Heat tracing device for liquid sulfur trioxide conveying pipe

Abstract

The utility model relates to a heat tracing device for a liquid sulfur trioxide delivery pipe, which comprises a liquid sulfur trioxide delivery pipeline and a heat tracing pipeline, one end of the liquid sulfur trioxide delivery pipeline is connected with an outlet of a liquid sulfur trioxide delivery pump, and the other end of the liquid sulfur trioxide delivery pipeline is connected with an inlet of a liquid sulfur trioxide storage tank. The heat tracing pipeline abuts against the liquid sulfur trioxide conveying pipeline and is wrapped by heat preservation cotton and a heat preservation aluminum sheet, one end of the heat tracing pipeline is connected with a circulating cooling water feeding pipe, a hot water feeding pipe and a steam header pipe, and the other end of the heat tracing pipeline is connected with a circulating water pool, a hot water tank and a steam condensation water tank. In the liquid sulfur trioxide conveying process, the heat tracing device is used for replacing a traditional tube type heat exchanger, heat exchange is conducted on conveyed liquid sulfur trioxide, and the safety risk caused by corrosion, perforation and leakage of heat exchanger tubes is avoided; meanwhile, safety interlocking is arranged through a circulating cooling water feeding adjusting valve, a hot water feeding adjusting valve, a steam adjusting valve and a corresponding water return adjusting valve which are arranged on the heat tracing device.

Description

Technical Field

[0001] The utility model belongs to the technical field of high-purity liquid sulfur trioxide production equipment, in particular to a device for heating a liquid sulfur trioxide delivery pipe. Background Art

[0002] Sulfur trioxide is a colorless, transparent, oily liquid or solid at room temperature (depending on the crystal form of sulfur trioxide). It is solid under standard conditions. It is corrosive to metals and a strong oxidant. It reacts violently and explosively with water. Sulfur trioxide commonly found in production is in the form of γ-SO3 crystals, with a melting point of 16.8°C and a boiling point of 44.8°C, and exists in liquid form.

[0003] In the production process of high-purity liquid sulfur trioxide, liquid sulfur trioxide pipeline transportation is mostly involved. In the traditional liquid sulfur trioxide pipeline transportation process, a shell-and-tube heat exchanger is generally used to cool or heat sulfur trioxide to prevent sulfur trioxide from gasifying or crystallizing in the pipeline. Because sulfur trioxide is corrosive, once the heat exchanger tubes are corroded and perforated, the heat exchange medium water or steam leaks into the sulfur trioxide, which will produce a violent reaction and even an explosion, posing a greater safety risk. At the same time, due to the low melting point of γ-SO3, sulfur trioxide pipeline crystallization blockage is prone to occur during sulfur trioxide pipeline transportation in winter. After crystallization, γ-SO3 will be converted into α-SO3 or β-SO3, with a melting point of up to 62°C. It is necessary to use a manual handheld steam-clamped cloth hose to heat and purge the crystallization pipeline to convert solid sulfur trioxide back into liquid sulfur trioxide to dredge the sulfur trioxide pipeline. Manual steam purging is difficult, labor-intensive and inefficient, affecting the stability of the device operation. Summary of the invention

[0004] In view of the problem that the liquid sulfur trioxide is prone to leakage of the heat exchanger tubes during transportation, resulting in safety accidents, and the risk of device shutdown due to crystallization blockage of the pipeline, the utility model provides a device for heating the liquid sulfur trioxide transportation pipeline, and its technical solution is: the device includes a liquid sulfur trioxide transportation pipeline and a heating pipeline, one end of the liquid sulfur trioxide transportation pipeline is connected to the discharge port of the liquid sulfur trioxide transportation pump, and the other end is connected to the feed port of the liquid sulfur trioxide storage tank. One end of the heating pipeline is connected to the circulating cooling water supply regulating valve, the hot water supply regulating valve and the steam regulating valve, and the other end is connected to the circulating return water regulating valve, the hot water return water regulating valve and the steam condensate regulating valve.

[0005] The liquid sulfur trioxide delivery pipeline and the heating pipeline are close together, and the outside is wrapped with thermal insulation cotton, and the outside of the thermal insulation cotton is further wrapped with a layer of thermal insulation aluminum sheet to prevent heat overflow and loss.

[0006] The thickness of the thermal insulation cotton is 30-50 mm, and the thickness of the thermal insulation aluminum skin is 0.8-1.0 mm.

[0007] The liquid sulfur trioxide delivery pipeline is provided with a remote temperature gauge and a remote pressure gauge to realize online monitoring of the temperature and pressure of the liquid sulfur trioxide in the liquid sulfur trioxide delivery pipeline.

[0008] The temperature of the remote temperature gauge is controlled at 30-42°C, and the pressure of the remote pressure gauge is controlled at 0.15-0.45MPa.

[0009] The liquid sulfur trioxide delivery pump is located in the small sulfur trioxide greenhouse, and the liquid sulfur trioxide storage tank is located in the large sulfur trioxide greenhouse. The temperature in the small sulfur trioxide greenhouse and the large sulfur trioxide greenhouse is maintained at 30-42°C.

[0010] The circulating cooling water supply regulating valve is connected to the circulating cooling water supply main, the hot water supply regulating valve is connected to the hot water supply main, the steam regulating valve is connected to the steam main, the circulating return water regulating valve is connected to the circulating return water main, the hot water return water regulating valve is connected to the hot water return water main, and the steam condensate water regulating valve is connected to the steam condensate water main.

[0011] The circulating cooling water temperature in the circulating cooling water main is controlled at 15-38°C, the hot water temperature in the hot water water main is controlled at 45-60°C, and the steam temperature in the steam main is controlled at 120-145°C.

[0012] The circulating cooling water supply regulating valve, circulating return water regulating valve, hot water supply regulating valve, hot water return water regulating valve, steam regulating valve and steam condensate water regulating valve are provided with safety interlocks. The circulating cooling water supply regulating valve and the circulating return water regulating valve are a group, the hot water supply regulating valve and the hot water return water regulating valve are a group, the steam regulating valve and the steam condensate water regulating valve are a group. When one of the groups of regulating valves is opened at will, the other two groups of regulating valves will be automatically closed, avoiding human error in operation and mixing of circulating water, hot water or steam, thereby improving the inherent safety of the device.

[0013] The circulating water return main pipe returns to the circulating water pool, the hot water return main pipe returns to the hot water tank, and the steam condensate water main pipe returns to the steam condensate water tank, thereby realizing the recycling of water resources.

[0014] The beneficial effects of the present invention are:

[0015] During normal production, the utility model replaces the original shell-and-tube heat exchanger to prevent the heat exchange medium (water or steam) from leaking into sulfur trioxide after corrosion and perforation of the heat exchanger tubes, leading to product quality contamination, violent reaction explosions and other quality and safety accidents, thereby improving the safety of device operation.

[0016] When the ambient temperature is high in summer, the device can switch to circulating cooling water for cooling to prevent sulfur trioxide from vaporizing during pipeline transportation; when the ambient temperature is low in winter, the device can switch to hot water for insulation to prevent sulfur trioxide from crystallizing during pipeline transportation; through the coordinated use of circulating water supply regulating valve, circulating return water regulating valve, hot water supply regulating valve, hot water return water regulating valve and remote temperature meter, the sulfur trioxide transportation temperature can be accurately controlled to improve the operating stability of the device.

[0017] When crystallization blockage occurs in the sulfur trioxide transmission pipeline, the steam regulating valve and steam condensate regulating valve can be opened by remote control, and observation with the remote thermometer can be carried out to quickly heat the molten solid sulfur trioxide and clear the liquid sulfur trioxide transmission pipeline, thus ensuring the safe and stable operation of the device.

[0018] The circulating cooling water supply regulating valve, circulating return water regulating valve, hot water supply regulating valve, hot water return regulating valve, steam regulating valve and steam condensate water regulating valve are equipped with safety interlocks. When any one of the medium regulating valves is opened, the other two medium regulating valves will be automatically closed, thus avoiding human error in operation that may cause mixing of circulating water, hot water or steam, thereby improving the inherent safety of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0020] In the figure: 1. Liquid sulfur trioxide delivery pipeline; 2. Liquid sulfur trioxide delivery pump; 3. Liquid sulfur trioxide storage tank; 4. Heating pipeline; 5. Circulating cooling water supply regulating valve; 6. Circulating return water regulating valve; 7. Hot water supply regulating valve; 8. Hot water return water regulating valve; 9. Steam regulating valve; 10. Steam condensate regulating valve; 11. Circulating cooling water supply main; 12. Circulating return water main; 13. Hot water supply main; 14. Hot water return main; 15. Steam main; 16. Steam condensate main; 17. Insulation cotton; 18. Insulation aluminum sheet; 19. Remote temperature gauge; 20. Remote pressure gauge; 21. Small sulfur trioxide greenhouse; 22. Large sulfur trioxide greenhouse. DETAILED DESCRIPTION

[0021] The utility model is further described in detail below based on the accompanying drawings and specific embodiments.

[0022] Example 1

[0023] A device for heating a liquid sulfur trioxide delivery pipeline, comprising a liquid sulfur trioxide delivery pipeline 1 and a heating pipeline 4, wherein one end of the liquid sulfur trioxide delivery pipeline 1 is connected to a discharge port of a liquid sulfur trioxide delivery pump 2, and the other end is connected to a feed port of a liquid sulfur trioxide storage tank 3. One end of the heating pipeline is connected to a circulating cooling water supply regulating valve 5, a hot water supply regulating valve 7 and a steam regulating valve 9, and the other end is connected to a circulating return water regulating valve 6, a hot water return water regulating valve 8 and a steam condensate regulating valve 10.

[0024] The liquid sulfur trioxide delivery pipeline 1 and the heating pipeline 4 are close together, and the outside is wrapped with thermal insulation cotton 17, and the outside of the thermal insulation cotton is further wrapped with a layer of thermal insulation aluminum sheet 18 to prevent heat overflow loss.

[0025] The thickness of the thermal insulation cotton 17 is 30-50 mm, and the thickness of the thermal insulation aluminum sheet 18 is 0.8-1.0 mm.

[0026] The liquid sulfur trioxide delivery pipeline 1 is provided with a remote temperature gauge 19 and a remote pressure gauge 20 to realize online monitoring of the temperature and pressure of the liquid sulfur trioxide in the liquid sulfur trioxide delivery pipeline.

[0027] The temperature of the remote temperature gauge 19 is controlled at 30-42°C, and the pressure of the remote pressure gauge 20 is controlled at 0.15-0.45MPa.

[0028] The liquid sulfur trioxide delivery pump 2 is located in the small sulfur trioxide greenhouse 21, and the liquid sulfur trioxide storage tank 3 is located in the large sulfur trioxide greenhouse 22. The temperature in the small sulfur trioxide greenhouse 21 and the large sulfur trioxide greenhouse 22 is maintained at 30-42°C.

[0029] The circulating cooling water supply regulating valve 5 is connected to the circulating cooling water supply main 11, the hot water supply regulating valve 7 is connected to the hot water supply main 13, the steam regulating valve 9 is connected to the steam main 15, the circulating return water regulating valve 6 is connected to the circulating return water main 12, the hot water return water regulating valve 8 is connected to the hot water return water main 14, and the steam condensate water regulating valve 10 is connected to the steam condensate water main 16.

[0030] The circulating cooling water temperature in the circulating cooling water main 11 is controlled at 15-38°C, the hot water temperature in the hot water water main 13 is controlled at 45-60°C, and the steam temperature in the steam main 15 is controlled at 120-145°C.

[0031] The circulating cooling water supply regulating valve 5, circulating return water regulating valve 6, hot water supply regulating valve 7, hot water return water regulating valve 8, steam regulating valve 9 and steam condensate water regulating valve 10 are provided with safety interlocks. The circulating cooling water supply regulating valve 5 and the circulating return water regulating valve 6 are a group, the hot water supply regulating valve 7 and the hot water return water regulating valve 8 are a group, and the steam regulating valve 9 and the steam condensate water regulating valve 10 are a group. If one group of regulating valves is opened at will, the other two groups of regulating valves will be automatically closed to avoid human error in operation, which will cause the circulating water, hot water or steam to be mixed, thereby improving the inherent safety of the device.

[0032] The circulating water return main pipe 12 returns to the circulating water pool, the hot water return main pipe 14 returns to the hot water tank, and the steam condensate water main pipe 16 returns to the steam condensate water tank, thereby realizing the recycling of water resources.

[0033] Example 2

[0034] The device described in Example 1 is used, and its operation process is as follows: during the production process of the high-purity liquid sulfur trioxide device, the temperature of the small sulfur trioxide greenhouse 21 and the large sulfur trioxide greenhouse 22 is controlled at 30-42°C.

[0035] When the ambient temperature is below 20℃ in winter, close the circulating cooling water supply regulating valve 5, circulating return water regulating valve 6, steam regulating valve 9 and steam condensate regulating valve 10, open the hot water supply regulating valve 7 and hot water return water regulating valve 8, and control the temperature of the remote temperature gauge 19 at 30-42℃ by controlling the opening of the regulating valves and observing the indication of the remote temperature gauge 19.

[0036] When the ambient temperature is higher than 35°C in summer, close the hot water supply regulating valve 7, hot water return regulating valve 8, steam regulating valve 9 and steam condensate regulating valve 10, open the circulating cooling supply regulating valve 5 and circulating return regulating valve 6, and control the temperature of the remote thermometer 19 at 30-42°C by controlling the opening of the regulating valves and observing the indication of the remote thermometer 19.

[0037] When the ambient temperature is between 20-35°C, according to the temperature displayed on the remote temperature meter 19, reasonably select hot water or circulating cooling water for heat exchange, or do not perform heat exchange, and control the temperature of the remote temperature meter 19 at 30-42°C.

[0038] When sulfur trioxide crystallization occurs in the liquid sulfur trioxide transmission pipeline 1, the temperature displayed on the remote temperature gauge 19 will be lower than 30°C, and the pressure displayed on the remote pressure gauge 20 will exceed 0.45MPa. Close the circulating cooling water supply regulating valve 5, the circulating return water regulating valve 6, the hot water supply regulating valve 7 and the hot water return water regulating valve 8, open the steam regulating valve 9 and the steam condensate regulating valve 10, and the temperature displayed on the remote temperature gauge 19 will gradually rise. When the displayed temperature reaches 63°C, the pressure displayed on the remote pressure gauge 20 will slowly decrease. When the pressure recovers to 0.15-0.45MPa, the liquid sulfur trioxide transmission pipeline 1 is unblocked, switch the steam regulating valve to hot water or circulating water for heat exchange, control the temperature of the remote temperature gauge 19 at 30-42°C, and the device resumes normal operation.

Claims

1. A device for heating a liquid sulfur trioxide delivery pipe, characterized in that: The device comprises a liquid sulfur trioxide delivery pipeline (1) and a heating pipeline (4); one end of the liquid sulfur trioxide delivery pipeline (1) is connected to the discharge port of a liquid sulfur trioxide delivery pump (2), and the other end is connected to the feed port of a liquid sulfur trioxide storage tank (3); one end of the heating pipeline (4) is connected to a circulating cooling water supply regulating valve (5), a hot water water supply regulating valve (7) and a steam regulating valve (9); and the other end is connected to a circulating return water regulating valve (6), a hot water return water regulating valve (8) and a steam condensate regulating valve (10).

2. The device for heating a liquid sulfur trioxide delivery pipe according to claim 1, characterized in that: The liquid sulfur trioxide delivery pipeline (1) and the heating pipeline (4) are placed close together and are wrapped with thermal insulation cotton (17) on the outside. The thermal insulation cotton is then wrapped with a layer of thermal insulation aluminum sheet (18) to prevent heat loss.

3. The device for heating a liquid sulfur trioxide delivery pipe according to claim 2, characterized in that: The thickness of the thermal insulation cotton (17) is 30-50 mm, and the thickness of the thermal insulation aluminum sheet (18) is 0.8-1.0 mm.

4. The device for heating a liquid sulfur trioxide delivery pipe according to claim 1, characterized in that: The liquid sulfur trioxide delivery pipeline (1) is provided with a remote temperature gauge (19) and a remote pressure gauge (20) to achieve online monitoring of the temperature and pressure of the liquid sulfur trioxide delivered in the liquid sulfur trioxide delivery pipeline.

5. The device for heating a liquid sulfur trioxide delivery pipe according to claim 1, characterized in that: The liquid sulfur trioxide delivery pump (2) is located in the small sulfur trioxide greenhouse (21), and the liquid sulfur trioxide storage tank (3) is located in the large sulfur trioxide greenhouse (22).

6. The device for heating a liquid sulfur trioxide delivery pipe according to claim 1, characterized in that: The circulating cooling water supply regulating valve (5) is connected to the circulating cooling water supply main pipe (11), the hot water supply regulating valve (7) is connected to the hot water supply main pipe (13), the steam regulating valve (9) is connected to the steam main pipe (15), the circulating return water regulating valve (6) is connected to the circulating return water main pipe (12), the hot water return water regulating valve (8) is connected to the hot water return water main pipe (14), and the steam condensate water regulating valve (10) is connected to the steam condensate water main pipe (16).

7. The device for heating a liquid sulfur trioxide delivery pipe according to claim 1, characterized in that: The circulating cooling water supply regulating valve (5), the circulating water return regulating valve (6), the hot water supply regulating valve (7), the hot water return regulating valve (8), the steam regulating valve (9) and the steam condensate regulating valve (10) are provided with a safety interlock, wherein the circulating cooling water supply regulating valve (5) and the circulating water return regulating valve (6) form a group, the hot water supply regulating valve (7) and the hot water return regulating valve (8) form a group, and the steam regulating valve (9) and the steam condensate regulating valve (10) form a group.

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