After a process description is completed and the mass and energy balances are done satisfactorily, oftentimes, you need to try and see how the process would behave if you scaled it up (or down) by a factor. In order to do that, you must visit all process input streams and adjust them by the scale-up (or scale-down) factor, and re-run the simulation. SuperPro Designer facilitates this process by offering you the option to do all this in just one step: All you have to do is select the Tasks } Adjust Process Throughput option from the main menu of the application. The Process Throughput Adjustment Dialog dialog shown in The Process Throughput Adjustment Dialog. will appear.
The Process Throughput Adjustment Dialog.
From the above dialog, you can simply type in the scale-up (or scale-down) factor and then SuperPro Designer will automatically increase (or decrease) all input stream flowrates by that factor. Alternatively, if you don’t wish to have all input streams scaled-up (or down) by the same factor, you can select the second option, and supply such a factor for each input stream.
Typically, after you have scaled up (or down) the process inputs, you must re-solve the M&E balances. If several pieces of equipment have their sizes specified (i.e., they are in rating mode), a scale-up adjustment may result in a process throughput that exceeds their capacity. In that case, the program will display appropriate warning messages and provides instructions on how to fix the problem.
|
|
For a batch process that has not been designed and built yet, a throughput adjustment is equivalent to a batch scale-up or scale-down. For an existing batch plant, with fixed equipment sizes, a scale-up action usually increases the minimum effective plant batch time and decreases the maximum number of batches per year. In other words, the number of batches per year decreases, but the amount produced per batch increases. As a consequence, there is an optimum value of batch throughput that corresponds to maximum annual throughput. |
For detailed definitions of the terms Conservative, Realistic and Theoretical throughputs, see Potential Maximum Throughput Size.
