Views:88 Author:Site Editor Publish Time: 2019-10-29 Origin:Site
In the era of rapid scientific development, liquid nitrogen tanks are essential equipment in most laboratories, such as sperm and egg cryopreservation for animal artificial insemination and cell cryopreservation, which need cryopreservation with liquid nitrogen. The use of liquid nitrogen tanks provides basic guarantee for human beings to explore unknown life.
Liquid nitrogen tanks can generally be divided into liquid nitrogen storage tanks and liquid nitrogen transport tanks. Liquid nitrogen storage tanks are mainly used for static storage of indoor liquid nitrogen, and should not be used for long-distance transportation under working conditions. In order to meet the requirements of transportation, special seismic design has been made for liquid nitrogen transport tanks. In addition to being statically stored, it can also be used for transportation under the condition of filling liquid nitrogen without violent collision and vibration.
1. The Inspection Before Use
Before filling the liquid nitrogen container, we should first check whether the outer casing is recessed or not, and whether the vacuum exhaust port is intact. If it is damaged, the degree of vacuum will decrease. In severe cases, the intake air can not keep warm, and the upper part of the tank will be frosted, and the value of continued use will be lost. Next, check the inside of the tank. If there is any foreign matter, it must be taken out to prevent the inner tank from being corroded.
2. Filling of Liquid Nitrogen
Be careful when filling liquid nitrogen. For the new tank or the tank in the dry state, they must be slowly filled and pre-cooled. In case the temperature drops too fast, the liner will be damaged. Do not pour liquid nitrogen on the vacuum vent when filling liquid nitrogen to avoid the vacuum decreasing.The cover plug is made of adiabatic material, which can not only prevent liquid nitrogen evaporation, but also play the role of fixing lifting cylinder. The wear and tear of the switch should be minimized to prolong its service life
3. Storage of Liquid Nitrogen in Liquid Nitrogen Tanks
When storing the liquid medium in the liquid nitrogen tank, be sure to close the inlet/drain valve and the pressure increasing valve, and open the vent valve.
When transporting liquid nitrogen medium in liquid nitrogen tank, it is necessary to ensure that the valve's switching state is the same as that in storage. Please put the base of the packing box under the container seat, and fix the container of liquid nitrogen tank reliably on the car with rope, so that the liquid nitrogen tank will not shake during transportation.
5. Infusion of Liquid Nitrogen in Liquid Nitrogen Tanks
If you want to export liquid nitrogen from a liquid nitrogen tank, follow the following procedures:
(1) Close the vent valve.
(2) Open the booster valve.
(3) Observe the pressure gauge. When the pressure rises to 0.05 MPa, open the drain valve.
6. The Inspection During Use
Check frequently during use. It can be observed by eyes or touched by hands. If frost is found on the outside, it should be stopped. Especially when the inner wall of the neck tube is frosted and icing, it is not advisable to use a knife to scrape it to prevent the inner wall from being damaged, resulting in poor vacuum. Instead, liquid nitrogen should be taken out to melt naturally.
1. Placement of Liquid Nitrogen Tanks
The liquid nitrogen tank should be stored in a well-ventilated and cool place, and should not be exposed to direct sunlight. Liquid nitrogen tanks are not allowed to tilt, horizontal, inverted, stack, impact each other or collide with other objects, so they should be palced lightly and kept upright all the time.
2. Cleaning of Liquid Nitrogen Tanks
When the liquid nitrogen tank is not in use, rinse it with clean water, drain the water, blow it dry with a blower, and place it in room. After the liquid nitrogen in the liquid nitrogen tank is volatilized, the remaining substances will melt quickly and become liquid substances attached to the inner liner, causing corrosion to the inner liner of the aluminum alloy. If a cavity is formed, the nitrogen tank must be scrapped, so it is necessary to scrub the tank after the liquid nitrogen in the liquid nitrogen tank is exhausted. The specific cleaning methods are as follows: first, take the cylinder out of the liquid nitrogen tank, remove the liquid nitrogen, and place it for 2-3 days, until the temperature in the tank rises to about 0°C, then pour warm water about 30°C, and scrub with cloth. If individual melting substances are found sticking to the bottom of the inner gallbladder, they must be carefully washed. Then rinse with clean water several times, then invert the liquid nitrogen tank,place it indoors safely and not overturn, dry naturally, or air dry with a blower as described above. Note that during the whole washing process, the action should be slow. The temperature of pouring water should not exceed 40°C, and the total weight should not exceed 2 kg.
3. Safe Transportation of Liquid Nitrogen Tanks
The liquid nitrogen tank must be padded and fixed in the wooden frame during transportation. The tank should be separated from the tank by fillers to prevent bumping and dumping. When loading and unloading the liquid nitrogen tank, it is necessary to prevent the liquid nitrogen tank from hitting, and it is not allowed to be dragged on the ground at will, so as not to reduce the service life of the liquid nitrogen tank.