Patent ID: 7727057

Claim:
Device ( 10 ) for heating an aircraft cabin, comprising: a first hot air supply line ( 12 ) leading to an air conditioning unit ( 14 ) for supplying hot air thereto; a flow control valve ( 16 ) that throttles the volume of hot air to the air conditioning unit ( 14 ), the flow control valve ( 16 ) disposed in the first hot air supply line ( 12 ) upstream from the air conditioning unit ( 14 ); a second hot air supply line ( 18 ) branching off from the first hot air supply line ( 12 ) between the flow control valve ( 16 ) and the air conditioning unit ( 14 ), bypassing the air conditioning unit ( 14 ) and connecting to a downstream end of the air conditioning unit ( 14 ) so as to enable mixing of the hot air supplied via the second hot air supply line ( 18 ) with cool air flowing out of the air conditioning unit ( 14 ) prior to delivery of the air to the aircraft cabin; a control device ( 28 ) adapted to adjust the mixing of the hot air supplied via the second hot air supply line ( 18 ) and the cool air flowing out of the air conditioning unit ( 14 ) so as to achieve a controlled cabin air temperature, during a normal mode of operation; a third hot air supply line ( 20 ) branching off from the first hot air supply line ( 12 ) upstream from the flow control valve ( 16 ) and connecting to the second hot air supply line ( 18 ) upstream of where the hot air supplied via the second hot air supply line ( 18 ) mixes with cool air flowing out of the air conditioning unit ( 14 ); a first close off mechanism ( 24 ) disposed in the second hot air supply line ( 18 ) upstream from the junction with the third hot air supply line ( 20 ), the first close off mechanism ( 24 ) operable to, when in a closed position, prevent a flow from the third hot air supply line ( 20 ) and the second hot air supply line ( 18 ) back to the first hot air supply line ( 12 ); a second close off mechanism ( 22 ) disposed in the third hot air supply line ( 20 ) upstream from the junction with the second hot air supply line ( 18 ) and operable to close off the third hot air supply line ( 20 ) during the normal mode of operation and to open the third hot air supply line ( 20 ) if the air conditioning unit ( 14 ) fails; and an ambient air inlet flap ( 30 ) connected to one of the second or third hot air supply lines ( 18 , 20 ) upstream of the aircraft cabin and adapted to feed cold ambient air for mixing with the hot air supplied via the third hot air supply line ( 20 ), when the air conditioning unit ( 14 ) fails, wherein the control device ( 28 ) is also adapted to adjust the mixing of the hot air supplied via the third hot air supply line ( 20 ) and the cold ambient air supplied by the ambient air inlet flap ( 30 ) when the air conditioning unit ( 14 ) fails, so as to achieve the controlled air cabin temperature.