Study and Apply on Field Test Instrument for Specific Resistivity of Fly Ash Burned Coal

The probe of this instrument can be inserted into the flue directly for testing the specific resistivity of fly ash. It adopts the ceramic filtration catcher and iso-speed sampling based on static pressure balance technique with parallel short-tube. The collection efficiency of ceramic filtration catcher (eta) can reach even exceed 99.9%, and the error of sampling in different velocities is less than 5%. All these make the sameness between samples and the actual fly ash in many facets, including size distribution, carbon content, element compositions, etc. The coefficient of optimizing ringed electrode for concentric cirques k is 14.6, which can adapt all kinds of fly ash whose specific resistivity is in the range from 10⁴ to 10¹³ Omega ldr cm. In addition, the ceramic filtration catcher made of white corundum powder can endure high temperature, high voltage, and acid cauterization. So this test instrument can work well under the conditions in which the flue temperature is from room temperature to 300degC and in the caustic gas. Ceramic filtration catcher also has many excellences, such as avoiding disassembly, cleaning ash easily, repeating use for long time. This instrument has obtained the invention patent in China and applied widely in the domestic range.