Tower groove combined bottom filtration method for blast furnace slag treatment and device

Abstract

The application provides a new type of blast furnace slag treatment method and device of tower groove combined bottom filtration method, and belongs to the technical field of blast furnace slag treatment.The blast furnace slag treatment method provided by the application comprises the following steps: shortening the length of a water slag groove, canceling a turning structure of the water slag groove, arranging a transverse slag groove for reducing the kinetic energy of a slag water mixture at the outlet of the water slag groove, and widening the width of the tail end of the water slag groove.The application adds a variable diameter design at the tail end of the water slag groove, widens the width of the slag groove, reduces the flow rate of the slag water mixture at the variable diameter position, adds a transverse slag groove, adds a drop design at the joint position of the water slag groove and the transverse slag groove, that is, there is a height difference between the bottom of the water slag groove and the bottom of the transverse slag groove, and the bottom of the water slag groove is higher than the bottom of the transverse slag groove, the slag treatment process of "directly dropping" can further reduce the speed of the slag water mixture entering the transverse slag groove in a short distance, compared with the prior art, the length of the slag groove can be greatly shortened, the turning radius of the slag groove can be canceled, the investment can be reduced, and the layout of the furnace front area can be optimized.

Description

Technical Field

[0001] This invention belongs to the field of blast furnace slag treatment technology, and particularly relates to a novel bottom filtration method and apparatus for blast furnace slag treatment that combines tower and trench. Background Technology

[0002] Bottom filtration is a process for treating blast furnace slag. After the blast furnace slag enters the slag flushing channel, water from a granulation head with a multi-hole nozzle is sprayed into it, and the slag-water mixture flows along the flushing channel into a filter tank for filtration and dewatering.

[0003] Powered by the hot water pump, water from the filter tank flows through the filter layer and porous branch pipes to the main pipe, entering the elevated cooling tower. The cooled water is stored in the slag flushing water tank below. The slag flushing pump then pumps water from the storage tank to the furnace for slag flushing. Therefore, slag flushing and filtration occur simultaneously, with coordinated and unified operation in a closed-loop cycle. After slag flushing is complete, the slag flushing pipe gate is closed, and the pump stops. At this time, the hot water pump is still running. When the water level in the filter tank drops to equal to or slightly below the surface of the I-beam mesh in the tank, all the slag is exposed, and the gate is closed. Slag removal is then performed. After slag removal, the slag flushing pump is started, and the gate of the backflushing water pipe is opened accordingly, allowing water to enter the filter tank as backfill water for the next slag flush, thus protecting the integrity of the filter layer. The pump stops after 5 minutes, the gate is closed, and the cycle is complete, awaiting the next slag flush. The above procedure is repeated.

[0004] The above-mentioned actions, such as slag flushing, filtration, and backflushing, are initiated by signals from the water level gauge and manually activated. To ensure reliable water level control, in addition to the water level gauge, a water level pressure gauge is also installed, along with audible and visual alarms.

[0005] Traditional bottom filtration slag treatment processes require long slag channels and large turning radii (over 15 meters) to reduce the flow velocity of the slag-water mixture entering the filter tank and to protect the refractory material in the bend sections of the slag channel. Figure 1 As shown, this creates difficulties in the layout of the ironmaking area. Furthermore, the slag pool occupies a large area in front of the furnace, resulting in a "difficult layout" and "large footprint" for the slag treatment area. For large blast furnaces, there are many tapholes, requiring separate placement of the slag treatment system's filter pool areas (such as...). Figure 2 As shown in the figure, equipment utilization will decrease.

[0006] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0007] To address the technical problems of "difficult layout", "large footprint" and "low equipment utilization" in the existing bottom filtration blast furnace slag treatment process, a novel bottom filtration blast furnace slag treatment method and device combining tower and trench is provided.

[0008] The first aspect of this invention provides a novel bottom-filtration method for treating blast furnace slag, comprising: shortening the molten slag flow path, eliminating the bend structure of the slag ditch, and increasing the molten slag drop difference; Widen the end of the slag ditch.

[0009] In some embodiments, the length of the slag ditch is shortened and the bend structure of the slag ditch is eliminated, and a transverse slag ditch is set at the outlet of the slag ditch to reduce the kinetic energy of the slag-water mixture. In some implementations, a tower-ditch combination is used, including a first slag trench and a second slag trench: The molten slag flowing out of the first slag trough comes into contact with the water sprayed by the granulator, and the granulated slag-water mixture flows along the water-slag trough toward the horizontal slag trough. The slag flowing out of the second slag ditch is processed by the granulation tower, and the resulting slag-water mixture flows along the water-slag ditch to the horizontal slag ditch.

[0010] In some embodiments, the water slag ditch is positioned higher than the horizontal slag ditch.

[0011] In some embodiments, the horizontal slag ditch is arranged perpendicularly to the water slag ditch; And / or, the horizontal slag ditch is provided with a slag-resistant and impact-resistant plate at a position opposite to the outlet of the water slag ditch.

[0012] A drop-down design is incorporated at the junction of the water slag ditch and the horizontal slag ditch, meaning there is a height difference between the bottom of the water slag ditch and the bottom of the horizontal slag ditch, with the bottom of the water slag ditch being higher than that of the horizontal slag ditch. At the same time, an anti-slag and impact-resistant plate is installed at the outlet of the horizontal slag ditch directly opposite the outlet of the water slag ditch. When the slag-water mixture falls from the water slag ditch into the horizontal slag ditch, the kinetic energy of the slag-water mixture acts on the anti-slag and impact-resistant plate and the refractory material at the bottom of the horizontal slag ditch, and part of the kinetic energy of the slag-water mixture is lost, thereby reducing the flow velocity of the slag-water mixture.

[0013] In addition, a variable diameter design is added to the end of the slag ditch to widen the ditch and reduce the flow velocity of the slag-water mixture at the variable diameter point.

[0014] In some embodiments, water replenishment points are provided at both ends of the horizontal slag ditch.

[0015] Because both the "direct-fall" process and the granulation tower reduce the flow velocity of the slag-water mixture, and the horizontal slag ditch has no slope, there is a possibility of insufficient slag kinetic energy in the ditch. To prevent slag accumulation due to reduced flow fluidity, water replenishment points are set at both ends of the horizontal slag ditch to improve the flow capacity of the slag-water mixture. The slag-water mixture in the horizontal slag ditch enters the filter tank through the slag ditch valve, where it undergoes filtration and dewatering. The bottom filter pump unit pumps water from the filter tank to the cooling tower and then into the cold water tank to achieve slag-water separation. After filtration, the grab bucket crane performs slag removal operations in the filter tank. After the slag removal operation, the granulation pump unit connects water to the filter tank through the backwash pipeline for backwashing. The pump is stopped after 5 minutes, the gate is closed, and the cycle is completed, awaiting the next slag flush. The above procedure is repeated.

[0016] A second aspect of the present invention provides a novel bottom-filtration blast furnace slag treatment device, comprising a first slag trough and a second slag trough; The slag flowing out of the first slag trough comes into contact with the water sprayed by the granulator, and the granulated slag-water mixture flows along the water-slag trough toward the horizontal slag trough; The slag flowing out of the second slag ditch is processed by the granulation tower, and the resulting slag-water mixture flows along the water-slag ditch to the horizontal slag ditch.

[0017] In some embodiments, the granulator is located below the outlet of the first slag ditch, and the transverse slag ditch is located below the outlet of the water slag ditch.

[0018] In some embodiments, the width of the slag ditch gradually widens along the flow direction of the slag-water mixture, or the end of the slag ditch is widened.

[0019] In some embodiments, the horizontal slag ditch is provided with a slag-resistant and impact-resistant plate at a position opposite to the outlet of the water slag ditch.

[0020] In some embodiments, water replenishment points are provided at both ends of the horizontal slag ditch.

[0021] The aforementioned novel bottom-filtration blast furnace slag treatment device incorporates a variable-diameter design at the end of the water slag ditch to widen the ditch, thereby reducing the flow velocity of the slag-water mixture at the variable-diameter point. The water slag ditch is positioned higher than the horizontal slag ditch, and a drop design is added at the junction of the water slag ditch and the horizontal slag ditch, meaning there is a height difference between the bottom of the water slag ditch and the bottom of the horizontal slag ditch, with the bottom of the water slag ditch being higher than the bottom of the horizontal slag ditch. When the slag-water mixture falls from the water slag ditch into the horizontal slag ditch, the kinetic energy of the slag-water mixture acts on the slag-resistant and impact-resistant plate on the side of the horizontal slag ditch and the refractory material on the bottom surface of the horizontal slag ditch, causing part of the kinetic energy of the slag-water mixture to disappear, thereby further reducing the flow velocity of the slag-water mixture.

[0022] The aforementioned novel bottom-filtration blast furnace slag treatment device employs a two-stage process: one stage uses a "direct-flow drop" process to reduce the velocity of the slag-water mixture, while the other stage uses a granulation tower to further reduce its velocity. Since the horizontal slag ditch has no slope, there is a possibility of insufficient slag kinetic energy after the slag-water mixture flows into it. To prevent slag accumulation due to reduced flowability, water replenishment points are installed at both ends of the ditch to improve the flow capacity of the slag-water mixture. The slag-water mixture in the ditch enters the filter tank through the ditch valve, where it undergoes filtration and dewatering. The bottom filter pump unit pumps water from the filter tank to a cooling tower, which then enters a cold water tank, achieving slag-water separation. After filtration, a grab bucket crane performs slag-grabbing operations on the filter tank. After slag-grabbing, the granulation pump unit connects water to the filter tank through a backwash pipeline for backwashing. After 5 minutes, the pump stops, the gate is closed, and the cycle is complete, awaiting the next slag flush. This process is repeated.

[0023] Compared with existing technologies, the technical effects achieved by this invention are as follows: (1) On the one hand, the present invention adds a variable diameter design at the end of the water slag ditch to widen the slag ditch and reduce the flow velocity of the slag-water mixture at the variable diameter point; on the other hand, the present invention adds a horizontal slag ditch and adds a drop design at the junction of the water slag ditch and the horizontal slag ditch, that is, there is a height difference between the bottom of the water slag ditch and the bottom of the horizontal slag ditch, with the bottom of the water slag ditch being higher than the bottom of the horizontal slag ditch. When the slag-water mixture falls from the water slag ditch into the horizontal slag ditch, the slag treatment process of "direct impact drop" can further reduce the speed at which the slag-water mixture enters the horizontal slag ditch within a short distance; compared with the prior art, the present invention can greatly shorten the length of the slag ditch and eliminate the turning radius of the slag ditch, reduce investment and optimize the layout of the furnace front area.

[0024] (2) The kinetic energy of the slag-water mixture flowing from the slag ditch to the horizontal slag ditch acts on the anti-slag and impact-resistant plate on the side of the horizontal slag ditch and the refractory material on the bottom of the horizontal slag ditch. Part of the kinetic energy of the slag-water mixture is absorbed and disappears by the anti-slag and impact-resistant plate and the refractory material on the bottom of the horizontal slag ditch, thereby further reducing the flow velocity of the slag-water mixture.

[0025] (3) The technical solution provided by the present invention adopts the "tower-ditch combination" process, which is highly flexible. According to the characteristics of the equipment itself, the "multiple ditches and one tower" or "multiple towers and one ditch" process is used for slag flushing. The slag-water mixture flowing out from different directions converges into the same filter pool in the horizontal slag ditch. This allows the filter pool, slag flushing pump and upper tower pump, overhead crane and other equipment that should have been arranged in different locations to be built together, thereby improving equipment utilization and reducing production costs. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of an existing blast furnace slag treatment device; Figure 2 This is a schematic diagram of another existing blast furnace slag treatment device; Figure 3 A schematic diagram of the novel bottom-filtration blast furnace slag treatment device provided by the present invention; Figure 4 This is a schematic diagram of the novel bottom filtration method for blast furnace slag treatment using a tower-groove combination provided by the present invention. Figure 5 for Figure 4 Side view of the structure of the device; In the picture: 1 Blast Furnace; 2 Filter Pool; 3 Pump Room; 4 Slag Trench; 4-1 First Slag Trench; 4-2 Second Slag Trench; 5 Water Slag Trench; 6 Temporary Slag Stack; 7 Granulation Tower; 8-1 First Granulator; 8-2 Second Granulator; 9 Horizontal Slag Trench; 10 Water Slag Trench Valve; 11 Bottom Filter Pipe; 12 Multi-stage Filter Layer; 13 Protective Frame; 14 Receiving Hopper; 15 Conveyor Belt; 16 Overhead Crane Grab Bucket; 17 Cold Water Pool; 18 Cooling Tower; 19 Granulation Pump Set; 20 Granulation Pipeline; 21 Bottom Filter Pump Set; 22 Backflushing Pipeline; 23 Return Water Pipeline; 24 Horizontal Slag Trench Valve; 25 Slag-resistant and Shock-resistant Plate; 26 Water Makeup Pipe. Detailed Implementation

[0027] The technical solution of the present invention will be described below with reference to the accompanying drawings and specific embodiments. It should be understood that the one or more steps mentioned in the present invention do not preclude the existence of other methods and steps before or after the combined steps, or that other methods and steps may be inserted between these explicitly mentioned steps. It should also be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Unless otherwise stated, the numbering of each method step is only for the purpose of identifying each method step, and not for limiting the order of each method or limiting the scope of the present invention. Changes or adjustments to their relative relationships, without substantial changes to the technical content, can also be considered as within the scope of the present invention.

[0028] The raw materials and instruments used in the examples are not subject to any specific restrictions on their source; they can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0029] Figure 1 , Figure 2 This is a common blast furnace slag treatment device in existing technology. The slag produced by blast furnace 1 is discharged from the slag trough 4, and the slag-water mixture obtained from the granulation trough flows to the water-slag trough 5. In order to reduce the flow velocity of the slag-water mixture into the filter pool 2 and protect the refractory material of the slag trough in the bend section, a long slag trough length and a large bend radius of the water-slag trough (more than 15 meters) are required. Alternatively, the flow velocity of the slag-water mixture can be reduced by the granulation tower 7. The filtered slag is piled up in the temporary slag heap 6. For large blast furnaces with many tapholes, it is necessary to arrange the slag treatment system filter pool area separately, which occupies a large space and results in low equipment utilization.

[0030] To address the technical problems existing in the prior art, a novel bottom-filtration method for blast furnace slag treatment is provided, comprising: shortening the length of the slag-water ditch and eliminating its bend structure; setting a transverse slag ditch at the outlet of the slag-water ditch to reduce the kinetic energy of the slag-water mixture; the slag-water ditch being positioned higher than the transverse slag ditch; the transverse slag ditch being perpendicular to the slag-water ditch; and an anti-slag-impact plate being installed in the transverse slag ditch opposite the outlet of the slag-water ditch. When the slag-water mixture falls from the slag-water ditch into the transverse slag ditch, the kinetic energy of the mixture acts on the anti-slag-impact plate and the refractory material at the bottom of the transverse slag ditch, causing partial loss of kinetic energy and thus reducing the flow velocity of the slag-water mixture.

[0031] In some implementations, the width of the end of the slag channel is increased. A variable diameter design is added to the end of the slag channel to widen the channel, thereby reducing the flow velocity of the slag-water mixture at the variable diameter point.

[0032] In some implementations, a tower-ditch combination is used, including a first slag trench and a second slag trench: The molten slag flowing out of the first slag trough comes into contact with the water sprayed by the granulator, and the granulated slag-water mixture flows along the water-slag trough toward the horizontal slag trough. The slag flowing out of the second slag ditch is processed by the granulation tower, and the resulting slag-water mixture flows along the water-slag ditch to the horizontal slag ditch.

[0033] The slag flowing out of the first slag channel is granulated by the granulator. The resulting slag-water mixture has its flow velocity greatly reduced by changing the width of the end of the slag-water channel and the drop design of the slag-water channel flowing into the horizontal slag channel. The slag flowing out of the second slag channel is granulated by the granulator. The resulting slag-water mixture is decelerated in the granulation tower and then flows out, where it merges with the slag from the first slag channel in the horizontal slag channel.

[0034] In some embodiments, water replenishment points are set at both ends of the horizontal slag ditch. Since both the "direct flushing" process and the granulation tower reduce the flow velocity of the slag-water mixture, and the horizontal slag ditch has no slope, there is a possibility that the slag in the horizontal slag ditch may lack sufficient kinetic energy. In order to prevent the slag flow from weakening and accumulating, water replenishment points are set at both ends of the horizontal slag ditch to improve the flow capacity of the slag-water mixture.

[0035] The slag-water mixture in the slag ditch enters the filter tank through the slag ditch valve, where it undergoes filtration and dewatering. The bottom filter pump unit pumps water from the filter tank to the cooling tower and then into the cold water tank, achieving slag-water separation. After filtration, the grab bucket crane performs slag removal from the filter tank. After the slag removal operation is completed, the granulation pump unit introduces water into the filter tank through the backwash pipeline for backwashing. The pump stops after 5 minutes, the gate is closed, and the cycle is complete, awaiting the next slag flush. The above procedure is repeated.

[0036] like Figures 3-5As shown, a novel bottom-filtration blast furnace slag treatment device combining tower and slag channels includes a first slag channel 4-1 and a second slag channel 4-2. The slag flowing out of the first slag channel 4-1 is optimized by reducing the slag flow rate and changing the slag path. The slag in the second slag channel 4-2 is further reduced by the granulation tower 7, and then merges with the slag discharged from the first slag channel 4-1 and enters the subsequent treatment system together.

[0037] Below the outlet of the first slag trench 4-1, there is a first granulator 8-1. The slag flowing out of the first slag trench 4-1 comes into contact with the water sprayed by the first granulator 8-1. The slag-water mixture obtained after granulation flows along the water-slag trench 5 to the horizontal slag trench 9. Below the outlet of the second slag trough 4-2, there is a second granulator 8-2. The slag flowing out of the second slag trough 4-2 is processed by the granulation tower 7, and the resulting slag-water mixture flows to the horizontal slag trough 9, where it merges with the slag-water mixture processed by the first granulator 8-1.

[0038] In some embodiments, the width of the slag ditch 5 gradually widens along the flow direction of the slag-water mixture, or the end of the slag ditch is widened.

[0039] In some embodiments, the horizontal slag ditch 9 is provided with a slag-resistant and impact-resistant plate 25 at a position opposite to the outlet of the water slag ditch 5.

[0040] A variable-diameter design is added to the end of the slag ditch 5 to reduce the flow velocity of the slag-water mixture at the variable-diameter point. The slag ditch 5 is positioned higher than the transverse slag ditch 9. A drop design is added at the junction of the slag ditch 5 and the transverse slag ditch 9, meaning there is a height difference between the bottom of the slag ditch 5 and the bottom of the transverse slag ditch 9, with the bottom of the slag ditch 5 being higher than the bottom of the transverse slag ditch 9. When the slag-water mixture falls from the slag ditch 5 into the transverse slag ditch 9, the kinetic energy of the mixture acts on the anti-slag and impact-resistant plate 25 on the side of the transverse slag ditch 9 and the refractory material on the bottom surface of the transverse slag ditch, causing some of the kinetic energy to disappear, thus further reducing the flow velocity of the slag-water mixture. The transverse slag ditch has no slope, so when the slag-water mixture flows into the transverse slag ditch, there is a possibility that the slag in the transverse slag ditch may lack sufficient kinetic energy. To prevent the slag flow from weakening and clogging due to slag accumulation, in some embodiments, water replenishment points 26 are set at both ends of the transverse slag ditch 9 to improve the flow capacity of the slag-water mixture.

[0041] The aforementioned novel bottom-filtration blast furnace slag treatment device has two streams. One stream of slag-water mixture originates from the first molten slag trough 4-1. By widening the slag trough at the end of the water-slag trough 5 and combining it with the "direct-flow drop" process (the water-slag trough 5 is higher than the horizontal slag trough 9), the flow velocity of the slag-water mixture is reduced. The other stream of slag-water mixture originates from the second molten slag trough 4-2. The flow velocity of the slag-water mixture is reduced by the granulation tower 7. The two streams of slag-water mixture converge into the horizontal slag trough 9. The slag-water mixture enters the filter tank 2 by opening the horizontal slag trough valve 24 and the water-slag trough valve 10. The filter tank 2 is equipped with a multi-stage filter layer 12 and a protective frame 13. Filtration and dewatering are carried out in the filter tank 2. The bottom filter pump group 21 pumps the water in the filter tank 2 to the cooling tower 18 through the bottom filter pipe 11 and then into the cold water tank 17 to achieve slag-water separation. After filtration, the overhead crane grab bucket 16 performs slag grabbing operation on the filter tank 2. The slag is collected by the overhead crane grab bucket 16 through the receiving hopper 14 onto the slag conveyor belt 15 and then transported outside the plant by the slag conveyor belt 15. After the slag removal operation is completed, the granulation pump unit 19 sends water through the granulation pipeline 20 and the backwash pipeline 22 into the filter tank 2 to achieve backwashing. After 5 minutes, the pump is stopped, the gate is closed, and the cycle is completed. Then, it waits for the next slag flushing and repeats the above procedure.

[0042] In some implementations, a construction method of "multiple trenches and one tower" or "multiple towers and one trench" can be adopted according to actual needs.

[0043] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A bottom-filtration method for treating blast furnace slag, characterized in that, include: Shorten the slag flow path, eliminate the bend structure of the slag ditch, and increase the slag drop distance; Widen the end of the slag ditch; The method employs a combination of tower and trench, including a first slag trench and a second slag trench: The molten slag flowing out of the first slag trough comes into contact with the water sprayed by the granulator, and the granulated slag-water mixture flows along the water-slag trough toward the horizontal slag trough. The slag flowing out of the second slag ditch is processed by the granulation tower, and the resulting slag-water mixture flows along the water-slag ditch to the horizontal slag ditch. The water slag ditch is located higher than the horizontal slag ditch; The horizontal slag ditch is set perpendicularly to the water slag ditch; The horizontal slag ditch is equipped with a slag-resistant and impact-resistant plate at the position opposite to the outlet of the water slag ditch.

2. The bottom-filtration method for treating blast furnace slag according to claim 1, characterized in that, Water replenishment points are set at both ends of the horizontal slag ditch.

3. A bottom-filtration blast furnace slag treatment device applicable to the treatment method described in claim 1.

4. The bottom-filtration blast furnace slag treatment device according to claim 3, characterized in that, The granulator is located below the outlet of the first molten slag ditch, and the horizontal slag ditch is located below the outlet of the water slag ditch.

5. The bottom-filtration blast furnace slag treatment device according to claim 4, characterized in that, The width of the slag ditch gradually increases along the flow direction of the slag-water mixture.

6. The bottom-filtration blast furnace slag treatment device according to claim 4, characterized in that, Water replenishment points are set at both ends of the horizontal slag ditch.

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