Air Circulation Furnace

Continuous air circulation furnace is Basically used for low-temperature applications such as tempering, annealing, normalizing and stress relieving of high-precision products. Impeller type fan is used for air circulation inside the chamber. This furnace is best suited for medium and large production.

The furnace has segmented zones with different preset temperatures. The soft materials will pass through the segmented zones and get heated according to the requirements and come out from the other side. In this, the air circulation helps with the better uniformity inside. These can be heated directly electrically or indirectly heated using electrical or gas/oil fires, which are circulated through blowers to maintain the accurate temperature gradient required in all the zones.

Numerous options such as mesh belt, pusher mechanism, flat belt or heavy link chain-based conveying methods can be selected as per operational function and necessity. All safety features are taken care of. Baffles or mufflers are provided in direct heating.

Fixed with precise, dynamically balanced air circulation fans aesthetically fitted to prevent noise and vibration and achieve uniform temperature. For safety, torque limiters are provided in any eventuality that the conveyor stops working. Limit switches, proximity sensors and other safety devices are provided for safe functioning. In addition, annunciators are given in control systems with hooters so that any errors or malfunctions are highlighted by audio and visual aids. Automatic pneumatic chain tensioners are provided so that chain sagging and derailing after exposure to thermal expansions are prevented. Smelter also manufactures feeding systems—bucket conveyor type or elevator-based with vibratory feeders for automated loading of components.

Components can be directed from the previous operation or loaded onto a hopper from where a PLC and/or SCADA based control system transfers and handles the components until they exit from the furnace cooling zone to the unloading station or area. Continuous operations that require fast cooling are provided with an additional cooling zone to bring down the temperature of components before unloading.

Continuous air circulation conveyor furnaces or ovens are offered for constant, high production jobs. In stress relief of various metals after forming or welding operations and hydrogen de-embrittlement (after plating), a continuous air circulation furnace is used.

These furnaces are used for stress-relieving, tempering and similar low-temperature processes that need air circulation. They are also used for drying parts after processing and painting and also in filter manufacturing industries for pleating, setting and curing of filter papers.

Specification:

Title	Description
Temperature Range	Up to 850°C
Loading Options	Mesh Belt, Conveyor Chain
Insulation	Vacuum Formed Ceramic Fibre Boards, Ceramic Fibre Blanket, Refractory Brick Lining
Heating Elements	Nichrome Wire/Special Alloy Resistance Heating Wire/Silicon Carbide/Molybdenum Disilicide/Molybdenum/Tungsten/Graphite
Instrumentation Options	Thyristor, Programmable Temperature Controller, Temperature Recorder, PLC, SCADA, HMI
Additional Features	Muffle for Controlled Atmospheres of Nitrogen/Hydrogen/Cracked Ammonia/Argon

Applications:

• Heat Treatment Applications:

1. Annealing
2. Tempering
3. Stress-relieving
4. Normalizing
5. Decarb annealing

• Other Applications:

1. Curing
2. Baking
3. Drying