Xylethon Hopper Liner Problem

Author
(not verified)
Posted in: , on 12. Jun. 2003 - 22:58

In our Titanium Dioxide plant, at the final section micronising, we do have

a feed hopper of 50 T holding capacity.

We are using a Xylethon liner in the hopper.

Over a period of two years, we have found that the non sticky nature of

liner has given away and we find bridging problem causing no flow out of

the hopper.

Xylethon is a highly water resistant material and has a very low

coefficient of friction.

I would like to pose this question to experts and try to understand the

following:

Is there a possibility if the stored material ( TiO2) - has a higher

moisture than normal ( Normal moisture is 0.3 % and it can reach upto 0.8 %

max) - which can cause sticking of the material on the liner even though

the liner is resistant to water.

What are the conditions/parameters which can cause the material to stick

to the liner.

The temperature of the material stored is of the order of 80 to 100 Deg. C

Regards

Sheshadri Mugundan

sheshadrimugundan@huntsman.com

paul.dean
(not verified)

Re: Xylethon Hopper Liner Problem

Erstellt am 13. Jun. 2003 - 05:11

Your problem may be more temperature related than moisture related.

I think this material softens at approx 80C, suggest you check this with the manufacturer.

Can you reduce the temperature or look for a material with higher temperature capabliity

Xylethon Vs Uhmw

Erstellt am 16. Jun. 2003 - 05:58

Have you thought of using slow speed/high force vibrators? They would work and we gaurantee.

Chamberland Engineering

Liners

Erstellt am 23. Jun. 2003 - 10:51

DEAR MR. MUGUNDAN,

LINERS ARE OK FOR SMALLER SILOS WHERE YOU CAN REFRESH THE FROM TIME TO TIME. FOR YOUR SILO I DINT THINK THAT THE LINER WILL STAY LONGER TIME.

IN YOUR CASE I WOULD SUGGEST YOU TO USE AN "IDEAL FLOW SILO" - A SILO WITHOUT THE CONE. THE MATERIAL IN THE SILO FLOWS ALONG THE WALL CLEAN THE WALLS BY MEANS OF FRICTION BETWEEN THE POWDER AND THE WALL.

LOOK TO OUR WEBSITE WWW.IPT-ONLINE.COM

BEST REGARDS

DR. IVAN PESCHL

Andre Bresler - RSA
(not verified)

Re: Xylethon Hopper Liner Problem

Erstellt am 29. Jun. 2003 - 08:42

Although I am not familiar with the Xylethon liner I assume it is possibly from the plastics range of liners.

Our experience, even though I am very fond of plastics in the correct application, is smilar to yours in our lab on the shear tester where the plastic tends to scratch over time destoying friction characteristics when handling certain types of solids.

Moisture does have a profound effect however at these temperatures and small increase in moisture I am doubtful that this is the case.

The plants in South Africa handling this type of product generally employ glass lining on the vessels as the harder lining materials display the opposite effect and polish with the action of material further improving friction coefficients.

In response to our second forum question I am certainly willing to test the materials, dsign check your bin and make the neccessary recommendations.

Stan King
(not verified)

Re: Xylethon Hopper Liner Problem

Erstellt am 2. Jul. 2003 - 10:12

Xylethon is simply a trade name for UHMW that has additive to crosslink it (resulting in a decrease in coef of expansion) however still much more that steel. Also has additives of silicone and moly to make it "slicker". Other UHMW (Ultra high molecular weight polyethelene) suppliers can provide similar UHMW. Xylathon reps have in the past had some "less than accurate" info out on physical properities of xylethon. It has similar properties to other UHMW.

As a plant engineer I use lots of UHWM for chain raceways, and chuting at marginal slide angles. Its great stuff.

UHMW starts to lose is mechanical strength around 80 deg C.

Redwood plastic has an new UHMW that has some compound of titanium as additive that results in a very low coef of friction.

Looks like heat over time may be your enemy, as mentioned by others.