IMPROVE Critical Orifice Flow Control
Eldred R. 1998. IMPROVE Critical Orifice Flow Control. CNL, University of California. Davis, CA
The primary purpose of flow control is to keep the volume flow rate through the cyclone or PM10 inlet as close as possible to the nominal rate for the 2.5 or 10 µm cut. There are several factors producing a variation in the flow rate for a critical orifice: the diurnal and seasonal variation of ambient temperature, the change in pressure drop across the filter associated with variation in clean filters, and the change in pressure drop across the filter associated with mass loading. The estimated total variation in inlet flow rate with a critical orifice controller from all three factors is generally less than 3%. This is similar to the standard deviation in flow rates observed in the network. The conclusion is that a critical orifice system is reasonable if a variation in flow rate of approximately 3% is acceptable.
- Type
- Published Report
- Authors
- Eldred, Robert
- Date of Issue
- 1998-05-04
- Publisher
- CNL, University of California
- Units
- ARD
- Keywords
- AIRBIB, critical orifice, Improve, volume flow rate