The vacuum engine. Another variant of external combustion is the vacuum engine. Commonly known as flame licker/gulper engines. A quantity of heated air is drawn through a port at the front of the cylinder. A mechanically operated valve closes off the cylinder at about 3/4 of the downward piston travel. The heated air rapidly cooled by the either air or water cooled cylinder forms a vacuum. The flywheel aids the piston to the bottom of the stroke before atmospheric pressure pushes it forward for the power stroke. An exhaust valve opens automatically to purge the now increasing pressure before the piston reaches the end of the stroke. The cycle is then repeated, over and over until the heat source is extinguished. The power is directly proportional to the area of piston diameter so these engines, in the main, weren’t that powerful. They found uses in driving things like sewing machines and, believe it or not, Dentists drill’s. This principle could also be reversed, if we had a cheap way of super cooling the cylinder we could run the engine from air at ambient temperature. The photo is of a range of vacuum engines that I designed over the last 20 years or so. They’re called CHUK, the V twin was the latest in the line completed just about 18 months ago. The video is of my favourite, own design, Nattie a wee toy based upon a beautiful design from the National gas engine company of Ashton under Lyne Manchester. https://youtu.be/2eorVwM7n64Cheers Grum.
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Nanny state ? Left at the gate !!  |
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Topic: Engines (Read 8736 times)
