Solid-to-gas ratio in coal powder transportation

The oxygen-to-coal ratio should be maintained at around 0.89, with corresponding adjustments needed for different types of coal

What is the relationship between transportation and the oxygen-coal ratio?

I’m a bit puzzled; 1. The oxygen-coal ratio is involved in coal gasification. It is an important indicator for fluidized bed gasification; when other conditions remain constant, the temperature of the gasifier depends mainly on the oxygen-to-coal ratio. Increasing this ratio can significantly raise the conversion rate of carbon. However, when too much oxygen is used, some of the carbon will burn completely to produce carbon dioxide, or it will burn incompletely to form CO (which then turns into carbon dioxide upon oxidation), thereby reducing the effective components in the gas and lowering the gasification efficiency. The appropriate oxygen-coal ratio is generally 1.0 Kg/Kg. I believe that for the transportation of coal powder in dry coal powder gasification, N2 should be used instead of air directly. When dry coal powder comes into contact with air – namely, the combustible coal powder and the oxidizing agent air (oxygen) – using air for transportation can result in sparks being generated due to friction between the coal powder and the pipes; these sparks may exceed the ignition point of the coal powder, leading to combustion in mild cases and explosions in severe cases. I earnestly ask experts to leave their comments!

Well, you’re right; that’s the term used in gasification. I am now using compressed air to transport coal powder for combustion in the boiler.

So I wondered, theoretically, can’t coal powder be transported using compressed air? :(

Yes, an inert gas must be used during transportation; otherwise it’s very dangerous

Nitrogen is generally used for transporting coal powder. An increased oxygen-to-coal ratio can accelerate coal gasification and raise the furnace temperature; therefore, the oxygen-to-coal ratio is a very important parameter

Hehe, I’m only familiar with the transportation of dry coal powder. When using nitrogen for transportation, the solid-to-gas ratio is roughly 6.53:1; this is just for reference

Hot air is used, but nitrogen is injected into it to ensure that the oxygen level does not exceed the allowed limit. The solid-to-gas ratio is 0.42; there are significant differences among different processes.

But currently, many steel plants use compressed air to transport coal powder to blast furnaces, and no explosions have occurred. And it is emphasized that nitrogen delivery must not be used