The utility model provides a barrel of fourth nozzle gasifier, vault warm oneself in front of a fire hand -deliver department of connecing and are able to bear or endure firebrick structure, includes gasification furnace arch foot m, the box hat inner wall q that outside -in set gradually and fixed resistant firebrick's the transition layer of being convenient for, weld one on the box hat inner wall q and hold in the palm brick board n, ask brick board n to run through in the transition layer stretches into the furnace body, ask brick board n to install resistant firebrick j, resistant firebrick k and resistant firebrick l from supreme the support in proper order down, resistant firebrick j, resistant firebrick k and resistant firebrick l's length increase in proper order and wherein one end paste tight transition layer, the one end that resistant firebrick j, resistant firebrick k and resistant firebrick l kept away from the transition layer forms the echelonment structure. The utility model discloses barrel, the vault face of waring oneself in front of a fire adopts level and smooth resistant firebrick structure, gu avoided the abrasion of liquid - air current to the resistant firebrick an of barrel, is favorable to safe, continuous, the long -lived operation of gasifier.