Novel dry quenching coke powder cooling system

Abstract

The invention discloses a novel dry quenching coke powder cooling system. The system comprises a dry quenching furnace, a primary dust remover, a waste heat boiler, a secondary dust remover, a circulating fan and an auxiliary economizer which are sequentially connected through pipelines to form an inert gas circulation loop, the system further comprises a conveying branch and a coke powder cooling device. The coke powder cooling device comprises a barrel and an air distribution plate arranged in the barrel, the air distribution plate is in a horn shape, a plurality of ventilation holes are evenly distributed in the air distribution plate, and the air distribution plate is arranged close to the inner bottom of the barrel. One end of the conveying branch is communicated with a pipeline between the circulating fan and the auxiliary economizer, and the other end of the conveying branch is communicated with the bottom of the barrel; and the top of the barrel is communicated with the bottom of the primary dust remover. According to the invention, high-temperature coke powder falling from the primary dust remover is rapidly cooled under fluidization by using the cold inert gas, so that the sensible heat loss of the coke powder in dry quenching is reduced, and the heat efficiency of the dry quenching waste heat boiler is improved; and meanwhile, the abrasion and pipe explosion risks of the waste heat boiler are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of dry quenching coke powder cooling, and more specifically, to a novel dry quenching coke powder cooling system. Background Art

[0002] In the CDQ production process, the high-temperature nitrogen that replaces the sensible heat of the red coke passes through the primary dust collector for gravity dust removal and then generates 3.82 MPa medium-pressure steam through the waste heat boiler, which is then recovered by the steam turbine generator for power generation. The primary dust collector is set between the CDQ furnace and the waste heat boiler to remove the high-temperature dust (coke powder with a particle size of more than 1 mm) generated when the coke exchanges heat with the circulating gas, ensuring that the mass concentration of coke powder in the high-temperature flue gas entering the waste heat boiler is 10g / m 3 The following can reduce the scouring of boiler tubes, extend the service life of the boiler, and ensure the stable operation of the dry coke quenching device. The large red-hot coke powder settled in the primary dust collector is usually discharged after being cooled by a water-cooling jacket. Due to design defects and the influence of circulating water quality, the water-cooling jacket leaks after 3 to 6 months of use. Water vapor enters the closed circulating nitrogen system, causing the system H2 and CO to exceed the standard, posing an explosion hazard. In addition, if the large red-hot coke powder settled in the primary dust collector is not discharged in a timely and thorough manner, the coke powder will enter the waste heat boiler, increasing the risk of wear and burst of the waste heat boiler. Summary of the invention

[0003] The present invention provides a novel dry quenching coke powder cooling system, comprising a dry quenching coke oven, a primary dust collector, a waste heat boiler, a secondary dust collector, a circulating fan and an auxiliary economizer which are sequentially connected through pipelines to form an inert gas circulation loop; further comprising a conveying branch and a coke powder cooling device; the coke powder cooling device comprises a cylinder and an air distribution plate arranged inside the cylinder, the air distribution plate is trumpet-shaped and evenly distributed with a plurality of ventilation holes, and the air distribution plate is arranged close to the inner bottom of the cylinder; one end of the conveying branch is connected to the pipeline between the circulating fan and the auxiliary economizer, and the other end is connected to the bottom of the cylinder; the top of the cylinder is connected to the bottom of the primary dust collector.

[0004] Preferably, the cylinder comprises a plurality of cylinder segments, and two adjacent cylinder segments are connected via an expansion joint.

[0005] Preferably, the diameter of the air distribution plate gradually increases from bottom to top, and its inclination angle relative to the horizontal plane is 15°~60°; the top of the air distribution plate is fixedly connected to the inner wall of the cylinder, and the bottom of the air distribution plate is connected to one end of the coke discharge pipeline, and the other end of the coke discharge pipeline extends vertically downward from the bottom of the cylinder.

[0006] Preferably, a plurality of rows of ventilation holes are arranged on the air distribution plate along its circumference, and each row of ventilation holes is arranged at intervals along the radial direction of the air distribution plate; and the aperture of the ventilation holes is 5-20 mm.

[0007] Preferably, one end of the coke discharge pipeline extending out of the cylinder is provided with a dust removal and ash discharge valve and a shut-off valve in sequence.

[0008] Preferably, the height of the coke powder bed in the cylinder is 0.5-2 m.

[0009] Preferably, the cylinder is a water-cooled cylinder, which includes an outer wall, an inner wall and a cooling water channel arranged therebetween, and a water outlet and a water inlet of the cooling water channel are respectively connected to a water inlet and a water outlet of the auxiliary economizer.

[0010] Preferably, the air volume introduced into the coke powder cooling device through the conveying branch accounts for 0.5% to 3% of the total air volume at the outlet of the circulating fan.

[0011] Preferably, one end of the conveying branch connected to the cylinder is divided into a plurality of sub-branches, each of the sub-branches is symmetrically arranged about the center of the cylinder, and all extend into the bottom of the cylinder and face the air distribution plate.

[0012] The present invention has at least the following beneficial effects: 1. The novel dry quenching coke powder cooling system provided by the present invention provides a coke powder cooling device at the bottom of the primary dust collector, so that the coke powder does not need to be accumulated at the discharge port of the primary dust hopper, reducing the risk of secondary carryover of coke powder, thereby reducing the wear of the waste heat boiler and reducing the risk of pipe bursting of the waste heat boiler. The original inert gas is introduced into the coke powder cooling device through the conveying branch, and the high-temperature coke powder is quickly cooled under fluidization, and the high-temperature heat of the dry quenching coke powder is converted into high-temperature circulating inert gas heat. With the help of the waste heat boiler device itself, the high-temperature heat energy is recovered, the sensible heat loss of the dry quenching coke powder is reduced, and the thermal efficiency of the dry quenching coke waste heat boiler is improved, thereby improving the overall power generation efficiency; and the coke powder is cooled based on the inert gas, avoiding the use defects of conventional water-cooled jacket cooling.

[0013] 2. The novel dry quenching coke powder cooling system provided by the present invention forms fluidized wind at the inner bottom of the cylinder by arranging an air distribution plate at the inner bottom of the coke powder cooling device, so that the coke powder in the bed layer continuously surges to form a bubbling state, thereby achieving the purpose of uniformly cooling the coke powder. At the same time, the coke powder will not be brought into the waste heat boiler, further reducing the risk of secondary carryover of coke powder.

[0014] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic structural diagram of the novel dry quenching coke powder cooling system of the present invention; Figure 2 This is a schematic structural diagram of the coke powder cooling device of the present invention; Figure 3 It is a schematic structural diagram of the air distribution plate described in the present invention. DETAILED DESCRIPTION

[0016] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0017] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the reagents and materials are commercially available unless otherwise specified; in the description of the present invention, the terms "lateral", "longitudinal", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply 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 on the present invention.

[0018] like Figures 1 to 3 As shown, the present invention provides a novel dry quenching coke powder cooling system, comprising a dry quenching coke oven 1, a primary dust collector 2, a waste heat boiler 3, a secondary dust collector 4, a circulating fan 5 and an auxiliary economizer 6 which are sequentially connected through pipelines to form an inert gas circulation loop, and also comprising a conveying branch 7 and a coke powder cooling device 8; the coke powder cooling device 8 comprises a cylinder 81 and an air distribution plate 82 arranged inside the cylinder 81, the air distribution plate 82 is trumpet-shaped and evenly distributed with a plurality of ventilation holes 821, and the air distribution plate 82 is arranged close to the inner bottom of the cylinder 1; one end of the conveying branch 7 is connected to the pipeline between the circulating fan 5 and the auxiliary economizer 6, and the other end is connected to the bottom of the cylinder 81; the top of the cylinder 81 is connected to the bottom of the primary dust collector 2.

[0019] In this technical solution, the air outlet of the upper part of the dry quenching coke oven 1 is connected to the air inlet of the primary dust collector 2 through a pipeline, the air outlet of the primary dust collector 2 is connected to the air inlet of the waste heat boiler 3 through a pipeline, the air outlet of the waste heat boiler 3 is connected to the air inlet of the secondary dust collector 4, the air outlet of the secondary dust collector 4 is connected to the air inlet of the circulating fan 5 through a pipeline, the air outlet of the circulating fan 5 is connected to the air inlet of the auxiliary economizer 6 through a pipeline, and the air outlet of the auxiliary economizer 6 is connected to the air inlet at the bottom of the dry quenching coke oven 1 to form an inert gas circulation loop. Then, by arranging the coke powder cooling device 8 at the bottom of the primary dust collector 2, the coke powder does not need to be accumulated at the discharge port of the primary dust hopper, which reduces the risk of coke powder secondary carryover, reduces the wear of the waste heat boiler 3, and reduces the risk of pipe explosion of the waste heat boiler 3. The inert gas is introduced into the coke powder cooling device 8 through the conveying branch 7, and the high-temperature heat of the CDQ coke powder is converted into the heat of the high-temperature circulating inert gas in the coke powder cooling device 8. Preferably, the inert gas can be nitrogen.

[0020] Specifically, the coke enters the dry quenching coke oven 1, and the cold inert gas from the auxiliary economizer 6 at the bottom of the dry quenching coke oven 1 is used for gas-solid heat exchange, and the coke is cooled from 900°C to 150°C and discharged. The rising high-temperature circulating inert gas carries coke powder particles of different sizes into the primary dust collector 2, and is separated by gravity separation in the primary dust collector 2. The large particles of coke then fall into the coke powder cooling device 8 at the bottom through the coke powder ash hopper at the bottom, and are cooled to 150°C on the bed in the coke powder cooling device 8 and discharged. The high-temperature inert gas then enters the waste heat boiler 3 from the primary dust collector 2 to exchange heat with the water-cooled pipe to produce high-temperature steam for waste heat power generation. The cooled inert gas then enters the secondary dust collector 4, and dust removal measures such as bags are used in the secondary dust collector 4 for secondary dust removal to further reduce the dust content in the inert gas. After the circulating gas after dust removal is pressurized by the circulating fan 5, a small part is sent to the coke powder cooling device 8 through the conveying branch 7, and the rest is sent to the sub-economizer 6 for further cooling and waste heat recovery. The sub-economizer 6 is used to reduce the inert gas from 170°C to 130°C, and the cooled circulating gas enters the bottom of the dry quenching furnace to cool the high-temperature hot coke, and this cycle is repeated endlessly. Preferably, the sub-economizer 6 can use high-efficiency heat exchangers such as heat pipes, tubes in tubes, and plate-fin heat exchangers. On the one hand, the wall temperature of the heat exchanger is increased to reduce condensation of the circulating gas, and on the other hand, the hot water outlet temperature of the sub-economizer 6 is regulated to ensure that the hot water temperature does not exceed the maximum water temperature requirement of the deaerator water.

[0021] In another technical solution, the cylinder 81 includes a plurality of cylinder segments, and two adjacent cylinder segments are connected by an expansion joint so that the coke powder cooling device 8 can expand freely up and down.

[0022] In another technical solution, Figure 2 and Figure 3 As shown, the diameter of the air distribution plate 82 gradually increases from bottom to top, and its inclination angle θ relative to the horizontal plane is 15°~60°; the top of the air distribution plate 82 is fixedly connected to the inner wall of the cylinder 81, and the bottom of the air distribution plate 82 is connected to one end of the coke discharge pipeline 83, and the other end of the coke discharge pipeline 83 extends vertically downward from the bottom of the cylinder 81.

[0023] The air distribution plate 82 is provided with a plurality of rows of ventilation holes along its circumference, and each row of ventilation holes is arranged at intervals along the radial direction of the air distribution plate 82; the aperture of the ventilation holes is 5-20 mm.

[0024] One end of the coke discharge pipeline 83 extending out of the cylinder 81 is provided with a dust removal and ash discharge valve 84 and a shut-off valve 85 in sequence.

[0025] In the initial stage, after the coke powder enters the coke powder cooling device 88, the inert gas pressurized by the circulating fan 5 is introduced at the bottom, and the coke powder forms a coke powder bed layer with a lower temperature at the bottom of the cylinder 81 under the action of the inert gas. The high-temperature coke powder that falls subsequently exchanges heat with the inert gas in a countercurrent flow, and continues to fully mix and exchange heat with the low-temperature coke powder at the bottom after falling to the bottom; the inert gas introduced at the bottom forms fluidized wind, so that the coke powder in the bed layer continuously surges on the air distribution plate 82 to form a bubbling state, so as to achieve the purpose of uniform cooling of the coke powder, and finally the coke powder is uniformly discharged after being cooled to 150°C, avoiding the problem of hot coke powder directly entering the low-temperature coke powder bin in the traditional coke powder cooling sleeve.

[0026] In another technical solution, the height h of the coke powder bed in the cylinder 81 is 0.5~2m. By controlling the height h of the coke powder bed, the falling coke powder is evenly mixed with the cold coke powder in the bed, so that the discharge temperature of the coke powder is uniform and stable. The fluidization at the bottom of the cylinder 81 is different from conventional fluidized bed combustion, fluidized bed solid waste treatment and other devices. It mainly cools high-temperature coke powder. Due to the difference in physical properties, the fluidization device needs to control the appropriate airflow rate. At the same time, by reasonably adjusting the coke powder feeding rate, the stability of the coke powder bed height is ensured. Preferably, a pressure monitoring device can also be set on the conveying branch 7, and the change of the bed height can be monitored in real time by the change of gas pressure.

[0027] In another technical solution, the cylinder 81 is a water-cooled cylinder, which includes an outer wall, an inner wall, and a cooling water channel arranged therebetween, and the water outlet and water inlet of the cooling water channel are respectively connected to the water inlet and water outlet of the auxiliary economizer 6. The cooling efficiency is improved by the water-cooled cylinder, so that the bottom coke powder forms a bed area with a temperature in the range of 150°C under the dual water cooling of the cooled inert gas and the water-cooled cylinder. Preferably, the water-cooled cylinder uses desalted water as cooling water. The desalted water then enters the auxiliary economizer 6 for heat exchange to recover part of the waste heat.

[0028] In another technical solution, the air volume introduced into the coke powder cooling device 8 through the conveying branch 7 accounts for 0.5% to 3% of the total air volume at the outlet of the circulating fan 5. By controlling the air volume introduced into the coke powder cooling device 8, the gas-to-solid ratio at the bottom of the cylinder 81 is 1000 to 1100 m / s. 3 / t.

[0029] In another technical solution, one end of the conveying branch 7 connected to the cylinder 81 is divided into a plurality of sub-branches 71, each of which is symmetrically arranged about the center of the cylinder 81 and extends into the bottom of the cylinder 81 and toward the air distribution plate 82. Through the plurality of sub-branches 71, it is ensured that the inert gas introduced into the cylinder 81 can be uniformly passed to the air distribution plate 82, so that the coke powder in the bed can be uniformly cooled.

[0030] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A novel dry quenching coke powder cooling system, comprising a dry quenching coke oven, a primary dust collector, a waste heat boiler, a secondary dust collector, a circulating fan and a secondary economizer which are sequentially connected through pipelines to form an inert gas circulation loop, characterized in that: It also includes a conveying branch and a coke powder cooling device; the coke powder cooling device includes a cylinder and an air distribution plate arranged inside the cylinder, the air distribution plate is trumpet-shaped and evenly distributed with multiple ventilation holes, and the air distribution plate is arranged close to the inner bottom of the cylinder; one end of the conveying branch is connected to the pipeline between the circulating fan and the auxiliary economizer, and the other end is connected to the bottom of the cylinder; the top of the cylinder is connected to the bottom of the primary dust collector.

2. The novel dry quenching coke powder cooling system according to claim 1, characterized in that: The cylinder comprises a plurality of cylinder segments, and two adjacent cylinder segments are connected via an expansion joint.

3. The novel dry quenching coke powder cooling system according to claim 1, characterized in that: The diameter of the air distribution plate gradually increases from bottom to top, and its inclination angle relative to the horizontal plane is 15°~60°; the top of the air distribution plate is fixedly connected to the inner wall of the cylinder, and the bottom of the air distribution plate is connected to one end of the coke discharge pipeline, and the other end of the coke discharge pipeline extends vertically downward from the bottom of the cylinder.

4. The novel dry quenching coke powder cooling system according to claim 3, characterized in that: The air distribution plate is provided with a plurality of rows of ventilation holes along its circumference, and each row of ventilation holes is arranged at intervals along the radial direction of the air distribution plate; and the aperture of the ventilation holes is 5-20 mm.

5. The novel dry quenching coke powder cooling system according to claim 3, characterized in that: One end of the coke discharge pipeline extending out of the cylinder is provided with a dust removal and ash discharge valve and a cut-off valve in sequence.

6. The novel dry quenching coke powder cooling system according to claim 1, characterized in that: The height of the coke powder bed in the cylinder is 0.5-2m.

7. The novel dry quenching coke powder cooling system according to claim 1, characterized in that: The cylinder is a water-cooled cylinder, which includes an outer wall, an inner wall and a cooling water channel arranged therebetween. The water outlet and the water inlet of the cooling water channel are respectively connected to the water inlet and the water outlet of the auxiliary economizer.

8. The novel dry quenching coke powder cooling system according to claim 1, characterized in that: The air volume introduced into the coke powder cooling device through the conveying branch accounts for 0.5% to 3% of the total air volume at the outlet of the circulating fan.

9. The novel dry quenching coke powder cooling system according to claim 1, characterized in that: One end of the conveying branch connected to the cylinder is divided into a plurality of sub-branches, each of which is symmetrically arranged about the center of the cylinder, and all extend into the bottom of the cylinder and face the air distribution plate.

Images