PEF Systems For Food And Waste Streams

Pulsed electric field (PEF) processing works through a process of electroporation in cells - destroying the cell membranes through application of short, very high voltage pulses across a liquid. PEF processing can also improve the performance of industrial processes such as the removal of water from sludge, or the extraction of sugars and starches from plants, because the ruptured cells release their intracellular liquids more easily into their surroundings. Modern PEF systems are based on conventional pulsed power technology, applied in a very different manner. In a conventional pulsed power system, the load determines the required voltage, current, and average power, and the system can be optimized to these specific parameters. PEF systems, in contrast, typically start with a desired field strength, and ranges of flow rate (processing volume), and fluid conductivities. Furthermore, both the flow rate and the conductivity can change significantly during the system operation. Designing a PEF system capable of adapting to these changes represents a significant challenge to the pulsed power system design and construction. In this paper, DTI will discuss the interrelationships between pulsed power and PEF processing, describe the unique requirements that PEF processing places on pulsed power designs, and present examples of system designs and configurations.