Temperature-control device for wax spraying machines

摘要

The temperature control of liquid wax to the optimum process injection temperature takes place conventionally by constant temperature regulation of the heat transfer medium. This regulation does not take account of the changeable mass throughput and therefore leads to great deviations from the set value in the wax. The proposed solution avoids these deviations and allows injection of structurally viscous wax. The temperature control process is completed during a sequence of control and regulation steps on a wax mass enclosed in the heat exchanger. For the subsequent wax change in a tube-bank heat exchanger, two solutions are indicated: A cooler with reversible flow is flowed through alternately in both directions, the separation of temperature-controlled and hot wax being maintained by floating pistons. A cooler with single-tube flow is flowed through in a timed manner in one direction, a mechanism in each case opening only one tube for flowing through. The device makes possible optimum adaptation of the temperature of wax on injection into the tool and thus guarantees a uniform accuracy of dimension and shape of wax models for example for precision cast parts using the lost-wax casting method. <IMAGE>