Note: Descriptions are shown in the official language in which they were submitted.
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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
1
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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
2
CA 02232858 2005-10-20
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
3
CA 02232858 2005-10-20
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
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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,
4
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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.
6
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
12
13
14
16
17
18
19
21
22
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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.
14
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
6
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1 wall, surround the projecting journal and are retained thereon. The spacer
2 washers are thus held captive.
3
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.
16
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.
7
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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
8
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1 shown in:
2
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
9
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.
13
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
9
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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.
6
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.
14
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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24 '..._ ..,. .. _. _ . _. _ ' , .. . . ... ..~ ' .._ .
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
10
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
11
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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.
13
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.
12
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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.
19
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
13
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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
14
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i subdivided into at least two separate parts, namely a strut carrier 5, 5'
and a
2 vane carrier 10, 10'.
3
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.
a . -.;CA 02232858 1998-03-24
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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
16
