Low-dew-point oxygen enrichment device based on negative pressure film

Abstract

The utility model relates to a gas separation technology, and aims to provide a low-dew-point oxygen enrichment device based on a negative pressure film. The low-dew-point oxygen enrichment device based on the negative-pressure film comprises an air filter, a ventilator and a negative-pressure film oxygen enrichment assembly which are sequentially connected through pipelines, an oxygen-enriched air outlet of the negative-pressure film oxygen enrichment assembly is sequentially connected with a vacuum pump, a drying machine, a booster fan and a preheater through pipelines, and an outlet of the preheater is used for supplying oxygen-enriched air to the outside. The device can directly dehumidify water vapor pumped out of oxygen-enriched gas so as to ensure that oxygen-enriched combustion reaches an efficient state, and more effective measures are taken to control the temperature and humidity of the oxygen-enriched gas so as to ensure that the oxygen-enriched combustion process is efficiently carried out; by optimizing the oxygen-enriched air treatment process, the efficiency problem, the cost problem and the safety problem of a high-temperature fan are solved; based on an electric automatic control system, the reliability and stability of the device can be further improved, and a foundation is laid for long-term stable operation and efficient management and control of the device.

Description

Technical Field

[0001] The utility model relates to the technical field of gas separation, in particular to a low dew point oxygen enrichment device based on a negative pressure membrane. Background Art

[0002] The industrial sector is the main battlefield for my country to achieve its "dual carbon" goals, and industrial scenarios involving fuel combustion generally have high carbon emissions. Oxygen-enriched combustion has the triple value of increasing production and efficiency, saving energy and reducing consumption, and reducing emissions. It is an energy-saving technology that the country vigorously promotes. One of the core technologies of oxygen-enriched combustion is how to produce oxygen-enriched gas at low cost.

[0003] Negative pressure membrane oxygen production is a method for preparing oxygen-enriched gas, specifically, extracting oxygen from the air through negative pressure membrane separation. This method utilizes the high selective permeability of specific membrane materials to oxygen. Under negative pressure, when air passes through the membrane material, oxygen molecules can pass through the membrane pores more easily, while other gas molecules are blocked, thereby achieving oxygen enrichment and purification. Due to the use of negative pressure operation, air does not require additional high-pressure gas when passing through the membrane, thereby reducing the energy consumption of the oxygen enrichment device and simplifying the equipment process.

[0004] In the negative pressure membrane oxygen production process, the water molecules and oxygen molecules in the air are both "fast gases" with very high permeability rates. After the air passes through the membrane separation, it will form a gas-liquid multiphase flow (oxygen-rich gas + water vapor) on the other side of the membrane. If the gas-liquid multiphase flow is directly sprayed into the kiln, the water vapor will quickly convert into steam during the combustion process. This process will not only take away a lot of heat, but also reduce the oxygen-rich combustion efficiency in the kiln.

[0005] Chinese patent CN108534169A describes an "integrated device for oxygen enrichment and combustion support", including an air supply device, an oxygen production device and a conveying device. The air is supplied to the oxygen-enriched generator by using the air supply device, and then the vacuum is extracted by a vacuum pump, and the obtained oxygen-enriched air is conveyed to the combustion device. Compared with the existing method of extracting vacuum by a water ring vacuum pump, the invention uses a dry vacuum pump to extract the oxygen-enriched film. The technical solution of this patent has obvious physical defects. Because in actual engineering applications, even if a dry vacuum pump is used for exhaust treatment, the obtained oxygen-enriched gas will still contain a large amount of water vapor, which undoubtedly affects the quality of the oxygen-enriched gas and the energy-saving effect of oxygen-enriched combustion support. In addition, the oxygen-enriched gas in this scheme is first heated by a preheater and then sent to the kiln through a booster fan. Sensible heat, the booster fan adopts a medium-pressure blower at one time. If the inlet gas temperature of the booster fan is increased, it will not only greatly reduce the operating efficiency and increase the equipment cost, but also the long-term operation of the high-temperature fan will have serious safety hazards.

[0006] Therefore, it is necessary to propose new technical solutions to solve the above problems. Utility Model Content

[0007] The technical problem to be solved by the utility model is to overcome the deficiencies in the prior art and provide a low dew point oxygen enrichment device based on a negative pressure membrane.

[0008] To solve the technical problem, the solution of the utility model is:

[0009] Provided is a low dew point oxygen enrichment device based on a negative pressure membrane, the device comprising an air filter, a ventilator and a negative pressure membrane oxygen enrichment component connected in sequence through pipelines, the oxygen-enriched air outlet of the negative pressure membrane oxygen enrichment component is connected in sequence through pipelines to a vacuum pump, a dryer, a booster fan and a preheater, and the preheater outlet is used to supply oxygen-enriched air to the outside;

[0010] The negative pressure membrane oxygen enrichment component includes a rectangular box body, and a plurality of air vents are arranged on the side panels of the air inlet end and the air outlet end of the box body. The air inlet end is connected to the ventilator through a pipeline and the air outlet end is directly connected to the atmosphere; a plurality of groups of membrane structures arranged in parallel are arranged inside the box body, and an exhaust pipe is arranged at the end of each group of membrane structures; a spacing is maintained between two adjacent groups of membrane structures to form an air flow channel, one end of the air flow channel is connected to the air inlet end of the box body for introducing air, and the other end is connected to the exhaust end of the box body for removing nitrogen-rich air that cannot penetrate the membrane material; after water molecules and oxygen enter the membrane structure, they are collected into the air collecting pipe through the exhaust pipe, and the oxygen-enriched air outlet is arranged at the end of the air collecting pipe.

[0011] As an improved solution, the membrane structure is a plate-type membrane structure or a roll-type membrane structure made of any one membrane material of polysulfone, polyimide or polyphenylene ether.

[0012] As an improved solution, the plate-type membrane structure is composed of two pieces of membrane materials arranged in parallel and maintaining a distance, the sides and both ends of which are closed to form a cavity, and an exhaust pipe is provided at one closed end to be connected to a gas collecting pipe.

[0013] As an improved solution, the vacuum pump is a dry vacuum pump, specifically any one of a vortex vacuum pump, a screw vacuum pump, a Roots vacuum pump or a magnetically suspended centrifugal vacuum pump.

[0014] As an improved solution, the outlet of the preheater is connected to an oxygen-enriched burner arranged in the combustion device through a pipeline.

[0015] As an improved solution, the preheater is a heat exchanger, whose heating medium inlet is connected to the flue of the combustion device through a pipeline, and the heating medium outlet is connected to the furnace of the combustion device through a pipeline, and the heat exchange medium used to heat the oxygen-enriched air is the flue gas drawn from the flue.

[0016] As an improved solution, the device also includes an electric automatic control system, which includes automatic control equipment and actuators; the actuators include electric control components arranged in the ventilator, vacuum pump, dryer and booster fan, and the automatic control equipment is connected to each electric control component in the actuator and a gas state sensor arranged on the preheater outlet pipeline through signal lines.

[0017] As an improved solution, the automatic control device is a PLC controller or a DDC controller.

[0018] As an improved solution, the self-control device is also connected to the cloud control platform via wired or wireless communication.

[0019] Technical principle description:

[0020] The membrane separation process of separating air by membrane components is a relatively mature technology in the application of air separation to produce nitrogen-rich gas and oxygen-rich gas. However, since moisture is generally regarded as a harmful component that affects the quality of gas products, the common practice is to use a dryer, a desiccant or a desiccant to remove water before introducing the air into the membrane separation component; then, the selective permeability difference of nitrogen and oxygen of the organic polymer dense film is used to obtain oxygen-rich gas and nitrogen-rich gas. However, given that air contains 78% nitrogen, if the air is dehydrated, most of the objects disposed of in this process are nitrogen discharged as "waste gas" in the oxygen production process. In addition, the front dryer, dryer or desiccant also causes air intake pressure loss. In order to ensure the normal operation of the membrane component, the workload of the vacuum pump needs to be increased. Obviously, the above practices are bound to bring about a huge increase in energy consumption or desiccant loss, which must be considered for industrial production.

[0021] When designing the device of the utility model, the applicant broke through the conventional design thinking that "water needs to be removed before the air enters the membrane separation device" and proposed the design scheme of the present application by utilizing the membrane material's permeability selectivity to both oxygen and water molecules. The oxygen-enriched air that passes through the membrane material carries water molecules and is discharged as a crude product, and then is dried and heated to obtain oxygen-enriched gas with a low dew point. Through this design, the volume of gas that needs to pass through the dryer or desiccant is greatly reduced relative to the air intake, greatly reducing the air pressure drop or the loss of desiccant.

[0022] In addition, in order to increase the temperature and pressure of the oxygen-enriched gas to meet the needs of kilns and other combustion devices, the oxygen-enriched air produced by the membrane assembly in the prior art is usually first heated by a preheater, and then sent to the combustion equipment through a booster fan. However, in actual production, the booster fan generally adopts a medium-pressure blower. If the inlet gas temperature of the booster fan is too high, it will not only greatly reduce the operating efficiency and increase the equipment cost, but also the long-term operation of the high-temperature fan will have serious safety hazards. Therefore, this application proposes to place the preheater after the booster fan, thereby solving this technical problem.

[0023] Compared with the prior art, the utility model has the following beneficial effects:

[0024] 1. The utility model can directly dehumidify the water vapor in the extracted oxygen-rich gas to ensure that the oxygen-rich combustion reaches a high efficiency state; the device controls the temperature and humidity of the oxygen-rich gas by taking more effective measures to ensure the high efficiency of the oxygen-rich combustion process.

[0025] 2. The utility model solves the efficiency, cost and safety issues of high-temperature fans by optimizing the process of oxygen-enriched air treatment.

[0026] 3. The device of the utility model controls the supply pressure and temperature and humidity of the oxygen-enriched gas according to the working condition requirements of oxygen-enriched combustion, thereby optimizing the combustion conditions in the combustion device and allowing the fuel to burn more fully and efficiently.

[0027] 4. The electric automatic control system based on the device of the utility model can further improve the reliability and stability of the device; after the device is connected to the cloud platform, it can further realize digital intelligent management and control and remote operation and maintenance, laying the foundation for the long-term stable operation and efficient management and control of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the overall structure of the low dew point oxygen enrichment device based on negative pressure membrane of the utility model;

[0029] Figure 2 It is a schematic diagram of the cross-sectional structure of the negative pressure membrane oxygen-enriched component of the utility model;

[0030] Figure 3 It is a flow chart of the utility model's China Electric Automatic Control System.

[0031] The accompanying drawings are marked as follows: 1. air filter; 2. ventilator; 3. negative pressure membrane oxygen-enriched component; 301. box; 302. gas collecting pipe; 303. membrane structure; 4. vacuum pump; 6. dryer; 7. booster fan; 8. preheater; 9. combustion device; 10. oxygen-enriched burner; 12. actuator; 13. automatic control equipment; 14. cloud control platform; 15. gas state sensor; 200. electrical automatic control system. DETAILED DESCRIPTION

[0032] The specific implementation of the utility model is described in detail below with reference to the accompanying drawings.

[0033] Part I. Description of the Structural Layout of the Device

[0034] like Figure 1 As shown, a low dew point oxygen enrichment device based on a negative pressure membrane in the utility model comprises an air filter 1, a ventilator 2 and a negative pressure membrane oxygen enrichment component 3 which are sequentially connected through pipelines, and the nitrogen-rich gas outlet of the negative pressure membrane oxygen enrichment component 3 leads to the atmosphere; the oxygen-rich gas outlet of the negative pressure membrane oxygen enrichment component 3 is sequentially connected to a vacuum pump 4, a dryer 6, a booster fan 7 and a preheater 8 through a pipeline, and the outlet of the preheater 8 is used to supply oxygen-rich air to the outside.

[0035] The negative pressure membrane oxygen enrichment component 3 includes a rectangular box 301, and a plurality of air vents are arranged on the side panels of the air inlet and exhaust ends of the box 301. The air inlet end is connected to the ventilator 2 through a pipeline, and the exhaust end is directly connected to the atmosphere; a plurality of groups of parallel membrane structures 303 are arranged inside the box, and an exhaust pipe is arranged at the end of each group of membrane structures 303; a distance is maintained between two adjacent groups of membrane structures 303 to form an air flow channel, one end of the air flow channel is connected to the air inlet end of the box for introducing air, and the other end is connected to the exhaust end of the box for removing nitrogen-rich air that cannot penetrate the membrane material; after water molecules and oxygen enter the membrane structure 303, they are converged into the collecting pipe 302 through the exhaust pipe, and the oxygen-enriched air outlet is arranged at the end of the collecting pipe 302.

[0036] The membrane structure 303 is a plate-type membrane structure or a roll-type membrane structure made of any one of polysulfone, polyimide or polyphenylene ether membrane materials. Figure 2 As shown in , the plate membrane structure is composed of two pieces of membrane materials arranged in parallel and maintaining a distance, the sides and both ends of which are closed to form a cavity, and an exhaust pipe is provided at one of the closed ends to connect to the gas collecting pipe 302. The membrane material can be flexibly selected according to different application environments. For example, in certain occasions, polysulfone materials are favored due to their excellent stability and separation efficiency; in other scenarios, polyimide is preferred due to its excellent high temperature resistance; in addition, polyphenylene ether materials stand out in certain specific applications due to their good chemical stability and mechanical strength. This diverse selection of materials ensures that the negative pressure membrane oxygen enrichment component 3 can adapt to various complex environments and perform at its best.

[0037] For example, the outlet of the preheater 8 is connected to the oxygen-enriched burner 10 provided in the combustion device 9 (such as a kiln) through a pipeline. The preheater 8 is a heat exchanger, whose heating medium inlet is connected to the flue of the combustion device 9 through a pipeline, and the heating medium outlet is connected to the furnace of the combustion device 9 through a pipeline. The heat exchange medium used to heat the oxygen-enriched air is the flue gas introduced from the flue.

[0038] The device also includes an electric automatic control system 200, which includes an automatic control device 13 and an actuator 12; the actuator 12 includes electric control components arranged in the ventilator 2, the vacuum pump 3, the dryer 6 and the booster fan 7, and the automatic control device 13 is connected to each electric control component in the actuator 12 through a signal line, as well as a gas state sensor 15 arranged on the outlet pipeline of the preheater. The gas state sensor 15 is used to monitor the pressure, flow rate, temperature and water content of the oxygen-enriched air, and the specific selection can be determined according to actual needs.

[0039] The automatic control device 13 is a PLC controller or a DDC controller, which receives the signal from the gas state sensor 15 through the signal line, and transmits the action execution signal to the actuator 11 through the signal line. Furthermore, the automatic control device 13 can also be connected to the cloud control platform 14 through wired or wireless communication. The operator can log in to the cloud control platform 13 through a computer or mobile terminal, and use the software program to realize the digital intelligent control and remote operation and maintenance of the device operation process.

[0040] In the utility model, the fan 2 can adopt a centrifugal fan that is mature in the market; the vacuum pump 4 is a dry vacuum pump, which can be a vortex vacuum pump, a screw vacuum pump, a Roots vacuum pump or a magnetic levitation centrifugal vacuum pump; the dryer 6 can adopt mature technology (such as a commercially available compression heat zero gas consumption dryer); the preheater 8 can adopt a plate heat exchanger that is mature in the market.

[0041] Part 2. Device Operation Method Description

[0042] First, the air is filtered through the air filter 1 and then flows into the ventilator 2 as raw air. The raw air is raised to a micro-pressure state in the ventilator 2 to overcome the air resistance in the pipeline. Next, the pressurized raw air enters the negative pressure membrane oxygen enrichment component 3, and the vacuum pump 4 operates to suck the raw air from the feed end of the negative pressure membrane oxygen enrichment component 3 to its outlet end. The gas after suction is a gas-water mixed multiphase flow (enriched oxygen + water molecules). In the process of suction, since oxygen (O2) and water molecules (H2O) are both fast gases, the oxygen and some water vapor molecules in the raw air can be quickly permeated and sucked out of the membrane, and the enriched nitrogen is discharged into the atmosphere.

[0043] As a specific example, the air intake volume of the ventilator 2 per unit time is 8 to 10 times the oxygen-enriched flow rate. For example, the flow rate of one unit is 600m 3 A ventilator with a capacity of 60 to 75 m3 / h can produce 60 to 75 m3 3 / h, with a concentration of about 29% oxygen-rich gas. In actual working conditions, users can select the model of the fan according to their needs to meet different oxygen supply requirements. The gas-water mixed multiphase flow passes through the dryer 6 for dehumidification. The dry oxygen-rich gas obtained after dehumidification is pressurized by the booster fan 7 and then sent to the preheater 8 for heat exchange and temperature increase. Finally, the finished oxygen-rich gas is sent to the combustion device 9 through the burner 10 for use as combustion-supporting gas.

[0044] In order to realize the digital start and stop control of energy-consuming equipment such as the ventilator 2, vacuum pump 4, dryer 6 and booster fan 7, and to facilitate users to read the parameter values ​​of the oxygen-rich gas flow and concentration; in the electric automatic control system 200, users can directly control the cloud control platform 14, and remotely start and stop the above energy-consuming equipment through the automatic control device 13 and the actuator 12. At the same time, after the gas state sensor 15 transmits the data to the automatic control device 12 for processing, the corresponding oxygen-rich gas pressure, flow, temperature and water content data can be uploaded to the cloud control platform 14 for users to read.

[0045] The low dew point mentioned in the invention subject of the utility model means that the water vapor content in the oxygen-rich gas finally produced is less than that in the air raw material. As for the specific value of the dew point control, it is determined according to the combustion process of the external combustion device. Those skilled in the art can adjust the operating conditions of the dryer according to the specific requirements of the process conditions. This content is not within the scope of protection of the utility model, so it is not limited to this.

[0046] It should be noted that the present utility model may involve computer control technology during actual use. For example, the use of the automatic control device 13 will involve the application of embedded software, and the cloud control platform 14 will involve the application of server or platform management software. However, the content of these software programs themselves to realize their functions does not belong to the protection scope of the present utility model. The applicant believes that after carefully reading the application documents and accurately understanding the implementation principle and purpose of the present utility model, in combination with the existing known technology, the technical personnel in this field can fully use the software programming skills they have mastered to realize the present utility model. A large number of existing public documents provide implementation solutions for relevant software function modules from various angles, which belong to the existing technology that the technical personnel in this field have mastered. Therefore, the implementation methods of the component system described in the present utility model and other contents do not belong to the content that must be recorded in the present utility model. In addition, the innovation of the present utility model lies in the organic combination and connection of hardware devices or components that were originally used independently, and the implementation process of the relevant calculation or control method does not belong to the scope of protection of the present utility model.

Claims

1. A low dew point oxygen enrichment device based on negative pressure membrane, characterized in that: The device comprises an air filter, a ventilator and a negative pressure membrane oxygen enrichment component which are sequentially connected through pipelines. The oxygen-enriched air outlet of the negative pressure membrane oxygen enrichment component is sequentially connected to a vacuum pump, a dryer, a booster fan and a preheater through pipelines. The preheater outlet is used to supply oxygen-enriched air to the outside. The negative pressure membrane oxygen enrichment component includes a rectangular box body, and a plurality of air vents are arranged on the side panels of the air inlet end and the air outlet end of the box body. The air inlet end is connected to the ventilator through a pipeline and the air outlet end is directly connected to the atmosphere; a plurality of groups of membrane structures arranged in parallel are arranged inside the box body, and an exhaust pipe is arranged at the end of each group of membrane structures; a spacing is maintained between two adjacent groups of membrane structures to form an air flow channel, one end of the air flow channel is connected to the air inlet end of the box body for introducing air, and the other end is connected to the exhaust end of the box body for removing nitrogen-rich air that cannot penetrate the membrane material; after water molecules and oxygen enter the membrane structure, they are collected into the air collecting pipe through the exhaust pipe, and the oxygen-enriched air outlet is arranged at the end of the air collecting pipe.

2. The low dew point oxygen enrichment device based on negative pressure membrane according to claim 1, characterized in that: The membrane structure is a plate-type membrane structure or a roll-type membrane structure made of any one of polysulfone, polyimide or polyphenylene ether membrane materials.

3. The low dew point oxygen enrichment device based on negative pressure membrane according to claim 2 is characterized in that: The plate-type membrane structure is composed of two pieces of membrane materials arranged in parallel and maintaining a distance, the sides and both ends of which are closed to form a cavity, and an exhaust pipe is arranged at one closed end to be connected to a gas collecting pipe.

4. The low dew point oxygen enrichment device based on negative pressure membrane according to claim 1, characterized in that: The vacuum pump is a dry vacuum pump, specifically any one of a vortex vacuum pump, a screw vacuum pump, a Roots vacuum pump or a magnetic levitation centrifugal vacuum pump.

5. The low dew point oxygen enrichment device based on negative pressure membrane according to claim 1, characterized in that: The outlet of the preheater is connected to an oxygen-enriched burner arranged in the combustion device through a pipeline.

6. The low dew point oxygen enrichment device based on negative pressure membrane according to claim 1, characterized in that: The preheater is a heat exchanger, whose heating medium inlet is connected to the flue of the combustion device through a pipeline, and whose heating medium outlet is connected to the furnace of the combustion device through a pipeline. The heat exchange medium used to heat the oxygen-enriched air is the flue gas introduced from the flue.

7. The low dew point oxygen enrichment device based on negative pressure membrane according to claim 1, characterized in that: The device also includes an electric automatic control system, which includes automatic control equipment and an actuator; the actuator includes electric control components arranged in a ventilator, a vacuum pump, a dryer and a booster fan, and the automatic control equipment is connected to each electric control component in the actuator and a gas state sensor arranged on the outlet pipeline of the preheater through signal lines.

8. The low dew point oxygen enrichment device based on negative pressure membrane according to claim 7, characterized in that: The automatic control device is a PLC controller or a DDC controller.

9. The low dew point oxygen enrichment device based on negative pressure membrane according to claim 7, characterized in that: The self-control device is also connected to the cloud control platform via wired or wireless communication.

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