RCM-2009 Reliability Centered Maintenance Managers' Forum - March 23-26 - Daytona Hilton Ocean Walk Village - Daytona Beach Florida Join or Manage Your Profile Posting Boards Machinery Condition Monitoring and Predictive Maintenance Posts About vibration/alignment/balance HP presssure pulsationin screw compressor
Join or Manage Your Profile Posting Boards Machinery Condition Monitoring and Predictive Maintenance Posts About vibration/alignment/balance HP presssure pulsationin screw compressorPage 1 2
|
Go
|
New
|
Find
|
Notify
|
Tools
|
Reply
|
|
how to reduce the HP gas pressure pulsation in a screw compressor
|
|||
|
You'll have re-design the silancer or install orifice plate in discharge line (energy loss).
|
||||
|
Run two compressors with a 180 degree phase difference in pulsations to cancel each other.
|
||||
|
If you are talking of gas pressure pulsation itself and not vibration caused by it, then why worry at all? Pressure pulsations are practically not present in the receiver tank.
|
||||
|
Volumetric compressor always has pressure pulsation coming from trapped low-pressure air being released from the rotating element into the high-pressure side of the system. The momentary back flow causes shock pulse throughout the compressor. I don’t know of any system that can help other than good maintenance practice like filter cleaning, system design, load, air temperature, etc. It should not affect the reliability of the compressor.
Best regard, Marcel |
||||
|
[QUOTE]Originally posted by David_G:
If you are talking of gas pressure pulsation itself and not vibration caused by it, then why worry at all? Pressure pulsations are practically not present in the receiver tank.[/QUOTE ]no that is causing a vibration of 25mm/sec pk in the initial time when taken on load,,,so some modification to be done!! |
||||
|
how to run with phase difference in pulsation 180 deg???system get loaded at 8 bar andunloaded at 9 bar |
||||
|
wat are the differnt ways of modificationthe silencer ??? |
||||
|
There are several companies I'm aware of specializing in these silencers. I know that even on new installations you can encounter a very high pulsation leading to piping vibration. As this is usually a high frequency phenomenon it's very damaging for the equipment and existing silencer if exposed to it can develop cracks. Some time silencer manufacturers are not too good and some consulting companies have to solve their design issues. I know that Engineering Dynamics from San Antonio has been working on this kind of issues.
http://www.engdyn.com/ |
||||
|
hey alex thanks for response.But suppose if i wanna modify the silencer in the site.wat are the things i shld consider? |
||||
|
dax,
Likely you are experiencing such a high vibration on the pipes. If so, run a simple bump test and install braces if at resonance. Has it been confirmed that vibration occurs at the pressure pulsation frequency? David |
||||
|
Dax,
Changing silencer design is not such a simple thing. It depends on type of silencer (reactive, reactive/dissipative, dissipative or splitter type) and you have to understand this specific design. I would not recommend any changes to be done without good understanding or knowledge in this subject. You can create more damage. |
||||
|
do u have some material on the remedies of HP gas pulsation |
||||
|
|
||||
|
Dax,
Could you describe some more about your issue? What compressor, what silencer, silencer location vs. discharge flange, why do you think there is a problem with pulsation, what's the frequuency vs. running speed etc? |
||||
|
Dax, first of all, what Alex is trying to get at is that these problems are often not simple, and require some pretty high tech engineering analysis to fix.
Having said that I am assuming you are talking about a process gas compressor of some kind at a fairly high power, and not a little bitty air compressor sitting on a receiver. The OEMs have some solutions, but my best experience has been with EDI as Alex recommended. There are also papers on their site on the subject. David_G, perhaps you are not understanding the issue? The primary problem with screw compressors is high frequency pulsation and damaging levels can certainly be present in the receiver. I was recently involved with a refrig compressor that was tearing up the receiver causing ammonia release. It is also typically much easier to reduce pulsation levels than it is to go out and bump test and detune every piece of piping, instrument line etc in the plant. e-mail me at steven dot schultheis at gmail dot com |
||||
|
Thank u steve and alex My compressor is a air compressor with 355kw motor.the running speed and the spectrum attached.if u see this is having a peak 40.5kcpm and at higher feqauencies 80.5kcpm(see HP female spectrum on load condition)The male rotor speed is 10098 rpm.thats y i doubt HP pulsation (see attachment given hp pulsation at 673 HZ).I also attach the schemetic wer u can see the location of the silencer .It is after the HP stage before after cooler(see attachment).So now can u help Doc1.doc (166 Kb, 22 downloads) |
||||
|
see spectrum hp_stage_pressure_pulsasion.doc (125 Kb, 20 downloads) |
||||
|
Doc111.doc (177 Kb, 20 downloads) |
||||
|
see attachmenrt Doc111.doc (164 Kb, 18 downloads) |
||||
|
| Previous Topic | Next Topic | powered by eve community | Page 1 2 |
 | Please Wait. Your request is being processed... |
|
|||
| Site | Join or Manage Your Profile | ||
| Servlet | eve1da019 | ||
| Version | 1.3.0 build 9383 | ||
| Module | Forums 4.0.3 | ||
| Stylesheet | "Eve" | ||
| Wordlet Set | "Default Wordlet Set" | ||
|
RCM-2009 Reliability Centered Maintenance Managers' Forum - March 23-26 - Daytona Hilton Ocean Walk Village - Daytona Beach Florida Join or Manage Your Profile Posting Boards Machinery Condition Monitoring and Predictive Maintenance Posts About vibration/alignment/balance HP presssure pulsationin screw compressor
Join or Manage Your Profile Posting Boards Machinery Condition Monitoring and Predictive Maintenance Posts About vibration/alignment/balance HP presssure pulsationin screw compressor
Contact Us | RCM-2009 Reliability Centered Maintenance Managers' Forum - March 23-26 - Daytona Hilton Ocean Walk Village - Daytona Beach Florida | Privacy Statement | Terms of Service
Copyright © 2004-2008 NetexpressUSA Inc. All rights reserved.