To make it possible to reduce a loss of a gas pressure by a simple structure and to thereby reduce a production cost.
A carriage means 20 retracts the first and the second washing nozzles 17 and 18 to a position outside a precipitator body 16 when the precipitator body 16 is not washed, and transfers them to a position facing to the body 16 when the body 16 is washed. In this way, the number of washing nozzles can be decreased because washing nozzles need not be fixedly formed in a position facing to the body 16. Because a damper for preventing the washing fluid from scattering can be dispensed with, the loss of the pressure of a gas can be decreased. Further, the reduction in the number of components such as washing nozzles and a damper can realize a reduced production cost.
INAGAKI MASAYA
ARAO YASUSHI
