POSEIDON SE7EN+ - Scrubber; Chapter 1 Page 31

Poseidon SE7EN+ User Manual Chapter 1 Page 31
13. Scrubber
The largest physical element of the rebreather is the CO
2
absorbent system, also referred to as
the “Gas Processor” unit (it physically includes the gas sensing and electronics control modules).
The outer shell of this system (shown in Figure 1-54) comprises the structural backbone of the
Poseidon SE7EN+ and both the diluent and oxygen cylinders attach to the side of this extruded
aluminium tube. The top section of the housing is the mounting structure for the electronics
module. The main tube is the housing for the CO
2
absorbent cartridge. The base plate seals
the housing and also allows for modular loading of the CO
2
absorbent cartridge.
Because CO
2
production rate is closely correlated with oxygen consumption, the Poseidon
SE7EN+ was designed such that the CO
2
absorbent cartridge duration corresponds to the
oxygen cylinder capacity. Thus, the absorbent cartridge MUST be replaced whenever the
oxygen cylinder is relled. To remove the spent cartridge, loosen all four (4) large hand nuts at
the bottom of the cartridge housing to the point where they spin freely (no tools are required;
see Figure 1-56).
The SE7EN and its repackable cartridge has been tested for CO2 endurance in two ways inline
with the tests described in EN14143:2013, a respiratory minute volume of 40 liter/minute, cold
water 4° Celsius and a CO2 injection rate of 1.6 liter/minute.
Scrubber duration standard test result:
A 40 meter static test – 130 min
Note: A static test is a simulated dive performed in a pressure chamber where the depth is
constant, i.e. there is no descent nor ascent in the dive.
Scrubber duration result at non-standard dive prole:
A 100m dive prole with a bottom time of 10 minutes – 200 min
With the nuts loose, pull the webbing handle on the bottom of the housing in a fashion, so that
it moves in the opposite direction from the electronics housing. Because o-ring seals can “set”
with time it may be necessary to restrain the tube with one hand while pulling with the other
(see Figure 1-57). Make sure that the nuts are completely free from the heli-coils before pulling
out the bottom lid.
Once the dual radial seals on the end cap have
cleared the end of the housing tube, the CO
2
absorbent cartridge will freely slide out, as
shown in Figure 1-58.
Outer shell - Cartridge housing
Figure 1-54.
Overview of the cartridge house and the CO
2
absorbent cartridge.
Figure 1-55.
The CO
2
Scrubber Cartridge with the Sofnolime
®
797.
Repackable
Scrubber Cartridge.
Only use Sofnolime 797