Canadian Underwater Mine Apparatus: Unmanned Performance Validation of the Second Prototype Second Stage Regulator.

摘要

The Canadian Underwater Mine Apparatus (CUMA) is a rebreather type apparatus employing a self-contained gas supply system that mixes pure oxygen with a diluent gas. The resultant gas mixture supplied to the counterlung has a constant oxygen partial pressure over the depth range of the apparatus. Operationally, the diluents used are nitrogen for depths up to 55 metres of seawater (msw) and helium to 80 msw. After the evaluation of the first prototype of the CUMA, it was recommended that the second stage regulator in diluent circuit be re-engineered to increase its compatibility with helium and saltwater before open water trials to 80 msw were attempted. The contractor, Fullerton, Sherwood Engineering Limited, produced a new regulator that the Experimental Diving Unit of the Defence and Civil Institute of Environmental Medicine evaluated prior to further manned dives with the CUMA prototype. Apparatus were set up to reproduce the diluent circuit and allow simulation of diving the circuit. Tests of the regulator were repeated three times for each combination of diluent (helium or nitrogen), high pressure supply (500 to 1000 pounds per square inch, gauge (psig) or 2000 to 3000 psig), first stage regulator output setting (140, 155 and 170 psig) and depth (pressures equivalent to 0 to 9 Bar gauge). The results showed a highly linear and repeatable function of the second stage regulator in relation to depth. Additionally, no gas leaks were found in the regulator. It was recommended that the new second stage regulator would be suitable for continued manned evaluations of the CUMA.