Dry quenching device and dry quenching production process based on nitrogen cooling

Abstract

This invention discloses a dry quenching device and production process based on nitrogen cooling, solving the problems of poor safety and stability and high production cost of existing dry quenching devices. The dry quenching device includes a dry quenching furnace, a red-hot coke pre-storage device, a circulating gas supply unit, a water-cooling tower, a primary dust removal device, a waste heat boiler, a secondary dust removal device, and a heat exchanger. The red-hot coke pre-storage device feeds high-temperature red-hot coke into the dry quenching furnace from the top, while the water-cooling tower cools the nitrogen cooling gas, which is then fed into the dry quenching furnace from the bottom. The nitrogen cooling gas exchanges heat with the high-temperature red-hot coke to form high-temperature circulating gas, which enters the waste heat boiler after passing through the primary dust removal device. The cooled red-hot coke is then stored in a finished product tank. The high-pressure steam formed by the heat exchange in the waste heat boiler is transmitted to the power generation equipment, while the medium-temperature circulating gas enters the heat exchanger for heat exchange, forming low-temperature circulating gas that is recycled back into the dry quenching furnace. Medium-temperature hot water is fed into the waste heat boiler to replenish water levels.

Description

Technical Field

[0001] This invention relates to a dry quenching coke production process, specifically to a dry quenching coke device and dry quenching coke production process based on nitrogen gas cooling. Background Technology

[0002] As a type of waste heat treatment device, dry quenching equipment has undergone more than 20 years of development and evolution since its industrialization. Currently, the market demand for dry quenching equipment is continuously expanding, driven by stricter environmental policies, upgrades in the steel industry, and the increasing benefits of energy conservation and carbon reduction. Its application has extended from the main steel industry to multiple fields such as chemicals and building materials, with the steel industry being the largest consumer, accounting for approximately 60%. Dry quenching equipment significantly improves coke quality (M40 strength increases by 3%~5%, M10 wear resistance is improved), reduces the blast furnace coke ratio by 2%~5%, and contributes to the stable operation of large blast furnaces, thus becoming a standard process in modern integrated steel enterprises. In addition, dry quenching coke can also be used in non-ferrous metal smelting, casting, and calcium carbide industries as a reducing agent, heating agent, or raw material for gun barrel clay. It can also be used in the chemical industry as a production coke, refractory material, and other special materials.

[0003] However, with the expansion of dry quenching coke production scale, the following problems have arisen: (1) The circulating gas used in the existing dry quenching coke equipment is high-purity nitrogen (>99.9%), which not only has a high production cost, but also the primary and secondary superheaters of the dry quenching furnace are prone to corrosion due to excessive dust content and even tube rupture accidents, which seriously threatens the safe and stable operation of the dry quenching coke equipment; (2) The boiler tubes of the existing dry quenching coke equipment have also experienced more and more shutdowns due to abrasion corrosion, resulting in reduced production efficiency; (3) The excessive emissions of particulate matter, VOCs and carbon dioxide not only affect the air quality of the steel concentration area, but also have a serious impact on the living environment of the surrounding residents.

[0004] The aforementioned problems not only affect the daily production of the coking plant, but may even impact the operation of the entire steel system and the normal lives of surrounding residents, thus causing serious economic losses and social impact. Summary of the Invention

[0005] The purpose of this invention is to solve the technical problems of existing dry quenching devices, such as poor safety and stability, low production efficiency, high production cost, and impact on air quality, and to provide a dry quenching device and dry quenching production process based on nitrogen cooling.

[0006] To achieve the above objectives, the technical solution provided by this invention is as follows:

[0007] A dry quenching device based on nitrogen-cooled waste gas is characterized by:

[0008] It includes a dry quenching furnace, a red coke pre-storage device, a circulating gas supply unit, a water cooling tower, a primary dust removal device, a waste heat boiler, a secondary dust removal device, and a heat exchanger;

[0009] The red coke pre-storage device is connected to the top of the dry quenching furnace and is used to input the high-temperature red coke stored inside into the dry quenching furnace; a finished product tank is installed at the bottom of the dry quenching furnace.

[0010] The input end of the circulating gas supply unit is used to connect to the air separation unit and store the waste nitrogen gas generated by the air separation unit; one end of the water cooling tower is connected to the output end of the circulating gas supply unit, and the other end is connected to the bottom of the dry quenching furnace. The water cooling tower is used to cool the waste nitrogen gas output by the circulating gas supply unit and input it into the dry quenching furnace.

[0011] The input end of the primary dust removal device is connected to the dry quenching furnace, and the output end is connected to the waste heat boiler. The polluted nitrogen gas in the dry quenching furnace cools the high-temperature red coke to form high-temperature circulating gas, which then enters the waste heat boiler after passing through the primary dust removal device. The high-temperature red coke is cooled to form dry quenched coke and stored in the finished product tank.

[0012] One end of the waste heat boiler is used to connect to external power generation equipment, and the other end is connected to a heat exchanger through a secondary dust removal device. The water stored in the waste heat boiler exchanges heat with the high-temperature circulating gas to form high-pressure steam and medium-temperature circulating gas. The high-pressure steam is transmitted to the external power generation equipment, and the medium-temperature circulating gas enters the heat exchanger after passing through the secondary dust removal device.

[0013] The heat exchanger is connected to the waste heat boiler, the dry quenching furnace and the external water supply unit respectively. After the medium-temperature circulating gas exchanges heat with the water in the heat exchanger, it forms low-temperature circulating gas and medium-temperature hot water. The low-temperature circulating gas enters the dry quenching furnace for recycling, and the medium-temperature hot water is input into the waste heat boiler to replenish the water volume.

[0014] Furthermore, a purifier is installed on the connecting pipeline between the circulating gas supply unit and the water cooling tower to purify the waste nitrogen gas.

[0015] Furthermore, at least one chiller unit is installed on the connecting pipeline between the purifier and the water cooling tower.

[0016] Furthermore, two lithium bromide chillers connected in series are installed on the connecting pipeline between the purifier and the water cooling tower.

[0017] Furthermore, the other end of the water-cooled tower is connected to the bottom of the dry quenching furnace via a blower;

[0018] The water cooling tower is equipped with a vent valve;

[0019] The circulating gas supply unit is equipped with a vent valve, and the vent valve is equipped with a silencer.

[0020] Furthermore, the primary dust removal device is a gravity cyclone dust collector, which includes a support body, a shell, and a dust hopper;

[0021] The support body is a cylindrical structure; the upper part of the shell is a hollow cylindrical structure, which is vertically installed on the support body; the side wall of the cylindrical structure is provided with an air inlet, which is connected to the dry quenching furnace through a pipe; the cylindrical structure is provided with a cylindrical baffle, the lower end of which is located at the lower part of the cylindrical structure, the upper end of which is installed on the cylindrical structure and its air outlet extends out of the top of the cylindrical structure, and is connected to the waste heat boiler through a pipe; the lower part of the shell is a conical structure with the small end facing down, which extends into the support body;

[0022] The ash hopper is located within the support body, and its upper end is connected to the small end of the conical structure via a flange, for collecting coke powder in the high-temperature circulating gas.

[0023] Furthermore, a desalination device is provided between the heat exchanger and the external water supply unit to desalinate the raw water supplied by the water supply unit.

[0024] Meanwhile, the present invention also provides a dry quenching coke production process based on sludge nitrogen cooling, which is characterized by employing the above-mentioned dry quenching coke device based on sludge nitrogen cooling, and includes the following steps:

[0025] Step 1: The high-temperature red coke in the red coke pre-storage device is loaded into the dry quenching furnace one by one from the top of the dry quenching furnace. At the same time, the waste nitrogen gas output from the circulating gas supply unit is cooled by a water cooling tower and sent into the dry quenching furnace through the bottom of the dry quenching furnace.

[0026] Step 2: Use sludge nitrogen to cool the high-temperature red coke in the dry quenching furnace to form a high-temperature circulating gas. After being removed by a primary dust removal device, the gas is sent into the waste heat boiler. The dry quenched coke formed after the high-temperature red coke is cooled is stored in the finished product tank.

[0027] Step 3: The high-temperature circulating gas is exchanged with the water in the waste heat boiler to form high-pressure steam and medium-temperature circulating gas. The high-pressure steam is then transmitted to the external power generation equipment for power generation, and the medium-temperature circulating gas is sent to the heat exchanger after being cleaned by the secondary dust removal device.

[0028] Step 4: After the medium-temperature circulating gas exchanges heat with the water in the heat exchanger, it forms low-temperature circulating gas and medium-temperature hot water. The low-temperature circulating gas is then sent into the dry quenching furnace for recycling, and the medium-temperature hot water is input into the waste heat boiler to replenish the water volume.

[0029] Step 5: Repeat steps 1 to 4 until the dry quenching process is complete.

[0030] Furthermore, in step 1, the temperature of the high-temperature red char is 950~1050℃; the nitrogen content in the waste nitrogen gas is 95%~98%;

[0031] The waste nitrogen gas is cooled to 130~190℃ using a water-cooling tower and then sent into the dry quenching furnace through the bottom of the dry quenching furnace by a blower.

[0032] Furthermore, in step 2, the temperature of the high-temperature circulating gas is 800~950℃;

[0033] In step 3, the temperature of the medium-temperature circulating gas is 160~200℃;

[0034] In step 4, the temperature of the low-temperature circulating gas is 130~160℃.

[0035] The beneficial effects of this invention are as follows:

[0036] 1. This invention uses the waste nitrogen gas discharged from the air separation unit as the circulating gas, which not only realizes the efficient use of energy, but also reduces production costs. Because the waste nitrogen gas contains a small amount of oxygen, it can effectively dilute the concentration of combustible components such as hydrogen and carbon monoxide in the circulating gas, thereby reducing the risk of explosion. During low-temperature stages such as annual inspection and maintenance, it can also avoid the accumulation of combustible gases and ensure the safety of operation.

[0037] 2. The high-temperature circulating gas discharged from the dry quenching furnace can enter the waste heat boiler after passing through a primary dust removal device, generate high-pressure steam, and be transmitted to external power generation equipment, thereby realizing the effective utilization of energy.

[0038] 3. The nitrogen gas used in this invention can maintain a stable heat exchange process, making the cooling of red coke more uniform, which helps to improve the heat exchange efficiency of the dry quenching furnace, reduce the gas-to-material ratio (gas consumption per unit of coke), and thus reduce energy consumption.

[0039] 4. Compared with traditional wet quenching, the dry quenching process using recycled nitrogen gas adopted in this invention avoids the emission of harmful substances such as phenol and cyanide carried by water vapor, significantly reduces the release of dust and pollutants, and thus improves the surrounding environment.

[0040] 5. The primary dust removal device of the present invention is a gravity cyclone dust collector, which has a simple structure, low operating cost, small footprint, and flexible layout.

[0041] 6. The present invention provides a demineralized water device between the heat exchanger and the external water supply unit, which can not only prevent scale formation on the furnace tubes, but also prevent corrosion of thermal equipment, thereby ensuring the safe and efficient operation of the dry quenching device.

[0042] 7. The invention improves overall safety, thereby reducing the number of shutdowns due to pipe bursts and thus improving production efficiency. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of an embodiment of the dry quenching device based on nitrogen gas cooling according to the present invention.

[0044] Figure 2 This is a schematic diagram of the primary dust removal device in an embodiment of the dry quenching coke device based on nitrogen cooling of the present invention.

[0045] The annotations in the attached figures are explained as follows:

[0046] 1-Support body, 2-Shell, 21-Air inlet, 22-Air outlet, 23-Cylindrical baffle, 3-Ash hopper. Detailed Implementation

[0047] To make the objectives, advantages, and features of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Those skilled in the art should understand that these embodiments are merely used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0048] like Figure 1 As shown, this embodiment provides a dry quenching coke device based on nitrogen gas cooling, including a dry quenching furnace, a red coke pre-storage device, a circulating gas supply unit, a water cooling tower, a primary dust removal device, a waste heat boiler, a secondary dust removal device, and a heat exchanger.

[0049] The red coke pre-storage device is connected to the top of the dry quenching furnace and is used to input the high-temperature red coke stored inside into the dry quenching furnace; the bottom of the dry quenching furnace is equipped with a finished product tank for storing the dry quenched coke produced.

[0050] The input end of the circulating gas supply unit is used to connect to the air separation unit and store the waste nitrogen gas produced by the air separation unit. In steel and coking production, the air separation unit generates a large amount of waste nitrogen gas with a lower temperature and slightly higher oxygen content. Originally, this waste nitrogen gas was mostly released, which not only wasted energy but also increased the carbon footprint. This invention uses it as a circulating cooling medium in the production of dry quenching coke, realizing the resource utilization of "waste" gas and turning waste into treasure, which is in line with the national advocacy of circular economy and green and low-carbon development. The waste nitrogen gas mentioned in this embodiment refers to nitrogen gas with a nitrogen content of 95%~98%, and the remainder being oxygen, argon, and other gases. Replacing the high-purity nitrogen gas (purity >99.9%) in the traditional dry quenching coke circulating gas with waste nitrogen gas can effectively utilize industrial by-product gas sources, reduce operating costs, and reduce the consumption of high-purity nitrogen gas, which has significant social benefits in terms of comprehensive resource utilization and energy conservation and emission reduction.

[0051] One end of the water-cooled tower is connected to the output of the circulating gas supply unit, and the other end is connected to the bottom of the dry quenching furnace via a blower. The water-cooled tower is used to cool the waste nitrogen gas output from the circulating gas supply unit, and the blower blows the cooled waste nitrogen gas from the bottom of the dry quenching furnace into the furnace as cooling circulating gas, which then exchanges heat with the falling high-temperature red-hot coke in a countercurrent flow. An automatic vent valve is also installed on the water-cooled tower.

[0052] In this embodiment, a purifier is installed on the connecting pipeline between the circulating gas supply unit and the water cooling tower to purify the waste nitrogen gas and improve the safety of the dry quenching device. Simultaneously, to ensure the temperature of the waste nitrogen gas, two lithium bromide chillers connected in series are installed on the connecting pipeline between the purifier and the water cooling tower. According to simulation calculations, if the total cooling capacity requires 120 × 10⁴ Kcal / h, one chiller is a 40 × 10⁴ Kcal / h lithium bromide chiller, and the other is an 80 × 10⁴ Kcal / h lithium bromide chiller.

[0053] In addition, to further improve the safety of the device, a vent valve is installed at the output end of the circulating gas supply unit, and a silencer is provided on the vent valve.

[0054] The input end of the primary dust removal device is connected to the dry quenching furnace, and the output end is connected to the waste heat boiler. The polluted nitrogen gas in the dry quenching furnace cools the high-temperature red coke to form high-temperature circulating gas, which then enters the waste heat boiler after passing through the primary dust removal device. The high-temperature red coke is cooled to form dry quenched coke and stored in the finished product tank.

[0055] like Figure 2 As shown, the primary dust removal device in this embodiment adopts a gravity cyclone dust collector, which includes a support body 1, a shell 2, and a dust hopper 3. The support body 1 is a cylindrical structure used to provide support for the shell 2.

[0056] The upper part of the shell 2 is a hollow cylindrical structure, vertically mounted on the support 1. An air inlet 21 is provided on the side wall of the cylindrical structure, with the air inlet 21 tangentially aligned with the cylindrical structure. The air inlet 21 is connected to the dry quenching furnace via a pipe. A cylindrical baffle 23 is located inside the cylindrical structure, with its lower end positioned at the bottom and its upper end mounted on the cylindrical structure. Its outlet 22 extends beyond the top of the cylindrical structure and is connected to the waste heat boiler via a pipe. The lower part of the shell is a conical structure with the smaller end pointing downwards, extending into the support 1.

[0057] The ash hopper 3 is located inside the support body 1, and its upper end is installed at the small end of the conical structure through a flange; the ash hopper 3 as a whole is also a conical structure, with the large end facing upward.

[0058] The high-temperature circulating gas in the dry quenching furnace enters the cylindrical structure at the top of the shell 2 through the air inlet 21 and rotates around the cylindrical baffle 23. During the rotation, the coke powder in the high-temperature circulating gas falls into the ash hopper 3. When the high-temperature circulating gas sinks to the bottom of the cylindrical baffle 23, it is discharged through the interior of the cylindrical baffle 23 and the air outlet 22, achieving primary dust removal. The high-temperature circulating gas discharged through the cylindrical baffle 23 enters the waste heat boiler through pipelines for effective utilization of thermal energy.

[0059] One end of the waste heat boiler is connected to external power generation equipment, and the other end is connected to a heat exchanger via a secondary dust removal device. Water stored inside the waste heat boiler exchanges heat with high-temperature circulating gas to form high-pressure steam and medium-temperature circulating gas. The high-pressure steam is transmitted to the external power generation equipment for power generation or integrated into the plant's pipeline network, achieving energy recovery. The medium-temperature circulating gas, after passing through the secondary dust removal device, enters the heat exchanger for further heat energy utilization.

[0060] The heat exchanger is a water preheating heat exchanger, which is connected to the waste heat boiler, the dry quenching furnace and the external water supply unit respectively. After the medium-temperature circulating gas exchanges heat with the water in the heat exchanger, it forms low-temperature circulating gas and medium-temperature hot water. The low-temperature circulating gas enters the dry quenching furnace for recycling, and the medium-temperature hot water is input into the waste heat boiler to supplement the water volume, realizing the closed-loop recycling of energy.

[0061] To ensure the safety of the device, this embodiment includes a desalination device between the heat exchanger and the external water supply unit. This device is used to desalinate the raw water supplied by the water supply unit, preventing calcium, magnesium, bicarbonate, and other substances in the water from forming scale at high temperatures, which could clog the pipes and reduce the heat exchange efficiency.

[0062] The dry quenching device used in this embodiment reduces coke burn-off, lowers volatile matter content, and improves quality. Simultaneously, the use of waste nitrogen significantly reduces production costs. Furthermore, the presence of oxygen and other gases in the waste nitrogen oxidizes or dilutes combustible components in the dust, drastically reducing the probability of tube rupture and significantly improving safety, thus lowering the risk of furnace collapse. In addition, improved safety significantly reduces the number of shutdowns due to tube rupture, thereby increasing production efficiency.

[0063] This embodiment also provides a dry quenching coke production process based on waste nitrogen cooling, including the following steps:

[0064] Step 1: After the high-temperature red coke at approximately 1000°C is pushed out of the coke oven and loaded into a coke can, it is transported by an electric locomotive to the bottom of the elevator. The elevator lifts the coke can to the red coke pre-storage device at the top of the dry quenching furnace, where the high-temperature red coke is stored. Then, the high-temperature red coke in the pre-storage device is loaded into the dry quenching furnace one by one from the top. At the same time, the waste nitrogen gas output from the circulating gas supply unit is cooled to 130~190°C by a water cooling tower and then blown into the dry quenching furnace from the bottom by a blower, where it comes into countercurrent contact with the falling high-temperature red coke for heat exchange.

[0065] Step 2: After heat exchange between the waste nitrogen gas and the high-temperature red coke, a high-temperature circulating gas of 800~950℃ is formed and discharged from the top of the dry quenching furnace. After the coarse coke powder is removed by the primary dust removal device, it is sent into the waste heat boiler. After cooling, the high-temperature red coke forms dry quenched coke and is stored in the finished product tank.

[0066] Step 3: After heat exchange between the high-temperature circulating gas and the water in the waste heat boiler, high-pressure steam (4.4MPa, 540℃) and medium-temperature circulating gas (160~200℃) are formed. The high-pressure steam is transmitted to the external power generation equipment for power generation, while the medium-temperature circulating gas is sent to the heat exchanger after the fine powder is removed by the secondary dust removal device.

[0067] Step 4: After the medium-temperature circulating gas exchanges heat with the water in the heat exchanger, it forms low-temperature circulating gas (about 130°C) and medium-temperature hot water. The low-temperature circulating gas is sent into the dry quenching furnace by a blower for recycling, while the medium-temperature hot water is sent into the waste heat boiler to replenish the water volume.

[0068] Step 5: Repeat steps 1 to 4 until the dry quenching process is complete.

[0069] The above process cools 1000°C red coke to below 200°C in a closed system using inert gas (dirty nitrogen), while recovering a large amount of its waste heat for power generation or heating. The whole process is highly efficient and environmentally friendly, and VOC emissions are reduced to 3%, avoiding the water pollution and heat waste of traditional wet quenching.

[0070] This embodiment uses a 190-ton dry quenching coke unit as an example to calculate coke loss: The reduction in oxygen is: 20000 * 0.05 (the local air contains 20.4% oxygen) = 1000 m°, which is equivalent to 1420 kg of oxygen. Since the ratio of carbon monoxide to carbon dioxide after oxygen decomposition cannot be measured, the oxygen is converted into carbon dioxide, which reduces the burn-off rate, to calculate the burn-off rate. Then: 1420 * (44 / 32) = 1953 kg, carbon dioxide mass 1953 kg, reduction in carbon burn-off = 2475 - 1420 = 533 kg; reduction in burn-off rate = 533 / 880000 x 95% / 31 / 24 = 0.59%.

[0071] If calculated based on a price of 600 yuan per ton for coke and ash: the annual revenue would be 8.8 million tons * 0.59% = 51,920 tons, resulting in an economic benefit of 31 million yuan from reducing coke consumption. In addition, the cost of demineralized water would be added at 4 million yuan.

[0072] Currently, the total flow rate of the 20,000 Nm³ / h air separation unit from the water-cooled tower and the waste nitrogen after molecular sieve regeneration is approximately 40,000 Nm³ / h. 3 / h- 45000Nm 3 / h(Nm) 3 / h is a unit of production, referring to the volumetric flow rate measured at 0℃ and 0.1013MPa(A), known as the standard flow rate. This basically meets the user's requirement for waste nitrogen for 110 tons of dry quenching coke. Based on the current operation of the air separation unit, this embodiment can combine excess nitrogen, waste nitrogen, and regenerated waste nitrogen from the three air separation units, pressurize them to the user's required pressure using a blower, and then send them out. The reuse of waste nitrogen strengthens the material flow coupling between ironmaking, oxygen production, and coking processes within the steel plant, improves the operational synergy and risk resistance of the industrial park, and provides support for building a modern green steel complex. It also reduces thermal pollution, lowers production and operating costs, and improves enterprise efficiency.

[0073] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, and such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

Claims

1. A dry quenching device based on nitrogen cooling, characterized in that: It includes a dry quenching furnace, a red coke pre-storage device, a circulating gas supply unit, a water cooling tower, a primary dust removal device, a waste heat boiler, a secondary dust removal device, and a heat exchanger; The red coke pre-storage device is connected to the top of the dry quenching furnace and is used to input the high-temperature red coke stored inside into the dry quenching furnace; a finished product tank is installed at the bottom of the dry quenching furnace. The input end of the circulating gas supply unit is used to connect to the air separation unit and store the waste nitrogen gas generated by the air separation unit; one end of the water cooling tower is connected to the output end of the circulating gas supply unit, and the other end is connected to the bottom of the dry quenching furnace. The water cooling tower is used to cool the waste nitrogen gas output by the circulating gas supply unit and input it into the dry quenching furnace. The input end of the primary dust removal device is connected to the dry quenching furnace, and the output end is connected to the waste heat boiler. The polluted nitrogen gas in the dry quenching furnace cools the high-temperature red coke to form high-temperature circulating gas, which then enters the waste heat boiler after passing through the primary dust removal device. The high-temperature red coke is cooled to form dry quenched coke and stored in the finished product tank. One end of the waste heat boiler is used to connect to external power generation equipment, and the other end is connected to a heat exchanger through a secondary dust removal device. The water stored in the waste heat boiler exchanges heat with the high-temperature circulating gas to form high-pressure steam and medium-temperature circulating gas. The high-pressure steam is transmitted to the external power generation equipment, and the medium-temperature circulating gas enters the heat exchanger after passing through the secondary dust removal device. The heat exchanger is connected to the waste heat boiler, the dry quenching furnace and the external water supply unit respectively. After the medium-temperature circulating gas exchanges heat with the water in the heat exchanger, it forms low-temperature circulating gas and medium-temperature hot water. The low-temperature circulating gas enters the dry quenching furnace for recycling, and the medium-temperature hot water is input into the waste heat boiler to replenish the water volume.

2. The dry quenching device based on nitrogen cooling according to claim 1, characterized in that: A purifier is installed on the connecting pipeline between the circulating gas supply unit and the water cooling tower to purify the waste nitrogen gas.

3. The dry quenching device based on nitrogen cooling according to claim 2, characterized in that: At least one chiller unit is installed on the connecting pipeline between the purifier and the water cooling tower.

4. The dry quenching device based on nitrogen cooling according to claim 3, characterized in that: Two lithium bromide chillers connected in series are installed on the connecting pipeline between the purifier and the water cooling tower.

5. The dry quenching device based on nitrogen cooling according to claim 1, characterized in that: The other end of the water-cooled tower is connected to the bottom of the dry quenching furnace via a blower; The water cooling tower is equipped with a vent valve; The circulating gas supply unit is equipped with a vent valve, and the vent valve is equipped with a silencer.

6. The dry quenching apparatus based on nitrogen cooling according to any one of claims 1 to 5, characterized in that: The primary dust removal device is a gravity cyclone dust collector, which includes a support body (1), a shell (2) and a dust hopper (3). The support body (1) is a cylindrical structure; the upper part of the shell (2) is a hollow cylindrical structure and is vertically installed on the support body (1); the side wall of the cylindrical structure is provided with an air inlet (21), which is connected to the dry quenching furnace through a pipe; the cylindrical structure is provided with a cylindrical baffle (23), the lower end of which is located at the lower part of the cylindrical structure, the upper end of which is installed on the cylindrical structure and its air outlet (22) extends out of the top of the cylindrical structure and is connected to the waste heat boiler through a pipe; the lower part of the shell is a cone structure with the small end facing down and extends into the support body (1); The ash hopper (3) is located inside the support body (1), and its upper end is connected to the small end of the cone structure through a flange, for collecting coke powder in the high-temperature circulating gas.

7. The dry quenching device based on nitrogen cooling according to claim 1, characterized in that: A desalination device is provided between the heat exchanger and the external water supply unit to desalinate the raw water supplied by the water supply unit.

8. A dry quenching coke production process based on nitrogen cooling, characterized in that, The dry quenching apparatus based on waste nitrogen cooling as described in any one of claims 1 to 7 includes the following steps: Step 1: The high-temperature red coke in the red coke pre-storage device is loaded into the dry quenching furnace one by one from the top of the dry quenching furnace. At the same time, the waste nitrogen gas output from the circulating gas supply unit is cooled by a water cooling tower and sent into the dry quenching furnace through the bottom of the dry quenching furnace. Step 2: Use sludge nitrogen to cool the high-temperature red coke in the dry quenching furnace to form a high-temperature circulating gas. After being removed by a primary dust removal device, the gas is sent into the waste heat boiler. The dry quenched coke formed after the high-temperature red coke is cooled is stored in the finished product tank. Step 3: The high-temperature circulating gas is exchanged with the water in the waste heat boiler to form high-pressure steam and medium-temperature circulating gas. The high-pressure steam is then transmitted to the external power generation equipment for power generation, and the medium-temperature circulating gas is sent to the heat exchanger after being cleaned by the secondary dust removal device. Step 4: After the medium-temperature circulating gas exchanges heat with the water in the heat exchanger, it forms low-temperature circulating gas and medium-temperature hot water. The low-temperature circulating gas is then sent into the dry quenching furnace for recycling, and the medium-temperature hot water is input into the waste heat boiler to replenish the water volume. Step 5: Repeat steps 1 to 4 until the dry quenching process is complete.

9. The dry quenching coke production process based on waste nitrogen cooling according to claim 8, characterized in that: In step 1, the temperature of the high-temperature red char is 950~1050℃; the nitrogen content in the waste nitrogen gas is 95%~98%; The waste nitrogen gas is cooled to 130~190℃ using a water-cooling tower and then sent into the dry quenching furnace through the bottom of the dry quenching furnace by a blower.

10. The dry quenching coke production process based on waste nitrogen cooling according to claim 8, characterized in that: In step 2, the temperature of the high-temperature circulating gas is 800~950℃; In step 3, the temperature of the medium-temperature circulating gas is 160~200℃; In step 4, the temperature of the low-temperature circulating gas is 130~160℃.

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