Dry quenching system

Abstract

The utility model discloses a dry quenching system which comprises a dry quenching furnace and a vertical external heating type pyrolyzing furnace, an annular flue of the dry quenching furnace is communicated with a combustion chamber of the pyrolyzing furnace, a flue gas outlet of the combustion chamber is sequentially connected with a primary dust remover, a primary air heat exchanger, a secondary dust remover, a secondary air heat exchanger and a circulating fan, and an outlet of the circulating fan is divided into two paths, the diffusion gas path is divided into two paths, one path is connected with a decarburization device, the other path is connected with a positive pressure gas protection cavity outside the pyrolyzing furnace, a carbon dioxide outlet of the decarburization device is connected with the bottom of a carbonization chamber through a carbon dioxide fan, and the top of the carbonization chamber is connected with a purification system through a gas collecting pipe; an air outlet of the primary air heat exchanger is connected with the combustion chamber, and an air outlet of the secondary air heat exchanger is connected with the low-rank coal hot air dehydration device. According to the utility model, the dry quenching furnace is coupled with the vertical externally-heated pyrolyzing furnace, so that the heat of red coke is comprehensively and efficiently utilized, the production operation is simplified, and water, energy and investment are saved.

Description

Technical Field

[0001] This utility model relates to the field of dry quenching technology, and in particular to a dry quenching system. Background Technology

[0002] Dry quenching, or dry coke quenching for short, involves using an inert gas (nitrogen) to exchange heat with high-temperature coke (red coke) in a dry quenching oven. The coke is cooled to a suitable temperature (below 180°C) and discharged. The inert gas (nitrogen) is then heated to a high temperature and sent to a waste heat boiler to exchange heat with demineralized water. The inert gas is then cooled to 160°C and discharged from the boiler to a circulating fan. The inert gas is then blown back into the dry quenching oven to exchange heat with the red coke in a counter-current flow. The demineralized water is heated into high-temperature, high-pressure steam, which is then sent to a turbine to generate electricity. This cycle continues, transferring heat from the red coke to the steam for power generation, while the coke temperature decreases from 1050°C to 180°C. This process has been used for nearly half a century since its development. Current technological development in dry quenching remains based on this process principle, focusing on increasing processing capacity, but without in-depth research into the process itself.

[0003] However, the above-mentioned technology has the following problems: 1. The heat from the red-hot coke is used to generate electricity through steam, resulting in low energy utilization efficiency; 2. Frequent accidents in the waste heat boiler affect the normal production of dry quenching coke ovens; 3. Waste heat boilers and steam turbine generators are production equipment subject to mandatory national inspection, requiring qualified personnel to operate them, which poses a challenge to the training of personnel in traditional coking enterprises; 4. Due to the influence of boiler materials, the temperature of the circulating gas at the boiler inlet generally cannot exceed 1050℃; 5. The boiler requires the replenishment of demineralized water and circulating cooling water, resulting in large water consumption, which poses a significant problem in water-scarce areas; 6. The combustible components in the circulating gas burn in the inclined duct outlet and the annular flue, generating thermal stress on the annular flue, affecting the structural stability and service life of the annular flue; 7. The high-temperature coke particles contained in the circulating gas exiting the inclined duct are removed in the primary dust collector, cooled, and then discharged for use as fuel, resulting in poor energy utilization.

[0004] In view of this, we propose a brand-new dry quenching coke system that eliminates the drawbacks of using waste heat boilers and steam turbines for dry quenching coke production, fully and efficiently utilizes the heat of red coke, simplifies production operations, saves water and energy, and reduces investment. Utility Model Content

[0005] The purpose of this invention is to provide a dry quenching coke system to solve the problems existing in the prior art. By coupling the dry quenching coke oven with a vertical external heating pyrolysis furnace, the drawbacks of using waste heat boilers and steam turbines for dry quenching coke production are eliminated. This system fully and efficiently utilizes the heat of red coke, simplifies production operations, saves water and energy, and reduces investment.

[0006] To achieve the above objectives, this utility model provides the following solution:

[0007] This utility model provides a dry quenching coke system, including a dry quenching furnace and a vertical externally heated pyrolysis furnace. The annular flue of the dry quenching furnace is connected to the combustion chamber of the pyrolysis furnace. The flue gas outlet of the combustion chamber of the pyrolysis furnace is sequentially connected to a primary dust collector, a primary air heat exchanger, a secondary dust collector, a secondary air heat exchanger, and a circulating fan. The circulating fan outlet is divided into two paths: one path connects to a venting gas path, and the other path connects to the upper and lower gas chambers of the dry quenching furnace. The venting gas path is also divided into two paths: one path connects to a decarburization device, and the other path connects to a positive pressure system outside the pyrolysis furnace. The gas protection chamber is connected to a carbon dioxide fan via the carbon dioxide outlet of the decarbonization device. The outlet of the carbon dioxide fan is connected to the bottom of the carbonization chamber inside the pyrolysis furnace. The top of the carbonization chamber is connected to a purification system via a gas collection pipe. The air inlet of the primary air heat exchanger is connected to a first air blower. The air outlet of the primary air heat exchanger is connected to the combustion chamber of the pyrolysis furnace. The air inlet of the secondary air heat exchanger is connected to a second air blower. The air outlet of the secondary air heat exchanger is connected to a low-rank coal hot air dehydration device.

[0008] In one embodiment, the primary dust collector is a cyclone dust collector or an inertial dust collector.

[0009] In one embodiment, the secondary dust collector is a bag filter or a cyclone dust collector.

[0010] In one embodiment, the combustion chamber of the pyrolysis furnace is provided with an air passage. The upper end of the air passage extends to the top of the combustion chamber of the pyrolysis furnace and is connected to the air outlet of the primary air heat exchanger. The lower end of the air passage extends to the bottom of the combustion chamber of the pyrolysis furnace and communicates with the combustion chamber of the pyrolysis furnace.

[0011] In one embodiment, the air outlet of the low-rank coal hot air dehydration device is connected to an air condenser.

[0012] In one embodiment, the combustion chamber of the pyrolysis furnace is provided with a desulfurization-decarbonization agent inlet and an ash discharge outlet.

[0013] The present invention achieves the following technical advantages over the prior art:

[0014] The dry quenching coke system provided by this utility model couples the dry quenching furnace with a vertical external heating pyrolysis furnace, and transfers the heat of high-temperature coke (red coke) to the heat required for the pyrolysis of low-rank coal through the dry quenching coke circulating gas. This eliminates the drawbacks of using waste heat boilers and steam turbines for dry quenching coke production, fully and efficiently utilizes the heat of red coke, simplifies production operations, saves water and energy, and saves investment. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a flow chart of the dry quenching process in an embodiment of this utility model.

[0017] In the diagram: 1-Dry quenching furnace, 2-Pyrolysis furnace, 3-Annular flue, 4-Primary dust collector, 5-Primary air heat exchanger, 6-Secondary dust collector, 7-Secondary air heat exchanger, 8-Circulating fan, 9-Decarbonization device, 10-Positive pressure gas protection chamber, 11-Carbon dioxide fan, 12-First air blower, 13-Second air blower, 14-Low-rank coal hot air dehydration device, 15-Air condenser. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] The purpose of this invention is to provide a dry quenching coke system to solve the problems existing in the prior art. It couples the dry quenching coke oven with a vertical external heating pyrolysis furnace, making full and efficient use of the heat from the red coke, simplifying production operations, saving water and energy, and reducing investment.

[0020] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Example 1

[0022] like Figure 1As shown, this embodiment provides a dry quenching coke system, including a dry quenching furnace 1 and a vertical externally heated pyrolysis furnace 2. The vertical externally heated pyrolysis furnace 2 is equipped with an independent carbonization chamber and a combustion chamber. The annular flue 3 of the dry quenching furnace 1 is connected to the combustion chamber of the pyrolysis furnace 2. The flue gas outlet of the combustion chamber of the pyrolysis furnace 2 is sequentially connected to a primary dust collector 4, a primary air heat exchanger 5, a secondary dust collector 6, a secondary air heat exchanger 7, and a circulating fan 8. The outlet of the circulating fan 8 is divided into two paths: one path connects to the venting gas path, and the other path connects to the upper and lower dry quenching gas chambers of the dry quenching furnace 1. The venting gas path is also divided into two paths: one path connects to the decarbonization device 9, and the other path connects to the positive pressure gas protection chamber 10 outside the pyrolysis furnace 2. The carbon dioxide outlet of the decarbonization device 9 is connected to the carbon dioxide blower 11. The air outlet of the carbon dioxide blower 11 is connected to the bottom of the carbonization chamber inside the pyrolysis furnace 2. The top of the carbonization chamber is connected to the purification system through the gas collection pipe. The air inlet of the primary air heat exchanger 5 is connected to the first air blower 12. The air outlet of the primary air heat exchanger 5 is connected to the combustion chamber of the pyrolysis furnace 2. The air inlet of the secondary air heat exchanger 7 is connected to the second air blower 13. The air outlet of the secondary air heat exchanger 7 is connected to the low-rank coal hot air dehydration device 14, which is used to heat and dehydrate the low-rank coal. The dehydrated low-rank coal is sent to the carbonization chamber of the pyrolysis furnace 2 for pyrolysis and carbonization.

[0023] In this embodiment, the decarbonization device 9 uses the amine method to separate carbon dioxide. The primary dust collector 4 is a cyclone dust collector or an inertial dust collector. The secondary dust collector 6 is a bag filter dust collector or a cyclone dust collector.

[0024] In this embodiment, the combustion chamber of the pyrolysis furnace 2 is provided with an air passage. The upper end of the air passage extends to the top of the combustion chamber of the pyrolysis furnace 2 and connects to the air outlet of the primary air heat exchanger 5. The lower end of the air passage extends to the bottom of the combustion chamber of the pyrolysis furnace 2 and connects to the combustion chamber of the pyrolysis furnace 2. The air, after being heated by the primary air heat exchanger 5, enters the air passage in the combustion chamber. As it flows downward in the air passage within the combustion chamber, it is gradually heated. Finally, it is ejected from the bottom of the combustion chamber and mixes with the combustible gas and coke powder in the dry quenching circulating gas for combustion, heating the furnace wall of the carbonization chamber and indirectly transferring heat to the carbonization chamber.

[0025] In this embodiment, the air outlet of the low-rank coal hot air dehydration device 14 is connected to the air condenser 15. After the air is heated and dehydrated by the low-rank coal in the low-rank coal hot air dehydration device 14, it is condensed and dehydrated by the air condenser 15, and the condensate is collected. The dehydrated air is then released.

[0026] In this embodiment, the combustion chamber of the pyrolysis furnace 2 is equipped with a desulfurization-decarbonization agent inlet and an ash discharge port to facilitate the addition of desulfurization and decarbonization agents for desulfurization and decarbonization treatment, and to facilitate the discharge of ash and slag.

[0027] Example 2

[0028] like Figure 1 As shown, this embodiment provides a dry quenching process, based on the dry quenching system described in Embodiment 1, including:

[0029] The dry quenching circulating gas enters the combustion chamber of the pyrolysis furnace 2 through the annular flue of the dry quenching furnace 1. In the combustion chamber of the pyrolysis furnace 2, the combustible gas and coke powder in the dry quenching circulating gas are burned, providing heat to the pyrolysis furnace 2. The air introduction rate is controlled according to the maximum combustion to burn the combustible gas and coke powder as thoroughly as possible. Then the dry quenching circulating gas is discharged from the combustion chamber of the pyrolysis furnace 2 and passes through the primary dust collector 4, the primary air heat exchanger 5, the secondary dust collector 6, the secondary air heat exchanger 7, and the circulating fan 8 in sequence.

[0030] After passing through the circulating fan 8, the dry quenching coke circulating gas is divided into two paths. One path enters the venting gas path, and the other path enters the upper and lower dry quenching coke gas chambers of the dry quenching furnace 1 to continue participating in the cooling process of the red coke in the dry quenching furnace 1. Then, it is circulated into the combustion chamber of the pyrolysis furnace 2 through the annular flue 3 of the dry quenching furnace 1.

[0031] The dry quenching gas entering the venting gas path is divided into two paths. One path enters the positive pressure gas protection chamber 10 outside the pyrolysis furnace 2 to form a positive pressure gas protection for the pyrolysis furnace 2 and prevent air from seeping into the circulating gas due to cracks in the refractory material. The other path uses the alkanolamine method to separate carbon dioxide and obtain carbon dioxide and nitrogen.

[0032] The separated carbon dioxide is introduced into the bottom of the carbonization chamber inside the pyrolysis furnace 2. It first exchanges heat with the semi-coke discharged from the pyrolysis furnace 2. The carbon dioxide is preheated and the semi-coke is cooled. Then the preheated carbon dioxide enters the high-temperature zone at the bottom of the carbonization chamber and undergoes a gasification reaction with the semi-coke. The generated carbon monoxide rises with the carbon dioxide and enters the dry distillation zone, preheating zone and drying zone of the carbonization chamber in sequence. Finally, it is discharged from the carbonization chamber with the dry distillation gas and then enters the purification system through the gas collection pipe for purification treatment.

[0033] Alternatively, some water vapor is mixed into the separated carbon dioxide, and then the mixture of carbon dioxide and water vapor is introduced into the bottom of the carbonization chamber in pyrolysis furnace 2. It first exchanges heat with the semi-coke discharged from pyrolysis furnace 2, preheating the carbon dioxide and water vapor and cooling the semi-coke. Then, the preheated carbon dioxide and water vapor enter the high-temperature zone at the bottom of the carbonization chamber and react with the semi-coke to form a gasification reaction. The generated hydrogen and carbon monoxide rise together with the carbon dioxide and water vapor and enter the dry distillation zone, preheating zone and drying zone of the carbonization chamber in sequence. Finally, they are discharged from the carbonization chamber together with the dry distillation gas and then enter the purification system through the gas collection pipe for purification treatment.

[0034] The first air blower 12 blows air into the primary air heat exchanger 5, where it exchanges heat with the dry quenching circulating gas before being introduced into the combustion chamber of the pyrolysis furnace 2; the residual heat of the dry quenching circulating gas is further used to preheat the air introduced into the combustion chamber.

[0035] The second air blower 13 blows air into the secondary air heat exchanger 7. After heat exchange with the dry quenching coke circulating gas, the low-rank coal is heated and dehydrated, further utilizing the waste heat of the dry quenching coke circulating gas. The dehydrated low-rank coal is sent to the carbonization chamber of the pyrolysis furnace 2 for pyrolysis carbonization. The air after heat exchange is discharged after condensation and water removal, and the collected condensed water is obtained.

[0036] In this process, the combustible gas is introduced into the combustion chamber of the pyrolysis furnace 2 for combustion, and the temperature can be greater than 1050 °C, generally around 1300 °C. The combustible gas burns in the combustion chamber of the pyrolysis furnace 2, avoiding the disadvantages of thermal stress on the annular flue due to combustion at the inclined flue outlet and in the annular flue, which affects the structural stability and service life of the annular flue.

[0037] In this embodiment, the primary air heat exchanger 5 preheats the air to 230 °C - 300 °C;

[0038] The secondary air heat exchanger 7 preheats the air to 230 °C - 280 °C, and the dry quenching coke circulating gas is cooled to below 60 °C;

[0039] Generally speaking, the moisture content of low-rank coal is relatively high, about 20 - 30%, or even higher. This process heats and dehydrates the low-rank coal with hot air, reducing the moisture content of the low-rank coal to below 10%, which is beneficial to reducing the heat required for pyrolysis and the wastewater content in the pyrolysis gas.

[0040] The purification technology of low-rank coal pyrolysis gas is basically the same as that of conventional coke oven gas purification technology. Therefore, in this utility model, for the dry quenching coke supporting conventional coke ovens, the pyrolysis gas of the pyrolysis furnace 2 is directly incorporated into the coke oven raw gas pipeline, and the coke oven gas purification technology can be used for treatment. The pyrolysis gas is cooled by ammonia water spraying, gas-liquid separation, condensation and blowing, desulfurization and other purification units to complete the purification of the pyrolysis gas. The light tar separated from the pyrolysis gas is distilled to obtain gasoline and diesel. The phenolic wastewater is treated to obtain phenolic products.

[0041] For the case of dry quenching coke supporting heat recovery coke ovens, since the heat recovery coke oven does not have a raw gas purification unit, the coke oven raw gas is directly introduced into the coke oven combustion chamber for combustion to generate high-temperature flue gas, and the heat of the high-temperature flue gas is recovered by a waste heat boiler for power generation. Therefore, in this case, a separate purification system needs to be set up for the purification treatment of the pyrolysis gas of the pyrolysis furnace 2. In this purification system, it can be treated according to the above-mentioned coke oven gas purification technology.

[0042] This utility model uses specific examples to illustrate its principles and implementation methods. The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the idea of ​​this utility model. In summary, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A dry quenching system, characterized in that: The system includes a dry quenching furnace and a vertical externally heated pyrolysis furnace. The annular flue of the dry quenching furnace is connected to the combustion chamber of the pyrolysis furnace. The flue gas outlet of the combustion chamber of the pyrolysis furnace is sequentially connected to a primary dust collector, a primary air heat exchanger, a secondary dust collector, a secondary air heat exchanger, and a circulating fan. The circulating fan outlet is divided into two paths: one path connects to a venting gas path, and the other path connects to the upper and lower gas chambers of the dry quenching coke chamber of the dry quenching furnace. The venting gas path is also divided into two paths: one path connects to a decarbonization device, and the other path connects to a positive pressure gas protection chamber outside the pyrolysis furnace. The carbon dioxide outlet of the decarbonization device is connected to a carbon dioxide blower. The outlet of the carbon dioxide blower is connected to the bottom of the carbonization chamber inside the pyrolysis furnace. The top of the carbonization chamber is connected to the purification system through a gas collection pipe. The air inlet of the primary air heat exchanger is connected to a first air blower. The air outlet of the primary air heat exchanger is connected to the combustion chamber of the pyrolysis furnace. The air inlet of the secondary air heat exchanger is connected to a second air blower. The air outlet of the secondary air heat exchanger is connected to a low-rank coal hot air dehydration device.

2. The dry quenching system according to claim 1, characterized in that: The primary dust collector is either a cyclone dust collector or an inertial dust collector.

3. The dry quenching system according to claim 1, characterized in that: The secondary dust collector is either a bag filter or a cyclone dust collector.

4. The dry quenching system according to claim 1, characterized in that: The combustion chamber of the pyrolysis furnace is provided with an air passage. The upper end of the air passage extends to the top of the combustion chamber of the pyrolysis furnace and is connected to the air outlet of the primary air heat exchanger. The lower end of the air passage extends to the bottom of the combustion chamber of the pyrolysis furnace and is connected to the combustion chamber of the pyrolysis furnace.

5. The dry quenching system according to claim 1, characterized in that: The air outlet of the low-rank coal hot air dehydration device is connected to an air condenser.

6. The dry quenching system according to claim 1, characterized in that: The combustion chamber of the pyrolysis furnace is equipped with a desulfurization-decarbonization agent inlet and an ash discharge outlet.

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