A cryogenic balance pipe for a cryogenic distillation system

Abstract

The utility model belongs to air separation rectification argon equipment technical field relates to a kind of air separation rectification argon system cold balance pipeline, including crude argon tower, liquid level meter is arranged on the crude argon tower, liquid level sensor is arranged on liquid level meter, crude argon tower bottom is led out with liquid outlet pipeline, crude liquid oxygen pump is arranged on liquid outlet pipeline, liquid outlet pipeline is connected to main rectification tower, manual valve is arranged on the rear side of crude liquid oxygen pump on liquid outlet pipeline, reflux pipeline is led out in the front side of manual valve, reflux pipeline is connected to crude argon tower, reflux valve is arranged on reflux pipeline, and reflux valve, crude liquid oxygen pump and liquid level sensor are electrically connected to frequency converter.The utility model maintains crude argon tower liquid level and cold balance, reduces energy consumption, and the liquid level of crude argon tower is monitored by liquid level sensor and signal is transmitted to frequency converter, and the speed of crude liquid oxygen pump and the opening of reflux valve are synchronously regulated by frequency converter to realize collaborative control, while reducing valve throttling loss and improving overall energy efficiency.

Description

Technical Field

[0001] This utility model belongs to the technical field of air separation distillation argon equipment, specifically relating to a cooling balance pipeline for an air separation distillation argon system. Background Technology

[0002] An air separation unit is an industrial device used to separate the various components of air to produce gases such as oxygen, nitrogen, and argon. The most common air separation method is cryogenic distillation. When extracting argon, an air separation distillation unit requires a crude argon column. The liquid level at the bottom of the crude argon column is a crucial parameter, affected by fluctuations in the feed gas flow rate and argon production. When the overall load of the air separation unit changes, it will cause changes in the feed gas and argon production. In such cases, the liquid level at the bottom of the crude argon column must be adjusted promptly to maintain the cooling balance between the main distillation column and the crude argon column.

[0003] Current technologies often employ variable frequency crude liquid oxygen pumps, with the frequency manually adjusted to address liquid level changes. However, this manual intervention relies on operator experience and is inherently lagging. The stability of the crude argon column liquid level indicates whether the cooling capacity of the main column and the argon column is balanced: an excessively high liquid level indicates excessive cooling capacity leakage from the main column; an excessively low liquid level indicates insufficient cooling capacity leakage from the main column. This imbalance in cooling capacity distribution disrupts distillation operations, affecting product purity and extraction rate. There is an urgent need for a piping system that can automatically, accurately, and rapidly adjust the crude argon column liquid level and continuously maintain cooling capacity balance between the main column and the argon column under varying load conditions. Therefore, a cooling capacity balancing piping system for an air separation distillation argon system is proposed. Utility Model Content

[0004] The purpose of this invention is to provide a cooling balance pipeline for an air separation distillation argon system. By using a frequency converter to coordinate the adjustment of pump speed and valves, the liquid level of the crude argon tower can be automatically and accurately controlled. This solves the problems of lag and inaccuracy in the existing technology that rely on manual adjustment, which leads to imbalance of cooling capacity between the main tower and the argon tower and unstable distillation conditions.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: This utility model provides a cold energy balance pipeline for an air separation distillation argon system, including a crude argon column, a level gauge and a level sensor installed on the crude argon column, an outlet pipe leading out from the bottom of the crude argon column, a crude liquid oxygen pump installed on the outlet pipe, the outlet pipe being connected to the main distillation column, a manual valve installed on the outlet pipe downstream of the crude liquid oxygen pump, a reflux pipe leading out from the front of the manual valve, the reflux pipe being connected to the crude argon column, a reflux valve installed on the reflux pipe, and the reflux valve, the crude liquid oxygen pump and the level sensor being electrically connected to a frequency converter.

[0006] Preferably, the liquid outlet pipe is equipped with a liquid outlet valve at one end near the crude argon column and a liquid inlet valve at the other end near the main distillation column.

[0007] Preferably, the reflux pipe is connected to the upper middle part of the crude argon tower.

[0008] Preferably, the output terminal of the frequency converter is electrically connected to the drive motor of the crude liquid oxygen pump.

[0009] Preferably, the manual valve is a shut-off valve, and the level gauge is a differential pressure level gauge.

[0010] Preferably, the system also includes a controller, with the frequency converter electrically connected to the controller, and the frequency converter serving as the controller's execution unit.

[0011] Preferably, the controller is a PLC.

[0012] Compared with the prior art, the advantages and positive effects of this utility model are as follows:

[0013] 1. This utility model maintains the balance between the crude argon tower liquid level and cooling capacity, reducing energy consumption. The liquid level of the crude argon tower is monitored by a liquid level sensor and the signal is transmitted to the frequency converter. The frequency converter synchronously adjusts the speed of the crude liquid oxygen pump and the opening of the reflux valve to achieve coordinated control, while reducing valve throttling losses and improving overall energy efficiency.

[0014] 2. This utility model achieves automatic and precise control of the crude argon column liquid level by coordinating the pump speed and valves with a frequency converter. This solves the problems of lag and inaccuracy caused by relying on manual adjustment in the prior art, which leads to imbalance of cooling capacity between the main column and the argon column and unstable distillation conditions. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of 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 some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the cooling balance pipeline of an air separation distillation argon system according to one embodiment;

[0017] In the above diagrams, 1. crude argon column, 2. level gauge, 3. level sensor, 4. outlet pipe, 5. crude liquid oxygen pump, 6. main distillation column, 7. outlet valve, 8. inlet valve, 9. manual valve, 10. reflux pipe, 11. reflux valve, 12. frequency converter, 13. controller. Detailed Implementation

[0018] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0019] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed in the following specification.

[0020] Example 1, such as Figure 1 As shown, a cold energy balance pipeline for an air separation distillation argon system includes a crude argon column 1. The crude argon column 1 is used for preliminary distillation of the incoming argon fraction to separate crude argon gas. The liquid level at the bottom of the crude argon column 1 is an indicator of cold energy balance. A level gauge 2 is installed on the crude argon column 1, and the level gauge 2 is connected to the bottom of the crude argon column 1. A level sensor 3 is installed on the level gauge 2. The level gauge 2 is used to visually display the liquid level height of the crude argon column 1, and the level sensor 3 is used to convert the liquid level signal into an electrical signal in real time and continuously.

[0021] A liquid outlet pipe 4 extends from the bottom of the crude argon column 1, and a crude liquid oxygen pump 5 is installed on the liquid outlet pipe 4. The liquid outlet pipe 4 is connected to the main distillation column 6. The liquid outlet pipe 4 is the channel through which liquid is transported from the bottom of the crude argon column 1 to the main distillation column 6, and the crude liquid oxygen pump 5 provides power for the liquid flow. A manual valve 9 is installed on the liquid outlet pipe 4 downstream of the crude liquid oxygen pump 5. The manual valve 9 acts as a shut-off valve, and closing it manually achieves safety isolation.

[0022] Manual valve 9 is installed at the rear outlet end of crude liquid oxygen pump 5, located between crude liquid oxygen pump 5 and main distillation column 6. A reflux pipe 10 is led out from the front of manual valve 9, connecting to crude argon column 1. A reflux valve 11 is installed on reflux pipe 10, providing a path for excess liquid to return to crude argon column 1. Reflux valve 11 is used to precisely control the reflux flow rate. Reflux valve 11, crude liquid oxygen pump 5, and liquid level sensor 3 are electrically connected to frequency converter 12. Frequency converter 12 receives the liquid level signal and synchronously outputs two control signals: one to adjust the speed of the crude liquid oxygen pump 5 motor, and the other to adjust the opening of reflux valve 11, achieving coordinated control with fast response and high control accuracy, solving the lag problem of manual adjustment.

[0023] The specific design of the aforementioned key components will be discussed in detail below:

[0024] The liquid outlet pipe 4 is equipped with a liquid outlet valve 7 at one end near the crude argon tower 1 and a liquid inlet valve 8 at the other end near the main distillation tower 6. The liquid outlet valve 7 is used to isolate the crude argon tower 1 from the crude liquid oxygen pump 5, and the liquid inlet valve 8 is used to isolate the liquid outlet pipe 4 from the main distillation tower 6. The liquid outlet valve 7 and the liquid inlet valve 8 facilitate segmented maintenance and improve operational safety.

[0025] The reflux pipe 10 is connected to the upper middle part of the crude argon column 1, and the reflux liquid enters a tray in the rectification section of the crude argon column 1. As a cooling medium and washing liquid, the reflux liquid can fully contact the rising vapor on the tray, undergoing heat and mass exchange, thereby improving the purity of the crude argon. This avoids the drastic fluctuations in liquid level and boiling point changes that might occur if the low-temperature reflux liquid were directly returned to the bottom of the column, which helps maintain the stability of the temperature and pressure gradient inside the rectification column. Simultaneously, the cold energy carried by the reflux liquid is directly utilized in the upper middle part of the crude argon column 1, resulting in higher cold energy utilization efficiency.

[0026] The output terminal of the frequency converter 12 is electrically connected to the drive motor of the crude liquid oxygen pump 5. The frequency converter 12 controls the crude liquid oxygen pump 5 by direct drive. The frequency converter 12 directly and linearly controls the speed of the drive motor by changing the frequency and voltage of the output power supply. The outlet flow rate of the crude liquid oxygen pump 5 is proportional to the speed, realizing precise and stepless adjustment of the liquid delivery volume.

[0027] The manual valve 9 is a shut-off valve. The shut-off valve has a simple structure, good sealing performance, reliable operation, and provides safety assurance. The level gauge 2 is a differential pressure level gauge. The differential pressure level gauge has mature technology, reliable measurement, good low temperature resistance, and is suitable for the low temperature environment of air separation distillation. It can provide a continuous and stable 4-20mA standard signal, which is convenient to connect with the controller 13 to realize automatic control.

[0028] It also includes a controller 13, with a frequency converter 12 electrically connected to the controller 13, serving as the execution unit of the controller 13. The controller 13 is a PLC. The controller 13 is responsible for logic operations and decision-making, while the frequency converter 12 is the execution unit responsible for executing instructions. The PLC can run advanced control algorithms such as PID, intelligently calculating the optimal control instructions for pumps and valves in real time based on liquid level deviations. The PLC can communicate with the host computer or DCS system of the air separation unit to achieve plant-wide automated management. Control parameters or logic can be adjusted by modifying the PLC program without hardware changes, adapting to process changes.

[0029] All standard parts used in this utility model can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art. In addition, the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here. The contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0030] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present utility model without departing from the technical solution of the present utility model shall still fall within the protection scope of the technical solution of the present utility model.

Claims

1. An air separation rectification argon system cold balance line, characterized in that, The system includes a crude argon column, a level gauge and a level sensor installed on the crude argon column, an outlet pipe leading out from the bottom of the crude argon column, a crude liquid oxygen pump installed on the outlet pipe, the outlet pipe being connected to the main distillation column, a manual valve installed on the outlet pipe downstream of the crude liquid oxygen pump, a reflux pipe leading out from the front of the manual valve, the reflux pipe being connected to the crude argon column, a reflux valve installed on the reflux pipe, and the reflux valve, the crude liquid oxygen pump and the level sensor being electrically connected to a frequency converter.

2. A cold balance line for an air separation distillation argon system as claimed in claim 1, characterized in that The liquid outlet pipe is equipped with a liquid outlet valve at one end near the crude argon column and a liquid inlet valve at the other end near the main distillation column.

3. The cold balance pipeline for an air separation distillation argon system according to claim 1, characterized in that, The reflux pipe is connected to the upper middle part of the crude argon column.

4. The cold load balancing pipeline for an air separation distillation argon system according to claim 1, characterized in that, The output terminal of the frequency converter is electrically connected to the drive motor of the crude liquid oxygen pump.

5. The cold balance pipeline for an air separation distillation argon system according to claim 1, characterized in that, The manual valve is a shut-off valve, and the level gauge is a differential pressure level gauge.

6. The cold balance pipeline for an air separation distillation argon system according to claim 1, characterized in that, It also includes a controller, with the frequency converter electrically connected to the controller, and the frequency converter serving as the controller's execution unit.

7. A cooling balance pipeline for an air separation distillation argon system according to claim 6, characterized in that, The controller is a PLC.

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