water / waste Flashcards
what are the main functional requirements of the waste water system? (3)
- provide potable water to consumers (washbins, galleys)
- provide sanitary facility and dispose of waste
- remove waste water from galleys, lavatories
what are additional functional requirements (3)
- operability (use by handicap. etc)
- servicability (use by crew)
- easy maintenence
what are design drivers for the ata 38 system? (3)
- weight
- reliability
- cost
how can the potable water system be pressurized?
- pneumatic system (bleed air or apu)
- dedicated compressor
- air pressurized on ground via external connection
what are shuttle valves? which fluid? operation?
control of pneumatic air system,
it is a t shape
there is a physical stop for one providing less pressure (to control between bleed and air ground supply)
what are the three subsystems?
- potable water
- water waste disposal
- sanitary toilets
what types of sensors exist for measuring quantitiy
rod
pressure sensor on top and bottom
is water ever drained from the potable water tank?
yes, if parked at night in freezing, though pipes are insulated
how can air tanks be pressurized?
bleed air supply, ground pressure, separate compressors
how much water does a passenger use per hour?
0.2 L
what is Bernoulis equation (with loss term)
rho * g * h1 + 1/2 * rho * v1^2 + p1 = rho * g * h2 + 1/2 * rho * v2^2 + (p2 + deltapL)
what components are on the service panel?
quantity reached light
- quantity indicator
- fill handle
- fwd drain open light
explain the electronic control architecture of the potable water system
the control is through the CIDS system.
The CIDS director is the computer and sole decision maker. The fap is connected through the panel network to the director. It is the UI.
The middle line connects DEU - B s to the director which are responsible for crew related functions.
several functions connect to the DEUS via can buses such as quantity indication, smoke detection, flush control unit.. etc The 28V DC is also connected to the DEUB
what functions does the DEUB connect to in regard to ATA 38?
flush control unit, drainmast control unit, potable water service paer, waste water service panel, vacuum generator overheat, liquid level transmitter, water quantity transmitter
explain the fill drain valve
you set the amount on the FAP, mechanically open the inlet and the valve will mechanically switch open the overflow valve (this will also via a discrete signal open the forward rain valve via an electric motor.
explain draining the potable water system
open all the drain valves and gravity does the work
differences with the A380 (larger)
- multiple water tanks
- designated air compressors
- CAN busses used to connect all features to the DEUBs
- water treatment modules
draw an a380 simple water treatment module sketch
see pic
inculde: pump, metal filter, water heater, control unit
what are distinct features of, advantages, and disadventages of teh CAN buses (more on a380)
- key characteristics:
- more controlers
- bit stuffing (as a means of synchronizations because return to zero coding is not used)
advantage:
- higher data rates
- more controllers per bus
- less wiring
disadvantage:
- software complexity
how is the fluid moved through the waste / water system
differential pressure (created by outside air or vaccuum generator (controlled by vacuum generator controlelr VGC)
how do solenoid valves work?
use electricity to mechanically open a valve via inducing an electromagnetic field, pushing a spring in a plunger and opening the valve
what does the FCU do
opens solenoid valve and electric motor valve underneath toilet to trigger flush sequence. one per toilet
what two qualities of the drain mast valve make it unique?
- heated so water doesn’t freeze
- has air stop valve so it is not always open
drwa the waste water system
see pic
draw the vaccuum toilet system
see pic
what is important in dimensioning the vacuum generator
- differential pressure needed to generate
- weight
- installation
- reliability
- electrical architecture
