US3302805A

US3302805A - Materials distributor of a blast furnace

Info

Publication number: US3302805A
Application number: US400827A
Authority: US
Inventors: Tsutsumi Teruo
Original assignee: IHI Corp
Current assignee: IHI Corp
Priority date: 1963-12-14
Filing date: 1964-10-01
Publication date: 1967-02-07
Anticipated expiration: 1984-02-07
Also published as: DE1433322C3; DE1433322A1

Description

Fell 1967 TERUO TSUTSUMI 3,302,805

MATERIALS DISTRIBUTOR OF A BLAST FURNACE Filed on. 1, 1964 v Sheets-Sheet 1 FBG. I

PRIOR ART INVENTOR- TERUO TSUTSUMI ATTORNEYS Feb, 7, 1967 Filed Oct. 1, 1964 BELL OPENINGS (SMALL BELL) (LARGE BELL) P-Po (TOP-PRESSURE ATMOSPHERE P (PRESSURE DIFFERENCE) ,0

TERUO TSUT5UMI MATERIALS DISTRIBUTOR OF A BLAST FURNACE 7 Sheets-Sheet 2 m 1 INPUT CYCLE INVENTOR.

TERUO TSUTSUMI WMWMi ATTORNEYS 1967 TERUO TSUTSUMI 3,302,805

MATERIALS DISTRIBUTOR OF A BLAST FURNACE Filed Oct. 1, 1964 '7 Sheets-Sheet 5 Feb, 7, 39%? Filed Oct. 1, 1964 BELL OPENINGS SMALL BELL MIDDLE BELL LARGE BELL TERUO TSUTSUM! MATERIALS DISTRIBUTOR OF A BLAST FURNACE P (P C) I INPUT CYCLE 7 Sheets-Sheet 4 (TOP-PRESSURE ATMOSPHERE) P-Po (TOP-PRESSURE -ATMOSPHERE) P (Pressure difference) 1 (TIME) INVENTOR.

ATTORNEYS 1957 TERUO TSUTSUMI MATERIALS DISTRIBUTOR OF A BLAST FURNACE Filed Odt. 1, 1964 '7 Sheets-Sheet 5 ATTORNEYS 1%? TERUO TSUTSUMI MATERIALS DISTRIBUTOR OF A BLAST FURNACE '7 Sheets-Sheet 6 Filed Oct. 1, 1964 mam ATTORNEYS Feb 1967 TEZRUO TSUTSUMI MATERIALS DISTRIBUTOR OF A BLAST FURNACE '7 Sheets-Sheet '7 Filed Oct. 1, 1964 R/ w 5 N7 0 5 .NL/ M H r ATTORNEYS United States Patent M 3,302,805 MATERIALS DISTRIBUTOR OF A BLAST FURNACE Teruo Tsutsumi, Yokohama-shi, Japan, assignor to ISM- kawajima-Harima Jukogyo Kabushiki Kaisha, Tokyoto, Japan, a company of Japan Filed Oct. 1, 1964, Ser. No. 400,827 Claims priority, application Japan, Dec. 14, 1963, 38/ 67,286 3 Claims. (Cl. 214-37) This invention relates to improvement in a materials distributor for use in blast furnaces.

Recently there has been introduced into the blast furnace operation the high top pressure process, in which the pressure of gas in the furnace is considerably elevated, and which is consequently accompanied by several difficulties in point of the furnace top charging equipment.

A description of the prior art blast furnace operation, illustrating the nature of the difiiculties which are present in the known furnaces and which are corrected by the inventive furnace herein, is described and shown in the accompanying figures and specification along with a complete description of the inventive blast furnace. In the figures:

FIG. 1 is a view in cross section of a two bell system as known in the prior art;

FIG. 2A is the diagrammatic explanation of the inter relation between the time and the pressure and difference between the upper and the lower sides of the large bell in the two bell system;

FIG. Z-B shows the same inter-relation with respect to the small bell in the same system;

FIG. 3 represents the cross section of the conventional three bell system;

FIG. 4-C illustrates the inter-relation between the time and the pressure difference between both sides of the large bell in the three bell distributor system;

FIG. 4-D shows the same inter-relation with respect to the middle bell in the said system;

FIG. 4-E also shows the same inter-relation with re spect to the small bell in said three bell system;

FIG. 5 is a view, in cross section, of the structure according to the present invention;

FIG. 6 is an enlarged View of the revolving chute and the gas sealing valve according to the present invention;

FIG. 7 is an enlarged view in cross section of the seal of the gas sealing valve shown in FIG. 6;

FIG. 8 is a fragmentary sectional elevation showing a different embodiment having a plurality of inlets; and

FIG. 9 is a sectional plan view taken along line 9-9 of FIG. 8 in the direction of the arrows.

In the drawings, a refers to the large bell; b to the middle bell; c to the small bell; d to the large bell hopper; e to the middle bell hopper; f to the small bell hopper; g to the primary dust catcher; h to the septum valve; 1' to the gas inlet of the two bell distributor; j to the primary clean gas inlet of the three bell system; k to the secondary clean gas inlet; 1 to the gas outlet; m to the skip; it to the stationary hopper; o to the charging materials; q to the seat; r to the grease seal; s to the upper roller; u to the side roller; v to the lower roller; w to the ring gear; at to the compressed gas receiver; and y to the gas compressor.

In the two bell charging system shown in FIG. 1, the blast furnace gases are partly cleaned by the primary dust catcher g, and fill the large bell hopper l1 located between the large bell a and the small hell 0 to level the pressure inside the large bell hopper d and the furnace top. But the pressure inside the large bell hopper d is lower than that of the furnace top (pressure below the large bell) 3,302,805 Patented Feb. 7, 1967 by the pressure loss (Ap) at the primary dust catcher.

Therefore,

(i) The pressure difference (usually about mm. Aq) is brought between, above and below the large bell a as is shown in FIG. 2-A, and as the result the gases move from the furnace top into the large bell hopper d through the gap between the large bell a and the large bell hopper d. These gases usually contain dust of about 20 grams per 1 Nin and abrade the seats of the large bell a and the large bell hopper d.

(ii) If the pressure in the large bell hopper d is higher, the small hell does not open. The pressure in the large bell hopper must then be lowered to atmospheric pressure by venting the gas in the large bell hopper to atmosphere. During this process, the pressure difference between, above and below the large bell a becomes equal to that between the atmosphere and the pressure at the furnace top. The period of time, in which the small bell is open, is about A of one charging cycle as shown in FIG. 2-A. The speed of the gases, which move from the furnace top into the large bell hopper :1, usually reaches that of sound, and as a result, the seats of the large bell a and of the large bell hopper d are subject to considerable degree of abrasion.

(iii) During this process, the pressure in the large bell hopper d, i.e. that below the small hell 0, is lower than that of the furnace top by the pressure drop (Ap) at the primary dust catcher g, and the pressure above the small bell is equal to that of atmosphere. So a great pressure difference between, above and below the small bell 0 results as is shown in FIG. 2-B. The speed of the gases, which pass through the gap between the small'bell c and the small bell hopper f reaches that of sound or a little less, causing the erosion on the seat of the small bell hopper f. The time required for this process is about of an input cycle as is shown in FIG. 2-B. Consequently, the small bell c wears out more quickly than the large bell a.

(iv) Each of the bells a and 0 also functions as the passage of the materials charged from the skip m; so when the bells a and c are lowered, the materials slide down, scratching the surface of the bells. Because of this and also of the previously mentioned erosion by gases, the gaps between the bells a and c and the bell hoppers d and f are widened in a short time, causing heavy gas leakage. Above all, the abrasion of the small bell c by the materials is severer than that on the large bell a, and consequently the high top pressure operation cannot be continued over a long period due primarily to the gas leakage at the small bell c. t

(v) The small bell c and the small bell hopper receive the incoming charge from the skip m at the fixed points. In order to distribute the incoming charge 0 uniformly on the circumference of the furnace, the so-called six point distribution is widely adpoted, that is, the small bell is rotated at 60, 240, 300, and 360 (0). Accordingly, the gas seal at the connecting part between stationary and revolving parts is necessary, and usually the grease seal r is applied to this area; however, the pressure in the large bell hopper being high, the grease seal can not last long, resulting in the gas leakage and the consequent suspension of the high top pressure operation.

The three bell distributor shown in FIG. 3 has the large bell a, the middle bell b and the small bell c. The pressure equalization described above is achieved by the blast furnace gas boosted by the compressor y. The pressure in the hoppers d, e and f is automatically controlled to maintain a little higher or the same as that of the furnace top. The pressure in the middle bell hopper e is reduced only when the small bell c is open.

When the pressure in the hoppers d, e and f is main tained at the level of that of the furnace top, no pressure difference above and below the large bell a is occasioned as is shown in FIG. 4C. Consequently, the gases do not move through the gap between the large bell a and the large bell hopper. Thus, no such troubles as are evidenced in the two bell system takes place. But the middle bell 12 remains under the same condition as the large bell a of the two bell distributor as shown in FIG. 4-D while the small bell remains under the same condition as the small bell c of the two bill system as shown in FIG. 4E. Besides, as the pressure in the large bell hopper d and the middle bell hopper e of the three bell system is higher than that of the two bell system, the speed of gases, which pass through the gap between the middle bell b and the middle bell hopper e or between the small bell c and the small bell hopper f may possibly reach the speed of sound even if it does not in the two bell system. Moreover, the gass feeding capacity of the three bell system to the hoppers is limited by the capacity of the compressor; on the other hand, with the two bell system the entire gas generated in the blast furnace can theoretically be supplied thereto. Therefore the allowable volume of gas leakage from the small bell c in the three bell system is less than that of the two bell system, and so the small bell thereof reaches its operational limit sooner. In short, the gas leakage from the small bell c is the principal cause that prevents the high top pressure operation even in the case of the three bell system. The problem of abrasion by the charged materials, the gas leakage from the grease seal r between the revolving and the stationary portions of the small hell 0 and the small bell hopper f still remains to be solved even in the case of the three bell system.

It is an object of this invention to eliminate the abrasion of the small hell by gases and materials as well as to prevent the gas leakage from the grease seal at the revolving and stationary portions of the small bell and the small bell hopper almost completely, thereby enabling the charging equipment to maintain the high top pressure operation for a longer period. According to this invention a revolving chute is installed in an air-tight bell hopper. The upper part of the shaft, which fastens said chute, is supported at its upper part outside the bell hopper so that it can turn freely to the desired position. The gas sealing valves are positioned between the required number of the materials inlets installed at the upper dome of the bell hopper which receives the charging materials from the skip or the conveyor. These are the characteristic features of the present invention. An explanation of a preferred embodiment of the invention is given with respect to FIGS. 5 to 7.

In the first bell hopper 1, which is made of an airtight vessel, a truncated oblique conical revolving chute 5 with an outlet 9 at the bottom, is housed. The ring gear 10 is fastened to the upper projection of the cylindrical shaft 6, on which the revolving chute 5 is mounted in the bell hopper 1. The ring gear 10 is supported by the lower rollers 11, the side rollers 12 and the upper rollers 13 so that it can rotate freely and that the weight of the said revolving chute 5 and the load of the charged materials can be sustained by

rollers

11, 12 and 13. A pinion 17, which is driven by a motor 16 installed on a pedestal on the dome 14 above the first bell hopper 1, is geared to the ring gear 10, so that the revolving chute 5 may be revolved through pinion 11, ring gear 10 and shaft 6 by driving motor 16.

One or two charging inlets 7 are installed on the dome 14 above the first bell hopper 1 so as not to obstruct the movement of ring gear 10. Inlets 7 are connected to the stationary bell hopper 8 by means of the gas sealing valve 19 in between. The valve disk 20 of gas sealing valve 19 is so designed that it can be withdrawn from the materials passage when the said valve is fully open. The double seal structure is adopted as shown in FIG. 7, that is, the hard facing of the contact area 22 of the valve disk 20 and the valve seat 21 is effected, and to ensure a satisfactory gas seal, rubber or a similar material 23 is fixed out of the way of the charge. At the bottom of the said first bell hopper 1 is positioned the first bell 2, and under bell 2 is placed the second bell hopper 4, and the second hell 3.

While the embodiment which includes a single inlet is shown in FIG. 5, FIGS. 8 and 9 illustrate the embodiment which includes a plurality of charging inlets 7, these inlets being provided with sealing valves 20 and 20' identical with that shown in FIG. 6, and of course the inlets 7 of FIG. 8 communicate fluid-tightly with the interior of the hopper in which the rotary chute 5 is located. As is apparent from FIGS. 8 and 9, this rotary chute 5 will receive charging material from both of the inlets. In addition, these inlets of FIG. 8 respectively coaot with a pair of outer

stationary supply hoppers

8 and 8, as indicated in FIG. 8.

In the drawings, 24 refers to the skip; 25 to the gas seal around shaft 6; 26 to the gland; 27 to the roller pedistal; 28 to the wearing ring of revolving chute 5 and shaft 6; 29 to the second bell seat; 30 to the first bell seat; 31 to the primary dust catcher; 32 to the gas compressor; 33 to the septum valve; 34 to the gas receiver; 35 to the primary gas main; 36 to the secondary gas main; 37 to the gas outlet; and 38 to the charging materials.

The sequence of the operation is now explained. While the skip 24 is being hoisted up the revolving chute 5 turns 60 and stays at the charging position above the first bell 2. The gas sealing valve 19 is fully opened just before the materials in the skip 24 is charged. The materials, which are charged from the skip 24, fall through the stationary bell hopper 8, the materials inlet 7 and the revolving chute 5, and they eventually form an oblique cone on the first hell 2. First bell 2 is lowered to let down the burden on to the second bell 3. After the above-mentioned operation has been carried out twice, the second bell 3 is lowered to pour the charge into the furnace just like the case of the conventional furnace top charging equipment.

In the drawings, an example of the three bell distributor or according to the invention is illustrated, but it is evident that the second bell alone can be installed, doing away with the first bell, under the said revolving chute when the present invention is applied to the two bell system, and a belt conveyor may be employed in place of the skip.

The advantages brought about by the present invention can be listed as follows:

(I) As a revolving chute is housed in thestationary air-tight vessel, which is equivalent to the conventional small bell hopper, the conventional grease seal becomes unnecessary, and the gas leakage from the grease seal is eliminated.

(II) As the conventional small bell is replaced by the gas sealing valve, the valve seat of which is out of contact with the burden and whose disk can withdraw from the materials passage, the seal is no longer subject to the frictional abrasion by materials.

(III) As the gas sealing area of the gas sealing valve is out of contact with the burden, the resilient materials such as rubber can be used to make a complete gas seal without being subject to abrasion by gases.

(IV) As the gas sealing valve is installed in the materials passage, the size thereof can be reduced substantially as compared with that of the conventional small bell which measures 2 meters in diameter. Therefore, even when the substance mentioned in the foregoing paragraph III wears out, the gas leakage is kept much less.

(V) As the gas sealing valve is small in size and not subject to the weight of the burden, the power required to operate is much smaller than that necessary for the operation of the conventional small bell.

(VI) The gas sealing valve, being compact in size and light in weight, can be installed completely outside of the furnace, and built of the flange and bolts, which facilitates the replacement of the parts.

(VII) With the conventional system, the burden is charged from the skip to the small bell hopper, and after the said hopper is rotated the small bell is lowered. But in the case of the present invention, the revolving chute is rotated to the desired position and then the said gas sealing valve is opened before the burden is charged from the skip, so that the small bell hopper revolving and the small bell opening is done while the skip is being pulled up. Therefore, the time required for one charging cycle is shortened.

(VIII) The conventional small bell hopper should be rotated at different angles as 60, 120, 180, 240, 300 and 360 (0) each time that the burden has been charged. But in the case of the present invention, it is rotated 60 successively, which permits the incorporation of an electric control.

(IX) As the revolving chute according to the present invention is not for the storage of the burden, but for the passage thereof, and as it rotates before the burden is charged, the power required to rotate the chute is very small as compared with that required for the operation of the conventional small bell hopper.

What I claim is:

1. An apparatus for distributing materials to a blast furnace having a given axis, said blast furnace including a bell and a first bell hopper having a common axis coinciding with said furnace axis and said first hopper being closed off from the outer atmosphere and an outer stationary hopper offset with respect to and situated to one side of said furnace axis outwardly beyond said first hopper, a rotatable chute housed within said first hopper, a rotary shaft having an axis coinciding with said furnace axis and fixed to said chute for transmitting rotary movement thereto, such shaft extending fluid-tightly along said furnace axis through said first hopper outwardly to the exterior thereof, means operatively connected with said shaft at the exterior of said first hopper for rotating said shaft for thus also rotating said chute, a charging inlet installed above said first hopper at the same side of said furnace axis as said outer stationary hopper, and said charging inlet communicating fluid-tightly with the in terior of said first hopper and situated beneath and being connected to said stationary hopper, and sealing means disposed between said stationary hopper and said inlet for sealing off said outer stationary hopper from said charging inlet, and means mounting said sealing means for movement between a sealing position sealing off said outer hopper from said inlet and an open position providing free communication between said outer hopper and said inlet so that charging material can flow from said outer hopper through said inlet into said first hopper, said sealing means being supported by said mounting means for movement to a location situated out of the path of movement of material from said outer hopper to said charging inlet when said sealing means is in said open position thereof.

2. In a blast furnace as recited in claim 1 and wherein a plurality of said charging inlets for introducing materials are distributed about said furnace axis and are disposed above and communicate fluid-tightly with the interior of said first bell hopper, and wherein a plurality of outer stationary hoppers are respectively situated over and connected with said charging inlets, and a plurality of sealing means installed respectively between said inlets and said outer hoppers, and a plurality of mounting means respectively mounting said plurality of sealing means for movement between said sealing positions cutting off communication between said outer hoppers and said inlets, respectively, and said open positions providing free communication between said outer hoppers and said inlets while each of said sealing means when in its open position is situated at said location out of the path of movement of the material.

3. In a blast furnace as recited in claim 2, a second bell hopper situated beneath said first bell hopper and a second bell in said second bell hopper.

References Cited by the Examiner UNITED STATES PATENTS 938,411 10/1909 Crockard 2l437 X 2,599,334 6/1952 Latham 214-36 2,912,126 11/1959 Alspaugh et al. 214-17 GERALD M. FORLENZA, Primary Examiner. ROBERT G. SHERIDAN, Examiner.

Claims

1. AN APPARATUS FOR DISTRIBUTING MATERIALS TO A BLAST FURNACE HAVING A GIVEN AXIS, SAID BLAST FURNACE INCLUDING A BELL AND A FIRST BELL HOPPER HAVING A COMMON AXIS COINCIDING WITH SAID FURNACE AXIS AND SAID FIRST HOPPER BEING CLOSED OFF FROM THE OUTER ATMOSPHERE AND AN OUTER STATIONARY HOPPER OFFSET WITH RESPECT TO AND SITUATED TO ONE SIDE OF SAID FURNACE AXIS OUTWARDLY BEYOND SAID FIRST HOPPER, A ROTATABLE CHUTE HOUSED WITHIN SAID FIRST HOPPER, A ROTARY SHAFT HAVING AN AXIS COINCIDING WITH SAID FURNACE AXIS AND FIXED TO SAID CHUTE FOR TRANSMITTING ROTARY MOVEMENT THERETO, SUCH SHAFT EXTENDING FLUID-TIGHTLY ALONG SAID FURNACE AXIS THROUGH SAID FIRST HOPPER OUTWARDLY TO THE EXTERIOR THEREOF, MEANS OPERATIVELY CONNECTED WITH SAID SHAFT AT THE EXTERIOR OF SAID FIRST HOPPER FOR ROTATING SAID SHAFT FOR THUS ALSO ROTATING SAID CHUTE, A CHARGING INLET INSTALLED ABOVE SAID FIRST HOPPER AT THE SAME SIDE OF SAID FURNACE AXIS AS SAID OUTER STATIONARY HOPPER, AND SAID CHARGING INLET COMMUNICATING FLUID-TIGHTLY WITH THE INTERIOR OF SAID FIRST HOPPER AND SITUATED BENEATH AND BEING CONNECTED TO SAID STATIONARY HOPPER, AND SEALING MEANS DISPOSED BETWEEN SAID STATIONARY HOPPER FROM SAID FOR SEALING OFF SAID OUTER STATIONARY HOPPER AND SAID INLET CHARGING INLET, AND MEANS MOUNTING SAID SEALING MEANS FOR MOVEMENT BETWEEN A SEALING POSITION SEALING OFF SAID OUTER HOPPER FROM SAID INLET AND AN OPEN POSITION PROVIDING FREE COMMUNICATION BETWEEN SAID OUTER HOPPER AND SAID INLET SO THAT CHARGING MATERIAL CAN FLOW FROM SAID OUTER HOPPER THROUGH SAID INLET INTO SAID FIRST HOPPER, SAID SEALING MEANS BEING SUPPORTED BY SAID MOUNTING MEANS FOR MOVEMENT TO A LOCATION SITUATED OUT OF THE PATH OF MOVEMENT OF MATERIAL FROM SAID OUTER HOPPER TO SAID CHARGING INLET WHEN SAID SEALING MEANS IS IN SAID OPEN POSITION THEREOF.