Consulting-Specifying Engineer - August 2007 - (Page A12)

For More Information Energen Technologies www.energentech.com E N E RGY SOLUTION S CE NTE R GrimmerSchmidt Air Compressors www.grimmerschmidt.com Ingersoll Rand www.ingersollrand.com More Information on Air Compressors www.aircompressor.org Scales Air Compressors www.scales-air.com Tecogen www.tecogen.com Waukesha Engine Division www.waukeshaengine.com York International www.york.com engine byproduct heat is used to heat the digesters to keep them at maximum efﬁciency. Baker points out that at least two of the engines are in use almost all the time. The team closely watches the performance and emissions from the engines and replaces spark plugs, checks spark timing, and changes oil as part of a general service process every 320 hours. They perform an upper engine overhaul approximately every two years and a lower overhaul every 70,000 hours. engine speed and load curves to that of the driven equipment.” He indicates that industrial managers considering direct drive applications should look for fuel efﬁciency in the engine equipment, and also need to consider life-cycle costs of the system over its entire operating life. USING WASTE HEAT IMPORTANT TO SUCCESS Cannestra also stresses the potential value from being able to capture the byproduct heat from the engine. “Any time you capture waste heat you continue to offset other energy purchases that you may be making. In some cases this is being done. There should be an onsite need for this energy.” Cannestra indicates that Waukesha is seeing growing product demand for water pumping applications, in municipal wastewater treatment plants, and in manufacturing plants where large amounts of compressed air are used. With today’s rapidly rising energy costs, it makes sense to evaluate all the places you are using power on your site, and to evaluate whether you are doing it the most economical way. Remember that natural gas-powered engines are an attractive alternative to large electric motors, and can allow you to use all of the energy you are buying. Especially if you have a process need for hot water for any comfort or process application, it’s worth ❮GT❯ a good look. water for hydrostatic testing, and where high pressure ﬂows are needed for spraying or fogging. Industrial pumps encompass a vast range of sizes, types, ﬂows and pressures. As with electric pumps, selection of a natural gas-ﬁred engine-driven pump should be done with the assistance of a pump industry expert to ensure that the desired results are achieved. Many pump manufacturers offer pumps designed for engine drives. ENGINE MANUFACTURERS SEE GROWING INTEREST In general, engine manufacturers also are seeing growing interest on the part of industrial energy users in natural gasﬁred direct drive equipment. According to Paul Cannestra, vice president of market and product management for Waukesha Engine, a business unit of Dresser, Inc., his ﬁrm is receiving a growing number of inquiries about using engine-driven equipment in industry. Many of these users ﬁnd it more practical to direct-drive a compressor, blower or a pump rather than to use an electric generator set to accomplish the same result. Cannestra says, “The big advantage is the variable speed capability of an enginedriven system. No variable speed drive is required; also, with engines you can maximize part-load efﬁciency by varying LONG HISTORY AT TREATMENT PLANT An example of the use of natural gas engines with blowers is the wastewater treatment plant of the city of Porterville, Calif. This facility uses three 400 hp Waukesha engines to drive two blowers moving 6200 CFM and one moving 5200 CFM of supply air for the wastewater treatment process. According to John Baker, engineering manager for the Porterville facility, the engines have been in operation since 1994, and have been very reliable. He notes that the engines are a lean-burn design to comply with stringent California air quality rules. “We are well below the state standard for NOx.” The Porterville plant uses both digester gas and natural gas to fuel the engines. Baker says, “Normally we don’t produce enough digester gas to supply the engines entirely.” This wastewater operation places high emphasis on using all of the resources available. The operation wastes less than .1% of the digester gas, and the Continued from Page A4, Recovering Waste Heat from Boilers of thousands of square feet of building space can be heated with this recovered energy,” he says. Abma adds that beneﬁcial uses can also be found for the condensate produced by the heat recovery process. He notes that with a typical pH of around 4.0, it may need to be buffered, but is entirely suitable for lawn or horticultural purposes. He says he loves asking architects and mechanical engineers, especially those involved in Green and LEED projects, “Have you ever seen natural gas irrigate the lawns and ﬂower beds?” TAKING THE NEXT STEP If you have completed a review of your industrial plant and have corrected all of the problems with your existing boiler plant, it might now be worthwhile to consider installing one or more heat recovery units on the system. For most owners, a one to three year payback is an exciting energy saving opportunity. Now would be a good time to ﬁnd out if your ❮GT❯ system has that potential. A12 http://www.energentech.com http://www.grimmerschmidt.com http://www.ingersollrand.com http://www.aircompressor.org http://www.scales-air.com http://www.tecogen.com http://www.waukeshaengine.com http://www.york.com

Table of Contents Feed for the Digital Edition of Consulting-Specifying Engineer - August 2007

Contents M/E Roundtable Giants 100 Pullout Poster Giants Stand Tall: CSE Giants 100 Report Electrical Design for Tall Buildings HVAC and Fire Safety for Elevator Systems How to Beat the Codes GAS Technology Supplement Recovering Waste Heat from Boilers New Applications for Tankless Water Heating Systmes Techniques Improve for Powder Coating MDF New Tools Available for Heat Treating Steel Direct Drive Engines

Consulting-Specifying Engineer - August 2007

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