GB2141149A - Supporting system for screen pipe - Google Patents

Abstract

A supporting system for the support of a screen pipe (1) to be used for the formation of a weblike stuff track. In order to prevent the screen pipe from deflecting and so that the support does not influence the stuff track to be formed, it is fundamentally characteristic to the system according to the invention that the rotating screen pipe (1) is supported from its inner side by supporting elements (7) that are essentially isolated from the finely separated materials in the screen drum and are fixed to the known fibre separating equipment in the axial direction of the pipe. <IMAGE>

Description

SPECIFICATION Supporting system for screen pipe The subject of this invention is a supporting system for the support of a screen pipe to be used in the formation of a weblike stuff track.

For the formation of the stuff track, that is the web, it is recognised to constrain material dispersed in air out through the casing of perforated drums with the aid of rotating brushes or blades. A device suitable to this application has been presented, for example in the Finnish Patent Application 812929. In equipment of the kind described in that application the ends of the perforated drum, that is the screen pipe, are supported by rotation bearings in which the screen pipe is made to rotate about its axis.

Because the screen pipe is to be made of relatively thin material, the screen pipe will deflect between its bearing points, particularly if the web to be formed is wide and when the pipe must therefore be long. The deflection is detrimental to both the screen pipe rotating about its axis and to the evenness of the stuff track to be formed. The longer the pipe and the higher the speed of rotation the greater the deflection. Because of this it is possible to improve track forming eqiupment based upon use of known screen pipes by also arranging support for the screen pipe along its casing.

Constructions that give support to pipes may not however affect the evenness of the stuff track to be formed, by for example changing the air and fibre flows inside the equipment itself. In addition the loose fibres have a tendency to adhere to one another whereupon undesirable bunching occurs. The supporting construction must not then in any way promote the aforementioned fibre bunching.

The intention of this invention is to prevent the deflection of the screen pipe without detrimentally affecting the track formation. It is fundamentally characteristic to the invention, in attaining this objective that the rotating screen pipe is supported from its inner side by supporting elements that are essentially isolated from the finely divided material in the screen drum and are fixed to the known fibre separating equipment in the axial direction of the pipe. Thus a supporting construction for a screen drum which fulfills the above requirements is simply attained.

It is characteristic to one advantageous application of the invention that the supporting elements are rotating elements. When support is founded upon the use of a rotating element, for example a rotating roller, the least friction is achieved between the supporting element and the casing of the screen pipe.

The invention is described in more detail in the following example with the aid of reference to the accompanying drawing in which, Figure 1 depicts an application of the support of a screen pipe in accordance with the invention, seen in half-section.

Figure 2 illustrates support of a screen pipe in accordance with the as seen in crosssection at point ll-ll of Fig. 1.

The reference number of Fig. 1 means a screen pipe with perforated casing which is rotated in the support of rotation bearings 3.

The ends of the screen pipe are furnished with solid bearings 2. Inside screen pipe 1 is the mixing cylinder 4, which is equipped with radial mixing rods 5 and which can be made to rotate in the opposite direction to the rotation of the screen pipe. Inside the screen pipe in its axial direction is the separating equipment 6 through which the material dispersed to air is blown into the inside of the screen pipe 1. It is endeavoured to divide the particles as evenly as possible by means of the separator 6 over the whole length of the perforated casing of screen pipe 1.

On top of the separator unit 6 a sufficient number of supporting elements 7 furnished with rollers are installed to support the screen pipe lover its whole casing length. The supporting elements 7 are encased so as to avoid the supporting elements 7 in the screen pipe 1 leading to the formation of fibre bunching.

The supporting elements 7 may also be sliding elements for example curved pieces the smooth convex half of which guide the screen pipe 1 casing.

The various forms of application of the invention are not limited to the example illustrated above but may be changed within the bonds of the patent ciaims hereinafter presented.

1. A supporting system for the support of a screen pipe to be used in the formation of a weblike stuff track, characterised in that the rotating screen pipe is supported from its inner side by supporting elements that are essentially isolated from the finely divided material in the screen drum and are fixed to the known fibre separating equipment in the axial direction of the pipe.

2. A system in accordance with Patent Claim 1, characterised in that the supporting elements are rolling elements.

3. A supporting system for the support of a screen pipe substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (3)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Supporting system for screen pipe The subject of this invention is a supporting system for the support of a screen pipe to be used in the formation of a weblike stuff track. For the formation of the stuff track, that is the web, it is recognised to constrain material dispersed in air out through the casing of perforated drums with the aid of rotating brushes or blades. A device suitable to this application has been presented, for example in the Finnish Patent Application 812929. In equipment of the kind described in that application the ends of the perforated drum, that is the screen pipe, are supported by rotation bearings in which the screen pipe is made to rotate about its axis. Because the screen pipe is to be made of relatively thin material, the screen pipe will deflect between its bearing points, particularly if the web to be formed is wide and when the pipe must therefore be long. The deflection is detrimental to both the screen pipe rotating about its axis and to the evenness of the stuff track to be formed. The longer the pipe and the higher the speed of rotation the greater the deflection. Because of this it is possible to improve track forming eqiupment based upon use of known screen pipes by also arranging support for the screen pipe along its casing. Constructions that give support to pipes may not however affect the evenness of the stuff track to be formed, by for example changing the air and fibre flows inside the equipment itself. In addition the loose fibres have a tendency to adhere to one another whereupon undesirable bunching occurs. The supporting construction must not then in any way promote the aforementioned fibre bunching. The intention of this invention is to prevent the deflection of the screen pipe without detrimentally affecting the track formation. It is fundamentally characteristic to the invention, in attaining this objective that the rotating screen pipe is supported from its inner side by supporting elements that are essentially isolated from the finely divided material in the screen drum and are fixed to the known fibre separating equipment in the axial direction of the pipe. Thus a supporting construction for a screen drum which fulfills the above requirements is simply attained. It is characteristic to one advantageous application of the invention that the supporting elements are rotating elements. When support is founded upon the use of a rotating element, for example a rotating roller, the least friction is achieved between the supporting element and the casing of the screen pipe. The invention is described in more detail in the following example with the aid of reference to the accompanying drawing in which, Figure 1 depicts an application of the support of a screen pipe in accordance with the invention, seen in half-section. Figure 2 illustrates support of a screen pipe in accordance with the as seen in crosssection at point ll-ll of Fig. 1. The reference number of Fig. 1 means a screen pipe with perforated casing which is rotated in the support of rotation bearings 3. The ends of the screen pipe are furnished with solid bearings 2. Inside screen pipe 1 is the mixing cylinder 4, which is equipped with radial mixing rods 5 and which can be made to rotate in the opposite direction to the rotation of the screen pipe. Inside the screen pipe in its axial direction is the separating equipment 6 through which the material dispersed to air is blown into the inside of the screen pipe 1. It is endeavoured to divide the particles as evenly as possible by means of the separator 6 over the whole length of the perforated casing of screen pipe 1. On top of the separator unit 6 a sufficient number of supporting elements 7 furnished with rollers are installed to support the screen pipe lover its whole casing length. The supporting elements 7 are encased so as to avoid the supporting elements 7 in the screen pipe 1 leading to the formation of fibre bunching. The supporting elements 7 may also be sliding elements for example curved pieces the smooth convex half of which guide the screen pipe 1 casing. The various forms of application of the invention are not limited to the example illustrated above but may be changed within the bonds of the patent ciaims hereinafter presented. CLAIMS

1. A supporting system for the support of a screen pipe to be used in the formation of a weblike stuff track, characterised in that the rotating screen pipe is supported from its inner side by supporting elements that are essentially isolated from the finely divided material in the screen drum and are fixed to the known fibre separating equipment in the axial direction of the pipe.

2. A system in accordance with Patent Claim 1, characterised in that the supporting elements are rolling elements.

3. A supporting system for the support of a screen pipe substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.