What values should be used for the flow rates in the main pipes and branch pipes for VOC waste gas?

Personally, I think it is related to the components; if there are no components with special requirements regarding flow rate, such as acetylene, then a flow rate of 10–15 m/s for the exhaust gas is generally sufficient

What flow rate is required for acetylene? Are there any other components that require a specific flow rate?

Dear, is there any basis for this flow rate, or can it be found in any books? Thank you!

The acetylene flow rate should generally not exceed 4 m/s, and the hydrogen flow rate should not exceed 8 m/s; that’s based on personal experience – I don’t know anything more about it

This post was last edited by Nanshan Qiuxue on 2022-9-2 at 10:31. It mainly refers to experience points; for specific requirements, please refer to Pages 56–62 of the second volume of the Chemical Process Design Manual

This post was last edited by hxm606 on 2022-9-3 09:10. It is related to concentration; there are several indicators involved. One is the rate, in Kg/h (for a certain pollutant), and the other is the emission concentration in mg/m3. It’s not correct to rely solely on the rate, as there are differences in various places depending on local environmental protection standards. For the calculation of gas velocity, the diameter of the pipe can be determined based on the above parameters and the safe flow velocity specified in the design standards; if the pipe diameter is fixed, the only option is to adjust the velocity to match it. In short, environmental standards and safety standards need to be taken into account simultaneously. If there are additional environmental protection VOC exhaust treatment facilities, then only the safety gas velocity standards need to be considered.

Considering only the gas velocity, it is generally 8 m/s for branch pipes and 12–15 m/s for main pipes; if there are other requirements, refer to the chemical process manual