Matters needing attention during the operation of laboratory nitrogen gas generator

　　After the nitrogen generation section is separated, the adsorption of oxygen by the molecular sieve reaches equilibrium. According to the characteristics of carbon molecular sieve adsorbing different amounts of adsorbed gas under different pressures, the downward pressure prevents the carbon molecular sieve from oxygen adsorption. The process is regeneration. According to the different regeneration pressure, It can be divided into vacuum regeneration and atmospheric pressure regeneration. Atmospheric pressure regeneration is conducive to the complete regeneration of molecular sieve, and it is easy to obtain high-purity gas.
　　If you want to obtain high-purity nitrogen, you need to add an appropriate amount of hydrogen and trace oxygen in the nitrogen to carry out a catalytic reaction to remove the oxygen and then cool it by a water condenser, remove water from a steam-water separator, and then pass through a dryer for deep drying. Two adsorption drying towers are used alternately, one for adsorption and drying to remove water, and the other for heating and desorption to obtain high-purity nitrogen.
　　After using the laboratory nitrogen gas generator for a period of time, it was found that the silica gel in the drying tube gradually changed color from bottom to top. When it exceeds a certain height, the silica gel should be replaced. The operation steps are as follows:
　　(1) Rotate the lid of the drying tube until it is completely unscrewed. Do not perform this operation under pressure.
　　(2) Take out the inner tube of the drying tube upwards, take out the cotton ball, and pour out the silica gel.
　　(3) Install new (or dried) silica gel, the amount should not exceed the small vent near the nozzle, cover with cotton ball, pay attention to not have cotton thread or other debris on the end of the drying nozzle (Otherwise it will cause air leakage), and then put the inner tube into the outer tube of the drying tube.
　　(4) Tighten the cover of the drying tube, and use soap to check for leaks after starting the machine.
　　(5) The method of replacing activated carbon is the same as that of replacing silica gel.

　　Matters needing attention in the process of using laboratory nitrogen gas generator:
　　1. The drying tube should be replaced regularly. When 50% of the discoloration silica gel in the drying tube changes color, the internal packing should be replaced. Replacement method: turn off the power supply and vent the system gas (the pressure drops to zero). Unscrew the purification tube in the direction indicated by the arrow, unscrew the end cap of the purification tube, and replace the silica gel desiccant.
　　2. When replacing the desiccant, you should pay attention to putting all the absorbent cotton into the tube to ensure that it has no effect on the sealed end surface, so as to ensure that the end cap can be sealed after being tightened.
　　3. Bake the color-changing silica gel in an oven at 120°C for 12 hours. The molecular sieve is burned in a muffle furnace at 250°C-300°C for 24 hours.
　　4. Tighten it in the direction indicated by the arrow during installation, use soap to check for leaks after starting up, and ensure the seal.
　　5. If electrolyte is consumed during work, distilled water should be added regularly according to the usage conditions to ensure that the liquid level is between the upper and lower limits.