Blog Thanks to the new __sand__ refrigerator, the castings are of higher quality.

The modernization that significantly enhances the quality of castings has been completed by the grey iron foundry of MOTORU JIKOV Foundry a.s. Over seven million crowns were invested in the installation of a new sand treatment cooler.
Ivan Hotový, the technical manager of the Grey Iron Foundry division at MOTORU JIKOV Foundry a.s., explained the purpose of the cooler: “Molten metal at temperatures up to 1400 degrees Celsius is poured into a sand molding mixture (PFS), which then passes through a line for an hour. The PFS entering the line at 35 degrees Celsius with a humidity between 2.5 and 3.5 percent naturally warms up and dries out. Since we reuse the mixture, it needs to be cooled and its moisture content adjusted, which is precisely what the cooler does,” he described. The device, known in English as a *cooling mixer*, mixes the PFS heated to over 75 degrees Celsius, adding water to humidify and cool the mixture.

Maintaining stable properties of the sand molding mixture is essential to achieve the desired quality of the castings, especially concerning surface and dimensional parameters. “If the PFS parameters are not met, defect rates increase, leading to higher costs for repairs and rework. During the period when we operated without a cooler, defect and rework costs rose by 35 percent. The investment cost will be recovered within two years,” emphasized Tomáš Vítů, Director of the Grey Iron Foundry division at MOTORU JIKOV Foundry a.s.
The new cooler, manufactured by the American brand Simpson, replaced a device that had been in operation for over thirty years. “Besides being more modern, we also improved the working cycle of the cooler. Previously, the PFS was fed directly from the molding line’s shaking out grids into the cooler. Now, we have installed a twelve-ton supply hopper that ensures cyclical operation of the cooler. Once the hopper is filled, a consistent amount of PFS is continuously supplied, making regulation easier and enabling the achievement of optimal properties of the PFS at the cooler’s output,” Ivan Hotový added.