초록 ▼

The present invention is directed to a method and apparatus for maintaining steady state conditions in a separator. Steady state is maintained by controlling mass flow rates of influent to, and underflow from the separator. Specifically, an influent specific gravity and flow rate signals are monitor

The present invention is directed to a method and apparatus for maintaining steady state conditions in a separator. Steady state is maintained by controlling mass flow rates of influent to, and underflow from the separator. Specifically, an influent specific gravity and flow rate signals are monitored by an influent mass flow controller. That controller responds to variation in these signals to maintain a constant mass feed rate into the separator. A mass flow signal, comprising a composite of influent specific gravity and influent mass flow signals, is produced. That signal is fed to a thickener controller which also monitors mass flow of the underflow. The thickener controller adjusts the mass flow rate of the underflow in response to the influent mass flow signal. However, fluctuation of an interface level between clear and unclear areas of the thickener can effect flow rate adjustment. The purpose of such an override is correction for errors in the mass control signal as well as for changes in flocculant feed rate. This invention can be adapted to operate a system containing multiple solid-liquid separation devices.

대표청구항 ▼

A method for controlling a liquid-solid separation process in which an interface is formed so that substantially steady state operation is maintained comprising steps for: (a) feeding a contaminated liquid-solid influent into a first separator; (b) withdrawing a substantially clear liquid overflow a

A method for controlling a liquid-solid separation process in which an interface is formed so that substantially steady state operation is maintained comprising steps for: (a) feeding a contaminated liquid-solid influent into a first separator; (b) withdrawing a substantially clear liquid overflow and a substantially solid contaminant underflow therefrom; (c) metering specific gravity and flow rate of the liquid-solid influent; (d) adjusting mass flow rate in response to fluctuations in the metered parameters of step (c) to maintain a desired substantially constant mass flow rate of liquid-solid influent into the separator; (e) metering specific gravity and flow rate of the substantially solid contaminant underflow; (f) adjusting mass flow rate of the substantially solid-contaminant underflow according to the adjustment of step (d); (g) monitoring an interface level between clear and unclear areas of the separator; and (h) correcting the adjustment of step (f) according to fluctuations of the interface level.