KR20070112472A - Granular fibre-free microporous thermal insulation material and method - Google Patents

Abstract

A granular fibre-free microporous thermal insulation material, having a thermal conductivity less than 0.05 W/mK and a shrinkage of not more than 10%, which is free flowing and consists of granules of an intimate mixture of: 30-95% dry weight microporous insulating material; 5-70% dry weight infrared opacifier material; 0-50% particulate insulating filler material; and 0-5% binder material. The material is made by mixing together the microporous insulating material and the infrared opacifier material to form an intimate aerated mixture with a first density; conveying the intimate mixture at a first volumetric flow rate to an extrusion means (5); extruding the intimate mixture as a compressed material with a second density greater than the first density at a second volumetric flow rate lower than the first volumetric flow rate; venting a proportion of air from the aerated intimate mixture through a porous membrane to relieve pressure generated within the intimate mixture due to the change from the first volumetric flow rate to the second volumetric flow rate; and granulating the compressed material.

Description

GRANULAR FIBRE-FREE MICROPOROUS THERMAL INSULATION MATERIAL AND METHOD}

The present invention relates to a microporous insulating material that is free of particulate fibers. The invention also relates to a process for the production of particulate fiber-free microporous thermal insulation materials.

The term “microporous” is used to define a porous or cellular material in which the substantial size of the cell or pore is less than the mean free path of air molecules in NTP, ie 100 nm or less. The microporous material thus exhibits very low thermal conductivity compared to air conduction (ie, collisions between air and molecules). Such microporous materials can be obtained from controlled precipitates from solution, and the temperature and pH are adjusted during the precipitation step to obtain open lattice precipitation. Other equivalent open lattice structures include exothermic (fumed) and heat transfer types, with a significant proportion of particles having a final particle size of less than 100 nm. Silica, alumina or other metal oxide based materials can be used to prepare the composition as defined above, microporous.

Use of blocks or sheets of insulating material (e.g. pipe-in pipe insulation such as exhaust pipe systems, furnace cavities, double skin linings, areas above fixed roofs, open joints and wall stoves for leveling furnace floors) Insulating filled insulation materials can be used to provide limited thermal insulation to certain high temperature applications.

In order to make the loosely filled insulation material efficient, the insulation material must flow relatively freely so that each piece of insulation material does not stick and mediate across the gap. Pieces of freely flowing insulating material must be able to move relative to each other so that the insulating material can settle in the densest packing arrangement, thereby preventing the formation of non-insulating zones. Granulation is known to make it easier to flow materials made from fine particles.

Sheets or blocks of microporous insulating material are known to have better thermal conductivity than other insulating materials due to the size of the voids, which are described below.

As the particulate insulation has relatively large voids (greater than microporous pores) between successive particulate portions of the insulation, the thermal conductivity of the particulate material is higher than that of the large continuous comparative insulation body. As such, particulate microporous thermal insulation materials are not commonly used because the large voids between the particles eliminate the thermal benefits obtained by the individual particles of the microporous thermal insulation with microporous pores. The large voids in the particulate microporous insulation result in partial formation of reinforcing fibers in the particles. These fibers form the particles to "hairy" and the ability to pack the particles densely is reduced.

Particulate microporous aerogel materials such as grade INOl beads from Cabot, for example sold under the registered trademark NANOGEL, are known. However, these insulating materials have a relatively high shrinkage rate when heated. For example, the height of the NANOGEL particulate airgel material in the crucible measured before and after heating for 24 hours is reduced by 12% after heating at 600 ° C. and by 24% after heating at 800 ° C.

 Particle morphology of non-microporous insulating materials having good free flow properties is known.

For example, vermiculite particles such as exfoliated fine grade vermiculite supplied by Skamol, Denmark, are 0.105 W / mK at an average temperature of 200 ° C. and 0.145 W / m at an average temperature of 400 ° C. Like mK, it has a relatively high thermal conductivity at a nominal density of 150 to 180 kg / m ³ .

Other forms of particulate free flowing thermal insulation material are based on particle mixtures of clay or sintered diatomaceous earth, for example Moler 05 aggregates supplied by Skamol, Denmark. Such insulating materials have a relatively high thermal conductivity, for example 0.2 W / mK at an average temperature of 200 ° C.

It is an object of the present invention to provide a particulate fiber-free microporous insulating material and a method for producing the same, which are free to flow, can withstand high temperatures and have a relatively low thermal conductivity.

According to one aspect of the invention, there is provided a particulate fiber-free microporous insulation material having a shrinkage not greater than 10% and a thermal conductivity of less than 0.05 W / mK, wherein the insulation material has a dry weight of 30 to 95%. It consists of particles prepared from a dense mixture of microporous insulating material, 5 to 70% dry weight infrared opacifier material, 0 to 50% particulate insulating filler material and 0 to 5% binder material and flows freely.

According to another feature of the invention, there is provided a method for producing a particulate fiber-free microporous insulating material, said insulating material having a shrinkage not greater than 10% and a thermal conductivity of less than 0.05 W / mK. Freely flowing and composed of particles prepared from a mixture of from about 95% dry weight microporous insulating material, from 5 to 70% dry weight infrared opacifying agent material, from 0 to 50% particulate insulating filler material and from 0 to 5% binder material. The method comprises the steps of mixing an infrared opacifying agent material and a microporous insulating material with each other to produce a dense aeration mixture having a first density, conveying the dense mixture to an extrusion means at a first volume flow rate, a first volume Compacted material with a second density greater than the first density at a second volumetric flow rate less than the flow rate Extruding the mixture, allowing a portion of the air from the dense aeration mixture through the porous membrane to relieve pressure generated in the dense mixture as it varies from the first volume flow rate to the second volume flow rate. And granulating the compacted material.

The first volume flow rate is 2.0 to 4.5 times the second volume flow rate.

The first volume flow rate may range from 100 to 300 liters / hour, preferably 125 to 280 liters / hour.

The second volumetric flow rate may range from 20 to 90 liters / hour, preferably 25 to 90 liters / hour.

The compacted mixture can be screwed into the extrusion means.

The compacted aeration mixture may be extruded by one or more rollers, preferably a pair of opposing rollers.

Pressure in the range of 2.5 to 20 bar, preferably 5 to 10 bar, may be applied to the dense aeration mixture.

The porous membrane is metallic and comprises pores having a nominal diameter of 5 to 50 microns, preferably 15 microns.

The compressed material may be in the form of a sheet of compressed material.

The compressed material may be ground into relatively small pieces, for example by rotary chopping, prior to granulation.

Granulating the compacted material may comprise pressing the material through a hole in the mesh, preferably a metal mesh, using the rotor.

Particulate fiber-free microporous insulation materials include 40-85% dry weight microporous insulation material, 15-60% dry weight infrared opacifier material, 0-50% particulate insulating filler material and 0-5% binder material. Contains the composition of.

The particle size of the particulate fiber-free microporous insulating material can be formed from 0.25 mm to 2.5 mm.

The bulk density of the particulate fiber-free microporous thermal insulation material may be between 180 and 350 kg / m ³ .

The tap density of the particulate fiber-free microporous insulating material can be 250 to 450 kg / m ³ .

Opaque agent materials include titanium dioxide, iron titanium oxide, zirconium silicate, zirconium oxide, iron oxide, silicon carbide, and mixtures thereof. Can be selected from.

The microporous insulating material may comprise silica, such as, for example, fumed and / or precipitated silica.

The fumed silica may have a BET specific surface area of from 180 m ² / g to 230 m ² / g, preferably 200 m ² / g.

Fumed silica can be hydrophobic surface treatment.

The particulate insulating filler material may be selected from vermiculite, pearlite, fly ash, volatile silica and mixtures thereof.

The binder can be, for example, an organic binder such as polyvinyl alcohol or an inorganic binder selected from, for example, sodium silicate, potassium silicate, aluminum orthophosphate and mixtures thereof.

In order to better understand the present invention and to show more clearly the method for carrying out in the following examples, a method of producing a particulate fiber-free microporous insulating material according to the present invention is shown schematically according to FIG. 1.

Example  One

Three granular fiber-free microporous thermal insulation materials (mixtures 1 to 3) are used to form an eggerding in Amsterdam to form an intimate homogenous aerated mixture. Fumed silica material available from Degussa AG under 40% dry weight infrared opacifier in the form of rutile (titanium dioxide) available from the Group and under the registered trademark "Mark AEROSIL A200". prepared by mixing together a mixture of nominally 60% dry weight microporous insulating material in the form of a silica material. The aeration mixture has a bulk density of 80 kg / m ³ .

Fumed silica has a nominal (BET) specific surface area of 200 m ² / g. The opacifier material has a nominal particle size where 100% of the material passes through a 9 micron sieve.

As shown in Fig. 1, each of the aeration mixtures 2 formed in the mixer 4 is, for example, Turbo Kogyo Co. It is fed to a feed hopper 1 of a roller compactor apparatus 3, such as a model FR compressor available from Ltd.

The roller compaction apparatus 3 comprises a feeding hopper 1, extrusion means in the form of a pair of opposing compression rollers 5 and screw conveyor means for transferring each mixture from the hopper to the compression roller 7. ). The walls of the screw conveyor means are provided with a metal porous membrane having micropores including a nominal diameter of approximately 15 microns.

The roller compaction apparatus includes a rotary chopper 9 and a granulator 11.

Each mixture is fed from a hopper 1 to a screw conveyor means 7 via a rotary valve (not shown). The screw conveyor means 7 transfer each mixture to the rollers at the first volume flow rate (shown in Table 1 below).

The screw conveyed mixture travels through a pair of compression rollers. Each roller is rotated about a substantially parallel axis, which is arranged such that one roller is disposed vertically and parallel on the other roller. The rollers are nominally separated at intervals of 1 mm. The pressure generated by the rollers on the mixture is selected to 5, 10 or 20 bar. As each mixture is conveyed from the hopper through the gaps between the rollers, the mixture is densified, compressed and extruded into a substantially planar sheet of compressed insulating material. The densely increased materials exiting the roller at the second volumetric flow rate are shown in Table 1.

Mixture number Roller pressure (bar) First volume flow rate (liters / hour) Second volume flow rate (liters / hour) Ratio of first flow rate to second flow rate One 5 275 87 3.2: 1 2 10 275 79 3.5: 1 3 20 225 55 4.1: 1

Table 1

As the compression roller acts on the mixture, the air present in the aeration mixture is removed from the mixture, thereby potentially increasing the air pressure in the screw conveyor means. The potential increase in pressure in the screw conveyor means is substantially prevented by the porous membrane provided to allow air to escape from the screw conveyor means.

Each planar sheet of compressed thermal insulation material is then passed from the roller 5 by means of deflecting means 15 to the rotary chopper 9, whereby due to the blades 17 provided on the rotary chopper 9. The compressed material is cut into relatively small pieces having a nominal thickness of 1 mm and a nominal diameter of 2 to 5 mm.

Relatively small pieces of each insulating material are moved to granulator 11. The granulator comprises a rotor 21 and a metal screen mesh 19 positioned relative to the screen mesh. The screen mesh has a nominal hole size of 2.5 mm. Due to the relative movement of the rotor relative to the screen mesh, the cut pieces of each thermal insulation material provided between the rotor and the mesh are pressed through the holes in the mesh to form a microporous thermal insulation material that is free of particulate fibers. Each particulate fiber-free microporous insulating material 25 is retained in the collecting means 23. Sieves are used to remove granules of collected particulate fiberless microporous insulating material having a nominal size of less than 0.6 mm.

The particle size of each particulate fiber-free microporous insulating material is measured by sieve analysis known to those skilled in the art. The particle size range for each mixture is formed from 0.25 mm to 2.5 mm.

Particulate fiber-free microporous insulating materials with a particle size of less than 0.6 mm are detected by particle size analysis when the particles of the material are ground to some extent due to handling and analytical process delays.

The bulk density of each of the particulate fiber-free microporous insulating materials is measured using apparatus known to those skilled in the art. The bulk density is shown in Table 2 below.

The tap density (also known as optimized density) of each particulate fiber-free microporous insulating material is determined in a container of a predetermined volume using an automated tapping device until the density of each material does not change further. It is determined by repeatedly tapping the known weight of the sample of each insulating material. The density at which no further change occurs after sustained tapping corresponds to the tapping density of the material. The measured tap densities of each particulate fiber-free microporous insulating material are shown in Table 2 below.

Each particulate fiber-free microporous insulating material was published in July 2001, vol. 8, no 2 and heat conduction at a tap density of the material and an average temperature of 400 ° C. as determined by the method using a cylindrical cell thermal conductivity method known to those skilled in the art. The degree is tested. The results are shown in Table 2 below.

The effect of temperature on each particulate fiber-free microporous insulating material is also tested. Alumina crucibles with a straight cross section are filled with microporous insulating material free of particulate fibers. Vibration is applied to the crucible during the filling process to form a substantially constant packing density of particulate fiber-free microporous insulating material in the crucible. The particulate fiber-free microporous insulating material is then nominally heated to 900 ° C. for 24 hours. The height of the particulate fiber-free microporous insulating material in the crucible is measured before and after heating and the percentage difference in height is shown (Table 2 below).

Negative values for height change indicate that the height of the microporous insulating material without particulate fibers in the crucible after heating is smaller than the height before heating.

Mixture number Bulk density (kg / m ³ ) Tap Density (kg / m ³ ) Thermal Conductivity (W / mK) % Change in height of heated material One 253 350 0.0387 -1.4 2 277 406 0.0418 -1.8 3 325 450 0.0473 -1.6

Table 2

Example 2

Two particulate fiber-free microporous thermal insulation materials (mixture numbers 4, 5) are prepared by mixing together a mixture of the microporous thermal insulation material described in Example 1 and an infrared opacifying agent.

Mixture 4 is prepared by mixing a mixture of a 50% dry weight infrared opacifier and a 50% dry weight microporous thermal insulation material with each other.

Mixture 5 is prepared by mixing a mixture of nominally 60% dry weight infrared opacifier and 40% dry weight microporous thermal insulation material with each other.

Each mixture is mixed to form a dense and uniform aeration mixture. The aeration mixture has a bulk density of 80 kg / m ³ .

The mixtures were fed into the roller compaction apparatus described in Example 1 to produce a particulate fiber-free microporous insulating material as described in Example 1.

The mixtures are transferred to the rollers by the screw conveyor 7 at the volume flow rate shown in Table 3.

The pressure formed by the rollers on the mixture is 5 bar.

The material with increased density exits the roller at the volume flow rate shown in Table 3.

Mixture number Roller pressure (bar) First volume flow rate (liters / hour) Second volume flow rate (liters / hour) Ratio of first flow rate to second flow rate 4 5 275 82 3.4: 1 5 5 188 59 3.2: 1

Table 3

The effects of bulk density, tap density, thermal conductivity and temperature are measured and determined as described in Example 1.

Mixture number Bulk density (kg / m ³ ) Tap Density (kg / m ³ ) Thermal Conductivity (W / mK) % Change in height of heated material 4 269 390 0.0357 -1.8 5 256 420 0.0373 -1.7

Table 4

Example 3

Particulate fiber-free microporous thermal insulation material (mixture No. 6) is a 15% dry weight infrared opacifying agent in the form of grade F1200D, silicon carbide, available from ESK, Germany, to form a dense and homogeneous breathable mixture. And a mixture of the nominally 85% dry weight microporous insulating material described in Example 1 are mixed with each other. The aeration mixture has a bulk density of 80 kg / m ³ .

The mixture was introduced into a roller compaction apparatus as described in Example 1 to produce a particulate fiber-free microporous insulating material as described in Example 1.

The mixture is conveyed to the roller by a screw conveyor 7 at a volume flow rate of 125 liters / hour.

The pressure generated by the rollers in the mixture is 5 bar.

The material with increased density exits the roller at a volume flow rate of 56 liters / hour. Accordingly, the ratio of the first volumetric flow rate to the second volumetric flow rate is 2.2: 1.

The bulk density of the particulate fiber-free microporous insulating material is measured at 180 kg / m ³ .

The tap density of the particulate fiber-free microporous insulating material is set at 250 kg / m ³ as described in Example 1.

The particulate fiber-free microporous insulating material was tested for thermal conductivity as described in Example 1 and measured at 0.0374 W / mK.

The effect of temperature on the microporous insulating material without the fibrous particles is tested as described in Table 1. The percent change in material height after nominally heating at 900 ° C. for 24 hours is −1.6 percent.

Example 4

The particulate fiber-free microporous thermal insulation material (mixture No. 7) is a nominally 35% dry weight of the microporous thermal insulation material as described in Example 1 to form a dense and homogeneous aeration mixture. Prepared by mixing together a 40% dry weight infrared opacifier and a 25% dry weight microporous insulating material in the form of a hydrophobic fumed silica material available from Degussa AG under the registered trademark AEROSIL R974 as described in Example 1. . The aeration mixture has a bulk density of 80 kg / m ³ .

The mixture was introduced into a roller compaction apparatus as described in Example 1 to produce a particulate fiber-free microporous insulating material as described in Example 1.

The mixture is conveyed to the roller by a screw conveyor 7 at a volume flow rate of 188 liters / hour.

The pressure generated by the rollers in the mixture is 5 bar.

The material with increased density exits the roller at a volume flow rate of 54 liters / hour. Accordingly, the ratio of the first volume flow rate to the second volume flow rate is 3.5: 1.

The bulk density of the particulate fiber-free microporous insulating material is measured at 276 kg / m ³ .

The tap density of the particulate fiber-free microporous insulating material is set at 420 kg / m ³ as described in Example 1.

The particulate fiber-free microporous insulating material was tested for thermal conductivity as measured in Example 1 and measured at 0.0337 W / mK.

The effect of temperature on the microporous insulating material without the fibrous particles is tested as described in Table 1. The percent change in material height after nominal heating at 900 ° C. for 24 hours is −1.3 percent.

Example 5

Two particulate fiber-free microporous thermal insulation materials (mixtures No. 8 and 9) are used in conjunction with the particulate thermally insulating filler material in the form of micron grade exfoliated vermiculite available from Hoben International. It is prepared by mixing a mixture of the infrared opacifying agent and microporous insulating material described in 1.

Mixture 8 is prepared by mixing a mixture of nominally 57.5% dry weight microporous insulating material, 37.5% dry weight infrared opacifier and 5% dry weight vermiculite.

Mixture 9 is prepared by mixing a mixture of nominally 55% dry weight microporous thermal insulation material, 35% dry weight infrared opacifier and 10% dry weight vermiculite.

Each mixture is mixed to form an intimate homogenous aerated mixture. The aeration mixture has a bulk density of 80 kg / m ³ .

The mixture was introduced into a roller compaction apparatus as described in Example 1 to produce a particulate fiber-free microporous insulating material as described in Example 1.

The mixture is conveyed to the roller by the screw conveyor 7 at the volume flow rate shown in Table 5.

The pressure generated by the rollers for the mixture is 5 bar.

The material with increased density exits the roller at the volume flow rate shown in Table 5.

Mixture number Roller pressure (bar) First volume flow rate (liters / hour) Second volume flow rate (liters / hour) Ratio of first flow rate to second flow rate 8 5 188 65 2.9: 1 9 5 200 66 3.0: 1

Table 5

The influence of volume density, tap density, thermal conductivity and temperature are measured and defined as described in Example 1.

Mixture number Bulk density (kg / m ³ ) Tap Density (kg / m ³ ) Thermal Conductivity (W / mK) Rate of change of height of heated material (percent) 8 230 335 0.0382 3.0 9 242 342 0.0372 5.0

Table 6

With the addition of vermiculite, the height of the particulate fiber-free microporous insulating material made from Mixture Nos. 8 and 9 is increased after nominally heating at 900 ° C. for 24 hours. The expansion of particulate fiber-free microporous thermal insulation material has the advantage that the thermal insulation can more adequately fill the potential space in the thermally insulating area that can provide a through-path to heat.

Example 6

Particulate fiber-free microporous insulation material (mixture No. 10) is nominally 48% dry weight microporous insulation material, 40% dry weight infrared opacifier and Germany to form a dense and homogeneous aeration mixture. Grade VAW available from RW Fuller of Degussa AG, 12% dry weight particulate insulating filler material in the form of volatile silica materia, can be prepared by mixing with each other.

Microporous insulating materials and infrared opacifiers are described in Example 1.

The aeration mixture has a bulk density of 80 kg / m ³ .

The mixture was introduced into a roller compaction apparatus as described in Example 1 to produce a particulate fiber-free microporous insulating material as described in Example 1.

The mixture is conveyed to the roller by a screw conveyor 7 at a volume flow rate of 250 liters / hour.

The pressure generated by the rollers for the mixture is 5 bar.

The increased concentration of material exits the roller at a volume flow rate of 70 liters / hour. Accordingly, the ratio of the first volumetric flow rate to the second volumetric flow rate is 3.6: 1.

The bulk density of the particulate fiber-free microporous insulating material is measured at 286 kg / m ³ .

The tap density of the particulate fiber-free microporous insulating material is set at 395 kg / m ³ as described in Example 1.

The particulate fiber-free microporous thermal insulation material was tested for thermal conductivity as described in Example 1 and measured at 0.0397 W / mK.

The effect of temperature on the microporous insulating material without the fibrous particles is tested as described in Table 1. The percent change in material height after nominally heating at 900 ° C. for 24 hours is −5.5 percent.

Example 7

Particle-free microporous thermal insulation material (mixture No. 11) is a nominally 48% dry weight microporous thermal insulation material (as described in Example 1) to form a dense and homogeneous aeration mixture, Degussa AG Prepared by mixing a mixture of 12% dry weight microporous thermal insulation material and 40% dry weight infrared opacifier (described in Example 1) in the form of precipitated silica material of Grade LS50 available from do. The aeration mixture has a bulk density of 80 kg / m ³ .

The mixture was introduced into a roller compaction apparatus as described in Example 1 to produce a particulate fiber-free microporous insulating material as described in Example 1.

The mixture is conveyed to the roller by a screw conveyor 7 at a volume flow rate of 238 liters / hour.

The pressure generated by the rollers for the mixture is 5 bar.

The increased concentration of material exits the roller at a volume flow rate of 69 liters / hour. The ratio of the first volumetric flow rate to the second volumetric flow rate is therefore 3.4: 1.

The bulk density of the particulate fiber-free microporous insulating material is measured at 276 kg / m ³ .

The tap density of the particulate fiber-free microporous insulating material is set at 380 kg / m ³ as described in Example 1.

The particulate fiber-free microporous insulating material was tested for thermal conductivity as measured in Example 1 and measured at 0.0405 W / mK.

The effect of temperature on the microporous insulating material without the fibrous particles is tested as described in Table 1. The percent change in material height after nominal heating at 900 ° C. for 24 hours is −7.1 percent.

According to the present invention a particulate fiber-free microporous insulating material is described, wherein the infrared opacifying agent material is rutile (titanium dioxide) or silicon carbide. Infrared opacifier materials include, for example, iron titanium oxide (e.g., titanium or leucoxin), zirconium silicate (zircon), zirconium oxide (zirconia), iron oxide (e.g. hematite) and mixtures thereof. And other suitable materials.

The fumed silica may have a specific surface area of 50 m ² / g to 400 m ² / g, preferably 180 m ² / g to 230 m ² / g.

In addition to the compositions described in the examples, the particulate fiber-free microporous insulating material according to the present invention is a fumed silica material in the range of 30 to 95% dry weight, an infrared opacifying agent in the range of 5 to 70% dry weight, in particular It may be composed of a particulate insulating filler material in the 0-50% dry weight range and a binder material in the 0-5% dry weight range.

The binder can be, for example, an organic binder such as polyvinyl alcohol or an inorganic binder such as, for example, sodium silicate, potassium silicate and / or aluminum orthophosphate.

Although Example 5 describes the addition of particulate insulating filler material in the form of vermiculite, the particulate insulating filler material may be pearlite, flyash and / or volatile silica (also known as arc silica or silica fume). It should be understood that it can.

The bulk density of the particulate fiber-free microporous insulating material according to the invention can be between 180 and 350 kg / m ³ .

The tap density of the particulate fiber-free microporous insulating material can be 250 to 450 kg / m ³ .

Although embodiments describe the use of a roller compaction device, it should be understood that any device may vent air from the vent mixture to provide a compacted material that can be used in particulate form.

Although the embodiments describe the extrusion means of the roller compaction apparatus to pressurize on the vented mixture at a pressure in the range of 5 to 20 bar, it should be understood that the pressure can be applied in the range of 2.5 to 20 bar. The preferred range of pressure is substantially 5 to 10 bar.

Although the diameter of the micropores of the porous membrane is described as approximately 15 microns, it should be understood that such micropores can have a diameter in the range of 5-50 microns.

The first volume flow rate may range from 2.0 to 4.5 times the second volume flow rate. The first volume flow rate may range from 100 to 300 liters / hour, preferably 125 to 280 liters / hour. The second volume flow rate may range from 25 to 90 liters / hour, preferably 50 to 90 liters / hour.

Although in the embodiments, the means for compressing the material is described as a pair of opposing rollers, for example, such as compression between a substantially flat substrate and a single roller or between a pair of substantially parallel compression surfaces. It should be understood that other compression means may be used.

The compressed material is described in the form of a sheet.

It should be understood that the compact material used to make the particulate fiber-free microporous insulating material may be formed in other thin sheets such as, for example, strips.

Although the rotary chopper in the embodiment is described as grinding the compressed material prior to granulation, it should be understood that other means, such as, for example, slicing means, can be used to grind the material.

The compacted material can be fed directly into the granulator without breaking into relatively small pieces.

The particulate fiber-free microporous insulating material produced according to the invention has a significantly smaller thermal conductivity than vermiculite or particulate mixtures of clay or calcined diatomaceous earth.

At an average of 400 ° C., the particulate fiber-free microporous insulating material according to the invention has a thermal conductivity less than the expanded vermiculite in its tap density.

The particulate fiber-free microporous insulating material produced according to the present invention has a significantly smaller height shrinkage than the particulate microporous airgel material.

Claims (51)

In the particulate fiber-free microporous insulation material, the particulate fiber-free microporous insulation material has a shrinkage not greater than 10% and a thermal conductivity of less than 0.05 W / mK, and flows freely, 30-95% dry weight microporous insulating material, 5 to 70% dry weight infrared opacifying agent material, 0-50% particulate insulating filler material and Insulating material consisting of particles made from a dense mixture of 0 to 5% binder material. The method of claim 1 wherein the thermal insulation material 40-85% dry weight microporous insulating material, 15-60% dry weight infrared opacifier material, 0-50% particulate insulating filler material and An insulation material comprising a composition of 0 to 5% binder material. 3. The thermal insulation material according to claim 1, wherein the particle size of the particulate fiber-free microporous thermal insulation material is formed from 0.25 mm to 2.5 mm. 4. 4. Insulation material according to any one of the preceding claims, wherein the bulk density of the particulate fiber-free microporous insulation material is between 180 and 350 kg / m ³ . Insulation material according to any of the preceding claims, wherein the tap density of the particulate fiber-free microporous insulation material is between 250 and 450 kg / m ³ . Insulation material according to any of the preceding claims, wherein the opaque material is selected from titanium dioxide, iron titanium oxide, zirconium silicate, zirconium oxide, iron oxide, silicon carbide and mixtures thereof. Insulation material according to any one of the preceding claims, wherein the microporous insulation material comprises silica. 8. The heat insulating material of claim 7, wherein the silica comprises precipitated silica. The heat insulating material according to claim 7 or 8, wherein the silica comprises fumed silica. 10. The thermal insulation material according to claim 9, wherein the fumed silica has a BET, specific surface area in the range of 180 m ² / g to 230 m ² / g. The insulating material of claim 10, wherein the fumed silica has a nominal BET specific surface area of substantially 200 m ² / g. 10. The thermal insulation material of claim 9, wherein the fumed silica is hydrophobic surface treated. Insulation material according to any of the preceding claims, wherein the particulate insulating filler material is selected from vermiculite, pearlite, fly ash, volatile silica and mixtures thereof. Insulation material according to any of the preceding claims, wherein the binder comprises an organic binder. 15. The thermal insulation material according to claim 14, wherein the organic binder comprises polyvinyl alcohol. The insulating material according to any one of claims 1 to 13, wherein the binder comprises an inorganic binder. 17. The insulating material of claim 16, wherein the inorganic binder is selected from sodium silicate, potassium silicate, aluminum orthophosphate, and mixtures thereof. A method for producing particulate fiber-free microporous insulation material having a shrinkage not greater than 10% and a thermal conductivity of less than 0.05 W / mK, wherein the insulation material is 30 to 95% dry weight microporous insulation material. , Freely flowing and composed of particles prepared from a mixture of 5 to 70% dry weight infrared opacifying agent material, 0 to 50% particulate insulating filler material and 0 to 5% binder material. Mixing the infrared opacifying agent material and the microporous insulating material together to produce a dense aeration mixture having a first density, Conveying the dense mixture to the extrusion means 5 at a first volume flow rate, Extruding the compacted mixture as a compressed material having a second density greater than the first density at a second volume flow rate less than the first volume flow rate, Venting a portion of the air from the dense aeration mixture through the porous membrane to relieve pressure generated in the dense mixture as it varies from the first volume flow rate to the second volume flow rate; and -Granulating fiber-free microporous insulating material, characterized in that it comprises granulating the compressed material. 19. The method of claim 18, wherein the first volume flow rate is 2.0 to 4.5 times the second volume flow rate. 20. The method of claim 18 or 19, wherein the first volume flow rate is in the range of 100 to 300 liters / hour. 21. The method of claim 20, wherein the first volume flow rate is in the range of 125 to 280 liters / hour. 22. The method according to any one of claims 18 to 21, wherein the second volume flow rate is in the range of 20 to 90 liters / hour. 23. The method of claim 22, wherein the second volume flow rate is in the range of 25 to 90 liters / hour. 24. The particulate fiber free micro-organism according to any one of claims 18 to 23, characterized in that the method comprises moving the dense mixture by means of a screw conveyor (7) to the extrusion means (5). A method for making a porous insulating material. 25. The method according to any one of claims 18 to 24, wherein the method comprises extruding the dense aeration mixture by one or more rollers (5). Method for manufacturing. 26. A method according to claim 25, wherein the dense aeration mixture is extruded by a pair of opposing rollers (5). 27. The method according to any one of claims 18 to 26, wherein a pressure in the range of 2.5 to 20 bar is applied to the dense aeration mixture. 28. The method of claim 27, wherein the applied pressure is substantially in the range of 5 to 10 bar. 29. The particulate fiber-free microporous insulating material of claim 18, wherein the porous membrane is metallic and comprises micropores having a nominal diameter in the range of 5-50 microns. Method for manufacturing. 30. The method of claim 29, wherein the micropores have a diameter of substantially 15 microns. 31. The method of any of claims 18 to 30, wherein the compressed material is in the form of a sheet of compressed material. 32. The particulate fiber-free microporous insulating material of any of claims 18 to 31, wherein the method comprises crushing the compressed material into relatively small pieces prior to granulation. Method for preparing the same. 33. The method of claim 32, wherein the compressed material is crushed by rotary chopping. 34. The particulate form according to any of claims 18 to 33, wherein the granulation of the compacted material comprises pressing the material through the holes in the mesh 19 using the rotor 9. A method for producing a fiber free microporous thermal insulation material. 35. The method of claim 34, wherein the mesh comprises a metal mesh (19). 36. The microporous thermal insulation material according to any one of claims 18 to 35, wherein the particulate fiber-free microporous thermal insulation material is 40 to 85% dry weight microporous thermal insulation material, 15 to 60% dry weight infrared opacifier. A method for producing particulate fiber-free microporous thermal insulation material, characterized in that it has a composition of from 50% particulate insulating filler material and 0-5% binder material. 37. The particulate fiber-free microporous insulation material according to any of claims 18 to 36, wherein the particle size of the particulate fiber-free microporous insulation material is in the range of 0.25 to 2.5 mm. Method for manufacturing. 38. The particulate fiber-free microporous insulation material according to any of claims 18 to 37, wherein the bulk density of the particulate fiber-free microporous insulation material is between 180 and 350 kg / m ³ . Method for preparing the same. 39. The particulate fiber-free microporous insulation material according to any of claims 18 to 38, wherein the tap density of the particulate fiber-free microporous insulation material is between 250 and 450 kg / m ³ . Method for preparing the same. 40. The particulate fiber of any of claims 18 to 39, wherein the opaque material is selected from titanium dioxide, iron titanium oxide, zirconium silicate, zirconium oxide, iron oxide, silicon carbide and mixtures thereof. A method for producing a microporous insulating material free of heat. 41. The method of any of claims 18-40, wherein the microporous heat insulating material comprises silica. 42. The method of claim 41, wherein the silica comprises precipitated silica. 43. The method of claim 41 or 42, wherein the silica comprises fumed silica. 44. The method of claim 43, wherein the fumed silica has a BET specific surface area in the range of 180 m ² / g to 230 m ² / g. 45. The method of claim 44, wherein the fumed silica has a nominal BET specific surface area of substantially 200 m ² / g. 46. The method of any of claims 43-45, wherein the fumed silica is hydrophobic surface treated. 47. The particulate fiber-free microporous insulating material according to any one of claims 18 to 46, wherein the particulate insulating filler material is selected from vermiculite, pearlite, fly ash, volatile silica and mixtures thereof. Method for preparing the same. 48. The method of any of claims 18 to 47, wherein the binder comprises an organic binder. 49. The method of claim 48, wherein the organic binder comprises polyvinyl alcohol. 48. The method of any of claims 18 to 47, wherein the binder comprises an inorganic binder. 51. The method of claim 50, wherein the inorganic binder is selected from sodium silicate, potassium silicate, aluminum orthophosphate, and mixtures thereof.

Images