PURPOSE: To prevent the damage of the sleeve in a quencher, and to improve the operation efficiency of the whole apparatus including the quencher, by providing the inner side walls of the sleeve with a cylindrical wire mesh.

CONSTITUTION: The inner side walls of the sleeve 5 of the main body of a quencher 4 are furnished with a cylindrical wire mesh 7. The upper edge 12 of the sleeve 7 is placed near the lower edge 13 of cone 11, which is fixed under a spray nozzle 6. Fluid sprayed into the sleeve 5 is first contacted with the wire mesh 7, and then with the inner side walls of the sleeve 5. The impact force of the sprayed fluid and the thermal stress caused by the heat of the hot gas, etc. can be absorbed by the deformation of the flexible wire mesh 7.