorption refrigeration apparatus including a cooling element, a generator, and a gas burner for heating said generator, a control device including a gas pressure operated valve for controlling flow of gas to said burner, means including a thermostat element and valve means mechanically connected to said element to vary said gas pressure to effect operation of said valve to maintain said cooling element in a temperature range, saidvalve means including a chamber having gas inlet and outlet valve members, said mechanical connection being such that said valve members are caused to operate in alternation upon movement in either direction of said thermostat element, and means to increase or decrease said temperature range, said last-mentioned means determining the position of said thermostat element at which said outlet valve member closes.

3. In absorption refrigeration apparatus having a cooling element, a generator, and a burner for heating the generator, a control device comprising structure including a diaphragm operated valve to control flow of fuel to the burner, said structure being so constructed and arranged that both sides of said diaphragm may be subjected to pressure of fuel, mechanism including an element responsive to temperature or pressure to control the fuel pressure on one side of said diaphragm and thereby effect operation of said valve in a temperature or pressure range to shut ofi flow of fuel at a low temperature or pressure value and instigate flow of fuel at a higher temperature or pressure value, means to adjust said mechanism to raise or lower the temperature or pressure range in which said valve is operated, and additional means independent of said lastmentioned means and including a part cooperating with said mechanism to increase or decrease said low temperature or pressure value at which flow of fuel is shut off without affecting the higher temperature or pressure value at which jected to pressure of fuel, mechanism including an element responsive to temperature or pressure to control the fuel pressure on one side of said diaphragm and thereby effect operation of said valve in a temperature or pressure range to shut off flow of fluid at a low temperature or pressure and instigate flow of fuel at a higher temperature or pressure, means including a first movable member to adjust said mechanism to raise or lower the temperature or pressure range in which said valve is operated, and means including a second movable member associated with said mechanism to widen or diminish said temperature or pressure range in which said valve is operated independent of and in addition to the regulation effected by said last-mentioned means.

5. In absorption refrigeration apparatus having a cooling element, a generator, and a burner for heating the generator, a control device comprising structure including a casing having an inlet and outlet, and a diaphragm operated valve in said casing for controlling flow of fuel between the inlet and outlet, said structure being so constructed and arranged that both sides of said diaphragm may be subjected to pressure of fuel, mechanism within said casing including an element responsive to temperature or pressure and a part actuated by such element to control the fuel pressure on one side of said diaphragm and thereby effect operation of said valve, means operable from the exterior of said casing to adjust said mechanism to regulate the operation of said valve, and means including a member associated with said part and operable from the exterior of said casing to further regulate the operation of said valve independent of and in addition to the regulation effected by said .lastmentioned means.

6. In absorption refrigeration apparatus having a cooling element, a generator, and a burner for heating the generator, a control device comprising structure including a diaphragm operated valve to control flow of fuel to the burner, said structure being so constructed and arranged that both sides of said diaphragm may be subjected to pressure of fuel, mechanism including an element responsiveto temperature or pressure to control the fuel pressure on one side of said diaphragm and thereby effect operation of said valve in a temperature or pressure range between a low and higher value to shut off and instigate fiow of fuel, means to bodily move said element to raise or lower said temperature or pressure range in which said valve is operated, and means independent of said last-mentioned means and including apart cooperating with said mechanism to increase or decrease one of the temperature or pressure values without affecting the other temperature or pressure value in the temperature or pressure range in which said valve is operated.

7. In absorption refrigeration apparatus having a cooling element, a generator, and a burner for heating the generator, a control device comprising structure including a diaphragm operated valve to control flow of gas to the burner, said structure being so constructed and arranged that both sides of said diaphragm may be subjected to pressure of fuel, an element responsive to temperature or pressure, mechanism associated with said element to effect operation of said valve in a temperature or pressure range, means to bodily move said element to raise or lower said temperature or pressure range in which said valve is operated, and means including an adjustable part associated with said mechanism to widen or diminish the temperature or pressure range in which said valve is operated without bodily moving said element. 1

8. In absorption refrigeration apparatus having a cooling element, a generator, and a burner for heating the generator, a control device comprising structure including a casing having an inlet and outlet for fuel, a diaphragm operated main valve within said casing to control flow of fuel between the inlet and the outlet, said structure being so constructed and arranged that both sides of said diaphragm may be subjected to pressure of fuel, mechanism to control the fuel pressure on one side of said diaphragm and thereby effect operation of said main valve, such mechanism including an expansible and contractible element within said casing and auxiliary valve means actuated by expansion and contraction of said element, means tobodily move said element to regulate the operation of said main valve, and means including a part associated with said mechanism to further regulate the operation of said main valve without bodily moving said expansible and contractible element.

9. In absorption refrigeration apparatus having a cooling element, a generator, and a burner for heating the generator, a control device comprising structure including a diaphragm operated main valve to control flow of fuel to the burner, said structure being so constructed and arranged that both sides of said diaphragm may be subjected to pressure of ,fuel, mechanism including an element responsive to temperature or pressure and auxiliary valve means actuated by said element to control the fuel pressure on one side of said diaphragm and thereby effect operation of said main valve, means to bodily move said element to regulate the operation of. said main valve, and additional means including a part associated with said mechanism to further regulate the operation of said main valve with out bodily moving said element.

10. In absorption refrigeration apparatus having a cooling element, a generator, and a burner for heating generator, a control device compris ing structure including a diaphragm operated main valve to control flow of fuel to the burner, said structure being so constructed and arranged that both sides of said diaphragm may be subjected to pressure of fuel, mechanism to control the fuel pressure on one side of said diaphragm and thereby effect operation of said main valve,

said mechanism including an element responsive to temperature or pressure, auxiliary valve means, and a part operatively associating said element and said auxiliary valve means, means to adjust said mechanism to regulate the operation of said main valve, and means including a member associated with said mechanism and arranged to cooperate with said part to further regulate the operation of said main valve in addition to the regulation effected by said lastmentioned means.

11. In absorption refrigeration apparatus having a cooling element, a generator, and a burner for heating the generator, a control device com- I prising a gas pressure operated main: valve for controlling flow of gas to the burner, means including an element responsive to pressure or temperature and auxiliary valve means operated by said element to vary said gas pressure to effect operation of said main valve in a temperature or. pressure range, said auxiliary valve means including a chamber having an outlet valve member, and means to increase or decrease the temperature or pressure range in which said aameie main valve is operated, said last-mentioned means including an adjustable member to determine the position of said element at which said outlet valve member closes.

SVEN W. E. ANDERSSON.

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