Screw Conveyor Wear
Are you sure the problem is only wear?
Could it be a corrosion problem?
Sometimes bark and wood waste can be corrosive when wet.
If that is the case then a corrosion resistant steel may be the answer. ■
Re: Bark Screw Trough Wear Problem
I agree with Mr Brown. Often the wear problem with bark is a combination of what we call erosion-corrosion. The paper and pulp industry in Scandinavia use as standard stainless stell material in both the screw and trough, sometimes solid but most commonly by lining of a mild steel construction. The material that has shown the best resistans is 1.4462.
Some mills also use ceramics with a good result, for example Densit.
Best Regards
Göran Jansson
Brunitec Engineering ■
Re: Bark Screw Trough Wear Problem
Good day sir,
Please visit us at: www.convoyeursbmw.com
Is it possible that the problem hasn't been caused only by wearing out?
Water, or humid substances keeping the auge from being dry may be part of the problem.
Jean-Philippe Bdard
Sales Department
Convoyeurs B.M.W. Conveyors Inc. ■
Re: Bark Screw Trough Wear Problem
Dear Wayne,
I agree with the earlier replies that the problem is likely to be the corrosion-cum-wear. My suggestion is to opt for stainless steel sheets fabricated trough. If you have similar problem for screw, then also use stainless steel material for the screw. Getting the screw conveyor of stainless steel will not be a problem because it is often used in food industry, etc.
Regards,
Ishwar G Mulani.
Author of Book : Engineering Science and Application Design for Belt Conveyor.
Email : parimul@pn2.vsnl.net.in
Tel.: 0091 (0)20 5882916 ■
Bark Screw Trough Wear Problem
Dear Sirs
Wear problems in troughs conveying bark can easily be solved by chromium carbide hardfaced plate.
Even when there is a combination of corrosion and abrasion this type of plate solves both problems.
If you insist on heaving a corrosion resistant system, we can make the base plate in stainless steel.
All the other solutions mentionned show a high risk of faillure :
we do a lot of UHMW-PE linings, but we never recommend them in this application
POLYURETHANE COATING could be a solution, but we prefer hardfaced plate
CERAMIC lining, which we do since 20 years, is not the right choice in this application because of heavy impact risk
ARNOLD VAN ACKER ■
Re: Bark Screw Trough Wear Problem
Dear Wayne,
Apparently, you are facing problems with conveying of bark by screw conveyors. I would just like to raise an issue that whether is this the right kind of equipment for the application. Please also look into the possibility of use of drag chain conveyor, belt conveyor, chain & flight conveyor, etc.
Well it is possible that with the existing equipment in use, it will be difficult to change the equipment, however I have put this information so that readers who are concerned with new equipment for bark may think about the possibility of using different kind of equipment also.
Regards,
Ishwar G Mulani.
Author of Book : Engineering Science and Application Design for Belt Conveyor.
Email : parimul@pn2.vsnl.net.in
Tel.: 0091 (0)20 5882916 ■
Square Trough Conveyors
We manufacture vibratory trough feeeders like you asked about(square tube)
We engineer them to order specific to the application requirements. We offer a variety of liners that would work to combat corrosion and wear in your application.
Please contact us for more detailed info and a quote.
Or visit our new web site for pics and details:
www.jvi-joest.com/new
Thanks and good luck,
Tiffany
JVI Engineered Vibratory Feeding Equipment ■
Wood Waste Conveying
I would recommend that you may want to consider replacing the auger screw conveyors with flat bottom chain conveyors. a design more suitable for this application. These type off conveying systems are designed with replaceable abrasion resistant side liners and bottoms.
Please visit our website for more information
http://tramcoinc.com
Gary Karaff
gary@tramcoinc.com ■
Wear Solution
Wayne
Conforma Clad's tunsten carbide protection may be a possible solution to your problem. Conforma Clad’s tungsten carbide technology is in use today across hundreds of industrial based applications where abrasion, corrosion, erosion or a combination thereof affects the life of components and related material handling equipment.
In the agricultural, forestry and lawn care markets, Conforma Clad provides tungsten carbide clad debarker blades, harvester bars, silage chopper blades, plow heads, lawn mower blades, rim and chipper knives, planer bedplates and side rails, and other components that are exposed to abrasive and sometimes corrosive environments.
Please visit www.conformaclad.com for more information.
Christy Eversmann
info@conformaclad.com
1-812-948-2118 ■
Re: Bark Screw Trough Wear Problem
Hello Wayne
If you have a problem with the wear plate in the screw conveyor wearing out, like the others have stated you need to address the application, what type of environment is the material being conveyed in. Is there a problem with corrosion, impact, abrasion, or heat. All of these factors must be addressed. Are there a lot of rocks and sand in your hog fuel?
There are also some other materials that you can use suck as:
Hatfield Manganese, it work hardens to about 500 Brinell, if you are having a problem with impact. It will get harder and more durable with impact.
Hardened plated CHT 400 or harder, depending on the material type of the screw, abrasion problem. If you want the screw to wear out and not the liner use a harder material on the liner, and it will wear the screw out first.
316 Stainless steel if you are having a problem with heat?? Most likely not.
If you need some help with a solution please contact us. ■
Screw Liner
We suggest you consider using Kryptane polyurethane liners which can be bent into position and bolted or glued into the casing. Also, the screw blades can be lined with the same material to reduce wear and corrosion.
Paul Haywood
Muller Beltex UK Ltd
www.mullerbeltex.com ■
Wear Reduction
We in our plant use a very effective material to combat wear..we transport approx 3 million plus tonnes of Bauxite through conveyors and chutes in order to fulfill our business requirements.My advice to you is to apply a coating of MEGA POXY ..this is a 2 part mix that is combined and then smeared into any application....very easy to apply and very durable...the product will conform to any chute shape you have now and a smooth finish is obtained simply by rubbing the product once applied with water....then when dry it is excellent...
I feel for cost effectiveness you cant beat it.. ■
Abrasion/Corrosion Wear In Screw Conveyors
If your application is horizontal or slightly inclined conveying, your best bet is switching to a belt conveyor. Rubber belts won't rust and are more resistant to wear than steel.
If you are running at an incline exceeding 16°, a sandwich belt conveyor (vertical or steep incline EleVeyor®) offers a great low-maintenance solution.
Belt conveyors by their nature sharply reduce abrasion wear compared with screw type or drag type conveyors, as the product is not required to slide along any surfaces. Minor friction may be produced at the impact area, that's all.
Werner Plaut
Product Manager
EleVeyor® Mfg Div., NFLLC
wplaut@eleveyor.com ■
Bark Screw Trough Wear Problem
We have been using UHMW (1/2") in the bottom of our feeders for 20 years without a problem. Once in a great while one will tear out but that is infrequently. The bottoms are replaced about once every 2-3 years at minimal cost with 2 or 3 workers in about 2 hours. If you want more detail contact me at
david.woods@avistacorp.com
D. Woods ■
Re: Bark Screw Trough Wear Problem
Lots and lots of people believe you are using the wrong equipment but you are not. If you were to use some of their suggestions then you would have far bigger problems.
As you are probably well aware the problem is one of sand and this chews through most materials quite quickly.
The options are simple. Increase the diameter of the trough to cater for a replacable liner. You may use many materials but stay away from plastics etc. I would not recomend the box type trough since the material in the bottom will hold water, turps and other horible chemicals and will rot the casing. It will also reduce the efficiency of the screw and require higher kW with lesser throughput.
Something to try out of curiosity. You probibly have the outer case epoxy painted. Try it on the liners and see how long it takes to wear off.
Engicon Systems (Pty) Ltd
tel +27-11-789-2102
fax +27-11-789-9664 ■
Bark Screw Trough Wear Problem
We are possibly looking at replacing our troughs that we use to convey bark and wood waste into our boiler.
The reason is that they have worn through in several places.
As I stated a while back we have tried to put in uhmw liners but they keep peeling out. We have been also looking at either a ceramic lining or putting in an industrial version of a "Rhino Lining" in the new troughs.
Our maintenance group is thinking about converting the screw troughs to a flat bottomed or box like design instead of the typical rounded bottom design.
I am leery of the flat boxlike design primarily because every screw system that I have ever seen where there is one screw per trough always has a round bottom that is just slightly larger than the screw diameter.
Could everyone please comment on all three of the issues
1) Plastic spray-on linings
2) ceramic linings
3) Square, flat bottomed screw troughs
Thank you all,
Wayne ■