Improvements in automatic systems for adjusting a filtration plant, operated by the filtered water requirement

摘要

693,101. Filters; controlling distribution of liquids to filters. CHABAL & CIE. C. March 24, 1949 [March 26, 1948; Feb. 25, 1949], Nos. 8021/49 and 8022/49. Class 46 [Also in Group XXIX] In an automatic filtration plant control system. responsive to demand wherein each of the units, e.g. 6, 7, in parallel respectively in a stage, e.g., 3, 4, of the plant is provided with means, controlling the unit water level, responsive to the next down. stream water level and comprising a flow adjusting device, e.g. 15, 16, at the downstream end of the unit, a water chamber, e.g. 40, associated with the device, means actuated by the head of water in the chamber for operating the device to control the passage of water inversely to the level in the chamber to keep the level in the chamber substantially constant at C, and an accurately sized orifice, e.g. 17, 18, downstream of the device for delivering into a common collector, e.g. 10, 11, for all the units under a head h' formed by the difference of water levels in the chamber and collector, a feeding canal e.g. 8, 9 provides a common inlet level for all the units of a stage fed from all the units of the next upstream stage. When the demand for filtered water increases at 5 the level in collector 11 tends to decrease and lower the level in chamber 40 so that the device 16 allows more water to flow from filter 7 to maintain the level. These steps are carried by degrees up to the decantirig reservoir 2 where an inlet adjusting device 12 allows more raw water to enter the plant. The level D in the collectors when the orifices are unwatered corresponds to the maximum flow. Before each stage level adjusting devices 13, 14, may be provided to stop the upstream level of the next. downstream stage at a predetermined level, but if they are dispensed with, the feeding and collecting canals are combined and the walls of the lower stages built up to accommodate large level variations. The adjusting devices may consist of balanced valves and may be operated by the level in a branched water chamber or a manometric capsule. A main pipe containing any device e.g. an automatic throttle valve, preventing the pressure in it decreasing below a minimum value may replace the collector.