Compressed Air Best Practices - March 2008 - (Page 20)

| 03/08 Focus Industry FOOD PROCESSING | MANAGING ROTARY SCREW AIR COMPRESSORS AT MIDWEST BAKERY Flow Measurement kW CO2 O Typically, large differentials between static and dynamic pressures indicate the following conditions: • Improperly sized inlet regulators • The air hose feeding the tool/ process is too small (hose diameters are notoriously small and result in poor transportation of compressed air) • Undersized couplings • Multiple couplings at a single distribution point • Poor compressed air distribution (piping) The flow measuring equipment used in this survey was an Accu-Flo Insertion Mass Flow Meter calibrated for the corresponding pipe size transmitting a -5 to +5 VDC. The signal was transformed into meaningful data and a data sample was recorded every 0.5 seconds. Data was then transferred onto computers and analyzed with print-out data summaries and data details. The probe locations were as follows in the piping system: p p p 3" Buffer 4" West 4" East Air Quality Measurement The compressed air in the Buffer Compressor Room was saturated with water, and we were therefore unable to take dewpoint readings. Drains on the after cooler and receiver were found to be malfunctioning and were going to be serviced. The air quality in the East Compressor Room is very poor. While the contaminant level is low, the measured pressure dewpoint of 64 °F is extremely high. The dryer and drains in this room should be serviced to make sure they are operating correctly. The air quality in the West Compressor Room is excellent. The measured pressure dewpoint of -36 °F is at the design level for the blower-purge regenerative dryer and the contaminant level is very low. An AQT-4 Air Compressed Air and Gas Analyzer was used to measure dewpoint. This equipment measures and records contaminant level, pressure, temperature and pressure dewpoint with an accuracy range for dewpoint of +/- 3 °F. “Static Pressure . is the gauge pressure with the tool at rest. Dynamic pressure is the gauge pressure with the tool at work.” Piping Pressure Drop and System Pressure Measurement The audit has reviewed the approximate surge flows at various distribution points to identify possible problems with pressure drop. The information gathered in this study indicates the plants ability to run substantially lower pressure than the compressor rating of 110/125 psig. We have outlined a plan to reduce horsepower on-line and overall usage in Section 10. We used pressure transducers and calibrated gauges to test the facility's compressed air system for static and dynamic air pressure. This test provides insight into the actual air pressure being delivered to the points of use, typically less than thought or shown on air regulator gauges, or other pressure gauges located throughout the compressed air system. Midwest Bakery has very good main header distribution lines with some major problems in sub-headers with static versus dynamic pressure. The second objective in the test is to determine the compressed air system's potential for an energy-saving intermediate flow controller application. Throughout our time walking through the facility, we asked different Midwest Bakery personnel what they thought the minimum acceptable air pressure required for their application was. The acceptable range was from a high of 100 psig to a low of 85 psig. 20 www.airbestpractices.com http://www.airbestpractices.com

Table of Contents Feed for the Digital Edition of Compressed Air Best Practices - March 2008

Compressed Air Best Practices - March 2008 Contents From the Editor Utility-Air News The Compressed Air Audit of the Month: Saving Energy with Blowers in Canada Do You Provide World-Class Service? Managing Rotary Screw Air Compressors at Midwest Bakery The Difference Between Acfm and Scfm for Proper Vacuum Sizing Best Practices — Multi-Module Process Air Dryers The Vacuum Formation Process in Building Compressed Air Filter Elements Solberg Manufacturing Real World Best Practices: Measuring Pressure Dewpoint in a Compressed Air System Resources for Energy Engineers: Training Calendar & Product Picks Wall Street Watch Advertiser Index Job Market

Compressed Air Best Practices - March 2008

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