What characterizes the Flash Type Distiller?

The option highlighting the use of lowering pressure and the introduction of preheated seawater is correct because this describes the fundamental operation of a Flash Type Distiller. In this process, seawater is first preheated, often by waste heat from another system such as the engine cooling or the heat exchangers. The pressure is then lowered in a chamber, which causes the preheated seawater to 'flash' into steam as the pressure drop allows the water to boil at a lower temperature. This steam can then be collected and condensed to produce fresh water, effectively separating it from the salts and impurities in seawater.

The Flash Type Distillation process is widely used because it's efficient and can produce a significant amount of water under varying energy inputs. This method capitalizes on both the principles of thermodynamics and the unique characteristics of seawater, making it a suitable choice for marine applications where fresh water is needed.