I need some suggestions on stopping carry back on a 42" discharge Belt. The belt is a discharge on a 6x20 triple deck dry screening plant. The screen cloth size is Top deck (2" square opening), the second deck is (3/4" square opening), the third deck (sometimes 1/4" sometimes1/8" end tensioning). Material sticks to this discharge belt like a magnet... it has a functioning Martin Dirt Hawg belt scraper on it. If I set the belt scraper any tighter it will grab the belt splice and tear it,,, belt splice is flexco fasteners that are skived in and countersunk. This plant is fed with a belt, and the material off this discharge belt drops to a transfer conveyor and then onto a 120 ft stacking conveyor. There is minimal(normal I'd say) stickage to any of the other belts. The fine material this discharge carries usually run's less then 10% retained on the #200 seive. Has anybody else faced this problem and how did you control it??? Thanks in advance..... Gramps
Is it a noticeable build up as in you can actually see the material staying on the belt, or is it just spilling and you noticed it that way?
Its sticking to the belt,,, flashing is all proper,,,, I might add this conveyor also has a winged tailpulley that sets up a small vibration to the belt. One would think this would aid in the clean, but I starting to lean towards the idea that this might be setting up some kind of harmonic balance thats causing my problem. :beatsme
Is the belt old and are the fines sticking in cracks it's really the only logical thing I can think of.
The belt has less than 1 season since new....
I believe a winged HEADPULLEY would help. This would create the vibrations at the TOP of the belt as opposed the bottom as you want the belt cleaned off before it returns back to the tailpulley. I dont think the winged tailpulley is doing anything for you as for cleaning the belt. There are rotary brushes that can be mounted at the top (underneath) that are driven by the belt that do help with sticky matl. Is the matl very wet?
we will sometimes put a tiger torch and stovepipe with a elbow underneath the belt in cold temps and that does the trick for keeping the belt clean
The material is not wet at all.... It never rained from july til freeze up this year... the material does have a trace of a grayish clay to it, but then why doesn't the feed or transfer or stacker retain any of this carryover? I've never seen a head pulley rigged up with a winged driver. Wonder if there would be enough surface to grab the belt to drive it?
I agree with bushcat maybe try applying some heat and see what happens.
We use to have winged headpulleys were I use to work. The wings were shaped like a T with a strip of lagging on the top flat part of the T if you know what I mean. The other way we use to do it was to take out every other strip of lagging on a fully lagged pulley to get the vibrations going. Driving the belt without slipping didnt seem to be a problem,only on the really cold mornings. Where I work now, some of the belts have a paddle wheel or a type of small winged pulley mounted under the belt on the return side just down from the headpulley that kind of beats on the belt & cleans it off at the pile. I hope you can picture what I mean, as they are not big on cameras at work anymore...
Thanks 61BG... I know what you mean... I just can't for the life of me figure out why this belt grabs material and the belts before and after it don't....:duh
I agree with the winged pulleys. We use those on the stackers for our screening plant, along with belt scrapers, and we haven't had problems with material sticking.
It has winged pulley and a new Martin Dirt HOG scraper...
Is it a cheap belt with a very soft rubber compound? Or has it any fine cuts to grab the material? We had a couple cheaper belts that were bad for it, but they didn't last long so they got replaced with good material and no more issue.
ben46a.... its a quality 3ply belt... I up graded from a two ply with no change.... I'm beginning to wonder if its some kind of harmonic balance.... I run two crusher spreads, two screening spread's and a washplant spread, and this is the only conveyor I have issue's with. anybody else running a 6x20 cederapids triple deck?
I have a 6x20 three deck cederapids screen on my crusher and a 5x14 2 deck on my washplant and don't have that problem. I've never seen a winged head pulley on a rock crusher before and on a 42" belt might not be a good idea? I also have a power screen and I'm not real fond of it but but it has a return roller on the top of the return side of the discharge conveyor that has bar stock welded to it to make the belt "viberate" on the return side as it turns?? Seems to work ok but I don't have much of a clay issue around here. I would have to guess that the fines 1/4- on that belt have some clay in it and thats what makes it stick. Bit I'm in Oregon and not Minnasota so I can't swing by and check it out. Good luck!!
Old thread I know..... But just wondering how you made out with your problem? The company I work for is running quite a few Terex/Cederapids decks.All of the 6x20 screens run 60" under screen discharge belts, and 72" under the 8x20. I am surprised to see a 42" under your screener. Does the material build up on the sides under the belly of the screener ?I once had that trouble with a 42" belt under a 5x16 . As far as your problem of material sticking to your belt, I think the scraper may solve the problem. I run the martin pv or pit viper pre cleaner scrapers with great success. The dirt hawg scraper is a secondary scraper , and will not perform very well without a pre-cleaner. In most cases I run only the pv with no secondary. But it wouldn't hurt you any to run both. The position and angle of the scraper is very important to it's performance, as well as a good skived splice so you don't ruin your blade .We run these in the worst sticky ore you can imagine with some belts running 3/8" minus and some as small as 5/32" minus, and I must say they save alot of clean up !!
I'm sorry its a 48 inch belt....am old and can't remember shh**t.. the belt is skived..... it seem's to be better as of late, but still have to clean under it daily.... it must collect about ten yards under it during a shift.
You can also get 'beater' return rollers. There is also a chemical that can be applied to the belting. We used it in extreme cold temps to keep the ore from freezing to the belts.
That's what I need...... a release agent....
If you have some return rollers weld some rebar or pipe on it so as the belt rolls the rollers it "thumps" the belt. Works freaking awesome.
Might be static electricity? They make some brush type rollers that work against the outside of the belt, one of those before your scraper might knock some of it loose?