1 reply to this topic

[NatarajK]

Hi

 

I have designed a stainless steel storage tank of horizontal cylindrical type (1 m dia, 2.2 m length and 10 mm thick, glass wool insulation of 50 mm thick ). In which R134a needs to be stored at a temperature of 14 deg C and pressure of 4.75 bar . Outside air temperature is 30 deg C. My process requirement is 20% of liquid in tank but I feel some additional liquid has to be stored as buffer. May I please know how much I have to store like 50% of 60% etc., and what would be the evaporation rate and pressure built up over a period of time. My tank design pressure is 12 bar. How long the evaporation takes to reach this design pressure?

 

 

Any help and suggestions are welcome.

 

 

Nataraj K

[Art Montemayor]

Nataraj K:

 

You use the term "storage".  This implies that the contents are held for long-term or intermittent static residence in the tank and not under steady-state requirements.  Why are you storing the saturated R134A liquid (a common refrigerant) at 14 ^oC when you could easily do it at its 30 ^oC saturated pressure (approx. 7.5 barA)?  ---- please identify logical engineering units:  is it bar or barA you mean?

 

You certainly need a vapor space over a saturated liquid and 20% of the total space in the tank is a normal amount for liquid expansion and operational range.

 

If you have a process need to maintain the R134A at 14 ^oC, then please so state it.  If not, then it seems your "storage" tank only needs a PSV set at its MAWP - which is probably higher than the maximum saturated pressure of the R134A at 30 ^oC.  In other words, why not store the refrigerant at 30 ^oC - like everyone else does?  In fact, that is how this liquid is transported and distributed in almost all industrial areas.

 

Please furnish ALL your basic data.  Giving our members piece-meal information is only going to confuse and turn this thread into a lengthy, rambling discussion of what is a simple and easy application.