Abstract
The disclosure relates to a machine for thermal treatment of bulk material, comprising, a stationary furnace which presents a support structure, and a plurality of pallet cars traveling through the furnace, said plurality of pallet cars together defining, at a lateral side thereof, a common engagement surface which extends through the furnace, wherein a gap is defined between the support structure of the furnace and the common engagement surface, said gap having a gap length, the machine further comprising: a sealing system comprising: one or more drop bars, wherein each drop bar of the one or more drop bars includes a brush arranged on the drop bar such that the brush is configured to be in engagement with the common engagement surface such that the one or more drop bars covers the gap over at least parts of the gap length.
Claims
1. A machine for thermal treatment of bulk material, comprising: a stationary furnace which presents a support structure, and a plurality of pallet cars traveling through the furnace along a traveling direction, wherein a series of the plurality of pallet cars located within the stationary furnace together define, at lateral sides of the plurality of pallet cars, a common engagement surface which extends through the furnace along the traveling direction, wherein the support structure of the furnace and the common engagement surface of the series of pallet cars of the plurality of pallet cars define a gap therebetween, said gap having a gap length along the traveling direction, the machine further comprising: a sealing system comprising: one or more drop bars distributed after each other along the traveling direction; wherein each drop bar of the one or more drop bars includes a brush arranged on the drop bar such that the brush is configured to be in engagement with the common engagement surface such that the one or more drop bars covers the gap over at least parts of the gap length.
2. The machine according to claim 1, wherein brush bristles of the brush are made of stainless steel.
3. The machine according to claim 1, wherein brush bristles of the brush has a length of at least 20 mm.
4. The machine according to claim 1, wherein each drop bar further comprises a drop bar structure slidably connected to the support structure of the furnace, wherein the brush is carried by the drop bar structure.
5. The machine according to claim 4, wherein the brush protrudes out from the drop bar structure such that a clearance is formed between the drop bar structure and the common engagement surface.
6. The machine according to claim 5, wherein the clearance between the drop bar structure and the engagement surface is at least 1 mm.
7. The machine according to claim 4, wherein the drop bar structure of each drop bar of the one or more drop bars comprises a recess configured to receive the brush therein.
8. The machine according to claim 4, wherein each drop bar of the one or more drop bars further comprises a fastening plate configured to connect the brush to the drop bar structure.
9. The machine according to claim 8, wherein each drop bar of the one or more drop bars further comprises a brush holder configured to hold the brush and wherein the fastening plate is configured to clamp the brush holder towards the drop bar structure.
10. The machine according to claim 1, wherein the brush is arranged on the drop bar such that brush bristles of the brush are directed substantially perpendicular to the common engagement surface.
11. The machine according to claim 1, wherein the brush is arranged on the drop bar such that brush bristles of the brush forms an oblique angle with the common engagement surface.
12. The machine according to claim 1 wherein brush bristles of the brush has a length of between 20 and 100 mm.
13. The machine according to claim 1 wherein brush bristles of the brush has a length of 50 mm.
14. The machine according to claim 5, wherein the clearance between the drop bar structure and the engagement surface is between 5 to 20 mm.
15. The machine according to claim 5, wherein the clearance between the drop bar structure and the engagement surface is 10 mm.
16. A machine for thermal treatment of bulk material, comprising: a stationary furnace which presents a support structure, and a plurality of pallet cars traveling through the furnace along a traveling direction, wherein a series of pallet cars of said plurality of pallet cars together define, at lateral sides thereof, a common engagement surface which extends through the furnace along the traveling direction, wherein the support structure of the furnace and the common engagement surface of the series of pallet cars of the plurality of pallet cars define a gap therebetween, said gap having a gap length along the traveling direction, the machine further comprising: a first sealing system comprising: one or more drop bars distributed after each other along the traveling direction; wherein each drop bar of the one or more drop bars includes a brush arranged on the drop bar such that the brush is configured to be in engagement with the common engagement surface such that the one or more drop bars covers the gap over at least parts of the gap length, wherein the machine further comprises a second sealing system connected to the support structure of the furnace and arranged along the traveling direction, the second sealing system being arranged to be in engagement with the common engagement surface so as to cover the gap over at least parts of the gap length, and wherein the second sealing system is arranged at a spaced distance from the first sealing system such that an elongate cavity is formed therebetween.
17. The machine according to claim 16, wherein the second sealing system comprises: a series of leaf members which are partially overlapping so as to form a sealing surface, wherein each leaf member of the series of leaf members is connected to the support structure at a first end thereof, and in engagement with the common engagement surface at a second, opposite, end thereof.
18. The machine according to claim 16, wherein the second sealing system comprises a further one or more drop bars distributed after each other along the traveling direction.
19. The machine according to claim 18, wherein each drop bar of the further one or more drop bars includes a brush arranged on the drop bar such that the brush is configured to be in engagement with the common engagement surface such that the further one or more drop bars covers the gap over at least parts of the gap length.
20. The machine according to claim 16, wherein the first sealing system and the second sealing system are arranged in parallel to each other so as to cover the gap along a common gap width which extends over at least a firing zone and a cooling zone of the furnace.
21. A sealing system for a machine for the thermal treatment of bulk material, wherein the machine comprises a stationary furnace having a support structure, and a plurality of pallet cars traveling through the furnace along a traveling direction, wherein a series of the plurality of pallet cars that are located within the stationary furnace together define, at lateral sides thereof, a common engagement surface which extends through the furnace along the traveling direction, wherein the support structure of the furnace and the common engagement surface of the series of pallet cars of the plurality of pallet cars define a gap therebetween, the sealing system comprising: one or more drop bars being configured to be distributed after each other along the traveling direction; wherein each drop bar of the one or more drop bars includes a brush arranged on the drop bar such that the brush is configured to be in engagement with the common engagement surface such that the one or more drop bars covers the gap over at least parts of the gap length.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The above, as well as additional objects, features and advantages of the present invention, will be better understood through the following illustrative and non-limiting detailed description of embodiments of the present invention, with reference to the appended drawings, where the same reference numerals may be used for similar elements, and wherein:
(2) FIG. 1A is a perspective view of a machine for thermal treatment of bulk material.
(3) FIG. 1B is a cross section of a machine for thermal treatment of bulk material.
(4) FIGS. 2A-2B illustrate a sealing system comprising a series of leaf members, as arranged when connected to the support structure of the machine.
(5) FIG. 3 illustrates a sealing system, providing some more details on the sealing functionality of the concept of using leaf seals.
(6) FIG. 4 illustrates a drawback that would occur if a more conventional long flexible seal member were to be used.
(7) FIG. 5A illustrates parts of the sealing system comprising a series of leaf members.
(8) FIG. 5B illustrates three overlapping leaf members.
(9) FIG. 6A illustrates parts of the sealing system comprising two series of leaf members and a series of flexible blanket members.
(10) FIG. 6B illustrates three overlapping leaf members and a flexible blanket member.
(11) FIG. 7 illustrates part of a machine comprising a sealing system.
(12) FIG. 8A is a perspective view of a sealing system which comprises a drop bar including a drop bar structure and a brush.
(13) FIG. 8B illustrates a front view of the sealing system illustrated in FIG. 8A.
(14) FIG. 8C illustrates a cross section of the sealing system illustrated in FIGS. 8A and 8B, wherein the brush forms an oblique angle to a common engagement surface.
(15) FIG. 9 illustrates a cross section of a sealing system, wherein the brush is perpendicular to a common engagement surface.
(16) FIGS. 10A-10B illustrate an embodiment of a sealing assembly comprising the sealing system with a series of leaf members, and a further sealing system comprising a drop bar.
(17) FIGS. 11A-11B illustrate an embodiment of a sealing assembly comprising the sealing system with a series of leaf members, and a further sealing system comprising a drop bar with a brush.
(18) FIG. 12 illustrates an embodiment of a sealing assembly comprising a sealing system comprising a drop bar including a drop bar structure and a brush, and a further sealing system comprising a drop bar.
(19) FIG. 13 illustrates an embodiment of a sealing assembly comprising a sealing system and a further sealing system, both comprising a drop bar including a drop bar structure and a brush.
(20) FIG. 14 illustrates an embodiment of a sealing assembly comprising a sealing system and a further sealing system, both comprising a respective series of leaf members, together with yet a further sealing system comprising a drop bar.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
(21) The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled person.
(22) The present disclosure relates to a machine for thermal treatment of bulk material and a sealing system for the machine. With reference to FIG. 1 of the present disclosure, the machine for thermal treatment of bulk material will be discussed. For the sake of clarity, a number of different seal designs that may be used in conjunction with the machine will be discussed in the following sections. With reference to FIGS. 2-6 of the present disclosure, a sealing system comprising a leaf seal design will be discussed. With reference to FIGS. 7-9 of the present disclosure, a sealing system comprising a brush seal design will be discussed. With reference to FIGS. 10-14 of the present disclosure, a sealing system comprising different combinations of seal designs will be discussed.
(23) In particular, the present disclosure relates to a single sealing system according to the sealing system discussed in connection with FIGS. 7-9. Further, the present disclosure also relates to dual sealing systems, or sealing assemblies, being any combination of sealing systems discussed throughout this disclosure in connection with FIGS. 2-9.
(24) FIGS. 1A-1B illustrate a part of a machine 100 for thermal treatment of bulk material, such as metal ore. However, it should be understood that only a part of the machine 100 is illustrated in the figures and hence, the machine 100 may comprise more features than discussed herein. The machine 100 may be any machine for thermal treatment of bulk material known in the art.
(25) The machine 100 comprises a stationary furnace 10 configured to process bulk material. By processing the material, is herein meant, drying, heating or cooling the bulk material using the stationary furnace 10.
(26) The machine 100 further comprises a plurality of pallet cars 12. The pallet cars 12 are configured to transport the bulk material through the stationary furnace 10. The pallet cars 12 are traveling through the stationary furnace 10 on a set of rails (not shown). The pallet cars 12 are traveling through the stationary furnace 10 along a traveling direction TD. The traveling direction TD extends along a substantially horizontal direction.
(27) The pallet cars 12 are arranged with holes in the bottom plate for receiving a gas flow through the bottom plate. Although not illustrated in FIGS. 1A-1B, the machine 100 comprises an arrangement below the track of the pallet cars 12 that by suction generates a flow of hot air or gas above the pallet cars 12 through the bulk material and the pallet cars 12. Such an arrangement may be, but is not limited to, wind boxes. Further, generation of gas or air flow may alternatively be used for cooling the bulk material in other parts of the machine 100.
(28) The stationary furnace 10 presents a support structure 16. The support structure 16 is a steady and stationary part of the furnace 10, located on either lateral side of the furnace 10. The support structure 16 is arranged such that when the plurality of pallet cars 12 travel through the furnace 10, the lateral sides of the pallet cars 12 pass in the vicinity of the support structure 16. The support structure 16 together with the pallet cars 12 defines a portion of the boundary between the interior of the furnace 10 and the ambient air.
(29) The plurality of pallet cars 12 together define a common engagement surface 14. The common engagement surface 14 extends through the stationary furnace 10 along the traveling direction TD. The common engagement surface 14 and the support structure 16 of the furnace 10 together define a gap 18 therebetween. The gap 18 has a gap length L along the traveling direction through the stationary furnace 10 along the traveling direction TD.
(30) The machine 100 further comprises a sealing system (not illustrated in FIG. 1). The sealing system is configured to seal the gap defined between the common engagement surface 14 and the support structure 16 so as to prevent gas, droplets and/or particulate matter from passing through the gap 18. The sealing system will be discussed in more detail in connection with FIGS. 2-11.
(31) FIG. 2A illustrates a sealing system 200 as arranged when connected to the support structure 16 of the machine 100. As discussed in relation to FIGS. 1A-1B, a gap 18 defined between the support structure 16 of the furnace 10 and the common engagement surface 14 of the plurality of pallet cars 12. A purpose of the sealing system 200 is to seal the gap 18 between the support structure 16 and the common engagement surface 14, so as to prevent gas, droplets and/or particulate matter from passing through the gap 18. In the present example embodiment, the sealing system 200 comprises a series 210 of leaf members 212 which are partially overlapping so as to form a sealing surface. The leaf members 212 in the present embodiment have a rectangular shape, however it is conceivable that leaf members in other embodiments may have different shapes. The sealing system 200 of the present embodiment further comprises a number of brackets 220. In FIG. 2A two brackets 220 are illustrated, although it should be understood that only a portion of the machine 100 is illustrated, and thus the number of brackets 220 in the full machine 100 may be different. Each of the brackets 220 comprises an attachment surface 222, onto which a first end 214 of each of the leaf members 212 is connected to a bracket 220. Further, the brackets 220 are attached to the support structure 16. In the present example embodiment, the attachment surface 222 of each of the brackets 220 is angled with respect to the engagement surface 14. The angled attachment surface 222 provides self-biasing of the leaf members 212 attached thereto, towards the common engagement surface 14. The angled attachment surface 222 may form an angle in relation to the common engagement surface being 10 to 50 degree. However, larger, or smaller, angles are also conceivable.
(32) The leaf members of the disclosure, such as the leaf members 212 may be made of thin spring steel. A property of such spring steel is that it is resilient and may thus return to its original shape despite being subjected to deflection and twisting. Leaf members of the disclosure may however alternatively be made of other types of material. By way of example, the leaf members may be made of, but are not limited to, stainless steel, iron, copper, polytetrafluoroethylene or fluoropolymers, such as used in Teflon™, plastics and composites such as steel with a rubber tip.
(33) As illustrated in FIG. 2A, the otherwise planar leaf members 212 take a bent shape as a result of the angled attachment surface 222 such that a second end 216 of each of the leaf members 212 in engagement with the engagement surface 14 is pushed against the engagement surface 14 by the resilient force of the leaf members 212. By the present arrangement the gap 18 between the support structure 16 and the common engagement surface 14 is covered and thereby sealed such as to prevent passage of gas, droplets and/or particulate matter from the interior of the furnace to the ambient air, or vice versa.
(34) FIG. 2B illustrates the same sealing system 200 as in FIG. 2A from a different point of view. Further to what has been discussed above, FIG. 2B illustrates that a significant portion of a length of each of the leaf members 212 is arranged in an overlapping manner with the common engagement surface 14. As the plurality of pallet cars 12 travel through the furnace an edge 218 of the second end 216 of each of the leaf members 212 may wear off. If the leaf members 212 were arranged in a planar manner, the wearing of the edge 218 would eventually result in loss of contact between the leaf members 212 and the common engagement surface 14, whereby the seal across the gap 18 would be impaired. However, as the leaf members 212 are arranged to be self-biased into engagement with the common engagement surface 14, the resilience of each leaf member 212 will push the second end 216 of the leaf member 212 towards the common engagement surface 14 even as the edge 218 wears off. By the present arrangement, contact between the leaf members 212 and the common engagement surface 14 is maintained, ensuring continued seal.
(35) FIG. 3 illustrates the sealing system 200 providing some more details on the sealing functionality of the concept of using leaf seals. A problem of sealing the gap 18 between the common engagement surface 14 and the support structure 16 may be that the engagement surfaces 14a, 14b, 14c of individual pallet cars 12 (pallet cars not shown in the present figure), may be shifted in a vertical direction with respect to each other. Such a shift may be due to slight variation in manufacturing of the pallet cars 12 or, more likely, that the pallet cars 12 sag over time partly due to a combination of carried heavy load and harsh environment with extreme temperatures in the furnace 10. Such a vertical shift is illustrated in FIG. 3 with the individual engagement surfaces 14a, 14b, 14c having different vertical positions. The leaf members 212 are arranged to be in good physical contact with the flat engagement surfaces 14a, 14b, 14c. However, at a transition from one engagement surface 14a to another engagement surface 14b, the common surface is no longer flat due to the difference in vertical position and thus the leaf members 212 are deformed to adjust to the shifting structure of the surface due to the resilience of the material out of which the leaf members 212 are made. It is illustrated in FIG. 3 that said deformation substantially occurs for the individual leaf members 212 at such transitions, whereas adjacent leaf members 212 are to a large extent unaffected by the transition and hence maintain contact with the engagement surfaces 14a, 14b, 14c. The present arrangement results in only a small gap 30 at the transition as a result of deformation of an individual leaf member 212. Consequently, only a small leak may result due to differences in vertical position of the pallet cars 12, thus maintaining high sealing efficiency.
(36) FIG. 4 illustrates a drawback that would occur if a more conventional long flexible seal member 210′ were to be used. The situation is similar to the one just described in relation to FIG. 3, wherein the engagement surface 14 of individual pallet cars 12 are shifted in the vertical direction with respect to each other. Since the long flexible seal 210′ is continuous it will be affected by the shift not only in the vicinity of the transition between individual pallet cars 12, but also along a larger portion of the common engagement surface 14. This may cause a significantly larger gap 30′ between the long flexible seal member 210′ and the common engagement surface 14, resulting in significantly larger leak through the seal than compared to the sealing system 200 based on a series 210 of leaf members 212.
(37) Returning now to FIG. 3, a further situation that may occur in sealing systems of a machine 100 for thermal treatment of bulk material is illustrated, namely that pellets may occasionally get stuck underneath the seal. In FIG. 3, a pellet 20 is illustrated to be stuck between the series 210 of leaf members 212 and an individual engagement surface 14b. The stuck pellet 20 may lift up some of the leaf members 212, which are thus deformed such that they are bent upwards. Said deformation substantially occurs for the individual leaf members 212 in contact with the pellet 20, whereas adjacent leaf members 212 to a large extent are unaffected by the stuck pellet 20 and hence maintain contact with the engagement surfaces 14a, 14b, 14c. Similarly to the situation at the transition between individual pallet cars 12, the present arrangement results in only a small gap 40 in the vicinity of the pellet 20 as a result of deformation of one or a few individual leaf members 212. Consequently, only a small leak may result due to the stuck pellet 20, thus maintaining high sealing efficiency.
(38) FIG. 5A illustrates the sealing system 200 viewed in the traveling direction TD. The leaf member 212 is illustrated to be connected to the bracket 220 by means of a bolt 224 and nut 226 arrangement. Bolts 224 are inserted into through holes of the bracket 220 and into through holes 217 of the leaf member 212. Nuts 226 are tightened onto the other end of the bolts 224, attaching the leaf member 212 to the bracket 220. To simplify replacement of individual leaf members, the bolts 224 may be pre-welded onto the bracket 220. It should be understood that also other means for connecting leaf members 212 to the bracket 220 are conceivable.
(39) In FIG. 5A it is further illustrated that the bracket 220 comprise an attachment surface 222 onto which the leaf member 212 is connected to the bracket 220. The attachment surface 222 is angled with respect to the engagement surface 14. The present arrangement provides the leaf member 212 with a curvature which due to the resilience of the material out of which the leaf member 212 is made, results in a self-biased state, thereby pushing the second end 216 of the leaf member 212 towards the engagement surface 14.
(40) FIG. 5B illustrates three leaf members 212a, 212b, 212c viewed in a direction perpendicular to the traveling direction TD. The three leaf members 212a, 212b, 212c are partially overlapping so that a through hole 217 of leaf member 212a coincides with a through hole 217 of the adjacent leaf member 212b and so on. The ratio of overlap may vary between different embodiments. FIG. 5B illustrates that in the present embodiment a leaf member 212a overlaps with the consecutive leaf member 212b by typically less than 50%.
(41) FIG. 6A illustrates a sealing system 300 viewed in the traveling direction TD. The sealing system comprises brackets 220 each of which having an attachment surface 222. Onto the attachment surface 222 is a first series 310 of leaf members 312 connected. The leaf members 312 in the first series 310 of leaf members 312 are partially overlapping so as to form a sealing surface. It should be understood that the first series 310 of leaf members 312 may be of the same type as in the series 210 of leaf members 212 in sealing system 200, or they may be of a different type.
(42) Further, the sealing system 300 comprises a series 330 of flexible blanket members 332. Each flexible blanket member 332 of the series 330 of flexible blanket members 332 is connected to the bracket at a first end 334 of the flexible blanket member 332. The series 330 of flexible blanket members 332 is positioned adjacent the first series 310 of leaf members 312 so as to cover overlapping edges of adjacent leaf members 312. The flexible blanket members of the disclosure may be made of, but are not limited to, Neopren (i.e. polychloroprene), welding blanket of woven blanket biomass, synthetic polymers such as Nylon, woven or nonwoven fiber blanket material, gasket material made of polytetrafluoroethylene or fluoropolymers, such as used in Teflon™.
(43) Further, the sealing system 300 comprises a second series 340 of leaf members 342. Each leaf member 342 of the series 340 of leaf members 342 is connected to the bracket at a first end 344 of the leaf member 342. It should be understood that the second series 340 of leaf members 342 may be of the same type as in the first series 310 of leaf members 312, or they may be of a different type. The second series 340 of leaf members 342 is positioned adjacent the series 330 of flexible blanket members 332 on an opposite side with respect to the first series 310 of leaf members 312, so as to sandwich the series 330 of flexible blanket members 332 between the first series 310 and the second series 340.
(44) The leaf members 312, 342 and the flexible blanket members 332 are illustrated to be connected to the bracket 220 by means of a bolt 224 and nut 226 arrangement. Bolts 224 are inserted into through holes of the bracket 220 and into through holes 317 of the leaf member 312, 342 and the flexible blanket members 332. Nuts 226 are tightened onto the other end of the bolts 224, attaching the leaf members 312, 342 and the flexible blanket members 332 to the bracket 220. To simplify replacement of individual leaf members, the bolts 224 may be pre-welded onto the bracket 220. It should be understood that also other means for connecting leaf members 312, 342 and the flexible blanket members 332 to the bracket 220 are conceivable.
(45) In FIG. 6A it is further illustrated that the bracket 220 comprise an attachment surface 222 onto which the leaf members 312, 342 and the flexible blanket members 332 are connected to the bracket 220. The attachment surface 222 is angled with respect to the engagement surface 14. The present arrangement provides the leaf members 312, 342 and the flexible blanket member 332 with a curvature which due to the resilience of the material out of which they are made, results in a self-biased state, thereby pushing the second ends 316, 336, 346 in a direction towards the engagement surface 14. In the illustrated example embodiment, the flexible blanket member 332 is shorter in length as compared to the leaf members 312, 342, such that the flexible blanket member 332 does not extend to reach the edge 318 of the second end 316 of the leaf member 312. The present arrangement allows the second end 316 of the leaf member 312 to be in direct engagement with the common engagement surface 14. An advantage with the present arrangement is that good sealing effect is provided, since the engagement of the leaf members 312 with the common engagement surface 14, which constitute the primary seal, is ensured.
(46) FIG. 6B illustrates three leaf members 312a, 312b, 312c viewed in a direction perpendicular to the traveling direction TD. The three leaf members 312a, 312b, 312c are partially overlapping so that a through hole 317 of leaf member 312a coincides with a through hole 317 of the adjacent leaf member 312b and so on. The ratio of overlap may vary between different embodiments. FIG. 6B illustrates that in the present embodiment a leaf member 312a overlaps with the consecutive leaf member 312b by typically less than 50%. In comparison to the three leaf members 312a, 312b, 312c also a flexible blanket member 332 is illustrated in FIG. 6B. As explained in relation to FIG. 6A, also the flexible blanket members 332 are connected by a bolt 224 and nut 226 arrangement, using through holes 317 in the flexible blanket members. The flexible blanket member 332 is wider than the leaf members 312 such that the flexible blanket member 332 covers the three leaf members 312a, 312b, 312c, in the present embodiment.
(47) FIG. 7 illustrates a sealing system 400 as arranged when connected to the support structure 16 of the machine 100. The sealing system 400 is also illustrated in isolation in FIGS. 8A-C. In the example embodiment, the sealing system 400 comprises a drop bar 402 having an elongated extension 401 (illustrated in FIG. 8A). The drop bar 402 is arranged along the traveling direction TD so as to form a sealing surface S (illustrated in FIG. 8A). However, it should be understood, as only a part of the sealing system 400 is illustrated in FIG. 7, the sealing system 400 may comprise more than one drop bar 402. If the sealing system 400 comprises more than one drop bar 402, the more than one drop bars 402 are distributed after each other along the traveling direction TD so as to form the sealing surface S.
(48) The drop bar 402 includes a drop bar structure 404 and a brush 406, wherein the brush comprises a plurality of bristles 407 (illustrated in FIG. 8A). The brush 406 is carried by the drop bar structure 404 such that the brush 406 is configured to be in engagement with the common engagement surface 14 of the pallet cars 12. In the example embodiment, the brush 406 is forced, by gravity, to be in engagement with the common engagement surface 14. Other engagement means are however conceivable, such as biasing by e.g. a spring. The attachment of the brush to the drop bar structure will be further discussed in relation to FIGS. 8C and 9.
(49) The drop bar structure 404 comprises connecting means 410 for connecting the sealing system 400 to the machine 100. As best illustrated in FIGS. 8A and 8B, in the example embodiment, the drop bar structure 404 comprises four connecting means 410, but it should be understood, as only a part of the machine 100 and the sealing system 400 is illustrated in the figure, that the drop bar structure 404 may comprise any number of connecting means 410. Connecting means for drop bars are well known in the art and may for example be embodied by an engagement between a pin 411 and an elongate opening 413, as illustrated in FIG. 8A.
(50) The drop bar structure 404 and the brush 406 together forms the sealing surface S that covers the gap 18 over at least parts of the gap length L.
(51) FIG. 8A illustrates the sealing system 400 in isolation and provides more details thereof. The sealing system 400 comprises the drop bar 402, wherein the drop bar 402 includes the drop bar structure 404 and the brush 406. In this example embodiment, the drop bar 402 further comprises a brush holder 416 which is configured to hold the brush 406. A fastening plate 420 is configured to clamp the brush holder 416 towards the drop bar structure 404. The fastening plate 420 is clamped towards the drop bar structure 404 by means of screws or bolts 422. FIG. 8A further illustrates how the brush 406 is configured to be in engagement with the common engagement surface 14 (illustrated here by surfaces 14a and 14b of two adjacent pallet cars), of the pallet cars 12. In the example embodiment, it is further illustrated that the brush 406 extends over the elongated extension 401 so as to form the sealing surface S.
(52) A problem of sealing the gap 18 between the common engagement surface 14 and the support structure 16 may be that the engagement surfaces 14a, 14b of individual pallet cars 12 (pallet cars not shown in the present figure), may be shifted in a vertical direction with respect to each other. Such a shift may be due to slight variation in manufacturing of the pallet cars 12 or, more likely, that the pallet cars 12 sag over time partly due to a combination of carried heavy load and harsh environment with extreme temperatures in the furnace. Such a vertical shift is illustrated in FIG. 8A with the individual pallet cars 14a, 14b having different vertical positions. The bristles 407 of the brush 406 are arranged to be in good physical contact with the flat engagement surfaces 14a, 14b. However, at a transition from one engagement surface 14a to another engagement surface 14b, the surface is no longer flat due to the difference in vertical position and thus the bristles 407 of the brush 406 are deformed to adjust to the shifting structure of the surface due to the resilience of the material out of which the bristles 407 of the brush 406 are made. It is illustrated in FIG. 8A that said deformation substantially occurs for one or more bristles, independently of the adjacent bristles, at such transitions, whereas adjacent bristles are to a large extent unaffected by the transition and hence maintain contact with the engagement surface 14a, 14b. The present arrangement results in only a small gap 412 at the transition as a result of deformation of one or more bristles of the brush 406. Consequently, only a small leak may result due to differences in vertical position of the pallet cars, thus maintaining high sealing efficiency.
(53) FIG. 8B illustrates a front view of the sealing system 400 illustrated in FIG. 8A. Further to what have been discussed above, FIG. 8B illustrates that each of the connecting means 410 are arranged with a distance from each other. In the example embodiment, each of the connecting means 410 are arranged with the same distance from each other, although it should be understood that each of the connecting means 410 may be arranged with different distances from each other as well.
(54) FIG. 8C illustrates the sealing system 400 viewed in the traveling direction TD. In addition to what have been discussed above, FIG. 8C illustrates how the brush 406 is carried by the drop bar structure 404 in more detail by means of a dedicated brush holder 416. The brush holder 416 has an upper extension arranged to be sandwiched between the drop bar structure 404 and the fastening plate 420. The lower end of the brush holder 416 is shaped so as to partially encompass the brush 406 to keep the brush 406 in a firm grip. In the example embodiment, the brush element 409 is shaped so as to be held in a firm position by the brush holder 416. The brush holder 416 is fastened in relation to the drop bar structure 404 such that the brush 406 protrudes out from a bottom end of the drop bar structure 404 towards the common engagement surface 14 such as the brush 406 is in engagement with the common engagement surface 14. This defines a clearance 418 between the drop bar structure 404 and the common engagement surface 14. As can be seen in the Figures, the clearance 418 is covered by the brush 406 and the resilient nature of the brush 406 allows the drop bar 402 to keep a more efficient sealing than a drop bar having no brush.
(55) The brush holder 416 is arranged such that the brush 406 forms an oblique angle α with the common engagement surface 14. The angle may preferably be within the range 20-40 degrees, but may alternatively be smaller, or larger.
(56) FIG. 9 illustrates a sealing system 500 according to an alternative embodiment. The sealing system 500 has many features in common with the sealing system 400 illustrated in FIGS. 8A-8B, namely a drop bar 502 which includes a drop bar structure 504 and a brush 506. However, in this example embodiment, the drop bar structure 504 further comprises a recess 514 for receiving the brush 506. The fastening plate 520 is for this embodiment received into the drop bar structure 404 in a further recess 515. This way, the drop bar structure 504 and the fastening plate 520 will have upper surfaces being flush with each other. The brush 506, which includes brush element 509 and bristles 507, may be clamped towards the drop bar structure 504 using bolts or screws 522 as illustrated in FIG. 9. The brush 506 is arranged with respect to the drop bar structure 504 such that the bristles 507 of the brush 506 are directed perpendicular, or substantially perpendicular, to the common engagement surface 14.
(57) As for FIG. 8C, FIG. 9 illustrates the clearance 418 between the drop bar structure 504 and the common engagement surface 14 such that the brush 506 is the only part of the sealing system 500 that is in engagement with the common support structure 14.
(58) FIGS. 8C and 9 illustrate two different example embodiments of the brush-based sealing system according to the disclosure, wherein the brush 406, 506 is arranged in different ways. However, it should be understood that theses embodiments are only examples and the arrangement of the brush is not limited to these embodiments. Thus, for example, the brush may be angled in any direction, towards or away from the drop bar structure but also along the drop bar structure. Alternative embodiments may include a drop bar including two or more brushes arranged parallel to each other. For example, in one embodiment the drop bar includes two brushes arranged on opposite sides of the drop bar, wherein each brush forms a respective oblique angle with the common engagement surface.
(59) FIGS. 10-14 illustrate different embodiments of the sealing system arranged in parallel with a further sealing system so as to define a sealing assembly of the machine.
(60) The further sealing system may be any of the sealing system discussed in relation to FIGS. 2-9, or alternatively another sealing system not disclosed therein. The further sealing system is connected to the support structure 16 of the furnace 10 and arranged along the traveling direction TD.
(61) A purpose of the further sealing system is to seal the gap 18 between the support structure 16 and the common engagement surface 14, so as to prevent gas, droplets and/or particulate matter from passing through the gap 18. The further sealing system is arranged at a spaced distance from the sealing system such that an elongate cavity is formed.
(62) FIGS. 10A-10B illustrate an embodiment of a sealing assembly 600 comprising the sealing system 200 in parallel with a sealing system 70 as arranged when connected to the support structure 16 of the machine 100. The sealing system 70 comprises a drop bar 60 of conventional type well known in the art. The sealing system 70 is slidably connected to the support structure in a manner similar to what has been described herein. The sealing system 70 is arranged at a spaced distance from the sealing system 200, at an interior side of the furnace 10, such that an elongate cavity 650 is formed between the two sealing systems 70, 200. For a person skilled in the art, it is conceivable that the sealing system, although illustrated here as a sealing system 200, may alternatively be a sealing system 300 according to the embodiment disclosed in FIGS. 6A-6B.
(63) FIGS. 11A-11B illustrate an embodiment of a sealing assembly 700 comprising the sealing system 200 in parallel with the sealing system 400 previously disclosed herein. As for sealing assembly 600, the two sealing systems 200, 400 are arranged in parallel to each other along the traveling direction TD. The sealing system 400 comprises a drop bar 402 including a drop bar structure 404 and a brush 406, as previously disclosed in detail with reference to FIGS. 7-8. The sealing system 400 is slidably connected to the support structure 16 via each of the drop bar structures 404. The sealing system 400 is arranged at a spaced distance from the sealing system 200, at an interior side of the furnace 10, such that an elongate cavity 750 is formed between the two sealing systems 200, 400. For a person skilled in the art, it is conceivable that the sealing system illustrated here as a sealing system 200, may alternatively be a sealing system 300 according to the embodiment disclosed in FIGS. 6A-6B. Similarly, for a person skilled in the art, it is conceivable that the sealing system illustrated here as a sealing system 400, may alternatively be a sealing system 500 according to the embodiment disclosed in FIG. 9.
(64) FIG. 12 illustrates an embodiment of a sealing assembly 800 of the sealing system 400 in parallel with sealing system 70 as arranged when connected to the support structure 16 of the machine 100.
(65) The sealing system 400 comprises a drop bar 402 including a drop bar structure 404 and a brush 406, according to the embodiment of a sealing system disclosed in FIGS. 7 and 8A-8C. The sealing system 70 comprises a drop bar 60 of conventional type known in the art. Thus, the main difference between the sealing system 70 and the sealing system 400 is that the sealing system 70 lacks a brush.
(66) The sealing system 70 is arranged at a spaced distance from the sealing system 400, at an interior side of the furnace 10, such that an elongate cavity 850 is formed between the two sealing systems 70, 400. For a person skilled in the art, it is conceivable that the sealing system 400 and the sealing system 70 may be arranged in an opposite way, such that the sealing system 400 is arranged facing the pallet cars 12 and the sealing system 70 is arranged on the opposite side facing the interior of the furnace 10. The sealing system 400 is connected to a first side of the support structure 16 and the sealing system 70 is connected to a second side of the support structure 16, opposite the first side, such that the sealing system 400 and the sealing system 70 are facing each other. For a person skilled in the art, it is conceivable that the sealing system, although illustrated here as a sealing system 400, may alternatively be a sealing system 500 according to the embodiment disclosed in FIG. 9.
(67) FIG. 13 illustrates an embodiment of a sealing assembly 900 of the sealing system 400a in parallel with another sealing system 400b as arranged when connected to the support structure 16 of the machine 100. In the example embodiment, the sealing system 400a and the sealing system 400b are similar to the sealing system 400 which comprises drop bar 402 including a drop bar structure 404 and a brush 406, according to the embodiment of a sealing system disclosed in FIGS. 7-8. The sealing system 400a is connected to a first side of the support structure 16 and the sealing system 400b is connected to a second side of the support structure 16, opposite the first side, such that the sealing system 400a and the sealing system 400b are facing each other. For a person skilled in the art, it is conceivable that any one of the sealing systems, although illustrated here as sealing system 400, may alternatively be a sealing system 500 according to the embodiment disclosed in FIG. 9.
(68) FIG. 14 illustrates an embodiment of a sealing assembly 1000 of the sealing system 200 in parallel with another sealing system 200′ as arranged when connected to the support structure 16 of the machine 100. In the example embodiment, sealing systems 200 and 200′ are of similar type. Specifically, both sealing system 200 and sealing system 200′ comprises a respective series 210, 210′ of leaf members 212, 212′ which are each partially overlapping so as to form a respective sealing surface. Bracket 220′ differs from bracket 220 in that it provides a respective attachment surface 222, 222′ for each of the series 210, 210′ of leaf members 212, 212′. A cavity 1050 is formed between the two sealing systems 200, 200′. As can be seen in FIG. 14, the sealing system 100 further comprises sealing system 70 based on a conventional drop bar 60. Consequently, for sealing system 1000, a further cavity 1050′ is formed between sealing system 70 and sealing system 200. Sealing system 200 and sealing system 200′ may share common features, such as the shape and structure of the leaf members 212, 212′. However, it is also conceivable that sealing system 200 and sealing system 200′ are different from each other in one or more ways.
(69) By the embodiments disclosed in FIGS. 10-14, the sealing may be even further improved. This is advantageous in the firing and cooling zones of the machine 100, and particularly in the transition therebetween referred to as the after firing zone, as the risk of leakage may otherwise be high. Leakage from this zone may cause hazards as combustible gases from the furnace 10 may mix with oxidants from ambient air, thereby creating a risk of unwanted ignition. Therefore, it is of particular interest to minimize leakage in these zones.
(70) Further, by the present arrangement, the innermost sealing system may protect the outermost sealing system from excessive thermal load.
(71) Moreover, the elongate cavity 650, 750, 850, 950, 1050 and 1050′ between the sealing systems may be provided with a gas flow so as to decrease the high temperature. By such an arrangement, the sealing systems may be cooled by the gas, enabling the use of even higher temperatures in the furnace than would otherwise be possible in order not to thermally damage the sealing systems.
(72) The person skilled in the art realizes that the present invention by no means is limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.
