My current job is to select vendor who will supply thermal oil heater. It is pretty hard work for me because I did not involve in thermal oil heater design since the beginning. Unlike water treatment plant which I deeply learnt since the beginning, I even don’t have any idea about thermal oil heater, so I need to learn harder. Since I am not a fast learner, I write this post as the methode (which I like the most) for me to understand what thermal oil heater is and how to select appropriate thermal oil heater.
Thermal Oil Heater for High Temperature Heating
Thermal oil heater and steam can be used as heat source in industry. However, thermal oil heater can easily reach temperature 300 deg C at atmospheric pressure compared with 80 bar with steam. It is more economical than steam heating (source). As the steam temperature increase, so does pressure. For a steam temperature 187 deg C, the steam pressure is 10.33 bar. The pressure increase to 30 bar at temperature of 230 deg C. Such high pressure steam systems can be expensive to install and operate. This is the main selection criteria for thermal fluid versus steam (source).
Advantages of Thermal Oil Heater Compared to Boiler Efficiency
Efficiency of thermal oil heater can be as much as 5% to 8% higher than conventional steam boiler system. Thermal oil heaters also do not suffer from losses (trap losses, blowdown loss, deaerator loss) as happen at steam boiler system, so that can be up to 31% more efficient (source).
Thermal fluid system maintenance time is significantly less than that involved with a steam system because thermal fluid is corrosion resistant, the danger of freezing is not present, and water treatments are not necessary (source).
The water in a steam system must be chemically treated to reduce corrosion. The chemical can not be discharged into sewers as they present considerable environmental hazard. Thermal oil heaters require no blowdown and unlike steam systems, are not subject to continual leakage. Thermal fluids also offer safe and easy disposal.
Purchase cost of steam systems can be less than thermal fluid systems. However, the paybacks are: decreased operating costs, maintenance costs, and environmental concerns -and increased production and product quality resulting from better control of heating and cooling. Combine these with improved safety and reduced manpower cost, and the overall economy of thermal fluid systems will far surpass steam system.