Bogie hearth furnaces, pit-type furnaces and also top hat furnaces are suitable for processes in which heavy and thick-walled components are heat treated and where quench delay times are not especially critical. The furnace is loaded and the hot charge is transferred to the quenching medium with a crane or forklift truck. The bogie of a bogie hearth furnace is loaded outside the furnace. When the design includes an electro-hydraulic lift door and a motorized bogie, the furnace can be opened while hot and the load can be removed for cooling or quenching.
Top hat furnaces, which allow a very compact design, are an alternative to bogie hearth furnaces. The top hat creates a very good seal with the movable table, which is a requirement for good temperature uniformity and energy efficiency. As the table moves to the side, this allows convenient loading. Especially sensitive charges can be loaded beneath the top hat and do not have to be moved much more.
If the components are high, pit-type furnaces are suitable for heat treatment. These furnaces can be opened at high temperatures and the charge is then transferred to the quench tank by a crane.
Many heat treatment processes for metals generally take place in protective or reaction gases or in vacuum to prevent or minimize oxidation of the components. Heat treatment systems for these processes can be found in our catalog "Thermal Process Technology 2, furnaces and heat treatment plants for processes under protective or reactive gases or in vacuum".