GB191218511A - Improvements in Absorption Machines for Transforming Heat, Cold and Mechanical Work. - Google Patents

Abstract

18,511. Altenkirch, E., and Tenckhoff, B. Aug. 11, 1911, [Convention date]. Vapour - engines.- Relates to machines an apparatus for transforming energy between the forms of heat, cold, and mechanical work, known in connexion with refrigerating processes as absorption machines, and consists principally in arranging such machines to work according to the polytropic cycle, wherein heat-transference occurs throughout at a small temperaturedifference. This is effected by arranging suitable temperature ranges in the absorber and generator and by applying the principle of counterflow to the liquid passing through these chambers. The machine, operating typically with an aqueous solution of ammonia, is shown diagrammatically in Fig. 1, wherein from the absorber a the cold rich liquor is forced by a pump e into the piping f, and goes back through the absorber in counterflow (taking heat therefrom) before leaving it. The liquor then enters a heatexchanger p and cools the hot weak liquor coming from the generator b, after which it enters the top of the generator b, where it descends, becoming denser as distillation proceeds, and, entering the pipe g at q, re-traverses the generator in counterflow. Thence it is forced through the exchanger, yielding heat to the liquor passing to the generator, and finally reaches the absorber. The circuit for the distilled ammonia vapour is through a condenser c to a refrigerator d in which it evaporates, and thence to the absorber. A steam-heating coil h supplies heat to the generator, and cooling-water coils i are provided for the absorber and condenser, the cold produced in the refrigerator being conveyed away by the pipes of a brine system n. In cases where distillation is increased so that the lowest temperature of the generator is the same as the highest temperature of the absorber, a heat-exchanger is not employed. In place of ammonia liquor, other binary or more complicated liquors, say liquid air, or brine, may be employed. The Specification as open to inspection under Section 91 (3) (a) comprises also the following. In cases wherein the highest temperature of the absorber exceeds the lowest temperature of the generator, those portions of the chambers which thus overlap in temperature may be arranged for mutual exchange of heat, provision being made for the difference in the quantities of heat to be exchanged. Fig. 4 (Cancelled) shows a plant wherein the exchange is effected between the parts of the absorber a and the generator b by means of tubes k of different cross-section, the gas evolved in the generator passing to the working-cylinder o of a vapour engine for the production of mechanical work. To prevent high pressure in the condenser, refrigeration is effected by absorption and gas generation, in place of condensation and evaporation, the above - mentioned principles of counterflow and of heat exchange being applied to the auxiliary generator and auxiliary absorber, and the lowest temperature of the auxiliary absorber may thus be considerably below that of the cooling-water, suitable pumps and controlling - valves being employed. In order to reduce pressure in the main absorber, the vapour leaving the refrigerator may be absorbed by a separate absorber, associated with a generator, from which the vapour passes to the main absorber, wherein the same final temperature is maintained but at a lower pressure, giving less concentration and therefore a higher lowest temperature of the main generator. Several stages of absorption and generation may be employed between the refrigerator and the main absorber, according to the desired fall of temperature and to the temperature of the cooling-water, a rectifier being sometimes employed for the removal of steam. Efficiency is secured by raising the highest temperature of the generator, for which purpose three or more absorption machines may be arranged in series as shown in Fig. 6 (Cancelled), the condenser c and absorber a of the second machine 2 exchanging heat with the generator b of the first machine 1, and since the heat generated in the condenser and absorber of a machine is always greater than that absorbed in the condenser, the quantity of heat to be supplied to the higher temperature machines becomes less for the same cooling effect, excess of heat being produced. The refrigerator of the second machine may cool the absorber of the first, and the relative dimensions may be such that the excess heat production in one machine suffices to heat the generator of another. An example is given of a similar three-stage plant for the production of mechanical work. By reversing the operation of all parts in the above process, high-temperature heat may be generated from a heat source at lower temperature. Fig 9 (Cancelled) shows a plant for heating steam boilers, wherein the heat of absorption of the absorber u of a watervapour absorption machine is used for the purpose of driving a reversed ammonia absorption machine. Thus the generator v cylinder o, absorber u, and heat-exchanger k correspond to the parts b, o, a, k respectively of the plant shown in Fig. 4. The heating-coil h passes through the generator of the reversed absorption machine, the heat of the colder end of the watervapour absorber u is used, by means of a heatexchanging coil w, to heat the auxiliary evaporator d, while the heat generated in the auxiliary absorber e assists, by means of a heating-coil w, to heat the generator v. This subject-matter does not appear in the Specification as accepted.