Hello,
we built a machine that has a pump that circulates the water on top of the dry ice and has a heating
element to keep the water warm.
right now we only have 1
element in it so the water temperature is about 150F. Is that hot enough to get a nice thick
fog?
Right now the
fog we get out as the fan pushes it seems thin and dissipates pretty quickly.
just wondering if anyone has any ideas on this.
Dry ice will QUICKLY chill your heated water then freeze it soon after.
Decades ago (Late 1970's / early 1980's), Stratford Ontario's Stratford Shakespearean Festival built three foggers each approximately a 36" cube (to fit through the necessary paths / passages of their then 3, now 4 theatres).
Within the box was a second fibre-glassed box, with the gap between insulated on the bottom and all sides. The inner box would've measured ~ 30" x 30" x 30"; heating elements, enclosed fused knife switches, thermostats, thermometers, a water pump and associated plumbing protruded from one "end" with a drain cock protruding from the opposite "end". The two sides maxed at ~36" to facilitate moving (on the attached dolly with its 'butch' casters). Atop each box sat a
Dewar flask containing LN02.
Being located in the center of hog breeding country with LNO suppliers regularly making weekly runs to refrigerate sperm has its advantages; admittedly the fragrant aroma of open trailers hauling squealing pigs through the centre of town on their way to abattoirs did little to attract / impress visiting
theatre patrons, especially when the trucks were idling at a stop light immediately outside several of Stratford's higher priced / elegantly fashionable / trendier dining establishments.
The inner box was heated with two, 2KW, 220 volt submersible heating elements.
Pre performance it took the two, 2KW heaters ~20 minutes to heat the water to just shy of a rolling boil (Boiling the water would produce steam which would
escape via a pressure
release valve, and require more frequent refilling of the water).
Pulsing the pump for ~5<7 minutes would chill the water to a temperature you'd be comfortable immersing your arms in up to your elbows; watch out for the
momentary button powering the
solenoid operated LN02 valve.
Dinner time, gotta toddle.
Toodleoo!
Ron Hebbard