What are the problems with seawater intake?
In the past, seawater intake was generally done using immersion type pumps such as a submerged pump or vertical pump. The main reason for this was because of the poor seawater pumping efficiency of land-based pumps. Difficult pumping conditions are common due to factors such as poor self-priming efficiency from the extrication of air and bubbles which occurs easily in seawater, too much distance from the water suction intake, and pipes crossing over embankments. With no strong self-priming pumps that could meet these demands, the solution closest at hand was “forced pumping operation” with submergible pumps. However, for submerged pumps, because the pump motor is submerged together with the pump, there are concerns with the power supply, corrosion, and the danger of damage caused by rough seas. Added to this is the troublesome work of pulling up a submerged pump to perform maintenance inspection. As for vertical pumps, because the main part of a vertical pump is submerged in water, the
