Patent GB-443574-A (GB)
Title: Improvements in or relating to absorption refrigerating apparatus
IPC: F25B17/08
Filed: 1934-08-28
Abstract: 443,574. Refrigerating; thermostats. SARNMARK, A. U., 1, Skeppsbroplatsen, Gothenburg, Sweden. Aug. 28, 1934, No. 24750. [A Specification was laid open to inspection under Sect. 91 of the Acts, March 1, 1935.] [Classes 29 and 64 (ii)] [See also Group XXIX] Absorption machines and systems.-In a system of the kind comprising two or more generator-absorber units operating to effect a more or less continuous cooling effect, the heat of absorption of one unit is transmitted to another unit to assist generation therein by a fluid, e.g. air or oil, circulating in a closed path. The fluid may be one that evaporates and condenses alternately during circulation. Further, the generator-absorbers of the system may be heated in succession by connection to a liquid heating circuit. Fig. 1 shows a system comprising generator-absorbers A, B, C, D, enclosed in a casing packed with, e.g., infusorial earth or magnesia, and adapted to be connected in turn with a liquid heater L, a cooler 28, and with one another through valves E, F. The generator-absorbers are connected by pipes. A3 .. D3, in heat-exchange with the copper sleeve 30 of a thermostat which controlsthroughpawl- and-ratchet gear and spur wheels 39, 40 the positions of the valves E, F, with a condenser 31 and an evaporator consisting of drums A4 .. D4 provided with tubes forming an ice tray compartment. In the initial position of the valves, the liquid heater L, which has a heating flue 3, Fig. 2, is connected through ducts 15, 17, Figs. 4, 5, in the valves with the jacket of the generator-absorber A. The vapour evolved from the solid absorbent e.g. calcium chloride, 8, Fig. 3, passes into the perforate pipe A3, which may be packed with iron wool, and thence to the condenser from which the condensate flows to the evaporator drum A4. Vapour is prevented from passing to the drum by inert gas. The consequent heating of the sleeve 30 results in the expansion of the rod 56, Fig. 8, of the thermostat and the forcing of the lever 43 from the core 50 of an adjustable magnet 51 and the movement of the ratchet wheel 42 by a pawl 44 carried by the lever. The movement of the wheel effects, through a shaft 41, the spur wheels 39, 40, and a shaft 25 the rotation of the valves through 90‹ thus connecting the liquid heater with the generator-absorber B, the jacket of the generator-absorber A with that of the generatorabsorber C through the ports 13, 14 in the valves, and the generator-absorber D with the cooler 28 through the pipes i, j. In this position of the valves, oil circulates between the generator-absorbers A, C, thus transferring heat from the former, which begins to absorb vapour from the evaporator drum A4, to the latter from which vapour is evolved. When the temperature of the vapour passing from the generator-absorber B reaches its maximum value, the thermostat, which has meanwhile returned to its initial position, is again actuated to rotate the valves through a further 90‹ thus connecting the liquid heater to the generatorabsorber C, the generator-absorber B to D, and that A to the cooler 28. The generatorabsorber A is thus further cooled by the circulation of the jacket oil through the cooler and absorption therein accelerated. The pipes A3 .. D3 pass through a heat-insulated metal sleeve 33 so that the condensate passing through any two of them to the evaporator is cooled by vapour returning through the others. In a modification, in which the thermostat is in heat-exchange with the liquid heater, the cooler 28 is arranged vertically and at the same height as the generator-absorbers, and the jackets and connecting pipes are connected to an oil expansion chamber. Thermostats.-The thermostat may consist of alternate strips of a metal known under the Registered Trade Mark " Invar " and brass connected together at their ends, the inner strip 9, Fig. 15, of Invar being secured to the liquid heater and the outer one of brass connected to a rod 54 which, through a link 64, and ratchet wheel and spur gears, effects the operation of the valves. The strips are enclosed in a casing filled with a lubricant, e.g. graphite, and are maintained in contact with one another by a spring 96. Fig. 20' shows another system in which the generator-absorbers are connected to a casing containing a rotatable plug having ducts 111, 112 and 115, 116 connected respectively to the cooler 28 and the liquid heater L. The cooler circuit includes an expansion vessel 66 and a pump 117. In this system air may be employed as the heating medium, and the generator-absorbers may each consist of a heat-insulated casing having partitions between which extend heating or cooling pipes 102, Fig. 21, and the space between which is packed with absorbent interpersed with bodies 83 of wire netting.