Displacement purging energy-saving purification pipeline of air separation device

Abstract

The utility model belongs to the technical field of air separation devices, and relates to an air separation device replacement purging energy-saving purification pipeline which comprises an air cooling tower, an outlet pipeline is arranged at the top of the air cooling tower and connected to a second molecular sieve container, a second regeneration air outlet pipe is led out of the outlet pipeline and connected to a blow-down pipe, and the blow-down pipe is connected with a second molecular sieve container. The tail end of the blow-down pipe is provided with an outlet pipe connected to a back connecting pipe, two ends of the back connecting pipe are connected to a regeneration gas header pipe, the back end of the regeneration gas header pipe is connected to a first molecular sieve container, the top of the first molecular sieve container is provided with an outlet header pipe, and the top of a second molecular sieve container is provided with a second outlet pipe connected to the outlet header pipe. The outlet header pipe is connected to the regenerated gas header pipe through a through pipe. Energy consumption is optimized, external compressed air is introduced to replace a self-configured large air compressor to start, electric quantity of the air compressor is saved, diffusion of the air compressor is avoided, and pipeline pressure fluctuation is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of air separation devices, and in particular relates to a replacement, purge and energy-saving purification pipeline for an air separation device. Background Art

[0002] The steel plant is equipped with a public auxiliary air separation unit. The air separation unit mainly uses deep freezing distillation to separate the oxygen, nitrogen and argon components in the air to provide industrial gas media for the steel plant. The air separation unit purification system is a key device for raw material air separation purification. It is equipped with two molecular sieve adsorbers, one for use and one for regeneration. Regeneration and activation use the excess dirty nitrogen gas from the air separation unit. When the air separation unit is shut down for maintenance and the flatness of the purified molecular sieve bed is checked, the dirty nitrogen gas and high temperature heat inside the container pose a threat to the safety of the operators.

[0003] When the air separation unit is shut down and the internal molecular sieve of the purification system is overhauled and inspected, the supporting air compressor needs to be turned on to provide compressed air to replace and purge the molecular sieve container. When the supporting air compressor of the air separation unit is running to provide compressed air for replacement and purge, there is a large amount of leakage of compressed air supplied by the compressor, and the leakage rate is about 80%. This is because the air supply of the supporting air compressor is designed according to the needs of normal production. Overhaul and replacement are special circumstances outside of normal production. Using the supporting air compressor for overhaul and replacement will result in uneconomical electricity consumption.

[0004] Therefore, a replacement purge energy-saving purification pipeline for an air separation unit is proposed. Utility Model Content

[0005] The utility model aims to provide an energy-saving purification pipeline for air separation device replacement and purge, which has the energy-saving function of replacement and purge, and solves the problem of uneconomical electricity consumption in the prior art of using a matching air compressor for maintenance and replacement.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is as follows: the utility model provides an energy-saving purification pipeline for replacement purge of an air separation device, including an air cooling tower, an outlet pipe is arranged at the top of the air cooling tower, the outlet pipe is connected to the No. 2 molecular sieve container, a pressure transmitter is arranged on the outlet pipe, a No. 2 regeneration outlet pipe is led out from the outlet pipe, the No. 2 regeneration outlet pipe is connected to the vent pipe, an outlet pipe is arranged at the end of the vent pipe to be connected to the return pipe, both ends of the return pipe are connected to the regeneration gas main pipe, the rear end of the regeneration gas main pipe is connected to the No. 1 molecular sieve container, a connecting pipe is arranged at the bottom of the No. 1 molecular sieve container to be connected to the outlet pipe, a No. 1 regeneration outlet pipe is led out from the connecting pipe to be connected to the vent pipe, an outlet main pipe is arranged at the top of the No. 1 molecular sieve container, an interconnecting pipe is led out from the regeneration gas main pipe to be connected to the No. 2 regeneration inlet pipe, both ends of the No. 2 regeneration inlet pipe are respectively connected to the regeneration gas main pipe and the No. 2 molecular sieve container, a No. 2 outlet pipe is arranged at the top of the No. 2 molecular sieve container, the No. 2 outlet pipe is connected to the outlet main pipe, and the outlet main pipe is connected to the regeneration gas main pipe through a through pipe.

[0007] Preferably, an inlet pipeline is provided on one side of the air cooling tower, an air compressor and a one-way valve are provided on the inlet pipeline, an air supply pipeline is led out from the inlet pipeline, and a compressed air supply valve is provided on the air supply pipeline.

[0008] Preferably, a vent muffler is provided at the end of the vent pipe.

[0009] Preferably, the return pipe is provided with an electric heater and a return valve.

[0010] Preferably, a regeneration gas main valve is provided at the front end of the regeneration gas main pipe, a No. 1 regeneration air intake valve is provided at the rear end of the regeneration gas main pipe, and a No. 2 regeneration air intake valve is provided on the No. 2 regeneration air intake pipe.

[0011] Preferably, the No. 1 regeneration outlet pipe is provided with a No. 1 outlet valve, and the No. 2 regeneration outlet pipe is provided with a No. 2 outlet valve.

[0012] Preferably, a No. 1 inlet valve is provided on the connecting pipe, a No. 2 inlet valve is provided at the end of the outlet pipe, a No. 1 outlet valve is provided at the front end of the outlet main pipe, an outlet main valve is provided at the end of the outlet main pipe, and a No. 2 outlet valve is provided on the No. 2 outlet pipe.

[0013] Preferably, manholes are provided on both sides of the No. 1 molecular sieve container and the No. 2 molecular sieve container.

[0014] Preferably, a control valve is provided on the regeneration gas main pipe between the connection points at both ends of the return pipe.

[0015] Preferably, the outlet pipe is provided with an outlet valve, the interconnection pipe is provided with an interconnection valve, and the through pipe is provided with a through valve.

[0016] Compared with the prior art, the advantages and positive effects of the utility model are:

[0017] 1. The utility model optimizes energy consumption by introducing external compressed air to start the large air compressor instead of itself, saving air compressor power, avoiding air compressor discharge, and improving pipeline pressure fluctuations;

[0018] 2. The utility model has the energy-saving function of replacement and purging, which solves the problem of uneconomical electricity consumption in the prior art of using a matching air compressor for maintenance and replacement. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor.

[0020] Figure 1 It is a structural schematic diagram of a replacement purge energy-saving purification pipeline of an air separation unit;

[0021] In the above figure, 1, air cooling tower, 2, inlet pipeline, 3, air compressor, 4, non-return valve, 5, air supply pipeline, 6, compressed air supply valve, 7, outlet pipeline, 8, No. 2 molecular sieve container, 9, pressure transmitter, 10, No. 2 inlet valve, 11, No. 2 regeneration outlet pipe, 12, vent pipe, 13, vent silencer, 14, outlet pipe, 15, return pipe, 16, outlet valve, 17, regeneration gas main pipe, 18, electric heater, 19, return valve, 20, control valve, 21, regeneration gas main Valve, 22, regeneration air inlet valve No. 1, 23, molecular sieve container No. 1, 24, connecting pipe, 25, inlet valve No. 1, 26, regeneration air outlet pipe No. 1, 27, air outlet valve No. 1, 28, outlet main pipe, 29, outlet valve No. 1, 30, outlet main valve, 31, interconnecting pipe, 32, regeneration air inlet pipe No. 2, 33, interconnecting valve, 34, regeneration air inlet valve No. 2, 35, outlet pipe No. 2, 36, outlet valve No. 2, 37, manhole, 38, through pipe, 39, through valve, 40, outlet valve No. 2. DETAILED DESCRIPTION

[0022] In order to more clearly understand the above-mentioned purpose, features and advantages of the utility model, the utility model is further described below in conjunction with the accompanying drawings and embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0023] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways than those described herein. Therefore, the present invention is not limited to the specific embodiments of the following disclosure.

[0024] Embodiment 1, as Figure 1 As shown, an energy-saving purification pipeline for replacement purge of an air separation unit includes an air cooling tower 1, which is used to cool compressed air to a required low temperature. An outlet pipe 7 is arranged at the top of the air cooling tower 1, and the outlet pipe 7 transports the cooled gas to the outside, and the outlet pipe 7 is connected to a No. 2 molecular sieve container 8.

[0025] The outlet pipe 7 is provided with a pressure transmitter 9, which can monitor the pressure in the outlet pipe 7 and provide data to the control system to ensure safe operation. The outlet pipe 7 is provided with a No. 2 regeneration outlet pipe 11, which is connected to a vent pipe 12. The No. 2 molecular sieve container 8 is vented to the outside through the No. 2 regeneration outlet pipe 11 and vented through the vent pipe 12.

[0026] An outlet pipe 14 is provided at the end of the vent pipe 12 and connected to the return pipe 15. Both ends of the return pipe 15 are connected to the regeneration gas main pipe 17. The regeneration gas main pipe 17 is connected to the vent pipe 12 through the return pipe 15 and the outlet pipe 14. The rear end of the regeneration gas main pipe 17 is connected to the No. 1 molecular sieve container 23. The surplus room-temperature contaminated nitrogen gas produced by the distillation system is sent into the No. 1 molecular sieve container 23 through the regeneration gas main pipe 17 for purging and regeneration. The room-temperature contaminated nitrogen gas enters the No. 1 molecular sieve container 23 through the regeneration gas main pipe 17.

[0027] A connecting pipe 24 is provided at the bottom of the No. 1 molecular sieve container 23 to connect to the outlet pipe 7, and the No. 1 molecular sieve receives the low-temperature gas in the outlet pipe 7 through the connecting pipe 24. A No. 1 regeneration outlet pipe 26 is led out from the connecting pipe 24 to connect to the vent pipe 12, and the No. 1 molecular sieve container 23 is discharged to the outside through the No. 1 regeneration outlet pipe 26, and the room-temperature dirty nitrogen gas sent to the No. 1 molecular sieve container 23 is discharged through the vent pipe 12; similarly, the No. 2 molecular sieve container 8 is discharged to the outside through the No. 2 regeneration outlet pipe 11, and the room-temperature dirty nitrogen gas sent to the No. 2 molecular sieve container 8 is discharged through the vent pipe 12.

[0028] An outlet main pipe 28 is provided on the top of the No. 1 molecular sieve container 23. The gas fed into the No. 1 molecular sieve container 23 through the connecting pipe 24 is discharged through the outlet main pipe 28. The regeneration gas main pipe 17 is connected to the No. 2 regeneration air inlet pipe 32 through an interconnection pipe 31. The interconnection pipe 31 plays a role in balancing the pressure. The two ends of the No. 2 regeneration air inlet pipe 32 are respectively connected to the regeneration gas main pipe 17 and the No. 2 molecular sieve container 8. The room temperature contaminated nitrogen passes through the regeneration gas main pipe 17 and the No. 2 regeneration air inlet pipe 32 into the No. 2 molecular sieve container 8.

[0029] A No. 2 outlet pipe 35 is provided on the top of the No. 2 molecular sieve container 8, and the No. 2 outlet pipe 35 is connected to the outlet main pipe 28. The gas fed into the No. 2 molecular sieve container 8 through the outlet pipe 7 is fed to the outlet main pipe 28 through the No. 2 outlet pipe 35 for discharge.

[0030] The outlet main pipe 28 is connected to the regeneration gas main pipe 17 through the through pipe 38. The through pipe 38 is used to introduce air into the outlet main pipe 28 to purge the high-temperature heat and retained asphyxiating gas in the No. 1 molecular sieve container 23 and the No. 2 molecular sieve container 8.

[0031] The following is a detailed description of the design of the above key components:

[0032] An inlet pipe 2 is provided on one side of the air cooling tower 1. The inlet pipe 2 is connected to an external compressed air source to introduce external air. An air compressor 3 and a one-way valve 4 are provided on the inlet pipe 2. The air compressor 3 provides compressed air, and the one-way valve 4 ensures that air can only flow in and will not leak out. An air supply pipe 5 is led out from the inlet pipe 2. A compressed air supply valve 6 is provided on the air supply pipe 5. The air supply pipe 5 supplies compressed air when necessary to keep the gas pressure stable. The compressed air supply valve 6 controls the opening and closing of the air supply pipe 5, adjusts the amount of air supplied by the air supply pipe 5, and optimizes the gas balance.

[0033] A vent muffler 13 is provided at the end of the vent pipe 12, and the vent muffler 13 reduces the noise when the exhaust gas is vented and discharged, reduces noise pollution, and improves the operating environment.

[0034] The return pipe 15 is provided with an electric heater 18 and a return valve 19. The electric heater 18 heats the gas in the return pipe 15. The return valve 19 controls the opening and closing of the return pipe 15. The return pipe 15 is opened or closed according to the need to lead out the gas in the regeneration gas main pipe 17 for reflux heating.

[0035] A regeneration gas main valve 21 is provided at the front end of the regeneration gas main pipe 17, and the regeneration gas main valve 21 controls whether the room temperature contaminated nitrogen gas is introduced from the outside. A No. 1 regeneration air intake valve 22 is provided at the rear end of the regeneration gas main pipe 17, and the No. 1 regeneration air intake valve 22 controls whether the room temperature contaminated nitrogen gas is introduced into the No. 1 molecular sieve container 23. A No. 2 regeneration air intake valve 34 is provided on the No. 2 regeneration air intake pipe 32, and the No. 2 regeneration air intake valve 34 controls whether the room temperature contaminated nitrogen gas is introduced into the No. 2 molecular sieve container 8.

[0036] The No. 1 regeneration outlet pipe 26 is provided with a No. 1 outlet valve 27, and the No. 1 outlet valve 27 adjusts the opening and closing of the No. 1 regeneration outlet pipe 26, and adjusts the flow rate of the discharge of the normal temperature contaminated nitrogen gas. The No. 2 regeneration outlet pipe 11 is provided with a No. 2 outlet valve 40, and the No. 2 outlet valve 40 adjusts the opening and closing of the No. 2 regeneration outlet pipe 11, and adjusts the flow rate of the discharge of the normal temperature contaminated nitrogen gas.

[0037] The connecting pipe 24 is provided with a No. 1 inlet valve 25, and the end of the outlet pipe 7 is provided with a No. 2 inlet valve 10. The No. 1 inlet valve 25 and the No. 2 inlet valve 10 respectively adjust the flow rate and flow velocity of the low-temperature gas entering the No. 1 molecular sieve container 8 of the No. 2 molecular sieve container 8; the front end of the outlet main pipe 28 is provided with a No. 1 outlet valve 29, and the No. 2 outlet pipe 35 is provided with a No. 2 outlet valve 36. The No. 1 outlet valve 29 and the No. 2 outlet valve 36 respectively adjust the flow rate and flow velocity of the low-temperature gas flowing out of the No. 1 molecular sieve container 23 of the No. 2 molecular sieve container 8, and the end of the outlet main pipe 28 is provided with an outlet main valve 30, and the opening and closing of the outlet main valve 30 is adjusted by the outlet main valve 30.

[0038] Manholes 37 are provided on both sides of the molecular sieve container No. 1 23 and the molecular sieve container No. 2 8, and the oxygen content in the molecular sieve container No. 1 23 and the molecular sieve container No. 2 8 is detected through the manholes 37, and the oxygen content inside the molecular sieve container No. 1 23 and the molecular sieve container No. 2 8 is analyzed using the manholes 37.

[0039] A control valve 20 is provided on the regeneration gas main pipe 17 between the two ends of the return pipe 15. The control valve 20 is used to close the regeneration gas main pipe 17 so that the gas inside the regeneration gas main pipe 17 enters the return pipe 15 for heating.

[0040] The outlet pipe 14 is provided with an outlet valve 16, which regulates the opening and closing of the outlet pipe 14; the interconnection pipe 31 is provided with an interconnection valve 33, which regulates the opening and closing of the interconnection pipe 31; the through pipe 38 is provided with a through valve 39, which regulates the opening and closing of the through pipe 38.

[0041] Example 2, as shown in Example 1, an air separation unit replaces the purge energy-saving purification pipeline, introduces an external surplus compressed air source to replace the air compressed by its own air compressor 3, the external compressed air pressure range is 0.4-0.6MPa, and the temperature is room temperature. Design the air supply pipeline 5, design the voltage stabilization interlock logic, and control the flow stability of the external air source.

[0042] The compressed air supply valve 6 is a pneumatic regulating valve, which is controlled by DCS (distributed collection and management system) and adopts PID automatic adjustment. The measured value of the compressed air supply valve 6 is the pressure data transmitted to the DCS by the pressure transmitter 9 on the outlet pipe 7 of the air cooling tower 1. The target value is a pressure value that can be manually set and modified. The maximum pressure setting value is 0.55MPa. When the measured value in the PID module controlled by the compressed air supply valve 6 is lower than the target setting value, the compressed air supply valve 6 gradually opens to make the pressure at the outlet of the air cooling tower 1 close to the target value; on the contrary, the compressed air supply valve 6 gradually closes.

[0043] During normal production, the compressed air supply valve 6 is in the closed state and the PID is in the manual position. When shutting down for maintenance, adjust the compressed air supply valve 6 to introduce the surplus compressed air into the compressed air station through the supply pipe 5. Under the action of the one-way valve 4 on the inlet pipe 2, the external compressed air directly enters the air cooling tower 1. According to the pressure detected by the outlet pipe 7 of the air cooling tower 1, the target pressure adjustment value is set. The PID of the compressed air supply valve 6 is automatically put into operation, and the supply air opening is automatically adjusted according to the change of the outlet pressure of the air cooling tower 1. The compressed air passes through the No. 1 molecular sieve container 23, and then the valve 39 is opened, and the regeneration gas main 17 is passed from the valve 38 to purge, replace and cool the No. 2 molecular sieve container 8. The purged compressed air carries the dirty nitrogen and heat and is discharged from the vent pipe 12 to the atmosphere through the vent silencer 13.

[0044] The air compressor 3 does not need to be started, which saves electricity and reduces venting. At the same time, external compressed air is introduced. When the air separation molecular sieve is overhauled, the subsequent users of the steel plant are often overhauled at the same time. The use of compressed air is often surplus and released. Therefore, the surplus of the compressed air network of the compressed air steel plant is reasonably allocated and utilized. The compressed air supply valve 6 automatically controls the pressure stabilization to achieve automation. After the overhaul is completed, the air supply pipeline 5 can be used to inflate and maintain the pressure of the air cooling tower 1, the No. 1 molecular sieve container 23 and the No. 2 molecular sieve container 8 to prevent the humid air in the external atmospheric environment from entering the interior.

[0045] The standard parts used in the utility model can all be purchased from the market, special-shaped parts can be customized according to the description in the specification and the drawings, the specific connection methods of each part adopt the conventional means such as mature bolts, rivets, welding, etc. in the prior art, the machinery, parts and equipment all adopt the conventional models in the prior art, and the circuit connection adopts the conventional connection method in the prior art, which will not be described in detail here. The content not described in detail in this specification belongs to the prior art known to professional and technical personnel in this field.

[0046] The above description is only a preferred embodiment of the present invention and does not limit the present invention in other forms. Any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes and apply it to other fields. However, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. An energy-saving purification pipeline for replacement purge of an air separation unit, characterized in that: The invention comprises an air cooling tower, wherein an outlet pipe is arranged at the top of the air cooling tower, the outlet pipe is connected to a No. 2 molecular sieve container, a pressure transmitter is arranged on the outlet pipe, a No. 2 regeneration outlet pipe is led out from the outlet pipe, the No. 2 regeneration outlet pipe is connected to a vent pipe, an outlet pipe is arranged at the end of the vent pipe and connected to a return pipe, both ends of the return pipe are connected to a regeneration gas main pipe, a rear end of the regeneration gas main pipe is connected to a No. 1 molecular sieve container, a connecting pipe is arranged at the bottom of the No. 1 molecular sieve container and connected to the outlet pipe, a No. 1 regeneration outlet pipe is led out from the connecting pipe and connected to the vent pipe, an outlet main pipe is arranged at the top of the No. 1 molecular sieve container, an interconnecting pipe is led out from the regeneration gas main pipe and connected to a No. 2 regeneration inlet pipe, both ends of the No. 2 regeneration inlet pipe are respectively connected to the regeneration gas main pipe and the No. 2 molecular sieve container, a No. 2 outlet pipe is arranged at the top of the No. 2 molecular sieve container, the No. 2 outlet pipe is connected to the outlet main pipe, and the outlet main pipe is connected to the regeneration gas main pipe through a through pipe.

2. The energy-saving purification pipeline of an air separation unit according to claim 1 is characterized in that: An inlet pipeline is arranged on one side of the air cooling tower, an air compressor and a one-way valve are arranged on the inlet pipeline, an air supply pipeline is led out from the inlet pipeline, and a compressed air supply valve is arranged on the air supply pipeline.

3. The energy-saving purification pipeline for replacement, purge and purification of an air separation unit according to claim 1, characterized in that: A vent muffler is provided at the end of the vent pipe.

4. The energy-saving purification pipeline for replacement purge of an air separation unit according to claim 1 is characterized in that: The return pipe is provided with an electric heater and a return valve.

5. The energy-saving purification pipeline for replacement purge of an air separation unit according to claim 1 is characterized in that: A regeneration gas main valve is arranged at the front end of the regeneration gas main pipe, a No. 1 regeneration air intake valve is arranged at the rear end of the regeneration gas main pipe, and a No. 2 regeneration air intake valve is arranged on the No. 2 regeneration air intake pipe.

6. The energy-saving purification pipeline for replacement, purge and purification of an air separation unit according to claim 1, characterized in that: The No. 1 regeneration air outlet pipe is provided with a No. 1 air outlet valve, and the No. 2 regeneration air outlet pipe is provided with a No. 2 air outlet valve.

7. The energy-saving purification pipeline for replacement, purge and purification of an air separation unit according to claim 1, characterized in that: The connecting pipe is provided with a No. 1 inlet valve, the end of the outlet pipe is provided with a No. 2 inlet valve, the front end of the outlet main pipe is provided with a No. 1 outlet valve, the end of the outlet main pipe is provided with an outlet main valve, and the No. 2 outlet pipe is provided with a No. 2 outlet valve.

8. The energy-saving purification pipeline for replacement purge of an air separation unit according to claim 1, characterized in that: Manholes are arranged on both sides of the No. 1 molecular sieve container and the No. 2 molecular sieve container.

9. The energy-saving purification pipeline for replacement purge of an air separation unit according to claim 1, characterized in that: A control valve is arranged on the regeneration gas main pipe between the connection points at both ends of the return pipe.

10. The energy-saving purification pipeline for replacement, purge and purification of an air separation unit according to claim 1, characterized in that: The outlet pipe is provided with an outlet valve, the interconnection pipe is provided with an interconnection valve, and the through pipe is provided with a through valve.

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