What Is a Tunnel Kiln?

Tunnel kiln is a kiln similar to a tunnel, built with refractory materials, thermal insulation materials and building materials. It is equipped with kiln cars and other transportation vehicles. It is a modern continuous firing thermal equipment.

The tunnel kiln started in 1765. At that time, only ceramic glazes could be burned. By 1810, some can be used to burn bricks or pottery. From 1906, it was used to burn porcelain tires. The first famous tunnel kiln was the Fukieren-style. After 1910, there were gradually many improvements.

The tunnel kiln is generally a long straight tunnel with fixed walls and vaults on both sides and the top, and a kiln car runs on the track laid at the bottom. The combustion equipment is located on the two sides of the middle of the tunnel kiln, forming a fixed high-temperature zone-the firing zone. The high-temperature flue gas generated by the combustion flows along the tunnel toward the kiln head under the action of the chimney or induced draft fan at the front of the tunnel kiln. At the same time, the products entering the kiln are gradually preheated. This section constitutes the preheating zone of the tunnel kiln. Cold air is blown into the kiln tail of the tunnel kiln to cool the products in the latter section of the tunnel kiln. After the cold wind blows through the products and is heated, it is drawn out and sent to the dryer as a heat source for drying the green body. This section constitutes the tunnel. Kiln cooling zone.

Place the load on the trolley

Tunnel kiln can be divided into preheating zone, firing zone and cooling zone.

1. The preheating zone accounts for 30-45% of the total length of the kiln, and the temperature range is from room temperature to 900 ° C. The green body on the car is in contact with the flue gas generated from the combustion of the burning zone fuel and is gradually heated to complete the preheating process of the green body .

2. The firing zone accounts for 10-33% of the total length of the kiln, and the temperature range is from 900 ° C to the maximum temperature; the green body reaches the required maximum firing temperature by using the heat released by the fuel combustion to complete the firing process of the green body .

3. The cooling zone occupies 38-46% of the total length of the kiln. The temperature range is the highest temperature ~ the temperature at which the products exit the kiln; Cooling process.

First, change the stacking form of the stack, add heads in the middle and lower parts to reduce the number of holes and lower the height of the lame legs. This measure is especially applicable to the case where the yard kiln method is not changed with the change of the season, and it is especially applicable to the manufacturers who still use the summer high lame legs in winter.

Second, reduce the use height of the near gate to slow down the temperature of the bottom of the insulation belt.

Third, extend the insulation belt appropriately to extend the distance and time of air supply.

Fourth, if the amount of cold air is too large, the temperature of the heat preservation zone will be cooled down too quickly, the amount of cold air can be reduced, and the rate of cooling and cooling of the heat preservation zone will be reduced.

Fifth, a small amount of Qin Tian, re-burning after the fire. Or through the eyes of the fire, add furnace ash in front of the first row of the insulation belt to "block the wind". ^[1]