Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
  • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
  • B02C18/00—Disintegrating by knives or other cutting or tearing members which chop material into fragments
  • B02C18/06—Disintegrating by knives or other cutting or tearing members which chop material into fragments with rotating knives
  • B02C18/14—Disintegrating by knives or other cutting or tearing members which chop material into fragments with rotating knives within horizontal containers
  • B02C18/146—Disintegrating by knives or other cutting or tearing members which chop material into fragments with rotating knives within horizontal containers with a rotor comprising a plurality of axially contiguous disc-like segments each having at least one radially extending cutting element
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
  • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
  • B02C18/00—Disintegrating by knives or other cutting or tearing members which chop material into fragments
  • B02C18/06—Disintegrating by knives or other cutting or tearing members which chop material into fragments with rotating knives
  • B02C18/14—Disintegrating by knives or other cutting or tearing members which chop material into fragments with rotating knives within horizontal containers
  • B02C18/142—Disintegrating by knives or other cutting or tearing members which chop material into fragments with rotating knives within horizontal containers with two or more inter-engaging rotatable cutter assemblies

Definitions

• the present invention relates to mineral sizing in particular to mineral sizer and a tooth construction.
• a mineral breaker including at least one breaker drum having breaker teeth projecting radially therefrom, the teeth being arranged so as to define a series of discrete circumferentially spaced helical formations extending along the drum.
• a tooth construction for a mineral breaker comprising a support and a removable tooth sheath which covers the support.
• the annuli when assembling a drum composed of a series of annuli, the annuli may be either independantly keyed or splined to the common shaft or they may be rings being fixedly secured to one another to form said drum.
• the former is presently preferred as it enables the drum to be disassembled.
• the assembly of annuli and shaft may be cast integrally to provide a support for the tooth sheaths.
• the tooth sheaths when in position on all projections serve to completely cover the support or drum to thereby protect it from abrasive wear caused by breakage of mineral.
• a mineral sizer having at least one rotatable drum assembly including a tooth construction as defined above.
• Figure 1 is a part perspective view of a mineral sizer according to one aspect of the present invention.
• Figure 2 is an end view, partly in section, of the sizer
• Figure 3 is a side view of the sizer shown in Figure 1;
• Figure 4 is a longitudinal section through the sizer shown in Figures 1 to 3 wherein the sizer teeth are arranged in lines parallel to the axis of rotation of the drums;
• Figure 5 is an exploded perspective view of a tooth sheath and support according to another aspect of the present invention;
• Figure 6 is a diagrammatic end view of the sizer drums shown in Figure 2;
• Figure 7 is a diagrammatic view of the sizer drums shown in Figure 2;
• Figure 8 is a similar view to Figure 4 showing an alternative embodiment according to the present invention
• Figure 9 shows ' a support ring for forming part of a breaker drum in a mineral sizer according to another embodiment of the present invention
• Figure 10 shows a section along line X-X in Figure 9;
• Figure 11 shows a support ring similar to the support ring shown in Figure 9 but of reduced diameter;
• Figure 12 is a front view of a tooth cap for fitting onto the support rings of Figures 9 to 11;
• Figure 13 is a side view of tooth cap of Figure 12;
• Figure 14 is a plan view of the tooth cap of Figure 12;
• Figure 15 is a section along line VII-VII in Figure 14;
• Figure 16 is a section along line VIII-VIII in Figure 14;
• Figure 17 is a side view of a further tooth sheath construction according to the present invention.
• Figure 18 is a section along line A-A in Figure 17;
• Figure 19 is an end view as seen in the direction of arrow B in Figure 17;
• Figure 20 is a side view of a further tooth sheath construction according to the present invention
• Figure 21 is a plan view taken along arrow C in Figure 20;
• Figure 22 is a section view taken along line BB-BB in
• Figure 23 isa part perspective view of a mineral sizer including drum assemblies made up of tooth sheaths and support rings illustrated in Figures 20 - 22.
• the sizer 10 includes a housing 11 having sides 12 and end walls 14.
• the housing 11 is conveniently fabricated from steel plate panels which are bolted and welded together.
• Eotatably mounted ⁇ to extend between the end walls 14 are a pair of breaker drum assemblies 15 each of which is geared at one end to the other so that they are driven from a common drive 18 to be rotated in opposite directions.
• the drums are rotated so as to direct material between them.
• the gear connection between the drums also serves to set the rotary positions of the drums relative to one another.
• Each drum assembly 15 is provided with circumferentially extending groups 19 of breaker teeth 20, the groups 19 being spaced axially along the drum assembly 15.
• the axial spacing of groups 19 on one drum assembly is staggered to that on the other drum assembly so the teeth 20 in a group 19 on one drum assembly pass between an adjacent pair of groups 19 on the other drum assembly.
• the teeth 20 are also preferably arranged to define a series of discrete helical formations 21 which are spaced circumferentially about each drum assembly 15.
• the helical formations 21 as shown in Figures 1 and 7 extend along the axes of each drum in a different sense, i.e.
• each helical formation 21 in extending along its respective drum passes through an arc of about 90°.
• wipo size are such that during use, two types of breaking action are present, viz a primary breaking action on larger pieces of mineral whereat the mineral is gripped between opposing leading faces 46 of teeth on opposite drums and a secondary breaking action wherein mineral is trapped between the rear edges 47 of teeth and the leading face 46 of another tooth.
• the arc through which end helical formation passes is such as to ensure that a secondary breaking action occurs.
• the spacing between the drums is chosen to that when the tips of teeth on one drum sweep passed the trough defined between groups 19 of teeth on the other drum there is sufficient clearance so that compaction of material is avoided. Accordingly by ' a suitable choice of spacing it is possible for fine material to quickly pass through the sizer without compaction, thus leaving the sizer to break down larger pieces of material either by the primary and/or secondary breaking action.
• teeth 20 are designed bearing in mind the hardness and tensile strength of the mineral to be broken.
• the teeth are designed to provide as much bite as possible for the primary type of breaking action for the diameter of the drum assembly so as to positively grip large pieces of material.
• the ratio of height of teeth relative to drum diameter is normally large.
• the tooth height to diameter of drum ratio can be 1 : 4.
• the cross-sectional extent of a bite region 70 for primary breaking is illustrated in Figure 6, the depth of the region 70 is defined by the trailing edge 47 of one tooth and the leading edge 46 of a succeeding tooth; and the length of the region 70 is defined between the leading face 46 of one tooth and the leading face 46* of an opposed tooth on the opposite drum.
• the trailing edge 47 which is slightly curved, but which may be straight if desired, is chosen to be approximately tangential to the drum diameter and the leading face 46 is chosen to be approximately located radially relative to the drum.
• the grip region between teeth on the same group may be varied to
• QMPI alter the size of the grip region by either altering the size of tooth or by altering the number of teeth in each group 19, the maximum grip region being achieved when the point of intersection of face 46 is on or behind (in the direction of rotation of the drum) the location whereat the trailing edge of-the preceding tooth merges into the periphery of the drum.
• a further advantage resulting from the actions imposed on a large piece of material by the helical formations is that the large piece is positively moved along the axes of the drums thereby permitting smaller pieces to pass downwardly thereby and pass through the mineral breaker.
• the mineral breaker is able to handle an in-fill of mineral which contains a large variation in size such as mineral obtained in open-cast quarrying which contains small particulate material as well as large lumps of mineral.
• the teeth impose tensile breaking forces onto the mineral and so positively breaks the material with minimal production of fines.
• each tooth passes between groups of teeth on the opposite drum positive sizing of mineral occurs since the maximum size of mineral passing through the sizer is determined by the space between the trailing edge 47 of one tooth and the leading face 46 of a succeeding tooth and the distance between adjacent groups 19 of teeth. Therefore if the in-fill material contains only large pieces of mineral the mineral on leaving the sizer will contain no pieces over a predetermined size and will contain a small quantity of fines.
• the breaker drums may be inclined to the horizontal and arranged so that large pieces of mineral are made to climb up the incline by the helical formations. Due to the agitation of the large piece of mineral it is likely to fall down the incline and is accordingly repeatedly moved along the drums until it has been broken down sufficiently to be broken by the secondary breaking action.
• the mineral sizer according to the present invention is normally located above a takeaway conveyor TC so that the axes of the drums are generally parallel to the direction of travel of the conveyor TC.
• the sizer By setting the sizer so that the spacing between the drums is generally located above the longitudinal axis of the conveyor material being deposited by the sizer onto the conveyor TC is arranged centrally thereon. This is advantageous as it minimises spillage.
• each drum assembly 15 is shown in longitudinal section in Figure 4 and includes a stepped shaft 25 on which is keyed a support sleeve 26 made up of three support sleeve portions 26a_, b_ and c_.
• the centre sleeve 26b is of larger internal diameter so that it can be easily slid over most of the shaft 25 during assembly and disassembly.
• the sleeve portions 26a, b_ and £ are fixedly secured to one another by weld lines 26d_ so as to form an integral sleeve 26 running the majority of the length of the shaft 25.
• a series of annular support rings 28 are mounted on each sleeve 26 and are secured to one another and also to sleeve 26 by weld lines 30.
• Each ring 28 has a series of teeth support projections 34 integrally formed therewith which are spaced circumferentially about its periphery.
• Each ring 28 is .conveniently formed from a cast metal.
• each ring 28 may be easily set during assembly to align or stagger the teeth support projections 34 of adjacent rings 28 by rotating the rings 28 on sleeve 26 and then fixedly securing them in that position.
• the projections 34 on adjacent rings 28 have been set so that the projections form longitudinally extending rows which are substantially parallel to the axis of rotation of the drum assembly 15 in contrast to the arrangement in Figure 1 wherein adjacent rings 28 have been set so that the projections 34 form the longitudinally extending helical formations 21.
• annular support rings 28 are each keyed or splined directly onto the shaft 25.
• Each ring 28 is therefore only in abutment with its neighbour and the assembly of rings 28 are prevented from axial movement by virtue of a shoulder 25_x and a removable collar 25z_. Accordingly should the shaft or a ring become damaged during use, the shaft and ring assembly may be disassembled for replacement of the damaged component.
• each ring may be easily angularly offset to its neighbour to provide the desired helical formation 21, the amount of offsetting being determined in steps dictated by the pitch of the splines.
• a further alternative is to cast the series of annular support rings and shaft integrally with one another.
• a tooth sheath 40 is secured to each projection 34 via a bolt 41, or other similar means such as a sprung spigot, which is located in pockets 42 in the sheath and are thus protected from damage during use.
• a bolt 41 or other similar means such as a sprung spigot, which is located in pockets 42 in the sheath and are thus protected from damage during use.
• all sheaths When all sheaths are in position they collectively form a cover over adjacent rings 28 so that the rings are protected from wear by mineral being sized.
• Each sheath 40 has an annular base portion 43 which follows the contour of ring 28 and a hollow tooth portion 45 integrally connected to the base portion 43.
• the tooth portion 45 has an internal pocket which is of a complementary shape to a projection 34 so when the tooth portion is seated upon a projection, loads imparted onto the tooth portion 45 during use are transmitted onto the projection 34.
• each tooth is exposed to two main sources of loadings; firstly a loading on its leading face 46 resulting from a primary or secondary breaking action and secondly a loading on its trailing edge 47 resulting from a secondary breaking action.
• the shape of projection 34 and that of tooth portion 45 is-chosen so that when the tooth is exposed to the first type of loading the face 46 transmits the loading onto the leading face 150 of projection 34 and is encouraged to move in a generally radially inward direction so that the sheath 40 is pressed onto the projection 34 and peripheral surface of ring 28.
• the shape of the trailing edge 47 and of the complementary surface 53 of projection 34 are chosen to provide a wedge effect to restrain movement of the sheath 40 in a generally circumferential direction about ri g 28, the wedge effect serving also to transmit loadings on the trailing edge 47 onto the complementary surface 53. Accordingly loadings arising from breakage of mineral are transmitted on to the rings 28 and so bolts 41 are not exposed to loadings and merely act to retain its associated sheath on a projection 34.
• a rebate 60 is preferably provided at the base of each face 46 to receive a marginal end portion of the annular base portion 43 of the pereceding sheath 40.
• the base of each tooth and the base portion 43 of each preceding sheath 40 may be joined together by welding to thereby form a more rigid annular cover for each ring 28. It will be apapreciated that during use, portions of each sheath 40 will wear away and that eventually the sheaths 40 will have to be replaced. This is easily and quickly done with the present sizer by removal of bolts 41 (and, if appropriate removal of weld) and so refurnishment of the sizer teeth may be quickly achieved on site by personnel without the need of heavy lifting gear.
• the inner surfaces of the side walls and end walls may be lined with steel plate which act as wear plates 50, 51 respectively to protect the side and end walls from abrasive wear.
• the wear plates are removably secured in position so that they can be replaced periodically after excessive wear has occurred.
• a row of teeth 62 are provided to extend longitudinally along each side wall to inter esh with teeth 20 to prevent material passing between the side wall and adjacent drum assembly.
• the teeth 62 are conveniently secured to wear plates 50 by welding.
• Each support ring 28 shown in Figures 9 and 11 is provided with a series of teeth support projections 34 which are integrally cast with the support ring.
• the tooth cap 130 illustrated in Figures 12 to 16 is cast from a suitable wear resistant material and its external shape is designed so as to be symmetrical about section lines VII-VII and VIII-VIII respectively.
• the terminal end of each cap 130 terminates in the form of a ridge 136 which extends in the direction of rotation of the drum. By varying the length of the ridge 136 the strength of the tip of the tooth can be adjusted.
• the cap 130 has an internal pocket or recess 131 for receiving a projection 34, the recess 131 having a shape complementary to the shape of projection 34 so that loadings are transmitted onto the projection 34.
• each projection 15 has a pair of recesses 118 (only one of which is visible in Figures 9 and 11) and the internal recess 131 of each cap 130 has inwardly projecting flanges 132 of complementary shapes to recesses 118 so that the flanges 132 and recesses 118 co-operate to positively key the tooth caps 130 in position.
• the caps 130 and projections 34 each have co-operating bores 134 passing therethrough to enable a bolt to be passed through for preventing removal of the cap from an associated projection.
• FIG. 17, 18 and 19 A further alternative of a tooth sheath is illustrated in Figures 17, 18 and 19 wherein the tooth sheaths 40 on a given support ring 28,in addition to being connected to a respective projection 34 by a bolt 41, the tooth sheaths are also connected to one another by a connection formation 200 which is itself preferably tooth shaped. Accordingly, at one circumferential end of each sheath 40 is provided first part 201 of the formation 200 and .at the other circumferential end with a second part 202 of the formation 200.
• the first part 201 is generally tooth shaped having a leading face 203 and trailing face 204.
• the first part 201 is provided with a centrally located recess 206 into which the second part 202 of a preceding sheath 40 projects.
• Both the first part 201 and second part 202 are provided with through bores 208 which align when adjacent sheaths are positioned on a ring 28 and through which a bolt (not shown) is passed in order to secure co-operating parts 201, 202 together.
• connection formations 200 stabilises the annulus of connected sheaths 40 extending about a given ring 28 and serves to
• OMPI y S ⁇ y WIPO reduce chatter between the sheaths 40 and ring 28 during use.
• the teeth 20 with a leading face 46 which has a positive rake as is clearly illustrated in Figure 17.
• a further alternative shape of tooth 20 and corresponding projection 34 is illustrated in Figures 20 to 23 wherein the tooth 20 is in the form of a pick having a generally cylindrical body.
• the sheaths 40 are secured onto a given ring 28 by being connected to one another by connection formations 200 only.
• drums assembled from any of the tooth sheath constructions described above are preferably arranged so that the teeth form helical formations 20.
• Figure 23 which is a view similar to Figure 1 and in which each drum includes a series of sheaths as shown in Figures 20 - 22 arranged to define helical formations 21. rt is however also possible in certain applications for the teeth 20 to be arranged in rows extending generally parallel to the axis of the " drum. It is also envisaged that the helical formations 21 on both drums may extend about their respective axes in the same sense.
• drums may be rotated in - opposite directions so that material deposited thereon is moved toward the side walls of the sizer for breaking.
• a sizer having a single breaker drum may be provided in which the teeth on the drum co-operates with a side wall of the sizer housing and/or static teeth mounted thereon for breakage of mineral.

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• Engineering & Computer Science (AREA)
• Food Science & Technology (AREA)
• Crushing And Grinding (AREA)
• Crystals, And After-Treatments Of Crystals (AREA)
• Disintegrating Or Milling (AREA)
• Preliminary Treatment Of Fibers (AREA)
• Preparation Of Compounds By Using Micro-Organisms (AREA)
• Saccharide Compounds (AREA)

Priority Applications (4)

Applications Claiming Priority (4)

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Cited By (13)

Families Citing this family (24)

Citations (7)

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• 1982
  • 1982-12-17 DE DE8585109073T patent/DE3280148D1/de not_active Expired - Lifetime
  • 1982-12-17 WO PCT/GB1982/000354 patent/WO1983002071A1/en active IP Right Grant
  • 1982-12-17 CA CA000417966A patent/CA1193586A/en not_active Expired
  • 1982-12-17 AT AT85109073T patent/ATE51768T1/de not_active IP Right Cessation
  • 1982-12-17 DE DE8383900287T patent/DE3278128D1/de not_active Expired
  • 1982-12-17 AT AT83900287T patent/ATE32567T1/de not_active IP Right Cessation
  • 1982-12-17 EP EP85109073A patent/EP0167178B1/de not_active Expired - Lifetime
  • 1982-12-17 BR BR8208018A patent/BR8208018A/pt unknown
  • 1982-12-17 EP EP83900287A patent/EP0096706B1/de not_active Expired
  • 1982-12-17 AU AU11063/83A patent/AU561740B2/en not_active Expired
  • 1982-12-20 NZ NZ202861A patent/NZ202861A/en unknown
• 1983
  • 1983-08-16 DK DK373183A patent/DK373183A/da not_active Application Discontinuation
• 1987
  • 1987-04-10 AU AU71432/87A patent/AU593090B2/en not_active Expired

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