RU2651922C2 - Method for manufacturing of mineral cotton blocks - Google Patents

Abstract

FIELD: materials.

SUBSTANCE: invention relates to the manufacture of universal mineral wool plates and the subsequent manufacture of large-sized products for the thermal insulation of pipes and pipelines, including large diameters, as well as cylindrical tanks. In the method, the mineral wool plates are ground from the lower and upper sides. Upper surfaces of the plates are treated with a glue composition based on sodium silicate. Then the plates are alternately stacked, placing them with their treated top surfaces on each other, so that the fibers of each layer are directed in the same direction. After that the untreated surface is treated with the adhesive composition and the stacking of the layers is repeated until the block is formed, after which a load is place and the adhesive composition is allowed to fully polymerize for 24-48 hours. Above method allows to produce a mineral wool block, consisting of at least two layers bonded with a glue composition based on sodium silicate, the fibers of each plate being arranged in one direction.

EFFECT: technical result consists in increasing the thickness of the mineral wool block by two or more times while maintaining the physicomechanical characteristics of the mineral wool product and the reliability of bonding the layers together.

3 cl, 6 dwg, 5 tbl

Description

The group of inventions relates to a method for manufacturing a block of mineral wool and to an article in the form of a volumetric multilayer composite block intended for the subsequent manufacture of large-sized products from it for technical thermal insulation of pipes and pipelines, including large diameters; tanks having a cylindrical shape; universal mineral wool boards with a vertical orientation of the fibers.

There are two known methods of manufacturing elements of pipe thermal insulation from mineral wool: by winding and milling.

In the first case, the production is carried out by winding the primary carpet of mineral wool on the shells of various diameters, followed by exposure of the resulting cylinder in the furnace, where the binder of the mineral wool is polymerized and the cylinder is molded. This method of production of heat-insulating products is used, in particular, by the Danish company ROCKWOOL and the Finnish PAROC. Methods of manufacturing insulating products from mineral wool are described in RU 2469967 (С03С 13/06; С03В 37/05, published December 20, 2012); RU 2439255 (Е04С 2/00, published January 10, 2012); RU 2265700 (ЕВВ 1/80, published December 10, 2005); RU 2468921 (B32B 17/02, B32B 5/02, B32B 5/24, published December 10, 2012); RU 2448830 (В28В 1/52, С03В 37/00, published April 27, 2012). The manufacture of insulation products in this way requires expensive equipment. In addition, it can only be carried out under the conditions of the existing production of mineral wool. Another disadvantage is that it is technologically impossible to obtain heat-insulating products for pipes of large diameters using this method.

Milling consists in the manufacture of heat-insulating products by cutting from a standard mineral wool plate a cylinder or a cylinder segment for a pipe using a moving abrasive string. This method is used by Russian companies HOTPIPE and CATVUL (see RU 92933 F16L 59/00, F16L 59/02, published on 04/10/2010). Thermal insulation cylinders provide cost-effective and efficient protection of pipelines. But the problem is that in this way it is impossible to make a large diameter insulating product. This is due to the fact that existing technologies for the production of mineral wool basalt fiber boards make it possible to obtain a standard board with a thickness of not more than 200-250 mm, from which it is impossible to make structural products of large sizes, for example, for insulation of pipes with a diameter of 1.0-2.0 m. So, a heat-insulating product made according to the indicated technology for pipes with an external diameter of 108 mm and more consists of four segments. Thermal insulation for a pipe with a diameter of 1.0 m, made by this technology, consists of 18-22 segments. Installation of a heat-insulating product from segments is very complicated and requires a lot of labor. In addition, the design of the heat-insulating shell made by this technology has a large number of longitudinal joints, which impair the heat-insulating ability of the structure and require special measures for their sealing.

Solving the problem of creating heat-insulating products in the form of half-cylinders or solid products of large sizes, up to 2.0 m in diameter, the authors excluded the methods of manufacturing the product by winding in view of the technological and technical impracticability due to the design features of the equipment. Continuing the research, it became obvious that for milling a full or half cylinder of large diameter up to 2.0 m, it is necessary to have a workpiece in the form of a block with a thickness of at least 1200 mm. But as mentioned above, heat-insulating plates produce a thickness of not more than 200-250 mm. Therefore, the question arose of creating a workpiece in the form of a large block of length up to 2400 mm, width up to 1200 mm, thickness up to 1200 mm. To this end, the authors have studied various methods for producing layered products from mineral wool.

The closest in technical essence is the combined heat-insulating material described in RU 92933 (F16L 59/00, F16L 59/02, published 04/10/2010), consisting of two interconnected insulation layers, one of which is made on the basis of mullite-siliceous fiber , and another of mineral wool insulation. As mineral wool insulation, mineral wool based on basalt fiber is used. The layers are bonded together using high-temperature mineral adhesive mixtures (for example, mineral water glass, etc.), or using mechanical fasteners (for example, steel wire staples, paper clips) that do not lose their fastening properties at temperatures above 350 ° C. A well-known utility model solves the problem of increasing the durability of the insulating material and products from it, but cannot be used for the manufacture of heat-insulating products of large diameters. The description indicates that the thickness of the outer layer can be from 20 to 200 mm, but not more. In addition, the use of mechanical fasteners for bonding layers is unreliable.

The present invention is directed to solving the problem of developing a method for manufacturing a bulk multilayer block from mineral wool insulation, from which it would subsequently be possible to produce heat-insulating products in the form of half-cylinders or solid products of large sizes up to 2.0 m in diameter. According to the authors, the solution of this problem will create a heat-insulating product for insulation of pipes and pipelines of large sizes, which in turn will facilitate installation and increase the efficiency of thermal insulation of pipes and pipelines of large sizes.

The essential features of the present invention ensure the achievement of a technical result, which consists in increasing the thickness of a block of mineral wool two or more times while maintaining the physical and mechanical properties of the product from mineral wool and the reliability of the bonding of the layers together.

The technical result is achieved by the proposed method, according to which the mineral wool slabs are ground from the lower and upper sides, the upper surfaces of the slabs are treated with a sodium silicate adhesive composition, then the mineral wool slabs are stacked alternately, connecting them with the upper surfaces treated with said adhesive composition, so so that the fibers of each layer are directed in one direction, they treat the untreated surface with adhesive and repeat laying the layers until a block is formed, after h the cargo is installed and left to complete polymerization of the adhesive composition for 24-48 hours at an air temperature of at least 30 ° C. The obtained method produces a block of mineral wool, consisting of at least two layers bonded with an adhesive composition based on sodium silicate, with the fibers of each plate located in one direction.

In the proposed method, mineral wool boards with the same parameters in thickness and density, or with different parameters in thickness and density are used.

The essence of the claimed invention is illustrated by the following graphic materials.

In FIG. 1 - shows a General view of a composite block of five plates of mineral wool;

In FIG. 2 - schematically shows the process of applying the adhesive composition;

In FIG. 3 - schematically shows the process of laying plates in a block;

In FIG. 4 is an example of a block of eleven plates of different densities and different thicknesses;

In FIG. 5 is an example of a block of two plates of different densities and different thicknesses;

In FIG. 6 is an example of using a composite block for milling a full cylinder and obtaining a large diameter insulating product.

The proposed method is a sequential implementation of the following actions. For the manufacture of block 1, slabs 2 made of mineral wool on a synthetic binder, for example, grades 75, 125, 175, 225, made in accordance with GOST 9573-96 “Slabs of mineral wool on a synthetic binder heat-insulating” or according to TU 5762-004-58256885 with density not less than 60 kg / m ³ (mineral wool boards). A block in the form of a parallelepiped is assembled from the finished plates, while for the formation of the block, plates of the same thickness and density, as well as with different indicators of the indicated parameters, can be used. The length and width parameters do not affect the implementation of the invention, therefore, the plates can be used in different sizes. For this, the plates are positioned so that the fibers of each layer are directed in the same direction. Depending on the purpose for which the resulting block will be used, from 2 to 12 plates are used, with a length of 1000 to 2500 mm, a width of 500 to 1200 mm, and a thickness of 50 to 200 mm. Since there are irregularities (perforations) on the surfaces of the plates formed by the forming elements during its manufacture, in order to improve the adhesion of the plates to each other, the surfaces of each plate from the upper and lower sides are pre-ground. An adhesive composition 5 based on sodium silicate is applied to the polished surface of each plate. Application of the adhesive composition to the upper 3 surface of the plates is carried out automatically on equipment, which is a set of spray nozzles for applying the adhesive composition and a roller table, promoting the movement of the plate under the nozzles (Fig. 2). As the adhesive composition, a mineral adhesive mixture is used, including based on sodium silicate. Then collect the plates in the block. For this, the first plate is placed on the pallet 8 so that the upper surface 3 with the adhesive composition is on top (Fig. 3). The second plate is placed by connecting its upper surface 6 (with the adhesive composition 5 applied to it) with the upper surface 3 of the first plate, i.e. connect two surfaces treated with adhesive composition, while the lower surface (surface 7) of the second plate becomes upper. On the specified surface 7 of the second plate, the adhesive is applied manually using a spray gun. The remaining plates are laid in a similar way. No glue is applied to the upper surface of the upper plate.

Then, to improve the adhesion of the layers, a load is installed on the surface of the upper plate and is held until the adhesive composition is fully polymerized for 24-48 hours. As a load, two metal plates are used, each with a block size of 15 kg. At the place of exposure of the workpiece, the air temperature should be at least 30 ° C. If necessary, the resulting workpiece is trimmed to a predetermined size.

A practical implementation of the invention is shown in the following examples 1-5. In the manufacture of the composite block, the proposed method was used. The resulting composite blocks were subjected to laboratory tests. Since standard high-quality plates were used to form the block, checked by the factory outlet control, only parameters that were influenced by the finished product parameters were subjected to laboratory tests:

- the maximum temperature for the use of the material, provided that the test sample contains at least one adhesive seam.

- adhesive strength of the adhesive joint;

- thermal conductivity in the direction of the heat flux along the coordinates X, Y, Z.

- water absorption during short-term immersion in the area of the adhesive joint;

- compressive strength at 10% linear deformation along X, Y, Z coordinates.

- compressive strength at coordinates X, Y, Z only for sandwich plates

- strength characteristics for shear along the Z axis only for sandwich plates.

All tests were carried out according to standard methods established for standard mineral wool slabs (mineral wool slabs). The test results are presented in tables.

Example 1. A block made of standard general-building plates with the following parameters:

- Density - 80 kg / m ³

- Length - 1000 mm

- Width - 500 mm.

- Thickness - 200 mm.

- Corrugation coefficient in the manufacture of 1.8.

- Number of plates - 5 pcs.

The block was kept under load until the adhesive was completely polymerized for 24 hours at an air temperature of 30 ° C. The overall dimensions of the obtained mineral wool block are: length 1000 mm, width 500 mm, thickness 1000 mm.

The test results are presented in table 1:

Example 2. A block made of standard sandwich plates with the following parameters:

- Density - 100 kg / m ³

- Length - 2400 mm

- Width - 627 mm

- Thickness - 122 mm

- Corrugation coefficient in the manufacture of plates - 1.1.

- Number of plates - 10 pcs.,

The block was kept under load until the adhesive was completely polymerized for 32 hours at an air temperature of 32 ° C-35 ° C. The overall dimensions of the obtained mineral wool block are: length 2400 mm, width 627 mm, thickness 1220 mm.

The test results are presented in table 2:

Example 3. A block made of a standard general construction plate with the following parameters:

- Density 150 kg / m ³

- Length 1000 mm

- Width - 500 mm

- Thickness - 100 mm

- Corrugation coefficient in the manufacture of 2.5.

- Number of plates - 10 pcs.,

The block was kept under load until the adhesive was completely polymerized for 40 hours at an air temperature of 32 ° C - 35 ° C. The overall dimensions of the obtained mineral wool block are: length 1000 mm, width 500 mm, thickness 1000 mm.

The test results are presented in table 3.

Table 3

These three options for research were chosen intentionally, since they cover almost the entire range of possible parameters encountered in practice for standard mineral wool slabs in terms of overall dimensions, density and corrugation coefficient. In all three examples, plates of the same density and thickness were taken for the manufacture of the block. However, the following examples show that for the manufacture of blocks according to the proposed method, plates of different density and thickness can be used. At the same time, the indicators indicated in the table below indicate that the block meets the necessary parameters of mineral wool slabs for any block thickness.

Example 4. A block made of 11 standard sandwich panels of different thickness and density (Fig. 4)

- 5 plates with a density of 100 kg / m ³ and 6 plates with a density of 130 kg / m ³ - Length - 2400 mm Length - 2400 mm - Width - 627 mm Width 627 mm - Thickness - 122 mm Thickness 102 mm - Corrugation coefficient in the manufacture of 1.5.

A block was formed alternating between plates with different densities and thicknesses. Then it was kept under load until the adhesive mixture was fully polymerized for 48 hours at an air temperature of 32 ° C - 38 ° C. The overall dimensions of the obtained mineral wool block are: length 2400 mm, width 627 mm, thickness 1222 mm.

The test results are presented in table 4:

Example 5. A block made of two standard building panels of different density and different thickness with the following parameters (Fig. 5):

- One plate - Density 80 kg / m ³ ; The second plate - density 60 kg / m ³ - Length 1000 mm Length 1000 mm - Width - 500 mm 500 mm wide - Thickness - 50 mm. Thickness 120 mm

After the block was formed from plates with different densities and thicknesses, it was held under load until the adhesive was completely polymerized for 24 hours at an air temperature of 32 ° C-38 ° C. The overall dimensions of the obtained mineral wool block are: length 1000 mm, width 500 mm, thickness 170 mm.

The test results are presented in table 5:

Table 5.

Blocks made of plates of various densities and thicknesses are of great interest, since they have good performance characteristics and on their basis it is possible to produce a large number of products with new properties.

Transportation and storage of products is carried out in accordance with the requirements of GOST 25880 and GOST 23208-2003.

Thus, the proposed invention allows to create mineral wool blocks with a thickness exceeding the traditional thickness for mineral wool boards two or more times with reliable bonding of layers and good physical and mechanical properties. The resulting composite block is used for the manufacture of heat-insulating products in the form of half-cylinders or solid products of large sizes, up to 2.0 m in diameter, for the production of universal mineral wool boards with a vertical orientation of fibers, which have higher strength values.

Claims (3)

1. A method of manufacturing a block of mineral wool, comprising connecting at least two layers, characterized in that each layer is a plate of mineral wool, which is polished, the upper surfaces of the plates are treated with a glue composition based on sodium silicate, and then alternately stack the plates of mineral wool cotton wool, connecting the surfaces treated with the specified adhesive composition so that the fibers of each layer are directed in the same direction, treat the raw surface with the adhesive composition and repeat the patterns the layers before the formation of the block, after which the load is set and left until the polymerization of the adhesive composition for 24-48 hours at an air temperature of at least 30 ° C. 2. The method according to p. 1, characterized in that they use mineral wool slabs with the same parameters in thickness and density. 3. The method according to p. 1, characterized in that they use mineral wool slabs with different parameters in thickness and density.

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