Low-energy-consumption system for reducing coke burning loss of dry quenching furnace

Abstract

The utility model relates to the technical field of dry quenching, and provides a low-energy-consumption system for reducing coke burning loss of a dry quenching furnace, the system comprises a dry quenching furnace, a primary dust remover, a waste heat boiler, a secondary dust remover and a circulating fan which are connected in sequence, and an air induced draft fan is arranged on a first pipeline between the dry quenching furnace and the primary dust remover; the second pipeline between the circulating fan and the dry quenching furnace is connected with a first circulating pipeline, the first circulating pipeline is connected with the air inlet end of the dry quenching furnace, and an air inducing device, a removing unit and a drying and dehumidifying unit are sequentially arranged on the first circulating pipeline; the first circulating pipeline between the drying and dehumidifying unit and the dry quenching furnace is connected with a branch pipe, the branch pipe is connected with the air inlet end of the air induced draft fan, and the removal unit at least can remove carbon dioxide in the circulating gas. By reducing the content of carbon dioxide at the inlet of the dry quenching furnace, the carbon solution reaction between carbon dioxide at the cooling section and coke is reduced, the burn-out rate of coke is effectively reduced, the discharge amount of circulating gas is reduced, and pollution is reduced.

Description

Technical Field

[0001] This application belongs to the technical field of coke dry quenching, and more specifically, it relates to a system for reducing coke burn - loss in a coke dry - quenching furnace with low energy consumption. Background Art

[0002] Due to the characteristics of high energy - saving efficiency, advanced technology, and environmental protection of the coke dry - quenching system, in recent years, with the increasingly strict environmental supervision and the improvement of the independent R & D capabilities of domestic enterprises, the number of coke dry - quenching devices in China has gradually increased, and the dry - quenching capacity has been steadily improved.

[0003] In the process of coke dry - quenching production, the dry - quenching circulating gas exchanges heat counter - currently with the very hot red coke in the cooling section of the coke dry - quenching furnace. The cooled dry - quenched coke passes through the dry - quenching discharge device and is transported to the subsequent coke conveying system. The heated dry - quenching circulating gas enters the primary dust collector for dust removal, and then heat is recovered in the dry - quenching waste heat boiler, and the boiler generates high - temperature and high - pressure steam. Then the cooled low - temperature dry - quenching circulating gas enters the secondary dust collector from the bottom of the boiler, and the low - temperature dry - quenching circulating gas re - enters the coke dry - quenching furnace through the dry - quenching gas circulating fan, forming a dry - quenching gas circulation system.

[0004] In the dry - quenching gas circulation system, the main component of the circulating gas flowing in a cycle is N2 (the proportion of nitrogen is about 70%), and there are also components such as carbon dioxide, carbon monoxide, oxygen, hydrogen, and water vapor. The coke dry - quenching furnace is a device for cooling incandescent red coke. During the coke dry - quenching production process, the components of combustible gases (hydrogen and carbon monoxide) in the circulating gas will gradually increase. It is necessary to control the components of flammable and explosive gases below the standard value. Therefore, during the production process, a small amount of air needs to be introduced to burn off the excess flammable gases so that the circulating gas can flow safely and stably.

[0005] When the circulating gas passes through the hot coke layer, under high - temperature conditions, a series of complex chemical reactions will occur between CO2, O2, H2, H2O in the circulating gas and the hot coke C, resulting in the loss of coke and carbon powder in the coke dry - quenching furnace, that is, the coke burn - loss in coke dry - quenching.

[0006] However, traditional coke dry - quenching processes such as Figure 1 shown, including a coke dry - quenching furnace a, a primary dust collector b, a waste heat boiler c, a secondary dust collector d, a circulating fan e, and an air induced - draft fan f. During its circulation process, it is necessary to introduce part of the new air through the air induced - draft fan f to burn off part of the combustible gas, then recover heat through the waste heat boiler c, and the circulating gas then returns to the coke dry - quenching furnace a. In the coke dry - quenching furnace a, carbon melting reactions occur between the red coke and O2, H2O, and CO2 in the circulating gas, resulting in the burn - loss of about 2% of the coke. At the same time, in order to maintain the pressure balance in the system, the circulating gas in the coke dry - quenching furnace will continuously discharge the circulating gas during the process of supplementing air for circulation. The CO2, SO2, and particulate pollutants contained in the waste gas will cause air pollution. Summary of the Invention

[0007] Aiming at the deficiencies of the above-mentioned prior art, the purpose of the embodiments of the present application is to provide a system for reducing coke burn loss in a coke dry quenching furnace with low energy consumption, which is used to reduce the content of carbon dioxide and water in the circulating gas, thereby effectively reducing the coke burn loss rate.

[0008] To achieve the above purpose, the technical solution adopted by the present application is: to provide a system for reducing coke burn loss in a coke dry quenching furnace with low energy consumption, including: a coke dry quenching furnace, a primary dust collector, a waste heat boiler, a secondary dust collector, and a circulating fan connected in sequence. An air induced draft fan is provided on the first pipeline between the gas outlet end of the coke dry quenching furnace and the primary dust collector. The gas outlet end of the circulating fan is connected to the gas inlet end of the coke dry quenching furnace through a second pipeline. A first circulating pipeline is connected to the second pipeline. The first circulating pipeline is connected to the gas inlet end of the coke dry quenching furnace. An air guiding device, a removal unit, and a drying and dehumidifying unit are sequentially provided on the first circulating pipeline; a branch pipe is connected to the first circulating pipeline between the drying and dehumidifying unit and the coke dry quenching furnace through a three-way interface. The branch pipe is connected to the gas inlet end of the air induced draft fan, and the removal unit can at least remove carbon dioxide in the circulating gas.

[0009] In one embodiment, the removal unit is an integrated carbon dioxide, sulfur dioxide, and dust removal tower. The gas phase outlet of the integrated carbon dioxide, sulfur dioxide, and dust removal tower is connected to the drying and dehumidifying unit. A second circulating pipeline is provided between the liquid phase outlet and the liquid phase inlet of the integrated carbon dioxide, sulfur dioxide, and dust removal tower. The gas inlet end of the removal unit is lower than the gas phase outlet and the liquid phase inlet; a rich liquid pump, an absorption liquid regenerator, a pressure filtration pump, a solid-liquid separation device, an absorption liquid buffer tank, and a lean liquid pump are sequentially provided on the second circulating pipeline; carbide slag is added to the absorption liquid regenerator, and strong alkali solution is added to the absorption liquid buffer tank.

[0010] In one embodiment, at least two absorption liquid regenerators are arranged in parallel, and a carbide slag input port is provided on the absorption liquid regenerator.

[0011] In one embodiment, the solid-liquid separation device is a plate and frame filter press, a belt filter press, or a centrifugal dewatering machine.

[0012] In one embodiment, the drying and dehumidifying unit adopts a condensation dehumidification device, an adsorption dehumidification device, a contact reaction dehumidification device with calcium oxide / calcium chloride, or a centrifugal dehumidification device.

[0013] In one embodiment, a first flow meter and a first control valve are provided on the branch pipe.

[0014] In one embodiment, a second flow meter and a second control valve are provided on the first circulating pipeline between the three-way interface and the coke dry quenching furnace.

[0015] In one embodiment, the removal of carbon dioxide in the removal unit adopts the organic amine absorption method, the alkali solution absorption method, the pressure swing absorption method or the membrane separation method.

[0016] In one embodiment, the gas flow rate in the first circulation pipeline is 1%-50% of the gas flow rate in the second pipeline.

[0017] In one embodiment, the gas flow rate in the branch pipe is 10%-30% of the gas flow rate in the first circulation pipeline

[0018] Another object of the present application is to provide a method for reducing coke burnout in a coke dry quenching furnace with low energy consumption. Based on the system for reducing coke burnout in a coke dry quenching furnace with low energy consumption as described above, the method includes the following steps:

[0019] S1. The circulating gas discharged from the coke dry quenching furnace flows successively through a primary dust collector, a waste heat boiler, a secondary dust collector and a circulating fan. After passing through the circulating fan, it is divided into two streams. One stream of circulating gas enters the coke dry quenching furnace, and the other stream passes through the first circulation pipeline and enters the removal unit for decarbonization, desulfurization and removal of soot particles, and then enters the drying and dehumidifying unit for dehydration and dehumidification. The circulating gas discharged from the drying and dehumidifying unit is also divided into two streams. One stream of circulating gas directly returns to the coke dry quenching furnace for recycling, and the other stream enters the air induced draft fan through the branch pipe and is mixed with fresh air;

[0020] S2. The removal unit uses the method of spraying strong alkali solution to remove carbon, sulfur and smoke particles from the circulating gas; the circulating gas contacts the strong alkali solution reversely from bottom to top;

[0021] S3. The strong alkali mixed solution after spraying is pumped into the absorbent regenerator, and carbide slag is added to the absorbent regenerator to react with the strong alkali mixed solution to generate solid phase products of CaCO3 precipitate and CaSO4 precipitate and strong alkali solution;

[0022] S4. The reaction products in the absorbent regenerator are sent to a solid-liquid separation device to separate the strong alkali solution from the solid phase products. The strong alkali solution flows back to the absorbent buffer tank for temporary storage and is then introduced into the removal unit again for spraying to realize the recycling of the strong alkali solution.

[0023] The beneficial effects of the system and method for reducing coke burnout in a coke dry quenching furnace with low energy consumption provided by the present application are as follows:

[0024] 1. By setting up the first circulation pipeline, part of the circulating gas is sent to the removal unit to remove carbon dioxide, and to the drying and dehumidification unit to remove moisture. The treated circulating gas is then sent back to the coke dry quenching furnace, effectively reducing the carbon dissolution reaction of the coke in the cooling section of the coke dry quenching furnace and effectively reducing the coke burn-off rate. The treated circulating gas is divided into two streams, which can effectively reduce the introduction amount of fresh air and the discharge amount of circulating gas, ensuring the system pressure balance while reducing air pollution.

[0025] 2. By increasing the functions of the removal unit, carbon dioxide, sulfur dioxide, etc. can be effectively removed, and the waste carbide slag can be utilized to fix carbon dioxide and sulfur dioxide, obtaining CaCO3 and CaSO4 products, achieving waste treatment with waste to achieve double economic benefits, reducing environmental pollution, and simultaneously realizing the three goals of increasing income, saving energy and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0027] Figure 1 It is a schematic flow chart of the traditional coke dry quenching process in the prior art;

[0028] Figure 2 It is a schematic flow chart of the system for reducing coke burn-off in a coke dry quenching furnace with low energy consumption provided in Embodiment 1 of the present application;

[0029] Figure 3 It is a schematic flow chart of the system for reducing coke burn-off in a coke dry quenching furnace with low energy consumption provided in Embodiment 2 of the present application.

[0030] Among them, the reference numerals in the drawings are as follows:

[0031] 1. Coke dry quenching furnace; 2. Primary dust collector; 3. Waste heat boiler; 4. Secondary dust collector; 5. Circulation fan; 6. Air induced draft fan; 7. Induced draft device; 8. Removal unit; 9. Drying and dehumidification unit; 10. First flowmeter; 11. First control valve; 12. Rich liquid pump; 13. Absorbent regenerator; 14. Filter press pump; 15. Solid-liquid separation equipment; 16. Absorbent buffer tank; 17. Lean liquid pump; 18. Second flowmeter; 19. Second control valve; 20. First pipeline; 21. Second pipeline; 22. First circulation pipeline; 23. Three-way interface; 24. Second circulation pipeline. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clear and understandable, the following further details this application in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit this application.

[0033] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0034] It should be understood that the orientation or positional relationship indicated by terms such as "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to this application.

[0035] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this application, "a plurality of" means two or more unless otherwise specifically defined.

[0036] Embodiment 1:

[0037] As Figure 2 shown, a system for reducing coke burn-off in a coke dry quenching furnace with low energy consumption provided by an embodiment of this application will now be described. This system for reducing coke burn-off in a coke dry quenching furnace with low energy consumption is improved on the existing basis as Figure 1 shown. Specifically, this system for reducing coke burn-off in a coke dry quenching furnace with low energy consumption includes: a coke dry quenching furnace 1, a primary dust collector 2, a waste heat boiler 3, a secondary dust collector 4, and a circulation fan 5 connected in sequence through pipelines. An air induced draft fan 6 is provided on a first pipeline 20 between the gas outlet end of the coke dry quenching furnace 1 and the primary dust collector 42. The air induced draft fan 6 is used to introduce fresh air into the circulating gas to burn off the excess flammable gas in the circulating gas. The gas outlet end of the circulation fan 5 is connected to the gas inlet end of the coke dry quenching furnace 1 through a second pipeline 21. An exhaust pipe is also provided on the second pipeline 21 to discharge part of the circulating gas into the air to ensure the pressure balance of the system.

[0038] The improvement of this embodiment lies in that: a first circulation pipeline 22 is connected to the second pipeline 21. The air inlet end of the first circulation pipeline 22 is connected to the second pipeline 21, and the air outlet end of the first circulation pipeline 22 is connected to the air inlet end of the coke dry quenching furnace 1. An air guiding device 7, a removal unit 8 and a drying and dehumidifying unit 9 are successively arranged on the first circulation pipeline 22; the circulated gas discharged by the circulation fan 5 enters into the second pipeline 21. Part of the circulated gas enters into the first circulation pipeline 22 under the action of the air guiding device 7, and carbon dioxide is removed through the removal unit 8, and then moisture is removed through the drying and dehumidifying unit 9. A branch pipe is connected to the first circulation pipeline 22 between the drying and dehumidifying unit 9 and the coke dry quenching furnace 1 through a tee joint 23, and the branch pipe is connected to the air inlet end of the air induced draft fan 6. The removal unit 8 can at least remove carbon dioxide in the circulated gas.

[0039] Part of the circulated gas discharged by the drying and dehumidifying unit 9 is directly introduced into the coke dry quenching furnace 1, effectively reducing the content of carbon dioxide in the circulated gas, thereby reducing the carbon dissolution reaction of the coke in the cooling section of the coke dry quenching furnace and effectively reducing the coke burn-off rate; the other part is introduced into the air inlet end of the air induced draft fan 6, the purpose of which is to reduce the introduction amount of fresh air, thereby reducing the discharge amount of redundant circulated gas, ensuring the system pressure balance and reducing air pollution at the same time.

[0040] In this embodiment, the air guiding device 7 can be a booster fan. In this embodiment, a first flowmeter 10 and a first control valve 11 are arranged on the branch pipe for controlling the proportion of the treated clean circulated gas discharged through the branch pipe. Specifically, the proportion of the circulated gas discharged through the branch pipe accounts for 10%-30% of the total amount of the circulated gas discharged through the drying and dehumidifying unit 9, that is, 70-90% of the clean circulated gas is directly introduced into the coke dry quenching furnace 1, effectively ensuring that the content of carbon dioxide in the circulated gas entering the coke dry quenching furnace 1 is low.

[0041] In this embodiment, the removal of carbon dioxide in the removal unit 8 adopts the organic amine absorption method, the alkali solution absorption method, the pressure swing absorption method or the membrane separation method. There are corresponding existing devices for these methods, which will not be introduced in detail here. In this embodiment, the drying and dehumidifying unit 9 adopts existing condensation dehumidification equipment, adsorption dehumidification equipment, contact reaction dehumidification equipment with calcium oxide / calcium chloride or centrifugal dehumidification equipment.

[0042] In this embodiment, through actual verification, when the gas flow rate in the second pipeline 21 exceeds 50% and above and is processed through the removal unit 8, the operation cost of the whole system is too high, the economic benefit is very low or negative; therefore, the gas flow rate in the first circulation pipeline 22 is 1%-50% of the gas flow rate in the second pipeline 21. The specific proportion control can set regulating valves and flowmeters on the second pipeline 21 and the first circulation pipeline 22, so as to ensure reducing the coke burn-off rate while making the operation cost of the whole system relatively low, ensuring the economic benefit and ensuring the normal operation of the factory.

[0043] The following provides three specific implementation cases and Figure 1 The existing system is compared with the one shown.

[0044] Specific embodiment 1: The circulating gas in this embodiment comes from a 190t / h dry quenching system, and the circulating gas flow rate is usually 200,000m 3 / h, the CO2 concentration in the circulating gas is 12-18%, the H2O concentration is 5-7%, and the burn-off rate is about 2%. After the improvement, 1.5% of the circulating gas volume is sent to the removal unit 8 through the first circulation pipeline 22 for decarbonization, with a decarbonization efficiency of 90%. After the removal unit 8 and the drying and dehumidification unit 9 are combined, the CO2 concentration in the circulating gas entering the CDQ coke oven 1 is gradually reduced to about 12%, and the H2O concentration is reduced to 4-6%, and the burn-off rate is controlled at 1.7%.

[0045] Specific embodiment 2: In this embodiment, the circulating gas comes from a 190t / h dry quenching system, and the circulating gas flow rate is usually 200,000m 3 / h, the CO2 concentration in the circulating gas is 12-18%, the H2O concentration is 5-7%, and the burn-off rate is about 2%. 15% of the circulating gas is sent to the removal unit 8 for decarbonization, with a decarbonization efficiency of 90%. After the removal unit 8 and the drying and dehumidification unit 9 are involved, the CO2 concentration in the circulating gas is gradually reduced to about 5%, the H2O concentration to 2-3%, and the burn-off rate is controlled at 0.8%.

[0046] Specific embodiment mode 3: In this embodiment, the circulating gas comes from a 190t / h dry quenching system, and the circulating gas flow rate is usually 200,000m 3 / h, the CO2 concentration in the circulating gas is 12-18%, the H2O concentration is 5-7%, and the burn-off rate is about 2%. 25% of the circulating gas is sent to the removal unit 8 for decarbonization, with a decarbonization efficiency of 90%. After the removal unit 8 and the drying and dehumidification unit 9 are involved, the CO2 concentration in the circulating gas is gradually reduced to about 3%, and the H2O concentration is reduced to 1-3%, and the burn-off rate is controlled at 0.6%.

[0047] According to Table 1, the higher the proportion of carbon removal treatment volume in the circulating gas to the total circulating gas volume, the larger the scale and load of the decarbonization system, and the higher the cost. When the carbon removal treatment volume accounts for 15-25%, that is, the gas flow rate in the first circulation pipeline 22 is 15%-25% of the gas flow rate in the second pipeline 21, the cost performance of the entire system is high and most in line with economic benefits.

[0048] The decarbonized circulating gas is divided into two paths and returns to the coke dry quenching furnace 1, and gradually reduces the introduction amount of fresh air and the discharge amount of circulating gas, controls the CO concentration in the circulating gas ≤ 6%, and maintains it at 3 - 5%, so as to reduce the intensity of the carbon dissolution reaction of the circulating gas in the dissolution loss section, and finally achieve the purpose of reducing the burning loss rate.

[0049] Comparative implementation method: As Figure 1 shown, the circulating gas in this embodiment comes from a 190t / h coke dry quenching system, and the circulating gas flow rate is usually 200000m 3 / h, the CO2 concentration in the circulating gas is 12 - 18%, the H2O concentration is 5 - 7%, and the burning loss rate is about 2%.

[0050] Table 1 shows the data related to the coke carbon loss of the specific implementation methods 1 - 3 and the comparative implementation method in the coke dry quenching.

[0051]

[0052] It can be seen from Table 1 that in the coke dry quenching furnace system of the same scale, compared with the comparative implementation method, for the specific implementation methods 1 - 3, the percentage content of CO2 in the circulating gas decreases, and the larger the proportion of the circulating gas treated, the more obvious the decrease in the CO2 concentration, which means the lower the burning loss. In the specific implementation method 2, 15% of the circulating gas is decarbonized, the CO2 concentration in the circulating gas is reduced by about 10 - 13%, the carbon burning loss rate is reduced by about 1.2%, and the carbon loss can be reduced by 18058t per year (calculated according to 8000 hours), which has great economic benefits.

[0053] Example 2:

[0054] This embodiment includes the content of Embodiment 1 and recovers the removed carbon and sulfur. Specifically, the system for reducing coke burn-off in a coke dry quenching furnace with low energy consumption includes: a coke dry quenching furnace 1, a primary dust collector 42, a waste heat boiler 3, a secondary dust collector 4, and a circulation fan 5, which are connected in sequence through pipelines. An air induced draft fan 6 is provided on the first pipeline 20 between the gas outlet end of the coke dry quenching furnace 1 and the primary dust collector 42. The air induced draft fan 6 is used to introduce fresh air into the circulating gas to burn off excess flammable gases. The gas outlet end of the circulation fan 5 is connected to the gas inlet end of the coke dry quenching furnace 1 through a second pipeline 21. An exhaust pipe is provided on the second pipeline 21 to discharge part of the circulating gas to ensure system balance. The improvement of this embodiment lies in that: a first circulation pipeline 22 is connected to the second pipeline 21. The inlet end of the first circulation pipeline 22 is connected to the second pipeline 21, and the outlet end of the first circulation pipeline 22 is connected to the gas inlet end of the coke dry quenching furnace. An induced draft device 7, a removal unit 8, and a drying and dehumidifying unit 9 are sequentially provided on the first circulation pipeline 22; the circulating gas discharged by the circulation fan 5 enters the second pipeline 21, and part of the circulating gas enters the first circulation pipeline 22 under the action of the induced draft device 7. A branch pipe is connected to the first circulation pipeline 22 between the drying and dehumidifying unit 9 and the coke dry quenching furnace through a tee joint 23, and the branch pipe is connected to the inlet end of the air induced draft fan 6. Specifically, the removal unit 8 is an integrated carbon, sulfur, and dust removal tower. The gas phase outlet of the integrated carbon, sulfur, and dust removal tower is connected to the drying and dehumidifying unit 9. A second circulation pipeline 24 is provided between the liquid phase outlet and the liquid phase inlet of the integrated carbon, sulfur, and dust removal tower. The gas inlet end of the integrated carbon, sulfur, and dust removal tower is lower than the gas phase outlet and the liquid phase inlet; a rich liquid pump 12, an absorption liquid regenerator 13, a pressure filtration pump 14, a solid-liquid separation device 15, an absorption liquid buffer tank 16, and a lean liquid pump 17 are sequentially provided on the second circulation pipeline 24; carbide slag is added to the absorption liquid regenerator 13, and strong alkali solution is added to the absorption liquid buffer tank 16.

[0055] Among them, the rich liquid pump 12 is used to pump the solution at the bottom of the integrated carbon, sulfur, and dust removal tower into the absorption liquid regenerator 13. The absorption liquid regenerator 13 is used to carry out a chemical reaction to generate solids and solutions. The pressure filtration pump 14 is used to pump the solids and solutions into the solid-liquid separation device 15. The solid-liquid separation device 15 is used to separate the solids and solutions. The solids are recycled, and the solutions are stored in the absorption liquid buffer tank 16 and then pumped into the integrated carbon, sulfur, and dust removal tower through the lean liquid pump 17 for spraying and reverse contact with the circulating gas.

[0056] By spraying a strong alkali solution in the integrated decarbonization, desulfurization and dedusting tower, carbon dioxide, sulfur dioxide and flue gas particles in the circulating gas are removed. The treated clean circulating gas is then dehydrated through the drying and dehumidifying unit 9, enabling the clean circulating gas to be recycled. The strong alkali solution containing carbon and sulfur reacts with carbide slag in the absorber liquid regenerator 13 to form calcium carbonate and calcium sulfate solids, allowing the strong alkali solution to be recycled and the waste carbide slag to be utilized. In this embodiment, waste carbide slag is used to fix CO2, achieving waste treatment with waste, producing CaCO3 products with dual economic benefits, reducing environmental pollution, and simultaneously achieving the three goals of increasing income, saving energy and environmental protection.

[0057] In this embodiment, at least two absorber liquid regenerators 13 are arranged in parallel, and the absorber liquid regenerator 13 is provided with a carbide slag inlet. Multiple absorber liquid regenerators 13 can work simultaneously or separately to be suitable for different working conditions or maintenance without shutting down.

[0058] In this embodiment, the integrated decarbonization, desulfurization and dedusting tower is provided with packing to make the circulating gas and the strong alkali solution contact more fully, improving the treatment effect.

[0059] In this embodiment, the solid-liquid separation device 15 is an existing plate and frame filter press, belt filter press or centrifuge.

[0060] In this embodiment, the drying and dehumidifying unit 9 adopts existing condensation dehumidification equipment, adsorption dehumidification equipment, contact reaction dehumidification equipment with calcium oxide / calcium chloride or centrifugal dehumidification equipment.

[0061] In this embodiment, a first flow meter 10 and a first control valve 11 are provided on the branch pipe. A second flow meter 18 and a second control valve 19 are provided on the first circulation pipe 22 between the three-way interface 23 and the coke dry quenching furnace 1. This can control the respective flow rates of the clean circulating gas divided into two streams and adjust according to actual needs. Among them, the gas flow rate in the first circulation pipe 22 is 1%-50% of the gas flow rate in the second pipe 21. The circulating gas flow rate in the branch pipe is 10-30% of the total gas discharged from the drying and dehumidifying unit 9.

[0062] In this embodiment, the strong alkali solution is NaOH solution and / or KOH solution.

[0063] Example 3:

[0064] This embodiment is based on Example 2 and is used to provide a method for reducing coke burnout in a coke dry quenching furnace with low energy consumption. The method includes the following steps:

[0065] S1. The circulating gas discharged from the coke dry quenching furnace 1 flows successively through the primary dust collector 42, the waste heat boiler 3, the secondary dust collector 4, and the circulating fan 5. After passing through the circulating fan 5, it is divided into two streams. One stream of the circulating gas enters the coke dry quenching furnace, and the other stream passes through the first circulation pipeline 22 and enters the removal unit 8 for decarbonization, desulfurization, and removal of soot particles, and then enters the drying and dehumidifying unit 9 for dehydration and dehumidification. The circulating gas discharged from the drying and dehumidifying unit 9 is again divided into two streams. One stream of the circulating gas directly returns to the coke dry quenching furnace 1 for recycling, and the other stream enters the air induced draft fan 6 through a branch pipe, mixes with fresh air, and then returns for circulation;

[0066] S2. The removal unit 8 uses the method of spraying strong alkali solution to decarbonize, desulfurize, and remove smoke particles from the circulating gas; the circulating gas contacts the strong alkali solution reversely from bottom to top;

[0067] S3. The sprayed strong alkali mixed solution is pumped into the absorber regenerator 13, and carbide slag is added to the absorber regenerator 13 to react with the strong alkali mixed solution to generate solid-phase products of CaCO3 precipitate and CaSO4 precipitate and strong alkali solution;

[0068] S4. The reaction products in the absorber regenerator 13 are sent to the solid-liquid separation device 15 to separate the strong alkali solution from the solid-phase products. The solid-phase products are recycled, and the strong alkali solution flows back to the absorber buffer tank 16 for temporary storage and is then fed into the removal unit 8 again for spraying to achieve the recycling of the strong alkali solution.

[0069] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A system for reducing coke burn loss in a coke dry quenching furnace with low energy consumption, comprising: The coke dry quenching furnace (1), primary deduster (2), waste heat boiler (3), secondary deduster (4) and recycle fan (5) are connected in sequence. An air induced draft fan (6) is provided on the first pipeline (20) between the gas outlet end of the coke dry quenching furnace (1) and the primary deduster (2). The gas outlet end of the recycle fan (5) is connected to the gas inlet end of the coke dry quenching furnace (1) through a second pipeline (21). It is characterized in that a first recycle pipeline (22) is connected to the second pipeline (21), the first recycle pipeline (22) is connected to the gas inlet end of the coke dry quenching furnace (1), and an induced draft device (7), a removal unit (8) and a drying and dehumidifying unit (9) are provided in sequence on the first recycle pipeline (22); a branch pipe is connected to the first recycle pipeline (22) between the drying and dehumidifying unit (9) and the coke dry quenching furnace (1) through a tee joint (23), and the branch pipe is connected to the gas inlet end of the air induced draft fan (6), and the removal unit (8) can at least remove carbon dioxide in the recycle gas.

2. The system for reducing coke burn-off in a coke dry quenching furnace with low energy consumption according to claim 1, characterized in that: The removal unit (8) is an integrated carbon dioxide removal, desulfurization and dedusting tower. The gas phase outlet of the integrated carbon dioxide removal, desulfurization and dedusting tower is connected to the drying and dehumidifying unit (9). A second recycle pipeline (24) is provided between the liquid phase outlet and the liquid phase inlet of the integrated carbon dioxide removal, desulfurization and dedusting tower. The gas inlet end of the removal unit (8) is lower than the gas phase outlet and the liquid phase inlet; a rich liquid pump (12), an absorbent regenerator (13), a filter press pump (14), a solid-liquid separation device (15), an absorbent buffer tank (16) and a lean liquid pump (17) are provided in sequence on the second recycle pipeline (24); carbide slag is added into the absorbent regenerator (13), and strong alkali solution is added into the absorbent buffer tank (16).

3. The system for reducing coke burn-off in a coke dry quenching furnace with low energy consumption according to claim 2, wherein: At least two absorbent regenerators (13) are arranged in parallel, and a carbide slag feeding port is provided on the absorbent regenerator (13).

4. The system for reducing coke burning loss in a coke dry quenching furnace with low energy consumption according to claim 3, characterized in that: The solid-liquid separation device (15) is a plate and frame filter press, a belt filter press or a centrifugal dehydrator.

5. The system for reducing coke burn-off in a coke dry quenching furnace with low energy consumption according to claim 4, characterized in that: The drying and dehumidifying unit (9) adopts a condensation dehumidification device, an adsorption dehumidification device, a contact reaction dehumidification device with calcium oxide / calcium chloride or a centrifugal dehumidification device.

6. The system for reducing coke burn-off in a low-energy coke dry quenching furnace according to claim 1 or 5, characterized in that: A first flowmeter (10) and a first control valve (11) are provided on the branch pipe.

7. The system for reducing coke burn-off in a low-energy coke dry quenching furnace according to claim 6, characterized in that: A second flowmeter (18) and a second control valve (19) are provided on the first recycle pipeline (22) between the tee joint (23) and the coke dry quenching furnace (1).

8. The system for reducing coke burn-off in a coke dry quenching furnace with low energy consumption according to claim 7, characterized in that: The gas flow rate in the first recycle pipeline (22) is 1%-50% of the gas flow rate in the second pipeline (21).

9. The system for reducing coke burn-off in a coke dry quenching furnace with low energy consumption according to claim 8, characterized in that: The gas flow rate in the branch pipe is 10%-30% of the gas flow rate in the first recycle pipeline (22).

Images