CA2232858C - Sorting device - Google Patents

Abstract

Described is .a sorting device intended in particular for the fibre suspensions produced when paper is pulped. Fitted to the body (1) of a rotor are vanes (2) which extend out from the surface of the rotor body (1) towards a screen wall (4). The supports for the vanes (2) are made up of several parts and may, for instance, consist o:f two parts - a vane carrier (10,10') and a strut (5,5'). The strut (5,5') is attached to the rotor body (1) by welding (6) for instance. The vane carrier (10,10') and the strut (5,5') are detachably connected to each other so that they cannot rotate, for instance by a screw joint (8,17). To secure the two parts (5,10; 5',10') against rotation, the joint is preferably of the inter-locking type.

Description

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SORTING DEVICE
DESCRIPTION
The invention relates to a sorting device adapted in particular for fiber suspensions for pulping paper.
It is known, for example, from US-A-3,909,400 that a sorting device of this type includes a rotor body with vanes positioned along the outer circumference of the rotor body and oriented towards a screen wall which encloses the rotor body. These vanes are also referred to as sorting vanes or cleaning elements;
they form, in cooperation with the screen wall, successively a suction and pressure zone in the mass flow region. The respective vanes are secured with threaded rods which are rigidly affixed to one end to the vanes, while the other end of the threaded rods is attached tc> the rotor body via a screwed connection employing a nut and a lock-nut. Each vane is supported by two threaded rods to prevent the vanes from rotating relative to the rotor body during the operation of the sorting device. The threaded conruection provides an adjustment capability so that the vanes can be properly positioned. This type of support requires at least two threaded rods, thereby incre<~sing the flow resistance and requiring a relative large electric current, and therefore a large amount of energy, for turning the rotor. Moreover, the carrier construction requires two threaded rods to ..,. ., ,.. .. .. ._,. .w~.::~. .. ,.,,_-~...~_. ..L ,.u:~"<,~.CA 02232858 1998-.Ø3'24:;: _. ' .. _ ~~_...,.,.;,r. _....L......... .,..~I:~ w....Y...,- .A - sr . ' _. . f f l exactly adjust the desired spacing between the outside contour of the vane, requiring trained personnel to perform the adjustment. The desired position, however, can change when the threaded rods are tightened. Since in the vicinity of the nuts, the threaded rods, etc., elements with sharp edges protrude from the carrier, fiber spinnings can accumulate near the support, which can cause a malfunction or at least diminish the efficiency of the sorting device.
Also known is a multi-vane rotor with vane-shaped cleaning elements which are rigidly connected through welding to the rotor body via a strut. In this design, the spacing between the outside contour of the vane-shaped cleaning element and the opposing screen wall is preset when the rigid weld is prepared.
Although the weld prevents the vane-shaped cleaning element from rotating - even if only one strut is used-, the vane-shaped cleaning elements are expensive to replace.
Moreover, the spacing between the outside contour of the vane-shaped cleaning element and the opposing screen wall can only be adjusted by removing, machining and then reinstalling the strut. Changing the spacing thus necessitates expensive and complex procedures. In addition, the weld joints are stressed, thus distorting the vane-shaped cleaning element and making the spacings irregular and variable.
A different rotor is known (see, for example, EP-A-0 487 224) wherein cleaning elements are secured to rails extending parallel to the axial direction of the rotor body. The gap between the outside contour of the cleaning element and the opposing screen wall can be adjusted by loosening the screw connection and shimming with a metal strip. Not only are relatively long metal strips required whose dimensions have to be adapted to the rotor, but the rails also produce a high flow resistance, resulting in high energy consumption.
It is therefore the object of the invention to provide a reliable and energy-saving sorting device of the type described above which is also designed to require very little maintenance, and wherein the gap between the outside contour of the vane and the opposing screen wall can be easily adjusted.
The object of the invention is solved by a sorting device, in particular a sorting device adapted for fiber suspensions when paper is pulped. In one aspect, there is provided a sorting device having a rotor body which is provided on an outer periphery thereof with vanes pointing in direction of a screen wall surrounding the same, and which are contoured such that they form in succession a suction and pressure zone in a stock flow region in cooperation with the screen wall, wherein each vane is attached to the rotor body via an essentially radially running support which comprises a vane support part and a strut support part attached to the rotor body which are connected to one another releasably and to be secure against rotation, characterised in that the releasable connection is formed by a screw connection which runs essentially axially and centrally in the support parts.
In the sorting device of the invention, the support member or the support for the respective vane is constructed from multiple elements, i.e. at least two elements, namely a vane carrier and a strut carrier. The strut carrier is secured to the rotor body, whereas the vane carrier supporting the respective vane is detachably connected to the strut carrier and secured against rotation therewith.
The device is designed for easy maintenance in that the vane carrier together with the vane can be quickly removed and replaced with a new vane carrier by simply loosening the detachable connection between the vane carrier and the 3a st-_~ ___.__ r.,______ ~.__ .______~.___.___..___. _.__~__~_~.__ .__ ..

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one strut, the flow resistance of the support is reduced so that the sorting device of the invention can operate energy-efficiently. Because the vane carrier and the strut carrier are detachably connected, the gap spacing and the spacing between the outside contour of the vane and the opposing screen wall can be adjusted easily and effectively, whereby these tasks can be performed by the customer, without the need for trained and experienced personnel. The problems caused by fiber spinnings on the carrier are also reduced, so that the sorting device of the invention operates reliably. Moreover, The detachable connection is preferably in the form of a screw connection which extends essentially axially in the center of the respective carriers. The detachable screw connection is thus not directly exposed to the mass flow and can therefore be easily loosened even after extended operating times of the sorting device. On the other hand, the screw connection does not generate fiber spinnings which can cause the sorting device to malfunction. With this design for the detachable connection, the two respective carrier elements and the rotor body to be rigidly connected to each other.
Preferably, an interlocking joint is provided between the respective carrier elements to prevent rotation therebetween. This interlocking joint can be formed by a polygonal, in particular quadrilateral, ., . .. . . , ' n ~' ; ~~i r~ :~".t ' 1.;'~' ;~.
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1 - .rectangular or triangular cross-section 2 of the respective carrier elements to be connected. The corresponding cross-3 sections preferably intermesh at the connection point between the vane carrier 4 and the strut carrier, thereby forming the formfitting connection for preventing rotation.

7 Alternatively, the formfitting connection can be formed by alignment pins engaging with corresponding alignment bores. Feasible are also combinations of different types of formfitting connections. Rotation between the carrier elements to can be prevented through a proper design of the carrier elements which are to 11 be connected with each other, so that no additional fTlPaCI I~GC fro rom nr....J

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1 In a preferred embodiment, the spacing between the outside contour of the 2 vane and the opposing screen wall, or the gap spacing, is adjustable. The vanes 3 can then advantageously be set to the desired spacing which can be adjusted 4 further at a later time. If subsequent adjustments are required on location, these s adjustments can easily be performed by the user. Because the spacing between 6 the outside contour of the vane and the opposing screen wall is adjustable, the device can easily be adapted to various other situations and applications.
s 9 For adjusting the spacing, spacer blocks, in particular spacer washers, are to preferably placed between the carrier elements which are to be connected, so 11 that the carrier elements are held captive and no fiber filaments are generated.
12 The spacer blocks perform quite effectively and reliably, in particular at the 13 interface between the two carrier elements to be connected.

is In a preferred embodiment of the invention, the interlocking joint is formed 16 by a projecting journal on the vane carrier and a corresponding seat on the strut 1~ carrier. The journal and the seat have the corresponding interlocking cross-1g sections described above so that a formfitting connection is created when the 19 journal engages the seat, which reliably prevents the two carrier members from 2o rotating relative to each other. The spacer washers which provide adjustment of 21 the spacing between the outside contour of the vane and the opposing screen __ . . .. . . .,.. __ .. ~ . __. .. ._CA 02232858 1998-03-24..;, ,:___:.~:. ;, _. . . . . _,.. .,. , ,. , . . ,.."~ ~ ~.., , 1 wall, surround the projecting journal and are retained thereon. The spacer 2 washers are thus held captive.

4 The cross section of the vane carrier andlor the strut carrier can be freely s selected. Preferably, however, the cross section is round or polygonal, 6 preferably quadrilateral or rectangular.
s To make the screw connection between the two carrier elements rigid, reliable and secure, the screw connE~ction preferably comprises a screw bolt to which is slightly recessed with respect to the outside contour of the vane and 11 which extends through the vane carrier and is screwed into a thread disposed in 12 the strut carrier. With this design, the screw bolt extends through the vane and 13 the vane carrier, particularly through the center of the vane carrier, with some 14 play, wherein the connection is tightened by screwing the screw bolt into the is thread in the strut carrier. This thread is preferably a female thread.

1~ The strut carrier is preferably secured to the rotor body by welding. This 1g provides a reliable and stable connection between the strut carrier and the rotor 19 body. The adjustment for the screen gap spacing and the mechanism for 2o preventing rotation between the two carrier elements are located next the carrier 21 element interface. This advantageously also facilitates assembly.

.....__ .._ . , _ .._ .. .... ._....... _..._, _ , . .. . _ . CA 02232858 1998-03-24..,: .._. _ _ . _ ... .._ . . _ i To facilitate the manufacturing process, the vane in the form of a vane 2 element is preferably welded to the vane carrier. The vane element is then 3 connected to the vane carrier in a rigid and predetermined manner, similar to the a rotor body.
s 6 The entire support for the vane is thus stable and unyielding and uses only a small number of components. The effective area of these components s projecting into the mass flow region is very small; in addition, reliable 9 adjustments and changes in the gap spacing are possible, while the carrier io elements are prevented from rotating relative to each other. The carrier element n supporting the respective vane can also be replaced easily, quickly and simply, i2 for example, during regular maintenance work. The multi-part design of the vane i3 support permits almost unlimited adjustment of the radial projection of the vane i4 over the outer circumference of the rotor body, so that this projection can be is adapted to the respective conditions. The spacers which in the present invention i6 have the form of spacer washers, are essentially independent of the specific i~ design of the strut and vane carrier's and can thus be prefabricated cost ig effectively and inserted in the required quantity as needed. Changes can be i9 implemented easily, even at a later time.
2i The invention will be described in the following with reference to preferred 22 embodiments and in conjunction with the appended drawings. In the drawings is - - _ .. . . . . ... .. .... . .-. _ _-_--.CA 02232858 1998-03-24-~~"-,.r_::.
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1 shown in:

3 FIG. 1 schematically, a partial cross-sectional view of a sorting 4 device with a rotor enclosed by a screen, s 6 FIG. 2 a sectional view taken along the line II-II of FIG. 1, s FIG. 3 a sectional view taken along the line III-III of FIG. 1, and to FIG.4 schematically, a perspective disassembled view of an 11 alternative embodiment of a detachable connection between the two carrier 12 elements with a modified design to prevent rotation.

la In the figures of the drawing, identical parts or parts having a similar is function are indicated with identical reference numerals. Details of the sorting 16 device not shown in the drawing are of conventional design and are hereinafter 1~ neither illustrated nor described in detail.
is 19 Referring now to FIGS. 1 to ;3, there is described in detail a first 2o embodiment of the invention. Indicated with the reference numeral 1 is a section 21 of the rotor body which can be in the form of a cylinder, for example a hollow 22 cylinder. The rotor body 1 can have several vanes 2 operating as cleaning ....._. _. . . . ~ ;,,:,;.~.w~..w i.;;~;. ,._ _.::~CA _02232858 1998-03-24 .
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1 elements or as sorting elements. The vanes 2 can be arranged along the outer 2 circumference of the rotor body 1 in a conventional manner. To provide a clearer 3 picture of the invention, only one support element of a single vane 2 will be 4 described. It is understood that the remaining vanes 2 can be secured to the s rotor body 1 in the same or in a similar manner.

The rotor body 1 with the attached vanes 2 is enclosed by a screen 3, with a the inside of the screen 3 forming a screen wall 4. The screen wall has, of 9 course, perforations which are not illustrated in detail. The respective vane 2 to moves across the screen wall 4 at a preset spacing which can be adjusted 11 between, for example, 1 mm and 12 mm. This spacing can be different from one 12 application to the next and from one sorting task to the next;
consequently, the 13 spacing should be adjustable.

is The support member for the vane 2 comprises a strut carrier 5 which, as 16 illustrated, projects radially slightly over the outside contour of the rotor body 1 1~ and is oriented towards the screen wall 4. This strut carrier extends partly is through the wall of the rotor body 1 and is rigidly connected with the rotor body 1 19 by a welded joint indicated by the numeral 6. On the front side, i.e. on the side 2o facing away from the rotor body, the strut carrier 5 has a recessed seat 7, which 21 in the illustrated example has a quadrilateral contour (see FIG. 2). A
female z2 screw thread 8 extends from this seat T through the center of the strut carrier 5.

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i The support member also includes a vane carrier 10 for supporting the vane 2 element or the vane 2, respectively. The vane 2 is rigidly affixed to the vane 3 carrier 10 by welding, as indicated for example at 11. The vane carrier 10 and a the strut carrier 5 have essentially identical cross-sectional dimensions along s most of their longitudinal extent. Projecting from the center of the vane carrier 10 s is a journal 12 which - according to FIG. 3 - has a quadrilateral cross-section which closely fits the quadrilateral contour of the seat 7. The vane carrier s furthermore has a through bore 13 extending axially past the internal screw 9 thread 8 of the strut carrier 5 and also penetrating the journal 12.
to l As indicated schematically in FIG. 1, the spacer blocks 14 surrounding the i2 journal 12 are in the form of spacer washers 15; the number of spacer washers i3 15 can be suitably selected to adjust the spacing between the shoulder of the i4 vane carrier 10 and the corresponding front face of the strut carrier 5.
With the is strut carrier 5 and vane carrier 10 forming a single unit, the spacing between the i6 outside contour of the vane 2 and the opposing screen wall 4 can be properly m adjusted.
is i9 A screw bolt 17 which preferably has a hexagon socket head 16, is 2o provided for detachably securing the vane carrier 10 including the vane 2 to the 2i strut carrier 5. In the position indicated in FIG. 1, the head 16 is set back, i.e.
22 recessed, relative to the outside contour of the vane 2. In the embodiment of the ,.a... . _.._.. ,__, .. _,... _ ...__ _..._.... _ ,_._._,.CA 02232858 1998-03-24..-. , ,...._ ..... _ , .._ ,.._ _,. ... ....
1 invention, the head 16 thus does not protrude from the support of the vane 2 .
2 The screw bolt 17 is installed by pushing the bolt 17 through the through bore 3 3 and by then screwing the bolt 17 into the female thread 8 of the strut carrier 5.
4 With the appropriately contoured seat 7 and journal 12, the formfitting s connection is secured against rotation, so that the vane carrier 10 cannot rotate 6 relative to the strut carrier 5 when the screw bolt 17 is tightened. The formfitting connection can have a shape which is differently from the illustrated s quadrilateral design of the journal 12 and seat 7. Preferred are, for example, 9 polygonal, rectangular, triangular or similar embodiments.
to 11 The spacer washers 15 can, for example, be prefabricated in bulk with 12 thicknesses in increments of 1 mm, and then inserted as needed.

14 As evidenced by the preceding description, the support construction for the is vane 2 is comprised of only one strut which is formed in several parts, namely in 16 at least two parts, and includes, for example, the strut carrier 5 and the vane 1~ carrier 10. The outer circumference of the connected assembly of strut carrier 5 is and vane carrier 10 has essentially no protruding elements, except for the vane 19 2 itself, so that fiber filaments are effectively eliminated. In addition, this design 2o also significantly reduces the flow resistance of the support in the mass flow 21 regime, so that operating the sorting device requires very little energy.

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_. - ... .. . .J_.1~:,~ . ..... ._.........1_ , 1 If, for example, a vane 2 is damaged or worn out, then maintenance work 2 on the device can be performed on location quickly and easily. First, the screw 3 bolt 17 is loosened and then removed from the strut carrier 5 together with the 4 vane carrier 10. A completely new vane carrier 10 with vane 2 is then installed;
s the screw bolt 17 is again inserted and tightened, thereby finishing the 6 maintenance work.
s If it becomes necessary to change the sorting conditions by adjusting, for 9 example, the spacing between the outside contour of the vane 2 and the screen to wall 4, then this can be accomplished by loosening the screw bolt 17 and by 11 removing or adding one or more spacer washers 15, depending if the spacing is 12 to be increased or decreased. The spacing can also be easily adjusted by the 13 user and even by untrained personnel. The sorting device can thus be retrofitted la in a timely and cost-effective manner. The design of the invention provides for is cost-effective manufacture of the individual support components for the vane 2;
i6 the vanes 2 can be secured to the rotor body 1 so that the assembly is not only 1~ easy to maintain and universally usable, but can also be fabricated cost-is effectively.

2o Referring now to FIG. 4, there is depicted schematically an alternative 21 design of a two-part embodiment of a strut; rotor body and vanes have been z2 omitted. The vane carrier supporting the vane (not shown) is designated with the ._ . . ... _ . , ,. . . ...... .. _ , .._. :.CA 0,2232858 1998-03-24 ' . .. .. ..,_ ._ _, ......_ . . . . .. . .. ~_::. . .. .;.:i'.... ._ .
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i reference numeral 10' and the corresponding strut carrier with the reference 2 numeral 5'. As illustrated, on the front face of the strut carrier 5', there are 3 provided e.g. two alignment bores 8 which are arranged, for example, in a 4 diametrically opposed relationship. From the vane carrier 10' which is to be s connected with the strut carrier 5', there are projecting two corresponding 6 alignment pins 19 which engage the alignment bores 18 when the two carrier members 5' and 10' are connected. In all other details, the connection between s these two carrier members 5' and 10' as well as between the rotor body and the 9 vanes is similar to the connection illustrated in FIG. 1 and described above. The Io cooperation between the alignment bores 18 and the alignment pins 19 prevents l the two carrier members which are to be connected, i.e. the vane carrier 10' and i2 the strut carrier 5', from rotating relative to each other; the interlock is similar to 13 that of the contoured journal 12 and seat 7. Consequently, this design also 14 formfittingly prevents relative rotation.
is 16 Of course, other means for preventing relative rotation can be employed by m a person skilled in the art without deviating from the spirit of the invention. The is invention is thus not restricted to the aforedescribed details or to similar i9 embodiments of the support construction for the vane 2. It is important, however, 2o that a respective vane 2 is detachably connected to the rotor body 1 via a strut-2i like connection wherein the vane 2 cannot rotate relative the the rotor body 1 22 and wherein the size of the projection can be adjusted. The strut is here ... ... ., _ .. . . . . _ _. , ~ CA 02232858 1998-03-24;. ' . . , ... _ ... _ .. . ,... . ..., ..,. . . ...._,_....._. .,.... .. . .. ..
_.... ~ . ,.:u:._'. La;....,::: .._.. r ,.... _ i subdivided into at least two separate parts, namely a strut carrier 5, 5' and a 2 vane carrier 10, 10'.

4 The cross section of the vane carriers 10, 10' and of the strut carriers 5, 5' s can be freely selected, and the respective carrier elements can be formed from 6 round stock or from stock with a quadrilateral or rectangular cross section.
Most importantly, however, the spacing between the outside contour of the vane 2 and s the opposing screen wall 4 is adjustable with the help of spacer blocks 14, 9 preferably in the form of spacer washers 15, which can be placed between the io two carrier members 5, 5' and 10, 10' which are to be connected.

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LIST OF REFERENCE NUMERALS
1 rotor body 2 vane 3 screen 4 screen wall (inner surface) , strut carrier 5' welded joint 7 seat 8 internal screw thread 10, vane carrier 10' 11 welded joint 12 journal 13 through bore 14 spacer blocks spacer washers 16 head 17 screw bolt 18 alignment bores 19 alignment pins

Claims (24)

1. Sorting device having a rotor body which is provided on an outer periphery thereof with vanes pointing in direction of a screen wall surrounding the same, and which are contoured such that they form in succession a suction and pressure zone in a stock flow region in cooperation with the screen wall, wherein each vane is attached to the rotor body via an essentially radially running support which comprises a vane support part and a strut support part attached to the rotor body which are connected to one another releasably and to be secure against rotation, characterised in that the releasable connection is formed by a screw connection which runs essentially axially and centrally in the support parts.

2. Sorting device according to claim 1, characterised in that a positive connection is provided between the support parts as security against rotation.

3. Sorting device according to claim 2, characterised in that the positive connection is formed by a polygonal cross-section of the support parts to be connected.

4. Sorting device according to claim 3, characterised in that the polygonal cross-section of the support parts is a square.

5. Sorting device according to claim 3, characterised in that the polygonal cross-section of the support parts is rectangular.

6. Sorting device according to claim 3, characterised in that the polygonal cross-section of the support parts is triangular.

7. Sorting device according to claim 2, characterised in that the positive connection is formed by alignment pins engaging in associated recess bores.

8. Sorting device according to any one of claims 1 to 7, characterised in that the distance of an outer contour of the vane from the facing screen wall is alterable.

9. Sorting device according to claim 8, characterised in that spacers are arranged between the support parts to be connected to alter the distance.

10. Sorting device according to claim 9, characterised in that the spacers are spacer discs.

11. Sorting device according to claim 10, characterised in that the spacer discs surround a projecting journal.

12. Sorting device according to any one of claims 2 to 7, characterised in that a projecting journal is provided on the vane support part and an assigned recess is provided on the strut support part to form the positive connection.

13. Sorting device according to any one of claims 1 to 12, characterised in that the vane support part is designed to be round in cross-section.

14. Sorting device according to any one of claims 1 to 12, characterised in that the vane support part is designed to be polygonal in cross-section.

15. Sorting device according to claim 14, wherein the polygonal cross-section of the vane support part is square.

16. Sorting device according to claim 14, wherein the polygonal cross-section of the vane support part is rectangular.

17. Sorting device according to any one of claims 1 to 16, characterised in that the strut support part is designed to be round in cross-section.

18. Sorting device according to any one of claims 1 to 16, characterised in that the strut support part is designed to be polygonal in cross-section.

19. Sorting device according to claim 18, characterised in that the polygonal cross-section of the strut support part is square.

20. Sorting device according to claim 18, characterised in that the polygonal cross-section of the strut support part is rectangular.

21. Sorting device according to any one of claims 1 to 20, further comprising a screw connection comprising a screw bolt, which is arranged to be sunken with respect to the outer contour of the vane, is pushed through the vane support part and screwed into a thread in the strut support part.

22. Sorting device according to any one of claims 1 to 21, characterised in that the strut support part is connected to the rotor body by welding.

23. Sorting device according to any one of claims 1 to 22, characterised in that the vane is welded onto the vane support part.

24. Sorting device according to any one of claims 1 to 23, wherein the sorting device is designed for fibre suspensions for paper pulping.