Classifications

• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21B—MANUFACTURE OF IRON OR STEEL
  • C21B7/00—Blast furnaces
  • C21B7/18—Bell-and-hopper arrangements
  • C21B7/20—Bell-and-hopper arrangements with appliances for distributing the burden
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
  • F27B1/00—Shaft or like vertical or substantially vertical furnaces
  • F27B1/10—Details, accessories, or equipment peculiar to furnaces of these types
  • F27B1/20—Arrangements of devices for charging
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D3/00—Charging; Discharging; Manipulation of charge
  • F27D3/0033—Charging; Discharging; Manipulation of charge charging of particulate material
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D3/00—Charging; Discharging; Manipulation of charge
  • F27D3/10—Charging directly from hoppers or shoots
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D3/00—Charging; Discharging; Manipulation of charge
  • F27D2003/0001—Positioning the charge
  • F27D2003/0006—Particulate materials
  • F27D2003/0007—Circular distribution
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D3/00—Charging; Discharging; Manipulation of charge
  • F27D2003/0001—Positioning the charge
  • F27D2003/0006—Particulate materials
  • F27D2003/0008—Longitudinal distribution

Definitions

• the present invention generally relates to distribution chutes to be used in a bulk material distribution device for distributing bulk material in an enclosure such as a metallurgical reactor and, in particular, a blast furnace. More specifically, the invention relates to a distribution chute that has a chute body defining a channel with a bent portion that diverts bulk material from a first flow direction, along which it flows immediately after impact on the chute in an inlet portion thereof, to a second flow direction with which the flow leaves the chute outlet.
• charging installations of the so-called "bell-less” type have found widespread use. These charging installations are arranged at the furnace top and comprise a distribution device and have a distribution chute as a key component.
• the distribution device is typically configured for rotating the chute about the vertical furnace axis and for pivoting the chute about a perpendicular horizontal axis.
• bulk charge falls vertically onto the distribution chute that distributes the material in circumferential and radial direction according to its rotational and pivotal position. Accordingly, virtually any desired charge material profile can be achieved on the charging surface.
• Distribution chute bodies that define a channel with a bent portion that diverts the flow from a first flow direction immediately after impact on the chute to a less steep second flow direction at the outlet said flow are known for instance from Japanese patent applications JP 59-020412 and JP 59-031807.
• JP 59-020412 proposes a generally trough-shaped chute body with a downstream portion that is generally straight (Fig.2: A-B) and an upstream portion (Fig.2: C-B) that is curved to an arcuate shape having a center of curvature at a radius of 0.5-4.0 times, more preferably 0.5-3.0 times the chute length. Accordingly, the flow of charge material changes its direction gradually along the curved shape of the chute. Manufacturing of such a curved shape is however uneconomical or likely to result in a relatively weak construction.
• JP 59-031807 proposes a very similar design.
• This trough-shaped chute body merely differs in that the upstream portion is formed of a succession of straight segments, which contact tangentially with an arc having a radius of 0.5-4.0 times the chute length. Accordingly, the segments proposed in JP 59-031807 approximate the aforementioned curved shape of JP 59- 020412 whilst being likely more economical in terms of manufacturing.
• Another chute body with a downstream portion that is less steep than the upstream portion is proposed in WO 2009/037508.
• the latter chute has a generally frusto-conical construction and is specifically suited for a so-called gimbal-type charging device, in which the chute pivots in cardanic manner about two perpendicular horizontal axes. Besides being incompatible with rotary and pivotal charging devices, this chute is held to be subject to more rapid wear on impact point.
• the invention proposes a distribution chute of the rotate-and-pivot type. It may be used in a bulk material distribution device, in particular for a charge material distribution device of a metallurgical reactor such as, e.g., a shaft furnace.
• the distribution chute comprises a chute body (i.e. the load-supporting structure of the distribution chute) having therein a channel with an inlet for receiving a flow of bulk material and an outlet for discharging the bulk material.
• the channel conveys the bulk material from the inlet to the outlet.
• the channel has a bend to divert the flow of material from a first flow direction in the inlet into a second flow direction in the outlet.
• the chute body is assembled of at least an upstream part, which comprises the inlet, and a downstream part, which comprises the outlet and which is fixed to the upstream part (i.e. the upstream and downstream parts are secured against relative displacement).
• the downstream part defines a straight portion of the channel, whereas the upstream part defines the inlet and the bend of the channel.
• the upstream part is thick-walled with respect to the (more thin-walled) downstream part.
• the first flow direction corresponds to the overall tangential direction (in the vertical central plane of the distribution chute) of the bottom of the inlet, where the flow of bulk material hits the distribution chute - at least for high discharge angles, i.e. above about 45°-
• the second flow direction corresponds to the overall tangential direction (in the vertical central plane of the distribution chute) of the bottom of the outlet.
• discharge angle designates the angle between the distribution chute outlet and the vertical direction.
• the upstream part is made of cast metal, e.g. cast iron or cast steel.
• cast metal e.g. cast iron or cast steel.
• the downstream part comprises one or more welded curved steel plates.
• the inlet of the channel of the distribution chute is preferably provided on the upstream part as an annular collar.
• the inlet is thus formed as a tubular section (which encloses the axis of the inlet circumferentially).
• the annular collar reinforces the upstream part, allowing it to take up higher torque without significant deformation.
• the downstream part comprises a tubular section that provides the outlet. As those skilled will appreciate, this reduces (or eliminates) lateral overflow of the bulk material, which ultimately results in an improved control of the charge distribution underneath the chute. Most preferably, the downstream part tapers from the coupling with the upstream part towards the outlet.
• the channel has a first channel axis (corresponding to the first flow direction) in the inlet and a second channel axis (corresponding to the second flow direction) in the outlet, between which the bend in the upstream part defines an angle.
• This angle is preferably in the range from 15 to 45°, more preferably in the range from 20 to 40°.
• the bend in the upstream part may be sharp (abrupt).
• the bend may define a curved transition between the channel bottoms in the inlet and the outlet. It will be appreciated that three-dimensionally curved surfaces can easily be achieved using casting techniques for the manufacturing of the upstream part.
• the upstream part comprises a coupling end opposite the inlet (with respect to the bend).
• the downstream part is preferably inserted into the coupling end, e.g. up to the bend, and fixed in that position using screws, bolts, rivets, weldings or any other suitable fixation means.
• the length of the overlap of the coupling end and the downstream part preferably amounts to at least 20%, e.g. between 20 and 40%, of the total length of the downstream part.
• the distribution chute comprises an insert in the upstream part and/or in the downstream part, which insert comprises retention chambers (stone boxes), which are open to the channel so as to be able to fill up with bulk material for protection of the distribution chute against wear.
• the inserts are arranged in such a way that any surface on which the entering flow of bulk material may impinge at an angle of at least about 30° is protected with a stone box. This way, one ensures that the regions on the channel surface that are most susceptible of being eroded by the impacting material flow are appropriately protected. It will be appreciated that the insert(s) may be exchanged separately from the chute body when they are worn. This helps to keep servicing costs low.
• inserts in the form of retention chambers it is also possible to provide inserts in the form of cast or ceramic wear plates.
• the outlet of the distribution chute is formed by a wear-resistant slide insert within the downstream part.
• the slide has an essentially smooth surface in the outlet in order to discharge an as concentrated and homogeneous stream of bulk material as possible.
• the chute body preferably has an opening on the interior side of the bend. Advantages of such an opening are, for instance, a reduction of the weight of the chute without compromising wear-resistance and the removal of an "obstacle" to the incoming flow of bulk material when the chute is oriented substantially vertical (i.e. when the discharge angle is less than about 15°) for center-charging.
• the distribution chute may comprise handling trunnions on the upstream part, on which the distribution chute may be supported by a tilting mechanism.
• the handling trunnions are preferably integrally formed with the upstream part.
• a preferred aspect of the invention concerns a metallurgical reactor, e.g. a shaft furnace, comprising a charging installation with a charge material distribution device equipped with a distribution chute as described herein.
• Fig. 1 is a perspective view illustrating a distribution chute according to a preferred embodiment of the invention
• Fig. 2 is a vertical cross-sectional view of a charging device equipped with a distribution chute according to Fig.1 ;
• Fig. 3 is top view of the distribution chute of Fig.1 .
• Identical numerals are used throughout these drawings to identify identical of functionally similar parts or elements.
• a distribution chute 10 according to a preferred embodiment of the invention is generally shown in Fig. 1 .
• the distribution chute 10 comprises a chute body 12, which is essentially composed of two structural parts: cast-steel upstream part 14 and downstream part 16, which is made from curved steel plates.
• the distribution chute 10 may be suspended to a charging device with trunnions 18 that are integrally formed with the upstream part 14, on the outside of the inlet 20 thereof.
• the inlet 20 is configured as a (circumferentially closed) tubular channel portion.
• the end opposite the inlet of the upstream part 14 is configured as a coupling portion, to which the downstream part is fixed.
• the upstream and downstream parts 14, 16 delimit in their interior a channel 22 that conveys bulk material entering the distribution chute 10 through the inlet 20 to the outlet 24, from which the material is then discharged, e.g. into the charging zone of a shaft furnace.
• FIG. 2 shows a shaft furnace charging device equipped with the distribution chute of Fig. 1 .
• the distribution chute 10 is pivotally suspended with its trunnions 18 to a rotatable structure 25.
• the rotatable structure 25 is rotatably supported in a stationary housing 30 by means of large diameter roller bearings 32.
• the inner race of roller bearings 32 is fixed to a top end flange 34 of the rotatable structure 25 whereas the outer race of roller bearings 32 is fixed to a top plate 36 of the stationary housing 30.
• the roller bearings 32 are configured so that the rotatable structure 25 and therewith the distribution chute 10 can rotate about the substantially vertical axis 38, which usually coincides with the central axis of the furnace.
• a central feeder spout 26 is centered on axis 38 and defines a passage for bulk material through the top plate 36.
• the charging device of Fig. 2 achieves distribution of charge material in the charging zone of the shaft furnace by rotating the distribution chute 10 about axis 38 and by varying the pivoting angle of the distribution chute 10 about pivot axis 39.
• Pivot axis 39 is generally perpendicular to axis 38. Details of mechanisms suitable for rotating and pivoting the distribution chute 10 are not shown in the figures and not further described herein. Those interested in such mechanisms may e.g. refer to US 3,880,302. [0031 ] When bulk material (e.g.
• coke, ore, pellets, etc. is fed through the feeder spout 26 onto the distribution chute 10, it strikes the bottom of the channel 22.
• the impact location depends on the tilting angle of the distribution chute 10. For a high discharge angle (which is herein the angle ⁇ between the velocity vector of the bulk material at the outlet 24 of the distribution chute 10 and the vertical axis 38), the bulk material impacts on the channel bottom close to the inlet 20. With decreasing discharge angle, the impact location moves away from the inlet 20 towards the outlet 24 of the chute 10.
• the channel 22 has a bend 28 in the upstream part 14 in order to progressively divert material that hits the channel bottom in the inlet 20 from the vertical to the discharge direction.
• Material hitting the channel bottom in the inlet 20 is first diverted into a first flow direction substantially parallel to the bottom of the inlet.
• the material is then diverted into a second flow direction parallel to the bottom of the outlet 24.
• the bend 28 defines an angle a in the range from 20 to 40° between the channel bottom of the inlet and the channel bottom of the outlet.
• the downstream part 16 and the upstream part 14 are fixed to one another at the coupling portion 40 of the upstream part 14.
• the coupling portion 40 is located opposite the inlet 20 with respect to the bend 28.
• the upper end of the downstream part 16 is inserted into the coupling portion 40 up to the bend 28 and fixed in that position.
• the length of the overlap of the coupling portion 40 and the downstream part 16 amounts to about one third of the total length of the downstream part 16.
• the distribution chute 10 comprises a first insert 42 that defines retention chambers in the upstream part 14 and a second insert 44 that defines retention chambers in the downstream part 16.
• the retention chambers are open to the channel so as to be able to fill up with bulk material and thus to protect the distribution chute against wear.
• the inserts are arranged in the regions that are most susceptible to erosion by the impacting bulk material.
• Each insert 42, 44 includes a plurality of transverse plates 46 that are inclined in a direction generally opposite to the flow of the bulk material.
• One or more longitudinal plates 48 subdivide the retaining chambers in the transversal direction of the channel in order to ensure a more uniform filling of the retaining chambers in the lateral regions of the chute 10.
• the outlet 24 of the distribution chute 10 is formed by a wear-resistant slide insert 50 arranged within the downstream part 16.
• the slide insert 50 forms an essentially smooth and slightly tapering channel portion in the outlet in order to discharge an as concentrated and homogeneous stream of bulk material as possible.
• the surface formed by the slide insert is essentially aligned with the top edges of the transversal plates 46 and the longitudinal plates downstream of the bend 28.
• the slope of the outlet determines the discharge angle ⁇ , which may be varied between about 10° (center-charging position) and about 50° by pivoting the chute about the pivot axis 39.
• the chute body 12 has an opening 52 on the interior side of the bend 28.
• the opening 52 is arranged so as to define a recess that allows increasing the inclination angle of the chute 10 without touching the radially inner edge 54 of the bottom end flange of the rotatable structure 25.
• Another advantage of the opening 52 is that in the "center-charging" position, the bulk material may fall straight through the chute 10 without substantial deflection at the bend 28 by the roof of the channel 22. Furthermore, the opening could even serve as an overflow in certain situations.
• the bend in the upstream part corresponds to a sharp transition between essentially straight channel portions.
• the bend could also be implemented as a smoothly curved transition between the channel bottoms in the inlet and the outlet.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Manufacturing & Machinery (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Chutes (AREA)
• Blast Furnaces (AREA)
• Vertical, Hearth, Or Arc Furnaces (AREA)

Priority Applications (8)

Applications Claiming Priority (2)

Publications (1)

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Country Status (11)

Cited By (5)

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Citations (6)

Family Cites Families (17)

• 2010
  • 2010-08-06 LU LU91716A patent/LU91716B1/en active
• 2011
  • 2011-07-18 WO PCT/EP2011/062282 patent/WO2012016818A1/en active Application Filing
  • 2011-07-18 PL PL11732496T patent/PL2601319T3/pl unknown
  • 2011-07-18 KR KR1020137005850A patent/KR101773454B1/ko active IP Right Grant
  • 2011-07-18 BR BR112013002927A patent/BR112013002927A2/pt not_active IP Right Cessation
  • 2011-07-18 EP EP11732496.2A patent/EP2601319B1/en not_active Not-in-force
  • 2011-07-18 RU RU2013109733/02A patent/RU2570258C2/ru not_active IP Right Cessation
  • 2011-07-18 UA UAA201302596A patent/UA107026C2/uk unknown
  • 2011-07-18 JP JP2013522182A patent/JP5764658B2/ja not_active Expired - Fee Related
  • 2011-07-18 CN CN201180038315.XA patent/CN103052721B/zh not_active Expired - Fee Related
  • 2011-07-26 TW TW100126330A patent/TWI571516B/zh not_active IP Right Cessation

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