System Assessments

As the Best Practices Magazines celebrate their twentieth anniversary, we wanted to take a moment to reflect on the remarkable system efficiency gains achieved since our first issue. We also wanted to give subscribers a peek at what the next decades might bring. To do this, we asked a hand-selected list of original equipment manufacturers, independent compressed air system sales and service companies, manufacturing plants and independent system auditors to share their thoughts, highlighting the changes they’ve seen over the past 20 years, then predicting what the next 20 years will bring.

Anecdotal reports from users of Tower Tech cooling towers across the U.S. have indicated the Tower Tech design provides substantial savings to the customer both in terms of lower chemical treatment requirements and substantial water savings. There are a number of mechanisms by which the Tower Tech design facilitates efficient, lower cost water treatment and usage. A few are described in this article.
A Gulf Coast chemical manufacturer of oxo derivative and intermediate products including alcohols, polyols, carboxylic acids, specialty esters, and amines experienced a failure in a critical chiller that shut down its entire Gulf Coast plant. A plant manager estimated a potential financial loss of over $1,000,000 each day the plant was down. The incident occurred over the weekend and there was great concern that locating a replacement chiller with sufficient capacity would be challenging.  
Controlled cooling is an essential part of manufacturing polyethylene stretch film. The process starts with granulated polyethylene raw product with very low strength, and develops thin, clear, strong film used in a variety of applications.  It does this by melting, extrusion, “casting” and winding.  See Figure 1 for a typical system diagram.  “Casting” is forming and cooling at the same time. The extruded polymer is stretched and cooled on large, chrome-plated rollers with cooling water flowing inside. Thinner film is for manual use, like wrapping around food products.  Thicker, stronger product is made for machine use, like automatically wrapping pallets of concrete bags.
Chrysler’s Technology Center (CTC), located in Auburn Hills, MI, is home to some fourteen thousand employees responsible for keeping the automotive giant in motion. Completed in 1991, the complex is essentially a small city, encompassing 5.3 million square feet situated on over 500 acres. In addition to corporate offices, the facility houses a full laboratory level of various wind tunnels with thermal testing capabilities, a 1.8-mile evaluation road, a noise/vibration facility, an electromagnetic compatibility center, an environmental test center (able to create rain, snow and extreme temperatures), and a pilot production plant.
This major mill complex upgraded their compressed air system and thereby eliminated $500,000 in annual rental compressor costs, reduced annual cooling-water costs by $500,000, and reduced electrical energy costs by $135,000 per year.
Pepco Energy Services’ (PES) Midtown Thermal Control Center (MTCC) in Atlantic City, New Jersey, sells chilled water and steam to multiple Atlantic City casinos, Boardwalk Hall and Pier Shops. PES is also responsible for stand-alone remote heating and cooling plants for the Atlantic City’s major casino’s as well as the Atlantic City Convention Center including its 2.4 Mw solar array.
Process cooling system applications experiencing constant production loads generating high process fluid temperatures are particularly good candidates to take advantage of low ambient temperatures. Low ambient temperatures can be used as a “free” energy source, replacing the electricity required to run refrigeration compressors, in what is known as a free-cooling chiller system.
Heat recovery opportunities have resulted in the largest amount of savings of our common projects our industrial energy management teams have implemented.  It is not the easiest type of project to implement but the amount of savings and the reduction of emissions makes this project very worthwhile.
When the topic of discussion is making ice cream, the first thing that comes to mind isn’t heat, but at Nestlé’s Ice Cream factory in Tulare, California, heat is recovered from air-cooled air compressors to heat process water. “Right out of the gate, everything is pneumatic,” explains Tom Finn, Project Engineer with Nestlé Ice Cream Division. “Air cylinders and air driven motors, the process piping valves which divert, route, stop/start, and mix process fluids, our packaging machinery including rejection, cleaning and vapor removal processes, all of these rely on compressed air.
There are several pieces of information that your cooling system specialist will need in order to properly engineer and build a cooling system for your new air compressor. There are many types of air compressors and each has different requirements of the cooling system in order to operate correctly. This article will take the mystery out of some of the terms and specifications for your cooling system.