CN204282112U

CN204282112U - Screen cloth

Info

Publication number: CN204282112U
Application number: CN201290000781.9U
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: DE102011081951A1; WO2013029930A1; EP2751336A1; EP2751336B1

Abstract

The utility model relates to a kind of for the treatment of the screen cloth of liquid state to paste medium, and it has multiple sieve aperture (1) and the feed side (3) pointed to against through-flow direction (2) of coating and the exit side (4) pointed to along through-flow direction (2) of coating.At this, thus by differently constructing the coating (5,6) of feed side (3) and exit side (4), the separating effect remained unchanged as far as possible can be realized 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 have multiple sieve aperture and coating, against through-flow direction point to feed side and coating, along through-flow direction point to exit side.

Background technology

This screen cloth such as selects fibrous suspension for wet screening, to remove the impurity wherein existed.It normally rigidity and different from being used in filter press and paper machine, flexible circulation screen cloth thus.

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 the screening characteristics such as by realizing according to the circular hole of the roughness of 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 higher 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, give screen cloth in feed side or both sides coating, especially with chromium, pottery or tungsten carbide coating usually.

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 is, keeps separating effect constant as far as possible when guaranteeing in operationally to measure constant as far as possible on through-flow.

By the utility model, this technical problem solves by the coating of feed side and exit side differently being constructed.

Also the different requirement in side and the better discussion of load do can be sieved to two by different coatings.Because feed side is subject to higher wearing and tearing usually, so the coating of feed side should be made up of very anti abrasive material.Be suitable for this especially pottery, chromium or sintering metal, as tungsten carbide.

In contrast, when selecting the coating of exit side of screen cloth, wearing and tearing (but being lower level wearing and tearing), corrosion and/or adhesiveness are all very important.

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.

Therefore advantageously, the coating of feed side is anti abrasive, and wherein, its hardness is preferably placed between 800 to 2800HV (Vickers hardnesses) and/or the coating of exit side has the adhesiveness of reduction, and wherein, its adhesion strength is less than 60mJ/mm ², be preferably placed at 15 to 30mJ/mm ²between.

Especially polytetrafluoroethylene (PTFE), nano particle, plastics are suitable for the adhering coating realizing having reduction.

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

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

Will be advantageous that at this, apply an only coating.If but to apply in two coatings to matrix and this matrix matrix that to be two coatings common, then expense is minimized.

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

At this, matrix by independent matrix or the matrix shared with other coating or can be formed by other coating itself.

In order to the eddy current strengthened on feed side is formed, the surface structure of screen cloth feed side is for having into type profile.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, expended with relatively little, 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 and Fig. 2 is the schematic partial cross sectional by heteroid screen cloth.

Detailed description of the invention

Screen cloth has multiple equally distributed as far as possible sieve aperture 1 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 under fibrous material disposition for the magnitude range of sieve aperture 1 especially typically, such as between 0.8 to 30 millimeters.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 the sieve aperture 1 with rotation asymmetry cross section: such as elongated hole, rectangle, rhombus, hexagon or there are 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 owing to flowing into and the wearing and tearing of increase that the medium of eddy current causes, 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. 1, two coatings 5,6 are applied on a common matrix 7.This is such as achieved by applying the sclerosis of coating 5,6 and subsequent coating 5,6 with the form of liquid or paste.

By Fig. 2 screen cloth with it unlike, two coatings 5,6 are applied to independent matrix 7, on 8 respectively.Two matrixes 7,8 are interconnected in detachable or non-removable mode at this.

Claims

1. one kind for the treatment of the screen cloth of liquid state to paste medium, its have multiple sieve aperture (1) and coating, the feed side (3) that points to against through-flow direction (2) and coating, the exit side (4) that points to along through-flow direction (2), it is characterized in that, the coating (5,6) of described feed side (3) and exit side (4) is different.

2. by screen cloth according to claim 1, it is characterized in that, the coating (5) of described feed side (3) is anti abrasive coating, wherein, described hardness preferably between 800 to 2800HV and/or the coating (6) of described exit side (4) there is the adhesiveness of reduction, wherein, its adhesion strength is preferably less than 60mJ/mm ², be especially in 15 to 30mJ/mm ²between.

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

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

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

6., 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.

7., by the screen cloth described in claim 1 or 2, it is characterized in that, at least one coating (5,6) is applied on matrix (7,8).

8., by screen cloth according to claim 7, it is characterized in that, two coatings (5,6) are applied on a preferred common matrix (7).

9., by the screen cloth described in claim 1 or 2, it is characterized in that, at least one coating (5,6) is formed by that connect with matrix (7,8) plane earth, independent screen layers.

10., by the screen cloth described in claim 1 or 2, it is characterized in that, the feed side (3) of described screen cloth is designed to have into type profile.