XPost: alt.home.repair   
   From: Paul@Houston.Texas   
      
   gtr wrote:   
   > What is the secret to how the soda stream works to carbonate water at home?   
   > Why does it work in only about fifteen seconds (three to five squirts)?   
   >   
   > How can I replicate that squirty nozzle using typical air compressor   
   > fittings (like an air gun of sorts, but with that long thin nozzle)?   
   > (snip)   
      
   This is my guess:  Think about a CO2 gun.  Pulling the trigger does not   
   empty the entire cartridge.  The needed CO2 fills a known volume.  The   
   volume has check valves in front and behind the volume.  When you pull   
   the trigger it opens the forward check valve causing the CO2 to go down   
   the barrel.  Since the pressure is now less than the cartridge it causes   
   the cartridge check valve to close until some other action causes it to   
   open (moving the lever on the gun or the handle or button on the SodaSteam.   
   If I were to make a soda device I would use a small pipe that is   
   inserted into the liquid so that the instantaneous release of the   
   calculated volume would be injected into the liquid causing the liquid   
   to swirl and foam.  Use of electrical solenoid valves would be tempting.   
     The volume would have to be carefully calculated.  It would not be   
   much, just a few CC's.  You could probably figure it out from the max   
   absorption of CO2 in water at a certain temp and pressure.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)