EP3785805A1 - Spray gun for spraying an insulating layer on a ceiling by means of a flow of liquid and method for producing such an insulating layer - Google Patents

Abstract

In a particular embodiment of the invention, there is provided a gun (7) for projecting an insulating layer onto a wall or a ceiling of a building, comprising at least one central nozzle (14) expelling a liquid supplied by a pipe under pressure and producing a projection cone (15), and at least one peripheral orifice (12) for the expulsion of a decompressed coating material conveyed by pressurized gas. This at least one expulsion orifice (12) is positioned around the central nozzle (14) to expel the coating material at the periphery of the projection cone (15) of said liquid. In this way, it is possible to reduce the consumption of spray liquid and to reduce the density of the insulating layer thus produced.

Description

1. FIELD OF THE INVENTION

The present invention relates to the field of construction and more particularly to the thermal insulation of surfaces. The invention relates more particularly to the fact of using a gun to project a mixture composed of insulating fibers such as slag wool and water, the gun projecting a cone of liquid in the central part and driving around this cone , insulating fibers.

2. TECHNOLOGICAL BACKGROUND

Nowadays, it is important to properly insulate construction buildings, for example in order to obtain the BBC or “Batiment Basse Consommation” sign. Good insulation with the outside guarantees both energy savings in winter and a certain coolness in summer. The insulating materials used for several decades are based on glass wool or polystyrene. These materials form an insulating layer of a very regular thickness producing a thermal insulation coefficient (often called "R") depending directly on said thickness. For several years, artificial mineral fibers have been used in industry and in construction for the manufacture of insulating wools. Currently, new ecological trends have prompted building professionals to develop green building materials, including using natural products and less and less chemicals.

These new materials come in the form of bags containing compacted fibers to take up less space during storage. Flocking involves spraying an insulating layer on the walls or ceilings of buildings using a spray gun. FMA (acronym for Artificial Mineral Fibers) generally consist of a mixture, produced in the factory, of wool fibers, oils and additives based on gypsum (or other inorganic binder). The gun is used to mix mineral fibers (FMA) and a spraying liquid under pressure, which is why this spraying technique is called "wet". The pressurized liquid allows the mixture to be projected a certain distance. On drying, the layer thus produced solidifies while adhering to the support and thus providing an insulating layer.

The spray gun at the end of the pipes connected to the spray machine makes it possible to mix at least the following two constituents: “DRY” constituent and “WET” constituent, the two constituents are brought under pressure.

The characteristics of these flows (DRY flow & WET flow) can be defined according to two categories. A “DRY” flow made up of light fibers and a “WET” flow made up of liquid (usually water). The “WET” flow made up of liquid (generally water) has a density close to that of water. The “DRY” flow is typically made up of fibers (slag wool fibers) and has a very low density.

The kinematics of these flows (DRY flow & WET flow) has, by virtue of their geometrical positioning, the following characteristics: a WET flow mixes and settles the DRY flow on the target support by saturating it with liquid. The "complex", thus projected, has a density of the order of 280 to 300 kg / m3. The drying time required for the water to evaporate completely can take several weeks. The density of the insulating layer thus produced is then of the order of 150 kg / m 3.

It is clear that the spray gun is decisive as regards the characteristics of the insulating layer produced, such as: thickness, drying time, insulating capacity. Nowadays, the spray gun has at least two outlet nozzles, one for the DRY component and the other for the WET component. The DRY component emerges in the middle of the gun and the WET component rather at the periphery. It has long been believed that this arrangement is advantageous because the pressurized water is expelled by forming a cone which channels the SEC component and which carries it towards the surface to be isolated. By moving the gun sideways, the water cone first wets the surface which then receives the SEC component, which seemed to ensure good adhesion.

• Le fait de disposer de plusieurs buses de projection d'eau tout autour de la buse d'éjection du constituant SEC compacté augmente la consommation de fibres minérales ainsi que la masse volumique du mélange. Cela pose des problèmes lorsque la couche isolante est projetée au plafond du fait qu'elle risque de retomber sur le sol. Pour atteindre une couche d'épaisseur importante, il est souvent nécessaire d'effectuer plusieurs passes.
• Une certaine quantité d'eau ne participe pas au mélange avec le constituant SEC, elle ruisselle sur le mur ou retombe sur le sol. Cela entraine une surconsommation d'eau.
• La couche isolante ainsi projetée est imbibée d'eau, nécessitant ainsi un temps de séchage long.
• Cette disposition a pour effet de trop tasser le constituant SEC compacté, ce qui entraîne une augmentation de la masse volumique de la couche isolante ainsi produite et diminue globalement ses performances isolantes.

The applicant of the present application noticed that this arrangement may have the following drawbacks:

• Having several nozzles for spraying water all around the ejection nozzle of the compacted SEC component increases the consumption of mineral fibers as well as the density of the mixture. This causes problems when the insulating layer is projected on the ceiling because it risks falling back. On the ground. To achieve a layer of significant thickness, it is often necessary to make several passes.
• A certain quantity of water does not participate in the mixture with the SEC component, it trickles down the wall or falls on the ground. This leads to overconsumption of water.
• The insulating layer thus projected is soaked in water, thus requiring a long drying time.
• This arrangement has the effect of over-packing the compacted SEC component, which leads to an increase in the density of the insulating layer thus produced and overall decreases its insulating performance.

3. OBJECTIVES OF THE INVENTION

There is therefore a real need to design a new way of projecting insulating materials onto a surface, in order to resolve the drawbacks listed above. Such a projection method must in particular make it possible to reduce the consumption of fibers and to reduce the density of the insulating layer thus produced.

4. PRESENTATION OF THE INVENTION

In a particular embodiment of the invention, there is provided a gun for projecting an insulating layer onto a wall or ceiling of a building, comprising at least one central nozzle expelling a liquid supplied by a pipe under pressure and producing a projection cone, and at least one expulsion port of a decompressed coating material conveyed by pressurized gas, characterized in that the at least one expulsion port is positioned around the central nozzle to expel the material coating on the periphery of the cone of projection of said liquid.

In this way, it is possible to reduce the consumption of mineral fibers and of water, to reduce the density of the insulating layer thus produced, and to reduce the implementation time and in particular the drying time of this insulating layer.

According to a first embodiment, the gun may include an outlet mouth whose diameter decreases in the direction of the outlet to create a venturi effect. In this way, the mixture can be thrown over a long distance.

According to one embodiment, the central nozzle is surrounded by a plurality of orifices for expelling the coating material.

According to another embodiment, the shape of the central nozzle is designed to create a projection cone having an angle between 30 ° and 60 °. In this way, the projection of the fibers on the support to be insulated is more efficient.

According to another embodiment, the pressurized gas used is chosen from the following group: air, nitrogen, argon.

According to another embodiment, the gun comprises a valve for regulating the flow rate of the liquid inlet and for varying the mass of water projected. In this way, the operator holding the gun can easily adjust the density of the mixture thus projected.

According to another aspect, the invention relates to a method of manufacturing an insulating layer on constructions comprising a projection system provided with a means of transport in a flow of gas under pressure of a decompressed fibrous material, d 'a means for pressurizing a spraying liquid and a spray gun receiving separately before spraying said decompressed fibrous material and said spraying liquid, characterized in that it comprises a step of spraying the pressurized liquid at outside the gun by forming a cone and a step of mixing the fibrous material with the pressure spraying and spraying liquid by positioning the fibrous material on the periphery of said cone.

5. DESCRIPTION OF FIGURES

• [Fig 1] : la figure 1 présente un exemple d'un système de projection permettant d'acheminer les constituants du pistolet de projection,
• [Fig 2] : la figure 2 illustre un pistolet de projection et un schéma montrant le flux de projection selon l'art antérieur,
• [Fig 3] : la figure 3 présente de profil un schéma d'un pistolet de projection selon un exemple préféré de réalisation de l'invention:,
• [Fig 4] : la figure 4 présente un exemple particulier d'un pistolet de projection 7 vue face à la bouche de sortie des constituants,
• [Fig 5] : la figure 5 présente de profil un schéma d'un pistolet de projection selon un exemple particulier de réalisation de l'invention.

Other characteristics and advantages of the invention will become apparent on reading the following description, given by way of indicative and non-limiting example, and the appended drawings, in which:

• [ Fig 1 ] : the figure 1 presents an example of a projection system for conveying the components of the projection gun,
• [ Fig 2 ] : the figure 2 illustrates a projection gun and a diagram showing the projection flow according to the prior art,
• [ Fig 3 ] : the figure 3 shows in profile a diagram of a spray gun according to a preferred embodiment of the invention :,
• [ Fig 4 ] : the figure 4 shows a particular example of a projection gun 7 seen facing the outlet of the constituents,
• [ Fig 5 ] : the figure 5 shows in profile a diagram of a spray gun according to a particular embodiment of the invention.

6. DETAILED DESCRIPTION OF AN EMBODIMENT

The Fig. 1 presents an example of a projection system making it possible to convey the constituents to the projection gun. The projection system 1 typically comprises a central 2 receiving the bags of insulating material containing for example FMA, enriched with inorganic binders, for example gypsum. These bags are emptied into an orifice in the upper part and their content is decompressed by toothed wheels 3 so as to free the fibers as much as possible between them and to give them a low density. The fibers descend by gravity into a duct where they are blown by a pressurizing means 4. The unit 2 has for this an air compressor 5 to create an acceleration at the inlet of the duct and a setting. under pressure in a flexible pipe 6 in order to transport the fibers in a flow of dry air under pressure to the spray gun 7 which constitutes a real spray head. On leaving the decompaction operation, the fibers typically have a density of 100 to 120 kilograms / m 3.

The gas used is generally air but can also be any gas, nitrogen for example, in the case where certain insulating material risks premature oxidation on contact with oxygen, rare gases of argon can also be used. The air compressor is advantageously integrated into the unit but can also come from any other means of supplying pressurized air, from pressurized bottles for example.

The system also includes a liquid compressor 8, typically water intended to provide a flow of water under pressure. The water inlet preferably consists of a pipe connected to a tap, according to an alternative embodiment, the water can be sucked from a container, a container 9 on a wheel for example. Water is here the most frequently used liquid, which in no way excludes other liquids compatible with the sprayed material and capable, on drying, of imparting hardness to the layer produced. The water compressor supplies water under pressure through a pipe 10 to the spray gun 7. The spray gun mixes the dry component supplied by the unit 2 and the liquid supplied by the compressor 8, and produces a flow of mixture intended to be projected onto a surface 11. This surface can be a wall, a ceiling or any flat surface or not, of a construction.

An operator holds the spray gun while placing it in front of the surface to be covered. The coating becomes hard after a certain drying time depending on the density of the water inside the mixture. The quantity of mixture in m3 / hour can be modulated by varying the air pressure generated by the compressor 5, which modifies the quantity of fibers transported by the pipe 6 of the spray gun 7.

If a thick coat is to be produced, the operator can apply several coats, while waiting for the previous coat to be dry enough to support the new one.

The Fig. 2 illustrates a spray gun and a diagram showing the spray flow according to the prior art. As can be seen on the left side of the figure, the decompressed fibers are routed to the center of the spray gun and pressurized water flows are generated around the center. The density of the WET component is approximately at 1000 kg / m3 and that of the stream component SEC approximately 150 kg / m3. In this way, the fibers of the SEC component are entrained and channeled by the various water flows which thus form a sort of projection cone. The mixture applied to the support has a density of the order of 280 to 300 kg / m3. Practice shows that such a mixture with a thickness of 80 millimeters dries completely after a period of 2 months.

As can be seen on the right-hand side, the projection flow produced comprises relatively dry fibers in the center and liquid at the periphery. Such a flow compresses the mixture thus produced and tends to increase its density when dry.

The present invention is to modify the spray gun to produce a mixture having a lighter density when dry. The modification of the spray gun also makes it possible to consume less water and thus shorten the drying time of the mixture.

The Fig. 3 shows in profile a diagram of a spray gun according to a preferred embodiment of the invention. The projection gun 7 has an outlet opening intended to project the flow 12 of the SEC component. In the axis 13 of the spray gun and in the center of the outlet mouth, a nozzle 14 is positioned to create the spray flow 15 of the WET component, typically water. This nozzle 14 is firmly attached to the rigid casing of the spray gun so that the flow generated remains as much as possible in the axis 13. This nozzle 14 is connected to the pipe 10 which transports the pressurized water from the tube. compressor 8. The outlet shape of the nozzle 14 is determined so as to form a projection cone 15 having a certain angle, typically 30 ° to 60 ° depending on the choice of the nozzle. The component stream 12 is driven by the stream 15 and passes all around it. The fibers of insulating material are projected onto the support 11 where the water is responsible for completing their humidification. The mixture is less loaded with liquid and is therefore lighter, it dries faster.

The Fig. 4 shows a particular example of a spray gun 7 seen facing the component outlet. This mouth is in the form of several concentric circles. The most central circle comprises a nozzle 14 for spraying the LIQUID component. According to the example illustrated in the Figure, the gun has several nozzles 14, in this case 3. In this way, by multiplying the number of nozzles 14, a more powerful WET flow is obtained than that generated by a single nozzle having a large diameter.

The outlet of the SEC component is located all around the nozzles 14. To obtain a greater projection speed of the SEC component, the gun 7 has different diameters ranging from the largest (120 millimeters) towards the rear to the smallest (60 millimeters) towards the front of the mouth. This reduction in the diameter in the direction of the supply of the SEC component produces a venturi effect which makes it possible to increase the speed of the flow 12 of the SEC component and to project the mixture further onto the support, which can be particularly useful when 'we want to project on a relatively high ceiling.

The gun 7 comprises a nozzle 16 for connection with the water supply pipe to the nozzles 14. This nozzle 16 is advantageously associated with a tap allowing an operator to reduce the water inlet section and thus to reduce its flow rate when spraying the mixture. In this way, the operator holding the gun can easily adjust the mass of water in the mixture thus projected.

The Fig. 5 shows in profile a diagram of a spray gun according to a particular embodiment of the invention. The flow 15 of projection of the WET component produced by the nozzle 14 is clearly visible at the top of the figure. The dotted lines show the flow of the SEC component, and its path through the various constrictions 16 of the spray gun to produce a Venturi effect. A valve 17 is shown to the left of the gun to adjust the flow of water supplied by the compressor.

The use of the spray gun according to the invention made it possible to produce a mixture applied to the support with a density of the order of 110 kg / m 3. Such a density allows for a layer of 80 millimeters to dry thoroughly in less than 60 days. Drying occurs more quickly and it is possible to apply a second coat 24 hours later, when the first does not exceed 80 to 90 millimeters.

• diminution de la masse de produit à projeter pour un même niveau d'isolation,
• diminution de la masse volumique du produit sec par un décompactage plus efficace,
• diminution de la masse volumique du mélange projeté,
• diminution du temps nécessaire pour projeter une même surface,
• diminution de la quantité d'eau pour produire un même volume de couche isolante,
• diminution du temps de séchage de la couche isolante, du fait que celle-ci est moins saturée en eau.

In addition to the production of a new spray gun, the invention also relates to a method of manufacturing an insulating layer on constructions comprising a spray system provided with a means of transport in a flow of gas under pressure d a fibrous material, a means for pressurizing a spraying liquid and a spray gun separately receiving said fibrous materials and spraying liquid before spraying. The process makes it possible to produce an insulating layer having particular and advantageous properties such as:

• reduction in the mass of product to be sprayed for the same level of insulation,
• reduction in the density of the dry product by more efficient decompaction,
• reduction in the density of the sprayed mixture,
• decrease in the time required to project the same surface,
• decrease in the quantity of water to produce the same volume of insulating layer,
• reduction in the drying time of the insulating layer, due to the fact that it is less saturated with water.

The invention is not limited to the embodiments which have just been described. In particular, the SEC component can be any type of particles capable of being projected into a liquid flow, and the LIQUID component can be any fluid in liquid form capable of generating a flow transporting said particles, when this fluid is pressurized. .

Claims (7)

Gun (7) for projecting an insulating layer on a wall or ceiling of a building, comprising at least one central nozzle (14) expelling a liquid supplied by a pressure pipe and producing a projection cone (15), and at at least one expulsion orifice (12) of a decompressed coating material supplied by pressurized gas, the coating material consisting of mineral fibers, characterized in that the at least one expulsion orifice (12) is positioned around the central nozzle (14) to expel the coating material at the periphery of the projection cone (15) of said liquid. Gun according to Claim 1, characterized in that it comprises an outlet mouth whose diameter decreases in the direction of the outlet to create a venturi effect. Gun according to Claim 2, characterized in that the central nozzle is surrounded by a plurality of orifices for expelling the coating material. Gun according to any one of the preceding claims, characterized in that the shape of the central nozzle (14) is designed to create a projection cone (15) having an angle between 30 ° and 60 °. Gun according to any one of the preceding claims, characterized in that the pressurized gas used is chosen from the following group: air, nitrogen, argon. Gun according to any one of the preceding claims, characterized in that the gun (7) comprises a valve (17) for regulating the flow rate of the liquid inlet and for varying the density of the projected insulating layer. Method of manufacturing an insulating layer on constructions comprising a projection system equipped with a means of transporting in a flow of gas under pressure a decompressed coating material consisting of mineral fibers, a setting means under pressure of a spraying liquid and of a spray gun receiving separately before spraying said coating material and said spraying liquid, characterized in that it comprises a step of spraying the pressurized liquid outside the gun by forming a cone and a step of mixing the coating material with the spraying liquid under pressure and spraying by positioning the coating material on the periphery of said cone.

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