Bark Screw Trough Wear Problem

Wayne W
(not verified)
Posted in: , on 25. Dec. 2001 - 04:48

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,


Peter Brown
(not verified)

Screw Conveyor Wear

Posted on 27. Dec. 2001 - 12:27

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.

(not verified)

Re: Bark Screw Trough Wear Problem

Posted on 7. Mar. 2002 - 07:43

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

BMW Conveyors
(not verified)

Re: Bark Screw Trough Wear Problem

Posted on 17. Mar. 2003 - 10:11

Good day sir,

Please visit us at:

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

Posted on 4. Sep. 2003 - 08:12

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.


Ishwar G Mulani.

Author of Book : Engineering Science and Application Design for Belt Conveyor.

Email :

Tel.: 0091 (0)20 5882916

Bark Screw Trough Wear Problem

Posted on 1. Dec. 2003 - 08:09

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


Re: Bark Screw Trough Wear Problem

Posted on 1. Dec. 2003 - 06:38

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.


Ishwar G Mulani.

Author of Book : Engineering Science and Application Design for Belt Conveyor.

Email :

Tel.: 0091 (0)20 5882916

Square Trough Conveyors

Posted on 13. Dec. 2003 - 10:24

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:

Thanks and good luck,


JVI Engineered Vibratory Feeding Equipment

Tiffany Moore Two companies under one roof: Experts in Applied Vibration - Industrial Vibrator Mfg. and JVI Vibratory Equipment Vibratory Feeder and Screen Mfg. Call toll free for info: 1 (800)231-0164
(not verified)

Wood Waste Conveying

Posted on 14. Dec. 2003 - 03:52

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

Gary Karaff

Conforma Clad
(not verified)

Wear Solution

Posted on 2. Feb. 2004 - 03:50


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 for more information.

Christy Eversmann


Dave - Ianco Products, U.K.
(not verified)

Re: Bark Screw Trough Wear Problem

Posted on 23. Jun. 2004 - 10:52

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.

Paul Haywood
(not verified)

Screw Liner

Posted on 22. Jul. 2004 - 03:29

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

Wear Reduction

Posted on 9. Oct. 2004 - 02:11

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..

Knowledge , is simply what is waiting to be discovered and used.
(not verified)

Abrasion/Corrosion Wear In Screw Conveyors

Posted on 17. Oct. 2004 - 12:21

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

David Woods - Avista Corp., USA
(not verified)

Bark Screw Trough Wear Problem

Posted on 21. Dec. 2004 - 01:13

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

D. Woods

Re: Bark Screw Trough Wear Problem

Posted on 9. Feb. 2005 - 09:20

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

Engicon specialises in correcting non-performing plants and low cost de-bottlenecking of systems.