US2958903A - Briquetting roller press - Google Patents

Description

J. B. DECKER BRIQUETTING ROLLER PRESS Nov. 8, 1960 4 Sheets-Sheet 1 Filed April 21. 1959 INVENTOP Nov. 8, 1960 J. B. DECKER BRIQUETTING ROLLER PRESS Filed April 21, 1959 4 Sheets-Sheet 2 INVENTOR Nov. 8, 1960 J DECKER 2,958,903

BRIQUETTING ROLLER PRESS Filed April 21, 1959 4 Sheets-Sheet 3 {1% Fig. 7

2 INVENTOR Nov. 8, 1960 Filed April 21, 1959 J. B. DECKER 2,958,903

BRIQUETTING ROLLER PRESS 4 Sheets-Sheet 4 IN VE N TOR United States Patent BRIQUETTIN G ROLLER PRESS Johannes Bernhard Decker, Koln-Rath, Germany, as-

signor to Kliickner-Humboldt-Deutz Aktiengesellschaft, Koln-Deutz, Germany, a corporation of Germany Filed Apr. 21, 1959, Ser. No. 807,859

Claims priority, application Germany Apr. 24, 1958 5 Claims. (Cl. 1821) My invention relates to roller presses for the briquetting of ore, coal or similar substances. 7

There are known briquetting roller presses whose two cooperating rollers, geared together for mutually opposed rotation, are each composed of a roller wheel and a wear-resistant jacket formed of a number of individual segments whose respective surfaces are provided with mold cavities for receiving the material to be briquetted. Relative to the axial direction of the rollers, the mold cavities are located in zigzag-shaped rows extending parallel to the roller axis. The longitudinal sides of the segments are planar and intersect a number of mold cavities. The planar shape of the lateral surfaces makes it necessary to have these surfaces placed tightly against each other, because the narrow gap otherwise remaining between adjacent segments may cause the coal or other briquetting material to adhere in those cavities that are bisected by the gaps, so that the pressed briquettes are ejected only incompletely and irregularly. In order to obtain the necessary tight fit between the lateral surfaces without leaving a gap, these surfaces must be machined. This is cumbersome, time-consuming and costly because of the hard material from which the wear-resistant segments are made.

It is an object of my invention to eliminate these disadvantages.

To this end, and in accordance with a feature of my invention, the lateral surfaces of the segments are given a wavy shape and the segments are so fastened on the roller wheel as to leave between each two segments a narrow gap of wave-shaped configuration approximately following the overall contour of the adjacent row of mold cavities.

According to the invention, therefore, the lateral surfaces of the segments do not intersect or bisect any mold cavities but circumvent all of them. Consequently, the narrow gap between the segments does not entail the possibility of briquetting material becoming permanently lodged in the mold cavities during operation of the briquetting press. The wave-shaped gap permits leaving the lateral sides of the segments unmachined so that these sides may be left as that result from molding the segments of cast iron or cast steel, thus affording" a considerable saving in the manufacture of the segments.

During operation of the press, the wavy gaps between the segments fill themselves very rapidly with briquetting material so that the rollers obtain a smoothjand closed surface. If the briquetting material being used is such that it will become decomposed or modified in the gaps during prolonged periods of time and thus may act detrimentally upon the fresh briquetting material, the gaps, according to another feature of my invention, are filled by casting a non-ferrous metal, for example copper, into the gaps, this metal having approximately the same thermal coefiicient of expansion as the cast iron or cast steel of which the segment is made.

According to another feature of my invention, the

segments are so arranged that the center axes of the seg ments, extending lengthwise of the roller axis, are substantially parallel to each other but are skewed relative to the roller axis, so that they form a relatively small acute angle with the generatrices of the cylindrical jacket surface. Such a design of the segments has the effect of considerably reducing any irregularities in the operation of the briquetting press which, if the segments are arranged parallel to the roller axis, are apt to result mainly from the fact that, in certain relative positions of rotation of the two rollers the gaps between the segments of one roller may simultaneously face respective gaps of the other roller.

It is preferable to join each segment on its inner side with the roller wheel by a tongue-and-groove engagement. According to a further feature of my invention, grooves and tongues, inclusive of the appertaining surfaces of mutual engagement, are so designed and arranged that the tongues, grooves and engaging surfaces are exclusively linear and planar, which permits machining these parts in a simple manner.

The drawing illustrates two embodiments of the invention by way of example.

Fig. 1 shows schematically a lateral view of a briquetting roller press.

Fig. 2 shows the pressure gap zone of the same press partly in section and on enlarged scale.

Fig. 3 is a view of one of the briquetting rollers of the press in a radial direction.

Fig. 4 is a perspective View showing schematically the roller wheel of the briquetting roller according to Fig. 3 without the jacket-forming segments.

Fig. 5 is a top view of one of the segments on enlarged scale.

Fig. 6 is a cross section of the segment taken along the line VI--VI in Fig. 5.

Fig. 7 is a cross section of the segment along the line VII-VII in Fig. 5.

Fig. 8 is a view of another embodiment of a press roller with segments extending in skewed relation to the roller axis.

Fig. 9 is a perspective view of two adjacent segments located in respective grooves of the roller wheel, corresponding to the roller according to Fig. 8.

Fig. 10 is a perspective schematical view of the briquetting roller according to Fig. 8 without the segments.

Fig. 11 shows the roller wheel of Fig. 10 by a view taken in the direction of the arrow XI in Fig. 10.

Fig. 12 is a cross section of the same roller wheel along the line XIIXII in Fig. 10.

The briquetting roller press schematically shown in Fig. 1 comprises two briquetting rollers 1 and 2 mounted on respective shafts 4 and 5 which extend parallel to each other. The shafts are journalled in bearings 6 and 7 of the machine frame structure 3. Each shaft carries a coaxial spur gear -8 slightly spaced axially from the roller. The diameters of the two spur gears are equal so that the gears mesh with each other for mutually opposed rotation of the two rollers. The spur gear 8 on shaft 5 meshes with a pinion 9 journalled on the machine frame structure 3 and connected with the drive motor (not shown). Located midway above the two rollers 1 and 2 is a feed hopper 10 represented in simplified manner.

As shown in Figs. 2 and 3, each roller comprises a roller body or wheel 11, 12 which is fastened to the shaft 4 or 5, for example by keys, wedges or the like. An annular jacket encloses the roller wheel and is composed of a number of peripherally sequential segments 15. 'The roller wheel consists of structural steel or cast steel of usual type which can be machined by means of cutting moving tools so that a number of grooves 14 can be milled into the peripheral surface 13 of the roller wheels by milling cutters similar to those used in the manufacture of spur gears.

The individual segments 15 are provided on their outer peripheral surface with oval mold cavities 16 for receiving the briquetting material, each cavity forming one-half of an individual mold. Seen in the direction of the roller axis, the cavities are displaced from each other so that the transverse rows of mold cavities, extending parallel to the roller'axis, have a zigzag over-all shape. These transverse rows are particularly well apparent from Fig. 5, especially in the partially illustrated segments located at the left and right of the illustration. The mold cavities 16 may also be looked upon as being arranged in staggered peripheral groups of which each is displaced from the adjacent one a distance equal to the center spacing between each two successive cavities.

Each segment possesses at on both ends respective extensions 17 and 18 which serve for fastening the segment to the roller wheel. Fastening screw bolts 19 pass through respective bores 28 of the extensions 17, 18 to permit loosening and removing the individual segments. This manner of attachment has the advantage that the pressure body proper of each segment, namely the middle portion with the mold cavities 16, is not interrupted or weakened by bores, so that there is no danger of the segment breaking at such localities. Each segment has a projection or tongue 21 on its inner peripheral side facing the roller wheel, and the roller wheel has respective grooves 14 engaging 14 engaging the tongues. This takes care of having the segments always located at the correct distance from each other, and that the segmentsare well securely prevented from displacement in the peripheral direction of the rollers. The pressure forces resulting from the briquetting operation are transmitted from each segment to the roller wheel through mutually engaging surfaces 22 and 23 which, as apparent from Fig. 4, are preferably given planar shape.

The segments consist of a hard, highly wear-resistant cast iron or cast steel having a hardness of about 54 to 62 Rockwell corresponding to 600 to 800 kg./mm. Vickers. The use of castings has the advantage that the shape of the segments can already be accurately produced during the casting operation. Due to its great hardness, however, such material cannot be machined by chip-removing tools of steel.

As is best apparent from Figs. to 7, the individual segments are so designed and arranged on the roller wheel that, according to the invention, there remains between the adjacent longitudinal sides 24 and 25 a gap 29 of waveshaped configuration following approximately the overall contour of a transverse row of oval mold cavities, each gap extending between two mutually adjacent segments from the outer periphery down to the peripheral surface of the roller wheel. This has the advantage that the individual segments can be directly cast to final dimensions and do not require any further machining at the wavy sides.

It will be seen from Fig. 5 that the wave length of the wavy shape corresponds to twice the spacing of the longitudinally adjacent rows of mold cavities and that the amplitude of the wave shape corresponds to the center spacing of two adjacent cavities in the peripheral rows.

The longitudinal surfaces 24, 25 of the segments are so designed that a bridge 26 of essentially constant width remains between a mold cavity 16 and the next adjacent longitudinal side surface of the segment. The lower edge of the surface 24 on each segment extends parallel to the wave-shaped upper edge, whereas the surfaces 25 of each segment are subdivided. The upper portion 27 of surface 25 has a shape similar to that of surface 24; that is the upper edge and the lower edge are parallel. The lower portion- 28 of surface 25 is inclined so that its lower edge forms a straight line which extends at such a distance from the tongue 21 that it is still located on the engaging surface 22 ofthe roller wheel.

The segments, prior to fastening them to the wheel, are ground at those surfaces that are to engage the roller wheel. In this manner, a particularly reliable area engagement is secured. After attaching the segments to the roller wheel, the jacket formed by the segments is ground at its peripheral surface to accurate cylindrical shape.

During operation of the press, the gaps 29 between the segments fill rapidly with briquetting material, thus giving the rollers a smooth and closed surface. In some cases it is also of advantage to fill the gaps by casting a non-ferrous metal, for example copper, into them. Preferably used is a filler metal having approximately the same thermal coefficient of expansion as the casting material of the segments. The filler metal prevents any briquetting material from becoming lodged between the segments. This is particularly of advantage when using a briquetting material that tends to become decomposed or altered in the gaps during prolonged periods of time and hence may have a detrimental effect upon the fresh briquetting material.

The embodiment illustrated in Figs. 8 and 12 differs from the one described above in that the segments 15 are so shaped and arranged on the roller wheel that the center lines 30 of the segments, extending from one to the other axial end of the roller, remain parallel with respect to each other but are skewed relative to the roller axis so that each center line forms a relatively small acute angle or together with a generatrix line 31 of the geometric cylinder surface defined by the totality of peripheral segment surfaces. This angle a is preferably given such a magnitude that one diagonal of the segment surface, namely the short diagonal, is coincident with'the generatrix 31, i.e. is parallel to the roller axis (Fig. 9).

The skewed arrangement of the segments secures a particularly smooth run of the briquetting press. As mentioned above, a bridge 26 of approximately constant width exists between the lateral, longitudinal surface of each segment and the adjacent mold cavities of the same segment. The next adjacent segment possesses a similar bridge portion 26, the gap 29 being located between these two bridges. Consequently the total width of the bridge area between each two segments is essentially greater than the width of the bridge between each two adjacent mold cavities of the same segment. When the segments are arranged in parallel relation to the roller axis as is the case in the embodiment described above with reference to Figs. 1 to 7, the two wave-shaped bridges with the intermediate gap, during rotation of the rollers, pass at several points simultaneously into the pressure zone between the rollers, and this may result in some disturbance in uniformity of the operation. In contrast, the inclined arrangement of the segments in the embodiment of Figs. 7 to 12 has the effect that the two bridges 26 together with the intermediate gap commence to enter at one side of the rollers into the pressure zone and, in the course of the rotary movement, travel gradually transversely over the width of the pressure zone until they emerge from that zone at the other side of the rollers. Only when a pair of bridges thus emerges at the other side, can the bridges and the intermediate gap of the next following segments pass into the pressure zone. Consequently at any one moment only a small portion of the two bridges and of the intermediate gap is located within the pressure zone, with the effect that the briquetting press exhibits a more regular and quieter run.

As in the embodiment first described, each segment 15 is provided with a projection or tongue 21 which engages a mating groove 14 machined into the roller wheel 11. Engagement faces 22 and 23 are provided in parallel relation to each groove 14 and on opposite sides thereof respectively, for transmitting the pressure forces of the briquetting operation from the segment to the roller wheel. Despite the skewed design of the segment, however, the vggrooves 14 and the projections 21,

clusive of the appertaining engagement faces 22 and 23, are so shaped and arranged that they possess exclusively hnear edges and planar surfaces. The design of Figs. to 12 is such that the bottom face of groove 14 or projection 21 is located in a plane which is uniformly spaced from the roller axis and extends parallel to that axis. The longitudinal edge 32 (Fig. 10) of this bottom face defines, together with a line 33 parallel to the jacket axis and located in the same plane, an angle 6 whlch is preferably equal to the angle a defined by the center line 30 of each segment and the above-mentioned generatrix 31. The two engagement faces 22 and 23 on opposite respective sides beside the groove 14, as well as the projection 21, preferably extend parallel to the bottom face of groove 14. This makes it possible to machine the grooves, projections and engagement faces, out of the peripheral surface of the roller wheel or the underside of the segments, exclusively by longitudinal milling with the aid of shaped milling cutters and by a milling feed motion parallel to the bottom face of the groove or projection. The position of the individual grooves 14 and the correlated engagement faces 22 and 23, relative to the peripheral surface 13 of the roller wheel, is particularly apparent from Fig. 10.

Once the number and shape of the segments 15 is chosen, the corresponding subdivision of the wheel periphery for the grooves 14 and engagement faces 22, 23 to be machined is likewise definitely determined, and the position and course of grooves 14 and faces 22, 23 then result constrainedly according to Fig. 10, it being necessary to always have material of sufficient thickness remain at the periphery of the roller wheel so that the desired dimensions, namely depth and width, of the groove 14 and the width of the faces 22 and 23 can be machined out of the periphery of the roller wheel. In other words, the plane in which the bottom face of groove 14 extends must be given a sufficient spacing from the periphery of the roller wheel. Of particular significance in this respect is the inclined position of the segments 15 of the grooves 14 relative to the axis of the segmented jacket, i.e. the angle a and ,6, both being preferably of the same size.

As mentioned, the projection 21 on the underside of the segment 15, the appertaining engagement faces 22, 23 as well as the extensions 17 possess straight edges and planar surfaces. The end faces on parts 17 of the segments are likewise planar. Otherwise, however, the segment body has spatially-curved surfaces, namely the peripheral outer surface with the mold cavities, and the longitudinal side surface 34 and 35 whose design corresponds to that of the longitudinal surfaces 24 and 25 of the straight segments described above with reference to Figs. 5 to 7, but which are skewed in accordance with the inclined position of the segments.

As in the first embodiment described, narrow gaps 29 of wavy configuration remain between each two adjacent, skewed lateral surfaces 34, 35 of the segments, the width of the gap being made sufficiently large so that the surfaces 34, 35 need not be machined. As mentioned above, this afiords a considerable reduction in manufacturing work.

I claim:

1. A briquetting press comprising two parallel and mutually adjacent press rollers geared together for rotation in mutually opposed directions and forming a pressure zone between each other, each roller having a roller wheel and a wear'resistant jacket composed of a plurality of peripherially sequential mold segments removably bolted to said respective wheels, said segments each being of a hard, highly wear-resistant material and having rows of mold cavities facing respective cavities of the segments on the other wheel when passing through said zone for forming the briquettes, an inner face of each of said segments being coextensively contiguous with an outermost peripheral surface of one of said rollers, the contiguous surfaces forming mating tongue and groove means between each segment and the outer periphery of a respective roller for preventing peripheral movement of the respective segment and for radial removal of the latter, the mutually opposed lateral surfaces of peripherally adjacent segments being spaced from each other sufficiently for as-cast tolerances in the maximum peripheral width of each segment and defining separation gaps between said segments so as to provide no mutual peripheral support between peripherally adjacent segments, said lateral surfaces forming the Walls of said gaps having a wavy configuration substantially following the over-all contour of the adjacent mold cavities.

2. A briquetting press comprising two parallel and mutually adjacent press rollers geared together for rotation in mutually opposed directions and forming a pressure zone between each other, each roller having a roller wheel and a wear-resistant jacket composed of a plurality of peripherally sequential mold segments removably bolted to said respective wheels, said segments each being of a hard, highly wear-resistant material and having a number of peripherally extending rows of equally spaced mold cavities for forming the briquettes, an inner face of each of said segments being coextensively contiguous with an outermost peripheral surface of one of said rollers, the contiguous surfaces forming mating tongue and groove means between each segment and the outer periphery of a respective roller for preventing peripheral movement of the respective segment and for radial removal of the latter, each row of cav ities being displaced in peripheral direction from each adjacent row a distance equal to one-half of the center spacing between the cavities, the mutually opposed lateral surfaces of peripherally adjacent segments being spaced from each other sufficiently for as-cast tolerances in themaximum peripheral width of each segment and defining: separation gaps between said segments so as to provide no mutual peripheral support between peripherally adja-- .cent segments, said lateral surfaces forming the walls of said gaps having a wavy configuration substantially following the over-all contour of alternately displaced mold cavities, the total amplitude of said wavy gap configuration being substantially equal to said displacement distance.

3. In a briquetting press according to claim 1, said roller wheel having a cylindrical peripheral surface, said segments having respective center axes substantially parallel to each other and skewed with respect to the wheel axis so as to form an acute angle with respective generatrix lines of the cylindrical roller peripheral surface, said lines being parallel to the roller axis.

4. In a briquetting press according to claim 2, said mating tongue and groove means being a joint of stepped formation comprising exclusively straight edges and planar surfaces, the bottom surfaces of said segments forming said joint with corresponding outer surfaces of said roller.

5. A roller briquetting press according to claim 1, and including segment spacing means filling said separation gaps between said segments, said spacing means being of a material having approximately the same coefiicient of expansion as said Wear-resistant material of said segments.

References Cited in the file of this patent UNITED STATES PATENTS 538,475 Albrecht Apr. 30, 1895 1,357,141 Bibb Oct. 26, 1920 1,856,906 Carvel Sept. 11, 1930 1,853,824 Krauss Apr. 12, 1932 2,842,071 Perky July 8, 1958

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