“Wikipedia
Roots type supercharger
…
The Roots type supercharger or Roots blower is a positive displacement pump which operates by pumping air with a pair of meshing lobes not unlike a set of stretched gears. Air is trapped in pockets surrounding the lobes and carried from the intake side to the exhaust. The supercharger is driven directly from the engine's crankshaft via a belt or, in a two-stroke diesel engine, by spur gears.
It is named for the brothers Philander and Francis Marion Roots of Connersville, Indiana, who first patented the basic design in 1860 as an air pump for use in blast furnaces and other industrial applications. In 1900, Gottlieb Daimler included a Roots-style supercharger in a patented engine design, making the Roots-type supercharger the oldest of the various designs now available.”
( http://en.wikipedia.org/wiki/Roots_type_supercharger )


“Mašinski fakultet Univerziteta u Nišu
…
Varijanta transporta sa povremenim produvavanjem cevovoda praktično se može primeniti u slučajevima kada mašine koje izazivaju strujanje vazduha imaju krutu radnu karakteristiku ( v V ≈ const ), kao što su, na primer, vakuumpumpe I Rutsove duvaljke.”
( http://masfak.info/wp-content/uploads/2009/03/leteci-pneumat... )

--------------------------------------------------
Note added at 13 hrs (2010-04-25 12:20:59 GMT)
--------------------------------------------------

AQUATEXT - Dictionary
…
Blowers - Devices which provide pressurised air, typically at pressures between 50mbar and 500 mbar. Most blowers use a turbine principle to provide the air pressure. Blowers have the advantage of being able to be all but closed off on the discharge side of the blower without damaging the blower or the discharge pipe. This is not the case with compressors. Most types of blower can also operate as low vacuum air suction pumps.
( http://www.aquatext.com/list-b.htm )


„Inženjering Kompanija“ d.o.o.
…
Oblast delovanja
- proizvodnja i održavanje visokog kvaliteta industrijskog vazduha, visokog pritiska ( kompresori ) i niskog pritiska (duvaljke )
( http://www.engineering.co.rs/oblastdelovanja.htm )
…
Scope of activities
- Producing and maintenance of high quality industrial air, high pressure (compessors) and low pressure (blowers).
( http://www.engineering.co.rs/EN/oblastdelovanja.htm )
…
Niskopritisni kompresori - duvaljke
ŠTA ODLIKUJE DUVALJKE
„Ingersoll Rand“ – Hibon?
• Velika mogućnost izbora
• po osnovu kapaciteta, pritiska i vakuma
• po osnovu medija koji se transportuje ( vazduh, gas......)
• Ekonomičnost – minimalna potrebna snaga po m³ proizvedenog medija
• Sigurnost u radu
• Jednostavno uvođenje u automatski vođene procese
• Lako održavanje
• Siguran servis
( http://www.engineering.co.rs/duvaljke.htm )