For production sintering operations, certain furnace design considerations are common regardless of whether you are working in metals, ceramics, or glass and regardless of what industry you work in. In order to achieve compression without liquefication, accurate temperature control and careful atmosphere monitoring are essential to uniformity and throughput.
Furnaces for normal sintering applications are often continuous-belt furnaces like our CM 600 Series. This type of furnace automatically conveys the parts through the furnace on an alloy belt. Mesh-belt furnaces however are usually not used above 2100°F/1100°C due to the limitations of the metallic alloy belt and muffle.
Instead at higher temperatures, furnace construction moves to designs like “pusher furnaces” or “walking beam furnaces”. In a pusher furnace, a series of boats or plates typically move material through the furnace by pushing up against one another in a continuous train, pausing only long enough to remove or add a boat at the ends of the line. A walking-beam furnace utilizes a pusher mechanism to bring the boat into the furnace and place it on the beams. These beams are analogous to a series of rails. The rails are on cams, which lift up, forward and down, essentially walking the boat or carrier through the furnace. At the exit end, the boats are then commonly transferred onto a belt for the cooling section.
In both the pusher and walking-beam furnace there is a high degree of automation. This automation allows the operator to run multiple furnaces. A return conveyor runs the length of the furnace, connecting the entrance and exit ends. This return conveyor is where the operator will load and unload product. The boats/carriers are automatically conveyed around the furnace. The return conveyor delivers the boats to a furnace entrance crossfeed. This crossfeed then moves the boats in front of the main pushing device. The boats are then pushed through the furnace at a constant speed. Upon exiting the furnace the boats move in front of an exit crossfeed, which delivers them back to the return conveyor.
The advantage of this type of furnace for high volume operations, is guaranteed throughput and repeatability. Every boat goes through a given profile at a constant speed. This ensures that every part will see the exact same conditions. The parts enter the furnace at room temperature and exit at room temperature. The interior of the furnace is in a protective atmosphere. Therefore, oxidation is not a problem.
The CM Furnace Solution to Continuous Sintering for Production
The CM 600 Series furnaces are available in a variety of configurations from manually loaded lab-scale units to fully automated production systems. The two basic system configurations are continuous belt furnaces and pusher style furnaces. Both types utilize nickel alloy muffles in the entrance and heated section.
These furnaces can be used for either inert or reducing atmosphere applications. The furnaces are constructed of heavy gauge steel that is welded and reinforced. All power components and controls are located on the main frame assembly. Ceramic plate heaters with embedded Kanthal A1 wire serve as heating elements. A high alumina fiber insulation package provides for efficient operation.
Controls include a microprocessor based temperature controller, a zero cross-over SCR power controller, type “N” thermocouples, and independent overtemperature instrumentation.
Please visit our page about our CM 600 series of Continuous Atmosphere Furnaces for Sintering and many other applications. Or contact our sales team today to discuss your requirements at (973) 338-6500