flow regulating in the vacuum system

[jiyoo]

What's the flow ragulator for vacuum? My system is

Particle source -> filter -> valve -> vacuum pump.

The flow rate is about 1 acfm. While the particulate is captured by filter, the pressure drop is increased. To maintain the flow rate, the valve should be opened gradually. Is there a type of regulator that I can use between filter and vacuum pump?

The particles are less than 1 miron coal ash, actually, the purpose of this system is collecting the particles for other experiment. The valve or pressure regulator should locate after filter.

Thanks in advance

 

[TedLinsle]

How about:
Particle source -> filter-->Vacuum Breaker-->Valve fully open-> vacuum pump

You might want to monitor the vacuum upstream of the filter as an indicator of the particulate resistance at the filter.

 

[TedLinsle]

Disregard. My suggestion wasn't a solution. I suppose you'd need a flow transducer ahead of the filter such that flow is controlled by an adjustment to a vacuum regulator, however, I'm not going attempt to write your specification.