Rethinking drainage element materials

RethinkingRethinking

Drainage ElementDrainage ElementMaterialsMaterials

Concept:

D K Singhal

[email protected]

The Day it Started……The Day it Started……

� It all began suddenly. A supplier of auto guides contact me, and offered to use his products. But I did not need these. He further asked, “You might have to replace palm of auto guide, it is more than 2 years palm of auto guide, it is more than 2 years old”. Before proceeding to discussions, I asked my maintenance (Instrumentation) man, and he told me that the palm is perfectly OK, and there is no need to change it in near future.

Rethinking Drainage Element Materials, October 2014 2

Palm of Auto GuidePalm of Auto Guide

� The palm of auto guide is always pressing wire, the contact area is very less, thus meaning relatively higher localized pressure acting on it. Still, no signs of wear pressure acting on it. Still, no signs of wear for two and a half years.

� On the contrary, every 8-10 months, we need to regrind/replace suction box tops. We have tried ceramix (ceramic mixed) tops, but in that case wire life was poor.


Material SelectionMaterial Selection

� Since long, we are doing our material selection on the basis of a test called “Sand Slurry Method”.

� In this method a disc of test material is � In this method a disc of test material is rotated in a slurry of sand for 24 hours at rated speed, and the loss of material is reported. The less the loss, the better is the material.

� But, did we forget something?


Testing the Test ItselfTesting the Test Itself

� Looking into the possible reasons, I started searching internet for more information, and ended up at the following link-following link-

� http://webcache.googleusercontent.com/search?q=cache:http://www.ewing1.com/_vendors/ads/AbrasionResistance.pdf


Some Data…Some Data…


Sand (Coarse or Fine)Sand (Coarse or Fine)

� As one can see, there is a significant difference in results with coarse and fine sand.

� For 15 fps, for coarse sand, polythene seems 4 times stronger than steel; while, for fine sand, it is just one third. Similarly, aluminum 4 times stronger than steel; while, for fine sand, it is just one third. Similarly, aluminum wears more than acrylic with coarse sand, but the pattern is reversed with fine sand. Further we can see that there seems no correlation between the sets of data.

� We neither use steel nor polythene; but this gives a reason to rethink.


Testing Our ProductsTesting Our Products

� Considering the observations, it seems necessary to conduct different tests and develop suitable standards for our applications.applications.

� Why sand only? Why should we not evaluate wear performance with OUR materials, with OUR clothings?

� A typical test bench schematic could be as under-


A Typical SchematicA Typical Schematic


Test BenchTest Bench

� The proposed test bench uses conventional synthetic forming fabric and felts being rub against sample materials.

� To create similarity with actual � To create similarity with actual environments, addition of water can also be done by means of a shower.


Drainage Elements to TestDrainage Elements to Test

� Typical drainage elements could be what we are using already-

◦ UHMWPE

◦ Modified products from reputed suppliers◦ Modified products from reputed suppliers

◦ Ceramic

� Later on, we may try alternate materials like steel, different alloys etc.


Clothing MaterialsClothing Materials

� As abrasive, we may use our clothing (wire, felt etc.) itself.

� This will also help us evaluate the performance of these against known performance of these against known materials for drainage elements.

� A step further, we may evaluate effect of weave patterns of forming fabrics etc.


Effect of VacuumEffect of Vacuum

� We all know, wear is faster if we apply more vacuum. With our test bench, we can apply different levels of vacuum against clothing, we may redesign test against clothing, we may redesign test specimen with provision for vacuum application to determine the effect of vacuum also.


Wear PerformanceWear Performance

� This way, we’ll be able to evaluate wear performance of different materials we use against different types of clothings we use.

� The overall study will be helpful to obtain � The overall study will be helpful to obtain wear rates of different fabric/clothing material and designs against known materials as ceramic, UHMWPE etc., and vice versa.


Thank You.Thank You.


About the Author:

Born in 1968, D K Singhal is B.E., M.E. (Pulp & Paper, 1993) from Deptt. of Paper Technology, University of Roorkee (now IIT, Roorkee). He is a Certified Energy Auditor and Chartered Engineer also.

With nearly 7 dozen publications, he has emphasized on development of low cost technologies and management practices for quality and profitability improvement. With publications on slideshare.net, energymanagertraining.com and paperonweb.com, he has been constantly contributing to IPPTA (Indian Pulp & Paper Technical Association). He is also serving IPPTA as a member of Editorial Board. Board.

An initiative by D K Singhal, a cyber campaign initiated against unjustified targeting of paper industry by “Idea” mobile, in their “Sirjee” advertisement campaign, after which this advertisement was taken off air.

He also moderated a Yahoo group, “PaperTechnology” (now at facebook) with nearly 750 members from India and abroad to discuss problems related to pulp & paper making for five years.

He can be contacted at [email protected]

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