Hi all -

is there somewhere with information on the design of a venturi to
produce suction or vacuum ?

We're trying to make a vacuum cleaner using compressed air and a coaxial
venturi and figuring out how big to make the parts and what size ratio
gives the best suction is turning out to be a problem.

A google turns up tons of venturi information but I couldn't find a
design formula relating orifice size, main tube size and restriction
size along with inlet pressure or flow rate.

Any pointers would be helpful...

Thanks in advance

Carla
Skilled politicians, like high-end hookers, are only for those who can
afford them. Michael Pearce

On Wed, 17 Sep 2008 23:58:27 -0700, Carla Fong
wrote:

Hi all -

is there somewhere with information on the design of a venturi to
produce suction or vacuum ?

We're trying to make a vacuum cleaner using compressed air and a coaxial
venturi and figuring out how big to make the parts and what size ratio
gives the best suction is turning out to be a problem.

A google turns up tons of venturi information but I couldn't find a
design formula relating orifice size, main tube size and restriction
size along with inlet pressure or flow rate.

Any pointers would be helpful...

Thanks in advance

Carla
Skilled politicians, like high-end hookers, are only for those who can
afford them. Michael Pearce


Is this what you're looking for?

http://www.spenroaircrafttool.com/sp...uum-p-217.html

Bob

Carla Fong writes:

is there somewhere with information on the design of a venturi to
produce suction or vacuum ?

Would be nice to know what pressure and flow rate you had in mind.

Bob wrote:

Is this what you're looking for?

http://www.spenroaircrafttool.com/sp...uum-p-217.html

Bob

No, sorry - see below.

Richard J Kinch wrote:

Carla Fong writes:

is there somewhere with information on the design of a venturi to
produce suction or vacuum ?

Would be nice to know what pressure and flow rate you had in mind.


Unfortunately, the application is covered by an NDA and has 'patent
pending' status so I can't really provide the details - but what I am
looking for is some general information about designing/building venturi
vacuum or suction generators .

Reference designs, formulas, etc.

Thanks for any help...

Carla

Is this weird or what? One of our local candidates for mayor has breast
implants - his campaign slogan is "Am I serious? Of course! The last
eight years have demonstrated that the public is perfectly willing to
elect boobs to public office!" http://www.voteforstu.com

Carla Fong wrote:
Hi all -

is there somewhere with information on the design of a venturi to
produce suction or vacuum ?

We're trying to make a vacuum cleaner using compressed air and a coaxial
venturi and figuring out how big to make the parts and what size ratio
gives the best suction is turning out to be a problem.

A google turns up tons of venturi information but I couldn't find a
design formula relating orifice size, main tube size and restriction
size along with inlet pressure or flow rate.

Any pointers would be helpful...

You might look at carburetors. Most old internal
compustion engine books have a section on the
venturi portion of a carb. What you're really
interested in is the Bernoulli effect in a cylindrical
form.

On Sep 18, 2:58*am, Carla Fong wrote:
Hi all -

is there somewhere with information on the design of a venturi to
produce suction or vacuum ?

We're trying to make a vacuum cleaner using compressed air and a coaxial
venturi and figuring out how big to make the parts and what size ratio
gives the best suction is turning out to be a problem.

A google turns up tons of venturi information but I couldn't find a
design formula relating orifice size, main tube size and restriction
size along with inlet pressure or flow rate.

Any pointers would be helpful...

Thanks in advance

Carla
Skilled politicians, like high-end hookers, are only for those who can
afford them. *Michael Pearce

I would try a Perry's or a Mark's engineering handbook. They probably
have the formulas you can need for sizing.

Carla Fong writes:

Would be nice to know what pressure and flow rate you had in mind.


Unfortunately, the application is covered by an NDA and has 'patent
pending' status so I can't really provide the details

Puh-leeze. Two numbers constitute an NDA and a patent? Contemptible
coyness.

On Fri, 19 Sep 2008 01:53:46 -0500, the infamous Richard J Kinch
scrolled the following:

Carla Fong writes:

Would be nice to know what pressure and flow rate you had in mind.


Unfortunately, the application is covered by an NDA and has 'patent
pending' status so I can't really provide the details

Puh-leeze. Two numbers constitute an NDA and a patent? Contemptible
coyness.

Isn't venturi vacuum about 1% efficient? Then you'd need 500HP to get
the same flow as a $35 shop vac, I'd think. Nexxxxxxxxxxxt!

--
Once we believe in ourselves, we can risk curiosity, wonder, spontaneous
delight, or any experience that reveals the human spirit.
--e e cummings

On Fri, 19 Sep 2008 05:22:37 -0700, Larry Jaques wrote:
On Fri, 19 Sep 2008 01:53:46 -0500, the infamous Richard J Kinch:
Carla Fong writes:

Would be nice to know what pressure and flow rate you had in mind.

Unfortunately, the application is covered by an NDA and has 'patent
pending' status so I can't really provide the details

Puh-leeze. Two numbers constitute an NDA and a patent? Contemptible
coyness.

Isn't venturi vacuum about 1% efficient? Then you'd need 500HP to get
the same flow as a $35 shop vac, I'd think. Nexxxxxxxxxxxt!

I don't think it's quite that bad, but my guess would be in the 3%
to 5% range, maybe 10% if all the stars and planets were aligned.
Which still sucks rocks -

Unless you have "free" energy like waste compressed air by the ton
and extreme space restrictions on the vacuum generating equipment (and
I can't see those two existing at the same time), you'd be much better
off using another energy source and/or vacuum generation method.

Hell, modifying a IC Engine turbocharger to take the air energy from
the exhaust turbine and use the compressor section as a vacuum blower
would probably be more efficient than a venturi.

About the only tricky part would be supplying a small lubrication
pump and a 1-quart lube oil tank for the center section bearings, and
keeping it powered after shutdown for spin-down lubrication - and if
it isn't being run by exhaust gases heat is not an issue. You get a
bit of compression heating, but that's nothing compared to the design
temps on the exhaust side.

-- Bruce --