Determination of the duration of forced cooling of castings in containers on foundry rotary-conveyor lines

Abstract

The article is devoted to the developing of a methodology for determining the duration of the technological cycle of cooling castings during the aerodynamic movement of dispersed refractory in containers of foundry rotary-conveyor lines. The use of rotary-conveyor lines is an effective solution for increasing the productivity of foundry technologies. To comply with the principles of construction of rotary-conveyor lines, the cooling time of castings in a mold, as one of the longest technological processes, must be minimized. This can be achieved by forced cooling of castings using the aerodynamic movement of dispersed refractory in the foundry container. As an example of the implementation of this method on a foundry rotary-conveyor line, the sequence of technological operations on the cooling module is described. Based on thermodynamic calculations, an expression for determining the time of forced cooling was obtained, which depends on the thermophysical and geometric characteristics of the casting, the heat transfer coefficient and the temperature pressure on the surface of the casting. An example of calculating the time of forced cooling of steel castings is given. It is shown that when applying the aerodynamic movement of dispersed refractory in the container, the cooling time of the castings to the knocking temperature can be reduced by 6.6-7.5 times compared to the conventional cooling in the sand mold. By changing the airflow rate that liquefies the refractory, the forced cooling operation can be flexibly controlled for different castings that are produced on foundry rotary-conveyor lines. Keywords: casting, cooling time, dispersed refractory, temperature, rotary-conveyor line.