Centrifugal Compessor - High suction temperature

[rickengg]

The application at hand involves a beam style inline multistage centrifugal compressor handling
a flow of 50,000 Nm3/hr of process gas with a pressure ratio
of 1.5 .The process gas temperature at suction is a high 180 degree
Celsius.
what effect will such a high suction temperature have on the compressor selection/
operation.I have run the estimator provided by Elliot and they have
a model for this process requirement but could not find one at dresser-datum.
need help to confirm material,reliability and other issues of running at such a high suction temp.

 

[rotw]

Is this an API617 application ? New application or existing equipment? What type of process gas (hydrocarbon, acid gas ?) will be compressed, what is the MW and inlet pressure ?
Temperature increases quickly with higher molecular weights, you should at least indicate the discharge temperature which is the worst case... just common sense so to say. What type of shaft end seals do you have : dry gas seals or labyrinths ?
Without the minimum of technical background on the application itself how can you expect useful orientation ?

180 degree C is not only high as suction, but is already high as discharge for a single shaft centrifugal compressor.
if you are using dry gas seals, you are at the commonly accepted temperature limit in terms of what dry gas seals can handle on suction side and definitely you will be exceeding it on the discharge side for an inline.
If you are using labyrinths at shaft ends, same rule applies as for others labyrinths in the rotor and it will all depends from the magnitude of your discharge temperature to define what are the elements that needs more close attention and what will qualify or not, but here again definitely uncommon suction temperature.

What is the rational behind this temperature, is it to have the gas superheated because of dew point issues ? or because someone just got a brilliant idea to drop out a process cooler from the plant or the process flow diagram ?

 

[rickengg]

This compressor is for a feasibility study so information is kind of sketchy.
The Gas is Hydrocarbon with a MW around 20.
The compressor type is supposed to be 617 , chapter 2 , with dry gas seals .
am not really sure if a 617 chapter 3 machine is suitable here , but considering the
low pressure ratio and similar flow , that might just work out.suction is at 20 bar(a).
Regarding the high temp and lack of coolers at the inlet , this was taken up
with the process guys but have not got a favorable response till now.

 

[rotw]

Try a double flow type single shaft compressor with 6 impellers of 300-350 mm. discharge will be about 220-225 degC. speed about 13500 rpm.