US3305090A

US3305090A - Readily renewable sectionalized trommel

Info

Publication number: US3305090A
Application number: US359741A
Authority: US
Inventors: Morawski Frederick Peter; Paul L Fontecchio
Original assignee: Erie Development Co
Current assignee: Erie Development Co
Priority date: 1964-04-14
Filing date: 1964-04-14
Publication date: 1967-02-21
Anticipated expiration: 1984-02-21

Description

Feb. 21, 1967 F. P. MORAWSKI ET AL 3,305,090

READILY RENEWABLE SECTIONALIZED TROMMEL 5 Sheets-Sheet 1 Filed April 14, 1964 Feb. 21, 1967 F, P. MORAWSKI ET AL READILY RENEWABLE SECTIONALIZED TROMMEL 3 Sheets-Sheet 2 Filed April 14, 1964 j j w I l m O L I a I h C L wum Tu Wm 1 I 1 1 h .LL

Feb. 21, 1967 p W K ET AL 3,305,090

READILY RENEWABLE SECTIONALIZED TROMMEL Filed April 14, 1964 5 Sheets-Sheet 5 United States Patent 3,305,090 READILY RENEWABLE SECTIGNALIZED TROMMEL Frederick Peter Morawski and Paul L. Fontecchio, both of Aurora, Minn., assignors to Erie Development Company, Cleveland, Ohio, a corporation of Delaware Filed Apr. 14, 1964, Ser. No. 359,741 3 Claims. (Cl. 209-488) This invention relates to screens, and more specifically to improvements in rotatable circular screens or trommels. The invention, which includes both process and apparatus aspects, finds particular application in connection with a cylindrical or frustoconical trommel of a balling drum of the general type disclosed in US. Patent No. 2,831,210, De Vaney.

The apparatus disclosed in said patent functions to form loose, moist, very finely divided solids into small balls or pellets by prolongedly rolling the fine material, together with nuclei or seed balls, in an inclined, generally horizontal rotatable balling drum and screening undersized balls and loose material from the stream of material constantly discharging at the low end of the drum.

The aforesaid trommel consists essentially of a cylindricalor, frustoconicalskeletal framework made up from an array of lengths of angle stock or girders or the like supporting members which are held in desired spaced relation by one or more transverse bands disposed at a 90 angle to said supporting members. The screening surface of the trommel is formed from an array of generally parallel, spaced wires or rods or equivalent screening members secured in any suitable manner to said supporting members, the width of the interstices between each two adjacent screening members determining the split as between (a) the spherical or spheroidal bodies which are retained on the trommel and are discharged at the low edge of the latter and (b) the nuclei and loose material which drop through said interstices (i.e., are screened out) and then returned to the feed end of the balling drum for a further passage through the latter. The trommel may be constructed as an integral part of the balling drum; or, it may be physically and functionally distinct from the balling drum, being independently mountedat the discharge end of the drumfor rotation and disposed to receive any and all material discharged from the drum.

Where-as is the case in the balling of finely divided mineral solids of the type of iron ore concentratesthe material being balled is abrasive with respect to the metal from which the spaced wires or rods of the trommel are formed, there exists a wear problem necessitating re-building, renewing or repairing the trommel as individual wires or rods become worn through or so badly worn as to cease to screen at desired tolerances. conventionally, such renewal of a trommel has meant withdrawing the involved balling drum from service, removing the entire trommel from the balling drum, rebuilding the removed trommel in its entirety and finally mounting the rebuilt trommel on the balling drum.

It has now been found that the trommel may be so formed that its renewal may be effected much more quickly than heretofore and with very substantial savings in cost of renewal (including both as to down time and as to labor cost and as to materials cost) and hence in the overall cost of the screening operation.

While the trommel of the present invention superficially appears to be identical with the conventional trommel it differs from the latter in being formed from a skeletal supporting structure to which there are readily detachably secured an array of individual panels each of which is independently detachable from and re-attachable to said supporting structure. Preferably, the panels are interchangeable. Each panel is composed of .a sub-frame structure to which there are secured a plurality of spaced, parallely disposed, arcuate rods having a modified T shape (with head and web portions) in cross-section. Preferably, the sub-frame structure comprises a plurality of inverted U-holders-each having a length equal to the width of the individual screening panelprovided with suitable slots or recesses in which slots there are fitted the web portions of the arcuate rods, these rods being tightly fitted into said slots and secured in place therein by means of elongated pinning members each of which latter extends through one U holder and through apertures provided in the webs of the rods.

The assembled trommel screen consists (over and above the aforesaid permanent skeletal supporting structure which is bolted in place at the discharge end of the balling drum proper) of .at least one ringand advantageously a plurality, e.g., three or more, of ringsof the above screen panels disposed with their rods running peripherally of the trommel, each such ring being composed of a plurality of panels, e.g., six more or less panels, the arcs of curvature of which add to a complete circle. The individual panels are disposed in the trommel per se by seating its U-holders on the inner edge portions of supporting framework members of the trommels permanent structure, and the panels are detachably secured to supporting framework members by means of a plurality of spring clips each of which embraces a U holder and a framing member of the supporting structure.

For assembling a panel there is used an assembly jig or positioning fixture comprising two end boards with a plurality of spaced supporting arms fixed between them, with their upper edges at a slightly lower level than that of the upper edges of the end pieces. The end pieces are arcuate, with the same radius of curvature as that of the rods. Preferably, there are the same number of supporting arms as there are U-holders per screen panel. Preferably, also, the cross-sectional characteristics of the supporting arms are made similar to those of the parts of the permanent skeletal framework of the trommel, so that when the completed panel is installed in the trommel, it will be located in the latter by seating its U- holders on the inner edge portions of said framework parts. Accordingly, the spacing of said arms is to be the same as is the spacing of said framework parts.

In assembling a screen panel U-holders are placed over the supporting arms, and the trommel rods are fitted into the slots of the U-holders with their pre-formed pin apertures positioned within the U-holders. Then, the pinning members are inserted above the upper edges of the supporting arms and beneath the U-holders, passing through the pinning apertures in the web portions of the rods, the diameter of these apertures being so selected that the pinning members have a snug fit in the pinning apertures of the rods.

As will, of course, be understood, a used panel may be renewed by replacing only the badly worn rods with new rods.

In replacing a screen panel which shows undesirably severe wear as to some one or more of its rods, the spring clips tying that panel to the skeletal supporting structure of the trommel are disengaged, the old panel is lifted out, a new panel is substituted in the place of the old one, and the newly placed panel is tied in place by means of a plurality of spring clips.

The invention will now be described in greater particularity with reference to the accompanying drawing, in which- FIG. 1 is a top plan view of a completed screen panel, according to the present invention, supported on an assembly jig;

FIG. 2 is a side elevational view of the panel and jig shown in FIG. 1;

FIG. 3 is a detailed showing of a fragmentary portion of the view in FIG. 2 illustrating the mode of securing the screen panel either-as illustrated-to a supporting arm of the assembly jig or to skeletal framework of the tromrnel;

FIG. 4 is a top plan view of the showing in FIG. 3;

FIG. 5 is a vertical sectional view of a portion of a screen panel and of the appertaining part of an assemy i F165. 6 and 7 are perspective views, as assembled and exploded, respectively, of a portion of an assembly jig and partially assembled screen panel; and

FIG. 8 is a fragmentary end view of a portion, only, of an assembled sectionalized trornmel according to the present invention, showing one end of one panel and adjacent portions of two laterally adjacent panels in place on the skeletal supporting structure of the trommel.

In FIGS. 1 and 2 an assembly jig for assembling an individual panel is composed of a stand, consisting of vertical members 1 and horizontal members 2, for arcuate end boards 3, 3 with their transverse support arms 4, 4 (here shown as being six in number). Inverted U-hoiders 6, 6 are disposed on the

arms

4, 4, in the slots 8, 8 of which U-holders there are fitted the

web portions

10, 10 of arcuate trommel rods R, the head portions 11, 11 of which rods extend above the U-holders. Apertures 14 are provided in the

web portions

10, 10 of rods R in line with

support arms

4, 4, and

elongated pinning members

15, 15 are inserted in these apertures to tie the several parts of the screen panel together. These parts can be, and usually are, secured in place, on the assembly jig, by means of

spring clips

18, 18. These spring clips more particularly function-in the use of the screen panel in the trommel-to secure the panel to the supporting framework members 20, (see FIG. 8) of the trommel.

A panel is installed in the trommel by locating the panel with its U-holders over the supporting framework members 20, 20, seating the U-holders on the latter members, and securing the panel to members 20, 20 by applying the

spring clips

18, 18. In case the location of the U-holders, in the panel, is out of phase with the spacing of supporting framework members 20, 20, the U-holders may be moved-to right or to left-to bring them into co-operating relationship with parts 20, 20. As will be apparentto any reader, demounting a worn panel is eifected by removing the spring clips and lifting out the panel.

We claim:

1, A readily renewable sectionalized cylindrical screen structure for sizing particulate material being discharged from a rotatable cylinder, which comprises a cylindrical skeletal supporting framework comprising a plurality of elongated generally parallel spaced ribs, said framework being adapted to be fixed endwise to an end of such rotatable cylinder;

a plurality of arcuately concave screening panels adapted to be detachably secured transverse to the ribs of said framework to constitute in toto a cylindrical screen coaxial with such cylinder,

each said panel being constituted by a sub-frame structure and a plurality of parallel spaced arcuate rods detachabiy secured thereon;

said sub-frame structure including a plurality of spaced generally parallel inverted U-holders having a length substantially equal to the width of the panel and having in the base of the U a plurality of spaced slots accommodating portions of said rods;

and means detachably securing said panels to the ribs of said skeletal supporting framework with the arcuate rods oriented in a direction generally normal to the longitudinal axis of said cylindrical frame work and with the confronting ends of the rods of said panels in substantial alignment with each other.

2. The sectionalized cylindrical screen defined in claim 1, in which said rods have a cross-sectional contour in the form of a modified T with head and web portions integral with each other, the web portions fitting into the slots in said U-holders, in that the web portions of the rods are provided with apertures at loci corresponding to the spacing of said U-holders, and in that elongated pinning members are disposed within said Uholders, said pinning members extending through the apertures in the web portions of said rods.

3. The sectionalized cylindrical screen defined in claim 1, in which each individual panel spans a plurality of ribs and is secured to said ribs with its U-holders seated on said ribs, and in which the detachable securing means are spring clips each of which embraces a U-holder and a rib.

References Cited by the Examiner UNITED STATES PATENTS 380,348 4/1888 Prinz 209-407 X 1,769,128 7/1930 Fisher 209-395 X 1,812,121 6/ 1931 Sklovsky. 2,633,852 4/1953 Lupton 209-407 X 2,711,557 6/1955 Russell 18-1 2,831,210 4/1958 De Vaney 18-1 2,834,043 5/1958 Haley et a1. 18-1 3,042,206 7/1962 Olender 209-405 X 3,073,449 1/1963 Iohanningmeier 209-11 X 3,081,874 3/1963 Corbin 209-403 X FOREIGN PATENTS 14,973 7/ 1901 Great Britain, 243,214 11/1925 Great Britain.

FRANK W. LUTTER, Primary Examiner.

WILLIAM J. STEPHENSON, HARRY B. TI-IORNTQN,

R. HALPER, Assistant Examiners, i

Claims

1. A READILY RENEWABLE SECTIONALIZED CYLINDRICAL SCREEN STRUCTURE FOR SIZING PARTICULATE MATERIAL BEING DISCHARGED FROM A ROTATABLE CYLINDER, WHICH COMPRISES A CYLINDRICAL SKELETAL SUPPORTING FRAMEWORK COMPRISING A PLURALITY OF ELONGATED GENERALLY PARALLEL SPACED RIBS, SAID FRAMEWORK BEING ADAPTED TO BE FIXED ENDWISE TO AN END OF SUCH ROTATABLE CYLINDER; A PLURALITY OF ARCUATELY CONCAVE SCREENING PANELS ADAPTED TO BE DETACHABLY SECURED TRANSVERSE TO THE RIBS OF SAID FRAMEWORK TO CONSTITUTE IN TOTO A CYLINDRICAL SCREEN COAXIAL WITH SUCH CYLINDER, EACH SAID PANEL BEING CONSTITUTED BY A SUB-FRAME STRUCTURE AND A PLURALITY OF PARALLEL SPACED ARCUATE RODS DETACHABLY SECURED THEREON; SAID SUB-FRAME STRUCTURE INCLUDING A PLURALITY OF SPACED GENERALLY PARALLEL INVERTED U-HOLDERS HAVING A LENGTH SUBSTANTIALLY EQUAL TO THE WIDTH OF THE PANEL AND HAVING IN THE BASE OF THE U A PLURALITY OF SPACED SLOTS ACCOMMODATING PORTIONS OF SAID RODS; AND MEANS DETACHABLY SECURING SAID PANELS TO THE RIBS OF SAID SKELETAL SUPPORTING FRAMEWORK WITH THE ARCUATE RODS ORIENTED IN A DIRECTION GENERALLY NORMAL TO THE LONGITUDINAL AXIS OF SAID CYLINDRICAL FRAMEWORK AND WITH THE CONFRONTING ENDS OF THE RODS OF SAID PANELS IN A SUBSTANTIAL ALIGNMENT WITH EACH OTHER.