US3921831A

US3921831A - Device for distributing raw materials into blast furnace

Info

Publication number: US3921831A
Application number: US451672A
Authority: US
Inventors: Masaoki Takahashi; Makoto Nishinomiya
Original assignee: IHI Corp
Current assignee: IHI Corp
Priority date: 1973-10-12
Filing date: 1974-03-15
Publication date: 1975-11-25
Anticipated expiration: 1992-11-25
Also published as: FR2283227A1; GB1481002A; FR2283227B1; JPS5222802B2; JPS5065405A; DE2418371B2; DE2418371A1; DE2418371C3

Abstract

A device for charging and distributing raw materials into a blast furnace is disclosed in which a distribution chute suspended from a rotary chute is adapted to rotate in unison with the rotary chute and to be tilted when a control rod extending through the rotary chute is vertically lifted or lowered. The pattern of distribution of raw materials may be arbitarily varied.

Description

United States Patent Takahashi et a1.

[451 Nov. 25, 1975 DEVICE FOR DISTRIBUTING RAW MATERIALS INTO BLAST FURNACE Inventors: Masaoki Takahashi; Makoto Nishinomiya. both of Yokohama,

Japan Assignee: Ishikawajima-I-Iarima Jukogyo Kabushiki Kaisha, Tokyo, Japan Filed: Mar. 15, 1974 Appl. No; 451,672

Foreign Application Priority Data Oct. 12,1973 Japan 48-114575 U.S.CI. ..2I4/35 R; 193/16;214/17 CB;

222/410 Int. Cl. 866C I7/08 Field of Search........ 222/410, 533', 193/16, 17

193/18, 19, 20, 21, 22, 23; 214/17 CB, 17.64, 35 R, 18 V [56] References Cited UNITED STATES PATENTS 619.128 2/1899 Bradford 193/16 1682.394 8/1972 Shivvers 4. 214/17 CB $693,812 9/1972 Mahr et a1. .4 214/17 CB Primary Examiner-Robert Br Reeves Assistant E.raminer-Hadd Lane Attorney Agenl. or Firm-Scrivener Parker Scrivener & Clarke [57] ABSTRACT A device for charging and distributing raw materials into a blast furnace is disclosed in which a distribution chute suspended from a rotary chute is adapted to rotate in unison with the rotary chute and to be tilted when a control rod extending through the rotary chute is vertically lifted or lowered. The pattern of distribu tion of raw materials may be arbitarily varied.

3 Claims, 6 Drawing Figures US. Patent Nov. 25, 1975 Sheet 1 of5 3,921,831

U.S. Patent Nov. 25, 1975 Sheet 2 of5 3,921,831

US. Patent Nov. 25, 1975 Sheet30f5 3,921,831

US. Patent Nov. 25, 1975 Sheet4 0f5 3,921,831

US. Patent Nov. 25, 1975 Sheet 5 of5 3,921,831

DEVICE FOR DISTRIBUTING RAW MATERIALS INTO BLAST FURNACE DETAILED DESCRIPTION OF THE INVENTION terial on the surface of stock line of the blast furnace. l

2. It must charge the materials of any quantity at any spot on the surface of stock line of the blast furnace. (flow rate controllability) 3. It must distribute the raw materials over the wide range in the stock line area.

4. It must charge the raw materials in such a way that the particle distribution on the stock line surface may be uniform.

5. A mechanism for driving the charging device must be such that it may be inspected at any time in a simple manner.

6. The inspection and replacement of parts of consumption must be made in a simple manner.

In order to overcome the defects and problems encountered in the conventional devices for charging the materials into the blast furnace. there have been devised and demonstrated various devices. For instance, there has been proposed a device which eliminates a bell. An inclined tray is rotatably supported at the top of the blast furnace, and a lip for distributing the raw materials is pivotably fixed to the lower end of the inclined tray. A push rod extended through the inclined tray vertically thereof is coupled to the lip with a pin so that when the push rod is vertically moved. the angle of the lip with respect to the axis of the blast furnace may be varied. Therefore. the raw materials may be distributed over the stock level radially of the axis of the blast furnace as the angle of the lip may be varied while the inclined tray is rotated.

However. the device of the type described following distinct defects:

a. Since the lip is fixed to the lower end of the inclined tray. the distribution of raw materials radially inwardly of the lip is limited. That is, the charging of raw materials at the center and the portion adjacent to the center of the furnace cannot be made.

b. Since the angle of the lip is varied by the push rod extending along the axis of the furnace, the push rod and its associated parts are located outside of the inclined tray. That is. they are exposed to the high temperature gases in the blast furnace. Since the temperature of the blast gases reaches 600-700C. the push rod and its associated parts are subjected to the very severe thermal conditions for a long time, thus resulting in the breakdowns.

c. The replacement of the worn lip involves the work within the furnace filled with poisonous furnace gases so that the replacement operation is very hazardous and the efficiency is very poor.

(I. Since the rotary member is very large in size, great power is required.

One of the objects of the present invention is therefore to provide a device for charging and distributing the stock or raw materials through a top into a blast furnace which device may completely eliminate the above and other defects encountered in the conventional devices.

has the The present invention will become more apparent from the following description of one preferred embodiment thereof taken in conjunction with the accompanying drawing in which:

FIG. I is a schematic view ofa conventional bell type device for charging the raw materials through a top into a blast furnace;

FIG. 2 is a sectional view of a device for charging the raw materials into a blast furnace. the charging device incorporating a raw material distributing device in accord with the present invention;

FIG. 3 is a sectional view taken along the line III of FIG. 2;

FIG. 4 is a view of an arrangement for controlling the vertical movement of a flow-rate control cone;

FIG. 5 is a perspective view of the raw material distributing device in accord with the present invention;

FIGS. 6(A) and 6(B) are views used for the explanation of the mode of operation of the conventional raw material distributing device; and

FIG. 6(C) is a sectional view looking in the direction indicated by 6(C) in FIG. 6(A).

Prior to the description of the preferred embodiment of the present invention, the prior art stock charging device will be described briefly with reference to FIG. I in order to point out its defects, which the present invention contemplates to overcome.

At the top of a stock level a is disposed a conical bell b which also functions as a distributor and makes up a bell hopper with a bell cup c. The raw materials stocked in the hopper is charged onto the stock level a when the bell b is opened downwardly.

Since the raw materials are distributed along the outer periphery of the bell b, they always from a conical pile of the same diameter in the stock portion. Furthermore. the prior art device has the defects that it cannot distribute the raw materials selectively in the circumferential and radial directions and that the quantity of raw materials to be charged and distributed into the blast furnace cannot be arbitarily controlled because no means for controlling the quantity of the raw materials is provided. Some blast furnaces are provided with a raw material distributing device d in order to overcome the above problems. However, the range over which are distributed the raw materials is limited so that even when the above auxiliary distributing devices are provided, the distribution of raw materials cannot be controlled in a satisfactory manner. Furthermore, because of the provision of the auxiliary distribution devices the installation costs of the blast furnaces are increased. Furthermore the maintenance becomes more complex and expensive.

Referring to FIGS. 3 and 5 which pertain to the present invention, a pair of vertical partition walls 3 have their side edges securely fixed to the inner wall of a main body ofa cylindrical rotary chute 2 symmetrically about the axis of the main body 2. A cover 4 is fixed to the upper edges of the pair of partition walls 3. Therefore. a chamber or space 5 is defined by the pair of par' tition walls 3, the inner wall of the cylindrical main body 2 and the cover 4, and no raw material passes through this space 5. The raw material passages difmed between the pair of partition walls 3 and the inner surface of the cylindrical main body 2 are substantially semi-circular in cross section as best shown in FIG. 3 and are lined with

liners

6 and 7 made of abrasive wear resisting material. An inverted U-shaped opening 8 is formed through the cylindrical main body 2 at one end of the space 5. The lower end of a rotary rod 9 is securely fixed to the cover 4.

A rotary chute I with the above construction is located coaxially of the blast furnace within a gas seal mantel 12 which in turn is joined to a top ring 11 at the top of a gas collection mantel I of the blast furnace. The hollow rotary rod 9 is securely fixed to the cover 4 of the rotary chute 1 so that the latter is rotated about the axis of the blast furnace. Around the outer surface of the cylindrical main body 2 is formed a guide track 13 into which is fitted a track 14 supported by a plurality of side rollers 15 disposed on the gas seal mantel so that the deviation of the rotary chute I during its rotation may be prevented.

A distribution chute I8 is detachably fixed to a U- shaped distribution chute support member 16 which is pivoted with pivot 17 to the lower outer side surface of the cylindrical main body 2 so that the angle of the distribution chute 18 with respect to the axis of the furnace may be varied.

The distribution chute 18 substantially U-shaped in cross section is lined with a liner [9 made of abrasive wear resisting material. A pair of brackets 20 are extended from the upper inner surface of the distribution chute I8 within a pair of partition walls 21. A plurality of lugs 22 are extended outwardly from the outer surface of the distribution chute l8 and engaged with the support member 16 with bolts and nuts 23 so that the distribution chute 18 may be securely held by the support member 16. The raw materials dropped through the raw material passages of the rotary chute 1 into the distribution chute I8 may flow therethrough to be charged into and distributed in the furnace.

One end of a link 25 is rotatably fixed to the brackets 20 with a shaft 24 and the other end is detachably pivoted to the lower end of a control rod 26 extending through the hollow rotary rod 9 and the cover 4 into the space 5. Therefore, in response to the vertical movement of the control rod 26, the support member 16 and hence the distribution chute 18 may be swung about the pivot pins 17. Furthermore, when the rotary rod 9 is rotated, the rotary chute l is rotated so that the distribution chute I8 may be also rotated about the axis of the furnace. The open bottom of the space 5 is covered by the distribution chute 18 which functions as a shield plate. In order to prevent the upward deflection of the distribution chute 18 by the furnace gases, projections 28 are extended from the inner side edges of the distribution chute 18. The projections 28 also serve as a guides when the distribution chute 18 is to be fixed to or detached from the support member 16. The connection between the lower end of the control rod 26 and the other end of the link 25 may be disconnected within the space 5 in the rotary chute 1. When the distribution chute 18 is detached from the support member 16, they may be removed outside of the furnace in a simple manner through an opening formed through the gas seal mantel 12.

A fixed or stationary chute 31 in communication with a plurality of air-tight hoppers is installed above the gas seal mantel l2 eccentrically of the axis of the furnace. The rotary rod 9 is extended upwardly through a cover 32 of the stationary chute 31, and a gear 33 fixed at the upper end of the rotary rod 9 is in mesh with an idle gear 36 in mesh with a pinion drivingly coupled to a hydraulic motor (not shown) so that the rotary rod 9 may be rotated by the hydraulic motor. The gear 33 carried by the rotary rod 9 is supported by a rotary 4 bearing 34 which in turn is fixed upon the chute cover 32.

The upper end of the control rod 26 extending through the hollow rotary rod 9 is rotatably supported by a bearing 37 which in turn is fixed to the hopper 33. The bearing 37 is coupled to a driving device such as a hydraulic cylinder 38 installed upon the hopper 30 so that the control rod 26 may be vertically moved within the hollow rotary rod 9 by the hydraulic cylinder 38.

Seal means 39 and 40 are interposed between the hollow rotary rod 9 and the control rod 26 and between the former and the chute cover 32 to provide the gastightness.

In an opening 41 of the fixed or stationary chute 31 immediately above the rotary chute l is disposed a flow-rate control cone 42 so as to be vertically movable coaxially of the axis of the furnace. The control cone 42 is vertically moved so as to control the space between the cone 42 and the opening 41 of the stationary chute 31 so that the flow rate of raw materials charged into the rotary chute 1 may be controlled.

Referring to FIG. 4, a hollow elevation rod 43 fixed to the flow-rate control cone 42 coaxially thereof is operatively coupled through

horizontal rods

44 and 44 to vertical rods 45 and 45'. The rod 45 is coupled to a hydraulic cylinder 46 installed outside of the furnace so that the vertical movement of the flow-rate control cone 42 may be controlled by the hydraulic cylinder 46.

Referring to FIG. 2, the elevating rod 43 is surrounded by a shielding 47 to prevent the rod from being directly exposed to the raw materials. A bushing 48 is interposed between the rotary rod 9 and the control rod 26 to permit the latter to move vertically within the hollow rotary rod 9 and to prevent rotation of the rod 26 within the rod 9.

Reference numeral 49 designates a level of stock of raw materials.

After the control rod 26 is disconnected from the link 25 and is drawn out of the hollow rotary rod 9, a joint 50 of the two sections of the rotary rod 9 may be disconnected so that the rotary chute may be removed out of the furnace through the manhole 29.

The inclined surface of the stationary chute 31 is lined with a liner 5! made of abrasive wear resisting material.

A gas seal valve 52 at the bottom of the hopper 30 not only functions as an on-off valve for charging the raw materials into the stationary chute 31 but also serves as a valve for gas-tightly sealing the chute 31. A valve stem 53 extending through a rod seal 55 and wearing 56 and the chute 31 has its upper end fixed to the gas seal valve 52 and its lower end fixed to a hydraulic cylinder 54 so that the valve 52 may be vertically raised or lowered, thereby closing or opening the bottom of the hopper 30. An annular seat ring is attached to the bottom opening of a hopper cone 57. A rubber packing 59 is attached to the seat ring 58, which is detachably attached to the hopper cone 57. The stationary hopper 30 is lined with a liner made of abrasive wear resisting material. A gas seal valve 61 (See FIG. 4) is disposed at the upper opening of the hopper 30. The hopper 30 and the stationary chute 31 are interconnected through an air-tight connection member provided with a manhole for inspection and replacement of the gas seal cone valve 52, the seat ring 58 and the rubber packing 59. The connection member 62 also serves as a heat insulating member which prevents the adverse effect of the high temperature furnace gases upon the rubber packing 59 when the flow-rate control cone 42 is closed completely.

Next the mode of operation will be described hereinafter. When the driving device (not shown) is driven, the rotary rod 9 is rotated through the pinion 35, the idle gear 36 and the gear 33 so that the rotary chute 1 is also rotated. Therefore the distribution chute 18 is also rotated about the axis of the furnace in unison with the rotary chute 1. The rotation of the distribution chute 18 is transmitted to the control rod 26 through the link 25, but since the upper end of the control rod 26 is rotatably supported by the bearing 37, the smooth rotation of the control rod 26 may be ensured.

When the control rod 26 is vertically lifted or lowered by the hydraulic cylinder 38, the distribution chute 18 is caused to swing about the pivot pins 17 because the lower end of the control rod 26 is connected through the link 25 to the brackets of the distribution chute 18. As a result the angle of the distribution chute 18 with respect to the axis of the shaft may be varied. More particularly when the control rod 26 is lifted, the right end of the distribution chute 18 is lifted by the link so that the support member 16 is caused to swing about the pivot pins 17 in the clockwise direction in FIG. 2. Therefore the distribution chute 18 is inclined in the direction indicated by the arrow x. When the control rod 26 is lowered, the support member 16 is caused to swing in the counterclockwise direction so that the distribution chute 18 is inclined in the direction indicated by the arrow y in FIG. 2. Since the opening 8 is formed through the cylindrical main body 2 of the rotary chute 1, the link 25, the partition plates 21 and the brackets 20 may be freely displaced in this opening 8.

The tilting and rotation of the distribution chute 18 may be simultaneously or individually made in the manner described above so that the lower end that is the discharge end of the distribution chute 18 may be displaced radially and circumferentially above the stock level area 49.

The raw materials to be charged into the blast furnace are led from the hopper through the stationary chute 31 and the flow-rate control cone 42 into the rotary chute l. The raw materials are led through the semicircular passages of the rotary chute 1 into the distribution chute 18, from which the raw materials are distributed on the stock level surface depending upon the rotation and inclination of the distribution chute 18.

When the angle of inclination of the distribution chute 18 is fixed while it is rotated about the axis of the furnace, the raw materials are piled in the form ofa circle spaced apart from the axis of the furnace by the same radius. It will be readily understood that the radius of the ring of pile of raw materials may be selectable by varying the angle of inclination of the distribution chute 18. When the opening of the flow-rate control cone 42 is maintained constant, the height of the circle shaped pile of raw materials is substantially same, but when the opening of the flow-rate control cone is varied, the height may be of course varied.

When the angle of inclination of the distribution chute 18 is varied while it is rotated, the raw materials may be piled or distributed in the form of a helix. When the rate ofchange in angle of inclination of the distribution chute 18 is slow and the opening of the flow-rate control cone 42 is suitably controlled, the raw materials may be flatly distributed on the stock level area 49. That is, the distribution device in accord with the present invention may accomplish the so-called flat chargmg.

When the distribution chute 18 is inclined or swung while the rotation thereof is stopped, the raw materials may be distributed radially along a straight line from the axis of the furnace. When the rotation of the distribution chute 18 is stopped at one point of a circle and the angle of inclination of the distribution chute 18 is suitably selected, the raw materials may be charged at any desired spot on the stock level area 49. That is. the spot charging is possible.

The raw materials are prevented from passing through the space 5 in the rotary chute l, the connection between the lower end of the control rod 26 and the upper end of the link 25 is not directly exposed to the raw materials so that the abrasive wear may be prevented. Furthermore, the raw materials falling onto the distribution chute 18 through the raw material passages in the rotary chute 1 are prevented from intruding into the joint between the lower end of the link 25 and the brackets 20 by the pair of partition members 21 so that the damage to the connection may be also prevented. The distribution chute 18 is normally maintained at an angle relative to the axis of the blast furnace when the raw materials are distributed, and it is very rare that the distribution chute 18 is held vertically. Therefore, unless the distribution chute is held vertically, it serves as a shield to the space 5 within the rotary chute 1 so that the link 25 and its joint to the lower end of the control rod 26 may be prevented from being directly exposed to the high temperature furnace gases.

The charging of raw materials into the hopper 30 is carried out according to a predetermined schedule. That is, the gas seal valve 61 (See FIG. 4) is wide opened at a predetermined time so that the raw materials lifted up to the top of the blast furnace by a belt conveyor or skip may be charged into the hopper 30. While the raw materials are being charged, the gas seal valve 61 is retracted away from the falling path of the raw materials so that the abrasive wear of the gas seal valve 61 may be prevented. After the raw materials are charged into the hopper 30, the gas seal valve 61 is completely closed, and the pressure in the hopper 30 is raised to a predetermined level by a pressure equalizing device (not shown). Thereafter the gas seal cone valve 52 is wide opened so that the raw materials in the hopper 30 drops into the stationary chute 31 and are piled upon the flow-rate control cone 42.

The reason why the flow-control cone 42 must be disposed in the bottom opening 41 of the stationary chute 31 and the mode of operation thereof will be described in more detail hereinafter. When the distribution chute 18 is not only rotated but also inclined when the raw materials are charged, the discharging lower end of the distribution chute 18 draws a helical locus. When the rotational speed of the distribution chute 18 is maintained constant and the raw materials fall through the rotary chute l at a constant flow rate, the quantity of raw materials piled per unit length is different widely between the portion adjacent to the shell of the furnace and the portion close to the axis of the furnace. That is, the closer the pile of raw materials is to the axis of the furnace, the higher the pile becomes so that the height of the pile is not uniform. The density. particle size, viscosity, the shapes and so on are widely different from iron ores and coke so that the pattern of pile is different between the iron ores and coke. Furthermore, various types of iron ores such as pellets. sintcred ores and unprocessed ores are used. and the ratio of mixture thereof is different. Therefore, the pattern of pile of raw materials different from one stock charge to another if the flow-rate control cone is not provided. Thus. it is required to control the flow rate of the raw materials charged into the furnace depending upon the types, kinds. particle sizes. mixing ratios and so on of the raw materials.

In order to control the flow-rate of the raw materials. there has been proposed a method shown in FIG. 6. A cut gate 102 is disposed at the discharge port at the bottom of a hopper 101 so as to control the flow rate of raw materials to be charged into the furnace. However. the raw materials discharged from one hopper 101 drops in a raw material guide 104 along the inner wall 103 opposite to the hopper 101 as shown in FIG. 6(C). Therefore. the cross sectional area of the raw materials falling down the guide 104 is less than one third of the cross sectional area of the guide 104. As a result, as shown in FIGS. 6(A) and 6(8) the distance over which the raw materials slide in the distribution chute 105 changes. That is. when the distribution chute 105 is in the position shown in FIG. 6(A). the distance L is longer than the distance L when the distribution chute 105 is located in the position shown in FIG. 6(B). It is well known in the art that the distance over which the raw materials slide in the distribution chute 105 has a considerable effect upon the distance R, or R between the axis of the blast furnace and the position where the raw materials drop. Therefore, the pile of raw materials is not a true circle. This tendency is inherent to each hopper. In general the raw material charging device is provided with two hoppers as shown in FIG. 6, and coke is stored in one hopper while iron ores are stored in the other hopper. As a result they cannot be distributed in the same pattern at all so that the furnace operation is adversely affected.

Since the raw materials enters into the guide I04 from the portion away from the axis thereof and they have the velocity in one direction at the inlet port of the guide 104, the raw materials flow in the guide 104 eccentrically thereof. This problem cannot be overcome even when the opening degree of the cut gate 102 is controlled. This is the reason why the flow-rate control cone 42 is disposed in the bottom opening 41 of the stationary chute 31. Therefore, the velocity of the raw materials discharged onto the flow-rate control cone 42 from the hopper 30 which is installed eccentrically of the axis of the blast furnace. becomes zero so that the effect of the velocity of the raw materials may be eliminated. In order to take the full advantage of the flowrate control cone. it is preferable to open the cone 42 after the raw materials have been completely piled upon the cone 42.

It should be understood that the position of the flowrate control cone 42 with respect to the bottom opening 41 of the stationary chute 31 may be arbitarily selected because of the reason described above. For instance. the cone 42 is so disposed as to move away from the opening 41 downwardly or to pass through the opening vertically.

To open or close the flow-rate control cone 42, the hydraulic cylinder 46 is actuated to vertically move the flow-rate control cone 42 through

levers

44 and 44 and the elevating rod 43 so as to vary the spacing between the opening 41 and the cone 42, thereby control- 8 ling the flow-rate of raw materials charged into the rotary chute I.

Next the method for replacing the distribution chute I8 and the rotary chute I will be described hereinafter. First the control rod 26 is lifted so that the distribution chute I8 is held upright as indicated by the tow-dot lines in FIG. 2. Thereafter, the operators disconnect the joint that is, the bolts and nuts 23 between the distribution chute l8 and its support member 16 through the manhole 29. The control rod 26 is lowered so that the distribution chute 18 may be held in the position indicated by the solid lines in FIG. 2, and the support member 16 is fixed to the distribution chute I or gas seal mantel 12. Next the joint between the lower end of the control rod 26 and the line 25 is released. Then. the distribution chute 18 may be removed out of the blast furnace through the manhole 29 as indicated by the imaginary lines in FIG. 2. In this case, the support member 16 serves as a guide. In order to mount a new distribution chute. the above steps may be reversed. Thus. according to the present invention, the replacement of the distribution chute 18 may be carried out from the outside of the blast furnace. The replacement of the link 25 may be carried out in manner substantially similar to that described above.

To replace the rotary chute 1, the distribution chute 18 must be removed out of the furnace in the manner described above. Thereafter the control rod 26 is lifted until a link eye 27 is lifted slightly above the joint of the hollow rotary rod 9. Next the support member 16 is held upright as indicated by the imaginary lines in FIG. 2 and is fixed to the rotary chute l with bolts and nuts. Thereafter, a rotary chute support beam is inserted into the gas seal mantel 12 through the manhole 29 to support the rotary chute l and the support member 16 while the joint 50 of the rotary rod 9 is released. Then, the rotary chute 1 may be removed out of the blast furnace along the support beam through the manhole 29. To mount a new rotary chute 1, the above steps are reversed. Thus. the replacement of the rotary distribution chute I may be also accomplished from the outside of the blast furnace.

According to the present invention, the function of the rotary chute l is to guide the raw materials when they are dropped onto the distribution chute so that the diameter of the rotary distribution chute I may be small. As a result. the diameter of the gas seal mantel may be made small so that the replacement of the rotary and distribution chutes l and 18 may be accomplished in the manners described above through the manhole 29 of the gas seal mantel 12.

The above description is merely an illustration of the preferred embodiment of the present invention. It is therefore to be understood that various modifications can be effected without departing from the true spirit of the present invention. For instance. instead of supporting the gear 33 by the rotary bearing 34, any other suitable means may be used as far as the smooth rotation of the rotary chute 1. Instead of supporting the rotary chute l and the support member 16 by the bearing 34. a plurality of supporting rollers may be disposed within the gas seal mantel 12 so as to support the distribution chute 18, the support member 16, and the rotary chute 1 so that the rotary bearing 34 may not support them but may support only the rotary rod. The joint of the rotary rod 9 may be a spline joint so that the two sections of the rotary rod 9 may be rotated in unison in the same direction and that they may be released from each other in the vertical direction in a simple manner. Therefore. the disassembly of the rotary rod 9 may be much facilitated when the rotary chute 1 must be replaced. Furthermore. instead of a load cell. a plurality of photoelectric cells (not shown) may be positioned in suitably spaced apart relation in the vertical direction within the hopper 30 so that the volume of raw materials charged into the hopper 30 may be detected. Moreover, in response to the signals from the photoelectric cells, the interlocked control of the gas seal valves 6] and the gas seal valve 52 may be effected. Therefore. the damages to the valve seats by the raw materials may be prevented. Furthermore. the complex construction using the elastic pipe or pipes when the load cell is used may be much simplified. be cause the elastic pipe or pipes may be eliminated. It is also possible to extend the elevating rod 43 of the flowrate control cone 42 coaxially of the axis of the furnace through the stationary chute cover 32 and to connect it to a hydraulic cylinder installed outside of the blast furnace. In this case, rod seal means are interposed between the stationary chute over 32 and the extended elevating rod 43 and between the rod 43 and the hollow rotary rod 9.

The important features and advantages of the present invention may be summarized as follows: I. The raw material distribution pattern may be varied arbitrarily. and the raw materials may be charged at any place between the axis of the blast furnace and the shell. ll. The lower end of the control rod is disposed within the space in the rotary chute which will not permit the passage of raw materials so that the lower end is prevented from being damaged by the raw materials. Ill. The number of parts disposed within the blast furnace is very few. That is, only the joints and rods are disposed in the furnace. Therefore, the operation in the high temperature furnace gases reaching higher than 600C is very reliable. Furthermore. the joints are so disposed as to be prevented from being directly exposed to and damaged by the raw materials. I

10 W. It is not necessary to provide a special shield plate to protect the rods and their joints from the high temperature furnace gases because the distribution chute itself serves as a shield plate. Therefore, their service life may be increased. V. The joint between the lower end of the control rod and the link is disposed within the space in the rotary chute so that it may be prevented from being damaged by the raw materials. Furthermore. the joint is releasable so that the control rod may be disconnected from the line in a simple manner. VI. The distribution chute may be removed out of the furnace and the joint is releasable as described in (V) so that the replacement of the distribution chute may be carried out easily and safely.

What is claimed is:

l. A spreader assembly for distributing raw material into the top of a blast furnace having a fixed distribution chute. comprising a rotary. cylindrical chute into which the raw material is introduced from said fixed chute. a pair of vertical partition walls disposed within the rotary chute, the side edges of the walls being fixed to the inner wall of said chute. a cover fixed to the upper edges of the pair of partition walls. said partition walls and cover defining a chamber, raw material passages defined between the pair of partition walls and the inner surface of the cylindrical chute. a distribution chute positioned below said passages. a control rod extending into said chamber and supporting said distribution chute. means in said chamber connected to said rod to control tilting and rotary movement of the distribution chute. and means to cause said control rod. distribution chute and cylindrical chute to rotate as a unit.

2. A device as defined in claim 1 wherein said distribution chute may be removed from the furnace and may be mounted again within the furnace.

3. A spreader assembly as called for in claim 1 comprising. in addition, a hopper disposed between said fixed distribution chute and said rotary chute and means to control the flow-rate of the raw materials into the rotary chute.

Claims

1. A spreader assembly for distributing raw material into the top of a blast furnace having a fixed distribution chute, comprising a rotary, cylindrical chute into which the raw material is introduced from said fixed chute, a pair of vertical partition walls disposed within the rotary chute, the side edges of the walls being fixed to the inner wall of said chute, a cover fixed to the upper edges of the pair of partition walls, said partition walls and cover defining a chamber, raw material passages defined between the pair of partition walls and the inner surface of the cylindrical chute, a distribution chute positioned below said passages, a control rod extending into said chamber and supporting said distribution chute, means in said chamber connected to said rod to control tilting and rotary movement of the distribution chute, and means to cause said control rod, distribution chute and cylindrical chute to rotate as a unit.

3. A spreader assembly as called for in claim 1 comprising, in addition, a hopper disposed between said fixed distribution chute and said rotary chute and means to control the flow-rate of the raw materials into the rotary chute.