GAS-SOLID CONTACTING DEVICE

Abstract

A device for processing a flow of particulate material by contact with a gas flow includes a housing defining a processing chamber. This chamber includes a gas distribution plate having openings. The gas distribution plate separates a lower gas plenum from a solid-gas contact zone. The contact zone has at least one cylindrical partition upstanding from the gas distribution plate dividing an inner section from an adjacent annular outer section. The at least one partition is provided with a transfer opening for the particulate material. The housing is also provided with an inlet for supplying particulate material to the inner section and an outlet for discharging processed particulate material from the annular outer section.

Claims

1.-18. (canceled)

19. A device for processing a flow of particulate material by contact with a gas flow, comprising a housing defining a processing chamber and having a gas inlet for introducing a gas flow in a plenum of the processing chamber, wherein the processing chamber comprises the plenum, arranged at the lower part of the processing chamber, a contact zone, arranged above the plenum, for contacting the flow of particulate material with the gas flow, wherein the plenum and contact zone are separated by a gas distribution plate, wherein the contact zone comprises a contact path for contact between the flow of particulate material and the gas flow, the contact zone having multiple cylindrical partitions upstanding from the gas distribution plate dividing an inner section of the contact path from an adjacent annular outer section, wherein each partition is provided with a transfer opening configured to allow passage of the particulate material from the inner section to the adjacent annular outer section of the contact path separated by the respective partition, wherein the inner section of the contact path is an annular inner section, and wherein the transfer opening of an inward partition and the transfer opening in an adjacent outward partition are at least 270° apart as seen in the particulate material displacement direction in the annular section of the contact path between the adjacent partitions, wherein the gas distribution plate is provided with openings configured to allow passage of the gas flow from the plenum to the contact zone in an obliquely upward direction to establish a displacement of particulate material in a displacement direction along the contact path in the contact zone, the housing further comprising an inlet for supplying particulate material to the inner section) of the contact path at a supply position upstream of the transfer opening in an adjacent partition as seen in the particulate material displacement direction in the inner section of the contact path; wherein the supply position in the inner section of the contact path and the transfer opening in the adjacent partition are at least 270° apart as seen in the particulate material displacement direction in the inner section of the contact path, and an outlet for discharging processed particulate material from the annular outer section of the contact path at a discharge position downstream of the transfer opening in an adjacent partition as seen in the particulate material displacement direction in the annular outer section of the contact path, wherein the discharge position in the annular outer section of the contact path and the transfer opening in the adjacent partition are at least 270° apart as seen in the particulate material displacement direction in the annular outer section of the contact path.

20. The device according to claim 19, wherein the gas inlet comprises a central duct extending through the contact zone into the gas plenum, the duct delimiting the inner side of the annular inner section of the contact path.

21. The device according to claim 19, wherein the transfer opening in an outward partition is adjacent to the transfer opening in the adjacent inward partition as seen in a direction opposite to the particulate material displacement direction in the annular section of the contact path between the adjacent partitions.

22. The device according to claim 19, wherein the gas distribution plate comprises outwardly directed, slit shaped openings that are arranged in annular sections.

23. The device according to, claim 22, wherein in each annular section the openings are arranged at a radial angle with respect to the radius of the gas distribution plate, preferably the radial angle of the openings decreases stepwise from the inner annular section to the outer annular section.

24. The device according to claim 19, wherein the gas distribution plate comprises outwardly directed, slit shaped openings that are arranged in annular sections, wherein the openings have an axial angle with respect to the axis of the contact zone in the direction of the flow of particulate material.

25. The device according to claim 19, wherein the gas distribution plate comprises slit shaped openings that are arranged in annular sections, wherein the width of a slit shaped opening) increases from its inner end to its outer end.

26. The device according to claim 19, wherein the plenum comprises a manifold, arranged below the gas distribution plate, having manifold openings that are adjustable in size.

27. The device according to claim 26, wherein the manifold comprises lower annular plate sections having lower manifold openings and upper annular plate sections having upper manifold openings, wherein co-operating lower and upper annular plate sections are displaceable concentrically with respect to each other.

28. The device according to claim 26, wherein the manifold openings have an arc sectioned slot configuration.

29. The device according to claim 19, wherein the outer annular section of the contact path has a deflector for directing processed particulate material to the discharge outlet.

30. The device according to claim 19, wherein a transfer opening has an adjustable size.

31. The device according to claim 30, wherein the lower edge of a transfer opening in a partition has an adjustable height above the gas distribution plate.

32. The device according to claim 19, wherein the downstream upstanding edge of the transfer opening has a part that is obliquely in the direction of the flow of particulate material adjacent the opening.

33. The device according to claim 19, wherein the top of a partition is provided with a retainer for preventing particulate material passing over the top edge from an inner section to an adjacent outer section.

34. A method of processing particulate material by contacting the particulate material with a gas or of processing the gas involved in a device according to claim 19, wherein said processing is selected from the group comprising thermally processing particulate biomass material comprising cooling, drying, torrefaction, pyrolysis, combustion and/or gasification thereof; chemical processing including catalytically processing, and cooling or drying of feed or food, separating particulate material into fractions based on shape, mass, size and/or density, comprising the steps of supplying the particulate material to the annular inner section of the contact path at the supply position upstream of the transfer opening in an adjacent partition as seen in the particulate material displacement direction in the inner section of the contact path; introducing a gas flow through the gas inlet in the plenum of the processing chamber and passing the gas through the openings of the gas distribution plate to the contact zone; displacing the particulate material by the gas flow from the supply position along the contact path to the discharge position in the annular outer section, and discharging the processed particulate material from the annular outer section through an outlet at the discharge position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The invention is further illustrated by the attached drawings, wherein:

[0038] FIG. 1 shows a diagram of an embodiment of a gas-solid contact device according to the invention;

[0039] FIG. 2 shows a cross-section of the contact zone of the embodiment of FIG. 1;

[0040] FIG. 3 shows a top view of a swirl opening in a gas distribution plate;

[0041] FIG. 4 shows the cross section A-A of FIG. 3;

[0042] FIG. 5 shows the cross-section B-B of FIG. 3;

[0043] FIG. 6 shows an embodiment of a manifold;

[0044] FIG. 7 shows a detail of a manifold opening; and

[0045] FIG. 8 shows an embodiment of a transfer opening in a partition.

DETAILED DESCRIPTION OF THE INVENTION

[0046] In FIG. 1 an embodiment of a gas-solid contact device is shown diagrammatically and is indicated in its entirety by reference numeral 10. FIG. 2 shows a cross-section at a level just above the gas distribution plate thereof.

[0047] The gas-solid contact device 10 comprises a cylindrical housing 12 having a bottom wall 14 and top wall 16 delimiting a processing chamber 18. The processing chamber 18 delimits a lower plenum 20, a contact zone 22 and a gas header section 24. The housing 12 is provided with a gas inlet 26, connected to a vertical central duct 28 that extends through a gas distribution plate 30 into the lower plenum 20. The gas distribution plate 28 is provided with a plurality of swirl openings 32, that are configured to inject directed gas jets from the gas plenum 20 into the contact zone 22. The swirl openings 32 have a size that prevents particulate material 31 (shown as two dotted lines in FIG. 1) to enter the plenum 20 from the contact zone 22. Cylindrical partitions 34 are arranged on top of the gas distribution plate 30 in the contact zone 22, thereby forming a contact path comprising an inner (innermost) annular contact path section 36, with adjacent intermediate annular contact path sections 38′ and 38″ respectively, and an outer (outermost) contact path section 40 having a tangential outlet 42 at a discharge position for discharging processed particulate material. The particulate material is fed by a feed injector 44 (see also FIG. 2), of which the outlet 46 at the supply position is positioned at the innermost section 36 between the central duct 28 and the innermost partition 34 and delivers the particulate material as a layer in a direction co-current to the gas flow through the swirl openings 32. The particulate material is forced by the gas flow in a spiralling contact path (see FIG. 2 and indicated by bold arrows) from the outlet 46 along the innermost section 36, through transfer opening 50 in the innermost partition 34, along the intermediate section 38′, through transfer opening 50′ in the intermediate partition 34′, along the intermediate section 38″, through transfer opening 50″ in the outermost partition 34″ and along outermost section 40 through the outlet 42. As shown, the transfer opening 50 in the innermost partition 34 is almost adjacent to the outlet 46 of the feed injector 44 in the innermost annular contact path section 34, such that the portion of particulate material transferred through the transfer opening 50 creates a void in the flow of particulate material in the innermost annular contact path section 34, which is subsequently filled by fresh particulate material supplied by the feed injector 44. This kind of transfer and subsequent refill is repeated in the intermediate sections and in the outermost section with respect to the discharge outlet 42. The transfer opening 50′ in the intermediate partition 34′ is situated adjacent but downstream of the transfer opening 50 in the innermost partition 34. The staggered configuration of the supply position, transfer openings and discharge position with respect to one another forces the particulate material to complete almost a full annular contact path section (arc section >270°) before being transferred to the adjacent section positioned outwardly. Optionally a deflecting wall 54 is positioned in the outermost annular contact path section 40 that directs the processed particulate material or a portion thereof through the outlet 42 at the outlet position. In this embodiment in the top of the processing chamber 18 the gas header section 22 houses one or more separators 60 such as cyclones, wherein dust and lighter particles are separated from the gas flow. The gas flow leaves the housing 12 trough gas outlet 62. FIG. 1 shows also that the inner partition 34 is provided with a retainer 64 for preventing flow of particulate material from the innermost annular contact path section 36 to the adjacent intermediate annular contact path section 38′. In the embodiment shown the plenum 20 is provided with a gas manifold 66.

[0048] FIG. 2 schematically shows that the swirl openings 32 have a slit shape. The slit length approaches the width of the respective annular contact path section. The slits are arranged at a radial angle α, wherein the radial angle α of the slits decreases stepwise from the innermost section 36 to the outermost section 40.

[0049] FIG. 3 shows an embodiment of a slit shaped swirl opening 32 in more detail. As is apparent from the cross-sections A-A and B-B in FIGS. 4 and 5 the slit shaped swirl opening also has an axial angle γ, while the width of the slit increases gradually from the inner end 68 towards the outer end 70.

[0050] FIG. 6 shows in part an embodiment of a diaphragm type manifold 66. The manifold 66 comprise an upper manifold plate comprising a number of annular upper manifold sections 72 held in position within profiled beams 74, in the lower part of which similar annular lower manifold sections 76 are arranged in a sliding manner. The upper and lower manifold sections 72 and 76 are provided with upper manifold openings 78 and lower manifold openings 80 respectively, typically arc sector like openings. By rotating of the lower manifold section 76 (indicated by an arrow) the flow through area for gas can be adjusted, as is shown in FIG. 7, wherein the lower manifold opening 80 is not fully aligned with the upper manifold opening 78.

[0051] FIG. 8 shows an embodiment of a transfer opening 50 in a partition 34 in more detail. The transfer opening 50 is delimited by an upstanding upstream edge 90, an upper edge 92, part of the top surface of the gas distribution plate 30 adjacent the upstanding upstream edge, an upwardly oblique downstream edge portion 94 of the partition 34, and an adjacent, downwardly sloping portion 96. The angled portion 94 serves as a sliding surface for particles, in particular long particles like fibres and prevent blocking of the transfer opening 50. At the bottom a movably, e.g. sliding, lower edge part 98 is arranged, whereby the transfer cross-section of the opening 50 can be adjusted. An actuator for positioning the lower edge part 98 is not shown. The same configuration can be applied to the discharge outlet for processed particulate material.