OPERATION CONTROLLER FOR DIFFERENT CAPACITY VARIABLE SPEED PUMP

PURPOSE:To make operation control automatically at high accuracy and to reduce effort of an attendant by controlling operation of each variable speed pump on the basis of flow rate information calculated by a flow rate information calculating means. CONSTITUTION:A large capacity variable speed pump 1 used when practical flow rate is large and a small capacity variable speed pump 2 used when practical flow rate is small suck liquid stored in a liquid reservoir 3 and supply to a load 5 through a common conduit 4. The conduit 4 is provided with a pressure detector 6 that detects discharge pressure of the fluid and a flow meter 7 that detects flow rate and detection signals S1, S2 are outputted to a controller 8. Pump characteristic data determined by capacity of pumps 1, 2 and conduit constant are inputted to the controller 8, and flow rate information D is calculated based on the data. The information is given to a pump controlling device 9, and pumps 1, 2 are controlled.