A positive pressure membrane air separation oxygen-enriched calcination application system for cement production line

Abstract

The utility model discloses a positive pressure membrane air separation oxygen-enriched calcination application system for a cement production line, comprising an air compressor air supply unit, a source gas processing unit, a positive pressure membrane nitrogen and oxygen separation component integrated unit, an oxygen collection and utilization unit and a nitrogen collection and utilization unit; the air compressor air supply unit, the source gas processing unit, the positive pressure membrane nitrogen and oxygen separation component integrated unit, the oxygen collection and utilization unit or the nitrogen collection and utilization unit are connected in sequence, the oxygen collection and utilization unit is connected to a kiln head burner, and the nitrogen collection and utilization unit is connected to a compressed air pipeline system of a cement production line; the utility model improves the efficiency of coal powder combustion through oxygen-enriched calcination, reduces the unit coal consumption of clinker, stabilizes the operating status of the cement kiln, improves the output and quality of the cement kiln, and reduces the emission of waste gas; the compressed air used in the cement production line is used to greatly reduce the installed energy of the oxygen production system, save investment, and the recovery and reuse of nitrogen reduces the waste of air and reduces the cost of oxygen production.

Description

Technical Field

[0001] The utility model relates to a positive pressure membrane air separation oxygen-enriched calcining application system for a cement production line. Background Art

[0002] my country is a major cement producer, and its cement output accounts for a high proportion of the world's total output. As the country has vigorously advocated or promoted energy-saving and emission-reduction technologies in recent years, the cement industry, as my country's main high-energy consumption and high-emission industry, is undoubtedly the focus and difficulty of energy conservation and emission reduction in the industrial field. Its energy-saving and emission-reduction effects play a vital role in achieving my country's energy consumption targets and industrial sustainable development. Therefore, further increasing energy conservation and emission reduction efforts and developing a low-carbon recyclable economy has become an arduous and urgent task facing the cement industry.

[0003] In cement clinker production, coal consumption basically accounts for more than half of the production cost. How to reduce coal consumption is directly related to the comprehensive economic benefits of cement enterprises. In order to solve such problems, some related technologies have been developed, among which oxygen-enriched calcination technology has been applied in cement clinker production.

[0004] The use of oxygen-enriched calcination in cement clinker production has the following advantages: increasing the activity of fuel coal, increasing the combustion speed of coal, and increasing its burnout rate; lowering the ignition point of coal, increasing the concentration and flame intensity of combustion, reducing the marginal loss of combustion, and increasing the utilization rate of combustion heat; increasing the absolute temperature of the flame, thereby increasing the combustion temperature and reducing the heat transfer process. loss; increase the flame blackness, thereby increasing the thermal radiation intensity in the rotary kiln; at the same time, it can also reduce the exhaust volume after combustion and reduce the heat carried away by the flue gas. From the application effect of the oxygen-enriched calcination technology used in the existing cement rotary kiln, there is a certain coal-saving effect.

[0005] At present, the oxygen-enriched calcination technologies used in cement rotary kiln clinker production include deep cooling, pressure swing adsorption, membrane separation and other air separation oxygen production technologies, among which membrane separation oxygen production mainly uses negative pressure membrane separation oxygen production technology. The common characteristics of these air separation oxygen production methods are: only the combustion-supporting properties of oxygen are used to calcine cement clinker, but the actual combustion-supporting effect and utilization effect of oxygen are not very obvious, and there are many areas that need to be continuously improved or enhanced; at the same time, a large amount of nitrogen is directly discharged as waste gas and is not fully utilized, which directly causes the following problems: one-time investment is too high, the system installed capacity is large, the oxygen production cost is high and the subsequent maintenance cost is high; therefore, it is necessary to develop a positive pressure membrane air separation oxygen-enriched calcination application system for cement clinker production line to solve the problems encountered in oxygen-enriched combustion in existing cement production. Utility Model Content

[0006] The technical problem to be solved by the utility model is to provide a positive pressure membrane air separation oxygen-enriched calcination application system for cement production lines, which is used in cement rotary kiln clinker calcination to achieve coal saving and stable production, and realize energy saving and consumption reduction of cement production lines. The system has practicality and wide application.

[0007] In order to solve the above problems, the utility model adopts the following technical solutions:

[0008] A positive pressure membrane air separation oxygen-enriched calcination application system for a cement production line comprises an air supply unit for an air compressor, a source gas processing unit, a positive pressure membrane nitrogen and oxygen separation component integrated unit, an oxygen collection and utilization unit and a nitrogen collection and utilization unit; the air supply unit for an air compressor, the source gas processing unit, the positive pressure membrane nitrogen and oxygen separation component integrated unit, the oxygen collection and utilization unit or the nitrogen collection and utilization unit are connected in sequence, the oxygen collection and utilization unit is connected to a kiln head burner, and the nitrogen collection and utilization unit is connected to a compressed air pipeline system of the cement production line.

[0009] Preferably, the air compressor air supply unit is used to supplement the compressed air in the cement production system when the compressed air pressure is unstable or reduced, and to supplement the compressed air extracted from the oxygen part after air separation oxygen production;

[0010] Preferably, the source gas processing unit performs cold drying, filtering and heating treatment on the compressed air entering the positive pressure membrane nitrogen and oxygen separation component;

[0011] Preferably, the positive pressure membrane nitrogen and oxygen separation component integrated unit is a device that uses positive pressure membrane air separation technology to separate oxygen and nitrogen in compressed air;

[0012] Preferably, the oxygen collection and utilization unit collects and stabilizes the oxygen generated by the positive pressure membrane air separation system, and connects the oxygen to the air inlet of the primary fan at the kiln head of the cement rotary kiln through a pipeline to achieve oxygen-enriched calcination of the cement rotary kiln;

[0013] Preferably, the nitrogen collection and utilization unit is used to collect nitrogen generated by the positive pressure membrane air separation system, and is connected to the original compressed air pipeline system of the cement production line through a pipeline to achieve nitrogen recovery and utilization.

[0014] Preferably, the air compressor air supply unit is composed of multiple air compressor systems, and the air compressor system includes a screw air compressor and a compressed gas storage tank;

[0015] Preferably, the source gas processing unit is composed of a cold dryer, a heat exchanger, a filter component 1 and a filter component 2;

[0016] Preferably, the positive pressure membrane nitrogen and oxygen separation component integrated unit includes a membrane oxygen production device.

[0017] Preferably, the oxygen collection and utilization unit comprises an oxygen-rich gas pressure-stabilizing tank and a plurality of valves;

[0018] Preferably, the nitrogen collection and utilization unit comprises a nitrogen-rich gas pressure-surge tank and a plurality of valves;

[0019] Preferably, a kiln head primary fan and a backup fan are provided between the oxygen collection and utilization unit and the kiln head burner.

[0020] Preferably, the filter assembly 1 includes a C-level filter, a T-level filter 1 and an A-level filter 1, and the filter assembly 2 includes a T-level filter 2, an A-level filter 2 and an H-level filter.

[0021] The beneficial effects of the utility model are as follows: the efficiency of coal powder combustion can be improved through oxygen-enriched calcination, the unit coal consumption of clinker can be reduced, the operation condition of the cement kiln can be stabilized, the output and quality of the cement kiln can be improved, and the emission of waste gas can be reduced; the compressed air used in the cement production line can be used to greatly reduce the installed energy of the oxygen production system, save investment, and the recovery and reuse of nitrogen can reduce the waste of air and reduce the cost of oxygen production. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below, but this does not limit the protection scope of the utility model.

[0023] Figure 1 It is a schematic diagram of the system principle of the utility model;

[0024] Figure 2 It is a schematic diagram of the connection between the air compressor air supply unit and the source air processing unit of the utility model;

[0025] Figure 3 This is a schematic diagram of the connection of the integrated unit of the positive pressure membrane nitrogen and oxygen separation component of the utility model;

[0026] Figure 4 This is a schematic diagram of the connection of the oxygen collection and utilization unit of the utility model;

[0027] Figure 5 This is a connection diagram of the nitrogen collection and utilization unit of the utility model;

[0028] Figure 6 This is a schematic structural diagram of the membrane oxygen production device of the present utility model.

[0029] Among them, 1. screw air compressor, 2. compressed gas storage tank, 3. filter component one, 4. cold dryer, 5. filter component two, 6. heat exchanger, 7. membrane oxygen production device, 8. oxygen-enriched gas pressure regulating tank, 9. standby fan, 10. kiln head primary fan, 11. kiln head coal supply air fan, 12. kiln head burner, 13. nitrogen-enriched gas pressure regulating tank, 14. cement production line compressed air pipeline system. DETAILED DESCRIPTION

[0030] See also Figures 1 to 6 A positive pressure membrane air separation oxygen-enriched calcination application system for a cement production line is shown, comprising an air compressor air supply unit, a source gas processing unit, a positive pressure membrane nitrogen and oxygen separation component integrated unit, an oxygen collection and utilization unit and a nitrogen collection and utilization unit; the air compressor air supply unit, the source gas processing unit, the positive pressure membrane nitrogen and oxygen separation component integrated unit, the oxygen collection and utilization unit or the nitrogen collection and utilization unit are connected in sequence, the oxygen collection and utilization unit is connected to the kiln head burner, and the nitrogen collection and utilization unit is connected to the compressed air pipeline system 14 of the cement production line.

[0031] Furthermore, the air compressor air supply unit is used to supplement the compressed air in the cement production system when its pressure is unstable or reduced, and to supplement the compressed air of the oxygen part extracted after air separation oxygen production.

[0032] Furthermore, the source gas processing unit performs cold drying, filtering and heating treatment on the compressed air entering the positive pressure membrane nitrogen and oxygen separation component.

[0033] Furthermore, the positive pressure membrane nitrogen and oxygen separation component integrated unit is a device that uses positive pressure membrane air separation technology to separate oxygen and nitrogen in compressed air.

[0034] Furthermore, the oxygen collection and utilization unit collects and stabilizes the oxygen generated by the positive pressure membrane air separation system, and connects it to the primary fan at the kiln head of the cement rotary kiln and its backup fan air inlet through a pipeline to achieve oxygen-enriched calcination of the cement rotary kiln.

[0035] Furthermore, the nitrogen collection and utilization unit is used to collect nitrogen generated by the positive pressure membrane air separation system, and is connected to the original compressed air pipeline system of the cement production line through a pipeline to achieve nitrogen recovery and utilization.

[0036] Furthermore, the air compressor air supply unit is composed of multiple air compressor systems, and the air compressor system includes a screw air compressor 1 and a compressed gas storage tank 2.

[0037] Furthermore, the source gas processing unit is composed of a cold dryer 4, a heat exchanger 6, a filter component 1 3 and a filter component 2 5.

[0038] Furthermore, the oxygen collection and utilization unit includes an oxygen-rich gas pressure-stabilizing tank 8 and a plurality of valves.

[0039] Furthermore, the nitrogen collection and utilization unit includes a nitrogen-rich gas pressure-surge tank 13 and a plurality of valves.

[0040] Furthermore, a kiln head primary air fan 10 and a backup air fan 9 are provided between the oxygen collection and utilization unit and the kiln head burner 12, and a kiln head coal supply air fan 11 is also connected to the kiln head burner.

[0041] Furthermore, the positive pressure membrane nitrogen and oxygen separation component integrated unit includes a membrane oxygen production device 7.

[0042] Furthermore, the filter assembly 3 includes a C-level filter, a T-level filter 1 and an A-level filter 1.

[0043] Furthermore, the filter assembly 2 5 includes a T-level filter 2, an A-level filter 2 and an H-level filter.

[0044] Furthermore, the valves include multiple stop valves, electric regulating valves, check valves, electric regulating butterfly valves, flange stop valves, back pressure valves, electric proportional valves, mechanically regulated overpressure vent valves, overpressure vent valves, breathing valves, oxygen-enriched release valves and regulating valves, etc.

[0045] When the utility model is installed, the screw air compressor is connected to the compressed air pipeline system of the cement production line through a pipeline, and the pipeline connection sequence is: screw air compressor-compressed gas storage tank-C-level filter-cold dryer-T-level filter one-A-level filter one-stop valve-T-level filter two-A-level filter two-H-level filter-heat exchanger-stop valve-electric regulating butterfly valve-flange-type stop valve-membrane oxygen production device, the membrane oxygen production device separates oxygen-rich gas and nitrogen-rich gas through positive pressure membrane air separation technology, and the oxygen-rich gas and nitrogen-rich gas are operated in two routes;

[0046] Line 1: oxygen-enriched gas outlet of membrane oxygen production device - flange stop valve - oxygen-enriched gas pressure regulating tank - check valve - electric regulating butterfly valve - breathing valve - kiln head primary fan and its backup fan - kiln head burner;

[0047] Line 2: Nitrogen-rich gas outlet of membrane oxygen production device - flange stop valve - electric regulating butterfly valve - back pressure valve - electric proportional valve - nitrogen-rich gas pressure regulating tank - electric regulating valve - check valve - compressed air pipeline system of cement production line.

[0048] Furthermore, an electric regulating butterfly valve is connected between the kiln head primary fan or its backup fan and the breathing valve, and one end of the electric regulating butterfly valve is an air inlet.

[0049] Furthermore, an oxygen-rich release valve is provided between the oxygen-rich gas pressure-stabilizing tank and the regulating valve.

[0050] Furthermore, an overpressure relief valve may be provided between the electric regulating butterfly valve and the back pressure valve.

[0051] Furthermore, a manually adjustable vent flow valve is provided between the electric proportional valve and the nitrogen-rich gas pressure-stabilizing tank, and a stop valve and a mechanically adjustable overpressure vent valve are connected to the manually adjustable vent flow valve.

[0052] Furthermore, an electric regulating butterfly valve is provided between the heat exchanger and the stop valve.

[0053] The utility model uses compressed air as the gas source, undergoes cold drying treatment and two-way (three-level each) precision filtration, and then heats the treated air to 30-50°C. The heated air enters the positive pressure membrane oxygen production equipment to produce oxygen, and produces oxygen-enriched gas containing 30-45% oxygen, which is mixed with the atmosphere to output 26-32% oxygen-enriched gas as a combustion aid, achieving oxygen-enriched combustion and saving energy. The production process uses positive pressure membrane as the oxygen production technology route, oxygen-enriched combustion, and comprehensive utilization of the oxygen production byproduct - nitrogen-enriched gas.

[0054] The oxygen concentration of the oxygen-enriched gas generated by the utility model reaches more than 35%, and the pressure is not less than 0.02MPa. The air volume of the oxygen-enriched air is configured according to the actual needs of different cement production line scales. The number of positive pressure membrane groups, the pressure of the nitrogen-enriched gas generated is not less than 0.5MPa.

[0055] Advantages of the utility model:

[0056] 1. Solved the comprehensive benefits of power consumption of oxygen production system and oxygen-enriched combustion and energy saving;

[0057] 2. By pre-treating the gas source, the oxygen production efficiency of the membrane oxygen generation is kept stable at 95% without decreasing, and the service life of the membrane is guaranteed to be greater than or equal to 8 to 10 years;

[0058] 3. It solves the problem of wider adaptability of industrial kilns to coal, and inferior coal can be used to replace high calorific value coal;

[0059] 4. Solve the problem of nitrogen-rich byproduct after oxygen-rich utilization, and realize comprehensive utilization;

[0060] 5. It solves the problem that the kiln head has high requirements for the calorific value of coal, but the kiln tail is insensitive to poor coal quality. In terms of operation, the decomposition rate at the cement kiln tail can be appropriately lowered, and the coal ratio between the kiln head and the kiln tail can be adjusted to achieve fast burning of thin materials, increase production and save energy.

[0061] The oxygen concentration of the oxygen-enriched gas generated by the present invention is set according to the optimal concentration of coal powder calcination in the cement rotary kiln, and is intelligently controlled and combined by a computer control system, and the computer control system integrates the operating parameters of the membrane oxygen production device.

[0062] When the utility model is implemented:

[0063] Solution 1: According to the O2 content and flow rate required for oxygen-enriched combustion in the factory, calculate and configure the specifications of the oxygen generator (the positive pressure membrane oxygen generator is modularly manufactured, and the oxygen production demand can be easily achieved by increasing or decreasing the number of membrane groups). At the same time, according to the compressed air volume of the original air compressor station in the factory, select and add a new air compressor unit (including cold dryer and precision filter) with a flow rate greater than or equal to the oxygen flow rate of the oxygen generator to supplement the compressed air of the oxygen-enriched part extracted after oxygen production, and use the compressed air produced by the original air compressor and the new air compressor as the air source. After being processed by a cold dryer and two three-stage precision filtration processes, the compressed air is heated to 30-45°C and enters the membrane oxygen production equipment, which can produce 20-50kpa oxygen-enriched gas with an oxygen content of 37% and nitrogen-enriched gas with a N2 concentration of more than 90% and a pressure 0.05MPa lower than the source gas (still meeting the factory's compressed air use requirements), and returns to the original compressed air pipeline system for the factory to use as compressed air (can be used for bag dust collection backwash air source, instrument gas, coal powder warehouse protection gas, etc.). The oxygen-enriched gas with an O2 content of 37% is mixed with the atmosphere through the primary fan and the standby fan air inlet of the kiln (cement kiln head), and the oxygen-enriched gas with an O2 content of about 30% is output for the kiln head burner of the kiln (cement kiln head) to support combustion, achieving the energy-saving requirements of oxygen-enriched combustion.

[0064] Solution 2: When the factory compressed air does not meet the oxygen production requirements (the factory has a demand for compressed air, but the compressed air output by the original air compressor station is less than 0.55MPa pressure):

[0065] According to the O2 content and flow rate required for oxygen-enriched combustion in the factory, the specifications of the oxygen generator (the positive pressure membrane oxygen generator is modularized and can easily meet the oxygen production requirements by increasing or decreasing the number of membrane groups) and the model and specifications of the compressed air compressor unit required for oxygen production are calculated and configured. The compressed air produced by the newly added air compressor is used as the gas source. After being processed by a cold dryer and two three-level precision filtration processes, the compressed air is heated to 30-45°C and enters the membrane oxygen production equipment. It can produce 20-50kpa oxygen-enriched gas with an oxygen content of 37% and nitrogen-enriched gas with a N2 concentration of more than 90% and a pressure 0.05MPa lower than the source gas (meeting the factory's compressed air usage requirements), and then returns to the original compressed air pipeline system for the factory to use as compressed air (can be used for bag dust collection back-blowing air source, instrument gas, coal powder bunker protection gas, etc.). Under the premise of ensuring production, the factory will make choices about the start and stop of the original air compressor system unit based on the compressed air usage. The oxygen-rich gas containing 37% O2 is mixed with the atmosphere through the primary fan and the backup fan air inlet of the kiln (cement kiln head), and the oxygen-rich gas containing about 30% O2 is output for the kiln head burner of the kiln (cement kiln head) to assist combustion, thereby achieving the energy-saving requirements of oxygen-rich combustion.

[0066] The utility model realizes the circulation of compressed air, oxygen-enriched air and nitrogen-enriched air through the connection of pipelines.

[0067] The above are only specific implementations of the utility model, but the protection scope of the utility model is not limited thereto. Any changes or substitutions that are not conceived through creative work should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope defined in the claims.

Claims

1. A positive pressure membrane air separation oxygen-enriched calcination application system for cement production line, characterized by: It includes an air compressor air supply unit, a source gas processing unit, a positive pressure membrane nitrogen and oxygen separation component integrated unit, an oxygen collection and utilization unit and a nitrogen collection and utilization unit; the air compressor air supply unit, the source gas processing unit, the positive pressure membrane nitrogen and oxygen separation component integrated unit, the oxygen collection and utilization unit or the nitrogen collection and utilization unit are connected in sequence, the oxygen collection and utilization unit is connected to the kiln head burner, and the nitrogen collection and utilization unit is connected to the compressed air pipeline system of the cement production line.

2. The positive pressure membrane air separation oxygen-enriched calcination application system for cement production line according to claim 1, characterized in that: The air compressor air supply unit is used to supplement the compressed air in the cement production system when its pressure is unstable or reduced, and to supplement the compressed air extracted from the oxygen part after air separation oxygen production; The source gas processing unit performs cold drying, filtering and heating treatment on the compressed air entering the positive pressure membrane nitrogen and oxygen separation component; The positive pressure membrane nitrogen and oxygen separation component integrated unit is a device that uses positive pressure membrane air separation technology to separate oxygen and nitrogen in compressed air; The oxygen collection and utilization unit collects and stabilizes the oxygen generated by the positive pressure membrane air separation system, and connects the oxygen to the primary air inlet of the cement rotary kiln head through a pipeline to achieve oxygen-enriched calcination of the cement rotary kiln; The nitrogen collection and utilization unit is used to collect nitrogen generated by the positive pressure membrane air separation system, and is connected to the original compressed air pipeline system of the cement production line through a pipeline to achieve nitrogen recovery and utilization.

3. The positive pressure membrane air separation oxygen-enriched calcination application system for cement production line according to claim 1, characterized in that: The air compressor air supply unit is composed of multiple air compressor systems, and the air compressor system includes a screw air compressor and a compressed gas storage tank; The source gas processing unit is composed of a cold dryer, a heat exchanger, a filter component 1 and a filter component 2; The positive pressure membrane nitrogen and oxygen separation component integrated unit includes a membrane oxygen production device; The oxygen collection and utilization unit includes an oxygen-rich gas pressure-stabilizing tank and a plurality of valves; The nitrogen collection and utilization unit includes a nitrogen-rich gas pressure-surge tank and a plurality of valves; A kiln head primary air fan and a spare air fan are arranged between the oxygen collecting and utilizing unit and the kiln head burner.

4. The positive pressure membrane air separation oxygen-enriched calcination application system for cement production line according to claim 3 is characterized by: The filter assembly 1 includes a C-level filter, a T-level filter 1 and an A-level filter 1, and the filter assembly 2 includes a T-level filter 2, an A-level filter 2 and an H-level filter.

Images