| 摘要 |
<p>PURPOSE:To prevent a clogging and a corrosion of a piping and to enable a long term and continuous operation by keeping an off-gas temperature higher than a condensation/deposition temperature of off-gas contents and lower than a melting temperature of a low melting point substance in the off-gas contents. CONSTITUTION:A thermometer 32 and a flow meter 34 are provided at an outlet part of an off-gas cooler 18, and a temperature regulator 36 and a flow regulating valve 38 of a cooling gas, at a feed line 42 of the cooled gas. Also, a controlling part 40 controlling the temperature regulator 36 and the flow regulating valve 38 based on a value measured by the thermometer 32 and the flow meter 34, is provided. At the controlling part 40, the off-gas temperature is controlled so as to be higher than a condensation/deposition temperature of off-gas contents and lower than a melting temperature of sticking powder dust. Moreover, to control a sticking of the powder dust in the off-gas to off-gas flowing pipes, a flow rate of the off-gas is controlled. In other words, a ratio of a flowing-in velocity of a cooling gas to an off-gas velocity is controlled to be within 0.6 to 1.4.</p> |
