Boilers can be heavy consumers of energy, so it's important to select an efficient unit for your process needs. In “Understanding Boiler Efficiencies,” Jim Albright of Clayton Industries, City of Industry, Calif., explains that the efficiency of a boiler should be an important part of a purchase evaluation because the annual cost of fuel can easily be two to three times the installed cost of the equipment. Therefore, a difference in efficiency and the resulting difference in fuel cost can easily offset a difference in installed cost. Albright explains the key terms and values to help you compare two boiler designs and really understand the differences.
Heat-tracing cable is installed in processing facility piping to maintain product temperature, control viscosity and protect against freezing. Tank farms and pipes between petrochemical facilities are other applications. No matter the use, it is important to understand how to select and size electric heat tracing so that it will provide optimal heating without draining your bank account. In “Calculating Heat Loss,” Mark Crombie of Pittsburgh-based Chromalox explains the basic principles of heat transfer and the calculations used for pipes and vessels. By understanding fundamental heat transfer concepts, you can use them used to arrive at a general formula that is used in heat loss calculations.
When comparing metal with plastic exchangers, the rate of heat transfer is important. But you must also consider operational factors such as fouling. “Using Plastic” looks at when plastic heat exchangers make sense.The use of radio frequency (RF) drying can offer many benefits over conventional drying, including faster line speeds, more consistent moisture levels, lower drying temperature and smaller equipment -- all of which might help you reduce energy costs. Ben Wilson of Cleveland-based PSC Inc., a Litzler Co., covers the essentials in “Radio Frequency Basics.”
Columnist Arthur Holland continues his series on troubleshooting extruders with more ways to tune your PID controller. Startup overshoot means your process demands more heat than it really needs during startup, wasting energy. Holland offers a way to avoid startup overshoot as well as tips on autotuning and how the controller varies power to the heater in this month's “Heating Highlights.”
And, for users of fuel-fired equipment, columnist Dick Bennett begins a new series that promises to be an “organized, systematic approach to improving your process heating operations.” In “Energy Notes” this month, Bennett explains Step 1 -- getting the best performance you can from your existing equipment. PH