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| rhysboi1991 |
 Posted: Fri Apr 11, 2008 9:00 am Post subject: vacuums and hoovers |
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Forum Freshman
Joined: 26 Jan 2008
Posts: 48
Location: Cumbria, North West England
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Here is a quick question...
Would a hoover work in an atmosphere that is mostly a vacuum lets say 90% vacuum.
please leave this question to people without qualifications above a-level.
think of how a hoover works. |
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| ajg624 |
| Posted: Fri Apr 11, 2008 9:08 am Post subject: |
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Forum Sophomore
Joined: 27 Feb 2008
Posts: 100
Location: Chicago Area
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don't know about your hoover but i would expect my electrolux to experience the same problem as any life form attempting to breathe in space. kaboom!!!
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| Harold14370 |
| Posted: Fri Apr 11, 2008 9:45 am Post subject: Re: vacuums and hoovers |
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Forum Professor
Joined: 13 Apr 2007
Posts: 1244
Location: Pennsylvania
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| rhysboi1991 wrote: |
Here is a quick question...
Would a hoover work in an atmosphere that is mostly a vacuum lets say 90% vacuum.
please leave this question to people without qualifications above a-level.
think of how a hoover works. |
What's a-level and why do you want to limit the question to unqualified people? |
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| Cat1981(England) |
| Posted: Fri Apr 11, 2008 10:00 am Post subject: |
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Forum Ph.D.
Joined: 09 Sep 2006
Posts: 827
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| Harold wrote: |
| What's a-level and why do you want to limit the question to unqualified people? |
An A-level is a qualification that people here usually gain between the ages of 16-18, the first level of voluntary education after compulsory education.
The reason he may want the answer limited is because (if you haven't noticed) the English tend to be rather thick. 
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| Pong |
| Posted: Fri Apr 11, 2008 1:05 pm Post subject: Re: vacuums and hoovers |
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Forum Senior
Joined: 08 Apr 2008
Posts: 309
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| rhysboi1991 wrote: |
| think of how a hoover works. |
Startup capacitor burst. No go.
Or, motor without startup cap:
Go! Unloaded impeller over-speeds. It's screaming yet doesn't make a sound!!! Air-cooled motor burns out in a few seconds (sooner than a locked rotor at sea level - where does the heat go?).
Uh, I do qualify.  Now, anybody want to explain how to fix the hoover? Please leave this question to people with qualifications above a-level.  |
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| JaneBennet |
| Posted: Fri Apr 11, 2008 1:40 pm Post subject: |
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Forum Junior
Joined: 06 Apr 2008
Posts: 219
Location: UK
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| Cat1981(England) wrote: |
| The reason he may want the answer limited is because (if you haven't noticed) the English tend to be rather thick. |
I just think Rhysboi1991 only wants to know if the question can be answered without using advanced university-level physics. |
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| william |
| Posted: Fri Apr 11, 2008 1:42 pm Post subject: |
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Forum Ph.D.
Joined: 23 Jun 2006
Posts: 905
Location: USA
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The absolute best any vacuum can do (on Earth) is 29.92" Hg. The absolute best any vacuum can do anywhere is one local atmosphere.
I will respect the OP and not address the question any further.
On a side note, I've always wanted to get two competing vacuum salesmen to come to my house and have at it. One told me that his machine would suck the dirt out of the other guy's vacuum if connected hose-to-hose and both running.  I'd like to see them do battle.
On another side note, it's kind of neat to see all the gimmicks these salesmen have to "show" how powerful their cleaners are. Neat if you understand some basic physics anyway....
Cheers
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| bit4bit |
| Posted: Fri Apr 11, 2008 3:44 pm Post subject: |
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Forum Bachelors Degree
Joined: 14 Jul 2007
Posts: 478
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Basically, the only reason a hoover 'sucks' is cause the air pressure inside is made to be lower than the air pressure outside (A partial vacuum), by an electrically powered impeller/pump inside it.
Fluid (i.e. air) always moves from areas of higher pressure to areas of lower pressure, so it's really the inverse operation of a fan.
Space is a complete vacuum, and once you put the vacuum cleaner in space, any air that might be in it will be sucked out straight away. At that point the pressure inside, and outside will be the same, so for a fluid there would be no movement....on top of that the fluid has been removed anyway, so there is 1.) nothing for the pump to pump, 2.) nothing to flow into the cleaner to pull in dust or dirt.
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| rhysboi1991 |
| Posted: Fri Apr 11, 2008 5:38 pm Post subject: |
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Forum Freshman
Joined: 26 Jan 2008
Posts: 48
Location: Cumbria, North West England
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Thank you very much janeBennet for "sticking up" for me and the reason i wanted people who had qualifications below A-level is that i am only a GCSE student and i didn't want people to use Degree level and higher terminology in case i did not understand it.
For the people that do not know GCSE is an abbreviation for General Certificate of Secondary Education which is a compulsory qualification for people in my age group to sit.
i was quite offended about you (cat1981(england)) saying that comment about the english being thick untill i realised that you were from england.
Also, thank you bit4bit for the explanation and william the sidenote you mentioned about two vacuum salesmen battling would be very interesting.
sorry if i come accros as being weird but i like to give people appreciation for answering my question and to explain why a ask certain things. |
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| Harold14370 |
| Posted: Fri Apr 11, 2008 5:59 pm Post subject: |
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Forum Professor
Joined: 13 Apr 2007
Posts: 1244
Location: Pennsylvania
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All right, I thought maybe you knew the answer already and wanted to quiz the lower level students to see if they knew it too.
Two valid answers have been given. The vacuum cleaner works by moving air past the dust and entraining the dust particles in the air current. Without air, there is nothing for the fan to move and nothing for the dust to get picked up in. Pong also points out that the motor would lack cooling and would quickly burn out.
What is the answer to Pong's question? I suppose you could relocate the motor outside the vacuum chamber, leaving only the impeller inside, or you could provide some cooling fluid to the motor windings. What's your answer, Pong? |
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| Pong |
| Posted: Fri Apr 11, 2008 10:58 pm Post subject: |
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Forum Senior
Joined: 08 Apr 2008
Posts: 309
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| Harold14370 wrote: |
| What is the answer to Pong's question? |
It wasn't a serious question. And what I had in mind - locating some buried fused section in the fantastic length of tightly wrapped wire, ought to turn anybody off.
But designing an effective hoover for service in very thin atmospheres, that's an interesting challenge and we may even want one.
...
I give up. Aim for volume, or pressure? Each is useless without the other. |
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