DJ Kast, Engine Room Tour with the Chief Engineer, June 2, 2015
NOAA Teacher at Sea Dieuwertje “DJ” Kast Aboard NOAA Ship Henry B. Bigelow May 19 – June 3, 2015
Mission: Ecosystem Monitoring Survey
Geographical area of cruise: East Coast
Date: June 2, 2015
Chief Engineer Tour of Engine Room!
SCHEMATICS- Drawn by John
Chief Engineer John Hohmann took me on a tour of the Engine room here on NOAA Ship Henry B. Bigelow. It was fascinating to learn all of the components that make this type of research vessel work. The electrical components, the seawater distillation apparatus, biological sewage treatment, etc. It was an amazing tour. The Bigelow has a diesel-electric drive system using four diesel generators to power to two electric motors. The motors turn one shaft which rotates the propeller. Overall rated horsepower for main propulsion is 3017hp.
The most fascinating part for me was the Evaporator.
Distillation is the production of pure water from sea water by evaporation and re-condensing. Distilled water is produced as a result of evaporating sea water either by a boiling or a flash process. This evaporation enables the reduction of the 32 parts per thousand of dissolved solids in sea water down to the one or two present in distilled water. The machine used is called an ‘evaporator’, although the word ‘distiller’ is also used.
The vacuum in the evaporation machine reduces the pressure to 30 inches of Hg or Mercury to boil water at 180F instead of 212 F
The sea water from the ship’s services is first circulated through the condenser and then part of the outlet is provided as feed to the evaporation chamber. Hot diesel engine jacket water or steam is passed through the heater nest and, because of the reduced pressure in the chamber, the sea water boils. The steam produced rises and passes through a water separator, or demister, which prevents water droplets passing through. In the condensing section the steam becomes pure water, which is drawn off by a distillate pump. The sea water feed is regulated by a flow controller and about half the feed is evaporated. The remainder constantly overflows a weir and carries away the extra salty water or brine. A combined brine and air ejector draws out the air and brine from the evaporator.
They need to make their own electricity on board ranging from 110 Volts for phones and computers to 750 Volts for some of the ship propulsion motors. Each of those require various circuit breakers seen below.