Oxygen-enriched combustion system of thermal oxidation type ceramic roller kiln

Abstract

The oxygen-enriched combustion system of the thermal oxidation type ceramic roller kiln is composed of an air compression unit, a membrane method oxygen making unit, a front cooling unit, a rear heating unit, a grading air distribution unit and an intelligent control system. The oxygen-enriched air is distributed to the roller kiln in the form of main combustion air and combustion-supporting air through graded air distribution and is brought into the roller kiln through waste heat of compressed air, meanwhile, the ratio of the oxygen-enriched air to fuel is automatically controlled by means of accurate regulation and control and real-time control of the intelligent control system on the electromagnetic valve and the oxygen meter, and the oxygen-enriched air is supplied to the roller kiln in the form of main combustion air and combustion-supporting air. According to the high-temperature oxygen-enriched kiln, sufficient combustion is achieved in the high-temperature oxygen-enriched environment, the heat efficiency in the kiln is improved, meanwhile, a constant and controllable high-temperature area is kept, the quality of products produced in the kiln is improved, nitric oxide generated in the combustion process is reduced, the emission reduction effect is greatly improved, meanwhile, the pollution discharge cost can be reduced, and practicability is high.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of oxygen-enriched combustion systems of hot oxygen type ceramic roller kiln, specifically belong to kiln combustion technical field. BACKGROUND

[0002] Ceramics are widely used in building decoration, industry, electronics and medicine due to their aesthetic appearance, durability, and easy cleaning. Roller kiln is the main firing equipment in the ceramic industry, which consumes a lot of energy. It is characterized by a flat passageway and continuous production with parallelly arranged sticks for conveying products. The kiln can be divided into three zones: preheating zone, firing zone and cooling zone. The temperature control during ceramic production is quite demanding. Therefore, the firing zone of the roller kiln usually has multiple burners. However, due to the lack of effective linkage mechanism in terms of air volume ratio and fuel supply, it is easy to cause insufficient combustion, low combustion efficiency, and low output efficiency of high-quality products in the kiln, which not only increases energy consumption but also increases the operating cost of enterprises.

[0003] With the approaching of the carbon peak commitment target in 2030, the ceramic industry, as a high energy-consuming industry, needs to implement low-carbon energy technology as soon as possible. Oxygen-enriched combustion technology uses oxygen-enriched air with oxygen concentration exceeding 21% for combustion, which has the advantages of reducing flue gas emission and heat loss, reducing operating cost, and effectively reducing pollutant emission. It has been preliminarily applied in industrial boilers, glass industry, and metallurgical industry. However, there is almost no related report on the successful application of oxygen-enriched combustion technology in ceramic roller kiln in China. However, research has shown that when 27% oxygen-enriched air is blown into the ceramic kiln, the energy-saving effect is better, with an energy-saving rate of about 25%. In a ceramic roller kiln with a daily output of 10,000 m 2 Using 29% oxygen-enriched air in a polished tile roller kiln can save 1157.1 tons of standard coal per year and reduce CO2 emission by about 3031.7 tons per year, which has good energy-saving and environmental benefits. Therefore, under the background of the "double carbon" policy, the utility model first proposes a hot oxygen type oxygen-enriched combustion technology to solve the problem of high energy consumption and high emission in the ceramic industry and help achieve the energy-saving and emission-reducing target of the ceramic industry. SUMMARY

[0004] To solve the above technical problems, the utility model provides an oxygen-enriched combustion system for a hot oxygen type ceramic roller kiln.

[0005] The oxygen-enriched combustion system for a hot oxygen type ceramic roller kiln of the utility model is composed of an air compression unit (1), a membrane oxygen production unit (2), a pre-cooling unit (3-1), a post-heating unit (3-2), a staged air distribution unit (4), and a smart control system (5).

[0006] Wherein: the air compression unit (1) contains air filter (101) and air compressor (102); membrane method oxygen production unit (2) is constituted by oxygen-rich generator (201), exhaust gas pumping device (202), vacuum pump (203), oxygen-rich buffer pressure stabilizing tank (204) and No. 1 oxygen meter (205); pre-cooling unit (3-1) and post-heating unit (3-2) contain pre-cooler (301) and post-heater (304), and heat conducting oil circulating pump (302) and booster fan (303) between them; the staged air distribution unit (4) contains hot oxygen main combustion air pipeline (401), oxygen-rich combustion air pipeline (402), electromagnetic valve (403), No. 1 electric stop valve (404-1), No. 2 electric stop valve (404-2), No. 3 electric stop valve (404-3), No. 4 electric stop valve (404-4), No. 5 electric stop valve (404-5), No. 6 electric stop valve (404-6) and No. 2 oxygen meter (405);

[0007] The air filter (101) is connected with the air compressor (102) through a pipeline, and then connected with the compressed air inlet of the pre-cooler (301) through a pipeline, and the compressed air outlet of the pre-cooler (301) is communicated with the oxygen-enriched generator (201) through a pipeline; the oxygen-enriched generator (201) is provided with a waste gas exhaust device (202), the oxygen-enriched air outlet of which is connected with the vacuum pump (203) through a pipeline, and then connected with the inlet of the oxygen-enriched buffer pressure stabilizing tank (204); the outlet of the oxygen-enriched buffer pressure stabilizing tank (204) is connected with the booster fan (303) through a pipeline; the outlet of the booster fan (303) is communicated with the inlet of the No. 4 electric stop valve (404-4) and the booster oxygen-enriched air inlet of the post-heater (304) through a pipeline; the heat conducting oil inlet of the pre-cooler (301) is communicated with the outlet of the heat conducting oil circulating pump (302) through a pipeline, the inlet of the heat conducting oil circulating pump (302) is communicated with the heat conducting oil outlet of the post-heater (304) through a pipeline, and the heat conducting oil inlet of the post-heater (304) is communicated with the heat conducting oil outlet of the pre-cooler (301) through a pipeline; the outlet of the No. 4 electric stop valve (404-4) is communicated with the inlets of the No. 5 electric stop valve (404-5) and the No. 6 electric stop valve (404-6) through an oxygen-enriched combustion-supporting air pipeline (402), wherein the outlets of the No. 5 electric stop valve (404-5) and the No. 6 electric stop valve (404-6) are respectively communicated with two oxygen-enriched combustion-supporting air inlets corresponding to the left and right sides of the front end region of the roller kiln firing belt through pipelines; the booster oxygen-enriched air outlet of the post-heater (304) is communicated with the inlet of the No. 1 electric stop valve (404-1) through a hot oxygen main combustion air pipeline (401); the outlet of the No. 1 electric stop valve (404-1) is communicated with the inlets of the No. 2 electric stop valve (404-2) and the No. 3 electric stop valve (404-3) through a pipeline, wherein the outlets of the No. 2 electric stop valve (404-2) and the No. 3 electric stop valve (404-3) are respectively communicated with the inlets of eight solenoid valves (403) symmetrically distributed on the left and right sides of the roller kiln firing belt through pipelines; the outlets of the eight solenoid valves (403) are respectively communicated with eight hot oxygen main combustion air inlets symmetrically distributed on the left and right sides of the roller kiln firing belt through pipelines; eight No. 2 oxygen meters (405) are symmetrically distributed on the left and right sides of the roller kiln firing belt; the intelligent control system (5) is connected with the automatic control electric elements of the air compression unit (1), the membrane oxygen generation unit (2), the pre-cooling unit (3-1), the post-heating unit (3-2) and the staged air distribution unit (4) through control lines to control the oxygen-enriched combustion state of the roller kiln.

[0008] The heat conducting oil circulating pump (302) is arranged between the pipelines connected between the pre-cooler (301) and the post-heater (304).

[0009] The oxygen content meter (205) is arranged on a pipeline between the oxygen-rich buffer pressure tank (204) and the booster fan (303).

[0010] The utility model discloses the beneficial effect:

[0011] The air compression unit compresses air and delivers the compressed air to the membrane method oxygen production unit, prepares oxygen-rich air of the oxygen concentration required for combustion, and finally distributes the oxygen-rich air to the air inlets of the burners of the roller kiln and the front end region of the firing zone of the roller kiln in the form of main combustion air and combustion-supporting air through the staged air distribution unit. The heat generated in the air compression process is used to heat the oxygen-rich air, so that the waste heat of the compressed air is brought into the roller kiln to improve the combustion efficiency. In the staged air distribution unit, the hot oxygen main combustion air pipeline and the oxygen-rich combustion-supporting air pipeline are used to perform staged air distribution on the ceramic roller kiln, the heated high-temperature oxygen-rich air is distributed to the air inlets of the burners on demand through the hot oxygen main combustion air pipeline, and the electromagnetic valves on the branch air pipes are designed in linkage with the oxygen content meters corresponding to the burners on the roller kiln, so that accurate regulation and real-time control of the air volume of each burner are realized, which is beneficial to improving the thermal efficiency in the kiln while maintaining a constant controllable high-temperature region, thereby improving the product quality in the kiln; the oxygen-rich air flow of each burner is regulated in real time according to the combustion condition in the roller kiln to accurately control the ratio of oxygen-rich air to fuel, so that the excess air coefficient is maximally reduced while the firing temperature required is ensured, thereby reducing nitrogen oxides generated in the combustion process, greatly improving the emission reduction effect, and reducing the pollution control cost. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 : The utility model discloses a hot oxygen type ceramic roller kiln oxygen-enriched combustion system subunit division schematic view;

[0013] Figure 1 Middle: 1, air compression unit;2, membrane method oxygen production unit;3-1, pre-cooling unit;3-2, post-heating unit;4, staged air distribution unit;5, intelligent control system;

[0014] Figure 2 : The utility model discloses a hot oxygen type ceramic roller kiln oxygen-enriched combustion system flow chart;

[0015] Figure 2Air filter 101, air compressor 102, oxygen-rich generator 201, exhaust gas extraction device 202, vacuum pump 203, oxygen-rich buffer stabilizing tank 204, oxygen content meter 205, pre-cooler 301, heat-conducting oil circulating pump 302, booster fan 303, post-heater 304, hot oxygen main combustion air pipeline 401, oxygen-rich combustion-supporting air pipeline 402, electromagnetic valve 403, No. 1 electrically-operated stop valve 404-1, No. 2 electrically-operated stop valve 404-2, No. 3 electrically-operated stop valve 404-3, No. 4 electrically-operated stop valve 404-4, No. 5 electrically-operated stop valve 404-5, No. 6 electrically-operated stop valve 404-6, and No. 2 oxygen content meter 405. DETAILED DESCRIPTION

[0016] Example 1

[0017] The oxygen-rich combustion system of the hot oxygen type ceramic roller kiln comprises an air compression unit (1), a membrane method oxygen production unit (2), a pre-cooling unit (3-1), a post-heating unit (3-2), a staged air distribution unit (4), and an intelligent control system (5);

[0018] The air compression unit (1) comprises an air filter (101) and an air compressor (102); the membrane method oxygen production unit (2) comprises an oxygen-rich generator (201), an exhaust gas extraction device (202), a vacuum pump (203), an oxygen-rich buffer stabilizing tank (204), and a No. 1 oxygen content meter (205); the pre-cooling unit (3-1) and the post-heating unit (3-2) comprise a pre-cooler (301) and a post-heater (304), and a heat-conducting oil circulating pump (302) and a booster fan (303) therebetween; the staged air distribution unit (4) comprises a hot oxygen main combustion air pipeline (401), an oxygen-rich combustion-supporting air pipeline (402), an electromagnetic valve (403), a No. 1 electrically-operated stop valve (404-1), a No. 2 electrically-operated stop valve (404-2), a No. 3 electrically-operated stop valve (404-3), a No. 4 electrically-operated stop valve (404-4), a No. 5 electrically-operated stop valve (404-5), a No. 6 electrically-operated stop valve (404-6), and a No. 2 oxygen content meter (405);

[0019] The air filter (101) is connected with the air compressor (102) through the pipeline, and then connected with the compressed air inlet of the pre-cooler (301) through the pipeline. The compressed air outlet of the pre-cooler (301) is communicated with the oxygen-enriching generator (201) through the pipeline. The oxygen-enriching generator (201) is provided with a waste gas exhaust device (202), and the oxygen-enriched air outlet is connected with the vacuum pump (203) through the pipeline, and then connected with the inlet of the oxygen-enriched buffer pressure stabilizing tank (204). The outlet of the oxygen-enriched buffer pressure stabilizing tank (204) is connected with the booster fan (303) through the pipeline. The outlet of the booster fan (303) is communicated with the inlet of the No. 4 electric stop valve (404-4) and the pressurized oxygen-enriched air inlet of the post-heater (304) through the pipeline. The heat conducting oil inlet of the pre-cooler (301) is communicated with the outlet of the heat conducting oil circulating pump (302) through the pipeline. The inlet of the heat conducting oil circulating pump (302) is communicated with the heat conducting oil outlet of the post-heater (304) through the pipeline. The heat conducting oil inlet of the post-heater (304) is communicated with the heat conducting oil outlet of the pre-cooler (301) through the pipeline. The outlet of the No. 4 electric stop valve (404-4) is communicated with the inlets of the No. 5 electric stop valve (404-5) and the No. 6 electric stop valve (404-6) through the oxygen-enriched combustion-supporting air pipeline (402). The outlet of the No. 5 electric stop valve (404-5) and the outlet of the No. 6 electric stop valve (404-6) are respectively communicated with the two oxygen-enriched combustion-supporting air inlets on the left and right sides of the front end region of the roller kiln firing zone through the pipeline. The pressurized oxygen-enriched air outlet of the post-heater (304) is communicated with the inlet of the No. 1 electric stop valve (404-1) through the hot oxygen main combustion air pipeline (401). The outlet of the No. 1 electric stop valve (404-1) is communicated with the inlets of the No. 2 electric stop valve (404-2) and the No. 3 electric stop valve (404-3) through the pipeline. The outlet of the No. 2 electric stop valve (404-2) and the outlet of the No. 3 electric stop valve (404-3) are respectively communicated with the inlets of the eight solenoid valves (403) distributed symmetrically on the left and right sides of the roller kiln firing zone through the pipeline. The outlets of the eight solenoid valves (403) are respectively communicated with the eight hot oxygen main combustion air inlets distributed symmetrically on the left and right sides of the roller kiln firing zone through the pipeline. Eight No. 2 oxygen meters (405) are symmetrically distributed on the left and right sides of the roller kiln firing zone. The intelligent control system (5) is connected with the automatic control electric elements of the air compression unit (1), the membrane oxygen generation unit (2), the pre-cooling unit (3-1), the post-heating unit (3-2) and the staged air distribution unit (4) through control lines, so as to control the oxygen-enriched combustion state of the roller kiln.

[0020] The heat conducting oil circulating pump (302) is arranged between the pipeline connecting the pre-cooler (301) and the post-heater (304). The No. 1 oxygen meter (205) is arranged on the pipeline between the oxygen-enriched buffer pressure stabilizing tank (204) and the booster fan (303).

[0021] Embodiment 2

[0022] The air compression unit (1) of the hot oxygen type ceramic roller kiln oxygen-enriched combustion system is connected with the oxygen-enriched heating unit (3), is used for compressing air, and obtains compressed air; and the oxygen-enriched heating unit (3) is used for cooling and recovering heat of the high-temperature compressed air, so that the temperature of the compressed air is reduced to the optimal temperature required for oxygen production.

[0023] The membrane method oxygen production unit (2) and the oxygen-enriched heating unit (3) are used for producing oxygen-enriched air by using the cooled compressed air, and the oxygen-enriched air produced by the membrane method oxygen production unit (2) is heated by using the heat recovered based on the oxygen-enriched heating unit (3), so as to obtain high-temperature oxygen-enriched air.

[0024] The staged air distribution unit (4) is connected with the oxygen-enriched heating unit (3), a low-temperature oxygen-enriched combustion-supporting air is led out before oxygen enrichment and heating, and is directly introduced into the terminal area of the roller kiln firing section through the oxygen-enriched combustion-supporting air pipeline, so as to adjust the oxygen concentration in the terminal environment; the hot oxygen main combustion air from the oxygen-enriched heating unit (3) is distributed to the air inlets of the burners on the left and right sides of the roller kiln through the pipeline in two ways, and the oxygen content meter is used to measure the data and the electromagnetic valve is used to realize real-time regulation and control of the oxygen-enriched air flow of each burner, so as to realize the purpose of staged air distribution, improve the thermal efficiency of the roller kiln, and reduce the production of nitrogen oxides in the flue gas.

[0025] The air compression unit (1) comprises an air filter (101), an air compressor (102), a membrane method oxygen production unit (2), an oxygen-enriched heating unit (3) and a staged air distribution unit (4).

[0026] The air filter (101) is used for preliminarily filtering the air entering the air compressor, and the filtered clean air enters the air compressor again.

[0027] The air compressor (102) is connected with the air filter (101), is used for compressing the preliminarily filtered air, and obtains compressed air; specifically, the air is pressurized to the pressure required for membrane method oxygen production, and in this process, the air temperature is also increased to 180±5℃, in order to meet the temperature of the compressed air required for membrane method oxygen production, the high-temperature compressed air produced by the air compressor (102) also needs to be cooled and cooled.

[0028] The membrane method oxygen production unit (2) comprises an oxygen-enriched generator (201), an oxygen-enriched compressor (202), an oxygen-enriched cooler (203) and an oxygen-enriched air pipeline (204).

[0029] The oxygen-enriched generator (201) is used for separating or enriching specific components of oxygen and other gases in the air under the action of pressure difference, so that the gas with a high permeation rate (such as oxygen) is enriched on the permeation side of the membrane, and the gas with a low permeation rate (such as nitrogen) is retained on the retention side of the membrane.

[0030] The exhaust gas extraction device (202) is used to extract the nitrogen enriched on the membrane side during the production of oxygen-rich air by the oxygen-rich air generator.

[0031] The vacuum pump (203) is connected to the exhaust end of the oxygen-rich air generator (201) through a pipeline to create a low-pressure environment for the output side of the oxygen-rich air generator (201).

[0032] The oxygen-rich air buffer pressure stabilizing tank (204) is used to buffer oxygen-rich air and stabilize the pressure of the oxygen-rich air in the pipeline of the entire system.

[0033] The No. 1 oxygen content meter (205) is used to monitor the oxygen content in the oxygen-rich air output from the oxygen-rich air buffer pressure stabilizing tank (204).

[0034] The oxygen-rich air heating unit (3):

[0035] The pre-cooler (301) is connected to the output end of the air compression unit (1) and is used to cool and recover the heat of the high-temperature compressed air generated by the air compression unit (1) to reduce its temperature to the optimal temperature required by the oxygen generation system.

[0036] The heat conducting oil circulating pump (302) is used to provide circulating power for the heat conducting oil in the pre-cooler and the post-cooler.

[0037] The booster fan (303) provides positive pressure for the oxygen-rich air entering the unit (4) to increase the flow rate of the oxygen-rich air in the pipeline.

[0038] The post-heater (304) is connected to the output end of the membrane method oxygen generation unit (2) and uses the heat of the compressed air absorbed by the pre-cooler (301) to heat the oxygen-rich air with an oxygen concentration of 29±1% produced by the membrane method oxygen generation unit (2) and supply it to each burner on the roller kiln in the form of hot oxygen to improve the combustion efficiency in the roller kiln.

[0039] The staged air distribution unit (4):

[0040] The hot oxygen main combustion air pipeline (401) is connected to the output end of the post-heater (304) to distribute the heated oxygen-rich air to the air inlets of each burner on the roller kiln as needed.

[0041] The oxygen-rich combustion-supporting air pipeline (402) is connected to the input end of the post-heater (304) and is used to directly deliver part of the oxygen-rich air without heating from the oxygen-rich combustion-supporting air pipeline (402) to the front end region of the firing zone of the roller kiln to make the region in an oxygen-rich environment and fully burn the unburned fuel in the flue gas.

[0042] The electromagnetic valve (403) is used to adjust the primary air flow into the burner of the roller kiln.

[0043] The No. 1 electrically operated stop valve (404-1) and the No. 6 electrically operated stop valve (404-6) are used to control the flow of oxygen-enriched air in each branch of the staged air distribution system.

[0044] The No. 2 oxygen content meter (405) is used to detect the oxygen concentration in the flue gas in the vicinity of each burner in the roller kiln.

[0045] The intelligent control system (5):

[0046] The intelligent control system (5) is connected with the No. 1 oxygen content meter (205), the electromagnetic valve (403), the No. 1 electrically operated stop valve (404-1), the No. 6 electrically operated stop valve (404-6), and the No. 2 oxygen content meter (405), and is used to monitor the oxygen concentration in the oxygen-enriched air produced by the membrane method oxygen production unit (2) and the oxygen concentration in the flue gas in the vicinity of each burner in the roller kiln in real time, so as to adjust the oxygen concentration of the oxygen-enriched air produced by the membrane method oxygen production unit according to the real-time oxygen concentration, and to adjust the flow of oxygen-enriched air into each burner, so that the firing zone inside the roller kiln is always in the best oxygen-enriched combustion condition. In addition, the intelligent control system is also connected with the air compressor (102), the vacuum pump (203), and the heat conduction oil circulating pump (302), and by adjusting the output of the air compressor (102) and the vacuum pump (203), the pressure difference on both sides of the oxygen-enriched generator (201) is controlled, and then the oxygen concentration in the oxygen-enriched air is adjusted; according to the pressure of the compressed air produced by the air compressor (102), the output of the heat conduction oil circulating pump (302) is adjusted in real time, so as to control the heat exchange efficiency of the oxygen-enriched heating system, so that the system heat exchange efficiency is at the best level.

[0047] Example 3

[0048] The operation process of the hot oxygen type ceramic roller kiln oxygen-enriched combustion system:

[0049] The air passes through the air compression unit (1), the membrane method oxygen production unit (2), the pre-cooling unit (3-1), the post-heating unit (3-2), and the staged air distribution unit (4) in turn, and the heat generated by the air compression unit (1) is collected and then reheated into the main combustion air of the kiln by using the oxygen-enriched heating unit between the air compression unit (1) and the staged air distribution unit (4). In addition, a part of the oxygen-enriched air produced by the membrane method oxygen production unit (2) is directly introduced into the oxygen-enriched combustion air pipeline before heating, so as to provide an oxygen-enriched environment for the front end region of the firing zone of the roller kiln, and the residual fuel in the flue gas can be fully combusted. The other part of the oxygen-enriched air after being heated by the post-heating unit (3-2) enters the burners on both sides of the roller kiln through the hot oxygen main combustion air pipeline, and the flow of oxygen-enriched air into each burner is adjusted by using the electromagnetic valve, so as to improve the efficiency of the staged air distribution and the hot oxygen type oxygen-enriched combustion, thereby improving the utilization rate of fuel and the combustion efficiency of the roller kiln. The specific implementation process of each unit is as follows:

[0050] The compressed air unit (1) is connected with the pre-cooling unit (3-1) and the post-heating unit (3-2):

[0051] The air is preliminarily filtered by the air filter (101) and then enters the air compressor (102) for compression. Since the air compressor (102) needs to compress the atmospheric pressure, the temperature of the compressed air will be increased. The pre-cooler (301) is used to cool the high-temperature compressed air at the outlet of the air compressor (102) and recover the heat. At this time, the high-temperature compressed air at 180±5℃ exchanges heat with the heat-conducting oil at 50±5℃, so that the temperature of the compressed air entering the oxygen-enriched generator (201) is maintained at the optimum temperature required by the membrane oxygen production process. The temperature of the heat-conducting oil after heat exchange is increased to 170±5℃, which enters the post-heater (304) through the heat-conducting oil circulating pump (302) and exchanges heat with the oxygen-enriched air at 25±5℃ pressurized by the booster fan (303), so that the temperature of the oxygen-enriched air entering the combustor is increased to 125±5℃. At this time, the temperature of the heat-conducting oil after heat exchange is reduced to 50±5℃, which is again delivered to the pre-cooler (301) by the heat-conducting oil circulating pump (302), thereby completing a heat exchange cycle.

[0052] The membrane oxygen production unit (2):

[0053] The compressed air cooled to 40±5℃ by the pre-cooler (301) enters the oxygen-enriched generator from the inlet pipe. At this time, the vacuum pump (203) at the outlet of the oxygen-enriched generator creates a low-pressure environment at the outlet pipe of the oxygen-enriched generator, so that a large pressure difference is formed on both sides of the gas permeation membrane in the oxygen-enriched generator. The compressed air passes through the gas permeation membrane through the processes of adsorption-dissolution-diffusion-desorption, and is enriched on the other side of the membrane. Since the oxygen molecules and nitrogen molecules in the air have different permeation rates in the gas permeation membrane, the amount of oxygen molecules passing through the membrane per unit time is more than that of nitrogen molecules, so the oxygen concentration of the air enriched on the other side of the membrane is higher than that of the air before permeation. The oxygen concentration of the oxygen-enriched air can be adjusted by adjusting the pressure difference on both sides of the gas permeation membrane, and the adjustable range is generally between 25% and 35%. The oxygen-enriched air produced is temporarily stored in the oxygen-enriched buffer tank (204), and the waste gas generated during the production of the oxygen-enriched generator (201) is discharged into the atmosphere by the waste gas exhaust device (202).

[0054] The staged air distribution unit (4):

[0055] The oxygen-enriched air with oxygen concentration of 29±1% prepared by the membrane method oxygen unit (2) is pressurized by the booster fan (303) and then enters the roller kiln in two ways. One way of the oxygen-enriched air is directly delivered to the combustion air inlet on both sides of the roller kiln through the combustion air pipeline without heat exchange of the post-heater (304). The combustion air inlet is located at the front end of the firing zone of the roller kiln in the form of an opening in the kiln body to directly deliver the oxygen-enriched air to the front end area of the firing zone, creating an oxygen-rich environment at the front end of the firing zone to further burn the unburned fuel in the flue gas and improve the overall thermal efficiency of the kiln. The other way of the oxygen-enriched air is heated by the post-heater (304) to a temperature of 125±5°C. At this time, the high-temperature hot oxygen air is delivered to the air inlet of each burner on both sides of the roller kiln through the hot oxygen main combustion air pipeline. Each hot oxygen main combustion air pipeline branch is uniformly controlled by the solenoid valve (403) before entering the burner to regulate the flow of oxygen-enriched air in each branch. The opening of the solenoid valve (403) corresponding to each burner is adjusted according to the real-time monitoring data of the oxygen meter (405) near each burner of the roller kiln, so that the combustion efficiency of each part of the firing zone of the roller kiln reaches the optimal level.

Claims

1. An oxygen-rich combustion system for a hot-oxygen ceramic roller hearth kiln, characterized by: The oxygen-enriched combustion system is composed of an air compression unit (1), a membrane oxygen production unit (2), a pre-cooling unit (3-1), a post-heating unit (3-2), a staged air distribution unit (4) and an intelligent control system (5); The air compression unit (1) comprises an air filter (101) and an air compressor (102); the membrane oxygen production unit (2) is composed of an oxygen-enriched generator (201), a waste gas exhaust device (202), a vacuum pump (203), an oxygen-enriched buffer stabilizing tank (204) and a No. 1 oxygen meter (205); the pre-cooling unit (3-1) and the post-heating unit (3-2) comprise a pre-cooler (301) and a post-heater (304), a heat-conducting oil circulating pump (302) and a booster fan (303) therebetween; the staged air distribution unit (4) comprises a hot oxygen main combustion air pipeline (401), an oxygen-enriched combustion air pipeline (402), an electromagnetic valve (403), a No. 1 electric stop valve (404-1), a No. 2 electric stop valve (404-2), a No. 3 electric stop valve (404-3), a No. 4 electric stop valve (404-4), a No. 5 electric stop valve (404-5), a No. 6 electric stop valve (404-6) and a No. 2 oxygen meter (405); The air compression unit (1) comprises an air filter (101) and an air compressor (102); the membrane oxygen production unit (2) is composed of an oxygen-enriched generator (201), a waste gas exhaust device (202), a vacuum pump (203), an oxygen-enriched buffer stabilizing tank (204) and a No. 1 oxygen meter (205); the pre-cooling unit (3-1) and the post-heating unit (3-2) comprise a pre-cooler (301) and a post-heater (304), a heat-conducting oil circulating pump (302) and a booster fan (303) therebetween; the staged air distribution unit (4) comprises a hot oxygen main combustion air pipeline (401), an oxygen-enriched combustion air pipeline (402), an electromagnetic valve (403), a No. 1 electric stop valve (404-1), a No. 2 electric stop valve (404-2), a No. 3 electric stop valve (404-3), a No. 4 electric stop valve (404-4), a No. 5 electric stop valve (404-5), a No. 6 electric stop valve (404-6) and a No. 2 oxygen meter (405); The air filter (101) is connected with the air compressor (102) through a pipeline, and then connected with the compressed air inlet of the pre-cooler (301) through a pipeline. The compressed air outlet of the pre-cooler (301) is communicated with the oxygen-enriched generator (201) through a pipeline. The oxygen-enriched generator (201) is provided with a waste gas exhaust device (202), and the oxygen-enriched air outlet thereof is connected with the vacuum pump (203) through a pipeline and then connected with the inlet of the oxygen-enriched buffer pressure stabilizing tank (204). The outlet of the oxygen-enriched buffer pressure stabilizing tank (204) is connected with the booster fan (303) through a pipeline. The outlet of the booster fan (303) is communicated with the inlet of the No. 4 electric stop valve (404-4) and the pressurized oxygen-enriched air inlet of the post-heater (304) through a pipeline. The heat conducting oil inlet of the pre-cooler (301) is communicated with the outlet of the heat conducting oil circulating pump (302) through a pipeline. The inlet of the heat conducting oil circulating pump (302) is communicated with the heat conducting oil outlet of the post-heater (304) through a pipeline. The heat conducting oil inlet of the post-heater (304) is communicated with the heat conducting oil outlet of the pre-cooler (301) through a pipeline. The outlet of the No. 4 electric stop valve (404-4) is communicated with the inlets of the No. 5 electric stop valve (404-5) and the No. 6 electric stop valve (404-6) through an oxygen-enriched combustion-supporting air pipeline (402). The outlet of the No. 5 electric stop valve (404-5) and the outlet of the No. 6 electric stop valve (404-6) are respectively communicated with two oxygen-enriched combustion-supporting air inlets corresponding to the left and right sides of the front end region of the roller kiln firing belt through a pipeline. The pressurized oxygen-enriched air outlet of the post-heater (304) is communicated with the inlet of the No. 1 electric stop valve (404-1) through a hot oxygen main combustion air pipeline (401). The outlet of the No. 1 electric stop valve (404-1) is communicated with the inlets of the No. 2 electric stop valve (404-2) and the No. 3 electric stop valve (404-3) through a pipeline. The outlet of the No. 2 electric stop valve (404-2) and the outlet of the No. 3 electric stop valve (404-3) are respectively communicated with the inlets of eight solenoid valves (403) symmetrically distributed on the left and right sides of the roller kiln firing belt through a pipeline. The outlets of the eight solenoid valves (403) are respectively communicated with eight hot oxygen main combustion air inlets symmetrically distributed on the left and right sides of the roller kiln firing belt through a pipeline. Eight No. 2 oxygen meters (405) are symmetrically distributed on the left and right sides of the roller kiln firing belt. The intelligent control system (5) is connected with the automatic control electric elements of the air compression unit (1), the membrane oxygen generation unit (2), the pre-cooling unit (3-1), the post-heating unit (3-2) and the staged air distribution unit (4) through control lines to control the oxygen-enriched combustion state of the roller kiln.

2. The oxygen-rich combustion system of a hot-oxygen ceramic roller hearth kiln according to claim 1, characterized in that: The heat conducting oil circulating pump (302) is arranged between the pipeline connecting the pre-cooler (301) and the post-heater (304).

3. The oxygen-rich combustion system of a hot-oxygen ceramic roller hearth kiln according to claim 1, characterized in that: The No. 1 oxygen meter (205) is arranged on the pipeline between the oxygen-enriched buffer pressure stabilizing tank (204) and the booster fan (303).

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