How Do Furnace Manufacturers Combat Humidity?
Industrial furnace manufacturers are tasked with developing heat treatment solutions that meet both broad and extremely specialized operating criteria. These may include wide temperature ranges with safety controls for extreme peak thermal conditions, unique considerations for future expansion, and specialist furnace geometries for processing difficult components.
Humidity is an almost unavoidable factor in industrial and laboratory heat treatment processes. It is produced when the internal temperature of samples is heated to the extent that moisture trapped within the material desorbs and enters the heat treatment chamber as a vapor. Dehydrating samples is a critical process for drying and curing ovens. However, furnace manufacturers must account for the phenomenon of reabsorption during cooling to ensure that moisture reuptake does not limit the product yield.
Moisture reuptake occurs when samples are left to cool in a humidified chamber that has not been correctly ventilated. As the sample’s structure contracts, it can reabsorb vapors from the chamber and succumb to hygroscopic expansion. This is a dynamic mechanism that is rarely uniform across the entirety of the sample and is characterized by localized swellings and uneven topographical flaws. These are undesirable end-product properties that decrease the chance of cured parts and samples meeting their design intention.
Furnace Manufacturer Solutions for Humidity
The simple solution for humidity in industrial drying applications is to equip furnaces with continuous ventilation to extract desorbed vapors from the process environment in situ. However, this demands careful consideration of the heating element chemistry, the operating temperature, and the composition of the process gas. There is a significant risk of process gases reacting with heating elements of specific chemistries, causing premature component failure. Nitrogen (N), for example, comprises up to 78% of ambient air. Yet it is highly reactive with carbon-rich surfaces such as silicon carbide (SiC) at high temperatures. Furnace manufacturers must consider novel heating element materials to replace silicon carbide for industrial drying with humidity controls.
Thermcraft, the US’s foremost furnace manufacturers, have developed a unique solution to this issue. Our CoilCraft Element Systems (CCES) are engineered for industrial drying ovens with long service for ventilated heat-treatment at high temperatures. This is based on a heavy-gauge heating wire comprised of a chemically-inert ceramic core, eliminating the risk of cross-reactivity with ventilating gases and reducing the risk of moisture reuptake in critical drying processes.
Thermcraft: Cutting-Edge Furnace Manufacturers
Thermcraft is one of the world’s leading furnace manufacturers for industrial and laboratory facilities. We have engineered a suite of solutions for simple and complex operating challenges in various heat treatment applications.
Industrial drying ovens equipped with our proprietary CCES can decrease the risk of product failure, or limited yield, due to moisture reabsorption during heat treatment processes. This unique system can also be easily retrofitted into existing furnace architectures to improve drying performance with significant reductions in cost and instrument downtime.