PLANT FOR THE PRODUCTION OF MINERAL WOOL

Description

[0001] The invention relates to the field of mineral wool manufacturing, such as glass wool, and more particularly to a mineral wool manufacturing installation comprising a mineral fiber distribution station on a conveyor belt of this installation.

[0002] Mineral wool manufacturing facilities typically include several successive stations, including a fiber-making station, in which virgin or recycled mineral fibers are formed, a mixing or gluing station for the mineral fibers thus formed with a binder, for example in liquid form, a distribution station for 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 the presence of mineral fibers and binder to form the mineral wool.

[0003] For example, mineral wool manufacturing facilities according to the prior art are known from WO 99 / 36623 A1 and EP 2 799 607 A1.

[0004] More specifically, it is known that the distribution station includes guidance systems for the assembly formed by the mineral fibers and the binder, allowing this assembly to distribute itself under suction, primarily following the airflow dictated by the settings of the fiber-spunting tools. Compressed air jets are added to macroscopically distribute the fiber clumps onto the conveyor belt. The resulting mat is then directed towards an oven, forming the calendering and crosslinking station, where the mat is successively dried and then subjected to a specific heat treatment that causes the polymerization (or "hardening") of the binder resin present on the surface of the fibers. The continuous mineral wool mat is then cut to form, for example, panels or rolls of thermal and / or acoustic insulation.The thermal and / or acoustic insulation performance of these panels, made of non-woven fibrous materials, depends in particular on the arrangement of the mineral fibers within the panel and therefore on their arrangement on the conveyor belt before they pass through the crosslinking station. It is thus clear that the configuration of the distribution station within the mineral wool manufacturing plant is essential.

[0005] Prior art, such as patent application EP2238281, is known to describe distribution stations configured to position fibers on the conveyor belt. These stations use toothed rollers to prevent fiber clumps formed during the mixing with the binder from being deposited directly onto the conveyor belt. The separated fibers are then drawn into a suction chamber located on the opposite side of the conveyor belt and deposited there.

[0006] If distribution stations of this type make it possible to improve the distribution of fibers within the fiber mattress, by preventing large piles of fibers from being present locally while areas of the mattress are without fiber, the present invention aims to propose an installation that greatly improves thermal insulation performance by seeking, in addition to the absence of agglomerates of mineral fibers within the mineral fiber mattress, the optimization of the positioning of each of the mineral fibers within such a mattress.

[0007] The present invention falls within this context and aims to propose a mineral wool manufacturing installation, comprising at least one mineral fiber feeding device and a fiber distribution station comprising a conveyor belt mobile in a longitudinal direction of movement and on which the mineral fibers are able to be received to form a mineral fiber mat, 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, the train of rollers comprising at least three rollers, each roller being able to be driven in rotation around 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.

[0008] The installation according to the invention is aimed in particular at the specific use of mineral fibers, whose dimensions, lightness, flexibility, for example are specific compared to other fibers such as wood fibers, which implies a specific positioning of the rollers in relation to the conveyor belt to ensure that the mineral fibers can be deposited regularly on the conveyor belt moving under the train of rollers, so as to be distributed homogeneously in the thickness of the layer of mineral fibers which forms on the conveyor belt.

[0009] In pursuit of the invention's objective of a homogeneous arrangement of mineral fibers within the thickness of the fiber mat, it is noteworthy that, according to the invention, the distribution station lacks any means of fiber suction, so that fiber distribution is achieved solely mechanically. The absence of such aerodynamic means allows for precise control of the mineral fiber deposit on the conveyor belt and their homogeneous distribution as the belt, on which the fiber mat is formed, unwinds. While the absence of aerodynamic means offers the advantage of controlling the mineral fiber deposition, this necessitates configuring the installation to prevent an excessive quantity of fibers from falling between the first rollers they encounter.

[0010] The rollers of the roller train can be distinguished in particular by the fact that a proximal roller is disposed at one end of the roller train, and more particularly the end closest to the feeding device, by the fact that a distal roller is disposed at the opposite end of the roller train and by the fact that a plurality of central rollers are arranged successively between the proximal roller and the distal roller.

[0011] According to the invention, the roller train is thus configured to ensure a homogeneous distribution of mineral fibers in the thickness of the mineral fiber mat, in particular by proposing a configuration allowing the passage of a substantially equivalent quantity of fibers between each pair of neighboring rollers of the roller train, thus preventing a large majority of the fibers encountering the roller train from crossing it between the first two rollers they encounter, namely a proximal roller and an immediately neighboring central roller.

[0012] According to one feature of the invention, the roller train comprises a plurality of rollers arranged in parallel with each other, among which a proximal roller is disposed at one end of the roller train, and the distribution station comprises mechanical guidance means for the mineral fibers towards the proximal roller so that all the mineral fibers entering this distribution station are directed towards the conveyor belt so that they fall on the proximal roller or between this proximal roller and the roller directly adjacent to it.

[0013] According to one feature of the invention, the roller train comprises a plurality of rollers arranged parallel to each other with a spacing between two adjacent rollers that varies from one end of the roller train to the other. In particular, the roller train can be configured such that the spacing between two adjacent rollers increases from one end of the roller train to the other, considering the direction of fiber flow along the conveyor belt.

[0014] In other words, according to one feature of the invention, the spacing between two successive rollers of the roller train varies by increasing regularly at each spacing in the direction of fiber movement from one roller to the next. The increase in spacing between two adjacent rollers can, in particular, be regular.

[0015] The rollers are driven in rotation to allow part of the mineral fibers to pass through the roller train towards the conveyor belt and to allow part of the mineral fibers to be transferred from one roller to another, so that some mineral fibers gradually reach the distal end of the roller train, opposite the proximal end of the roller train which is directly above the arrival of the mineral fibers in the distribution station.By increasing the spacing between rollers according to the direction of mineral fiber flow from one roller to the next, the spacing between the first rollers reached by the mineral fibers is reduced. This forces a large portion of the mineral fibers to spread towards subsequent rollers, ensuring that a sufficient quantity of mineral fibers passes through the roller assembly between the central and distal rollers. The spacing between the first rollers is therefore small to prevent a massive natural movement of mineral fibers towards the conveyor belt under the influence of gravity and to ensure that a sufficient quantity of mineral fibers is directed towards the other rollers.At the end of the roller train, at the end of the mineral fiber transport chain, the larger spacing allows the fibers to be directed towards the conveyor belt despite the transverse speed they may have acquired through the rotation of the rollers.

[0016] According to the invention, each roller is driven by individual drive means. A control module for the operation of the mineral wool manufacturing plant is configured to provide a specific command to each drive means associated with a roller, and in particular to provide a command relating to the rotational speed of that roller. As a result, the rollers in the same roller train can be driven at different rotational speeds.

[0017] According to one feature of the invention, each roller is driven at a different rotational speed than the neighboring rollers, with the rotational speeds of the rollers decreasing in the direction of fiber movement from one roller to the next. The first rollers reached by the mineral fibers accelerate the speed of the fibers to move them towards the following rollers, and the speed of the rollers successively reached by these mineral fibers decreases to allow them to pass through the roller train as they move along it.

[0018] According to one feature of the invention, a conveyor belt travel speed is between 5 and 100 m / min so that the mineral fiber mattress has a volumetric density between 5 and 40 kg / m3, more particularly between 6 and 35 kg / m3, even more particularly between 7 and 30 kg / m3.

[0019] The installation is unique in that the mineral fiber mats produced at the distribution station have a lower volumetric density than mats made of other types of fibers, such as wood fibers. This volumetric density is achieved by modulating the surface density through controlled speed of the conveyor belt, allowing a specific number of mineral fibers to be deposited within a given timeframe.

[0020] According to one feature of the invention, the mineral wool manufacturing installation includes a conveyor belt arranged between the mineral fiber feeding device and the mineral fiber distribution station so that mineral fibers exiting the conveyor belt are able to fall by gravity onto the conveyor belt via a passage between the rollers of the roller train, the speed of movement of the conveyor belt being a function of the speed of movement of the conveyor belt and the desired volumetric density of the mineral fibers in the fiber mat.

[0021] According to one feature of the invention, the distribution station is equipped with a deflector configured to guide the mineral fibers exiting the feeding device, and in particular exiting the conveyor belt, to the conveyor belt. This deflector can be movable to modify the area of ​​the roller train onto which the mineral fibers and the associated binder are directed exiting the conveyor belt.

[0022] More specifically, the distribution station includes mechanical means for directing the mineral fibers into a section of the roller assembly containing the proximal roller. These mechanical means can take the form of a funnel-shaped tray with a large surface area for receiving the fibers exiting the feeding device, particularly the conveyor belt, and a narrower surface area opposite the conveyor belt, directly above the proximal roller. In this way, the mineral fibers are directed by gravity to the desired section of the roller assembly, allowing them to then pass progressively from the proximal roller to the distal roller. The rollers operate sequentially for the fibers that do not pass directly between the first rollers, ensuring that the fibers are distributed evenly along the length of the roller assembly.It should be noted that such distribution is not possible in prior art systems where the fibers are blown and sucked into a casing of the installation and deposited on any area of ​​the conveyor belt after passing randomly between one or the other pair of neighboring rollers.

[0023] In this context, the deflector means may consist of a wall of the mechanical means whose determined inclination allows the mineral fibers to slide precisely onto the desired area of ​​the roller train, namely the proximal roller or in the immediate vicinity of this proximal roller, or it may consist of a movable wall at the outlet of the funnel-shaped tray mentioned previously, the inclination of which is adjusted by an appropriate actuator to direct the mineral fibers onto the proximal roller or near it depending on the quantity of fibers present on the proximal roller.

[0024] According to one feature of the invention, each roller has raised features on its surface, arranged regularly along the axis of rotation of the rollers. It should be noted that by raised features, we mean both hollows and bumps, and more particularly grooves or protrusions, designed to break the regular profile of the peripheral surface of the rollers, in order to ensure the gripping and / or detachment of the mineral fibers by these rollers.

[0025] According to other features of the invention, the rollers consist of toothed rollers, each tooth forming a radial projection of the rotating roller body. At least one toothed roller has a plurality of teeth arranged annulally and distributed regularly around the periphery of the roller.

[0026] The radial dimension of the teeth can be considered when calculating the vertical clearance of the corresponding roller. This ensures, firstly, that the teeth allow simultaneous contact of the mineral fibers with the conveyor belt or the already formed fiber mat and one of the teeth, thus orienting the fibers longitudinally. Secondly, it ensures that the teeth can make contact with fibers previously deposited on the conveyor belt that may not yet be properly pressed against the surface of the mineral fiber mat, thus finalizing the longitudinal orientation of the mineral fibers and 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 the conveyor belt.

[0027] According to one feature of the invention, at least one roller comprises a plurality of toothed rings arranged parallel to each other along the transverse axis of rotation of the corresponding roller.

[0028] Additionally, without limiting the invention, the rollers can be configured to ensure longitudinal orientation of the mineral fibers on the conveyor belt, in particular by considering the distance between the rollers of the roller train and the surface of the conveyor belt on which the mineral fibers are deposited after passing through the roller train, this distance being hereafter referred to as vertical clearance.

[0029] One particular characteristic of these mineral fibers is that they readily form agglomerates by sticking together, so the average length of a single mineral fiber can vary. For example, individual mineral fibers may have an average length of less than 10 millimeters, but these fibers, completely separate from the others, may represent only a tiny fraction of the total fiber arriving at the distribution station compared to fiber agglomerates whose average length, depending on the average number of mineral fibers forming these agglomerates, can be on the order of 20 to 30 millimeters.It is therefore advantageous to design an installation that accommodates this characteristic specific to mineral fibers, as the presence of fiber clumps can be further increased when the mineral fibers used are recycled, with binder residues holding several of these fibers together. The installation according to the invention can be configured based on an average fiber length or fiber clump size, particularly to adjust the vertical clearance value, i.e., the distance between the rollers of the roller train and the surface of the conveyor belt on which the fibers are deposited, and to ensure that the vast majority of mineral fibers, whether alone or in clumps, are correctly deposited on the conveyor belt.

[0030] According to one feature of the invention, the roller train comprises a plurality of rollers arranged in parallel with each other, among which a proximal roller is disposed at one end of the roller train.

[0031] According to one feature of the invention, the distribution station includes mechanical guidance means for mineral fibers towards the proximal roller so that all mineral fibers entering this distribution station are directed towards the conveyor belt so that they fall onto the proximal roller or between this proximal roller and the roller directly adjacent to it.

[0032] According to a feature of the invention, a vertical clearance between this proximal roller and the conveyor belt is less than a threshold value that is a function of the average length of the mineral fibers processed by the installation.

[0033] As previously mentioned, it should be noted that the concept of the average length of the mineral fibers processed by the installation according to the present invention can refer either to the average length of a single mineral fiber, when properly separated from other mineral fibers, or to the average length of an average clump of fibers agglomerated together. By way of example, the average length could more specifically be in the range of 20 to 30 millimeters, this value being particularly representative of the inventors' observation of the average length of a clump of mineral fibers representatively present in the mineral fiber mat.

[0034] The vertical clearance is measured here 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 be distinguished in particular by the fact that a proximal roller is located at one end of the roller train, and more specifically the end closest to the feeding device, by the fact that a distal roller is located at the opposite end of the roller train, and by the fact that a plurality of central rollers are arranged successively between the proximal roller and the distal roller.

[0035] 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 towards the conveyor belt, with one free end hanging towards the belt and one end remaining in contact with the roller.

[0036] The average length of the mineral fibers and the vertical clearance, which must be less than a threshold equal to this average fiber length (which may be between 20 and 30 millimeters), ensure that the free end of each mineral fiber passing through the roller assembly between the proximal roller and the immediately adjacent central roller makes contact with the belt while it is still in contact with the roller. In this way, as the free end of the mineral fiber is carried longitudinally by the movement of the conveyor belt, the mineral fiber is stretched and positioned longitudinally.

[0037] It should be noted that this characteristic of a vertical clearance value below a threshold, here 30 millimeters, is similar for the other rollers in the roller train, this time measured between the axis of rotation of that other roller and the upper surface of the mineral fiber mat intended to rest on the conveyor belt directly above that roller. Therefore, analogously to what was mentioned above, the free end of each mineral fiber passing through the roller train between that other roller and the immediately adjacent roller comes into contact with the mineral fiber mat already present on the belt while it is still in contact with that other roller, thus ensuring the stretching and longitudinal positioning of the mineral fiber.

[0038] According to one feature of the invention, the roller train extends primarily along an axis inclined relative to the principal plane of elongation of the conveyor belt. In other words, each roller of the roller train extends a specific distance from the conveyor belt, with this distance increasing progressively with respect to the direction of travel 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 on the conveyor belt tends to increase with respect to the direction of travel of the conveyor belt, and the inclination of the roller train is calculated so that each roller has a vertical clearance value less than the chosen threshold value, relative to the surface directly above that roller, considering the thickness of the mineral fiber mat assumed to be beneath that roller.

[0039] According to one feature of the invention, the inclination of the roller train relative to the main elongation plane of the conveyor belt is determined by an angle calculated as a function of 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.

[0040] According to one feature of the invention, the distribution station may include means for adjusting the inclination of the roller train.

[0041] According to one feature of the invention, the mineral fiber feeding device comprises means for feeding non-bonding mineral fibers and a binder of the powder type or of pre-bonded mineral fibers, that is to say composed of a mineral fiber core and a coating surrounding this core and comprising a dried uncooked binder.

[0042] In one embodiment, the conveyor belt is arranged within a separation tank that also includes means for separating the fibers. It is understood from this configuration that the mineral fibers and the associated binder are treated in a first preliminary separation stage to separate the largest fiber clumps, and that the distribution station's main function is to distribute these separated fibers longitudinally within the mat, possibly carrying out a final separation stage for the few fibers that were not separated from each other in the separation tank.

[0043] Other features, details, and advantages of the present invention will become clearer upon reading the detailed description given below by way of example, in relation to the various embodiments of the invention illustrated in all the figures, among which: there figure 1 is a schematic representation of part of a mineral wool manufacturing installation, illustrating in particular the mineral fiber distribution station according to one aspect of the invention; the figure 2 is a schematic representation of the distribution station of the 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 when deposited 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 train of rollers and a homogeneity of the fibers in the thickness of the fiber mat thus formed; the figure 3 is a detailed view of the roller train of the figure 2 , in a top view; the figure 4 is a perspective representation of a toothed ring forming part of a toothed roller of the roller train of the figure 3 ; there figure 5 is a schematic representation of two toothed rollers from the roller train intended to illustrate the cooperation of these rollers with a bed of mineral fibers formed on the conveyor belt; the figure 6 is a schematic representation of an alternative version of the distribution station of the 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 when deposited on the conveyor belt.

[0044] As a reminder, the invention relates to the particular configuration of a station in a mineral wool manufacturing installation, and more particularly a mineral fiber distribution station configured to distribute mineral fibers in an appropriate orientation.

[0045] We illustrated on the figure 1 a part of such a manufacturing installation 1 of mineral wool, for example glass wool, with different successive stations participating in the creation of an insulating mat composed of mineral fibers and more particularly the distribution station 2 specific according to the invention.

[0046] Upstream of this distribution station, considering the direction of mineral fiber flow within the installation, a first station includes a fiber feeding device (4) in which virgin or recycled mineral fibers are mixed with a binder capable of ensuring the fibers adhere to each other when the mixture is heated at the end of the installation. Where applicable, the recycled mineral fibers are, for example, mineral fibers manufactured for blown-in insulation applications, or fibers processed into mineral wool for thermal and / or acoustic insulation. In the latter case, the recycled mineral fibers already contain a hardened binder, which does not preclude processing them using the same method, namely by subsequently adding another binder.

[0047] In the following description, when reference is made to mineral fibers suitable for passing through a roller train and being deposited on a conveyor belt in the distribution station, it may refer interchangeably to virgin mineral fibers or recycled mineral fibers, or to mineral fibers mixed with binder or to pre-bonded mineral fibers, whether it is for a single mineral fiber, perfectly separated from the other mineral fibers, or a mass of several intertwined fibers.

[0048] The term "virgin mineral fiber" can refer here to mineral fiber, particularly glass or rock wool fiber, obtained by internal or external centrifugation, whose fibers are not bonded to each other by an organic binder. Virgin mineral wool fibers may be coated with a thin layer of sizing or lubricant. The term "recycled mineral fiber" refers here to mineral fiber bearing on its surface an insoluble and infusible organic binder that is already cross-linked. Of course, it is possible that the mineral fibers present in the distribution station may be a mixture of virgin and recycled mineral fiber, in any proportions.

[0049] The fiber feeding device has an output feed duct connected to a conveyor belt 8. The conveyor belt 8 is configured to move at a first speed, which can be changed by an appropriate control instruction. The conveyor belt 8 has a fiber distribution end 9 that is positioned above the distribution station 2 mentioned previously.

[0050] The distribution station 2 includes at least one roller train 12 equipped with rollers 13 and a conveyor belt 14 on which a layer of fibers 15 is able to form as the mineral fibers and binder are deposited on the conveyor belt. The roller train 12 is arranged on the path of the mineral fibers between the conveyor belt 8 and the conveyor belt 14.

[0051] The roller train consists of a plurality of rollers 13 arranged parallel to each other and capable of pivoting around parallel axes of rotation. As will be detailed below, these rollers 13 are configured to allow, on the one hand, the separation of mineral fibers and prevent the deposition of agglomerated mineral fibers on the conveyor belt, and on the other hand, the 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 roller train in which the rollers 13, which rotate in the same direction of rotation, participate in directing some 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 roller train and be discharged further along the conveyor belt.

[0052] As mentioned previously, the conveyor belt 8 has a fiber distribution end 9 which is positioned above the distribution station 2 and thus above the roller train 12. This roller train comprises a proximal roller 131, located at the first end 121 of the roller train 12 closest to the conveyor belt 8, a distal roller 132 located at the opposite end 122 of the roller train 12, and a plurality of central rollers 133 arranged successively between the proximal and distal rollers. The distribution station includes mechanical guidance means to direct the mineral fibers arriving at the fiber distribution end 9 towards the roller train 12, and more specifically towards the proximal roller 131. These mechanical guidance means can take various forms, including a flexible conduit or a rigid funnel-shaped tray, as illustrated in my figure 6 or a guide ramp as illustrated on the figures 1 et 2 , these mechanical guidance means consist of guiding, in particular towards the proximal roller 131 and the immediately adjacent rollers, the mineral fibers falling by gravity in an environment where they are neither blown nor sucked up.

[0053] The distribution station is also configured to give these mineral fibers 3 a longitudinal orientation, i.e. parallel to the direction of movement of the conveyor belt, this longitudinal orientation of the mineral fibers 3 in the mattress 15 being optimal in terms of thermal insulation.

[0054] More specifically, the distribution station 2 allows for this optimal longitudinal orientation of the mineral fibers, notably through the size of the rollers and their arrangement relative to the conveyor belt, and the impact this has on how the fibers are deposited on the conveyor belt, instead of falling onto it as can occur in prior art installations. The mineral fibers 3 and pre-bonded mineral fibers 5, or where applicable, fibers bonded with a liquid binder or in powder form, are deposited on the conveyor belt 14 by being laid on the surface of this conveyor belt after passing between two adjacent rollers 13, under conditions that ensure longitudinal traction and stretching, and by being combed onto the surface of the fiber mat 15 by the contact of the rollers of the roller train 12, as will be detailed below.

[0055] The conveyor belt 14 is extended by a conveyor belt, which carries the mattress 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.

[0056] It is understood that such an installation line is suitable for the production of glass wool fiber products, as will be described, but that it is obviously also suitable for the production of mineral fiber products.

[0057] More specifically, the distribution station and the roller train it includes are adapted to the processing, and as mentioned above to the orientation of the fibers relative to each other, of mineral fibers and for example glass fibers, which have specific dimensions and whose average length can vary in particular depending on the size of the cluster which they help to form where applicable with other mineral fibers, these mineral fibers being more particularly intended to agglomerate than other fibers such as wood fibers, and / or may consist of recycled mineral fibers agglomerated together by dried binder residues.

[0058] The configuration of the roller train 12 is particularly well-suited to a mixture of mineral fibers 3 and binder 5, in which the binder is formed by pre-bonded fibers. The roller train thus allows for optimal arrangement of the mineral fibers and pre-bonded fibers in the fiber mat that falls onto the conveyor belt.

[0059] Pre-bonded fibers are more specifically here fibers composed of a core of mineral fibers, advantageously the same mineral fiber as the non-bonding mineral fibers present and a shell surrounding the core which is made with a sprayed and dried binder.

[0060] The binder may consist of a low-formaldehyde binder, preferably even formaldehyde-free, for example, binders based on bio-based products. This type of binder is at least partially derived from a renewable raw material base, particularly plant-based, notably of the type based on hydrogenated or non-hydrogenated sugars.

[0061] The fact that the binder is implemented via a pre-bonded mineral fiber, based on a mineral fiber similar to that processed elsewhere in the installation, allows the arrangement of the binder in the mineral fiber mat to be treated in a similar way to that of non-bonding fibers.

[0062] We will now describe in more detail the fiber distribution station 2 according to one aspect of the invention, particularly with reference to figures 2 à 5 .

[0063] The fiber distribution station 2 includes, in addition to the roller train 12 and the conveyor belt 14 previously mentioned, at least one housing 18 and a support 20 for the roller train.

[0064] 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, passing through the roller train 12.

[0065] One or more mechanical guiding means 19, and for example a deflector as illustrated on the figures 1 et 2 or a container as illustrated on the figure 6 , can be provided to guide the mineral fibers arriving at the end of the fiber distribution 9 towards the roller train 12 and more particularly towards the proximal roller 131. These mechanical guiding means can be arranged projecting from one or more walls of the housing 18 to guide the non-bonding mineral fibers and the binder towards the rollers 13 of the roller train 12. More particularly, the deflector means can be movable, so as to be able to modify the area of ​​the roller train onto which the mineral fibers falling from the conveyor belt are directed, it being understood that these mineral fibers falling by gravity are mainly directed via the mechanical guiding means 19 towards the area of ​​the roller train 12 including the proximal roller and therefore the area substantially above the end of the fiber distribution 9 of the conveyor belt 8.

[0066] As illustrated on the figure 6 , the tray forming the mechanical guidance means 19 may have a funnel shape with a wide-opening upper end to collect a large quantity of mineral fibers falling at the end of the conveyor belt and a lower end whose opening is reduced compared to the upper end to target the desired area for depositing fibers on the roller train, namely the area immediately near the proximal roller 131.

[0067] The roller train support 20 is in the form of a frame fixed to the walls of the housing 18 to ensure the position of the rollers 13 relative to the housing, possibly via means for adjusting the roller inclination. The roller train support is configured so that all the fibers come into contact with the roller train 12.

[0068] The support 20 is configured so that the roller train 12 is inclined relative to the conveyor belt 14. In other words, the rollers are arranged parallel to each other along an axis A of the roller train, which is inclined relative to a plane P in which the surface of the conveyor belt, on which the mineral fiber mat rests, extends. As mentioned, means for adjusting the inclination of the rollers 100 can be provided and associated with the roller train support 20 to decrease or increase the angle of inclination α between the axis A of the roller train and the plane P of the conveyor belt.

[0069] There figure 6 This illustrates in particular an example of the implementation of means for adjusting the inclination of rollers 100, it being understood that this example is not limiting and that the inclination adjustment means could take another form. The inclination adjustment means 100 here comprise a chain or belt 101, fixed on one side to a post of the housing 18 and on the other side to a distal end 202 of the support 20 of the roller train, while the opposite proximal end 201 of the support 20 is fixed relative to the housing 18 at a height lower than the height at which the chain or belt is fixed to the housing post.The means for adjusting the inclination further include means for adjusting the length of the chain or belt, and for example a motor 102 in contact with the belt or chain, and whose actuation makes it possible to reduce or increase the length of the chain or belt between the upright of the housing and the distal end 202 of the support 20, and thus to lower or raise this distal end 202 and generate accordingly the desired inclination of the support 20 and the roller train 12.

[0070] The roller train can be inclined relative to the conveyor belt plane P at an angle of 1° to 30°, preferably between 5° and 20°. This inclination can be fixed throughout the mineral wool manufacturing process, the angle being chosen according to the desired thickness of the mineral fiber mat at the end of the conveyor belt before curing. The operator orients the roller train support to the desired inclination using the inclination adjustment means 100, and then locks the position of this support before the start of the manufacturing process. Alternatively, the inclination adjustment means 100 could be automated, with automatic control of the position of the distal end 202 of the support based on the desired inclination of the roller train during the process, particularly if system parameters are modified.

[0071] The roller train's inclination value can be influenced by the conveyor belt speed. Specifically, the lower the conveyor belt speed, the greater the required roller train inclination angle.

[0072] The rollers 13 of the roller train 12 are identical here, and each has the same number of teeth 22 regularly distributed around the perimeter of the rollers.

[0073] As mentioned previously, in the roller train we distinguish a proximal roller 131, disposed at a first end 121 of the roller train 12 closest to the conveyor belt 8, a distal roller 132 disposed at the opposite end 122 of the roller train 12 and a plurality of central rollers 133 arranged successively between the proximal roller and the distal roller.

[0074] The rollers 13 are driven in rotation, all in the same direction of rotation, so as to allow the progression of the mineral fibers 3 from one end to the other of the roller train, with a part of these fibers passing between the rollers 13 to fall onto the conveyor belt 14. We can define an upper part of the rollers and a lower part of the rollers according to their position relative to a median plane of the roller train, the lower part being the part of the rollers closest to the conveyor belt and the fiber mat, and we can define the direction of rotation of the rollers such that the upper part of the rollers rotates from the first end to the opposite end of the support.

[0075] Each roller 13 is driven by its own drive device 24, so that each roller can rotate at a specific rotational speed (Va, Vb...Vg), independent and where appropriate different from the rotational speeds of the other rollers in the same roller train.

[0076] A device for removing impurities, not shown here, may include a suction hood which is arranged at the end of the roller train support and which is configured to suction the conglomerates of fibers which could not be separated by the action of the rollers of the roller train.

[0077] As previously mentioned, the distribution station 2 according to the invention has technical characteristics and dimensions of its various components that are specific to an application with mineral fibers 3 bonded with a binder 5 in powder form or with pre-bonded mineral fibers. Several of these characteristics are particularly visible in the representation of the figure 2 .

[0078] As illustrated on the figure 2 The center-to-center distance D between the rollers, and therefore the spacing 130 between these rollers (assuming all rollers are of the same shape and dimensions), varies depending on the rollers considered. In other words, the center-to-center distance D1 between the proximal roller 131 and the central roller 133 adjacent to this proximal roller is different from the center-to-center distance D6 between the distal roller 132 and the central roller 133. More specifically, the dimensional variation of the center-to-center distances is regular along the direction of elongation of the roller train, such that the center-to-center distances progress successively from the proximal roller 131 to the distal roller 133. This dimensional variation of the center-to-center distances D allows an equivalent quantity of mineral fibers to pass between the rollers, whether at the proximal or distal roller, preventing a major portion of the mineral fibers from passing through the first two rollers they encounter.

[0079] More specifically, the variable spacing increasing in the direction of movement of the conveyor belt and circulation of the fibers can be explained by the fact that for the rollers first reached 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 larger spacing is needed thereafter because the mineral fibers that circulate along the train of rollers passing from roller to roller have acquired a transverse speed, and here an upward speed due to the inclination of the train of rollers, which forces the mineral fibers to pass between the rollers to reach the conveyor belt.

[0080] The roller spacing 130 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 a projection of the rollers 13.

[0081] Furthermore, the mineral wool manufacturing plant is advantageously configured in that the rotational speeds of each of the 13 rollers are varied, bearing in mind that the rollers are driven independently of one another. It is desirable that the rotational speed of the first rollers reached by the fibers be high so that these first rollers can accelerate and carry the mineral fibers away from the conveyor belt towards which they are attracted by gravity, particularly when the roller train is inclined, which implies an upward movement for the mineral fibers to reach the subsequent rollers of the roller train. It is also desirable to gradually decrease the rotational speed of the rollers to create a downward movement of the mineral fibers towards the conveyor belt.

[0082] 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 roller train 12. This avoids the formation of a stratified fiber mat with layers whose fiber density is different from each other, and in particular with a lower layer denser than the others, which could be formed if the mineral fibers pass mainly between the first two rollers of the roller train.

[0083] It may be possible to combine the characteristics of increasing the gap between the rollers and decreasing the speed of the rollers, in the direction of movement of the fibers.

[0084] Furthermore, the distribution station 2 is configured to allow for longitudinal orientation of the mineral fibers within the fiber mat. To this end, the vertical clearance DV between the proximal roller 131 of the roller train and the conveyor belt 14—that is, the minimum distance between the components of this proximal roller 131 and the conveyor belt—has a value less than a threshold value that depends on the type of fibers to be deposited on the conveyor belt, and therefore, in this case, on the size of the mineral fibers. The vertical clearance can be measured, in particular, between the outer peripheral surface of the proximal roller and the conveyor belt. The vertical clearance DV is less than 30 millimeters here.This vertical clearance value, again smaller than that which could be used in wood fiber applications, ensures that the mineral fibers, after passing through the roller assembly, remain in contact with the roller at one end as they are deposited on the conveyor belt. As will be detailed below, this ensures the longitudinal orientation of the fibers on the conveyor belt, parallel to the belt's direction of travel.

[0085] Means for adjusting the vertical clearance 150 may be provided to adjust, at least at the start-up of the mineral wool manufacturing process, the value of the vertical clearance DV and adapt it according to the lengths of average fibers intended to fall onto the roller train 12 via the conveyor belt 8 and the mechanical guiding means 19. The figure 6 This illustrates, in particular, an example of the embodiment of vertical clearance adjustment means 150, it being understood that this example is not limiting and that the vertical clearance adjustment means could take another form. The vertical clearance adjustment means 150 here comprise a plate 151 fixed to the proximal end 201 of the support 20, said plate 151 being mounted on a rail 152 fixed to an upright of the housing 18. The vertical movement of the plate 151 along the rail 152 allows adjustment of the vertical position of the proximal end 201 of the support 20 and therefore the position of the proximal roller 131 relative to the conveyor belt 14, which remains fixed. Once the desired vertical position is reached, the position of the proximal end 201 of the support 20 is fixed by attaching the plate to the upright of the housing.

[0086] To account for the increasing thickness of the fiber mat 15 as it progresses along the conveyor belt, the roller train 12 is inclined as previously described. Consequently, the characteristic concerning the maximum vertical clearance DV mentioned for the proximal roller—namely, the maximum distance the proximal roller 131 extends from the surface of the conveyor belt 14 onto which the mineral fibers carried by this proximal roller can be deposited—can be replicated for each of the rollers in the roller train 12. This time, however, the surface of the fiber mat 15 is considered instead of the surface of the conveyor belt 14. The roller train 12 is configured so that the fibers carried by the central rollers 133 and the distal roller 132 are deposited onto a layer of mineral fibers already present on the conveyor belt.

[0087] Another characteristic of the installation and distribution station is specific to the use of mineral fibers, namely the travel speed V14 of the conveyor belt 14. This travel speed V14 allows, on the one hand, the mineral fibers 3 still in contact with the roller 13, which have participated in the passage of the mineral fibers through the roller train, to be carried and stretched, and on the other hand, it is calculated to allow the production of mineral fiber mats with a fiber volumetric density of less than 40 kg / m³. As a non-limiting example, the travel speed of the conveyor belt can be on the order of 5 to 100 meters per minute. Furthermore, for the production of mats with such a density, the travel speed V8 of the conveyor belt 8 bringing the mineral fibers into contact with the roller train and the differential travel speeds between the conveyor belt and the conveyor belt can also be considered.

[0088] There figure 3 makes support 20 of the roller train particularly visible.

[0089] 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 retaining brackets 25 for the motorized drive means 24 and rotation bearings 26 associated with each of the rollers 13, with a bracket and a rotation bearing alternating on the same long side.

[0090] Each roller 13 has on its 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.

[0091] In the illustrated example, the reliefs are formed by a plurality of teeth 22. In other words, each roller 13 has teeth forming projections arranged in successive parallel rings along the axial dimension of the roller, the rings of teeth 22 being separated from each other along the same roller by a pitch of 220. This is noticeable in the top view of the figure 4 that the rollers 13 are arranged so that the tooth rings 22 of two neighboring rollers are axially offset, to avoid any interaction between the teeth of two neighboring rollers during their rotation.

[0092] Each roller 13 can notably be formed by a plurality of toothed rings 28 pressed against each other along the axial dimension of the roller. As illustrated in the figure 4 Such a ring 28 may comprise a ring body 280 adapted to be fixed to the roller's rotation shaft and a toothed peripheral portion 282, and these two parts of the ring may advantageously be made of two different materials. The toothed portion may, for example, be overmolded onto the ring body, with attachment means based on complementary shapes.

[0093] Each ring of teeth 22, and in particular when it is formed by a toothed ring 28 visible on the figure 4 , has 22 teeth regularly distributed angularly, here numbering twenty, the teeth being thus characterized by an angular pitch, here of the order of 18°, between two successive teeth on the perimeter.

[0094] Each tooth 22 extends in projection from an external surface of the ring, a radial dimension DR of the tooth being measured between the free end 222 of the tooth and the external surface of the ring.

[0095] The teeth 22 are specifically dimensioned so that their free ends 222 can comb the mineral fibers 3 not yet pressed onto 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 roller train comprising the axes of rotation of the rollers.

[0096] The previously mentioned roller spacing of 130 is determined by considering the center distance D between the axes of rotation of two adjacent rollers and the radial dimension DR of the teeth, notably visible on the figure 4 the spacing being measured between the free end of the teeth of one roller and the adjacent roller.

[0097] As can be seen from the preceding detailed description, the invention addresses the technical problem of orienting mineral fibers in the fiber mat to be directed towards the crosslinking station, specifically by providing a particular roller configuration close to the conveyor belt, and more specifically here, less than 30 millimeters from the conveyor belt for the proximal roller and less than 30 millimeters from the surface of the mat formed by the mineral fibers that may be present on the conveyor belt directly above the other rollers. This configuration allows the mineral fibers to be deposited on the conveyor belt with their ends in simultaneous contact with both the conveyor belt and the rollers. This avoids having to release the fibers at a distance from the conveyor belt, as in the prior art, and allowing them to then settle themselves, under the effect of gravity, onto 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 cross-linking the fiber mat.

[0098] This longitudinal arrangement of mineral fibers on the conveyor belt can be further ensured when the rollers have teeth and these are positioned and sized to comb the surface of the mineral fiber mat and more particularly the mineral fibers likely to protrude from this surface of the mat, in a combing direction opposite to that of the direction of movement of the conveyor belt.

[0099] These characteristics and the resulting advantages are detailed more precisely with reference to the figure 5 , which schematically represents the action of the rollers, here toothed rollers, on the fibers to orient them longitudinally.

[0100] As mentioned, the proximal roller 131 is positioned 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 axis of extension of the roller train 12 with respect to the surface of the conveyor belt ensures that the other rollers are positioned so that an equivalent vertical clearance DV, i.e. 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 fiber mat formed on the conveyor belt at the right of said roller.

[0101] In this configuration, if we refer to the schematic representation of the proximal roller 131 and a first mineral fiber 31 passed through the roller train 12 between this proximal roller and the adjacent central roller, the rollers are dimensioned, and where applicable the teeth forming radial projections of the roller body, and arranged at a distance from the conveyor belt such 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. Thus, it is noteworthy that according to the invention, the mineral fibers are in simultaneous contact with the roller and the conveyor belt, or with the layer of fibers 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 towards the conveyor belt, with a first free end hanging towards the belt and a second end remaining in contact with the roller.

[0102] The average length of the mineral fibers, at least 30 millimeters as previously mentioned, and the vertical clearance less than this average fiber length (here 30 millimeters), ensure that the free end of each mineral fiber passing through the roller assembly between the proximal roller and the immediately adjacent central roller makes contact with the belt while it is still in contact with the roller. In this way, as the free end of the mineral fiber is carried longitudinally by the movement of the conveyor belt, the mineral fiber is stretched and positioned longitudinally.

[0103] If we refer to the first mineral fiber 31 illustrated on the figure 5 , the mineral fibers are stretched by the movement 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.

[0104] Each mineral fiber thus deposited on the conveyor belt or fiber mat assumes a principal longitudinal orientation, with the first free end 31a pressed against the fiber mat. This can result from the deposit of the mineral fiber once released from the roller, as illustrated in the figure 5for 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 roller train, with central rollers and the distal roller arranged with a vertical clearance less than the previously mentioned threshold value, makes possible a combing function for this second mineral fiber, and more generally for all the mineral fibers not yet pressed against 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.

[0105] In general, the embodiment described above is by no means limiting: variants of the invention may include only a selection of the described features isolated from the other features mentioned in this document, if this selection of features is sufficient to confer a technical advantage or to differentiate the invention from the prior art.

[0106] As an example, in an alternative embodiment (not shown) and without limiting the number of possible variations, the installation includes a separation tank in which the conveyor belt can be placed and which incorporates separation means (not shown here) that perform an initial fiber separation stage, notably to prevent large fiber clumps. These separation means may consist of toothed rollers and / or blowing devices. The fiber separation tank is configured so that the fibers processed by the separation means enter a fiber feed duct connecting the separation tank to the previously mentioned distribution station. Specifically, the fiber feed duct may be configured to allow the processed fibers to fall by gravity.

Claims

1. Mineral wool production plant (1), comprising at least one feeding device (4) for mineral fibers (3) and a fiber distribution station (2) including a conveyor belt (14) movable in a longitudinal direction and on which the mineral fibers (3) are adapted to be received to form a mineral fiber mat (15), the fiber distribution station comprising a roller assembly (12) arranged in the path of the mineral fibers (3) intended to fall by gravity onto the conveyor belt (14), the roller assembly (12) comprising at least three rollers (13), each roller (13) being adapted to be rotationally driven 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), characterized in that each roller (13) is driven by individual drive means (24), a control module for the operation of the mineral wool production plant is configured to provide a specific control instruction to each of the drive means associated with a roller (13), and in particular to provide a control instruction relating to a rotational speed of this roller, the rollers (13) of the same roller assembly (12) being able to be rotationally driven at different rotational speeds from one roller (13) to another.

2. Mineral wool production plant (1) according to claim 1, characterized in that the roller assembly (12) comprises a plurality of rollers (13) arranged parallel to one another with a spacing (130) between two adjacent rollers (13) that varies from one end to the other of the roller assembly (12).

3. Mineral wool production plant (1) according to the preceding claim, characterized in that the spacing (130) between two successive rollers of the roller assembly (12) increases regularly from one spacing to the next in the direction of fiber movement from one roller (13) to another.

4. Mineral wool production plant (1) according to any one of the preceding claims, characterized in that each roller (13) is driven at a rotational speed different from that of the adjacent rollers, the rotational speeds of the rollers (13) decreasing in the direction of fiber movement (3) from one roller to another.

5. Mineral wool production plant (1) according to any one of the preceding claims, characterized in that a movement speed (V14) of the conveyor belt (14) is between 5 and 100 m / min such that the mineral fiber mat (15) has a bulk density between 5 and 40 kg / m3.

6. Mineral wool production plant (1) according to the preceding claim, characterized in that a conveying belt (8) is arranged between the feeding device (4) for mineral fibers and the fiber distribution station (2) such that mineral fibers (3) exiting the conveying belt (8) are adapted to fall by gravity onto the conveyor belt (14) via a passage between the rollers (13) of the roller assembly (12), the movement speed (V14) of the conveyor belt (14) being a function of the movement speed (V8) of the conveying belt (8) and the desired bulk density of the mineral fibers (3) in the fiber mat (15).

7. Mineral wool production plant (1) according to any 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) from the feeding device (4) to the conveyor belt (14).

8. Mineral wool production plant (1) according to any one of the preceding claims, characterized in that the rollers (13) each have surface reliefs, regularly arranged along the axis of rotation of the rollers.

9. Mineral wool production plant (1) according to any 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.

10. Mineral wool production 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 transverse axis of rotation of the corresponding roller.

11. Mineral wool production plant (1) according to any one of the preceding claims, characterized in that the roller assembly (12) comprises a plurality of rollers (13) arranged parallel to one another, among which a proximal roller (131) is disposed at one end of the roller assembly (12).

12. Mineral wool production plant (1) according to claim 11, characterized in that the distribution station (2) comprises mechanical guiding means (19) for guiding the mineral fibers toward the proximal roller (131) such that all mineral fibers entering this distribution station (2) are directed toward the conveyor belt (14) so that they fall onto the proximal roller (131) or between this proximal roller (131) and the roller directly adjacent thereto.

13. Mineral wool production plant (1) according to claim 11 or 12, characterized in that a vertical clearance (DV) between the proximal roller (131) and the conveyor belt (14) is less than a threshold value dependent on the average length of the mineral fibers (3) processed by the plant (1).

14. Mineral wool production 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).

15. Mineral wool production plant (1) according to any one of the preceding claims, characterized in that the roller assembly (12) extends mainly along an axis inclined relative to the main extension plane of the conveyor belt (14).

16. Mineral wool production plant (1) according to any one of the preceding claims, characterized in that the distribution station (2) comprises adjustment means (100) for adjusting an inclination of the roller assembly (12).

17. Mineral wool production plant (1) according to any one of the preceding claims, characterized in that the feeding device (4) for mineral fibers comprises feeding means for non-binding mineral fibers and a binder of the powder type or pre-bonded mineral fibers.