M. TECH. SEMINAR
Atmospheric Control of
Closed Systems
CHE 702
ENVIRONMENTAL CONTROL
& LIFE SUPPORT SYSTEMS
PRESENTED BY:
SANJAY KATHERIA
11102036
ECLSS
AIR REVITALAIZATION
ECLSS
WASTE WATER
MANAGEMENT
AIR REVITALIZATION
ECLSS
SOLID WASTE
MANAGEMENT
M. Tech Seminar
TEMPERATURE &
HUMIDITY CONTROL
Sanjay Katheria
17th April, 2012
AIR REVITALIZATION
AIR REVITALIZATION
OXYGEN PRODUCTION
CO2 REMOVAL
TRACE CONTAMINANT
CONTROL
HUMIDITY CONTROL
M. Tech Seminar
Sanjay Katheria
17th April, 2012
SPACECRAFT CABIN AIR QUALITY PARAMETERS
* Spacecraft maximum allowable concentration
Source: Report on AIR PURIFICATION IN CLOSED ENVIRONMENTS:
OVERVIEW OF SPACECRAFT SYSTEMS by Jay L. Perry, NASA George C.
Marshall Space Flight Center
AIR REVITALIZATION
OXYGEN PRODUCTION
Electrolysis of Water
M. Tech Seminar
Sanjay Katheria
Solid Fuel Oxygen
Generator
17th April, 2012
AIR REVITALIZATION
Electrolysis of Water: Elektron
H2O + Electricity
H2 + 0.5 O2
- Source of water: Water from waste water recovery section of
ECLSS system. Main source of oxygen in shuttle.
- For emergency purpose oxygen bottles and SFOG’s.
M. Tech Seminar
Sanjay Katheria
17th April, 2012
AIR REVITALIZATION
- Electrolysis of water by 30% KOH solution.
- 12 electrolysis cells
- Oxygen supplied to cabin while hydrogen is
vented in space.
- The decomposition of 1 kg (2.2 1bs) of
water yields 25 L (0.88 ft³) of oxygen per
hour at a pressure of 760 mmHg, which is enough to support
one crew member for one day.
- Power consumption of the process is ~1 kW.
M. Tech Seminar
Sanjay Katheria
17th April, 2012
AIR REVITALIZATION
Solid Fuel Oxygen Generator: Vika & TTK
- Chemical Oxygen Generator: Solid Fuel Oxygen Generator
(SFOG)
-A replaceable cartridge with an igniter, a striker mechanism, a
filter, a dust collection filter, and a fan that are located inside one
case.
M. Tech Seminar
Sanjay Katheria
17th April, 2012
AIR REVITALIZATION
- Release of oxygen by means of chemical reaction
- Use of Lithium Perchlorate (LiClO4), at 400oC decomposes in
oxygen and Lithium Chloride.
- Mixing of N2 to cool down and to form air mixture.
- One cartridge yields 600 L (21.2 ft³) of oxygen. The contents of
the cartridge take 5-20 minutes to decompose at a reaction
temperature of 450-500°C (842-932°F). Temperature of the outer
surface of the ТГК may reach 50°C (122°F).
- Emergency supply of oxygen in Aircrafts .
M. Tech Seminar
Sanjay Katheria
17th April, 2012
AIR REVITALIZATION
Carbon dioxide Removal Assembly: Vozdukh
CDR Bed Containing
Zeolite 5A
These beds contains alternative layers of
Silica Gel and Zeolite 13X.
AIR REVITALIZATION
- The Vozdukh system can be divided into three parts:
1) The Preliminary Purification unit
2) A heat exchanger unit
3) An atmosphere purification unit (CDR Bed)
- This system consists of three molecular sieve beds, two
desiccant beds, two electrical heating units, an air-to-air heat
exchanger, an air-to-liquid heat exchanger, a vacuum pump,
eight valves, and a fan. The desiccant material is silica gel.
- Carbon dioxide is removed from the atmosphere by molecular
sieves, consisting of Zeolite, a solid porous adsorbent material.
M. Tech Seminar
Sanjay Katheria
17th April, 2012
AIR REVITALIZATION
- Once saturated, the Zeolite is regenerated by exposing the bed
to vacuum.
- The air must first be dehumidified because the Zeolite in the
molecular sieve bed preferentially adsorbs water.
- Moisture absorption by silica-gel is an exothermic process,
generating a bed temperature of 30-50°C (86-120°F).
- Carbon dioxide absorbent canisters The lithium oxide-based
carbon dioxide absorbent canisters of the SM provide a backup
means of removing carbon dioxide from the atmosphere of
habitable compartments.
M. Tech Seminar
Sanjay Katheria
17th April, 2012
AIR REVITALIZATION
TRACE CONTAMINANT CONTROL SUBASSEMBLY (TCSS)
- Trace contaminant sources:
1) from off-gassing (from structural materials, electronic
equipment or materials used in experiments, etc.)
2) from system failures (leaks, equipment overheating, fires,
etc).
3) from the crew itself (metabolic products).
4) from ECLSS itself.
M. Tech Seminar
Sanjay Katheria
17th April, 2012
TCCS
Activated carbon bed
treated with
phosphoric acid to
absorb ammonia.
To remove any acidic
oxidation products.
Catalyst bed containing
Pt group component on
alumina base
AIR REVITALIZATION
- TCCS consists of following main components: two regenerable
activated-charcoal cartridges, a cartridge containing a catalytic
oxidizer, a filter, a fan, and valves.
- The charcoal beds adsorb high molecular weight trace
contaminants. The catalyst oxidizes carbon monoxide to carbon
dioxide, and the hydrogen to water.
- The process flow rate is 15.3 m3/h through the carbon bed,
which contains 22.7 kg of granular activated carbon treated with
10% by weight phosphoric acid.
- The cartridges must be regenerated every 20 days for a 12-hour
period. During regeneration, the cartridges are heated to 200°C
(390°F).
-
M. Tech Seminar
Sanjay Katheria
17th April, 2012
AIR REVITALIZATION
M. Tech Seminar
Sanjay Katheria
17th April, 2012
AIR REVITALIZATION
HUMIDITY CONTROL
- Humidity levels are controlled within manned spacecraft using
condensing heat exchangers.
- All drinking water aboard the Mir Space Station either originates
from reclaimed humidity condensate, or resupply from the
ground.
M. Tech Seminar
Sanjay Katheria
17th April, 2012
Current Research & Future Challenges
- improvements are needed to further minimize air purification
system mass, power, volume, and logistics requirements.
- Solid amine chemical adsorbent media for carbon dioxide
control.
- Structured oxidation catalyst substrates that improve mass
transfer, allow direct catalyst heating, and compact reactor
design.
- Structured adsorbent substrates to eliminate adsorbent bed
dust generation caused by size attrition and reduce volume,
mass, and power required for temperature swing adsorption
systems.
M. Tech Seminar
Sanjay Katheria
17th April, 2012
Source & references
• Report on “Air purification in closed environments: Overview of
spacecraft systems” by Jay L. Perry NASA George C. Marshall
Space Flight Center and M. Douglas LeVan, Department of
Chemical Engineering, Vanderbilt University, Nashville, Tennessee,
USA.
•
Astronaut Training Manuals for the ISS , RSA
• http://people.oregonstate.edu/~atwaterj/o2.htm (Oragon State
University, USA)
•
Wikipedia: http://en.wikipedia.org/wiki/ISS_ECLSS
Thank You
Presentation uploaded @
http://home.iitk.ac.in/~katheria
M. Tech Seminar
Sanjay Katheria
17th April, 2012