Plate heat exchangers and plate-and-shell heat exchangers
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1. I have recently come across a heat exchange unit: on one side, there is pentafluoropropane at a pressure of around 7 bar and a temperature of 70–40°C; on the other side, there is cooling water. Could you all advise me whether I should choose a plate heat exchanger or a shell-and-tube heat exchanger? 2. Plate-and-shell heat exchangers should be non-detachable; what are the requirements for the medium? 3. The plates can be removed; when performing heat transfer calculations, can the fouling on the water side be ignored?
A plate heat exchanger can be chosen; however, I’m not very familiar with pentafluoropropane – is it in a gaseous or liquid state at temperatures of 70-40 degrees? It is necessary to know this situation in order to determine the process design. In heat transfer calculations, the fouling coefficient on the water side can be ignored; plate heat exchangers need to be cleaned regularly when the water quality is poor. A design margin for amplification is required.
Of course, plate heat exchangers are convenient!
I’m not very familiar with what pentafluoropropane is. If it’s toxic and explosive, leaks must be avoided; in such cases, semi-welded plate heat exchangers should be used to contain pentafluoropropane within a sealed space for heat exchange, thereby preventing leaks
The pentafluoropropane side is condensed from gas to liquid, and leaks are not allowed.
This post was last edited by Qianchui Bailian on 2017-6-20 at 11:42. Plate-type systems cannot be used, mainly because the working pressure is not sufficient; a minimum working pressure of 0.1 MPa is required for plate-type systems. If the work pressure is high enough, a plate-type one will work.
It is explosive and toxic; it is designed to be non-detachable. Plate-and-shell heat exchangers generally have fine corrugations, so they require high-quality water – the water must not contain too many impurities, nor should it be too hard, otherwise the chemical cleaning cycle will be very short
With our company’s semi-welded plate heat exchangers, pentafluoropropane flows through sealed channels; there are no gaskets, so no leakage occurs. On the other side, cooling water is used with gaskets, and this setup is generally employed in liquid ammonia evaporation to prevent leaks of liquid ammonia