PURPOSE: To remarkably improve working environment by collecting all the leak gases leaking from a furnace cap to the projecting part of a dust collecting hood and capturing the gases by a dust collecting duct provided to the projecting part.
CONSTITUTION: The inside diameter of a side plate 40 is made larger than the outside diameter of an outer cap 1. An electrode insertion hole 50, a lance insertion hole 52 and a measuring instrument insertion hole 54 are provided to an upper plate 48 of the dust collecting hood 6 so as to respectively face an electrode insertion hole 42, lance insertion hole 44 and measuring instrument insertion hole 46 of the furnace cap 1. The periphery of the electrode insertion hole 50 of the plate 48 is projected upward to form the projecting part 56. The electrode insertion hole 42 of the cap 1 and the electrode insertion hole 50 of the dust collecting hood 6, the lance insertion hole 44 and the lance insertion hole 52 as well as the measuring instrument insertion hole 46 and the measuring instrument insertion hole 54 are made coaxial with each other. The dust collecting hood 6 is disposed above the furnace cap 1 in such a manner that the bottom end of the side plate 6 is positioned below the top surface of the furnace cap 1. The dust collecting duct 8 is connected to the dust collecting hood 6 in the projecting part 56.
HARADA EIJIRO
KATAOKA KUNIO
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