|
Rotary Union' is Duff-Norton's registered trade name for a type of
product known as a rotating joint, rotary joint, swivel joint or rotating
union. A rotating joint is a precision mechanical device that allows for the
transfer of medium from a stationary fluid supply to a revolving drum or roll.
It is often necessary to heat or cool drums or rolls in
process industries like textile, rubber, plastic, paper, and many others. In
the paper industry, for example, dryer cans must be kept at a certain
temperature in order to dry the wet paper moving over the rolls. Steam is
injected into the rolls to heat them up to make the paper dry. However, the
dryer cans must keep turning, and the steam supply hose is stationary.
A rotating joint is used to transfer the steam (the medium in this case) from
the stationary hose that is supplying the steam to the dryer can, which is
continually revolving.
|
Another example is in the steel industry.
Continuous casters use internally and externally cooled rolls to cool the steel
slab as it goes through the bender sections. Specially treated water is used to
cool the rolls from the inside. Since the rolls are continually rotating to
move the slab through the process, a rotating joint is used to get the water
from the hose into the revolving roll.
An "everyday" example that almost everyone has seen are the swivel joints that
are used in automated car washes. Hoses carry water and soap to the brushes,
which twist and turn to clean the cars as they pass through the car wash. A
swivel joint (a type of rotating joint) is used to transfer water (the medium)
from the stationary supply (the hose) to the brushes, which are turning. |