Patent GB-190201034-A (GB)
Title: Improvements in Refrigerating Machinery.
Inventor: CRACKNELL RICHARD JOHN
Filed: 1902-01-14
Granted: 1903-04-14
Abstract: 1034. Cracknell, R. J. Jan. 14. Refrigerating. - Ammonia-absorption machines are simplified in construction to reduce the cost of manufacture. The rectifier B, heater C, absorber D, condenser E, and generator F<1> are arranged and connected as shown in Fig. 12. The generator, which is shown in section in Figs. 1, 2, and 3, consists of a cylindrical vessel A, preferably with one end B welded in, and the other end C bolted on. The steam pipes D are closed at one end, and are screwed or expanded at the open ends into the part C. Surrounding the open ends is a cover E. Perforated pipes H, arranged as shown, are closed at one end, and the open ends are secured to a header J. On each pipe H is hung a curtain or screen of wire gauze L, attached to which is a hood M. At the top of the generator is a perforated pipe P, closed at one end and connected to an outlet pipe Q. At the bottom is a similar pipe S connected to a pipe T. Perforated or slit pipes U, partially closed at one end, are connected at the open ends to a supply pipe W. A tie-bolt Y is secured to the ends of the generator, as shown, and over one end of the bolt is fitted a cap C', the construction being such as to ensure a gas-tight joint. The strong ammonia liquor, which is pumped back through the heater, enters the pipe H by the pipe K, and, passing into the hood, flows down along the wire gauze, being heated and partially evaporated by the ascending ammonia gas, the escaping gas passing through the perforated pipe P and outlet Q to the rectifier, from which the condensed vapour impurity returns to the generator by the pipe W. The weak liquor passes to the heater along the outlet pipe T. The condenser is constructed like the generator, and is entirely fitted with pipes corresponding with the pipes D of the generator. Within these pipes are fitted smaller pipes, the cooling-water circulating in the lower part of the condenser through the smaller pipes, and back through the larger pipes, and in the upper part of the condenser in the reverse direction. The ammonia gas from the rectifier passes by the pipe L<1> to the top of the condenser, and the liquefied gas escapes to the refrigerator coils by the pipe M<1>. In the absorber the water circulates as in the condenser, and the larger pipes are surrounded by sheaths of wire gauze, on which the weak liquor falls from a perforated tray fitted with side wings, and takes up the ammonia gas entering by the pipe Z, Fig. 12, from the refrigerator coils. The strong ammonia liquor thus formed passes through the pipe R to the suction pipe of the ammonia pump, and thence by the pipe V to the heater C. The closed-ended cooling-tubes in the heater extend over only a portion of its length, the remainder being fitted with similar pipes, or with pipes which are expanded into annular headers, through which the strong ammonia liquor circulates, escaping by the pipe U back to the generator. The hot weak liquor from the generator enters the top of the heater by the pipe T, gives up heat to the strong liquor, becomes further cooled by the cooling- tubes, and finally passes by the pipe X to the absorber. The rectifier is suitably fitted with baffle-plates to ensure the circulation of the ammonia gas round the cooling-tubes, and thus the condensation of the accompanying vapour. The flow of weak liquor into the absorber is regulated by a float-actuated valve, Figs. 9 and 10, consisting of a casing H<1> having a branch K<1>, in which is fixed a sleeve Q<1>, having four holes R<1> corresponding with four holes in an inner rotating valve S, on one end of which a float U<1> is mounted by means of an arm V<1>. The weak liquor enters by the pipe X<1>, and passes through the perforations in the valve and sleeve into an annular space S<2>, and thence by the pipe P to the absorber, from which it is pumped through the pipe R. The valve casing being connected with the top and bottom of the absorber by the pipes Z<1>, Y<1>, the level of the liquid in the casing corresponds with that in the absorber, and the float accordingly, by rotating the valve, serves to regulate the flow of weak liquor. The valve is further regulated by a screw O<1>, which moves the valve longitudinally to regulate the effective size of the apertures.