Graph query

[Mihit Parekh]

In the contact process, for the plot of SO2 conversion v/s temperature, Zig-Zag lines are plotted, where each pair of horizontal and vertical lines indicates a step or lets say bed.. We use 4 beds, so we obtain 4 steps in zig-zag line.. So my query is what does each line represent? like what is significance of horizontal line and vertical line?? Also why are this lines parallel to each other?? Can there be manipulation possible so as to bring down working temperature?? 

[Vishwanath Dalvi]

Anyone care to have a go at this?

[Anish Acharya]

From whatever i understood, Each slanting line is an exothermic reaction happening and the horizontal line is just cooling of the system components. like if we had just 1 slanting line that is just 1 stage of the reaction the conversion will be where the stage 1 line intersects the conversion plot. The cooling is done so that we are increasing conversion, keeping down the working temperature in the range specified where the catalyst is active. Successive cooling is a manipulation that we are doing.