Thermic fluid heater. A thermic fluid heater (TFH), also known as a thermal oil heater, is a device used for indirect heat transfer through a thermic fluid. 
It heats the fluid to a desired temperature and then transfers that heat to various processes without any direct contact between the heating source and the product. This type of heater is commonly used in industries where precise temperature control is essential and where high temperatures are required, such as in chemical processing, textile, pharmaceuticals, oil, gas, and food processing.

Working principle 
The basic working principle of a thermic fluid heater is indirect heating. It uses a heating medium, typically a thermic fluid or heat transfer oil, which circulates through a closed-loop system. The thermic fluid absorbs heat generated by the combustion of fuel and then transfers this heat to the required processes or equipment via heat exchangers.

 Combustion: The fuel is burned in the combustion chamber, generating heat.
 Heat transfer: This heat is transferred to the thermic fluid flowing in coils or pipes surrounding the combustion area.
 Circulation: The heated fluid is pumped to the heat exchanger, where it transfers its heat to the process.
 Return: The cooled fluid returns to the heater for reheating, creating a continuous cycle.

The advantage of using thermic fluid heaters is that they can achieve high temperatures without the need for high pressure, as is required in steam boilers.

Types of thermic fluid heaters 
Thermic fluid heaters can be classified based on their design, fuel type, and applications. The most common classification is based on the type of fuel used for heating.

1. Solid fuel thermic fluid heaters 
Solid fuel thermic fluid heaters use materials such as coal, wood, biomass, or agricultural waste as the primary fuel source. These heaters are commonly employed in regions where solid fuels are abundant and economical.

Advantages:

 Cost-effective in areas with easy access to solid fuel.
 Ideal for industries with specific environmental policies regarding waste utilization.

Disadvantages:

 Requires more maintenance due to ash handling and emissions.
 Less efficient compared to liquid or gas fuel systems.

2. Liquid fuel thermic fluid heaters 
Liquid fuel thermic fluid heaters run on petroleum-based fuels like furnace oil (FO), light diesel oil (LDO), or heavy fuel oil (HFO). These heaters are more common in industries that have access to refined oil products.

Advantages:

 High efficiency and ease of operation.
 Lower emissions compared to solid fuel systems.

Disadvantages:

 High operational cost due to fuel price volatility.
 Requires proper storage and handling of liquid fuels.

3. Gas-fired thermic fluid heaters 
Gas-fired thermic fluid heaters use natural gas, liquefied petroleum gas (LPG), or other gaseous fuels for heating. These are highly efficient systems often used in industries requiring a cleaner and more environmentally friendly heat source.

Advantages:

 High efficiency and low emissions.
 Minimal maintenance compared to solid and liquid fuel heaters.
 Fast heating time.

Disadvantages:

 Dependent on gas availability and infrastructure.
 Higher initial investment compared to some other systems.

4. Electric thermic fluid heaters 
Electric thermic fluid heaters operate using electricity and are commonly employed in areas where alternative fuels are scarce or where environmental regulations prohibit the use of combustion-based heating methods.

Advantages:

 Clean and environmentally friendly.
 No emissions or combustion by-products.
 Precise temperature control.

Disadvantages:

 High operational costs due to electricity consumption.
 Limited use in industries requiring very high heating capacities.

Advantages of thermic fluid heaters 

 High Temperature at Low Pressure: These heaters can reach higher temperatures i.e. 300 °C without pressurization, which reduces safety concerns compared to steam boilers.
 Energy Efficiency: The closed-loop system minimizes heat loss, leading to better energy efficiency.
 Low Maintenance: Fewer components (no boiler, drum, or water treatment) result in reduced maintenance requirements.
 Flexibility: Suitable for a wide range of industrial applications and can be fueled by various energy sources.

Applications 
Thermic fluid heaters are widely used in industries such as:

 Chemical Industry: For heating reactors, distillation columns, and other chemical processes.
 Textile industry: For dyeing, printing, and other fabric processing tasks.
 Pharmaceutical industry: For sterilization and production of pharmaceuticals.
 Food industry: For processes like frying, baking, and dehydration.
 Oil & Gas industry: For heating crude oil, regeneration of catalysts, and other petrochemical processes.

Safety and Environmental Considerations 
While thermic fluid heaters are generally safer than steam-based systems due to the low-pressure operation, there are still important safety considerations:

Emission Control: Heaters using solid, liquid, or gaseous fuels need proper emission control systems, such as scrubbers or filters, to minimize environmental impact.

Leakage: Since the thermic fluid operates in a closed-loop system, any leakage can lead to safety concerns, including fire hazards.

Proper operation, maintenance, and the use of high-quality thermic fluids can mitigate many of these risks.

References

Boilers
heating