What Is an Aspirator?
Aspirators are suction machines that create a state of reduced pressure.
By depressurizing the inside of the device, the object can be “pulled”.
Aspirators are commonly used to reduce pressure using water and are widely used in scientific experiments and medical applications.
Aspirators use water pressure to create a decompressed state easily and inexpensively.
However, the degree of depressurization can be unstable due to the unevenness of water pressure.
Therefore, in order to maintain a constant state of depressurization, circulating type products and dry type products that do not use liquid have been developed.
In medical applications, simple products that can also be used in homes are also available.
Uses of Aspirators
Uses of scientific aspirators are:
- Decompression during concentration with a rotary evaporator
- Medium exchange in cell culture
- Vacuum manifolds for solid-phase extraction
- Suction filtration and others
Also, for medical use:
- Aspiration of nasal discharge
- Drainage of body fluids in surgery
- Liposuction in cosmetic surgery
- Saliva aspiration during dental procedures
- Suction and removal of uterine contents
and many other applications.
Even more unique applications include research into the collection of otoliths from tiger pufferfish using a medical aspirator.
Aspirator Principle
When a channel has a narrower diameter than another, the pressure is lower when water passes through that area than through a larger area.
This is called the Venturi effect. Aspirators were invented based on this principle.
When a tornado-like rotation is generated in a stream of water, the air around the discharge point is sucked in, creating a reduced pressure.
The simplest aspirators invented based on this principle are glass or metal aspirators that are installed directly into the water supply.
However, water pressure varies depending on the water temperature and installation conditions, and there are disadvantages, such as inconsistent depressurization or insufficient vacuum, so a rotary pump or similar device may be used to depressurize the water.
There are also dry-type aspirators, which have a water tank to circulate water or a diaphragm dry pump built in.
Note that the suction effect of an aspirator is only as good as the balance between the force of the flowing water and the reduced pressure, and if this balance is lost, the water may backflow, so care should be taken.