A hollow fiber membrane separation nitrogen generation system

Abstract

The utility model discloses a hollow fiber membrane separation nitrogen making system, including air compressor, gas -liquid separator, refrigeration type drying machine, primary precision filter, super-precision filter, activated carbon filter, air heat exchanger and nitrogen making unit that connect gradually. Nitrogen making unit is composed of multiple parallel membrane separator, is equipped with hollow fiber membrane bundle in each membrane separator, is used for gas separation. System removes oil, water and particulate matter through multistage filtration and activated carbon adsorption effectively, guarantees the long -term stable operation of membrane component, adopts heat exchanger and preheating device control inlet temperature, and optimization separation efficiency, and nitrogen export is equipped with oxygen analyzer and purity control valve, realizes purity real -time monitoring and automatic regulation. The utility model has the advantages of compact structure, simple operation, purity adjustable, strong adaptability etc. is applicable to the high -purity nitrogen preparation of chemical industry, electronics, food and other many fields.

Description

Technical Field

[0001] This utility model relates to the field of nitrogen generation equipment technology, and in particular to a hollow fiber membrane separation nitrogen generation system. Background Technology

[0002] Nitrogen, as an important industrial gas, is widely used in chemical, electronics, food preservation, and oil extraction fields. Traditional nitrogen production methods mainly include cryogenic air separation and pressure swing adsorption (PSA). While cryogenic air separation can produce high-purity nitrogen, it involves complex equipment, high investment, and slow start-up. PSA equipment is relatively simple, but it suffers from high energy consumption, frequent valve switching, and a large amount of maintenance work.

[0003] Membrane separation for nitrogen production is a novel technology developed in recent years. It utilizes the difference in permeation rates of gas components within a membrane material to achieve separation. "Fast gases" such as oxygen and water vapor permeate through the membrane at a much higher rate than "slow gases" such as nitrogen. When compressed air passes through the membrane separator, oxygen and water vapor preferentially permeate through the membrane wall and are discharged, while nitrogen is enriched and collected on the other side of the membrane. This method offers advantages such as simple operation, rapid start-up, no moving parts, and convenient maintenance.

[0004] However, the pretreatment systems of existing membrane separation nitrogen generation systems are inadequate. Impurities such as oil, liquid water, and micron- and submicron-sized particles can easily cause hollow fiber membrane contamination, blockage, or even failure, severely affecting membrane life and separation efficiency. The structural design and integration method of the membrane separator affect the system's compactness and maintainability. The system's control over the stability of inlet gas temperature and pressure is insufficient, affecting the stability of nitrogen purity and yield. The real-time monitoring and automatic control capabilities for product gas purity are insufficient, and the yield of product gas is difficult to regulate.

[0005] Therefore, in view of the shortcomings of the existing technology, it is necessary to design a hollow fiber membrane separation nitrogen generation system to solve the above problems.

[0006] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete explanation of the technical solution of this utility model and facilitating the understanding of those skilled in the art. It should not be assumed that the above content is known to those skilled in the art simply because it has been described in the background section of this utility model. Utility Model Content

[0007] To overcome the shortcomings of the existing technology, the present invention discloses a hollow fiber membrane separation nitrogen generation system to solve the problems of membrane fouling caused by imperfect pretreatment, unstable system operating parameters, poor product gas purity and poor production control capability in the existing system.

[0008] This utility model discloses a hollow fiber membrane separation nitrogen generation system, comprising an air compressor, a gas-liquid separator, a refrigerated dryer, a primary precision filter, an ultra-precision filter, an activated carbon filter, an air heat exchanger, and a nitrogen generation unit, connected sequentially by pipelines, wherein:

[0009] The first-stage precision filter contains a filter element with a filtration accuracy of 1μm, and the ultra-precision filter contains a filter element with a filtration accuracy of 0.01μm.

[0010] The outlet of the air heat exchanger is connected to the gas inlet pipe of the nitrogen generator unit via a pipeline;

[0011] The nitrogen generation unit includes multiple membrane separators connected in parallel, and the membrane separators are detachably installed in the nitrogen generation unit. Each membrane separator includes a shell and multiple hollow fiber membranes disposed within the shell. The hollow fiber membranes are arranged in parallel at intervals to form a bundle structure. One end of the bundle structure is connected to the air inlet pipe, and the other end is connected to the nitrogen exhaust pipe.

[0012] Preferred technical solution: An oxygen analyzer and a purity control valve are installed on the nitrogen exhaust pipeline.

[0013] Preferred technical solution: The nitrogen exhaust pipeline is also equipped with an evacuation solenoid valve, which is connected to the oxygen analyzer signal.

[0014] Preferred technical solution: Temperature and pressure sensors are also installed on the pipeline between the activated carbon filter and the air heat exchanger to monitor gas parameters in real time.

[0015] Preferred technical solution: The membrane separator is equipped with a preheating device and an insulation jacket on its outer shell.

[0016] Preferred technical solution: All system components are installed on a steel structure frame, and the connecting pipelines of the membrane separator are made of stainless steel.

[0017] Preferred technical solution: The primary precision filter, ultra-precision filter and activated carbon filter are all equipped with differential pressure display gauges and automatic drain valves.

[0018] Preferred technical solution: The air heat exchanger is a tubular heat exchanger made of SS304 stainless steel.

[0019] Preferred technical solution: The outer space of the bundle-like structure is connected to the oxygen-enriched air outlet pipe.

[0020] Due to the application of the above technical solution, the beneficial effects of this utility model compared with the prior art are as follows:

[0021] This invention employs a specific purification process of "1μm precision filtration + 0.01μm ultra-precision filtration + activated carbon adsorption" to construct a progressive deep purification unit. This unit effectively removes over 99% of oil, water, and particulate matter from compressed air, particularly thoroughly eliminating submicron-level impurities. This prevents contamination and clogging of the hollow fiber membrane at the source, significantly extending the membrane module's lifespan. Through a parallel design of multiple membrane separators and a purity feedback control mechanism, a wide range of high-precision, flexible adjustments to nitrogen production and purity are achieved. Some membrane separators can be started and stopped according to actual needs to control gas production and reduce unnecessary energy consumption. An oxygen analyzer configured on the nitrogen outlet pipeline monitors the product gas purity in real time and links with the purity control valve and venting solenoid valve. If the oxygen content exceeds the standard, it automatically vents or adjusts the airflow to ensure that the output nitrogen always meets the set purity, avoiding production interruptions or gas waste caused by purity fluctuations. Meanwhile, by installing temperature and pressure sensors at key nodes and combining them with air heat exchangers and membrane separator preheating devices, precise control of the intake air conditions is achieved, ensuring that membrane separation always takes place at the optimal temperature, thus improving separation efficiency and the system's adaptability to environmental changes. The design of multiple membrane separators connected in parallel and capable of independent start-stop allows for stepless adjustment of gas production according to actual needs, avoiding energy waste. The entire system is integrated onto a steel frame, featuring a compact structure and high modularity, facilitating the expansion or adjustment of the number of membrane modules based on actual gas volume requirements. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art 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 from these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the layout of a hollow fiber membrane separation nitrogen generation system according to the present invention.

[0024] In the attached diagram above, 1 is an air compressor; 2 is a gas-liquid separator; 3 is a refrigerated dryer; 4 is a primary precision filter; 5 is an ultra-precision filter; 6 is an activated carbon filter; 7 is an air heat exchanger; 8 is a membrane separator; and 9 is an oxygen analyzer. Detailed Implementation

[0025] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.

[0026] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be used interchangeably where appropriate for the purposes of describing embodiments of this application herein. Furthermore, the terms "comprising" and "having," and their synonyms, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0027] In this application, the terms "upper," "lower," "left," "right," "front," "back," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this utility model and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0028] Furthermore, in addition to indicating direction or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this utility model according to the specific circumstances.

[0029] Furthermore, the terms "installation," "setting," "equipped with," "connection," "linking," "fitting," and "fitting" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, components, or parts. Similarly, "fitting" can mean completely or partially fitted. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0030] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0031] like Figure 1 As shown, this utility model discloses a hollow fiber membrane separation nitrogen generation system, including an air compressor 1, a gas-liquid separator 2, a refrigerated dryer 3, a primary precision filter 4, an ultra-precision filter 5, an activated carbon filter 6, an air heat exchanger 7, and a nitrogen generation unit, which are connected in sequence through pipelines. The main components of this utility model will be described in detail below:

[0032] The first-stage precision filter 4 contains a filter element with a filtration accuracy of 1μm, and the ultra-precision filter 5 contains a filter element with a filtration accuracy of 0.01μm; the combination of the two ensures that the gas entering the nitrogen generation unit is clean, prevents membrane fouling and clogging, and extends membrane life.

[0033] The outlet of air heat exchanger 7 is connected to the gas inlet pipe of the nitrogen generation unit via a pipeline;

[0034] The nitrogen generation unit includes multiple membrane separators 8 arranged in parallel. The membrane separators 8 are detachably installed in the nitrogen generation unit. Each membrane separator 8 includes a shell and multiple hollow fiber membranes disposed within the shell. The hollow fiber membranes are arranged in parallel at intervals to form a bundle structure. One end of the bundle structure is connected to the air inlet pipe, and the other end is connected to the nitrogen exhaust pipe.

[0035] In some embodiments, an oxygen analyzer 9 and a purity control valve are installed on the nitrogen discharge pipeline. The oxygen content at the nitrogen outlet is monitored in real time, and the opening of the purity control valve is adjusted via feedback control to ensure that the nitrogen purity remains stable within the set range, thus achieving automatic purity adjustment.

[0036] In some embodiments, a venting solenoid valve is also provided on the nitrogen exhaust pipeline, and the venting solenoid valve is connected to the oxygen analyzer 9 via a signal connection. Linked with the oxygen analyzer, when the nitrogen purity is detected to be substandard, the valve automatically opens and vents the substandard gas, preventing contamination of the output gas source and ensuring product quality.

[0037] In some embodiments, a temperature sensor and a pressure sensor are also provided on the pipeline between the activated carbon filter 6 and the air heat exchanger 7 to monitor gas parameters in real time, provide data support for temperature control and system operating status, and ensure stable system operation.

[0038] In some embodiments, the membrane separator 8 is provided with a preheating device and an insulation jacket outside its housing. Preheating the membrane separator at low temperatures prevents condensation and membrane performance degradation, ensuring rapid system startup and maintaining optimal operating temperature.

[0039] In some embodiments, the system components are mounted on a steel frame, and the connecting pipes of the membrane separator 8 are made of stainless steel. This enhances the rigidity and stability of the system.

[0040] In some embodiments, the primary precision filter 4, the ultra-precision filter 5, and the activated carbon filter 6 are all equipped with differential pressure gauges and automatic drain valves. The differential pressure gauges display the filter differential pressure in real time, prompting for filter element replacement; the automatic drain valves discharge condensate water periodically or as needed, reducing manual maintenance and ensuring filter efficiency.

[0041] In some embodiments, the air heat exchanger 7 is a tubular heat exchanger made of SS304 stainless steel.

[0042] In some embodiments, the outer space of the bundle-like structure is connected to an oxygen-enriched air outlet pipe. This allows "fast gases" such as oxygen and water vapor that have passed through the hollow fiber membrane to be discharged from the system, maintaining the pressure difference across the membrane and ensuring the continuous operation of the gas separation process.

[0043] The operation process of the hollow fiber membrane separation nitrogen generation system of this utility model is carried out in the following order:

[0044] 1) Ambient air is compressed by an air compressor 1 with a discharge capacity of 39 m³ / min and a discharge pressure of 1.25 MPa. The outlet is connected to a 5 m³ air storage tank, which plays a role in stabilizing pressure and buffering, and at the same time, initially separates liquid moisture.

[0045] 2) Compressed air then enters the gas-liquid separator 2 to remove more than 99% of the liquid water and oil droplets.

[0046] 3) The air after gas-liquid separation enters a refrigerated dryer 3 with a processing capacity of 50 m³ / min, where it is further condensed and water vapor is discharged.

[0047] 4) The air passes through a multi-stage filtration system, including:

[0048] The first-stage precision filter 4 is equipped with a filter element with a filtration accuracy of 1μm: it removes fine particles and micron-sized oil mist, reducing the oil mist content to 0.5mg / m³;

[0049] The ultra-precision filter 5 is equipped with a filter element with a filtration accuracy of 0.01μm: it removes submicron-level oil colloids and solid particles, reducing the oil mist content to 0.01mg / m³;

[0050] Activated carbon filter 6: Filled with high-efficiency activated carbon particles to remove heavy hydrocarbons from the gas source, so that the oil vapor content is ≤0.003mg / m³.

[0051] All filters are equipped with local differential pressure display and electronic timed / manual drain valves, which automatically alarm or drain when the differential pressure exceeds the limit.

[0052] 5) The purified air enters the SS304 stainless steel tubular air heat exchanger 7, and the temperature controller precisely controls the inlet air temperature within the optimal range of 25-60℃ through PID adjustment, providing stable operating conditions for membrane separation.

[0053] 6) The temperature-controlled clean compressed air enters the nitrogen generation unit at a pressure of 1.1 MPa. This unit consists of 18 membrane separators 8 connected in parallel. Each membrane separator 8 can generate nitrogen with a flow rate of ≥60 m³ / h and a purity of ≥98% under standard operating conditions.

[0054] The outer shell of the membrane separator 8 is made of aluminum alloy, and tens of thousands of hollow fiber membranes are encapsulated inside. Compressed air enters the inner cavity of the hollow fiber membrane through the air inlet pipe at one end. "Fast gases" such as oxygen and water vapor preferentially pass through the membrane wall and are discharged through the oxygen-enriched air outlet pipe; "slow gases" such as nitrogen are enriched in the inner cavity of the hollow fiber membrane and are output from the nitrogen outlet pipe at the other end.

[0055] The membrane separator 8 is equipped with a preheating device and an insulation jacket to ensure rapid start-up and maintain the optimal operating temperature in low-temperature environments.

[0056] 7) The produced nitrogen gas first enters the nitrogen purity control system. This system uses an online oxygen analyzer to monitor the oxygen content of the product gas in real time, and maintains the nitrogen purity continuously adjustable between 95% and 98% by adjusting the purity control valve. When the purity exceeds the set value, the venting solenoid valve automatically opens, releasing the substandard gas into the atmosphere.

[0057] 8) The qualified nitrogen then enters a nitrogen booster, which is a single-stage, air-cooled compressor with a power of 55kW. It can boost the nitrogen pressure from 0.2-0.8MPa to the required 2.5MPa to meet the high-pressure gas demand.

[0058] Meanwhile, the hollow fiber membrane separation nitrogen generation system is centrally controlled by a PLC fully automatic control system, integrating monitoring and regulation functions for pressure, temperature, purity, and flow. The PLC drives relevant actuators through sampling and detection, and after PID calculation, realizes automatic system start-up and shutdown, closed-loop purity control, fault alarm and interlock protection, and can remotely transmit signals to achieve unattended operation.

[0059] Finally, it should be noted that the above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A hollow fiber membrane separation nitrogen generation system, comprising an air compressor (1), a gas-liquid separator (2), a refrigerated dryer (3), a primary precision filter (4), an ultra-precision filter (5), an activated carbon filter (6), an air heat exchanger (7), and a nitrogen generation unit, connected sequentially by pipelines, characterized in that: The first-stage precision filter (4) is equipped with a filter element with a filtration accuracy of 1μm, and the ultra-precision filter (5) is equipped with a filter element with a filtration accuracy of 0.01μm. The outlet of the air heat exchanger (7) is connected to the gas inlet pipe of the nitrogen generation unit via a pipeline; The nitrogen generation unit includes multiple membrane separators (8) arranged in parallel. The membrane separators (8) are detachably installed in the nitrogen generation unit. The membrane separators (8) include a shell and multiple hollow fiber membranes disposed in the shell. The hollow fiber membranes are arranged in parallel at intervals to form a bundle structure. One end of the bundle structure is connected to the air inlet pipe, and the other end is connected to the nitrogen exhaust pipe.

2. The hollow fiber membrane separation nitrogen generation system according to claim 1, characterized in that: The nitrogen discharge pipeline is equipped with an oxygen analyzer (9) and a purity control valve.

3. The hollow fiber membrane separation nitrogen generation system according to claim 2, characterized in that: The nitrogen exhaust pipeline is also equipped with an air venting solenoid valve, which is connected to the oxygen analyzer (9) via signal connection.

4. The hollow fiber membrane separation nitrogen generation system according to claim 1, characterized in that: Temperature and pressure sensors are also provided on the pipeline between the activated carbon filter (6) and the air heat exchanger (7) for real-time monitoring of gas parameters.

5. The hollow fiber membrane separation nitrogen generation system according to claim 1, characterized in that: The membrane separator (8) is equipped with a preheating device and an insulation sleeve on the outside of its shell.

6. The hollow fiber membrane separation nitrogen generation system according to claim 1, characterized in that: The components of the system are mounted on a steel frame, and the connecting pipes of the membrane separator (8) are made of stainless steel.

7. The hollow fiber membrane separation nitrogen generation system according to claim 1, characterized in that: The primary precision filter (4), ultra-precision filter (5), and activated carbon filter (6) are all equipped with differential pressure gauges and automatic drain valves.

8. The hollow fiber membrane separation nitrogen generation system according to claim 1, characterized in that: The air heat exchanger (7) is a tubular heat exchanger made of SS304 stainless steel.

9. A hollow fiber membrane separation nitrogen generation system according to claim 1, characterized in that: The outer space of the bundle-like structure is connected to an oxygen-enriched air outlet pipe.

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