How to increase throttle limiit for an excel calc engine when using POI with Java?

We have a excel based calc engine that we read using POI and Java. As of now开发者_如何学Go the throttle limit is approx 30-40 concurrent users. We want to increase this to 100. In current design we take user inputs and pass them to calc engine which does some very complex calculations and then we read the results from given cells from same workbook aka calc engine. What are the possible ways to increase the throttle limit for calc engine? Can we have 2-3 copies of calc engine and redirect user to alternate calc work book? Will this increase performance? Is there anything else we can do make performance better?

We used 2 copies of calc engine and redirect user to alternate calc work book - this worked for us.