A grate bar for a sintering machine

Abstract

The utility model discloses a grate bar for sintering machine, including long strip shape body, left and right two upper support structures and two lower support structures, have two mutually perpendicular symmetry plane. The top surface thickness of long strip shape body is greater than the bottom surface thickness, and the front side and rear side of long strip shape body are symmetrically arranged, and the top surface of long strip shape body is provided with cylindrical crossbeam along the length direction, the diameter of crossbeam section is greater than or equal to the top surface thickness of long strip shape body, one upper support structure is arranged at the both ends of crossbeam respectively, and two upper support structures are symmetrically arranged, and the upper surface of upper support structure is in the shape of arch, and the outside part of upper support structure is stretched out long strip shape body and forms upper support arm, and the inside part of upper support structure is located above long strip shape body and is connected with the transition of crossbeam, and the highest point of upper support structure is higher than crossbeam. The grate bar structure of the patent can improve the support strength of the grate bar, reduce the deformation and fracture of the grate bar in the sintering process, and obviously prolong the service life of the grate bar.

Description

Technical Field

[0001] This utility model specifically relates to a grate bar for a sintering machine, belonging to the technical field of steelmaking equipment. Background Technology

[0002] Sintering machines are used in major steel plants. They are primarily used to sinter raw materials such as iron ore, fuel, and flux in a specific ratio. Through heating, the powdery material is formed into sinter with a certain strength and particle size, providing high-quality raw materials for subsequent blast furnace ironmaking processes. The sintering trolley is a key component that carries the sintering raw materials and moves it on the sintering machine to complete the sintering process. It consists of the trolley body, wheels and rails, and sealing devices. The trolley body itself is composed of a frame, side plates, and multiple grate bars. The frame provides overall support, the side plates prevent the raw materials from scattering during sintering, and the grate bars support the raw material layer while allowing exhaust gases from combustion to pass through smoothly. The grate bars are typically long and narrow, with multiple bars closely arranged on a grate plate to form a grid-like structure, supporting the upper layer of sintering raw materials. Their main functions are support and ventilation. Furnace grates operate in harsh environments characterized by high temperatures, high dust levels, high loads, and the presence of corrosive gases. Therefore, they must meet the following performance requirements: High-temperature resistance: They must be able to operate stably for extended periods at temperatures up to 1000℃ or even higher, without deformation or softening affecting their support and ventilation functions; High strength and toughness: They must withstand the heavy pressure of the sintering material layer and the impact forces that may occur during sintering, preventing breakage, bending, or other damage; Corrosion resistance: They must resist the corrosive gases in the sintering exhaust gas and the corrosion caused by moisture and other factors, extending their service life; Good thermal conductivity: Facilitating heat transfer between the grate bars and the material layer, as well as within the grate bars themselves, promoting heat balance and efficiency in the sintering process. In the actual operation of sintering machines, grate bars are consumables. Existing grate bars often experience the following problems: Deformation and damage: Under long-term high-temperature and high-load operating conditions, grate bars may deform, bend, or even break; Blockage: Due to the large amount of dust generated during sintering, the gaps in the grate bars may become clogged, affecting ventilation; Corrosion: The grate bars may corrode, becoming brittle and breaking, or thinning and bending. Therefore, during sintering machine operation, the integrity of the grate bars should be checked regularly. If any signs of deformation or damage are found, they should be replaced promptly to ensure the normal operation of the sintering machine. The gaps in the grate bars need to be cleaned regularly, using methods such as high-pressure air purging or mechanical cleaning. To address potential corrosion issues, grate bars made of materials with better corrosion resistance can be selected. Furthermore, if signs of corrosion are observed during operation, protective measures such as applying anti-corrosion coatings can be taken. These maintenance procedures all require shutdown and overhaul. Generally, the service life of furnace grate bars is around 12 months. After this period, they need to be scrapped and replaced due to deformation, clogging, corrosion, etc. Therefore, how to design and manufacture a furnace grate bar with a long service life has become an important problem that steel mills need to solve. Summary of the Invention

[0003] In view of the problems existing in the prior art, this utility model optimizes and improves the mechanical structure and casting process of the grate bar, and provides a sintering machine grate bar with a long service life.

[0004] The technical solution of this utility model is as follows:

[0005] A sintering machine grate bar, integrally formed using a casting process, comprises a long strip-shaped body, two upper support structures (left and right), and two lower support structures, with two mutually perpendicular symmetrical planes. The top surface thickness of the long strip-shaped body is greater than its bottom surface thickness. The front and rear sides of the long strip-shaped body are symmetrically arranged. A cylindrical crossbeam is provided along the length of the top surface of the long strip-shaped body, and the diameter of the cross-section of the crossbeam is greater than or equal to the top surface thickness of the long strip-shaped body. An upper support structure is provided at each end of the crossbeam, symmetrically arranged. The upper surface of the upper support structure is arched, with the outer part of the upper support structure extending out of the long strip-shaped body to form an upper support arm. The inner part of the upper support structure is located above the long strip-shaped body and transitionally connects with the crossbeam. The highest point of the upper support structure is higher than the crossbeam. By using the cylindrical crossbeam and the arched upper support arm structures at both ends of the crossbeam on the long strip-shaped body, the support strength of the grate bar can be greatly improved without increasing or minimizing the amount of material used, significantly reducing the deformation and breakage of the grate bar during sintering.

[0006] Furthermore, the cross-section of the upper support arm includes an upper arc surface, a left vertical surface, a right vertical surface, a left inclined surface, a right inclined surface, and a lower plane. The left and right vertical surfaces are vertical planes, symmetrically arranged, with the distance between them greater than the diameter of the cross-section of the beam. The left and right inclined surfaces are inwardly inclined planes, symmetrically arranged, and the lower plane is a horizontal plane. The left, lower, and right inclined surfaces are sequentially connected to form a frustum structure. This design of the upper support arm's cross-sectional shape allows the grate bars to contact the support beam on the trolley frame via the lower plane during use. The narrow width of this lower plane results in a small contact area with the support beam below, minimizing heat conduction. Furthermore, the left and right inclined surfaces on both sides provide space for the grate bars to swing left and right. The relative movement between adjacent grate bars effectively prevents material from clogging the gaps between them, improving ventilation efficiency.

[0007] Furthermore, lower support structures are respectively provided at the left and right ends of the bottom surface of the elongated body. The two lower support structures are symmetrically arranged, and the bottom of the lower support structure extends outward to form a lower support arm. The inner upper surface of the lower support arm is an arc-shaped surface, and the length of the lower support arm is less than the length of the upper support arm. The upper support arm, the lower support arm, and one outer surface of the elongated body on the same side of the elongated body form a semi-enclosed support structure. The semi-enclosed support structure ensures that the grate bars do not fall off during the sintering trolley's cyclic operation. After the trolley unloads, the grate bars are hung upside down on the support beam by the lower support arms. Since the inner upper surface of the lower support arms is an arc-shaped surface, i.e., the arc-shaped lower support arm contacts the support beam, the grate bars are in an unstable state. As the trolley moves, the grate bars collide with each other, and the sintered material adhering to the grate bars can be effectively detached, achieving a self-cleaning effect for the grate bars.

[0008] Furthermore, reinforcing ribs are provided on both the left and right sides of the front and rear sides of the elongated body. The upper part of the reinforcing rib is connected to the left or right facade of the upper support arm via an air guide slope, and the lower part of the reinforcing rib extends along the semi-enclosed support structure to the end of the lower support structure. The reinforcing ribs increase the structural strength of the grate bars and improve their service life. In addition, in conjunction with the air guide slope, they improve airflow efficiency and sintering efficiency.

[0009] Furthermore, a boss is centrally located on the inner side of the vertical surface of the semi-enclosed support structure. This boss reduces the contact area between the grate bars and the support beam, acting as a heat insulation pad and reducing energy consumption.

[0010] Furthermore, at least one spacer block is provided at corresponding positions on the front and rear sides of the elongated body. The two spacer blocks at corresponding positions on the front and rear sides are symmetrically arranged, and the distance between the outer surfaces of the two spacer blocks at corresponding positions on the front and rear sides is greater than the diameter of the crossbeam. The thickness of the spacer block determines the gap between two adjacent grate bars. This gap allows airflow to pass through, and at the same time, this gap needs to be smaller than the particle diameter of the sintered material to prevent the sintered material from falling out of the gap.

[0011] Beneficial effects: By optimizing and improving the mechanical structure of the grate bars as described above, this utility model significantly improves the mechanical strength of the grate bars, reduces deformation, breakage, and clogging, improves sintering efficiency, saves energy, and extends their service life from the original 18-24 months to more than 30 months. If improvements are made to the casting process and formula, their corrosion resistance can be further enhanced, extending their service life to more than 40 months, resulting in significant economic benefits. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the three-dimensional structure of the grate bars.

[0013] Figure 2 This is a front view of the grate bars.

[0014] Figure 3 This is a left view of the grate bars.

[0015] Figure 4 This is a top view of the grate bars.

[0016] Figure 5 yes Figure 2 AA section view in the image.

[0017] Figure 6 This is a schematic diagram showing the installation and usage status of the grate bars.

[0018] Figure 7 yes Figure 6 Top view.

[0019] The diagram is marked as follows: 1. Long strip-shaped body; 2. Cylindrical crossbeam; 3. Upper support structure; 4. Lower support structure; 5. Boss; 6. Air guide slope; 7. Reinforcing rib; 8. Spacer support block; 9. Heat insulation pad support beam; 10. Ventilation gap; 31. Upper support arm; 311. Upper arc surface; 312. Left elevation; 313. Right elevation; 314. Left slope; 315. Right slope; 316. Lower plane; 41. Lower support arm; 411. Arc surface. Detailed Implementation

[0020] The present invention will now be described in a clear and complete manner with reference to the accompanying drawings and embodiments.

[0021] like Figure 1-5 As shown, a grate bar for a sintering machine is integrally formed using a casting process. It has two symmetrical planes, namely symmetrical plane E and symmetrical plane F (see...). Figure 4 Furthermore, the planes of symmetry E and F are perpendicular to each other, and the grate bar includes a long strip-shaped body 1, two upper support structures 3 on the left and right, and two lower support structures 4 on the left and right.

[0022] Specifically, the top surface of the elongated body is thicker than the bottom surface. This design facilitates the smooth descent of the leaking material and prevents blockage. The front and rear sides of the elongated body are symmetrically arranged, meaning the cross-section of the elongated body 1 is an isosceles trapezoid, wider at the top and narrower at the bottom (see...). Figure 5 (The lower half of the shaded area in the image) A cylindrical crossbeam 2 is provided along the length of the top surface of the elongated body. The diameter of the crossbeam is greater than or equal to the thickness of the top surface of the elongated body (see...). Figure 5The upper half of the shaded area in the diagram), the cylindrical crossbeam can bear greater pressure; an upper support structure 3 is provided at each end of the crossbeam 2, the two upper support structures are symmetrically arranged, the upper surface of the upper support structure is arched to increase the load-bearing capacity and prevent warping deformation due to heat, the outer part of the upper support structure extends out of the long strip body to form a suspended upper support arm 31, the inner part of the upper support structure is located above the long strip body and is integrally connected with the crossbeam, the highest point of the upper support structure is higher than the crossbeam (superior to the planar structure of existing grates, enhancing the load-bearing capacity and preventing deformation); as Figure 3 As shown, the cross-section of the upper support arm includes an upper arc surface 311, a left elevation 312, a right elevation 313, a left inclined surface 314, a right inclined surface 315, and a lower plane 316. The left and right elevations 312 and 313 are vertical planes, symmetrically arranged, with the distance between them greater than the diameter of the cross-section of the beam, increasing ventilation. The left and right inclined surfaces 314 and 315 are inwardly inclined planes, symmetrically arranged, while the lower plane 316 is a horizontal plane. The left and right inclined surfaces 314, 316, and 315 are sequentially connected to form a frustum structure (or an isosceles trapezoidal structure). During trolley tilting, this structure achieves a material unloading rate of over 95%, exhibiting a significant anti-clogging effect, greatly reducing the labor and time costs of cleaning clogging, minimizing maintenance time, and resulting in significant economic benefits.

[0023] Lower support structures 4 are respectively provided at the left and right ends of the bottom surface of the elongated body 1. The two lower support structures are symmetrically arranged. The bottom of the lower support structure extends outward to form a lower support arm 41. The inner upper surface of the lower support arm is an arc surface 411 (when the trolley is turned over, the arc surface is conducive to the left and right swaying of the grate bar, so that the residual material can fall off smoothly and prevent clogging). The length of the lower support arm 41 is less than the length of the upper support arm 31. The upper support arm 31, the lower support arm 41 and one outer side of the elongated body 1 on the same side form a semi-enclosed support structure. A boss 5 is provided in the center of the vertical surface of the semi-enclosed support structure. The boss 5 can reduce the contact area between the grate bar semi-enclosed support structure and the heat insulation pad support beam 9, increase the ventilation volume, facilitate heat dissipation, extend service life and facilitate the falling off of small materials. Reinforcing ribs 7 are provided on both the left and right sides of the front and rear sides of the elongated body. The upper part of the reinforcing rib 7 is connected to one of the left or right facades of the upper support arm through a guide slope 6, and the lower part of the reinforcing rib 7 extends along the semi-enclosed support structure to the ends of the front and rear surfaces of the lower support arm 41. The reinforcing ribs improve the deformation resistance of the entire grate.

[0024] Furthermore, at least one spacer block 8 is provided at corresponding positions on the front and rear sides of the elongated body 1. The two spacer blocks 8 at corresponding positions on the front and rear sides are symmetrically arranged. The shape of the spacer block can be circular, semi-circular, annular, semi-annular, square, triangular, etc., preferably a semi-annular structure with the opening facing downward, which can not only serve as a spacer but also reduce material costs and is not easy to clog. In this example, two spacer blocks 8 are provided at corresponding positions on the front and rear sides of the elongated body 1, and their shape is circular. The distance between the outer surfaces of the two spacer blocks at corresponding positions on the front and rear sides of the elongated body 1 is greater than the diameter of the crossbeam and less than the thickness of the upper support arms at both ends, so as to limit the minimum gap between the two grates when they are placed side by side. Preferably, the outer surface of the spacer block is coplanar with one of the left or right surfaces of the upper support arm.

[0025] like Figure 6-7 As shown, when using the grate bars, multiple grate bars are placed side-by-side and parallel to each other on two parallel, spaced heat-insulating support beams 9 of the sintering trolley. At this time, the upper support arm of the grate bar is in contact with the upper surface of the heat-insulating support beam, and there is a ventilation gap 10 between adjacent grate bars. Multiple trolleys are installed side-by-side on the guide rail. A layer of sintering material is laid on the grate bars of the trolley in the charging area. The particle size of the sintering material is larger than the gap between the grate bars. Then, the ignition is started, and negative pressure is used for ventilation. The airflow passes through the material layer and flows through the guide slope and gaps of the grate bars. The trolley moves along... Figure 7 The trolley moves forward in the direction of the middle arrow until it reaches the unloading area. In the unloading area, the trolley tilts and flips, allowing the material to fall freely. At the same time, the grate bars hang upside down. When the grate bars are upside down, the lower support arm of the grate bar contacts the lower surface of the heat insulation pad support beam. Since the inner surface of the lower support arm is set as an arc surface, that is, the arc-shaped lower support arm contacts the heat insulation pad support beam, the grate bars are in an unstable state. As the trolley moves, the grate bars move freely, and the swaying grate bars collide with each other. The sintered material adhering to the grate bars or between the grate bars can be effectively removed, achieving the self-cleaning effect of the trolley grate bars.

Claims

1. A grate bar for a sintering machine, comprising a long strip-shaped body, an upper support structure, and a lower support structure, characterized in that, A cylindrical crossbeam is provided on the top surface of the elongated body along its length. An upper support structure is provided at each end of the crossbeam. The two upper support structures are arranged symmetrically. The upper surface of the upper support structure is arched. The outer part of the upper support structure extends out of the elongated body to form an upper support arm. The inner part of the upper support structure is located above the elongated body and transitions to the crossbeam. The highest point of the upper support structure is higher than the crossbeam.

2. The grate bar for a sintering machine according to claim 1, characterized in that, The cross-section of the upper support arm includes an upper arc surface, a left elevation, a right elevation, a left inclined surface, a right inclined surface, and a lower plane. The left and right elevations are vertical planes, symmetrically arranged, and the distance between the left and right elevations is greater than the diameter of the cross-section of the beam. The left and right inclined surfaces are inwardly inclined planes, symmetrically arranged, and the lower plane is a horizontal plane.

3. A grate bar for a sintering machine according to claim 2, characterized in that, Reinforcing ribs are provided on both the left and right sides of the front and rear sides of the elongated body. The upper part of the reinforcing ribs is connected to the left or right facade of the upper support arm through a guide slope, and the lower part of the reinforcing ribs extends to the end of the lower support structure.

4. A grate bar for a sintering machine according to claim 1, characterized in that, Lower support structures are provided at the left and right ends of the bottom surface of the elongated body. The two lower support structures are arranged symmetrically. The bottom of the lower support structure extends outward to form a lower support arm. The inner upper surface of the lower support arm is an arc-shaped surface. The length of the lower support arm is less than the length of the upper support arm. The upper support arm, the lower support arm, and one outer side of the elongated body on the same side form a semi-enclosed support structure.

5. A grate bar for a sintering machine according to claim 4, characterized in that, A heat insulation pad is placed in the center of the vertical surface of the semi-enclosed support structure.

6. A grate bar for a sintering machine according to claim 1, characterized in that, At least one spacer block is provided at corresponding positions on the front and rear sides of the elongated body. The two spacer blocks at corresponding positions on the front and rear sides are symmetrically arranged, and the distance between the outer surfaces of the two spacer blocks at corresponding positions on the front and rear sides is greater than the diameter of the crossbeam.

7. A grate bar for a sintering machine according to claim 1, characterized in that, The diameter of the crossbeam section is greater than or equal to the thickness of the top surface of the elongated body, the thickness of the top surface of the elongated body is greater than the thickness of its bottom surface, and the front and rear sides of the elongated body are symmetrically arranged.

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