Device IDA-51M is developed in 1969. Works on the closed cycle of breath with regeneration of a gas mix exhaled by the person. The device is intended for rescue of members of crew of an emergency submarine from depth up to 200 meters. In this device for the first time for breath the helium-oxygen mix and substance O3 for regeneration of a gas mix.
(text thanks to Valery Mukhin)

IDA-51M
 

Nitrogen - helium - oxygen isolating respiratory device IdA-51m. The breast independent device providing breath on various depths for a long time. It is used for carrying out of a decompression of divers in decompression chambers. The device has a respiratory bag, a two-wall regenerative box under the regenerative substance, two small-displacement cylinders; one for oxygen, another — for Nitrogen - helium - oxygen mixes, Oxygen the submitting mechanism, the manual actuator of a gas mix, valves a box, the corrugated tubes of a breath and an exhalation, poisoning both safety valves and a bib. The device is supplied by a bag for storage and a bag with the tool and spare parts.

Application instead of nitrogen of compressed air which should be preliminary cleared of impurity of oils and harmful gases is supposed. Breath in the device is carried out through a mouthpiece, inclusion in the device — at filling of a respiratory bag with pure oxygen.

The exhaled mix arrives in a regenerative box where it is cleared of carbonic gas and is enriched with oxygen, then completely restored arrives in a bag for the next breath. At immersing (pressure lifting in the chamber) for completion of volume and diluting of pure oxygen from a cylinder in a respiratory bag manually the actuator moves Nitrogen - helium - oxygen a mix. At transition to an oxygen decompression the mix of a respiratory bag is replaced with pure oxygen carrying out of triple washing, using the manual actuator of an oxygen cylinder.

Cylinder volume...................2 Х 1.3 liter
Max. cylinder pressure........200 bar
Dive time duration................5 hour
Counterlung inspire..............8 liter
Weight empty in air.............14 kg
MOD..................................100 mtrs
Scrubber............................2.2 kg
Constant giving of gas.........0.3 - 0.5 liters in a minute
Dimensions of the device laid in a bag.......55Х40Х22 Centimeters