GB252421A - Improvements in centrifugal liquid purifiers - Google Patents

Abstract

252,421. De Laval Chadburn Co., Ltd., and Chadburn, W. R. Jan. 27. 1925. Density separators; discharging; preventing atmospheric reaction. -An inert, or otherwise desirable gas, is introduced through the stationary casing of a centrifugal purifier for liquids, into the chambers in which the liquids are sprayed from the bowl, so that the gas can operate by direct contact with the liquids. In the arrangement shown in Fig. 1, the bowl 1 discharges freely one liquid which is collected in the casing 3 and passes through the spout 4 to the collecting-tank 9. The desirable gas is supplied from the reservoir 7 through the pipe 6 and regulating valve 8 so that the chamber inside the casing 3 is kept at a pressure above atmospheric pressure. As it is sprayed through the chamber the liquid absorbs gas and passes on to the tank 9 where more gas may be absorbed from that carried over by the liquid as the separation in the tank often takes a considerable time. Gas absorbed by the liquid before it is supplied to the centrifugal machine will be replaced by the desirable gas during the action. In a modified form of apparatus, economy of the desirable gas, such as carbonic acid gas, oxygen, or nitrogen is effected by circulating arrangements. A vacuum pump 12, Fig. 2, is used to withdraw air from the system at starting; its connection to the system includes the valve 15 which shuts automatically when a predetermined difference of pressure exists between inside and outside the system. The desirable gas is then supplied. The outlet 4 from the centrifugal machine is connected by a pipe to the enclosed tank 10 and this pipe not only conveys liquid and gas to the tank, but conveys separated gas from the tank back to the casing 3. If desired, another pipe 16 may be used to convey the gas back from the tank. As soon as the liquid in the tank 10 reaches a certain height a flow commences in the pipe 11. As the system works under a pressure greater than that of the atmosphere, packing joints and liquid seals are used to prevent leakage. In another modification, the separator delivers two liquids to chambers in its casing which are connected to two separate tanks. To equalize the gas pressures these tanks are connected by a pipe, and the pipe may include some moistureabsorbing arrangement. The collecting-tanks used in these systems may contain a number of thin partitions 22, Fig. 4, inclined to the vertical; the liquid passes through in thin layers and the escape and return of the desirable gas is facilitated. With the apparatus described, oxygen in oils may be replaced by inert gases such as carbonic acid gas or nitrogen, or oxygen in boiler-feed water may be replaced by inert gas to precent corrosion of the boiler.