Patent ID: 7549507

Claim:
A heat insulating and sound insulating duct wall structure comprising a gas flow channel, the duct wall structure comprising: an inner plate at a gas flow side; an outer plate at an atmospheric side; at least one intermediate member having a lengthwise direction disposed in parallel to the inner plate and outer plate in an intermediate portion between the inner plate and the outer plate; a plurality of first supporting members both ends of which are, respectively, fixed at the inner plate and intermediate member in order to retain the spacing between the inner plate and the intermediate member; a plurality of second supporting members both ends of which are, respectively, fixed at the outer plate and intermediate member in order to retain the spacing between the outer plate and the intermediate member; a vibration deadening washer attached to a connection portion at the intermediate member side of the second supporting members, wherein the attaching position of the vibration deadening washer is provided in an area in a duct wall having a temperature of 400° C. or less; and a heat insulating member filled in a clearance between the intermediate member, the first and second supporting members and the vibration deadening washer between the inner plate and the outer plate.