EP3398682A1 - Refiner element for the refining of fibrous material - Google Patents

Abstract

The invention relates to a method for producing a set (2, 3) for treating aqueous suspended pulp (1) in a treatment gap (4), comprising a base body (5) with treatment elements (6) facing the gap (4).

In this case, the production cost is to be reduced by the fact that the treatment elements (6) applied at least partially in layers of a liquid or solid material and thereby subjected to a physical or chemical curing or melting process.

Description

The invention encompasses a clothing for treating aqueous suspended pulp in a treatment gap bounded by two treatment surfaces rotating relative to each other about a rotation axis and formed by sets, consisting of a base body with treatment elements pointing radially to the gap, elongated and at least one directional component the method according to the invention.

Such sets are to be suitable for the mechanical treatment of suspended pulp material. This means, above all, the grinding of paper fibers, the dispersion of impurities and fibers, and the de-staining, ie the dissolution of fiber agglomerates.
Trimmings are z. B. in grinding machines - so-called refiner - installed. The suspension in refiners has a solids content of about 2-8%.
Similar densities are also driven in Entstippern.
For machines for higher densities one speaks z. As high consistency mills, dispersers or kneaders.
The mechanical processing taking place therein can detect the entire fibrous material, thus also dispersing the impurities contained therein.

Such machines have at least one rotor and at least one stator with either disc-shaped or conical surfaces on which the trimmings are mounted, so that gaps can form between them. Many trimmings have webs and grooves on the work surfaces, which is why we also speak of "knife trimmings". Other trimmings are in the form of toothed rings.

It is known that in addition to the shape of such webs, grooves and teeth and the material of which they are made, has effects on the processing of the pulp.

The trimmings are subject to wear and therefore must be in certain Intervals are replaced. In addition, wear can cause the machining effect to change during the service life.

A significant portion of the operating costs associated with the mechanical treatment of pulp in the pulp and paper industry stem from energy costs. Therefore, it has always been an effort to build sets and the machines used and operate so that - measured by the desired success - not too high energy consumption is required.

It is therefore understandable that considerable effort is devoted to the development of trimmings, which is reflected in the design of their shape and in the choice of material.
To thereby reduce the manufacturing cost of trimmings, is for example in the DE 10 2004 016 661 A1 proposed to assemble the sets of several elements and then welded or soldered together.
From the FR 2 707 677 A1 It is known to coat the knife surface of the sets by means of laser with an abrasive material.

The object of the invention is to increase the freedom of design in such sets with economically justifiable effort.

According to the invention, this object is achieved in that the treatment elements are at least partially applied in layers of a liquid or solid material and thereby subjected to a physical or chemical curing or melting process.
Due to the layered application, the material and shape of the

Treatment elements easier and more comprehensive adapted to the specific requirements.
It is advantageous if in each case one core of the treatment elements is integrally connected to the main body and at least one outer region, Preferably, the treatment gap facing the outer part of the treatment elements applied in layers of a liquid or solid material and thereby subjected to a physical or chemical curing or melting process.

In this way, the treatment elements can be provided with a wear layer. If the color of the core differs from that of the outer part of the treatment elements, it can be concluded that the wear limit has been reached via the color change.
Also, the reprocessing of worn sets is possible on the application of the wear layer.
The core of the treatment elements not only acts as a connecting element to the body but also reduces the amount of required and usually expensive, wear-resistant material.

However, if more space is to be given to the arrangement and design of the treatment elements, it is advantageous if the treatment elements are applied as a whole in layers of a liquid or solid material and subjected to a physical or chemical hardening or melting process.
This also allows the use of universally applicable bodies.

Since the layered material is usually expensive, a cheaper, different material can be used for the base body.

Because of the high load in such machines for grinding, dispersing or deflaking fibrous materials, the layered material should be powdered and / or comprise one or more metals or metal compounds.
It is advantageous if the layered material is sintered or fused by means of laser.

Even ceramic layers can be produced in this way.

In addition, the surface roughness of the treatment element can be influenced by the grain size of the powder.

The production method according to the invention makes it possible to select materials according to the specific requirements, which is why at least part of the surface of the treatment elements, each of two side surfaces and the intermediate upper side facing the gap, should consist of a material which differs from the material of the Body differentiates. Thus, the treatment elements can be made very wear resistant with minimal use of expensive materials such as tungsten carbide.

Because of the generally higher loading of the treatment elements with regard to the base body, at least the majority of, preferably all, treatment elements should in particular consist entirely of a material which differs from the material of the base body.

By material selection, but in particular by the layered application, it is possible to form at least profiled the surface of the treatment elements facing the gap, which improves the fibrillation of the fibers.

It is advantageous if this profile of the top of the treatment elements is formed by recesses which are delimited by webs extending therebetween and also at the edge of the top by webs forming part of the side surface of the treatment elements.
Because of the high stress on this profile during the rotation of the treatment surfaces or the treatment of the pulp suspension should at least along a side surface of the treatment elements, which preferably at a rotating treatment surface in the direction of rotation and a fixed treatment surface opposite to the direction of rotation (the other, rotating treatment surface), the webs have a greater width than the webs extending between the recesses.
A comprehensive protection of the profile regardless of the direction of rotation can be ensured by having along both side surfaces of the treatment elements, the webs, which form part of the side surfaces, a greater width than the extending between the recesses webs.

With regard to the production methods preferred here, it has proved to be advantageous in the interests of simplification that at least the outer region of the treatment elements lying below the profile is completely filled with the corresponding material over a thickness of at least 2 mm, preferably at least 4 mm , wherein the density of this material in the sections with overlying webs is higher than in sections with overlying recesses.
This allows a two-dimensional, layered application of the particular powdery material over the entire cross section of the treatment element, the material applied then only or particularly intense in the region of the webs a melting process, preferably is subjected by laser.
Because of the small dimensions of the recesses and webs in the range of usually much less than 1 mm, this is extremely simplistic for the production.

If the profile of the treatment elements is removed as a result of wear, material is increasingly being loosened or washed out of the recesses so that a certain tread depth remains ensured over a long service life. The dissolved material is not critical to the pulp processing process because of the small amount of material relative to the amount of pulp being treated.

Alternatively or additionally, it may also be advantageous if the course of the webs changes at least partially perpendicular to the top of the treatment elements. In this way, recesses can be realized under the top of the treatment elements, which only with increasing wear for Open top. This can effectively counteract a permanent closure of the recesses on fiber or fines and increase the stability of the treatment elements.

In general, treating machines for pulp processing have circular or annular treatment surfaces, which are composed of several sets. In this case, the advantages of the manufacturing method according to the invention in terms of manufacturability and cost-effectiveness, in particular, when the main body, the shape of a circular segment or a

Circular segment has and the product of segment angle (in °) and the circle diameter (in cm) is greater than 6000, preferably greater than 6500. The manufacturing process according to the invention allows larger sets and thus reduces their number per treatment area, which improves the homogeneity of the treatment.
The circle diameter of the body should be between 35 and 150 cm.

In contrast to the usual casting of the trimmings, it is possible by the inventive method, the thickness of the body and thus reduce their material requirements and weight. It has proven to be particularly advantageous that the thickness of the base body is less than the height of the treatment elements and in particular less than 85%, preferably less than 75% of the height of the treatment elements.
When considering the thickness of the body remain localized thickening, for example, for attachment in the housing o. unconsidered.

The targeted use of very wear-resistant materials, the emanating from the body height of the treatment elements can be reduced with the same operating time, which in turn simplifies their stratified order. In addition, there is a reduced idle power of the machine, with a small amount of treatment elements is beneficial.

Therefore, the height of the treatment elements should be at least partially, preferably entirely below 5 mm, preferably below 4 mm.

In order to intensify the treatment, the production method according to the invention, in contrast to conventional casting, allows very narrow treatment elements and equally small distances between adjacent treatment elements. For this reason, the treatment elements should be parallel
to the base an elongated cross-sectional shape and at least partially, preferably entirely have a width between 0.1 and 5 mm, in particular between 0.1 and 1 mm and / or the distance between adjacent treatment elements at least partially, preferably entirely between 0.1 and 5 mm, in particular between 0.1 and 2 mm.

Furthermore, it is advantageous if the radius at the transition between the base body and treatment element is less than 1 mm, preferably less than 0.3 mm and the treatment elements can be implemented without Ausformschräge. This leads to a larger open groove surface, a better conveying effect of the trimmings and an optimal use of the treatment surface.

The inventive method now also allows undercuts in the treatment elements. For example, it may be advantageous for at least one side surface of the treatment elements to be inclined with respect to a perpendicular to the rotation direction of a treatment surface.
In order to produce a conveying effect with regard to the pulp to be treated, in a rotating treatment surface, the side surface of the treatment elements facing in the direction of rotation should be inclined with respect to a perpendicular to the direction of rotation counter to the direction of rotation.

In the interest of an optimal arrangement of the treatment elements, it is often advantageous if the elongate treatment elements are at least partially odd. ie are curved or have a kink.

Due to the preferred manufacturing method this is now possible in conjunction with inclined side surfaces.

• Figur 1: einen schematischen Querschnitt durch eine Mahlanordnung;
• Figur 2: eine Draufsicht auf eine Garnitur 2,3 der Mahlanordnung;
• Figuren 3-6: Teilquerschnitte durch unterschiedliche Garnituren 2,3 und
• Figuren 7-9: Draufsichten auf zwei unterschiedliche Behandlungselemente 6.

The invention will be explained in more detail below with reference to several exemplary embodiments.
In the attached drawing shows:

• FIG. 1 a schematic cross section through a grinding arrangement;
• FIG. 2 a plan view of a set 2,3 of the grinding arrangement;
• Figures 3-6 : Partial cross sections through different sets 2,3 and
• Figures 7-9 : Top views of two different treatment elements 6.

In the housing of the grinding arrangement is according to FIG. 1 a grinding gap 4 formed by a fixed and coupled to the housing grinding surface and a rotating about a rotation axis 15 grinding surface.
In this case, the two annular grinding surfaces (treatment surfaces parallel to each other, wherein the distance between these is usually adjustable.

The rotating grinding surface is here moved by a rotatably mounted in the housing shaft 16 in the direction of rotation. This shaft 16 is driven by a drive also present in the housing.

In the example shown here, the fiber suspension 1 to be ground passes via an inlet through the center into the grinding gap 4 between the two grinding surfaces. However, a supply via openings in the clothing is possible.

The fiber suspension 1 passes the cooperating grinding surfaces radially outwards and leaves the adjoining annular space through a drain.
Not shown are the means known per se, with which a force is generated to press the two grinding surfaces against each other.

Both grinding surfaces are each of a plurality of circular segment or annular segment-shaped grinding sets 2.3 according to FIG. 2 formed, which extend over in each case a peripheral segment of the corresponding grinding surface.

Sequined next to each other in the circumferential direction give the sets 2, the fixed and the other sets 3, the rotating grinding surface.

The sets are 2.3, as in FIG. 2 shown in each case by a base plate 5 with a plurality of substantially radially extending, strip-shaped treatment elements 6 and grooves 9 formed therebetween.

The cross section of the treatment elements 6, also called knife, is, as in the FIGS. 3, 4 and 6 represented, generally rectangular, but there are other forms.
So can according to Figure 5a-c Also, one or both of the approximately perpendicular to the direction of rotation 17 of the grinding surface extending side surfaces 18 of the treatment elements 6 in or against the direction of rotation 17 may be inclined. A conveying effect in the grinding gap 4 and thus also an intensification of the fiber treatment is achieved if, as in Figure 5a-c shown, in a rotating grinding surface facing in the direction of rotation 17 side surface 18 of the treatment elements 6 is inclined with respect to a perpendicular to the rotation direction 17 opposite to the direction of rotation 17.
Corresponding FIG. 5c Both sides of the treatment elements 6 are inclined in the same direction.
In order to reinforce in particular the upper region of the treatment elements 6 because of their heavy wear, it can according to FIG. 5a the opposite to the direction of rotation 17 facing side surface 18 may be inclined against the Roatationsrichtung 17 or as at FIG. 5b perpendicular to Roatationsrichung 17 run.
However, the variation of the inclinations of the side surfaces 18 is not limited to this, but can be done depending on the desired effect, for example, even with fixed grinding surfaces.

Parallel to the base 5, the treatment elements 6 have an elongated cross-sectional shape, wherein the treatment gap 4 facing upper side 19 of the treatment elements 6 is generally parallel to the outer surface of the base body 5.
In order to optimize their arrangement and their effect, the treatment elements 6 often run at least over a radial section odd, ie curved, wavy or as in FIG. 2 to see it kinked.
This is now possible in connection with the subsequent manufacturing process even with inclined side surfaces 18.

In order to reduce the manufacturing costs of the sets 2,3, only the treatment elements 6 of the trimmings are at least partially applied in layers of a liquid or solid material and subjected to a physical or chemical curing or melting process.
This means that the materials can be chosen according to the specific demands and requirements.
Thus, in particular the main body 5 can be cast from a cheap metal and have the same shape for differently shaped sets 2.3. Even a reuse of the main body 5 is possible.
Since the base body 5 is not exposed to increased wear in operation, there are no special requirements for its wear resistance.

In contrast, the treatment elements 6 are subject to increased wear, which is why at least part of each of two side surfaces 18 and the intermediate, directed to the gap 4 top 19 surface of the treatment elements 6 consists of a wear-resistant material, which differs from the material of the base body 5.

Because of the extremely high stress in machines for the treatment of pulp 1 is particularly the layered application of powdery material, which ceramic or one or more metals or metal compounds includes. This layered material can then be sintered or fused by laser after each layer.

at FIGS. 3 and 5 the arrangement of the treatment elements 6 on the base body 5 can be selected as needed.

This is made possible by the fact that all treatment elements 6 consist entirely of a material which differs from the material of the main body 5. Therefore, the treatment elements 6 can be applied as a whole layer by layer from a liquid or solid material and thereby undergo a physical or chemical curing or melting process.

In contrast, the treatment elements 6 at FIGS. 4 and 6 each one integral with the main body 5 connected core 7. Thus, although the arrangement of the treatment elements 6 is given, but on the other hand ensures a very strong fixation on the body 5 via the cores 7. Accordingly, only an outer region of the treatment elements 6 is applied in layers of a liquid or solid material and thereby subjected to a physical or chemical curing or melting process.

While at FIG. 4 the entire surface of the treatment elements 6 is produced in layers, this is done at FIG. 6 only on the top of the treatment gap 4 facing 19th
For example, tungsten carbide is suitable as the outer wear layer for the layered structure, whereby a thickness of this wear layer of 1 mm is usually sufficient.

Since the layered material often differs in color from the material of the base body 5, a complete abrasion of the material applied in layers on the upper side 19 of the treatment elements 6 facing the gap 4 can easily be detected.

This is especially true for the treatment elements 6 with core 7, which are particularly well suited for a reprocessing of worn treatment elements 6.

In order to improve the fibrillation of the fibers, at least the top 4 of the treatment elements 6 facing the gap 4 can be made profiled.
This profile essentially comprises recesses 20 on the upper side 19 which are delimited by webs 21 running between the recesses 20 and also by webs 22 forming part of the side surface 18 of the treatment elements 6 at the edge of the upper side 19. In FIGS. 7 and 9 be the recesses 20 of the gap 4 open towards slots and at FIG. 8 formed by open honeycombs.
Since the profile is exposed to a large stress, the webs 22 at
FIG. 8 along a side surface 18 of the treatment elements 6 a greater width than the others, in particular extending between the recesses 20 webs 21st
The reinforced webs 21 are located at a rotating grinding surface in the direction of rotation 17 and a fixed grinding surface in the opposite direction of rotation 17 (the opposite, rotating grinding surface) facing side.

In contrast, the webs 22 at FIG. 7 along both side surfaces 18 of the treatment elements 6 a greater width than the webs 21 extending between the recesses 20.

It is also essential here that the outer region of the treatment elements 6 situated below the profile is completely filled with the corresponding material over a thickness of at least 4 mm, the density of this material being higher in the sections with overlying webs 21, 22 than in Sections with overlying recesses 20 is.
While this density difference is at FIG. 3b exemplarily extends over a substantial part of the treatment element 6, this is at FIG. 6a down to the core 7 to find.

This simplifies the production because the powdery material for the treatment element 6 no longer has to be applied exactly only for the webs 21, 22, but can also come to rest in the region of the gap 20 situated in the direction of the gap 4.
However, the sintering of this material after the application of each layer then takes place as far as possible only in the region of the webs 21, 22 situated in the direction of the gap. While the molten portion of the material is relatively hard and wear resistant, the portion of the material that is not or only slightly laser-treated is porous. With increasing wear of the profile of this porous material is washed out, resulting in a depression of the original recess 20.
As a result, the set 2,3 remains much longer usable.

FIG. 9 shows an embodiment in which the course of the webs 21,22, perpendicular to the top 19 of the treatment elements 6, changes. Concretely, the treatment elements 6 here consist of several layers arranged one above the other towards the grinding gap 4, whereby the webs 21 of a layer extend essentially over the slot-shaped recesses 20 of the layer lying below ,
In this way, the effect of the profile over a long period of operation can be maintained.

Since the entire set 2.3 is no longer cast, the thickness 11 of the main body 5 can now be less than the height 10 of the treatment elements 6, which has a positive effect on the weight and the handling of the set 2.3. This in turn also makes it possible to select the segment angle 8 of the set 2,3 greater than usual, so that the product of segment angle 8 (in °) and the circle diameter (in cm) is greater than 6000, preferably greater than 6500.
Here, the circle diameter of the base body 5 is between 35 and 150 cm. The height 10 of the treatment elements 6 is here, for example, less than 5 mm, the width 12 of the treatment elements 6 between 0.1 and 1 mm and the distance 13 between adjacent treatment elements 6 between 0.1 and 2 mm.

The new manufacturing process also allows at the transition between the base body 5 and treatment element 6 smaller radii 14 of less than 0.3 mm, which is positive for the conveying effect.

Claims (14)

Set (2,3) for treating aqueous suspended pulp (1) in a treatment gap (4) bounded by two treatment surfaces rotating relative to each other and formed by sets (2,3), consisting of a base body (5) leading to the gap ( 4) pointing, elongated and at least one direction component radially extending treatment elements (6), wherein the treatment elements (6) at least partially applied in layers of a liquid or solid material and thereby subjected to a physical or chemical curing or melting process, wherein at least a part the surface of the treatment elements (6) formed in each case by two side surfaces (18) and the intermediate upper side (19) which is directed towards the gap (4) consists of a material which differs from the material of the main body (5), characterized in that at least the top (19) of the treatment elements facing the gap (4) te (6) has a profile which is formed by recesses (20) which are bounded by webs (21) extending therebetween and also by webs (22) forming part of the side surface (18) of the treatment elements (6) and the sub-profile outer region of the treatment elements (6) is completely filled with the corresponding material over a thickness of at least 2 mm, the density of this material being higher in sections with overlying ridges (21, 22) than in sections with overlying recesses (20). Set according to claim 1, characterized in that at least the plurality of, preferably all treatment elements (6), in particular entirely consist of a material which differs from the material of the base body (5). Set according to claim 1 or 2, characterized in that at least along a side surface (18) of the treatment elements (6), which preferably at a rotating treatment surface in the direction of rotation (17) and a fixed treatment surface opposite to the direction of rotation (17), the webs (22) have a greater width than the between the recesses (20) extending webs (21). Set according to one of the preceding claims, characterized in that along both side surfaces (18) of the treatment elements (6) the webs (22) have a greater width than the webs (21) extending between the recesses (20). Fitting according to one of the preceding claims, characterized in that the lying under the profile, the outer region of the treatment elements (6) over a thickness of at least 4 mm is completely filled with the corresponding material, the density of this material in the sections with overlying Webs (21,22) is higher than in sections with overlying recesses (20). Set according to one of the preceding claims, characterized in that the course of the webs (21,22) at least partially changes perpendicular to the top (19) of the treatment elements (6). Set according to one of the preceding claims, characterized in that the base body (5) has the shape of a circle segment or a circular ring segment and the product of segment angle (8) (in °) and the circle diameter (in cm) greater than 6000, preferably greater than 6500 is. Set according to one of the preceding claims, characterized in that the thickness (11) of the base body (5) is less than the height (10) of the treatment elements (6). Set according to one of the preceding claims, characterized in that the height (10) of the treatment elements (6) is at least partially, preferably entirely below 5 mm, preferably below 4 mm. Set according to one of the preceding claims, characterized in that the elongate treatment elements (6) at least partially, preferably entirely have a width (12) between 0.1 and 5 mm, in particular between 0.1 and 1 mm. Set according to one of the preceding claims, characterized in that the radius (14) at the transition between the base body (5) and treatment element (6) is less than 1 mm, preferably less than 0.3 mm. Set according to one of the preceding claims, characterized in that at least one side surface (18) of the treatment elements (6) is inclined with respect to a perpendicular to the rotational direction (17) of a treatment surface. Fitting according to claim 12, characterized in that in a rotating treatment surface facing in the direction of rotation (17) side surface (18) of the treatment elements (6) with respect to a perpendicular to the rotation direction (17) against the rotation direction (17) is inclined. Set according to one of the preceding claims, characterized in that the elongate treatment elements (6) extend at least partially odd.

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