Serves you right if you hang out with gangs.
By the way he sent me the tequila.
Mezcal '86 if I'm not mistaken, and very nice too. In fact I might have
a wee sleep now.
Cheers
Steve
-----Original Message-----
From: Paul Bowers [mailto:pbowers@pipingdesign.com]
Sent: Friday, August 13, 2004 11:43 PM
To: PipingDesign@yahoogroups.com
Subject: Re: [PipingDesign] NH3 Refrigeration System Piping
Bah, I'm giving up on Gerardo and his gang. I figure if they can't be bothered to join the list and participate, it's not worth it.
I guess I have been trolled, even though I was offered free Tequila.
Paul
> Hi Gerardo
> I have looked at the sketches you sent Paul
> where is the pump?
> Are you hoping it will work through natural convection? Have you
worked
> through this?
> If so, you will need to ensure the PHE discharge line is close to
below
> the accumulator.liquid level.
> As drawn, it is no surprise you have problems.
> Can you raise the accumutator or lower the PHE?
> For a wet evaporator, it doesn't stand much chance of working as
drawn.
>
> Cheers
>
> Steve
>
>
> -----Original Message-----
> From: Paul Bowers [mailto:pbowers@pipingdesign.com]
> Sent: Friday, August 13, 2004 2:38 AM
> To: PipingDesign@yahoogroups.com
> Subject: Re: [PipingDesign] NH3 Refrigeration System Piping
>
>
> Gerardo sent some drawings of his system and I've uploaded them to the
> website. I don't know if this will explain the situation any better or
> help to find a solution:
>
> http://www.pipingdesign.com/drawings/Ortogonalviews.JPG
> http://www.pipingdesign.com/drawings/isometrico.JPG
>
> ________________________________________________________
>
>
> Paul: I am sending you the drawings of the unit that I am having
> problems with. This unit doesnt have the same performance (it is like
> 30% less
> performance) than others who are practically the same (same
compressor,
> same acumulator, same condenser and same evaporator). The 02
diferences
> that this package refrigeration system (PRS) has are: The piping
> arrangement from the heat exchanger to the acumulator (return
> line)
> The height of the heat exchanger, the evaporator is 4" higher.
>
> ========================================================
>
> Gerardo sent:
>
> People of Piping design: I am writing to you because I have some
doubts
> about an instalation of a flooded refrigeration system with ammonia.
The
> main problem seems to be in the pipe arrangement of a flooded
evaporator
> (plate evaporator). It is a package for cooling Glycol. This client of
> mine has a lot of this package refrigeration systems and one of them
> does not have the same performance than the others who are practically
> the same design. One of the diferences is on the return line of the
> evaporator to the suction acumulator. This reurtn line goes above the
> control level of liquid like about 5". The plate heat exchanger is
about
> 10 feet away form the acumulator, and the return line from this heat
> exchanger to the accumulator goes up from the heat exchanger to obtain
a
> 2% inclination to the acumulator. Which means that when the equipoment
> is off, the liquid entraped in this line will go to the accumulator.
> Since the equipment doesnt have the same performance as the other
> package inastalled in my client plant. We think that the fact that
this
> line has to go up in order to achieve the 2% inclination has something
> to do with the performance. What are your thought regarding this
matter.
>
> Steve answered:
>
> have you checked to see that the plate evaporator is not filled up
with
> oil? This is more common with CFC type refrigerants but can happen
> occasionally with ammonia., especially if the vertical pipe is
oversized
> (the oil runs back down the pipe). Have you checked that your
> circulation pump is working properly? It may not be producing enough
> head to overcome the evaporator resistance and push the gas/refrig/oil
> mixture back into the accumulator. I am not convinced you need 2% fall
> on the return line; the gas/ refrigerant mixture should sweep it
clean.
http://www.pipingoffice.us/ =========================================Main site: http://www.pipingdesign.com
Yahoo! Groups Links Received on Fri Aug 13 07:49:00 2004
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