US3040375A

US3040375A - Pelletizing apparatus

Info

Publication number: US3040375A
Application number: US82481A
Authority: US
Inventors: Harold E Rowen
Original assignee: Mcdowell Co Inc
Current assignee: Mcdowell Co Inc
Priority date: 1956-03-06
Filing date: 1961-01-13
Publication date: 1962-06-26
Anticipated expiration: 1979-06-26

Description

June 26, 1962 H. E. Row-EN 3,040,375

'PELLETIZING APPARATUS Original Filed March 6, 1956 INVENTOR. H1/201.0 E. Rowe/v,

ATTORNEY.

3,04a375 l PatentedgJune 26, 1962 g tice PELLETIZING APPARATUS Harold E. Rowen, Lakewood, Ohio, assignor to Mc- Dowell Company, Inc., Cleveland, Ohio, a corporation of Ohio Original application'Mar. 6, 1956, Ser. No. 569,919. Divided and this application Jan. 13, 1961, Ser. No.

2 Claims. (cl. 18-1) The present sole application of Harold E. Rowen is filed as a division of a former joint application of Edward A. Gambon and Harold E. Rowen, Serial No. 569,919, led March 6, 1956, and now abandoned.

The present invention, described and claimed herein, is concerned with one form only of that formerly clescribed and claimed in said joint application. As before,

' however, it relates to apparatus for making pellets or small round masses or balls of nely, divided material such as ore, ore concentrates, cement mixes, calcareous marls or like materials in preparation 'for subsequent treatment such as sintering or other steps or processes in which it is desirable to have the material in nodular form.

An object of the present invention is to provide such an apparatus which would be simple in construction and eilicient in operation in the forming or nodules or balls of Ivarious materials and for a wide variety of kinds of subsequent treatment.

A further object of the present invention is to provide such a balling apparatus or machine which may be effective and uniform in its operation while handling relatively large quantities of materials and pelletizing or balling the material in continuous operations.

A still further object of the invention is to render it capable of delivering uniform sizes within minimum and maximum ranges suitable for the intended subsequent treatment, such as sintering, burning in a furnace, etc.

Heretofore, rotating containers of various shapes have been utilized for rolling or tumbling masses of such materials while in a moist condition, but various diiculties or limitations have been encountered as to which the present invention has marked improvement. For example, if the mass being rolled or tumbled in a revolving container becomes too deep, it may move with the rotation of the container and fall in large, heavy masses. Further, the mass may accumulate to such a depth at the lower portion of the container that partially or `fully formed pellets will be crushed, thus greatly decreasing the eiliciency and reducing the amount of finished pellets delivered in a given time from the container; By the present invention, the volume of material treated with relationship to the size of the container is so controlled as to produce the most elective rolling and cascading and pelletforming action of the material.

Furthermore, an object `of the invention is to so shape and position the surface of the container that the balls will be rapidly formed and continuously delivered with a -minimum of escape or overflowing of unformed, unpelletized materials.

In carrying out the present invention, there is provided a large container having a disk-like bottom or inner face, a short cylindrical side wall portion joined to the bottom Wall, and an outwardly llaring frusto-conical Wall portion having a slope which has a predetermined relationship to the axis of rotation of the container. The angle of the axis of rotation may be varied. to position the container for the most effective formation and delivery of the balls or pellets.

The particular novel arrangement of the balling vessel comprising the present invention includes the provision of a corner trough between the flat-disk-like bottom and the short cylindrical side wall portion and the provision of a corner or ridge with relation to the cylindrical wall portion at the connection with the flaring frusto-conical Wall portion. The flaring conical surface serves toy continue and complete the formation-of the pellets.

In the drawings, the balling vessel is shown in vertical axial section, and the mounting and driving means therefor are shown in elevation except `for special sectional de,- tail.

Referring to the details of the illustrative structure shown in the drawing, 9 designates a 'disk and sloping cone assembly comprised of a flat circular disk 10 suitably mounted to be rotated on its central axis. A cylindrical wall 11 of relatively short longitudinal extent is rigid with the perimeter of the disk, and connected to the cylinder wallll and extending outwardly away from the disk is a flaring cone wall 12 which is open at its outer per. imeter 13. The ilare or slope of this conical wall portion 12 is formed at an angle from the axis of the cone which may range from 25 degrees to 30 degrees or more.

In the form of the invention shown, the depth of the vessel or drum formed by the bottom wall 10 and the cylindrical and conical side wall portions 11 and 12, respectively, is less than the diameter `of the bottom wall. The height or axial extent of the conical side wall, on the other hand, is several times the height or axial extent ofthe cylindrical side wall. A particularly successful construction is one in which the depth of the vessel or drum is approximately one-half the diameter of the bottom wall, and the axial extent of the cylindrical side wall is one-tenth to one-fifth that of the conical side wall.

The assembly 9 is mounted with its central axis of rotation at an langle with the horizontal corresponding to the angle of the flare or slope of the conical wall 12, preferably 20 to 25 degrees or more. In the preferred form of the invention, this angle of the axis of rotation of the assembly is made adjustable in any suitable manner, as for example, by the structure described below.

'As shown, the structure for adjustably mounting the above-described assembly and for rotating it about its central axis includes a frame 15 directly connected to the undersurface of disk 10 and to which is secured at 17 an inwardly kextended flange of a spur gear 18, which, in turn, is driven by a pinion 20.

A speed change gear unit 22 having a shaft 21 on which the pinion 20 is rigidly carried is also shown as having a pulley 23 which may be driven by V-belts 24, in turn, driven by the pulley on the shaft of the motor 25. This motor may be carried on a suitable adjustably slidable base 26 for permitting regulation of the tension on the belts. The base 26 of the motor 25 is mounted on the top of a housing 30.

Within the housing 30 is a suitable bearing support (not shown) for a shaft (not shown) connected to the disk 10 and supporting the assembly for rotation. This housing is shown as being pivotally mounted on a suitable pedestal 34 provided with a transverse pivot pin or shaft 35, the pedestal in turn being mounted on a suitable base indicated at 38.

Extending laterally from the base and beneath the overhanging portion of the housing 30 are rigid members 32 which may carry the nut of a suitable jack Lpivoted at 36 to the supporting housing 30 and having a screw portion 33, and which may be operated by a suitable hand wheel W. Obviously this jack may tilt the housing 30 to adjust the angle of the axis of rotation of the assembly. f

As indicated above, the angle of rotation and the positionof the conical side wall 12 may be critical in the pelletizing operation and may need adjustment for varyshatters ing conditions and kinds of materials. An ideal position of the angle of the disk for many materials is that at which the lower portion of the conical side wall 12 is substantially horizontal or tilted upwardly only slightly, as shown in the drawing.

It will thus be seen that when the gear 18 is rotated, the support shaft (not shown) for the assembly 9 will revolve on its bearing support, thus turning the assembly about its axis of rotation while being held at the desired axial position by the housing 30.

It is to be understood, however, that the foregoing structure for mounting and rotating the assembly 9 forms no part of the present invention, and that the invention is not to be limited to the speciiic structure shown, since other supporting and rotating arrangements obviously will be equally well suited for the purposes described.

In operation, the material to be pelletized is preferably fed against the disk l above the center of rotation, as by a suitable conveyor such as a belt 45 or the like, running on a roller 46. The material is shown falling against the disk ttl at A.

Assuming that the disk lil is rotating in a clockwise direction, it is desirable to cause the material to fall upon or meet the disk at a position in a zone at one side of the center, which position may correspond to three or four oclock. The material rolls and cascades on the surface of the disk and is accumulated only to'a limited depth at B in the trough formed at the lower portion of the cylndirical wall lll.

This moving mass is carried upwardly by the cylindrical wall and disk so that the kernels form pellets or balls of increasing size which move outwardly along the lower portion of the conical wall l2 and are discharged over the outer lip l. As the partially formed pellets move outwardly, they are subjected to increasing peripheral speed of surface of rotation of the cone which benecially elects the formation of the pellets or balls.

By this arrangement I attain the combined advantages of the cylindrical side wall type of balling disk and the advantages afforded by the continued, axially longer, ilaring frusto-conical wall. The pelletizing of a larger volume of material is possible and more eective without the heavy deep accumulations of material at the lower portion of the vessel. By the formation shown, the pelletizing is eilected in the Vfollowing three stages: First by cascading on the sloping disk; next by continued rolling and accumulation in the relatively shallow corner trough, and, third, the pelletizing is continued and completed as the material is carried upwardly and falls and rolls back toward the bottom against the upwardly moving surface, while, moving progressively outwardly of the flaring cone. l

lt may be understood that the length or depth of the ilaring cone may be increased or maintained in a relation such that its surface is approximately three or more times the height of the cylindrical wall. The ridge between the cylindrical portion and the ilaring cone has the eilect of a separating rib or zone over which the formed pellets flow and beyond which they may continue to increase in size in the extended conical surface. Thus, the balling vessel is a three element construction and provides a three stage pellet forming operation.

Having thus described the invention, what isv claimed 1s:

l. A -pelletizing apparatus for moist pulverulent material comprising a rotatable drum of a depth less than its diameter and having a relatively large open end and a relatively small closed end, said drum being formed by a lat, round disk-like bottom wall, a cylindrical side wall portion of relatively short axial depth extending from said bottom wall, and a frusto-conical side wall portion of relatively great axial depth fixed to said cylindrical wall portion and daring radially outwardly away from said bottom wall, and the angle of the axis of rotation of said drum forming an angle with the horizontal equal to approximately one-half of the included angle of said frustoconical side wall portion.

2. An apparatus for a pelletizing operation in three stages, comprising a rotatable sloping disk, a rigid cylindrical wall rising from its perimeter, and a frusto-conical surfaceextending from the cylindrical surface and forming a continuation thereof interrupted by an angular ridge portion, and means for delivering pulverulent material to the face of the disk at a position to cascade downwardly of the same while it is rotating and whereby pelletizing is effected on the disk and continued in a trough-like zone between the disk and cylindrical portion, and is further continued as the material ilows. outwardly along the substantially horizontal lower segment of the conical surface.

References Cited in the iile of this patent UNITED STATES PATENTS 2,662,641 Clark et al. Dec. 15, 1953 2,726,959 Lushbough et al. Dec. 13, 1955 2,860,598 Loesche Nov. 18, 1958 2,876,491 Meyer Mar. l0, 1959