Low-temperature vertical cylinder bag pump and cold insulation structure thereof

Abstract

The application discloses a low-temperature vertical cylinder bag pump and a cold insulation structure thereof, and the cold insulation structure comprises a swan neck inlet pipeline which is arranged outside the low-temperature vertical cylinder bag pump and is used for conveying low-temperature medium into the low-temperature vertical cylinder bag pump, the swan neck inlet pipeline has opposite inflow and outflow openings, the outflow opening is communicated with a cylinder bag of the low-temperature vertical cylinder bag pump, and the communication position is located below a secondary impeller of the low-temperature vertical cylinder bag pump; and a heat preservation cylinder is arranged outside the cylinder bag and the swan neck inlet pipeline, the heat preservation cylinder is filled with heat insulation medium to form a cold insulation cavity, and the inflow opening is located outside the heat preservation cylinder. The swan neck inlet pipeline is independently arranged outside the low-temperature vertical cylinder bag pump, the heat preservation cylinder is filled with the heat insulation medium to form the cold insulation cavity, the low-temperature medium in the swan neck inlet pipeline is pre-cooled, the temperature rise of the low-temperature medium is effectively reduced, and the unloading efficiency is improved; and the heat preservation cylinder is designed in a detachable connection mode, so that the convenience and interchangeability of disassembly and assembly during maintenance are ensured.

Description

Technical Field

[0001] This utility model relates to the field of cryogenic vertical tubular bag pump technology, and in particular to a cryogenic vertical tubular bag pump and its cold insulation structure. Background Technology

[0002] In the petrochemical industry, ethylene is a key basic raw material, and its long-distance transportation often relies on tank truck liquid phase transport. During the safe transfer of liquid ethylene from tank trucks to spherical tanks, cryogenic vertical bag pumps are commonly used as unloading pumps for cryogenic ethylene.

[0003] The unloading pump operates under sensitive conditions, and gas-liquid mixing is strictly prohibited. This is because the sliding bearings will experience dry friction due to a lack of lubrication from liquid ethylene for a short period, leading to mechanical friction between the impeller and the pump casing, creating a significant safety hazard. Existing unloading systems have shortcomings in liquid phase monitoring, failing to accurately determine the amount of ethylene in the liquid pipeline. This makes it difficult for operators to determine the appropriate time to stop the pump, frequently resulting in equipment damage accidents caused by idling. This technological deficiency severely restricts the efficiency and safety of liquid ethylene unloading operations.

[0004] Existing unloading pumps have the following drawbacks: During the pre-cooling stage and after unloading is completed, the liquid ethylene in the pump body and pipeline is prone to vaporization phase change. To ensure the safety of the next pump start-up, repeated pre-cooling is required. The gaseous ethylene is usually discharged into the flare system, resulting in material waste. The unloading operation is intermittent. After each unloading, restarting requires re-pre-cooling and venting, which takes a long time and results in low unloading efficiency, making it difficult to meet the high-efficiency transportation requirements of ethylene unloading. Traditional cryogenic pumps often have an integral insulation layer design, such as an insulation layer composed of a foam glass layer, a polyurethane layer, and a vacuum layer, with a thickness of 150-200 mm. Disassembly and maintenance require destroying the entire insulation layer, resulting in extremely high maintenance costs. Utility Model Content

[0005] The purpose of this invention is to provide a low-temperature vertical bag pump and its insulation structure to solve the problem that existing low-temperature medium unloading pumps cannot achieve efficient pre-cooling, insulation and unloading.

[0006] The inventors discovered that in existing technologies, the pump inlet channel is closely integrated with the main structure of the bag pump. When conveying cryogenic media, the ambient temperature and heat generated by efficiency losses during pump operation are easily transferred to the cryogenic media inside the bag, causing a temperature rise in the cryogenic media. This, in turn, increases the pump's net positive suction head (NPSH), easily leading to pump cavitation and affecting the pump's stable operation and service life. Therefore, by independently setting the pump inlet channel outside the main body of the bag pump, creating a relatively independent space between the inlet channel and the main body, the impact of temperature rise during pump operation on the cryogenic media inside the inlet channel can be reduced.

[0007] The above-mentioned objectives of this utility model can be achieved by the following technical solutions:

[0008] This utility model provides a cold insulation structure for a low-temperature vertical bag pump, comprising: a swan-neck inlet pipe disposed outside the low-temperature vertical bag pump for conveying a low-temperature medium into the pump; the swan-neck inlet pipe having an inlet and an outlet, the outlet being connected to the bag of the pump, and the connection point being located below the secondary impeller of the pump; and an insulation cylinder sealed around the bag and the swan-neck inlet pipe, the insulation cylinder being filled with a heat-insulating medium to form a cold insulation cavity, the inlet being located outside the insulation cylinder.

[0009] Preferably, the swan neck inlet pipe has at least one pipe section with a length equal to the total axial length of all the secondary impellers.

[0010] Preferably, the outlet is positioned directly opposite the upper part of the inner cylindrical tube located between the primary impeller and the secondary impeller in the cryogenic vertical bag pump, and at least one guide plate is connected to the inner cylindrical tube, with at least one guide plate positioned directly opposite the outlet.

[0011] Preferably, there are two guide plates, which are symmetrically connected to both sides of the inner cylindrical tube.

[0012] Preferably, the insulation cylinder is connected to an inlet pipe and an outlet pipe, the inlet pipe is provided with an inlet control valve, and the outlet pipe is provided with an outlet control valve.

[0013] Preferably, the cold insulation cavity is equipped with an internal temperature transmitter and an internal pressure transmitter, and the outlet section of the cryogenic vertical tubular bag pump is equipped with an outlet temperature transmitter.

[0014] Preferably, the insulation cylinder is a hollow structure with one end closed and the other end open. The open end forms an opening for the bag and the swan neck inlet pipe to enter and exit. The open end is detachably connected to the bag flange of the low-temperature vertical bag pump. The surface of the bag flange and the surface facing each other of the insulation cylinder form the top wall of the cold insulation cavity.

[0015] Preferably, the insulation cylinder is integrally formed, or the insulation cylinder is composed of multiple cylinder segments connected in series, and each of the two adjacent cylinder segments is provided with a connecting flange on the opposite end, and the multiple cylinder segments are detachably connected through the connecting flange to form the insulation cylinder.

[0016] Preferably, the cryogenic vertical bag pump is provided with an exhaust pipe at the mechanical seal, and an exhaust valve is provided on the exhaust pipe for discharging the gasified medium inside the cryogenic vertical bag pump.

[0017] Another objective of this invention is to provide a low-temperature vertical tubular bag pump, which includes the cold insulation structure described above.

[0018] The features and advantages of this utility model are as follows: The cold insulation structure of the low-temperature vertical bag pump provided by this utility model independently sets the swan-neck inlet pipe outside the low-temperature vertical bag pump, so that a relatively independent space is formed between the swan-neck inlet pipe and the main structure of the bag pump. The low-temperature medium directly reaches the top of the first-stage impeller of the low-temperature vertical bag pump through the swan-neck inlet pipe, which greatly reduces the impact of temperature rise during pump operation on the low-temperature medium in the swan-neck inlet pipe. Furthermore, by filling the insulation cylinder with heat-insulating medium to form a cold insulation cavity, the low-temperature medium in the swan-neck inlet pipe is pre-cooled, further reducing the impact of ambient temperature on the low-temperature medium. This effectively avoids the vaporization of the medium caused by the pump's operating temperature rise, reduces the pump's net positive suction head (NPSH), and improves the pump's anti-cavitation performance. It enables the pump to maintain stable operation during intermittent transport in the cryogenic medium unloading system. This solves the problem in existing cryogenic medium unloading processes where the cryogenic medium easily absorbs ambient temperature during long-term shutdowns, leading to increased pre-cooling and venting time during subsequent unloading, and wasting resources. It effectively reduces the temperature rise of the cryogenic medium and improves unloading efficiency. Furthermore, the insulation cylinder adopts a detachable connection design, ensuring convenience and interchangeability for disassembly and installation during maintenance and repair. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the cold insulation structure of the low-temperature vertical cylindrical bag pump provided in this embodiment of the utility model;

[0021] Figure 2 This is a schematic diagram of the upper connection of the cold insulation structure of the low-temperature vertical tubular bag pump provided in this embodiment of the present utility model;

[0022] Figure 3 This is a schematic diagram of the lower connection of the cold insulation structure of the low-temperature vertical cylindrical bag pump provided in this embodiment of the utility model;

[0023] Figure 4 for Figure 1 A sectional view along line AA.

[0024] Explanation of icon numbers:

[0025] 1. Low-temperature vertical bag pump; 11. Bag; 12. First stage impeller; 13. Secondary stage impeller; 14. Bag flange; 15. Inner cylindrical tube;

[0026] 2. Swan neck inlet pipe; 20. Inlet bend section; 21. Straight pipe section; 22. Inlet flange; 23. Elbow;

[0027] 3. Insulation cylinder; 30. Cold insulation cavity; 31. Upper cylinder section; 32. Lower cylinder section; 33. Intermediate sealing gasket; 34. Inlet pipe; 35. Outlet pipe; 36. Inlet control valve; 37. Outlet control valve; 38. Exhaust pipe; 39. Exhaust valve;

[0028] 4. Supporting stiffener structure; 41. Triangular stiffener; 42. Rectangular stiffener;

[0029] 5. Install the sealing gasket;

[0030] 6. Deflector plate;

[0031] 7. Intracavity temperature transmitter;

[0032] 8. Intracavity pressure transmitter;

[0033] 9. Outlet temperature transmitter. Detailed Implementation

[0034] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0035] like Figures 1 to 4 As shown, this utility model provides a cold insulation structure for a low-temperature vertical bag pump 1, including: a swan-neck inlet pipe 2, disposed outside the low-temperature vertical bag pump 1, used to transport a low-temperature medium into the low-temperature vertical bag pump 1; the swan-neck inlet pipe 2 has a corresponding inlet and outlet; the outlet is connected to the bag 11 of the low-temperature vertical bag pump 1, and the connection point is located below the secondary impeller of the low-temperature vertical bag pump 1 to avoid the heat generated during pump operation affecting the low-temperature medium in the swan-neck inlet pipe 2; and a heat insulation cylinder 3, sealed around the bag 11 and the swan-neck inlet pipe 2; the heat insulation cylinder 3 is filled with a heat insulation medium to form a cold insulation cavity 30 to pre-cool the low-temperature medium entering the swan-neck inlet pipe 2; the inlet is located outside the heat insulation cylinder 3. The low-temperature medium includes ethylene, and the heat insulation medium includes nitrogen, inert gas, etc. The flow direction of the low-temperature medium within the cold insulation structure is as follows: Figures 1 to 3As indicated by the middle arrow. Preferably, the insulation cylinder 3 is detachably connected to the low-temperature vertical bag pump 1. In a feasible embodiment, as... Figure 1 and Figure 2 As shown, the insulation cylinder 3 is a hollow structure with one closed end and the other open end. The open end forms an opening for the bag 11 and the swan neck inlet pipe 2 to enter and exit. The open end is detachably connected to the bag flange 14 of the cryogenic vertical bag pump 1 by connecting bolts. The surfaces of the bag flange 14 and the insulation cylinder 3 facing each other form the top wall of the cold insulation cavity 30. Preferably, an upper sealing gasket 5 is connected between the insulation cylinder 3 and the bag flange 14 to ensure the sealing performance of the cold insulation cavity 30. In this embodiment, dry nitrogen is selected as the heat insulation medium. By replacing the dry nitrogen, a low thermal conductivity inert gas environment is formed inside the insulation cylinder 3 to prevent heat from the external environment from being transferred into the bag 11, thus maintaining the temperature stability of the cryogenic medium inside the pump. The dry nitrogen pressure only needs to be maintained at 1 barg, without the need for complex vacuum equipment. In addition, nitrogen, as a gas with inert properties, can suppress the risk of ethylene leakage. After stopping the pump, the next tanker can be unloaded directly, significantly reducing the pre-cooling waiting time.

[0036] The cryogenic vertical bag pump 1 provided by this utility model has a cold insulation structure that independently sets the swan-neck inlet pipe 2 outside the cryogenic vertical bag pump 1, creating a relatively independent space between the swan-neck inlet pipe 2 and the main pump structure of the bag pump 11. The cryogenic medium directly reaches the top of the first-stage impeller 12 of the cryogenic vertical bag pump 1 through the swan-neck inlet pipe 2, greatly reducing the impact of temperature rise during pump operation on the cryogenic medium in the swan-neck inlet pipe 2. Furthermore, by filling the insulation cylinder 3 with heat-insulating medium to form a cold insulation cavity 30, the cryogenic medium in the swan-neck inlet pipe 2 is pre-cooled, further reducing the impact of ambient temperature on the cryogenic medium. This effectively avoids the vaporization phenomenon caused by the pump's operating temperature rise, reduces the pump's net positive suction head (NPSH), and improves the pump's anti-cavitation performance. It enables the pump to maintain stable operation during intermittent transport in the cryogenic medium unloading system. This solves the problem in existing cryogenic medium unloading processes where the cryogenic medium easily absorbs ambient temperature during long-term shutdowns, leading to increased pre-cooling and venting time during subsequent unloading, and wasting resources. It effectively reduces the temperature rise of the cryogenic medium and improves unloading efficiency. Furthermore, the insulation cylinder 3 adopts a detachable connection design, ensuring convenience and interchangeability for disassembly and installation during maintenance and repair.

[0037] According to one embodiment of this utility model, the swan neck inlet pipe 2 has at least a pipe section with a length equal to the total axial length of all secondary impellers 13. This ensures that the flow path of the cryogenic medium within the insulation chamber is sufficiently long, guaranteeing that the cryogenic medium can enter the cryogenic vertical bag pump 1 in a cryogenic liquid state, thereby ensuring that the cryogenic vertical bag pump 1 can maintain stable operation over a long period. As a preferred embodiment, such as... Figure 1As shown, the swan neck inlet pipe 2 adopts a "swan neck" structural design to reduce the flow resistance of the low-temperature medium in the swan neck inlet pipe 2.

[0038] According to one embodiment of the present invention, such as Figure 1 and Figure 2 As shown, the swan neck inlet pipe 2 forms an inlet bend section 20 extending from the inlet cylinder 3 near the inlet. The inlet bend section 20 is fixedly connected to the cylinder flange 14 of the cryogenic vertical cylinder pump 1 by a supporting stiffener structure 4. The connection between both ends of the swan neck inlet pipe 2 and the cryogenic vertical cylinder pump 1 ensures the installation stability of the swan neck inlet pipe 2.

[0039] According to one embodiment of the present invention, such as Figure 1 and Figure 2 As shown, to facilitate the connection between the swan neck inlet pipe 2 and the cryogenic medium transport tanker, the inlet bend section 20 includes a straight pipe section 21 perpendicular to each other and an inlet flange 22, as well as an elbow 23 connecting the straight pipe section 21 and the inlet flange 22, with the inlet located on the inlet flange 22. As a preferred embodiment, such as... Figure 2 As shown, the supporting stiffener structure 4 includes at least triangular stiffeners 41 and rectangular stiffeners 42 symmetrically arranged on both sides of the swan neck inlet pipe 2. The triangular stiffeners 41 are located on the outside of the elbow 23 and connected between the straight pipe section 21 and the tubular flange 14. The rectangular stiffeners 42 are located on the inside of the elbow 23 and connected to the straight pipe section 21, the elbow 23, the inlet flange 22, and the tubular flange 14. In this way, a stable connection of the swan neck inlet pipe 2 is achieved.

[0040] According to one embodiment of the present invention, such as Figure 1 and Figure 3 As shown, the outlet is positioned directly above the upper part of the inner cylindrical tube 15 located between the primary impeller 12 and the secondary impeller 13 in the cryogenic vertical bag pump 1. At least one guide plate 6 is connected to the inner cylindrical tube 15, and the guide plate 6 is positioned directly opposite the outlet. Specifically, in the prior art, during the process of the cryogenic medium entering the bag 11 from the swan-neck inlet pipe 2, turbulence easily occurs in the flow field, leading to unstable flow of the cryogenic medium, increased cavitation margin of the pump, and affecting the normal operation of the pump. This invention, by setting the guide plate 6, can effectively adjust the flow direction of the fluid entering the pump, reduce the generation of eddies and turbulence, and allow the cryogenic medium to flow smoothly into the impeller inlet, reducing energy loss during the flow of the cryogenic medium and reducing the cavitation risk of the cryogenic vertical bag pump 1. As a preferred embodiment, such as... Figure 3 and Figure 4 As shown, a preset gap is left between the guide plate 6 and the tubular bag 11 to ensure the circumferential uniformity of the flow of the cryogenic medium entering the tubular bag 11 towards the impeller inlet. Furthermore, as... Figure 4As shown, the guide surface of the guide plate 6 near the inner wall of the tube 11 is arc-shaped to further reduce eddies and turbulence. In this embodiment, the guide plate 6 is fixedly connected to the inner cylindrical tube 15 by welding.

[0041] According to one embodiment of the present invention, such as Figure 1 , Figure 3 and Figure 4 As shown, there are two guide plates 6, symmetrically connected to both sides of the inner cylindrical tube 15, to ensure better flow stability of the cryogenic medium entering the cylindrical bag 11. The guiding direction of the guide plates 6 for the cryogenic medium entering the cylindrical bag 11 is as follows: Figure 4 As indicated by the middle arrow.

[0042] According to one embodiment of this utility model, the insulation cylinder 3 is integrally formed, or the insulation cylinder 3 is composed of multiple cylinder segments connected in series. A connecting flange is provided on the opposite ends of two adjacent cylinder segments. The multiple cylinder segments are detachably connected via the connecting flanges to form the insulation cylinder 3, thus meeting the disassembly and maintenance requirements when the main structure of the low-temperature vertical bag pump 1 is too long. The detachable design of the insulation cylinder 3 allows for convenient disassembly and installation of the cold insulation structure during maintenance and repair, helping to maintain the low-temperature vertical bag pump 1 in good working condition, reducing the difficulty of maintenance due to temperature fluctuations or leaks, and improving the reliability and stability of the entire unloading system. In this embodiment, as... Figure 1 and Figure 3 As shown, the insulation cylinder 3 includes an upper cylinder section 31 and a lower cylinder section 32. An intermediate sealing gasket 33 is connected between the upper cylinder section 31 and the lower cylinder section 32 to ensure the overall sealing performance of the insulation cylinder 3. The connection between the upper cylinder section 31 and the lower cylinder section 32 is located on the outside of the inner cylindrical tube 15. Thus, when periodically draining the water accumulated at the bottom of the low-temperature vertical cylinder pump 1, only the lower cylinder section 32 needs to be disassembled, further saving disassembly and assembly time.

[0043] According to one embodiment of the present invention, such as Figure 1 and Figure 2 As shown, the insulation cylinder 3 is connected to an inlet pipe 34 and an outlet pipe 35. An inlet control valve 36 is installed on the inlet pipe 34, and an outlet control valve 37 is installed on the outlet pipe 35. The inlet pipe 34 is positioned close to the inlet to ensure better pre-cooling of the low-temperature medium within the swan-neck inlet pipe 2. Specifically, when filling with the insulation medium, the inlet control valve 36 and the outlet control valve 37 are opened. After the insulation cylinder 3 is completely filled with the insulation medium, the inlet control valve 36 and the outlet control valve 37 are closed to seal the cold insulation cavity 30, ensuring its insulation effect.

[0044] According to one embodiment of the present invention, such as Figure 1 and Figure 2As shown, to monitor the temperature inside the bag 11 in real time and detect leakage risks promptly, an internal temperature transmitter 7 and an internal pressure transmitter 8 are installed in the cooling chamber 30, and an outlet temperature transmitter 9 is installed at the outlet section of the cryogenic vertical bag pump 1. During the unloading and transportation of cryogenic media, temperature changes and leakage within the bag 11 are crucial factors affecting the safe operation of the unloading system. Traditional monitoring methods often cannot obtain real-time and accurate pre-cooling temperature and pressure data within the bag 11, making it difficult to detect potential safety hazards in a timely manner. This invention, by installing high-precision internal pressure transmitters 8 and 7 within the cooling chamber 30, can acquire the pressure and temperature signals of the cooling chamber 30 in real time and transmit these data to the control system for analysis and processing. When the outlet temperature transmitter 9 detects a fluctuation of 5-10 degrees Celsius in the outlet temperature of the bag 11, the pump's operating status needs to be checked promptly or the pump should be shut down for troubleshooting. When the cryogenic medium temperature is -110 degrees Celsius, and the cavity temperature transmitter 7 detects a slow decrease in the internal temperature of the insulation chamber 30, if it falls below -50 degrees Celsius, the insulation medium needs to be replenished or the cryogenic vertical bag pump 1 needs to be refilled and vented. When the cavity pressure transmitter 8 detects an increase in pressure within the insulation chamber 30, if it exceeds 1.2 Bar, it indicates a possible cryogenic medium leak, requiring a shutdown for inspection. This invention, through the above-mentioned design, achieves intelligent monitoring of the state within the insulation chamber 30, improving the system's safety and reliability, reducing downtime and accident losses caused by safety hazards, and providing crucial assurance for the long-term stable operation of the cryogenic vertical bag pump 1 in the cryogenic medium unloading system. As a preferred embodiment, the cavity temperature transmitter 7 is positioned close to the swan neck inlet pipe 2 to achieve precise monitoring of the pump's operating status, ensuring the safety and reliability of the cryogenic medium unloading process.

[0045] According to one embodiment of the present invention, such as Figure 1 and Figure 2 As shown, in order to avoid the accumulation of vaporized medium in the cryogenic vertical bag pump 1 and affect the pump performance, the cryogenic vertical bag pump 1 is equipped with an exhaust pipe 38 at the mechanical seal, and an exhaust valve 39 is installed on the exhaust pipe 38 to discharge the vaporized medium in the cryogenic vertical bag pump 1.

[0046] Based on the above description, the cold insulation structure of the low-temperature vertical cylindrical bag pump 1 provided in this embodiment of the present invention has the following beneficial effects:

[0047] The cryogenic vertical bag pump 1 provided in this embodiment of the invention features a cold insulation structure that independently sets the swan-neck inlet pipe 2 outside the cryogenic vertical bag pump 1, creating a relatively independent space between the swan-neck inlet pipe 2 and the main pump structure 11. The cryogenic medium directly reaches the top of the first-stage impeller 12 of the cryogenic vertical bag pump 1 through the swan-neck inlet pipe 2, greatly reducing the impact of temperature rise during pump operation on the cryogenic medium inside the swan-neck inlet pipe 2. Furthermore, by filling the insulation cylinder 3 with heat-insulating medium to form a cold insulation cavity 30, pre-cooling of the cryogenic medium inside the swan-neck inlet pipe 2 is achieved, further reducing the impact of ambient temperature on the cryogenic medium. This effectively avoids vaporization caused by temperature rise during pump operation, reduces the pump's net positive suction head (NPSH), and improves the pump's anti-cavitation performance. This allows the pump to maintain stable operation during intermittent transport in the cryogenic medium unloading system. It solves the problem in existing cryogenic medium unloading processes where the cryogenic medium easily absorbs ambient temperature during long-term shutdown, leading to increased pre-cooling and venting time during subsequent unloading, and wasting resources. This invention effectively reduces the temperature rise of the cryogenic medium and improves unloading efficiency. The system boasts advantages in vehicle efficiency; the insulation cylinder 3 features a detachable connection design, ensuring convenient disassembly and installation during maintenance and repair, as well as interchangeability; the swan-neck inlet pipe 2 employs a "swan-neck" structure design to reduce the flow resistance of the cryogenic medium within it, ensuring a sufficiently long flow path for the cryogenic medium within the cold insulation chamber, thus guaranteeing that the cryogenic medium remains in a cryogenic liquid state before entering the cryogenic vertical bag pump 1, thereby ensuring the long-term stable operation of the cryogenic vertical bag pump 1; by setting the guide plate 6, the flow direction of the fluid entering the pump can be effectively adjusted, reducing the generation of eddies and turbulence, allowing the cryogenic medium to flow smoothly into the impeller inlet, reducing energy loss during the flow of the cryogenic medium, and reducing the cavitation risk of the cryogenic vertical bag pump 1; by setting the internal temperature transmitter 7, internal pressure transmitter 8, and outlet temperature transmitter 9, intelligent monitoring of the state within the cold insulation chamber 30 is achieved, improving the safety and reliability of the system, reducing downtime and accident losses caused by safety hazards, and providing an important guarantee for the long-term stable operation of the cryogenic vertical bag pump 1 in the cryogenic medium unloading system.

[0048] This utility model also provides a low-temperature vertical bag pump 1, including the above-mentioned cold insulation structure of the low-temperature vertical bag pump 1. By setting the above-mentioned cold insulation structure, the low-temperature vertical bag pump 1 can achieve the technical effect achieved by the embodiment of the cold insulation structure of the low-temperature vertical bag pump 1. For details, please refer to the specific description of the above embodiment, which will not be repeated here.

[0049] The above descriptions are merely a few embodiments of this utility model. Those skilled in the art can make various modifications or variations to the embodiments of this utility model based on the content disclosed in the application documents without departing from the spirit and scope of this utility model.

Claims

1. A cold insulation structure for a low-temperature vertical cylindrical bag pump, characterized in that, include: The swan neck inlet pipe is located outside the cryogenic vertical bag pump and is used to deliver cryogenic medium into the cryogenic vertical bag pump. The swan neck inlet pipe has a corresponding inlet and outlet. The outlet is connected to the bag of the cryogenic vertical bag pump, and the connection point between the two is located below the secondary impeller of the cryogenic vertical bag pump. An insulation cylinder is sealed and fitted over the bag and the swan neck inlet pipe. The inside of the insulation cylinder is filled with a heat-insulating medium to form a cold-insulating cavity. The inlet is located outside the insulation cylinder.

2. The cold insulation structure of the low-temperature vertical cylindrical bag pump according to claim 1, characterized in that, The swan neck inlet pipe has at least one pipe section with a length equal to the total axial length of all the secondary impellers.

3. The cold insulation structure of the low-temperature vertical cylindrical bag pump according to claim 1, characterized in that, The outlet is positioned directly above the upper part of the inner cylindrical tube located between the primary impeller and the secondary impeller in the low-temperature vertical bag pump. At least one guide plate is connected to the inner cylindrical tube, and at least one guide plate is positioned directly above the outlet.

4. The cold insulation structure of the low-temperature vertical cylindrical bag pump according to claim 3, characterized in that, There are two guide plates, which are symmetrically connected to both sides of the inner cylindrical tube.

5. The cold insulation structure of the low-temperature vertical cylindrical bag pump according to claim 1, characterized in that, The insulation cylinder is connected to an inlet pipe and an outlet pipe. The inlet pipe is equipped with an inlet control valve, and the outlet pipe is equipped with an outlet control valve.

6. The cold insulation structure of the low-temperature vertical cylindrical bag pump according to claim 1, characterized in that, The cold insulation cavity is equipped with an internal temperature transmitter and an internal pressure transmitter, and the outlet section of the low-temperature vertical cylindrical bag pump is equipped with an outlet temperature transmitter.

7. The cold insulation structure of the low-temperature vertical cylindrical bag pump according to claim 1, characterized in that, The insulation cylinder is a hollow structure with one end closed and the other end open. The open end forms an opening for the bag and the swan neck inlet pipe to enter and exit. The open end is detachably connected to the bag flange of the low-temperature vertical bag pump. The surface of the bag flange and the surface facing the insulation cylinder form the top wall of the cold insulation cavity.

8. The cold insulation structure of the cryogenic vertical tubular bag pump according to claim 1 or 7, characterized in that, The insulation cylinder is integrally formed. Alternatively, the insulation cylinder is composed of multiple cylinder segments connected in series, and each of the two adjacent cylinder segments is provided with a connecting flange on the opposite end. The multiple cylinder segments are detachably connected through the connecting flange to form the insulation cylinder.

9. The cold insulation structure of the low-temperature vertical cylindrical bag pump according to claim 1, characterized in that, The cryogenic vertical bag pump is equipped with an exhaust pipe at its mechanical seal, and an exhaust valve is installed on the exhaust pipe to discharge the gasified medium inside the cryogenic vertical bag pump.

10. A cryogenic vertical tubular bag pump, characterized in that, The cryogenic vertical bag pump includes the cold insulation structure of the cryogenic vertical bag pump as described in any one of claims 1 to 9.

Images