Putting steam on fires
Very very cool technology...
About a year ago,
New Scientist had an article about using steam to propel boats. The steam was injected into a ventrui shaped jet under water and when it hit the water, it collapsed, drawing water in from the intake and blasting it out the rear. No moving parts, unaffected by foreign stuff in the water (rope / seaweed) and efficient. The water emerges from the unit ony a few degrees warmer than intake water so there is no danger to marine life.
Today,
New Scientist is reporting that the people involved in devlopment of this engine tried it out above water with input from a low-pressure garden hose. They were very surprised to find that the output was a jet of fine water droplets that extended out 20 meters (65 feet). Here is the article:
bq. During the tests, a technician squirted water into it with a garden hose "purely out of curiosity", says John Heathcote, Pursuit’s CEO. To everyone’s surprise, the water emerged as a jet of fine droplets that drenched anyone standing within 20 metres of it.
bq. The engineers later found that shock waves, generated as steam emerges from the nozzle, were breaking the water down into a fine spray, which was projected at high speed (see diagram).
And more:
bq. The droplets in the spray are between 14 and 30 micrometres across, about 10 times the size of droplets in clouds, and this turns out to be within the optimum range for extinguishing fires. The device creates far larger volumes of spray than conventional water mist systems.
bq. The stainless steel "water-mist cannon" is just 20 centimetres long and 9 centimetres in diameter, and weighs 2.5 kilograms. In tests it was able to project the spray more than 40 metres, fed only by low-pressure steam from a small boiler and water from a hose flowing at about 13 litres per minute.
Very cool stuff - small, light weight, no moving parts and the perfect output for fighting fires - no tweaking needed... Here is a
link to the company
Posted by DaveH at March 5, 2004 5:03 PM