Production details for the ducting of dust extraction systems

Whether we know how to design, we have a common sense, in the choice of dust collector pipe, will give priority to the use of round pipe. Then some people ask, why is this? In fact, it is very simple, I'll explain for you one by one.

A. Why is the pipe round tube?

    1, round pipe save material: we know a system air volume is determined, then the pipe diameter size = pipe cross-sectional area * wind speed. Wind speed remains unchanged in the case of comparison rectangular tube and round tube, the same 1 square meter cross-sectional area, the perimeter of the square tube is 4m, while the perimeter of the round tube is 3.544m, saving 11.4% of the material!

    2, round tube strength is high: dust system pipeline generally withstand thousands of pa pressure, we look at the pressure vessel a few is square, very obvious, common sense issues do not explain.

    3, round tube pressure loss is small: why, because the square tube has angular, turbulent flow serious ah.

    4, round tube is not easy to corner accumulation of ash, more convenient production, etc.

Summary: Unless there are special circumstances, it is generally recommended to use round pipes.

B. How to choose the wind speed of the pipe?

The role of the duct is to convey the dust collected by the air hood and exhaust port to the filtering equipment.

If the air speed of the duct is low, dust will be deposited in the duct causing the duct to accumulate dust, the duct will accumulate dust causing the duct resistance to increase, the duct resistance will increase causing the dust removal effect to be poor; furthermore, if the duct accumulates more dust, if the duct is not installed firmly, it will cause the duct to fall and collapse, the consequences will be very serious, how dangerous it is. And if it is a general dust is okay, if it is combustible dust, it will be more dangerous.

The last thing worth mentioning is the waste of materials and the high investment cost. The lower the air speed of the same air volume, the larger the diameter of the pipe, the larger the diameter of the pipe, the more materials are needed, and the more materials are needed, the more money is needed.

What if the air speed of the duct is high: high, the duct investment saves money! But then, the higher the pipe resistance, the greater the pipe resistance system fan power required is also greater, the fan power, the investment is large, not to mention that the fan consumption of electricity costs also increased.

So how to choose the correct it, general dust removal ducts recommended 18m / s or more, large particles, large quality, and then choose a larger; explosive dust has specifications, 20m / s to start. Different dust pipeline air speed is not the same, please choose at your discretion.

C. Pipe tee angle: 15 ° - 45 °.

D. The exhaust pipe (chimney) duct wind speed should be taken as 10-15m / s.

E. Chimney pipe height: different standards and norms are different, choose as appropriate.

F. Pipe layout, as few elbows as possible, as large as possible turning radius.