As you can float in

摘要

PROBLEM TO BE SOLVED: To simplify a device configuration, and to dilute a concentration stably by accurately controlling the amount of supply of a chemical liquid and a liquid for dilution and generating a dilution chemical liquid with a stable concentration and then mechanically controlling the operation. ;SOLUTION: A liquid B for dilution is supplied to a tank 22 for diluting chemical liquid and the supply is stopped by a switching valve 23, and a constant amount of chemical liquid C is supplied by a metering pump 24. The switching valve 23 is opened and closed by the up/down movement of a rocking arm 26a being mounted to one edge of a float 25 being floated in a diluted chemical liquid A of the tank 22 for diluting chemical liquid. The liquid B for dilution from the switching valve 23 is temporarily stored in an auxiliary container 27, and a hydraulic fluid supply pipe 29 branches the liquid B for dilution at the upstream side of the switching valve 23 and feeds a hydraulic liquid D to the metering pump 24. A pump drive control valve 30 is provided halfway, and the hydraulic fluid supply pipe 29 is released to the tank 22 for dilution chemical liquid due to the descent of the rocking arm 26a, thus stopping the supply of the hydraulic liquid D to the metering pump 24. A dilute chemical liquid supply control valve 31 opens and closes a delivery port 21 along with the rocking of the rocking arm 26a and supplies the liquid to an equipment at a rear stage.;COPYRIGHT: (C)1998,JPO