Justification of the method for calculating the calibration sleeve for the production of thermoplastic pipes

The task of improving the quality of the production of pipes for engineering networks of various purposes with forecasting performance takes on special importance in the face of increased demand in modern conditions. A significant influence on the solution of this problem is found in the organization of heat exchange in the calibrated device. Based on the theoretical analysis of heat exchange during pipe calibration, an improved method is proposed, which consists of calculating the temperature field in the pipe wall during the movement of the pipe billet through different zones of the calibrator with controlled thermal resistance between the surfaces of the polymer pipe and the calibrator. This approach makes it possible to determine the intensity of heat removal, depending on the state of the pipe material during solidification at a given speed of movement of the workpiece, taking into account the change in the thermophysical properties of the pipe material and to more accurately determine the rational heat exchange surface in the calibrator, which is expressed in the length of its sleeve. The proposed method was approved when calculating the calibrator during the production of a polyethylene pipe with a diameter of 500 mm and a wall thickness of 30 mm with a pipe production speed of 8 m/min. in which the calculated length is 862 mm, the working length of the sleeve is 880 mm, the convergence is 98 %.