To provide a structure of an upper part of a stack which does not require so frequent maintenance as a variable nozzle, and prevent the down-wash to the arbitrary outside air speed.
A structure of an upper part of a stack is provided with an outer cylinder 1, an inner cylinder 4 which is provided in the outer cylinder 1 to be a passage of the exhaust gas, an opening part 1a which is provided in the outer cylinder 1 to introduce the air in the horizontal direction into the outer cylinder, an inside-opening door 14 to cover the opening part 1a, and an inner cylinder 15 for air curtain to generate the air curtain at an outer circumferential part of the inner cylinder 4 by discharging the air introduced by opening the inside-opening door 14 upward of the outer cylinder.
TAKAGAKI HIDEAKI
MASUDA HIROSHI
