How Vacuum Cleaners Work

Even though it may appear to be a very complicated
machine, the conventional vacuum cleaner is actually
made up of six essential components: intake port,
exhaust port, electric motor, fan, porous bag, and
a housing that stores all of the other components.

When you plug the vacuum cleaner into the outlet and
turn it on, the following happens:
1. First of all, the electric current will
operate the motor, which is attached to the fan,
which resembles an airplane propeller.
2. As the blades begin to turn, they will
force the air upwards, towards the exhaust port.
3. When the air particles are driven forwards,
the density of the particles will increase in front
of the fan and therefore decrease behind it.

The pressure drop that occurs behind the fan is
similar to the pressure drop when you take a drink
through a straw. The pressure level in the area
that is behind the fan will drop below the pressure
level that is outside of the vacuum cleaner.

This will create a suction inside of the vacuum
cleaner. The ambient air will push itself into the
vacuum cleaner through the intake port because the
air pressure that is inside of the vacuum cleaner
is much lower than the pressure on the outside.

Picking the dirt up
The stream of air that the vacuum generates is just
like a stream of water. The air particles that move
will rub against any loose dust or debris and if
it is light enough, the friction will carry the
material around the inside of the vacuum cleaner.

As the dirt continues on to the exhaust port, it
will pass through the cleaner bag. They tiny holes
in the vacuum cleaner bag are large enough to let
the air pass through, although too small for the
dust particles to fit through. Therefore, when
the air current gets into the bag, the dirt and
debris will be collected there.

You can stick the bag anywhere along the path
between the intake tube and the exhaust port, just
as long as the air current passes through.

The power of a vacuum cleaner’s suction will depend
on several factors. The suction can be stronger
or weaker depending on:
1. Fan power – In order to generate a
strong suction, the motor needs to turn at a good
2. Air passageway – When a lot of debris
builds up in the bag, the air will face a greater
level of resistance on the way out. Each particle
of air will move slowly due to the increase in
drag. This is the reason why a vacuum cleaner
works much better once you’ve replaced the bag
than when you have been using it for a while.
3. Size of the intake port – With the
speed of the vacuum fan being constant, the amount
of air that passes through the vacuum cleaner per
second is also constant.


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