Hydraulic ram

A hydraulic ram, ram, ram lift water or water ram is a water-driven, intermittiernd operating pump. The Ram uses the pressure shock or dynamic pressure effect to lift a portion of the water with which the pump is driven at a higher level. It is particularly suitable for pumping near rivers to operate with sufficient slope.

Areas of application

For agriculture, mountain huts and cottages that are near flowing waters, Aries are used to supply water to you. Mostly it is to property in remote areas, which are connected neither to the public water supply nor to the public power network or be used for other reasons only temporarily.

New hydraulic rams are used particularly in development aid. There are, for example, an application hydraulic ram in southeastern China for small-scale agriculture as an alternative to diesel pumps.

History

The hydraulic ram is the automation of the 1772 invented by John Whitehurst pulsation engine, in which the caused by the closing of a faucet water castle vibration raises a column of water above the amount of the inflow. By repeatedly opening and closing the valve larger amounts of water were lifted. 1796 replaced the Frenchman Joseph Michel Montgolfier the tap of the pulsation engine by again automatically closes off valve.

The hydraulic ram is mentioned for the first time in the recording of the Académie des Sciences on 14 July 1797. The "citizens" Montgolfier gave a lecture with the title Sur un très moyen d' simple elever l' eau the fleuves ( " About a very simple means to raise the water of rivers "). The French patent for the invention was granted in November 1797. For England the grant of a patent ( number 2207 ) is proved on 13 December 1797, the steam engine pioneer Matthew Boulton, who made the application on his behalf for Montgolfier.

The first American patent was granted in 1809 to J. Cerneau and SS Hallet. In the U.S. interest in hydraulic rams from 1840 increased sharply, which have been granted more patents and domestic companies began production.

One of the first manufacturers in Switzerland was Johann Georg Schlumpf, 1885 sold the first hydraulic ram. In 1923, he developed the " self- venting ". This automatically completed the regular replenishment of the air cushion, creating a decades- long maintenance-free operation is possible.

Only after the mid-20th century, the interest went back again, as the use of electricity and electric pumps spread out.

A hydraulic ram consists of four main components:

• A water intake as a reservoir
• The " surge tank " as a pressure vessel
• The connected riser

These components together form an oscillatory system, which continues to oscillate even controlled after a single offense, as long as sufficient water supplies will be provided. Since the system has only two moving parts ( shock and pressure valve ) can be the manufacturing cost, the maintenance is easy and the unit is extremely reliable.

From a reservoir, which is fed by a spring or a stream, water flows through a not too short drive line and occurs at the end by the shock valve ( the ram ). The surge valve is initially held open by a spring or its own weight until the velocity of the accelerated by gravity emerging body of water is large enough to entrain the shock valve - it closes abruptly. The engine in the line flowing to date body of water is so abruptly blocked the outflow. The water mass reacts due to its mass inertia with a tremendous increase in pressure, which can be calculated (see here):

Flows, for example, water at 3 m / s through a 5 m long tube, which is cut off within 5 ms, the pressure rises briefly to 60 bar. This surge causes two operations:

This maximum occurring pressure surge, however, only occurs when the closing time of the closing element is shorter than the time he needed to get to the inlet of the penstock and back to back ( 2 * L ) closure - the so-called reflection time tR of the pressure wave.

With the example values ​​selected above result is T = 10 ms. This very short time can only be registered with measuring instruments, the two valves can not react quickly enough because of their inertia.

The engine water now flows while in the air chamber, until the back pressure the pressure valve closes again. This part of the headrace is retained in the wind due to a rise boiler internal pressure. The pipe friction ensures that the pendulum motion of the water column rapidly decays. The surge valve opens and the process begins again.

A familiar observer therefore sees in Aries system an oscillating water column with a water-filled, long and sloping tube on one side and a partly filled, voluminous pressure vessel with an air cushion on the other side. Thus, this system converts automatically (consuming headrace ) a flowing amount of water in a under ( high ) pressure water amounts to.

This in the air chamber under ( high ) pressure standing water is tapped through a riser and fed to the higher of use. Can thereby generate water pressures up to 30 bar, the heads correspond to 300 m. Typical slope heights of the penstock are between 30 cm and 5 m. Experiments have shown that the ratio of height of fall: should drive line length between 1:3 and 1:12 are. These lengths typically result in a cycle time of 1 to 2 seconds.

With the help of a series connection of several Aries also high heads can be achieved. However, with each stage reduces the amount of the pumped water, since only 10% of the flowing water can be pumped.

Using so-called " white water ram " can also be different waters and for the ram drive and pumping water use. Thus, for example, the ram operated at surface water while the water is to be pumped from a well separated from the engine water by an elastic diaphragm. The pressure pulses of the engine water so drive a kind of patch membrane pump.

Comparison with electrical circuit

The hydraulic ram also has an electrical analogue which is much more common: the boost converter, which can produce higher pulsed voltage spikes considerably from a low DC voltage. This match:

• Current in the inductor = inertial mass of the water in the penstock
• Switch S = shock valve
• Rectifier D = pressure valve
• Capacitor C = Windkessel

Typical operating problems

Typical operating problems are air in the drive line, blocking the water supply or the valves and freezing in winter.

Too little air in the air chamber can be avoided just upstream of the check valve ( pressure relief valve) by a small air valve (1-2 mm bore ) or a snifter valve. In this case, some air is sucked in for each stroke, and pressed into the vessel.

Hydraulic Ram in Central Europe ( selection)

Germany

• In Neukirch - Wildpoltsweiler. There the animals one located near wildlife parks throughout the summer. The cable length is 700 m, the difference in height about 50 m.
• On pushbutton Rain ( Single homestead in the community Eberhardzell in the district Biberach ); functional.
• The Energy Museum in Hottingen there is a ram that drives a water wheel and two meters slope of the Murg ( Southern Black Forest ), the water pumps seven feet high.
• The water supply to the Hohenzollern Castle in Hechingen, hydraulic rams are used due to the exposed location. About a 700 m long riser, the water is pumped up about 220 m.
• At the exhibition mine in Neubulach in the northern Black Forest.
• In Walldürner district Hornbach (Neckar -Odenwald -Kreis) a Lambachpumpe 1924 1995 reset functional repaired and refurbished the engine house of 1894.
• In Bad Herrenalb to supply the Hahnenfalzhütte.

• Three functional Aries in Oberstdorf (one next to the church, one in the adjacent Oytal, halfway from Oberstdorf to Oytal house and one on the Rappenseehütte ).
• In Scheidegg (Western Allgäu) on the playground at the Scheidegger waterfalls and other water - conveying systems, in addition to a hydraulic ram set up with boards.
• View object on Isarradweg Uster Ling in the district of Dingolfing / Landau.
• In Pfaffenhofener district Tegernbach the high-altitude short - estate was supplied without external power solely by means of a ram with water for decades. Even today it is functional and contributes to the supply of cattle at. Tegernbach at Oberpfaffenhofen
• In Pelkering, a hamlet in Triftern ( Lower Bavaria ), functional and in use for the supply of houses and gardens of some farmers.
• Tauchersreuth in Lauf an der Pegnitz: Reconstruction of an originally dating from the 1907 system.
• In the Franconian Open Air Museum of Bad Windsheim is situated in a frost -free months driven ram with a capacity of approximately one liter per minute to demonstrate the technique.
• On the Great Waldstein in the Fichtelgebirge.

• In Hinterbach, Odenwald ( functional).
• Built in Vielbrunn, Odenwald, on the trail to Geiersmühle, in Art Nouveau style and functional.

• In Gödenstorf in the district of Harburg, entertained by the open-air museum at Kiekeberg.

• A non-functional Lambachpumpe, named after its founder Wilhelm Lambach (1875-1944) from Oberemmel, is located in a pump house reconstructed in folklore and open-air museum Roscheider Hof, Konz
• A Lambachpumpe is still operated in Nomborn Westerwald to supply the local fountain.
• In Ernzen as a water supply for the fountain in the Ernzer rock pond.

• In Stollberg / Erzgeb. promotes a ram im Rosental (former drinking water catchment area with over 30 collecting ducts) into a newt pond.
• In the district of Görlitz Tauchritz. At the edge of the open pit residual hole Berzdorfer See the moated castle Tauchritz stands on oak piles in a castle pond. In connection with the construction of a flood trench for strip mining, a system with four rams installed in 2003 to maintain the water level in the pond. With a propulsion water volume of 25 l / s 4 l / s ( 15 m³ / h) promoted by 13 m. The excess foaming water is supplied to the flood ditch again.
• City Park Strehla.
• In Kamenz since 2005 is a fully-functional Hydraulic Ram ( medium pressure eureka Aries Appendix No. 6 to the Company Merkel jun. Dresden ) which lifted 1905-1929 drinking water in an elevated reservoir.

• In the open-air museum Molfsee near Kiel was a ram (currently both non-operating) is from 1800 right next to the historic water mill.

• Look investment in hydropower Museum Ziegenriick is set during tours in operation.

Other countries

• Radeckalm in Anlauftal in Bad Gastein - Bockstein (Salzburg ) powers the hut with drinking water.
• In Schwaz (Tyrol ) the Kellerjochhütte the Austrian Alpine Association is supplied with water.

• Below mountain inn Mesmer, Alpstein ( Appenzell -Innerrhoden ).
• In the hotel Faulhorn whether Grindelwald (Canton Bern ).
• In chalets, Kästhal ( Aargau ). The plant has been in operation for 70 years and feeds an old farmstead. Pumping height 70 m.

• In Kainen, a district of brown forest near Olsztyn, East Prussia.

• On access to the pasture " Brunarica pri Ingotu ", south of Gozd Martuljek at Kranjska Gora, supplies the hut.