50KW electric heating thermal oil furnace

I. Overview and Working Principle of a 50KW Electric Heat Conduction Oil Furnace:

1. 50KW Electric Heating Thermal Oil Furnace Overview:

A 50KW electric heating thermal oil furnace is a new type, safe, and highly efficient energy-saving industrial furnace that operates at low pressure (under atmospheric pressure or lower pressure) and provides high-temperature thermal energy. It uses thermal oil as the heat carrier, circulated by a thermal oil pump, to transfer heat to the heat-using equipment.

The electrically heated thermal oil system is a modular assembly comprising an explosion-proof electric heater, an organic heat carrier furnace, a heat exchanger (if applicable), an on-site explosion-proof control box, thermal oil pump, expansion tank, etc. Users simply need to connect the power supply, inlet and outlet pipes for the medium, and some electrical interfaces to start using it.

2.50KW electric heating thermal oil boiler working principle:

The 50KW electrically heated thermal oil boiler generates and transfers heat through electric heating elements immersed in the thermal oil. Using thermal oil as the medium and a circulating pump, it forces the thermal oil to circulate in the liquid phase, transferring heat to one or more heating equipment. After the heat is unloaded by the heating equipment, it returns to the heater through the circulating pump, absorbs more heat, and then transfers it to the heating equipment again, repeating this cycle continuously to achieve continuous heat transfer. This raises the temperature of the heated object to meet the heating process requirements.

Section 2: Design Conditions for a 50KW Electrically Heated Thermal Oil Heater

Design thermal load. There should be a margin between the thermal load and the effective thermal load of a 50KW electrically heated thermal oil heater, typically ranging from 10% to 15%.

(2) Design Temperature. The design temperature of the 50KW electric heating thermal oil boiler is determined by its operating temperature and should be designed in accordance with the relevant provisions in GB9222 "Strength Calculation for Pipe锅炉 Components."

(3) Design Pressure. The design pressure of the thermal oil should be slightly higher than the working pressure and not less than the opening pressure of the safety valve. The design pressure for the vapor phase furnace is 1.2 to 1.5 times the working pressure; for the liquid phase furnace, it should be 1.05 to 1.2 times the pressure; the pressure difference between the inlet and outlet of the thermal oil in the liquid phase furnace should be greater than 0.15 MPa (1.5 kgf/cm²).

(4) The temperature for the import and export of thermal oil. The design should prioritize both economy and safety, creating an appropriate temperature difference for the operation of the thermal oil within the system, which should be less than 30°C.

(5) The flow rate of thermal oil inside the pipe. The design flow rate of the thermal oil within the pipe should be sufficient to prevent coking due to localized overheating. Generally, the flow rate for the radiation section pipe is 2~4 m/s, and for the convection section pipe, it is 1.5~2.5 m/s. When determining this parameter, consideration should also be given to the thermal oil resistance within the pipe and factors ensuring turbulent flow of the thermal oil. A larger pipe diameter allows for a higher flow rate, while a smaller diameter requires a lower flow rate.

(6) Average thermal intensity of the furnace tubes. The design requires the average thermal intensity of the furnace tubes to be within a certain range, to prevent the thermal oil from overheating while fully utilizing the heat transfer area of the furnace tubes. Generally, the average thermal intensity of the furnace tubes in the radiant section is 0.084~0.167 GJ/(m².h), and for the six-section furnace tubes, it is 0.033~0.047 GJ/(m².h).

(7) Exhaust Gas Temperature. The difference between the exhaust gas temperature and the thermal oil temperature is controlled between 80~120℃ based on the operating temperature of the thermal oil. The exhaust gas temperature should be maintained at 350~400℃ to prevent the heat transfer surface from being too large. To maximize the use of heat energy, the 50KW electric heating thermal oil furnace with higher exhaust gas temperatures should be equipped with a waste heat recovery system to recycle and reuse this heat, especially for larger 50KW electric heating thermal oil furnaces, which should be given more consideration and attention.

(8) All pipes and accessories in contact with thermal oil must be prohibited from being made of non-ferrous metals and cast iron. Flanges and valves should be made of cast steel with a nominal pressure of 2.5MPa (about 25kgf/cm2) or more. Sealing materials should be heat-resistant and oil-resistant. When using biphenyl mixture thermal oil, use tenon and groove or male and female face flanges for connection.

(9) The 50KW electric heating thermal oil boiler must be equipped with a low-point drain valve, which is required to fully drain the material to ensure no residue remains.

Section 3: Model and Specifications of 50KW Electric Heat Transfer Oil Furnace

Four: Application scope of the 50KW electric heating thermal oil boiler:

The 50KW electric heating thermal oil boiler is widely used in the petrochemical, textile dyeing and finishing, light industry, building materials, and other industrial fields.

1. The 50KW electric thermal oil heater is used in industrial applications, primarily for heating crude oil and natural gas, as well as processing, storage, and transportation of mineral oils. Refineries use thermal oil to preheat cold materials and it has been successfully employed to heat evaporators for solvents and extractants in the lubricant manufacturing process.

2. In the chemical industry, the 50KW electric heating thermal oil furnace is primarily used for heating in distillation, evaporation, polymerization, condensation/dewaxing, esterification, drying, melting, dehydrogenation, forced insulation, and for heating synthetic equipment such as pesticides, intermediates, antioxidants, surfactants, and fragrances.

3. In the lipid industry, a 50KW electric heating thermal oil furnace is primarily used for heating equipment involved in oil decomposition, fatty acid distillation, esterification, nitration, hydrogenation reaction, concentration, and vacuum deodorization.

4. In the food industry, the 50KW electric heating thermal oil furnace is primarily used for bread baking equipment, biscuit baking equipment, candy production units, grain drying equipment, oil extraction and refining units, distillation pots, autoclaves, and conveyor belt dryers.

In the textile dyeing and finishing industry, a 50KW electric heating thermal oil boiler is primarily used for heating purposes in drying and shaping equipment, thermal dyeing units, dyeing and printing machines, dryers, dryers, calenders, flattening machines, washing machines, roller machines, pressing machines, and hot air sizing.

6. In the medical industry, the 50KW electric heating thermal oil boiler is primarily used for heating equipment and units in drug preparation, raw material mixing, formulation, sterilization, distillation, evaporation, and melting processes.

7. In the synthetic fiber industry, the 50KW electric heating thermal oil boiler is primarily used for heating in processes such as polymerization, melting, spinning, heat curing, fiber finishing, stretching, and drying equipment. In the papermaking industry, it is mainly used for heating purposes, including coating paste rolls, drying rolls, drying rooms, drying cabinets, thermal melting machines, wax melting pots, and corrugated paper processing.

8. In the paper industry, a 50KW electric heating thermal oil furnace is primarily used for heating purposes, such as in the coating of sizing rolls, drying rolls, drying rooms, drying cabinets, thermal melting machines, wax pots, and the processing of corrugated paper.

9. In the plastic and rubber industries, the 50KW electric heat conduction oil furnace is primarily used for thermal pressing, stretching, extrusion, blending, compounding, vulcanization molding, injection molding machines, paste mixers, conveyor belt dryers, screw extruders, and heating and temperature maintenance of molds.

10. In the wood industry, a 50KW electric heating thermal oil boiler is primarily used for the hot pressing molding of fiberboard, particleboard, plywood, laminated panels, decorative panels, as well as for heating wood drying equipment, drying equipment, coating machines, and adhesive machines.

11. In the building materials industry, the 50KW electric heating thermal oil boiler is primarily used for gypsum board drying, concrete component curing protection and prefabrication production, tile molding, decorative material drying, and heat supply for the asphalt felt production line.

In road construction projects, the 50KW electric heating thermal oil boiler is primarily used for asphalt heating, dissolution, storage, asphalt concrete, and emulsified asphalt heating and insulation.

13. In metallurgy, machining, and foundry industries, a 50KW electrically heated thermal oil furnace is primarily used for heating purposes in metal degreasing tanks, acid tanks, acid dipping baths, washing tanks, electroplating tanks, Luyang board oxidation tanks, electrode manufacturing, shower heat treatment equipment, phosphate treatment facilities, baking rooms, sand core drying, varnish spraying and drying, and assembly processing units.

14. The 50KW electric heating thermal oil boiler is primarily used for centralized or decentralized heating in factories, offices, hospitals, residential buildings, and hotels in the air conditioning and electrical equipment industry; as well as for heating polishing machines, rolling machines, vacuum machines, dryers, drying rooms, and vacuum chambers in the electrical equipment manufacturing industry.

15. In the fat and paint industries, the 50KW electric heat conduction oil furnace is primarily used for heating high-pressure reactors, dryers, distillation vessels, evaporation equipment, paint curing, baking, drying, and high-temperature curing.

16. In the coking industry, the 50KW electric heating thermal oil furnace is primarily used for heating and insulation of gas storage tanks, mixing stations, and distribution stations.

17. In the automotive manufacturing industry, the 50KW electric heating thermal oil boiler is primarily used for tunnel drying rooms, degreasing pools, and heating of phosphoric acid treatment equipment.

18. In national defense scientific research, the 50KW electric heating thermal oil boiler is primarily used as a high-temperature heat source for the development of new technologies, materials, and products in national defense scientific research.

19. In the carbon industry, the 50KW electric heating thermal oil furnace is primarily used for graphite electrodes, carbon products, asphalt melting, kneading pot heating, and extrusion molding heating.

In the shipping industry, the 50KW electric heating thermal oil furnace is primarily used for heavy oil tanks, asphalt tanks, sulfur tanks on vessels, as well as for heating and insulation of containers.

V. Key Features of the 50KW Electric Heating Thermal Oil Boiler:

1. Features low pressure, high temperature, safety, and energy-efficient performance.

2. Equipped with comprehensive operation control and safety monitoring systems, capable of precisely regulating working temperatures.

3. Reasonably structured, complete with accessories, short installation cycle, easy operation and maintenance, and convenient for boiler layout.

4. The electrically heated organic heat carrier boiler, with its advanced explosion-proof structure, is suitable for explosion-proof application in Factory Zone II, achieving an explosion-proof grade up to C.

The Zhenjiang 3D Electric Heater offers a free 50KW electric heating thermal oil furnace technical solution as per customer requirements.

Section 6: Operation and Maintenance Instructions for a 50KW Electrically Heated Thermal Oil Heater

A 50KW electric heating thermal oil furnace operator should have received training in the knowledge of the 50KW electric heating thermal oil furnace and be certified by the local boiler safety supervision authority.

Unit using the 50KW electric heating thermal oil furnace must establish an operation procedure for the 50KW electric heating thermal oil furnace. The procedure should include methods and precautions for starting, operating, shutting down, and emergency shutdown of the 50KW electric heating thermal oil furnace. Operators must follow the procedure during operation.

Three "di" pipes within the 50KW electric heating thermal oil boiler range should be insulated, but jacketing measures are not advisable for the flange connections.

Four 50KW electric heating thermal oil boilers should open the exhaust valve on the boiler multiple times during the ignition and pressure increase process to expel air, water, and mixed steam of organic heat carriers. For gas phase boilers, after the temperature and pressure of the organic heat carriers are in corresponding relation, stop exhausting and enter normal operation.

Five items: Organic heat carriers must be dehydrated before use. Different organic heat carriers should not be mixed. When mixing is necessary, the mixing conditions and requirements should be provided by the organic heat carrier manufacturer prior to mixing.

Di six items: The organic heat carrier in use should have its residual carbon, acid value, viscosity, and flash point analyzed annually. If two of the analyses are不合格 or the content of decomposed components in the heat carrier exceeds 10%, the heat carrier should be replaced or regenerated.

Item 7: The heating surface of the 50KW electric heating thermal oil furnace should be inspected and cleaned regularly, and the inspection and cleaning records should be kept in the boiler technical file.

Prior to operation, after the installation or major repair of the 50KW electric heating thermal oil boiler, a hydrostatic test at 1.5 times the working pressure must be conducted by the user and the installation or repair company. For gas-phase boilers, refer to clause di15 for airtightness tests. Operation can only commence upon passing these tests. The local boiler safety supervision authority should send personnel to attend the hydrostatic and airtightness tests.

Di nine, the boiler room should have effective fire prevention and extinguishing measures.

Section 7: Questions and Solutions for 50KW Electric Heating Thermal Oil Heater

Cause and Solution for Leakage in the Thermocouple of a 50KW Electric Heating Thermal Oil Furnace:

(1) Causes of leakage on thermocouple:

1) The refractory bricks on the 50KW electric heating thermal oil furnace exhibit poor insulation at high temperatures, making it easy for the heating wires to come into contact with the thermocouples inserted into the furnace wall with metallic pipes. The refractory bricks are good insulating materials at room temperature, but the insulation performance of our product - the level gauge - significantly decreases as the temperature rises.

2) Contact between the filament and thermocouple, the platinum-rhodium thermocouple protection tube is an alumina ceramic tube. The thermocouple wires are insulated with a ceramic tube to prevent short circuits. However, the insulation performance may degrade at high temperatures, leading to leakage and eventually causing the leakage to reach the thermocouple, resulting in alternating current leakage signals on the thermocouple.

(2) Solution for leakage on thermocouple:

Keep thermocouples from contacting refractory bricks.

2) Ground the negative pole of the thermocouple to eliminate any leakage signals on the thermocouple.

3) Install a filter device at the thermocouple output.

4) Derive the ground wire from the hot junction of the thermocouple and connect it to ground.

5) Apply a heat-resistant steel pipe or silicon carbide pipe as an outer sheath to the thermocouple tube, and connect the magnetic flip level gauge to ground.

2.50KW electric heating thermal oil furnace coking causes and solutions:

Reason for coking in a 50KW electric heating thermal oil boiler:

1) 50KW electric heating thermal oil furnace quality

Analyzing the formation process of the above fouling, it was found that the oxidation stability and thermal stability of the 50KW electric heating thermal oil furnace are closely related to the speed and quantity of fouling. Many fires and explosions are caused by the poor thermal stability and oxidation stability of the 50KW electric heating thermal oil furnace, leading to severe fouling during operation.

2) Design and installation of the heating system

The parameters provided by the heating system design and the rationality of equipment installation directly affect the coking tendency of the 50KW electric heating thermal oil boiler. Each equipment installation situation is different, which also impacts the lifespan of the 50KW electric heating thermal oil boiler. Equipment installation must be reasonable, and timely adjustments are needed during debugging to benefit the lifespan extension of the 50KW electric heating thermal oil boiler.

3) Daily Operation and Maintenance of the Heating System

Operators with varying educational backgrounds and technical proficiency levels, even when using the same heating equipment and a 50KW electric heat conduction oil furnace, exhibit differing control levels over the heating system's temperature and flow rate factors. Temperature is a crucial parameter in the thermal oxidation and thermal polymerization reactions of the 50KW electric heat conduction oil furnace. As the temperature rises, the reaction rates of these two reactions急剧 accelerate, and the tendency to coking also increases. According to relevant theories of chemical engineering: as the Reynolds number increases, coking rate slows down. The Reynolds number is directly proportional to the flow rate of the 50KW electric heat conduction oil furnace. Therefore, the higher the flow rate of the 50KW electric heat conduction oil furnace, the slower the coking process.

(2) Causes of coking in a 50KW electrically heated thermal oil heater:

1) Select an appropriate 50KW electric heating thermal oil boiler and monitor its physical and chemical property trend.

2) Rational design and installation of the heating system

The design and installation of a 50KW electric heating thermal oil heater system must strictly comply with the national regulatory standards for the design of 50KW electric heating thermal oil heaters, to ensure the safe operation of the heating system.

3) Standardize daily operations of the heating system

The daily operation of the 50KW electric heating thermal oil heater heating system must strictly comply with the safety supervision regulations for organic heat carrier heaters formulated by relevant national departments. Continuous monitoring of the temperature and flow rate changes in the heating system should be conducted. In actual use, the average temperature at the outlet of the heating furnace should be at least 20℃ lower than the highest operating temperature of the 50KW electric heating thermal oil heater. The temperature of the 50KW electric heating thermal oil heater in the expansion tank of the open system should not exceed 60℃, and the maximum temperature should not be higher than 180℃. The flow rate of the 50KW electric heating thermal oil heater in the thermal oil heater should not be less than 2.5 meters per second to increase the turbulence, reduce the thickness of the stagnant layer in the heat transfer boundary layer, decrease the heat transfer resistance by convection, enhance the coefficient of convective heat transfer, and achieve the purpose of strengthening fluid heat transfer.

4) Cleaning of the heating system

Thermal oxidation and polymerization products initially form a high-carbon, thick, sticky substance that adheres to the pipe wall. This material can be removed through chemical cleaning. The high-carbon sticky substance then further forms incomplete graphitization deposits, with chemical cleaning only effective on the uncarbonized parts. Once fully graphitization coke is formed, chemical cleaning is no longer a solution, and mechanical cleaning is commonly used abroad.

Regular inspections are recommended during use. If high-carbon, thick substances have not yet carbonized, users can purchase chemical cleaning agents for cleaning.

A 50KW electric heating thermal oil furnace operator should have received training in the knowledge of the 50KW electric heating thermal oil furnace and be certified by the local boiler safety supervision authority.

Unit operating a 50KW electric heating thermal oil furnace must establish an operational procedure for the 50KW electric heating thermal oil furnace. The procedure should include start-up, operation, shutdown, and emergency shutdown procedures, as well as precautions to be taken. Operators must follow the operational procedure.

Insulation measures should be taken for the pipelines within the 50KW electric heating thermal oil boiler's scope, but the flange connection areas are not suitable for wrapping.

Four-pass 50KW electric heating thermal oil furnace: During the ignition and pressure increase process, the exhaust valve on the boiler should be opened multiple times to expel air, water, and mixed steam of organic thermal carrier. For gas phase furnaces, stop exhausting once the temperature and pressure of the organic thermal carrier are in the corresponding relationship, and then enter normal operation.

Five items: Organic heat carriers must be dehydrated before use. Different organic heat carriers should not be mixed. When mixing is necessary, the mixing conditions and requirements should be provided by the organic heat carrier manufacturer prior to mixing.

Di six items: The organic heat carrier in use should be analyzed annually for residual carbon, acid value, viscosity, and flash point. If two of the analyses are不合格 or the content of decomposed components in the heat carrier exceeds 10%, the heat carrier should be replaced or regenerated.

The heating surface of the 50KW electric heating thermal oil boiler should be inspected and cleaned regularly, and the inspection and cleaning records should be kept in the boiler technical files.

Prior to operation, after the installation or major repair of a 50KW electric heating thermal oil furnace, a hydraulic test at 1.5 times the working pressure must be conducted by the using unit and the installation or repair unit. For gas phase furnaces, the air tightness test should be carried out according to di15. Operation can only commence upon passing these tests. During the hydraulic and air tightness tests, the local boiler safety supervision authority should send personnel to attend.

Di nine: The boiler room should have effective fire prevention and extinguishing measures.

Section 7: Questions and Solutions for 50KW Electric Heating Thermal Oil Heater

Reasons and Solutions for Leaking of Thermal Couple in 1.50KW Electric Heating Thermal Oil Heater

Reason for leakage on the thermocouple:

1) The insulating properties of the refractory bricks on a 50KW electric heating thermal oil boiler are poor under high temperatures. Inserting a thermocouple with a metal tube into the 50KW electric heating thermal oil boiler wall with heating elements is prone to cause contact between the heating elements and the thermocouple. The refractory bricks are good insulating materials at room temperature, but the insulation performance of our product - the level gauge, significantly decreases as the temperature rises.

2) The contact between the filament and thermocouple, the platinum rhodium thermocouple protection tube is an alumina ceramic tube. The thermocouple wire is inserted into the ceramic tube for insulation. At high temperatures, the insulation performance also decreases, causing leakage, which eventually leaks to the thermocouple, resulting in AC leakage signals on the thermocouple.

(2) Solution for leakage on thermocouple:

1) Keep the thermocouple from contacting the refractory brick.

2)接地 the negative electrode of the thermocouple to eliminate any leakage signal on the thermocouple.

3) Install a filter device at the thermocouple output end.

4) Draw the earth wire from the hot junction of the thermocouple and ground it.

5) Apply a heat-resistant steel tube or silicon carbide tube as an outer casing on the thermocouple tube, and ground the magnetic flip-level gauge.

2.50KW electric heating thermal oil boiler fouling causes and solutions:

Reason for coking in a 50KW electric heating thermal oil boiler:

1) 50KW electric heating thermal oil boiler quality

After analyzing the formation process of the above coking, it was found that the oxidation stability and thermal stability of the 50KW electric heating thermal oil boiler are closely related to the coking speed and quantity. Many fire and explosion accidents are due to the poor thermal stability and oxidation stability of the 50KW electric heating thermal oil boiler, which cause severe coking during operation.

2) Design and installation of the heating system

The parameters provided by the heating system design and the rationality of equipment installation directly affect the coking tendency of the 50KW electric heating thermal oil boiler. Each equipment installation is different, which also impacts the lifespan of the 50KW electric heating thermal oil boiler. Proper equipment installation is essential, and timely adjustments during commissioning are necessary to extend the lifespan of the 50KW electric heating thermal oil boiler.

3) Daily Operation and Maintenance of the Heating System

Operators with different educational backgrounds and technical proficiency levels may control the heating system's temperature and flow rates differently, even when using the same heating equipment and a 50KW electric heating thermal oil furnace. Temperature is a critical parameter for the thermal oxidation and thermal polymerization reactions in a 50KW electric heating thermal oil furnace. As the temperature rises, the reaction rates of these two processes increase dramatically, as does the tendency to coking. According to relevant theories in chemical engineering: the coking rate slows down with the increase in the Reynolds number. The Reynolds number is proportional to the flow rate of the 50KW electric heating thermal oil furnace. Therefore, the higher the flow rate of the 50KW electric heating thermal oil furnace, the slower the coking.

(2) Causes of coking in a 50KW electric heating thermal oil boiler:

1) Select an appropriate 50KW electric heating thermal oil furnace and monitor its trend of physical and chemical indicators.

2) Reasonable design and installation of the heating system

The design and installation of the 50KW electric heating thermal oil heating system must strictly comply with the national departmental regulations for the design of 50KW electric heating thermal oil heaters to ensure the safe operation of the heating system.

3) Standardize daily operations of the heating system

The daily operation of the 50KW electric heating thermal oil heating system must strictly comply with the safety supervision regulations for organic heat carrier boilers issued by relevant national authorities. Continuously monitor the temperature and flow rate variations in the heating system, particularly the 50KW electric heating thermal oil boiler. In actual use, the average temperature at the outlet of the heating furnace should be at least 20℃ lower than the maximum operating temperature of the 50KW electric heating thermal oil boiler. The temperature in the expansion tank of the open system should be below 60℃, and the maximum temperature should not exceed 180℃. The flow rate of the 50KW electric heating thermal oil in the thermal oil boiler should not be less than 2.5 meters per second to enhance turbulence, reduce the thickness of the stagnation layer in the heat transfer boundary layer, decrease the heat transfer resistance by convection, increase the coefficient of convective heat transfer, and achieve the purpose of intensified fluid heat transfer.

4) Cleaning of the heating system

Thermal oxidation and polymerization products initially form high-carbon, thick, sticky aggregates that adhere to the tube walls. These substances can be removed through chemical cleaning. The high-carbon aggregates further develop into incomplete graphitization deposits, where chemical cleaning is only effective on the uncarbonized parts. Once fully graphitized into coke, chemical cleaning no longer addresses the issue, and mechanical cleaning is commonly used abroad.

Regular inspections are recommended during use. If high-carbon, thick substances have not yet carbonized, users can purchase a chemical cleaner for cleaning.