off topic airplane

Discussion in 'The Coffee Shop ~ Chit Chat' started by 9191gmc, Jun 11, 2010.

  1. 9191gmc

    9191gmc Rockstar 100 Posts

  2. 2COR517

    2COR517 Epic Member 5+ Years 1000 Posts

    Good question. Is there an APU in there somewhere?
  3. murdog94

    murdog94 Epic Member 5+ Years 5000 Posts

    I am thinking that is the APU.. Or something along those lines..
  4. 2COR517

    2COR517 Epic Member 5+ Years 1000 Posts

    I looked up cabin pressurization on Wiki after reading this post. Bleed air off the engine compressors has been used to pressurize planes for years. But Boeing went back to electric compressors on the 787.
  5. 9191gmc

    9191gmc Rockstar 100 Posts

    o were too large and heavy, Sinnett says. "Now we have the weight, cost, power and reliability that works on an aircraft."

    There are four cabin compressors, two on each of the two air-conditioning packs in the wing-to-body fairing. They compress outside air to roughly 15 psia. and an outlet temperature around 200F. The 6,000-ft. cabin is at 11.8 psia. The compressor wheel is about one ft. in diameter and turns 42,000 rpm. on oilless foil air bearings, though the speed of the permanent magnet motor varies in practice. Each one can produce 90-100 hp. The ozone-removing catalyst normally operates around 350F entry temperature and engineers had to make sure it works at 200F.

    The low compressor pressure biases the heat rejection task away from the turbine-compressor air cycle machine, because it uses pressure drop for cooling. Instead, the new pack requires a larger radiator to dump the heat to outside air, and that increases cooling drag compared to current practice.
  6. shivam

    shivam New Member

    the pic is good,it looks so heavy and its capacity also high i think so......

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