US3706387A

US3706387A - Blast furnace charging apparatus for high top pressure

Info

Publication number: US3706387A
Application number: US218341A
Authority: US
Inventors: Leo T Tokarz
Original assignee: John Mohr and Sons
Current assignee: John Mohr and Sons
Priority date: 1972-01-17
Filing date: 1972-01-17
Publication date: 1972-12-19
Anticipated expiration: 1989-12-19

Abstract

An improved blast furnace charging apparatus for blast furnaces operating with the high top pressure, the apparatus including a revolving multi-chamber distributor hopper with swing valves to define a gas seal below the distributor hopper and material gates to prevent discharge of material on to the swing valves; the revolving mechanism being removed from any pressurized chamber of the charging apparatus.

Description

United States Patent (151 13 6, Tokarz [451 Dec. 19, 1972 BLAST FURNACE CHARGING [56] References Cited APPARATUS FOR HIGH TO PRESSURE UNITED STATES PATENTS [72] Inventor: Leo T. Tokm, 13419 Greenbay 3,476,374 11/1969 Colijn .;...2l4/37 X Ave. Chicago, L 606127 7 3,482,714 l2/l969 Ogurl et al ..2l4/37 [73] Assignee: John Mohr & Sons, Chicago, [11. Primary Examiner-Robert G. Sheridan [22] Filed: Jam 17, 1972 Attorney-Howard T. Markey et all [21] App]. No.2 218,341 [57] ABSTRACT Related s Application Data an irpproved blast -furnacehclfitrglilngh apparatus for ast urnaces operating wit t e ig top pressure, [63] Contmuano of 1 the apparatus includingarevolving multi-chamber dis- 1969, abandoned tribu tor hopper with swing valves to define a gas seal below the distributor hopper and material gates to 52 US. Cl ..214/37, 266/27 prevent discharge f material on o the swing valves; Int. Cl ..F27b 5/12 the revoking mechanism a removed f any Field of Search "214/35 R, 35 A, 36, 37; 266/27 pressurized chamber of the charging apparatus.

6 Claims, 4 Drawing Figures PMENFEWEB 1 1572 3.706; 387

SHEET 1 BF 2 CZZLIQI, ZQIRI'IJTQ I PATENTED um: 19 I872 SHEET 2 BF 2 Invent)? LQQ Tl Toka a" BLAST FURNACE CHARGING APPARATUS FOR HIGH TOP PRESSURE I CROSS-REFERENCE TO RELATED APPLICATIONS.

tions. The first function of the charging equipment associated with a blast furnace, of course, is to receive the burden materials such as coke, ore, sinter, pellets,

and the like, and to discharge the materials into the furnace proper; It is well known in the art that uniform distribution of the materials within the furnace is critical to assure proper operation in the production -ofiron. Also,-it is essential that the material be deposited into the furnace at a predetermined charging rate to keep the burden in the furnace at the desired level. v If the materials are not uniformly distributed about the furnace area the larger pieces of material may have a tendency to collect along one side to give rise to a condition which is known as channeIing When'thiS condition arises the gases within the furnace will move along a path which has less resistance to their flow to thedischarge stack of the furnace. If this occurs serious temperature problems may arise and, also, the material will not be reduced properly.

Various means. have been employed from time-totime to introduce materials into the furnace in a way that segregation of particles will not occur. Many of these means involve periodically loading materials into a charging hopper at different portions 'of the hopper to assure load-to-load distribution of the materials prior to depositing them into the furnace.

The other main function of the blast furnace charg- I ing apparatus is to prevent the escape of furnace gases. Furnace gases generated during the forming of pig iron in a blast furnace are captured for subsequent use and processing. Any leakage or loss of blast furnace gas not only will result in discharge of pollutantsinto the atmosphere, but also may result in operating and economical problems.

Accordingly, the blast furnace charging apparatus must be appropriately sealed to prevent the unwanted discharge of furnace gas through the charging apparatus.

It has been found in recent years that the efficiency of the blast furnace in terms of production can materially be improved by increasing the gas pressure in the furnace. In some instances the furnaces have been operated such that the top pressure of the furnace is at 15 psi, or higher. Operation pressures higher than 15 psi, with conventional charging equipment presently in use, may result in'excessive gas loss and failure of some parts of the charging apparatus in the system. The escaping gases, of course, are very hot and also have a high content of abrasive dust particles which will cause excessive wear in the area of the leak. In view of these difficulties, it often is difficult to have a furnace operate for substantially long periods where the top pressure is relatively high.

The present invention is directed to the provision of a charging apparatus which is intended to avoid the difficulties inherent in earlier structures. One of themain advantages is to provide a system wherein the rotating parts are removed from direct exposure to the high top pressures in the furnace. It is accordingly a primary object of the present invention to provide an improved blast furnace charging apparatus having a revolving distributor hopper and intended for use in blast furnaces operating with a high top pressure.

Other objects and advantages of the invention reside in the provision of an improved blast furnace charging apparatus for use in blast furnaces operating with high top pressure wherein the rotating parts of the charging apparatus are removed from exposure to the abrasive gases which are under pressure; where the gas seal in the small chamber of the charging apparatus is defined, in part, by aswing check ,valve; where the gas seal valves are protected from direct contact, with materials being charged to the fumace; that iseco'nomical' to manufacture and to use and that is easy to maintain; that may be manufactured from readily formed elements of the structure; and thatis readily adapted for "use in present blast furnace installations.

The novel features which I believe to be characteristic of my invention are set forthwith particularity in the appended claims. My invention itself, however, together with further objects and advantages thereof will best be understood by reference to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a view, partly in section, of the charging apparatus of the present invention illustrating it in assembled relation to the top portion of a blast furnace;

FIG. 2 is a top view of the apparatus of FIG. 1 taken along lines 2-2 of FIG. 1 showing the distributor hopper receiving area of the apparatus;

FIG. 3 is a fragmentary enlarged view of the gear for the distributor hopper and. one of the guide means associated with the gear; and y FIG. 4 is, a view taken along lines 4-4 of FIG. 1 showing the swing check valve area of the blast furnace charging apparatus.

Referring more particularly now tothe drawings the upper portion of a blast furnace is illustrated generally at 10. The blast furnace 10 defines an inner chamber 12 within which the materials are deposited. Take-off ducts l4, 16, 18 and-20 extend from the top portion of the inner chamber 12 of the furnace 10 to carry the furnace gases from the top of the blast furnace to another area for use.

The upper portion 12 of the blast furnace 10 is provided with a top opening 22 within which the first chamber 24 of the charging apparatus is mounted. The

first chamber 24' isstructurally defined by in inverted frusto-conical wall portion 26 secured at its upper terminal 28 to a channel ring 30 which defines theinner periphery of the opening 22 in the furnace top.

The first chamber 24 is further defined by a second frustmconical portion 32 which is secured to and exsecond chamber indicated generally at 34 which is mounted-above and in axially aligned relation with the first chamber 24 of the apparatus. The second chamber 34 is structurally defined by a lower wall portion 36 extending from the upper terminal 33 of the lower chamber wall 32. A second wall portion 38 completes definition of the chamber opening 40 of the second chamber 34. The openings 40, of course, are adapted to receive materials which are to be'charged into the blast furnace l0.

A conventional bell closure system with associated bell rods is provided'to close the bottom openings 27 and 35 of the lower chamber 24 and upper chamber 34,

respectively. A large bell 42 is operatively associated withthe large chamber to close the bottom opening 27 bell 42 and extends axially through the opening of the first chamber 24 and opening 40 of the second chamber 34 to a suitable operating means (not shown). A second rod 48 is secured at one end thereof to the upper terminal of the smaller bell 44 and is telescopicallyreceivedover the rod 46. The second rod 48 extends upwardly to an appropriate rod opening means (not shown). The second, or smaller chamber, 34 is fully sealed against the escape of gas therefrom with the seal being defined by the

chamber walls

36 and 38 on the outer periphery of the chamber 34 and by a downwardly depending flange wall 50 which extends about the bell rods 46 and 48. The wall 50 is joined at its lower periphery by a radially extending portion 52 which extends between the wall 50 and a rod seal element 54. The rod seal element 54 is packed to provide for vertical movement of the bell rods 46 and 48 while preventing escape of gas between the bell rods and the ,member 54.

Thecharging apparatus of the present invention is provided, witha multi chamber distributor hopper indicated generally 58. The hopper 58 is divided into three

chambers

60, 62 and 64, .respectively. Partitions 66 extendbetween the walls of the separate chambers and in spaced relation to the central opening for the bell rods 46 and 48.

In the illustrations specifically set forth herein a conveyor materials loading means is provided and is indicated generally at 68. The materials are deposited on the conveyor at the storage area (not shown) and move along with the conveyor 70 to the discharge chute 72 where they fall off of the conveyor and are deposited in the

materials receiving hoppers

60, 62 and 64, as noted hereinabove. v

The bottom of the

materials receiving hoppers

60, 62 and 64, respectively, are sealed against unintentional discharge of materials from the hoppers by closure members 74. The closure members 74 define a gate like element pivoted on pins 76which elements 74 are moveable in response to the position of a gate operator 78 to open or close the bottom openings of the

material hoppers

60, 62 or 64. Each of the hoppers is provided with a separate gate operator means 78. The gate elements 74 do not define a gas seal but merely prevent discharge of large particles from the hoppers prior to charging sequence when the material is deposited from the hoppers into the small chamber 40 of the blast furnace charging apparatus. r

As shown in FIG. 2 of the drawings, each of the

hop pers

60,62 and 64, respectively, is provided with a pair of discharge openings 80 through which the materials pass from the hoppers into the "small chamber 34. lt should be observed that each of the hoppers could be provided with only one discharge opening to permit materials to pass from the hoppers, or a partition could be defined between the pairs of openings. within each hopper to segment the materials holding means into six separate compartments. None of the above variations in structure would depart from the true. spirit and'scope of this invention. a v

A swing check valve 82 is provided .beloweach of the openings 80 of the charging apparatus as shown in FIGS. 1 and 40f the drawings. The swing check valve 82 is pivotally mounted on a pin 84 and is adapted to swing about said pin. The valve. 82 is adapted to define a gas seal against the depending lip 86 of the channel defined between the

materials receiving hoppers

60, 62 and 64 and the small. chamber 34 of the blast furnace charging apparatus. The channels extending from each of the lips 86 of the charging apparatus are substantially coaxial with the opening 80 of the charging apparatus and define means for directing materials from each of the hoppers noted above into the smaller chamber 34 directly below said openings. The only critical portion in the manufacture of these channels is in the uniform characteristic of the lower terminal lips 86 so that a suitable seal may be defined between the lips 86 and the sealing face of the swing check valve 82.

A valve operating member 88 is provided for each of the swing check valves 82. The valve operator member 88 may be defined by a piston-cylinder means or a solenoid means. Of course, other suitable operating devices may be employed to move the valves 82 between the sealing and opening position thereof. 71A connecting rod extends from the valve operator means 88 to the valve 82 (for each valve) and is adapted to orient the swing check valve 82 in predetermined positions depending upon operation of the control means 88. It can readily be seen that relatively little force will be required to move the valve since it is not a load supporting member and the pressure differential across the valve is not significant in terms of the operating power requirements for moving the valve between the positions.

The operating means specifically illustrated herein involve a crank-arm whereby when the operator 88 is controlled to extend the rod 89 thereof the valve 82 will be moved to its open position, illustrated by thedashed lines 82 in FIG. 1. When the rod 89 is withdrawn the valve member 82 will be repositioned in tight seal. It can readily be seen that small particles might be trapped between the sealing faces of the bell and its mating surface to prevent full closure of the valve against its sealing surface. Accordingly, a small area would be defined through which the furnace gases would pass at a relatively high velocity. The furnace gases, as noted above, are laden with abrasive particles which would cause a rapid erosion of the sealing faces of the bell and quickly destroy the ability of the bell member to define a gas seal.

Distribution of the load within the furnace may be realized through proper operation of the charging apparatus set forth herein. It is to be noted that the

materials receiving hoppers

60, 62 and 64 are mounted on a rotatable table 94 so that materials may alternately be charged tosuccessive hoppers as they are carried along to the charging apparatus by the conveyor belt 70. The table 94 is defined by a ring gear having gear teeth 96 about the outer periphery thereof as shown in the fragmentary enlarged view of FIG. 3.

A table operating means is' illustrated generally at 98 and includes a motor 100, speed reducing means 102 and a pinion gear 104. The output shaft 101 of the motor 100 is drivingly connected to the speed reducing means 102. The output speed of the motor shaft 101 is reduced to a useable level in the means 102. The output shaft 103 of the speed reducing means 102 is directly connected to the pinion gear 104 of the table operating apparatus 98.

When the means 98 is operated the gear 104 will rotate to cause the table 94 to move in accordance with movement of the pinion 104.

Guide rolls and stabilizing means are indicated generally at 106 in FIGS. 1 and .2 of the drawings The guide rolls and stabilizing means 106 are supported on a structure which is rigidly mounted on a suitable sup- 'port member not directly connected to the rotating mechanism of the blast furnace charging apparatus. The guide and stabilizing means 106 includes a first roll 108 mounted above the upper surface of the table 94 and adapted to ride on the upper surface to stabilize the table 94 against vertical upward movement. A second roll 110 is mounted in opposed relation to the roll 108 and is below the table 94 to support and stabilize the table against downward movement. A third roll 112 may be in the form of a flange-like roll havinglegs straddling the gear teeth 96 and riding on an inset shoulder on the table 94 to stabilize the table against radial deflection. The stabilizing and guide means 106 are provided about the periphery of the table to provide the desired support and guide function for the apparatus.

In accordance with usual practice, materials are moved from a storage area to the blast furnace on an irregular basis. The materials are deposited onto the conveyor belt 70 at the storage area and moved along the beltto the discharge chute 72 where they are deposited into the hopper 58. The hopper is intended to provide means for eventual uniform distribution of the materials within the chamber 12 of the blast furnace 10. This function is provided by intermitent rotation of the hopper to position one of the

chambers

60, 62 or 64 beneath the discharge chute 72. The distributor hopper may be rotated through a predetermined angle in either direction. For example, the three chamber hopper specifically illustrated here will require movement through 120 to bring successive chambers beneath the dischargechute 72. It should be noted, however, that materials may be charged to different portions of the individual chambers. For example, loading may begin on one side of the chamber and the table 94 then rotated through 60 to bring the other side of the same veyor 70. As noted he'reinabove, the materials are held in the chamber by the closure members 74. When the gas seal valve 82 is opened the closure members 74 will be withdrawn and the materials within the selected chamber will drop past the closure members 74 and swing check valve 82 into the chamber 34. By varying the position of the hopper upon discharge of materials, the materials may be-distributed relatively uniformly in the small chamber 34 of the blast furnace charging apparatus. This will assure proper distribution of the ore, limestone and coke with the chamber as well as assuring relatively uniform distribution of particle .size within the chamber. This distribution will be maintained when the materials are dropped from the small bell chamber 34 into the large bell chamber 24.

It is well known in the art that materials are moved from the small bell chamber to the large bell chamber by dropping the small bell 44 and permitting the materials to pass through the small bell opening 25 into the large bell chamber 24. As also is known in the art, the large chamber is intended to hold several times the amount of material that the small bell chamber can hold. When the large bell chamber 24 is loaded, the large bell 42 will be lowered to the position shown in the dashed lines 42' of FIG. 1 and the materials in large bell chamber will drop into the upper portion-12 of the blast furnace 10.

Indexing of the rotating charging means of the blast charging apparatus disclosed herein may be realized by any suitable blast furnace charging mechanism known in the art. For example, the rotary stepping switch mechanism may be employed and will be operatively associated with the blast furnace charging program control and indicating system to open and close the proper valves and material gates in the desired sequence.

The apparatus set forth herein provides that all rotating mechanisms are disposed and mounted wholly outside of pressurized chambers. The advantage of this structure is that gas sealing problems are minimized and abrasive and corrosive wear of rotating members will be avoided by removing them from exposure to such a medium. Also, the rotating members are available for relatively easy maintenance in the event of failure or disruption of control.

The sequence of operation and of pressurization of the large and small chambers of the charging apparatus depends upon the desired charging mode employed in use of the blast furnace, many of which are known to those skilled in the art. In the furnace charging system set forth herein, for example, the upper chamber may be kept pressurized at all times except for the period of again in gas sealing position, the chamber may be presbell chamber to'thefurnace.

- Because of this unique rotating charging means described above, the small bell hopper has a reduced volume relative to similar hoppers associated with conventionalcharging'means. With thisreduced volume a reduction in height is obtained so that the materials charged do not drop as great a distance, as with conventional systems, thereby minimizing segregation of the charged materials. The reduced size of the small bell hopper allows pressurization with a lesser amount of gas and in less time than the hoppers associated with conventional charging means. i

While I have shown and described aspecific embodiment of the present invention it will, of course, be un' derstood that other modifications and alternative constructions may beused without departing from the true spirit and scope of this invention. l therefor intend by the appended claims to cover all such modifications and alternative constructions as fallwithin their true spirit and scope.

lclaim:

1. An improved blast furnace charging apparatus for blast furnaces operated with high top pressure and having a rotating multi-compartmerit distributor hopper associated therewith, said apparatus comprising:

at least one charging chamber adapted to temporarily hold materials prior to charging said materials to the blast furnace, said chargingchamber having top openings to receive materials;

valve means associated with said chamber to seal the top openings and prevent the escape of gases from said chamber during one period of operation of the charging apparatus, said valve means being open during another period of operation of the charging apparatus to permit passage of materials through said openings; and

said distributor hopper being mounted above said chamber, said hopper having a plurality of hopper chambers, said hopper chambers each having at least one opening registerable with said top opening sealed by said valve means when the hopper is in a predetermined position, said hopper chambers each having a materials holding gate disposed over said openings, respectively, to. prevent uninten-' tional passage of materials through the hopper chamber opening, said valve means being opened prior to openingof the materials holding gate so that the materials do not rest upon or move against the plate during operation ofthe apparatus thereby protecting the valve means.

2. The blast furnace charging apparatus of claim 1 the path of movement of materials from the distributor hopper to the charging chamber to prevent abrasive wear of said valve by movement of materials thereover and less degrading of burden materials by impact.

3. The blast furnace charging apparatus of claim 1 wherein the valve means is adapted to seat against a de-' pending flange associated with the apparatus, said flangebeing disposed downwardly andaway from the path of movement of materials through the top opening of charging chamber to protect it from abrasive wear during use of the apparatus;

4. The blast furnace charging apparatus of claim 1 wherein the distributor hopper is rotatable through a predetermined angle in either direction to position any desired hopper chamber and associated opening over one of the top openings of the charging chamber of the apparatus to provide means for uniform distribution of materials within the charging chamber.

5. The blast furnace charging apparatus of claim 1 wherein the holding gates are defined by pivotable cuplike elements'adapted to prevent passage of materials from the hopper chambers in the closed position and to permit discharge of materials when they are pivoted to an open position, said cupdike members of the holding gate further adapted to move said materials inwardly of

Claims

1. An improved blast furnace charging apparatus for blast furnaces operated with high top pressure and having a rotating multi-compartment distributor hopper associated therewith, said apparatus comprising: at least one charging chamber adapted to temporarily hold materials prior to charging said materials to the blast furnace, said charging chamber having top openings to receive materials; valve means associated with said chamber to seal the top openings and prevent the escape of gases from said chamber during one period of operation of the charging apparatus, said valve means being open during another period of operation of the charging apparatus to permit passage of materials through said openings; and said distributor hopper being mounted above said chamber, said hopper having a plurality of hopper chambers, said hopper chambers each having at least one opening registerable with said top opening sealed by said valve means when the hopper is in a predetermined position, said hopper chambers each having a materials holding gate disposed over said openings, respectively, to prevent unintentional passage of materials through the hopper chamber opening, said valve means being opened prior to opening of the materials holding gate so that the materials do not rest upon or move against the plate during operation of the apparatus thereby protecting the valve Means.

2. The blast furnace charging apparatus of claim 1 wherein the valve of the valve means, when open, moves into a recess in said one charging chamber out of the path of movement of materials from the distributor hopper to the charging chamber to prevent abrasive wear of said valve by movement of materials thereover and less degrading of burden materials by impact.

3. The blast furnace charging apparatus of claim 1 wherein the valve means is adapted to seat against a depending flange associated with the apparatus, said flange being disposed downwardly and away from the path of movement of materials through the top opening of charging chamber to protect it from abrasive wear during use of the apparatus.

5. The blast furnace charging apparatus of claim 1 wherein the holding gates are defined by pivotable cup-like elements adapted to prevent passage of materials from the hopper chambers in the closed position and to permit discharge of materials when they are pivoted to an open position, said cup-like members of the holding gate further adapted to move said materials inwardly of the materials passage to avoid unnecessary abrasive contact of the materials with any portion of the valve means during passage of said materials from the distributor hopper to said charging chamber.

6. The blast furnace charging apparatus of claim 1 wherein the multi-compartment distribution hopper is capable of receiving materials from a conveyor or other means and at the same time discharging materials from another compartment into the smaller bell chamber, thereby decreasing the load distributing cycle time.