Improved sintering or hardening belt for sintering or pelleting plants

Abstract

A sintering belt (10) includes a grate car chain (12), a support structure configured to support and allow movement of the grate car chain (12), at least two longitudinal seal elements parallel to a direction (D) of movement of the grate car chain (12) along the sintering or consolidation belt (10), at least two transverse seal elements (14) intersecting the direction (D) of movement of the grate car chain (12) along the sintering or consolidation belt (10) and partially obstructing movement of the grate car chain, and at least one suction duct (16). The suction duct (16), the at least two longitudinal seal elements, the at least two transverse seal elements (14), and a bottom surface of the grate car (12) are configured to define at least one plenum chamber (PC). The suction duct (16) is further configured to generate low or high pressure within the plenum chamber (PC). The transverse sealing element (14) comprises at least one sealing roll (18, 18.1-18.15), the sealing roll (18, 18.1-18.15) being configured to partially impede movement of the grate wheel chain (12), the sealing roll (18, 18.1-18.15) comprising an inner roll (18a) defining an inner radius and an elastically deformable outer sleeve (18b) defining an outer radius, and the transverse sealing element (14) comprises a plurality of parallel sealing rolls (18, 18.1-18.15) defining at least one roller table (20). The roller table (20) comprises at least two interlocking seal rolls (18.1-18.5), the distance between two adjacent interlocking seal rolls (18.1-18.5) being strictly contained between the sum of their inner radii and the sum of their outer radii, and successive interlocking seal rolls (18.1-18.5) defining a continuous surface (20') of the roller table (20).

Description

[Technical Field]

[0001] The present invention relates generally to sintering or pelleting plants, and more particularly to a sintering or hardening belt having improved durability and low operating costs. [Background technology]

[0002] Sinter plants are widely used to agglomerate fine materials into sinter that can be used in a blast furnace.

[0003] Sinter / pellet plants typically include a mixing drum and hopper for mixing the different fine materials in the desired proportions, a sintering or consolidation belt (when pellets are processed, the belt is called a consolidation belt) for conveying the mixture of fine materials, and an ignition hood near the upstream end of the belt or strand for igniting some of the fine materials. At the end of the belt, the resulting aggregate material can be crushed and cooled before storage.

[0004] Conventionally, the belt comprises a continuous chain of grate cars for conveying the mixture of fine materials, a support structure for supporting and enabling movement of the chain of grate cars along the belt, at least two longitudinal sealing elements, at least two transverse sealing elements, and at least one suction duct. The bottom surfaces of the cars in the chain of grate cars are configured to allow gas flow while preventing the passage of fine materials.

[0005] The suction duct, the longitudinal and transverse seal elements, and the bottom surface of the chain of grate wheels are configured to define at least one plenum chamber. The suction duct is further configured to generate low or high pressure within the plenum chamber. Thus, a pressure differential created by the suction duct generates a gas flow through the bottom surface of the chain of grate wheels and the mixture of fine material. If some of the fine material has previously been ignited by the ignition hood, such flow can aid in the propagation of a flame through the mixture.

[0006] Typically, the lateral seal elements are equipped with adaptive plates whose heights can be adjusted to allow the passage of the incoming grate car and which ensure a minimal or no gap with the grate car to achieve airtightness (i.e., to prevent unauthorized air from entering or exiting the plenum chamber in the gap between the grate car and the lateral seal element). Without a gap, the contact pressure required to ensure airtightness contributes to abrasive wear caused by friction between the adaptive plates and the grate car. This contact also tends to block chain movement. However, even small gaps on the adaptive plates can cause extreme sandblasting wear due to the high pressure differential and the presence of fine material in the gas flow. The size of such gaps can be orders of magnitude larger, allowing unauthorized airflow. Summary of the Invention [Problem to be solved by the invention]

[0007] It is an object of the present invention to provide a sintering or hardening belt for a sintering or pelleting plant that is more durable, less susceptible to abrasive and sandblast wear, easier to maintain, and minimizes improper air flows.

[0008] This object is achieved by a sintering or curing belt according to claim 1. [Means for solving the problem]

[0009] To overcome the above problems, a sintering belt or a hardening belt for conveying a load through a sintering plant or a pellet plant is provided, a chain of grates having a bottom surface; a support structure configured to support and allow movement of the chain of the grate car; at least two longitudinal sealing elements parallel to the direction of movement of the chain of grate wheels along the sintering or hardening belt; at least two transverse sealing elements which cross the direction of movement of the chain of grate cars along the sintering or hardening belt and partially obstruct the movement of the chain of grate cars; at least one suction duct; Equipped with.

[0010] The suction duct, the at least two longitudinal sealing elements, the at least two transverse sealing elements, and the bottom surface of the grate car are configured to define at least one plenum chamber, in particular, the suction duct ensures airtightness of the bottom end of the plenum chamber, the longitudinal sealing elements ensure airtightness of the sides, the transverse sealing elements ensure airtightness of the upstream end and downstream end, and the adjacency of the grate car ensures partial airtightness of the top end.

[0011] The suction duct is further configured to create a low or high pressure in the plenum chamber.

[0012] The lateral sealing element includes at least one sealing roll configured to partially impede movement of the grate wheel chain, the sealing roll including an inner roll defining an inner radius and an elastically deformable outer sleeve defining an outer radius.

[0013] The advantages of using a seal roll according to the present invention are numerous.

[0014] First, the seal roll is unlikely to completely block the movement of the grate car. In fact, even if the incoming grate car is worn and the grate car height is lower than expected, the grate car's trajectory will be corrected upon contact with the seal roll and deformation of the outer sleeve.

[0015] Second, the use of sealing rolls localizes the contact of the grate car with the transverse sealing elements to a smaller area, thereby allowing for higher contact pressures and improving tightness. The use of soft or flexible materials for the outer sleeve further improves tightness.

[0016] Third, because the seal rolls can rotate in response to the friction exerted by the grate car movement, the overall abrasive wear of the transverse seal elements is reduced, even if the material is sensitive to wear. Furthermore, the abrasive wear is distributed over the outer sleeve. The seal rolls can be easily maintained by simply installing new outer sleeves on their inner rolls.

[0017] The transverse sealing element comprises a plurality of parallel sealing rolls defining at least one roller table. The use of multiple rollers further enhances the aforementioned technical effect and allows for various configurations as described below.

[0018] According to the invention, the roller table may comprise at least two interlocking seal rolls, the distance between two adjacent interlocking seal rolls being strictly contained between the sum of their inner radii and the sum of their outer radii, and successive interlocking seal rolls defining a continuous surface of the roller table, the airtightness between the interlocking seal rolls being ensured by contact pressure between their outer sleeves or by the mutual interlocking of their outer sleeves.

[0019] Preferably, the grate cars of the grate car chain are provided with transversely extending stiffening beams on the bottom surface of the grate car, so that during operation, the transversely extending stiffening beams contact the seal rolls as the grate cars pass through the seal rolls. The diameter and / or pitch of the engaging seal rolls of the successive surfaces are preferably selected so that the grate chain, which rotates the rolls by friction, cannot rotate two or more engaging rolls in a rotational direction incompatible with their natural transmission. This configuration prevents abrasive wear between adjacent engaging rollers, since adjacent engaging rollers in a successive surface always rotate in opposite directions. Note that with this configuration, the rotation of each roller oscillates as the grate car's transverse stiffening beams advance through the successive surfaces.

[0020] Preferably, the continuous surface includes an odd number of interlocking sealing rollers. Because the rotation of each roller oscillates as the grate car advances through the continuous surface, having an even number of rollers can result in only a narrow portion of the outer sleeve repeatedly contacting the grate car. This results in an outer sleeve that is largely intact around its periphery but rapidly wears in the narrow portion.

[0021] The sintering or curing belt may be provided with complementary rotational drives to improve torque transmission between the seal rolls, ensuring that the seal rolls rotate in their intended direction, thus reducing friction and abrasive wear, especially between adjacent mating seal rolls.

[0022] The complementary rotary drive may be selected from gears, motors, and outgrowths on the inner rolls.

[0023] The roller table may include at least two non-engaging seal rolls such that the distance between two adjacent non-engaging seal rolls is equal to or greater than the sum of their outer radii, and the successive non-engaging seal rolls define a discontinuous surface of the roller table. Because the non-engaging seal rolls have only one direction of rotation, multiple seal rolls within the discontinuous surface may be driven by a single motor and belt.

[0024] Such discontinuous surfaces may include complementary sealing elements configured to prevent the flow of gas between the non-engaging sealing rolls through the discontinuous surfaces.

[0025] Such complementary sealing elements may be selected from lateral sealing pads, sealing bottoms, and complementary sealing rollers.

[0026] Preferably, each grate car includes at least one, and preferably at least two, laterally extending stiffening beams on the bottom surface of the grate car, so that during operation, the laterally extending stiffening beams contact the sealing roll as the grate car passes over the sealing roll. The laterally extending stiffening beams preferably include longitudinal extrusions at their bottom ends. The laterally extending stiffening beams can localize the force exerted by the grate car against the roller, improving the airtightness between the roller and the grate car. The longitudinal extrusions further improve the airtightness between the roller and the grate car by ensuring contact with the roller throughout the grate car's movement.

[0027] The outer sleeve may be made of a soft or flexible material, such as rubber or a brush-like material, which improves the airtightness between the sealing rollers of the continuous surface, and generally between the sealing rollers and the grate wheel.

[0028] At least one rotation sensor may be arranged to detect the rotation of the sealing roller. By monitoring the rotation of the roller, a faulty roller can be identified and maintenance work can be planned accordingly.

[0029] The longitudinal sealing element may be a scraping seal pad.

[0030] Preferably, the bottom surface of at least one car of the chain of grate cars is configured to allow gas flow and prevent the passage of load. [Brief explanation of the drawings]

[0031] Further details and advantages of the invention will become apparent from the following detailed description of non-limiting embodiments, with reference to the accompanying drawings. [Figure 1a] 1 is a cross-sectional view of an embodiment of a sintered or cured belt according to the prior art. [Figure 1b] 1 is a cross-sectional view of an embodiment of a sintered or cured belt according to the present invention. [Figure 2] 2a, 2b, 2c, 2d and 2e are schematic illustrations of an embodiment with successive sections according to the invention at different stages of the grate car's movement. [Figure 3a] 1 is a schematic diagram of an embodiment having different discontinuous sections according to the present invention. [Figure 3b] 1 is a schematic diagram of an embodiment having different discontinuous sections according to the present invention. [Figure 3c] 1 is a schematic diagram of an embodiment having different discontinuous sections according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0032] 1a and 1b show cross-sectional views of embodiments of a sintering or consolidation belt 10 according to the prior art and the present invention, respectively.

[0033] In both embodiments, the belt 10 comprises a chain of grate cars 12 having wheels 12a supported by rails (not shown) on a support structure. The rails support the cars 12 and allow movement of the cars 12 along the belt in a conveying direction D. The grate cars have bottom surfaces 12a configured to allow gas flow and prevent passage of load through the bottom surfaces 12a of the grate cars.

[0034] Furthermore, longitudinal sealing elements (not shown) are arranged in vertical longitudinal planes on both sides of the belt 10, while suction ducts 16 are arranged below and along the chain of the grate car 12.

[0035] 1a and 1b differ in that in 1a, several adaptation plates are arranged along the conveying direction D. The adaptation plates are configured to adjust their height to allow the passage of the incoming grate car 12 while providing sufficient contact pressure or minimal gap to manage the tightness.

[0036] 1b, on the other hand, multiple sealing roller tables 20 are arranged along the conveying direction D. Each sealing roller 18 of the roller table 20 comprises an inner roll 18a and an outer sleeve 18b made of a brush-like material. The rollers 18 in the roller table 20 are arranged parallel to each other and perpendicular to the conveying direction D. The outer sleeve 18b of each roller 18 is engaged with the outer sleeves 18b of two other rollers 18 (or a single other roller 18 in the case of rollers at the ends of the roller table 20). Thus, gas flow between the rollers 18 is prevented.

[0037] The roller table 20 is further configured to partially obstruct the path of the grate car 12 upon contact between the incoming grate car and the upstream-most roller of the roller table 20, such that the grate car 12 moves upward along the curvature of the roller 18. Ultimately, the weight of the grate car 12 compresses the outer sleeve 18b of the sealing roller 18 of the roller table 20, thereby preventing gas flow between the grate car 12 and the roller 18.

[0038] Thus, both the plurality of adaptive plates of FIG. 1a and the plurality of roller tables 20 of FIG. 1b function as transverse sealing elements 14 in their respective embodiments.

[0039] The transverse sealing elements 14, the longitudinal sealing elements, the bottom surfaces 12a of the plurality of grate cars 12, and the suction ducts 16 are arranged to define a plurality of plenum chambers PC below the chain of grate cars 12. Thus, when low or high pressure is created in the plenum chambers PC by the suction ducts 16, the only flow path available for the gas is through the bottom surfaces 12a of the grate cars 12 and the fine material loaded therein.

[0040] 2a-2e show schematic diagrams of an embodiment according to the present invention having a continuous surface 20'. In particular, FIGS. 2a-2e show the rotational direction 18c of the engaging rollers 18.1-18.5 at different stages of the grate wheel's movement along the roller table. The grate wheel (not fully shown) runs along the conveying direction D and has a bottom surface 12.a and a pair of transverse stiffening beams 12.b that terminate in longitudinal extrusions 12.c. As can be seen from FIGS. 2a, 2c, and 2e, as the grate wheel moves to the right and contacts the odd-numbered (18.1, 18.3, 18.5) sealing rollers, the rollers rotate clockwise, while the even-numbered (18.2 and 18.4) sealing rollers rotate counterclockwise. Conversely, as can be seen from Figures 2b and 2d, as the grate wheel moves to the right and contacts the even-numbered seal rollers (18.2 and 18.4), the rollers rotate clockwise, while the odd-numbered seal rollers (18.1, 18.3, 18.5) rotate counterclockwise. Thus, the roller rotation oscillates as the grate wheel advances along the direction of motion D. The interlocking of the outer sleeves 18b of the seal rollers 18.1-18.5 prevents gas flow through the continuous surface 20', i.e., between the seal rollers. Similarly, the grate wheel of the longitudinal extrusion 12c and the outer sleeves 18b of the seal rollers 18.1-18.5 cooperate to prevent gas flow between the sealing table and the grate wheel.

[0041] Figures 3a-3c show various embodiments according to the present invention having different discontinuous surfaces 20". In particular, Figure 3a shows a table having two sealing rollers 18.6, 18.7 with a lateral sealing pad 22a, Figure 3b shows a table having four rollers 18.8-18.11 interconnected by a sealing bottom 22b, and Figure 3c shows a table having four rollers 18.12-18.15 with complementary sealing rollers 22c therebetween. The lateral sealing pad 22a of Figure 3a, the sealing bottom 22b of Figure 3b, and the complementary sealing rollers 22c of Figure 3c prevent gas flow between the sealing rollers 18.6-18.15 of the respective discontinuous surfaces 20". Additionally, the complementary sealing rollers 22c of Figure 3c function as complementary rotational drives capable of transmitting torque between the sealing rollers 18.12-18.15 such that all sealing rollers 18.12-18.15 rotate in the same direction 18c. The embodiment of Figures 3a-3c further comprises a rotation sensor 24 configured to monitor the rotation of the sealing rollers.

[0042] The above-described embodiments are purely illustrative and do not limit the scope of the present invention in any exclusive manner. In particular, it should be noted that the present subject matter includes combinations of the disclosed embodiments, such as a roller table 20 having both one or more continuous surfaces 20′ and one or more discontinuous surfaces 20″.

Claims

1. A sintering or consolidation belt (10) for conveying a load through a sintering or pelleting plant, comprising: a chain of grates (12) having a bottom surface (12a); a support structure configured to support and allow movement of said grate wheel chain (12); at least two longitudinal sealing elements parallel to the direction of movement (D) of the chain of grate wheels (12) along the sintering or curing belt (10); at least two transverse sealing elements (14) that intersect the direction of movement (D) of the chain of grate wheels (12) along the sintering or curing belt (10) and partially impede the movement of the chain of grate wheels; at least one suction duct (16); Equipped with the suction duct (16), the at least two longitudinal sealing elements, the at least two transverse sealing elements (14), and the bottom surface of the grate wheel (12) are configured to define at least one plenum chamber (PC); The suction duct (16) is further configured to generate a low or high pressure in the plenum chamber (PC); the transverse sealing element (14) comprises at least two sealing rolls configured to partially impede movement of the grate wheel chain (12), the sealing rolls comprising an inner roll (18a) defining an inner radius and an elastically deformable outer sleeve (18b) defining an outer radius; a plurality of parallel seal rolls of the at least two seal rolls defining at least one roller table (20); 1. A sintering or consolidation belt, comprising: a plurality of parallel seal rolls defining the roller table (20); the plurality of parallel seal rolls including at least two interlocking seal rolls, each adjacent seal roll engaging with the other; a distance between two adjacent interlocking seal rolls being strictly contained between the sum of their inner radii and the sum of their outer radii; and successive interlocking seal rolls defining a continuous surface (20') of the roller table (20).

2. 2. The sintering or hardening belt according to claim 1, wherein the grate wheels (12) of the chain of grate wheels are provided with transversely extending stiffening beams (12b) on the bottom surface (12a) of the grate wheels (12), so that during operation, when the grate wheels (12) pass the sealing rolls, the transversely extending stiffening beams (12b) come into contact with the sealing rolls, and the diameter and / or pitch of the engaging sealing rolls of the successive surfaces are selected so that the chain of grate wheels (12), which rotates the engaging sealing rolls by frictional forces, cannot rotate two or more of the engaging engaging sealing rolls in a rotational direction incompatible with their natural transmission.

3. A sintered or hardened belt (10) as described in claim 1, wherein an odd number of the interlocking seal rolls define the continuous surface (20').

4. A sintered or hardened belt (10) as described in claim 1, further comprising a complementary rotary drive device that improves torque transmission between the sealing rolls.

5. 5. The sintering or consolidation belt (10) of claim 4, wherein the complementary rotational drive is selected from gears, motors, and outgrowths on the inner rolls.

6. A sintered or hardened belt (10) as described in any one of claims 1 to 5, wherein the parallel plurality of seal rolls defining the roller table (20) further include at least two non-engaging seal rolls, adjacent seal rolls being non-engaging with each other, the distance between two adjacent non-engaging seal rolls being equal to or greater than the sum of their outer radii, and the non-engaging seal rolls defining a discontinuous surface (20") of the roller table (20).

7. 7. The sintering or consolidation belt (10) of claim 6, further comprising complementary sealing elements (22a, 22b, 22c) configured to prevent gas flow between the non-engaging sealing rolls through the discontinuous surface (20'').

8. 8. The sintering or consolidation belt (10) of claim 7, wherein the complementary sealing elements (22a, 22b, 22c) are selected from lateral sealing pads (22a), sealing bottoms (22b), and complementary sealing rollers (22c).

9. 2. The sintering or consolidation belt (10) of claim 1, wherein each grate car (12) comprises at least one transverse stiffening beam (12b) extending transversely on the bottom surface (12a) of the grate car (12) so that during operation, when the grate car (12) passes over the sealing roll, the transversely extending stiffening beam (12b) contacts the sealing roll, and the transverse stiffening beams (12b) comprise longitudinal extrusions (12c) at their bottom ends.

10. A sintered or hardened belt (10) as described in claim 1, wherein the outer sleeve (18b) of the sealing roll is made of a soft or flexible material such as rubber or a brush-like material.

11. 10. The sintering or curing belt (10) of claim 1, wherein at least one rotation sensor (24) is positioned to detect rotation of the sealing roll.

12. 2. The sintering or curing belt (10) of claim 1, wherein the longitudinal sealing elements are scrape-off sealing pads.

13. 2. The sintering or curing belt (10) of claim 1, wherein a bottom surface (12a) of at least one wheel (12) of the chain of grate wheels is configured to allow gas flow and prevent the passage of the load.

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