| Author | Message | ||
     Bob uk Unregistered guest Posted From: 94.197.122.89 |
Hydraulic accumulators were invented about 1850. Before that they used water towers about 200 ft high. One of which still exists in a English port and is a local land mark.(1750) Tower bridge London has two accumulators which slide down tubes to force a ram a develop pressure. They have five ton weights on them. They are in the towers. They are still used to raise the bridge. (1890) London hydraulic pumped high pressure Water around London which was used to work lifts and stage equipment in theatres. The manhole covers are still there and have London hydraulic co. Written on them. Also accumulator towers are still around. For smaller stuff gas or springs are used. First gas ones 1900. Gas types are bladder, piston, bellows and diaphragm. Some accumulators are connected to a pressurized bottle of gas permanently. 4 reasons for accumulators. Source of pressure without running a pump. Damping of pressure pulses. Allows a smaller pump to be used. Allows expansion of liquids in volumes between valves that are shut. RR Citroen systems use all 4 of the reasons. The first 3 are obvious. The fourth is when the acv non return valve is shut and the brakes are off the fluid between the non return valve and the brake valve and the ride control has no pressure relief valve. If the temperature rises then the accumulator will absorb the expansion. Without the accumulator the pressure rise from expansion could burst something ( the SS braided hoses are favourites) Pressure pulses are similar to water hammer and can destroy systems. It's like hitting the machinery with a sledge hammer. This can wreak pumps and pump drives. I have heard of RR camshafts with badly worn pump eccentrics. And also again the pipe work gets battered. Hydrophores. This is just of interest to gear heads like me. These Work on water hammer. Water flows along a pipe to a closed end with a valve that is float controlled. The water flows and suddenly the float shuts the valve. These causes a reflected pressure pulse, water hammer. Just before the float valve is a small tee which has a flap valve the pulse forces the flap open and water at high pressure comes out. A upright cylinder with a diaphragm in the middle like an accumulator with air at atmospheric pressure is used to absorb the shock loading. If the diaphragm fails the pulses will wreak the machine. New York city uses these to pump water up skyscrapers because hydrophores are automatic and need no power apart from the original water pressure. Local to me is a hydrophore by the River Stour. They use a large volume at lower pressure to pump water at a higher pressure. (Message approved by david_gore) | ||
| Bob uk Unregistered guest Posted From: 94.197.122.74 |
The water tower is at Grimsby Port and was built 1850. Armstrong ( Armstrong Vickers) Shortly after installed the first weight type accumulator at Grimsby. The tower was almost taken down because the Luftwaffe were using it as a landmark to bomb the docks. Now it is used as a radio mast. The very very first water towers are 2000 bc. But were not used hydraulically. (Message approved by david_gore) | ||
| Randy Roberson Grand Master Username: wascator Post Number: 306 Registered: 5-2009 |
Better yet: the Humphrey gas pump. A four-stroke cycle water pump which uses water as the piston; hence it is called a liquid-piston pump. See here http://www.murrayriver.com.au/event/396-cobdogla-irrigation-steam-museum-humphrey-pump-steam-train/ for the only working example in the world. There is one at least in England, though no longer running. see here: http://www.humphreypump.co.uk/history.htm Oh! To be in England (before the libs and muslims ruined it). | ||
| Bob uk Unregistered guest Posted From: 94.197.122.77 |
It's a mad idea that works. It's like blowing water out of a pipe with an explosion. You would have thought that the water would short out the spark plug. A similar idea is an electric element in a u tube the water hits the element and turns to steam fast. The pressure rise forces Water out of the other leg of the U and then it cycles again. (Message approved by david_gore) |
