If you have studied liquid-cooled products, you may come across two options, shell-and-tube or tubular or plate heat exchangers. Both Shell and tube-and-tube heat exchangers use the same principle to exchange heat between two fluids through heat transfer, but the methods used are quite different. If you don't understand the benefits of any design, then deciding which method is best for you can be difficult.
Shell and Tube Heat Exchangers
The shell and tube heat exchanger consists of a small tube in a large cylinder (or casing) and is a simple but effective structure that has been in existence for more than 100 years (see Steam Turbine Construction) Due to their simplicity and flexibility, they can be manufactured at low cost, even at low capacity. They are ideal for applications that require regular maintenance and repair, such as in marine environments, as most designs are easy to remove.
Advantages of Shell and Tube Heat Exchangers;
Smaller designs can be lower cost
Much easier to service
O Ring seals also make them cheap to service
A better solution for sea water coolant, or other fluids at risk of clogging in narrow spaces
Can provide better installation options (three pass, two pass header configurations etc.)
Ideal solution for hydraulic power packs, mining machinery, sea water cooled vessels and swimming pool heating.
Plate Heat Exchangers
Although the principle of a plate heat exchanger is very similar to that of a shell and a pipe, the structure is quite different. Plate heat exchangers use a multi-layer plate stack instead of a bundle of tubes to form a series of channels through which liquid flows. They are generally more compact and sometimes less expensive than housings and tubes, but do not have as much design flexibility as housings and tubes. However, their all-stainless steel construction makes them ideal for applications such as food processing and pharmaceutical production.
Advantages of Plate Heat Exchangers;
More compact design
A lower cost option wherever stainless steel is required
Higher operating pressure capabilities
Higher temperature capabilities
Ideal for small district heating, beverage cooling, food and pharmaceutical production and low duty oil cooling applications.
Shell and tube heat exchangers are still the first choice for many engineers because they are easy to service and are compatible with seawater coolants. If you want to use a plate heat exchanger with sea water, it must be a gasketed plate assembly with a titanium plate, so the cost is usually higher than the equivalent shell tube (even with titanium tubes)
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