Put a Yardstick to Your Process
If you're like me, the framework for a new homemade worksheet is in this issue of Process Heating. “Calculating Heat Requirements,” an article from Wood Dale, Ill., based Tempco Electric Heater Corp., details nearly a dozen equations you can use to calculate startup and operating heat requirements. Performing the calculations before you submit the purchase order can help ensure that the heater you receive will meet the needs of your process. And if you specify heaters often, creating a spreadsheet that allows you to just plug in the numbers and go can give you hours of fun!
Also in this issue, Matt Litzler, president of C.A. Litzler Co. Inc., Cleveland, provides an overview of dryer types in “Understanding Drying Methods.” Litzler explains common methods of heat transfer used in dryers and ovens such as conduction, convection, infrared/radiant, and radio frequency and outlines each method's benefits and challenges for manufacturing processes. He also describes combination systems, which utilize the benefits of two or more technologies together. Bone up on your dryer know-how by turning to page 26.
Dealing with sealless pumps for temperature control systems and chillers is the focus of “Using Sealless Pumps Effectively,” which begins on page 23. Co-authored by engineers from Lydall Industrial Thermal Solutions, Ossipee, N.H., and Magnatex Pumps Inc., Houston, the article notes that a combination of the user's tolerance for leaks and the size of the budget will dictate the style of pump needed. And, although sealless pumps can significantly minimize maintenance requirements, some maintenance is still required to optimize the system's uptime. But, with minor preventive care, some sealless pumps have been known to operate for 15 years or more without requiring maintenance.
Preventive care and maintenance of another kind -- on your ovens and dryers -- is on the mind of Energy Notes columnist Dick Bennett this month. As Bennett notes, it's a well-established fact that setting up combustion systems for too much excess air wastes fuel. He shows that even at low operating temperatures, getting excess or dilution air under control can pay handsomely in terms of reduced energy losses. He cautions, though, to keep safety the top priority: Safety considerations always trump fuel savings.
Finally, columnist Arthur Holland, our sensors and controls specialist, looks at selecting thermocouples (shape, size and material) to match the process. He outlines your choices, in ascending order of size and mass, with corresponding increases in robustness and response time. It's good information to have whenever it's time to specify thermocouples, and with a little creativity, I bet you could use the information to make a spreadsheet.