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Andy
02-08-2002, 03:14 PM
:) Hi,
I have attached a photo of a NH3 refrigeration plant, this plant has two 150hp compressors fitted to a common oil separator and Low Pressure Receiver. This is a 5 year old plant, with the picture taken last week when I was on site.
The photo is a side veiw with the black insulated LPR on the left and the screw pack on the right.
All comments apreciated good or bad, I hope the photo comes out alright give us a shout if it doesn't.
:) Regards. Andy.

SteveDixey
05-08-2002, 12:15 AM
Errrr.....

Looks..."compact" doesn't it. Which generally means you cannot get to anything important without hanging by your toes off some steel beam.

Perhaps we ought to have new thread here...do the people who design plants and machinery ever get to think about servicing them..

Integrated hydraulics - there's a good phrase - means you have to be a triple jointed midget to get at anything - perhaps these designers have something in common with the makers of these packaged units that equipment makers are trying to sell us.

I realise now why I have never seen an overweight fridge engineer - they would never stand a chance getting to the gear to service it;)

Steve

Andy
05-08-2002, 10:05 AM
:) Hi, Steve
I suppose from that side it does look compact, that's the side that I normally wouldn't be working at much. I have attached another photo of the unit from the frount showing the two Howdens. The whole thing is 20' long, not so compact really, not a bad unit to work on, the big bits are very easy to get at.
But you are right, some units are real pigs to work at, that ice rink pack was a bit tight for working at, especially if you had to take the heads off No3 compressor.
I hope the picture below looks a little better to you.:o
:) Regards. Andy.

Industrial tech
26-05-2003, 03:13 AM
Hi Andy, doesnt look to bad to work on. What kind of screws are those? I do alot of work on the Frick screws and am curious to find out about some of the other brands out there.

Andy
26-05-2003, 10:35 PM
Hi Industrial Tech,
welcome to the Industrial Section:D
Theses are Howden screws, built in Glasgow. 165-145 rotor profiles and the smallest product we use from Howden.
Quite a nice screw to work on and simple to work on.
Everlasting, given a little care and maintenance.
On this side of the pond, Fricks were sold by Gram under licience:cool:
I have worked on a few, with little bother, except the dinky little LVDT used to give the slide position to PLC controller.
Regards. Andy

Dave Goodings
26-05-2003, 11:12 PM
Alright Andy
Have you worked on any Stal screws I have worked on the vertical mini screw using thermo syphon oil coolers seemed a decent machine
regards Dave

Andy
27-05-2003, 07:12 PM
Hi, Dave,
I have not worked on any Stall screws recently. I am afraid to say the Stal mini-screw has a bad name in Ireland, or at least in the circles I move in. Although this is probably down to one contractor who mis-applied them on most of his industrial plants. These plants were nearly alway DX R22, with a hot gas defrost that dumped liquid into a suction accumulator, which had no boil off coil, leading to flood back.
Worked on a few Stal Recips, now those are a great machine:)
Are they still made. I doubt it as they were far to good and nearly everlasting, not what manufacturers want today:rolleyes:
Marc
As I recall, the twin screw is still made under licence from the original patent and profile developed in Sweden:confused:
SRC or something similar profile name.
Regards. Andy:)

Andy
28-05-2003, 07:44 PM
Hi Marc,
roughly translated as Swedish Rotor Machine:confused:
Regards. Andy:) :D

Mark C
16-06-2003, 07:54 PM
The last Stahls I voluntarily worked on had just catastrophically failed.... They had shaft-driven oil pumps. As those shaft drive bearings failed, they fell out of the race, and straight into the suction of the screw.... Screaming one minute, and a sound like a buzzsaw... then silence. :eek: Those were probably 1970s models. Since Stahl is now associated with one those larger manufacturers...

ask
19-04-2008, 12:03 PM
hey,

I am a finaly year chemical engineering student studying in the UK. I have my final design project which is due in two weeks. I am a bit stuck with this as I haven't got much knowledge on this subject.:confused: My project is to design a chiller with NH3 as the refrigerant. this chiller is used to cool a water stream that comes out of a condenser at 20 C down to 3C. I specified the temperatures of the NH3 stream to be -45 C to 15 C and calculated the flow rate. Anyways I just wanted to get some basic idea about the main components of such a system and thing that you think might be useful for my design. Gosh you would be a life saviour if you could help out.. thank you...hope to hear from you soon:)

Josip
26-04-2008, 08:24 PM
Hi, ask :)


hey,

I am a finaly year chemical engineering student studying in the UK. I have my final design project which is due in two weeks. I am a bit stuck with this as I haven't got much knowledge on this subject.:confused: My project is to design a chiller with NH3 as the refrigerant. this chiller is used to cool a water stream that comes out of a condenser at 20 C down to 3C.

.... so you have to cool water having freezing point at 0*C


I specified the temperatures of the NH3 stream to be -45 C to 15 C and calculated the flow rate. Anyways I just wanted to get some basic idea about the main components of such a system and thing that you think might be useful for my design. Gosh you would be a life saviour if you could help out.. thank you...hope to hear from you soon:)

...:confused::confused: why you decide to use ammonia with temperature of -45*C

.... can you make a sketch of your system showing where you think to have ammonia with -45*C to 15*C

... try to think about chiller with evaporating temperature of ammonia at 0*C ;)

BTW you should open a new thread with your question and not to use this one 5 years old:rolleyes:

Best regards, Josip :)