Raw gas source upgrading system for internal heating type vertical furnace

Abstract

The utility model relates to a raw gas source upgrading system for an internal heating type vertical furnace. The raw gas source upgrading system comprises a dry distillation furnace, a carbon dioxide removal device and a pure oxygen preparation device, the device further comprises a first multi-stage mixer, a second multi-stage mixer, a gas sampling analysis tube and a gas component detector. Pure oxygen is adopted as a combustion improver, so that the content of nitrogen in the raw gas is greatly reduced, and the application scene of coal gasification production and deep processing of the internal heating type vertical furnace is expanded; the components of combustion-supporting gas, combustible gas and inert gas in mixed gas in a lattice wall of the dry distillation furnace are controlled by adopting double-circulation control of carbon dioxide and recirculated gas, the combustion intensity and the uniformity degree are strictly controlled under the condition that dry distillation heat supply is met, and scabbing and burning loss of a dry distillation furnace body are avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to low rank coal dry distillation technical field especially relates to a heat type vertical furnace raw coal gas source head upgrading system. BACKGROUND

[0002] The characteristics of low rank coal resources are large reserves, shallow burial and low mining cost. The geological reserves of low rank coal in the world are about 4 trillion tons, accounting for about 40% of the total coal reserves in the world. High-quality coal resources such as bituminous coal and anthracite in China have been fully utilized, and large-scale development and utilization of low rank coal has just begun.

[0003] At present, the industrial mainly uses the heat type vertical furnace to upgrade the low rank coal, realizes the utilization of low rank coal; it adopts the way of passing into the mixed gas of coal gas and air into the furnace, and carries out dry distillation of low rank coal in the furnace, the produced coal gas is large and low in quality, the content of nitrogen and other invalid components is more than 50%, this low-grade coal gas can only be sent to the power plant for combustion and power generation, and cannot be used for subsequent deep processing of chemical products.

[0004] Therefore, it is necessary to develop a reasonable low rank coal dry distillation system and method to improve the grade of dry distillation coal gas, reasonably utilize coal resources in stages, and meet the needs of producing high-calorific-value coal gas, high-efficiency purified coal tar and high-quality semicoke.

[0005] The Chinese patent application with the application publication number CN111187632A discloses a "coal gas quality separation back to the furnace inner heat type low temperature oxygen-enriched coal dry distillation process method and system", the inner heat type low temperature coal dry distillation furnace passes in dehydrogenation coal gas, air and oxygen; air and oxygen are mixed to form oxygen-enriched combustion-supporting gas, and dehydrogenation coal gas is oxygen-enriched combusted with the oxygen-enriched combustion-supporting gas in the inner heat type low temperature coal dry distillation furnace; but because the oxygen-enriched combustion intensity is intense, it will cause uneven combustion.

[0006] The Chinese invention patent with the authorization announcement number CN1966612B discloses a "low temperature coal dry distillation production process", which adopts internal combustion and internal heating heating mode and large cavity design, realizes uniform feeding, uniform heating and uniform discharging, improves single furnace output and product quality, and focuses on improving the tar yield. At the same time, the temperature control of the dry distillation process is realized by regulating the heating air and coal gas dilution ratio and regulating the total amount of heating gas, which is simple and easy to operate. But the produced raw coal gas is low in grade and contains a large amount of nitrogen, which is difficult to use for deep processing of chemical products.

[0007] A Chinese patent application with the publication number CN116515501A discloses "an electric heating dry distillation furnace with dry quenching device", which adopts indirect electric heating, combined with temperature measuring device and low-temperature carrier gas cooling device coupling control, realizes precise control of low-rank coal dry distillation heating, and improves the quality of dry distillation solid products; a dry quenching device is arranged at the lower part of the dry distillation furnace to recover heat from the dry distillation solid, and the dry quenching device uses low-temperature carrier gas as a cold source. However, due to the use of electric heating dry distillation form, the industrial production capacity cannot be expanded, and the economic benefit is low. SUMMARY

[0008] In view of the above-mentioned deficiencies of the prior art, the utility model provides a kind of inner heating type straight furnace raw coal gas source head upgrading system, using pure oxygen as combustion improver, greatly reduce the nitrogen content in raw coal gas, expand inner heating type straight furnace coal gasification production deep processing application scene;Adopt carbon dioxide and back furnace gas double circulation control, control dry distillation furnace flower wall in mixed gas combustion-supporting gas, combustible gas and inert gas component, in the case of meeting dry distillation heat supply, strictly control combustion intensity and uniformity, avoid dry distillation furnace body scab and burn loss.

[0009] In order to achieve the above purpose, the utility model adopts the following technical scheme:

[0010] An inner heating type straight furnace raw coal gas source head upgrading system, comprising a dry distillation furnace, a carbon dioxide removal device and a pure oxygen preparation device; the dry distillation furnace is sequentially provided with a feeding section, a drying section, a dry distillation section, a cooling section and a discharging section from top to bottom; the inner heating type straight furnace raw coal gas source head upgrading system further comprises a multi-stage mixer one, a multi-stage mixer two, a gas sampling and analyzing pipe and a gas component detector; a ventilation flower wall is arranged in the furnace body of the dry distillation section along the central axis, and the furnace body outside the two ends of the ventilation flower wall is respectively provided with the multi-stage mixer one and the multi-stage mixer two, and the mixed gas outlet of the multi-stage mixer one and the multi-stage mixer two extends into the ventilation flower wall of the corresponding end; the carbon dioxide inlet of the carbon dioxide removal device is connected to the raw coal gas outlet of the dry distillation furnace gas collection system through a coal gas inlet pipeline, and the coal gas inlet pipeline is provided with a raw coal gas cooling and purifying device and a coal gas fan; the coal gas inlet pipeline upstream of the carbon dioxide removal device is additionally connected to the back furnace gas inlets of the multi-stage mixer one and the multi-stage mixer two through a back furnace gas pipeline; the carbon dioxide removal device is provided with a purified coal gas outlet and a carbon dioxide outlet, wherein the carbon dioxide outlet is respectively connected to a carbon dioxide external delivery pipeline and a circulating carbon dioxide pipeline, and the circulating carbon dioxide pipeline is additionally connected to the circulating carbon dioxide inlets of the multi-stage mixer one and the multi-stage mixer two; the pure oxygen outlet of the pure oxygen preparation device is connected to the pure oxygen inlets of the multi-stage mixer one and the multi-stage mixer two through a pure oxygen pipeline; a mixed gas sampling point is arranged in the middle of the dry distillation section, the mixed gas inlet end of the gas sampling and analyzing pipe is located at the mixed gas sampling point, and the mixed gas outlet end of the gas sampling and analyzing pipe is connected to the gas component detector arranged outside the dry distillation furnace.

[0011] The multi-stage mixer one and the multi-stage mixer two are the same in structure, and are composed of coaxially arranged inner sleeve pipe, middle sleeve pipe and outer sleeve pipe; the inner sleeve pipe is provided with pure oxygen inlet, the middle sleeve pipe is provided with circulating carbon dioxide inlet, and the outer sleeve pipe is provided with back furnace gas inlet.

[0012] The back furnace gas adjusting valve is arranged on the back furnace gas pipeline, the circulating carbon dioxide adjusting valve is arranged on the circulating carbon dioxide pipeline, and the pure oxygen adjusting valve is arranged on the pure oxygen pipeline.

[0013] The feeding section of the dry distillation furnace is provided with a coal charging sealing device, the cooling section of the dry distillation furnace is provided with a semi-coke cooling device, the semi-coke cooling device is provided with a coke extinguishing cooling medium inlet, the discharging section of the dry distillation furnace is provided with a coke pusher and a scraper, and the raw gas inlet pipeline is provided with a raw gas cooling and purifying device.

[0014] Compared with the prior art, the present application has the following beneficial effects:

[0015] 1) The pure oxygen is used as a combustion-supporting agent, the nitrogen content in the raw gas is greatly reduced, and the deep processing application scene of the coal gasification of the internal heating type vertical furnace is expanded.

[0016] 2) The carbon dioxide and back furnace gas double circulation control is adopted, the combustion-supporting gas, combustible gas and inert gas components in the mixed gas in the flower wall of the dry distillation furnace are controlled, the burning intensity and uniformity are strictly controlled under the condition of meeting the dry distillation heat supply, and the scarring and burning loss of the dry distillation furnace body are avoided. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the raw gas source upgrading system of the internal heating type vertical furnace.

[0018] In the figure: 1. coal charging sealing device 2. dry distillation furnace 3. ventilation flower wall 4. multi-stage mixer one 5. multi-stage mixer two 6. semi-coke cooling device 7. coke pusher 8. scraper 9. dry distillation furnace gas collecting system 10. gas cooler 11. electric tar precipitator 12. gas fan 13. carbon dioxide removal device 14. pure oxygen preparation device 15. pure oxygen adjusting valve 16. circulating carbon dioxide adjusting valve 17. back furnace gas adjusting valve 18. gas sampling and analyzing pipe 19. gas component detector

[0019] A. raw coal B. mixed gas in flower wall C. coke extinguishing cooling medium D. semi-coke E. raw gas F. purified raw gas G. external delivery carbon dioxide removal purified gas H. external delivery carbon dioxide I. pure oxygen J. circulating carbon dioxide K. back furnace gas DETAILED DESCRIPTION

[0020] The specific implementation manner of the present application will be further described below in combination with the drawings:

[0021] As Figure 1 The utility model discloses a kind of inner heating type vertical furnace raw coal gas source head upgrading systems, including dry distillation furnace 2, carbon dioxide removal device 13 and pure oxygen preparation device 14;The dry distillation furnace is sequentially provided with feeding section, drying section, dry distillation section, cooling section and discharge section from top to bottom;The inner heating type vertical furnace raw coal gas source head upgrading system further includes multistage mixer one 4, multistage mixer two 5, gas sampling analysis pipe 18 and gas composition detector 19;A pass wall 3 is provided in the furnace body of dry distillation section along the central axis, and multistage mixer one 4 and multistage mixer two 5 are respectively provided in the furnace body outside both ends of pass wall 3, and the mixed gas outlet of multistage mixer one 4 and multistage mixer two 5 is inserted into the corresponding end pass wall 3;The carbon dioxide inlet of carbon dioxide removal device 13 is connected with the raw coal gas outlet of dry distillation furnace gas collection system 9 by coal gas inlet pipeline, and raw coal gas cooling and purification device and coal gas fan 12 are arranged on the coal gas inlet pipeline;The coal gas inlet pipeline upstream of carbon dioxide removal device 13 is additionally connected with the back furnace gas inlet of multistage mixer one 4 and multistage mixer two 5 by back furnace gas pipeline;Carbon dioxide removal device 13 is provided with purified gas outlet and carbon dioxide outlet, wherein the carbon dioxide outlet is connected with carbon dioxide external delivery pipeline and circulating carbon dioxide pipeline respectively, and the circulating carbon dioxide pipeline is additionally connected with the circulating carbon dioxide inlet of multistage mixer one 4 and multistage mixer two 5;The pure oxygen outlet of pure oxygen preparation device 14 is connected with the pure oxygen inlet of multistage mixer one 4 and multistage mixer two 5 by pure oxygen pipeline;Mixed gas sampling point is arranged in the middle of dry distillation section, the mixed gas inlet end of gas sampling analysis pipe 18 is located at the mixed gas sampling point, and the mixed gas outlet end of gas sampling analysis pipe is connected with gas composition detector 19 arranged outside dry distillation furnace.

[0022] The structure of multistage mixer one 4 and multistage mixer two 5 is same, and each is composed of inner sleeve pipe, middle sleeve pipe and outer sleeve pipe arranged coaxially;The inner sleeve pipe is provided with pure oxygen inlet, the middle sleeve pipe is provided with circulating carbon dioxide inlet, and the outer sleeve pipe is provided with back furnace gas inlet.

[0023] The back furnace gas regulating valve 17 is arranged on the back furnace gas pipeline, the circulating carbon dioxide regulating valve 16 is arranged on the circulating carbon dioxide pipeline, and the pure oxygen regulating valve 15 is arranged on the pure oxygen pipeline.

[0024] The feeding section of dry distillation furnace 2 is provided with coal loading sealing device 1;The cooling section of dry distillation furnace 2 is provided with semicoke cooling device 6, and the semicoke cooling device 6 is provided with quenching medium inlet;The discharge section of dry distillation furnace 2 is provided with coke pusher 7 and scraper 8;The raw coal gas cooling and purification device arranged on the coal gas inlet pipeline includes coal gas cooler 10 and electric tar precipitator 11.

[0025] The working process of the utility model discloses a kind of inner heating type vertical furnace raw coal gas source head upgrading system as follows:

[0026] 1) After being pre-stored by the coal charging and sealing device, the raw coal enters the dry distillation furnace. The coke discharge speed is controlled by the coke pusher at the bottom of the dry distillation furnace. After drying and dry distillation, the raw coal forms semi-coke. Multi-stage mixer I and multi-stage mixer II are set up opposite each other outside the dry distillation section of the dry distillation furnace. Pure oxygen, circulating carbon dioxide and recycled coal gas are mixed in multi-stage mixer I and multi-stage mixer II and then enter the ventilation wall inside the furnace to provide heat for the dry distillation of the raw coal. After cooling, the semi-coke is discharged from the dry distillation furnace by scraper conveyor.

[0027] 2) The gas collection system of the dry distillation furnace extracts the raw coal gas produced by the dry distillation of low-rank coal. The raw coal gas then enters the gas cooler and the electrostatic precipitator to remove ash, moisture, and tar. After being pressurized and purified by the gas blower, the raw coal gas is divided into two paths: one path is used as return coal gas and is burned in the furnace through multi-stage mixer I and multi-stage mixer II; the other path enters the carbon dioxide removal device. The purified coal gas after carbon dioxide removal is sent out for subsequent deep processing of coal gas or preparation of chemical products. The carbon dioxide removed from the raw coal gas is divided into two paths: one path is sent out as carbon dioxide product, and the other path is returned to the dry distillation furnace as circulating carbon dioxide as an inert gas. Pure oxygen extracted from the air by the pure oxygen preparation device is also sent into the dry distillation furnace simultaneously.

[0028] 3) Pure oxygen, circulating carbon dioxide, and recycled gas are each separated into two streams, which enter the inner, middle, and outer sleeves of multi-stage mixer one and multi-stage mixer two, respectively. The inner and middle sleeves achieve uniform mixing of pure oxygen and circulating carbon dioxide, while the middle and outer sleeves achieve uniform mixing of pure oxygen, circulating carbon dioxide, and recycled gas. A mixed gas sampling point is set in the middle of the ventilation wall inside the dry distillation furnace. The gas is sent to an external component detector through a gas sampling and analysis tube to analyze the concentration of oxygen, carbon dioxide, and combustible gas in the mixed gas. The flow rates of various gases are controlled based on the analysis results. The flow rate of pure oxygen is controlled by a pure oxygen regulating valve, the flow rate of circulating carbon dioxide is controlled by a circulating carbon dioxide regulating valve, and the flow rate of recycled gas is controlled by a recycled gas regulating valve.

[0029] like Figure 1 As shown, raw coal A, after being pre-stored by the coal charging and sealing device 1, enters the top of the dry distillation furnace 2. The coke discharge speed is controlled by the coke pusher 7 at the bottom of the dry distillation furnace 2. The coal passes through the drying section, the dry distillation section, and the cooling section in sequence, and finally, the semi-coke D is discharged through the scraper conveyor 8. The particle size of raw coal A is 6-30 mm, and the dry distillation temperature is controlled at 550-850℃. Multi-stage mixer 4 and multi-stage mixer 5 are respectively installed on both sides of the dry distillation section of the dry distillation furnace 2. Pure oxygen, circulating carbon dioxide, and recycled coal gas are mixed in the two multi-stage mixers and then enter the ventilation wall 3 to provide heat for the dry distillation reaction of the raw coal. The cooling section of the dry distillation furnace 2 is equipped with a semi-coke cooling device 6, which introduces a coke quenching medium C to achieve the coke quenching function.

[0030] The dry distillation furnace gas collection system 9 is connected to the raw gas outlet of the top of the dry distillation furnace 2, and the raw gas E produced by dry distillation of low-rank coal is led out of the dry distillation furnace 2. The raw gas E enters a coal gas cooler 10 and an electric tar precipitator 11 in sequence through a pipeline, and the ash, water and tar are removed. The purified raw gas outlet of the electric tar precipitator 11 is connected to a coal gas fan 12 through a pipeline, and the purified raw gas is pressurized. The pressurized purified raw gas F is divided into two routes: one route is used as the back-to-furnace gas K and is led into the multi-stage mixer 1 4 and the multi-stage mixer 2 5 for back-to-furnace combustion, and the other route is led into a carbon dioxide removal device 13 through a pipeline, and the purified coal gas G for external delivery is obtained, which is used for subsequent coal gas deep processing or chemical product preparation.

[0031] The carbon dioxide obtained after removal is divided into two routes through a pipeline: one route is the external delivery carbon dioxide H, and the other route is the circulating carbon dioxide J, which is used as inert gas and is fed into the dry distillation furnace 2. The pure oxygen I extracted from air in the pure oxygen preparation device 14 is also fed into the dry distillation furnace 2.

[0032] The pure oxygen I, the circulating carbon dioxide J and the back-to-furnace gas K are all divided into two routes and are respectively led into the inner sleeve, the middle sleeve and the outer sleeve of the multi-stage mixer 1 4 and the multi-stage mixer 2 5. The pure oxygen I and the circulating carbon dioxide J are uniformly mixed through the inner sleeve and the middle sleeve, and the pure oxygen I, the circulating carbon dioxide J and the back-to-furnace gas K are uniformly mixed through the middle sleeve and the outer sleeve. A mixed gas sampling point is arranged in the middle of the ventilation flower wall 3 in the dry distillation furnace 2, and the mixed gas is led into a gas composition detector 19 outside the furnace through a gas sampling analysis pipeline 18, and the concentrations of oxygen, carbon dioxide and combustible gas in the mixed gas in the ventilation flower wall 3 are analyzed, which are used for controlling the flow rates of various gases. The composition of the mixed gas in the ventilation flower wall 3 is controlled as follows: oxygen 5% to 10%; carbon dioxide 50% to 70%; nitrogen 1% to 2%; carbon monoxide 3% to 15%; hydrogen 3% to 15%; and methane 3% to 12%.

[0033] The flow rates of the pure oxygen I, the circulating carbon dioxide J and the back-to-furnace gas K are respectively controlled by corresponding pure oxygen regulating valves 15, circulating carbon dioxide regulating valves 16 and back-to-furnace gas regulating valves 17. The concentration of the pure oxygen in the pure oxygen preparation device is controlled at 92% to 100%, and the concentration of the circulating carbon dioxide in the carbon dioxide removal device is controlled at 92% to 100%. The composition of the back-to-furnace gas is controlled as follows: carbon dioxide 42% to 62%; nitrogen 1% to 2%; carbon monoxide 5% to 18%; hydrogen 5% to 18%; and methane 5% to 14%. The required amount of pure oxygen for dry distillation of raw coal is 80 to 120 Nm 3 / t of coal, the required amount of circulating carbon dioxide is 250 to 330 Nm 3 / t of coal, and the required amount of back-to-furnace gas is 670 to 730 Nm 3 / t of coal, and the amount of raw coal dry distillation produced raw gas is 1100 to 1400 Nm 3 / t coal; the purified coal gas amount after the carbon dioxide is sent out is 220-280 Nm 3 / t coal; the carbon dioxide amount sent out is 50-75 Nm 3 / t coal.

[0034] The above is only the preferred specific implementation of the present application, but the protection scope of the present application is not limited to this, any skilled person in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. An endothermic straight furnace raw coal gas source upgrading system, comprising a dry distillation furnace, a carbon dioxide removal device and a pure oxygen preparation device; the dry distillation furnace is sequentially provided with a feeding section, a drying section, a dry distillation section, a cooling section and a discharging section from top to bottom; characterized in that, The inner heating type vertical furnace raw coal gas source head upgrading system further comprises a multi-stage mixer one, a multi-stage mixer two, a gas sampling analysis pipe and a gas component detector; a ventilation flower wall is arranged along a central axis in the furnace body of the dry distillation section, and the multi-stage mixer one and the multi-stage mixer two are respectively arranged at both ends of the furnace body outside the ventilation flower wall, and the mixed gas outlets of the multi-stage mixer one and the multi-stage mixer two extend into the ventilation flower wall at the corresponding end; the carbon dioxide inlet of the carbon dioxide removal device is connected with the raw coal gas outlet of the dry distillation furnace gas collection system through a coal gas inlet pipeline, and the coal gas inlet pipeline is provided with a raw coal gas cooling and purification device and a coal gas fan; the coal gas inlet pipeline upstream of the carbon dioxide removal device is additionally connected with the back-to-furnace coal gas inlets of the multi-stage mixer one and the multi-stage mixer two through a back-to-furnace coal gas pipeline; the carbon dioxide removal device is provided with a purified coal gas outlet and a carbon dioxide outlet, wherein the carbon dioxide outlet is respectively connected with a carbon dioxide external delivery pipeline and a circulating carbon dioxide pipeline, and the circulating carbon dioxide pipeline is additionally connected with the circulating carbon dioxide inlets of the multi-stage mixer one and the multi-stage mixer two; the pure oxygen outlet of the pure oxygen preparation device is connected with the pure oxygen inlets of the multi-stage mixer one and the multi-stage mixer two through a pure oxygen pipeline; a mixed gas sampling point is arranged in the middle part of the dry distillation section, the mixed gas inlet end of the gas sampling analysis pipe is located at the mixed gas sampling point, and the mixed gas outlet end of the gas sampling analysis pipe is connected with the gas component detector arranged outside the dry distillation furnace.

2. The system for upgrading raw coal gas source at the source according to claim 1, characterized in that, The multi-stage mixer one and the multi-stage mixer two have the same structure and are each composed of an inner sleeve, a middle sleeve and an outer sleeve arranged coaxially; the inner sleeve is provided with a pure oxygen inlet, the middle sleeve is provided with a circulating carbon dioxide inlet, and the outer sleeve is provided with a back-to-furnace coal gas inlet.

3. The system for upgrading raw coal gas source at the source according to claim 1, characterized in that, A back-to-furnace coal gas regulating valve is arranged on the back-to-furnace coal gas pipeline, a circulating carbon dioxide regulating valve is arranged on the circulating carbon dioxide pipeline, and a pure oxygen regulating valve is arranged on the pure oxygen pipeline.

4. The system for upgrading raw coal gas source at the head of an internal heating type upright furnace according to claim 1, characterized in that, The feeding section of the dry distillation furnace is provided with a coal charging sealing device; the cooling section of the dry distillation furnace is provided with a semi-coke cooling device, and the semi-coke cooling device is provided with a coke extinguishing cooling medium inlet; the discharging section of the dry distillation furnace is provided with a coke pusher and a scraper; and the raw coal gas cooling and purification device arranged on the coal gas inlet pipeline comprises a coal gas cooler and an electric tar precipitator.

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