Patent ID: 8344299

Claim:
A cylinder heater comprising a hollow circular cylinder symmetrical about a longitudinal axis and having a first end, a second end, a cylinder length between said first and second ends, a first inner surface having a first inner diameter adjacent said first end, a second inner surface having a second inner diameter adjacent said second end, and a third inner surface having a third inner diameter between said first inner surface and said second inner surface; a support for rotating said hollow circular cylinder about said longitudinal axis at a plurality of predetermined rotational speeds; a metallic powder layer contacting said third inner surface; a vibration sensor coupled to said hollow circular cylinder for indicating a vibration level of said hollow circular cylinder; at least one temperature sensor for indicating at least one temperature of said hollow circular cylinder; at least one circumferential induction heating coil around said hollow circular cylinder for heating said hollow circular cylinder and said metallic powder layer, each said circumferential induction heating coil being movably coupled to said support and having a coil length along said longitudinal axis, and each said circumferential induction heating coil being longitudinally positionable over a plurality of predetermined portions of said hollow circular cylinder; a controller communicating with said vibration sensor, at least one said temperature sensor, said support, and at least one said circumferential induction heating coil, said controller controlling longitudinal positioning and power output from at least one said circumferential induction heating coil, and said controller controlling rotational speed of said hollow circular cylinder; wherein said third inner diameter exceeds said first inner diameter and said second inner diameter; and wherein said metallic powder layer comprises at least one abrasion-resistant material and at least one cement, each said abrasion-resistant material having greater density than each said cement.