Shell and tube heat exchangers are highly efficient devices used to transfer heat between two fluids, making them an ideal choice for fluid heating applications. They consist of a series of tubes, one set containing the hot fluid that needs to transfer heat and the other containing the fluid to be heated. The design allows for a large heat transfer surface area while maintaining a compact size. The fluids flow through the tubes in counter-current or co-current configurations, which maximizes the efficiency of heat exchange. These exchangers are favored in various industries due to their robustness, versatility, and ease of maintenance. The ability to handle high-pressure and high-temperature fluids makes them particularly valuable in processes requiring fluid heating.