APPARATUS FOR EXTRACTING HEAT FROM A HYGROSCOPIC PULVERULENT MATERIAL WITH A TEMPERATURE LOWER THAN 100 DEGREES CENTIGRADE

摘要

Spray nozzles (16, 18, 20) inject just sufficient water to produce the desired cooling of hot powdered substance by evaporation of the water. The water is sprayed finely and uniformly onto said substance to avoid wet lumps agglomerating. The substance comes from a hopper (2), and flows through the apparatus in the opposite direction to a drying gas flow from inlet (21) to a condenser (22) where the heat is recovered from the water vapor. Application to recycling foundry sand and, more generably, to using sand which has been heated.