Transfer of the heat from thermally treated foundry sand to the used sand to be regenerated

摘要

The foundry sand reprocessing can be carried out according to the invention in a considerably more economical manner if the heat of the thermally treated sand is used for preheating the sand which is to be regenerated. A single-stage heat exchange via heat exchange surfaces forming vertical honeycomb-like channels or in a rotary pipe cooler with an inner drum and an outer drum is preferred. The interposition of a liquid medium for the heat transfer to a second heat exchanger, in which the cold used foundry sand is preheated, is also possible. While allowing for two specific difficulties, namely the transport of the sand which is to be preheated, and increased wear, considerable quantities of energy can be saved without substantial investment costs and operating material costs. <IMAGE>