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

Definitions

• the present invention relates to a device for distributing bulk materials with a rotating chute with variable angle of inclination. It relates more particularly to a device for distributing bulk materials comprising: a discharge chute for bulk materials, a first rotor with substantially vertical axis of rotation, the chute being suspended from said first rotor so as to be able to pivot around a substantially horizontal pivot axis; and a second rotor, with an axis of rotation substantially coaxial with said first rotor.
• Such devices for distributing bulk materials are, for example, used in devices for loading ovens with vats, in particular blast furnaces.
• the chute then distributes the loading material on a loading surface inside the shaft furnace.
• the first rotor essentially imposes a rotation on the chute around a vertical axis.
• the second rotor interacts with the chute so as to determine its angle of inclination relative to the vertical.
• the second rotor is connected to the chute by a pivoting mechanism transforming a variation of the angular offset between the two rotors into a variation of the angle of inclination of the chute in its vertical pivot plane.
• Document US-A-4,368,813 proposes a device of the type described in the preamble in which the rotor also comprises a toothed ring coaxial with the vertical axis of rotation of the chute. This toothed ring cooperates with an input pinion with a vertical axis of a connecting rod-crank mechanism supported by the first rotor. The rod of this mechanism is contained in the pivot plane of the chute and is articulated with its free end on the rear surface of the chute.
• Document US-A-4,941,792 proposes two embodiments of a device of the type described in the preamble. In a first embodiment, a pivoting lever supported by the first rotor is used so as to be able to pivot in the pivoting plane of the chute.
• This pivoting lever is connected via a rod with ball joints to the second rotor.
• the chute comprises two lateral suspension pins which are each provided with a crank.
• a forked rod (a stirrup) connects the pivot rod to the two cranks of the chute.
• the second rotor supports a toothed annular segment which cooperates with a toothed sector secured to a journal for lateral suspension of the chute.
• Document US-A-5,002,806 proposes a device of the type described in the preamble in which the second rotor is connected to a crank secured to a journal for lateral suspension of the chute using a rod with spherical joints.
• Document US-A-5,022,806 proposes a device of the type described in the preamble, in which the chute comprises a lateral arm which slides by means of a shoe articulated on this arm in a guide groove.
• This guide groove is defined by a curved element supported by the second rotor.
• the center of curvature of the curved element defining the guide groove is located at the point of intersection of the pivot axis and the axis of rotation of the chute.
• the object of the present invention is to improve in a device of the type described in the preamble the transmission of forces between the second rotor and the chute.
• a device for distributing bulk materials comprising a chute for discharging bulk materials, a first rotor with a substantially vertical axis of rotation, the chute being suspended from said first rotor so as to be driven.
• the pivoting ring generates, during a relative rotation in the plane of rotation defined by said guide means of the second rotor, a pivoting of the chute around the horizontal pivot axis of the latter.
• the guide means force the pivoting ring, which is provided with a suspension of the Cardan type, to evolve strictly in a plane of inclined rotation defined in a reference attached to the second rotor.
• These guide means thus impose on the axis of suspension of the pivoting ring, a variable inclination between - ⁇ and + ⁇ in a frame attached to the first rotor; which produces a variation in the angle of inclination of the chute in its pivoting plane.
• the proposed device produces in the pivot plane of the chute a pivoting of the chute with an angular amplitude 2 ⁇ to return to its initial position.
• the chute produces a moment around its pivot axis. This moment, which will be called the pivoting moment "of the chute, is proportional to the weight of the chute and to the horizontal distance which separates its center of gravity from the vertical plane containing its pivot axis. This distance is of course a function of the chute inclination angle in its pivot plane.
• the guide means of the second rotor define in said inclined plane of rotation at least three points of contact with the pivoting ring. These are the reactions at these points of contact which oppose said moment of pivoting of the chute.
• the pivoting ring constitutes a simple, but clever element for optimally taking up around the chute the reactions of said guide means and thus opposing a moment of reaction to said pivoting moment of the chute.
• the number of contact points between the pivoting ring and the chute can be greater than three.
• these contact points can also be contact surfaces.
• the distribution of these contact points around the chute can be arbitrary, as long as the kinematic constraint in relation to said inclined plane of rotation is satisfied. There are therefore many possibilities for optimizing said contact points, in particular as a function of the contact pressures which must be transmitted.
• the pivoting ring defines an ideal interface between the chute on one side and the second rotor on the other side, to resume with the second rotor said pivoting moment of the chute.
• the pivoting ring involves, in the device according to the invention, a particularly important lever arm in the recovery of said pivoting moment of the chute. This naturally has a favorable influence on the importance of the forces to be transmitted in the device.
• said guide means can for example comprise isolated supports circumferentially spaced around the second rotor. The latter then cooperate with a bearing surface of the pivoting ring to define said inclined plane of rotation in a frame attached to the second rotor.
• isolated supports include, for example, roller or skid supports.
• Said guide means may however also include bearing surfaces which cooperate with insulated bearings (for example rollers or pads) or with corresponding bearing surfaces of the pivoting ring.
• said means for guiding the second rotor and the contact points associated therewith with the pivoting ring are preferably designed so as to transmit forces perpendicular to said plane of rotation inclined in two opposite directions. This is for example the case if two bearing surfaces are arranged so as to define a guide groove for elements in relative rotation in this groove.
• said guide means comprise a large diameter suspension bearing.
• the latter comprises two rings which are movable in rotation relative to each other while being able to transmit axial forces in two directions and overturning moments.
• the first of these rings is secured to the pivot ring of the chute, and the second of these rings is secured to the second rotor so as to define said angle ⁇ for said inclined plane of rotation of the pivot ring.
• the rolling elements arranged between the two rings of the bearing can be assimilated to multiple supports, which are distributed circumferentially around the chute and all actively contribute to the transmission in two directions of forces perpendicular to said inclined plane. of rotation. It will therefore be appreciated that all the rolling elements of the bearing participate in the resumption of said pivoting moment of the chute.
• Another advantage of this embodiment lies in the fact that the bearing can be more easily protected against fouling by dust or smoke than bearings with rollers or insulated pads and their associated rolling surfaces.
• the chute is advantageously fixed, in a rigid but removable manner, to a support plate provided with a central opening for the passage of the material to be distributed by the chute.
• This support plate is then connected to the pivoting ring using a first pair of pivots so as to define the suspension axis around which the pivoting ring can pivot, and to the first rotor using 'a second pair of pivots so as to define the pivot axis of the chute. It is a simple way of hanging the chute, which allows excellent transmission of said pivoting moment of the pivoting ring on the chute.
• the support plate constitutes a sort of annular protective screen above the chute.
• the chute can be disassembled without having to disassemble its suspension and that of the swivel ring.
• Said first rotor and said second rotor are advantageously suspended in an external carcass which can be mounted in leaktight manner on an enclosure, for example a tank furnace.
• a central feed channel then opens tightly into the external carcass and passes axially through said first and said second rotor and said central opening of the support plate of the chute.
• the pivoting ring advantageously supports an insulation sheath coaxial with the axis of rotation which defines with an annular surface of the external carcass an air seal or annular slot.
• the central supply channel is advantageously provided with a spherical bead which cooperates with the central opening of the support plate in which it is arranged, so as to define therein an air seal or slot annular.
• the support plate is advantageously a disc limited by a spherical crown which cooperates with a central opening of the pivoting ring in which it is arranged so as to define therein an annular seal.
• Figure 1 shows a section through a device for distributing bulk material according to the invention.
• a device for loading a shaft furnace in particular a blast furnace.
• This device comprises a chute 10 which can rotate around a substantially vertical axis 12 and whose inclination can be varied during its rotation.
• the angle of inclination ⁇ of the chute with respect to the vertical can be varied while the chute rotates around the axis 12.
• the reference 14 indicates a supply channel into which the bulk materials to be distributed are distributed by the chute 10.
• This supply channel 14 is supported by an external carcass 16.
• the carcass 16 is supported tightly on a shaft furnace, and the supply channel 14 is tightly connected to a hopper serving as a lock airlock upstream of the distribution or loading device (the shaft furnace and the hopper locks are not shown in the Figures).
• the loading material flowing from the lock hopper then crosses the feed channel 14 to fall on the chute 10 and be guided by the latter towards the loading surface of the shaft furnace.
• the point of impact of the loading material on the loading surface is varied by turning the chute around the axis of rotation 12 and / or by varying its angle of inclination ⁇ .
• the chute In order to allow the chute to rotate around the axis 12, it is suspended from a first rotor 18, which forms a sort of rotary cage suspended using a first suspension bearing 20 in the carcass 16. It can be seen that the suspension bearing 20 is a large diameter bearing which surrounds the supply channel 14. A toothed crown 22 which is integral with the first rotor 18 and coaxial with the axis 12 is driven by a pinion 24. This pinion 24 makes it possible to give the first rotor 18 a rotational movement of speed ⁇ 1 around the axis 12. It will be noted that the rotor 18 surrounds the channel supply 14 and is provided at its lower part with two suspension flanges 28 and 28 'to support the chute 10.
• the chute 10 is preferably rigidly fixed but easily removable on a support plate 30, which is provided with a central opening 32 for the passage of the supply channel 14.
• This support plate 30 is then connected to the flanges of suspension 28 using a pair of pivots 32 'and 32 ", so as to define a pivot axis 33 for the chute 10.
• this pivot axis 33 is horizontal, therefore perpendicular to the axis of rotation 12. In FIG. 1, this pivot axis 33 is perpendicular to the plane of the drawing.
• a pivot ring 38 which generates the pivoting of the chute 10, is mechanically connected to the support plate 30 by means of a second pair of pivots or trunnions 34 and 34 'These are located in the pivot plane of the chute at two diametrically opposite points relative to the pivot axis 33 of the chute 10. They define for the pivot ring 38 a pivot axis 36 which is perpendicular and copianary to the pivot axis 33 of the chute 10 and which forms with the chute 10, in the pivoting plane thereof, an angle ⁇ . It will be noted that the pivoting ring could now: 1) pivot around the axis 36; 2) pivot around the axis 33; 3) rotate around the axis 12. In other words, the pivoting ring 38 is equipped with a suspension of the Cardan type in rotation around the axis 12. It will however be seen below that some of these movements are limited by guide means supported by a second rotor which is generally identified by the reference 40.
• the suspension and the drive of the second rotor 40 are produced in a similar manner to that described for the first rotor 18.
• This second rotor in fact comprises a large diameter suspension bearing 42 and a toothed ring 44.
• This toothed ring 44 is driven by a second pinion 46 to give the second rotor 40 a rotational movement of speed ⁇ 2 around axis 12.
• ⁇ 1 and ⁇ 2 can preferably be varied independently of one another.
• the second rotor 40 is suspended from the bearing 42 and surrounds the first rotor 18. It is provided with an annular support flange 50 in an inclined plane making an angle ⁇ with a horizontal reference plane. M will be noted that in Figure 1 said inclined plane is perpendicular to the plane of the drawing.
• a third suspension bearing 52 of large diameter is mounted with one of its two rings (for example with its outer ring) on this support flange 50.
• the other ring of the bearing 52 (in FIG. 1 it is the inner ring) is on the other hand fixed to the pivoting ring 38.
• the two rings of this bearing 52 are movable in rotation relative to each other while being able to transmit axial forces and enough overturning moments important in both directions.
• the bearing 52 guides the pivoting ring 38 in a plane of rotation which forms with an horizontal reference plane an angle ⁇ . In the device shown in Figure 1 this angle ⁇ is approximately 25 °.
• FIG 2 is in principle identical to Figure 1.
• the chute makes with the axis 12 an angle ⁇ of about 50 °. For the device shown, this is the maximum angle of inclination.
• This angle of inclination ⁇ of the chute will remain constant as long as the first rotor 18 and the second rotor 40 rotate at the same speed; that is to say as long as there is no angular offset between the two rotors 40 and 18.
• to decrease the angle of inclination ⁇ of the chute 10 it suffices to cause an angular offset between the first rotor 18 and the second rotor 40.
• this angular offset represents 90 ° relative to Figure 2.
• ⁇ is now 25 °.
• the chute performs in its pivot plane (stationary in rotation) a pivoting of an amplitude of 2 ⁇ and of frequency ⁇ 2 / 60, where ⁇ 2 represents the speed of rotation in revolutions per minute of the second rotor 40.
• the chute performs in a pivoting plane (this time turning with the first rotor 18) a pivoting of an amplitude of 2 ⁇ and of frequency ⁇ 1 / 60, where ⁇ 1 represents the speed of rotation in revolutions / minutes of the first rotor 18.
• the angular offset between the two rotors 18 and 40 increases regularly and the chute 10 performs a movement of periodic pivoting between its maximum tilt position ( ⁇ max) and its minimum tilt position ( ⁇ min).
• the pivoting ring 38 supports a cylindrical insulation sheath 54.
• This insulation sheath 54 is coaxial with the axis of rotation 12 and forms with an annular surface 56 of the carcass 16 an annular air seal (or slot).
• annular space 58 is defined in the external carcass 16 which can be maintained under slight overpressure by injection of a gas.
• the arrow 60 schematically represents means (for example pipes) for injecting such a gas. This reduces the penetration of dust and smoke into this annular space 58, in which are located in particular the bearings 20, 42, 52, the toothed rings 22, 44 and the pinions 24, 46.
• this injected gas can be used when the device cools.
• the insulation sheath 54 is advantageously provided with thermal insulation; while the annular surface 56 is advantageously cooled by a cooling liquid and, in the case of a blast furnace for example, provided with a coating protecting against thermal radiation from the loading surface. Such protection against thermal radiation is also advantageously applied or fixed below the pivoting ring 38 and the support plate 30.
• the supply channel 14 is provided with a spherical bead 62 which is adjusted in the central opening 32 of the support plate 30.
• This opening 32 includes a throttle section in which the bead 62 defines an annular air seal (or slot).
• the plate support 30 is also advantageously a disk whose lateral surface 64 is a spherical ring which defines in the pivoting ring 38 an annular air seal (or slot).
• the plate 30 could however also be rectangular and be adjusted in a rectangular opening in the ring of the pivoting ring 38. In this case it would be sufficient for the two lateral edges parallel to the axis 36 to take the form of a cylinder coaxial with the axis 36.
• annular space 66 is created between the feed channel 14 and the rotor 40 which can be put under overpressure by injection of a gas under pressure into the carcass 16. Most often the annular spaces 58 and 66 are in direct communication with one another so as to avoid pressure differences inside the external carcass 16. Such pressure differences could indeed have a negative influence on the efficiency of the annular air seals (or slots) described above.
• the bearing 52 is advantageously integrated in an annular cavity defined for example by the insulation sheath 54, the pivoting ring 38 and the annular flange 38 of the second rotor 40. In this way the bearing 52 is further protected further against excessive dust penetration and direct contact with hot or corrosive gases.
• the first and the second rotor 18 and 40 are advantageously connected using a rotary connector to a cooling circuit (not shown). In this way, the main mechanical elements which are integral with either the first or the second rotor can be effectively cooled.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Manufacturing & Machinery (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Blast Furnaces (AREA)
• Electrotherapy Devices (AREA)
• Discharge Of Articles From Conveyors (AREA)
• Filling Or Emptying Of Bunkers, Hoppers, And Tanks (AREA)
• Physical Deposition Of Substances That Are Components Of Semiconductor Devices (AREA)
• Chutes (AREA)
• Saccharide Compounds (AREA)
• Silicates, Zeolites, And Molecular Sieves (AREA)
• Medicines Containing Plant Substances (AREA)
• Processes Of Treating Macromolecular Substances (AREA)
• Crushing And Pulverization Processes (AREA)
• Paper (AREA)
• Threshing Machine Elements (AREA)
• Jigging Conveyors (AREA)

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Publications (2)

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• 1994
  • 1994-02-01 LU LU88456A patent/LU88456A1/fr unknown
• 1995
  • 1995-01-09 BR BR9506605A patent/BR9506605A/pt not_active IP Right Cessation
  • 1995-01-09 AU AU13862/95A patent/AU1386295A/en not_active Abandoned
  • 1995-01-09 SK SK999-96A patent/SK280100B6/sk unknown
  • 1995-01-09 CN CN95191708A patent/CN1060523C/zh not_active Expired - Lifetime
  • 1995-01-09 PL PL95315776A patent/PL180501B1/pl not_active IP Right Cessation
  • 1995-01-09 RU RU96117589A patent/RU2126451C1/ru not_active IP Right Cessation
  • 1995-01-09 EP EP95905127A patent/EP0742840B1/de not_active Expired - Lifetime
  • 1995-01-09 CZ CZ962279A patent/CZ284435B6/cs not_active IP Right Cessation
  • 1995-01-09 WO PCT/EP1995/000060 patent/WO1995021272A1/fr active IP Right Grant
  • 1995-01-09 ES ES95905127T patent/ES2110312T3/es not_active Expired - Lifetime
  • 1995-01-09 AT AT95905127T patent/ATE160381T1/de active
  • 1995-01-09 JP JP52033895A patent/JP3665338B2/ja not_active Expired - Fee Related
  • 1995-01-09 DE DE69501079T patent/DE69501079T2/de not_active Expired - Lifetime
  • 1995-01-09 US US08/682,771 patent/US5799777A/en not_active Expired - Lifetime
  • 1995-01-09 UA UA96083371A patent/UA39132C2/uk unknown
• 1996
  • 1996-07-24 BG BG100738A patent/BG61845B1/bg unknown

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