Horizontal heat treatment (HHT) lines and ageing furnaces for plates
Exacting quality demands placed on the final product in automotive and aerospace applications as well as reduced emission and energy consumption targets characterize today's customer requirements.
The most recent OTTO JUNKER technology, derived from many years of experience and our ongoing improvement and innovative research effort, matches customer specifications to their full extent.
Apart from the above quality considerations, OTTO JUNKER plate heat treatment lines are designed with ease of maintenance and operating convenience in mind.
Plate heat treatment lines essentially consist of the following subassemblies:
Loading and unloading roller tables:
The dimensions of the entry and exit roller tables are essentially determined by the minimum and maximum plate sizes.
Powered conveying rollers are provided in groups at defined intervals. Proper spacing of the charge and full synchronism of the individual drive units are ensured by state-of-the-art technology.
Rapid and uniform heating results are achieved through an optimized flow management and separately adjustable heating power top and bottom.
The OTTO JUNKER design concept makes it possible to provide both electrically heated and indirectly gas-fired furnaces by changing just a few components. Customer requests for a specific heating system can thus be easily accommodated.
The modular structure of the individual furnace zones enables us to meet individual demands in terms of achievable throughput and maximum plate length. As a rule, the charge will be oscillated during the heating cycle instead of passing continuously through the furnace. This optimizes the length of the heat treatment line.
Quench and aftercooling section:
Stepless adjustments of the conveying speed and an optimized nozzle spray pattern have made it possible to quench the plates on the run. This design reduces equipment length and saves investment cost while maintaining quench rate and accuracy.
Due to the installation of hard and soft quench within the same enclosure, plates of different thickness can be quenched with different amounts of water. Cooling rates may be set to suit the specific requirements. The immersion pumps employed are fitted so as to ensure easy maintenance and replacement in the event of a malfunction. In order to prevent the ingress of water back into the furnace section, water and air wiper systems are installed at the entry to the quench.
Once the plates have cooled down through the application of water they exhibit a water-wetted surface. This water is removed through the combined action of an air wiper and an integrated dryer. The dry plates are then placed on the exit conveyor.
Like all products from our range, OTTO JUNKER plate ageing furnaces are fully in compliance with customer quality demands. This is true particularly with regard to temperature uniformity. As each furnace is subdivided into individually controlled zones and equipped with reversible recirculation fans, the metal will be perfectly heated both across and along the plate. Depending on requirements and on the number of furnaces to be served, OTTO JUNKER ageing furnaces are loaded by means of a charging machine or with bogies which remain in the furnace for the duration of the ageing cycle.
Charging / discharging:
- By means of a rugged and dependable charging machine or
- By rugged bogies which remain in the furnace throughout the ageing cycle.
- Highly efficient self-recuperative high-velocity burners for direct heating or indirect in the radiant tube
- Reversible axial-flow re-circulating fans.