Do you have any rock boxes in your system? They can greatly reduce the amount of liner wear and can also be used to minimize the impact on the belt.

Only a properly designed chute can minimize the issues that you are experiencing. We offer Bulk Flow Analysis and chute design services. ■

The loading from the tippler has to shift the tonnage downstream before the next car opens and the material does not have time to settle down. That might explain the high wear in the 'chute'.

A thorough study of the whole system does seem in order because there is no mention of excess wear on the crusher which receives the same material.

I am not aware of a flow guidance device for wagon tipplers which really works: yours is probably taking a severe beating before it starts to slide belt-wards.

A line diagram will help.

I would also try for a better balance between crusher capacity and wagon availability. Surge is normally provided to the plant operations and not to inadequate equipment. If you had an adequate crusher you could seriously reduce the lining wear.

How wet is the coal for your supercritical boiler? ■

Dear Bhaskar,

Based on the tonnages I presume your delivery belt speed is over 2.5 m/s and this precludes the use of rock boxes as they operate as a capacity constraint over this speed. I also presume that you have significant fines in your coal as well as the lump. For abrasion to be a serious concern the flow control through your transfer must be very poor. In addition you say you have belt tracking issues also indicative of poor flow control. If this coal is dry I would also guess dust is a big problem as is skirt maintenance and spillage. Given all this you are up for a new transfer chute if you want to solve your problem and such designs that will deliver a complete and guaranteed solution cost money. We can design a solution and we can solve your issues but I am not going to do this for free over the Forum.

Cheers

Colin Benjamin

Gulf Conveyor Systems Pty Ltd

colin.benjamin@gcsm.com.au

www.conveyorsystemstechnology.com ■

If the parent shell (mother plate?) of your receiving hopper is getting damaged then you obviously need to straighten and reinforce the side-plates after which you can bolt on thicker liners. The problem seems to be that the hopper is just not strong enough and neither is the centralising plate and its support. Most coal in India is wetted somewhere along the line and so dust and rock boxes can be discounted. I've sent coal through HDPE lines chutes and the problem there was distortion of the lining due to water ingress. That was with belts running at 4.5ms^-1 and4,000th^-1 and very wet coal. Without further information I cannot envisage how you have problems downstream of the tippler catcher.

Folk drop a wagon load of r-o-m straight down onto a belt below, between full height skirts and expect the r-o-m to somehow avoid wearing the skirts. Come on.

You have to fabricate a pair of stronger upstream skirts and then proceed downstream as you replace strengthened panels.

Where's the diagram? ■

Take a look on "Foundations" book from Martin Engineering which include chapters about chutes, lining, belt tracking and etc. ■

What is the MOC of liner? Is it sailma/Sailhard/Tiscral. Replace it with SS-409M. You can expect a better abrasion resistance. If the chute liner is fixed with mother plate using countersunk bolts, replace the method of joining by using plug welding. ■

Originally Posted by jishnubhel

What is the MOC of liner? Is it sailma/Sailhard/Tiscral. Replace it with SS-409M. You can expect a better abrasion resistance. If the chute liner is fixed with mother plate using countersunk bolts, replace the method of joining by using plug welding.

I really don't believe that plug welding could be considered as a fixing method for replaceable liners. Mind you, I have seen Indian maintenance crews welding hard screen deck to the side panels. They fell away about 20 minutes after start-up. Although plug welded liners will probably stay in place longer there is going to be a lot of discussion when it comes to choosing a reasonable liner removal method. Throughout the known world it would be necessary to obtain a hot working permit underneath a wagon tippler packed with residual coal dust....for each and every liner as it wears. It is most unlikely that all liners will wear out at the same time so the annual downtime might be considerable. The thread starter has already mentioned that the parent plates are distorted. Until that state of affairs is corrected the liner material selection can be put on the back burner: so to speak...cutting torches and coal so to speak.

Where's the sketch, please? ■

"Issues are the driving force behind development. Fear of exposure isn't."

Sometimes a respondent can get a smattering of facial egg due to his or her oversight but more often due to the lack of substance in the original questions. Highly active participants in these our discussions are now rarely giving their opinions. There are other websites which try to do the same job as these forums and fear of exposure is still apparent. I retired from them years ago.

To get back on the rails: I feel that this tippler installation was performed and sanctioned under tight cost considerations. Now it is getting beaten out of shape and the operator is looking for free advice about a cheap fix. If he gets the cheap fix it is probably going to be as good as the first attempt. I confined my answers to the tippler zone because no information has been given about the stacking and reclaiming method in relation to segregation etc. Nor can any information be expected and in that context we should all take an indefinite tea break on this one. ■

Hello,

The solution requires technical and engineering analysis (investigation) to find the reasons for the problems and remedial measures. This concerns the material velocity / movement within chute at critical locations, chute layout, etc. The remedial measures are decided for the least changes and disturbance to the running plant.

The satisfactory handling of (-) 300 mm size coal lumps is a very routine matter. It is neither very large nor very dense. If you have necessary design set up you can manage yourself or you have to take the services of some designer cum consultant.

Ishwar G. Mulani

Author of Book: ‘Engineering Science And Application Design For Belt Conveyors’. Conveyor design basis ISO (thereby book is helpful to design conveyors as per national standards of most of the countries across world). New print Nov., 2012.

Author of Book: ‘Belt Feeder Design And Hopper Bin Silo’

Advisor / Consultant for Bulk Material Handling System & Issues.

Pune, India. Tel.: 0091 (0)20 25871916

Email: conveyor.ishwar.mulani@gmail.com

Website: www.conveyor.ishwarmulani.com ■

This problem seems to rest at Fichtners' door.

From a forum point of view there are no reference drawings indicated yet forum memebers are being asked to offer advice about a complete coal handling system.

There is also a 3yr (almost) lapse between Revisions B & C which should not reasonably be in the original EPC. It is impossible to deduct where, when or how the problem came about. There is no devil in the detail....unless there is detail. ■

Originally Posted by BHASKAR

We have used liner plate of Sailhard 12MM THK & Fixing on mother plate by plug welding.

But within 3-4 Monthe liner plate has been worn out and motherplate also damanged in downsteam due to the ROM Coal.

Dear Bhaskar,

3/4 months means nothing.

How long the liner last in terms of quantity handled.

The problem can be fixed by experienced material handling Engineers,of course after a detailed inspection and study.

We were handling 200 mm size iron ore lumps with out much difficulty.

There is no fit and forget method in material handling,you may require some modifications,adjustments of stone box etc.

Narayanan Nalinakshan,

Mob-8129621008. ■

There is something wonderfully absurd in welding liner plate onto mother plate. If the mother plate is not strong enough then the liner plate serves to distort the mother plate, but to a lesser extent. Eventually the liner wears out and then you must throw away the mother plate and liner. So the mother plate is doing nothing useful. Add to that the cost of the specialist welding rods.

A reinforcing grid, which you don't appear to have, should be strong enough to hold up the liners without any parent plates at all. What .....the? But it hopefully serves to illustrate the principle that lining is one thing and containment is another. Lining was surely an afterthought along the operational experience/history of chute design. I doubt that lined chutes were specified in pioneering days and when it was found that liners were atually needed then the thick parent material persisted simply because it was there.

None of that answers your situation and I boil it down to learned respondents advice to engage a consultant. You've seen previous design work and reviews and should be able to make your own choice. ■

Dear Bhaskar,

would you please give us a drawing or sketch from the chute and where liners worn. ■

Hello,

Your coal handling plant has wagon tippler and you are handling (-) 300 mm size coal. From wagon tippler; you might be conveying coal to primary crusher or directly to ring granulator type coal crusher. So, as you have said, your problem about chute damage / wear / maintenance is concerning to only this portion of CHP (from wagon tippler to first crushing).

ROM coal of (-) 300 mm size is being handled at very large number of power stations in India, and the problem you are mentioning is probably of rare occurrence. It seems the chute work in this zone requires redesigning from flow point of view, and possibly it also requires strengthening.

The aforesaid investigation and recommendation can best be done by CHP designer and manufacturer. Such designer should be familiar with the chute design at crushers, screens, feeders, conveyors, etc. So contact them to assign the work. If you think manufacturer / designer who is willing to undertake such work, is not competent enough, tell him to take design support services from expert for such work.

Each chute design / analysis is a specific case with specific recommendation. So forum discussions or general opinions can not be converted into directly usable solution for practical implementation (because it requires specific analysis for each case and manufacturing / modification drawings for implementation while taking into consideration the hindrance to plant operation).

Such short coming in performance can be consequence of many reasons such as budget constraint, inadequate importance to pre-qualifications, inadequate know-how among concerned parties and so on. This point is referred so as to prevent re-occurrence of present situation.

You can also visit some existing coal handling plant (well designed by reputed consultants of buyer and supplied by reputed designers and manufacturers) to get the information about your concerned issue.

Ishwar G. Mulani

Author of Book: ‘Engineering Science And Application Design For Belt Conveyors’. Conveyor design basis ISO (thereby book is helpful to design conveyors as per national standards of most of the countries across world). New print Nov., 2012.

Author of Book: ‘Belt Feeder Design And Hopper Bin Silo’

Advisor / Consultant for Bulk Material Handling System & Issues.

Pune, India. Tel.: 0091 (0)20 25871916

Email: conveyor.ishwar.mulani@gmail.com

Website: www.conveyor.ishwarmulani.com ■

Originally Posted by I G Mulani

.........

You can also visit some existing coal handling plant (well designed by reputed consultants of buyer and supplied by reputed designers and manufacturers) to get the information about your concerned issue.

Ishwar G. Mulani

I would anticipate visits to existing plants as most unwelcome. They are in Europe. Plant Owners see no reason to give information away after they have paid for the work. Another point is that the material properties might not match. The Main Contractor on this job was/is reputable and the trouble could only be attributed to failure to monitor the Subcontractor and faulty reviews by the Inspection Authority or Consultant, whoever. check the latest drawing revision history.

There has been no realistic feedback (surprise, surprise); the upstream/downstrream relevance of the crusher and tippler had been mentioned very early and I suggest that we abandon this thread so that the starter can proceed at his own risk without hindrance. ■

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