Welcome to the world of paper mill re-pulpers. Imagine the tub in a 30 foot diameter top loading washing machine. Inside the tub are several sets of rotating blades and paddles. Now fill it with 200 pound bundles of used recycled paper and water. The shaft that drives the blades and paddles enters the tub from the bottom and the shaft is rotated by a gearbox that is the size of an automobile. The rotating shaft is sealed to the tub with a stuffing box filled with rings of square cross section rope packing which is compressed by a follower gland (flange). The amount of packing compression is set by adjusting the tightness with hex nuts on studs. Mechanics are supposed to adjust the packing gland to reduce the leakage rate down to a fast drip or a very small stream. If the packing compression is too loose, it will leak too much, and if adjusted too tight, the packing and the shaft will quickly wear out or burn up.
The chopping process can be very violent. They shake rattle and roll. The shaft and packing take a beating and leaks can be more frequent than sealing. Below the stuffing box and packing gland will be a coupling to connect the re-pulper shaft to the gear box output shaft. Next is the gearbox output shaft and the output shaft bearing seal. This is where the Isomag bearing seal will be installed.
You probably already have a very ugly mental picture. It looks just like the nasty gooey mess of paper stock, water and grease you see in the photographs. That is why we came up with the Isomag magnetic bearing V8 seal with the cutter flange. The plan was to elevate the seal above the paper stock and water that accumulates on top of the gearbox and add a shear point near the outside diameter of the seal rotary face to remove a large portion of the paper stock away from the sealing faces. Adding a large diameter slinger ring between the gearbox output upper bearing seal and the stuffing box packing gland also helps divert the packing leakage away from the seal.
This is an ugly and messy application. Isomag magnetic bearing isolators' approach combines our flat face sealing technology with simple concepts of practical machine design to prevent the ingress of water into the gearbox.
If it were an easy application a lip seal might be good enough. Do not let the mess and filth scare you away. Isomag bearing isolators have what it takes to make a big difference.
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