|
 |
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| AIR SYSTEM CASE STUDIES The professionals at Air Power USA believe the best way to demonstrate the potential for cost savings via your compressed air system is by example. The following case studies are a sampling of the results we've been able to achieve for our customers. Contact us if you'd like more information or are interested in case studies that are more closely related to your situation.
Plastics Injection Molding Company $70,898 Annual Energy Savings No Capital Investment Plant air usage was 100% load of three 110 bhp full-load rotary screw compressors with all presses running. The Air Power USA compressed air systems analysis determined that 28 presses had improperly adjusted control regulators, were running off almost full line pressure, and had been doing so for three years. Estimated annual power cost: $ .05 kwh 1470 cfm 330 hp / 8640 hours/year = approx. $118,000 After proper adjustments were made to the control regulators, the actual demand fell to about 740 cfm, using only two of the three 110 hp rotary screw compressors with modulating controls. One 110 hp compressor was shut off. The approximate total hp draw for the two 110 hp compressors on modulation control was 187 bhp (converted from amperage reading).
Follow-up by Air Power USA and plant personnel to readjust compressor unloading controls to On-Line/Off-Line further reduced hp draw:
Total annual energy savings of $70,898 with no capital investment. ADDITIONAL BENEFITS The customer will set up a demand-side control system and a continuing leak-management program. The compressor unloading system is capable of translating 80% to 85% of the demand reduction into reduced electrical costs.  Testing Laboratory for Brake Calipers 42% Reduction in Air Use w/Same Productivity $7,100 Annual Power Cost Reduction $385 Capital Investment The test lab personnel felt they needed 250 psig to operate their test benches effectively. Two air-cooled reciprocating compressors supplied air through an aftercooler and dryer to a 400-gallon air receiver. Each compressor delivered 100 cfm at 250 psig full load pressure. Both units were set at 225 psig cut-in/250 psig cut-out and ran 90-95% loaded all the time. Due to this extreme duty cycle, valve and ring life were very short. Air Power USA, Inc. helped the lab people determine that they could actually operate effectively at 225 psig cut-in pressure and that 215 psig was feasible. Accordingly, we recommended creation of a simple demand-side control system. This consisted of a $385 pressure flow control regulator installed between the air source (receiver tank) and demand point (test benches). The regulator permitted the compressors to operate at their most efficient load/unload points, allowed the receiver to store extra air to soften demand cycles, and created the necessary operating pressure band to provide a steady fixed minimum pressure flow to the test benches. Reducing pressures at the test benches eliminated "artificial demand" (higher pressures automatically caused more air usage with no gain in productivity) and reduced overall demand from 190 to 165 cfm. Further adjustments to the newly stabilized system established that the optimum minimum operating pressure at the test benches was 190 psig. Reducing the regulated air flow from 215 to 190 psig again eliminated enough "artificial demand" to reduce demand to 130 cfm with the compressors operating automatic start/stop at about 65% on load and 35% off. Total air-use reduction was almost 42% with no loss in productivity. Compressors run well without high valve and ring maintenance. POWER COST BREAKOUT
Aluminum Extrusion Plant $15,200 Annual Power Cost Reduction $3,500 Capital Investment One of three Compressors Deactivated The company asked us to evaluate whether they should purchase an additional 75 hp or 100 hp class rotary screw compressor to get their system pressure up. They said their two 75 hp and one 60 hp class rotary screws (990 cfm) were running fully loaded all the time (6,640 hours/year) and could hold only 85 psig during full production. Another compressed air consultant had calculated that the company needed an additional 250 cfm to get the system up to 110 psig. Investigation by Air Power USA personnel indicated that 1) all compressors were modulation controlled, 2) none of the compressors was running over 40% loaded, and 3) the pressure loss was caused by several significant piping chokes and backfeeds. The company performed the piping corrections we recommended at a cost of $3,500 with these results:
Large Machinery Manufacturer $69,825 Annual Energy Savings $21,900 Capital Investment Shut Down 1 of 3 Compressors Customer considered adding a third 250 hp class, two-stage, double-acting, water-cooled air compressor to their 35-year-old plant because their two existing units were running 90-95% fully loaded. Yet during peak production runs they did not have enough air. We conducted a complete Compressed Air System Analysis and recommended:
PLANT IMPLEMENTED OVER A TWO-YEAR PERIOD
Bicycle Manufacturing Plant Increases Production 30% Lowers Compressed Air Cost 60% Energy Savings $31,340 Per Year An eastern bicycle manufacturer planned a 30% production increase, including personnel, floor space and compressed air. Their existing air system consisted of 4 rotary screw packages with a refrigerated dryer in two basic locations, using 294 bhp and delivering 816 cfm at 125 psig full load at current production. The plant operated 4160 hours per year at .044 kwh with a $44,600 electric power cost for the compressors and dryers and a total estimated compressed air cost of $59,600 including maintenance and repairs. THE PROBLEMS
AN EQUIPMENT SUPPLIER RECOMMENDED A NEW SYSTEM A local compressed air equipment dealer said the existing air supply system should be replaced and used only as a back up. Correcting the existing shortage and providing air for increased production and future growth would require a new primary system consisting of two new 150 hp (172 bhp each) compressors and dryers. AIR POWER USA CONSOLIDATED THE CURRENT SYSTEM We were called in to conduct a Level I Survey and design a compressed air system for the plant's planned production increase. We determined that no new air should be required to handle production growth. Instead we recommended an "efficiency consolidation" of all compressed air generation equipment at one location:
THE OVERALL RESULT
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Air Power USA Inc. | P.O. Box 292 | Pickerington, OH 43147 | Ph: 740.862.4112 | Fax: 740.862.8464
Design and Search Engine Optimization by Pilot Fish