How Does A Vacuum Cleaner Work ?
A vacuum cleaner is based on the same principal used in drawing up liquid through a straw. When we suck in at one end of a straw with our mouth, a partial vacuum is created inside the opposite end of the straw. As the air near the top end is drawn into our mouth, the air inside the straw moves upwards creating an empty space at the bottom end.
As a result, the liquid pushes its way in and occupies the space exited by the air. This is because matter has a tendency to occupy space. Also, sucking causes a pressure difference at both ends of the straw. The top end of the straw sees a rise in pressure while the bottom end sees a drop. This induces the liquid, which has a higher pressure than the air at the lower end of the straw, to enter the straw.
A vacuum cleaner relies on centrifugal force to draw up dust. It is fitted with an air pump that creates a partial vacuum and a pressure difference to propel dust through the inlet pipe and into the dust bag at the other end.
A vacuum cleaner consists of a suction port, an exhaust port, a centrifugal fan attached to a motor, a dust bag, a filter and an enclosure for holding all of it together. Upon powering up, the motor starts the fan which collects and shoves chucks of air towards the exhaust vent. This increases the density of air molecules in front of the fan and decreases it behind it.
As a result, atmospheric pressure in front of the fan rises and drops behind it. This causes the air from outside the vacuum cleaner (where the air pressure is higher that behind the fan) to be drawn into the fan, and pumped in the direction of the exhaust. This is called suction and it creates a partially empty space inside the gadget to suck in matter (air and dirt) through friction.
The moving air molecules pick up dust particles through friction and propel them into the cleaner. Once inside, the dirty air is made to pass through a dust bag which acts as a filter. It retains the debris and lets out clean air which is expelled through the outlet port. This is the basic mechanism used by all vacuum cleaners.
Vacuum cleaners come in various sizes and capacities. There are small hand-held cleaners for light cleaning, wheeled canister cleaners for domestic household cleaning, large industrial-grade cleaners for factories and high-capacity vacuum trucks for municipal cleaning. Some vacuum cleaners run on battery and some on direct electricity from wall sockets.