Operation policy for micro chemical plants with external numbering-up structure

One of the critical operational issues of micro chemical plants with external numbering-up structure is to keep a uniform flow distribution among parallelized microdevices even when blockage occurs in one or more microdevice. Since it is not practical to install flow controllers in all the microdevices, a simple and effective operation policy against blockage occurrence needs to be developed. In this research, micro chemical plants having four or eight parallelized microdevices are constructed to analyze the influence of blockage on the flow distribution among the parallelized microdevices. The numerical and experimental results show that pressure drop control is superior to total flow control. In addition, two control structures based on pressure drop control, pumping pressure control and pressure drop control over the parallelized section, are investigated. It is clarified that the latter control structure enables us to successfully keep the flow rate in each unblocked microdevice at a normal level when blockage occurs. Pressure drop control over the parallelized section is applied to a micro chemical plant having four parallelized micro heat exchangers, and its validity is demonstrated.