Making light alloy heat exchanger of complex shape using lost polystyrene casting procedure, coats model with thin layer of porous ceramic before casting in conventional sand box without binder

摘要

A model of the heat exchanger is made in plastic, which vaporizes at the melting temperature of the metal. The surfaces of the model are coated with a gas-permeable, supportive layer of heat-resistant material. Molten metal is cast onto the copy, within the gas permeable layer, vaporizing the plastic and replacing it with metal. An Independent claim is included for the heat exchanger so made. Preferred features: The ceramic coating is overcoated with a supportive, porous, second heat resistant material (i.e. sand in sand box). The heat exchanger includes a number of structures summarized as inlet and outlet channels, thermal transfer elements, a U-shaped flow path, a common flanged construction of inlet and outlet, a flow channel with spaced turns. In addition the structure is further detailed in terms of its projections and convolutions; features all emphasizing the complex nature of the casting.