A trompe is a water-powered

air compressor An air compressor is a pneumatic device that converts power (using an electric motor, diesel or gasoline engine, etc.) into potential energy stored in pressurized air (i.e., compressed air). By one of several methods, an air compressor forces m ...

, commonly used before the advent of the electric-powered compressor. A trompe is somewhat like an

airlift pump An airlift pump is a pump that has low suction and moderate discharge of liquid and entrained solids. The pump injects compressed air at the bottom of the discharge pipe which is immersed in the liquid. The compressed air mixes with the liquid c ...

working in reverse. Trompes were used to provide compressed air for bloomery furnaces in

Catalonia Catalonia (; ca, Catalunya ; Aranese Occitan: ''Catalonha'' ; es, Cataluña ) is an autonomous community of Spain, designated as a '' nationality'' by its Statute of Autonomy. Most of the territory (except the Val d'Aran) lies on the nort ...

and the

USA The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

. The presence of a trompe is a signature attribute of a Catalan forge, a type of bloomery furnace. Trompes can be enormous. At Canadian Hydro Developers' Ragged Chute facility in New Liskeard,

Ontario Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central C ...

, water falls down a shaft deep and across to generate compressed air for mining equipment and ventilation.Ragged Chutes

Operation

Trompes are very simple devices. They consist of four main parts: ''water-supply pipe'' or ''shaft'' with an ''air-inlet'' inside it, ''water outflow pipe'', ''separation chamber'' and ''takeoff'' ''air-pipe''. The vertical pipe or shaft goes down from higher point to a separation chamber; a pipe, that is typically narrower than previous one, coming away from that chamber, allows the water to exit at a lower level, and another pipe (air-pipe) coming from the chamber allows the compressed air to exit as needed. upright=1, lang=en, Sketch of a hydraulic trompe with the name of its different constituent elements. Water rushing down the vertical pipe falls through a constriction. The constriction produces a lower pressure because of the

venturi effect The Venturi effect is the reduction in fluid pressure that results when a fluid flows through a constricted section (or choke) of a pipe. The Venturi effect is named after its discoverer, the 18th century Italian physicist, Giovanni Battista ...

, and an external port allows air to be sucked in thus creating a constant air supply. The air forms bubbles in the pipe. As the bubbles go down the pipe they are pressurized proportionally to the hydraulic head, which is the height of the column of water in the pipe. The compressed air rises to the top of the separation chamber (wind box). The separation chamber has a compressed-air takeoff pipe, and the compressed air can be used as a power source. The energy of the falling water creates a partial vacuum inside the pipe that is compensated by the air from the outside atmosphere provided through inlet. The air is compressed by surrounding water pressure (which increases under a column due to the discharge to atmospheric pressure). The pressure of the air delivered cannot exceed the hydraulic head of the discharge pipe of the separation chamber. Large trompes were often situated at high

waterfall A waterfall is a point in a river or stream where water flows over a vertical drop or a series of steep drops. Waterfalls also occur where meltwater drops over the edge of a tabular iceberg or ice shelf. Waterfalls can be formed in severa ...

s so that ample head was available. (However, trompes can raise the water, via siphon-effect, nearly to 70% of its initial elevation.) The Ragged Chute plant on the Montreal River near the town of Cobalt, Ontario, is a trompe and tourist attraction. It is now owned by

TransAlta TransAlta Corporation (formerly Calgary Power Company, Ltd.) is an electricity power generator and wholesale marketing company headquartered in Calgary, Alberta, Canada. It is a privately owned corporation and its shares are traded publicly. It o ...

(formerly by Canadian Hydro Developers) and exists beside a modern hydroelectric plant. Compressed air from a trompe is at the temperature of the water, and its partial pressure of water vapor is that of the

dewpoint The dew point is the temperature to which air must be cooled to become saturated with water vapor, assuming constant air pressure and water content. When cooled below the dew point, moisture capacity is reduced and airborne water vapor will co ...

of the water's temperature. If the water is cool, the compressed air can be made very dry by passing it through pipes that are warmer than the water. Often, ordinary outside air can warm the pipes enough to produce dry, cool compressed air. Today, trompes constructed of plastic pipe are being used to provide aeration for mine drainage treatment. In this application, mine water is used to drive the trompe and the compressed air that is generated is used to oxygenate the mine water and to drive off excess dissolved

carbon dioxide Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is trans ...

that may be present thus raising the pH of the water being treated.Leavitt, Bruce R. (2011); Aeration of Mine Water Using a TROMPE; 2011 West Virginia Surface Mine Drainage Task Force Symposium (past symposium papers/2011 symposium papers/ at wvmdtaskforce.com)
/ref> The trompe is closely related to the

Sprengel vacuum pump Sprengel is a surname. Notable people with the surname include: * Hermann Sprengel (1834–1906), chemist * Karl or Carl Sprengel (1787–1859), botanist * Kurt Sprengel (1766–1833), botanist * Christian Konrad Sprengel (1750–1816), teacher and ...

which uses mercury falling through a tube to create a vacuum instead of pressure. upright=1.8, lang=en, Principle of a Taylor hydraulic trompe.

References

External links

{{Commons category, Trompes
Farga Rossell a catalan furnace
in

Andorra , image_flag = Flag of Andorra.svg , image_coat = Coat of arms of Andorra.svg , symbol_type = Coat of arms , national_motto = la, Virtus Unita Fortior, label=none (Latin)"United virtue is stro ...

(retrieved April 2, 2011)
Article
in

Mother Earth News ''Mother Earth News'' is a bi-monthly American magazine that has a circulation of 500,520 . It is published in Topeka, Kansas. Since its founding, ''Mother Earth News'' has promoted renewable energy, recycling, family farms, good agricultural ...

(retrieved October 15, 2011)
Ragged Chutes
in Cobalt Ontario. Uses a 17-meter head. (previously retrieved August 27, 2009, as of May 19, 2010 cobalt.ca no longer has technical details of the chute)
Cobalt Mining Legacy
Ragged Chutes technical details (retrieved August 6, 2010)
C. H. Taylor
pioneer hydraulic compressor designer including Ragged Chutes in Cobalt Ontario (retrieved August 6, 2010)
Illustrated Book
by C.H. Taylor: Taylor Hydraulic Air Compressor (1897) (retrieved October 16, 2011)
Trompe Catalan Furnace
in San Juan Capistrano, California Energy conversion Pumps Industrial furnaces Gas compressors

Operation

See also

References

External links