Liquid Nitrogen Tank: Essential Guide for Laboratory Use

This article will explore everything you need to know about liquid nitrogen tanks, including types, applications, storage considerations, safety protocols, and maintenance.

What Is a Liquid Nitrogen Tank?

A liquid nitrogen tank, also known as a dewar or cryogenic tank, is a specialized container designed to hold liquid nitrogen at extremely low temperatures (-196°C or -320°F). Liquid nitrogen is widely used in laboratories due to its ability to maintain stable cryogenic conditions, making it ideal for preserving biological specimens, conducting chemical reactions, and performing material tests.

Types of Liquid Nitrogen Tanks

There are several types of liquid nitrogen tanks, each designed for specific applications. These tanks come in various sizes, from small portable dewars to large industrial tanks capable of storing thousands of liters of liquid nitrogen.

1. Storage Dewars

   These are the most common type of liquid nitrogen tanks used in labs. Storage dewars are designed to hold and preserve samples over long periods. They typically have thick insulation and are available in various sizes, depending on the volume of liquid nitrogen required.

2. Transport Dewars

   Transport dewars are built to move liquid nitrogen from one location to another. They have reinforced casings and a more robust design to handle the stress of transportation. These tanks are critical when samples need to be transferred between labs, research facilities, or industrial sites.

3. Pressurized Liquid Nitrogen Tanks

   These tanks are used in industrial applications where liquid nitrogen needs to be dispensed under pressure. They are equipped with specialized valves to regulate the flow of nitrogen, ensuring controlled delivery for processes such as cryogenic freezing or cooling.

4. Cryoshippers

   Cryoshippers are designed for safely transporting biological samples across long distances. They maintain cryogenic temperatures for days and are used by biotech companies, hospitals, and research institutions to ship sensitive materials like tissues, vaccines, and cells.

Key Features to Consider

When selecting a liquid nitrogen tank or other types of cryogenic storage, several features should be taken into account to ensure it meets the needs of your laboratory:

1. Capacity
   Tanks range in capacity from a few liters to several hundred liters. Choose a size that fits your lab’s requirements, considering both storage and usage demands.

2. Insulation
   Effective insulation is critical for minimizing nitrogen loss due to evaporation. Double-walled stainless steel with vacuum insulation is a common design for maximizing efficiency.

3. Durability
   Materials like stainless steel or aluminum provide longevity and resistance to corrosion, which is essential for maintaining tank integrity over time.

4. Safety Features
   Look for tanks with pressure relief valves, lockable lids, and protective outer shells. Safety is paramount when handling cryogenic liquids due to their extreme temperatures.

5. Portability
   If your lab frequently moves liquid nitrogen, choose a model with wheels or handles for easy transport. Larger units may require forklifts or other handling equipment.

Applications of Liquid Nitrogen Tanks

Liquid nitrogen tanks play a critical role in numerous industries and research fields:

1. Biological Sample Preservation
   Liquid nitrogen tanks are widely used in laboratories to store biological samples such as DNA, blood, tissues, and cell cultures. Cryogenic storage ensures long-term viability and minimizes degradation.

2. Cryosurgery and Medical Treatments
   In the medical field, liquid nitrogen is used for cryosurgery to remove skin lesions, warts, and certain types of cancers. It’s also applied in cryopreservation of reproductive cells, such as sperm and embryos.

3. Material Testing and Engineering
   In engineering, liquid nitrogen is used for material testing, such as impact tests at extremely low temperatures. It also assists in machining processes for metals, plastics, and rubbers.

4. Cryogenic Freezing in Food Processing
   Liquid nitrogen is used for flash freezing foods, ensuring that products retain their freshness and texture. It's commonly used in food research and processing industries.

5. Chemical Reactions and Research
   Liquid nitrogen can control and stabilize chemical reactions, making it essential for research in physics, chemistry, and material sciences.

Storage and Maintenance Best Practices

Proper storage and regular maintenance are key to ensuring the longevity of your liquid nitrogen tanks. Follow these best practices:

1. Store in a Well-Ventilated Area
   Since nitrogen displaces oxygen, liquid nitrogen tanks should be stored in a well-ventilated area to prevent oxygen depletion and potential asphyxiation hazards.

2. Regular Inspection and Cleaning
   Regularly check the tank for signs of wear, such as cracks or dents, and clean it according to the manufacturer's guidelines. Leaks can cause dangerous spills and nitrogen loss.

3. Monitor Nitrogen Levels
   Use level indicators to monitor the liquid nitrogen in the tank. It’s important to maintain sufficient levels to avoid exposing samples to warmer temperatures.

4. Pressure Relief Valves
   Ensure that the pressure relief valve is functioning correctly to prevent over-pressurization, which can be hazardous.

5. Avoid Overfilling
   Never overfill the tank, as this can lead to pressure build-up and potential failure of the tank. Follow the manufacturer’s guidelines for maximum capacity.

Safety Considerations

Handling liquid nitrogen requires stringent safety measures to avoid injury:

1. Personal Protective Equipment (PPE)
   Always wear protective gear such as cryogenic gloves, face shields, and long sleeves to protect against frostbite or burns.

2. Use Proper Handling Tools
   Never touch liquid nitrogen or its container with bare hands. Use specialized tools designed for handling cryogenic materials.

3. Be Aware of Oxygen Displacement
   Nitrogen is an inert gas, and in confined spaces, it can displace oxygen and pose a risk of asphyxiation. Always ensure proper ventilation when using or storing liquid nitrogen tanks.

4. Train Personnel
   Ensure that all personnel who handle liquid nitrogen are properly trained in its safe use and emergency procedures.

Summary

Liquid nitrogen tanks are an indispensable part of laboratory operations, providing essential storage and transport capabilities for temperature-sensitive materials. Whether used for biological sample preservation, material testing, or medical treatments, understanding the various types and applications of these tanks is crucial for safe and efficient lab operations.

By selecting the right tank for your lab’s needs, following best practices for maintenance and safety, and keeping your personnel well-trained, you can ensure the longevity and optimal performance of your liquid nitrogen tank.

For more information on liquid nitrogen tanks or to explore available models for your lab, visit LabX.com. LabX offers a wide range of tanks from trusted manufacturers, ensuring that your laboratory stays equipped with the latest cryogenic technology.