For chemicals, food processing and other liquid, semi-liquid, and pumpable or conveyed solid materials moving through a pipe, the heating process has been a difficult one. Typically heat is applied from the outside of the pipe resulting in overheating of material near the pipe wall while leaving material in the center of the pipe unaffected. IMS has developed a Cylindrical Heater incorporating a microwave "Focusing Structure" that widens the microwave field strength in the exposure region so that all the material flowing through the IMS Cylindrical Heater is uniformly exposed to microwave energy. As a result, there is virtually no temperature gradient between the material flowing against the wall of the pipe and the material flowing through its center. In addition, the pipe used in the Cylindrical Heater is invisible to microwave energy so it does not heat up, reducing or eliminating burn on and fouling. In traditional heating, the material throughput must be restricted or the heat transfer must take place over great lengths of pipe to compensate for dramatic temperature gradients. With the IMS Cylindrical Heater solution, throughput can be increased, the length of exposure region is minimized, and the speed with which target temperatures are achieved is maximized, while product quality and yields are unsurpassed.