What is the difference between powder grinding for coal gasification and powder grinding used in power plant coal-fired boilers?

This post was last edited by cherry660 on 2012-6-7 08:08. As far as I know, under normal circumstances, the coal powder produced in power plants is directly injected into the boiler for combustion without being stored; coal gasification units generally use storage bins to hold the ground coal powder. The coal mills used in power plants include ball mills and medium-speed mills. The coal mills used in pulverized coal gasification are generally medium-speed mills.

In power plants, the ground coal is directly injected into the boiler for combustion without being stored; coal gasification units generally use silo-type systems to store the ground coal powder. The coal mills used in power plants include ball mills and medium-speed mills.

What is the difference between powder grinding for coal gasification and powder grinding used in power plant coal-fired boilers? I’m seeking advice from fellow sailors

Firstly, the requirements regarding particle size differ; in power plants, R90 is generally required to be less than 30%, while in powder gasification it is required to be less than 10%； Secondly, the powder delivery medium is different: in boilers, the powder is delivered by mixing hot air and cold air, while in gasification, it is delivered using an inert gas ； Most boilers use a positive-pressure powder feeding system, while gasification seems to rely more on negative pressure. As for storage, boilers generally do not store fuel; it seems that larger units even less so these days. In the past, boilers did have intermediate storage bins for powder, which were then fed into the furnace using fans. The safety standards for power generation are not as strict as those in the chemical industry when it comes to explosion prevention and fire suppression, but brown coal is generally not allowed to be stored in such intermediate storage bins in power generation applications.

There are no requirements regarding moisture or particle size for the coal powder used in power plants, whereas gasification of coal powder imposes quite strict requirements on these aspects – both particle size and moisture content must meet specific standards. Power plants do not have units for generating thermally inert gases for the preparation of coal powder, but gasification processes for coal powder do include such units!