Aspirator


Aspirator

Infobox Laboratory equipment
name = Aspirator


caption = A copper aspirator. The water inlet and outlet are at the top and bottom, respectively; the air inlet is on the side.
acronym =
other_names = Eductor-jet pump Injector/Ejector Filter pump
uses = Vacuum generation Suction
inventor =
manufacturer =
model =
related = Injector Vacuum pump
An aspirator, also called an eductor-jet pump or filter pump, is a device that produces vacuum by means of the Venturi effect. In an aspirator, fluid (liquid or gaseous) flows through a tube which then narrows. When the tube narrows, the fluid's speed increases, and because of the Venturi effect, its pressure decreases. Vacuum is taken from this point.

Operation

The cheap and simple water aspirator is the most common type of aspirator. It is used in chemistry and biology laboratories and consists of a tee fitting which is attached to a faucet and has a hose barb at one side. The flow of water passes through the straight portion of the tee, which has a restriction at the intersection, where the hose barb is attached. The vacuum hose should be connected to this barb.

If a liquid is used as the working fluid, the strength of the vacuum produced is limited by the vapor pressure of the liquid (for water, 3.2 kPa (32 mbar) at 25 degrees Celsius.) If a gas is used, however, this restriction does not exist. The industrial steam ejector (also called the steam jet ejector, steam aspirator, or steam jet aspirator) uses steam as a working fluid.

In order to avoid using too much steam, a single steam ejector stage is generally not used to generate vacuum below approximately 10 kPa (75 mmHg).High Vacuum Pumping Equipment, B. D. Power, New York: Reinhold Publishing Corporation, 1966, chapter 4.] To generate higher vacuum, multiple stages are used; in a two-stage steam ejector, for example, the second stage provides vacuum for the waste steam output by the first stage. Condensers may be used between stages to reduce the load on the later stages. Steam ejectors with two, three, four, five and six stages may be used to produce vacuums down to 2.5 kPa, 300 Pa, 40 Pa, 4 Pa, and 0.4 Pa, respectively.

The air ejector or venturi pump is similar to the steam ejector but uses high-pressure air as the working fluid. Multistage air ejectors can be used, but since air cannot easily be condensed at room temperature, an air ejector is usually limited to two or three stages. [ [http://www.graham-mfg.com/downloads/218.pdf Air Ejectors Cheaper Than Steam] ]

Medical aspirators

Medical aspirators are small suction machines used to remove mucus and other bodily fluids from a patient. They are often designed to be portable for use in ambulances and nursing homes, and can run on AC/DC or battery power. Major manufacturers include Allied Healthcare (under the Gomco brand) and Impact.

Insect aspirator

An insect aspirator, often called a pooter, is a device for collecting small insects or spiders using light suction. A motorized device is occasionally used, but normally the suction produced is through the lungs. The most common design is a long, flexible tube held in the mouth, connected to the stopper of a capture vial; the stopper is also fit with a rigid nozzle through which the insect is sucked.

References

ee also

* Injector
* Diffusion pump
* Vacuum pump


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Look at other dictionaries:

  • Aspirātor — Aspirātor, Apparat zur Erzeugung eines Luftstromes oder eines luftverdünnten Raumes. Der einfachste A. besteht aus einer großen, am Boden mit einer seitlichen Öffnung versehenen Flasche, die mit Wasser gefüllt und oben mit einem Kork verschlossen …   Meyers Großes Konversations-Lexikon

  • aspirator — ASPIRATÓR, OÁRE, aspiratori, oare, adj., s.n. 1. adj. Care aspiră (1). 2. s.n. Aparat pentru aspirarea fumului, a prafului, a gazelor etc. – Din fr. aspirateur. Trimis de cata, 11.02.2004. Sursa: DEX 98  aspiratór adj. m …   Dicționar Român

  • Aspirator — As pi*ra tor, n. 1. (Chem.) An apparatus for passing air or gases through or over certain liquids or solids, or for exhausting a closed vessel, by means of suction. [1913 Webster] 2. (Med.) An instrument for the evacuation of the fluid contents… …   The Collaborative International Dictionary of English

  • Aspirator — (Sauger), s.u. Gasbeleuchtung, A) c) …   Pierer's Universal-Lexikon

  • Aspirator — Aspirator, im allgemeinen jede Vorrichtung, die geeignet ist, Luft, Gase, Dämpfe anzusaugen und weiter zu befördern. Es sind daher streng genommen alle Gebläse der Technik als Aspiratoren zu betrachten, auch wenn das Saugen Nebensache, das Blasen …   Lexikon der gesamten Technik

  • Aspirator — Aspirātor (lat.), Apparat, der entweder einen Luftstrom durch ein mit demselben verbundenes Gefäß saugen oder in einem andern Apparat einen luftverdünnten Raum herstellen soll; dient neuerdings in Fabriken zum Absaugen von Staub, schädlichen… …   Kleines Konversations-Lexikon

  • aspirator — aspìrātor m DEFINICIJA 1. tehn. aparat koji uvlači prašinu, služi za čišćenje kuće; usisavač 2. med. aparat za otklanjanje krvi, sekreta, eksudata, sadržaja šupljih organa i plinova; prijeko potreban pri kirurškim intervencijama 3. općenito,… …   Hrvatski jezični portal

  • aspirator — {{/stl 13}}{{stl 8}}rz. mnż I, D. a, Mc. aspiratororze, med. {{/stl 8}}{{stl 7}} urządzenie funkcjonujące na zasadzie ssącej pompy próżniowej, które służy do aspiracji w zn. 1. <łac.> {{/stl 7}} …   Langenscheidt Polski wyjaśnień

  • aspirator — [as′pə rāt΄ər] n. [see ASPIRATE] any apparatus for moving air, fluids, etc. by suction; specif., an apparatus using suction to remove a fluid or gas from a body cavity …   English World dictionary

  • Aspirator — As|pi|ra|tor 〈m. 23〉 Vorrichtung zum Ansaugen od. Wegblasen von Luft, Gasen usw. [zu lat. aspirare „einhauchen“] * * * Aspirator   der, s/... toren, Absaugvorrichtung für Gase.   * * * As|pi|ra|tor, der; s, ...oren [engl. aspirator, zu lat.… …   Universal-Lexikon