The filter material of the high temperature dust bag usually used, the glass fiber needle felt filter material temperature is highest, the long-term working temperature can reach 280 °C. But the industrial furnace kiln flue gas can reach hundreds or even thousands of degrees Celsius. Bag filter The use of the material will be limited by the temperature resistance of the filter. To solve this problem, we must take measures to reduce the temperature of the flue gas to the temperature range of the high temperature dust bag filter. The commonly used cooling method is as follows.
(1) Direct cooling with mixed cold air: Usually a three-way pipe is installed on the inlet pipe of the precipitator. Outside air can enter the flue and mix with the flue gas to reduce the flue gas temperature. The advantage of this method is that the cooling rate is fast. Only the three-way pipe and the valve for controlling the air flow and other simple components are needed. The disadvantage is that the amount of smoke will increase. The larger the cooling rate is, the more the volume of flue gas increases. Therefore, the filter area of the filter should be increased accordingly. The equipment volume increases the investment of equipment, ducts and fans, and also increases the operating costs. Electrostatic precipitator accessories
(2) Indirect cooling: High-temperature flue gas passes through a heat exchanger (usually made of steel pipe), smoke flows through one side of the steel pipe, and cold water or outdoor air flows through the other side of the steel pipe. Smoke is made without contact with each other. The temperature of the gas is reduced. The advantage of this method is that it does not increase the amount of flue gas, and because the temperature is reduced, the actual flow of flue gas will also be reduced and the moisture content of the flue gas will not increase. The disadvantage is that the heat exchanger has a large volume. , Consuming more steel, high investment. At the same time, the heat exchanger has a certain resistance, which increases the power consumption of the fan. At the same time, the heat of the flue gas can be recycled. The above several methods of cooling have a certain scope of application of fuel electrostatic dust Device
(3) Spray direct cooling: the water is sprayed through the nozzle to form a fine mist and sprayed into the high-temperature flue gas. The water mist evaporates and absorbs a lot of heat, so that the flue gas can be cooled. The advantage of this method is that the flue gas cools quickly and the equipment needed is And the investment is not much. Its disadvantage is that the moisture content of flue gas increases, which may cause condensation of smoke and damage the dust filter bag. If the sprayed water mist is not fine enough to become larger water droplets, then the water droplets may not be able to evaporate before entering directly. Bag type dust collector, high temperature dust bag is easy to be blocked. Therefore, you need to use excellent performance nozzles, while using a computer to accurately control the amount of spray, this equipment is expensive / complex control.