admin
1156 posts
TimePosted 22/08/2006 10:21:26
admin says

Preheaters Question 1

Thanks for your reesponse on our cracking problems. We have ordered a new cone and in the mean time we have welded the effected part and have used dye penetration test for finding the magnitude of crack. But what in I am interested is the reasons;thats why such cracks develop, either due to misappropriate operating, startup /shutdown procedures. improper jackingup the mill at the startup time, overdue servicing of trunion etc. Or only due to matelurgical/ casting failure. Furthermore please let me have the diagnoses procedure/test for the above.

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admin
1156 posts
TimePosted 22/08/2006 10:21:26
admin says

Re: Preheaters

The main reasons why these cracks occur are due to the high stresses that the mill end castings are subjected to and therefore metal fatigue. Most suppliers have taken steps to reduce metallurgical or casting failures as much as possible, but pre-delivery inspection and testing would be one step. Many problems are caused insufficient care by the maintenance department when welding, grinding the mill shell, or cutting bolts/drilling holes for fixing bolts. Of course there are steps you can take to during operation to mitigate against these cracks developing, (i) broken wear protection plates must be replaced immediately, (ii) temperature monitoring. Ultimately there is no alternative to frequent and rigorous inspection.

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admin
1156 posts
TimePosted 22/08/2006 10:21:26
admin says

Preheaters Question 2

What is function of preheater immersion pipe? What is the behavior of material inside cyclone if immersion pipe is missing ? If we have any immersion pipe missing it will effect on decarbonation degree or not ?

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admin
1156 posts
TimePosted 22/08/2006 10:21:26
admin says

Re: Preheaters

The function of the vortex finder is the improve the material separation efficiency in the preheater cyclones. If the vortex finder is not there then separation efficiency and preheater performance will decline. Yes, it will affect the decarbonation degree … some decarbonated material will pass back up the preheater and recarbonate. The biggest effects will be on fuel consumption and kiln output.

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