Dear Mark, 

this is my first time as a chair. The session consists of 3 papers in 1 hour and a half, so I would allocate 30 minutes to each paper. I've read that each paper should be allocated 15 minutes for presenting, while discussants should be allocated 12 minutes each (I suppose for the whole session). I plan to elicit discussion after each paper, rather than at the end. So, after the 15 minutes presentation, I plan to give 4 minutes to each discussant. Then, if some time remains after the presenters' answer to discussants' comments, I will elicit questions from the audience (as soon as 30 minutes pass, however, I would move on to the next paper). Is this a correct roadmap? 

Thanks,
Mattia