Multiple Unit Large Volume Filtration System
deployment during the Canadian Joint Global Ocean Flux Study (C-JGOFS)
The image shows one of the Large Volume pumps being deployed from the
afterdeck of the
during the Febuary 1996 C-JGOFS expedition along
Line P to Station Papa
The people from left to right are Steve (deck hand),
Hugh (UBC tech),
(MULVFS owner) and John (bosun).
Since the 1996-1997 campaign, MULVFS has been to sea in the California Current (2001) Southern Ocean (2002) during the SOFeX (Southern Ocean Iron Experiment), Station ALOHA near Hawaii (2004) and Station K2 in the Oyashio current near Japan (2005).
The MULVFS has 12 pump/filtration units, each capable of filtering
up to 16,000 L of seawater through a filter series consisting of 53 um
polyester mesh and a pair of 1 um quartz fiber filters. Each of the pumps also processes
2500 L through adsorber cartridges designed to trap dissolved natural uranium
series radionuclides (particularly Th-234/U-238) present in seawater. Another flow channel
allows processing of 100-200 L through specialized adsorber/filter
The 12 light-weight/low-drag pumps are operated simultaneously in profile
from the surface to 1000 m depths using
ship-generated 440VAC 3-phase power. This is accomplished via an
uniquely engineered 1000 m long electromecanical cable and cable handling system. Depth and flowrate information is transmitted
in real time from several pump units during operation.
Typical station time is 7-8 hours including deployment and recovery. Operations require a minimum of 2 people at sea. The system is designed to be tolerant of winter time conditions.
FTP access to 1996 and 1997 results from MULVFS along
"CJGOFS Line P data archives".
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