In this issue of Process Heating, we include articles about heat transfer fluids, heat recovery and pollution control technologies, among others.
Long-time readers of this column will be familiar with Process Heating's webinar series on thermal fluids for high temperature industrial processes. There’s just a few more months to view the on-demand webinars on our website. (Visit www.process-heating.com/HTFwebinars to register or login.)
Fortunately, that’s not the end of our thermal fluid coverage. In this issue of Process Heating, Mark Smith of MultiTherm looks at “Flashpoint Concerns in a Closed-Loop Thermal Oil System.” Smith explains how flashpoint testing is conducted and looks at conditions that could support a thermal fluid flash fire.
Elsewhere in this issue, Jessica Irons of Honeywell looks at using air-to-air heat exchangers for industrial process heat recovery. Even when fuel prices are relatively low, as they are now, companies in energy-intensive industries can realize a relatively short payback from adding heat recovery system, Irons says in “Heat Recovery for Process Efficiency.” But, of course, to best realize that heat recovery, it pays to carefully consider your process, the materials being used for heat recovery, and the equipment that best can handle the flow with minimal areas of inefficiency. For instance, dimple-plate-type heat exchangers are better able to withstand dirty process airstreams but sinusoidal- or wave-plate exchangers offer better heat transfer effectiveness. Can your process use a sinusoidal-plate exchanger or will the airstream media demand another design? Making the wrong choice can diminish expected ROI from heat recovery, so it pays to weigh choices carefully.
Another system that can offer good ROI if carefully selected for the process and plant equipment is pollution-control equipment. In “How Deliberate Integration of Air Pollution Control Equipment Optimized Production,” Kevin Stevens of Pollution Systems notes that many companies focus on specifying equipment for air pollution control independently from efforts to design and optimize the production processes. By taking a holistic approach, industrial processors can reap greater efficiencies and achieve better long-term operating and economic results. Many industrial thermal systems can benefit, Stevens says. For instance, the exhaust from air-abatement equipment can be used as an input for a boiler system. Other possible reapplications of exhaust waste heat include preheating combustion air in process ovens or preheating fresh air for the facility.
Recapturing waste heat to repurpose it in the plant requires thinking about your process in ways you may not have before. Another article in this issue explains how looking at a known process with new eyes can help solve process bottlenecks. “Craft Brewery Drives Success with Process Automation Swap” describes how one brewery’s plan to add additional brewing capacity in the form of three heating/cooling loops on a new uni-tank was nearly derailed by unexpected results with solenoid diaphragm valves. By looking at the power-management challenge from many angles, the valves-maker was able to suggest a solution that allowed the brewery to stay on a tight startup schedule while gaining full tank temperature control.
Also in this issue, “Direct-Contact Water Heaters for Concrete Plants” explores using on-demand water heating for industrial processes such as cement plants. For processes that require hot water in the 140 to 160°F (60 to 71°C) range, on-demand water heating systems allow users to avoid stored heating losses and free up plant space. Robert Rizza of Power Flame Inc., and Michael Maddox of CEI Enterprises explain the technology and how ultra-low-NOX premix burners allow the burners to stay below emissions limits.
Finally, in “Boiler Cleaning Drives Benefit to Bottom Line,” Ray Field of Goodway Technologies describes how a maintenance plan that includes chemical and mechanical cleaning can keep industrial boilers clear of scale buildup and maintain effective heat transfer. Benefits from planned boiler cleanings include improved energy efficiency.