CN204282111U

CN204282111U - Screen cloth

Info

Publication number: CN204282111U
Application number: CN201290000780.4U
Authority: CN
Inventors: W.布雷特施奈德; C.斯泰恩马斯尔
Original assignee: Voith Paper Patent GmbH
Current assignee: Voith Patent GmbH
Priority date: 2011-09-01
Filing date: 2012-08-07
Publication date: 2015-04-22
Anticipated expiration: 2022-08-07
Also published as: DE102011081957A1; WO2013029931A2; EP2751335A2; EP2751335B1; WO2013029931A3

Abstract

The utility model relates to a kind of for the treatment of the screen cloth of liquid state to paste medium, it is by multiple coating (5,6,7) form, and there is multiple sieve aperture (1) and the feed side (3) that points to against through-flow direction (2) and the exit side (4) pointed to along through-flow direction (2).At this, realize by being made up of exit side (4) the adhering coating (6) with reduction keeping screening effect constant as far as possible when through-current capacity is constant as far as possible.

Description

Screen cloth

Technical field

The utility model relates to a kind of for the treatment of the screen cloth of liquid state to paste medium, its be made up of multiple coating and have multiple sieve aperture and against through-flow direction point to feed side and along through-flow direction point to exit side.

Background technology

This screen cloth is such as wet screening fibrous suspension, so that the impurity that removal wherein exists.It normally rigidity and different from being used in filter press and paper machine, flexible circulation screen cloth.

The characteristic of this screen cloth is formed by the size of the sieve aperture be positioned at wherein, shape and quantity substantially.They keep less than material to be sifted out usually.

Advantageously such as in for the preparation of the pulper of paper fiber suspension, auxiliary pulper and screening machine, use this screen cloth, wherein, their task stops impurity.

For this applicable cases especially produced in papermaking and pulp industry, this screen cloth should have such as by the screening characteristics of the circular hole realization of (roughness depending on material) between 0.8mm to 30mm.

Certainly, make every effort to realize through-current capacity large as far as possible in this screen cloth, that is a large amount of as far as possible should passing hole by the material stopped yet.This can be achieved by there is hole as much as possible.Generally speaking, people make every effort to a kind of whole surface of relative screen element free compass screen surface large as far as possible.

Another requirement is the relatively high intensity overcoming hydraulic pressure.This screen element is used in production work, and wherein, it also can disturb, this cause screen element different and sizable pressure loading.Because not total energy gets rid of the possibility of blocking, thus quite high pressure and in corresponding large face very large power can be applied on the surface of this screen element.These power increased must be born by screen cloth, and occur without any infringement.

Wearing and tearing the least possible in order to ensure screen cloth and not corroding, usually give screen cloth in feed side or both sides coating, especially coating is with chromium, pottery or tungsten carbide.

Certainly show, separating effect and through-current capacity can operationally interiorly change, and this is not received in numerous applications.

Summary of the invention

Therefore, technical problem to be solved in the utility model be operationally in guarantee to keep constant as far as possible screening effect when through-current capacity is constant as far as possible.

By the utility model, this technical problem is by being made up of exit side the adhering coating with reduction and solving.

First show to during paste medium in process liquid state, the exit side of screen cloth is easy to deposition usually, is wound around, and this produces passive effect to through-current capacity.When processing solid, in most cases obviously less with the reaction of the exit side of screen cloth.

At this advantageously, the adhesion strength with the adhering coating of reduction is less than 60mJ/mm ², preferably 15 to 30mJ/mm ²between.Especially polytetrafluoroethylene (PTFE), nano particle, plastics are suitable for the adhering coating realizing having reduction.

Because the feed side of screen cloth is subject to higher wearing and tearing usually, so the feed side of coating is made up of very wear-resisting material.Be applicable to especially pottery, chromium or sintering metal therewith, as tungsten carbide.

At this advantageously, the hardness of feed side wear-resistant coating is between 800 to 2800HV (Vickers hardness).

Also the different requirement in side and the better discussion of load do can be sieved to two by different coatings.

Especially for thin coating advantageously, this thin coating is applied on matrix.This such as can by applying coating or realizing by the bonding of film or welding with liquid or cream form.

Will be advantageous that at this, apply an only coating in this wise.If but apply two coatings, to be also applied on matrix by wear-resistant coating and the adhering coating with reduction and it to be two coatings common, matrix in inter coat form, then expense is minimized.

First each coating be subject to very large stress time, at least one coating by with base plane the independent screen layers that connects form and can be conducive to being formed firmly and relative thick coating under most cases.

Have nothing to do with the type of coating and character, each coating adjacent along through-flow direction should be interconnected by plane earth.

As requested and condition, screen cloth can be rigidity or flexibility.In addition, also depend on screen cloth flat or uneven, be especially designed to cylinder.

In order to the eddy current strengthened on feed side is formed, the surface structure of screen cloth feed side becomes to have into type profile in cross section.This can by applying weld seam or relatively simply realizing by laser.

Because be particularly suitable for processing the liquid ability to paste medium, especially be advantageously applied to process by screen cloth of the present utility model to be applicable to manufacturing paper web, board web, the fibrous suspension of tissue webs or other fibrous cloth width or advantageously apply in the treatment of waste water or in food industry.

Thus, achieve with relatively little expending, keep separating effect and through-current capacity relative constancy within the very long time interval, this affects energy consumption, process stability and maintenance cost energetically.

Accompanying drawing explanation

Followingly set forth the utility model further with multiple embodiment.In the accompanying drawings:

Fig. 1 to Fig. 3 is the schematic partial cross sectional by heteroid screen cloth.

Detailed description of the invention

Multilayer screen cloth has multiple equally distributed as far as possible sieve aperture at this, and this sieve aperture has equal minimum cross-section to guarantee identical separating effect.

The cross section of all sieve apertures 1 is as by round-formed.

Enough wall thickness should must be had for the reason of intensity for the treatment of the screen cloth of suspension.Especially particularly advantageous technique can be used, as punching press or laser cutting for the magnitude range of sieve aperture 1 especially typically, such as between 0.8 to 30 millimeters under fibrous material disposition.This causes the cost than producing when holing less usually.

The method for generation of sieve aperture is in addition: the shaping or broaching of milling, the cutting of water bundle, etching, the electrochemical boring of burn into, discharge orifice.

Therefore, also can be easier to produce sieve aperture 1, its cross section right and wrong are rotational symmetric: such as elongated hole, rectangle, rhombus, hexagon or have other polygons at angle of rounding.

At this, sieve aperture 1 also can expand towards the feed side 3 of sieve aperture and/or exit side 4.

In most cases, all adjacent sieve apertures 1 have equal distance to each other, and this guarantees to effectively utilize compass screen surface when higher stability.

At this, sieve aperture 1 is arranged to parallel row usually.

At this, fibrous suspension crosses such as flat screen cloth from feed side 3 along through-flow direction 2 percolation.Larger impurity is stopped at this and such as can be removed by broaching tool on feed side 3.

In order to ensure enough stability, the thickness of screen cloth is between 3 to 30mm in this applications.

Because feed side 3 is subject to wearing and tearing due to the increase flowed into and the medium of eddy current causes, thus the feed side 3 of screen cloth by chromium matter, ceramic material or the abrasion-resistant coatings 5 of tungsten carbide material formed.At this, hardness is positioned at the scope between 800 to 2800HV (Vickers hardness).

In order to especially liquid to the adhesion overcome during paste medium on the exit side 4 of screen cloth in process, exit side 4 is by the adhering coating 6 with reduction, and so-called anti-adhesion layer is formed.

The running time of screen cloth in the constant situation of running parameter can be extended significantly at this.Also can save or reduce expending for cleaning one such trash screen.

According to can correspondingly change structure to the requirement of screen cloth.

In the form of implementation of pressing Fig. 3, two coatings 5,6 are applied in the common matrix of 7 forms in inter coat.This such as to be applied with form that is liquid or paste by coating 5,6 and subsequent coating 5,6 sclerosis and realize.

Solution according to Fig. 1 and Fig. 2 demonstrates modification, and two coatings 5,6 individually, that is form screen cloth in the mode of the inter coat 7 not between them.In this case, at least one coating 5,6 exists in solid form, therefore other coating 6,5 can be applied in this at least one coating.If as in Fig. 1, two coatings 5,6 exist in solid form, then they are interconnected to form screen cloth in detachable or non-removable mode.

Screen cloth shown in Fig. 2 has the stable coating 5 that form is the wear-resistant coating 5 be made up of stainless steel, standard steel, plastics or composite, therefore this form be anti-adhesion layer 6, other coating 6 is such as applied to as film in stable coating 5.

Claims

1. one kind for the treatment of the screen cloth of liquid state to paste medium, this screen cloth is by multiple coating (5,6,7) form, and the feed side (3) that there is multiple sieve aperture (1) and point to against through-flow direction (2) and the exit side (4) pointed to along through-flow direction (2), it is characterized in that, described exit side (4) is formed by the adhering coating (6) with reduction.

2., by screen cloth according to claim 1, it is characterized in that, the adhesion strength with the adhering described coating (6) of reduction is less than 60mJ/mm ², preferably 15 to 30mJ/mm ²between.

3., by screen cloth according to claim 1, it is characterized in that, described feed side (3) is made up of wear-resistant coating (5).

4., by screen cloth according to claim 3, it is characterized in that, the hardness of described wear-resistant coating (5) is between 800 to 2800HV.

5., by the screen cloth described in claim 3 or 4, it is characterized in that, between described feed side (3) and the coating (5,6) of described exit side (4), be provided with at least one inter coat (7).

6., by the screen cloth described in claim 1 or 2, it is characterized in that, adjacent described coating (5,6,7) plane earth is interconnected.

7., by the screen cloth described in claim 1 or 2, it is characterized in that, described screen cloth is rigidity.

8., by the screen cloth described in claim 1 or 2, it is characterized in that, described screen cloth is flexible.

9., by the screen cloth described in claim 1 or 2, it is characterized in that, described screen cloth is flat.

10., by the screen cloth described in claim 1 or 2, it is characterized in that, described screen cloth is uneven, is especially designed to cylinder.

11. by the screen cloth described in claim 1 or 2, and it is characterized in that, the feed side (3) of described screen cloth is configured with into type profile.