Why is a horizontal shell and tube heat exchanger preferred over a vertical one?

A horizontal shell and tube heat exchanger having more than one pass is a distinctive advantage that enhances its performance in heat transfer applications. In a shell and tube heat exchanger, the heat transfer process occurs between two fluids flowing in separate channels. A multi-pass design allows one of the fluids to flow through multiple passes within the shell side or tube side.

This configuration increases the surface area for heat exchange, improves the temperature gradient between the fluids, and leads to more effective heat transfer. By facilitating multiple passes, the heat exchanger can achieve better thermal efficiency without significantly increasing the size, which is particularly advantageous in systems where space or footprint is a concern.

Additionally, the design of a horizontal heat exchanger often allows for more effective fluid distribution and minimizes the effect of gravitation on fluid flow dynamics, hence further enhancing its efficiency. This makes horizontal units desirable in applications requiring high performance and efficiency, justifying the preference over vertical designs.