Control of grinding mill supplying pulverised coal burner

摘要

The drive system is for a solid fuel burner adapted for burning coal and accepting powdered coal from a commutation mill. Various properties of the coal, including moisture content and ash content, affect the combustion process especially production of steam. In normal practice a sample of the coal supply is taken and chemically analysed using a wet process. The sampling and analysis procedures are done so that the results arrive just as the sampled coal is about to go into the grinding machine. The action of the grinding machine is optimised in the light of this data. The modified control system uses real-time analysis of the incoming coal. It involves production of a plasma of vaporised coal and a spectroscopic analysis machine directly connected to automatic controls. The temperature of the carrier air stream is regulated in accordance with the moisture content of the coal.