Mixer with coolant fed shaft for hot materials - such as coal pyrolysis and briquetting materials

摘要

A mixer has >=1 mixer shaft through which a coolant flows, and which is particularly for operation at temps. in excess of 500 degrees C. The shaft incorporates a coolant pipe and an air gap is maintained between the outside of the coolant pipe and mixer shaft. Lower intensity cooling can be achieved to reduce heat losses from the material being mixed and to minimise thermal stresses in the coolant shaft. This lower intensity cooling is achieved using water cooling, which is cheaper simpler and safer than cooling with oil, steam etc. The mixer can be usefully applied in situations where a recycled fine-grained heat carrying solid is mixed with fresh cold material, e.g. in pyrolysis of coal and prodn. of hot briquetting materials.