An electrically heated molten salt system for supplying heat to a wiped film evaporator

Abstract

The utility model relates to an electric heating molten salt system for heat supply of a wiped film evaporator, belonging to the technical field of heat supply equipment, including heat supply return pipe, heat supply inlet pipe, molten salt tank, electric heater one, molten salt inlet pipe, suction groove, molten salt pump, electric heating molten salt furnace, be equipped with spiral pipe in electric heating molten salt furnace, be equipped with electric heater two on spiral pipe, the upper and lower ends respectively connected with feed pipe no. One and feed pipe no. Two of spiral pipe, the one end of feed pipe no. One and heating jacket connection is higher than the other end, the one end of feed pipe no. Two and spiral pipe connection is higher than the other end. The utility model discloses through the electric heating mode fast melting solid molten salt, and through molten salt pump realizes the forced circulation into the spiral pipe in electric heating molten salt furnace, carries out heating through electric heater two, ensures that molten salt is evenly heated, and high -efficiently provides heat source. When parking, molten salt can automatically return to the molten salt tank, avoid the solidification of molten salt in the pipeline.

Description

Technical Field

[0001] This utility model belongs to the technical field of heating equipment, specifically relating to an electrically heated molten salt system for heating a scraped film evaporator. Background Technology

[0002] With the continuous advancement of industrial technology, high-temperature heat sources are increasingly widely used in various technological processes. Scraped film evaporators, as important chemical equipment, play a crucial role in industries such as chemical, pharmaceutical, and food processing. Their working principle involves scraping a thin film of material onto the heating surface, achieving efficient evaporation. However, the evaporation efficiency of scraped film evaporators largely depends on the quality and stability of the provided heat source. Traditional heating methods for scraped film evaporators mainly include steam heating and thermal oil heating. While steam heating is mature and stable, it consumes a lot of energy, and energy is lost during steam generation and transportation. Thermal oil heating, although having high thermal efficiency, is prone to oxidation and decomposition at high temperatures, requiring regular replacement and resulting in high maintenance costs. Therefore, developing a new, efficient, stable, and environmentally friendly scraped film evaporator heating system is particularly important.

[0003] Molten salt, as an excellent high-temperature heat transfer medium, possesses characteristics such as high boiling point, low vapor pressure, and good thermal and chemical stability, and has received widespread attention in the field of high-temperature heat source supply in recent years. Molten salt heating systems melt solid molten salt using electric heating and heat it to the required temperature. The high-temperature molten salt is then transported to the heat-using equipment via a circulating pump to achieve heat transfer. However, existing molten salt heating systems still have some problems, such as uneven heating, affecting the heating effect of scraped film evaporators, and the inability of molten salt to flow back into the pipes when not in use or during shutdown, leading to easy solidification and blockage of the pipes. These problems limit the application of molten salt heating systems in the field of scraped film evaporator heating. Therefore, developing an electrically heated molten salt system that provides uniform heating and effectively prevents molten salt solidification and blockage is of great significance. Utility Model Content

[0004] Therefore, it is necessary to provide an electrically heated molten salt system for heating a scraped film evaporator, addressing the problems of existing technologies.

[0005] To solve the problems of the existing technology, the technical solution adopted by this utility model is as follows: An electrically heated molten salt system for heating a scraped film evaporator includes a heat supply return pipe and a heat supply inlet pipe connected to the upper and lower ends of a heating jacket of the scraped film evaporator, respectively. The other end of the heat supply return pipe is connected to a molten salt tank. An electric heater is installed inside the molten salt tank. A molten salt inlet pipe is provided at one end of the top of the molten salt tank, and a suction groove is provided at the other end of the bottom of the molten salt tank. A molten salt pump extending into the suction groove is fixed at the top of the molten salt tank. An electrically heated molten salt furnace is provided next to the molten salt tank. A spiral coil is provided inside the electrically heated molten salt furnace. Multiple electric heaters are evenly arranged on the spiral coil and extend into it. A feed pipe is connected to the upper and lower ends of the spiral coil, respectively. The other ends of the feed pipes are connected to the lower port of the heating jacket and the outlet of the molten salt pump, respectively. The end of the feed pipe connected to the heating jacket is higher than the other end, and the end of the feed pipe connected to the spiral coil is higher than the other end.

[0006] As a preferred embodiment, the top and bottom of the electrically heated molten salt furnace are respectively fixed with a bottom plate and a top plate, and the top plate, bottom plate, and inner wall of the electrically heated molten salt furnace are all equipped with insulation layers. The all-around insulation layer design can significantly reduce heat loss, improve energy utilization, and allow the top plate to be opened for maintenance.

[0007] As a preferred embodiment, a support rod is fixed to the top of the base plate, and the top of the support rod is fixed to the bottom of the spiral coil. The support rod provides stable support for the spiral coil and enhances structural stability.

[0008] As a preferred design, the top of the molten salt tank is inclined, with the left side lower than the right. A nitrogen inlet pipe is fixed to the top of the left end of the molten salt tank, and a mounting flange pipe is fixed to the top of the right end. The top of the mounting flange pipe is equipped with a sealing plate to close it off. The molten salt pump is fixed to the sealing plate, and an exhaust pipe is fixed to the mounting flange pipe. The inclined top facilitates the accumulation and discharge of gas inside the tank through the exhaust pipe; the introduction of inert gas into the nitrogen inlet pipe prevents oxidation of the molten salt and reduces safety hazards; the fit between the mounting flange pipe and the sealing plate facilitates the installation and maintenance of the molten salt pump.

[0009] As a preferred option, a pressure sensor is installed on the top of the molten salt tank.

[0010] As a preferred embodiment, a pressure measuring tube is fixed to the top of the molten salt tank. A pressure measuring branch pipe is connected to the top of the pressure measuring tube via a flange. A cooling ring pipe is fixed to the top of the pressure measuring branch pipe, and a pressure sensor is fixedly connected to the top of the cooling ring pipe. A needle valve is installed on the pressure measuring branch pipe. The cooling ring pipe cools the gas entering the pressure sensor, preventing high temperatures from damaging the sensor or affecting measurement accuracy.

[0011] The advantages of this utility model compared with the prior art are: The system rapidly melts solid molten salt through electric heating, and then uses a molten salt pump to force circulation into the spiral coil inside the electric heating molten salt furnace for further heating by electric heater II, ensuring uniform heating of the molten salt and providing an efficient heat source.

[0012] The heating jackets of the molten salt tank, the electrically heated molten salt furnace, and the scraped film evaporator all have height differences. Combined with the inclined feed pipes one and two, the molten salt can automatically flow back to the molten salt tank when the machine stops, preventing the molten salt in the pipes from solidifying. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 yes Figure 1 Partial structural diagram Figure 1 ; Figure 3 yes Figure 1 Partial structural diagram Figure 2 ; The numbers on the map are: 1. Molten salt tank; 2. Molten salt pump; 3. Electric heater one; 4. Nitrogen inlet pipe; 5. Mounting flange pipe; 6. Conveyor pipe two; 7. Electric heating molten salt furnace; 8. Trailing rod; 9. Spiral coil; 10. Insulation layer; 11. Top plate; 12. Conveyor pipe one; 13. Electric heater two; 14. Bottom plate; 15. Scraped film evaporator; 16. Heating return pipe; 17. Molten salt inlet pipe; 18. Pressure sensor; 19. Cooling ring pipe; 20. Pressure measuring branch pipe; 21. Exhaust pipe; 22. Suction groove. Detailed Implementation

[0014] To further understand the features, technical means, and specific objectives and functions achieved by this utility model, the following detailed description of this utility model is provided in conjunction with the accompanying drawings and specific embodiments.

[0015] Example 1, Reference Figures 1 to 3 This utility model relates to an electrically heated molten salt system for heating a scraped film evaporator, comprising a heat supply return pipe 16 and a heat supply inlet pipe respectively connected to the upper and lower ends of the heating jacket of the scraped film evaporator 15. The other end of the heat supply return pipe 16 is connected to a molten salt tank 1. An electric heater 3 is installed inside the molten salt tank 1; the electric heater 3 is a tubular heater, which is prior art and will not be described here. A molten salt inlet pipe 17 is provided at one end of the top of the molten salt tank 1, and a suction groove 22 is provided at the other end of the bottom of the molten salt tank 1. An extension tube 22 is fixed to the top of the molten salt tank 1. The molten salt pump 2 is located in the suction groove 22. An electric heating molten salt furnace 7 is located next to the molten salt tank 1. A spiral coil 9 is located inside the electric heating molten salt furnace 7. Multiple electric heaters 13 extending into the spiral coil 9 are evenly arranged on the spiral coil 9. The upper and lower ends of the spiral coil 9 are respectively connected to a first conveying pipe 12 and a second conveying pipe 6. The other ends of the first conveying pipe 12 and the second conveying pipe 6 are respectively connected to the lower port of the heating jacket and the outlet of the molten salt pump 2. The end of the first conveying pipe 12 connected to the heating jacket is higher than the other end. The end of the second conveying pipe 6 connected to the spiral coil 9 is higher than the other end.

[0016] During operation, a preset amount of molten salt is injected into the molten salt tank 1 through the molten salt inlet pipe 17, and the valve of the molten salt inlet pipe 17 is closed. The electric heater 3 is activated, initially heating the molten salt in the molten salt tank 1. Once the solid molten salt melts and is heated to a certain temperature, the molten salt pump 2 is activated. The molten salt pump 2 draws molten salt from the suction groove 22 at the bottom of the molten salt tank 1 and transports it to the spiral coil 9 through the feed pipe 6. After secondary heating by the electric heater 13, it is transported to the heating jacket of the scraped film evaporator 15 through the feed pipe 12. It undergoes sufficient heat exchange with the material in the scraped film evaporator 15, providing stable heat for material evaporation. After heat exchange, the temperature of the molten salt decreases, and it flows back into the molten salt tank 1 through the heat return pipe 16, where it is reheated by the electric heater 3 before entering the next cycle. When the system stops, the height difference allows all the molten salt in the pipes to flow back to the molten salt tank 1.

[0017] In Example 2, based on Example 1, a bottom plate 14 and a top plate 11 are fixed to the top and bottom of the electrically heated molten salt furnace 7, respectively. Insulation layers 10 are provided on the top plate 11, the bottom plate 14, and the inner wall of the electrically heated molten salt furnace 7. The electric heater 3 consists of multiple electric heating wires or tubes connected in parallel; alternatively, electric heating wires wound around the outer wall of the spiral coil 9 can be used. The ternary molten salt system is a mixture composed of 53 wt% potassium nitrate, 40 wt% sodium nitrite, and 7 wt% sodium nitrate raw materials by mass percentage. A temperature sensor is installed at the upper end of the feed pipe 12, connected to a controller. The controller is connected to the electric heater 3, the electric heater 13, and the molten salt pump 2. By controlling parameters such as the power of the electric heater 3 and the electric heater 13, and the flow rate and pressure of the molten salt pump 2, the heating and circulation process of the molten salt is regulated.

[0018] A drag bar 8 is fixed to the top of the base plate 14, and the top of the drag bar 8 is fixed to the bottom of the spiral coil 9.

[0019] The top of the molten salt tank 1 is inclined from left to right. A nitrogen inlet pipe 4 is fixed to the top of the left end of the molten salt tank 1, and a mounting flange pipe 5 is fixed to the top of the right end of the molten salt tank 1. The top of the mounting flange pipe 5 is equipped with a sealing plate to close it. The molten salt pump 2 is fixed to the sealing plate, and an exhaust pipe 21 is fixed to the mounting flange pipe 5. After molten salt is added into the molten salt tank 1 through the molten salt inlet pipe 17, the valve on the molten salt inlet pipe 17 is closed, and then the exhaust pipe 21 and the nitrogen inlet pipe 4 are opened to expel air. The inclined top of the molten salt tank 1, with the nitrogen inlet pipe 4 and the exhaust pipe 21 located on the left and right sides respectively, makes air expulsion more convenient and faster. The molten salt tank 1 is filled with nitrogen and maintained at positive pressure, effectively isolating external air, ensuring the quality of the molten salt, and improving system safety.

[0020] A pressure sensor 18 is installed on the top of the molten salt tank 1.

[0021] A pressure testing pipe is fixed to the top of the molten salt tank 1. A pressure testing branch pipe 20 is connected to the top of the pressure testing pipe via a flange. A cooling ring pipe 19 is fixed to the top of the pressure testing branch pipe 20, and a pressure sensor 18 is fixedly connected to the top of the cooling ring pipe 19. A needle valve is provided on the pressure testing branch pipe 20. When the pressure sensor 18 needs to be replaced, the needle valve can be closed, allowing the pressure sensor 18 to be disassembled and replaced. Furthermore, for areas where molten salt may accumulate, such as pipe bends and valves, jacketed heating can be added as needed to maintain the temperature of these areas through external heating, thus better preventing the molten salt from solidifying.

[0022] The above embodiments only illustrate one or more implementations of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. An electrically heated molten salt system for heating a scraped film evaporator, comprising a heat supply return pipe (16) and a heat supply inlet pipe respectively connected to the upper and lower ends of the heating jacket of the scraped film evaporator (15), characterized in that: The other end of the heating return pipe (16) is connected to a molten salt tank (1). An electric heater (3) is installed inside the molten salt tank (1). A molten salt inlet pipe (17) is installed at one end of the top of the molten salt tank (1). A suction groove (22) is installed at the other end of the bottom of the molten salt tank (1). A molten salt pump (2) is fixed at the top of the molten salt tank (1) and extends into the suction groove (22). An electric heating molten salt furnace (7) is installed next to the molten salt tank (1). A spiral coil is installed inside the electric heating molten salt furnace (7). (9) Multiple electric heaters (13) are evenly arranged on the spiral coil (9) and extend into it. The upper and lower ends of the spiral coil (9) are respectively connected to the first conveyor pipe (12) and the second conveyor pipe (6). The other ends of the first conveyor pipe (12) and the second conveyor pipe (6) are respectively connected to the lower port of the heating jacket and the outlet of the molten salt pump (2). The first conveyor pipe (12) is connected to the heating jacket at one end higher than the other end, and the second conveyor pipe (6) is connected to the spiral coil (9) at one end higher than the other end.

2. The electrically heated molten salt system for heating a scraped film evaporator according to claim 1, characterized in that, The top and bottom of the electric heating molten salt furnace (7) are respectively fixed with a bottom plate (14) and a top plate (11). The top plate (11), the bottom plate (14) and the inner wall of the electric heating molten salt furnace (7) are all provided with a heat insulation layer (10).

3. The electrically heated molten salt system for heating a scraped film evaporator according to claim 2, characterized in that, A drag bar (8) is fixed to the top of the base plate (14), and the top of the drag bar (8) is fixed to the bottom of the spiral coil (9).

4. The electrically heated molten salt system for heating a scraped film evaporator according to claim 1, characterized in that, The top of the molten salt tank (1) is inclined with the left side lower and the right side higher. A nitrogen inlet pipe (4) is fixed on the top of the left end of the molten salt tank (1), and a mounting flange pipe (5) is fixed on the top of the right end of the molten salt tank (1). A sealing plate is provided on the top of the mounting flange pipe (5) to close it. The molten salt pump (2) is fixed on the sealing plate, and an exhaust pipe (21) is fixed on the mounting flange pipe (5).

5. The electrically heated molten salt system for heating a scraped film evaporator according to claim 1, characterized in that, A pressure sensor (18) is provided on the top of the molten salt tank (1).

6. The electrically heated molten salt system for heating a scraped film evaporator according to claim 5, characterized in that, A pressure measuring pipe is fixed on the top of the molten salt tank (1). A pressure measuring branch pipe (20) is connected to the top of the pressure measuring pipe via a flange. A cooling ring pipe (19) is fixed on the top of the pressure measuring branch pipe (20). A pressure sensor (18) is fixedly connected to the top of the cooling ring pipe (19). A needle valve is provided on the pressure measuring branch pipe (20).

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