Title:
CONTROL SYSTEM FOR RATIO FLOW RATE
Document Type and Number:
Japanese Patent JPS59136816
Kind Code:
A
Abstract:
PURPOSE:To secure a desired flow rate ratio despite of a fault generated at an operation terminal by changing the standard detection terminal for ratio when the difference is large between the detected flow rate of a control system for ratio flow rate and the target value. CONSTITUTION:A flow rate control system consisting of a detecting terminal 3, a controller 1 and a control valve 5 is set at a flow rate decided by a setter 8. While a ratio flow rate control system consisting of a detecting terminal 4, a controller 2 and a control valve 6 controls the flow rate by defining the value obtained by multiplying the flow rate detection value given from the terminal 3 by a ratio through a ratio setter 10 as the target value. This target value of flow rate is compared with the output of the terminal 4 by a deviation alarm 11, and an alarm signal is delivered. When the valve 6 is unable to secure a normal flow rate due to the stay of the fluid, etc., a switch 9 is actuated with the signal of the alarm 11. Then the target value of a flow rate control system is turned into the output of a ratio setter 7. The target value of the controller 2 is kept at the output value of the terminal 3 set right before the switching by a set value holder 12. Then the ratio of the setter 7 is set at a reciprocal number of the setter 10. Thus it is possible to keep a constant flow rate ratio for those two control systems before and after the switching.
Inventors:
TAIRA MAKOTO
Application Number:
JP982183A
Publication Date:
August 06, 1984
Filing Date:
January 26, 1983
Export Citation:
Assignee:
HITACHI LTD
International Classes:
G05D11/13; (IPC1-7): G05D11/13
Attorney, Agent or Firm:
Akio Takahashi