However, with the right strategies in place, many plants can minimize their exposure to energy shortages and price hikes. According to the U.S. Department of Energy (DOE), heating processes consume about 5.2 quadrillion British thermal units (Btu) of energy in the U.S. annually, which accounts for nearly 17% of all industrial energy use. In many cases, implementing smart operating practices and/or advanced technologies can offer significant energy savings.
The DOE’s Office of Industrial Technologies (OIT) has identified a number of “best practices” for energy savings and process efficiency, which it promotes through its BestPractices program. Through cost-shared funding of R&D projects, plant assessments, support of emerging technologies, training sessions, energy analysis software and other methods, BestPractices is helping dozens of U.S. companies cut costs by identifying energy saving opportunities.
For example, heating efficiency is reduced considerably if the air supply to a fuel-fired furnace, oven or kiln is significantly higher or lower than the theoretically required air. Periodically checking and resetting the air-fuel ratios can be a simple yet effective way to ensure that the firing process is operating as efficiently as possible. Using preheated combustion air is another way to save energy, since recycling the heat from the exhaust gas stream reduces the amount of purchased fuel needed by the furnace.
For electric furnaces and kilns, choosing the right heating elements can be key to maximizing operating efficiency. Using an element from a class with a high maximum element surface temperature (MET) in an application where the maximum furnace/process temperature is far below the MET can be unnecessarily costly—both in terms of the initial cost of the element and the power required to operate the furnace. (See this month’s cover story “Selecting Heating Elements for Electric Furnaces and Kilns” for tips on how to select the right heating elements.)
In some cases, new technologies might provide a solution. A new vacuum hot extrusion process, for example, offers the potential to reduce a number of processing steps in making ceramic products. Additionally, the primary heating step has low heat losses and directly heats the raw material to processing temperature, which tends to be lower than that required in conventional ceramic firing, significantly reducing energy requirements compared to conventional processes. (Read the feature “Forming Ceramics Through Vacuum Hot Extrusion.”)
The volatility in the energy sector is not likely to disappear any time soon. However, by proactively seeking ways to reduce our energy requirements, we can make our manufacturing operations much less vulnerable to sudden changes in energy pricing and/or availability.