During evaporation process of liquid nitrogen gaseous nitrogen at a low temperature is formed, and its density is higher than air density. Therefore, after evaporation nitrogen can accumulate initially at the lower level of the room and then gradually create increased concentration throughout the whole space. This leads to decreasing the oxygen concentration in the air and when its value reduces below 18%, a person in the room is in serious danger - rhythm of breathing is violated, pulse becomes faster, followed by disturbance of consciousness, sensitivity decrease, lost ability to move, nausea and vomiting, consciousness lost and death in a few minutes. Special hazard is in that fact that this happens painlessly and the person is not aware of his condition.
It is allowed to work with open cryogenic vessels in the rooms with natural ventilation, if the room volume in cu.m exceeds the volume of the liquid in the Dewar vessels not less than 7 times in liters.
Short-term contact of liquid nitrogen with your skin is not dangerous, because in this case an air layer with low thermal conductivity is formed on the skin, which protects the skin from direct contact with liquid nitrogen. Prolonged contact of liquid nitrogen or a material cooled with liquid nitrogen with skin or eyes can cause serious damages. Handle the liquid nitrogen carefully! If there is a leak of liquid nitrogen, ventilate the room.
About liquid nitrogen
It depends on the type of vessel and its volume, usually the evaporation characteristics are indicated in the passport or the operating instructions of the Dewar vessels` manufacturer. Evaporation discharge (liquid nitrogen) is measured in kg/hour or in vol.% per day. The average storage time of liquid nitrogen before its full evaporation can be from several weeks to a year.
First of all, it is volatility. For example, the vessel SDS35Bio60 produced in Ukraine holds nitrogen during 210 days, and its French analog B2036 - 360 days. Also more attractive appearance of the French manufactured Dewar vessels is one more important difference.
To close the neck of the vessel tightly with any foreign plugs is not allowed. Use only original plugs and covers, which among other things prevent liquid nitrogen splashing. And also it prevents formation of "snow coat", ice in the neck and on the outer surface of the Dewar vessel. If mechanical damages and/or "snow coat" appear on the outer surface of the vessel (especially when it is completely frozen!), it is necessary to empty the vessel from liquid nitrogen, leave to warm and contact us for consultations.
Foreign objects in a vessel with liquid nitrogen can create an ice cork and result to the vessel destruction.
In accordance with the Rules of the "European Agreement concerning the International Carriage of Dangerous Goods by Road (ADR)", liquid nitrogen in quantities up to 333 kg can be transported without observing restrictions specified for dangerous goods. This rule is confirmed by Order №73 of the Ministry of Transport of the Russian Federation dated 08/08/1995.
It is allowed to be transported in one transport unit without observing the above Rules for Dewar vessels SC-16 filled with liquid nitrogen in amount up to 15 pcs.
Delivery of nitrogen is carried out within two working days, in summer - within three working days. We cannot say in advance when exactly the order will be delivered, it depends on the route of the drivers.
Principle of operation of the liquid transfer device is based on pressure increasing in the cryogenic vessel by introducing "warm" mass into the liquid and using gas-lift effect. After sealing the neck of the vessel evaporated part of the liquid creates overpressure in it, followed by liquid transfer to siphon and further into the filled container.
No additional devices for liquid transfer are required.
A part of the liquid transfer device inserted into the Dewar vessel is a rigid structure and is adapted only to a vessel of certain height.
A liquid transfer device for Dewar vessels with necks of different diameters is possible to be used with an additional seal.
Dewar vessels SK-16 or SK-25 depending on the patient stream. The cryosurgical unit CryoInej is to be periodically refilled, so it is necessary to choose the vessels to which there is a liquid transfer device. To pour liquid through the funnel is uncomfortable and difficult.
Equipment and Dewar vessels
To avoid redundant evaporation of liquid nitrogen, it is not recommended to put the Dewar vessel near the heating devices. Store and use liquid nitrogen only in ventilated areas. High content of gaseous nitrogen in enclosed spaces reduces oxygen concentration and can result to asphyxiation. For more detail see Safety Rules for handling with cryogenic equipment and liquid nitrogen.
No. Practice has shown that doctors do not like to transfer their cryotherapy devices to other colleagues.
10 nozzles of different sizes and shapes for different purposes.
Yes, you can. To do this, use an additional set of contact probes.
CryoStick is convenient for removing small tumors - warts, papilloma, moles. A thin metal rod is cooled in liquid nitrogen and applied to the affected zone.
Dewar containers SK-6 or SK-16 depending on customers` stream.