Device and method for improving air permeability of sintered material layer

Abstract

The invention discloses a device and method for improving air permeability of a sinter bed and relates to the field of ferrous metallurgy. The punching device comprises a punching support, a moving trolley and a punching assembly through a control center, the punching support is arranged above a trolley, the moving trolley is arranged on the punching support, an electric push rod is further arranged on the moving trolley, and the punching assembly is located at the bottom of the punching support and connected with a push rod at the bottom of the electric push rod. The punching devices are arranged above the trolley at intervals, the punching speed and the returning speed are controlled through the PLC control system, a series of uniform holes are formed in the material face of the sintering trolley, an ore forming belt hindering ventilation on the upper portion of a material layer of the sintering trolley is broken, the overall resistance of the ore forming belt is reduced, the vertical sintering speed and production efficiency are improved, and energy consumption is reduced. The method is beneficial to reducing the FeO content in the finished sinter, improving the reducing performance of the finished sinter, improving the quality and creating good raw material conditions for further increasing the yield and saving coke in blast furnace ironmaking.

Description

Technical Field

[0001] The invention relates to a device and a method for improving the air permeability of a sintering material layer, and relates to the field of iron and steel metallurgy. Background Art

[0002] Sintering is the most widely used method for agglomerating iron-containing raw materials by steel companies at home and abroad. The sintering process can be summarized as follows: the sintering mixture (iron-containing raw materials, fuel, flux and return ore, etc.) is mixed with an appropriate amount of water, mixed and granulated by a mixer, and then spread on the trolley of the sintering machine. After the surface of the sintering material is ignited, the fuel in the material layer burns from top to bottom and releases heat under the forced ventilation of the lower bellows. The mixture undergoes a series of physical and chemical changes under the action of high temperature and finally consolidates into sintered ore. Sintered ore, as a raw material for ironmaking, is composed of pelletized ore, lump ore, coke and other materials in a certain ratio and put into a blast furnace for smelting.

[0003] The sintering process has obvious stratification. According to the temperature changes and the physical and chemical reactions that occur, the sintering material layer is divided into five zones from top to bottom, namely: sintering ore zone, combustion zone, preheating and drying zone, water vapor condensation zone and original sintering material zone; the air flow flows through the sintering material layer, and the resistance loss per unit height of the material layer varies in each zone; the influence of the structure of the sintering raw material layer itself on the permeability can be improved by strengthening granulation, improving the particle size composition of raw materials, controlling reasonable moisture content, preheating the mixture, and mixing large particles into the sintering material; the influence of the gravity factor of the sintering cake in the sintering ore zone itself must be solved by other external means, such as installing appropriate supporting components on the sintering machine trolley to reduce the influence of the dead weight of the sintering cake in the sintering ore zone on the permeability of the sintering raw material layer.

[0004] Since the sintering mineralization zone has been consolidated into blocks, and with the continuous sintering process, the thickness of the sintering mineralization zone gradually increases, and the resistance to airflow also increases accordingly. How to reduce the resistance of the sintering mineralization zone itself and improve the permeability of the material layer is of great significance to improving the vertical sintering speed and production efficiency. Summary of the invention

[0005] The object of the present invention is to provide a device and method for improving the air permeability of the sintering material layer in view of the defects or shortcomings in the prior art. By arranging a punching device at intervals above the trolley and controlling the punching speed and the retracting speed through a PLC control system, a series of uniform holes are formed on the material surface of the sintering trolley, breaking the mineralization zone on the upper part of the sintering trolley material layer that hinders the permeability, reducing the overall resistance of the sintering mineralization zone, and increasing the amount of air and the flow rate passing through the sintering mineralization zone, the vertical sintering speed and production efficiency can be improved to a certain extent, and the energy consumption can be reduced; at the same time, the oxidizing atmosphere of the sintering process is enhanced, which is beneficial to reducing the FeO content in the finished sintered ore, improving the reduction performance of the finished sintered ore, and improving the quality, creating good raw material conditions for further increasing production and saving coke in blast furnace ironmaking.

[0006] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: it includes a punching device, which includes a punching bracket 1, a moving trolley 2, and a punching assembly 3 through a control center. The punching bracket is arranged above the trolley 5, and the moving trolley 2 is arranged on the punching bracket 1. An electric push rod 4 is also arranged on the moving trolley 2. The punching assembly 3 is located at the bottom of the punching bracket 1 and is connected to the push rod at the bottom of the electric push rod 4.

[0007] Furthermore, an igniter is provided at 30m in the opposite direction of the punching device and the trolley 5.

[0008] Furthermore, there are two groups of punching devices, the two groups of punching devices have the same structure and are arranged at a distance of 1m.

[0009] Furthermore, the punching assembly 3 includes five spike teeth 31, each spike tooth 31 is arranged at an interval of 900 mm, and the stroke of the spike teeth 31 is 500 mm.

[0010] Furthermore, a double layer of heat insulating asbestos 11 is provided on the surface of the perforated bracket 1 , and an anti-heat radiation panel 12 is provided on the bottom of the perforated bracket 1 .

[0011] Furthermore, the punching bracket 1 is provided with a track matching the moving trolley 2, and a position detection proximity switch 6 and a limit stop 7 are provided 30 m away from the igniter.

[0012] Furthermore, the cross section of the spike tooth 31 is an equilateral triangle with an arc groove in the middle, and the side length is 40 mm, forming a triangular pyramid structure.

[0013] Furthermore, the mobile trolley 2 is provided with a driving motor and rollers, the driving motor is controlled by a frequency converter, and the electric push rod 4 is also controlled by the frequency converter.

[0014] The working principle of the present invention is as follows: the sintering trolley and the punching device are controlled by a PLC control system, and the control system adopts a Siemens PLCs7-1500 system. At the same time, a control cabinet is provided on site, and automatic, manual and stop control buttons are arranged on the control cabinet. The trolley running speed and the punching device movement and punching speed are set in the control system according to production needs. During normal operation, the automatic button can be directly pressed to start normal punching operation. The punching device is located 30m away from the igniter. At this time, the position detection proximity switch 6 detects the punching device and feeds back a signal to the PLC system. The PLC program detects the current start and stop status of the trolley 5, the trolley 5 speed, the gas ignition and other signals, and determines that the trolley 5 is in normal production, and the punching device starts to work; according to the sintering trolley 5 speed signal, the rated speed of the motor of the mobile trolley 2, the reduction ratio and other parameters, the variable frequency output frequency of the mobile trolley 2 is automatically calculated, so that the moving speed of the mobile trolley 2 follows the ignition device. The trolley 5 moves at the same speed. At the same time, the electric push rod 4 starts to push the punching assembly 3 downward to punch holes. The punching depth is set to 300mm. The two sets of punching devices punch a total of 10 holes in a row. After the punching is completed, the electric push rod 2 retreats, driving the nail teeth 31 to retreat synchronously. The nail teeth 31 retreat 500mm to avoid interference and affect the stroke of the mobile trolley 2. The mobile trolley 2 moves in the opposite direction of the trolley 5 after the nail teeth 31 retreat into place. The retreat speed is twice the speed of the trolley 5. When it returns to the initial position, that is, 30m away from the igniter, the position detection proximity switch 6 detects the signal again, and feeds back to the control system to send a stop signal, waiting for the next operation cycle to start. The device operation cycle is the time required for the trolley 5 to travel a fixed distance. Through evenly spaced punching, a series of uniform holes are formed on the surface of the sintering trolley material, breaking the mineralization zone on the upper part of the sintering trolley material layer that hinders the permeability, thereby achieving the purpose of increasing the permeability of the trolley material layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0016] Figure 1 It is a schematic diagram of the structure of the present invention;

[0017] Figure 2 yes Figure 1 View from direction B at point A in the middle;

[0018] Figure 3 is a schematic structural diagram of the spike teeth 31 of the present invention;

[0019] Figure 4 yes Figure 3Middle CC section view;

[0020] Figure 5 It is a diagram showing the position of the sintering material in the present invention.

[0021] Explanation of the reference numerals: punching bracket 1 , moving trolley 2 , punching assembly 3 , electric push rod 4 , trolley 5 , position detection proximity switch 6 , limit stop 7 , double-layer thermal insulation asbestos 11 , anti-thermal radiation panel 12 , nail teeth 31 . DETAILED DESCRIPTION

[0022] See also Figure 1-Figure 5 As shown, the technical solution adopted in this specific embodiment is: a device for improving the air permeability of the sintering material layer, which includes a punching device, which is controlled by a central punching device. The punching device includes a punching bracket 1, a mobile trolley 2, and a punching assembly 3. The punching bracket is arranged above the trolley 5, and the mobile trolley 2 is arranged on the punching bracket 1. The mobile trolley 2 is also provided with an electric push rod 4. The punching assembly 3 is located at the bottom of the punching bracket 1 and is connected to the push rod at the bottom of the electric push rod 4. In this embodiment, a 360m2 sintering machine (trolley width 5m, effective sintering length 80m, trolley railing height 900mm) is used. , trolley length 1500mm, trolley travel speed is 0-2m / min, and the trolley travel speed is about 1.5m / min during normal production) as an example, the punching device is provided with an igniter 30m in the opposite direction of the trolley 5, and an igniter and a feeding device are provided above the trolley to carry out sintering operations. The punching device is arranged at a distance of 30m from the igniter, that is, at 1 / 3 of the effective sintering length. The thickness of the sintered mineralization zone here is about 300mm. There are two groups of punching devices, the two groups of punching devices have the same structure, and the movements are synchronized. The distance is set at 1m, see Figure 2 As shown, in this embodiment, position A is indicated, which is the punching device closest to the igniter side, 30m away from the igniter. After starting the equipment, the trolley starts to run, and the mobile trolley moves on the punching bracket. The control of the trolley and the mobile trolley is uniformly controlled by the Siemens PLCs7-1500 system. The electric push rod drives the punching assembly to punch holes on the sintering belt. The punching depth is 300mm, penetrating the sintering ore belt and the combustion zone, thereby forming a series of uniform holes on the material surface of the sintering trolley, reducing the overall resistance of the sintering ore-forming zone, increasing the air volume and flow rate passing through the sintering ore-forming zone, and can improve the vertical sintering speed and production efficiency and reduce energy consumption to a certain extent; at the same time, the oxidizing atmosphere of the sintering process is enhanced, which is beneficial to reduce the FeO content in the finished sintered ore, improve the reduction performance of the finished sintered ore, and improve the quality, creating good raw material conditions for further increasing production and saving coke in blast furnace ironmaking.

[0023] More specifically, the punching assembly 3 includes five spike teeth 31, each spike tooth 31 is arranged at an interval of 900mm, the stroke of the spike tooth 31 is 500mm, the cross-section of the spike tooth 31 is an equilateral triangle with an arc groove in the middle, the side length is 40mm, and a triangular pyramid structure is formed. In this embodiment, by setting a triangular pyramid spike tooth with a groove as a punching mechanism, the surface breaking effect can be increased and the extrusion to form a new condensation layer on the material surface can be reduced, and the punching stroke of the spike tooth is set to 500mm, which can ensure that the spike tooth completely withdraws from the sintering belt after the punching is completed and stays away from the sintering belt. In order to prevent the uneven material layer from hindering the movement of the trolley during the non-punching period, and to prevent the trolley from being out of sync with the trolley speed during the acceleration period when the device just starts to run, causing irregular punching, the first group of punching devices are provided with five spike teeth, and two groups can punch ten holes at the same time to ensure the air permeability of the material layer.

[0024] To be more specific, the surface of the punching bracket 1 is provided with a double layer of insulating asbestos 11, and the bottom of the punching bracket 1 is provided with an anti-heat radiation panel 12. Since the punching bracket is located above the trolley and close to the igniter, the amount of heat radiation is large, and the insulating asbestos is provided on the surface for heat insulation, and the anti-heat radiation panel 1 is provided on the bottom to effectively protect the bracket. In another embodiment, a double layer of insulating asbestos is also provided on the surface of the mobile trolley for heat insulation protection to extend the service life of the equipment.

[0025] To be more specific, the punching bracket 1 is provided with a track matching the mobile trolley 2, and a position detection proximity switch 6 and a limit stop 7 are provided 30m away from the igniter. The punching assembly is detected by setting the position detection proximity switch, specifically, the position of the mobile trolley is detected. The mobile trolley has a sensor plate corresponding to the nail tooth position. The switch is triggered when the sensor plate reaches the detection position. The position detection proximity switch feeds back the detection signal to the PLC control system, and the system issues an operation instruction and limits the mobile trolley through the limit stop to prevent movement out of range.

[0026] To be more specific, the mobile trolley 2 is provided with a drive motor and rollers, the drive motor is controlled by a frequency converter, and the electric push rod 4 is also controlled by a frequency converter. In this embodiment, the drive motor and the electric push rod of the mobile trolley are frequency-controlled by a PLC control system to ensure the accuracy of the stroke.

[0027] This embodiment also provides a method for improving the air permeability of a sintered material layer, which comprises the following steps:

[0028] Step 1, start the equipment, set the moving trolley 2, set the travel speed of the trolley 5, and set the retraction time of the moving trolley 2; in this embodiment, the travel speed is set to 1.5m / min, and the retraction speed of the moving trolley is 3m / min. After starting the equipment, when the field control box is in the automatic control state, the punching device is at the position A, the proximity switch detects the device to receive the signal, and feeds back to the PLC system. The PLC program detects the current trolley start and stop state, trolley speed and gas ignition signals, and determines that the trolley is in normal production. The device starts working, and the trolley and the moving trolley move synchronously;

[0029] Step 2, drilling; in this embodiment, the stroke of the electric push rod is 500 mm, the drilling depth is 300 mm, the drilling time is 20 seconds, the retraction is 10 seconds, and the drilling operation starts after the mobile trolley starts moving;

[0030] Step 3, the mobile trolley 2 retreats; the retreat time of the mobile trolley is the end time of the total stroke of the electric push rod. In this embodiment, it starts to retreat after 30s. At this time, the trolley has traveled about: 1.5*(30 / 60)=0.75m in the forward direction of the trolley. The trolley retreat speed is 3m / min, and the time taken for the trolley to retreat to point A is about: 0.75 / 3*60=15s. It can be obtained that when the device returns to point A, it has been running for 30+15=45s, and the time delay for the trolley to start accelerating forward and turn from forward to backward is about 5s, so it takes about 50s for the trolley to return to point A from the beginning of operation;

[0031] Step 4, stop punching and wait for the next punching to start; when the mobile trolley retreats to position A, the position detection proximity switch detects a signal and feeds back to the PLC control system, sending a stop signal. According to the trolley travel speed of 1.5m / min, the trolley travels 1.25m in 50s. At this time, the punching device punches two rows of holes each time, with a row distance of 1m. That is, the next cycle of the device will start punching when the trolley moves forward 2m, that is, the device needs to stop and wait for about (2-1.25) / 1.5*60=30s before starting the next cycle of punching (the specific downtime does not need to be calculated, it only needs to automatically calculate the time it takes for the trolley to move 2m according to the trolley movement speed and set it as the device operation cycle. The front and rear hole spacing can be adjusted by setting the cycle, and it only needs to ensure that the cycle is greater than 50s).

[0032] After adopting the above technical scheme, the beneficial effects of the present invention are as follows: by arranging the punching devices at intervals above the trolley and controlling the punching speed and the retracting speed through the PLC control system, a series of uniform holes are formed on the material surface of the sintering trolley, breaking the mineralization zone on the upper part of the material layer of the sintering trolley that hinders the air permeability, reducing the overall resistance of the sintering mineralization zone, increasing the amount of air and the flow rate passing through the sintering mineralization zone, which can improve the vertical sintering speed and production efficiency and reduce energy consumption to a certain extent; at the same time, the oxidizing atmosphere of the sintering process is enhanced, which is beneficial to reduce the FeO content in the finished sintered ore, improve the reduction performance of the finished sintered ore, improve the quality, and create good raw material conditions for further increasing the production and saving coke in blast furnace ironmaking.

[0033] The above description is only used to illustrate the technical solution of the present invention rather than to limit it. Other modifications or equivalent substitutions made to the technical solution of the present invention by ordinary technicians in this field should be included in the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solution of the present invention.

Claims

1. A device for improving the air permeability of a sintering material layer, characterized in that: The punching device comprises a punching bracket (1), a movable trolley (2), and a punching assembly (3) controlled by a control center. The punching bracket is arranged above the trolley (5), the movable trolley (2) is arranged on the punching bracket (1), an electric push rod (4) is also arranged on the movable trolley (2), and the punching assembly (3) is located at the bottom of the punching bracket (1) and is connected to the push rod at the bottom of the electric push rod (4).

2. The device for improving the air permeability of a sintering material layer according to claim 1, characterized in that: An igniter is arranged at 30m in the opposite direction of the travel of the punching device and the trolley (5).

3. The device for improving the air permeability of a sintering material layer according to claim 1, characterized in that: There are two groups of punching devices in total. The two groups of punching devices have the same structure and are arranged at a distance of 1m.

4. The device for improving the air permeability of a sintering material layer according to claim 1, characterized in that: The punching assembly (3) comprises five spike teeth (31), each spike tooth (31) is arranged at an interval of 900 mm, and the stroke of the spike teeth (31) is 500 mm.

5. The device for improving the air permeability of a sintering material layer according to claim 1, characterized in that: The surface of the perforated support (1) is provided with a double layer of heat insulating asbestos (11), and the bottom of the perforated support (1) is provided with an anti-heat radiation panel (12).

6. The device for improving the air permeability of a sintering material layer according to claim 1, characterized in that: The punching bracket (1) is provided with a track matching the moving trolley (2), and a position detection proximity switch (6) and a limit stop (7) are provided 30 meters away from the igniter.

7. The device for improving the air permeability of a sintering material layer according to claim 4, characterized in that: The cross section of the nail teeth (31) is an equilateral triangle with an arc groove in the middle, with a side length of 40 mm, forming a triangular pyramid structure.

8. The device for improving the air permeability of a sintering material layer according to claim 1, characterized in that: The mobile trolley (2) is provided with a driving motor and rollers. The driving motor is controlled by a frequency converter, and the electric push rod (4) is also controlled by the frequency converter.

9. A method for improving the air permeability of a sintering material layer, characterized in that: It includes the following steps: Step 1, start the equipment, set the moving trolley (2), set the travel speed of the trolley (5), and set the retraction time of the moving trolley (2); the travel speed is 1.5m / min, and the retraction speed of the moving trolley is 3m / min; Step 2, punching; Step 3, the moving trolley (2) moves back, and the moving trolley (2) moves back for the same time as the total stroke end time of the electric push rod (4); Step 4, stop punching and wait for the next punching to start; when the mobile trolley (2) retreats to position A, the position detection proximity switch (6) detects a signal and feeds it back to the PLC control system, which sends a stop signal. The time taken for the trolley (5) to move 2m is automatically calculated based on the moving speed of the trolley (5) and set as the device operation cycle.

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