View Full Version : NH3 Flash Intercooler

25-03-2008, 06:38 PM
Dear Friends and Gurus
Please find attached a sketch of an flash intercooler for a two stages Ammonia system .

The low stage compressor discharge at +63C in the pipe marked with "A" ( see sketch)

The Pipe "A" is immersed in ammonia liquid a -10 due to the sucction of the second stage so the condensation of the low estage compressor is at -10C.

The mass flow coming from low stage compressor bubble in the ammonia inside the tank

The question are:

What area should have the holes in the pipe "A" to garantee complete condensation?
The holes should be under or above the pipe?
What length should have the pipe "A" in order to garantee the residential time to condensate the ammonia coming from the compressor?
The pipe "A" is show in the form or a letter "L" may be it is better to make a configuration in form of a inverter "T". To garantee better flow distribution.If you have any literature about this topic I will appreciatte it
Best regards

06-04-2008, 02:06 AM
May I do the same questions?

06-04-2008, 08:34 PM
The purpose of this vessel is not to condense everything entering it from the low stage compressors. It is purely to de-superheat the vapour entering it from the low stage so that the suction vapour entering the high stage compressors is not too hot causing high discharge temperatures. (If it was used as a condenser everything being condensed would cause some of the liquid in the vessel to evaporate so no gain) The holes in the pipe generally face up and allow the vapur to bubble up through the saturated liquid in the vessel. The size and spacing of the holes in the pipe are designed so that they do not cause a pressure drop across them yet evenly distribute the vapour bubbles to come out of the pipe along its full length. As the superheated vapour from the low side compressors bubbles up through the -10 saturated liquid it gives up its superheat to and causes some of the liquid in the vessel to change to a vapour. The desuperheated vapour from the low stage and the evaporated vessel vapour is then drawn off by the high stage compressors.

07-04-2008, 01:40 AM
Thanks Coolblade
I agree with your post
I saw a drawing of an intercooler where the holes were replaced for two longitudinal grooves looking downwards forming angulo 60 grad
This dising does not like to me
How do you garantee the resident time?
How do you garantee a good gas distribution?