A distribution device and a discharging method for reducing distribution segregation of a top of a shaft furnace

Abstract

The application discloses a kind of reducing and tank type blast furnace top distribution segregation distribution device and discharging method, it is related to blast furnace ironmaking technical field, including material tank, T type pipe discharging hopper, center throat pipe and blanking mechanism, the inside of T type pipe discharging hopper is equipped with rectangular discharging chamber, the bottom wall of T type pipe discharging hopper is equipped with T type pipe discharging hopper discharge port, the inside left and right sides bottom end of T type pipe discharging hopper is equipped with platform, can make furnace burden natural accumulation and form material pile, the material tank discharge port is located in the just above of platform;The section of center throat pipe is oval, and the upper end of center throat pipe is communicated with the discharge port of hopper.The application improves the phenomenon of furnace burden drop point and quality segregation at blast furnace throat circumference when distributing in the aspect of parallel tank type no material bell distribution device, on the other hand, the mutual collision between furnace burden can be increased to form material pile, so as to protect the scouring and wearing of furnace burden to T type pipe discharging hopper and center throat pipe, prolongs the service life of both.

Description

Technical Field

[0001] This invention relates to the field of blast furnace ironmaking technology, and in particular to a charging device and charging method for reducing the segregation of the charging material at the top of a double-boiler blast furnace. Background Technology

[0002] Blast furnace ironmaking is the most crucial and resource-intensive stage in the entire steel production process. Long-term blast furnace production practice has proven that a rational gas flow distribution is the core of blast furnace operation. The upper charge distribution process refers to the process of distributing ore and coke into the furnace throat according to a prescribed system using a charging device. The distribution of the charge within the furnace directly affects factors such as the morphology of the bulk zone, the rate of chemical reaction between the gas and solid phases, and the permeability of the bulk zone. In other words, by adjusting the distribution of the charge in the upper part of the blast furnace, normal furnace conditions such as smooth operation and gas utilization are ensured; upper charge distribution influences the gas flow distribution.

[0003] Due to its strong material feeding capacity, high fault tolerance, flexible material feeding, and convenient maintenance, and because it solves the sealing requirements of blast furnaces, the parallel-bottle bell-less charging device is widely used in the top charging equipment of large blast furnaces both domestically and internationally.

[0004] However, due to the special structure of the two charge tanks of the bell-less charging device, which deviates from the center line of the bottom discharge port of the blast furnace, there is a phenomenon of charge drop point and quality segregation at the throat of the blast furnace during charging, which has an adverse effect on blast furnace production. Summary of the Invention

[0005] The purpose of this invention is to provide a method for reducing the segregation of the charge at the top of a parallel-boiler blast furnace, which solves or partially solves the technical problems of charge landing point and mass segregation at the blast furnace throat during the charging of a parallel-boiler bell-less charging device in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a charging device for reducing charge segregation at the top of a blast furnace, which is installed at the top of the blast furnace and includes: a charge hopper, a T-shaped charging funnel, a central throat, and a charging mechanism.

[0008] The two charging hoppers are symmetrically distributed around the center line of the blast furnace. The bottom of each charging hopper is provided with a charging hopper outlet, which is parallel to the blast furnace axis and is vertically downward.

[0009] The T-shaped tube feeding funnel has a rectangular feeding chamber inside, and the inlet of the rectangular feeding chamber is connected to the outlet of the material tank. The bottom wall of the T-shaped tube feeding funnel has a T-shaped tube feeding funnel outlet, which is located at the center of the bottom end of the rectangular feeding chamber. The interior of the T-shaped tube feeding funnel is provided with at least two platforms, and the at least two platforms are arranged radially opposite to each other along the outlet of the T-shaped tube feeding funnel. The furnace charge in the material tank falls to the platform through the outlet of the material tank and naturally accumulates on the platform to form a material pile. The outlet of the material tank is located directly above the platform.

[0010] The cross-section of the central throat is elliptical, the feed end of the central throat is connected to the discharge port of the T-shaped tube discharge funnel, and the vertical projections of at least two of the platforms are located on both sides of the central throat.

[0011] The feeding end of the feeding mechanism is connected to the discharge end of the central throat.

[0012] According to the material distribution device for reducing material segregation at the top of a blast furnace provided by the present invention, the center line of the discharge port of the T-shaped tube charging hopper, the center line of the central throat pipe, and the center line of the blast furnace are on the same straight line.

[0013] According to the present invention, the material distribution device for reducing the segregation of the top charge of a blast furnace is provided, wherein the inner angle of the charge pile formed by the platform is greater than the outer angle, and the inner angle is equal to or approximately equal to the natural angle of the charge.

[0014] According to the material distribution device for reducing and reducing the segregation of the top charge of a blast furnace provided by the present invention, the inner angle of the material pile formed by the platform is 25-45° and the outer angle is 0-15°.

[0015] According to the material distribution device for reducing material segregation at the top of a blast furnace provided by the present invention, the height of the center line of the material pile formed at the platform is 200-900mm.

[0016] According to the present invention, the ratio of the minor axis of the elliptical central throat pipe to the diameter of the material tank outlet is 0.6-0.8; and the ratio of the major axis of the elliptical central throat pipe to the diameter of the material tank outlet is 1.2-1.5.

[0017] According to the present invention, the charging device for reducing the segregation of the charging material at the top of a blast furnace includes a chute, which is connected to the central throat pipe, and the discharge port of the charging tank is perpendicular to the plane formed by the rotation of the chute.

[0018] Secondly, the present invention provides a method for feeding a charging device to reduce the segregation of the charging charge at the top of a blast furnace. The method using the aforementioned charging device for reducing the segregation of the charging charge at the top of a blast furnace includes the following steps:

[0019] Step 1: With both feed hoppers closed, open one of the feed hoppers, allowing the furnace charge in one of the feed hoppers to fall vertically onto one of the platforms inside the T-tube feed hopper. The furnace charge accumulates on one of the platforms, and as the amount of the first pile increases, the first pile is formed.

[0020] Step 2: When the inner angle of the first pile reaches 25-45°, the furnace charge in one hopper continues to fall into the first pile. After being decelerated by the first pile, it slowly slides into the central throat pipe with an elliptical cross section until the furnace charge in one hopper is emptied.

[0021] Step 3: Close the discharge port of one hopper and open the discharge port of the other hopper, so that the furnace charge in the other hopper falls vertically to another platform in the T-tube discharge funnel. The furnace charge accumulates on the other platform. As the amount of the second pile increases, a second pile is formed.

[0022] Step 4: When the inner angle of the second pile reaches 25-45°, the furnace charge in the other hopper continues to fall into the second pile. After being decelerated by the second pile, it slowly slides into the central throat pipe with an elliptical cross section until the furnace charge in the other hopper is emptied.

[0023] Step 5: Repeat steps 1-4 until the fabric is finished.

[0024] The advantages and effects of this invention are:

[0025] 1. Because the upper end of the T-tube feeding hopper is connected to the discharge port of the charging hopper, the furnace charge first enters the T-tube feeding hopper. The vertical projections of the throttling valves controlling the material flow in the two charging hoppers are located on both sides of the T-tube feeding hopper. Therefore, the furnace charge first contacts the platform of the T-tube feeding hopper. As the furnace charge falls, it begins to accumulate at the platform of the T-tube feeding hopper, forming a pile. As the volume of the pile increases, the furnace charge slowly moves towards the discharge port of the T-tube feeding hopper. A pile with an inner angle of 25-45°, an outer angle of 0-10°, and a centerline height of 200-900mm can be formed at the platform of the T-tube feeding hopper to buffer the kinetic energy of the material flow descending from the discharge port of the charging hopper, reduce the horizontal velocity of the furnace charge, and improve the phenomenon of the furnace charge descending along the opposite side of the central throat.

[0026] 2. The upper end of the elliptical central throat is connected to the discharge port of the T-shaped tube feeding hopper. Since the material pile formed at the platform of the T-shaped tube feeding hopper has a buffering effect on the material flow, the furnace charge velocity has been reduced. Therefore, the furnace charge will slowly slide into the elliptical central throat and will not cause the phenomenon of the material flow velocity being too high and hitting the opposite side of the central throat. On the one hand, it improves the phenomenon of charge landing point and mass segregation at the circumference of the blast furnace throat during charging by the bell-less charging device. On the other hand, the formed charge pile can increase the mutual collision between charges, thereby protecting the charge from erosion and wear on the T-tube charging hopper and the central throat, and extending their service life. After the charge enters the elliptical-section central throat, the charge flow becomes more concentrated, and the center line of the charge flow is closer to the center line of the blast furnace, which can reduce the extreme value of the charge landing point trajectory on the chute, and can further improve the phenomenon of charge landing point and mass segregation at the circumference of the blast furnace throat during charging by the bell-less charging device. Since the charging mechanism is connected to the lower end of the elliptical-section central throat, the charge will enter the blast furnace through the charging mechanism. Attached Figure Description

[0027] Figure 1 (a) is a schematic diagram of a charging device for reducing the segregation of the charging material at the top of a blast furnace according to an embodiment of the present invention; (b) is a top view of a T-shaped tube cross-section.

[0028] Figure 2 A schematic diagram of the material pile formed by the material flow in the plane of the T-shaped pipe according to an embodiment of the present invention;

[0029] Figure 3 A schematic diagram of the trajectory of the furnace charge falling on the chute after the Y-shaped tube is replaced with a T-shaped tube in an embodiment of the present invention;

[0030] Figure 4 A schematic diagram illustrating the movement of the furnace charge during the descent of the Y-shaped tube and T-shaped tube feeding hoppers according to an embodiment of the present invention;

[0031] Figure 5 A schematic diagram of the trajectory of the charge falling at the throat of the furnace when the Y-shaped tube is replaced with a T-shaped tube in an embodiment of the present invention;

[0032] Figure 6 A schematic diagram of the trajectory of the furnace charge falling on the chute after the central throat tube with a circular cross-section is changed to a central throat tube with an elliptical cross-section in an embodiment of the present invention.

[0033] Figure 7 Schematic diagrams showing the movement of furnace charge in central throats with different cross-sections according to embodiments of the present invention;

[0034] Figure 8 A schematic diagram of the trajectory of the furnace charge at the furnace throat after the circular central throat is replaced with an elliptical central throat in an embodiment of the present invention;

[0035] Figure 9A schematic diagram of 12 regions around the furnace throat in an embodiment of the present invention;

[0036] Figure 10 A schematic diagram of the pellet stockpile formed at the platform in an embodiment of the present invention;

[0037] Figure 11 A schematic diagram of the material flow distribution at the end of the central throat of the pellets according to an embodiment of the present invention;

[0038] Figure 12 A schematic diagram of the furnace charge mass distribution in each region of the five rings of pellet ore feeding according to an embodiment of the present invention;

[0039] Figure 13 A schematic diagram of the furnace charge mass distribution in each region of the pellet ore feeding rings 1-5 of this invention;

[0040] Figure 14 A schematic diagram illustrating the variation trend of pellet feed flow velocity with feeding time in an embodiment of the present invention;

[0041] Figure 15 A schematic diagram illustrating the variation trend of pellet ore flow velocity during the feeding time of 39-43s in an embodiment of the present invention;

[0042] Figure 16 Schematic diagram of the standard deviation of furnace charge quality in embodiments of the present invention: Y-type tube feeding funnel + round tube and T-type tube feeding funnel + elliptical tube.

[0043] Figure 17 A schematic diagram of the coke pile formed at the platform in an embodiment of the present invention;

[0044] Figure 18 A schematic diagram of the coke flow distribution at the end of the central throat in an embodiment of the present invention;

[0045] Figure 19 A schematic diagram of the mass distribution of furnace charge in each region of the 12 rings of coke feeding in an embodiment of the present invention;

[0046] Figure 20 A schematic diagram of the furnace charge mass distribution in each region of coke feeding rings 1-12 of this invention;

[0047] Figure 21 A schematic diagram illustrating the variation trend of coke feed velocity with feeding time in an embodiment of the present invention;

[0048] Figure 22 A schematic diagram illustrating the variation trend of coke material flow velocity during the feeding time of 70-75s in an embodiment of the present invention;

[0049] Figure 23 Schematic diagram of the standard deviation of furnace charge quality in embodiments of the present invention: Y-type tube feeding funnel + round tube and T-type tube feeding funnel + elliptical tube.

[0050] In the picture:

[0051] 1. Material tank,

[0052] 2. T-shaped tube feeding funnel, 2-1. Rectangular feeding chamber, 2-2. Platform.

[0053] 3. Central throat tube,

[0054] 4. Material feeding mechanism, 4-1. Chute. Detailed Implementation

[0055] To better understand the purpose, structure, and function of this invention, the following description is provided in conjunction with the appendix. Figure 1-23 The present invention provides a more detailed description of the charging device and feeding method for reducing the segregation of the charging material at the top of a double-boiler blast furnace.

[0056] The bell-less charging device with two charging hoppers is one of the main pieces of equipment for charging large blast furnaces. It consists of two charging hoppers, a Y-shaped charging funnel, a central throat, and a chute. Because the centerline of the discharge port at the bottom of the charging hopper deviates from the blast furnace centerline, the charge falls along the opposite side of the central throat during its descent, causing a distribution point and mass segregation of the charge around the throat circumference. Previous researchers have tried to improve this distribution segregation by reducing the diameter of the central throat and improving its internal structure. Reducing the diameter of the central throat directly shortens the trajectory of the charge on the chute, but it affects the normal descent of the charge, and in severe cases, can cause blockages.

[0057] Improving the internal structure of the central throat can be divided into two parts: First, adding an inner lining that facilitates flow can reduce the scouring and wear of the furnace charge on the central throat, but it is not effective in improving the segregation of the charge. Second, designing the central throat at an angle so that when the furnace charge is fed along the inner wall of the central throat, it will converge towards the center. However, when the charge flow is large, this design will also affect the normal downward flow of the furnace charge, and in severe cases, it will cause blockage.

[0058] This invention improves the bell-less charging device by replacing the Y-shaped charging hopper with a T-shaped charging hopper and the circular central throat with an elliptical central throat. The platform of the T-shaped charging hopper increases the interaction between the charges, thereby increasing the kinetic energy loss during the charge descent and reducing the horizontal velocity of the charges. The elliptical central throat can reduce the radial trajectory of the charges on the chute, ultimately improving the landing point and mass segregation of the charges at the blast furnace throat.

[0059] See Figure 1 This invention provides a charging device for reducing the segregation of the charging material at the top of a blast furnace, which is installed at the top of the blast furnace; it includes: a charging hopper 1, a T-shaped charging funnel 2, a central throat pipe with an elliptical cross section 3, and a charging mechanism 4.

[0060] The two material tanks 1 are symmetrically distributed around the center line of the blast furnace. The bottom of each material tank 1 is provided with a material tank outlet, which is parallel to the blast furnace axis and is vertically downward.

[0061] The T-shaped tube feeding funnel 2 has a rectangular feeding chamber 2-1 inside. The inlet of the rectangular feeding chamber 2-1 is connected to the outlet of the material tank. The bottom wall of the T-shaped tube feeding funnel 2 has a T-shaped tube feeding funnel outlet. The outlet of the T-shaped tube feeding funnel is located at the center of the bottom end of the rectangular feeding chamber 2-1. The T-shaped tube feeding funnel 2 has at least two platforms 2-2 inside. The at least two platforms 2-2 are arranged radially opposite to each other along the outlet of the T-shaped tube feeding funnel. The furnace charge in the material tank 1 falls to the platform 2-2 through the outlet of the material tank and naturally accumulates on the platform 2-2 to form a material pile. The outlet of the material tank is located directly above the platform 2-2.

[0062] The cross-section of the central throat 3 is elliptical. The feed end of the central throat 3 is connected to the discharge port of the T-shaped tube discharge funnel. The vertical projections of the two platforms 2-2 are located on both sides of the central throat 3.

[0063] The feeding end of the feeding mechanism 4 is connected to the discharge end of the central throat 3.

[0064] In this specific embodiment, since the discharge port at the bottom of the material tank 1 is connected to the inlet at the top of the T-shaped tube feeding hopper 2, the furnace charge enters the T-shaped tube feeding hopper 2. After entering the T-shaped tube feeding hopper 2, a material pile will be formed at the platform 2-2 of the T-shaped tube feeding hopper 2 to buffer the kinetic energy of the material flow descending from the discharge port of the material tank, reduce the horizontal velocity of the furnace charge, and improve the phenomenon of the furnace charge descending along the opposite side of the central throat pipe 3.

[0065] Because the upper end of the elliptical cross-section central throat 3 is connected to the discharge port of the T-shaped charging hopper 2 at its lower end, the furnace charge enters the elliptical cross-section central throat 3. Due to the buffering effect of the charge pile on the charge flow, the charge slowly falls into the elliptical cross-section central throat 3, preventing the charge from impacting the opposite side of the central throat 3 due to excessive flow velocity. On the one hand, this improves the phenomenon of charge landing point and mass segregation at the circumference of the blast furnace throat during charging with a parallel-type bell-less charging device. On the other hand, the formed charge pile can intensify the mutual collision between charges, thereby protecting the charging hopper and central throat from erosion and wear, and extending their service life. After the charge enters the elliptical cross-section central throat 3, the charge flow becomes more concentrated, and the centerline of the charge flow is closer to the centerline of the blast furnace, which can reduce the extreme value of the radial landing point trajectory of the charge on the chute, further improving the phenomenon of charge landing point and mass segregation at the circumference of the blast furnace throat during charging with a parallel-type bell-less charging device. Since the feed inlet at the upper end of the feeding mechanism 4 is connected to the lower end of the central throat 3 with an elliptical cross section, the furnace charge will enter the blast furnace through the feeding mechanism 4.

[0066] The present invention provides a charging device for reducing blast furnace charge segregation. The phenomenon of charge segregation in terms of landing point and mass at the circumference of the blast furnace throat has been improved. The charge can be evenly distributed around the throat, improving the gas flow distribution, increasing gas utilization efficiency, and helping to improve various indicators of the blast furnace.

[0067] The structure of the T-shaped tube feeding funnel 2 is described in detail below.

[0068] Please see Figures 1-2 The T-shaped tube feeding funnel 2 has a rectangular feeding chamber 2-1 inside. The inlet of the rectangular feeding chamber is connected to the outlet of the material tank. The bottom wall of the T-shaped tube feeding funnel 2 has a T-shaped tube feeding funnel outlet. The outlet of the T-shaped tube feeding funnel is located at the center of the bottom end of the rectangular feeding chamber 2-1. The T-shaped tube feeding funnel 2 has at least two platforms 2-2 inside. The at least two platforms 2-2 are arranged radially opposite to each other along the outlet of the T-shaped tube feeding funnel. The furnace charge in the material tank 1 falls to the platform 2-2 through the outlet of the material tank and naturally accumulates on the platform 2-2 to form a material pile. The outlet of the material tank is located directly above the platform 2-2. This embodiment of the invention takes two platforms 2-2 as an example.

[0069] The T-shaped feeding funnel outlet at the bottom of the rectangular feeding chamber 2-1 is connected to the central throat 3, which has an elliptical cross-section. The furnace charge passes sequentially through the furnace outlet at the bottom of the hopper 1, through the rectangular feeding chamber 2-1, and reaches the bottom of the T-shaped feeding funnel 2 to form a material pile, and then slowly slides into the central throat 3, which has an elliptical cross-section; thus reducing the scouring and wear of the furnace charge on the central throat 3.

[0070] The centerline of the discharge port of the T-shaped tube feeding hopper, the centerline of the central throat 3, and the centerline of the blast furnace are on the same straight line.

[0071] Understandably, after the furnace charge enters the central throat 3 with an elliptical cross-section, the material flow becomes more concentrated, and the center line of the material flow gets closer to the center line of the blast furnace. This can reduce the extreme value of the landing point trajectory of the furnace charge on the chute, and can further improve the phenomenon of the furnace charge landing point and mass segregation at the circumference of the blast furnace throat when the charging device is used for charging.

[0072] Furthermore, the ratio of the long side of the rectangular feeding chamber 2-1 to the diameter of the bottom outlet of the material tank 1 is 2-5. This arrangement ensures the volume of the furnace charge forming a pile in the T-shaped tube feeding funnel.

[0073] The vertical distance between the side of the T-shaped tube feeding hopper 2 and the center line of the blast furnace is 1000-1500mm.

[0074] The vertical distance between the bottom of the T-shaped feeding funnel 2 and the discharge port of the material tank is 1200-2500mm.

[0075] The purpose of this design is to constrain the volume of the material pile. If the volume is too small, the speed reduction of the material flow after hitting the pile will not be significant.

[0076] The inner angle of the material pile formed by platform 2-2 is greater than the outer angle, and the inner angle is equal to or approximately equal to the natural angle of the furnace charge; the inner angle of the material pile formed by platform 2-2 is 25-45°, and the outer angle is 0-15°; the height of the center line of the material pile at the platform is 200-900mm.

[0077] Specifically, in this embodiment, the platform 2-2 will form an inner pile angle of 25-45° and an outer pile angle of 0-15° due to the obstruction of the wall. The center line height of the pile is 200-900mm. This configuration is used to buffer the kinetic energy gained by the furnace charge due to gravity when it falls from the discharge port of the charging tank 1, so that the descending material flow collides with the pile, increasing the kinetic energy loss and reducing the horizontal velocity of the furnace charge.

[0078] Furthermore, the ratio of the width of the platform 2-2 to the diameter of the discharge port at the bottom of the material tank 1 is 1.5-2, to avoid the platform 2-2 being too wide and causing excessive accumulation of furnace charge at the platform 2-2.

[0079] The structure of the central throat 3, which has an elliptical cross-section, is described in detail below.

[0080] See also Figure 1The cross-section of the central throat 3 is elliptical. The feed end of the central throat 3 is connected to the discharge port of the T-shaped tube discharge funnel. The vertical projections of the two platforms 2-2 are located on both sides of the central throat 3.

[0081] The ratio of the minor axis of the elliptical central throat 3 to the diameter of the discharge port of the material tank 1 is 0.6-0.8, in order to ensure smooth flow of the furnace charge. The ratio of the minor axis of the elliptical central throat 3 to the diameter of the discharge port of the material tank 1 is 1.2-1.5, in order to ensure smooth flow of the furnace charge.

[0082] Furthermore, the ratio of the cross-sectional area of ​​the central throat 3, which has an elliptical cross-section, to the diameter of the bottom outlet of the material tank 1 is 0.5-2, ensuring smooth descent of the furnace charge.

[0083] The structure of the feeding mechanism 4 is described in detail below.

[0084] The feeding end of the feeding mechanism 4 is connected to the bottom end of the central throat 3;

[0085] The material feeding mechanism 4 includes: a chute 4-1, which is connected to the central throat pipe 3. The material tank outlet is perpendicular to the plane formed by the rotation of the chute 4-1. The feeding end of the material feeding mechanism 4 is the connection between the chute 4-1 and the central throat pipe 3.

[0086] The chute 4-1 is connected to the central throat 3 with an elliptical cross-section, so that the furnace charge enters the chute 4-1 through the central throat 3 with an elliptical cross-section, and the furnace charge is distributed into the blast furnace through the chute 4-1.

[0087] To more clearly illustrate the embodiments of the present invention, the following description focuses on the material feeding method of the embodiments of the present invention.

[0088] This invention also provides a method for feeding a charging device that reduces charge segregation at the top of a double-boiler blast furnace. The method using the aforementioned charging device for reducing charge segregation at the top of a double-boiler blast furnace includes the following steps:

[0089] Step 1: With the discharge ports of both hoppers closed, open the discharge port of one of the hoppers, so that the furnace charge in one hopper 1 falls vertically into one of the platforms 2-2 in the T-tube discharge hopper 2. The furnace charge accumulates at one of the platforms 2-2. As the amount of the first pile increases, the first pile is formed.

[0090] Step 2: When the inner angle of the first pile reaches 25-45°, the furnace charge in one hopper continues to fall into the first pile. After being decelerated by the first pile, it slowly slides into the central throat 3 with an elliptical cross section until the furnace charge in one hopper 1 is emptied.

[0091] Step 3: Close the discharge port of one material tank 1 and open the discharge port of the other material tank 1, so that the furnace charge in the other material tank 1 falls vertically to another platform 2-2 in the T-shaped tube discharge funnel 2. The furnace charge accumulates at the other platform 2-2. As the amount of the second pile increases, a second pile is formed.

[0092] Step 4: When the inner angle of the second pile reaches 25-45°, the furnace charge in the other hopper continues to fall into the second pile. After being decelerated by the second pile, it slowly slides into the central throat 3 with an elliptical cross section until the furnace charge in the other hopper 1 is emptied.

[0093] Step 5: Repeat steps 1-4 until the fabric is finished.

[0094] Specifically:

[0095] The charging conveyor belt loads the furnace charge (sintered ore, pellets, lump ore, and coke, etc.) into the symmetrical charge tank 1 about the center line of the blast furnace, closes the upper sealing valve, and completes the pressure equalization of the charge tank, waiting to be charged into the blast furnace;

[0096] When the charging signal is received, the lower sealing valve and the throttle valve are opened in sequence. At this time, the furnace charge with a certain initial velocity flows out from the discharge port of the charging tank 1. The furnace charge continues to descend and reaches the rectangular discharge chamber 2-1 of the T-tube discharge funnel 2. After the furnace charge reaches the rectangular discharge chamber 2-1, it forms a material pile on the platform 2-2 with an inner pile angle of 25-45°, an outer pile angle of 0-10°, and a centerline height of 200-900mm. This material pile serves to buffer the kinetic energy of the material flow descending from the discharge port of the charging tank and reduce the horizontal velocity of the furnace charge.

[0097] Due to the buffering effect of the material pile on the material flow, the material flow will slowly slide down to the central throat 3, thus preventing the phenomenon of the material flow velocity being too high and impacting the opposite side of the central throat. The furnace charge descends through the outlet of the T-shaped tube charging funnel 2 into the central throat 3 with an elliptical cross-section, making the material flow more concentrated, and reducing or even coinciding the distance between the center line of the material flow and the center line of the blast furnace;

[0098] The furnace charge descends through the central throat 3, which has an elliptical cross-section, into the chute 4-1, and is finally delivered into the blast furnace by the chute 4-1, completing the charging process.

[0099] The charging device provided by this invention, which reduces blast furnace charge segregation, improves the point and quality segregation of the charge at the circumference of the blast furnace throat during charging. This allows the charge to be evenly distributed around the throat, improving the gas flow distribution, increasing gas utilization efficiency, and ultimately enhancing various blast furnace performance indicators.

[0100] The following evaluation uses a particle model and numerical simulation to assess the improved embodiments of the present invention (changing the Y-shaped tube feeding funnel to a T-shaped tube feeding funnel; changing the central throat with a circular cross-section to a central throat with an elliptical cross-section).

[0101] The particle model method treats pellets as particles without size, disregarding the shape and size of the pellets, and analyzes the force situation of the particles at different stages of the feeding process, using equations of motion to describe the feeding process.

[0102] See Figures 3-5 Because the improved Y-shaped tube feeding hopper allows the material pile to absorb most of the kinetic energy of the furnace charge, it causes the charge to slowly slide down to the central throat, reducing the trajectory of the charge at the chute. Figure 3 As shown. By comparing the furnace charge in the Y-type tube charging funnel and the T-type tube charging funnel 2, the effective descent height from the end of the central throat 3 to the surface of the chute 4-1, the velocity upon reaching the surface of the chute 4-1, the effective distance within the chute 4-1, the velocity at the end of the chute 4-1, the travel time within the chute 4-1, and the landing point at the furnace throat are as follows: Figure 4 As shown, the particles in the T-shaped tube feeding hopper 2 move more uniformly in speed and time within the chute 4-1, with smaller extreme values. Therefore, this can improve the point of material fall and the quality segregation at the furnace throat.

[0103] Due to the buffer suction of the charge pile, the velocity of the charge in the T-tube charging hopper 2 is lower than that in the Y-tube charging hopper. The landing point of the charge in the T-tube charging hopper 2 is closer to the blast furnace centerline. By increasing the angle of the chute 4-1, the landing point of the charge in the T-tube charging hopper 2 is made the same as that in the Y-tube charging hopper. This allows for a comparison of the charge landing point deviation at the blast furnace throat during the charging process of the T-tube charging hopper 2 and the Y-tube charging hopper. Figure 5 As shown.

[0104] See Figure 6-8 Because the central throat with a circular cross-section was improved, the furnace charge converges axially in the chute, reducing the radial trajectory of the charge on the chute. Figure 6 As shown. By comparing the effective drop height from the end of the central throat 3 (circular cross-section) to the chute surface, the effective distance within the chute 4-1, the velocity at the end of the chute 4-1, and the travel time within the chute 4-1 in a central throat 3 with a circular cross-section and a central throat 3 with an elliptical cross-section, as shown... Figure 7 As shown. The radial drop point of the charge is small at the central throat 3 with an elliptical cross-section, and the velocity at the end of the chute 4-1 is more uniform. Therefore, when the charge falls to the surface of the blast furnace throat, the drop point of the charge is more uniform, thereby reducing the segregation of the charge drop point at the blast furnace throat during charging. Figure 8 As shown.

[0105] Numerical simulation: The particle model ignores the influence of the interaction between particles on the material flow trajectory. Therefore, it is necessary to conduct numerical simulation of the improved scheme using the discrete element method based on Newton's second law.

[0106] Numerical simulations were performed on the original and improved feeding devices using ore pellets and coke. Table 1-1 below shows the number of ore pellets and coke particles and the total mass of particles during the simulation.

[0107] Pellet 30000 90.5 Cock 30000 24.64

[0108] Table 1-1 shows the mass and quantity of pellets and coke in the numerical simulation. The particle size distribution and mass proportion of pellets and coke are shown in Table 1-2.

[0109] 20.5 6.84％ 80 20.72％ 14.25 74.84％ 50 52.31％ 11.25 18.32％ 32.5 26.97％

[0110] Table 1-2 Particle size distribution and mass percentage of pellets and coke in numerical simulation.

[0111] The sliding friction coefficient, rolling friction coefficient, coefficient of restitution, Poisson's ratio, Young's modulus, and other parameters of pellets and coke are shown in Table 1-3 below.

[0112] Poisson's Ratio 0.25 0.22 0.30 SolidsDensity 3015kg / m3 934kg / m3 7850kg / m3 ShearModulus 3.5*107pa 5.4*106pa 7.5*10¹⁰ Pa

[0113] Coeff of Restitution 0.30 0.54 0.35 0.5 Coeff.ofStaticFriction 0.25 0.48 0.87 0.71 Coeff of RollingFriction 0.02 0.06 0.15 0.31

[0114] Table 1-3 Parameters of pellets and coke in numerical simulation

[0115] like Figure 9 As shown, the circumference of the furnace throat is divided into 12 regions.

[0116] The following are the numerical simulation results of pellet ore being distributed in 5 cycles with the right-side feed tank, chute 4-1 rotating counterclockwise, chute 4-1 tilted at 40°, and feed line height at 1.5m:

[0117] like Figure 10 As shown, in the patented technical solution, the Y-shaped tube feeding funnel is replaced with a T-shaped tube feeding funnel; the central throat with a circular cross-section is replaced with a central throat with an elliptical cross-section; numerical simulation studies are conducted on the original and improved feeding devices when charging pellets into the blast furnace. The pellets form a pile at platform 2-2 of the T-shaped tube feeding funnel, with an inner pile angle of 28.18° and a centerline height of 500mm.

[0118] like Figure 11As shown, the distribution of pellets at the end of the central throat pipe 3 is as follows: the center of the pellet flow in the Y-shaped pipe feeding funnel + round pipe is 217.09 mm from the blast furnace centerline, and the center of the pellet flow in the T-shaped pipe feeding funnel 2 + elliptical pipe is 160.80 mm from the blast furnace centerline. The measurement results show that the center of the pellet flow in the T-shaped pipe feeding funnel 2 + elliptical pipe moves 56.29 mm towards the blast furnace centerline, which can effectively improve the extreme value of the axial landing point trajectory of the furnace charge on the chute, thereby improving the landing point and quality segregation of the pellets at the furnace throat.

[0119] like Figure 12 As shown, when the charge is distributed in 5 rounds, the mass distribution of the charge in each region varies greatly. The mass distribution of the charge in each region is significantly different for the Y-shaped tube charging funnel + round tube, with a maximum value appearing in the seventh region. The mass of the pellets in the seventh region is 222.93 kg higher than the average mass of all regions. The mass distribution of the charge in each region is relatively uniform for the T-shaped tube charging funnel + elliptical tube. Although a maximum value appears in the tenth region, the mass of the pellets in the tenth region is only 132.25 kg higher than the average mass of all regions.

[0120] like Figure 13 As shown, the mass distribution of pellets in each region of the furnace throat circumference is as follows: the mass distribution of the Y-shaped feeding hopper + circular pipe has a relatively large extreme value, with a maximum value in region seven and a minimum value in region two. In the first ring of charging, the T-shaped feeding hopper 2 + elliptical pipe needs to generate a material pile at platform 2-2 of the T-shaped feeding hopper 2, so the mass of the furnace charge in each region is relatively small. In rings 2-5, the mass distribution in each region is more uniform, with a maximum value in region ten and a minimum value in region two. The pellet velocity in the T-shaped feeding hopper 2 + elliptical pipe is relatively low, therefore the region with the maximum mass value is delayed.

[0121] like Figure 14 The figure shows the velocity variation trends during pellet feeding in the Y-shaped feed hopper + circular pipe and the T-shaped feed hopper 2 + elliptical pipe. In both the original and improved feeding devices, the pellet flow velocity shows the same trend over time, but the pellet flow velocity in the T-shaped feed hopper 2 + elliptical pipe is lower. The maximum velocity of the pellet flow in the Y-shaped feed hopper + circular pipe is 8.4686 m / s, while the maximum velocity in the T-shaped feed hopper 2 + elliptical pipe is 7.2298 m / s. Calculations show that the maximum velocity of the pellet flow in the T-shaped feed hopper 2 + elliptical pipe is 13.8% lower than that in the Y-shaped feed hopper + circular pipe.

[0122] like Figure 15 As shown, by magnification Figure 14The pellet feeding time is 39-43s. It can be seen that the timing of the sharp decrease in pellet flow velocity differs between the Y-shaped feed hopper + circular pipe and the T-shaped feed hopper 2 + elliptical pipe. In the Y-shaped feed hopper + circular pipe, the pellet flow velocity decreases sharply upon impact with the central throat 3, chute 4-1, and the furnace throat surface. In the T-shaped feed hopper 2 + elliptical pipe, the pellet flow velocity decreases sharply upon impact with the material pile at the T-shaped pipe platform, chute 4-1, and the furnace throat surface. In the Y-shaped feed hopper + circular pipe, the coke flow velocity decreases from 5.3697m / s to 5.232m / s after impacting the central throat. The higher pellet flow velocity results in a greater impact on the central throat 3, leading to more severe wear on the central throat 3. After the coke flow in the T-shaped pipe feeding hopper 2 and the elliptical pipe impacts the material pile at the T-shaped pipe plane, the velocity decreases from 5.2530m / s to 1.8330m / s. The material pile can absorb 65.1% of the kinetic energy of the material flow and prevent the pellet ore flow from impacting the opposite side of the central throat, thus extending the service life of the central throat 3.

[0123] As shown in Figure 16, with the increase in the number of feeding rings, the standard deviation of the circumferential quality of the pellets in the furnace throat increases for both the Y-shaped feeding funnel + round tube and the T-shaped feeding funnel 2 + elliptical tube. Comparing the two, the Y-shaped feeding funnel + round tube shows a faster rate of increase in the standard deviation of the circumferential quality of the pellets in the furnace throat, reaching 174.92 in the fifth ring. The T-shaped feeding funnel 2 + elliptical tube shows a standard deviation of 78.18 in the fifth ring, a decrease of 55.3% compared to the Y-shaped feeding funnel + round tube. In the first cycle, because the T-shaped feeding hopper 2 + elliptical tube needs to form a material pile at platform 2-2 of the T-shaped feeding hopper 2, the standard deviation of the circumferential pellet quality in the furnace throat is larger than that of the Y-shaped feeding hopper + round tube. In cycles 2-5, the standard deviation of the circumferential pellet quality in the furnace throat of the T-shaped feeding hopper + elliptical tube is smaller than that of the Y-shaped feeding hopper + round tube. The average standard deviation of the circumferential pellet quality in the furnace throat of the five cycles of Y-shaped feeding hopper + round tube is 40.362. The average standard deviation of the circumferential pellet quality in the furnace throat of the five cycles of T-shaped feeding hopper 2 + elliptical tube is 21.624, which is 46.4% smaller than that of the Y-shaped feeding hopper + round tube.

[0124] The following are the numerical simulation results of coke being distributed in 12 revolutions with the right-side feed hopper, chute 4-1 rotating counterclockwise, chute 4-1 tilted at 40°, and feed line height at 1.5m:

[0125] like Figure 17 As shown, a numerical simulation study was conducted on the original and improved charging devices for feeding coke into the blast furnace. The coke pile formed at platform 2-2 of the T-shaped tube charging hopper has an inner pile angle of 43.69° and a centerline height of 850 mm.

[0126] like Figure 18As shown, the distribution of coke at the end of the central throat pipe 3 is as follows: the center of the coke flow in the Y-shaped pipe feeding funnel + round pipe is 224.25 mm from the blast furnace centerline, and the center of the coke flow in the T-shaped pipe feeding funnel 2 + elliptical pipe is 152.79 mm from the blast furnace centerline. The measurement results show that the center of the coke flow in the T-shaped pipe feeding funnel 2 + elliptical pipe moves 71.46 mm towards the blast furnace centerline, which can effectively improve the extreme value of the axial landing point trajectory of the furnace charge on the chute 4-1, thereby improving the coke landing point and quality segregation at the furnace throat.

[0127] like Figure 19 As shown, when the charge is distributed in 12 rings, the mass distribution of the charge in each region varies greatly in the Y-shaped tube charging funnel + round tube throat region, with a maximum value in the seventh region. The coke mass in the seventh region is 220.61 kg higher than the average mass of all regions. The mass distribution of the charge in the T-shaped tube charging funnel 2 + elliptical tube region is more uniform in each region, and also has a maximum value in the seventh region. The coke mass in the seventh region is 105.49 kg higher than the average mass of all regions.

[0128] like Figure 20 As shown, the mass distribution of coke in each region of the furnace throat circumference is as follows: The mass distribution of coke in the circumference of the Y-shaped tube feeding hopper + circular tube furnace throat exhibits large extreme values, with a maximum value in region seven and a minimum value in region two. The first ring of the T-shaped tube feeding hopper 2 + elliptical tube requires the formation of a material pile at platform 2-2 of the T-shaped tube feeding hopper 2, resulting in a larger standard deviation of coke mass in the circumference of the furnace throat. In rings 2-11, the mass distribution in each region is more uniform, with a maximum value in region seven and a minimum value in region two.

[0129] like Figure 21 The figure shows the velocity variation trends during coke feeding in the Y-shaped feeding hopper + circular pipe and the T-shaped feeding hopper 2 + elliptical pipe. In both the original and improved feeding devices, the coke flow velocity shows the same trend over time, but the coke flow velocity in the T-shaped feeding hopper 2 + elliptical pipe is lower. The maximum velocity of the coke flow in the Y-shaped feeding hopper + circular pipe is 9.2526 m / s, while the maximum velocity in the T-shaped feeding hopper 2 + elliptical pipe is 6.4649 m / s. Calculations show that the maximum velocity of the coke flow in the T-shaped feeding hopper 2 + elliptical pipe is 30.1% lower than that in the Y-shaped feeding hopper + circular pipe.

[0130] like Figure 22 As shown, by magnification Figure 21With a coke feeding time of 70-75 seconds, it can be seen that the time of the sharp decrease in coke flow velocity differs between the Y-shaped feeding hopper + circular pipe and the T-shaped feeding hopper 2 + elliptical pipe. In the Y-shaped feeding hopper + circular pipe, the coke flow velocity decreases sharply upon impacting the chute 4-1 and the feed surface at the furnace throat. In the T-shaped feeding hopper 2 + elliptical pipe, the coke flow velocity decreases sharply upon impacting the material pile at the T-shaped feeding hopper platform and the feed surface at the furnace throat. In the Y-shaped feeding hopper + circular pipe, the coke flow velocity increases more slowly after impacting the central throat, from 5.7416 m / s to 6.2503 m / s, due to the impact of the coke flow on the sidewall of the central throat. After the coke flow in the T-shaped tube feeding hopper 2+ elliptical tube impacts the material pile at platform 2-2 of the T-shaped tube feeding hopper 2, the velocity decreases from 4.4083m / s to 1.6904m / s. The material pile can absorb 61.7% of the kinetic energy of the material flow and prevent the material flow from impacting the opposite side of the central throat.

[0131] like Figure 23 As shown, with the increase in the number of feeding rings, the standard deviation of coke quality in the circumferential direction of the furnace throat increases for both the Y-type feeding funnel + round tube and the T-type feeding funnel + elliptical tube. Comparing the two, the standard deviation of coke quality in the circumferential direction of the Y-type feeding funnel + round tube increases faster, reaching 101.94 in the twelfth ring. The standard deviation of coke quality in the circumferential direction of the furnace throat in the T-type feeding funnel + elliptical tube is 60.86 in the twelfth ring, a decrease of 40.3% compared to the Y-type feeding funnel + round tube. The standard deviation of coke quality in the circumferential direction of the furnace throat in each ring of the Y-type feeding funnel + round tube is higher than that in the T-type feeding funnel + elliptical tube. The average standard deviation of coke quality in the circumferential direction of the furnace throat in the Y-type feeding funnel + round tube over twelve rings is 10.966. The average standard deviation of circumferential coke quality in the T-shaped tube feeding funnel + elliptical tube twelve-ring furnace throat is 8.234, which is 24.9% lower than that in the Y-shaped tube feeding funnel + round tube.

[0132] Finally, it should be noted that the above specific embodiments are only illustrative of the technical solutions of the present invention and not limiting. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for feeding a charging device to reduce material segregation at the top of a double-boiler blast furnace, characterized in that, Includes the following steps: Step 1: With both feed hoppers closed, open one of the feed hoppers, allowing the furnace charge in one of the feed hoppers to fall vertically onto one of the platforms inside the T-tube feed hopper. The furnace charge accumulates on one of the platforms, and as the amount of the first pile increases, the first pile is formed. Step 2: When the inner angle of the first pile reaches 25-45°, the furnace charge in one hopper continues to fall into the first pile. After being decelerated by the first pile, it slowly slides into the central throat pipe with an elliptical cross section until the furnace charge in one hopper is emptied. Step 3: Close the discharge port of one hopper and open the discharge port of the other hopper, so that the furnace charge in the other hopper falls vertically to another platform in the T-tube discharge funnel. The furnace charge accumulates on the other platform. As the amount of the second pile increases, a second pile is formed. Step 4: When the inner angle of the second pile reaches 25-45°, the furnace charge in the other hopper continues to fall into the second pile. After being decelerated by the second pile, it slowly slides into the central throat pipe with an elliptical cross section until the furnace charge in the other hopper is emptied. Step 5: Repeat steps 1-4 until the fabric is finished; The charging device for reducing and reducing the segregation of the charging material at the top of the blast furnace is installed at the top of the blast furnace and includes: The two hoppers are symmetrically distributed around the center line of the blast furnace. The bottom of each hopper is provided with a discharge port, which is parallel to the blast furnace axis and is vertically downward. The T-shaped tube feeding funnel has a rectangular feeding chamber inside, the inlet of which is connected to the outlet of the hopper. The bottom wall of the T-shaped tube feeding funnel has a T-shaped tube feeding funnel outlet, which is located at the center of the bottom of the rectangular feeding chamber. The T-shaped tube feeding funnel has at least two platforms inside, which are arranged radially opposite to each other along the outlet of the T-shaped tube feeding funnel. The furnace charge in the hopper falls onto the platform through the outlet of the hopper and naturally accumulates on the platform to form a material pile. The outlet of the hopper is located directly above the platform. A central throat with an elliptical cross-section, the feed end of the central throat being connected to the discharge port of the T-shaped tube feeding funnel, and the vertical projections of at least two of the platforms being located on both sides of the central throat. A feeding mechanism, wherein the feeding end of the feeding mechanism is connected to the discharge end of the central throat tube; The inner angle of the material pile formed by the platform is greater than the outer angle, and the inner angle is equal to or approximately equal to the natural angle of the furnace charge. The inner angle of the material pile formed by the platform is 25-45°, and the outer angle is 0-15°. The height of the centerline of the material pile formed on the platform is 200-900mm.

2. The charging device for reducing charge segregation at the top of a blast furnace according to claim 1, characterized in that: The centerline of the discharge port of the T-shaped tube feeding hopper, the centerline of the central throat pipe, and the centerline of the blast furnace are on the same straight line. The ratio of the minor axis of the central throat, which has an elliptical cross-section, to the diameter of the discharge port of the hopper is 0.6-0.

8. The ratio of the major axis of the central throat, which has an elliptical cross-section, to the diameter of the discharge port of the material tank is 1.2-1.

5. The material feeding mechanism includes a chute, which is connected to the central throat pipe, and the material tank outlet is perpendicular to the plane formed by the rotation of the chute.

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