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
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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
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:)
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.
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
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
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
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
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.
Hi Jryffel:)
Vitler make a single/mono screw:confused:
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:cool:
Have you a link to the Vitler site so we can have a look see.
Regards. Andy:)
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.
The track record is there. My clients have had generally good experiences with them. I would pause before using one at low temperatures, however.Quote:
Originally posted by Jryffel
http://www.vilter.com/ .......we will need Vilter to have some track record before we spec a single screw.
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:eek:
Kind Regards. Andy.:)
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.
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.
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.
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,...)
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
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....... ;)
Hello everybody,Quote:
Originally Posted by dvtruc
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.
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.
Hello energy,Quote:
Originally Posted by energy
You can send me your inquiry regarding J&E Hall comp. ericdelmo@hotmail.com
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.Quote:
Originally Posted by energy
Kind Regards. Andy:)
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.
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?
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.
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
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.
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?
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
Oh, I don't think so.:(Quote:
Originally Posted by hendry
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.:cool:Quote:
Originally Posted by hendry
Sure, how much experience do you have?Quote:
Originally Posted by hendry
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.
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:)
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
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