I'm doing a project on vacuum cleaner. Now at first i'm wondering how to make suction. Some says that i don't need motor but instead what i need is pneumatic valve. so can i have a clear view on how to suck dust or even small objects?
please and thank in advanced for helping me

 

The usual means of creating the pressure differential is pretty successful - why not stay with what works?

 

Are you interested in how objects are carried by the vaccuum stream, or something else? What immediately comes to mind is a can-vac connected to a clear PVC pipe, so that a visible indication of velocity and lift can be made.

Cheers, DPW [Spent years making heaters out of op-amps.]

 

ermmm what i want to know is that is it i just need an AC motor and a fan then i can create suction?

 

Yes, although there is a difference between a fan that is designed to move air, and a vacuum fan designed to move air rapidly enough to pick up dirt and work against significant back pressure.

 

A vacuum cleaner is more like turbine. It uses a fan to create fast moving air. The air is sucked into the tube together with dust. The dust ends in the bag and out comes clean air(almost). The air will pass the motor on the way out and cool it down. You will very quickly overheat and burn out the motor if you use it to maintain vacuum. Not only due to reduced cooling but it will also be overloaded making even more heat. It is not made for such use.

 

Acually, blocking the airflow to a typical centrifugal fan or blower (such as a vacuum cleaner) reduces the motor loading.

Try putting your hand over the end of the pickup pipe - the motor pitch increases, as the load has been reduced. (The fan is no longer having to accelerate 'new' air, so it's not having to do any work).

Whether or not any particular machine can run indefinitely like this is another thing, you would have to monitor the motor temperature to ensure it did not get too hot.

The other method of creating a vacuum is a venturi tube operated by compressed air. These are often used in small mechanical handling systems, for such as lifting or erecting small cardboard packs and electronic component 'pick and place' machines.

 

Ouch I was to quick on that one. I do not have the habit of using a vacuum cleaner for anything than cleaning
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1713722/pdf/brmedj00028-0030b.pdf
But it sounds correct. If the motor do not have move any air it will, do less work. But the heating problem is still important.