refrigeration and ventilation 4 Flashcards
label this diagram
what are the uses of ventilation? (5)
cooling of electronics
CBRN
habitability
main machinery space cooling
galley ventilation
why do we use fans on exhaust and supply and in which compartments?
to remove fumes and moisture in compartments where people work
found in
machinery spaces
galley’s
laundries
WC/ heads
why do we use fan supply and natural exhaust?
to supply fresh air in places like stores and workshops
natural supply/exhaust where is it used
this is only used in minor unoccupied compartments and lobbies
where do we use natural supply fan exhaust and why?
inflame, paint ,sprit stores to remove toxic or flammable gases
what type of filters do we use in ventilation? (6)
panel filters (fitted to air conditioning to remove impurities)
supply filters (fitted to Air treatment units between the plenum chamber and cooler)
grease filter(fitted in the galley to exhaust canopies)
lint filters( fitted to prevent lint accumulation)
dust filters (fitted to computers and sick bay)
flameproof gauzes (prevents flames traveling through the vents)
Certain compartments have Fire Flaps built into their exhaust trunking what are they (3)
Galleys
Main Machinery Spaces
Magazines
what areas require special filters?(6)
galleys(grease filters and fire flaps)
storerooms (panel filters)
auxiliary machinery spaces (supply filter and fire flaps )
magazines (flameproof gauzes and fire flaps)
paint stores (flame proof gauzes)
Sewage treatment plants
what are the ventilation requirements for sewage treatment plants? (3)
15 air changes per hour
separate exhaust system
excess of exhaust to supply (negative pressure)
what percentage of air is recirculated in the ATU?
67%
what percentage of fresh air is used in the ATU?
33%
what does ATU stand for?
Air Treatment Unit
what does AFU stand for?
Air Filtration Unit
what state are AFU’s used?
CBRN DC state 1 condition Zulu Alpha
citadel state.
3 stages of filtration in AFU’s?
pre particular filter (paper filter)
particulate filter (made of glass filter)
gas filter(made of charcoal)
paper filter, what does it remove?
removes coarse particulate matter including radio active fall out.
particulate filter, what does it remove?
removes particulate such as bacteria by entrapment.
gas filter, what does it remove?
remove all chemical warfare agents in the form of gasses or vapours by absorption in the active charcoal filling
what is the procedure to close down in to a citadel state? (7)
close all openings on the citadel boundary
normal ventilation on recirculation
open AFU inlets and start AFU’s
restrict access to and from the citadel
search for leaks carry out temp repairs
monitor pressure for 2 inches on the water gauge
record the results in the SEF & D171 part 2 survey report
when is the citadels integrity is checked?(4)
annually
during harbour and sea acceptance e trails
before FOST
before and after refit or major dockyard work
how do you normalise pressure between compartments
use Air bleed valve(lift at 1/2 inch on the water gauge)
how do you shut all ventilation in a emergency?
use the Crash stop button in the SCC and HQ1
what must you do before restarting the vent system?
check around the vent intake for smoke, fumes and debris.
what are the four types of refrigeration plants?
cold rooms(freezers)
cold rooms (fridges)
domestic refrigerators ( in sickbay)
ice making machines