Shaft furnaces

Shaft furnaces

Shaft furnaces for special applications

Shaft furnaces are manufactured in very diverse designs and modes of heating (gas/electric power) in our factory. These are often used in solution annealing and ageing of aluminium parts. A shaft furnace can also be used to release tension in, anneal and temper iron and non-ferrous materials or in thermo-chemical processes like nitriding, carburising case hardening, final and bright annealing. Batch masses of 20-3,000 kg can be implemented, in special applications even heavier batches.

Circulation shaft furnace for different temperature ranges

The illustration shows a standardised circulation shaft furnace for temperature ranges of up to 350 °C, 650 °C or up to 950 °C. These furnaces can also be used for applications under nitrogen atmosphere. The sidewalls are isolated using ceramic fibre modules. There are meandering heat conductors on all sides of these modules. The furnace floor is lined with hard refractory bricks. The bottom ring is laid on the refractory bricks and the batch rack is then placed on the ring. The guide cylinder, in which the input material is placed, is centred with the bottom ring. There is a large-volume circulation fan in the cover of these industrial furnaces, which drives the circulating gases through the batch via a special guiding device. For lifting, lowering and swinging purposes, a pneumatic lifting device has been mounted on the rear part of the furnace and can be operated using buttons or levers.

Shaft furnace as a tempering plant

The illustrated shaft furnace-tempering plant consists of two tempering furnaces, an oil quenching bath and a tempering furnace. The tempering furnace is heated with high speed burners using natural gas. The maximum batch mass is 3,000 kg and has the following dimensions: diameter of 1,400 mm and height of 1,500 mm. The cover is lifted from the shaft furnace with the help of an electromotive cover lifting and displacement device. The oil quenching bath is equipped with an electrical heating system, a circulation fan and a cooling system. The plant also has an electrically heated tempering furnace.

Shaft stove with a retort

The tempering plant illustrated here is heated electrically. The meandering heating elements are fastened to the module lining of the sidewalls. The additional cooling of the bottomless retort from the outside makes it possible to attain the required cooling for tempering processes, from the carburising temperature to the tempering temperature. The plant is designed for a gross batch of 2,750 kg and can be used up to a maximum batch diameter of 1,500 mm and a maximum batch height of 2,500 mm. In addition, this shaft furnace has a polymer quenching bath, a washing bath and a tempering furnace.

Special shaft furnaces for small batch weights

The electrically heated tempering plant shown here can be used for smaller batch weights. This plant has a closed retort which can be transferred to a separate cooling shaft for purposes of batch cooling during the carburising processes. For tempering processes, the lid can be opened with the help of an indoor crane. The maximum gross batch contains a maximum batch diameter of 600 mm and a maximum batch height of 800 mm. In addition, this shaft furnace also has a polymer quenching bath, a washing bath, an extra exchangeable retort and two storage spaces.

Tempering aluminium parts in the shaft furnace

These electrically heated industrial furnaces can be used for tempering aluminium parts. The plant has a tempering shaft furnace, a relocation shaft furnace and a water quenching bath. The water quenching bath has a separate water-air cooler. To increase the quenching intensity, two mixers have been integrated into the bath. The maximum batch dimensions for this plant are 1,300 mm in diameter and 1,700 mm in height. The gross weight of the batch is 500 kg.

Top-loading furnaces - electrical with air circulation

Top-loading furnace for heating parts

This type of furnace also has its advantages when it comes to loading the furnace with the crane. Long parts can be placed horizontally. A symmetrically erected heating device supported by a high air circulation device ensures that there is good temperature distribution. The shaft furnace cover can be opened manually or automatically. Here is a picture of a top-loading furnace for heating parts