AshScanDuo® online coal ash and moisture analyser
The AshScanDuo online coal ash and moisture analyser combines dual energy gamma ray transmission (DUET) technology, also referred to as LET technology, to measure ash, with microwave technology to measure moisture.
The dual energy gamma-ray transmission utilises two sources of energy; Americium-241 (Am-241), a low energy source, and Cesium-137 (Cs-137),a high energy source.
A collimated beam of duel energy radiation is emitted from the sources mounted under the belt conveyor, through the coal, to a detector mounted above the coal on the conveyor.
Both the intensity of Am-241 and Cs-137 depend on the mass per unit area of coal. The intensity of the low energy Am-241 however, also depends on the total atomic number of the coal, which varies in proportion to the amount of ash-in-coal.
By separately measuring the intensities of Am-241 and Cs-137 using a scintillation detector, total ash in coal, independent of thickness, layering and vertical segregation, is accurately measured.
Microwave transmission measures the moisture in coal, in real time, on a conveyor. A microwave transmitter is mounted underneath the conveyor belt and a microwave receiver is mounted above the coal on the conveyor. By measuring variation in the absorption of the microwave signal moisture content in the coal is determined.
The DUET and microwave technologies are integrated into a C-Frame which is attached to the stringers on the conveyor. This enables the AshScanDuo on-line coal ash and moisture analyzer to determine the ash percentage in coal on a dry basis.
The AshScanDuo is commonly used in the coal and power industries for:
Online Coal Ash and Moisture Analyser – AshScan Duo Brochure
Application Data Sheet – Application Questionnaire