GB2048728A - Centrifuge With Abrasion- resistant Conveyor - Google Patents
Centrifuge With Abrasion- resistant Conveyor Download PDFInfo
- Publication number
- GB2048728A GB2048728A GB7916758A GB7916758A GB2048728A GB 2048728 A GB2048728 A GB 2048728A GB 7916758 A GB7916758 A GB 7916758A GB 7916758 A GB7916758 A GB 7916758A GB 2048728 A GB2048728 A GB 2048728A
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- GB
- United Kingdom
- Prior art keywords
- conveyor
- abrasion
- tile
- abrasion resistant
- resistant
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
- B65G33/00—Screw or rotary spiral conveyors
- B65G33/24—Details
- B65G33/26—Screws
- B65G33/265—Screws with a continuous helical surface
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
- B04B—CENTRIFUGES
- B04B1/00—Centrifuges with rotary bowls provided with solid jackets for separating predominantly liquid mixtures with or without solid particles
- B04B1/20—Centrifuges with rotary bowls provided with solid jackets for separating predominantly liquid mixtures with or without solid particles discharging solid particles from the bowl by a conveying screw coaxial with the bowl axis and rotating relatively to the bowl
- B04B1/2008—Centrifuges with rotary bowls provided with solid jackets for separating predominantly liquid mixtures with or without solid particles discharging solid particles from the bowl by a conveying screw coaxial with the bowl axis and rotating relatively to the bowl with an abrasion-resistant conveyor or drum
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Centrifugal Separators (AREA)
- Belt Conveyors (AREA)
- Screw Conveyors (AREA)
Abstract
In a conveyor centrifuge abrasion resistant edge members (28J) are mounted on the flights (22) of the conveyor using an intermediate shock absorbent backing tile (26J) secured to the conveyor flight e.g. by welding (as at 30) and to which the abrasion resistant members are secured by a mechanical connection, e.g. a rivet (94) as shown. <IMAGE>
Description
SPECIFICATION
Centrifuge with Abrasion-Resistant Conveyor
This invention relates to centrifuges for separating solids-liquid mixtures which include a rotatable bowl and an abrasion-resistant conveyor within the bowl, rotatable on a common axis therewith.
Abrasion-resistant conveyors are desirable in centrifuges to prolong centrifuge life by retarding conveyor wear. In the absence of an abrasionresistant conveyor, centrifuge life may be unacceptably short due to presence of abrasive materials in the input solids-liquid mixture or due to careless input of solids-liquid mixtures for which the centrifuge was not designed and which contain extraneous materials (tramp metals, large stones, etc.) not anticipated by the centrifuge process engineers. Such abrasive materials cause the centrifuge conveyor to wear quickly.
Early techniques for producing an abrasionresistant centrifuge conveyor involved melting and fusing a more abrasion-resistant material, such as a nickel or cobalt alloy, directly onto the conveyor helical flight using an oxy-acetylene gas torch, in a manner similar to welding or brazing.
Later, preformed pieces of abrasion-resistant material were mechanically secured, typically with bolts, directly to the conveyor outer edge.
(As used herein, the word "mechanical," and variations thereof, when modifying an expression of means for performing the function of structurally connecting and fastening two members, denotes those means which function without requiring simultaneous application of heat to both of the two members for the members to be immovably secured one to another.) The brittle character of the preformed pieces of abrasion-resistant material resulted in the pieces cracking and subsequently failing. (Most known abrasion-resistant materials are quite brittle.
Indeed, as a general rule, the more abrasion
resistant is a material, the more brittle is the
material.) The preformed pieces of abrasion
resistant material were unable to withstand
stresses created when extraneous solids in the
input solids-liquid mixture impacted the
preformed pieces of abrasion-resistant material.
Loosening and unscrewing of the bolts also
resulted in failure of the preformed pieces.
Subsequently, preformed pieces of abrasion
resistant material were bonded directly to the
conveyor helical flight with adhesives. In such
applications, it proved impossible to achieve
adequate bonding of the abrasion-resistant
material pieces to the conveyor due to the
difficulty in properly preparing the conveyor
helical flight surface to receive the adhesive.
These ad hesive-secu red abrasion-resistant
material pieces failed too, by loosening form the
conveyor flight, due to stress created in the
adhesive joints when extraneous solids in the
solids-liquid mixture impacted the preformed
pieces of abrasion-resistant material.
When preformed pieces of abrasion-resistant material were brazed directly to the helical flight, unsatisfactory results were again obtainedthe high heat input over a wide area of the conveyor sometimes caused serious warping of the conveyor whereupon it became impossible to insure good brazing adhesion of the preformed pieces to the conveyor. Particularly in the cases of centrifuge conveyors operated at high speeds, imperfect braze bonds between the preformed pieces and the conveyor were susceptible to breakage with consequent risk of damage to surrounding parts. Furthermore, conveyors having preformed pieces of abrasion-resistant material brazed directly thereto were difficult to repair by brazing replacement pieces of abrasion-resistant material in place, because such brazing again required application of heat to a broad area of the conveyor.This adversely affected the braze bonds between the conveyor and the pieces of abrasionresistant material proximate the replacement piece.
Later, abrasion-resistant materials were bonded (by brazing or with adhesives) to intermediate backing tiles formed of metals weldable to the conveyor to form assemblies which were subsequently welded to the conveyor, as disclosed in U.S. patent 3,764,062. The approach disclosed in the '062 patent has been quite successful.
Other approaches to providing an abrasionresistant conveyor include that of West German
Offenlegungsschrift 2,450,337, which discloses lugs secured to the conveyor near the conveyor distal edge, with pieces of abrasionresistant material contacting the conveyor and held in interlocking engagement with the lugs by shims interposed between the pieces of abrasionresistant material and the conveyor or between the pieces of abrasion-resistant material and the lugs. The shims wedge the pieces of abrasionresistant material against the lugs, preventing the pieces of abrasion-resistant material from moving radially outwardly with respect to the conveyor. In the constructions disclosed in Offenlegungsschrift 2,450,337, the pieces of abrasion-resistant material abut the conveyor and hence are not stress-isolated from the conveyor.
Yet another approach is to weld a number of machines lugs to the conveyor surface so that the lugs' sloped lateral surfaces, together with the radially extending surface of the conveyor, provide a series of dovetail grooves. Pieces of abrasionresistant material having tapered lower portions fit in the dovetail grooves and form the abrasionresistant surface of the conveyor. Adjacent pieces of abrasion-resistant material alternately have rectangularly and trapezoidally configured upper portions. When inserted in the grooves these alternating rectangularly and trapezoidally configured pieces wedge against each other, thereby maintaining their positions on the conveyor outer edge.
Abrasion-resistant materials used in centrifuges include carbides, ceramics, cermets and special metal castings, are typically hard and brittle and have very little impact strength.
(Carbides are the most desirable material for obtaining the abrasion-resistant property on the conveyor because carbides are more resistant to scratching, grinding and gouging abrasion, and are tougher, than ceramics and other abrasionresistant materials). Because of such physical properties, abrasion-resistant materials generally require support where they are subject to impact loading such as routinely experienced by centrifuge conveyors. One successful approach to providing support when abrasion-resistant materials are used on centrifuge conveyors is the intermediate backing tile concept disclosed in the '062 patent. The backing tile is preferably a material more ductile, and hence more shockabsorbing and more shock-resistant, than the abrasion-resistant material.
Where abrasion-resistant materials are used in centrifuges and are supported by more ductile and therefore more shock-resistant materials, the abrasion-resistant material must be tightly secured to the support material, to assure that the support material receives the shock loads experienced by the abrasion-resistant material.
Furthermore, the abrasion-resistant material, the shock-absorbing support material, the means securing the abrasion-resistant material to the shock-absorbing support material to the conveyor must all withstand high centrifugal, thermal, corrosive and impact load conditions within centrifuges. Moreover, when the abrasionresistant material is secured to the shockabsorbing support material and when the shockabsorbing support material is secured to the conveyor helical flight, the means securing these members together should be chosen to avoid creation of residual stresses in the abrasionresistant material and in the shock absorbing support material.If residual stresses, however created, are present, either in any part of the abrasion-resistant material assemblies secured to the conveyor outer edge or in the means used to secure the assemblies together and to the conveyor outer edge, the residual stresses necessarily increase the failure rate of the abrasion-resistant material assemblies and accordingly shorten the conveyor service life.
Also, it is desirable to minimize, and preferably eliminate, physical contact between the abrasionresistant material and the conveyor, to insulate the abrasion-resistant material from the effects of dynamic stresses and strains occurring in the conveyor helical flight during centrifuge operation.
To further increase service life of abrasionresistant conveyors used in centrifuges by minimizing residual stresses in abrasion-resistant material assemblies secured to the conveyor outer edge and by insulating the abrasionresistant material from dynamic stresses and strains occurring in the conveyor during centrifuge operation, this invention provides centrifuge apparatus with abrasion-resistant
material assemblies mounted at the conveyor outer edge which use mechanical attachments to secure an abrasion-resistant member to a shockabsorbing backing tile. The mechanical attachments may also be used to secure the shock-absorbing backing tile to the conveyor helical flight. The mechanical attachments are preferably made of corrosion-resistant materials which retain their strength at high temperatures.
Use of such mechanical attachments allows the elimination of exposed brazed joints between members within the centrifuge; the braze material is preferably shielded from the mixture being separated within the centrifuge. This is desirable since some mixtures separated in centrifuges are not only hot but also chemically attack braze material.
The invention is further described with reference to the accompanying drawings, in which:
Figure 1 is a broken side sectional view of a centrifuge embodying the invention.
Figure 2 is a broken sectional view taken at arrows 2-2 in Figure 1, with the centrifuge bowl shown in phantom lines.
Figure 3 is a schematic sectional view of a preferred embodiment of an abrasion-resistant conveyor surface assembly embodying the invention, taken at arrows 3-3 in Figure 2.
Figure 4 is a sectional view taken at arrow 44 in Figure 3.
Figures 5 and 6 are sectional views of other embodiments of abrasion-resistant conveyor surface assemblies manifesting the invention, both taken at the position denoted by arrows 33 in Figure 2.
Figure 7 is a perspective view of an urging means member portion of the abrasion-resistant conveyor surface assembly illustrated in Figure 6.
Figures 8 through 23 are sectional views of other embodiments of abrasion-resistant conveyor surface assemblies manifesting the invention, all taken at the position denoted by arrows 3-3 in Figure 2.
Figure 24 is a sectional view taken at arrows 24-24 in Figure 23.
Figures 25 and 26 are sectional views of other embodiments of abrasion-resistant conveyor surface assemblies manifesting the invention, both taken at the position denoted by arrows 33 in Figure 2.
Figure 27 is a broken view of a shockabsorbing backing tile and an abrasion-resistant member of an abrasion-resistant conveyor surface assembly embodying the invention, illustrating tile-member interlocking.
Figure 28 is a sectional view of yet another embodiment of an abrasion-resistant conveyor surface assembly manifesting the invention, taken at the position denoted by arrows 3-3 in Figure 2.
Figure 29 is a broken sectional view of a portion of a backing tile into which a rivet, also shown but not in section, is swaged in place to secure the abrasion-resistant member to the backing tile in the embodiment illustrated in
Figure 17.
Figure 30 is a broken view of a shockabsorbing backing tile taken at the position denoted by arrows 30-30 in Figure 27.
Figure 31 is a view of an abrasion-resistant member taken at the position denoted by arrows 31-31 in Figure 27.
Figure 32 is a sectional view of yet another embodiment of an abrasion-resistant conveyor assembly manifesting the invention, taken at the position denoted by arrows 3-3 in Figure 2.
Description of the Preferred Embodiments
A centrifuge embodying the invention is illustrated in vertical section in Figure 1, and is designated generally 10. The centrifuge includes a rotatable bowl 12 with a screw conveyor designated generally 14 therewith in, with the screw conveyor rotatable on a common axis with the bowl. During operation the bowl and conveyor are rotated at slightly different speeds by motor and gear means, which have been substantially broken away and are denoted 1 3. Bowl 12 rotates on bearings within a housing 151which has been largely broken away in Figure 1), is of frustocylindrical configuration and includes a solids discharge port 1 7 in the frustum end thereof.
Conveyor 14 includes a generally central hub 20 with a helical flight 22 extending radially therefrom. Mounted at the distal edges of flight 22 are a plurality of preferably abutting, and in any case at least closely spaced, abrasionresistant surface assemblies designated generally 24; relationship of these assemblies 24 to conveyor flight 22 is shown in Figure 2.
During operation, an input slurry is introduced to the centrifuge through a feed tube 32 and passes through inlet port 18 in hub 20 into space between bowl 12 and conveyor 14. As the bowl and conveyor rotate, centrifugal forces cause the heavier, more dense solids to move radially outwardly with respect to the conveyor to positions proximate the bowl interior surface 34.
The conveyor, rotating at a slightly different speed than the bowl, moves the separated solids towards solids discharge port 1 7. Separated liquid moves to a liquid discharge port, not shown.
Referring to Figure 2, abrasion-resistant surface assemblies 24 are mounted at the distal outer edge of helical flight 22 of the conveyor and prolong conveyor life by retarding wear of the conveyor outer edge. A plurality of assemblies 24 are mounted, preferably in abutting relationship, to present a preferably substantially continuous helical surface at the conveyor outer edge, to convey solids towards the solids discharge port and to resist abrasive wear due to extraneous materials in the solids.Each abrasion-resistant surface assembly 24 is secured together mechanically and preferably is thereafter secured to the conveyor outer edge: mechanical fastening means minimize residual stresses in the abrasionresistant material assemblies and insulate the abrasion-resistant material in the asssemblies from dynamic stresses and strains which occur in the conveyor during centrifuge operation.
Referring to Figure 3, which sets forth the best mode presently comtemplated for carrying out the invention, a first embodiment of an abrasionresistant surface assembly, designated generally 24, is secured to a distal edge of conveyor flight 22, preferably by weldments 38, and includes a shock-absorbing backing tile 26, preferably welded to conveyor flight 22, and an abrasionresistant member 28 mechanically secured to backing tile 26 by locking bar 36. The abrasionresistant member is separated and therefore shock and vibration isolated from the conveyor flight by the backing tile. (For additional shockisolation of abrasion-resistant member 28 from the conveyor flight, shock-absorbing grout, which acts as a cushion, is preferably provided between the abrasion-resistant member and the backing tile.The grout fills voids which exist between the mating surfaces of the abrasion-resistant member and the backing tile; such voids necessarily exist since it is not within the scope of present technology to machine a perfectly flat surface.
Suitable grouts include pastes, lead foils, etc. The grout is not an indispensable portion of the invention but use of grout is desirable since the grout further enhances the reliability of centrifuges embodying the invention by providing additional shock-isolation of the abrasionresistant members from the conveyor flight.
Unless otherwise stated hereinbelow, in each embodiment use of grout between the abrasionresistant member and the shock-absorbing backing tile is understood.)
Interlocking complementary mating surfaces 27 and 29, of tile 26 and abrasion-resistant member 28 respectively, prevent radially outward movement of abrasion-resistant member 28 with respect to conveyor flight 22 during centrifuge operation. Locking bar 36 contacts both the abrasion-resistant member and the backing tile at positions remote from complementary mating surfaces 27 and 29 and serves as means for mechanically connecting the abrasion-resistant member to the backing tile.Locking bar 36 passes through at least one passageway in backing tile 26 and has a transversely extending section 36B which abuts a canted inboard lower surface 60 of the abrasion-resistant member, so that bar 36 thereby additionally acts as means for urging the abrasion-resistant member radially outwardly with respect to the conveyor hub (upwardly as viewed in Figure 3) until complementary mating surfaces 27 and 29 are tightly engaged. Lower surface 60 is canted towards the conveyor hub as lower surface 60 extends from solids displacing surface 41 of abrasion-resistant member 28.
The canted configuration of lower surface 60 results in the abrasion-resistant member moving radially outwardly, as the locking bar 36 is wedged into place during assembly of the abrasion-resistant surface assembly 24, to
engage complementary mating surfaces 27 and
29. Such canted surfaces, and variants thereof,
are used in many embodiments illustrated herein
to affect engagement of complementary mating
surfaces of the backing tiles and the abrasion
resistant members when the abrasion-resistant
surface assemblies are produced. (The phrase
"canted surface" and variants thereof are used to
denote a configuration similar to that illustrated in
Figure 3, i.e. a surface which slopes towards the
conveyor hub as the surface extends in the axial
direction with respect to the conveyor).
Bar 36 is maintained in position by a neck
portion 36C, which passes through passageway
140 in backing tile 26, and by a head portion 36A
which is deformed against the backing tile after
bar 36 has been positioned in the backing tile
passageway. This construction is best shown in
Figure 4. Transverse portion 36B of locking bar
36 is preferably interference fitted between
canted inboard lower surface 60 of abrasion
resistant member 28 and backing tile 26. Locking
bar head 36A is a deformable material such as
steel and, after the locking bar has been inserted
into a passage-way through the backing tile, is
deformed against backing tile 26 to retain the
locking bar urging means in contact with the
abrasion-resistant member and the backing tile.
The configuration of the abrasion-resistant member and the backing tile which provides interlocking engagement of these two members, preventing radially outward movement of the abrasion-resistant member with respect to the conveyor helical flight as the conveyor rotates, is best shown in Figures 27, 30 and 31.Abrasionresistant member 28 has a distal surface 40, which is distally remote with respect to the conveyor hub and faces radially outwardly with respect thereto, a radially extending solids displacing surface 41 which extends generally outwardly with respect to the conveyor axis of rotation and faces generally towards the solids discharge port, a first rear surface 42 and a second rear surface 43 connected via angularly disposed complementary mating surface 29, with the juncture between surface 29 and surface 42 forming a radially outwardly facingxconvex (with respect to the conveyor axis of rotation) vertex 55 and with the juncture of surface 29 and surface 43 forming a radially outwardly facing convex (with respect to the conveyor axis of rotation) vertex 44.Solids displacing surface 41 may be perpendicular to the conveyor axis of rotation, as shown, or may be at angle thereto. Shockabsorbing backing tile 26 has a distal surface 50 facing outward with respect to the conveyor axis of rotation, a first forward surface 52 and a second forward surface 51 connected to surface 52 by angularly disposed (with respect to the conveyor axis of rotation) complementary mating surface 27. The juncture of surfaces 51 and 27 forms an inward facing (with respect to the conveyor axis of rotation) concave vertex 54 while the juncture of surfaces 27 and 52 forms an inward facing (with respect to the conveyor axis of rotation) concave vertex 53.
Vertices 44, 53, 54 and 55, formed by the juncture of two surfaces, are curved lines, as best shown in Figures 30 and 31. The vertices are denominated as either concave or convex based on the shape of the line defined by the surface junctures. The junction of surfaces 51 and 27 forms vertex 54 which, as seen in Figure 30, is an edge on backing tile 26 which is concave with respect to the axis of conveyor rotation; hence vertex 54 is demoninated as "concave". Juncture of surfaces 52 and 27 forms vertex 53 which, as also seen in Figure 30, is an edge on backing tile 26 which is concave with respect to the axis of conveyor rotation and hence vertex 53 is also denominated as "concave".Juncture of surfaces 43 and 29 forms vertex 44 while juncture of surfaces 29 and 42 forms vertex 55; these vertices both are edges on abrasion-resistant member 28 which are "convex" with respect to the conveyor axis of rotation and hence are so denominated.
As abrasion-resistant member 28 is forced into engagement with backing tile 26 by one of the various mechanical securing means within the scope of the invention, such as locking bar 36 illustrated in Figures 3 and 4, abrasion-resistant member 28 moves radially outwardly with respect to the conveyor hub, with abrasionresistant member second rear surface 42 in sliding contact with backing tile first forward surface 52. As the abrasion-resistant surface assembled, with the abrasion-resistant member secured in place, complementary mating surfaces 27 and 29 come into contact, inwardly facing concave vertex 54 is received bv outwardly facing convex 44 and outwardly facing convex vertex 55 is received by inwardly facing concave vertex 55 is received by inwardly facing concave vertex 53.
The angular disposition of complementary mating surfaces 27 and 29, with mating vertices 44 and 54 positioned more radially inboard with respect to the conveyor hub than mating vertices 53 and 55, prevents radially outward movement of the abrasion-resistant member when complementary mating surfaces 27 and 29 are in tight engagement and convex vertices 44 and 55 have been received by concave vertices 54 and 53 respectively. This configuration, and variants thereof, is used in many embodiments illustrated herein. Moreover, when the phrase "compiementary mating surfaces" and variants thereof are used hereinafter, they shall be understood to denote a configuration such as illustrated in Figure 27, with equivalents to the complementary mating surfaces 27 and 29 and equivalents to the mating pairs of concave and convex vertices 54, 53 and 55, 44 oriented in a similar manner, to prevent radially outward movement of the abrasion-resistant member with respect to the tile as the conveyor rotates and to concomitantly effectively fix the abrasionresistant member in place with respect to the shock-absorbing backing tile.
Figure 5 illustrates another embodiment of an
abrasion-resistant surface assembly designated
generally 24A wherein the mechanical
connection means for securing shock-absorbing
backing tile 26A and abrasion-resistant member
28A together includes a wedge plate 62 secured
in place by one or more screws 44 passing
through passageway 1 50 in backing tile 26A and
threadably engaging corresponding tapped holes
in wedge plate 62. Backing tile 26A is secured to
the distal edge of helical flight 22, preferably by
weldments 30. Wedge plate 62 abuts canted
lower surface 60 of abrasion-resistant member
82A.As screw 44 is tightened, it urges wedge
plate 62 to the left as viewed in Figure 5; due to
the canting of surface 60 and of the unnumbered
surface of the wedge plate which slidably
contacts surface 60, leftward movement of wedge plate 62 urges abrasion-resistant member
28A radially outward with respect to the conveyor
hub (upwards as viewed in Figure 5) with
complementary mating surfaces 27 and 29 thus being forced into tight engagement. Screw 44 serves as means for mechanically securing the wedge plate urging means to the shockabsorbing backing tile.
Figure 6 illustrates another embodiment of an abrasion-resistant surface assembly designated generally 24B wherein the mechanical connection means for securing shock-absorbing backing tile 26B and abrasion-resistant member 28B together includes a wedge plate 62A secured in place by means of two pins 63 which extend from the wedge plate through a passageway 180 in the backing tile and are welded to a rear surface of backing tile 26B. Backing tile 268 is secured to the distal edge of helical flight 22, preferably by weldments 30. Wedge plate 62A abuts canted lower surface 60 of abrasion-resistant member 28B.When pins 63 are welded to the rear surface of backing tile 26B, after wedge plate 62A has been forced, with an interference fit, into the recess formed by surface 60 of the abrasionresistant member and by a notch, unnumbered, in the backing tile, abrasion-resistant member 288 is effectively restrained against movement by wedging action of wedge plate 62A and contact of complementary mating surfaces 27 and 29.
The configuration of wedge plate 62A and the curved shape of pins 63, which facilitates welding of the pins to backing tile 26B, are best illustrated in Figure 7.
Figure 8 illustrates another embodiment of an abrasion-resistant surface assembly designated generally 24C wherein the mechanical connection means for securing shock-absorbing backing tile 26C and abrasion-resistant member 28C together includes a wedge plate 62B secured in place by a screw 44A which is threadably engaged with a tapped hole in wedge plate 62B and which passes through both the shock-absorbing backing tile 26C and the conveyor helical flight 22. Shock absorbing backing tile 26C is secured to conveyor helical flight 22 by weldments 30 and by compression force exerted thereon by wedge plate 62B as screw 44A is tightened.
Complementary mating surfaces 27 and 29 are provided on abrasion-resistant member 28C and shock-absorbing backing tile 26C respectively, to prevent radially outward movement of the abrasion-resistant member with respect to the conveyor hub. Wedge plate 62B fits between canted lower surface 60 of abrasion-resistant member 28C and a shoulder 64 formed in the shock-absorbing backing tile. During assembly, as screw 44A is threaded into wedge plate 628, the canted configuration of surface 60, where it abuts wedge plate 62B, effectively urges the complementary mating surfaces of the abrasionresistant member and the shock absorbent backing tile into tight engagement by forcing abrasion-resistant member 28C vertically upward as viewed in Figure 8.Although in the embodiment illustrated in Figure 8 the shockabsorbing backing tile has been secured to the conveyor by weldments 30, in another embodiment holes through the conveyor flight and the shock-absorbing backing tile are tapped (in addition to the hole in wedge plate 62B), so that when screw 44A is threadably engaged through conveyor flight 22, shock-absorbing backing tile 26C and into wedge plate 628, the component parts of abrasion-resistant assembly 24C are secured together, without the necessity of welding the backing tile to the conveyor helical flight.
Figure 9 illustrates another embodiment of an abrasion-resistant surface assembly designated generally 24D wherein the mechanical connection for shock-absorbing backing tile 26D and abrasion-resistant member 28D is provided by means of dovetail groove-configured cavity cut into shock-absorbing backing tile 26D and a complementary configured dovetail portion of abrasion-resistant member 28D slidably resident therein. Shock-absorbing backing tile 26D is secured to conveyor flight 22, preferably by weldments 30. The vertex forming the more radially outboard portion of the dovetail groove, denoted by circle A in Figure 9, is configured substantially as shown in Figure 27 and as described above with reference thereto.These complementary mating surfaces of the abrasionresistant member and the shock-absorbing backing tile effectively prevent movement of the abrasion-resistant member radially outward with respect to the conveyor hub. Canted lower surface 60 of abrasion-resistant member 28D diverges from angularly disposed complementary mating surface 29 of the abrasion-resistant member, as one proceeds axially away from the solids displacing surface 41. Similarly, the lower shoulder formed in the shock-absorbing backing tile 26D, which, as viewed in Figure 9, forms the lower portion of the dovetail groove, is configured to complementally receive surface 60 when the abrasion-resistant member is slidably inserted into the shock-absorbing backing tile. This configuration prevents the abrasion-resistant member from moving, with respect to the backing tile, radially inwardly towards the conveyor hub.
Assembly of the dovetail portion of abrasionresistant member 28D into the dovetail groove portion of shock-absorbing backing tile 26D is preferably performed before backing tile 26D is welded to the conveyor helical flight.
Figure 10 illustrates another embodiment of an abrasion-resistant surface assembly designated generally 24E wherein the mechanical connection means for securing shock-absorbing backing tile 26E and abrasion-resistant member 28E together is provided by a deformable portion 25, extending from shock-absorbing backing tile 26E, which portion is bent against abrasion-resistant member 28E during assembly to urge the abrasionresistant member radially outwardly with respect to the conveyor hub and thereby retain the complementary mating surfaces (which are not numbered in Figure 10) of abrasion-resistant member 28E and shock-absorbing backing tile 26E in tight contact. The backing tile is undercut, as shown at 190, to make portion 25 more deformable. Shock absorbing backing tile 26E is again secured to conveyor helical flight 22, preferably by weldments 30.The abrasionresistant surface assembly is depicted in the assembled condition in Figure 10, with deformable portion 25 bent into place against abrasion-resistant member 28E. The position of deformable portion 25 before bending is shown in dotted lines.
Figure 11 illustrates another embodiment of an abrasion-resistant surface assembly designated generally 24F wherein the mechanical connection means for securing shock-absorbing backing tile 26F and abrasion-resistant member 28F together includes protruding deformable means 25A, preferably but not necessarily formed as a portion of backing tile 26F. Deformable means 25A preferably extends from a central area of backing tile 26F and resides at least partially in a tapered passageway 29 through abrasion-resistant member 28F. Passageway 29 tapers from a smaller diameter at the tile-member interface to a greater diameter at the abrasion-resistant membsr's solids displacing surface 41.When deformable means 25A is separated and the portions thereof are urged against the walls of passageway 29, the protruding deformable means effectively resists radially outward and radially inward movement of the abrasionresistant member with respect to the tile. In this embodiment, no complementary mating surfaces (in the sense that that term is defined with respect to Figure 27) are required; deformable means 25A resident in passageway 29 of the abrasion-resistant member effectively performs the function of resisting radially outward movement of the abrasion-resistant member as the conveyor rotates. The shock-absorbing backing tile 26F is again secured to the conveyor helical flight, preferably via weldments 30. As a variation, passageway 29 need not extend entirely through abrasion-resistant member 28F; passageway 29 may also be configured as a cavity with a closed bottom.As a further variation, the configuration shown in Figure 11 may be reversed. In such case, the passageway or cavity may be provided in the shock-absorbing backing tile, with a deformable protruding portion for insertion thereinto extending from the abrasion-resistant member.
Figure 12 illustrates another embodiment of an abrasion-resistant surface assembly designed generally 24V wherein the mechanical connection means for securing shock-absorbing backing tile 26V and abrasion-resistant member 28V together includes a rivet 150, having a deformable shaft portion 152, where the rivet head resides in a counterbore 1 54 in the abrasion-resistant member. During assembly, deformable portion 1 52 is urged against the walls of passageway 1 56 in shock-absorbing backing tile 26V, to retain abrasion-resistant member 28V in tight contact against backing tile 26V. Passageway 1 56 preferably tapers from a lesser diameter at the tile-member interface to a greater diameter at the rear surface of the shock-absorbing backing tile, remote from the tilemember interface.Preferably two deformable rivet-cou nterbore-passageway combinations are used to secure the abrasionresistant member to the shock-absorbing backing tile, to prevent the abrasion-resistant member from rotating with respect to the tile. The shockabsorbing backing tile is secured to the conveyor helical flight 22, preferably via weldments 30.
Similarly to the embodiment illustrated in Figure
11, the embodiment illustrated in Figure 12 does not require complementary mating surfaces of the type described with reference to Figure 27 to prevent movement of the abrasion-resistant member radially outwardly with respect to the conveyor hub. Such movement is prevented by deformable shaft portion 1 52 residing within and contacting the walls of passageway 1 56.
Figure 32 illustrates another embodiment of an abrasion-resistant surface assembly designated generally 24G wherein the mechanical
connection means for shock-absorbing backing tile 26G and abrasion-resistant member 28G
includes a rivet 80 secured to abrasion-resistant
member 28G, preferably by brazing with the
brazing done so that the braze material is entirely
between rivet 80 and abrasion-resistant member
28G so corrosive materials being separated within the centrifuge cannot attack the braze
material. The rivet connects the abrasion-resistant
member to the shock-absorbing backing tile by virtue of at least one rivet shaft portion 81 which
resides in at least a portion of passageway 82 through backing tile 26G. The shaft portion of the
rivet is deformed, as shown, or welded against the
interior walls of passageway 82 during fabrication
of the abrasion-resistant surface assemblies.
Alternately, adhesives may be used to secure the
shaft portion 81 of rivet 80 to backing tile 26G
and may also be used to secure rivet 80 to
abrasion-resistant member 28G; brazing could
also be used. Backing tile 26G is secured to
conveyor flight 22, preferably by weldments 30.
Similarly to the embodiment illustrated in Figure 11, the embodiment illustrated in Figure 32 does not require complementary mating surfaces of the type described with reference to Figure 27 to prevent movement of the abrasion-resistant member radially outwardly with respect to the conveyor hub. Such movement is prevented by shaft portion 81 of rivet 80 residing within and contacting the walls of passageway 82 and by rivet head residing in a counterbore formed in abrasion-resistant member 26G. Moreover, as a variation, passageway 82 need not extend entirely through shock-absorbing backing tile 26G;lpassageway 82 may also be configured as a cavity with a closed bottom.
Figure 13 illustrates another embodiment of an abrasion-resistant surface assembly designated generally 24H wherein the mechanical connection means for securing shock-absorbing backing tile 26H and abrasion-resistant member 28H together includes a deformable metal sleeve 84 resident in both a preferably tapered passageway 82 through backing tile 26H and a preferably tapered passageway 83 through abrasion-resistant member 28H. Production of abrasion-resistant surface member 24H is accomplished by inserting sleeve 84 into passageways 82 and 83, after abrasion-resistant member 28H has been positioned on backing tile 26H so as to align the two passageways at the tile-member interface, whereupon sleeve 84 is expanded against the walls of passageways 82 and 83 by a suitable hand or machine tool.
Passageway 82 and 83 each preferably taper from wider mouths at the surfaces of the backing tile and the abrasionresistant member which are remote the juncture of the backing tile and the abrasion-resistant member, to a narrow confluence where the abrasion-resistant member and backing tile abut one another. Similarly to the embodiment illustrated in Figure 12, the embodiment illustrated in Figure 13 does not require complementary mating surfaces of the type described with reference to Figure 27 to prevent movement of the abrasion-resistant member outwardly with respect to the conveyor hub. Such movement is prevented by the presence of sleeve 84 within and contacting the walls of preferably tapered passageways 82 and 83.Moreover, as a variation either or both of passageways 82 and 84 may be configured as cavities with closed bottoms and, instead of sleeve 84, a solids plug, secured in the cavities by an adhesive, may be substituted.
Figure 14 illustrates another embodiment of an abrasion-resistant surface assembly designated generally 241 wherein the mechanical connection means for shock-absorbing backing tile 261 and abrasion-resistant member 281 includes a downwardly extending lip portion 90 of backing tile 261. The connection means also includes a deformable portion 25, extending from shockabsoring backing tile 261, which during assembly is bent against abrasion-resistant member 281 to urge the abrasion-resistant member radially outwardly with respect to the conveyor hub and thereby retain the abrasionresistant member and the shock-absorbing backing tile in tight contact.
Interposed between abrasion-resistant member 281 and shock-absorbing backing 261 is a backup insert 92, preferably formed of stainless steel, which fits into vertex 44 and cushions the abrasion-resistant member as it is urged against lip 90 when tile portion 25 is deformed against canted lower surface 60 of the abrasion-resistant member. Shock-absorbing backing tile 261 is preferably formed from a continuous stainless steel extrusion which is rolled and then secured to conveyor flight 22 by weldments 30.
In the embodiment illustrated in Figure 14, when it is desired to replace a worn or cracked abrasion-resistant member, the abrasion-resistant member is fractured and then removed from between lip 90 and deformable portion 25.
Deformable portion 25 is then bent open, by bending portion 25 downwardly as viewed in
Figure 14, whereupon a new abrasion-resistant member is position, along with a new backup insert 92, until the vertex of the backup insert contacts lip 90, whereupon deformable portion 25 is bent against canted lower surface 60. In this embodiment, complementary mating surfaces of the type illustrated in Figure 27 are not provided; interference of lip 90 with the vertex of insert 92 is sufficient to prevent radially outward movement of abrasion-resistant member 281 with respect to the conveyor hub as the conveyor rotates.As a variation, if the abrasion-resistant member is formed of a sufficiently malleable material, deformable portion 25 may be fabricated as an extension of the abrasionresistant member with the deformable portion bent against the shock-absorbing backing tile during assembly of the tile-member combination, to secure the abrasion-resistant member in place.
Figure 15 illustrates another embodiment of an abrasion-resistant surface assembly designated generally 24J wherein the mechanical connection means for securing shock-absorbing backing tile 26J and abrasion-resistant member 28J together is provided by a hard-surfaced rivet 94, preferably with a countersunk head portion 94A resident in a countersunk passageway 1 60 through abrasionresistant member 28J and with a shaft portion 94B resident in a passageway 1 62 through backing 26J, with rivet 94 welded to backing tile 26J. The countersunk configuration of the head of rivet 94 and the corresponding countersunk passageway 1 60 through abrasion-resistant member 28J serve to retain the abrasionresistant member in position once the rivet is welded to the backing tile.Preferably two rivets are used, to prevent the abrasion-resistant member from rotating. The backing tile is again secured to the conveyor flight 22, preferably by weldments 30. As a variation, either passageway 160 or passageway 162 may be configured as a cavity with a closed bottom, with the rivet 94 passing through the remaining passageway and into the cavity. The rivet may also be secured with adhesives, or the cavity may be tapped and a machine screw substituted for the rivet.
Figure 1 6 illustrates another embodiment of an abrasion-resistant surface assembly designated generally 24K wherein the mechanical connection means for securing shock-absorbing backing tile 26K and abrasion-resistant member 28K together includes a wedge plate 62K secured in place by welding the wedge plate to shoulder formed in backing tile 26K. Abrasion-resistant member 28K has a canted lower surface 60 abutted by wedge plate 62K. Once wedge plate 62K is positioned and welded in place, the complementary mating surfaces of abrasion-resistant member 28K and backup tile 26K effectively prevent radially outward movement of the abrasion-resistant member with respect to the conveyor hub as the conveyor rotates. Shock-absorbing backing tile 26K is again secured to conveyor flight 22, preferably by weldments 30.
Figure 17 illustrates another embodiment of an abrasion-resistant surface assembly designated generally 24L wherein the mechanical connection means between shock-absorbing backing tile 26L and abrasion-resistant member 28L includes a hard-surfaced rivet 94L fitted into counterbored passageway 1 64 in abrasion-resistant member 28L with rivet 94L passing therethrough and into a passage-way 1 66 through shock-absorbing backing tile 26L. Rivet 94L has thereabout an annular depression 95 into which a portion of shock-absorbing backing tile 26L is swaged in order to secure together the component parts of abrasion-resistant surface assembly 24L.
Swaging, to force material of the shock-absorbing backing tile into annular ring 95, produces depression 96 in the rear surface of shockabsorbing backing tile 26L. The shock-absorbing backing tile is secured to conveyor flight 22, preferably via weldments 30. Hard-surfaced rivet 94L, at least partially resident in counterbored passageway 1 64 through abrasion-resistant member 28L and swaged into place within passageway 1 66 in the backing tile, provides means for effectively preventing radially outward movement of the abrasion-resistant member with respect to the conveyor hub as the conveyor rotates. The configuration of shockabsorbing backing tile 26L after the swaging operation is shown in Figure 29.
Figure 1 8 illustrates another embodiment of an abrasion-resistant surface assembly designated generally 24M wherein the mechanical connection means for securing shock-absorbing backing tile 26M and abrasion-resistant member 28M together includes a soft, preferably stainless steel, bar 196 squeezed into a dovetail-shaped cavity 140 formed in abrasion-resistant member 28M with the bar then squeezed into a passageway 142 through backing tile 26M.
Passageway 142 preferably tapers from a wider mouth, at the surface of backing tile 26M which is remote from abrasion-resistant member 28M, to a narrow mouth at the juncture of the backing tile and the abrasionresistant member. Preferably the dovetail shaped cavity 140 in abrasion-resistant member 28M and the tapered passageway 142 in the shock-absorbing backing tile are each elongated in the transverse direction (perpendicular to the paper as viewed in Figure 18) so that the soft bar, in addition to preventing radially outward movement of the abrasionresistant member with respect to the conveyor hub when the conveyor is rotating, prevents rotation of the abrasion-resistant member (about the bar) with respect to the shock-absorbing backing tile. The shock-absorbing backing tile 26M is preferably secured to conveyor helical flight 22 via weldments 30.
Figure 19 illustrates another embodiment of an abrasion-resistant surface assembly designated generally 24N wherein the mechanical connection means between shock-absorbing backing tile 26N and abrasion-resistant member 28N is provided by a soft wire 98 swaged into a dovetail groove 100 formed in the shockabsorbing backing tile with soft wire 98 abutting canted lower surface 60 of abrasion-resistant member 28N. As wire 98 is swaged into place against canted lower surface 60, abrasionresistant member 28N is forced radially outward with respect to the conveyor hub (upward as viewed in Figure 19) until complementary mating surfaces of the abrasion-resistant member and the shockabsorbing backing tile, which have not been numbered, are engaged.Engagement of these surfaces prevents further radially outward movement of the abrasion-resistant member with respect to the shock-absorbing backing tile as the centrifuge conveyor rotates. The shock-absorbing backing tile 26N is preferably secured to conveyor helical flight 22 via weldments 30. In this embodiment, the soft wire has at least a portion which is deformable and bent against either the tile or the abrasion-resistant member or both the tile and the abrasion-resistant member, to retain the wire in place. The soft wire acts as means for urging the unnumbered complementary mating surfaces into engagement and contacts both the tile and the abrasion-resistant member. As a variation, the soft wire urging means may be mechanically secured to either the tile or the abrasion-resistant member. One preferred configuration of wire 98 before it is deformed is shown in dotted lines.
Figure 20 illustrates another embodiment of an abrasion-resistant surface assembly designated generally 24P wherein the mechanical connection means for securing shock-absorbing backing tile 26P and abrasion-resistant member 28P together includes a clamp member 102 which abuts canted lower surface 60 of abrasion-resistant member 28P and extends through a passageway in shock-absorbing backing tile 26P to the rear surface of the tile where clamp member 102 is secured to shock-absorbing backing tile 26P, preferably via weldments 104. Once clamp member 102 is secured in place abutting canted lower surface 60 of abrasion-resistant member 28P, the abrasion-resistant member is urged radially outwardly with respect to the conveyor hub, until complementary mating surfaces of the abrasion-resistant member and the shockabsorbing backing tile engage one another.When this occurs, additional movement of the abrasionresistant member radially outward with respect to the conveyor hub is precluded; moreover, abutment of clamp member 102 against canted lower surface 60 prevents movement of the abrasion-resistant member 28P with respect to the shock-absorbing backing tile 26P. The shockabsorbing backing tile is secured to the conveyor helical flight 22, preferably via weldments 30.
Figure 21 illustrates another embodiment of an abrasion-resistant surface assembly designated generally 24Q wherein the mechanical connection means between shock-absorbing backing tile 26Q and abrasion-resistant member 28Q includes an intermediate plate member 106, preferably formed of a relatively soft, shockabsorbing material, secured in place by a screw 108 threaded into plate 106 through a counterbored hole 110 in shock-absorbing backing tile 26Q. Intermediate plate member 106 and abrasion-resistant member 280 have complementary mating surfaces which, when engaged, prevent radially outward movement of abrasion-resistant member 280 with respect to the helical conveyor hub while the conveyor is rotating.Canted lower surface 60 of abrasionresistant member 28Q is received by a sloped shoulder 112 formed in the shock-absorbing backing tile. Shoulder 112, the complementary mating surface portion of plate member 106 and first forward surface 52 of shock-absorbing backing tile 260 together form a dovetail groove within which a dovetail-shaped extended portion of abrasion-resistant member 280 resides.
Canted lower surface 60 and sloped shoulder 112 are complemental mating surfaces and are both disposed at an angle so that the two surfaces are closer to the centrifuge conveyor hub at a position more removed from the abrasionresistant member's solids displacing surface 41 than at the junction of lower surface 60 and solids displacing surface 41. With this configuration, canted lower surface 60 and sloped shoulder 112, when engaged, effectively resist radially inward movement of the abrasionresistant member with respect to the tile. Shock-absorbing backing tile 260 is preferably secured to conveyor helical flight 22 via weldments 30.
Figure 22 illustrates another embodiment of an abrasion-resistant surface assembly designated generally 24R wherein mechanical connection means for securing shock-absorbing backing tile 26R and abrasion-resistant member 28R together is formed by a protruding dovetail portion 11 4R of abrasion-resistant member 28R, which extends from a central area of abrasion-resistant member 28R in a direction away from radially extending solids displacing surface 41 R. This dovetailshaped extension fits into a dovetail groove 11 6 formed in shock-absorbing backing tile 26R. The shock-absorbing backing tile 26R is preferably secured to conveyor helical flight 22 via weldments 30.When a centrifuge utilizing the embodiment of abrasion-resistant surface assemblies illustrated in Figure 22 is assembled, the shockabsorbing backing tiles are positioned such that dovetail grooves 11 6 of adjacent shockabsorbing backing tiles are aligned. Once the shock-absorbing backing tiles 26R are so positioned, the abrasion-resistant members 28R are fitted therein, by sliding a series of abrasionresistant members 28R into the helically extending dovetail-shaped groove formed by the individual dovetail-shaped grooves 11 6 in the individual shock-absorbing backing tiles which have been mounted on the distal edge of the conveyor helical flight.The last backing tile inserted into the groove must be retained therein by suitable means which prevents transverse movement of the abrasion-resistant member with respect to the associated backing tile. One suitable means is the structure disclosed in
Figures 23 and 24 and described below.
An an alternative mode of assembly of the abrasion-resistant surface assembly illustrated in
Figure 22, the individual abrasion-resistant members are first inserted into the dovetailshaped grooves in the corresponding individual shock-absorbing backing tiles whereupon the individual backing tiles are welded, one or a few at a time, to the conveyor helical flight.
A variation of the embodiment illustrated in
Figure 22 is provided when a dovetail groove, to directly receive the dovetail-shaped extensions 11 4R of abrasion-resistant members 28R, is formed in the conveyor helical flight. This eliminates the need for shock-absorbing backing tile 26R.
Figures 23 and 24 illustrate another embodiment of an abrasion-resistant surface assembly designated generally 24S wherein the mechanical connection means for securing shockabsorbing backing tile 26S and abrasion-resistant member 28S together is provided by a deformable staple 11 8 which preferably fits entirely around the backing tile 26S, but in any case is at least partially circumjacent to the tile,
and has portions 11 8S which are deformable
against abrasion-resistant member 28S. The
deformable portions 118S of staple 11 8 fit into a
rectangular cutout 120 in abrasion-resistant
member 28S and effectively restrain the
abrasion-resistant member against movement
away from the shock-absorbing backing tile.
Shock-absorbing backing tile 26S is secured to
the conveyor helical flight, preferably via
weldments 30. Although not illustrated, in
another embodiment the position of staple 11 8 is
reversed with portions 11 8S deformed against
the shock-absorbing backing tile while the main
backbone portion 11 8' of staple 11 8 abuts the
abrasion-resistant member, rather than the
shockabsorbing backing tile as illustrated in
Figures 23 and 24.
Figure 25 illustrates another embodiment of an
abrasion-resistant surface assembly designated generally 24T-wherein the mechanical connection means for securing shock-absorbing backing tile 26T and abrasion-resistant member 28T together includes a double dovetail-shaped insert 122 which is slidably resident in opposed dovetail grooves 124 and 126 formed in shock-absorbing backing tile 26T and abrasion-resistant member 28T respectively. Shock-absorbing backing tile 26T is secured to conveyor helical flight 22, preferably via weldments 30. Double dovetailshaped insert 1 22 has complementary mating surfaces configured for close, sliding mating with dovetail grooves 124 and 1 26 to resist radially outward movement of abrasion-resistant member 28T with respect to shock-absorbing backing tile 26T.Transverse movement of abrasion-resistant member 28T and insert 122 is prevented by adjacent, preferably abutting, abrasion-resistant members and adjacent, preferably abutting, double dovetail-shaped inserts associated with a series of shock-absorbing backing tiles secured around the radial extremity of conveyor helical flight 22.
Figure 26 illustrates another embodiment of an abrasion-resistant surface assembly designated generally 24U wherein the mechanical connection means for securing shock-absorbing backing tile 26U and abrasion-resistant member 28U together includes an insert 1 28 which has a dovetail portion 1 30 slidably resident in dovetail groove 126 in abrasion-resistant member 28U and has a shaft portion 132, with a countersunk head, not numbered, residing in a countersunk, dovetail-shaped opening to a passageway 1 34 through shock-absorbing backing tile 26U. The backing tile is secured to helical flight 22, preferably via weldments 30.
Figure 28 illustrates another embodiment of an abrasion-resistant surface assembly designated 24V wherein the mechanical connection means for securing shock-absorbing backing tile 26V and abrasion-resistant member 28V together is provided by adhesive disposed between at least a portion of tile 26V and a portion of abrasionresistant member 28V. The adhesive has been shown in Figure 28 as a layer 190; when the abrasion-resistant surface assembly is fabricated, the adhesive can be dispersed in any manner and, indeed, the adhesive need not be a layer which completely separates the backing tile from the abrasion-resistant member as depicted in Figure 28. The backing tile is secured to the conveyor helical flight 22, preferably via weldments 30.
Suitable adhesives include those members of the epoxy family which are resistant to high temperatures and corrosive mixtures encountered within centrifuges. Of course, when an adhesive is used to bond the abrasion-resistant member to the shock-absorbing backing tile, grout is not normally used between the member and the tile.
Variations and combinations, including reversals of parts from those shown, and other modifications fall within the scope of this invention. Particularly, the means described herein for securing the various embodiments of the abrasion-resistant member to an associated shock-absorbing backing tile may also be used to secure the shock-absorbing backing tiles to the conveyor helical flight, with grout used therebetween as required. Furthermore, it is not necessary that the abrasion-resistant members and the shock-absorbing backing tiles be matched on a one-to-one basis. Several abrasion-resistant members may be mounted on a single shockabsorbing backing tile, if desired. The above particular description is by way of illustration and not of limitation.
Claims (13)
1. A conveyor centrifuge, the distal edge of the helical flight of the conveyor of which is provided with abrasion resistant edge members, said abrasion resistant edge members being mounted on intermediate shock-absorbing backing tiles secured to the distal edge of said conveyor flight, wherein said abrasion resistant members are each mounted on said backing tiles by a mechanical, as hereinbefore defined, mounting.
2. A conveyor centrifuge according to claim 1, wherein said backing tiles are secured to the conveyor flight by welding.
3. A conveyor centrifuge according to claim 1 or 2, wherein said abrasion resistant members and said backing tiles each have complementary undercut mating surfaces and wherein the abrasion resistant members are mechanically secured in position on the backing tiles by a connecting member which serves to urge said abrasion resistant member radially with respect to the backing tile thereby to bring the undercut mating surfaces into engagement.
4. A conveyor centrifuge according to claim 3, wherein said connecting member is a wedge member which is an interference fit between an abutment surface on the abrasion resistant member and an abutment surface on the backing tile.
5. A conveyor centrifuge according to claim 3, wherein said connecting member is a tongue member integral with the backing tile and deformable against the abrasion resistant member to urge said mating surfaces into engagement.
6. A conveyor centrifuge according to claim 1 or 2, wherein the backing tile has a dovetail groove in the surface thereof extending generally circumferentially of the conveyor axis, and the abrasion resistant member has a complementary dovetail projection, which is an interference fit in said dovetail groove.
7. A conveyor centrifuge according to claim 1 or 2, wherein the abrasion resistant members and the backing tiles are mechanically secured together in face-to-face relationship by a connecting member extending through said tile and the abrasion resistant member and forming a mechanical connection with at least one of said tile and said abrasion resistant member.
8. A conveyor centrifuge according to claim 7, wherein said connecting member is integral with one or said abrasion resistant member or said tile and having a portion deformable against a surface on the other to hold the two together.
9. A conveyor centrifuge according to any one of claims 1-8, wherein a film of shock-absorbing grout is provided between the superposed surfaces of the abrasion resistant members and the backing tiles.
10. A conveyor centrifuge according to claim 1 or 2, wherein the abrasion resistant members are secured to the backing tiles by a layer of adhesive.
11. A conveyor centrifuge according to claim 10, wherein the abrasion resistant members and backing tiles are adhesively secured to each other in face-to-face relation, and wherein the abrasion resistant members and tiles have undercut complementary mating surfaces which serve to resist movement of the abrasion resistant members relative to the backing tiles radially outward with respect to the axis of the centrifuge.
1 2. A conveyor centrifuge according to claim 1 substantially as hereinbefore described with reference to the accompanying drawings.
13. A conveyor centrifuge, the distal edge of the helical flight of the conveyor of which is provided with abrasion resistant inserts, wherein the inserts are mounted on the conveyor flight by means of a dovetail groove in the surface of the conveyor flight adjacent the distal edge thereof and a complementary dovetailed projection on said insert which is an interference fit in said groove.
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7916758A GB2048728B (en) | 1979-05-15 | 1979-05-15 | Centrifuge with abrasion-resistant conveyor |
| SE7904275A SE427901B (en) | 1979-05-15 | 1979-05-15 | CENTRIFUG WITH NOTIFICATION |
| GB8217198A GB2098517B (en) | 1979-05-15 | 1979-05-15 | Centrifuge with abrasion-resistant conveyor |
| CA000327823A CA1171824A (en) | 1979-05-15 | 1979-05-17 | Hard-surfacing decanter conveyors |
| NL7904014A NL7904014A (en) | 1979-05-15 | 1979-05-22 | CENTRIFUGE, EQUIPPED WITH A WEAR-RESISTANT TRANSPORTER. |
| DE19792924047 DE2924047A1 (en) | 1979-05-15 | 1979-06-15 | CENTRIFUGE FOR SEPARATING A SOLID-LIQUID MIXTURE |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7916758A GB2048728B (en) | 1979-05-15 | 1979-05-15 | Centrifuge with abrasion-resistant conveyor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2048728A true GB2048728A (en) | 1980-12-17 |
| GB2048728B GB2048728B (en) | 1983-02-16 |
Family
ID=10505149
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB7916758A Expired GB2048728B (en) | 1979-05-15 | 1979-05-15 | Centrifuge with abrasion-resistant conveyor |
Country Status (5)
| Country | Link |
|---|---|
| CA (1) | CA1171824A (en) |
| DE (1) | DE2924047A1 (en) |
| GB (1) | GB2048728B (en) |
| NL (1) | NL7904014A (en) |
| SE (1) | SE427901B (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0048733A1 (en) * | 1980-03-31 | 1982-04-07 | Pennwalt Corp | Hard surfacing for a centrifuge conveyor. |
| EP0081938A2 (en) * | 1981-12-09 | 1983-06-22 | Alfa-Laval Separation A/S | Conveyor screw |
| GB2120195A (en) * | 1982-05-21 | 1983-11-30 | Berstorff Gmbh Masch Hermann | Bark processing machine |
| GB2266287A (en) * | 1992-04-23 | 1993-10-27 | John Drury Roger | Auger conveyor |
| GB2273253A (en) * | 1992-12-10 | 1994-06-15 | Alfa Laval Sharples Ltd | Screw conveyor for centrifuges |
| WO1995021025A1 (en) * | 1994-02-01 | 1995-08-10 | Dag Ommundsen | Wear element for screw presses or the like |
| US20100016140A1 (en) * | 2006-12-12 | 2010-01-21 | Siebtechnik Gmbh | Endless screw of a centrifuge |
| US9908124B2 (en) * | 2013-05-15 | 2018-03-06 | Andritz S.A.S. | Protection tiles for scroll conveyor flights |
| EP4309797A1 (en) | 2022-07-20 | 2024-01-24 | Alfa Laval Corporate AB | Wear assembly for a helically formed, metal decanter screw conveyor |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4666033A (en) * | 1984-03-16 | 1987-05-19 | Reid Rod B | Auger apparatus |
| DE102005005134A1 (en) * | 2005-02-04 | 2006-08-17 | Hiller Gmbh | Wear protective element |
| DE102017103069B4 (en) | 2017-02-15 | 2023-03-23 | Flottweg Se | Solid bowl centrifuge screw |
| CN110181241A (en) * | 2019-06-25 | 2019-08-30 | 李坚 | A kind of blade production technology |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE422606A (en) * | 1936-08-13 | |||
| US3764062A (en) * | 1972-02-28 | 1973-10-09 | Pennwalt Corp | Centrifuge apparatus |
| DE2450337A1 (en) * | 1974-10-23 | 1976-04-29 | Kloeckner Humboldt Deutz Ag | SOLIDS EXTRACTION SCREW OF A FULL-SLEEVE SCREW CENTRIFUGE |
-
1979
- 1979-05-15 SE SE7904275A patent/SE427901B/en not_active IP Right Cessation
- 1979-05-15 GB GB7916758A patent/GB2048728B/en not_active Expired
- 1979-05-17 CA CA000327823A patent/CA1171824A/en not_active Expired
- 1979-05-22 NL NL7904014A patent/NL7904014A/en not_active Application Discontinuation
- 1979-06-15 DE DE19792924047 patent/DE2924047A1/en not_active Ceased
Cited By (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0048733A4 (en) * | 1980-03-31 | 1984-03-01 | Pennwalt Corp | Hard surfacing for a centrifuge conveyor. |
| EP0048733A1 (en) * | 1980-03-31 | 1982-04-07 | Pennwalt Corp | Hard surfacing for a centrifuge conveyor. |
| EP0081938A2 (en) * | 1981-12-09 | 1983-06-22 | Alfa-Laval Separation A/S | Conveyor screw |
| EP0081938A3 (en) * | 1981-12-09 | 1984-08-01 | Alfa-Laval Separation A/S | Conveyor screw |
| GB2120195A (en) * | 1982-05-21 | 1983-11-30 | Berstorff Gmbh Masch Hermann | Bark processing machine |
| GB2266287A (en) * | 1992-04-23 | 1993-10-27 | John Drury Roger | Auger conveyor |
| GB2266287B (en) * | 1992-04-23 | 1995-09-13 | Roger John Drury | Auger conveyor |
| GB2273253B (en) * | 1992-12-10 | 1996-11-20 | Alfa Laval Sharples Ltd | Apparatus with screw conveyor |
| GB2273253A (en) * | 1992-12-10 | 1994-06-15 | Alfa Laval Sharples Ltd | Screw conveyor for centrifuges |
| WO1994013403A1 (en) * | 1992-12-10 | 1994-06-23 | Alfa Laval Separation A/S | Apparatus with screw conveyor |
| WO1995021025A1 (en) * | 1994-02-01 | 1995-08-10 | Dag Ommundsen | Wear element for screw presses or the like |
| US5845764A (en) * | 1994-02-01 | 1998-12-08 | Ommundsen; Dag | Wear element for screw presses or the like |
| US20100016140A1 (en) * | 2006-12-12 | 2010-01-21 | Siebtechnik Gmbh | Endless screw of a centrifuge |
| US8523751B2 (en) * | 2006-12-12 | 2013-09-03 | Siebtechnik Gmbh | Endless screw of a centrifuge with ceramic wear plates |
| US9908124B2 (en) * | 2013-05-15 | 2018-03-06 | Andritz S.A.S. | Protection tiles for scroll conveyor flights |
| AU2013389694B2 (en) * | 2013-05-15 | 2018-05-10 | Andritz S.A.S. | Protection tiles for scroll conveyor flights |
| EP4309797A1 (en) | 2022-07-20 | 2024-01-24 | Alfa Laval Corporate AB | Wear assembly for a helically formed, metal decanter screw conveyor |
| WO2024017615A1 (en) | 2022-07-20 | 2024-01-25 | Alfa Laval Corporate Ab | Wear assembly for a helically formed, metal decanter screw conveyor |
Also Published As
| Publication number | Publication date |
|---|---|
| SE427901B (en) | 1983-05-24 |
| NL7904014A (en) | 1980-11-25 |
| CA1171824A (en) | 1984-07-31 |
| GB2048728B (en) | 1983-02-16 |
| SE7904275L (en) | 1980-11-16 |
| DE2924047A1 (en) | 1981-01-08 |
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| Date | Code | Title | Description |
|---|---|---|---|
| 732 | Registration of transactions, instruments or events in the register (sect. 32/1977) | ||
| PE20 | Patent expired after termination of 20 years |
Effective date: 19990514 |