Liquid nitrogen storage dewars are essential tools used in laboratories, hospitals, and research facilities for storing and transporting liquid nitrogen. These dewars are designed to safely contain the extremely cold liquid nitrogen, which has a boiling point of -196 degrees Celsius (-321 degrees Fahrenheit). In this article, we will discuss the functions, types, features, and best practices for using liquid nitrogen storage dewars.
Functions of liquid nitrogen storage dewars:
Liquid nitrogen storage dewars serve two primary functions: storing and transferring liquid nitrogen. These dewars are vacuum insulated containers that can keep liquid nitrogen at its ultra-low temperature for extended periods. The insulation helps minimize evaporation, ensuring that the stored liquid nitrogen remains at the desired temperature.
Types of liquid nitrogen storage dewars:
There are two main types of liquid nitrogen storage dewars: pressurized and non-pressurized. Pressurized dewars are equipped with a pressure buildup valve that allows for controlled release of pressure to prevent over-pressurization. Non-pressurized dewars, on the other hand, rely on the static pressure of the liquid nitrogen to maintain the desired temperature.
Features of liquid nitrogen storage dewars:
Liquid nitrogen storage dewars come in various sizes, ranging from small, portable models to large, stationary units. They are typically made of stainless steel or aluminum for durability and corrosion resistance. Some dewars are equipped with caster wheels or handles for easy transportation, while others have built-in pressure gauges for monitoring internal pressure levels. Additionally, most dewars have a venting system to release excess pressure and prevent dangerous build-up.
Best Practices for Using Liquid Nitrogen Storage Dewars:
When using liquid nitrogen storage dewars, it is essential to follow certain best practices to ensure safety and efficiency. Here are some tips for using liquid nitrogen storage dewars:
1. Handle with care: Liquid nitrogen is extremely cold and can cause frostbite or burns upon contact. Always wear appropriate protective gear, such as gloves and goggles, when handling liquid nitrogen or dewars.
2. Inspect regularly: Check the dewar for signs of damage or wear, such as cracks, leaks, or pressure irregularities. Any abnormalities should be addressed promptly to prevent accidents.
3. Fill properly: When filling the dewar with liquid nitrogen, do not overfill it. Leave some room for expansion to prevent over-pressurization and potential leaks.
4. Monitor pressure: Keep an eye on the pressure gauge to ensure that the internal pressure is within safe limits. If the pressure exceeds the recommended levels, vent the excess gas to avoid a dangerous buildup.
5. Store in a well-ventilated area: Liquid nitrogen releases nitrogen gas as it evaporates, which can displace oxygen and create a risk of asphyxiation in poorly ventilated spaces. Store dewars in well-ventilated areas to prevent this hazard.
In conclusion, liquid nitrogen storage dewars are vital tools for storing and transporting liquid nitrogen safely and efficiently. By understanding their functions, types, features, and best practices, users can make the most of these essential containers in various scientific and medical settings. Whether you are working in a laboratory, hospital, or research facility, liquid nitrogen storage dewars play a crucial role in maintaining the integrity of your samples and experiments. Remember to handle liquid nitrogen and dewars with care, and always follow proper safety procedures to prevent accidents and ensure smooth operations.