Have a process application which would run under following conditions .
NH3 Economized VSD -33 C SST
+ 48 C SDT
Apart from possible higher pressure rated casting would anything else have to be "SPECIAL" about it ?
Anyone have experience ?
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Have a process application which would run under following conditions .
NH3 Economized VSD -33 C SST
+ 48 C SDT
Apart from possible higher pressure rated casting would anything else have to be "SPECIAL" about it ?
Anyone have experience ?
Why not a normal cascade system with NH3 on the low stage, and some other natural refrigerant on the high stage?
Air cooled on R-717 is comparable to these conditions; considerable data on that in the IIAR technical sessions. Also more recently on using R-717 in central heat pump arrangements. Check the Vilter web site; they did nice work on a "small channel" single rotor screw for such purposes; high side to 85-deg C condensing.
http://www.emersonclimate.com/Docume...%20Version.pdf
Limits on Vilter standard Single Screws are MAWP above 33 bar and pressure ratio 20:1.
This application is within the limits, no need for their special high pressure compressors (MAWP 75 bar).