Vacuum System Tube and Suction Cup Orifice Sizing

[Izicial]

Hello Everyone,

I have to design what is essentially a vacuum system that picks up the part and places it into the next machine in the line. I am pretty familiar with fluid mechanics from school, however we basically never touched vacuum systems.
I know to spec the suction cup itself I can use a simple Area of Suction Cup = Force/Pressure equation to find the force the cup needs to bare, however I have no idea how to go about selecting the orifice that goes into the cup or the size of the vacuum tube itself.

Below I have posted a picture of the setup that we will have. The large box is the vacuum generator, the straight lines are the tubes themselves, and the small squares are fittings that connect the tube sections to the suction cup assemblies.

Weight of part being lifted is 65 lbs.

The specs for the vacuum generators they have are listed here:
Operating Pressure: 6 bar
Flow Rate: 500 L/min

Any help or guidance is appreciated.

Thank you.

 

[3DDave]

The main factor is to look at the volume of gas to be ejected from the cups and the supply line. Smaller lines means smaller amounts to be ejected so a quicker response. I would expect anything larger than a millimeter in the vacuum cup is enough.

Check to see the actual capacity of the cup. Part of the force needs to be borrowed to maintain the seal and prevent leakage so the full diameter cannot be used to calculate the usable force. If the full load based on that diameter then there is no force left to provide the seal.

 

[bimr]

Consider the use of an accumulator tank between the pump and suction cups. The accumulator tank stores a vacuum force should the vacuum pump fail.

 

[LittleInch]

Well first off vacuum lift is a potentially hazardous operation as there are many reasons why the vacuum can fail and the part drops off the lifting device.

Second, your details appear to be incorrect as there is no information on the vacuum level being applied by the "vacuum generator" - whatever this is.

So you need to have a good idea on what level of safety you're looking at for lifting - commonly for hooks etc it is 3 or 4 - , how you're going to keep the personnel under it safe, what level of anti collapse you can have / excess flow valves.

What is the sealing surface like?

How do the cups grip the unit.

Why are you designing this and not giving it to an experienced vacuum vendor?

A simple search on vacuum lifting design shows many vendors and things like this

https://www.hse.gov.uk/work-equipment-machinery/vacuum-lifting-equipment.htm

Follow the links and see what it says.

There's even a standard - EN 13155 which covers this.

I think you need to do a LOT more reading on this before even attempting the design of something like this. IMHO.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.