Coal ball-mill crusher level continuous indicating appts.

摘要

The appts. continuously monitors the quantity of coal inside a crusher of coal nuts supplying a coal burning boiler. An emitter (35) of ultrasonic or electromagnetic waves passes waves through at least part of the interior of the crusher towards a receiver (36). An electronic circuit monitors the received wave and calculates the quantity of coal present by comparison with previous readings obtained during a calibration process. The measurement can be used to control the feed of nuts into the crusher. Analysis of the received wave may be by the absorption of the wave within the coal or by modification to its speed of transmission.