# Determine the pressure gradient for suction

## Main Question or Discussion Point

Hello,
Im designing a product which will pump components as vaccum cleaner does.
I have 2 questions:

Im trying to calculate the pressure different in order to pump those metal component with :
M=0.2 kg , dimensions (mm) cylinder with diameter 5.5 mm length 600mm .

the formula for pressure is F\A: which A should i take :
1. (1\4)*pai*diameter^2
2. diameter* length
3. cross section of suction area which can be determined as i wish?

Which mechanism can i rely on?

I have been thinking about air blower, but im afraid the blades will fail quickly (i pump metal components)
Air blower : https://www.mcmaster.com/#9960k51/=1bb5u6o

which method can i rely on ? (no hydraulic only pneumatic)

thanks

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jrmichler
Mentor
You are trying to invent a pneumatic conveyor. Google that term. You will find the answer to your questions, and give you some ideas.

You are trying to invent a pneumatic conveyor. Google that term. You will find the answer to your questions, and give you some ideas.
You right, thats the term.
But still my application is a bit different, my product goal is to lift and transport those metal partical.
The pneumatic conveyor just transport solid from one place to another.

jrmichler
Mentor
Pneumatic conveyors are built with the fan at the pickup end, with the fan at the discharge end (as in your sketch), and with the fan off to the side. The systems with the fan off to the side inject air into the middle of the conveyor line through an arrangement similar to an eductor (google the term).

Your sketch will get the job done. You merely need to figure out how to separate the metal pieces from the air so they don't get sucked into the fan. For some ideas, look at shop vacuums and look up cyclone separators.