PURPOSE: To attain, at the time of the occurrence of a flame or an explosion, prevention of the spread thereof, limiting of the pressure increase in a vessel and vessel protection, by disposing a plurality of fire protection devices of particular structure in a space of a pressure vessel of a coal gasifier oven so as to partition the space into small compartments.

CONSTITUTION: A plurality of fire protection devices 8 are disposed at appropriate interstices in the space 17 of a pressure vessel 1 of a coal gasifier oven 2 so as to partition the space 17 into small compartments. The device 8 comprises a block of fibrous refractory materials 21 sandwiched by wire meshes 22 (pref. about 10W40 mesh). Since the inside of the pressure vessel 1 of the gasifier oven is partitioned into small compartments by the fire protection devices 8, even if a flame or an explosion happens, the same can be minimized, thereby contributing to protection of the pressure vessel 1 of the gasifier oven.