The Baghouse Dust Collection System Deals with Special Dusts

Ⅰ. The measures that the baghouse dust collection system needs to take to deal with special dust

1. Gas with high dust concentration

To process gas with high dust concentration, cyclone dust collector or gravity dust removal equipment can be installed as pre-dust removal, but this will increase the resistance of the system and increase the power consumption. Therefore, when the dust or finished materials do not need to be classified, most of them directly use bag dust collector.

2. Dust-containing gas containing tar mist

It is difficult to deal with gas containing only tar mist by baghouse dust collection system. However, when the oil mist in the gas is not large and the amount of dust is considerable, it can be directly filtered. For example, in an asphalt concrete plant, the flue gas from the stone dryer is the main source, plus dust from the conveyor and other exhaust gases enter the equipment. In addition, the tar mist generated by the heated asphalt concrete also enters the equipment at the mixing machine and the unloading of finished materials. In this case, the amount of dust accumulated on the filter cloth far exceeds the amount of oil mist, which can prevent the trouble of oil mist adhesion and ensure stable operation.

3. Hygroscopicity and deliquescence dust

CaO, Na₂CO_3, NaHCO₃, NaCI, etc. tend to absorb moisture and harden on the surface of the filter cloth, or become viscous liquid after deliquescence, which will cause difficulty in cleaning, increased pressure loss, and even force to stop operation. In this case, the general precautions for handling hygroscopic and deliquescent dust are listed below.

① The dust source facility should not be operated continuously regardless of whether it is operating or not, and should only be activated when the dust source facility is activated. When dust is accumulated on the filter cloth into layers, the humid air should not be passed through.

② Use filter cloth with lint-free and lint-free surface. Such as the use of felt filter material. Surface treatment should be carried out.

The selection principle is:

a. Post-treatments such as surface coating and calendering can also improve wear resistance. For glass fiber filter materials, silicone oil, graphite, and polytetrafluoroethylene resin treatment can improve wear resistance and folding resistance.

b. Chemical fiber is better than glass fiber, and expanded glass fiber is better than general glass fiber; thin, short and crimped fibers are better than thick, long and smooth fibers.

c. Felt material is better than fabric. Needle punching should be used in felt material to strengthen the entanglement between fibers. Among the fabrics, satin weave fabric is the best. The brushing of the fabric surface is also a measure to improve wear resistance.

③ An off-line cleaning operation system should be adopted. When the bag filter stops working, the dust on the surface of the filter cloth is fully removed.