Hot fluid ducts with clad internal insulation - ceramic pellets between metal liners keep pressure walls cool

摘要

A duct to carry very hot gases or liqs. is lined internally with insulation clad on both sides to protect the pressure walls from heat. A large dia. duct is lined with a layer of insulating matl. located between two liners. This insulating matl. could for example be hollow pebbles of ceramic matl. The insulation is kept in posn. axially by 'Z' shaped baffles between the two liners, which also serve to locate the liners. The clearance between the outer liner and the duct wall must be sufficient to permit the differential expansion. Outside the pressure duct there is a corrugated cover, provided with air cooling and outside this a layer of protective insulation.