Improved sintering or induration belt for sintering or pelletizing installations

Abstract

A sintering belt (10) comprising a string of grate cars (12), a support structure configured to support and allow the movement of the string of grate cars (12), at least two longitudinal sealing elements parallel to the string of grate cars (12) along the direction of movement (D) of the sintering or calcining belt (10), at least two transversal sealing elements (14) intersecting the string of grate cars (12) along the direction of movement (D) of the sinner or calcining belt (10) and partially obstructing the movement thereof, and at least one suction duct (16). The suction duct (16), the at least two longitudinal sealing elements, the at least two transversal sealing elements (14) and the bottom surface of the grate cars (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 transversal sealing elements (14) comprise at least one sealing roller (18, 18.1-18.15) configured to partially obstruct the movement of the string of grate cars (12) and comprising an inner roller (18a) defining an inner radius and an elastically deformable outer sleeve (18b) defining an outer radius, and the transversal sealing elements (14) comprise a plurality of parallel sealing rollers (18, 18.1-18.15) to define at least one roller table (20). The roller table (20) comprises at least two joint sealing rollers (18.1-18.5) such that the distance between two adjacent joint sealing rollers (18.1-18.5) is strictly comprised between the sum of their inner radii and the sum of their outer radii, and consecutive joint sealing rollers (18.1-18.5) define a continuous surface (20') of the roller table (20).

Description

Technical Field

[0001] This invention generally relates to sintering or pelletizing apparatus. More specifically, this invention relates to sintering or baking belts with improved durability and lower operating costs. Background Technology

[0002] Sintering equipment is widely used to agglomerate fine-grained materials into sinters that can be used in blast furnaces.

[0003] Sintering / pelletizing equipment typically includes: a mixing drum and hopper for mixing different fine-particle materials in a desired proportion; a sintering belt or calcining belt (in the case of pelletizing, this belt is called a calcining belt) for carrying the mixture of fine-particle materials; and an ignition hood near the upstream end of the belt or belt to ignite a portion of the fine-particle material. At the end of the belt, the resulting agglomerated material can be crushed and cooled before storage.

[0004] Traditionally, the belt includes: a continuous series of grate-type trolleys for carrying a mixture of fine-grained materials; a support structure for supporting and allowing the series of grate-type trolleys to move along the belt; at least two longitudinal sealing elements; at least two transverse sealing elements; and at least one suction pipe. The bottom surfaces of the trolleys in the series of grate-type trolleys are configured to allow gas flow while preventing the passage of fine-grained materials.

[0005] The suction pipe, longitudinal sealing element, and transverse sealing element, along with the bottom surface of a series of grate-type trolleys, are configured to define at least one plenum chamber. The suction pipe is further configured to generate low and high pressures within said plenum chamber. Therefore, when the suction pipe generates a pressure difference, an airflow is produced passing through the bottom surface of the series of grate-type trolleys and through a mixture of fine-particle material within the series of grate-type trolleys. This airflow can support flame propagation through the mixture, provided that a portion of this fine-particle material has previously been ignited by an ignition shroud.

[0006] Typically, these transverse sealing elements comprise multiple adapter plates that are adjustable in level to allow the passage of incoming grate trolleys while ensuring minimal or no clearance with the trolleys for a tight seal (i.e., ensuring no air leakage into / out of the air supply chamber through the gap between the grate trolley and the transverse sealing element). Without clearance, the contact pressure required to ensure a tight seal results in wear due to friction between the adapter plates and the trolleys. This contact also readily impedes the movement of the entire string of trolleys. However, even with small gaps formed in the adapter plates, extreme blasting abrasion can occur due to high pressure differentials and the presence of fine-grained material in the airflow. The size of such gaps can then increase by several orders of magnitude, leading to significant leakage flow. Summary of the Invention

[0007] The purpose of this invention is to provide a sintering belt or calcining belt for a sintering or pelletizing apparatus that is more durable, less susceptible to abrasion and sandblasting wear, easier to maintain, and minimizes gas leakage.

[0008] This objective is achieved through the sintering belt or calcining belt of the present invention.

[0009] To overcome the above problems, a sintering belt or calcining belt for transporting loads through a sintering device or pelletizing device includes:

[0010] - A series of grate-type trolleys with a bottom surface.

[0011] - Support structure, configured to support and allow the movement of a series of grate-type trolleys.

[0012] - At least two longitudinal sealing elements, parallel to the direction of movement of a series of grate-type trolleys along the sintering or baking zone.

[0013] - At least two transverse sealing elements intersect with and partially impede the movement of a series of grate-type trolleys along the direction of movement of the sintering or baking zone, and

[0014] - At least one suction tube.

[0015] The suction pipe, at least two longitudinal sealing elements, at least two transverse sealing elements, and the bottom surface of the grate trolley are configured to define at least one air delivery chamber. Specifically, the suction pipe ensures tightness at the bottom end of the air delivery chamber, the longitudinal sealing elements ensure lateral tightness, the transverse sealing elements ensure tightness at the upstream and downstream ends, and the adjacency of the grate trolley ensures partial tightness at the top.

[0016] The suction tube is further configured to generate low or high pressure in the air delivery chamber.

[0017] The transverse sealing element includes at least one sealing roller configured to partially impede the movement of a series of grate trolleys, and the sealing roller includes an inner roller defining an inner radius and an elastically deformable outer sleeve defining an outer radius.

[0018] The advantages of using the sealing roller according to the invention are numerous.

[0019] First, the sealing roller cannot completely block the movement of the grate trolley. In fact, even if the incoming grate trolley is worn and its height is lower than expected, the trajectory of the grate trolley will be corrected when it contacts the sealing roller and deforms the outer sleeve of the sealing roller.

[0020] Second, by using sealing rollers, the contact between the grate-type trolley and the transverse sealing element is positioned in a smaller area, thereby allowing for higher contact pressure to improve tightness. Tightness is further improved by using soft or flexible materials in the outer sleeve.

[0021] Third, because the sealing roller can rotate in response to the friction exerted by the movement of the grate trolley, the total wear on the transverse sealing element is reduced, even though the material is sensitive to wear. Furthermore, the wear is distributed on the outer sleeve. Therefore, the sealing roller can be easily maintained by simply fitting a new outer sleeve onto its inner roller.

[0022] The transverse sealing element comprises a plurality of parallel sealing rollers to define at least one roller table. The use of multiple rollers further enhances the aforementioned technical effects and allows for various configurations as described below.

[0023] According to the invention, the roller table may include at least two engaging sealing rollers such that the distance between two adjacent engaging sealing rollers is strictly between the sum of their inner radii and the sum of their outer radii, and a plurality of consecutive engaging sealing rollers define a continuous surface of the roller table. The tightness between the engaging sealing rollers is ensured by the contact pressure between their outer sleeves or by the mutual engagement of their outer sleeves.

[0024] Preferably, the grate trolleys in a series of grate trolleys include a rigid beam extending laterally on the bottom surface of the grate trolley, such that during operation, the laterally extending rigid beam contacts the sealing roller as the grate trolley passes the sealing roller. The diameter and / or pitch of the engaging sealing rollers constituting the continuous surface are preferably selected such that a series of grate trolleys rotating the rollers due to friction cannot cause two or more engaging rollers to rotate in a direction of rotation incompatible with their natural drive. Since adjacent engaging rollers within the continuous surface rotate in opposite directions at any given time, this configuration prevents wear between adjacent engaging rollers. Note that with this configuration, the rotation of each roller varies back and forth between two directions as the transverse rigid beam of the grate trolley travels across the continuous surface.

[0025] Preferably, the continuous surface comprises an odd number of engaging sealing rollers. Since the rotation of each roller varies back and forth between two directions as the grate trolley travels across the continuous surface, having an even number of rollers may result in only a small portion of the outer sleeve repeatedly contacting these grate trolleys. This would leave most of the outer sleeve's periphery intact, but a small portion of the outer sleeve wearing out rapidly.

[0026] The sintering or baking belt may include a complementary rotary actuator to improve torque transmission between the sealing rollers. The complementary rotary actuator ensures that the sealing rollers rotate in their intended direction, thereby reducing friction and wear, especially between adjacent mating sealing rollers.

[0027] Complementary rotary drives can be selected from gears, motors, and protrusions on inner rollers.

[0028] The roller table may include at least two non-engaged sealing rollers such that the distance between two adjacent non-engaged sealing rollers is equal to or greater than the sum of their outer radii, and the continuous non-engaged sealing rollers define a discontinuous surface of the roller table. Since the non-engaged sealing rollers have only one direction of rotation, multiple sealing rollers within the discontinuous surface may be driven by a single motor and belt.

[0029] Such discontinuous surfaces may include complementary sealing elements configured to prevent gas from flowing between these non-engaged sealing rollers across the discontinuous surface.

[0030] Such complementary sealing elements can be selected from transverse sealing gaskets, sealing bottom portions, and complementary sealing rollers.

[0031] Preferably, each grate trolley includes at least one, preferably at least two, transverse rigid beams extending laterally on the bottom surface of the grate trolley, such that during operation, the transverse rigid beams contact the sealing roller as the grate trolley passes the sealing roller. The transverse rigid beams preferably include longitudinal extrusion portions at their bottom ends. The transverse rigid beams enable the localization of the force applied to the roller by the grate trolley, thereby improving the tightness between the roller and the grate trolley. The longitudinal extrusion portions further improve the tightness between the roller and the grate trolley by ensuring contact with the roller throughout the entire movement of the grate trolley.

[0032] The outer sleeve can be made of soft or flexible materials, such as rubber or brush-like materials. This outer sleeve improves the tightness between the sealing rollers on a continuous surface and, overall, improves the tightness between the sealing rollers and the grate trolley.

[0033] At least one rotation sensor can be arranged to detect the rotation of the sealing roller. By monitoring the rotation of the roller, faulty rollers can be identified and maintenance operations can be planned accordingly.

[0034] The longitudinal sealing element can be a scraping gasket.

[0035] Preferably, the bottom surface of at least one of the grate-type trolleys is configured to allow gas flow and prevent the load from passing through. Attached Figure Description

[0036] 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, in which:

[0037] Figure 1a and Figure 1b These are cross-sections of embodiments of sintering belts or baking belts according to existing technology and the present invention;

[0038] Figure 2a, Figure 2b , Figure 2c , Figure 2d and Figure 2e This is a schematic diagram of different stages of the movement of the grate trolley according to an embodiment of the present invention having continuous sections;

[0039] Figure 3a , Figure 3b , Figure 3c This is a schematic diagram of an embodiment of the present invention with different discontinuous segments. Detailed Implementation

[0040] Figure 1a and Figure 1b Cross sections are shown respectively according to the prior art and embodiments of the sintering belt or calcining belt 10 according to the present invention.

[0041] In both embodiments, the belt 10 includes a series of grate-type trolleys 12, each trolley having a plurality of wheels 12a supported by rails (not shown) on a support structure. These rails support the trolleys 12 and enable them to move along the belt in the transport direction D. The grate-type trolleys have a bottom surface 12a configured to allow gas flow and prevent the load from passing over it.

[0042] In addition, longitudinal sealing elements (not shown) are arranged on both sides of the belt 10 in a vertical longitudinal plane, while suction pipes 16 are arranged below a series of grate trolleys 12 and along the series of grate trolleys.

[0043] Figure 1a and Figure 1b The difference is that in Figure 1a, multiple adapter plates are arranged along the transport direction D. These adapter plates are configured to adjust their horizontal height to provide sufficient contact pressure or minimum clearance to manage tightness while allowing the grate trolley 12 to pass through.

[0044] At the same time, Figure 1b In this configuration, multiple sealing roller tables 20 are arranged along the transport direction D. The sealing rollers 18 of each roller table 20 include inner rollers 18a and outer sleeves 18b made of a brush-like material. The multiple rollers 18 within the roller table 20 are arranged parallel to each other and perpendicular to the transport direction D. The outer sleeve 18b of each roller 18 engages with the outer sleeves 18b of two other rollers 18 (or, in the case of rollers at the end of the roller table 20, a single other roller 18). This prevents gas from flowing between the multiple rollers 18.

[0045] The roller table 20 is further configured to partially obstruct the path of the grate carriage 12, such that when the entering grate carriage comes into contact with the upstream roller of the roller table 20, the grate carriage 12 moves upward along the curvature of the roller 18. Ultimately, the weight of the grate carriage 12 compresses the outer sleeve 18b of the sealing roller 18 of the roller table 20, thereby preventing gas from flowing between the grate carriage 12 and the roller 18.

[0046] Therefore, the multiple adapter boards in Figure 1a and Figure 1b The multiple roller tables 20 both act as transverse sealing elements 14 in their respective embodiments.

[0047] The transverse sealing element 14, the longitudinal sealing element, the suction pipe 16, and the bottom surfaces 12a of the multiple grate trolleys 12 are arranged to define multiple air delivery chambers PC below a series of grate trolleys 12. Therefore, when the suction pipe 16 generates low or high pressure in the air delivery chamber PC, the only flow path available to the gas is through the bottom surfaces 12a of the grate trolleys 12 and through the fine particulate material loaded in the grate trolleys.

[0048] Figures 2a to 2e A schematic diagram of an embodiment having a continuous surface 20' according to the present invention is shown. Specifically, Figures 2a to 2e The rotational direction 18c of the joining rollers 18.1-18.5 during different stages of the grate trolley's movement along the roller table is shown. The grate trolley (not fully shown) travels along the transport direction D and has a bottom surface 12.a and a pair of transverse rigid beams 12.b terminating at the longitudinal extrusion section 12.c. (As shown in...) Figure 2a , Figure 2c , Figure 2e As can be seen, when the grate trolley moves to the right and contacts the odd-numbered sealing rollers (sealing rollers 18.1, 18.3, 18.5), the rollers rotate clockwise, while the even-numbered sealing rollers (sealing rollers 18.2, 18.4) rotate counterclockwise. Conversely, as in... Figure 2b , Figure 2d As can be seen, when the grate trolley moves to the right and contacts the even-numbered sealing rollers (sealing rollers 18.2, 18.4), these rollers rotate clockwise, while the odd-numbered sealing rollers (sealing rollers 18.1, 18.3, 18.5) rotate counterclockwise. Therefore, the rotation of these rollers oscillates between the two directions as the grate trolley moves along the direction of motion D. The interlocking of the outer sleeves 18b of the sealing rollers 18.1-18.5 prevents gas from flowing across the continuous surface 20', i.e., between these sealing rollers. Similarly, the longitudinal extrusion section 12c of the grate trolley cooperates with the outer sleeves 18b of the sealing rollers 18.1-18.5 to prevent gas from flowing between the sealing roller platform and the grate trolley.

[0049] Figures 3a to 3c Different embodiments of the invention with different discontinuous surfaces 20” are shown. In particular, Figure 3a A stage with two sealing rollers 18.6 and 18.7 and a transverse sealing gasket 22a is shown. Figure 3b A stage with four rollers 18.8-18.11 interconnected by a sealed bottom portion 22b is shown, and Figure 3c A stage with four rollers 18.12-18.15 and a complementary sealing roller 22c between them is shown. Figure 3a lateral sealing gasket 22a, Figure 3b The sealed bottom portion 22b and Figure 3c The complementary sealing rollers 22c prevent gas from flowing between their respective discontinuous surfaces 20” of the sealing rollers 18.6-18.15. Furthermore, Figure 3c The complementary sealing roller 22c acts as a complementary rotary actuator capable of transmitting torque between the sealing rollers 18.12-18.15, causing all the sealing rollers 18.12-18.15 to rotate in the same direction 18c. Figures 3a to 3c The embodiments also include a rotation sensor 24 configured to monitor the rotation of the sealing roller.

[0050] The embodiments discussed above are merely exemplary and do not exclusively limit the scope of the invention. In particular, it should be noted that the subject matter of the invention includes combinations of the disclosed embodiments, such as a roller table 20 comprising one or more continuous surfaces 20' and one or more discontinuous surfaces 20'".

Claims

1. A sintering belt or calcining belt (10) for transporting loads through a sintering device or pelletizing device, comprising: - A series of grate-type trolleys (12), the grate-type trolleys having a bottom surface (12a); - A support structure configured to support a series of said grate trolleys (12) and enable the series of said grate trolleys to move; - At least two longitudinal sealing elements, parallel to the direction of movement (D) of a series of said grate trolleys (12) along the sintering belt or calcining belt (10); - At least two transverse sealing elements (14) intersect with a series of the grate trolleys (12) along the direction of movement (D) of the sintering or roasting belt (10) and partially impede the movement of the grate trolleys; - At least one suction tube (16); The suction pipe (16), at least two of the longitudinal sealing elements, at least two of the transverse sealing elements (14), and the bottom surface of the grate trolley (12) are configured to define at least one air delivery chamber. The suction tube (16) is configured to generate low or high pressure in the air delivery chamber; The transverse sealing element (14) includes at least one sealing roller configured to partially impede the movement of a series of grate trolleys (12), and the sealing roller includes an inner roller (18a) defining an inner radius and an outer sleeve (18b) defining an outer radius that can elastically deform. The transverse sealing element (14) includes a plurality of parallel sealing rollers to define at least one roller table (20). The roller table (20) is characterized in that it includes at least two engaging sealing rollers (18.1-18.5) such that the distance between two adjacent engaging sealing rollers (18.1-18.5) is strictly between the sum of the inner radii of the two adjacent engaging sealing rollers and the sum of the outer radii of the two adjacent engaging sealing rollers, and the continuous engaging sealing rollers (18.1-18.5) define a continuous surface (20') of the roller table (20).

2. The sintering belt or calcining belt (10) according to claim 1, wherein, A series of the grate trolleys (12) includes a rigid beam (12b) extending laterally on the bottom surface (12a) of the grate trolley (12) such that, in operation, when the grate trolley (12) passes the engagement sealing rollers (18.1-18.5), the laterally extending rigid beam (12b) contacts the engagement sealing rollers (18.1-18.5); and wherein the diameter and / or pitch of the engagement sealing rollers (18.1-18.5) forming a continuous surface are selected such that a series of the grate trolleys (12) that rotate the rollers due to friction cannot cause two or more engagement sealing rollers (18.1-18.5) to rotate in a direction of rotation incompatible with their natural drive.

3. The sintering or baking belt (10) according to claim 1 or 2, comprising an odd number of the joining sealing rollers (18.1-18.5) to define the continuous surface (20').

4. The sintering or baking belt (10) according to claim 1 further includes a complementary rotary drive to improve torque transmission between the joint sealing rollers.

5. The sintering belt or calcining belt (10) according to claim 4, wherein, The complementary rotary actuator is selected from a gear, a motor, or a protrusion on an inner roller.

6. The sintering belt or calcining belt (10) according to claim 1, wherein, The roller table (20) includes at least two non-engaged sealing rollers (18.6-18.15) such that the distance between two adjacent non-engaged sealing rollers (18.6-18.15) is equal to or greater than the sum of the outer radii of the two adjacent non-engaged sealing rollers, and the plurality of said non-engaged sealing rollers (18.6-18.15) define a discontinuous surface (20”) of the roller table (20).

7. The sintering or baking belt (10) according to claim 6 further includes complementary sealing elements (22a, 22b, 22c) configured to prevent gas from flowing between the non-jointed sealing rollers (18.6-18.15) through the discontinuous surface (20”).

8. The sintering belt or calcining belt (10) according to claim 7, wherein, The complementary sealing elements (22a, 22b, 22c) are selected from the transverse sealing gasket (22a), the sealing bottom portion (22b), or the complementary sealing roller (22c).

9. The sintering belt or calcining belt (10) according to claim 1, wherein, Each of the grate trolleys (12) includes at least one transverse rigid beam (12b) that extends laterally on the bottom surface (12a) of the grate trolley (12) such that, in operation, when the grate trolley (12) passes the engagement sealing rollers (18.1-18.5), the transversely extending rigid beam (12b) contacts the engagement sealing rollers (18.1-18.5).

10. The sintering belt or calcining belt (10) according to claim 1, wherein, The outer sleeve (18b) of the sealing roller is made of a flexible material or a brush-like material.

11. The sintering belt or calcining belt (10) according to claim 1, wherein, At least one rotation sensor (24) is arranged to detect the rotation of the sealing roller.

12. The sintering belt or calcining belt (10) according to claim 1, wherein, The longitudinal sealing element is a scraping sealing gasket.

13. The sintering belt or calcining belt (10) according to claim 1, wherein, The bottom surface (12a) of at least one of the grate trolleys in a series is configured to allow gas flow and prevent the load from passing through.

14. The sintering belt or calcining belt (10) according to claim 10, wherein, The flexible material is rubber.

15. The sintering belt or calcining belt (10) according to claim 9, wherein, Each of the grate trolleys (12) includes at least two transverse rigid beams (12b), the transverse rigid beams (12b) including a longitudinal extrusion section (12c) at the bottom end of the rigid beams.

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