There are a number of myths surrounding hot oil heating systems and their apparent disadvantages compared to steam heaters. But before we begin addressing these concerns, let’s first define what hot oil heating even is.
Otherwise known as thermal fluid heating, hot oil heating is a type of indirect heating in which a liquid-phase heat transfer medium is heated and circulated to one or more heat energy users within a closed loop system. Thermal oil, glycol, and water are commonly used heat transfer fluids for these systems.
Hot oil heating systems are used in a variety of applications, including heating presses for rubber and plastic molds, circuit boards, lamination, and plywoods. These systems are also used for chemical and petrochemical processing equipment such as reactors, heat exchangers, dryers, and evaporators.
Below, we’ll delve into the differences between hot oil heaters and steam heaters while exploring the advantages of hot oil heating over the older, more traditional steam heating process.
Isn’t there more maintenance involved in hot oil heating?
One of the most common misconceptions here is that hot oil systems require more maintenance than steam systems. But this is not true. One of the primary goals of innovation, of course, is to reduce the cost of ownership, and the newer technologies involved in hot oil heating allow for fewer maintenance needs, thereby reducing overall costs.
While steam is still the more traditional method — with water being comparatively inexpensive and the process of converting steam into energy serving as a time-tested method — it’s no longer the most efficient means of transferring heat. Water vaporization requires higher temperatures and pressurization, which, in turn, demand sturdier equipment, such as thicker pipes and specially constructed lines, along with high-pressure pumps. All of these requirements increase the cost of construction, installation, and operation.
Hot oil systems are also much more efficient, requiring lower pressurization. This means less expensive pumps can be used for the transfer process, since the lines and pipes do not need to be nearly as thick. And in terms of maintenance and replacement needs, materials won’t be as costly, which is especially important when the effects of corrosion are taken into account.
Steam requires water, air, and salt, which we all know take their toll on metal pipes, lines, and pumps — virtually the entire system. Hot oil, though, is noncorrosive. It is much gentler on metal surfaces, significantly reducing operational costs.
While the water used in steam heaters is chemically treated to reduce corrosion, this makes disposal a nightmare, given all the associated environmental restrictions and regulations. Thermal fluids, on the other hand, can essentially be recycled to make other useful products. And the bonus? You’re now a part of the circular economy everyone’s raving about.
Can a hot oil heater replace steam?
Yes. Easily. While the upfront costs of replacing steam may tempt business owners and plant managers to continue with antiquated systems and pay for any necessary updates, eventually the constant repairs and need to comply with heavier regulations will prove time-consuming, costly, and inefficient. Thermal fluid heating systems are inherently less expensive to construct and install, mitigating the initial costs.
This increased efficiency, combined with reduced maintenance, less required supervision, and easier disposal processes, will eventually pay for these upfront costs. And, as various innovations continue to improve hot oil systems, companies that have made the switch will already have their systems in place; any needed upgrades will be far less costly and time-consuming than having to catch up to the 21st century down the road.
Are leaks normal in hot oil heating systems?
Given the higher viscosity of thermal fluid, it is likely that seepage will occur throughout the system around threaded fittings and gaskets. But these droplets cool quickly once exposed to air. Also, with a properly trained workforce and careful attention to maintenance procedures, these common leaks will remain as such — just leaks — and not warrant any safety concerns or cause any kind of equipment failure. To effectively resolve any issues, staff should be able to recognize the difference between normal leakage and signs of danger or failure.
What about toxicity?
The words “oil” and “fluids” have negative connotations for many people, as they’re sometimes associated with toxicity. But the fact is, there are several different types of fluids you can use for hot oil fluid systems; there are even organic, petroleum-based products that reduce the chemical imprint. It just depends on what’s best for your business and budget. Also, standards for disposal are as simple and easy as they are for motor oil and hydraulic fluids. Still, there are certain applications that will require synthetic fluids, and those are available, too.
Below are some examples of synthetic fluids.
- Chevron
- Dowtherm
- Essotherm
- Glycol
- Marlotherm
- Mobiltherm
- Multitherm
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In many applications, thermal fluid heating systems are a much wiser choice than the costly dinosaurs of steam heating systems. Allowing for significantly reduced maintenance and increased efficiency, hot oil heating systems boost the bottom line while propelling operations into the 21st century, allowing you to be more competitive in your field. With proper maintenance, comprehensive training and education, and use of quality components, this equipment will last longer than steam heating systems while keeping operational costs low.
References:
http://www.tfsheat.com/technical-info.html
https://en.wikipedia.org/wiki/Oil_heater
http://www.nationalboard.org/SiteDocuments/General%20Meeting/5-Wadkinson.pdf
https://pdfs.semanticscholar.org/ff26/ae243f96d9dc3d926a7e56180055cf38699c.pdf