Tank base systems for atmospheric ammonia storage tanks
Thermal insulation tank base solutions for liquid ammonia storage in atmospheric tanks operating at below ambient temperatures. Our tank base systems provide adequate compressive strength to carry the tank and its contents while limiting possible heat transfer to protect the structural material against extreme temperatures.
While ammonia is a valuable compound for a wide range of applications, mishandling or improper storage can lead to catastrophic consequences.
1. Toxicity
Ammonia is highly toxic, posing serious health hazards upon inhalation or skin contact. Exposure to even low concentrations can cause irritation, respiratory problems, and in severe cases, fatal outcomes.
2. Corrosiveness
Liquid ammonia is corrosive to many metals, which can lead to structural damage or leakage in storage vessels or connecting pipework over time. Corrosion compromises the integrity of the storage tank, increasing the likelihood of accidents with the risk of possible environmental contamination or acute danger for people working in the vicinity of the storage area.
3. Flammability
Although not highly flammable in its liquid form, ammonia can ignite under specific conditions, such as in the presence of certain catalysts or at elevated temperatures. This flammability poses a significant fire risk if not properly contained.
specifying the appropriate insulation material
When specifying the appropriate insulation material for refrigerated ammonia tanks, these important considerations should be taken into account. Next to the material properties of ammonia, the storage conditions also have a big impact on which insulation material is suited for this application. Some considerations include:
1. Impermeability
Regardless if the tank foundation is built on piles or straight on soil, the bottom plate should be protected by an impermeable insulation material to prevent any moisture in liquid or vapor form from penetrating the concrete foundation and reaching the steel bottom plate as this could lead to issues with corrosion with risk to the structural integrity of the tank.
Additionally, insulation materials that are not completely impermeable risk absorbing any liquid ammonia or ammonia vapors. A saturated insulation material increases the risk of heat leak into the tank bottom with a consequent increase in vaporization. Furthermore, insulation that is saturated with ammonia can lead to issues related to stress corrosion cracking of the carbon steel tank bottom plate.
2. Compressive strength
The material used for the storage tank bottom insulation should be able to withstand high loads without deforming over time.
Lack of compressive strength can result in an unacceptable settlement which may result in a loss of thermal insulating capacity, ground heaving and foundations being brought to temperatures that could result in failures.
In the case of uneven subsidence, rupture in the tank’s steel bottom could result in a subsequent loss of product which in the case of poisonous ammonia would have major hazardous consequences.
3. Thermal performance
Often the tank is built standing on piles but tanks have also been placed directly on foundations that are in direct contact with the soil.
In areas where water is available in the ground it is important to prevent the problem of frost heave by shielding the ground from the freezing temperature of the liquid ammonia within the tank.
This is accomplished by building the tank on top of a layer of insulation and with heat coils installed between the insulation and the ground to compensate for heat loss from the ground into the tank so the ground can be maintained at above freezing temperatures.
The dedicated tank base insulation under the ammonia tank acts as a barrier that protects structural materials against extreme temperatures that could otherwise cause them to become brittle with possible mechanical problems as a consequence.
The specified tank base insulation material should boast excellent thermal insulation properties, effectively minimizing heat transfer and maintaining consistent temperatures within storage vessels.
This not only enhances energy efficiency but also helps prevent temperature fluctuations that could compromise the stability of liquid ammonia.
Given these inherent risks, it's imperative to implement robust safety measures, including appropriate insulation solutions with a suitable material, to mitigate the potential hazards associated with liquid ammonia storage.
Closed-cell FOAMGLAS® cellular glass insulation is the industry standard for insulating the tank bottoms of liquid ammonia storage tanks due to its combination of material properties.
FOAMGLAS® cellular glass insulation
for insulating liquid ammonia storage tank bottoms*
1. High compressive strength
From the standpoint of compressive strength, FOAMGLAS® insulation is remarkable in many respects. Properly designed FOAMGLAS® insulation systems can withstand high loads with little or no deformation. Cellular glass insulation retains its compressive strength over time without any influence of below ambient temperatures.
2. Impermeability and moisture resistance
Cellular glass insulation is impermeable to moisture in liquid or vapor form. This prevents liquid ammonia or ammonia vapors to ingress and subsequent cause corrosion of metal surfaces. The closed-cell structure also helps to ensure long-term moisture resistance, which helps to maintain material performance and prevent any boil-off issues or other risks associated with saturated insulation materials.
3. Chemical Inertness
Cellular glass insulation is chemically inert and resistant to a wide range of corrosive substances, including liquid ammonia. Its non-reactive nature supports long-term stability and helps prevent degradation, safeguarding the integrity of the material and the storage tank it is applied to. Its inertness helps protect the steel tank against stress corrosion cracking which adds to overall tank safety and minimizes the need for expensive repairs.
4. Low Thermal Conductivity
Closed-cell cellular glass insulation boasts excellent thermal insulation properties, effectively minimizing heat transfer and support maintaining consistent temperatures within storage tanks. This not only enhances energy efficiency but also helps prevent temperature fluctuations that could compromise the stability of liquid ammonia.
5. Non-Flammable
cellular glass insulation is non-combustible, making it inherently safe for use in environments where flammable substances are present. It does not contribute to fire propagation, reducing the risk of fire-related incidents significantly.
* The material's performance is in conformity with the declared values in the DOP.
Typical Configuration
for low temperature tank base applications:
- Multi-layer system of FOAMGLAS® HLB insulation.
- PITTCOURSE™ DPC interleaving membrane or other appropriate interleaving for the application temperature range.
Legal notice
The information relating to the products and systems contained on this website is provided in good faith and for general information purpose only. Such information is in any event subject to our product’s legal notice, the content of which users are invited to acknowledge under the following link: Legal Notice