FR3120372A1 - MINERAL WOOL MANUFACTURING FACILITY - Google Patents

Abstract

Mineral wool manufacturing facility Mineral wool manufacturing installation (1), comprising at least one mineral fiber feeding device (4) (3) and a fiber distribution station (2) comprising a conveyor belt (14) movable in a direction of movement longitudinal and on which the mineral fibers (3) are capable of being received to form a mattress of mineral fibers (15), characterized in that the fiber distribution station comprises a train of rollers (12) arranged on the passage of the fibers minerals (3) intended to fall by gravity onto the conveyor belt (14) and in which each roller (13) is capable of being rotated around a transverse axis of rotation, the rollers (13) being configured to arrange the mineral fibers (3) homogeneously in the thickness of the fiber mattress (15) formed on the conveyor belt (14). Figure for abstract: figure 2

Description

MINERAL WOOL MANUFACTURING FACILITY

The invention relates to the field of the manufacture of mineral wool, of the type for example glass wool, and it relates more particularly to an installation for the manufacture of mineral wool comprising a station for distributing the mineral fibers on a conveyor belt of this installation.

Mineral wool manufacturing facilities conventionally comprise several successive stations, including a fiber-drawing station, in which virgin or recycled mineral fibers are formed, a station for mixing or sizing the mineral fibers thus formed with a binder, for example under liquid form, a station for distributing the mineral fibers on a conveyor belt, a calendering station, and a crosslinking station in which the mat formed on the conveyor belt is transformed by heating by the presence of mineral fibers and binder to form the mineral wool.

More particularly, it is known that the distribution station comprises means for guiding the assembly formed by the mineral fibers and the binder allowing this assembly to be distributed under suction, mainly following the aeraulics imposed by the settings of the tools. drawing, to which jets of compressed air are added in order to macroscopically distribute the clusters of fibers on the conveyor belt and the mat thus formed is then directed towards an oven forming the calendering and crosslinking station, in which the The mattress is successively dried and then subjected to a specific heat treatment which causes the polymerization (or “hardening”) of the resin of the binder present on the surface of the fibres. The continuous mat of mineral wool is then intended to be cut to form, for example, panels or rolls of thermal and/or acoustic insulation.

The thermal and/or acoustic insulation performance of these panels, consisting of non-woven fibrous materials, depends in particular on the arrangement of the mineral fibers in the panel and therefore on the arrangement of the mineral fibers on the conveyor belt before they pass in the curing station. It is therefore understood that the configuration of the distribution station within the mineral wool manufacturing installation is essential.

We know from the prior art, and for example the application EP2238281, distribution stations configured to allow the positioning of the fibers on the conveyor belt, with toothed rollers which make it possible to prevent conglomerates of fibers formed in the station of distribution mixture with the binder are placed as they are on the conveyor belt. The fibers thus separated are then sucked up via a suction box placed on the other side of the conveyor belt so as to be deposited on this conveyor belt.

If distribution stations of this type make it possible to improve the distribution of the fibers within the fiber mat, by avoiding that large piles of fibers are present locally while areas of the mat are without fiber, the present invention aims to to propose an installation which greatly improves the performance of thermal insulation by seeking, in addition to the absence of agglomerates of mineral fibers within the mat of mineral fibers, the optimization of the positioning of each of the mineral fibers within such a mat.

The present invention falls within this context and aims to provide a mineral wool manufacturing facility, comprising at least one mineral fiber supply device and a fiber distribution station comprising a conveyor belt movable in a direction of longitudinal movement. and on which the mineral fibers are capable of being received to form a mat of mineral fibers, characterized in that the fiber distribution station comprises a train of rollers arranged on the passage of the mineral fibers intended to fall by gravity onto the conveyor belt and in which each roller is capable of being driven in rotation about a transverse axis of rotation, the rollers being configured to arrange the mineral fibers homogeneously in the thickness of the fiber mat formed on the conveyor belt.

The installation according to the invention is aimed in particular at the specific use of mineral fibers, the dimensions, lightness and flexibility of which, for example, are specific compared to other fibers such as wood fibers, which implies a specific positioning rollers with respect to the conveyor belt to ensure that the mineral fibers can be deposited evenly on the conveyor belt moving under the train of rollers, so as to be evenly distributed in the thickness of the mineral fiber mat that forms on the conveyor belt.

With the desired aim of the invention of a homogeneous arrangement of the mineral fibers in the thickness of the fiber mat, it is notable that according to the invention, the distribution station is devoid of fiber suction means, so that the distribution of the fibers is done only mechanically. The absence of such aeraulic means makes it possible to control the deposit of the mineral fibers on the conveyor belt and their homogeneous distribution as the conveyor belt unrolls on which the fiber mat is formed. If the absence of aeraulic means has the advantage of being able to control the deposition of mineral fibers, this requires configuring the installation to prevent too large a quantity of fibers from falling between the first rollers that the fibers encounter.

According to the invention, the train of rollers is thus configured to ensure a homogeneous distribution of the mineral fibers in the thickness of the mat of mineral fibers, in particular by proposing a configuration allowing the passage of a substantially equivalent quantity of fibers between each pair of rollers adjacent to the train of rollers, thus preventing a large majority of the fibers encountering the train of rollers from crossing the latter between the first two rollers that they encounter, namely the proximal roller as it could be identified previously and the immediately adjacent central roll.

According to one characteristic of the invention, the train of rollers comprises a plurality of rollers arranged parallel to each other with a spacing between two neighboring rollers which is variable from one end of the train of rollers to the other. The train of rollers can in particular be configured so that the spacing between two neighboring rollers increases from one end to the other of the train of rollers, considering the direction of advance of the fibers along the conveyor belt.

In other words, according to a characteristic of the invention, the spacing between two successive rollers of the roller train varies by increasing regularly with each spacing in the direction of movement of the fibers from one roller to the other. The increase in the spacing between two neighboring rollers can in particular be regular.

The rollers are driven in rotation to, on the one hand, allow the passage of a part of the mineral fibers through the train of rollers towards the conveyor belt and, on the other hand, to allow the transfer of a part of the mineral fibers from one roller to the other, so that certain mineral fibers gradually reach the distal end of the set of rollers, opposite the proximal end of the set of rollers located directly above the arrival of the mineral fibers in the distribution station. The fact of providing a spacing between two rollers which increases according to the direction of advance of the mineral fibers from one roller to the other makes it possible to reduce the spacing between the first rollers reached by the mineral fibers and to force a large part of the mineral fibers to propagate in the direction of the following rolls to ensure step by step that a sufficient quantity of mineral fibers passes through the train of rolls between a central roll and the distal roll of this train of rolls. The spacing between the first rollers is thus small in size to avoid a massive natural displacement of the mineral fibers towards the conveyor belt under the effect of gravity and to ensure that a sufficient quantity of mineral fibers is directed towards the others. rolls. At the end of the train of rollers, at the end of the mineral fiber movement chain, the greater spacing makes it possible to direct the fibers towards the conveyor belt despite the transverse speed that they have been able to acquire through the rotation rollers.

According to a characteristic of the invention, each roller is driven by individual drive means. A module for controlling the operation of the mineral wool manufacturing installation is configured to give a specific control instruction to each of the drive means associated with a roller, and in particular to give a control instruction relating to a speed of rotation of this roll. As a result, the rollers of the same train of rollers can advantageously be driven in rotation with different rotational speeds from one roller to another.

According to a feature of the invention, each roller is driven at a speed of rotation different from that of the neighboring rollers, the speeds of rotation of the rollers decreasing in the direction of movement of the fibers from one roller to another. The function of the first rollers reached by the mineral fibers is to accelerate the speed of the fibers to drive them towards the following rollers and the speed of the rollers successively reached by these mineral fibers decreases to allow as they move along the roller train their passage through this roller train.

According to one characteristic of the invention, a speed of movement of the conveyor belt is calculated to obtain a mat of mineral fibers with a volume density of between 5 and 40 kg/m3, more particularly between 6 and 35 kg/ m3, even more particularly between 7 and 30 kg/m3.

The installation is in this particular sense in that the mats of mineral fibers obtained at the outlet of the distribution station have a volume density of mineral fibers which is lower than that of mats of other types of fibers, such as wood fibers by example. This volume density is obtained in particular by modulating the surface density via the control of a speed of movement of the conveyor belt which allows the deposit of a given number of mineral fibers in a given time.

According to one characteristic of the invention, the mineral wool manufacturing installation comprises a conveyor belt arranged between the mineral fiber supply device and the mineral fiber distribution station so that mineral fibers at the outlet of the conveyor belt are suitable for falling by gravity onto the conveyor belt via a passage between the rollers of the train of rollers, the speed of movement of the conveyor belt being a function of the speed of movement of the conveyor belt and the desired volume density of the mineral fibers in fiber mat.

According to a characteristic of the invention, the distribution station is equipped with a deflector means configured to guide the mineral fibers at the outlet of the feed device, and in particular at the outlet of the conveyor belt, as far as the conveyor belt. This deflector means can be movable to modify the zone of the train of rollers on which the mineral fibers and the associated binder are directed at the outlet of the conveyor belt.

According to one characteristic of the invention, the rollers each have reliefs on the surface, arranged regularly along the axis of rotation of the rollers. It should be noted that by relief is meant both hollows and bumps, and more particularly grooves or prominences, intended to break the regular profile of the peripheral surface of the rollers, in order to ensure the attachment and/or the unhooking of the mineral fibers by these rollers.

According to other characteristics of the invention, the rollers consist of toothed rollers, each tooth forming a radial projection of the roller body driven in rotation. At least one toothed roller comprises a plurality of teeth which are arranged annularly and are regularly distributed around the periphery of the roller.

The radial dimension of the teeth can be considered for the calculation of the value of the vertical clearance of the corresponding roller, to ensure on the one hand that the teeth can make it possible to ensure simultaneous contact of the mineral fibers with the conveyor belt or the mattress. of fiber already formed and one of the teeth, with the aim of orienting the fibers longitudinally and to ensure on the other hand that the teeth can be in contact with the fibers previously deposited on the conveyor belt and likely not to be still correctly plated on the surface of the mineral fiber mat, in order to finalize the longitudinal orientation of the mineral fibers and in the thickness of the fiber mat. In other words, the vertical clearance can be measured between the conveyor belt, or the mineral fiber mat intended to rest on the conveyor belt, and the free radial end of the tooth closest to this conveyor belt.

According to one characteristic of the invention, at least one roller comprises a plurality of toothed rings arranged parallel against each other along the transverse axis of rotation of the corresponding roller.

Additionally, without this being limiting of the invention, the rollers can be configured to ensure a longitudinal orientation of the mineral fibers on the conveyor belt, in particular by considering the distance between the rollers of the train of rollers and the surface of the conveyor belt. on which the mineral fibers are deposited after having passed through the train of rollers, this distance being subsequently designated by the term vertical clearance.

A special feature of these mineral fibers consists in particular in the fact that they easily form agglomerates of fibers by sticking to each other, so that the average length of a mineral fiber to be considered can vary. By way of non-limiting example, mineral fibers alone may have an average length of less than 10 millimeters, but these mineral fibers entirely separated from the others may represent only a minimal part within the fibrous assembly arriving in the post of distribution relative to clusters of fibers whose average length, depending on an average number of mineral fibers forming these clusters, can be of the order of 20 to 30 millimeters. It is therefore advantageous to provide an installation taking care of this particularity specific to mineral fibers, the presence of clusters of fibers being able moreover to be increased when the mineral fibers used are recycled fibers, with residues of binder joining together several of these mineral fibers. The installation according to the invention can be configured according to an average dimension of a length of fibers or clusters of fibers, in particular to adapt the vertical clearance value, that is to say the distance between the rollers of the roller train and the surface of the conveyor belt on which the fibers are deposited, and allow the vast majority of mineral fibers, whether alone or in clusters, to be correctly deposited on the conveyor belt.

According to one characteristic of the invention, the train of rollers comprises a plurality of rollers arranged in parallel to each other, among which a proximal roller is arranged at one end of the train of rollers so that a vertical clearance between this proximal roller and the conveyor belt is below a threshold value depending on the average length of the mineral fibers processed by the installation.

As may have been mentioned previously, it should be noted that the notion of average length of the mineral fibers treated by the installation, according to the present invention, can indifferently extend to the average length of a single mineral fiber, when 'it is correctly separated from the other mineral fibers, or at the average length of an average mass of fibers agglomerated between them. According to a non-limiting example, the average length may more particularly be of the order of 20 to 30 millimeters, this value being more particularly representative of an observation made by the inventors of the average length of a cluster of mineral fibers present from representative way in the mineral fiber mattress.

The vertical clearance is here measured between a peripheral surface of the proximal roller and the surface of the conveyor belt on which the mineral fibers are deposited. The rollers of the roller train can in particular be distinguished in that a proximal roller is arranged at a first end of the roller train, and more particularly the end closest to the feed device, in that a distal roller is disposed at the opposite end of the train of rollers and in that a plurality of central rollers are arranged successively between the proximal roller and the distal roller.

The fibers driven by the rotation of the proximal roller and passing between the proximal roller and the central roller directly adjacent to the proximal roller are oriented by gravity in the direction of the conveyor belt, with a free end which hangs in the direction of the belt and an end which remains in contact with the roller.

The average length of the mineral fibers and the vertical clearance of a value lower than the threshold value equal to this value of average length of the mineral fibers, which can be included without limitation between 20 and 30 millimeters, make it possible to ensure that the The free end of each mineral fiber passing through the train of rollers between the proximal roller and the directly adjacent central roller comes into contact with the mat while it is still in contact with the roller. In this way, the free end of the mineral fiber being driven longitudinally by the running of the conveyor belt, the mineral fiber is stretched and positioned longitudinally.

It should be noted that this characteristic of a vertical clearance value below a threshold value, here 30 millimeters, is similar for the other rollers of the set of rollers, being measured this time between the axis of rotation of this other roller and the upper surface of the mineral fiber mat intended to rest on the conveyor belt to the right of this roller. Therefore, analogously to what was mentioned above, the free end of each mineral fiber passing through the set of rollers between this other roller and the directly neighboring roller comes into contact with the mineral fiber mat already present on the carpet while it is still in contact with this other roller, which ensures the stretching and the longitudinal positioning of the mineral fiber.

According to a characteristic of the invention, the train of rollers extends mainly along an axis inclined with respect to the main elongation plane of the conveyor belt. In other words, each roller of the roller train extends its own distance from the conveyor belt, with a progressive increase in this distance considering the direction of movement of the conveyor belt, i.e. as one moves away from the proximal roller of the roller train. It should be noted that the thickness of the mineral fiber mat present on the conveyor belt tends to increase considering the direction of movement of the conveyor belt, and the inclination of the train of rollers is calculated so that each roller is at a value of vertical clearance less than the chosen threshold value, with respect to the surface directly above this roller, considering the thickness of the mineral fiber mat which is supposed to be under this roller.

According to one characteristic of the invention, the inclination of the train of rollers with respect to the main elongation plane of the conveyor belt is determined by an angle calculated according to the thickness of the mineral fiber mat intended to rest on the conveyor belt. , so that the vertical clearance is constant between each of the rollers and the upper surface of the mineral fiber mat.

According to a characteristic of the invention, the distribution station may comprise means for adjusting an inclination of the train of rollers.

According to one characteristic of the invention, the device for supplying mineral fibers comprises means for supplying non-binding mineral fibers and a binder of the powder type or of the pre-bonded mineral fiber type, that is to say composed a core of mineral fiber and a coating encasing this core and comprising an uncured dried binder.

In an alternative embodiment, the conveyor belt is arranged within a separation tank also comprising means for separating the fibers. It is understood from this configuration that the mineral fibers and the associated binder are treated in a first separation draft stage in order to separate the largest fiber conglomerates and that the distribution station essentially has the function of distributing longitudinally in the mattress these fibers separated, if necessary by carrying out a separation finishing step for the few fibers which have not been separated from each other in the separation tank.

Other characteristics, details and advantages of the present invention will emerge more clearly on reading the detailed description given below by way of indication, in relation to the various exemplary embodiments of the invention illustrated in all of the figures among which:

• Figure 1 is a schematic representation of part of a mineral wool manufacturing facility, illustrating in particular the mineral fiber distribution station according to one aspect of the invention;
• Figure 2 is a schematic representation of the distribution station of Figure 1, according to the invention with a train of rollers and a conveyor belt which are arranged at a distance from each other to allow the rollers to orient the mineral fibers during deposit on the conveyor belt and with rollers specifically arranged relative to each other to allow a regular passage of mineral fibers between each pair of neighboring rollers of the roller train and a homogeneity of the fibers in the thickness of the mat of fibers thus constituted;
• Figure 3 is a detail view of the train of rollers of Figure 2, in a top view;
• Figure 4 is a representation in perspective of a toothed ring forming part of a toothed roller of the train of rollers of Figure 3;
• FIG. 5 is a schematic representation of two toothed rollers of the roller train aimed at illustrating the cooperation of these rollers with a mat of mineral fibers formed on the conveyor belt.

As a reminder, the invention relates to the particular configuration of a station of a mineral wool manufacturing installation, and more particularly a mineral fiber distribution station configured to distribute mineral fibers in an appropriate orientation.

We have illustrated on the a part of such a manufacturing facility 1 for mineral wool, for example glass wool, with different successive stations participating in the creation of an insulating blanket composed of mineral fibers and more particularly the specific distribution station 2 according to the invention.

Upstream of this distribution station, if we consider the direction of circulation of the mineral fibers within the installation, a first station comprises a fiber supply device 4 in which are mixed mineral fibers, virgin or recycled , and a binder capable of holding the fibers together when the mixture is heated at the end of installation. Where applicable, the recycled mineral fibers are, for example, mineral fibers manufactured for a blowing wool application, or even fibers transformed in the form of mineral wool for thermal and/or acoustic insulation. In the latter case, the recycled mineral fibers already contain a hardened binder, which does not prevent it from being treated by the same process, namely by subsequently adding another binder.

In the rest of the description, when mention is made of mineral fibers capable of passing through a train of rollers and of being deposited on a conveyor belt in the distribution station, reference may be made indiscriminately to virgin mineral fibers or to recycled mineral fibers, or else to mineral fibers mixed with binder or with pre-bonded mineral fibers, and whether for a single mineral fiber, perfectly separated from the other mineral fibers, or else a cluster of several intermingled fibers.

The term "virgin mineral fiber" may in particular designate here mineral fiber, in particular glass or rock wool fiber, obtained by internal or external centrifugation, the fibers of which are not bonded to each other by means of an organic binder. Virgin mineral wool fibers can be coated with a thin layer of size or lubricant. The term “recycled mineral fiber” designates here mineral fiber carrying on its surface an insoluble and infusible organic binder, already crosslinked. Of course it can be envisaged that the mineral fibers present in the distribution station are a mixture of virgin mineral fiber and recycled mineral fiber, in any respective proportions.

The fiber supply device comprises at the output a supply duct connected to a conveyor belt 8. The conveyor belt 8 is configured to move at a first running speed, which can be modified by an appropriate control instruction . The conveyor belt 8 has a fiber distribution end 9 which is arranged overhanging the distribution station 2 mentioned above.

The distribution station 2 comprises at least one train of rollers 12 equipped with rollers 13 and a conveyor belt 14 on which is able to form, as the mineral fibers and the binder are deposited on the conveyor belt, a mattress of fibers 15. The train of rollers 12 is arranged on the path of the mineral fibers between the conveyor belt 8 and the conveyor belt 14.

The train of rollers is formed of a plurality of rollers 13 arranged parallel to each other and capable of pivoting about axes of rotation parallel to each other. As will be detailed below, these rollers 13 are configured to allow, on the one hand, to achieve a separation of the mineral fibers and to avoid the deposition of agglomerated mineral fibers on the conveyor belt and, on the other hand, to achieve a longitudinal orientation of these mineral fibers, perpendicular to the axis of rotation of the rollers, within the fiber mat 15. In other words, the distribution station 2 is configured to separate the mineral fibers 3 from each other for the mineral fibers which would not have been completely separated in the separation tank, in particular by the arrangement of the rollers in a train of rollers within which the rollers 13, which rotate in the same direction of rotation, participate in directing part of the mineral fibers 3 between two neighboring rollers towards the conveyor belt and another part of the fibers towards the neighboring roller to advance along the train of rollers and be discharged further on the conveyor belt.

The distribution station is also configured to give these mineral fibers 3 a longitudinal orientation, that is to say parallel to the direction of movement of the conveyor belt, this longitudinal orientation of the mineral fibers 3 in the mat 15 being optimal in terms of thermal insulation.

More particularly, the distribution station 2 makes it possible to give this optimal longitudinal orientation of the mineral fibers in particular by the size of the rollers and their arrangement of the rollers with respect to the conveyor belt, and the impact that this can have on the way in which the fibers are caused to settle on the conveyor belt, instead of falling on it as may be the case in the installations of the prior art. The mineral fibers 3 and pre-bonded mineral fibers 5, or where appropriate, the fibers glued with a liquid binder or in the form of a powder, are deposited on the conveyor belt 14, being deposited on the surface of this conveyor belt after having passed between two neighboring rollers 13, under conditions which ensure drive and longitudinal stretching, and being combed to the surface of the fiber mat 15 by the contact of the rollers of the roller train 12, as will be detailed below.

The conveyor belt 14 is extended by a conveyor belt, which takes the mat 15 composed of these mineral fibers 3 and the binding elements 5 to an oven not shown here and inside which they are heated to crosslink the binder.

It is understood that such an installation line is suitable for the production of products based on glass wool fibers, as will be described, but that it is obviously suitable for the production of products based on mineral fibers .

More particularly, the distribution station and the train of rollers which it comprises are suitable for the treatment, and as mentioned above for the orientation of the fibers with respect to each other, of mineral fibers and for example of fibers glasses, which have specific dimensions and the average length of which may in particular vary according to the dimension of the cluster that they participate in forming, where appropriate, with other mineral fibers, these mineral fibers being more particularly intended for s 'agglomerate than other fibers such as wood fibers, and / or may consist of recycled mineral fibers agglomerated together by residues of dried binder.

The configuration of the train of rollers 12 is moreover particularly suited to an assembly formed of mineral fibers 3 and binder 5 in which the binder is formed by pre-bonded fibers. The train of rollers thus allows an optimal arrangement of the mineral fibers and the prebonded fibers in the mattress of fibers fallen on the conveyor belt.

The pre-bonded fibers here are more particularly fibers composed of a core of mineral fibers, advantageously the same mineral fiber as the non-binding mineral fibers present and of a shell surrounding the core which is made with a pulverized and dried binder.

The binder may in particular consist of a binder with a low formaldehyde content, preferably even without formaldehyde, for example binders based on biobased products. This type of binder is at least partially derived from a base of renewable raw material, in particular vegetable, in particular of the type based on hydrogenated or non-hydrogenated sugars.

The fact that the binder is implemented via a pre-bonded mineral fiber, based on a mineral fiber similar to that treated elsewhere in the installation, makes it possible to treat the arrangement of the binder in the mineral fiber carpet in a similar way to that non-binding fibers.

We will now describe in more detail the fiber distribution station 2 according to one aspect of the invention, in particular with reference to Figures 2 to 5.

The fiber distribution station 2 comprises, in addition to the train of rollers 12 and the conveyor belt 14 mentioned above, at least one casing 18 and a support 20 of the train of rollers.

The casing 18 is delimited by a plurality of walls inside which the mineral fibers and the associated binder are directed, from the conveyor belt 8, to the conveyor belt 14, crossing the train of rollers 12.

One or more deflector means 19 can be arranged projecting from one or more walls of the casing 18 to guide the non-binding mineral fibers and the binder in the direction of the rollers 13 of the train of rollers 12. More particularly the deflector means can be movable, to be able to modify the area of the roller train on which the mineral fibers falling from the conveyor belt are directed.

The support 20 of the train of rollers here has the form of a frame fixed to the walls of the casing 18 to ensure the position of the rollers 13 with respect to the casing, if necessary via means for adjusting the inclination of the rollers. The roller train support is configured so that all the fibers come into contact with the roller train 12.

The support 20 is configured so that the train of rollers 12 is inclined with respect to the conveyor belt 14. In other words, the rollers are arranged parallel to each other along an axis A of the train of rollers which is inclined with respect to a plane P in which extends the surface of the conveyor belt on which the mineral fiber carpet rests. As mentioned, means for adjusting the inclination of the rollers can be provided and associated with the support 20 of the set of rollers to reduce or increase the angle of inclination α between the axis A of the set of rollers and the plane P of the conveyor belt.

The rollers 13 of the train of rollers 12 are here identical, and each have the same number of teeth 22 regularly distributed around the periphery of the rollers.

A proximal roller 131 can be distinguished in the train of rollers, disposed at a first end 121 of the train of rollers 12 closest to the conveyor belt 8, a distal roller 132 disposed at the opposite end 122 of the train of rollers 12 and a plurality of central rollers 133 arranged successively between the proximal roller and the distal roller.

The rollers 13 are driven in rotation, all in the same direction of rotation, so as to allow the progress of the mineral fibers 3 from one end to the other of the train of rollers, with a part of these fibers which pass between the rollers 13 to fall on the conveyor belt 14. An upper part of the rollers and a lower part of the rollers can be defined according to their position relative to a median plane of the train of rollers, the lower part being the part of the rollers closest of the conveyor belt and of the fiber mat, and the direction of rotation of the rollers can be defined such that the upper part of the rollers rotates from the first end to the opposite end of the support.

Each roller 13 is driven by a drive device 24 of its own, so that each roller can rotate at a specific rotational speed (Va, Vb...Vg), independent and, if necessary, different from the rotational speeds of the others. rolls of the same roll train.

A device for removing impurities, not shown here, may comprise a suction hood which is arranged at the end of the roller train support and which is configured to suck up the conglomerates of fibers which have not been able to be separated by the action of the rollers of the roller train.

As may have been mentioned previously, the distribution station 2 in accordance with the invention has technical characteristics and a dimensioning of the various components of this station which are specific to an application to mineral fibers 3 glued with a binder 5 in the form powder or with pre-bound mineral fibres. Several of these characteristics are particularly visible on the representation of the .

As shown on the , the center distance D between the rollers, and therefore the spacing 130 between these rollers when the rollers are all of the same shape and the same dimensions, is variable depending on the rollers considered. In other words, the center distance D1 between the proximal roller 131 and the central roller 133 adjacent to this proximal roller is different from the center distance D6 between the distal roller 132 and the central roller 133. More particularly, the dimensional variation of the centers is regular along the direction of elongation of the train of rollers, so that the centers progress successively from the proximal roller 131 to the distal roller 133. Such a dimensional variation of the centers D makes it possible to pass between the rollers a quantity equivalent of mineral fibers whether at the level of the proximal roller or at the level of the distal roller, avoiding that a major part of the mineral fibers 3 does not pass through the first two rollers that they encounter.

More particularly, the variable spacing increasing in the direction of movement of the conveyor belt and of circulation of the fibers can be explained by the fact that for the rollers reached first by the mineral fibers, a small spacing is necessary because the mineral fibers move naturally between the rollers towards the conveyor belt under the effect of gravity, while a greater spacing is necessary thereafter because the mineral fibers which circulate along the train of rollers passing from rollers in rollers have acquired a transverse speed, and here an upward one due to the inclination of the train of rollers, which forces the mineral fibers to pass between the rollers to reach the conveyor belt.

The spacing 130 of the rollers is considered here as a function of the center distance D between the rollers, but it is also necessary to take into account the radial dimension of the teeth 22 forming the projection of the rollers 13.

This dimensional variation of the center distances D can in particular be coupled with a variation of the speeds of rotation of each of the rollers 13, it being recalled that the rollers are driven independently of each other. More particularly, the fact that the dimension of the center distances between the rollers progresses from a proximal roller to a distal roller can be accompanied by an increase in the speed of rotation of the rollers from the proximal roller to the distal roller. In combination with what has been described previously, it is desired that the speed of rotation of the first rollers reached by the fibers be high so that these first rollers can accelerate and drive the mineral fibers away from the conveyor belt towards which they are attracted by gravity, and in particular when the train of rollers is inclined and involves a movement with an upward component for the mineral fibers to reach the following rollers of the train of rollers, and it is desired to gradually lower the speed of rotation of the rollers to create a falling movement of the mineral fibers towards the conveyor belt.

It is understood that these characteristics make it possible to ensure a homogeneous arrangement of the mineral fibers 3 in the thickness of the fiber mat 15 formed on the conveyor belt 14, by ensuring that a substantially equal quantity of mineral fibers 3 is able to pass in a given time between each pair of rollers 13 adjacent to the train of rollers 12. This avoids the formation of a layered mat of fibers with strata whose fiber density is different from one another, and in particular with a lower stratum denser than the others, which could be formed if the mineral fibers mainly pass between the first two rolls of the train of rolls.

Furthermore, the distribution station 2 is configured to allow a longitudinal orientation of the mineral fibers in the fiber mat. For this purpose, the vertical clearance DV between the proximal roller 131 of the roller train and the conveyor belt 14, that is to say the minimum distance between the components of this proximal roller 131 and the conveyor belt, has a lower value at a threshold value depending on the type of fibers brought to be deposited on the conveyor belt, and therefore here depending on a dimension of the mineral fibers. The vertical clearance can in particular be measured between the outer peripheral surface of the proximal roller and the conveyor belt. The vertical clearance DV is here less than 30 millimeters. Such a vertical clearance value, again smaller than that which could be implemented in applications to wood fibers, makes it possible to ensure that the mineral fibers, after having crossed the train of rollers, remain in contact with the roller at one of their ends when they come to rest on the conveyor belt. As will be detailed below, this makes it possible to ensure a longitudinal orientation of the fibers on the conveyor belt, parallel to the axis of advancement of the conveyor belt.

In order to take into account the thickness of the fiber mat 15 which increases as it advances on the conveyor belt, the train of rollers 12 is inclined in accordance with what has been mentioned. In this way, the characteristic concerning the maximum vertical clearance DV mentioned for the proximal roller, namely a maximum distance at which the proximal roller 131 extends from the surface of the conveyor belt 14 on which the mineral fibers that this proximal roller carries can be deposited, can be reproduced for each of the rollers of the roller train 12 by considering this time the surface of the fiber mat 15 rather than the surface of the conveyor belt 14, the roller train 12 being configured so that the fibers that the rollers central 133 and the distal roller 132 cause are deposited on a mattress of mineral fibers already present on the conveyor belt.

Another characteristic of the installation and of the distribution station is specific to the use of mineral fibers, namely the speed of movement V14 of the conveyor belt 14. This speed of movement V14 makes it possible on the one hand to drive and to stretch the mineral fibers 3 still in contact with the roller 13 which have participated in the crossing by the mineral fibers of the train of rollers, and it is calculated to allow the production of mineral fiber mats having a volume density of fibers less than 40kg / m3 . By way of non-limiting example, the speed of movement of the conveyor belt can be of the order of 5 to 100 meters per minute. Moreover, for the production of mattresses with such a density, it can also be considered the speed of movement V8 of the conveyor belt 8 bringing the mineral fibers into contact with the train of rollers and the difference in movement speeds between the conveyor belt and the conveyor belt.

There makes the support 20 of the train of rollers more particularly visible.

The support frame 20 has a rectangular shape, with two long sides 21 perpendicular to the axis of rotation of the rollers and two short sides 23 connecting these long sides. On the long sides are arranged holding yokes 25 of the motorized drive means 24 and rotation bearings 26 associated with each of the rollers 13, with alternately on the same long side a yoke and a rotation bearing.

Each roller 13 has on the surface, that is to say on its peripheral surface arranged around the axis of revolution, reliefs which are arranged regularly along the axis of rotation of the rollers to break the regular profile of the peripheral surface of the rollers, in particular to control the interaction between the mineral fibers and these rollers.

In the example illustrated, the reliefs are formed by a plurality of teeth 22. In other words, each roller 13 comprises teeth forming projections arranged in successive parallel rings on the axial dimension of the roller, the rings of teeth 22 being separated from each other along the same roll of a pitch 220. It is noticeable on the top view of the that the rollers 13 are arranged so that the rings of teeth 22 of two neighboring rollers are offset axially, to avoid any interaction between the teeth of two neighboring rollers during their rotation.

Each roller 13 may in particular be formed by a plurality of toothed rings 28 pressed against each other along the axial dimension of the roller. As illustrated on the , such a ring 28 may comprise a ring body 280 adapted to be secured to the rotation shaft of the roller and a toothed peripheral portion 282, and these two parts of the ring may advantageously be made of two different materials of a part to another. The toothed portion can for example be molded onto the ring body, with hooking means by complementarity of shapes.

Each ring of teeth 22, and in particular when it is formed by a toothed ring 28 visible on the , comprises teeth 22 regularly distributed angularly, here twenty in number, the teeth thus being characterized by an angular pitch, here of the order of 18°, between two successive teeth on the periphery.

Each tooth 22 projects from an outer surface of the ring, a radial dimension DR of the tooth being measured between the free end 222 of the tooth and the outer surface of the ring.

The teeth 22 are in particular dimensioned so that their free ends 222 can comb the mineral fibers 3 not yet plated on the surface of the mineral fiber mat 15, when the teeth pass during their rotation between the conveyor belt and the median plane of the train of rollers comprising the axes of rotation of the rollers.

The spacing 130 of the rollers mentioned above is determined by considering the center distance D between the axes of rotation of two neighboring rollers and the radial dimension DR of the teeth, in particular visible on the , the spacing being measured between the free end of the teeth of a roller and the neighboring roller.

As results from the preceding detailed description, the invention solves the technical problem of orientation of the mineral fibers in the carpet of fibers to be directed towards the crosslinking station, in particular by providing a particular configuration of the rollers at a short distance from the carpet. conveyor, and more particularly here at less than 30 millimeters from the conveyor belt for the proximal roller and at less than 30 millimeters from the surface of the mattress formed by the mineral fibers likely to be present on the conveyor belt directly above the other rollers . This configuration allows a deposition of the mineral fibers on the conveyor belt with the ends of the mineral fibers which are in contact simultaneously with the conveyor belt and the rollers, which avoids having to release the fibers at a distance from the conveyor belt as in the prior art and that these are then deposited as they please, under the effect of gravity, on the conveyor belt. The simultaneous contact of the mineral fibers with the conveyor belt or the fiber mat and one of the rollers allows the fibers to be stretched and positioned in an optimal longitudinal position for the thermal insulation of the mineral wool obtained after crosslinking of the mat. of fibers.

This longitudinal arrangement of the mineral fibers on the conveyor belt can be even better ensured when the rollers have teeth and these are positioned and sized to comb the surface of the mat of mineral fibers and more particularly the mineral fibers likely to protrude from this surface of the mattress, in a combing direction opposite to that of the direction of movement of the conveyor belt.

These characteristics and the resulting advantages are more precisely detailed with reference to the , which schematically represents the action of the rollers, here toothed rollers, on the fibers to orient them longitudinally.

As mentioned, the proximal roller 131 is arranged at a distance from the conveyor belt 14 such that a vertical clearance DV is less than a minimum value chosen according to the dimensions of the mineral fibers 3 intended to be deposited on the conveyor belt 14 The value of the angle of inclination of the elongation axis of the train of rollers 12 with respect to the surface of the conveyor belt makes it possible to ensure that the other rollers are arranged so that an equivalent vertical clearance DV , that is to say less than the minimum value chosen according to the dimensions of the mineral fibers 3, is formed between the roller and the upper surface of the mat of fibers formed on the conveyor belt in line with said roller.

In this configuration, if we refer to the schematic representation of the proximal roller 131 and of a first mineral fiber 31 passed through the train of rollers 12 between this proximal roller and the neighboring central roller, the rollers are dimensioned, and where appropriate the teeth forming radial projections of the roller body, and arranged at a distance from the conveyor belt so that the first mineral fiber 31 is deposited on the conveyor belt or on first mineral fibers already present on the belt while one end of this first mineral fiber is still in contact with a part of the proximal roller 131, here a tooth 22. In this way, it is notable that according to the invention, the mineral fibers are in simultaneous contact with the roller and the mat conveyor, or the fiber mat present on the conveyor belt, at the time of their deposit on the conveyor belt. The fibers driven by the rotation of a roller and passing between this roller and the central roller directly adjacent to this roller are oriented by gravity in the direction of the conveyor belt, with a first free end which hangs in the direction of the belt and a second end which remains in contact with the roller.

The average length of the mineral fibers, at least equal to 30 millimeters as previously mentioned, and the vertical clearance of a value less than this value of average length of the mineral fibers, here 30 millimeters, make it possible to ensure that the free end of each mineral fiber passing through the roller train between the proximal roller and the directly adjacent central roller comes into contact with the carpet while it is still in contact with the roller. In this way, the free end of the mineral fiber being driven longitudinally by the running of the conveyor belt, the mineral fiber is stretched and positioned longitudinally.

If we refer to the first mineral fiber 31 illustrated in the , the mineral fibers are stretched by the displacement of the conveyor belt which in the illustrated example brings a first free end 31a of the first mineral fiber 31 in one direction and by the rotation of the roller which in the illustrated example tends to bring the second free end 31b in the other direction or which tends at least to retain this second free end 31b.

Each mineral fiber thus deposited on the conveyor belt or on the fiber mat takes on a main longitudinal orientation, with the first free end 31a pressed against the fiber mat. It may result from the laying down of the mineral fiber once released by the roller, as shown in the for a second mineral fiber 32, that the second free end 32b of this second mineral fiber remains raised and is not pressed against the surface of the fiber mat. The arrangement of the train of rollers, with central rollers and the distal roller which are arranged according to a vertical clearance less than the threshold value mentioned above, makes possible a function of combing this second mineral fiber, and more generally of the whole mineral fibers not yet plated on the surface of the mineral fiber mat, the rotational movement of the lower part of the roller, and in particular of the teeth 22, tending to push the second end of the teeth towards the conveyor belt.

In general, the embodiment which has been described above is in no way limiting: it is possible in particular to imagine variants of the invention comprising only a selection of the characteristics described isolated from the other characteristics mentioned in this document, if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention from the prior state of the art.

By way of example, in a variant embodiment not shown and without this being limiting of the number of variants which can be envisaged, the installation comprises a separation tank in which the conveyor belt can be arranged and which comprises means of separation, here not represented, which allow a first step of separation of the fibers, in particular to avoid large agglomerates of fibers. These separating means may in particular consist of toothed rollers and/or blowing means. The fiber separation tank is configured so that the fibers treated by the separation means enter a fiber supply conduit connecting the separation tank to the distribution station mentioned above. In particular, the fiber supply conduit can be configured to allow the fall by gravity of the fibers treated by the separation means.

Claims (17)

Installation for manufacturing mineral wool (1), comprising at least one supply device (4) for mineral fibers (3) and a fiber distribution station (2) comprising a conveyor belt (14) movable in a direction of movement longitudinal and on which the mineral fibers (3) are capable of being received to form a mat of mineral fibers (15), characterized in that the fiber distribution station comprises a train of rollers (12) arranged on the passage of the fibers minerals (3) intended to fall by gravity onto the conveyor belt (14) and in which each roller (13) is able to be driven in rotation about a transverse axis of rotation, the rollers (13) being configured to arrange the mineral fibers (3) homogeneously in the thickness of the fiber mat (15) formed on the conveyor belt (14). Mineral wool manufacturing plant (1) according to Claim 1, characterized in that the train of rollers (12) comprises a plurality of rollers (13) arranged parallel to one another with a spacing (130) between two rollers (13 ) neighbors which is variable from one end to the other of the train of rollers (12). Mineral wool manufacturing plant (1) according to the preceding claim, characterized in that the spacing (130) between two successive rolls of the train of rolls (12) varies by increasing regularly with each spacing in the direction of movement of the fibers of a roller (13) to the other. Mineral wool manufacturing plant (1) according to one of the preceding claims, characterized in that each roller (13) is driven by individual drive means (24). Installation for manufacturing mineral wool (1) according to the preceding claim, characterized in that each roller (13) is driven at a speed of rotation different from that of the neighboring rollers, the speeds of rotation of the rollers (13) decreasing in the direction of movement of the fibers (3) from one roll to another. Installation for manufacturing mineral wool (1) according to one of the preceding claims, characterized in that a displacement speed (V14) of the conveyor belt (14) is calculated to obtain a mat of mineral fibers (15 ) with a volumetric density between 5 and 40 kg/m3. Mineral wool manufacturing plant (1) according to the preceding claim, characterized in that a conveyor belt (8) is arranged between the mineral fiber supply device (4) and the fiber distribution station (2). mineral fibers so that mineral fibers (3) leaving the conveyor belt (8) are able to fall by gravity onto the conveyor belt (14) via a passage between the rollers (13) of the roller train (12), the displacement speed (V14) of the conveyor belt (14) being a function of the displacement speed (V8) of the conveyor belt (8) and the desired volume density of the mineral fibers (3) in the fiber mat (15). Installation for manufacturing mineral wool (1) according to one of the preceding claims, characterized in that the distribution station (2) is equipped with a deflector means (19) configured to guide the mineral fibers (3) leaving the feed device (4) to the conveyor belt (14). Mineral wool manufacturing plant (1) according to one of the preceding claims, characterized in that the rollers (13) each have surface reliefs arranged regularly along the axis of rotation of the rollers. Mineral wool production plant (1) according to one of the preceding claims, characterized in that the rollers (13) consist of toothed rollers, each tooth (22) forming a radial projection of the roller body driven in rotation. Mineral wool manufacturing plant (1) according to the preceding claim, characterized in that at least one roller (12) comprises a plurality of toothed rings (28) arranged parallel to one another along the axis of rotation transverse of the corresponding roller. Mineral wool manufacturing plant (1) according to one of the preceding claims, characterized in that the train of rollers (12) comprises a plurality of rollers (13) arranged in parallel with one another, among which a proximal roller (131 ) is arranged at one end of the train of rollers (12) so that a vertical clearance (DV) between the proximal roller (131) and the conveyor belt (14) is less than a threshold value depending on the average length of the fibers minerals (3) processed by the installation (1). Mineral wool manufacturing plant (1) according to the preceding claim, characterized in that the vertical clearance (DV) is measured between an outer peripheral surface of the proximal roller (131) and the conveyor belt (14). Mineral wool manufacturing plant (1) according to one of the preceding claims, characterized in that the train of rollers (12) extends mainly along an axis inclined with respect to the main plane of elongation of the conveyor belt (14) . Mineral wool manufacturing plant (1) according to the preceding claim, combined with one of claims 12 or 13, characterized in that the inclination of the train of rollers (12) with respect to the main elongation plane of the conveyor belt (14) is determined by an angle calculated as a function of the thickness of the mineral fiber mat (15) intended to rest on the conveyor belt (14), so that the vertical clearance is constant between each of the rollers (13) and the top surface of the mineral fiber mat. Mineral wool manufacturing plant (1) according to one of the preceding claims, characterized in that the distribution station (2) comprises means for adjusting an inclination of the train of rollers (12). Installation for manufacturing mineral wool (1) according to one of the preceding claims, characterized in that the device (4) for supplying mineral fibers comprises means for supplying non-binding mineral fibers and a binder of the powder or pre-bound mineral fibres.