Vacuum pump design

[achraf mecanique]

Hello everyone,

I’m working on a project where I need to use a cylindrical tube with a vacuum pump to suck in mechanical parts. The tube approaches the part, and the vacuum generated by the pump draws the part into the tube. I want to understand how to link the key parameters of the system: the cross-sectional area of the tube, the flow rate of the pump, the suction force generated, and the distance between the part and the tube.

Here’s what I’m trying to model:

1. Suction force generated (Pressure difference) using the pump air flow and the tube cross section,
2. The maximum distance between the part and the tube at which the part can still be sucked in,
3. How to calculate the maximum mass of the part that can be sucked in.

Could anyone explain howto use bernoulli equation to solve this problem

Thanks for your help!

 

[berkeman]

Welcome to PF.

The tube approaches the part, and the vacuum generated by the pump draws the part into the tube.

What shape is the part? Can it have any orientation, or will it always be oriented the same way? Does the cylindrical vacuum nozzle approach the part from above or from the side?

Also, is this question for your schoolwork?

 

[achraf mecanique]

Welcome to PF.


What shape is the part? Can it have any orientation, or will it always be oriented the same way? Does the cylindrical vacuum nozzle approach the part from above or from the side?

Also, is this question for your schoolwork?

Thank you for your response
This is part of a project where I’ll be buying a vacuum pump, and this question helps me choose the right specifications of the pump (like the airflow ). The part is placed on a table, and the nozzle approaches it from above, with the suction being vertical. For the initial analysis, I’ll assume the part has a flat surface area S and mass m. The part's orientation will remain the same during the process.

 

[russ_watters]

Even if fully specified (which this is not, you're asking for a general solution), this is an exceptionally difficult problem to solve analytically. It's about airflow past the part leading to a pressure differential from one side of the part to the other (aka drag), which moves the part. This sort of thing I'd want to either model with CFD or test -- both after establishing one or more fully specified scenarios.

 

[jrmichler]

Your vague description would require me to write a book on picking and holding with vacuum. As @russ_watters said above, you need to fully tell us exactly what you are trying to do. How large an object, a diagram of the shape, the weight, the orientation on the table, spacing to the nearest adjacent object, pick rate (objects per second/minute/hour), how you will keep it from being sucked into the vacuum source, how far will it be transported, how you want to set it down, is it moving when it is picked up, fragility, and anything else relevant to the problem. A written description is not enough, we need diagrams.

I have extensive experience at picking, holding, and transporting with vacuum. I want to help, but need full information in order to get started.

 

[Ivan Nikiforov]

I can offer you the following solution to your problem. The process you mentioned is complex and involves aerodynamics. In addition, the mass and shape of the parts are variable. In such cases, experimental installations are used, real parameters are measured, analyzed, and mathematical models are formed based on them. This is exactly what wind tunnels are needed for in the aircraft industry. You can solve your problem using a regular household vacuum cleaner. Check which parts, which mass of the mold it absorbs or does not absorb. You can request parameters from the manufacturer of the vacuum cleaner (air consumption, created discharge, etc.) and build a mathematical model based on these data

 

[Hop-AC8NS]

There are two kinds of physicists: theoretical and experimental. A good physicist IMO embodies both. Try an experiment with a vacuum cleaner first. This is the most essential part of the scientific method used to discover truth. Based on what you observe and/or measure, create an hypothesis of what you think will work. Do some more experiments with variables YOU control, for example: flow rate of air, diameter and shape of the "pick up" nozzle, weight of the objects you want to lift, shape and size of those objects, etc. Try to find out which variables influence how well objects are lifted and optimize them for your application. Wash, rinse, repeat.

This is exactly what wind tunnels are needed for in the aircraft industry.

Spot on!