This is the most popular type of design with a shell accompanying several tubes and the flow of liquid to be cooled is mainly through tubes, whereas the second liquid flows over the tube inside the shell. In this heat exchanger, the complete shell is fitted with a tube stack or commonly known as the shell.
Two end plates are sealed on both sides of the shell and a provision is made at one end to cater for the expansion. The cooling liquid passes through the tubes which are sealed on either end into the tube plate. The tubes are secured in the tube plate by bell mouthing and expansion.
The shell is enclosed with water chambers that surround the tube plates. The coolers could either be single-pass or double-pass exhibiting the flow of cooling liquid.
Gaskets are fitted between the tube plates and the shell; similarly, between the tube plate and the end cover to cater to the leakages from the cooler.
The other side of the tube plate, which is not fixed is free to move and has seals on either side of a safety expansion ring. The cooling liquid or the liquid to be cooled could then leak out and will hence be visible preventing any intermixing or contamination.
Baffles are fitted on the tube bundle which leads the liquid to be cooled up and down, thus increasing the effective surface area of cooling. They also support the tubes, providing strength and rigidity to the bundle.
Aluminum brass is generally used for the construction of the tubes which is 76% copper; 22% zinc and 2% aluminium. Sacrificial anodes are used on the seawater side for corrosion prevention as they corrode first and prevent the material with seawater being the electrolyte.