Vacuum pneumatic conveying of PVC components

nick_w
(not verified)
Posted in: , on 10. Mar. 2004 - 07:57

Hi,

I am wanting to pneumatically convey small flexible PVC parts (10x20x10mm) without any risk of damage. The only problem is I cant feed with a rotary or screw feeder as i cant guarantee the product wont be damaged on pinch points. (?) Is there another way of controller feeding apart from through an opening from the hopper?

I am planning on vacuum pneumatic conveying in batches from the hopper (bulk storage). However, if I want to stop the flow of product and therefore stop the vacuum pump, the inclined/vertical pipework will become full up with product. I imagine this is going to introduce problems when i restart the pump. Will the product begin to flow again or will a blockage occur? Should the incline/vertical pipe be stepped up with horizontal sections so all the product doesnt fall into one part of pipe? Would introducing air bleed points in the pipe help?

Any help would be much appreciated.

Regards

Nick Williams

Pneumatic System Feed

Erstellt am 15. Mar. 2004 - 11:02

Yes .

you can use a vibrating feeder , Roy marcus in South Africa used a pressurized system with a vibrating feeder , long time ago for large rock particles, this might be of use to you.

he also used direct feed into a fan for box demolition purposes.

Rotary feeders with wide clarances and lock hoppers can also be used if you are afraid of the possivility of pinching , or a vacumm system . it all depends how far are you going and the especific pressure drop.

rotary tables have been used and almos any thing you can imagine , partcle attrition concersn are mostly related to bend and discharge points impact.

Good luck

regards

marco

TECMEN Consultant in: Sponge Iron (DRI) handling Sponge Iron DRI Automated Storage Firefighting and Root Cause Analysis Pneumatic Conveying Consultants Phone 5281 8300 4456.
Dennis Hauch - Freeport, TX, USA
(not verified)

Conveying Pvc Parts

Erstellt am 17. Mar. 2004 - 03:37

Nick,

Vacuum conveying is the best choice because a pressure seal is not required at the material pickup point (no rotary valve).

A vibratory feeder can be used to meter the product but a pinch valve in the material feed line might prove to be a simpler solution. A pinch valve should not damage the small PVC parts.

Your system is a dilute-phase system which requires that the material feed be stopped and the convey line be allowed to clear before the vacuum blower is stopped.

Convey lines should be vertical or horizontal only, avoid inclined / sloped lines. Stepped lines or booster stations are not required for your system.

Regards,

Dennis Hauch

nick_w
(not verified)

Re: Vacuum Pneumatic Conveying Of Pvc Components

Erstellt am 17. Mar. 2004 - 10:02

Thanks for all your advice. Some more things for me to think about.

regards

Nick

It's Been Done Before

Erstellt am 27. May. 2004 - 04:26

Transferring moulded components from storage or directly from the moulders has been done many times before by my company. A well known razor manufacturer uses our systems for just this purpose to bring all of the components to an assembly line.

If the distances are not too far we would use a special fan powered 'soft' venturi (no airlocks etc), a selected grade of plastic transfer pipe and a final separator with no metal impact points.

Send me your email for further deetails/contacts etc.

If you don't believe true Low Velocity is possible ask me for a demo CD!