Method and apparatus for curing a foundry core

Abstract

A method and apparatus is disclosed for the high-speed production of foundry cores of the type in which a foundry aggregate is mixed with a curable binder, preferably an isocyanate or phenolic material, to form a core mixture which is carried within a hermetically sealed core box and is hardened by the introduction into the core box of a gaseous curing agent, preferably an amine. A positive displacement pump pumps a predetermined amount of liquid amine from a holding tank to a vaporizer where it is heated and completely vaporized. The vaporized curing agent is forced from the vaporizer by the introduction of an inert gas, preferably nitrogen, and the mixture of the inert gas and the vaporized curing agent is entrained in a low pressure air stream which carries it to the core box, thereby curing the core. After the core is cured, valves close to stop the flow of the low pressure air stream, the mixture of inert gas and curing agent to the low pressure air stream, and the flow of inert gas to the vaporizer. At this time, a high pressure air stream is introduced into the core box thereby purging the curing agent from the core, and, simultaneously, the positive displacement pump is activated to dispense another predetermined amount of liquid amine into the vaporizer to initiate the process. The system includes a control for sequentially opening and closing the valves and activating the positive displacement pump.

Dependencies are inferred from the claim text.