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Title:
ROTARY VENTILATION BAR IN A SINTERING MACHINE
Document Type and Number:
WIPO Patent Application WO/2003/093746
Kind Code:
A1
Abstract:
The present invention relates to a ventilation bar in use for a charging apparatus in a feeding unit of a sintering machine. In particular, the ventilation bar of the invention has an improved structure, which can obtain uniform grain size distribution when mixed raw material is charged into trucks of the sintering machine, and by which the ventilation bar can be automatically rotated under the moving force of mixed raw material so as to maximize the breathability of charged layers of mixed raw material and prevent creation of ore deposits, partial accumulation of mixed raw material and abrasion of the bar. The rotary ventilation bar of the invention comprises: a body rotatably mounted by its first end to a link member via a bearing, the link member depending from a shaft movable forward/backward as well as adjustable in angle; and wings mounted on a second end of the body, whereby movement of mixed raw material on trucks rotates the wings and the body to form a layer of lower density in mixed raw material ensuring breathability.

Inventors:
YOON YEONG-BAE
WOO WON-SOO
Application Number:
PCT/KR2003/000732
Publication Date:
November 13, 2003
Filing Date:
April 11, 2003
Export Citation:
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Assignee:
POSCO (KR)
International Classes:
F27B21/06; F27B21/08; F27B21/10; F27D3/00; F27D3/10; (IPC1-7): F27B21/08
Foreign References:
JPH11294961A1999-10-29
JPH08226773A1996-09-03
JPH04289131A1992-10-14
JPH04289132A1992-10-14
Attorney, Agent or Firm:
Son, Won (Daelim Acrotel 467-6 Dogok-don, Gangnam-ku Seoul 135-270, KR)
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Claims:
Claims
1. A rotary ventilation bar of a charging apparatus in a sintering machine, comprising: a body 2 rotatably mounted by its first end to a link member 29 via a bearing 32, the link member 29 depending from a shaft 121 of the charging apparatus which is movable forward/backward as well as adjustable in angle ; and wings 27 mounted on a second end 26 of the body 2, whereby movement of mixed raw material on trucks 104 rotates the wings 27 and the body 2 to form a layer K of lower density in mixed raw material M ensuring breathability.
2. A rotary ventilation bar of a charging apparatus as set forth in claim 1, wherein the wings 27 are twisted to 180 deg while growing wider as extending to their distal end, and fixed to the second end 26 of the body 2 which is tapered to reduce its crosssectional area.
3. A charging apparatus in a sintering machine which serves to charge mixed raw material M into the sintering machine, comprising: a shaft 121 movable forward/backward as well as adjustable in angle ; and a number of ventilation bars 1 described in claim 1 or 2.
4. A charging apparatus as set forth in claim 3, further comprising hollow housings 28, respectively, in lower ends of the link members 29 to which the bodies 2 are connected, each of the bodies 2 being inserted into each of the housings 28, wherein each of the housings 28 includes: a dust seal 31 and a ball bearing 32 assembled to the housing 28; a lock nut 34 fastened to the second end of the body 2 via a washer 33; a split pin 35 inserted into holes in the nut 34 and the second end of the body 2 to prevent unlocking of the lock nut 34; a cover 36 assembled to the housing 28 via a bolt 36a; and a grease nipple 37 assembled to a hole in an upper part of the housing 28 to enable greasing.
Description:
ROTARY VENTILATION BAR IN A SINTERING MACHINE TECHNICAL FIELD The present invention relates to a ventilation bar in use for a charging apparatus in a feeding unit of a sintering machine.

In particular, the ventilation bar of the invention has an improved structure, which can obtain uniform grain size distribution when mixed raw material is charged into trucks of the sintering machine, and by which the ventilation bar can be automatically rotated under the moving force of mixed raw material, thereby maximizing the breathability of charged layers of mixed raw material while preventing creation of ore deposits, partial accumulation of mixed raw material and abrasion of the bar.

BACKGROUND ART In general, a sintering machine is a main equipment of a sintering plant for producing sintered ore which is consumed as a main raw material in blast furnaces. A charging apparatus 100 in a feeding unit of the sintering machine charges mixed raw material into trucks 104. After an ignition furnace 103 ignites mixed raw material on the trucks 104, a sintering process is performed until mixed raw material reaches a discharging unit.

Upon completion of sintering, sintered ore is crushed by a

crusher 106 and then discharged therefrom. Sintered ore is cooled and then sorted according to grain size before final sintered ore is conveyed into a blast furnace (not shown).

During such a sintering process, a main blower 111 disposed under the trucks 104 applies an absorbing pressure to form a negative pressure within wind boxes 107 which are disposed under the trucks 104. This negative pressure causes mixed raw material to be sintered downward. Gas absorbed by the blower 111 flows through the wind boxes 107 and a gas main duct 108, collects dust in an electric dust collector 10, and then exhausted to the outside via a main stack 112.

In this sintering process, as shown in Fig. 8, the charging apparatus 100 lays a predetermined amount of upper ore on bottoms of the trucks 100, and then charges mixed raw material stored in a surge hopper 113 on upper portions of the trucks 104. The quantity of mixed raw material dispensed from the hopper 113 is adjusted through opening/closing of a hopper (not shown) and rotation of a drum feeder 115. As the trucks 104 further proceed, the thickness of mixed raw material is determined by a cut-off plate 119.

While being charged into the trucks 104 through a deflector plate 114, mixed raw material has non-uniformity in grain size distribution and charging concentration under the influence of its dropping rate and ores deposited to the above components.

As a result, such non-uniformity leads to degradation of productivity and quality in the sintering process.

Korean Patent Application Serial No. 1997-21973 was devised in order to overcome the foregoing problems, in which a number of variable ventilation bars 116 are inserted into a charging unit of a sintering machine to previously form air holes within mixed raw material in order to promote the sintering rate and productivity of mixed raw material.

As shown in Figs. 9 and 11, in the ventilation bars 116 of the prior art, both ends of a shaft 121 are inserted, respectively, into housings 124 through bearings 126. Each of the bearings 126 is connected at its one side to a rack gear 128 which is meshed with a pinion gear 130. The pinion gear 130 is rotated by a handle 132 outside each housing 124. One end of the shaft 121 is fitted with a worm wheel 134 with which a worm gear 136 is meshed. The shaft 121 of the worm gear 136 is extended out of the housing 124 and connected to a handle 138.

In the above construction, as an operator turns the handle 132, the shaft 121 is moved forward and backward via the pinion gear 130 and the rack gear 128. Turning the handle 138 changes the angle of the shaft 121 via the worm gear 136 and the worm wheel 134. Thus this construction allows the shaft 121 to be adjusted in its angle as well as to be moved forward and backward.

The ventilation bars 116 made of fixed iron bars are mounted in plurality on the tubular shaft 121. The shaft 121 is installed together with the ventilation bars 116 under the deflector plate in order to impart fine ventilation to mixed

raw material. However, as shown in Fig. 10, a locally concentrated abrasion 116D is formed in an upper part of the ventilation bar 116. Also, mixed raw material containing moisture may form a deposition 116C on the upper part of the ventilation bar 116. Then, raw material may be partially accumulated, or voids can be formed in some portions of raw material from which ore deposits to the upper part of the ventilation bar 116.

Further, ore deposits are detached from the ventilation bar 116 and mixed into raw material, thereby functioning as a factor of rather deteriorating the quality of sintered ore.

DISCLOSURE OF THE INVENTION The present invention has been made to solve the foregoing problems of the prior art and it is therefore an object of the present invention to provide an improved rotary ventilation bar of a charging apparatus in a sintering machine which can fundamentally prevents creation of ore deposits, artificially forms a layer of lower density in charged raw material to enhance sintering rate and productivity, and produce sintered ore of excellent quality.

It is another object of the invention to provide charging apparatus in a sintering machine which serves to charge mixed raw material M into the sintering machine and incorporates a number of the above-described rotary ventilation bars.

According to an aspect of the invention for realizing the above objects, it is provided a rotary ventilation bar of a charging apparatus in a sintering machine, comprising: a body rotatably mounted by its first end to a link member via a bearing, the link member depending from a shaft movable forward/backward as well as adjustable in angle ; and wings mounted on a second end of the body, whereby movement of mixed raw material on trucks rotates the wings and the body to form a layer of lower density in mixed raw material ensuring breathability.

According to another aspect of the invention for realizing the above objects, it is provided a charging apparatus in a sintering machine which serves to charge mixed raw material into the sintering machine. The charging apparatus comprises: a shaft movable forward/backward as well as adjustable in angle ; and a number of the above-described ventilation bars.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of a sintering machine-charging apparatus which is mounted with rotary ventilation bars according to the invention; Fig. 2 is a detailed perspective view of the rotary ventilation bars according to the invention; Fig. 3 is an exploded perspective view of Fig. 2; Fig. 4 is a sectional view of the rotary ventilation bar according to the invention ;

Fig. 5 is a side sectional view of the sintering machine-charging apparatus which is mounted with the rotary ventilation bars according to the invention; Fig. 6 illustrates the operation of the rotary ventilation bar according to the invention; Fig. 7 illustrates a sintering machine to which the invention is applied; Fig. 8 is a perspective view of a sintering machine-charging apparatus which is mounted with rotary ventilation bars of the prior art; Fig. 9 is a detailed perspective view of the rotary ventilation bars of the prior art; Fig. 10 illustrates some problems of the rotary ventilation bar of the prior art; and Fig. 11 illustrates a forward/backward movement-adjusting device and a angle-adjusting device of the rotary ventilation bar of the prior art.

BEST MODE FOR CARRYING OUT THE INVENTION The following detailed description will present a preferred embodiment of the invention in reference to the accompanying drawings.

Fig. 1 illustrates rotary ventilation bars 1 of a sintering machine-charging apparatus of the invention.

The rotary ventilation bars 1 of the sintering

machine-charging apparatus of the invention have a structure enabling the bars 1 to be automatically rotated under the force of raw material which is transported on trucks 104.

Fig. 2 illustrates an assembly of the rotary ventilation bars 1 of the invention, in which the rotary ventilation bars 1 are supported by a shaft 121, which extends by its both ends through bearings 122 assembled thereto. Angle-adjusting devices 117 and forward/backward movement-adjusting devices 118 are assembled to the ends of the shaft 121 as in the prior art. Brackets 121a are installed in lower portions of the shaft 121 and link members 29 are fixed to the brackets 121a to rotatably fix a number of tubular bodies 2 of the rotary ventilation bars 1.

Fig. 4 is a sectional view showing one of the ventilation bars 1 of the invention in detail. The rotary ventilation bar 1 has the tubular body 2 with its one end 26 being tapered to reduce its cross-sectional area. Wings 27 fixed to the end 26 are twisted to 180 deg while growing wider as extending to their distal ends. The other end of the body 2 functions as a fixing section for mounting a hollow housing 28 to the lower end of each link member 29, and is so formed that a bearing 32 and a lock nut 34 can be fastened to the other end of the body 2.

The inside wall of the housing 28 is so formed that the body 2 of the ventilation bar 1 is assembled to the housing 28.

As shown in Fig. 3, after inserting the body 2 into the housing 28, a dust seal 31 and a thrust ball bearing 32 are assembled

into the housing 28. The lock nut 34 is fastened to the other end of the body 2 via a washer 33. A split pin 35 is inserted into holes of the other end of the body 2 and the lock nut 34 in order to prevent unlocking of the lock nut 34. A cover 36 is assembled to the housing 28 via bolts 36a. A hole is formed in an upper part of the housing 28, and a grease nipple 37 is assembled to the hole to enable greasing.

The link 29 integral with the housing 28 is fixed by its upper end to the bracket 121a in the lower portion of the shaft 121 via bolts 30.

Upon being assembled as above, the rotary ventilation bars 1 operated as shown in Fig. 5 when they are installed under the deflector plate 114 of the charging apparatus as in the prior art.

The invention of the above construction has the following operation and effect.

The rotary ventilation bars 1 of the invention are inserted into mixed raw material and automatically rotated under the force of moving raw material which is being charged into the trucks. As a result, any separate power is not required to actuate the rotary ventilation bars 1 of the invention.

As shown in Fig. 5, the ventilation bars 1 are installed parallel with bottoms of the trucks 104 with the angle-adjusting device 117 and the forward/backward movement-adjusting device 118. As the operation begins, mixed raw material M is charged into the trucks 104 via the deflector plate 114 so that the

ventilation bars 1 are buried in raw material M.

Then, as shown in Fig. 6, mixed raw material M on the trucks 104 is transported toward a discharging side (or wing portions of the ventilation bars) as the trucks 104 move to the left in the drawing.

As mixed raw material M is transported on the trucks 104, mixed raw material M naturally applies a horizontal pressure to the wings 27 so that the linear motion of raw material M is converted into the rotational motion of the wings 27 to rotate the bodies 2 of the ventilation bars 1. In the bodies 2 of the ventilation bars 1, the thrust ball bearings 32 in assembled sections opposed to the wings 27 minimize frictional force to prevent deceleration of rotational force.

Therefore, after passing through the charging apparatus equipped with the rotary ventilation bars 1, layers K of lower density are formed in mixed raw material M as designated with 'E'in Fig. 5. As a result, mixed raw material M has very excellent breathability during sintering.

INDUSTRIAL APPLICABILITY According to the present invention as set forth above, mixed raw material M is charged into the trucks 104 of the sintering machine with uniform charging density as well as has fine breathability during sintering thereby promoting the productivity and quality of sintered ore. The invention can

prevent creation of ore deposits on the ventilation bars 1 which may cause nonuniform partial accumulation of raw material M or drops of the ore deposits from mixing into raw material, which may potentially cause nonuniform sintering reaction degrading the quality of sintered ore. Furthermore, rotation of the ventilation bars 1 prevents concentrated abrasion in some portions of the ventilation bars 1 thereby prolonging the lifetime thereof.