Flue gas and dust control in the asphalt mixing industry
With the rapid development of China's economy and society, the total volume of various engineering
construction projects is constantly increasing. Especially during the production process of asphalt mixing,
a large amount of dust is generated, which will cause certain pollution to the surrounding environment.
The asphalt mixing plant is a place for producing asphalt concrete mixture. The main process is as follows:
Raw stone materials, raw asphalt, etc. are heated to a certain temperature in accordance with the pavement
design specifications. Then, they are mixed with raw stone powder and additives by weight measurement and
added to the mixer to form asphalt concrete mixture for later use. The heat energy required for drying and
heating is supplied by the burner by consuming various fuels. The commonly used fuels at present are liquid
fuel (heavy oil), gaseous fuel and liquid-gas mixed fuel.Atmospheric emission cargo aircraft
The belt conveyor of the H material collection bin, the secondary powder material recovery, the secondary dust
collector, the fine material storage wall, and the batch material storage are difficult
The dust mainly comes from the asphalt concrete mixing equipment, accounting for 70-80% of the total dust sources.
The rest is generated from the hot material elevator, vibrating screen and mixer, etc. The main component of the dust
is fine aggregate powder. In addition, due to the different fuels used in the dryer and the use of recycled materials,
asphalt fumes, carbon black and tar particles may be produced. If these dusts are directly discharged, they will cause
serious pollution to the surrounding environment, and nearby residents and crops will also be affected. Therefore, to
ensure that the flue gas discharged from asphalt mixing meets the emission standards, a dust removal system is needed
to filter out the dust. 2. Characteristics of flue gas
As the current mainstream process is the production of asphalt concrete with a mixed ratio of raw and recycled materials,
the output, combustion medium and raw materials are different, and the working conditions of the generated flue gas are
also different. Currently, there are no standard flue gas parameters. Based on experience, the characteristics of the flue gas are summarized
The points are:
(1) The range of flue gas volume to be processed is relatively large;
(2) The temperature range is between 60℃ and 170℃.
Based on industry experience, the general use of NOMEX coated dust removal can effectively filter flue gas
The parameters are as follows
nomex Needle Felt（芳纶/诺梅克斯/美塔斯针刺毡）
Fiber Aramid fiber
Weight 500 g/m2
material 100% nomex
Air premeability 400-480L/m2/s
Warp Tensile Strength 950N/5X20cm
Weft Tensile Strength 1100N/5X20cm
After Treatment Singeing, heat setting
Continue Working Temperature（ 200℃
Max. Working Temperature 240℃
Chemical Properties
Anti-acid Good (好）
Anti-alkali Good (好）
Anti-oxidative Good (好）
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