Title:
LEVEL CONTROLLER FOR WATER DIVIDING TANK OF WATER PURIFICATION PLANT
Document Type and Number:
Japanese Patent JPS63279309
Kind Code:
A
Abstract:
PURPOSE:To minimize the level fluctuation of a water dividing tank against the change of a requested shift transfer rate by supplying the set value for control of the transfer flow rate after a primary delay of the waste time is calculated by a waste time unit. CONSTITUTION:When the measured level of a water dividing tank 4 exceeds a fixed range, an operation output obtained by applying an intermittent PI operation to the difference between said level of the tank 4 and the prescribed level is supplied to a 1st level control means 8 via a switch means 19. Then a transfer flow rate is set via a waste time element. The flow rate correction value is calculated from the difference of time integration between the measured level of a water path 3 and that of the tank 4. Then the operation output obtained by applying a control operation to the difference from the measured level of the path 3 with the sum of the arithmetic output of said flow rate correction value and the set transfer rate defined as the set value is supplied to the means 8 as the cascade set value via the means 19 in case the level of the tank 4 is kept within a fixed range. In such a way, the level fluctuation of the tank 4 is minimized.
Inventors:
AKAMATSU NOBUO
Application Number:
JP11509187A
Publication Date:
November 16, 1988
Filing Date:
May 12, 1987
Export Citation:
Assignee:
YOKOGAWA ELECTRIC CORP
International Classes:
G05D9/12; (IPC1-7): G05D9/12
Attorney, Agent or Firm:
Shinsuke Ozawa