Chapter 9 - Design Considerations for Applicators in Continuous-flow Microwave/RF Processing

Abstract

This chapter emphasizes flowable solids and webs and discusses RF and microwave continuous systems. It focuses on the important issue of reducing RF/microwave emissions from entry and exit ports to comply with safety and communication regulations. Continuous-flow processes, as opposed to batch processes, provide better economy in most cases where high throughput and low labor costs are required. Batch processes are used in special cases where specific process ambient conditions, such as a vacuum, are necessary in high value-in-use products with limited production volume. The automatic feedback control of RF/microwave continuous processes provides unique opportunities and challenges as compared with conventional processes. One advantage of the use of RF/microwave equipment is control agility because of the volumetric and instantaneous nature of energy deposition into the product without the delay associated with conventional heat transfer. Since the material's bulk temperature reacts quickly with any changes in the power input, the feedback delay is greatly reduced.