In a shell-and-tube condenser using NH3 and sea water, what metal is recommended for the condenser?

Muntz metal is a brass alloy, typically containing about 60% copper and 40% zinc. This material offers good resistance to corrosion in marine environments where sea water is present, making it an ideal choice for applications involving seawater cooling systems like a shell-and-tube condenser.

Using galvanized steel, while it provides some level of corrosion resistance due to its zinc coating, is not as effective as Muntz metal in highly corrosive environments such as those involving ammonia (NH3) and seawater. Muntz metal's properties allow it to withstand the chemical interactions and corrosive effects inherent in these systems better than galvanized steel, leading to a longer-lasting and more reliable condenser.

In contrast, black iron is typically not suitable for saline or corrosive environments as it can rust and deteriorate quickly. Copper, although it is a good conductor of heat, can corrode in the presence of ammonia, especially in high-temperature applications, making it less ideal in this context. Therefore, the recommendation of Muntz metal stems from its superior performance in resisting corrosion and ensuring the longevity of the condenser when using NH3 and sea water.