TEETER BED DENSITY CONTROL DEVICE AND METHOD

摘要

A teeter bed density control device is disclosed in a hindered-settling fluid classifier of the type having a teeter fluid supply system in a chamber with a fluidized teeter bed zone, an overflow zone and an underflow discharge outlet with the control device comprising an upper sensor for measuring average particle density from the upper boundary of the teeter bed zone to the top of the overflow zone, a lower sensor for measuring average particle density from the lower boundary of the teeter bed zone to the top of the overflow zone, a controller connected to the sensors for generating a compensating control signal based upon a preselected density standard and the average density of the teeter bed zone as determinable from the upper and lower average particle density measurements, and an actuable valve for regulating the discharge of the underflow discharge outlet with the controller being connected to the valve for actuation thereof responsive to the compensating control signal. A method for controlling the density of a teeter bed zone of a hindered-settling fluid classifier is also disclosed including the steps of selecting a desired value of average density of the teeter bed zone, measuring the average particle density from the upper boundary of the teeter bed zone to the top of the overflow zone and from the lower boundary of the teeter bed zone to the top of the overflow zone, and regulating the under flow discharge in proportion to the measured average particle densities to adjust the average density of the teeter bed zone to the selected value.