Emerson’s Peter Woodhead presented Remote Control Panels: Innovative & Effective Solution for Isolation Valves at the 2019 Emerson Exchange conference. Peter is from Brisbane, Australia where they design and manufacturer Lunkenheimer slurry valves.
The mining customer challenged the Emerson team to remotely control some slurry isolation valves. The isolation valves were applied on a backpressure vessel with the digestion stage in an alumina factory. The backpressure vessel is located on a steel platform with 3 of 5 isolation valves positioned 3 meters above the platform. They wanted to remotely control the valves to improve personnel safety and eliminate fixed access walkways.
This type of remote control had never been done before. Factory testing could not simulate the temperature conditions found in the actual process. The approach to solve this challenge was to control the hydraulic system using PLCs, digital I/O, relays and pressure & position sensors. Push-button operation was adopted for most operations to improve simplicity and reliability.
Peter described how typical manual operations work on these valves. A pinion shaft is rotated to open & close the valve. A staple in is for open & close and out to grind the seat. In this process, scaling is a problem and the lines and isolation valves must be flushed periodically with a caustic chemical with and valve grinding operation to remove the scale.
For remote control, an innovative disc brake replaced the staple. For this application the disc brake required 6 kN.m brake torque. It’s activated remotely via hydraulic pressure. There is no need for a hammer which reduces risks for operators.
The second innovation was a clutch to replace the jam nut in the manually-operated approach. The third innovation was the remote-control panel. It included push-button control, manual/maintenance/emergency manual modes, selectable switch for seat back-off to suit available grinding torque, open/close sensors displayed on control panel, and PLC control.
The panel had 5 modes—open, close, grind, manual & maintenance. Visual LED indicators indicate feedback such as achieved mode change result, warning, mode, and seat backoff range.
This project developed first-of-their-kind mechanisms, and control system to remotely operate a globe valve with innovations—disc brake, hydraulic clutch, and remote-control panel.