velocity / differential pressure?

[cdnrookie]

Hey Guys,

Long story short,

We have a 4 x 4 foot ventilation shaft from a downdraft paint system. This particular system is in the floor of the plant and we cureently have no way of judging when the filters are depleted (saturated)

I was looking at a differential pressure between the pit and behind the filters but the dirty environment would have it continually plugged.

It may be hard to picture but, here I go.

There are two stacks outside the plant, the fans are located at the base of the stacks.

the stacks then go down to the 4x4 foot vents that travel 20 feet to our paint pits. Here there are two pits, each 4 x40 feet. The air is drawn down, through the grates, filters then exhauseted.

Any thoughts on how to capture the quality of the filters?

 

[Tom Jenkins]

If you measure differential pressure between the downstream side of the filters and ambient you should avoid the clogging problems. The downstream side of the filter is presumably relatively clean. You could run an impulse tube from the high side of the dp transmitter/switch to a clean location - indoors or on the roof or whatever. Perhaps not as accurate as dp across the filter itself, but probably sufficient for the purpose.

 

[osmanmom]

not idea on the question,probably this related,

https://www.components.omron.com/components/web/pdflib.nsf/0/8FBA18C1B56EF053862572E2005568AC/$file/MEMS+clogged+filter+PR_Mar2007.pdf

 

[danw]

Nothing says you have to use tiny, small diameter impulse tubing for DP on the high (dirty) side. If plugging is a concern, use a relatively large, 1/2" ID impulse line and reduce it down for a connection at the gauge end.

There's no flow through the impulse tube because the DP gauge/transmitter is closed, hence the tube is dead-headed.

 

[cdnrookie]

I just found two ProSense Differential Air Pressure Transmitters - DPTA Series on our shelves, im wondering if I can use an old logix 5550 we have sitting here collecting dust.

 

[rdrast]

Nothing wrong with the 5550, if it will serve your needs. About the only really issue with them was the battery backup didn't last very long. If you have concerns about power quality, try looking for the 1756-BATM battery module.

 

[cdnrookie]

thanks, will do