Temperature control is essential for any manufacturing environment: changing temperatures can have a significant impact on processes, products and people. Some applications, such as food, chemicals, plastics or pharmaceuticals manufacturing, require heating for production. Manufacturers in these industries must consider not only how the temperature of circulating fluid will impact product quality, but how it will impact the entire facility.
Health and safety teams should monitor air temperature to ensure it does not negatively impact employee productivity or safety. While employee safety is paramount, engineering managers should also monitor air temperature to ensure that equipment remains operational: as equipment overheats, energy consumption increases and equipment efficiency decreases. Electronic controls can fail when temperatures exceed 40°C.
While a thermal fluid system is built for indirect heat transfer, exceeding the intended operating temperature can negatively impact productivity. One area that can be particularly affected is the expansion tank, which when heated can be up to 20% of system volume. To allow for this, as well as provide a sufficient safety factor, the expansion tank should always be approximately a third full when the system is cold. When the system is at full working temperature, at the level in the expansion tank where oil contacts the atmosphere should not exceed 60°C. If the tank exceeds 60°C, the oil inside will oxidise, leading to a build-up of acid and carbon. Over time this will reduce the heat transfer efficiency of the equipment and could lead to costly downtime.
KEEP IT COVERED
Investing in correct, and properly installed, insulation is the best way to regulate air temperature in the facility, control the temperature of equipment and better protect employees. Insulation ensures that heat created in the manufacturing process does not heat up the facility elsewhere. Insulating parts of the system also means that manufacturers can better regulate the temperature of equipment that must operate at specific temperatures, such as the expansion tank.
When choosing insulation for a heat transfer system, manufacturers should consider what material best suits the application. During its lifespan, a heat transfer fluid will degrade. The degradation process introduces by-products into the fluid, such as carbon that forms inside and acid corrodes unseen parts of a thermal fluid system. If this continues without intervention, small holes can appear in the coil, allowing fluid to leak, posing a fire hazard. Thermal oil would soak into porous insulation, increasing the risk of fire and other hazards, so using a non-porous insulation, such as blown glass, works best in areas of the system where fluid could leak, including flanges.
While insulation is key to improving conditions for employees and equipment, there are added benefits. Insulation prevents heat from escaping, improving heat transfer efficiency. Over time, manufacturers will find that less energy wasted from heat escaping will reduce energy usage in the facility while also reducing the carbon footprint of the process.
Regulating air temperature can prevent health and safety risks, reduce the risk of downtime and improve equipment efficiency.