Dewar liquid gas recovery

With the popularity of Dewar flasks, the gas loss during filling of Dewar flasks has accounted for a considerable proportion, causing serious hidden losses to enterprises. In response to the above situation, Henan Jianshen Metal combined with the actual situation of the company to carry out the technical transformation of the original Dewar filling process to reduce the gas loss in the pressure vessel filling and improve economic benefits.

1. Filling process transformation to reduce exhaust gas
Change the pressure difference filling to the cryogenic liquid pump filling. Before the original process transformation, connect the liquid outlet valve at the bottom of the storage tank to the Dewar liquid inlet valve through a metal hose, and use the pressure between the liquid storage tank and the Dewar bottle. Poor liquid filling. Because the metal hose cannot be insulated, a large amount of heat is absorbed by the liquid during the filling process, causing the liquid in the pressure vessel to vaporize and produce a large amount of gas, which causes the pressure of the Dewar to continue to rise. When the internal pressure of the Dewar is equal to the internal pressure of the storage tank, the filling process cannot continue. Because of this, the gas cylinder has to open the gas phase valve of the Dewar after a certain stage of filling to reduce the internal pressure of the Dewar, maintain the relative pressure difference with the storage tank, and ensure the smooth filling of the pressure vessel. get on.
　　
After a period of filling, it was discovered that there are two disadvantages in the above process. The first is that the pressure of the storage tank must be maintained 2kg/cm2 higher than the Dewar during the filling process. Liquid below or equal to this pressure cannot be filled into the Dewar. In order to meet the filling requirements smoothly and quickly, a large amount of gas phase generated during filling will be wasted due to pressure reduction, followed by the gas phase generated during filling Increase the pressure of the Dewar bottle to extend the filling time and reduce the production efficiency. In order to overcome the disadvantages of this process, we consulted relevant technical data, after a long time of practice and exploration, replaced the original busbar and connecting pipes with insulated vacuum tubes, increased the number of filling bottles, and filled three at a time. The gas cylinder is filled with a liquid pump, which greatly reduces the gas loss and improves the production efficiency. 2. Recover gas with membrane press
Although the application of the new process has reduced a considerable part of the gas loss, the filled liquid will still produce some gas. In response to this phenomenon, our company further reformed the problem of gas recovery discharged from the Dewar bottle during the filling process. Behind the Dewar bottle exhaust valve, a metal hose is connected to the gas recovery exhaust after the vaporizer absorbs heat. , Concentrate to the gas storage tank by pipeline. Then press the gas in the gas storage tank into the gas cylinder through a membrane compressor to minimize gas venting, improve utilization, and increase economic benefits.
　　
Dewar liquid filling gas recovery process transformation not only improves production efficiency, but also effectively utilizes the gas generated during the filling process, which brings benefits to the enterprise.