How to collect dust
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I have a wood chip hot air drying system that uses a cyclone to collect the dry wood chips; however, a large amount of fine dust is still emitted along with the exhaust gas. I’m thinking of installing another cyclone on the exhaust pipe to capture this dust – will that work? The fan is equipped with a 45KW motor, has an air volume of 21,000 m3/h and an air pressure of 4,100 Pa. The existing cyclone has a diameter of 1.4 meters, a total height of about 2.8 meters, and an exhaust pipe of 0.6 meters in length. I would like to ask that expert to design a solution for the dust collector I mentioned as needing to be added on the backend. Thank you.
If a standard cyclone dust collector is used, the effect is likely to be limited, with a large amount of fine particles still escaping. The lower the particle size and mass, the lower the capture efficiency of the cyclone chamber. In the return conveyor of the cyclone in a circulating fluidized bed boiler, D50 and D90 correspond to different particle sizes. What the poster has captured are fine wood dust particles, which have a low specific gravity; therefore, the separation efficiency of traditional cyclones is very low. Since the system is relatively small, a bag filter or a wet dust collector can be considered.
Multi-stage diameter-changing dust collectors are used in starch processing, but they have a relatively large structure, and the fact that the filter bags collect such large amounts of dust is also a problem.
These days, in many cases where the installation of coal boilers is delayed, bag filters are used; those with more resources opt for electroadsorption. Both methods yield good results, and since it’s wood chips and the temperature isn’t high, bag filters are sufficient.
Thank you. I want to collect the fine powder for reuse in a spraying and burning process; using fabric bags for collection is costly, requires a lot of space, and has high operating expenses.
First separate by centrifugation and then use a bag filter; the cost is not very high. Most of the dust is separated by centrifugation, and then captured by bag filters.
We have done something similar before, which involves a cyclone tower combined with a filter cartridge dust collector, followed by further treatment. What we were doing at that time was granulation
You can add whatever you want, but be sure to verify the air volume and pressure carefully. It’s best to have two stages: first a cyclone, then a belt type