To provide an anti-seizure measures for a self-supported type rotary joint for introducing a heat transfer medium such as steam or water into a rotating drum.

The rotary joint 12 is supported upon a drum structure through a rotating bearing housing 18 and a stationary nipple 66 is supported by bearings 52, 54 in the rotating bearing housing. The stationary nipple 66 supports stationary rotary joint body head 30 and a stationary siphon retaining tube 22, and the stationary siphon retaining tube 22 supports a stationary siphon structure inside of a drum 10. When the nipple 66 is caused to rotate as unity due to a seizure of the bearings 52, 54, for the purpose of preventing a breakage of hoses which introduce steam or water to the rotary joint body head 30 and remove condensate water or condensed water from the rotary joint 12, the rotary joint body head 30 is fixed on the outer end of the nipple 66 by a breakable connectors 90 through a shear pin 80 to avoid excessive torque being imposed thereon.