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29-03-2008, 09:58 PM #1
Compressors - screw or reciprocating?
Hi,
many times on RE forums we had discussion about.... here are, from the first hand some thoughts about....how to save some energy
Originally Posted by http://www.sabroe.com/information/screw-or-reciprocating.html
http://www.sabroe.com/information/sc...procating.html
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.
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29-03-2008, 10:13 PM #2
Re: Compressors - screw or reciprocating?
Very good read Josip.
I`ve always liked screws compared to recips but i dont get involved with them as much as i`d like.If it ain't broke, it doesn't have enough features yet.
Damo
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31-03-2008, 03:18 AM #3
Re: Compressors - screw or reciprocating?
I do not have any problems with screws, recips or centrifugals as long as they are applied in the proper application.
A lot of people with limited experience will migrate to a compressor which they have some experience.
Take for instance the argument that a recip ins terrible and a screw is better....blanket statement.
I have applied a lot of recips successfully in projects and maintenance hsa not been a problem. The trick is to design the system properly and do not apply the compressors at the extremes of their operating envelopes. Watch the pressure ratios, such superheat and rotational speed.
One very capable compressor in ***** applications is the carrier 5H and 5F series. They are very reliable machines when selected and rated at 1200 RPM instead of the air conditioning rating of 1800 RPM. The 5H**6 series (long stroke) work as well if you keep the piston speed down to something much less than the 1000 plus feet/ minute range.
The big thing is to design the system for the proper fit, application and equipment.
ken
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31-03-2008, 04:34 AM #4
Re: Compressors - screw or reciprocating?
Originally Posted by TXiceman
It's not the compressor so much as it is the application (or available space).
Th eCarrier open drive recip.'s are hard to beat for ***** applications. I'm looking at these now for a project. Did you know Carrier used to sell these for ammonia service a long time ago?If all else fails, ask for help.
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31-03-2008, 01:32 PM #5
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31-03-2008, 01:40 PM #6
Re: Compressors - screw or reciprocating?
We have a few Sullair ammonia compressors, they don't have any real capacity control, but they are great running screws.
Thanks for the info Josip
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01-04-2008, 03:13 AM #7
Re: Compressors - screw or reciprocating?
Yepper, I know about the Carrier NH3 recips and have also used them on propane service. I still have some of the old propane data around here.
Also have done several Vilter 440's on propane. If I remember correctly, they went to Israel.
Also done several screws on isobutane.
Ken
ken
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01-04-2008, 04:39 AM #8
Re: Compressors - screw or reciprocating?
I always liked the old Sullair screws. It's a shame they got out of the refrigeration business.
The only isobutane project I worked on was for very high temperature heat recovery using thermosyphons. After all of the research and engineering it seemed it was too risky by the owner and the project was shelved. Too bad really... I thought it was pretty slick.If all else fails, ask for help.
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02-04-2008, 06:07 PM #9
Re: Compressors - screw or reciprocating?
Isobutane is tricky to work with due to the way the vapor dome slopes off tot he right. The compression lines do go back intot he dome and you have to have a lot of superheat in the suction to get you clear of the saturated vapor line at discharge conditions. Other wise it is a great refigerant.
Another problem is having long and uninsulated suciton runs in an industrial application. The vapor pressure is so low that it can condense in the suction line at failry warm ambients.
Ken
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02-04-2008, 06:59 PM #10
Re: Compressors - screw or reciprocating?
Originally Posted by TXiceman
What you mentioned above is an interesting fact that most people are not aware of. I've seen this happen in suction lines in ammonia systems when they operate for long periods of low capacity.
During full load the suction pipes are a little colder due to the slightly lower suciton pressures. Then when the compresors unload the suction pressure rises justa bit and the gas starts to condense.
Refrigerants are funny things sometimes.If all else fails, ask for help.
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18-04-2008, 09:26 AM #11
Re: Compressors - screw or reciprocating?
Ken's post of 31.03.08 is perfect I wish there were people with similar thoughts in our country.
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18-04-2008, 02:46 PM #12
Re: Compressors - screw or reciprocating?
hi,josif,
that was a balance statement on both type comp.many thanks for the info.
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19-04-2008, 01:42 AM #13
Re: Compressors - screw or reciprocating?
You will get a much more balanced approach from a company that has more than one type of compressor to sell. If all you have to sell is screws....guess what, they are the best compressor for every job ...especially if you want to continue to eat.
I enjoyed working foe many years with a company that could offer screws, recips and centrifugals for a while. It was actually fun to hear some of the "stories" the competitors came up with why you had to use certain type of compressor.
It also helps to have experienced and open minded engineers...but that seems to be something the industrial industry is loosing.
I am currently out of the refrigeration field after 37 years. My choosing due to location and $$$$. I can make a lot more at a large EPC firm.
Ken
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19-04-2008, 11:52 AM #14
Re: Compressors - screw or reciprocating?
Thanks for the info
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24-12-2008, 10:37 AM #15
Re: Compressors - screw or reciprocating?
Hello Josip ,
thanks for sharing those information .
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25-01-2009, 01:08 AM #16
Re: Compressors - screw or reciprocating?
I have both screws and recips at my facility. the screws have a lot less maintenance issues than the recips and they also load and unload in more precise increments to maintain a constant suction pressure as opposed to recips that load and unload one bank at a time. I personnaly prefer the lower noise levels of the screw compressors
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25-01-2009, 08:23 PM #17
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25-01-2009, 08:41 PM #18
Re: Compressors - screw or reciprocating?
NH3Wizard, I operate a cold storage facility for a major grocery supply chain in the northern US.
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27-01-2009, 10:36 PM #19
Re: Compressors - screw or reciprocating?
if its energy savings your after - yorks YCIV variable speed compressors are one of the best options available at present
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