Compressed Air Best Practices - March 2008 - (Page 14)

| 03/08 Focus Industry FOOD PROCESSING | COMPRESSED AIR AUDIT OF THE MONTH Saving Energy with Blowers in Canada Measuring and Managing with Local and Master Control Panels A new control system was proposed to completely replace the existing system. This included three HSI 3100 LCP (Local Control Panel) variable frequency drive control logic controllers and one HSI 3100 MCP (Master Control Panel). The 3100 LCPs included sensors for the blower bearing temperature and vibration RTDs, inlet and discharge temperature and pressure, motor bearing and winding RTDs and surge and overload protection. The local control panel uses a combination of thermodynamic calculations and physical “fingerprinting” through detailed performance testing of the blower, motor and VFD package to allow for above-average blower turndown which results in energy savings. The local control panel can also revert to inlet throttle-valve control as well. The 3100 MCP (Master Control Panel) permits complete sequencing and total power optimization of the three blower units. It includes a complete connection to the plant’s SCADA system through an Ethernet port. Plant DCS can tell the MCP to operate to any control variable including total pressure or total flow and it will operate the blowers to its most efficient combination. CO2 O The project delivered energy savings of 6,793,000 kWh annual savings (910 hp) worth $543,440 per year. kW Finally, the audit proposed two new 1750 hp, 4160 volt, VFDs — reusing the one existing soft starter for the third unit. The third unit, used for backup, would still operate with inlet throttle-valve control. The blower supplier, HSI, also incorporated the design to reuse the existing electric motors to save on capital expense. Also included in the proposal were new actuated valves, check valves, expansion joints and modified bases. The food processor evaluated the performance gains from a variety of blower designs including single stage type blowers. The proposed system offered the lowest 20-year life-cycle cost when considering efficiency and total capital cost. Verification and Qualifying for Cooperative Capital This energy-saving project was eligible for cooperative capital from the local utility. In order to qualify for a complete change in system, the verification was broken up into four stages. Each stage was to demonstrate the payback in terms of reduction in energy that the new system offered. Measurements were taken and documented by the utility company to verify the new performance levels after each stage of the project: 1. 2. 3. Stage 1: Replace (1) existing blower with the new optimized HSI blower. The measured and verified savings were of 1,742,000 kWh per year Stage 2: Replace the second existing blower with another new optimized HSI blower. The measured and verified savings were 2,049,000 kWh per year Stage 3: Replace the third existing blower with another new optimized HSI blower. This was not measured and was not part of the utility companys’ project due to the lack of summer weather to prove results. The expected savings were 500,000 kWh per year Stage 4: Install the VFD control system on the new blowers. The measured and verified savings were of 2,502,000 kWh per year 4. 14 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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