A well-designed hot zone can offer a long service life, even heat distribution, and short heating and cooling cycles. At the core of each MIM furnace is the molybdenum hot zone. In combination with its exceptionally efficient heating elements, detailed and accurate design of the hot zone can guarantee a hygienic environment, high temperatures, and shield packs to lessen heat loss.
Figure 1. Metal hot zone for MIM furnaces
High Performance and Energy-Efficient Hot Zones
PLANSEE makes use of pioneering lightweight construction methods, as well as creep-resistant molybdenum alloys, to improve the performance and energy efficiency of the hot zones of high-temperature furnaces.
As well as having excellent performance capabilities, PLANSEE’s hot zones are simple to install and to operate. For example, bearing in mind that the MIM hot zone doors would be closed and opened on multiple occasions between cycles, PLANSEE has carried out extensive work in the design of this element.
Design of the MIM Hot Zone Door
In standard designs, opening the door to the hot zone requires the use of both hands. Additionally, prior to opening the door, users must separate the actuating mechanism for the shutter assembly, to stimulate instant cooling. The need for multiple processes increases the likelihood of user error, yet in most designs currently on the market, there is no way around these steps.
PLANSEE’s newest designs entirely eradicate the need to separate and join the fastenings on the door when opening and closing between cycles. Upon closing of the door, a fastening mechanism engages automatically as a result of the counterweighted handle, ensuring a powerful seal.
Preinstalled Shutters and Related Guide Rods
Figure 2. Hot zone door with preinstalled shutters
The fastening assembly for the cooling shutter mechanism is typically delivered separately and must be installed on-site. Conversely, PLANSEE have designed their hot zones with shutters and other linked guide rods pre-installed to allow for simple installation. Additionally, the shutters have been redesigned to further protect against loss of heat.
New Design for Retort Chamber
A novel design has also been developed for the retort door of PLANSEE’s hot zone. In typical hot zones, thermal deformation can result in doors becoming tricky to open. To ensure resistance to such warping, PLANSEE has employed reinforcing structural angles or the interior and exterior sides of the retort door.
With the combination of these reinforcements alongside the creep-resistant molybdenum alloys, these new doors have a greatly reduced risk of distortion and can be separated and joined with ease, without sticking.
Figure 3. Door of the retort
PLANSEE’s door is connected to the retort, and a series of hooks are placed on either side of the retort to fix the door in place. These innovative counterweighted hooks make use of the door’s own weight to create a safe seal against the retort opening, ensuring integrity of the atmosphere. As such, with a PLANSEE MIM hot zone, loading and unloading are fast, simple and efficient processes.
This information has been sourced, reviewed and adapted from materials provided by PLANSEE.
For more information on this source, please visit PLANSEE.