Answer: The newly installed distillation column must be thoroughly heated and blown off before starting and returning to work after long-term parking. After being put into operation, when the liquid suspension failure of the distillation column can not be eliminated, or the pressure difference before and after the heat exchanger pressure at the end of the operation period is more than 0.5MPa, or the purity of oxygen and nitrogen and the output decrease, it should be heated and blown off.
First of all, make preparations before heating:
1) discharge the liquid in the tower;
2) dismantle the flow meter and thermometer at the outlet of oxygen, nitrogen and distillation, dismantle the upper and lower joints of the liquid air and liquid oxygen level gauge, and dismantle all the pressure gauges except the low pressure gauge;
3) close the high pressure air General inlet valve, joint-1 valve, oxygen and nitrogen products outlet valve and heating Inlet general valve;
4) open the top rod of the inlet and outlet valves of the expansion machine;
5) open all through valves, throttle valves, analysis valves, blow-off valves, upper and lower valves of the liquid level gauge, pressure gauge valves and heating valves on the shell of the distillation column;
6) fill up distilled water of the heating furnace.
The operation of heating is as follows: start the air compressor, when the pressure of the purifier rises to the normal working pressure, slowly open the heating main inlet valve, and use this valve to control the pressure of the purifier under the normal working pressure. After blowing with dry air for half an hour, switch on the heating furnace and control the outlet air temperature of the heating furnace to 70 ~ Between 80℃.
During heating, the temperature of each outlet should be adjusted frequently. Close the outlet valve with high temperature a little smaller, and open the outlet valve with low temperature a little bigger
And pay attention to that the pressure on the tower should not be greater than the normal working pressure at any time. When the outlet temperature is higher than room temperature (15℃ in summer, winter
Above 5℃), the heating can be stopped after the gas is discharged and dried.
0.5 before heating ends ~ 1 h, each throttle valve stem should be pulled out to blow off, and the impurities in the screw thread of the valve stem and the moisture in the valve sleeve should be removed to prevent the flexible rotation during normal operation.
