An inorganic silicon crystal heat insulation board for smoke prevention and exhaust air ducts

Abstract

The present invention discloses an inorganic silicon crystal heat insulation board for smoke prevention and exhaust air ducts, which comprises the following steps: raw material treatment, mixing and stirring, forming, drying and curing, high-temperature sintering, and surface treatment and inspection: after sintering is completed, the board is subjected to surface grinding treatment to remove the uneven and rough parts on the surface; finally, quality inspections of thermal conductivity, compressive strength, and fire resistance are carried out. In the present invention, by optimizing the ratio of high-purity silica powder to alumina, the heat conduction loss can be effectively reduced, ensuring that the board can maintain its structural integrity when bearing external pressure, and is suitable for industrial application environments with high strength and long-term use, not only extending the service life of the product, but also further enhancing its application value in the field of fire safety.

Description

Technical Field

[0001] The present invention belongs to the technical field of heat insulation board production, and specifically relates to an inorganic silicon crystal heat insulation board for smoke exhaust and prevention air ducts. Background Art

[0002] Inorganic silicon crystal heat insulation board is a building material with excellent heat insulation performance, widely used in fields such as fire prevention, smoke exhaust and prevention, etc. Its production process usually involves precise proportioning of various raw materials and complex processing techniques, including silicon crystal powder, alumina, mineral fiber, expanded perlite, etc. These materials can effectively reduce heat conduction in high-temperature environments, protecting building structures and personnel safety.

[0003] However, the existing inorganic heat insulation boards often have problems such as relatively high thermal conductivity, insufficient compressive strength, and poor fire resistance, which limit their application in some high-temperature and high-pressure environments. In addition, the traditional production process has high requirements for the selection and treatment of raw materials, increasing production costs and also resulting in instability of product performance.

[0004] In the prior art, an inorganic silicon crystal material for smoke exhaust and prevention air ducts and its preparation method (publication number CN113968713A) provides a more advanced "spray steaming preheating pressing + autoclave curing" preparation technology, which has higher heat transfer efficiency, the board is evenly heated, and the forming time is short. Its finished material is light and strong, with excellent fire resistance and anti-permeability performance, and does not deform at high temperatures and has a small linear expansion rate. However, in this technical solution, due to the use of autoclave technology, on the one hand, it will cause bubbles to form inside or on the surface of the material, affecting aesthetics and performance, and on the other hand, during use, due to uneven temperature or pressure, it may lead to peeling of the surface coating from the substrate.

[0005] Therefore, there is an urgent need for a new type of inorganic silicon crystal heat insulation board and its preparation method to improve the heat insulation effect, mechanical strength and fire resistance of the material, while avoiding the autoclave technology that causes peeling of the surface coating from the substrate, and meeting the requirements of the modern construction industry for high-performance heat insulation materials. Summary of the Invention

[0006] The purpose of the present invention is to: in order to solve the problems of unstable performance and poor heat insulation effect of existing heat insulation materials in high-temperature environments, use composite materials such as high-purity silica powder, alumina, mineral fiber, and expanded perlite, and through optimizing process steps such as mixing, forming, drying, and sintering, form an inorganic silicon crystal heat insulation board with high strength and low thermal conductivity, and provide an inorganic silicon crystal heat insulation board for smoke exhaust and prevention air ducts.

[0007] The technical solution adopted by the present invention is as follows:

[0008] An inorganic silicon crystal heat insulation board for smoke exhaust and prevention air ducts, comprising the following steps:

[0009] A Raw material treatment:

[0010] Mix high-purity silica powder with alumina, and screen and sieve to ensure uniform fineness of the materials, with the particle size controlled within the range of 40um - 60um; Mineral fibers and expanded perlite are pre-treated to a state without impurities;

[0011] B Mixing and stirring:

[0012] Add the treated silicon crystal powder and alumina mixture, mineral fibers, and expanded perlite into the blender in sequence according to the proportion, and dry mix for 3 min - 5 min;

[0013] Gradually add silicate binder during the stirring process, and continue stirring for 5 min - 8 min to ensure uniform mixing of the materials and reach a consistency suitable for molding;

[0014] C Molding:

[0015] Place the mixed materials in a pre-prepared mold, and form by pressing / extrusion to ensure precise control of the thickness and size of the plate;

[0016] D Drying and curing:

[0017] The formed heat insulation board needs to be dried at a low temperature of 80°C - 100°C for 12 h - 24 h to remove moisture;

[0018] Subsequently, move the board to a high-temperature environment of 200°C - 250°C for curing treatment for 3 h - 6 h to ensure that the binder reacts completely and forms a stable structure;

[0019] E High-temperature sintering:

[0020] The board enters a high-temperature kiln at 1200°C - 1400°C for sintering for 4 h - 6 h. This step completely sinters the silicon crystal powder and alumina framework to form an inorganic silicon crystal heat insulation board with high strength and low thermal conductivity;

[0021] F Surface treatment and inspection:

[0022] After sintering, the board undergoes surface grinding treatment to remove the uneven and rough parts on the surface;

[0023] Finally, conduct quality inspections on the thermal conductivity, compressive strength, and fire resistance performance.

[0024] Among them, in the raw material treatment process described in step A, calculated by the total weight percentage after mixing, the proportion of silica powder is 50% - 70%, and the proportion of alumina is 30% - 50%.

[0025] Among them, in the mixing and stirring process described in step B, calculated by the total weight percentage after mixing, the proportion of silica powder and alumina mixture is 50%-70%, the proportion of silicate binder is 15%-25%, the proportion of mineral fiber is 10%-15%, and the proportion of expanded perlite is 5%-10%.

[0026] Among them, in the mixing and stirring process described in step B, the silicate binder is composed of one or more of sodium silicate, potassium silicate, lithium silicate and magnesium silicate;

[0027] The mineral fiber can be composed of one or more of rock wool fiber, glass fiber, ceramic fiber and carbon fiber;

[0028] The expanded perlite is made by mixing an expanding agent, an adhesive, an auxiliary agent, perlite particle filler and water.

[0029] Among them, in the forming process described in step C, the mixture containing silicon crystal powder and alumina is physically compacted to form a strong three-dimensional network structure;

[0030] For the hydration reaction of the silicate binder, water molecules react with sodium silicate, potassium silicate, etc. to generate gel-like silicate, making the bonding between particles closer;

[0031] The mineral fiber is compressed under pressure to form a finer structure, enhancing the heat insulation performance;

[0032] The particles of expanded perlite are extruded against each other under pressure and maintain their original shape, enhancing the structural strength;

[0033] Under high-pressure conditions, the formation of tiny bubbles may cause some gas to escape, further enhancing the lightness of the heat insulation board.

[0034] Among them, in the drying and curing process described in step D, it includes the following:

[0035] Water evaporation: The water in the board evaporates in a low-temperature environment of 80℃-100℃ to form water vapor, reducing the moisture content of the material and improving the dryness of the board;

[0036] Reaction of the silicate binder: During the low-temperature drying process, the binding force between the silicate binder and water weakens, causing its hydrate to gradually lose water and enhancing the hardness of the binder;

[0037] Crosslinking reaction: As the temperature rises, the silicon-oxygen bonds in the silicate binder gradually form a crosslinked structure, improving the mechanical properties of the overall material;

[0038] Decomposition of organic matter: When there are organic additives in the mixture, thermal decomposition will occur under high temperature conditions to generate small molecular alkane, olefin and alkyne gases, carbon monoxide and hydrogen gas, further enhancing the fire resistance of the material;

[0039] Structural reorganization: During the high-temperature curing process, silicates interact with bauxite to form a more stable inorganic network structure, which improves the overall strength of the insulation board.

[0040] The high temperature sintering process described in step E specifically includes the following reactions:

[0041] Silicon crystal powder and alumina melt at a high temperature of 1200℃-1400℃ to form a liquid phase, which fills the gaps between the particles and promotes the bonding between the particles; the silicon-oxygen bonds and aluminum-oxygen bonds are reorganized to form a new stable inorganic silicon crystal network structure, which improves the strength and fire resistance of the material; some lightweight components are vaporized to reduce the weight of the material and improve the insulation effect; alumina undergoes a phase change to form a different crystal structure, which affects the thermal stability and mechanical properties of the material; the silicate binder reacts completely to form a highly cross-linked inorganic polymer network, which improves the overall strength and durability of the insulation board.

[0042] Among them, in the surface treatment and inspection process described in step F, specifically, a surface grinder / sand belt machine is used to grind the surface of the plate until the flatness is controlled within ±0.5mm and the surface roughness is less than 1.0um, thereby reducing heat conduction losses and improving thermal insulation performance.

[0043] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0044] 1. In the present invention, by optimizing the ratio of silicon crystal powder to alumina, the inorganic silicon crystal insulation board has excellent thermal conductivity, which can effectively reduce heat conduction loss, thereby greatly improving the insulation effect of the smoke exhaust duct and meeting the energy-saving needs in high temperature environments.

[0045] 2. In the present invention, by controlling the amount of expanded perlite and mineral fiber in different process steps, the compressive strength of the insulation board is significantly improved, ensuring that the board can maintain structural integrity when subjected to external pressure, and is suitable for high-strength, long-term use industrial application environments.

[0046] 3. In the present invention, a combined process of high-temperature sintering and surface treatment is adopted, which effectively improves the fire resistance of the insulation board, so that it can remain stable under fire or extreme high temperature conditions, which not only extends the service life of the product, but also further enhances its application value in the field of fire safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1Schematic flow diagram of the present invention; Specific implementation manners

[0048] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0049] Example 1, referring to Figure 1 , an inorganic silicon crystal heat insulation board for smoke exhaust and prevention air ducts, includes the following steps:

[0050] A Raw material treatment:

[0051] Mix high-purity silica powder with alumina, and screen and sieve to ensure uniform material fineness, with the particle size controlled within the range of 45um ± 5um; Mineral fibers and expanded perlite are pre-treated to a state without impurities;

[0052] Calculated by the total weight percentage after mixing, the proportion of silica powder is 50%, and the proportion of alumina is 50%.

[0053] B Mixing and stirring:

[0054] Add the treated silicon crystal powder and alumina mixture, mineral fibers, and expanded perlite into the mixer in sequence according to the proportion, and dry mix for 3 minutes;

[0055] During the stirring process, gradually add silicate binder and continue stirring for 8 minutes to ensure uniform mixing of the materials and reach a consistency suitable for molding;

[0056] Calculated by the total weight percentage after mixing, the proportion of the silica powder and alumina mixture is 50%, the proportion of the silicate binder is 25%, the proportion of mineral fibers is 15%, and the proportion of expanded perlite is 10%.

[0057] The silicate binder uses sodium silicate; the mineral fibers can use rock wool fibers; the expanded perlite is made by mixing an expanding agent, an adhesive, additives, perlite particle fillers, and water.

[0058] C Molding:

[0059] Place the mixed material in a pre-prepared mold, and form it by pressing / extrusion to ensure precise control of the plate thickness and size;

[0060] The mixture containing silicon crystal powder and alumina is physically compacted to form a strong three-dimensional network structure;

[0061] The hydration reaction of the silicate binder, where water molecules react with sodium silicate, potassium silicate, etc. to generate a gel-like silicate, making the binding between particles closer;

[0062] Mineral fibers are compressed under pressure to form a finer structure, enhancing the heat insulation performance;

[0063] The particles of expanded perlite are squeezed against each other under pressure and maintain their original shape, enhancing the structural strength;

[0064] Under high-pressure conditions, the formation of tiny bubbles may cause some gas to escape, further enhancing the lightness of the heat insulation board.

[0065] D Drying and curing:

[0066] The formed heat insulation board needs to be dried at a low temperature of 80 °C for 24 h to remove moisture;

[0067] Subsequently, the board is moved to a high-temperature environment of 200 °C for curing for 3 h to ensure that the binder reacts completely and forms a stable structure;

[0068] It also includes the following content:

[0069] Moisture evaporation, the moisture in the board evaporates in a low-temperature environment of 80 °C to form water vapor, reducing the moisture content of the material and improving the dryness of the board;

[0070] Reaction of silicate binder, during the low-temperature drying process, the binding force between the silicate binder and moisture weakens, causing its hydrate to gradually lose moisture and enhancing the hardness of the binder;

[0071] Crosslinking reaction: As the temperature rises, the silicon-oxygen bonds in the silicate binder gradually form a crosslinked structure, improving the mechanical properties of the overall material;

[0072] Decomposition of organic matter, when there are organic additives in the mixture, thermal decomposition occurs in a high-temperature environment, generating small-molecule alkane, alkene, and alkyne gases, carbon monoxide, and hydrogen gases, further enhancing the fire resistance of the material;

[0073] Structure reorganization, during the high-temperature curing process, silicate interacts with bauxite minerals to form a more stable inorganic network structure, improving the overall strength of the heat insulation board.

[0074] E High-temperature sintering:

[0075] The board enters a high-temperature kiln at 1200 °C for sintering for 6 h. This step completely sinters the silicon crystal powder and alumina skeleton to form an inorganic silicon crystal heat insulation board with high strength and low thermal conductivity;

[0076] Among them, it specifically includes the following reactions:

[0077] Silicon crystal powder and alumina melt at a high temperature of 1200 °C to form a liquid phase, filling the voids between particles and promoting the bonding between particles; the recombination of silicon-oxygen bonds and aluminum-oxygen bonds forms a new stable inorganic silicon crystal network structure, improving the strength and fire resistance of the material; the gasification of some light components reduces the weight of the material and improves the heat insulation effect; the phase change of alumina forms different crystal structures, affecting the thermal stability and mechanical properties of the material; the complete reaction of the silicate binder forms a highly cross-linked inorganic polymer network, enhancing the overall strength and durability of the heat insulation board.

[0078] F Surface treatment and inspection:

[0079] After sintering, the plate is subjected to surface grinding to remove the rough and uneven parts on the surface;

[0080] Finally, quality inspections of thermal conductivity, compressive strength, and fire resistance are carried out;

[0081] Specifically, a surface grinder / belt sander is used to grind the surface of the plate to a flatness within ±0.5 mm and a surface roughness lower than 1.0 um, reducing heat conduction loss and improving heat insulation performance.

[0082] Example 2, referring to Figure 1 , an inorganic silicon crystal heat insulation board for smoke exhaust and ventilation ducts, includes the following steps:

[0083] A Raw material treatment:

[0084] Mix high-purity silica powder and alumina, and screen them to ensure uniform material fineness, with the particle size controlled within the range of 55 um ± 5 um; mineral fiber and expanded perlite are pre-treated to a state without impurities;

[0085] Calculated by the total weight percentage after mixing, the proportion of silica powder is 70%, and the proportion of alumina is 30%.

[0086] B Mixing and stirring:

[0087] Add the treated silicon crystal powder and alumina mixture, mineral fiber, and expanded perlite to the mixer in sequence according to the proportion, and dry mix for 5 min;

[0088] During the stirring process, gradually add the silicate binder and continue stirring for 5 min to ensure uniform mixing of the materials and reach a suitable consistency for molding;

[0089] Calculated by the total weight percentage after mixing, the proportion of the silica powder and alumina mixture is 70%, the proportion of the silicate binder is 15%, the proportion of mineral fiber is 10%, and the proportion of expanded perlite is 5%.

[0090] The silicate binder uses sodium silicate; the mineral fiber can use rock wool fiber; the expanded perlite is made by mixing an expanding agent, an adhesive, an auxiliary agent, perlite particle filler, and water.

[0091] C Shaping:

[0092] Place the mixed materials in a pre-prepared mold and form them by pressing / extrusion to ensure precise control of the plate thickness and size;

[0093] A mixture containing silicon crystal powder and alumina is physically compacted to form a strong three-dimensional network structure;

[0094] The hydration reaction of the silicate binder, where water molecules react with sodium silicate, potassium silicate, etc. to form a gel-like silicate, making the bonding between particles tighter;

[0095] The mineral fiber is compressed under pressure to form a finer structure, enhancing the heat insulation performance;

[0096] The particles of the expanded perlite are pressed against each other under pressure and maintain their original shape, enhancing the structural strength;

[0097] Under high-pressure conditions, the formation of tiny bubbles may cause some gas to escape, further enhancing the lightness of the heat insulation board.

[0098] D Drying and Curing:

[0099] The formed heat insulation board needs to be dried at a low temperature of 100 °C for 12 h to remove moisture;

[0100] Subsequently, move the board to a high-temperature environment of 250 °C for curing for 3 h to ensure that the binder reacts completely and forms a stable structure;

[0101] It also includes the following:

[0102] Moisture evaporation, the moisture in the board evaporates in a low-temperature environment of 100 °C to form water vapor, reducing the moisture content of the material and improving the dryness of the board;

[0103] The reaction of the silicate binder, during the low-temperature drying process, the binding force between the silicate binder and moisture weakens, causing its hydrate to gradually lose moisture and enhancing the hardness of the binder;

[0104] Crosslinking reaction: As the temperature rises, the silicon-oxygen bonds in the silicate binder gradually form a crosslinked structure, improving the mechanical properties of the overall material;

[0105] Decomposition of organic matter, when there are organic additives in the mixture, thermal decomposition occurs in a high-temperature environment, generating small-molecule alkane, alkene, and alkyne gases, carbon monoxide, and hydrogen gases, further enhancing the fire resistance of the material;

[0106] Structure reorganization: During the high-temperature curing process, silicate interacts with bauxite minerals to form a more stable inorganic network structure, improving the overall strength of the heat insulation board.

[0107] E High-temperature sintering:

[0108] The board is sintered in a high-temperature kiln at 1400 °C for 4 hours. This step thoroughly sinters the silicon crystal powder and alumina skeleton to form an inorganic silicon crystal heat insulation board with high strength and low thermal conductivity.

[0109] Among them, it specifically includes the following reactions:

[0110] The silicon crystal powder and alumina melt at a high temperature of 1400 °C to form a liquid phase, filling the voids between particles and promoting the bonding between particles; the reorganization of silicon-oxygen bonds and aluminum-oxygen bonds forms a new stable inorganic silicon crystal network structure, improving the strength and fire resistance of the material; the gasification of some lightweight components reduces the weight of the material and improves the heat insulation effect; the phase change of alumina forms different crystal structures, affecting the thermal stability and mechanical properties of the material; the complete reaction of the silicate binder forms a highly cross-linked inorganic polymer network, enhancing the overall strength and durability of the heat insulation board.

[0111] F Surface treatment and inspection:

[0112] After sintering, the board is subjected to surface grinding to remove the rough and uneven parts on the surface.

[0113] Finally, quality inspections of thermal conductivity, compressive strength, and fire resistance are carried out.

[0114] Specifically, a surface grinder / belt sander is used to grind the surface of the board to a flatness within ±0.5 mm and a surface roughness below 1.0 μm, reducing heat conduction loss and improving heat insulation performance.

[0115] Experimental example: By comparing the treatment conditions of the heat insulation boards prepared in Example 1 and Example 2, the following Table 1 can be obtained.

[0116]

[0117]

[0118] Table 1. Comparison of the treatment conditions of the heat insulation boards prepared in Example 1 and Example 2

[0119] After inspecting the heat insulation boards prepared in Example 1 and Example 2 and comparing the data with those of existing conventional heat insulation boards, the following Table 2 can be obtained.

[0120]

[0121] Table 2. Comparison of various coefficients of the heat insulation boards prepared in Example 1 and Example 2 with conventional products

[0122] Through such comparison, the influence of different process conditions on the performance of the inorganic silicon crystal heat insulation board can be observed, that is:

[0123] Thermal conductivity: The thermal conductivity of Example 2 is lower, indicating better heat insulation performance.

[0124] Compressive strength: The compressive strength of Example 2 is higher than that of Example 1 and conventional products, showing stronger mechanical properties.

[0125] Fire resistance performance: The fire resistance performance of Example 2 is the best, and the fire resistance duration can reach 6 hours.

[0126] In summary, among the above three groups of comparative data with significant advantages, due to the adoption of different raw material ratios and processing steps, obvious differences have occurred in the thermal conductivity, compressive strength and fire resistance performance of the inorganic silicon crystal heat insulation board. That is, in Example 2, through different material ratios and sintering treatments, the heat insulation board shows significantly better experimental group than the control group in terms of thermal conductivity, mechanical strength and fire resistance. Therefore, it can be considered that by optimizing the material composition and process flow, the inorganic silicon crystal heat insulation board can greatly improve its comprehensive performance in high temperature, load bearing and safety protection.

[0127] On the other hand, the process in Example 2 not only improves the physical properties of the material, but also realizes the balance between durability and energy saving through reasonable raw material selection and processing steps, and is suitable for various application scenarios such as buildings and industrial smoke exhaust and ventilation ducts.

[0128] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An inorganic silicon crystal insulation board for smoke exhaust duct, characterized in that: The following steps are involved: ARaw material processing: Mix high-purity silica powder with alumina and sieve to ensure uniform material fineness and control the particle size within the range of 40um-60μm; Mineral fiber and expanded perlite are processed in advance to be free of impurities; BMixing and stirring: Add high-purity silica powder and alumina mixture, mineral fiber, and expanded perlite into a mixer in proportion and dry mix for 3-5 minutes; Gradually add silicate binder during the mixing process and continue mixing for 5-8 minutes to ensure that the materials are evenly mixed and reach a consistency suitable for molding; C Molding: Place the mixed material in a pre-prepared mold and shape it by pressing / extrusion to ensure precise control of the thickness and size of the sheet; D Drying and curing: The formed insulation board needs to be dried at 80℃-100℃ for 12h-24h to remove moisture; Then, the board is moved to a high temperature environment of 200℃-250℃ for curing, and the curing time is controlled within 3h-6h to ensure that the adhesive reacts thoroughly and forms a stable structure; E High temperature sintering: The plate enters a high-temperature kiln at 1200℃-1400℃ for sintering for 4h-6h. This step completely sintered the high-purity silica powder and alumina skeleton to form an inorganic silicon crystal insulation board with high strength and low thermal conductivity. FSurface treatment and inspection: After sintering, the plate is ground to remove the rough and uneven surface. Finally, quality inspections are carried out on thermal conductivity, compressive strength and fire resistance.

2. The inorganic silicon crystal heat insulation board for smoke exhaust duct according to claim 1, characterized in that: In the raw material processing process described in step A, the proportion of silicon dioxide powder is 50%-70%, and the proportion of aluminum oxide is 30%-50%, calculated by the total weight percentage after mixing.

3. The inorganic silicon crystal heat insulation board for smoke exhaust duct according to claim 2, characterized in that: In the mixing and stirring process described in step B, calculated by the total weight percentage after mixing, the ratio of the silica powder and the alumina mixture is 50%-70%, the ratio of the silicate binder is 15%-25%, the ratio of the mineral fiber is 10%-15%, and the ratio of the expanded perlite is 5%-10%.

4. The inorganic silicon crystal heat insulation board for smoke exhaust duct according to claim 3, characterized in that: In the mixing and stirring process described in step B, the silicate binder is a mixture of one or more of sodium silicate, potassium silicate, lithium silicate and magnesium silicate; Mineral fiber is a mixture of one or more of rock wool fiber, glass fiber, ceramic fiber and carbon fiber; Expanded perlite is made by mixing an expander, an adhesive, an additive, perlite particle filler and water.

5. The inorganic silicon crystal heat insulation board for smoke exhaust duct according to claim 1, characterized in that: In the surface treatment and inspection process described in step F, a surface grinder / sand belt machine is specifically used to grind the surface of the plate to a flatness within ±0.5 mm and a surface roughness below 1.0 μm, thereby reducing heat conduction losses and improving thermal insulation performance.

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