2 replies to this topic

[carly]

Hi

I need to cool hot PSV release (liquid) to a safe temp 60 degC prior to rundown to slop tank. Besides air fin cooler, anyone has heard of using water bath cooler for cost saving?

[Zauberberg]

From operational point of view, using water bath cooling is applicable in following cases:

- Intermittent flow of hot fluid (i.e. sampling or draining)
- Maximum temperature of water will not exceed boling point temperature at maximum heat load (flow rate and temperature level) of process stream, considering the worst case flow and temperature

Simply looking at heat balance, you need sufficient amount of stagnant water capable to absorb heat from process stream at any condition.
However, cooling PSV discharge is somewhat different and - I suppose we are talking here about 100% liquid product going to storage tank - what I have seen is to route this stream through product line and cool it down to required temperature level in existing heat transfer devices (heat exchangers or air coolers for product cooling in regular operation). Switching flow from product tank to slop oil tank is usually done at the plant battery limit after stream is already cooled to desired temperature.

[carly]

Yea, this is kinda unconventional, because normally air fin cooler is used. The overpressure source is 100% liquid relief and caused by block outlet, and there are measures to minimise the probabilty of PSV blowing. So the chances of utilitising the AFC is quite low and hence economically not good...