Aerogel felt is a new kind of insulation material made of aerogel matrix composite reinforced fiber. Aerogel felt can not only provide low thermal conductivity, but also reduce the total insulation thickness compared to some traditional industrial insulation materials. Although low thermal conductivity is the basic property of thermal insulation products, aerogel felt has other properties: hydrophobicity, mechanical properties, durability, and so on.

These performance characteristics have led to the adoption of the material in the industrial market: some of the world's largest refineries and petrochemical companies are using aerogel felt insulation. These applications can be found in pipes as well as equipment and tanks, including steam pipes, reactors, bitumen and melted sulfur tanks, and from coke barrels to heat exchangers, lighting pipes, flues, submarine pipes, and more. Sales of aerogel felt materials continue to grow each year in the United States and overseas. This growth includes the use of aerogel felt in cryogenic applications.

1, aerogel felt in low temperature applications

While cryogenic applications represent only a small portion of the industrial insulation market, insulating cryogenic pipes and equipment presents special technical challenges for applications on or under the environment. The low temperature threshold is generally considered to be at or below -100 ° C. (-74 ° C), absolute zero - the theoretical temperature at which molecular motion comes closest to stopping - marks the lower bound effective at -460 ° C (-273 ° C). Extreme temperature differences (T) under normal ambient conditions) and pipes and equipment (T operating at low temperatures presents three major challenges for any insulation layer: extreme heat transfer requires a large insulation thickness, strong steam drive to cold surfaces, and severe shrinkage within containers or pipes containing cryogenic liquids. These performance requirements limit the amount of suitable insulating material. However, elastic aerogel felt is suitable to meet these challenges.

Although aerogel felt insulation is hydrophobic and does not allow liquid water to pass through at ambient pressure, it is water vapor permeable. Steam entry is impeded by an integral vapor barrier film found on each overburden. But importantly, the unique nanopore inhibited ice formation inside the aerogel layer.

Structure of aerogel. Silicon aerogels are characterized by pore sizes ranging from 5 to 100 nanometers, with pore diameters of about 12 nanometers found in the aerogel structure of the elastic aerogel felt. To provide a sense of scale,1 nanometer is equal to one millionth of a meter (10) -9)- about 10 carbon atoms wide, while the diameter of a red blood cell is about a 10-5 meter. A water molecule is about 0.29nm in diameter. The formation of ice crystals requires 275 water molecules, more than the pore diameter of the aerogel. The space inside the aerogels is too small for enough water molecules to aggregate to form ice crystals. When there is a gap in the steam barrier of the insulating layer, ice formation is localized and superficial. In fact, it is the highly complex structure of this nanopore that makes the aerogel's thermal conductivity very low. Because the pores are about 5,000 times smaller than the cells in doisocyanate foam or cell glass, heat transfer is reduced.

For low temperature applications, it is important that the insulation of aerogel felt remains flexible at minimum low temperature ---- minimum temperature ---- up to -321 ° C. (-196℃). This unique property allows the use of aerogel felt without the need to shrink the joints, which can both save considerable installation costs and avoid the potential risks of steam penetration and heat gain that these joints may carry in low-temperature insulation systems. The relatively low glass transition temperature of aerogel felt ---- the ability to remain resilient at very low temperatures ---- allows the material to accommodate thermal shock and provide considerable low temperature splash protection.

2, low temperature pipeline and equipment installation

The thickness of aerogel insulation materials is usually 5 mm and 10 mm. The pipe surface is coated in multiple layers with traditional "cigarette" packaging to achieve the desired total insulation thickness. In order to ensure that the insulation layer has no joint, the circumferential joint between the rolled felt parts is staggered. Aerogel felt can be temporarily secured to the pipe surface with fiberglass reinforced packaging tape. When installing blankets on large or irregular surfaces, an adhesive spray suitable for use on polystyrene is usually used.

The aerogel felt is equipped with a monolithic, factory-laminated vapor barrier film. This provides significant redundancy to the system, as each layer includes this integral vapor barrier film. The inner layer of the blanket closest to the surface of the pipe or equipment is not sealed, and the interface temperature between the surface of the cryogenic pipe or equipment and the insulation layer is lower than the recommended service temperature for common industrial adhesives and sealants. Once the appropriate layer has been applied within the range of use of the sealing tape to achieve the projected interface temperature, the complete vapor barrier film is sealed with foam-faced butyl tape to form a secondary vapor barrier film in the system. As mentioned above, no shrinkage joint is required. Vacuum stops are used on both sides of the pipe support to isolate any possible system damage. A primary vapor barrier, such as butyl rubber on a foam surface, is then installed, followed by a mechanical protective cover, such as aluminum or striped stainless steel, or a non-metallic system, such as glass reinforced plastic (GRP).

Installing elastic aerogel felt on cryogenic pipes and equipment is fairly simple. In some cases, the installation time can be significantly reduced compared to traditional rigid insulation materials.

3, low temperature application

Aerogel felt insulation is utilized in a number of low-temperature applications, primarily in certain parts of the LNG service. LNG facilities, which serve as liquefaction (export) or regasification (import) terminals, operate primarily at -165 ° C and are the largest cryogenic plants.

Aerogel felt allows to reduce the risk of damage to pipes and equipment during transportation or installation. For example, aerogel felt has been used in areas where LNG is loaded with weapons at risk of mechanical damage due to falling ice. As with other types of insulation used in cryogenic applications, pre-insulation of pipes and equipment is possible, and the use of aerogel felt is also practical. Pre-insulated piping and equipment reduces the total installation cost and compresses the overall project schedule by moving most of the insulation to a lower cost location under more controlled assembly line conditions.

The continuous flexibility of the gas condensate layer at low temperatures eliminates the shrinking joints that are usually required for low temperature insulation. Shrink joints in low temperature insulation systems are complex and require highly skilled craftsmen. The natural flexibility of aerogel felt also makes it a solution for flexible pipes such as elastic joints in large pipes. The blanket maintains its flexibility even at low temperatures, which also eliminates thermal shock damage to the insulation material, while also enabling the material to provide low-temperature splash protection for insulated pipes and equipment.

Aerogel insulation materials are known for their low thermal conductivity. Able to prevent heat transfer, also for the material passive fire protection (PFP) and acoustic properties. In low temperature applications, aerogel insulation properties are good in swimming pools and jet fire protection in application thickness.

On facilities that limit the field footprint, aerogel insulation can meet the required PFP requirements, often with the same total insulation thickness specified for condensation control. Aerogel felt, with a total installed thickness of 80 mm, which is the thickness common in LNG services to control condensation, can provide a pool of water for more than 2 and a half hours.

Protection (UL1709) and 60 minutes of jet fire protection. This has become an important consideration in LNG facilities, with NFPA59A guidelines requiring minimum easements between storage and processing areas. In situations where space may be limited, such as in the expansion or renovation of an existing facility, or in offshore or offshore facilities, the insulators' ability to provide the necessary private sector Funding and Partnerships Division is critical to the success of the project. Similarly, the underlying physical structure of silica gel provides a flexible gas-condensate layer with considerable acoustic benefits. By adding mass-loaded vinyl aerogel felt, aerogel can meet the requirements of ISO15665 classes A, B and C, as well as the more stringent "shell D" insertion loss requirements. This can usually be done with the same total insulation thickness specified for condensation control in cryogenic services. Therefore, aerogel felt insulation can uniquely provide thermal, acoustic and PFP in a single application.

Insulated pipes and equipment for cryogenic services can be complex and time consuming, requiring a degree of experience that is not required in applications outside of low temperatures or environments. As oil and gas exploration and production moves to more remote locations and offshore fields, ease of installation and logistics is becoming increasingly important. Aerogel insulation in blanket form offers a fairly simple installation, reducing the impact of qualified labor shortages in remote areas. The logistics are also simplified because the aerogel is long-lasting in Taweel. Aerogel felt is manufactured and packaged in rolls, any diameter can be from the rolls. Insulation materials for pipes, equipment, valves and other accessories can be manufactured on site. Both streamline the supply chain, allowing irregular and atypical parts to be completed quickly on site.