Chris Horsley, managing director, Babcock Wanson, explains the benefits of thermal fluid heating systems, such as energy efficiency, ease of use and compact size, when compared to a steam boiler system
Thermal fluid heating systems have revolutionised process heating, making energy hungry and heavily manned plant rooms a thing of the past in most industries. Whereas a plant room based around large fire tube steam boilers required lots of space for equipment and was relatively complex to use and maintain, thermal fluid heating systems are compact, easy to use and offer important energy savings.
Thermal fluid heating is based on a similar principle to a domestic hot water system. It consists of a heater connected to carbon steel flow and return pipework which can provide heat to one or more users or systems. Instead of water running through that pipework, a thermal fluid – most often a simple industrial oil – is used as the heat transfer medium.
One of the key factors in achieving system energy efficiency is the ability of a thermal fluid system to work at high temperatures (up to 350°C in standard form) in a simple closed loop. When compared to a steam system this means no change of state of the fluid, so no condensate and therefore no flash steam losses, no blow down losses or make up water required, no effluent discharge and a corrosion free system without the need for chemical treatment. This all adds up to significant savings.
Using thermal fluid as opposed to water has other key benefits including removing the problems caused by scaling and changes to ambient temperatures, as well as improved safety. In a water system, pressure rises as a function of temperature: the higher the temperature, the greater the potential for problems within the system and the higher the system’s materials cost. This is not so in a thermal fluid system as there is little relationship between temperature and cost, so the fluid doesn’t have to be kept under pressure (other than the very small pressure of the circulating pump). This offers advantages in the sizing and cost of heat exchangers.
Size is another reason for the uptake of this technology. A thermal fluid heater is compact and needs no specialist site work, so it can usually be sited in the most convenient location, often close to the user, meaning savings in specialist plant rooms and distribution pipe work. It’s also a flexible system, as different thermal fluids can be used to meet specific process heating requirements.
Reduced bills, increased control
Robert Horsfall, finance director of Wire and Strip manufacturer Webster & Horsfall, sums up the modern love affair for thermal fluid heating: “The new heater is one third more efficient than our previous steam based boiler, which allows us to operate more efficiently, reduce our energy bills and have a considerable impact on reducing our Carbon footprint. What we hadn’t expected initially though is the level of control the new system provides us with; it’s amazing. It alerts us to any potential issues, is easy to maintain (no annual statutory inspection is required) and is quick to respond. All that and it doesn’t take up much room.”
Webster & Horsfall is using a Babcock Wanson TPC600B thermal fluid heating system for heating tanks for metal treatment. This system provides between 20-50% energy savings when compared to the transfer of the same amount of heat using traditional steam boilers. The system matches fuel input to plant energy requirements for high efficiency. With lower energy input demand also comes lower total exhaust emissions.
Of course, not every industrial process is suited to thermal fluid heating systems. There are a number applications, usually where both direct and indirect heating are required simultaneously, where steam generation is the only viable solution. Even though such systems have advanced to meet changing requirements, thermal fluid heaters have outpaced steam generation in the majority of process heating applications.
Babcock Wanson offers a complete range of products and services for boiler houses and other process heating needs. These include steam boilers, thermal fluid heaters, rapid steam generators and hot water boilers to VOC and odour treatment by thermal oxidation, water treatment or process air heating solutions.
T: 0208 953 7111