Rotary joint for stationary siphon

#1. Field of the Invention

#The present invention relates to a rotary joint which is applied to a stationary siphon for discharging drain which is generated from a roll of a drier of a machine such as a paper machine and by the condensation of heating steam which has been introduced into the interior of the drier and used in heating the roll.

#2. Description of the Prior Art

#FIG. 1 is a sectional view of a rotary joint for a stationary siphon in accordance with a first embodiment of the present invention;

#FIG. 2 is a sectional view of a part of a rotary joint for a stationary siphon in accordance with a second embodiment of the invention; and

#FIG. 3 is a sectional view of a conventional stationary siphon.

#The present invention will now be described with reference to FIG. 1 showing a first embodiment of the present invention.

#Reference number 1 designates a drier roll of a paper machine. The drier roll 1 is rotatably supported to a frame, not shown, through a bearing 13. A substantially cylindrical main body 2 is secured to an axial end of the drier roll 1. A supporting pipe 3 is inserted through the main body 2 and an axle portion of the drier roll 1. This supporting pipe 3 is firmly mounted to the frame through a bracket 4, and is provided at one end portion thereof with an opening 15 through which steam is introduced. A tubular member 6 having an end face which is shaped so as to form part of a sphere is mounted to the outer periphery of the supporting pipe 3 at a position corresponding to the main body 2. This tubular member 6 is mounted in such a manner that, by providing a key 9, the member 6 is axially slidable on the outer periphery of the pipe 3 but is not rotatable relative thereto. An O-ring 7 is provided between an outer surface of the supporting pipe 3 and an inner surface of the tubular member 6 so as to seal the clearance therebetween. A carbon 8 is interposed between an inner wall of the main body 2 and the sphere-forming portion of the tubular member 6, and the tubular member 6 is constantly urged at its sphere-forming portion toward the carbon 8 by the force of a spring 10, thus forming a seal. A steam inlet metal member 11 having an L-shaped tubular member 12 is fixed to the other end of the supporting pipe 3 which is disposed on the side of the drier roll 1. A siphon line 5 is fixed to this tubular member 12 and to the supporting pipe 3.

#Steam supplied from the opening 15 of the supporting pipe 3 passes through the inside of the supporting pipe 3, and is introduced into the interior of the drier roll 1 through the steam inlet metal member 11. Although a portion of the steam enters the cavity within the axial portion of the drier roll 1, this steam is sealed off by the main body 2, carbon 8, and the tubular member 6, and thus is prevented from escaping outside the system. After steam has been supplied to the interior of the drier roll 1, its latent heat is taken away when the moisture of wet paper placed on the roll vaporizes, and the steam is thus converted into condensed water, i.e. drain. The thus produced drain is stored at the bottom portion of the roll 1 at a low rotational speed of the roll 1, while it is sprayed annularly onto the inner surface of the roll 1 at a high rotational speed of the roll because of a rimming action. In either case, the drain is then discharged outside the system through the siphon line 5 which is directed downwardly. The carbon 8 is a member having spherical surfaces and flat surfaces and is thus capable of automatically adjusting the center. The provision of such a carbon 8, therefore, enables compensation for any mounting error or any rotational vibration. Further, because the sealing portion of the carbon 8 can be brought into direct contact with steam and thus be lubricated thereby, the surface of the sealing portion will not become rough, thereby lengthening the useful life of the carbon 8. Even in the event that the carbon does become broken, the structure is so designed that carbon will not be scattered outside, thus providing an increased degree of safety.