I’m working on a cooler device that will be pretty similar to the devices commonly used in cryotherapy for cooling skin. Meaning that my device will use liquid nitrogen provided to the handle so the liquid gas will be expanded in the handle instead of low temperature, gaseous nitrogen through the application pipe. Everything seems to be quite good, but the flow is not continuous from the handle’s nozzle. I’ve tried everything (that I could imagine) – pipe insulation, heater influence, solenoid valve, etc. I still have the same “puffing” from the nozzle. What am I doing wrong?
1 Comment
Glen E. McIntosh, PhD
August 1, 2008You are getting slug flow of liquid and vapor bubbles in your equipment. This is typical in small tubes where there is no way for vapor to separate from liquid. If I understand correctly, you want cold vapor, not liquid, for your application. If so, you need an enlargement in the flow passage which will allow vapor to separate from the liquid to vent out to your apparatus.