[shantanu]

Industrial process or reactor design to carry-out the exothermic decomposition of solid reactant - in
which no solvent can be used in the reaction

This is a problem statement
 help in any form is welcomed.

[curiouscat]

Incomplete statement.

[Arkcon]

I'm not a CE, but like curiouscat said, this is in no way a useful question.  If this is really all they've given you for an assignment, I'm sorry for you, but I've got to hope you've left much of the detail out.

Exothermic decomposition of a solid reactant without solvent?  How is this different from burning wood, or coal in a barbeque?  OK, so, maybe your reactant is more esoteric.  Maybe you're not burning it in air for an exothermic reaction.  But what problems would your reaction face, that my solution doesn't address?  You'll have to tell us why.

[shantanu]

I confirm, this is the complete statement!
It is given by an industry.
But I am also confused about it.
I don't know hot to approach this problem. Which reactor should I use? How should the cooling be? etc...
Please help me to tackle it. Which books should I go through, what literature survey or sites should i visit?

A friend of mine suggested me to use a paddle mixer.
Any comments or suggestion?

[Arkcon]

I confirm, this is the complete statement!

That is disappointing.

It is given by an industry.

Which industry?  For what application?  What is the reactant?  What product is there supposed to be produced?

But I am also confused about it.
I don't know hot to approach this problem.

Me either.  But I flatter myself that I can ask good questions to begin to solve the problem, even if I don't understand various industrial apparati well.

Which reactor should I use? How should the cooling be? etc...

What's wrong with an open furnace?  That's what I suggested.  Why is it no good?  If you know why then why not tell us more about the reaction?  If you don't know why, then you can't say what's wrong with my suggestion, or the next suggestion.

Please help me to tackle it.

I would start by asking the same questions I asked.

Which books should I go through, what literature survey or sites should i visit?

Any of them.  All of them.  None of them will help you if you don't have the answers I've asked for.

A friend of mine suggested me to use a paddle mixer.
Any comments or suggestion?

Why?  What does he know about the reaction that you haven't told us?  What does he suggest you not use, and must use a paddle mixer for?  And why?

Look, here's a link to the Wikipedia page for a blast furnace.  It uses mixture of solids, burning, in an exothermic reaction to convert carbon and iron ore to produce iron.  It occurs on an industrial scale worldwide.  It uses no cooling or paddle mixing.  Are you doing that?  Are you not doing that, but instead something else?  Then what?  If they don't tell you, then just use this example, until they do.

http://en.wikipedia.org/wiki/File:Blast_furnace_NT.PNG

[curiouscat]

Any comments or suggestion?

Yes. Go back to the textbooks.