TL-4 model Direct burning furnace with 3 layers sleeve consists of 3 layers of cylinders. It uses fully burned natural gas to obtain high-temperature flame, and mixing this temperature with fresh air to achieve the required hot air device. Due to the use of fully automatic single-stage fire, two-stage fire or modulating burner, the output hot air is extremely clean by natural gas fully burned, , meeting the drying and dehydration needs for most stuffs. The external fresh air enter the furnace body under negative pressure, takes two strokes and sequentially cools the middle cylinder and the inner tank. After being fully mixed with the high-temperature flame in the mixing zone, it is extracted from the furnace body and enter the drying room. When the temperature reach the setting number, the main burner stops working and the auxiliary burner continues to burn to maintain the temperature. When the temperature drops to the set lower limit temperature, the main burner will be run again. 4ã??Advantages/features 1. Simple structure and easy installation 2. Small air volume, high temperature, adjustable from normal temperature to 500â?? 3. Stainless steel high temperature resistant inner tank, durable 4. Automatic gas burner, complete combustion, high efficiency. (After setting up, the system can control the ignition+cease fire+temperature adjust automatic), 5. The fresh air has a long stroke that can fully cool the inner tank, so the outer tank can be touched without insulation. 6. Equipped with high temperature resistant centrifugal fan, large pressure center and long lift