I need a MYCOM's manual, because i have to select an oil for an ammonia system, and want to see what is the MYCOM'S recomendations.
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I need a MYCOM's manual, because i have to select an oil for an ammonia system, and want to see what is the MYCOM'S recomendations.
Have you tried contacting Mycom direct through their website -
http://www.mycomus.com
Hi, ingherrera :)
See if this is ok for you ;)Quote:
Originally Posted by ingherrera
Best regards,
Josip :)
Ridiculous time schedule.
Hi, NoNickName :)
Why you think so?Quote:
Originally Posted by NoNickName
Best regards,
Josip :)
1000 hours check the oil
10000 hours major overhaul
In one year, a plant working 24/7 adds up 8700 hours.
I can't possibly tell any customer that the compressor he/she bought has to be rebuilt while warranty is still pending.
Hi Nick:)Quote:
Originally Posted by NoNickName
service intervals given here are common to all manufacturers:)
Most compressors that are worked hard run 5000 to 6000 hours a year;)
What this equates to is a top end inspsection every year (valves checked) these may be replaced or allowed to run another year dependant on wear and hours run. The next year the piston rings and valve plate will usually be changed and the third year the bearings will be replaced.
You can let them run until something smashes, but that is not preventative maintenance, anyone can change the oil and let it run:(
You may get 30000 hours out of a set of main bearings, but all you are doing is shortening the life of the compressor shaft, which is the most expensive part.
These are high tolerance high effeciency compressors, unlike the commercial semi compressors, which sacrifice the effeciency for longevity:eek:
A semi will run for years at high speed on the original bearings, but the energy consumed would be much much greater than any industrial compressor, the chaep compressor is the high tolerance high effeciency compressor that has to be maintained on a on going basis, the real enviromentally friendly option:)
Kind Regards Andy:)
No, they are not. Bitzer do not want the oil to be replaced EVER on the screw semis range.Quote:
Originally Posted by Andy
And?Quote:
Originally Posted by Andy
We've got scrolls from copeland running 8000 a year in CCUs.
And this is a nonsense. Please let me know a single industrial plant who can accept an offline of one day for programmed preventive maintenance of the cooling system. Not in the UK. I've got a number of plants with our chillers and the customer would not stop them even for replacing a single contactor.Quote:
Originally Posted by Andy
Nonsense in a teapot. It takes less time to replace a compressor than overhaul it.Quote:
Originally Posted by Andy
Yeah, sure. At least this is the spam what they tend to feed us with.Quote:
Originally Posted by Andy
Hi,
Maybe on ***** plants, but with ammonia we have to change oil filters every 3 months and oil each year(Bitzer screw). That plant is new one (2 years old) installed to liquify CO2 in one brewery.Quote:
Originally Posted by NoNickName
For how many years?Quote:
Originally Posted by NoNickName
Until is broken, what then?Quote:
Originally Posted by NoNickName
What about compressors with input power on shaft of 200-355 kW?Quote:
Originally Posted by NoNickName
Industrial compressors are running 20-30 or more years with proper maintenance. I am living witness ;)Quote:
Originally Posted by NoNickName
Many years ago I have been told (by people from Stal-Astra Sweden) you can build only two types of refrigeration plants:
1. Cheap plant without maintenance usually with short life - expensive
2. Expensive plant with maintenance to assure long life - cheap
Hope other guys will come with comments too ;)
Best regards,
Josip :)
Proper industrial users have standby plant just for maintenance, they can't afford not to have:)Quote:
Originally Posted by NoNickName
Mycom are now using a hitachi scroll with aluminum windings on Ammonia, we will see how this goes
Nonsense in a teapot:D :D
try replacing a 8WB Mycom in the time it takes to do an overhaul, well you probably could but it would take a crane to do so, bit of a nonsense really:D
You have hit the nail on the head, this short service interval is whay recips died out for a few years. The reason they are now popular is the screws have poor part load effeciencies:eek:
When you take into account the seasonal EER the recip wins hands down.
We sell a range of packaged chillers, but we also seel ammonia chillers with water cooled condensers and flooded chillers, for people who care how much electric they are using:) and what effect this has on the enviroment;)
Kind Regards Andy:)
At least they should have one backup. Ordinary reality is much sadder than that.Quote:
Originally Posted by Andy
It all depends on proper chiller design. For our air cooled and water cooled, compressors are replaced and restarted in less than 6 hours.Quote:
Originally Posted by Andy
Overhauling (on-site or off-site) is a matter of days.
Well, you may be well right, BUT! ST microelectronics in Milan runs a plant with a total overall power consumption of over 100MW. Would you reckon what difference few dozens kWh per year makes?Quote:
Originally Posted by Andy
Definitely.Quote:
Originally Posted by Andy
And I always thought the screw compressor salesmen did such a nice job.:pQuote:
Originally Posted by Andy
I have heard some of these stories used to sell screws. 100,000 hour bearing life, no valves to replace, more efficient, can ingest liquid with no harm, cheaper to install, etc, etc.
When screw compressors were being sold some time ago, the salesman all said variable Vi was better than fixed Vi.
Recip compressors were less efficient than screws. All sorts of sales tactics were being used.
I think the simple fact is; both compressor types have some benefits that can be utilized... if done properly.
Screws can operate at high pressure ratios more efficiently. They require smaller areas for the equivalent capacity (on big systems).
But, I have never heard a salesman tell the owner the screw compressor is a lot more inefficient than a recip compressor at part load when trying to sell a screw.
And... I have never heard a screw salesman say recip's already have variable Vi. They don't even need control systems for variable Vi.:cool:
Although I would like to see someone add a manifold to a recip for economizers.:D
I'm in agreement with Andy. A lot of arguments are used to sell one compressor over another type. I think the arguments are based on what the salesman is trying to sell. Sometimes these are vary one-sided.
I think people are starting to get smarter about how they select compressors.Quote:
Originally Posted by Andy
There's a place for both. Now people are starting to use VFD's on screws. That's a big benefit for part load improvements.
2 dozen kWh is not much a savings.;) However, on the serious side, if the plant is using 100 MW, there has to be some room for improvement in energy use.Quote:
Originally Posted by NoNickName
I quite agree with this.Quote:
Originally Posted by Josip
Number 1 is usually a system that is designed to be cheap on the first install price. Then the system is operated in a "run to failure" mode. No maintenance is done... just spend enough money to keep it running. This is not much different than HVAC systems.
Number 2 does cost more up for the initial install and continuing operation. These are usually systems where the people recognize the loss of cooling costs more in lost production time, than the cost of the maintenance.
Of course there are all sorts of arguments that can be made for this too. In general, I think Josip summed it up very nicely.
thank you. In the PDF file, there is a PETRO CANADA oil, i have a tech data a it seems to work ulntil 15000 hr
Hi,
I was thinking (couple of days before) to start a new thread with those opinions to ask you, what do you think : where are we today?Quote:
Originally Posted by US Iceman
Best regards,
Josip :)
i want to use screw compressor instead of recip. i want to know -ve of screw compressors vs recip compressor OR benefits