How vacuum cleaners work (2)

The suction of a vacuum cleaner depends on many factors.The strength of the suction depends on:

Fan power: in order to generate strong suction, the motor must rotate at a good speed.

Blockage of the air passage: when large amounts of debris accumulate in the vacuum bag, the air will face greater resistance as it is discharged.As the drag increases, each air particle moves more slowly.That's why vacuum cleaners work better when you've just changed your bag than when you've been vacuuming.

Size of the opening at the end of the inlet: since the speed of the vacuum fan is constant, so is the amount of air passing through the vacuum cleaner per unit time.The number of air particles entering a vacuum cleaner per second is the same regardless of the size of the inlet.If you make the port smaller, individual air particles have to move faster to get through it all in that time.Because of Bernoulli's principle, pressure decreases as air speed increases.The decrease in pressure translates into greater suction at the inlet.Because they produce stronger suction, narrower vacuum attachments and wider attachments can absorb heavier dust particles

At the most basic level, this is what a vacuum cleaner is all about.Since the invention of the electronic vacuum a century ago, many innovative thinkers have expanded and modified the idea to create different types of vacuum systems.

So far, we've looked at the most typical types of vacuum cleaners: upright and cylindrical, which collect dust in a porous bag.These have been the most popular designs for most of the history of the vacuum cleaner, but there are many other ways to configure the vacuum system.

For heavy cleaning, many people use a wet/dry vacuum cleaner. This model can pick up both liquids and solids.Liquid materials can saturate paper or cloth filters, so these cleaners require a different collection system.

The basic design is simple: in passing through the cleaner, the airflow passes through a larger area, which is located above the barrel.As it reaches this larger area, the flow slows, just as it speeds up through a narrow appendage.This speed drop effectively relaxes the air's grip, so droplets and heavier dirt particles can fall out of the air stream into the bucket.After you have vacuumed, you simply dump the contents collected in the bucket.

One recent change to vacuum cleaners is the so-called "cyclone vacuum."Developed by James Dyson in the 1980s, the machine has no traditional bag or filtration system.Instead, it sends air through one or more cylinders along a high-speed spiral path.This action is similar to a dryer, roller coaster, or merry-go-round.When the airflow spirals, all the dust particles are subjected to a powerful centrifugal force: they are pulled away from the airflow.This way, dirt can be extracted from the air without any filter.It just collects at the bottom of the cylinder.

Compared to conventional vacuum cleaners, the cyclone system is significantly improved - there are no replaceable bags, and the suction does not decrease as you add more dust.

Robot vacuum

Until recently, no matter how powerful the vacuum, someone needed to push it.Enter the robot vacuum.Thanks to a combination of motors, sensors and navigation systems, the gadgets can clean themselves.

In the future, we will definitely see more improvements in the basic vacuum cleaner design, with new vacuuming mechanisms and collection systems.But the basic idea of collecting dust and debris with flowing air is likely to stay there for a while.