Atmosphere control/gas free engineering Flashcards
Purpose of the Submarine atmosphere control program
Close as practicable to a normal atmosphere
Accomplished by:
proper atmosphere monitoring
proper equipment operating procedures
control of materials introduced into the submarine
Common terms
gas
toxic
asphyxiant
Gas: Material whose boiling point is below room temp. Take shape of their enclosure
Toxic: gas which is poisonous to human body
Asphyxiant: affects the absorption of O2 by hemoglobin in the blood stream thereby causing o2 starvation
terms
Aerosols
particulates
Aerosols and particulates: small finely divided solid or liquid particles:
Dust
Fumes
Smoke
Mists
either remain suspended or settle to surface
substantial amount from cooking and lube oil
terms
volatile material
Hydrocarbons
Aliphatics
Aromatics
Volatile material- evaporates or vaporizes quickly
Hydrocarbons- Compounds containing carbon and hydrogen combined by a carbon-hydrogen compound
Aliphatics: Hydrocarbon with single carbon-carbon bonds
Aromatics: Compounds containing a bezene ring which is more toxic and more difficult to burn than aliphatics
Units of measurement
Partial Pressure
Each gas in a mixture of gases makes its own contribution to the total pressure of the mixture, each separately is partial pressure, total is the totl pressure
Dalton’s Law
PT= pp1 + pp2 + pp(n)
PP/PT x 100 volume concentration
TORR
unit of pressure equaling the weight of a column of mercury having the height of 1mm (760 TORR = 1 ATM)
Conversion for Volume % and TORR
TORR= (PT/100) x volume
Volume %= (TORR/PT) x 100
Atmosphere control system
Maintain air in the submerged submarine as close as practicable to the composition of clean air found in the earth’s atmosphere
reports to CO
Instrumental methods of analysis
Infrared spectrophotometry
mass spectrometry
colorimetric detection (detector tubes)
photoionization
Atmosphere monitoring equipment
CAMS
Trace Gas Analyzer (TGA)
Portable Oxygen Analyzer
Colorimetric Detector Tubes (Draegers)
CAMS-
Central Atmosphere monitoring system
primary
routine monitoring schedule- 3 spaces
Always fan room must be one
Reactor Compartment sampled prior to entry
Hourly underway
Daily in port
Characteristics of gases found in submarine atmosphere
Greater Variability in O2
Wide Range of organic and inorganic contaminants aerosols gases, and vapors
Inherent toxicity of various substances
composition of clean dry air
Nitrogen 78.09 TORR 593
O2 20.95 TORR 159
Argon 0.93 TORR 7
CO2 0.03 TORR 1
Factors determining effects of toxic substances on human body
Length of exposure
Concentration
Chemical Considerations such as solubility in body fluids and tissue proliferation
type of gas or toxic medium
Corrective measures for abnormal atmosphere conditions
Exposure limits: tables 3-5 and 3-6 of the ATM manual. based on 90 day exposure
Established for healthy adult personnel population under medical surveillance
90 day exposure limit
Represents an average value for continuous exposure which may be temporarily exceeded
24 hr exposure limits
represent values used in the event of the release of a large amount of a single contaminant such as from a spill
1 hr exposure limit
Applied to possible accidental situation which are rare single events in the lifetime of an individual, and are not to be exceeded.
Replenish O2
Ventilation- at least one hour weekly
Electrolytic O2 generator (EOG)
Stored in air banks
Oxygen Candles (Chlorate Candles)
produce chlorine, carbon monoxide and water vapor
Lithium Hydroxide Canisters
Removes CO2
Backup to scrubbers
Removing gases while submerged
Ventilation system: recirculation and surface ventilation
Red-Devil Blower
scrubbers and burners:
CO2 - Scrubber
CO-H2 burner
atmosphere monitoring requirements during evolution and casualties
Fire
High CAMS readings
Refrigerant handling
Requirements for monitoring atmosphere when fixed monitors are out of commission
Draeger tubes
Supplement atmosphere oxygen
decrease carbon dioxide release
