Installing a 6,000,000 Kcal thermal oil furnace in Nam Dinh. To install a thermal oil furnace safely and efficiently, it is necessary to follow the manufacturer’s instructions, check the safety valve system, not operate above the specified pressure and temperature, and conduct periodic inspections to minimize the risk of problems.
Installing a 6,000,000 Kcal thermal oil furnace in Nam Dinh
A thermal oil furnace is a specialized device used to transfer thermal energy from a source (such as thermal oil, hot water or steam) to other processes or systems through a heat transfer medium. The main role of a thermal oil furnace is to provide and maintain a stable temperature level, meeting the specific requirements of production processes.
The outstanding advantage of a thermal oil furnace lies in its ability to transfer heat quickly, efficiently and stably. This device can be flexibly adjusted to suit the individual temperature needs of each process or system. Thermal oil furnaces are widely used in many industries, especially in fields such as wood drying, wood pressing, and textile dyeing, etc.
The thermal oil furnace requires technical parameters to strictly comply with international and national standards. In particular, the ASME (American Society of Mechanical Engineers) standard is a prestigious international standard, applied to measure, test, and evaluate the quality of pressure and pressure-bearing equipment. In addition, thermal oil furnaces also need to meet Vietnamese standards (TCVN) on design, manufacture, installation and operation to ensure safety and optimal performance.
Below are the important technical parameters of thermal oil furnaces:
Heat capacity: Varies from 1 to 30 Gcal/h, suitable for many different scales and production requirements.
Thermal oil pressure: From 5 BarG to 15 BarG, allowing the system to operate stably in high-pressure environments.
Fuel: Thermal oil boilers can use a variety of fuels, including biomass, coal dust from Indonesia, industrial waste, rags, etc.
Boiler efficiency: For fluidized bed boiler systems, the efficiency is over 86%; for systems using chain grate, the efficiency is over 82%.
Structure of thermal oil boilers
A thermal oil boiler is an industrial device that uses heat transfer oil as a medium to transport heat from the combustion chamber to heating devices. The system operates at low pressure but can reach high temperatures (200°C – 400°C), helping to save costs and is safer than systems using high-pressure steam.
Here is the basic structure of a thermal oil boiler system:
Combustion chamber
The combustion chamber is where the fuel combustion process takes place, creating a hot air stream to heat the heat transfer oil.
For liquid/gas fuels: use a burner to burn gas, DO oil.
For solid fuels: can be a static grate combustion chamber, chain grate or fluidized bed combustion chamber, suitable for burning coal, firewood, rice husks, pellets, etc.
Optimal combustion chamber design to increase combustion efficiency and reduce emissions.
Oil furnace body (heat exchanger)
The furnace body is where the oil is heated indirectly through heat exchange tubes:
Includes two main zones: the radiation zone (receiving heat directly from the combustion chamber) and the convection zone (receiving heat from the smoke stream).
The oil pipe is often twisted or arranged in a honeycomb tube array to increase the heat transfer area.
Forced circulation oil flow design to ensure minimum flow velocity, avoiding local overheating that causes oil decomposition.
Oil circulation pump assembly
High temperature resistant pump, with the function of:
Pushing hot oil from the furnace to heat-using equipment (steamer, dryer, paint dryer, etc.).
Suction of cold oil from the equipment back to the furnace, forming a closed cycle.
The pump must be accurately calculated for flow, pressure head, viscosity and type of heat transfer oil used.
Expansion tank and oil tank
Expansion tank: located at the highest position in the system, containing the oil that expands when the temperature increases. Has the ability to prevent overflow and has a safety valve.
Oil tank: used to recover all oil when the furnace needs to be drained for maintenance, ensuring safety and savings.
Smoke – wind system
Including:
Air supply fan: brings air into the combustion chamber, ensuring enough oxygen for the combustion process.
Smoke exhaust fan: creates negative pressure in the combustion chamber, sucks hot air through the furnace body and pushes it out through the chimney.
Chimney: has a suitable height to release exhaust gas into the environment without affecting the surrounding area.
Exhaust gas treatment system (optional)
Depending on the fuel used and environmental requirements, the treatment system may include:
Cyclone for coarse dust separation
Fabric bag filter, electrostatic filter to collect fine dust
Dry or wet filter tower to treat toxic gases such as SOx, NOx
Central control cabinet
Automatically controls the entire fuel supply process, oil pump, air supply, temperature control, pressure and fire safety.
Can integrate HMI, PLC, or SCADA touch screen if required.
Sensors and measuring devices
Equipped with temperature, pressure, flow, oil level sensors, safety valves… to help the system operate stably and safely.
Operating principle of thermal oil furnace
The thermal oil furnace operates based on the principle of heat transfer from fuel to the carrier oil, then the oil is led through the pipe system to provide heat for industrial processes or heat-using systems.
The operating principle of the thermal oil furnace is as follows:
Fuel supply and combustion:
Fuel is transferred from the storage tank to the combustion chamber through the automatic fuel supply system. Fuels such as biomass, coal or industrial waste are spread evenly on the furnace grate surface, ensuring even distribution.
Fresh air after being heated through the heat recovery unit is blown onto the grate surface. This process provides enough oxygen for the combustion process, helping the fuel burn evenly and quickly, optimizing combustion efficiency.
Heating the carrier oil:
The heat generated from the combustion process will directly heat the oil pipes through thermal radiation. At the same time, the exhaust gas stream continues to transfer heat to the convector’s tubes, where the heat-transfer oil is heated to the desired temperature.
The heated oil will circulate through the piping system and be led to the loads (equipment or system that needs heat), ensuring a stable and efficient heat transfer process.
Exhaust gas treatment:
The exhaust gas after leaving the combustion chamber will be led through the heat recovery unit to take advantage of the remaining heat. This recovered heat continues to heat the air supplied to the combustion chamber, helping to reduce heat loss and improve the overall efficiency of the furnace.
Exhaust gas after leaving the heat recovery unit with a temperature less than 200°C will be led to the exhaust gas treatment system before being discharged directly into the outside environment.
Important notes during installation and operation:
Follow the manufacturer’s instructions:
Always refer to the thermal oil furnace manufacturer’s manual for proper installation and safe operating parameters.
Check the safety system:
Ensure that the system’s safety valves are functioning properly, such as high oil temperature protection, minimum oil level in the expansion tank, and oil flow protection.
Operate within safe limits:
Never operate the furnace beyond the specified allowable pressure and temperature.
Update information from the manufacturer:
Any changes to the structure or operating principle of the furnace must be recommended by the manufacturer or competent authority.
Periodic Inspection and Monitoring:
Perform periodic system inspections as per manufacturer’s instructions to ensure proper operation of the equipment and record daily monitoring results to detect early signs of damage.
Stop operation when signs of damage appear:
If any signs of damage or failure are detected on the equipment, stop operation immediately and carry out emergency maintenance.
