The nature of dusty gas has a great influence on the dedusting effect, so we should pay attention to the following points when choosing filter bags:

Temperature

The temperature of dusty gas is an important factor in the selection of filter bags. Usually, dusty gas < 130℃ is called normal temperature gas, and the dusty gas > 130℃ is called high temperature gas.

Therefore, the filter bags can be divided into 2 types: normal temperature filter bags below 130℃ and high temperature filter bags higher than 130℃. In daily work, a suitable filter bag should be selected according to the flue gas temperature.

Humidity

The dusty gas is divided into 3 types according to the relative humidity: dry gas (humidity < 30%), general gas (30% < humidity < 80%), and high humidity gas (humidity > 80%).

• (1) When the gas humidity is high, the dust collected on the surface of the filter bag will be wetted and bonded. Filter bags with smooth surface, long fiber and easy dust removal, such as nylon and glass fiber, should be selected.
• (2) High temperature and humidity will affect the filter bags’ temperature resistance. Try to avoid filter bags with poor hydrolytic stability, such as nylon, polyester, imide and so on.
• (3) When the humidity is high, circular filter bags should be used to avoid complex and compact filter bags, such as flat filter bags and diamond filter bags.
• (4) The dusty gas inlet temperature should be higher than the dew point 10-30 ℃.

Chemistry

In all kinds of furnace flue gas and chemical waste gas, it often contains a variety of chemical components, such as acid, alkali, oxidant, organic solvent and so on, and is often affected by temperature, humidity and other factors. Therefore, when choosing the filter bag, we must grasp the main factors and comprehensively consider the chemical composition of the dusty gas.

Finally, when choosing filter bags, we should also consider the dust properties and the dust cleaning method, and comprehensively consider the measurement to ensure that the appropriate filter bag is selected to ensure the dust removal effect.