Kiltel's RamControl consists of a position sensor that attaches to the ram (or a similarly moving component such as a counterweight), and an electronics package that produces an output signal proportional to the instantaneous ram speed. This allows precise push speed control directly to a cars-per-day setpoint.

 

Position measurements from very slow-moving (0-3"/minute) objects such as a kiln ram show such small changes over short intervals that it is not possible to convert the difference to a speed using standard 12-bit analog-digital converters. The RamControl digitizes the position signal at 24-bits, resulting in 12-bit resolution on the difference, and then produces an output voltage proportional to the speed, which is input to a loop controller. The loop controller's current-loop output drives a VFD regulating the ram pump motor, completing the feedback control loop. The slow-speed output is frozen during the retraction and fast take-up portions of the loading cycle, and control at the proper speed is regained immediately when the forward push resumes.

The RamControl is stand-alone—it can be given a setpoint in cars/day either manually at the unit or automatically via communications with a Kiltel supervisory system -- and regulates the speed of the moving object directly, rather than controlling some inferential parameter such as VFD hertz or oil flow which are poorly related to the actual push rate. The unit can be installed quickly on most pushers without modifications to the existing hydraulic plumbing or pump.

 

RamControl units have been working on tunnel kilns in brick and ceramics plants for years, and out-perform any other approach on the market. The system price includes all components except the pump motor VFD.