System Assessments

Compressed air is used as a convenient and often necessary source of air flow to perform blow-offs, cooling, or drying.  And since compressed air is a costly utility, a frequent recommendation in this magazine and audits is to reduce the compressed air use by using high efficiency engineered nozzles.  Using these nozzles is a good practice as they are designed in a way that uses the compressed air to accelerate the surrounding air to deliver the same mass transfer effect as a standard nozzle (or tube) with a much larger orifice.

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.

The Lafarge Cement Distribution terminal located in Winnipeg, Canada has significantly reduced the site electrical demand and energy charges by changing the way they transport their cement.  Two new low-pressure rotary screw air compressors have replaced two large high-pressure air compressors that previously powered their dense phase transport system.  The resulting power reduction has saved the company 46 percent in transport operating costs.

A small Australian company, Basil V.R. Greatrex (BVRG), is shaking up the compressed air industry in Australia. While other companies focus on the sale of more and bigger compressed air production equipment, BVRG is helping customers reduce their compressed air system size and lower system flow by attacking waste, inappropriate use, and at the same time improving air quality.

At a Midwest window manufacturing plant, the cooling process for the plastic frame pieces, after leaving the extruder, was critical to process productivity and quality. Too much cooling air (or not enough cooling air) would generate scrap and rejected product. The plants’ 17 extruders and 55 separate blow-offs in these lines had similar cooling stations at the cooling boxes. They consisted of about three hoses at each exit frame angled down to the extruded piece moving past it. The compressed air flow was controlled by a manual control valve set by an operator. The operator used his experience to control the flow delivered and thereby control the product quality.

Facility managers, how would you like the peace of mind from knowing the system you had installed or modified is thoroughly tested - to the same degree as a new production line?  How would you like to be confident that the money you spent is still paying back benefits, year after year? 

A major poultry processor and packager spends an estimated \$96,374 annually on energy to operate the compressed air system at its plant located in a southern U.S. state.  The current average electric rate, at this plant, is 8 cents per kWh.

“Retro-Commissioning” (ReCX) of compressed air systems has become a trendy activity with many utility demand-side-management programs emerging in the last 5-10 years.  This is intended to be the process of “tuning up” a compressed air system, getting low cost savings from mostly adjustments and repairs.  The term was borrowed from the building/HVAC industry, where it means to get a system operating as it was originally “commissioned”. 

UniFirst is one of North America’s largest workwear and textile service companies. They outfit nearly two million workers in clean uniforms and protective clothing each workday. Founded in an eight-stall garage in 1936, the Company has grown to 240 customer servicing locations throughout the U.S. and Canada servicing 300,000 business customer locations. The subject of this article is an energy-saving Air Demand Analysis (ADA), conducted by Kaeser Compressors, at UniFirst’s centralized 320,000 square foot hub Distribution Center located in Owensboro, Kentucky.

MHPSC Canada is a large facility specializing in machining and manufacturing large pieces for power generation (gas turbines, large hydro, wind) and deep sea oil and gas operations.  Smaller machining and manufacturing are also done in the facility, as well as welding and piping fabrication. MHPSC purchased flow meters for two systems, the Large and Small Machine Shops, to measure the total compressed air production.  Since the two systems have piping that is physically close together, it was felt that there was an opportunity to tie the two systems together to save energy.  The readings showed that the compressed air demand was indeed low enough in the two systems to enable a 100 hp VFD compressor to feed the combined systems.