Self-pressurizing liquid nitrogen tanks are essential for storing liquid nitrogen in central laboratories. They operate by utilizing a small amount of liquefied gas inside the container to generate pressure, automatically releasing liquid to replenish other containers.
For example, the Shengjie Liquid Nitrogen Replenishment Series offers the latest in high-performance low-temperature liquid nitrogen storage containers. These products are primarily designed for laboratory and chemical industry users for liquid nitrogen storage or automatic replenishment.
Featuring a stainless steel design structure, they can withstand the harshest operating environments while reducing evaporation loss rates. Each product in this series comes equipped with a booster valve, drain valve, pressure gauge, safety valve, and vent valve. Additionally, all models are fitted with four movable universal casters for easy mobility between different locations.
In addition to replenishing liquid nitrogen tanks, these self-pressurizing liquid nitrogen tanks can also replenish each other. To do so, prepare tools such as wrenches in advance. Before injecting liquid nitrogen, open the vent valve, close the booster valve and drain valve, and wait for the pressure gauge reading to drop to zero.
Next, open the vent valve of the tank that requires replenishment, connect the two drain valves with an infusion hose, and tighten them with a wrench. Then, open the booster valve of the liquid nitrogen storage tank and observe the pressure gauge. Once the pressure gauge rises above 0.05 MPa, you can open both drain valves to replenish the liquid.
It's important to note that when injecting liquid nitrogen for the first time or after extended periods of non-use, it's advisable to first inject 5L-20L of liquid nitrogen to cool the container (approximately 20 minutes). After the inner liner of the container has cooled down, you can formally inject the liquid nitrogen to avoid excessive pressure caused by high inner liner temperatures, which can lead to liquid nitrogen overflow and damage to safety valves.
During operation, personnel should wear appropriate protective gear to prevent injury from splashing liquid nitrogen. When charging liquid nitrogen into self-pressurizing liquid nitrogen tanks, for safety reasons, they should not be completely filled, leaving approximately 10% of the container's geometric volume as gas phase space.
After completing the liquid nitrogen replenishment, do not immediately close the vent valve and install the locking nut to prevent frequent jumping of the safety valve due to low temperatures and damage. Allow the tank to stand still for at least two hours before closing the vent valve and installing the locking nut.
Post time: Apr-02-2024
