EP2994431A1

EP2994431A1 - Device and method for producing mineral fibres by internal centrifuging

Info

Publication number: EP2994431A1
Application number: EP14729395.5A
Authority: EP
Inventors: Julien THIERY; Kenichiro Teragami; Arnaud Marchal
Original assignee: Saint Gobain Isover SA France
Current assignee: Saint Gobain Isover SA France
Priority date: 2013-05-07
Filing date: 2014-05-06
Publication date: 2016-03-16
Also published as: FR3005465A1; KR20160005701A; JP2016523795A; CN105189382A; KR102311594B1; FR3005465B1; US20160115071A1; WO2014181063A1; JP6606065B2; JP2019172571A; MY183064A; CN105189382B

Abstract

The invention concerns a device for producing mineral fibres by internal centrifuging, comprising:- a centrifuge (1) designed for forming mineral fibres by drawing from molten mineral material, - at least one crown (16, 17) designed to spray water onto the mineral fibres as they are formed. The invention can be used to produce dry mineral fibres while saving energy.

Description

DEVICE AND METHOD FOR MANUFACTURING MINERAL FIBERS BY

INTERNAL CENTRIFUGATION

The invention relates to a device and a process for manufacturing inorganic fibers by internal centrifugation, in particular to produce mineral fibers adapted to vacuum insulation panels (VIP = "vacuum insulation panels" in English).

The vacuum insulation panels are for example mineral fiber panels, compressed and held under vacuum.

Mineral fibers for vacuum insulation panels must be free of binder to prevent degassing after fabrication, which would prevent vacuum retention. However, it is necessary to wet the fibers to cool the atmosphere in the reception during fiber drawing and thus facilitate the aspiration of fumes, or to lubricate the fibers. The sizing ring can be used to bring water to the fibers. Water is then sprayed on the fibers already formed, before reception on the carpet receiving fibers. Fibers fall wet on the receiving mat.

To achieve the vacuum properly, it is advantageous that the mineral fibers are as dry as possible. Also, after receiving them on the receiving mat, they are passed through at least one oven to dry before they can be used in a vacuum insulation panel. However, the passage in an oven is expensive in energy.

There is therefore a need for a device and method for manufacturing mineral fibers that can produce dry mineral fibers by achieving energy savings.

For this, the invention proposes a device for manufacturing inorganic fibers by internal centrifugation, comprising:

a centrifuge adapted to form mineral fibers by fiberizing from molten mineral material,

- At least one ring adapted to spray water on the mineral fibers in formation.

In another feature, a ring is disposed between 150 and 300 mm under the centrifuge and / or a ring is disposed just above the centrifuge. According to another feature, the water spray angle by the ring disposed under the centrifuge is between -45 ° and + 45 ° relative to the horizontal, preferably between -30 ° and + 30 °.

In another feature, the water spray angle by the crown disposed above the centrifuge is vertical or inclined at an angle less than or equal to 20 ° from the vertical to the axis of symmetry of the centrifuge.

In another feature, the total amount of water spray is between 5 L / h and 400L / h, preferably between 100 L / h and 250L / h.

In another feature, the total amount of water spray is between 5 and 550 L per ton of glass.

In another feature, the amount of water sprayed by the ring disposed above the centrifuge is between 0% and 80% of the total amount of water and the amount of water sprayed by the ring disposed under the centrifuge is between 20% and 100% of the total amount of water.

According to another feature, the ring disposed above the centrifuge is adapted to blow compressed air simultaneously with the water spray.

In another feature, the water spray is atomized water.

The invention also relates to a process for manufacturing mined fibers by centrifugation using the device described above, comprising the following steps:

- formation, by a centrifuge, of mineral fibers from molten mineral material,

- Water spraying, by a crown, on the mineral fibers in formation.

The invention also relates to a method of manufacturing vacuum insulating panels, comprising the following steps:

- mineral fiber manufacturing process described above,

bagging of the mineral fibers obtained, preferably under a primary vacuum, or even under a secondary vacuum, preferably with the insertion of a desiccant material.

The invention also relates to a product obtained by the process described above, comprising a moisture content of less than 0.1% after manufacture, without passing through an oven. According to another feature, the product has a punching force of between 500 and 800 N.

According to another feature, the product is packaged in a sealed package, the package containing a desiccant material in an amount preferably less than 1 g per kg of product.

Other features and advantages of the invention will now be described with reference to the drawings in which:

• The figure shows a sectional view of the mineral fiber manufacturing device according to the invention.

In the whole of the patent application, the terms "above" and

"Below" are defined in fibering position when the centrifuge is in the fiberizing position, that is to say when the axis of rotation of the centrifuge is along a vertical axis.

In addition, throughout the description, the expression "between ... and ..." includes the terminals.

The invention relates to a device for manufacturing mineral fibers by centrifugation, comprising an internal centrifugation device adapted to form mineral fibers from molten mineral material and at least one ring adapted to spray water, preferably atomized. , on mineral fibers during fiber drawing, during their formation.

Thus, water is sprayed onto the forming mineral fibers, i.e., during drawing of the fibers, and then, once they are stretched, until they are fully solidified. The atmosphere being very hot around the fibers in formation, the water evaporates almost immediately, which allows to obtain dry fibers on the carpet of reception of the fibers.

In addition, the fact of spraying water on the fibers in formation gives them hydrophobic properties, which makes it possible to avoid the use of an oven when the fibers are used after their manufacture. If necessary, drying agents may be used during storage to avoid moisture uptake. However, since the fibers have hydrophobic properties, the amount of desiccant required is minimal.

FIG. 1 represents a device for manufacturing mineral fibers according to the invention. The device comprises a centrifuge 1, also called pitching plate, having an annular wall 10 pierced with a plurality of orifices 1 January. The annular wall 10 is extended, to form the top of the centrifuge 1, by a web 13 ending in a tulip 14.

The device also comprises a hollow shaft 2 and shaft 9, adapted to be rotated by a motor (not shown). The centrifuge 1 is fixed to the shaft 2 via the tulip 14. When the mineral fiber forming device is in the fiberizing position, the axis 9 is vertical. At its upper end, the shaft 2 is connected to means for supplying molten glass. At its lower end, the shaft 2 is connected either to a basket 3 if the centrifuge has no bottom, or directly to the centrifuge 1 in the case of a centrifuge with a bottom. In the case of a device with basket, as shown in the figure, the basket 3 is located inside the centrifuge 1. The basket 3 comprises an annular wall 30 pierced with a plurality of orifices 31.

When the mineral fiber forming device is in operation, the centrifuge 1, the shaft 2 and possibly the basket 3 are rotated about the axis 9 of the shaft 2. Molten glass flows into the shaft 2, from the molten glass supply means to the centrifuge, in which the molten glass is spread. In the case of a centrifuge with basket, the molten glass flows to the basket 3 and is projected onto the annular wall 30 of the basket, passes through the plurality of orifices 31 of the basket and, in the form of bulky filaments 5 , is projected onto the peripheral wall 10 of the centrifuge 1. A permanent reserve of molten glass is then formed in the centrifuge to feed the plurality of orifices 1 1 pierced in the annular wall 10 of the centrifuge 1. Melted glass passes through the plurality of orifices 1 1 of centrifuge 1 to form flow cones 6 extending forward of fibers 7.

The mineral fiber forming device also comprises at least one annular burner 4 generating a gas stretching jet at high temperature. The gaseous draw jet is a high temperature gas stream, which leaves the annular burner 4 via its exit 40 provided with lips 41, so that the gaseous drawing jet is substantially tangential to the annular wall 10 of the centrifuge 1 . In the fiberizing position, the outlet 40 of the annular burner 4 is situated above the annular wall 10 of the centrifuge 1. The gaseous drawing jet makes it possible to heat both the annular wall 10 of the centrifuge 1 and the fibers in the form of at the exit of the centnugger 1. Under the action of the gaseous drawing jet of the annular burner, the fore fibers 7 stretch, their end portion generating discontinuous fibers 8, which are then collected on a receiving belt (not shown) under the centrifuge 1. No binder is used to produce the product according to the invention; the mineral fiber forming device has no sizing device, in particular no sizing ring.

The mineral fiber forming device also comprises at least one ring 16, 17 which sprays water, preferably atomized, onto the forming fibers. The fibers in formation are the fibers which are not completely solidified. A ring 16 is disposed just above the centrifuge and / or a ring 17 is disposed under the centrifuge. Each ring 16, 17 is substantially horizontal and has a plurality of atomized water outlet ports.

The orifices of the ring 16 disposed just above the centrifuge 1 are oriented downwards and arranged at the same height as the lips 41 of the burner gas outlet 4. The water atomized by the ring 16 is sprayed vertically or with an inclination towards the axis 9 of the centrifuge. The angle β of spray is between 0 ° and + 20 ° relative to the vertical. The disposition of the ring 16 and the orientation of the atomized water jet are such that the atomized water is sprayed onto the forming fibers, that is to say the discontinuous fibers 8 not yet solidified.

The orifices of the ring 17 disposed under the centrifuge 1 are oriented more or less horizontally. The ring 17 is arranged such that its orifices are situated at a distance of between 100 and 300 mm from the bottom of the centrifuge 1, preferably between 150 and 300 mm from the bottom of the centrifuge 1, or at a distance of between 350 and 500 mm from the lips 41 of the burner 4. The atomization angle a atomized water atomized by the ring 17 is between -45 ° and + 45 ° relative to the horizontal, preferably between -30 ° and + 30 ° , more preferably between 0 ° and + 45 °, or between 0 ° and + 30 °, that is to say preferably horizontally or upwards. The ring 17 and the angle of spray of its orifices are such that the atomized water is sprayed on the fibers in formation, that is to say the discontinuous fibers 8 not yet fully solidified.

The total amount of water is between 5 L / h and 400L / h, preferably between 100 L / h and 250L / h. In other words, the total amount of water spray is preferably between 5 and 550 L of water per tonne of glass. The amount of water pulverized by the ring 16 disposed above the centrifuge device is between 0% and 80% of the total amount of water and the amount of water sprayed by the ring 17 disposed under the centrifuge is between 20% and 100% of the total amount of water.

The temperature at the ring 16 disposed above the centrifuge 1 is of the order of the temperature of the gases leaving the burner at the lips, that is to say for example around 1400 ° C. . The temperature at the crown 17 is between 650 ° C and 1100 ° C. The atmosphere in which the water is sprayed is thus very hot, which allows that contact with forming fibers, themselves very hot, the water evaporates almost instantly. The fibers then arrive dry, that is to say with a moisture content of less than 0.1% on the receiving belt. On the contrary, in a plant according to the prior art, water is sprayed on the fibers already formed in a saturated humidity atmosphere where the temperature is about 200 ° C. The fibers arrive so wet on the carpet of reception. The device according to the invention makes it possible to manufacture a dry product which avoids the use of an oven and thus makes it possible to save energy.

Spraying or vaporizing atomized water in a very hot atmosphere creates water vapor, which cools the atmosphere and facilitates the aspiration of the fibers to the receiving mat and thus improves the distribution of the fibers. on the reception mat.

In addition, the spraying or vaporization of atomized water on very hot fibers in formation, so not yet solidified, at least on the inside, allows a quenching of the fibers. This makes it possible to improve the mechanical properties of the fibers, in particular the stamping property. This makes it possible to improve, for the same density, the resistance of the vacuum insulation panels to the vacuum. This also improves the thermal conductivity of the vacuum insulation board.

The stamping property is measured according to the following protocol: it rolls in the form of cigar 4g of fibers, it is introduced into a cylindrical cell. A rod is then introduced into the cylindrical cell which compresses the fibers by compression. We then measure a punching force of the fibers in Newtons. The punching force of the products obtained by the process according to the invention is between 500 and 800N. The moisture content is measured according to the following protocol: three surface test specimens in section 305 mm x 305 mm are prepared. Each test piece is weighed and its initial mass P, _n i is noted. The test pieces are passed to the oven at 180 ° C. for 30 minutes and then to the desiccator for 1 hour. Each test piece is weighed again and its final mass Pf, _n . For each test piece, the moisture content is: (P, _n i - Pfin) / Pfin-

Preferably, the ring 16 disposed above the centrifuge 1 allows, in addition to spraying water, to blow compressed air. Blowing compressed air avoids dispersion of the fibers too far from the axis 9 of rotation of the centrifuge 1.

The mineral fiber-forming device also optionally includes an induction ring 20 under the centrifuge and / or an internal burner for heating the lowest zone of the centrifuge and avoiding or limiting the creation of a temperature gradient. on the height of the centrifuge.

The invention also relates to a process for manufacturing mineral fibers by centrifugation using the device as described above, comprising the following steps:

- formation, by a centrifugation device, of mineral fibers from molten mineral material,

- spraying water on the mineral fibers being formed.

After manufacture, the mineral fibers are, for example, bagged, preferably under a primary vacuum, or even under a secondary vacuum, where appropriate with insertion of a desiccant material into the package, preferably in an amount of less than 1 g per kg of product.

The product obtained by the process according to the invention comprises less than 0.1% moisture after manufacture, without passing through an oven.

An example of a product has been produced with the device according to the invention under the following conditions:

- 10 tons per day,

a temperature of the gases leaving the burner at the lips 41 of

1400 ° C,

a burner pressure of 400 mm WC (water column), a flow of water of 70 L / h from the ring 17 disposed at 150 mm under the centrifuge, the ring 17 being in an atmosphere at a temperature of 700 ° C.,

- A water flow rate of 130 L / h of the ring 16 disposed just above the centrifuge, at the lips of the burner.

The product obtained has a moisture content of 0.05% and a punching force of 650 N.

By comparison, a standard product obtained under similar spinning conditions but without water spray just above the centrifuge and with a 320 mm water spray under the centrifuge at a position below the centrifuge. stretching area and fiber formation, in an atmosphere at a temperature of 200 ° C where the fiberglass is no longer deformable or stretchable, with a flow rate of 350L / h, at a moisture content of 0.35% and a punching force of 400 N.

The product according to the invention is therefore a dry product, which is not the case for products made in standard, with reinforced mechanical properties.

Claims

1. Device for manufacturing inorganic fibers by internal centrifugation, comprising:

- a centrifuge (1) adapted to form mineral fibers by fiberizing from molten mineral material,

- At least one ring (16, 17) adapted to spray water on the mineral fibers in formation.

2. Device according to claim 1, wherein a ring (17) is disposed between 150 and 300 mm under the centrifuge (1) and / or a ring (16) is disposed just above the centrifuge (1).

3. Device according to claim 2, wherein the water spray angle by the ring (17) disposed under the centrifuge (1) is between -45 ° and + 45 ° relative to the horizontal, preferably between -30 ° and + 30 °.

4. Device according to claim 2 or 3, wherein the water spray angle by the ring (16) disposed above the centrifuge (1) is vertical or inclined at an angle less than or equal to 20 ° by vertical ratio to the axis (9) of symmetry of the centrifuge.

5. Device according to one of claims 2 to 4, wherein the total amount of water spray is between 5 L / h and 400L / h, preferably between 100

L / h and 250L / h.

6. Device according to one of claims 2 to 5, wherein the total amount of water spray is between 5 and 550 L per tonne of glass.

7. Device according to claim 6, wherein the quantity of water sprayed by the ring gear (16) disposed above the centrifuge (1) is between 0% and 80% of the total quantity of water and the amount of water sprayed by the ring gear (17) disposed under the centrifuge (1) is between 20% and 100% of the total amount of water.

8. Device according to one of claims 2 to 7, wherein the ring (16) disposed above the centrifuge (1) is adapted to blow compressed air simultaneously with the water spray.

9. Device according to one of claims 2 to 8, wherein the water spray is atomized water.

Process for the production of inorganic fibers by internal centrifugation using the device according to any one of Claims 1 to 9, comprising the following steps:

- formation, by a centrifuge (1), of mineral fibers from molten mineral material,

- Spraying water, by a ring (16, 17) on the mineral fibers in formation.

1 1. A method of manufacturing vacuum insulating panels, comprising the steps of:

process for producing mineral fibers according to claim 10,

12. Product obtained by the process according to claim 10 or 1 1 comprising a moisture content of less than 0.1% after manufacture, without passage in an oven.

13. The product of claim 12, having a punching force between 500 and 800 N.

14. Product according to one of claims 12 or 13, packaged in a sealed package, the package containing a desiccant material in an amount preferably of less than 1 g per kg of product.