Last year we purchased a new-to-us Noble & Wood Cycle Beater for beating pulp for papermaking. It has, since then, been sitting in a corner in our shop taking up space. This was mainly because we also had so many other things also sitting around in the shop taking up space that there was no room to work on the beater.
Since then we’ve managed to develop another storage area so there is actually space to move the beater into the middle of the room and remove its top cover.
The cover is a heavy lift for one person in proper posture, but removing it from the beater would require lifting the cover almost at arm’s length, and overcoming not only its weight but also some friction between the cover and the beater roll.
Now that we had room to get the forklift next to the beater we’ve finally removed the cover to have a look:
Inside the beater, Behind the roll, the vertical rod is the adjustment for the minimum gap, and behind that, the pulley for the lifter auger.
This is a view of the roll from the outfall side. The interior of the tank may have been originally galvanized but that has eroded away over the years allowing some rust to form. The beater bars appear to be bronze, and the spacers are wood, perhaps mahogany or maybe teak. They are a bit loose right now but when the beater is in use the moisture makes them swell to a tight fit. They don’t really provide any structural support to the beater bars, but they limit the size of the cavity between the bars to control the overall pulp flow.
One of the wooden spacers seemed particularly loose so I undid the two stainless steel wood screws that retain it and had a look underneath.
One of the beater bar spacers
Under the spacer showing the wooden roll core and one of the holes from the wood screws that retain the spacer
The core of the roll also seems to be a fairly substantial hunk of wood, which the wood screws bed into. The spacer still seemed loose after replacement, so this may require more investigation.
After inspecting the roll, I used the forklift to raise it on its pivots to reveal the bedplate, but foolishly neglected to take any photos of this. There were some lumps of dried pulp to remove, and more surface rust that will have to be dealt with. The bedplate itself looked good, and also not easy to remove as it seems to have been bedded into some sort of tar or pitch to hold it solidly and seal any leaks.
With the roll raised I removed the seized minimum-gap adjustment and this is now soaking in penetrating oil. I have to get it unseized, and also make a handwheel for it so the operator can set a specific gap.
The next step would be to actually remove the roll and its support frame, detaching it at the pivots, and also remove the auger assembly, to give full access to the tank. Then I can bring it outside, clean out the rust, and I would like to try to repair the galvanizing, assuming that’s what it is. The good surfaces inside the tank have a dull grey colour which could be zinc, or perhaps it was tinned so the coating is tin or a tin/lead solder.
This beater has plenty of nooks and crannies that could trap pulp, causing two problems: Trapped pulp holds water and encourages rust, and it also will contaminate the next beater batch if a different pulp is used. This means that being able to do a full cleanout easily is important, and this would require removing the lid and lifting the roll. For doing this regularly it would seem worthwhile to fit the beater with a small hoist, maybe some sort of jib crane, that can lift the cover, swing aside to put it down, and then raise the roll. But for now the forklift will have to suffice for this.
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