Originally Posted by sanjay.ksg

Dear Sir,

Should we do the drive alignment before placement and tensioning of belt or it should

be done after belt placement and tensioning.

==================================================================================================== ==========================================================================

About your conveyor it sounds as if you have never been around them or

installed them before; is this the case????

There is a lot of work to be done before you can even think about pulling a

belt and splicing it.

Please expand your explanation on your conveyor belt system. ■

You have given very little information about your system for anyone to give you any kind of a reasonable answer.

size of belt?

length?

inclined?

declined?

HP?

does it have a back stop?

These would be a minimum to start with. ■

Originally Posted by sanjay.ksg

Dear Sir,

Should we do the drive alignment before placement and tensioning of belt or it should be done aftre blet placement and tensioning.

I'll give you the benefit of doubt; presume you are trying to raise one of those hypothetical situations for which the sub-continent is becoming notorious for and answer thus simply with a question which others are too polite to mention.

How do you work on the alignment of a belt in tension?

My father was a belt man and coal cutter contractor at Clock Face Colliery during the 1920's. 30's & 40's. He used to laugh at me when I mentioned belt alignment. "When you have gone down pit, walked three miles to the face; seen the engine left there because the first shift couldn't get it under the hanging; with a room of coal stood there staring at you, which has to be at pit bottom before the 12 o'clock cage you do what you have to. Offer the lads a ten shillings bonus; tip the engine on its side; slide it through and get the belt running. If it needs straightening pull it straight with Sylvestors (Tirfors nowadays) around the tail drum. Don't talk to me about textbooks." He used to make a lot of money abusing machines but funnily enough the machines never complained and neither did his men.

So you see, you can work on a belt in tension. But you'd better know what your doing. Do you? ■

Good stuff John as always but I think he is referring to a drive alignment and not the belt alignment and without know anything about the system pretty hard to give him an answer. ■

Originally Posted by sanjay.ksg

Dear Sir,

Should we do the drive alignment before placement and tensioning of belt or it should be done aftre blet placement and tensioning.

If it is done after belt tensioning then you have spliced a belt knowing that the drive might be askew. Then you would probably have to resplice after drive realignment.

Whether or not you remember to slacken the belt is your own affair, as I mentioned previously.

I remember the Nordell Spriggs posting where they claimed that the drive should be works tested before despatch: presumably regardless of the equipment sources. However the basic intent is that drives should be safely aligned somewhere before the belt is placed.

It is always advisable to minimise the workload, even in times of limited work.

But thanks for the post because it gives some insight into the proliferation of early failures in other spheres.

Finally, what do your drawings tell you. I bet there are no geometric tolerances shown, only a centreline. If there are plan and end elevations which give the centreline elevations then, to the letter of the law, you must ensure that these are just that. All drive items must be concentric. Otherwise the drive cannot be accepted for site test and payment. Alternatively, read the drawings and see what the acceptable run out is and work to that. Handy things drawings. ■

Your belt is very short and therefore would have very minimal tensions to be concerned whether the drive alignment is done before or after the belt is tensioned. Is this a feeder?

On Large conveyor system it is common to have the alignment done prior to belt tensioning and rechecked after tensioning ■

Hello,

For the conveyor being installed, one will need drive unit for its operation, only when practically complete conveyor is installed, including power supply connection. So advanced and finished alignment of drive unit with drive pulley, looks to be less logical. As for your point:

1) If you are confident that your erection men will install head terminal on its foundation firmly by correct tightening of bolt-nut and pulley bearings also firmly on the head terminal by correct tightening of bolt-nut; such that belt tensioning will not shift them by few millimetre or fraction of an inch then one can have drive unit coupled to drive shaft, before tensioning of the belt.

2) If you do not want to take such chance then first tighten the belt (this can only be done when all items of the conveyor are in place). Check / retighten head terminal and pulley bearing mounting, and then have connection (also final) between pulley shaft and drive shaft. The drive unit may already be at its place, ready for such connection.

3) For shaft mounted drive unit, the issue will not be so prominent.

Well, installation experts can follow their own practice which will have relevance to the competence and reliability of their team.

Ishwar G. Mulani

Author of Book : Engineering Science And Application Design For Belt Conveyors (new print November, 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 ■

You should get it roughly right before you tension the belt but the final alignment must be done after the belt is tensioned and the counterweight droppped. It can be simply done without any reversion to surveyors using simple geometry

Cheers

Colin Benjamin

Gulf Conveyor Systems P/L

www.conveyorsystemstechnology.com ■