An airtight cooling transition
pipe assembly facilitating safe
insertion and extraction of a spray gun at a blast-furnace
tuyere is characterized in that one side of a three-way transition
pipe is connected with a blowdown
pipe, an inner cavity of the three-way transition pipe is a
coal injection gun channel, an inner cavity of the blowdown pipe is a high-pressure
nitrogen channel, and the end, away from the three-way transition pipe, of the blowdown pipe is connected with a first
ball valve through a
flange; the other end of the first
ball valve is connected with a second
ball valve through a
flange, and a quick connector is installed at the outer end of the second ball valve. The
assembly has the advantages that high-pressure
nitrogen is reversely blown into the blast-furnace
tuyere through the
gun barrel, meanwhile, a gap between the
gun barrel and the gun can be sealed when the gun is pulled out or inserted,
blast furnace hot air and hot
coke breeze are prevented from being sprayed out of the gap, meanwhile, a
cold air wall formed by the
nitrogen can cool the
gun barrel, and the
blast furnace tuyere is cooled through the
cold air wall. The gun
barrel is prevented from being heated to deform and expand in the plugging and unplugging process, the safety of the operation of plugging and unplugging the
coal injection gun by a
blast furnace operator is effectively improved, and the goal of safety, greenness, high efficiency and low consumption in the blast furnace ironmaking process is promoted to be achieved.