Lifting hearth plant/ Top-hat-furnaces

Lifting hearth plant/ Top-hat-furnaces

Efficient lifting hearth plants from PADELTTHERM®

Lifting hearth furnaces with a fixed lifting platform

A lift­ing hearth fur­nace can be used for the ther­mal treat­ment of par­tic­u­larly long com­po­nents. Load­ing is done using a charg­ing ma­chine which places the input ma­te­ri­als di­rectly on the fur­nace. With this type of plant it is pos­si­ble to open the lift­ing hearth in the upper tem­per­a­ture ranges and to keep the heat losses much lower than with the con­ven­tional bogie hearth fur­nace.

The di­a­gram shows a fur­nace for tem­per­ing and an­neal­ing rail pieces of up to 35 m in length for high-speed trains. The batch di­men­sions are 1,500 x 35,000 x 400 mm (width x length x height) and the op­er­at­ing mass is 35 t. The plant is heated using 42 re­cu­per­a­tor burn­ers, whereby every three burn­ers form a con­trol zone. For in­su­la­tion pur­poses we se­lected a low-heat-re­tain­ing full fibre lin­ing. The hearth is sealed off against the bon­net with an all-round ce­ramic fibre seal. Fur­ther­more, the fur­nace is de­signed in such a way that it can be ex­tended by 65 m of ef­fec­tive length.

Lifting hearth furnaces with a mobile lifting platform

For this type of fur­nace, the lift­ing plat­forms can be dri­ven to the front of the fur­nace to en­able load­ing with the crane. There­after the lift­ing plat­form is au­to­mat­i­cally dri­ven under the fur­nace and then re­tracted up into the fur­nace.

Shown here is a plant for 28 t with batch di­men­sions of 3,000 x 12,940 x 2,000 mm (width x length x height). It was built by col­lec­tors for an­neal­ing and re­leas­ing ten­sion for high per­for­mance steam gen­er­a­tors. A par­ti­tioned bogie hearth en­sures that the fur­nace can also be op­er­ated with two in­de­pen­dent sin­gle cham­bers. Tem­per­a­ture is reg­u­lated ac­cord­ing to the tem­per­a­ture of the input ma­te­ri­als. This made it pos­si­ble to at­tain a de­vi­a­tion of less than +/- 2K of the set tem­per­a­ture in the range of 150-850 °C.

Universal thermal treatment plants

The pic­ture shows a uni­ver­sal fur­nace for a va­ri­ety of ther­mal treat­ment tech­nolo­gies, dif­fer­ent as­sort­ment sizes and a wide range of di­men­sions for the input ma­te­ri­als.

Many black­smith work­shops and foundries are faced with the sit­u­a­tion that a very di­verse as­sort­ment of sizes with rel­a­tively small num­bers of pieces must be sub­jected to con­stantly chang­ing ther­mal treat­ment processes at short no­tice.

The prob­lem is how to im­ple­ment the re­quired ther­mal treat­ment tech­nolo­gies in a fur­nace in the small­est in­stal­la­tion room with the high­est pos­si­ble through­put and in the process be able to at­tain re­pro­ducible val­ues and the con­ti­nu­ity of re­sults.

The so­lu­tion lies in the au­to­matic ex­pi­ra­tion of the ther­mal treat­ment in a com­plete plant with ac­cept­able costs/per­for­mance, sub­di­vided into in­ter­linked tech­nolo­gies.

Custom-built for blacksmith and foundry operations

A lift­ing hearth plant was de­vel­oped and built by PADELT­THERM GmbH where al­most the whole range of re­quired tech­no­log­i­cal ther­mal treat­ments, such as

can be cov­ered by black­smiths and foundries.

The top hat furnace - in accordance with individual customer wishes

The top hat fur­nace is a coun­ter­part to the lift­ing hearth fur­nace. The fur­nace is firmly fixed to the ground and the bon­net to­gether with the heat­ing de­vice is moved up­wards.

Over 50 dif­fer­ent types have al­ready been de­signed. These in­clude, for ex­am­ple, those with us­able space of 60 m³ or also with an ef­fec­tive width of 35 m. Heat­ing is done with elec­tric­ity or gas. These fur­nace sys­tems, like all our in­dus­trial fur­naces, stand out par­tic­u­larly due to their solid man­ual work­man­ship and use of the most mod­ern ma­te­ri­als.

Thermal treatment plants for sintering and dewaxing

Shown here is a plant for de­wax­ing and sin­ter­ing re­frac­tory clay moulds. The di­am­e­ter of the us­able space is 2,840 mm and the height is 4,000 mm. The gas heater and the air cir­cu­la­tion sys­tem are in­te­grated into the bon­net. The ther­mal treat­ment takes place up to 750 °C. In this case the bon­net can sim­ply be lifted with a crane and placed aside next to the fur­nace. In this way the floor with in­ter­change­able out­let noz­zles is left free for the load­ing process.