CONTROL DEVICE FOR A DISTRIBUTOR CHUTE IN A SHAFT FURNACE, PARTICULARLY A BLAST FURNACE
United States Patent 3864984
A control device for a distributor chute for raw material arranged in the top of a shaft furnace particularly a blast furnace, wherein the drive for rotating the chute is constructed seperately and independently from the drive for modifying the pitch angle of the chute.
US Patent References:
MACHINE TOOL
Hahn - February 1972 - 3640138
APPARATUS FOR CHARGING SHAFT-TYPE FURNACES
Pantke - August 1971 - 3598257
FURNACE TOP DISTRIBUTOR FOR SHAFT FURNACE,PARTICULARLY FOR BLAST FURNACES
Schneider - October 1970 - 3533522
APPARATUS FOR STORING INFORMATION ELEMENTS
Pierrat - April 1969 - 3440610
Power-transmission mechanism
Nieman - March 1930 - 1751650
MACHINE TOOL
Hahn - February 1972 - 3640138
APPARATUS FOR CHARGING SHAFT-TYPE FURNACES
Pantke - August 1971 - 3598257
FURNACE TOP DISTRIBUTOR FOR SHAFT FURNACE,PARTICULARLY FOR BLAST FURNACES
Schneider - October 1970 - 3533522
APPARATUS FOR STORING INFORMATION ELEMENTS
Pierrat - April 1969 - 3440610
Power-transmission mechanism
Nieman - March 1930 - 1751650
Application Number:
05/403900
Publication Date:
02/11/1975
Filing Date:
10/05/1973
Export Citation:
Assignee:
Des, Anciens Etablissements Paul Wurth S. A. (Luxembourg, LU)
Primary Class:
Other Classes:
266/96, 414/301, 74/425, 266/183
International Classes:
C21B7/20; C21B7/18; F16H27/02
Field of Search:
266/27 74/89.15,425,424.8
View Patent Images:
US Patent References:
| 1472848 | Drag-spindle mechanism | November 1923 | Maag |
Primary Examiner:
Ratliff Jr., Wesley S.
Claims:
What is claimed is
1. In a furnace, the furnace being provided with a material feed spout and a movable distribution chute arranged to receive material from the spout, an improved chute position control comprising;
2. The control of claim 1 wherein said rod means comprises a rod having an extended S-shape and formed in a T-shaped manner at its first end.
3. The control of claim 1 wherein said coupling means comprises:
4. The control of claim 3 wherein said vertically movable drive means is coaxial with and exterior of the feed spout and comprises:
5. The control of claim 4 wherein the engaging means are arranged about the periphery of the roller rotary connection and are displaced by 120° relative to one another.
6. The control of claim 5 wherein said rod means comprises:
7. The control of claim 6 wherein said engaging means each comprise:
8. The control of claim 7 wherein said synchronous drive means includes:
9. The control of claim 4 wherein said engaging means each comprise:
10. The control of claim 9 wherein said synchronous drive means includes:
11. The control of claim 1 further comprising:
12. The apparatus of claim 11 wherein said positive pressure establishing means comprises:
13. Method for charging a shaft furnace, the furnace having a rotatable and angularly adjustable charge distribution chute mounted therein comprising the steps of rotating the charge distribution chute by means of a rotary casing separately and independently therefrom adjusting the pitch angle of the distribution chute relative to the blast furnace central axis.
1. In a furnace, the furnace being provided with a material feed spout and a movable distribution chute arranged to receive material from the spout, an improved chute position control comprising;
2. The control of claim 1 wherein said rod means comprises a rod having an extended S-shape and formed in a T-shaped manner at its first end.
3. The control of claim 1 wherein said coupling means comprises:
4. The control of claim 3 wherein said vertically movable drive means is coaxial with and exterior of the feed spout and comprises:
5. The control of claim 4 wherein the engaging means are arranged about the periphery of the roller rotary connection and are displaced by 120° relative to one another.
6. The control of claim 5 wherein said rod means comprises:
7. The control of claim 6 wherein said engaging means each comprise:
8. The control of claim 7 wherein said synchronous drive means includes:
9. The control of claim 4 wherein said engaging means each comprise:
10. The control of claim 9 wherein said synchronous drive means includes:
11. The control of claim 1 further comprising:
12. The apparatus of claim 11 wherein said positive pressure establishing means comprises:
13. Method for charging a shaft furnace, the furnace having a rotatable and angularly adjustable charge distribution chute mounted therein comprising the steps of rotating the charge distribution chute by means of a rotary casing separately and independently therefrom adjusting the pitch angle of the distribution chute relative to the blast furnace central axis.
Description:
BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION
The invention relates to a control device for a distributor chute for raw material arranged in the top of a shaft furnace particularly a blast furnace.
2. DESCRIPTION of the PRIOR ART
The known bell-type charging installations are unable to keep pace with the requirements of the blast furnace operator for an increased blast furnace yield and with the continual increase in size of the blast furnace units without reaching impossibly large sizes and weights.
In U.S. Pat. No. 3,693,812 which is assigned to the assignee of the present invention a novel charging installation without a bell-type distributing device has been described which permits the arbitrary determination of the charging configuration to be made and which can be produced in relatively small sizes and weights.
According to U.S. Pat. No. 3,693,812 a rotary distributor chute is arranged centrally in the blast furnace top, its pitch angle being adjustable relative to the blast furnace central axis. The charge to be supplied is fed to the distributor chute in controlled quantities via a central feed channel from stroage hoppers mounted above the distribution device.
To permit the charging process to be performed in arbitrary manner a control device has been designed which permits the rotation and pitch angle adjustment of the centrally arranged distributor chute to be performed as two independent movements.
Accordingly the distributor chute is pivotally mounted, so as to permit an adjustable pitch angle, on the underside of a rotary ring which is concentric to the central feed channel. The rotary ring is connected with a main drive via a first rotary sleeve, which rotates the rotary ring and the distributor chute fixed to the underside thereof. A second rotary sleeve is provided for the pitch angle adjustment of the distributor chute; the second sleeve having a sinusoidal slot on its innerside and being arranged outside the first rotary sleeve and concentrically to the central feed channel. The second rotary sleeve is driven synchronously with the first rotary sleeve. The drive means includes a planet gear which permits the speed of the second sleeve to be increased or decreased relative to the first sleeve. A runner engages in the sinusoidal slot on the inside of the second rotary sleeve and can slide along this slot. The runner is fixed to a cylinder which is displaceably connected with the inner rotary sleeve in a vertical direction. Via a rod connection, the cylinder is connected with the end of the chute remote from the discharge end of the distributor chute. As the distributor chute is arranged in pitch adjustable manner on the underside of the rotary ring, the angle of inclination of the distributor chute may be varied relative to the blast furnace central axis by raising or lowering the rod connection.
The particular setting of the angle of inclination or pitch of the distributor chute is determined by the position or relative speed of the two concentrically rotating rotary sleeves. With synchronised rotary speeds of the two rotary sleeves the runner, which is carried along by the cylinder and which as noted is vertically displaceable in the channel of the inner rotary sleeve, does not change its position relative to the outer rotary sleeve on the sinusoidal slot. However, if the outer rotary sleeve is moving faster or slower than the inner rotary sleeve the runner runs along the sinusoidal slot so that a raising or lowering of the rod connection is brought about leading to a change in the angle of inclination of the distributor chute.
Although this known drive for the independent rotary movement and pitch angle adjustment of the charging distributor chute permits a satisfactory arbitrary control of the charging process, it does have certain shortcomings. Thus, for example, the pitch angle adjustment of the distributor chute is limited by the highest and lowest point of the sinusoidal slot on the outer rotary sleeve. Furthermore, the two rotary sleeves, the runner and the rod connection, as well as all their bearing and drive members, are necessarily exposed to the pressure and dust of the blast furnace resulting in additional mechanical stress and relatively rapid wear particularly as far as the bearings are concerned.
The shortcomings linked with this drive have led the Applicants to design an improved drive for the distributor chute. Thus, in co-pending Applications Ser. No. 355,730, now U.S. Pat. No. 3,814,403, and 368,867, which are assigned to the assignee of the present invention, two further drives as well as mounting devices for the distributor chute are described.
According to said co-pending application Ser. No. 355,730 the distributor chute is suspended on the underside of a rotary disc arranged concentrically to the central feed channel, said rotary disc being caused to rotate via a rotary sleeve by a main drive motor and intermediate gears. On the top of the rotary disc is arranged a toothed rim which can be rotated via a planet gear and an auxiliary motor independently of the rotation of the rotary disc. The toothed rim located on the top of the rotary disc drives a shaft passing through the rotary disc and rotably mounted therein which in turn drives a device for the angular adjustment of the distributor chute arranged on the bottom of the rotary disc. The attachment of the distributor chute is arranged in such a way that, at its material feed end, it is attached at one of its longitudinal sides to a suspension device whereby the chute can be secured or detached from a drive chamber located above the rotary disc. At its opposite longitudinal side the material feed end of the distributor chute is firmly but detachably connected with an adjusting arm. The adjusting arm represents the connection between the distributor chute and the angular adjusting drive.
Although the apparatus of copending application Ser. No. 355,730 precipitates considerable advantages, certain minor short-comings become apparent from a construction stand-point. Thus the gear box placed on the bottom of the rotary disc, which is exposed to the direct heat of the blast furnace, cannot be given maximum heat protection. Heat surges in the blast furnace, which can for brief periods reach 1,000°C, could under unfavourable conditions lead to the blocking of the gear located in the gear box. More particularly, the gear in the gear box cannot be cooled by a through-flow of inert gas or purified and cooled blast furnace gas. As the pitch angle adjusting force in said drive device only acts on one longitudinal side of the distributor chute, high demands are made on the material of the chute. The adjusting force is transferred through the chute to its second longitudinal side up to a mounting. As a result, torsional forces occur in the distributor chute itself, and this is even more pronounced during the charging process when the distributor chute is further loaded with charge material.
To eliminate the above-discussed shortcomings, the apparatus of co-pending Application Ser. No. 368,867, wherein the distributor chute is suspended in a pitch angle adjustable manner on a rotary casing arranged concentrically to the central feed, was invented. The rotary casing is caused to rotate by a gear via a rotary sleeve and, on the side of the rotary casing remote from the blast furnace, two gear boxes are provided for the pitch angle adjustment of the distributor chute. These gear boxes are constructed homologously relative to a plane formed by the blast furnace central axis and the distributor chute longitudinal axis. Each of the gear boxes drives a shaft which passes through the rotary casing horizontally to the central feed. The distributor chute itself is at both longitudinal sides fixed to the ends of the shafts projecting into the blast furnace.
The drive apparatus of Application Ser. No. 368,867 and a planet gear as well as an auxiliary motor for the pitch angle adjustment of the distributor chute.
Although this drive eliminates the above indicated disadvantages of the prior art, it takes up a relatively large space and its manufacture is relatively costly compared with the drives described hereinbefore.
It is stressed that the drive as described in the herein-before mentioned co-pending application Ser. No. 368,867 comprises a planet gear which is driven on the one hand by a main motor and on the other by an auxiliary motor. Whilst the main motor also effects the rotation of the distributor chute, the planet gear and the auxiliary motor adjust the inclination angle of the distributor chute. The inclination angle of the distributor chute is therefore brought about by the relative movement of two independently rotatable members such as, e.g., the combination rotary sleeve - rotary sleeve or rotary sleeve - toothed rim.
Despite its relatively simple construction, the planet gears and the members which rotate relative to one another require a relatively large amount of space, and utilizes comparatively complex equipment and therefore makes the complete installation more costly.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a drive which, whilst retaining the advantages of the known drive devices such as e.g., the independent performance of the rotary movement and the pitch angle adjustment of the distributor chute, can be simply constructed in a light weight design and eliminate to the greatest possible extent the above-indicated disadvantages of previous drive devices.
The invention provides a control device for a distributor chute in a shaft furnace, particularly a blast furnace, wherein the distributor chute is connected at its two longitudinal sides in a pivotable manner at the underside of a rotary casing. The chute is provided, at the end remote from its discharge end with a rod connection. The rod connection comprises, at its end remote from the distributor chute, a mounting which can be raised or lowered via a drive to modify the pitch angle of the chute relative to the blast furnace cantral axis. Thus, in accordance with the present invention, drive for modifying the pitch angle of the distributor chute is constructed separately and independently from the drive for rotating the distributor chute via the said rotary casing.
According to the invention the means for the pitch angle adjustment of the distributor chute, in contradistinction to the prior art, is not connected via a planet gear with the drive for rotating the distributor chute. Similarly, in the present invention there are no relative movements between the individual members of the two drives. The two individual drives and their appropriate gears are therefore completely separate from one another.
In the present invention, the distributor chute is suspended in a pitch angle adjustable manner in the blast furnace top centrally on a rotary casing which is concentric to the central feed channel. The control bringing about the rotary movement of the rotary casing comprises, in addition to a drive motor, an intermediate gear in order to adapt the speed of the drive motor to the necessary rotary casing speed.
In order to bring about the pitch angle adjustment or change of the distributor chute, the distributor chute is suspended in rotary manner on its two longitudinal sides on two diametrically opposite points of the rotary casing. Furthermore the distributor chute is connected at its end remote from the material discharge point with a rod connection which, as a result of its upward and downward movement, causes the distributor chute to pivot about its connection with the rotary casing and thereby varies the pitch angle or angle of inclination of the distributor chute relative to the blast furnace central axis.
In a preferred embodiment the rod connection is T-shaped at its lower end and is connected in a pivotable manner with the end of the distributor chute remote from the discharge channel. This connection is constructed in such a way that it can be detached or fixed from a hand hole on the blast furnace wall without any difficulty. On its end remote from the distributor chute the rod connection is connected with a device for raising or lowering the latter. It is stressed that the engagement point of the rod connection on the distributor chute as well as its displacement path are selected in such a way that the distributor chute can without difficulty be pivoted from the vertical into the horizontal position.
The device for raising or lowering the rod connection comprises a rotary ring arranged concentrically to the rotary casing with which the end of the rod connection remote from the distributor chute is connected in a pivotable manner. This rotary ring is in turn mounted in a roller rotary connection; e.g., a Rothe Erde ring, and retained in the latter. The rotary ring is rotated by the distributor chute via the rod connection. Via a drive and an appropriate gear, the roller rotary connection may be raised or lowered over its complete periphery. The rotary ring as well as the rod connection connected with the latter also necessarily carries out this raising or lowering movement.
In the preferred embodiment the roller rotary connection is carried by three positioning devices or mountings periphally displaced by 120°. Each of said positioning devices comprises a holder for the roller rotary connection as well as an inner thread which engages an endless screw. The endless screws of the three positioning devices are rotated by a common drive so that the roller rotary connection is uniformly raised or lowered over its complete periphery.
Furthermore in order to bring about a permanent and easily achievable sealing of the throat relative to the outer atmosphere the complete installation as described above is surrounded by a gas-tight outer casing. The two drive motors and part of the appropriate gears are placed on the outside of this casing. In each case only one shaft of these two gears is mounted in the casing and can be well sealed in a conventional manner.
Furthermore, as is already known from the patent and patent applications mentioned hereinbefore, purified and cooled blast furnace gas or inert gas can be introduced from the outside into the casing for cleaning and cooling the gears exposed to dust and temperature in the throat of the blast furnace.
BRIEF DESCRIPTION OF THE DRAWING
The present invention may be better understood and its numerous objects and advantages will become apparent to those skilled in the art by reference to a preferred embodiment of the invention represented in the accompanying drawings wherein like reference numerals refer to like elements in the several figures and in which:
FIG. 1 is a longitudinal section through the installation according to the invention, the distributor chute being represented assuming two different positions in two planes perpendicular to each other,
FIG. 2 is a cross section of a preferred embodiment of the drive as well as of the gear for the pitch angle adjustment for the distributor chute,
FIG. 3 is a cross section through a construction of the guide for the positioning devices and
FIG. 4 is a view of the rod device.
DESCRIPTION of the PREFERRED EMBODIMENT:
As shown in FIG. 1 a distributor chute 2 (only partially shown) is arranged centrally in a rotary and pitch angle adjustable manner in a blast furnace top 4 whereby the rotation and pitch angle adjustment of the distributor chute 2 are two independent movements which are performed by two separate and different drives and gears. The charge is supplied to the distributor chute 2 via a centrally arranged feed channel 6.
To bring about the rotary movement of the distributor chute 2 the latter is suspended in a pivotable manner at its two longitudinal sides via the connections 8 and 10 on the underside of a rotary casing 12 arranged concentrically to the central feed channel 6. The rotary casing 12 is on its upper side held and mounted via a toothed rim 20 in a roller rotary connection 14 which is fixed to the underside of the upper wall 16 of a drive chamber 18 as will be explained hereinafter. The rotary drive, in addition to the toothed rim 20 and the rotary casing 12 fixed to the latter, comprises a drive motor 22, a reduction gear 24, a transmission shaft 26 having a suitable pinion 28 fixed thereon, as well as a spacer gear wheel 30. Drive motor 22 and reduction gear 24 are mounted on the outer casing 32 of drive chamber 18. Only transmission shaft 26 passes through the outer casing 32 and is mounted in a gas-tight manner in the latter. The pinion 28 engages in spacer gear wheel 30 which forms the connection to toothed rim 20. The reduction gear adapts the speed of the drive motor 22 to the necessary speed of rotation of rotary casing 12. The spacer gear wheel 30 has for its object merely a spatially advantageous arrangement of the rotary drive components.
To bring about the pitch angle adjustment of the distributor chute 2 the latter is connected at its end remote from the discharge channel with a device which by raising and lowering varies the inclination angle of the distributor chute 2 relative to the blast furnace central axis A. This raising and lowering device comprises a rod connection 34 which is constructed in T-shaped manner at its one end. As shown in FIG. 4, this T-shaped connection 36 is connected in pivotable manner to the underside of the distributor chute 2. A raising or lowering of rod connection 34 brings about a pivoting movement of distributor chute 2 about its two connections 8 and 10 and therefore varies the pitch angle of distributor chute 2.
At its end remote from the distributor chute 2 the rod connection is connected via a ball and socket joint 38 with a retaining ring 40. Retaining ring 40 is fixed in rigidizing section 42 which also embraces a rotary ring 44. Rotary ring 44 is mounted and retained in a roller rotary connection 46 which is in turn firmly but detachably fixed to a device which permits the raising or lowering, in a uniform peripheral manner, of the roller rotary connection.
On the periphery of the roller rotary connection 46 there are provided a plurality, and preferably three, positioning devices 48, 50 and 52 (see FIG. 1 and 3) displaced by 120° relative to one another. The positioning devices are connected to the roller rotary connection 46 via detachable spindles. Each of the positioning devices 48, 50 and 52 is provided with a thread which engages respective vertically arranged endless screw 54, 56 and 58. The three endless screws 54, 56 and 58 are driven synchronously via a common drive 60 (FIG. 2). Therefore the endless screws 54, 56 and 58 are provided at their upper ends with respective pinion or worm wheels 62, 64, 66 which are rotated via respective worm threads 68, 70, 72. As may be seen from FIG. 2, the worm threads are interconnected and connected with the common drive 60 via shafts 74, 76 and 78 and via angle connections 80 and 82. Drive 60 comprises a reversible drive motor 84, as well as an intermediate gear 86 which drives the shaft 76.
Drive 60, worm gears 62, 68, 64, 70, 66, 72 as well as the shafts are constructed so as to be mounted on the outer casing 32 of drive chamber 18. The upper ends of the three endless screws 54, 56 and 58, which are not threads, are mounted in gas-tight manner in the upper sealing cover of outer casing 32. Furthermore the endless screws are held in bearings at their lower ends. In addition the positioning devices 48, 50, 52, as shown in FIG. 3, in order to bring about increased rigidity are held respectively by two slide bars 88, 90, or 92, 94, or 96, 98 which are held at their two ends on the inner side of outer casing 32.
As already mentioned the complete installation is surrounded by a gas-tight casing 32 to permit operation of the blast furnace with a high pressure at the throat. Only the connecting shaft 26 and the three endless screws 48, 50 and 52 pass through the outer casing 32 and are rotatably mounted therein. With the present state of the art their sealing presents no problem and can be achieved in conventional manner. Since however that part of the installation located in casing 32 is exposed to the direct heat as well as the dust of the blast furnace, cooled and cleaned throat gas or inert gas is passed through connection pipe 100. This gas is under a slightly higher pressure than that occurring at the throat so that there is maintained a limited gas flow from the drive chamber 18 into the blast furnace top. The cooling or cleaning gas flow is indicated by arrow 102 in FIG. 1. Furthermore to avoid excess gas consumption rotary casing 12 is provided on its underside with a horizontal sealing disc 104 which only leaves a small gap relative to the outer casing 32 through which the gas flows. Sealing disc 104 only has an appropriate recess for the passage of rod 34. In order to keep this recess as small as possible rod 34 is shaped like an extended S-line. On raising and lowering rod 34 when viewed horizontally the latter remains virtually unchanged in position at the level of sealing disc 104. In order to further reduce the gas flow a ring 106 bears on sealing disc 104 and is carried freely by rod 34 so as to follow the movement changes of rod 34 and partly or completely covers the remaining gap in the recess for the passage of rod 34.
In addition, outer casing 32 has three bulges which surround in a gas-tight manner the positioning devices 48, 50 and 52 as well as worms 54, 56 and 58 and their guides.
Since the roller rotary connection 46 is not easily accessible from the outside for lubrication purposes it is connected via a flexible hose 108 with the outer casing 32 and a lubricant supply. Flexible hose 108 is fixed to the outer casing 32 preferably at half the height thereof, so that for a minimum length it still reaches the highest or lowest point of the movement of the roller rotary connection 46.
For the assembly or disassembly of the distributor chute 2 located centrally in the blast furnace top 4 on the blast furnace outer wall two large hand holes 110 (in FIG. 1 only one is shown) are provided at two diametrically opposite points which during blast furnace operation are sealed in gas-tight manner and are only opened on assembly or disassembly of the distributor chute. The two pivoting connections 8 and 10 and the attachment of rod 34 to the distributor chute 2 can be easy to reach from these holes 110. Furthermore on the blast furnace wall an appropriate recess is provided through which the distributor chute which has been detached from its connections can be introduced or removed in per se known manner with the aid of a crane cross bar.
Whilst the above-described embodiment is preferred it is obvious that further of components of the drive according to the invention are possible.
Thus for example the rotary ring 40 can be replaced by a segment-shaped partial ring whereby the length of said ring must be made such that its rotation within the roller rotary connection 46 is not impaired.
Furthermore it is possible that the drive for endless screws 54, 56 and 58 can be achieved via a chain drive rather than through utilization of axial connections 74, 76 and 78 and angle connections 80 and 82 as shown.
The advantage of the installation according to the invention lies mainly in the simplicity of the basic concept of the control and the construction of the individual components of the installation. The relative movements of the drives for the rotation or pitch angle adjustment of the distributor chute are no longer necessary and their relatively large and complicated gears are replaced by two simple separate drives. In addition, the main components subject to wear are easily accessible and can be replaced without shutting down the furnace for a long time.
In addition cooled and cleaned throat gas or inert gas can be introduced in an effective small amount in the control device of the invention for cooling and cleaning of the gear parts located within the gas-tight casing and which are exposed to the heat and the dust present in the top of the furnace.
While a preferred embodiment has been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.
1. FIELD OF THE INVENTION
The invention relates to a control device for a distributor chute for raw material arranged in the top of a shaft furnace particularly a blast furnace.
2. DESCRIPTION of the PRIOR ART
The known bell-type charging installations are unable to keep pace with the requirements of the blast furnace operator for an increased blast furnace yield and with the continual increase in size of the blast furnace units without reaching impossibly large sizes and weights.
In U.S. Pat. No. 3,693,812 which is assigned to the assignee of the present invention a novel charging installation without a bell-type distributing device has been described which permits the arbitrary determination of the charging configuration to be made and which can be produced in relatively small sizes and weights.
According to U.S. Pat. No. 3,693,812 a rotary distributor chute is arranged centrally in the blast furnace top, its pitch angle being adjustable relative to the blast furnace central axis. The charge to be supplied is fed to the distributor chute in controlled quantities via a central feed channel from stroage hoppers mounted above the distribution device.
To permit the charging process to be performed in arbitrary manner a control device has been designed which permits the rotation and pitch angle adjustment of the centrally arranged distributor chute to be performed as two independent movements.
Accordingly the distributor chute is pivotally mounted, so as to permit an adjustable pitch angle, on the underside of a rotary ring which is concentric to the central feed channel. The rotary ring is connected with a main drive via a first rotary sleeve, which rotates the rotary ring and the distributor chute fixed to the underside thereof. A second rotary sleeve is provided for the pitch angle adjustment of the distributor chute; the second sleeve having a sinusoidal slot on its innerside and being arranged outside the first rotary sleeve and concentrically to the central feed channel. The second rotary sleeve is driven synchronously with the first rotary sleeve. The drive means includes a planet gear which permits the speed of the second sleeve to be increased or decreased relative to the first sleeve. A runner engages in the sinusoidal slot on the inside of the second rotary sleeve and can slide along this slot. The runner is fixed to a cylinder which is displaceably connected with the inner rotary sleeve in a vertical direction. Via a rod connection, the cylinder is connected with the end of the chute remote from the discharge end of the distributor chute. As the distributor chute is arranged in pitch adjustable manner on the underside of the rotary ring, the angle of inclination of the distributor chute may be varied relative to the blast furnace central axis by raising or lowering the rod connection.
The particular setting of the angle of inclination or pitch of the distributor chute is determined by the position or relative speed of the two concentrically rotating rotary sleeves. With synchronised rotary speeds of the two rotary sleeves the runner, which is carried along by the cylinder and which as noted is vertically displaceable in the channel of the inner rotary sleeve, does not change its position relative to the outer rotary sleeve on the sinusoidal slot. However, if the outer rotary sleeve is moving faster or slower than the inner rotary sleeve the runner runs along the sinusoidal slot so that a raising or lowering of the rod connection is brought about leading to a change in the angle of inclination of the distributor chute.
Although this known drive for the independent rotary movement and pitch angle adjustment of the charging distributor chute permits a satisfactory arbitrary control of the charging process, it does have certain shortcomings. Thus, for example, the pitch angle adjustment of the distributor chute is limited by the highest and lowest point of the sinusoidal slot on the outer rotary sleeve. Furthermore, the two rotary sleeves, the runner and the rod connection, as well as all their bearing and drive members, are necessarily exposed to the pressure and dust of the blast furnace resulting in additional mechanical stress and relatively rapid wear particularly as far as the bearings are concerned.
The shortcomings linked with this drive have led the Applicants to design an improved drive for the distributor chute. Thus, in co-pending Applications Ser. No. 355,730, now U.S. Pat. No. 3,814,403, and 368,867, which are assigned to the assignee of the present invention, two further drives as well as mounting devices for the distributor chute are described.
According to said co-pending application Ser. No. 355,730 the distributor chute is suspended on the underside of a rotary disc arranged concentrically to the central feed channel, said rotary disc being caused to rotate via a rotary sleeve by a main drive motor and intermediate gears. On the top of the rotary disc is arranged a toothed rim which can be rotated via a planet gear and an auxiliary motor independently of the rotation of the rotary disc. The toothed rim located on the top of the rotary disc drives a shaft passing through the rotary disc and rotably mounted therein which in turn drives a device for the angular adjustment of the distributor chute arranged on the bottom of the rotary disc. The attachment of the distributor chute is arranged in such a way that, at its material feed end, it is attached at one of its longitudinal sides to a suspension device whereby the chute can be secured or detached from a drive chamber located above the rotary disc. At its opposite longitudinal side the material feed end of the distributor chute is firmly but detachably connected with an adjusting arm. The adjusting arm represents the connection between the distributor chute and the angular adjusting drive.
Although the apparatus of copending application Ser. No. 355,730 precipitates considerable advantages, certain minor short-comings become apparent from a construction stand-point. Thus the gear box placed on the bottom of the rotary disc, which is exposed to the direct heat of the blast furnace, cannot be given maximum heat protection. Heat surges in the blast furnace, which can for brief periods reach 1,000°C, could under unfavourable conditions lead to the blocking of the gear located in the gear box. More particularly, the gear in the gear box cannot be cooled by a through-flow of inert gas or purified and cooled blast furnace gas. As the pitch angle adjusting force in said drive device only acts on one longitudinal side of the distributor chute, high demands are made on the material of the chute. The adjusting force is transferred through the chute to its second longitudinal side up to a mounting. As a result, torsional forces occur in the distributor chute itself, and this is even more pronounced during the charging process when the distributor chute is further loaded with charge material.
To eliminate the above-discussed shortcomings, the apparatus of co-pending Application Ser. No. 368,867, wherein the distributor chute is suspended in a pitch angle adjustable manner on a rotary casing arranged concentrically to the central feed, was invented. The rotary casing is caused to rotate by a gear via a rotary sleeve and, on the side of the rotary casing remote from the blast furnace, two gear boxes are provided for the pitch angle adjustment of the distributor chute. These gear boxes are constructed homologously relative to a plane formed by the blast furnace central axis and the distributor chute longitudinal axis. Each of the gear boxes drives a shaft which passes through the rotary casing horizontally to the central feed. The distributor chute itself is at both longitudinal sides fixed to the ends of the shafts projecting into the blast furnace.
The drive apparatus of Application Ser. No. 368,867 and a planet gear as well as an auxiliary motor for the pitch angle adjustment of the distributor chute.
Although this drive eliminates the above indicated disadvantages of the prior art, it takes up a relatively large space and its manufacture is relatively costly compared with the drives described hereinbefore.
It is stressed that the drive as described in the herein-before mentioned co-pending application Ser. No. 368,867 comprises a planet gear which is driven on the one hand by a main motor and on the other by an auxiliary motor. Whilst the main motor also effects the rotation of the distributor chute, the planet gear and the auxiliary motor adjust the inclination angle of the distributor chute. The inclination angle of the distributor chute is therefore brought about by the relative movement of two independently rotatable members such as, e.g., the combination rotary sleeve - rotary sleeve or rotary sleeve - toothed rim.
Despite its relatively simple construction, the planet gears and the members which rotate relative to one another require a relatively large amount of space, and utilizes comparatively complex equipment and therefore makes the complete installation more costly.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a drive which, whilst retaining the advantages of the known drive devices such as e.g., the independent performance of the rotary movement and the pitch angle adjustment of the distributor chute, can be simply constructed in a light weight design and eliminate to the greatest possible extent the above-indicated disadvantages of previous drive devices.
The invention provides a control device for a distributor chute in a shaft furnace, particularly a blast furnace, wherein the distributor chute is connected at its two longitudinal sides in a pivotable manner at the underside of a rotary casing. The chute is provided, at the end remote from its discharge end with a rod connection. The rod connection comprises, at its end remote from the distributor chute, a mounting which can be raised or lowered via a drive to modify the pitch angle of the chute relative to the blast furnace cantral axis. Thus, in accordance with the present invention, drive for modifying the pitch angle of the distributor chute is constructed separately and independently from the drive for rotating the distributor chute via the said rotary casing.
According to the invention the means for the pitch angle adjustment of the distributor chute, in contradistinction to the prior art, is not connected via a planet gear with the drive for rotating the distributor chute. Similarly, in the present invention there are no relative movements between the individual members of the two drives. The two individual drives and their appropriate gears are therefore completely separate from one another.
In the present invention, the distributor chute is suspended in a pitch angle adjustable manner in the blast furnace top centrally on a rotary casing which is concentric to the central feed channel. The control bringing about the rotary movement of the rotary casing comprises, in addition to a drive motor, an intermediate gear in order to adapt the speed of the drive motor to the necessary rotary casing speed.
In order to bring about the pitch angle adjustment or change of the distributor chute, the distributor chute is suspended in rotary manner on its two longitudinal sides on two diametrically opposite points of the rotary casing. Furthermore the distributor chute is connected at its end remote from the material discharge point with a rod connection which, as a result of its upward and downward movement, causes the distributor chute to pivot about its connection with the rotary casing and thereby varies the pitch angle or angle of inclination of the distributor chute relative to the blast furnace central axis.
In a preferred embodiment the rod connection is T-shaped at its lower end and is connected in a pivotable manner with the end of the distributor chute remote from the discharge channel. This connection is constructed in such a way that it can be detached or fixed from a hand hole on the blast furnace wall without any difficulty. On its end remote from the distributor chute the rod connection is connected with a device for raising or lowering the latter. It is stressed that the engagement point of the rod connection on the distributor chute as well as its displacement path are selected in such a way that the distributor chute can without difficulty be pivoted from the vertical into the horizontal position.
The device for raising or lowering the rod connection comprises a rotary ring arranged concentrically to the rotary casing with which the end of the rod connection remote from the distributor chute is connected in a pivotable manner. This rotary ring is in turn mounted in a roller rotary connection; e.g., a Rothe Erde ring, and retained in the latter. The rotary ring is rotated by the distributor chute via the rod connection. Via a drive and an appropriate gear, the roller rotary connection may be raised or lowered over its complete periphery. The rotary ring as well as the rod connection connected with the latter also necessarily carries out this raising or lowering movement.
In the preferred embodiment the roller rotary connection is carried by three positioning devices or mountings periphally displaced by 120°. Each of said positioning devices comprises a holder for the roller rotary connection as well as an inner thread which engages an endless screw. The endless screws of the three positioning devices are rotated by a common drive so that the roller rotary connection is uniformly raised or lowered over its complete periphery.
Furthermore in order to bring about a permanent and easily achievable sealing of the throat relative to the outer atmosphere the complete installation as described above is surrounded by a gas-tight outer casing. The two drive motors and part of the appropriate gears are placed on the outside of this casing. In each case only one shaft of these two gears is mounted in the casing and can be well sealed in a conventional manner.
Furthermore, as is already known from the patent and patent applications mentioned hereinbefore, purified and cooled blast furnace gas or inert gas can be introduced from the outside into the casing for cleaning and cooling the gears exposed to dust and temperature in the throat of the blast furnace.
BRIEF DESCRIPTION OF THE DRAWING
The present invention may be better understood and its numerous objects and advantages will become apparent to those skilled in the art by reference to a preferred embodiment of the invention represented in the accompanying drawings wherein like reference numerals refer to like elements in the several figures and in which:
FIG. 1 is a longitudinal section through the installation according to the invention, the distributor chute being represented assuming two different positions in two planes perpendicular to each other,
FIG. 2 is a cross section of a preferred embodiment of the drive as well as of the gear for the pitch angle adjustment for the distributor chute,
FIG. 3 is a cross section through a construction of the guide for the positioning devices and
FIG. 4 is a view of the rod device.
DESCRIPTION of the PREFERRED EMBODIMENT:
As shown in FIG. 1 a distributor chute 2 (only partially shown) is arranged centrally in a rotary and pitch angle adjustable manner in a blast furnace top 4 whereby the rotation and pitch angle adjustment of the distributor chute 2 are two independent movements which are performed by two separate and different drives and gears. The charge is supplied to the distributor chute 2 via a centrally arranged feed channel 6.
To bring about the rotary movement of the distributor chute 2 the latter is suspended in a pivotable manner at its two longitudinal sides via the connections 8 and 10 on the underside of a rotary casing 12 arranged concentrically to the central feed channel 6. The rotary casing 12 is on its upper side held and mounted via a toothed rim 20 in a roller rotary connection 14 which is fixed to the underside of the upper wall 16 of a drive chamber 18 as will be explained hereinafter. The rotary drive, in addition to the toothed rim 20 and the rotary casing 12 fixed to the latter, comprises a drive motor 22, a reduction gear 24, a transmission shaft 26 having a suitable pinion 28 fixed thereon, as well as a spacer gear wheel 30. Drive motor 22 and reduction gear 24 are mounted on the outer casing 32 of drive chamber 18. Only transmission shaft 26 passes through the outer casing 32 and is mounted in a gas-tight manner in the latter. The pinion 28 engages in spacer gear wheel 30 which forms the connection to toothed rim 20. The reduction gear adapts the speed of the drive motor 22 to the necessary speed of rotation of rotary casing 12. The spacer gear wheel 30 has for its object merely a spatially advantageous arrangement of the rotary drive components.
To bring about the pitch angle adjustment of the distributor chute 2 the latter is connected at its end remote from the discharge channel with a device which by raising and lowering varies the inclination angle of the distributor chute 2 relative to the blast furnace central axis A. This raising and lowering device comprises a rod connection 34 which is constructed in T-shaped manner at its one end. As shown in FIG. 4, this T-shaped connection 36 is connected in pivotable manner to the underside of the distributor chute 2. A raising or lowering of rod connection 34 brings about a pivoting movement of distributor chute 2 about its two connections 8 and 10 and therefore varies the pitch angle of distributor chute 2.
At its end remote from the distributor chute 2 the rod connection is connected via a ball and socket joint 38 with a retaining ring 40. Retaining ring 40 is fixed in rigidizing section 42 which also embraces a rotary ring 44. Rotary ring 44 is mounted and retained in a roller rotary connection 46 which is in turn firmly but detachably fixed to a device which permits the raising or lowering, in a uniform peripheral manner, of the roller rotary connection.
On the periphery of the roller rotary connection 46 there are provided a plurality, and preferably three, positioning devices 48, 50 and 52 (see FIG. 1 and 3) displaced by 120° relative to one another. The positioning devices are connected to the roller rotary connection 46 via detachable spindles. Each of the positioning devices 48, 50 and 52 is provided with a thread which engages respective vertically arranged endless screw 54, 56 and 58. The three endless screws 54, 56 and 58 are driven synchronously via a common drive 60 (FIG. 2). Therefore the endless screws 54, 56 and 58 are provided at their upper ends with respective pinion or worm wheels 62, 64, 66 which are rotated via respective worm threads 68, 70, 72. As may be seen from FIG. 2, the worm threads are interconnected and connected with the common drive 60 via shafts 74, 76 and 78 and via angle connections 80 and 82. Drive 60 comprises a reversible drive motor 84, as well as an intermediate gear 86 which drives the shaft 76.
Drive 60, worm gears 62, 68, 64, 70, 66, 72 as well as the shafts are constructed so as to be mounted on the outer casing 32 of drive chamber 18. The upper ends of the three endless screws 54, 56 and 58, which are not threads, are mounted in gas-tight manner in the upper sealing cover of outer casing 32. Furthermore the endless screws are held in bearings at their lower ends. In addition the positioning devices 48, 50, 52, as shown in FIG. 3, in order to bring about increased rigidity are held respectively by two slide bars 88, 90, or 92, 94, or 96, 98 which are held at their two ends on the inner side of outer casing 32.
As already mentioned the complete installation is surrounded by a gas-tight casing 32 to permit operation of the blast furnace with a high pressure at the throat. Only the connecting shaft 26 and the three endless screws 48, 50 and 52 pass through the outer casing 32 and are rotatably mounted therein. With the present state of the art their sealing presents no problem and can be achieved in conventional manner. Since however that part of the installation located in casing 32 is exposed to the direct heat as well as the dust of the blast furnace, cooled and cleaned throat gas or inert gas is passed through connection pipe 100. This gas is under a slightly higher pressure than that occurring at the throat so that there is maintained a limited gas flow from the drive chamber 18 into the blast furnace top. The cooling or cleaning gas flow is indicated by arrow 102 in FIG. 1. Furthermore to avoid excess gas consumption rotary casing 12 is provided on its underside with a horizontal sealing disc 104 which only leaves a small gap relative to the outer casing 32 through which the gas flows. Sealing disc 104 only has an appropriate recess for the passage of rod 34. In order to keep this recess as small as possible rod 34 is shaped like an extended S-line. On raising and lowering rod 34 when viewed horizontally the latter remains virtually unchanged in position at the level of sealing disc 104. In order to further reduce the gas flow a ring 106 bears on sealing disc 104 and is carried freely by rod 34 so as to follow the movement changes of rod 34 and partly or completely covers the remaining gap in the recess for the passage of rod 34.
In addition, outer casing 32 has three bulges which surround in a gas-tight manner the positioning devices 48, 50 and 52 as well as worms 54, 56 and 58 and their guides.
Since the roller rotary connection 46 is not easily accessible from the outside for lubrication purposes it is connected via a flexible hose 108 with the outer casing 32 and a lubricant supply. Flexible hose 108 is fixed to the outer casing 32 preferably at half the height thereof, so that for a minimum length it still reaches the highest or lowest point of the movement of the roller rotary connection 46.
For the assembly or disassembly of the distributor chute 2 located centrally in the blast furnace top 4 on the blast furnace outer wall two large hand holes 110 (in FIG. 1 only one is shown) are provided at two diametrically opposite points which during blast furnace operation are sealed in gas-tight manner and are only opened on assembly or disassembly of the distributor chute. The two pivoting connections 8 and 10 and the attachment of rod 34 to the distributor chute 2 can be easy to reach from these holes 110. Furthermore on the blast furnace wall an appropriate recess is provided through which the distributor chute which has been detached from its connections can be introduced or removed in per se known manner with the aid of a crane cross bar.
Whilst the above-described embodiment is preferred it is obvious that further of components of the drive according to the invention are possible.
Thus for example the rotary ring 40 can be replaced by a segment-shaped partial ring whereby the length of said ring must be made such that its rotation within the roller rotary connection 46 is not impaired.
Furthermore it is possible that the drive for endless screws 54, 56 and 58 can be achieved via a chain drive rather than through utilization of axial connections 74, 76 and 78 and angle connections 80 and 82 as shown.
The advantage of the installation according to the invention lies mainly in the simplicity of the basic concept of the control and the construction of the individual components of the installation. The relative movements of the drives for the rotation or pitch angle adjustment of the distributor chute are no longer necessary and their relatively large and complicated gears are replaced by two simple separate drives. In addition, the main components subject to wear are easily accessible and can be replaced without shutting down the furnace for a long time.
In addition cooled and cleaned throat gas or inert gas can be introduced in an effective small amount in the control device of the invention for cooling and cleaning of the gear parts located within the gas-tight casing and which are exposed to the heat and the dust present in the top of the furnace.
While a preferred embodiment has been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.