advice needed: rotary feeder seal and bearings

[MaadzPO]

I'm looking for some advice on the rotary feeder at our aggregate plant. We've got a new system in place that handles a mix of wet sand and gravel, and the main shaft that drives the rotor is giving us headaches. It's about 150mm in diameter and rotates relatively slowly, but the material is incredibly abrasive.

The issue is with the bearings and seals where the shaft exits the feeder housing. We're currently using a standard heavy-duty lip seal, similar to what you'd find on a loader axle, but the abrasive slurry from the wet sand and gravel is just eating it alive, leading to frequent bearing failures.

Our supplier suggested a purge system using grease pressure to keep the grit out, but I'm wondering if anyone out there has implemented something similar or has other creative solutions for preventing abrasive ingress in slow-speed, high-abrasion rotary applications like this? Any real-world experience or alternative seal types would be a huge help!

 

[DeliDude]

@MaadzPO oh, we ran into this exact issue years ago. A grease purge helps, but we also found immense improvement by switching to braided packing with a strong flush/purge.
Instead of a lip seal, consider a packing gland, but ensure you have a constant, controlled purge of clean water or grease through the packing to keep the grit out. It's an older technology, but incredibly robust when implemented correctly for abrasive slurries

 

[sm1th.op]

I'm looking for some advice on the rotary feeder at our aggregate plant. We've got a new system in place that handles a mix of wet sand and gravel, and the main shaft that drives the rotor is giving us headaches. It's about 150mm in diameter and rotates relatively slowly, but the material is incredibly abrasive.

The issue is with the bearings and seals where the shaft exits the feeder housing. We're currently using a standard heavy-duty lip seal, similar to what you'd find on a loader axle, but the abrasive slurry from the wet sand and gravel is just eating it alive, leading to frequent bearing failures.

Our supplier suggested a purge system using grease pressure to keep the grit out, but I'm wondering if anyone out there has implemented something similar or has other creative solutions for preventing abrasive ingress in slow-speed, high-abrasion rotary applications like this? Any real-world experience or alternative seal types would be a huge help!

The grease purge system your supplier mentioned is definitely a good path to explore.
We had a similar issue with a pugmill shaft, then we implemented a continuous low-pressure grease purge on our seals, and it significantly extended their life.
The trick is maintaining just enough pressure to keep the grit out without blowing the seal out.
We also experimented with a labyrinth seal design combined with the grease purge, which offered an extra layer of protection.
You might also look into specialized composite seals designed for extreme abrasive environments, though they can be pricey.

 

[Yacob. f]

Try grease purged labyrinth seal setup, should be way more resistant to wear than lip seals and gives the grease somewhere to go while still keeping grit out, saw someone try that thing