Abstract
It is necessary to use a supplied gas having humidity as low as possible for gas-shielded metal arc welding. But it is not always easy to get everywhere the recommended gas for welding, i.e. super-pure and super-dried gas charged into a specially treated cylinder.
The authors carried out experiments about drying of gas supplied from a cylinder with some desiccants : sodium alumino silicate, activated alumina and silica gel. The dew point of the gas flowing out through a desiccator was continuously measured until the given amount of a desiccant broke. Carbon dioxide was used for the supplied gas.
The results are as follows :
1) Sodum alumino silicate has a drying capacity larger than activated alumina and silica gel. The sodium alumino silicate of 640 g warrants a supply of CO2 gas under -25°C dew point for 112 hrs., i.e. 7 cylinders. The dew point of gas through the desiccant is under -40°C from the first cylinder to fifth.
2) Activated alumina and silica gel warrant a supply of only two cylinders of CO2 gas under -20°C dew point through each desiccant.
3) An experimental formula was established for the relation between charged weight of sodium alumino silicate and break-time.
