The hydraulic ram strikes again
Article in Science and Future in November 2003. David Larousserie. Some people came out of oblivion this ingenious machine born with the Republic, 1792. She might even know a bright, because it works non stop without energy.
The hydraulic ram is not dead. This water pump system, invented there are more than two hundred years, takes the same service, with a French company and a small group of students. It was time ! Few people actually know this rustic technology, economic, ecological and yet effective, unless plumber and install antibélier systems to protect pipelines. Or to have heard in his youth, the poom-poom feature of this machine, the edge of a stream or a source.
The principle of the ram based on the pressure created when the flow of a liquid is suddenly interrupted, for example, when the rapid closure of a valve. The shock wave resulting damage is often violent and unprotected pipes. Industrial and inventor Joseph Montgolfier had the idea, in 1792, divert this purpose wisely. After flying balloons with his brother Stephen, he filed a patent for this autonomous and efficient pump and ram called, because of the noise and violence of the blow. A large bell cast firmly attached to a base to withstand the pressure, two bronze valves, two water inlets and voila. Installed near a source or a waterfall, the machine to mount the liquid up to tens of meters without power other than that provided by the current (see diagram). Once launched, it will not stop. Or almost. Only the lower inflow, freezing or impurity in the water that would block the valves ends its regular strokes of the battering.
The ram is also indestructible. The castle of the Ménardière (Deux-Sèvres), for example, over 120 years working copy yet, having just suffered a mild recovery. The invention of the Montgolfier brothers spread slowly and had its heyday between 1870 and 1900. The brand rams Bollee, Pilter or Mangin then allow watering parks, gardens and vegetable gardens. The 200 hectares of Richelieu city of gardens (Indre-et-Loire) are, for example, still fed by a ram which carries water over 600 meters. In 1876, leading manufacturer of archives, Bollee, were documenting in a hundred around the department of Indre-et-Loire. After World War II, electrification plans and water supply put a stop to this yet indestructible machine.
In 1950, France had about ten manufacturers. There remains only one today, SARL Walton, Bordeaux, specialized in watering and pumping. "In 1998, I refused to stop what my grandfather had launched in 1910, I created a website to talk about the hydraulic ram, which we sold only one or two pieces per year. At first, I had only installed the reproduction of one of our models dating from 1936, "recalls Richard Walton, its director. In spite of the poverty of the site, it is the success. The company today sells about 50 rams a year and counts 250 users in its files. There are object lovers who opt for the smallest model. Farmers, Limousin or Cantal, who choose more efficient models, some of which are sufficient to supply water to a herd of 100 heads, about a flow of 10 000 liters per day. Other customers are in Africa, where Walton rams feed villages from 600 to 1000 people needing a flow of up to 40 000 liters per day. "For these countries, the advantage is also that the fountain, the water flows continuously, which avoids the stagnation of the liquid and the risk of contamination," said Richard Walton, who also has customers in Vietnam. The lack of external power supply and easy maintenance are particularly suitable for developing countries.
Two photos of hydraulic rams. Left, a recent model of the French society Walton, the only market still rams. A law a model still in operation after 50 years.
Proportionately, it is a ram that saved a French village in the nineteenth century. "If there had not been, this system, our ancestors could not exploit the nursery that attracted jobs and wealth," said Gilbert Barbier, deputy mayor of Saint-Appolinaire (Rhone), to 50 kilometers from Lyon. A century later, Gilbert Barbier wanted to revive the ram of his commune that many had forgotten, and which nobody knew the operation. Taking advantage of an open day at the professional high school Jules-Verne of Tarare, 15 miles away, Gilbert Barbier asks for help from the headmaster. His students were looking for a project to participate in the Olympics Physics, a friendly competition between different French high schools, based on experimentation. Laurent Buccini, Loïc Jacquemot, Adrien Rabany, Guillaume Rousset and Gregory Saint-Paul, with their teachers Mustapha Errami and Benjamin Topouzkhanian, get to work. They build their own ram, and it works!
Water rises even to the sixth floor of their high school. At the competition, in February, in Paris, the jury, impressed by this system that "watered" the attic of the Palais de la Découverte, gave them the prize of the French Society of Nuclear Energy ...
New consecration, the 14 June, with the presentation in the village of Saint-Appolinaire. The hundred or so inhabitants were present to see the water rise to the church steeple, at 17 meters from the ground, violently twisting the plastic pipes with each water hammer. "I'm happy to have saved this object and given back the honor to the professional training", testifies Gilbert Barbier.
The students have since completed their trade bac with honors and communal ram feeds, not the nursery, but reserve 50 cubic meters of water for firefighters.
The students were then went to the Moscow Exposcience in July with their machine. Teachers discussed for hours with them in Russian and English. A German even wanted to buy them the prototype!
"We preferred to explain to him how to make it himself, testifies Grégory Saint-Paul. It's not hard. It's just pleasure. "At each presentation, it was the feast of science," says Mustapha Errami, one of his teachers.
The hydraulic ram still resists science. Curiously, its exact performance has still not been calculated. "The ram is impossible to put into equations. This machine does not like engineers. It is a peasant machine made by a peasant for other peasants, "summarizes, a provocative nothing, Richard Walton. The ram is not dead, he is still pumping.