How the hybrid kiln works
For transport through the hybrid kiln, the products are placed either on carrier plates or in capsules / saggars, the so-called ‘kiln furniture’. These can be either made of metallic, ceramic or praphite material. The kiln furniture (KF) holding the product is then pushed into the entrance double door lock via an automatic pushing device. After the atmosphere has been changed, through either simple purging or evacuation, the product is conveyed in front of the pushing machine. The pusher pusher the roduct through the furnace until it reaches the Double Door Hot Sluice and the roller conveyor.
The hybrid kiln has a modular design. Because of that design, the heat treatment process can comprise up to five partial steps. In a first heating zone, a debinding process can take place. In a second heating zone a sintering process can take place at up to 1600 °C. In a third heating zone with a controlled atmosphere, a carbonation process, for example, can take place at up to 1200 °C. For the next step an indirect cooling zone can be connected, which cools the product down to approx. 500–800 °C. The Double Door Hot Sluice described above divides the indirect from the direct cooling zone. In front of the Double Door Hot Sluice, the product conveyor changes from the push-through to the roller kiln principle. The direct cooling zone can be designed for quick cooling, to create extreme cooling gradients. Cooling times of a few minutes from 800 °C to below 200 °C are possible and can be used for hardening powder-metal components, for example. The abrupt cooling can be done in an atmosphere of nitrogen or other protective gases. Finally, a further cooling zone is added to cool the products down to the final temperature of below 60 °C.
The product is conveyed to the outside through a gas-tight exit double door lock. If needed, a fully automated return line conveys the porducts and kiln furniture to the unloading and loading station. They can also be fully automated.
