Summary: | 碩士 === 大同工學院 === 材料科學(工程)研究所 === 81 === It is a trend that the fluidized bed technique has been
recently applied in heat treatment industry,however, the appli-
cation of fluidized bed furnace in Taiwan is not popular as in
some foreign countries,it may due to the reasons as follows:
firstly, the gas consumption is far beyond the treating cost in
domestic market,and secondly,the unstable atmosphere
composition between the lower and upper positions of the
fluidized bed on account of direct boosting of the fuel gas and
air/nitrogen from bottom of the bed,in consequence narrowing
the effective treating zone of the bed,and because of the
fluctuation of the atmosphere composition,the carbon potential
of the carburizing atmosphere is very difficult to control.
This project is aimed to improve the stability of the carbu-
rizing atmosphere by adopting the following methods: 1.Reduce
the carbon potential gradient of the bed by applying a back
pressure in virtue of adjusting the opening of the exhaust
stack,so as to reduce the trapped air. 2.Equalize the carbon
potential of the bed by feeding the enrich gas into the venting
end. 3.By using the methods above accompanied with the gas
recircula- tion system control the carbon potential of the
atmosphere.
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