PURPOSE: To automate a spraying operation by incorporating a lance shifter into a rotary drum and incorporating a lance holding cylinder fitted with a lance body to the lance shifter.

CONSTITUTION: The lance body 4 having a spraying head at the top end is held by the lance holding cylinder 5 and various pipe junctures are provided to the terminal end of the lance body 4, to which part various pipings are connected by a rotary joint. The drum 15 is rotated when a pin gear 18 provided to the outside circumference at the center of the drum 15 is driven by a driving device 16 for swiveling the lance. The lance holding cylinder 5 is securely supported to the drum 15 and the lance shifter 11 for applying swiveling motion to the lance body 4 by shifting the center of rotation of the drum 15 and the center of the lance body 4 is incorporated into the rotary drum 15.