How the Retort Kiln works
The correct heat treatment of high-performance ceramics
The fill structure loaded with the products to be manufactured is transported to the furnace floor and lifted upwards via a lifting portal. As soon as the floor has reached its position under the furnace, both are locked together. To prevent heat from escaping and, at the same time, ensure a gas-tight seal, a floating seal with spring-loaded elements is used. The lifting portal is then used for loading and unloading other parallel furnaces.
During the debinding phase (up to 500 °C), the furnace load is heated by circulating hot air, which has previously been preheated by an external heater. The waste gas contaminated with the binder is cleaned in a thermal afterburning plant. At the end of the debinding phase, further heating is carried out by electrical heating elements in the furnace.
The process gas can also be kept in circulation at elevated temperatures up to 800 °C. This contributes to optimum temperature homogeneity during the heating process. The circulation of the process gas ends at temperatures above 800 °C.
Also in the subsequent process steps, no gas or air circulation takes place until the maximum temperature is reached. This is because turbulence in the furnace atmosphere is often very critical for sintering and crystallisation processes. At the end of the process, the workpieces are cooled with tempered air or gas. For this purpose, an external heating system regulates the temperature of the cooling medium in advance before it reaches the product carriers and the products. After cooling down to approx. 250 °C, the furnace floor is transferred from the lifting portal to a cooling chamber where the products are finally cooled down to room temperature.