Device for distributing materials in bulk with a rotary chute having a variable angle of inclination

Information

  • Patent Grant
  • 6213275
  • Patent Number
    6,213,275
  • Date Filed
    Friday, November 12, 1999
    24 years ago
  • Date Issued
    Tuesday, April 10, 2001
    23 years ago
Abstract
A device for distributing materials in bulk comprises a first rotor (20) and a second rotor (30). The first rotor (20) carries two suspension bearings (44, 46) in which a distribution chute (42) is suspended so that it can pivot about a substantially horizontal axis. A gear transmission (52), carried by the first rotor (20), includes an input shaft (54) and an output shaft (60). The input shaft is provided with a pinion (56) which meshes with an annular gear (58) of the second rotor (30). The output shaft of the transmission is parallel to the pivoting axis of the chute (42) and incorporates two cranks (64, 66). The chute (42) is provided with a pivoting lever (48, 50) at the level of each of its two suspension bearings (44, 46). Each of these two pivoting levers (48, 50) is symmetrically connected to one of the two cranks (64, 66) of the gear transmission (52) by a connecting rod (68, 70).
Description




The present invention relates to a device for distributing materials in bulk with a rotary chute having a variable angle of inclination. It relates more particularly to a device for distributing materials in bulk comprising a chute, a first rotor with a substantially vertical rotation axis, on which the chute is suspended so that it can pivot about a substantially horizontal pivoting axis, and a second rotor, having a rotation axis substantially coaxial with said first rotor.




Such devices for the distribution of materials in bulk are used, for example, in devices for charging shaft furnaces, particularly blast furnaces. The rotary and pivoting chute provides for the distribution of the charge over a charge surface inside the shaft furnace.




In the device described in the preamble, the first rotor essentially rotates the chute about a vertical axis. The second rotor interacts with the chute so as to fix its angle of inclination to the vertical. For this purpose, the second rotor is connected to the chute through a pivoting mechanism converting a variation in angular displacement between the two rotors into a variation in the angle of inclination of the chute in its vertical plane of pivoting.




Different variants have been proposed for the embodiment of this pivoting mechanism, which generates the torque required to pivot the chute about its horizontal pivoting axis and which transmits this torque to the chute.




The patent U.S. Pat. No. 3,766,868 proposes a device of the type described in the preamble in which a linking rod located in the pivoting plane of the chute is coupled at one end to the rear surface of the chute. The other end of this linking rod is guided in a sinusoidal guiding track on the second rotor.




The patent U.S. Pat. No. 3,814,403 proposes a device of the type described in the preamble in which the second rotor comprises an annular gear. The latter, through the intermediary of a first pinion, drives a worm which, through the intermediary of a second pinion, acts on a sector gear fixed laterally on to a suspension journal for the chute.




The document U.S. Pat. No. 4,368,813 proposes a device of the type described in the preamble in which the rotor also comprises an annular gear. The first rotor carries a worm drive. The input shaft of the latter is provided with a pinion which meshes with the annular gear of said second rotor. The output shaft is parallel to the pivoting axis of the chute and is equipped with a crank. A connecting rod. contained in the pivoting plane of the chute, is coupled at one end to the rear surface of the chute and at the other end to the crank.




The document U.S. Pat. No. 4,941,792 proposes two devices of the type described in the preamble. A first embodiment uses a pivoting lever supported by the first rotor so that it can pivot in the pivoting plane of the chute. This pivoting lever is connected to the second rotor by means of a linking rod having ball-and-socket joints. The chute comprises two lateral suspension journals each of which is provided with a crank. A forked linking rod connects the pivoting linking rod to the two cranks on the chute. In the second embodiment the second rotor supports an annular segment gear which cooperates with a sector gear attached to a lateral suspension journal on the chute.




The document U.S. Pat. No. 5,002,806 proposes a device of the type described in the preamble in which the second rotor is connected to a crank attached to a lateral suspension journal on the chute using a linking rod having ball-and-socket joints.




The objective of the present invention is to propose a simple and compact device making it possible to transmit large pivoting torques to the rotary chute. In conformity with the invention, this objective is achieved by a device according to claim


1


.




A device for distributing materials in bulk according to the invention comprises a first rotor and a second rotor having a common substantially vertical rotation axis. Said first rotor carries two suspension bearings, in which a distribution chute is suspended so that it can pivot about a substantially horizontal pivoting axis. The device also comprises a gear transmission, which is also carried by said first rotor. This transmission comprises an input shaft and an output shaft. The input shaft is fitted with a pinion which meshes with an annular gear of said second rotor. The output shaft of the transmission is parallel to the pivoting axis of the chute. According to an important feature of the present invention, the output shaft incorporates two cranks, while the chute is fitted with a pivoting lever at the level of each of its suspension bearings. Each of these two pivoting levers is then connected to one of the two cranks of the gear transmission by means of a connecting rod. A difference between the angular rotational speed of the first rotor and that of the second rotor produces a rotation of the input pinion of the gear transmission about its own axis and hence also a rotation of the two cranks carried by the output shaft of the transmission. These two cranks then symmetrically transmit, through the intermediary of the above-mentioned pair of connecting rods and levers, the pivoting torque to the chute. This makes it possible to transmit large pivoting torques to the rotary chute with a simple and compact device.




Such a distribution device will usually comprise a fixed vertical charging duct positioned so as to pour the material in bulk into the chute. Said first rotor then advantageously comprises a vertical suspension sleeve which surrounds the fixed charging duct and is provided at its lower end with a horizontal flange. The latter carries the bearings for the suspension of the chute and the gear transmission on its upper surface.




The gear transmission is advantageously symmetrical with respect to a symmetry plane of the two suspension bearings. It comprises a worm drive or an equivalent system of gears having an input shaft and an output shaft perpendicular to each other. The worm drive has the particular advantage that it can easily be designed to be self-locking, so that the torque due to the weight of the chute will not be taken up by the second rotor.




When the device according to the invention is installed in a furnace, it will advantageously include a casing provided at its lower end with a fixed screen. This screen is then provided with a circular opening into which a flange of said first rotor is fitted. A gas injection pipe is positioned along said circular opening so as to be able to inject a cooling gas into a hollow space of the flange. A cooling system for the device may also include a cooling circuit positioned in an annular space between said first rotor and the fixed vertical charging duct used to pour the material in bulk into the chute.











Other special features and characteristics of the invention will emerge from the detailed description of an advantageous embodiment, described below as an illustrative example, referring to the appended drawings. These show:




FIG.


1


: a vertical cross-section through a device for the distribution of materials in bulk according to the invention; and




FIG.


2


: a horizontal cross-section through the line labelled


2





2


in FIG.


1


.











The device for distributing materials in bulk


10


shown in the figures is more particularly intended to form part of a feeding device for a shaft furnace, such as a blast furnace, represented schematically by its upper end


12


.




The device


10


comprises an outer casing


14


, which is mounted in an impervious manner on the upper end


12


of the shaft furnace. This casing


14


is provided with a fixed charging duct


16


, which is substantially coaxial with the vertical axis


18


of the shaft furnace. In the casing


14


, a first rotor


20


is suspended by means of a first large-diameter roller ring


22


. This first rotor


20


comprises a vertical suspension sleeve


24


, which surrounds the fixed charging duct


16


and is provided, at its lower end, with a horizontal flange


26


. A second large-diameter roller ring


28


is used to suspend the second rotor


30


in the casing


14


. This second rotor


30


surrounds the first rotor


20


, and its rotation axis is coaxial with the rotation axis of the first rotor


20


.




The two rotors


20


and


30


are driven in rotation about their common rotation axis by a driving device denoted in general in

FIG. 1

by the reference number


32


. It comprises a first pinion


34


, which meshes with an annular gear


36


of the first rotor


20


, and a second pinion


38


, which meshes with an annular gear


40


of the second rotor


30


. With the help of two motors


41


and a differential mechanism


43


, which are installed outside the casing


14


, this driving mechanism


32


is suitable for driving the two rotors


20


,


30


either with perfectly synchronised rotational speeds or with different rotational speeds.




The reference number


42


denotes a chute for the distribution of materials in bulk through the charging duct


16


. This chute


42


is suspended from the first rotor


20


by means of two suspension bearings


44


,


46


so that it can pivot about a substantially horizontal pivoting axis. The suspension bearings


44


,


46


are positioned on the flange


26


of the first rotor


20


on either side of its suspension sleeve


24


. At the level of each of its suspension bearings


44


,


46


, the chute


42


is equipped with a pivoting lever


48


,


50


protruding upwards with respect to the suspension bearings


44


,


46


.




The reference number


52


denotes in a general way a gear transmission carried by the flange


26


of the first rotor


20


. This transmission


52


comprises an input shaft


54


, which is parallel to the rotation axis of the two rotors


20


,


30


and which is provided with a pinion


56


which meshes with an annular gear


58


of the second rotor


30


. It also comprises an output shaft


60


, which is itself parallel to the pivoting axis of the chute


42


, and comprises two free ends, each of which is equipped with a crank


64


,


66


. A worm drive


62


interconnects the input shaft


54


and the output shaft


60


, so as to convert a rotation of the vertical input shaft


54


into a rotation of the horizontal output shaft


60


. Two connecting rods


68


,


70


connect the two cranks


64


,


66


symmetrically to the pivoting levers


48


,


50


of the chute


42


. It follows that a rotation of the input pinion


56


of the gear transmission


52


produces a rotation of the cranks


64


,


66


, which is converted by the connecting rods


68


,


70


and the pivoting levers


48


,


50


into a pivoting of the chute


42


. Now, the input pinion


56


rotates if there is a difference of angular speed between the first rotor


20


and the second rotor


30


. To make the chute


42


pivot from a first inclined position into a second inclined position, it is therefore sufficient to drive the second rotor


30


at an angular speed different from the first rotor


20


. To make the chute rotate with a constant angle of inclination, it is sufficient to drive the second rotor


30


with the same angular speed as the first rotor


20


. It should be appreciated that the device described makes it possible, with a relatively simple and compact equipment, to transmit appreciable pivoting forces to the chute


42


.




It remains to indicate a few important details about the protection of the distribution device


10


against the heat prevailing inside the furnace


12


. It should first be noted that the flange


26


of the first rotor


20


is positioned with a small working clearance in a circular opening in a lower screen


72


of the casing


14


. This lower screen


72


is provided with insulation


74


and with a closed cooling circuit


76


. The flange


26


itself is provided on its lower side with insulation


80


which is separated from the upper metallic flange


26


by a hollow space


82


open at the side. This hollow space


82


is cooled by injecting a gas through a circular duct


84


, which is positioned along the edge of the circular opening in the lower screen


72


. The first rotor


20


is advantageously cooled by a cooling circuit


86


positioned in the annular space remaining between the sleeve


24


of the first rotor


20


and the fixed charging duct


16


. The annular space in which the second rotor


30


and the gear transmission


52


are placed is advantageously cooled by injection of a gas.



Claims
  • 1. Device for distributing materials in bulk comprising:a chute (42); a first rotor (20) with a substantially vertical rotation axis carrying two suspension bearings (44, 46), said chute (42) being suspended in these two suspension bearings (44, 46) so that it can pivot about a substantially horizontal pivoting axis; a second rotor (30) with a rotation axis coaxial with said first rotor (20), this second rotor (30) being equipped with an annular gear (58); a gear transmission (52) carried by said first rotor (20), said gear transmission (52) comprising: an input shaft (54), which is provided with a pinion (56) which meshes with the annular gear (58) of said second rotor (30); an output shaft (60), which is parallel to the pivoting axis of the chute (42) and with which is associated a crank and connecting rod system producing a pivoting of the chute (42) when said input shaft (54) is driven by the annular gear (58) of said second rotor (30); characterised in that said output shaft (60) comprises two cranks; said chute (42) is provided with a pivoting lever (48, 50) at the level of each of its two suspension bearings (44, 46); and each of these two pivoting levers (48, 50) is symmetrically connected by means of a connecting rod to one of the two cranks (64, 66).
  • 2. Device according to claim 1, characterised by:a vertical charging duct; said first rotor (20) comprising a vertical suspension sleeve which surrounds said vertical charging duct and is provided, at its lower end, with a horizontal flange; said suspension bearings (44, 46) of the chute (42) being positioned on said flange on either side of said suspension sleeve; said gear transmission (52) being mounted on said horizontal flange between said suspension bearings (44, 46).
  • 3. Device according to claim 1, characterised in that said gear transmission (52) is symmetrical with respect to a plane of symmetry of the two suspension bearings (44, 46).
  • 4. Device according to claim 1, characterised in that said gear transmission (52) includes a worm drive (62).
  • 5. Device according to claim 1, characterised by:a casing (14) provided at its lower end with a fixed screen (72), said fixed screen (72) being provided with a circular opening, and said first rotor (20) being equipped at its lower end with a flange (26) which is fitted into said circular opening with a certain amount of play; and a gas injection pipe (84) positioned along said circular opening so that it can inject a cooling gas into a hollow space (82) in said flange.
  • 6. Device according to claim 1, characterised by:a fixed charging duct (16) surrounded by said first rotor (20); and by a cooling circuit (86) positioned in an annular space between said first rotor (20) and said fixed charging duct (16).
Priority Claims (1)
Number Date Country Kind
90319 Nov 1998 LU
US Referenced Citations (4)
Number Name Date Kind
4243351 Legille et al. Jan 1981
4368813 Mailliet Jan 1983
4547116 Legille et al. Oct 1985
5273148 Lonardi et al. Dec 1993