2013



Page 1 of 2 12 LastLast
Results 1 to 50 of 57
  1. #1
    Join Date
    May 2003
    Location
    Vietnam
    Age
    55
    Posts
    19
    Rep Power
    0

    Post Single screw compressor


    Hi all,

    As your experience, could you advise me a comparison between single and twin screw compressor and also application field of the single one (reffering to J & E HallScrew).

    Many Thanks



  2. #2
    Join Date
    Jun 2001
    Location
    N.Ireland
    Age
    41
    Posts
    1,654
    Rep Power
    15
    Hi dvtruc,
    in my experience there is little differance in performance or effeciency, the only draw back with single Halls screws is the increased maintenance requirement compared to a single screw of the same duty. This is offset a little by the loe cost of the service spares. If you have a number of Halls screw requiring the same tool kit costs are reduced, if not it is very expensive to buy the tools just to maintain one or two screw compressors.
    Stick to a twin screw such as a Howden unless you are able to do the overalls yourself and you have the tools.
    Regards. Andy

  3. #3
    Join Date
    Dec 2002
    Location
    South Africa
    Posts
    4
    Rep Power
    0

    Hall Screw

    Interesting chat re the single - screw compressor. Generally speaking, they have not been popular for the reasons outlined by Andy. Grasso manufactured a range called the "Mono Screw" in the 70's. These were also maintenance intensive and in general they did not handle fluctuating loads in the way that we now take for granted with the twin screw machines.

    I am evaluating a multi compressor installation using Hall Screw HS 35's on ammonia. - High Stage (-10/+35), Low Stage booster(-40/-10) and "Swing changeover " applications on either duty. Please, can anyone assist with a set of capacity / selection curves for this machine? J & E Hall have not helped me.

  4. #4
    Join Date
    May 2003
    Location
    Vietnam
    Age
    55
    Posts
    19
    Rep Power
    0
    Hi Sexton,

    Hall Screw sent me a Dos selection sofware for their new 4200 single screw compressor. You can refer to it. Tell me to sent it via net.

    Truc

  5. #5
    Join Date
    Dec 2002
    Location
    South Africa
    Posts
    4
    Rep Power
    0

    Hall Screw

    Hi dvtruc,

    Thanks very much for your advice. This gives me more hope. I specifically need the data for the HS35. Perhaps you could let me know the details of the contact person who helped you at Halls. I might be more successful if I talk to a specific person.

    Thanks so much for your help.

    Regards. Sexton

  6. #6
    Join Date
    May 2003
    Location
    Vietnam
    Age
    55
    Posts
    19
    Rep Power
    0
    Hi Sexton,

    Sorry for my late reply. His name is Mr Tony Payne - a Sales Manager, but I don't know who a technical man is.

    Office phone no. +44 1332 253477

    Regards,

    DVTruc

  7. #7
    Join Date
    Dec 2002
    Location
    South Africa
    Posts
    4
    Rep Power
    0

    Contact @ JE Hall

    Hi DV Truc,

    Thanks for your help. I have been contacted by Dave Ball who is giving me assistance.

    Thanks for your contribution - this forum is really helpful.

    Best regards,

    Sexton

  8. #8
    Join Date
    Apr 2001
    Location
    South Georgia
    Posts
    8
    Rep Power
    0
    The modern era of single screws is manufactured by Vilter Manufacturing. They are having great success with these units however the marketing is hampered by all the bad press Grasso & Hall received. Vilter has gotten rid of the bugs in this design and even backs it with a 5-year warranty. I sell verey few parts for these machines. As a Vilter distributor the only real parts I need to stock are for the micro. As far as maintenance I see no more than a twin screw.

  9. #9
    Join Date
    Jun 2001
    Location
    N.Ireland
    Age
    41
    Posts
    1,654
    Rep Power
    15
    Hi Jryffel
    Vitler make a single/mono screw
    Nothing wrong with a mono screw, just they haven't kept up with the times on my side of the pond.
    Priced a maintenance contract with a HS35 on it recently, looks like I am going to see quite a bit of mono screws in the next few months
    Have you a link to the Vitler site so we can have a look see.
    Regards. Andy

  10. #10
    Join Date
    Apr 2001
    Location
    South Georgia
    Posts
    8
    Rep Power
    0
    http://www.vilter.com/ This is their site. I am a Vilter distributor
    however we use Vilter recips alot but have not yet put in a single screw. After all the horror stories we have heard on the Hall mono screw we will need Vilter to have some track record before we spec a single screw. It does not seem like they are gaining their share of the market. We use twin screw FES or M&M at this time with great results. Most of our designs include both screws and recips. Screws for main load and recips to cycle on and off as needed to best match the loads.

  11. #11
    Join Date
    Jun 2003
    Location
    Georgia
    Posts
    72
    Rep Power
    12
    Originally posted by Jryffel
    http://www.vilter.com/ .......we will need Vilter to have some track record before we spec a single screw.
    The track record is there. My clients have had generally good experiences with them. I would pause before using one at low temperatures, however.

  12. #12
    Join Date
    Jun 2001
    Location
    N.Ireland
    Age
    41
    Posts
    1,654
    Rep Power
    15
    Hi Mark C
    I have seen a little more of the technology behind the Vilter recently, the cool compression seems a good idea. I don,t think Vilter are going for the low temperature market
    Kind Regards. Andy.

  13. #13
    Join Date
    Mar 2005
    Location
    Philippines
    Age
    49
    Posts
    4
    Rep Power
    0

    Re: Single screw compressor

    Food day dvtruc, I am also doing a JE Hall HS2022, we do not have local rep for this machine, the one who sold the unit have already close out, wwe are now having a problem with the fridge watch controller, the micro just hang up. The supplier of the unit did not even left a IOM manual which we could use as a reference, I tried sending email to JEHelp line but nobody bother to care.

    Can send me info, if you have any idea. Your help will be appreciated.

  14. #14
    Join Date
    Nov 2004
    Location
    China
    Posts
    176
    Rep Power
    10

    Re: Hall Screw

    The HS 35 Had a swept volume of 1728 M3/hr at 2950 RPM. You should get close to the capacity by comparing it to another machine of similar displacement.

  15. #15
    Join Date
    Mar 2005
    Location
    USA
    Age
    67
    Posts
    641
    Rep Power
    10

    Re: Single screw compressor

    My past experience with a Hall single screw was not good. The machines had limited range of capacity and efficiency was not good for lower temperature applications. On ammonia we had bad star seal problems and once that was fixed, bearings last hardly more than a year in ammonia medium temp service.

    I have sold against the Vilter machine and they make sure you see the success stories. I found plenty of non-success stories which they are very quiet about.

    One plant, after 3 years of failures, had the compressor set removed from the skid and replaced it with a conventional twin rotor screw. The machine was crashing every 6 months to maybe a year.

    One of the Cool Compression installations had such oil carry over problems, the machine could not operate more than 2 days before having to add oil. After several repair attempts, Vilter finally did some work inside the separator and go the oil carry over under control. I will say that the machine was very quiet though.

    The Vilter distributors are very loyal to the single screw. But for every "success" story they publish, I have found more than one failure.

    I've been involved with large industrial screws for 30 years now and the twin rotor screw is the only way to go. While the single screw design is interesting, it has not proven itself well in the field.

  16. #16
    Join Date
    May 2003
    Location
    Vietnam
    Age
    55
    Posts
    19
    Rep Power
    0

    Re: Single screw compressor

    Hi Energy,
    I did contact and buy one HS 2022 a year ago as a replacement. For open drive they have two new series - HS 2000(2024, 2028, 2031, 2035) and HS 4200, with swept volume from 508 (HS 4221) to 2486 m3/h(2035), I think they're more suitable to medium/high temp. app. because of liquid injection for cooling and efficiency(for ex. McQuay chiller). You have a problem with a controller, it's better to contact the controller supplier (maybe Eliwell or Danfoss,...)

  17. #17
    Join Date
    Jun 2005
    Location
    Malaysia
    Posts
    25
    Rep Power
    0

    Re: Single screw compressor

    Hello Energy,
    can you tell me more what happen to the controller? maybe i can help to repair it back or design a new control system. if screw compressor controller maybe we can buy a programable controller a rewirte our own way.

    w.l.ong

  18. #18
    Join Date
    Jun 2005
    Location
    sydney australia
    Age
    36
    Posts
    2
    Rep Power
    0

    Cool Re: Single screw compressor

    Hi all just wanted to add my opinion on the single screw comps. Having had quite alot of experience on these machines i found that they are as reliable as any other screw on the market. I se what people say about howdens and they are too a very good machine but the hallscrew has proved when installed in the right way and correctlly engineered job they are no problems. Infact i carried out a inspection on a HS2020 that had been running for 8 years with 25,000hours and there was'nt a thing wrong with it. The customer was over the moon as a simple inspection could be done with out striping the whole compressor down. With the new range these comps will Be seen alot more...so watch out.......

  19. #19
    Join Date
    Mar 2006
    Location
    Philippines
    Age
    44
    Posts
    125
    Rep Power
    9

    Re: Single screw compressor

    Quote Originally Posted by dvtruc
    Hi all,

    As your experience, could you advise me a comparison between single and twin screw compressor and also application field of the single one (reffering to J & E HallScrew).

    Many Thanks
    Hello everybody,
    I'm Eric Delmo and I work for J&E Hall compressor for 15 years. I am the local Service & Parts here in the Philippines. I'm willing to help for any information regarding Hallscrew compressor.

  20. #20
    Join Date
    Mar 2006
    Location
    Philippines
    Age
    44
    Posts
    125
    Rep Power
    9

    Re: Single screw compressor

    hi dvtruc,
    I also work with Grasso and I had bad experience with twin screw.

    Twin screw is very dificult to do service, sometimes got welded to each other. And also the constraction of the casing is not very good accesible for the service.

    I think the diffirence is more on the service accesible.

  21. #21
    Join Date
    Mar 2006
    Location
    Philippines
    Age
    44
    Posts
    125
    Rep Power
    9

    Thumbs up Re: Single screw compressor

    Quote Originally Posted by energy
    Food day dvtruc, I am also doing a JE Hall HS2022, we do not have local rep for this machine, the one who sold the unit have already close out, wwe are now having a problem with the fridge watch controller, the micro just hang up. The supplier of the unit did not even left a IOM manual which we could use as a reference, I tried sending email to JEHelp line but nobody bother to care.

    Can send me info, if you have any idea. Your help will be appreciated.
    Hello energy,
    You can send me your inquiry regarding J&E Hall comp. ericdelmo@hotmail.com

  22. #22
    Join Date
    Jun 2001
    Location
    N.Ireland
    Age
    41
    Posts
    1,654
    Rep Power
    15

    Re: Single screw compressor

    Quote Originally Posted by energy
    Food day dvtruc, I am also doing a JE Hall HS2022, we do not have local rep for this machine, the one who sold the unit have already close out, wwe are now having a problem with the fridge watch controller, the micro just hang up. The supplier of the unit did not even left a IOM manual which we could use as a reference, I tried sending email to JEHelp line but nobody bother to care.

    Can send me info, if you have any idea. Your help will be appreciated.
    Look thru the posts, it gives Tony Paynes number, they will assist you Fridge Watch is well supported, I have Had to replace the main system board due to vibration cracking it, no major problems to sort this out, although this is about as major as you can get on Fridge Watch.

    Kind Regards. Andy

  23. #23
    Join Date
    Oct 2006
    Location
    India
    Age
    41
    Posts
    11
    Rep Power
    0

    Re: Single screw compressor

    I have been using J&E Hall screw compressors last 12 years and absoultly no problem with compressors. I used in the range +5 deg down to Minus 75 Deg C with all refrigerants and till today we never opened the compressor for major maintenance. I don't think the problems discussed above are nothing to do with compressors reliability and are related to the system accessories problems. We buy only compressors and packaging the same with indegenously made accessories like oil separator, oil cooler, controllers etc.

  24. #24
    Join Date
    Jul 2006
    Location
    USA
    Age
    64
    Posts
    642
    Rep Power
    11

    Re: Single screw compressor

    Have been watching threads on single and double screws in various sections of this forum.
    Am out of town working and bored waiting to fly home, so I thought I would weigh in.
    Thirty years ago I worked on the install of a Mcyom Twin Screw on a FES High Statge NH3 Package. I was new and very green.
    A few monthes ago I replaced the existing 250 HP motor with a 350 HP as part of a system remodel. We were raising the itermediate pressue and the 250 was at its limits. We brought them up to 1100HP total. And it is still not enough.
    But I stray from the thought at hand.
    I asked the Plant Manager, who was the operator back then, what he had done to the machine.
    I am sure this is not a complete record, but is what he related to me.

    One Oil Pump
    Machine open twice for bearings
    Various electric controls
    One motor rewind

    Bear in mind this machine runs 24/7, and slugs often. I mentioned that the liquid was bad for the health of the machine. He replied that if that was true it should have broken in thirty years.
    I had nothing to say in answer to that.
    Can you expect any more from a machine that that?

  25. #25
    Join Date
    Dec 2005
    Location
    Norfolk, England
    Age
    56
    Posts
    132
    Rep Power
    9

    Re: Single screw compressor

    Hi all we still run 5 old Grasso MS compressors, Two high side MS 1030 units and the rest are Low side MS 1034 units built back in 1982 to 1984. They now run 24-7 for 21 days and stoped for 2 days. All that we have done in that time is oil and filters, suction filter, loading gear parts and gland service. On the howdens we have we have had new rotors and bearings, oil and filters and gland service and they are up to 12 years old.
    Arthur.

  26. #26
    Join Date
    Aug 2007
    Location
    UK
    Age
    33
    Posts
    135
    Rep Power
    7

    Re: Single screw compressor

    if your bearings are going you need to check your liquid injection isn't too aggressive try for 75'c ish. anymore probs give me a post ill try to reply
    Last edited by HallsEngineer; 08-08-2007 at 08:54 AM. Reason: additional

  27. #27
    Join Date
    Jun 2005
    Location
    Quito
    Age
    55
    Posts
    22
    Rep Power
    0

    Re: Single screw compressor

    Dear friend:
    I have seen many Vilter single screw compressor working very well during let say 10 years, they perform fine and there is not a lot of repair cost, in fact they just need little maintenance.
    Also because of their continuous Vi they are more efficient.

  28. #28
    Join Date
    Dec 2007
    Location
    malaysia
    Posts
    160
    Rep Power
    7

    Re: Single screw compressor

    hola guys,

    i notice some blinds leading the blinds here!

    does any of you work for compressor manufacturer before?

    it is of danger if rookie engineer applies what you have said.

    single vs twn screw?
    1] perfromance difference = yes;
    2] cost difference = yes;
    3] maintenance diffirence = yes.

    twn screw use smaller e-motor compared to single @ similar cooling cap.

    initial cost is low for single.

    maintenance cost is low for single.

    runnign cost is high for same cap.

    any other thing you wish to know?

  29. #29
    Join Date
    Jul 2006
    Location
    USA
    Age
    64
    Posts
    642
    Rep Power
    11

    Re: Single screw compressor

    Quote Originally Posted by hendry View Post
    i notice some blinds leading the blinds here! does any of you work for compressor manufacturer before? it is of danger if rookie engineer applies what you have said. any other thing you wish to know?
    Where is a Mod when you want one?

  30. #30
    Join Date
    Mar 2001
    Location
    Dorset
    Age
    66
    Posts
    10,046
    Rep Power
    40

    Re: Single screw compressor

    Quote Originally Posted by NH3LVR View Post
    Where is a Mod when you want one?
    We're on the case buddy, hold on a little longer.

    Brian
    Brian - Torquay, Devon, UK
    I have to stop saying "how stupid can you be?" to my co-workers.
    They're starting to take it as a challenge...

    BASIC MAINTENANCE. If it doesn't move and it should then use WD40. If it moves but it shouldn't then use Duct Tape.

  31. #31
    Join Date
    Mar 2005
    Location
    USA
    Age
    67
    Posts
    641
    Rep Power
    10

    Re: Single screw compressor

    Having used both single and twin rotor machines, each has a place. In GENERAL, the single rotor machines do better on high evaporator temps or lower pressure ratio jobs and the power is better than a twin rotor.

    A twin rotor machine will typically do better on a low temp evaporator of higher pressure ratios.

    I certainly hope that the single rotor machines have the star seals and bearing problems solved which I suffered through.

    As for twin rotor machines, I have seen a pair of small Fricks that had close to 90,000 hours on them...R22 service, evap condenser on a large cooler. The only repairs were on the oil pumps and each had a shaft seal.

    Seen plenty with 50,000 hours plus in a well designed system.

    It all boils down to the fact that you can put the best compressor built in a poor system and it will not do well. Put a poorly built compressor in a well designed system and it will do OK, maybe not well though. So for the best, design your system properly and use a well proven compressor.

    For the money, I'll still stick to a twin rotor machine...be it GEA, Frick, Mycom or Howden. I tend to shy away from the other brands.

    Ken

  32. #32
    Join Date
    Aug 2005
    Location
    USA
    Posts
    5,340
    Rep Power
    16

    Re: Single screw compressor

    Quote Originally Posted by hendry
    i notice some blinds leading the blinds here!
    Oh, I don't think so.

    Quote Originally Posted by hendry
    does any of you work for compressor manufacturer before?
    YES, some of us have worked for compressor manufacturers. You might want to try to be a little more subtle in your posts. I can think of just several guys here who total over 100 years worth of experience. If I looked for more, it is there.

    Quote Originally Posted by hendry
    any other thing you wish to know?
    Sure, how much experience do you have?
    If all else fails, ask for help.


  33. #33
    Join Date
    Dec 2007
    Location
    malaysia
    Posts
    160
    Rep Power
    7

    Re: Single screw compressor

    discussion ... oh ... discussion.

    anyway, at least some immediate issue is resolved so that our supervisor do not jump on us.

    isn't that the aim of party who turn to RE for helps?
    i, too, look for some good answers to common refrigeration problems.

  34. #34
    Join Date
    Jun 2001
    Location
    N.Ireland
    Age
    41
    Posts
    1,654
    Rep Power
    15

    Re: Single screw compressor

    Quote Originally Posted by TXiceman View Post
    Having used both single and twin rotor machines, each has a place. In GENERAL, the single rotor machines do better on high evaporator temps or lower pressure ratio jobs and the power is better than a twin rotor.

    A twin rotor machine will typically do better on a low temp evaporator of higher pressure ratios.

    Ken
    Hendry

    this would be the reason single screws are still applied.

    I overhauled HS 34 and after some initial problems it is running very well. That is after 25 odd years of service.

    Mono screws are long lasting in certain applications, but engineers have less experience working on them.

    When you have worked on a few mono screws you will have better regard for them.

    Kind Regards Andy
    If you can't fix it leave it that no one else will

  35. #35
    Join Date
    Mar 2005
    Location
    USA
    Age
    67
    Posts
    641
    Rep Power
    10

    Re: Single screw compressor

    Andy, for the most part, my career has been spent on low temperature refrigeration, so most of the applications lend themselves to twin rotor machines. My industrial refrigeration experience goes back 37 years now and has covered engineering, service and trouble shooting.

    Ken

    Ken

  36. #36
    Join Date
    Dec 2007
    Location
    malaysia
    Posts
    160
    Rep Power
    7

    Re: Single screw compressor

    Quote Originally Posted by Andy View Post
    Hendry

    this would be the reason single screws are still applied.

    I overhauled HS 34 and after some initial problems it is running very well. That is after 25 odd years of service.

    Mono screws are long lasting in certain applications, but engineers have less experience working on them.

    When you have worked on a few mono screws you will have better regard for them.

    Kind Regards Andy
    Thanks Mr. Andy.
    i've physically overhauled both twin & mono screw compressors.
    and, I'm doing it eventhough i've moved up in enigneering ladder.
    thank you for your advice/s & i'll not leave anything behind in my next overhaul.

  37. #37
    Join Date
    Jun 2005
    Location
    Quito
    Age
    55
    Posts
    22
    Rep Power
    0

    Re: Single screw compressor

    Quote Originally Posted by hendry View Post
    hola guys,

    i notice some blinds leading the blinds here!

    does any of you work for compressor manufacturer before?

    it is of danger if rookie engineer applies what you have said.

    single vs twn screw?
    1] perfromance difference = yes;
    2] cost difference = yes;
    3] maintenance diffirence = yes.

    twn screw use smaller e-motor compared to single @ similar cooling cap.

    initial cost is low for single.

    maintenance cost is low for single.

    runnign cost is high for same cap.

    any other thing you wish to know?
    Hendry:
    Please read this attachment.
    Best Regards
    Gonzalo
    Attached Files Attached Files

  38. #38
    Join Date
    Sep 2007
    Location
    Somerset
    Age
    60
    Posts
    3,669
    Rep Power
    24

    Re: Single screw compressor

    I work on both types of screw and can recommend models from both Camps.
    In simple terms "You get what you pay for". Yes Hall Screws are High Maintenace. Compaired with some cheaper " sealed for life" twin screws.
    But when you refer to a Halls maintenace manual.
    It says something like " Every 24 years or 100,000 hrs (11.4 yrs of running) Renew the main bearings.
    That's pretty impressive in my book.
    More importantly when they do go wrong you can repair them. Because the Star wheel is sacraficial compared to comprable damage on a twin screw.
    Likewise I have a site with 2 stahl (twin) screws ( On Ammonia) that in nearly 20 yrs have only needed Oil Filter changes and a shaft seal each.
    Brilliant Machines no longer made ( to well engineered making them expensive to produce. I Believe?)
    To often equipment is purchased purely on cost and not longevity nowadays.
    There appears to be cheap twin screw models out there that are supplied on a disposable basis. When it breaks rip it out and put another one in. These cannot be compaired with the more expensive and reliable models from both camps.
    Yes I did work for J&E Hall.
    But I can appreciate good kit wherever it is made.
    Sometimes good equipment fails because those looking after it are not up to the job!
    Grizzly

  39. #39
    Join Date
    Dec 2007
    Location
    malaysia
    Posts
    160
    Rep Power
    7

    Re: Single screw compressor

    Quote Originally Posted by Gonzalo Arias View Post
    Hendry:
    Please read this attachment.
    Best Regards
    Gonzalo
    thanks Gonzalo!

    will remember that ...

  40. #40
    Join Date
    Dec 2007
    Location
    malaysia
    Posts
    160
    Rep Power
    7

    Re: Single screw compressor

    Quote Originally Posted by energy View Post
    Food day dvtruc, I am also doing a JE Hall HS2022, we do not have local rep for this machine, the one who sold the unit have already close out, wwe are now having a problem with the fridge watch controller, the micro just hang up. The supplier of the unit did not even left a IOM manual which we could use as a reference, I tried sending email to JEHelp line but nobody bother to care.

    Can send me info, if you have any idea. Your help will be appreciated.
    your region is covered under our local rep.
    could we have your details in separate discussion?
    probably we could help.

  41. #41
    Join Date
    Aug 2007
    Location
    UK
    Age
    33
    Posts
    135
    Rep Power
    7

    Re: Single screw compressor

    Any machine under the size of 2024 is now obolsete, good luck finding one. can change for a 3200 or a 4200 machine just a small pipe work mod i think.

  42. #42
    Join Date
    Feb 2007
    Location
    UK
    Age
    48
    Posts
    165
    Rep Power
    8

    Re: Single screw compressor

    I've not had much experience with HallScrews, the only time i ever opened one due to excessive vibration, found a chunk of steel broken off the rotor, from one of the splines. The piece was still inside the casing, and was approx 40mm x 15mm. Impact marks inside the case suggested it had bounced about for a while before comming to rest in the bottom. The star wheel was a little chewed up, but the machine still worked with almost no drop in performance. Only outward sign of the problem was this huge vibration.
    I don't know what became of the machine as the site was due for closure a few months later and i left the company during those months.

  43. #43
    Join Date
    Feb 2008
    Location
    Napa, CA
    Age
    45
    Posts
    33
    Rep Power
    0

    Re: Single screw compressor

    Mono Screw... I going to give an opinion. I can do and have done alot more with Vilter Screws than I ever could do with FES's. There is a difference with the machine, first the slide valves allow for variable compression, unlike fixed compression allows for lower energy cost when reducing compression(i.e. floating head). When your dealing with percentages they count. The machine is solid and easy to repair, i've been though a few(for fun).

    The company on the other hand. The problems start and end with Ron. They appartly have been working on the problem and have increased there customer service.

    I haven't bought a VSS/VSM for 4 years and have been using FES on my projects due to the small market thought process. I do plan to buy them again...

    Great Sales help nice guys, great machine! Past Vilter appologist.

    Rick

  44. #44
    Join Date
    Mar 2006
    Location
    China
    Posts
    85
    Rep Power
    9

    Re: Single screw compressor

    I wanna know about Vilter single screw compressor. product qualities, markets,etc.

  45. #45
    Join Date
    Mar 2006
    Location
    China
    Posts
    85
    Rep Power
    9

    Re: Single screw compressor

    It seems that anyone don't wanna talk about the compressor manufacture.
    I know few about single screw.Maybe twin screw is better.
    But, how about going to work for Vilter company???

  46. #46
    Join Date
    Jan 2006
    Location
    Croatia
    Age
    58
    Posts
    1,939
    Rep Power
    14

    Re: Single screw compressor

    Hi, sagittarius

    Quote Originally Posted by sagittarius View Post
    It seems that anyone don't wanna talk about the compressor manufacture.
    I know few about single screw.Maybe twin screw is better.
    But, how about going to work for Vilter company???
    ....seems all of us here are users of compressors and not manufacturers...and for us is not easy to speak about...simply, it is not our field of interest..., but maybe I am wrong...

    mono or twin screw compressor....which is better.... there are always pro and contra points, so.... but, definitely each manufacturer should always declare "our compressor is the best one" ... for us remain, only to believe or not, ........usually from our experience we have a slightly different story...

    ....to work or not for Vilter, either, must be your decision only....

    Best regards, Josip

    It's impossible to make anything foolproof because fools are so ingenious...

    Don't ever underestimate the power of stupid people when they are in large groups.

    Please, don't teach me how to be stupid....
    No job is as important as to jeopardize the safety of you or those that you work with.

  47. #47
    Join Date
    Aug 2005
    Location
    USA
    Posts
    5,340
    Rep Power
    16

    Re: Single screw compressor

    Quote Originally Posted by sagittarius
    I know few about single screw.Maybe twin screw is better.
    But, how about going to work for Vilter company???
    Why does it matter which screw compressor is better? Or, for that matter is there a better compressor?

    And, what does this have to do with the manufacturer and why you might want to work for them?

    One month you ask about markets and product quality and then the next month you ask about working for a manufacturer?????

    Asking which compressor is better is like asking a man if a woman is pretty. Some say yes, others may not (but not in front of the woman)
    If all else fails, ask for help.


  48. #48
    Join Date
    Feb 2008
    Location
    Norway
    Age
    47
    Posts
    447
    Rep Power
    7

    Re: Single screw compressor

    The subject of variable Vi is very interesting. As i have said before, i have not any experience with large and/or industrial systems. On dual screw compressors with variable Vi, i clearly see the need for fully independent movement of the capasity slide and the varable Vi slide in order to maintain the best isentropic efficiency at all pressure and load ratios. I have however got the impression that variable Vi is not fully acomplished when the compressor is running in part load. Can someone explain if this is the case and why?

  49. #49
    Join Date
    Mar 2005
    Location
    USA
    Age
    67
    Posts
    641
    Rep Power
    10

    Re: Single screw compressor

    Variable Vi has been over sold in the market. There are lots of applications where variable Vi is not worth the cost. Frick only offered machines with Variable Vi and FES offered both.

    For a booster, variable Vi is a waste of money and adds complexity tot he compressor as well as additional rebuild cost.

    On a high stage compressor, you will see a small gain with varying head pressure. A much better gain is seen whe you vary the suction pressure.

    Vi = Vol @ suction/Vol @ discharger ....or
    Vi = (Pd/Ps)^k.

    Work out the numbers and it is pretty easy to see.

    I am old school and prefer the twin rotor design over the single rotor. My experience on the single rotor machines has been with the old Grasso and Hall machines. As for Vilter, I have see way to many "problem" jobs.

    AS for the twin rotor machines, FES (GEA), Frick, Howden and Mycom (alphabetical order) all build very good machines. Which is better, depends on the specific application.

    Ken

  50. #50
    Join Date
    Mar 2006
    Location
    China
    Posts
    85
    Rep Power
    9

    Re: Single screw compressor

    Maybe I have asked a stupid question.
    It's a flash idea in my mind to work for manufacuture.
    Yes. Each of manufacuture says "I'm the best,Im No.1..."

Page 1 of 2 12 LastLast

Similar Threads

  1. Experience with a specific screw compressor
    By TXiceman in forum Commercial
    Replies: 17
    Last Post: 07-04-2009, 07:00 AM
  2. do u have any data on comparison of single screw and twin screw?
    By vuputuri in forum Technical Speculations
    Replies: 5
    Last Post: 22-02-2008, 04:52 PM
  3. single stage screw compressor
    By murugan in forum Trouble Shooting
    Replies: 0
    Last Post: 18-05-2006, 01:27 PM
  4. Screw compressor vibration
    By jpumarada in forum Industrial Compressors
    Replies: 14
    Last Post: 26-04-2006, 01:43 PM
  5. screw compressor failure
    By aygul in forum Trouble Shooting
    Replies: 23
    Last Post: 09-12-2004, 10:09 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •