Charley
18th Dec 2004, 22:50
The conceptual launches of both the 7E7 and the A350 played up the benefits of the 'bleedless' engines that both designs would incorporate. Does bleedless really mean completely bleedless, for all stages of flight?
Meanwhile, consider ozone - which is, of course, noxious. It occurs naturally in the atmosphere from 35,ooo-ish feet upwards. Unless I misunderstand things the presence of ozone in the cabin is kept to safe levels by the high tempartures in the compressor core destroying much of the ozone, before the air is bled off, fed into the packs and circulated around the cabin.
Does anyone know how the manufacturers intend to reduce the quantities of ozone in the ingested air in aircraft types with new bleedless engines? Presumably the intention is to have the cabin air supply taken from a different source rather than from the engines. Will it still be fed through a compressor (an always-on APU, for example) or will the manufacturers revert to using carbon filters or perhaps catalytic converters? I gather carbon filters were used in aviation in days gone by but were undesirable due to their weight.
I'm strangely interested in the answer to this. I suppose it shows what the combination of days spent studying ATPL notes and a curious mind have reduced me to...
Charley :=
Meanwhile, consider ozone - which is, of course, noxious. It occurs naturally in the atmosphere from 35,ooo-ish feet upwards. Unless I misunderstand things the presence of ozone in the cabin is kept to safe levels by the high tempartures in the compressor core destroying much of the ozone, before the air is bled off, fed into the packs and circulated around the cabin.
Does anyone know how the manufacturers intend to reduce the quantities of ozone in the ingested air in aircraft types with new bleedless engines? Presumably the intention is to have the cabin air supply taken from a different source rather than from the engines. Will it still be fed through a compressor (an always-on APU, for example) or will the manufacturers revert to using carbon filters or perhaps catalytic converters? I gather carbon filters were used in aviation in days gone by but were undesirable due to their weight.
I'm strangely interested in the answer to this. I suppose it shows what the combination of days spent studying ATPL notes and a curious mind have reduced me to...
Charley :=