Heating systems may typically be categorized as indirect or direct. Indirect heating systems allow for more fine-tuned temperature control. There are many ways to indirectly heat substances, and one of the foremost is through the use of a thermal fluid system—also known as a thermal oil heater.
Many industrial companies have turned to thermal fluid heating or hot oil heating because of the various advantages it offers over other heating systems. A thermal fluid system is a closed looped system in which a fluid—most commonly oil—is used to heat the desired substance indirectly.
The fluid within the system can be heated in several ways, most commonly through electrical power, coalwood, natural gas or oil. Once the fluid within the thermal system has reached a specified temperature, the heat will be transferred to the end user target.
This page will provide you with all of the information you need to determine if thermal fluid heating is right for you.
Major Components of Thermal Fluid Heating Systems
As with all heat-generating systems, it’s important to know the major components of the system. Thermal fluid heating systems include these essential parts:
- Control panels
- High-temperature pumps
Burners are application-specific. System designers choose burners based on the heater’s combustion chamber size. The burners will be selected based on their capability to supply handle the heat load to the chamber.
Automated systems are safer and easier to regulate, which is why many existing thermal fluid heating systems include—or have been retrofitted to include—programmable logic controller (PLC) control packages. These systems offer smarter control of the heating system without direct interference from operators. They also allow operators to maintain safe distance from heated parts to reduce any risk of injury or accidents.
PLC control packages can integrate with a plant’s distributed control system (DCS) for quick and straightforward adoption. Some elements of these control panels include:
- Continuous flow monitoring. PLC control packages include differential pressure switches and orifice plates in every heater coil to monitor continuous heat cycles.
- Alarms. High stack temperature alarms and redundant fluid outlet temperature alarms monitor for temperature surges. Systems can also include tank level alarms and high or low fuel pressure alarms.
- Automatic interlock. The system prevents surges in firing during startup to prevent damage to the heating system.
- Burner supervision. UV flame scanners and electronic flame programmers monitor the performance of burners.
Hot water and boiler feed pumps aren’t appropriate for thermal fluid systems. They require specially designed high-temperature pumps that can handle the fluid’s pressure drops and fluid gravity. In well-designed systems, every pump is specifically made to match the expected function and heated fluid.
Common types of pumps in thermal fluid heating systems include:
- Centrifugal pumps, which require ductile or cast iron wetted material.
- Positive-displacement pumps, which work best when they’re made from alloy steel.
- Air-cooled mechanical seal pumps, which depend on the system and usage.
Some alternatives to air-cooled mechanical seal pumps include water-cooled, magnetically coupled, or API pumps. Pumps should also have bellows-type seals.
Thermal Oil Boiler vs. Steam Boiler
Thermal fluid systems and steam boilers are two of the most common industrial heating systems. Thermal fluid heating systems offer the following advantages over steam boilers:
- Better temperature control
- Greater reliability
- Greater temperature range (because oils have higher boiling points than water)
- No corrosion
Steam boilers pose a corrosion risk without proper monitoring, and they provide a lower range of temperatures for heating applications. Installing a thermal oil heating system to replace an older steam boiler can drive significant efficiencies for industrial facilities.
This can also greatly reduce maintenance demands because newer automated thermal fluid systems self-monitor their own condition and warn operators of any problems. Thermal fluid systems that use oil are also continuously lubricated by heating fluid itself, which keeps the system in better condition throughout its lifespan.
Design of Thermal Fluid Systems
Thermal Fluid Systems, Inc. specializes in designing thermal fluid heating systems tailored to specific applications and facilities.
Our full system configuration services include:
- Designs for exterior or interior applications
- Electrical heating system options
- Optional drain tanks and secondary heating controls for varying applications
- Physical unit options, such as horizontal or vertical configurations and stand-alone or skid-mounted heating units
- Thermal fluid systems that can use gas, oil, or waste fuel by design—fluid options include biodiesel; bunker C; fuel oils #2, #4, or #6; natural gas; propane; or waste gas product
- Three-pass, high-efficiency heater designs that evenly distribute heat throughout the system
We also provide all system components, such as:
- Control packages
- Isolation valves
Thermal Fluid Systems, Inc. offers a wide selection of individual components for repairs, maintenance, and retrofitting. We also provide additional services such as inspections, maintenance plans, operator training, and complete turnkey installation.
Each of our systems provides a high degree of energy output and energy efficiency. Energy output ranges from 0.5 BTU to over 50,000,000 BTU per hour. The units also have up to 90% LHV efficiency. Our systems can be designed to meet the following industry standards:
- NEMA ratings: 1, 3R, 4, 4X, 7, 12
Advantages of Thermal Fluid Systems
There are numerous advantages to using hot oil heating systems, the foremost of which is their ability to control the temperatures of other fluids used in processing indirectly. This power to change certain temperature aspects is especially important in systems requiring finely tuned temperature control. The fact that the thermal system operates by heating fluids also gives it the capability to precisely time heating for the end user target.
Also, thermal systems can maintain high temperatures for extended durations, while at the same time operating at low pressures. This low-pressure operation significantly increases the level of safety for those working near the unit.
Furthermore, these systems are known for being very reliable due to their simplistic, rugged design. The longevity of the system can help industrial companies save a lot of money because they won’t have to replace the unit after a few years, as is the case with other similar competitive systems.
Thermal Fluid Applications
The applications in which a thermal fluid heater can be used are nearly endless. Some of the most widely used applications including heating of fryers, process reboilers, and convection ovens.
Often an electric heating system is preferred because it does not have any harmful emissions—such as carbon dioxide or nitrous oxide—which are common byproducts when using coal-generated heat. Therefore, they are much safer and very efficient as well.
Here for All Your Thermal Liquid and Hot Oil System Needs
When it comes to heating process fluids, few methods offer the advantages of thermal fluid systems. By implementing this type of a system, the temperature of the end product can be finely tuned, and the heat can be applied at a precise moment, allowing for extreme control. The low operating pressures of a thermal system mean that employees will be much safer when working in the vicinity of the unit.
There are dozens of uses for this type of fluid heating system, and some of the most popular include industrial convection ovens and liquid tank heating. Thermal Fluid Systems, Inc. is here to help you find the ideal solution that will improve your production and help business run efficiently.