14 posts
TimePosted 12/01/2009 19:26:26
fatih says

### raw meal homogenization

Hello,

We have a raw meal bunker above the kiln feed weighfeeder, it's capacity is 20 tons. We are thinking about that some amount of raw meal to feed back to elevator from bunker during operation ( elevator transport the raw meal from silo to the raw meal bunker mentioned)

We think that this will improve raw meal homogenization.

We have made some calculation that standart deviation goes down to 0,50 from 0,75.

What do you think about that? Thank you very much.....

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138 posts
TimePosted 12/01/2009 19:44:00
lalbatros says

### Re: raw meal homogenization

Hello,

The best way to express what I think is to ask you another question:

How do you define the standard deviation?

I can expect a logical answer: it is based on the statistics of individual sample. Then I come with another question:

How do you obtain your samples ?
By averaging over 1 , 10 , 100 or 1000 tons ?

And a further question I would like you to consider is the following:

What kind of smoothing would be of some good for your kiln?
Is it useful to smooth the raw meal on 1, 10, 100 or 1000 tons?

If your simulation spreadsheet relates to these questions, you might well be on a good track.

And maybe I missed one question:

How did you come to your 0.50-0.75 estimate ?

Hope it helps.

14 posts
TimePosted 12/01/2009 21:58:52
fatih says

### Re: raw meal homogenization

Thank you very much for your interest.

Of course i need too much data for standart deviation. Shortly we can say i estimated it. I got actual kiln feed LSF values measured by XRF. I put about 200 LSF value to excel and i reversed ( reversed column accepted feed back from bunker ) as first value is last value. Then i accepted 1/3 of raw meal fed to bunker is fed back to elevator. Fresh feed LSF * 2/3 + Feed back LSF * 1/3 = Mix LSF.

Standart dev ( calculated by excel) of fresh feed LSF : 0,75

Standart dev ( calculated by excel) of feed back LSF : 0,50

And also i feel that it works. Is it comic?

Note: Elevator and other raw meal transport equipments' capacities are sufficient.

Regards.

14 posts
TimePosted 12/01/2009 22:01:17
fatih says

### Re: raw meal homogenization

* Something was wrong i am correcting;

Thank you very much for your interest.

Of course i need too much data for standart deviation. Shortly we can say i estimated it. I got actual kiln feed LSF values measured by XRF. I put about 200 LSF value to excel and i reversed ( reversed column accepted feed back from bunker ) as first value is last value. Then i accepted 1/3 of raw meal fed to bunker is fed back to elevator. Fresh feed LSF * 2/3 + Feed back LSF * 1/3 = Mix LSF.

Standart dev ( calculated by excel) of fresh feed LSF : 0,75

Standart dev ( calculated by excel) of mix* LSF : 0,50

And also i feel that it works. Is it comic?

Note: Elevator and other raw meal transport equipments' capacities are sufficient.

Regards.