Silica Aerogels and Industrial Applications

1. The magical microstructure advantages of aerogel and composite absolute felt

Silica Aerogel is a solid material with a three-dimensional network nanoporous structure. With its special structure, it has held 15 Guinness World Records. Among these excellent properties, the three notable features of high porosity, small pore size, and ultra-low thermal conductivity have been applied on a large scale by humans.

More than 90% of the nanoporous structure of silica aerogel is "still" air, and the pore size is concentrated between 20-30nm, which is much smaller than the mean free path (70nm) of air molecules. On the other hand, the "labyrinth"-like three-dimensional network of silica constitutes an "infinitely long" path, which minimizes the two major heat transfer methods of air convection and solid heat conduction, and the aerogel is super strong This is the secret of thermal insulation. The thermal conductivity of aerogel can be as low as 0.015w/(m.k), which is far less than that of dry air at room temperature.

Aerogel composite insulation felt is composed of silica aerogel and glass fiber material. A large number of millimeter-scale holes in the original fiber material are replaced by aerogel with lower thermal conductivity, and the surface of the fiber is covered by aerogel , effectively isolate the wire from the wire, on the one hand, the air convection heat transfer is greatly reduced, and on the other hand, the solid thermal bridge is reduced!

Traditional inorganic thermal insulation materials rely on fiber filaments to block air movement for insulation: on the one hand, the direct contact between filaments increases solid heat transfer, on the other hand, millimeter-scale pores cannot prevent air heat convection, especially when the temperature rises and air molecules After exercising.

2. Overview of the advantages of aerogel composite insulation felt
1) Wide application temperature range: from -200°C to 650°C, all are suitable for aerogel application temperature range;
2) Ultra-low thermal conductivity: the thermal conductivity at room temperature is lower than 0.020w/(m.k), the thermal conductivity at 300°C is lower than 0.036w/(m.k), and the thermal conductivity at high temperature is only 1/3-1/4 of that of traditional materials ;
3) Ultra-thin thickness: Due to the ultra-low thermal conductivity at high temperature, the thickness of use is only 1/3-1/4 of that of traditional materials, and the pipes and equipment are significantly slimmed down, saving energy and providing enough maintenance space;
4) Energy saving of more than 40%: Since the thickness of the used material is greatly reduced compared to the traditional material, the heat dissipation area is reduced by more than 40%, so under the same surface temperature, the line heat dissipation loss of the traditional material is reduced by more than 40%;
5) Overall super hydrophobicity: The re-molecular structure is bonded with hydrophobic groups, and the overall hydrophobicity rate can reach 98%, which can maintain the hydrophobicity for life and effectively prevent corrosion under the insulation layer (CUI), which greatly prolongs the use of pipelines and equipment. life;
6) Long-lasting and stable performance: Nano-pore special structure, compressive and tensile resistance, extremely stable performance, no fear of stepping on settlement and other external forces, little attenuation in 25 years, and a stable energy-saving income of more than 40% per year; traditional material performance declines seriously year by year , the attenuation is more than half in 5 years, and the energy saving income is less than 10%;
7) Class A non-combustible: it reaches the class A non-combustible level in the international GB8624-2012 "Classification of Combustion Performance of Building Materials and Products", which is very suitable for petroleum, refining, chemical synthesis and other working conditions with high fire protection requirements;
8) The comprehensive energy-saving benefits are obvious: Compared with traditional materials, the initial investment is high, but the aerogel thermal insulation project relies on energy-saving, and can recover part of the higher income within 2 years, and recover all the thermal insulation investment within 5 years. %above;
9) Easy to use: the aerogel felt is light and thin, easy to cut, easy to store and transport, and easy to construct;
10) Repeated use: No deformation after disassembly of aerogel, the effective life is more than 5 times that of traditional materials, and it can be reused, which greatly saves maintenance costs;
11) Green and environmental protection: aerogel can be recycled and is green and environmentally friendly; traditional materials cannot be reused, and they become waste after repair or replacement, and the disposal cost is extremely high.

3. Typical industrial applications of aerogel composite insulation felt
1) Heat preservation and energy saving of pipelines for high temperature steam, heat transfer oil, process medium and other fluids
High-temperature steam, heat transfer oil and process fluid medium pipelines are vital equipment in the fields of thermoelectricity, oil refining, chemical industry, medicine, etc. The pipelines are exposed to the air all the year round, and their heat loss accounts for the vast majority of the natural heat loss in the entire plant area, and the pipelines transported The energy retention rate of the medium is directly related to the quality and quantity of the product, so the selection of excellent thermal insulation materials is very important, so aerogel is a high-quality choice.

2) Thermal insulation of reactors, towers, steam turbines, storage tanks, flues and other equipment

3) Cold storage of equipment and pipelines in cryogenic fields such as liquid ammonia, liquid oxygen, liquid nitrogen, and LNG

4) Other industrial uses such as spinning tunnels, oil wellheads, ship cabins, vehicle bodies, power batteries, etc.

4. Summary
Although the initial investment of aerogel insulation is higher than that of traditional materials, its many excellent properties, lasting energy-saving benefits, and significant green environmental protection advantages make it a comprehensive cost-effective energy-saving product, which can solve many problems for owners. The trouble of heat preservation and energy saving brings long-term energy saving benefits.