Vacuum cleaners have been around since over a century now. They are considered to be indispensable units for housecleaning purposes. They are known for their convenience and efficiency. Running a vacuum cleaner over the surface to be cleaned will effectively remove the dirt and dust present in that particular area. Vacuum cleaners are known to remove any object from the surface provided it is light enough for the suction that it creates and can enter its inlet valve.
One reason why vacuum cleaners are preferred over traditional cleaning equipment such as brooms and mops is that they do not need the mechanical force that these devices need and because they are much more effective at the cleaning process itself. One more advantage is that vacuum cleaners can be used on horizontal, vertical as well as inclined and inverted surfaces and can clean even inaccessible nooks and crannies easily, something that traditional cleaning devices cannot do.
There are various kinds of vacuum cleaners used for a variety of purposes today. The hundred odd years since their first invention has allowed them to evolve and become highly convenient and purposeful objects today. There are vacuum cleaners that are designed to remove solid as well as liquid particles known as wet/dry vacuum cleaners, vacuum cleaners that can be used in an upright posture known as upright vacuum cleaners, canister vacuum cleaners, handheld vacuum cleaners, lint removers, bug cleaners and many more. Some of the more versatile vacuum cleaners comes outfitted with hoses of various dimensions. At the same time, there are vacuum cleaners of various shapes, sizes and bulk.
A typical vacuum cleaner will contain an inlet valve, a fan with electric motor and an exhaust valve. The fan is the most important component. It is designed with slanted blades so that when it moves, it can create a higher pressure below (where the inlet valve is present) and a lower pressure above (where the exhaust valve is present). Air has a tendency of moving from an area at higher pressure to an area at lower pressure. Thus, when the fan is put on, a current of air begins to move from the inlet valve to the exhaust valve. The electric motor connected to the fan energizes it for its motion.
The inlet valve is separately energized. It contains a horizontal cylinder with a spiral brush arrangement on it. When the cylinder rotates (it can rotate at high speeds), the entire brush comes in contact with its surface. As it moves, the brush sweeps out the dust and dirt particles from the surface. Once loosened, these particles move with the flow of air in the direction of the current.
A dust bag is attached somewhere between the inlet valve and the exhaust valve. It may be placed in between the inlet valve and the fan (as in canister vacuum cleaners) or it may be placed between the fan and the exhaust value (as in upright vacuum cleaners). The purpose of the bag is to collect the particles as they move with the air current. These bags also act as filtration devices. They are porous but with pores so tiny that the air can pass out of it but the dust and dirt particles remain trapped within.
Bags will accumulate these particles till they collect so much of it that it will reduce the efficiency of the cleaning process and will need to be emptied out. From here, the air current moves out of the exhaust valve. The current is continuous as long as the vacuum cleaner is in operation.
Some vacuum cleaners will need their bags to be replaced often while some of them will not use bag arrangements at all, but a compartment where the particles are collected. Even these will need to be emptied out, but they make replacement bags unnecessary due to which they have become more popular.
Vacuum cleaners are measured by two factors – the amperage, which is the power of the motor driving the fan, and the gallon capacity, which is a reference of how much air current it can take in at one time.