Exhaust System
There are flue pipes running along both the top and bottom of the kiln chamber. A suction fan is used to pull flue gases through multiple branch pipes into a mains pipe. Each branch pipe comes with a manually adjusted valve for gas flow control so the kiln chamber always maintains a constant negative pressure.

Branch pipes at the top as well as the gate inside the gate valve are made of stainless steel so they do not shed or flake to contaminate the gas flow. Instead of discharging flue gas through one central pipe, this exhaust system has several branch pipes that pull in flue gas at the start of each segment of the roller kiln. As water removed from the workpiece is turned into water vapor and gas emits from chemical reactions, they are carried along branch pipes into the mains pipe.

As the hot flue gas flows back from the firing zone through the preheating zone, it is met by the material that moves in the reverse direction. During the time the flue gas and material pass each other, they exchange heat, which allows flue gas to cool down gradually. This discharge method makes the best use of exhaust heat to minimize energy consumption. Upon request, we can add a VFD to the suction fan for automatic control of gas flow speed.

Combustion Air Supply System
This air supply system is made of a blower fan, mains pipe, and branch pipes. The system starts by pulling room-temperature air into the mains pipe. When the air travels over the rapid cooling zone, it enters into a heat exchanger where the cold air absorbs heat from the hot kiln chamber. In this way, the air is heated. After that, the heated air enters the mains pipe again and flows into a burner to aid in combustion. Perhaps the biggest plus of using a combustion air supply system is that it takes advantages of the residual heat in the kiln chamber for heating purpose. That is why this system saves energy and improves fuel economy.

Air Cooling System
The air cooling system is useful in the rapid cooling, gentle cooling, final cooling and residual heat recovery segments of the roller kiln.