US3131424A

US3131424A - Lining for drum-type or disk-type balling device

Info

Publication number: US3131424A
Application number: US857968A
Authority: US
Inventors: Ishimitsu Akitoshi; Yoshikawa Yutaka
Original assignee: Yawata Iron and Steel Co Ltd
Current assignee: Yawata Iron and Steel Co Ltd
Priority date: 1958-12-06
Filing date: 1959-12-07
Publication date: 1964-05-05
Anticipated expiration: 1981-05-05

Description

M y 1964 AKITOSHI ISHlMlTSU ETAL 3,131,424.

LINING FOR DRUM-TYPE OR DISK-TYPE BALLING DEVICE Filed Dec. 7, 1959 FlG.l

"W MSF FM United States Patent 3,131,424 LINING FOR DRUM-TYPE GR DISK-TYPE BALLHVG DEVEQE Akitoshi lshimitsu, Minoru Kawarnura, and Yutaka Yoshikawa, Yawata, Japan, assignors to Yawata Iron and Steel Co, Ltd Tokyo, Japan, a corporation of fapan Filed Dec. 7, 1959, Ser. No. 357,968 Claims priority, application Japan Dec. 6, 1958 8 (Ilaims. (Cl. 18-4.)

This invention relates to a drum-type or disk-type balling device for agglomerating moist fines, and more particularly, to an improved lining adapted for the interior surface thereof.

It is known that the interior surface of the rotating drum or disk has to be coated by a layer or lining of the pulverant material which is to be processed in an appropriate condition for the purpose of obtaining balls or pellets from fine iron ore by means of such drum-type or disk type balling devices. In case the whole lining of the material does not adhere fully to the interior surface of the balling apparatus or a part thereof peels ofr, then the material begins to slip over the surface of the steel plate from which the apparatus is constructed so that the steel surface is abraded and polished again and again, which results in a decrease of friction and a loss of agglomerating action, because the material does not roll over the surface due to the increase of slip over the polished steel surface.

It is also known that a knurled surface consisting of a series of spaced internal ribs is provided over the interior surface of the balling drum with a view to maintaining a layer of pulverant material in a suitable condition.

In view of the above, the present invention contemplates the provision of a better and more effective lining than hitherto proposed which is adapted for the interior surface of either drum-type or disk-type balling apparatus.

According to this invention, the interior surface of the balling device is provided with a layer or lining of a rugged feature having a rough, uneven surface which is full of abrupt ups and downs firmly adhered thereto with or without a binding agent resulting from the formation of a rough surface forming material, such as, rough granules having angular, shar-ends of irregular shape, for example, pumice-stone, mineral slag, coke, porous concrete, broken pieces of brick, ore or rock, fibre, saw-dust and porous synthetic resin, etc., singly or combined together of at least two of the substances described above.

An object of the invention is to provide a balling device the interior surface of which is provided with a rugged feature having a rough, uneven surface full of abrupt ups and downs in order to insure the maintenance of the material layer or lining over the interior surface, whereby the wide range of agglomerating action is attained.

Another object is to provide a layer or lining of a rugged uneven feature firmly adhered to the interior surface of the balling device, the material of which is selected from the group of pumice-stone, mineral slag, coke, porous concrete, broken pieces of brick, or ore rock, fibre, saw-dust and porous synthetic resin, etc., singly or combined together of two substances mentioned above with a binding agent or without it.

Still another object is to provide a porous layer or lining resulting from the addition of a foam-forming agent, soluble substances or easily destructible substances into 3,131,424 Patented May 5., 1964 the rough surface forming material so that the moisture contained in the pulverant material to be processed is adjusted by the action of pores in such manner that either the excess of moisture in the fine material is absorbed into the pores or the lack of moisture is replenished with the moisture absorbed therein, whereby the balling action is carried out in a stable state of moisture.

Other obiects of the invention will become apparent from the following description in connection with the ac companying drawings which exemplify several preferred embodiments of the invention in which:

FIG. 1 is a sectional view of a part of the interior surface of the balling device provided with a scratched steel surface embodying a preferred example of the invention.

FIG. 2 is a sectional view of a part of the interior surface provided with a lining of granular substances embodying another modified example of the invention.

FIG. 3 is a sectional view of a part of the interior surface provided with a lining of porous substances embodying another modified example of the invention.

FIG. 4 is a sectional view of a part of the interior surface provided with a lining of fibre embodying another modified example of the invention.

Referring to FIG. 1, which shows one of the several embodiments of the invention, the interior surface 1 of steel of the balling apparatus is provided with a rough feature full of abrupt ups and downs by means of a scratching, shaving and scraping operation at random imparted directly to the surface of steel plate from which the apparatus is constructed. Groove scratches in the direction of an axis are preferred, and scrapes in the form of an indented hemisphere are also preferable. Preferably the burrs left on cut metal may remain as such, because the more burrs the better due to an effect resembling to that of a grater. It is also a beneficial effect that the rotation of the apparatus is made easy and smooth because the weight thereof decreases due to the loss of steel material resulting from the above scraping operation. It is to be understood that the formation of a layer or lining of the material 3 to be processed we have in view upon the thus roughened interior surface is easily obtained by this rough uneven rugged surface. It is also to be understood that the provision of a scratched, shaved and scraped surface on a hard lining of other material than metal adhered directly to the interior surface of steel, which can be formed either prior to solidification or in the course of being solidified.

Referring to FIG. 2 showing a modified embodiment of the invention, the interior surface of steel of a balling device is provided with a rough layer or lining of granular material 5 having a surface full of a abrupt ups and downs by means of adhesion by a binding agent or either adhesion by fusion or by spray fusion.

The size of granular material is not limited in this invention. However, the granular material less than 1 cm., that is, about 15 mm. in diameter is adapted for our purpose, and more particularly, the granular material with sharp ends of strongly irregular outline is preferred for attaining the desired effect. For example, any material such as, ore, sulphite slag, coke, concrete, broken rock, brick, shamotte, turnings and chips from machining operation, metal, alloy, or metallic compound, etc., is employed, provided that it is neither soft nor collapsible. As a binding agent, any composition of matter derived 3,1s1,aas

from rubber, tar, asphalt, synthetic resin or cement of a known origin can be employed. A binding agent of an epoxy resin origin is particularly effective, and of a polyester resin origin is applied at room temperatures due to its property of being set at room temperatures. in addition, the formation of a layer or lining having a rough uneven surface consisting of either thermoplastic or thermosetting resin can be obtained by the application of chemical actions, such as, thermosetting, adhesion by fusion, or adhesion by spray fusion.

By this balling apparatus provided with the rough un even surface thus formed, a lining or layer of such coarse material as cannot be usually formed in a conventional balling means is easily produced with the result that a stable agglomerating action is achieved. Furthermore, the lining or layer of pulverant material can be maintained over the interior surface of the balling device due to its increased area caused by the rough surface resulting from the process of this invention. When the lining is softer than the mixture of granular substance and binding agent 4, there is an advantage that the rough surface of the lining is automatically replaced, although the surface is polished due to peeling off of the material lining. Further, the slip of the material lining can be prevented so as to maintain an adherent layer of the material against the interior surface of the balling device. Accordingly, the repair of the lining consisting of the granular material can be easily performed, too. Compared with a large metallic projection welded to the interior surface of the balling device in order to prevent material slip, the granular substance lining of this invention can decrease the overall weight of the device and increase the surface area of the lining due to its abrupt ups and downs, which results in the increase of adhesion of the material lining and also in an easy rotation of the device because of its light weight.

Referring to FIG. 3 showing another modified embodiment of the invention, the interior surface of the balling apparatus is provided with a layer or lining of a porous material or a porosity-forming material.

A wide variety of porous material, either soft or hard, can be employed for the lining or layer of this modified embodiment of the invention. The use of a porous material can be applied either as an overall surface lining or a part thereof. For example, a granular as well as porous material can be applied, or a porous material can be inserted between two areas of a granular material, all of which are included in this invention.

Soft porous materials, such as, rubber and soft synthetic resin, and hard porous materials, such as, ebonite, asphalt, hard synthetic resin, pumice-stone, mineral slag, coke, broken brick, porous concrete, etc., are employed. Other materials than rubber, synthetic resin and concrete are employed with a suitable binding agent.

As the lining consisting of porous material embodying this invention has lots of pores all over its surface full of abrupt ups and downs, the surface area is increased so as to prevent material from slip and peeling off from the surface thereof. Besides, the rough uneven surface with abrupt ups and downs of the lining exhibits resistance to abrasion for an extended period of time. Generally speaking, porous material has pores and vesicles and also lots of capillaries, hence it absorbs excess moisture from the lining of fine moist material to be processed to hold it when it is in excess and supplies it when it runs short. This automatic control of moisture is able to increase production. The interior surface of the balling device of a non-absorbent type of prior art becomes wet when the material to be processed contains too much water, which causes the material to slip therealong to decrease adhesion thereof.

When a coarse material is to be processed by the balling apparatus, agglomerating action depends on the moisture of the coarse material, which results in a narrow range of agglomeration. However, a wider range of agglomeration can be achieved by the provision of a lining or layer of porous material adhered to the inside surface of the balling device. Such limitations as the fineness of material to be processed, the proportion thereof and an amount of water to be added, are easily adjusted so as to insure a stable operation in the production of balls and pellets.

As the lining of porous material is light in weight because of its porosity, there are advantages, such as, less power for rotating the device, and less abrasion resulting from less oscillation, etc.

Porous material is applied to the inside surface of the balling device by several means, such as, adhering a soft sheet in which porous material is incorporated, solidifying it as desired, embedding granular porous material into a lining of binding agent, and incorporating a foam-forming agent into the lining of porous material.

Another modified process comprises providing a layer or lining of porous material added with a collapsible substance, such as, saw-dust, pearlite and other porous, lightweight collapsible substances, or a soluble substance, such as, salt and water-soluble paste. Such a lining as described becomes porous as its surface destroys gradually according to attrition.

Particularly, if the upper layer of the porous lining is required to be more porous than the lower layer, the addition of a collapsible or soluble substance to the upper layer of the lining will meet the above requirement.

Referring to FIG. 4 showing another modified embodiment of the invention, the inside surface ll of the balling device is lined with a layer or lining in which fibre 7 is incorporated exposed on the surface thereof. Fibre 7 is incorporated in the lining, but exposed above the surface thereof. For example, a lining of slag wool in the form of a granule embedded into a polyester synthetic resin is provided on the interior surface of the balling apparatus, and then scraped off to expose fibre. It is preferable that the binding agent does not penetrate fully into a granule of fibre. If fibre is removed from the lining, the lining remains porous leaving lots of pores. Further, fibre is intertwined with the lining of material to be processed so as to maintain an adherent layer of the moist material.

Any fibre, such as, natural, artificial, mineral and vegetable fibre, can be used. Any material for a lining incorporated with fibre can be employed, provided that it has a binding ability, and any material of cement, rubber, synthetic resin, or asphalt origin will meet the above requirement.

It is to be understood that the above lining in which fibre is exposed can be applied with a combination of lining materials described hereinabove, such as, granular or porous substance added with or without a collapsible or soluble substance.

While We have shown and described only a few embodiments of our invention, it is apparent that modifications may arise. Therefore we do not wish to be limited to the disclosure set forth, but only by the scope of the appended claims.

We claim:

I. In a balling drum apparatus for obtaining pellets from fine ores, the improvement comprising a foundation lining with a roughened surface on the interior wall of said drum, said lining consisting essentially of a binder and rough granules of irregular shape and of a hard porous material and having sharp corners embedded in the binder, at least a portion of said rough granules having the sharp corners thereof projecting from the surface of said binder to form said roughened surface, whereby a lining of the material being balled is built on said roughened surface of the foundation lining.

2. The improvement as claimed in claim 1 in which said rough granules are of pumice-stone.

3. The improvement as claimed in claim 1 in which said rough granules are of mineral slag.

4. The improvement as claimed in claim 1 in which said rough granules are of coke.

5. The improvement as claimed in claim 1 in which said rough granules are brick fragments.

6. In a balling drum apparatus for obtaining pellets from fine ores, the improvement comprising a foundation lining with a roughened surface on the interior wall of said drum, said lining consisting essentially of a binder and rough granules of irregular shape and of a soft porous material and having sharp corners embedded in the binder, at least a portion of said rough granules having the sharp corners thereof projecting from the surface of said binder to form said roughened surface, whereby a lining of the material being balled is built on said roughened surface of the foundation lining.

7. The improvement as claimed in claim 6 in which said rough granules are of rubber.

8. The improvement as claimed in claim 6 in which said rough granules are of soft synthetic resin.

References Cited in the file of this patent UNITED STATES PATENTS 2,164,164 Price June 27, 1939 2,411,873 Firth Dec. 3, 1946 2,543,898 De Vaney Mar. 6, 1951 2,728,940 Yesberger et al Jan. 3, 1956 2,778,056 Wynne Jan. 22, 1957 2,831,210 De Vaney Apr. 22, 1958 2,834,043 Haley et al. May 13, 1958 2,947,026 De Vaney Aug. 2, 1960

Claims

1. IN A BALLING DRUM APPARATUS FOR OBTAINING PELLETS FROM FINE ORES, THE IMPROVEMENT COMRISING A FOUNDATION LINING WITH A ROUGHENED SURFACE ON THE INTERIOR WALL OF SAID DRUM, SAID LINING CONSISTING ESSENTIALLY OF A BINDER AND ROUGH GRANULES OF IRREGULAR SHAPE AND OF A HARD POROUS MATERIAL AND HAVING SHARP CORNERS EMBEDDED IN THE BINDER, AT LEAST A PORTION OF SAID ROUGH GRANULES HAVING THE SHARP CORNERS THEREOF PROJECTING FROM THE SURFACE A LINING OF THE MATERIAL BEING BALLED IS BUILT ON SAID ROUGHENED SURFACE OF THE FOUNDATION LINING.