FLOW RATE CONTROL DEVICE FOR SLURRY FLUID

摘要

PURPOSE:To obtain the title controller stably controllable for a long period of time without clogging in the vicinity of valves by installing a flow regulating valve in a flow channel of a slurried fluid containing a solid content, providing the flow regulating valve with valve control power based on a PID control signal and with a rapid switching action to control flow rate. CONSTITUTION:In a flow rate controller of slurried fluid such as heavy oil of liquefied coal, a flow regulating valve 2 is installed in a flow channel 1 of a slurried fluid containing a solid content and a driving part 3 of the flow regulating valve 2 is provided with valve control power which is obtained by inputting a detected signal PV discovered by a liquid level detector, a set signal SV, etc., into a PID controller 4 and synthesizing valve divergence analog output based on the PID control signal and alternating rectangular wave output to alternatively in positive and negative generate pulses having pulse amplitude of about several % of valve divergence analog output corresponding to whole opening of valve and about several seconds of pulse period so that a flow rate is infinitely controlled while intermittently supplying rapidly switching action to the flow regulating valve 2.