Bark Screw Trough Wear problem

Wayne W
(not verified)
Posted in: , on 25. Dec. 2001 - 04:36

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

Trough Wearing

Posted on 26. Dec. 2001 - 10:21

Hi there,

We supply a fair quantityof our Eli-Cote FR1008 fot this exact application.

FR1008 is a trowelable epoxy with alumina chip and ceramic bead fillers held in a mortar binder.

It is mixed quickly, goes on easily, and be built up to any thickness.

This is a more cost effective solution to a ceramic linings, with an impressive lifespan in this application.

For more detail, feel free to contact me on :

globalresins@hotmail.com

or check out the products on :

www.globalresins.demon.co.uk/minqua.htm

Regards,

Aram Friedrich

Bark Screw Trough Wear Problem

Posted on 26. Dec. 2001 - 11:44

Hi Wayne,

Wood waste can be very abrasive, particularly within a pneumatic conveying system.

You don't mention the diameter of the auger, or the clearance between it and the wear face of the trough. Since you have tried polyethylene liners, I will assume that the operating temperature of the screw feeder is quite low.

If possible, forget about a flat bottomed trough in favour of a low friction wear resistant lining system.

I haven't used spray-on plastic linings in over 20 years, so I am not really qualified to comment on their effectiveness.

Hard faced plate is an option that may increase the trough life by a factor of, perhaps, 3 to 5 times that of hot rolled mild steel.

Curved Ni-hard cast liners are another option, if you are able to accept a larger diameter trough, and I have even seen cement/aggregate linings used successfully in this type of application.

Ceramic tiles bonded to the steel trough with a flexible, high strength, adhesive is a further option; these could be flat or curved tiles, depending on the clearance between the screw and the trough. Ceramic liners are used very successfully to resist abrasion and corrosion in many types of screw feeder trough applications. The most successful high abrasion resistant trough linings use large area curved ceramic tiles, that are capable of handling very high torque loadings. Wood waste polishes the wear face of ceramic linings quite quickly, resulting in low friction, reduced torque transmission to the trough and lower power requirements. The expected wear life of a +90% alumina ceramic should be around 5-10 times greater than that of welded hard facing and Ni-hard.

The choice of which material to use in a wear resistant lining system should be a cost against performance issue.

HDPE is a good slide promoting, non-stick, material, but it may only exhibit half the wear resistance of hot rolled mild steel in a pure sliding, non-corrosive, chute lining application.

If you would like general information relating to cost/performance of materials commonly used as wear resistant linings, please use the following URL:

Http://www.omegaslate.com/producti.htm#cpvwrlm

Regards,

Mike Griffiths.

cstolpe
(not verified)

Re: Bark Screw Trough Wear Problem

Posted on 22. Dec. 2006 - 09:06

Have much experience in bark augers, and bins. have done augers with Tungsten carbide flights, chrome carbide flights, ceramite lined flights and barrels,and liners out of just about everything. I can help you out with this, just send me your email and I will get you the needed information on ceramics (not cast) and overlay steel products.

Originally posted by Mike Griffiths

Hi Wayne,

Wood waste can be very abrasive, particularly within a pneumatic conveying system.

You don't mention the diameter of the auger, or the clearance between it and the wear face of the trough. Since you have tried polyethylene liners, I will assume that the operating temperature of the screw feeder is quite low.

If possible, forget about a flat bottomed trough in favour of a low friction wear resistant lining system.

I haven't used spray-on plastic linings in over 20 years, so I am not really qualified to comment on their effectiveness.

Hard faced plate is an option that may increase the trough life by a factor of, perhaps, 3 to 5 times that of hot rolled mild steel.

Curved Ni-hard cast liners are another option, if you are able to accept a larger diameter trough, and I have even seen cement/aggregate linings used successfully in this type of application.

Ceramic tiles bonded to the steel trough with a flexible, high strength, adhesive is a further option; these could be flat or curved tiles, depending on the clearance between the screw and the trough. Ceramic liners are used very successfully to resist abrasion and corrosion in many types of screw feeder trough applications. The most successful high abrasion resistant trough linings use large area curved ceramic tiles, that are capable of handling very high torque loadings. Wood waste polishes the wear face of ceramic linings quite quickly, resulting in low friction, reduced torque transmission to the trough and lower power requirements. The expected wear life of a +90% alumina ceramic should be around 5-10 times greater than that of welded hard facing and Ni-hard.

The choice of which material to use in a wear resistant lining system should be a cost against performance issue.

HDPE is a good slide promoting, non-stick, material, but it may only exhibit half the wear resistance of hot rolled mild steel in a pure sliding, non-corrosive, chute lining application.

If you would like general information relating to cost/performance of materials commonly used as wear resistant linings, please use the following URL:

Http://www.omegaslate.com/producti.htm#cpvwrlm

Regards,

Mike Griffiths.