Industrial Utility Efficiency    

Technology

It is becoming a “best practice” to install a variable frequency drive (VFD) air compressor whenever one is replacing an old air compressor.  As a result, real systems have fixed-speed and VFD air compressors, mixed.  I have observed several VFD compressor sizing methods.  In my last article, I referred to a common method: size one VFD compressor for the whole system.  This can work.  However, if it doesn’t meet a higher peak demand, one or more of the old compressors will be started, and a mixed system results.   Another method is to replace a compressor with the same size, but with a VFD.  If the compressor that was replaced is large, a big VFD is installed.  If small, a small one.

Air Compressors

There are many choices of compressor technology and types of controls that can be used for variable demands. Some examples are rotary screw compressors with inlet valve control: variable speed drives: load/unload control; or centrifugal compressors with variable inlet guide vanes. However, in many cases, the efficiency of the overall compression process can be reduced significantly during lower flow demands, leading to more power per unit of air flow being delivered. It is very important to evaluate different available options and see how a plant can run most efficiently.

Air Treatment

Compressed air is dried to prevent condensation and corrosion which can disrupt manufacturing processes and contaminate products. Water is the primary promotor of chemical reactions and physical erosion in compressed air systems. A myriad of desiccant dryer designs have been devised to provide “commercially dry” air, air having a dew point of -40°F or less, to prevent corrosion.  Desiccant dryers use solid adsorbents in granule form to reduce the moisture content of compressed air.

Blowers

High speed bearing technology is applicable for aeration blowers operating at much higher speeds than the typical 60Hz, 3600RPM for cast multistage units. High Speed Turbo (HST) units are usually single stage (though some utilize multiple cores) and rotate from 15,000 to 50,000RPM. At such high speeds, standard roller bearings cannot offer the industry standard L10 bearing life. Two types of bearing technologies have come to dominate the wastewater treatment market for these types of machines: airfoil and magnetically levitated. Often the two technologies are compared as equals, however, in many significant ways they are not.

Compressor Controls

When a system has the right combination of VFD and base-load air compressors, how do you coordinate their control? What tells the air compressors to run and load, to have just enough (or no) base-load air compressors and a VFD running, all the time air is needed? Appropriate master controls are needed. These controls are often called “sequencers” or “master control systems”.

Instrumentation

Compressed Air Best Practices® Magazine interviewed Mr. Warwick Rampley, the National Sales Manager for Sydney (Australia) based, Basil V.R. Greatrex Pty Ltd. It’s not every day one is asked to deliver a system able to provide both a reliable compressed air dew point of -80°C (-112°F) and high purity nitrogen.  We work with some excellent technology suppliers and have engineered a rather interesting system.  Although our firm was founded in 1919, this application is one of the most demanding we’ve encountered. Basil V.R. Greatrex is a unique company as we focus only on compressed air measurement, compressed air quality and compressed air efficiency.

Pneumatics

The design of wastewater treatment plants is changing, and it has something to do with LEGO® bricks. More specifically, it has to do with how large and complex LEGO structures are built. If you follow the instructions carefully, you build module after module, eventually piecing them together to create a fully functional and cohesive unit.

Vacuum

It’s one thing to move materials during the production process, but when it’s a finished product on the packaging line, choosing the right material handling system is essential. Getting it wrong results in squandered production time when product loss occurs, and wasted raw materials.

Cooling Systems

As a result of compressed air awareness training and a focus on energy management, two facilities in different parts of the world have reduced their compressed air demand substantially by removing vortex style cabinet coolers from some of their electrical panels and reworking the cooling systems.  These facilities were previously unaware of the high cost of compressed air and how much could be saved if other methods of cooling were used. This article describes some of their efforts in demand reduction.
Compressed Air Best Practices Magazine interviewed Sid Van der Meer (President) and Terry Nickel (Office Manager) of the Northwest Equipment Company.
Compressed Air Practices interviewed Mark McKean (National Sales Manager) from Prevost Corporation.
Compressed Air Best Practices spoke with Jay Hedges (General Manager) of Mattei Compressors.
Compressed Air Best Practices Magazine interviewed Bogdan Markiel (CEO) and Garth Greenough (President) (last name & title) of Devair, Inc.
Motor Coach Industries, headquartered in Schaumburg, Illinois, is the largest manufacturer of intercity tour coaches for the tour, charter, line-haul, scheduled service, commuter transit and conversion markets in the U.S. and Canada. The company operates a four screw-type air compressor system at its Clarence Avenue plant in Winnipeg. To maintain adequate system pressure at the plant, Motor Coach was forced to run all four compressors 24 hours a day, seven days a week.
A four thousand, five hundred and fifty pound (4550 lbs.) race car is running at 170 mph and facing wind resistance of 150 mph. The car then enters a curve creating a three-degree “yaw” (the change in angle from the direction the car is headed and the airstream).  The car struggles to maintain speed as the yaw changes and the dynamic downforce load on the car changes.  Suddenly, the driver-less car comes to a stop on the stainless-steel track...
New Flyer Industries is a Winnipeg based heavy duty bus manufacturer, supplying vehicles to the US and Canadian markets.  The company specializes in vehicles with†alternative-fuel drives such as electric trolleys, gasoline-electric and diesel-electric hybrid vehicles; as well as standard diesel buses.
The NFPA 99 (National Fire Protection Agency) Standard for Healthcare Facilities (2005 Edition) is the current Code by which Healthcare facilities in the U.S. design their compressed air systems.  The NFPA 99 Standard covers many requirements for medical gases, with compressed air being just a component of the Standard.