I work in the food and beverage industry and I am working on developing a system for recirculating powder back into a powder filling machine, and my main idea was using a vacuum pump. Then I got confused and came across compressed air (pneumatic) pumps and air compressors. I know I can use either positive or negative pressure to convey powders, but which equipment applies best to my application?

I have attached a flowsheet of my ideas in this post.

• My 1st idea is to connect some steel piping between filling machine, pump, and a holding container where operators can dump material in and powder would be recirculated. I don't know if this is possible to do continuously, or at all.
• My 2nd idea was to have a station where the operators can bring reject containers, stick it under a steel pipe, and vacuum the powder away to the filling machine (kind've like a manual dust collection system).

My main concern was if these ideas were physically possible since I am not familiar with pumps/compressors, and how big of an issue leaks or backflow would be. Also, is it correct that I need valves downstream and upstream of the pump/compressor/blower to start and stop powder flow into the filling machine? Thanks and I appreciate any help.

• https://files.engineering.com/getfile.aspx?folder=26b91eb9-118d-4989-9081-8