pneumatic circuit design 1

[mattc80]

Hi,

I need to design a pneumatic system which has 12 outlet tubes split into 3 independent groups of 4 tubes. I need to control each group to either suck or blow air through the 4 tubes. I will be using venturi valves, solenoid valves and a 6 bar air supply. I hope to control the solenoid valves with an arduino uno board using an input from an optical sensor.

I have drawn 3 possible circuit designs (attached), using festo fluid draw software, which I think may work. I am unfamiliar with pneumatics circuit design and require advice on the most suitable design in terms of simplicity, cost and least pressure loss. I am aware of pressure drop in parallel flow when tubes are split but know little else about reducing pressure losses in circuits. In the diagrams I have used 5/2 solenoid valves but am considering using 5/3 valves to give a third 'off' option. Figure b) seems to me like the best design but figure c) would be slightly cheaper as it uses 2/2 valves. In figure c) I have assumed that if port 3 of the venturi valve is blocked, then air will blow through port 2, which is where air is usually sucked in. Will this work? Figure a) I am least confident about but I drew it because someone recommended this solution to me. I think this design would need to include non-return valves? Any feedback or other circuit suggestions would be very useful.

The triangle at the bottom of each diagram is the air supply and the groups of lines at the top are the 12 outlet tubes. Apologies if any features of the diagrams are incorrect. Any help would be greatly appreciated.

 

[gerhardl]

I am not that familiar with pneumatic design, but I suggest you should think through and discuss with local experts across the table following:

Unbalance in air in/out in the different paths could be a problem, depending on total demand in balance with total supply.
- Check valves to prevent 'backlash' between the three systems?
- Checkvalves near outlet? (Systems without checkvalves give often inbalance)
- Flow capacity of mainline and valves large enough? (Remember that solenoid valves often are mentioned by connection size (1/4" as an example) but bore and capacity could be vastly different.
- Throttle valves near (each?) outlet to balance the system, if necessary?
- 5/3 valves are usually higher in price and give more restriction in selection. Try to go for 2/2, 3/2 and 5/2.
- Combined filter, regulator and water removing before the total system (possibly other places if long lines)
- If polluted air (dust) is sucked through solenoid valves this is not a good idea.

 

[bingbingwang]

Agree to gerhardl.
[highlight #3465A4]Combined filter, regulator and water removing before the total system (possibly other places if long lines)[/highlight]
12 tubes venting at same time will draw down the pressure of the header, a regulator will be a good idea.
venturi valve needs to be carefully selected, because how low the vacuum that the venturi valve can make is depending on the air flow through the valve. you need some rough estimation on the air consumption.----find out what is the worst condition.
---a little curious , why use venturi to make vacuum to suck "what" out??


Get help and return with helps!!.

 

[EnergyMix]

ouch Bingbinwang. That line was a bit hard to read! But good advice!