Expert Consulting: Stainless Steel Nitrogen Storage Vessels

Liquid nitrogen (LN₂) is an essential medium in numerous industrial, medical, and scientific applications. From the cryopreservation of biological samples to food freezing and high-performance cooling processes in industry – efficient storage and dispensing of LN₂ require specialized containers that meet both safety and performance standards.

The Auguste Cryogenics AC Liquid Cylinder Series offers a technically advanced solution with various pressure classes, which we analyze in detail in this comprehensive guide. This article will assist you in selecting the optimal model for your specific requirements.

The inner and outer vessel are constructed of top grade stainless steel. The ultra-low evaporation rates are ensured by a special super insulation and the Auguste Cryogenics GOLD Standard vacuum technology.

Of course all cylinders of the Auguste Cryogenics AC Liquid Cylinder Series comply with the European Directive 2010/35/EU for transportable pressure equipment (TPED), making them flexible and valuable elements in the liquefied gases supply chain in various industrial, medical, research and food production applications.

The AC Liquid Cylinders from Auguste Cryogenics are available in several sizes ranging from 70 to 240 liters usable volume and can be equipped with or without pressure build-up. These are transportable units designed and built to robust construction standards, intended for transport when filled. They are either designed for low-pressure cryogenic filling and liquid withdrawal or for high-pressure gas distribution.

Key Features of the Containers:

• Material: Stainless steel inner and outer vessels

• Insulation: Multi-layer super insulation

• Certifications: Compliant with TPED 2010/35/EU for transportable pressure equipment

• Safety Systems: Safety valve set to | Max. allowed working pressure (MAWP):

  • 1.5 | 10 bar for N₂, O₂, Ar

  • 15.9 | 15.9 bar for N₂, O₂, Ar

  • 24 | 24 bar for N₂, O₂, Ar, CO₂, and N₂O

• Connections:

  • CGA 295 for N₂, Ar, CO₂, and N₂O

  • CGA 540 for O₂

The liquid nitrogen withdrawal process follows clear thermodynamic laws. The saturation vapor pressure in the container directly determines the potential withdrawal rate. In low-pressure models (LP), pressure increase occurs through natural evaporation ("self-pressurization"), while PB/MP/HP systems use active pressure regulation circuits.

The series offers four technically differentiated systems with specific pressure profiles:

*Pressure build-up time: Approximate time until stable withdrawal capability after starting the withdrawal process (at 20°C ambient temperature).

Another important consideration when selecting the right nitrogen storage cylinder is its size and mobility options. Depending on the specific requirements of your application, you need to consider the appropriate volume and handling flexibility of the cylinder. Models with casters offer high mobility and can be easily moved between locations, while stationary models without casters are suitable for applications where the cylinder is installed in a fixed location. 

The following table provides an overview of the different models in the Auguste Cryogenics AC Liquid Cylinder Series, their volumes, mobility options, and pressure ratings.

Note: Containers without wheels require a special transport cart for movement.

Low Pressure (LP) Models:

• 30-60 minutes waiting time until withdrawal capability

• Requires manual pressure build-up via valves

• Available in desired working pressure from 1.5 to 10 bar

• Withdrawal rate increases linearly with pressure (1-10 bar)

• Maximum rate achieved only at 10 bar

• Available in 120, 160, 180, and 240-liter variants

Pressure Building (PB) Models:

• 10-20 minutes waiting time until withdrawal capability

• Integrated automatic pressure build-up

• Available in desired working pressure from 1.5 to 10 bar

• Stable working pressure ensures consistent withdrawal

• Available in 70, 120, 180, and 240-liter variants

Medium Pressure (MP) Models:

• Very quick withdrawal capability (<5 min lead time)

• Integrated automatic pressure build-up

• Constant 15.9 bar working pressure

• Available only in 170-liter variant

High Pressure (HP) Models:

• Immediate withdrawal capability

• Integrated automatic pressure build-up

• Constant 24 bar working pressure

• Available in 170, 200, and 240-liter variants

The optimal choice of an LN₂ container depends on your specific requirements. Consider these four key points when selecting the right model:

• Pressure Requirements: The selection of the appropriate model depends on the demands of your system and the required pressure. Choose a model that can reliably provide the desired operating pressure based on your needs.

• Waiting Times for Withdrawal Capability: The waiting time for withdrawal capability depends on your workflow and how much time you can allocate for LN₂ withdrawal. If you can plan ahead, an LP model may suffice. However, if you require spontaneous withdrawals, a PB model that offers quicker availability is recommended.

• Size: The right size depends on your LN₂ consumption in your operations. The models vary in volume, so you can choose the appropriate model with the right capacity based on withdrawal needs and frequency of use.

• Mobility: If you need to move your containers regularly within your operation, models with wheels are the best choice. For stationary applications, models without wheels are available, but they can easily be moved with a special transport cart.

For individual advice tailored to your specific use case, we are happy to assist. Contact us for a detailed process analysis and customized system recommendations.

Cryonos – Your Expert Partner for High-Quality Cryogenic Solutions.