Previous in Forum: project   Next in Forum: Oil flow rate for a babbit guide bearing
Close
Close
Close
16 comments
Rate Comments: Nested
Power-User
India - Member - New Member Germany - Member - New Member France - Member - New Member Engineering Fields - Mechanical Engineering - New Member Popular Science - Weaponology - New Member Engineering Fields - Energy Engineering - New Member Hobbies - RC Aircraft - New Member

Join Date: Jun 2009
Location: India-maharashtra-kalyan
Posts: 116

pneumatic cylinder

01/30/2010 8:44 AM

hi,

I m trying to make some reciprocating compressed air engine.

the source cylinder is filled with copressed air which is at 300atm.but the problem is when the is dicharged from cylinder the pressure of air inside the cylinder decreases.

thu my que. is how to sort out this pressure problem?

__________________
Be an engineer not a degree holder!
Register to Reply
Pathfinder Tags: Pneumatic Cylinder
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Guru

Join Date: Oct 2008
Posts: 42355
Good Answers: 1693
#1

Re: pneumatic cylinder

01/30/2010 9:04 AM

There is nothing to sort out. That's how it works. The pressure inside the cylinder is used to make the car go. You have to find a way to replace it.

Register to Reply
Guru

Join Date: Mar 2007
Location: City of Light
Posts: 3943
Good Answers: 183
#2

Re: pneumatic cylinder

01/30/2010 12:15 PM

I very much doubt that you want to work in your engine with 300bar compressed air.

What you can do is to use a detender between the high pressure cylinder and your engine and work at a reasonable pressure on the pistons. In fact the best would be to have for different reasons two reservoirs: a high pressure one as you already have and a low pressure one connected to the engine. The detender being between the two reservoirs. This way you have a constant affordable pressure in front of your engine.

What LL wrote is correct your energy reserve will decrease when your engine runs so that you are obliged to recharge it.

As far as I know Tata took a French license for a pneumatic car which runs very well. Are you aware of it?

Register to Reply
Power-User
India - Member - New Member Germany - Member - New Member France - Member - New Member Engineering Fields - Mechanical Engineering - New Member Popular Science - Weaponology - New Member Engineering Fields - Energy Engineering - New Member Hobbies - RC Aircraft - New Member

Join Date: Jun 2009
Location: India-maharashtra-kalyan
Posts: 116
#4
In reply to #2

Re: pneumatic cylinder

01/30/2010 1:39 PM

I m agree with u but i want constant force on my engine's pistone thus i must supply constant pressure air to engine. If the pressure of source cylinder decreases then power developed by engine also decreases so that speed decreases. So the way only is to fill the air at greater pressure than i required.But the source cylinder may damage if i exceed the pressure.

__________________
Be an engineer not a degree holder!
Register to Reply
Guru

Join Date: Mar 2007
Location: City of Light
Posts: 3943
Good Answers: 183
#5
In reply to #4

Re: pneumatic cylinder

01/30/2010 3:12 PM

I think that you did NOT understand what I wrote so it would be better you let it and do not try to make some think if you do not get the point. I made the suggestion which offers you exactly what you need a CONSTANT pressure in front of the engine!

Register to Reply
Power-User
India - Member - New Member Germany - Member - New Member France - Member - New Member Engineering Fields - Mechanical Engineering - New Member Popular Science - Weaponology - New Member Engineering Fields - Energy Engineering - New Member Hobbies - RC Aircraft - New Member

Join Date: Jun 2009
Location: India-maharashtra-kalyan
Posts: 116
#8
In reply to #2

Re: pneumatic cylinder

01/31/2010 2:57 AM

I search for detender on internet but i don't get any proper information. Can u help me?

__________________
Be an engineer not a degree holder!
Register to Reply
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21017
Good Answers: 795
#9
In reply to #8

Re: pneumatic cylinder

01/31/2010 5:59 PM

Another term for this is "pressure regulator". It would be similar to the regulators on welding tanks, perhaps in a larger size.

If the air tank(s) on a car are damaged, the car will turn briefly into a rocket. This would be a safety issue, to say the least.

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
Power-User
India - Member - New Member Germany - Member - New Member France - Member - New Member Engineering Fields - Mechanical Engineering - New Member Popular Science - Weaponology - New Member Engineering Fields - Energy Engineering - New Member Hobbies - RC Aircraft - New Member

Join Date: Jun 2009
Location: India-maharashtra-kalyan
Posts: 116
#12
In reply to #9

Re: pneumatic cylinder

02/05/2010 11:31 AM

can u tell me which company(web site) supplies the high pressure gas cylinder upto 300atm.

if i connect pressure regulator to this cylinder & i fixed certain pressure then how to calculate discharge of the cylinder.

__________________
Be an engineer not a degree holder!
Register to Reply
Anonymous Poster
#13
In reply to #12

Re: pneumatic cylinder

02/05/2010 4:48 PM

rajeshbhanushali123,

In your quest of higher knowledge, I suggest that you pay some attention to the written word, as it is most important in putting forth what you wish to communicate and will yield a higher degree of response when presented properly and coherently.

"can u tell me..."

The first letter of the first word of a sentence is capitalized, as in Can.

In using the word can as you have, you are asking whether or not a person is capable of responding to you, not whether or not they are willing to respond. Will or would are the words more appropriately used when making a request; e.g., "Would you (see below for you) kindly (or please) inform me as to where I might access...........

The letter "u" is meaningless in and of itself and or out of context. The second person pronoun that should be used in this case is you.

The first person pronoun used to denote oneself is the capital I, not "i".

For me, CR4 is a friendly forum of mostly mature professionals who prefer the traditional manners of communication. Please leave the u's and i's for your texting communications.

Register to Reply
Power-User
India - Member - New Member Germany - Member - New Member France - Member - New Member Engineering Fields - Mechanical Engineering - New Member Popular Science - Weaponology - New Member Engineering Fields - Energy Engineering - New Member Hobbies - RC Aircraft - New Member

Join Date: Jun 2009
Location: India-maharashtra-kalyan
Posts: 116
#16
In reply to #13

Re: pneumatic cylinder

02/06/2010 7:48 AM

Thanks for improving my english

__________________
Be an engineer not a degree holder!
Register to Reply
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21017
Good Answers: 795
#14
In reply to #12

Re: pneumatic cylinder

02/05/2010 10:02 PM

Google "high pressure air tanks" to find some manufacturers of 4500 psi (300 bar) cylinders. Lots of hits.

To drive your vehicle, you need an "air motor"--Google that also. I'm not sure of all the types that might be offered (vane, screw, piston, etc.) Many manufacturers are likely to have Web-accessible data on operating pressure, HP or KW produced, and air flow. Many such motors operate around 100 psi (~7 bar). Whatever pressure rating it is, your pressure regulator's range must include this value, and its flow rate needs to match the flow rate of the air motor.

I am not expert enough in pneumatics to do the calculations from first principles, so my approach here is based on manufacturers' commercial data.

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
Guru

Join Date: Mar 2007
Location: City of Light
Posts: 3943
Good Answers: 183
#15
In reply to #12

Re: pneumatic cylinder

02/06/2010 5:28 AM

Please do not take what I write the wrong way.

Your knowledge is at such a level that you have a high risk of accidents in the development you try to start.

Before you go further try either to learn more about thermodynamics or to find in your neighbourhood somebody able to support your efforts from the technical point of view. CR4 cannot help you as much as you need considering your letters and questions.

Register to Reply Off Topic (Score 5)
Guru

Join Date: Oct 2008
Posts: 42355
Good Answers: 1693
#3

Re: pneumatic cylinder

01/30/2010 1:34 PM
Register to Reply
Guru
Hobbies - CNC - New Member Hobbies - DIY Welding - New Member Engineering Fields - Electromechanical Engineering - New Member

Join Date: Aug 2007
Posts: 23647
Good Answers: 420
#6
In reply to #3

Re: pneumatic cylinder

01/30/2010 7:40 PM

I'm surprise at you, the clip puts a spin on it to sound that it can be self generating

__________________
“ When people get what they want, they are often surprised when they get what they deserve " - James Wood
Register to Reply
Guru

Join Date: Oct 2008
Posts: 42355
Good Answers: 1693
#7
In reply to #6

Re: pneumatic cylinder

01/30/2010 8:46 PM

Sorry,

I have so little faith in the concept that I never watched the entire video.

Take it with a grain of salt.

LL

Register to Reply
Anonymous Poster
#10
In reply to #7

Re: pneumatic cylinder

01/31/2010 10:01 PM

pinch of salt!

Register to Reply
Associate

Join Date: Oct 2006
Posts: 40
Good Answers: 1
#11
In reply to #10

Re: pneumatic cylinder

02/02/2010 5:22 PM

No, you should be sodium free for a healthy diet.

Register to Reply
Register to Reply 16 comments
Copy to Clipboard

Users who posted comments:

Anonymous Poster (2); hurdent (1); lyn (3); nick name (3); phoenix911 (1); rajeshbhanushali123 (4); Tornado (2)

Previous in Forum: project   Next in Forum: Oil flow rate for a babbit guide bearing

Advertisement