Patent GB-251251-A (GB)
Abstract: 251,251. Siemens - Schuckertwerke Ges. April 23, 1925, [Convention date]. Refrigerating, absorption machines and processes for.-In continuous-cycle systems wherein a neutral gas such as air is mixed with the vapour of the refrigerant, such as ammonia sulphur dioxide or carbonic acid, to equalize the pressures throughout the system, the refrigerant is evolved from the solution into the inert gas at the cold-producing part of the system, and is again absorbed without undergoing condensation. The system may operate at a total pressure of about one atmosphere, and therefore need not be closed to the air. Preferably it is sealed by liquid columns in a U-tube. The cycle is shown diagrammatically in Fig. 1, a complete plant being shown in Fig. 2. a suitable construction of absorber in Fig. 3. an evaporator in Fig. 7, and a rectifier in Fig. 10. The generator comprises an electrically heated inclined spiral tube 15, Fig. 1, through which strong liquor flowing from the absorber 11 is lifted by the development of gas bubbles. The gas and liquor enter a separator 17 from which weak liquor rises through a pipe 12 to the absorber 11 while gas flows through a pipe 6 to a coiled riser pipe 7, through which it raises weak cold liquor flowing down the pipe 5 from the evaporator 1. The mixture enters a reabsorber 8, which is cooled by a coil 9 to effect absorption, and the strong liquor rises from the reabsorber 8 through a pipe 10 to the evaporator 1. The refrigerant vapour given off from the solution in the evaporator 1, mixed with the inert gas supplied through a pipe 3, from the absorber 11, flows through the pipe 4 to the absorber, a circulation being induced by an injector device 18, 20, as described in Specification 229,332, fed with pressure vapour from the pipe 6. The absorber is cooled by the coil 13 and the medium to be cooled flows through a coil 2 in the evaporator. The pipe 3 is open to a U-tube 21 having enlargements 22, 23 and containing a liquid seal, which also serves as a pressure gauge. In the complete plant shown in Fig. 2, two riser coils 60, 61 are employed in the generator, and the refrigerant vapour rises from the separator 64 through a rectifier 65, cooled in its upper part, and flows through a pipe 72 to a riser pipe 73 delivering into the reabsorber 76. A part of the vapour from the rectifier passes through a pipe 88 and is cooled in a jacket 112 around the gas circulating pipe 85, and is subsequently used in an injector in the pipe 86 to induce a gas circulation between the absorber 70 and evaporator 81. Heat-exchangers 67, 68, and 78, 79 are provided in the respective liquor circuits. Any solvent carried over into the evaporator eventually flows into the gas pipe 87 and down a pipe 90 to the return liquor pipe. The reabsorber 76 has an upward extension 83 which is cooled to prevent separation of vapour, but any unabsorbed vapour escapes through a pipe 84 into the gas pipe 85. A plant similar to that described above may be used for giving out heat at a relatively high temperature by passage of a medium through the cooling coil of the reabsorber, heat of lower temperature being taken in by the evaporator and absorber and also by the generator, the heating- medium of this last vessel being of only moderate temperature. Specification 7425/00 also is referred to. Absorbers. The absorber may comprise a closed casing 91. Fig. 3, fitted with a cooling- pipe 96 formed into spaced sinuous coils. An absorbent wick is wound over these coils and the liquor is sprayed over the wicks from a perforated pipe 69 at the top. The rich gas mixture enters through a pipe 86 at the bottom and the inert gas flows out at the top through a pipe 87. Evaporators. The evaporator comprises a closed vessel 98, Fig. 7, fitted with spaced plates 102 having staggered openings 103, these plates consisting of cloth washers retained between wire gauze discs. The strong liquor rises through a central pipe 80 and is sprayed downwards by a perforated plate 105, the weak liquor flowing out through a pipe 82 at the bottom. Rectifiers. The rectifier comprises a column 65, Fig. 10, fitted with segmental plates 107 providing a tortuous path for the vapour, the bulk of which passes through a pipe 72 to the reabsorber, while a part leaves by a pipe 88 to operate the injector. A cooling coil 108 is located at the top.