Intelligent crust breaking cylinders
Published: 11 April, 2007
Parker - manufacturer of motion and control technology - is helping the Elkem Aluminium plant in Mosjøen, Norway to streamline processes and significantly increase efficiency through the use of its intelligent pneumatic crust breaking cylinders. As well as being able to withstand the extreme conditions within an aluminium smelter, the cylinders feature closed loop control, to improve the performance of the feeders and enable the plant's cell operators and maintenance crew to respond to problems quickly, reducing the number of anode effects (and thereby greenhouse emissions) and also increasing productivity.
The successful smelting of aluminium relies both on a controlled supply of aluminium oxide, also known as alumina, in order for production to be optimised and for anode effects to be prevented, to minimise greenhouse emissions and potline disturbances .
Prior to implementing the Parker technology, the Elkem plant was operating conventional crust breaking cylinders with fixed dwell times, regularly attempting to break the crust which forms on top of the alumina and cryolite mixture in a smelting pot, as a part of the alumina feed operation. The dwell time selected was a compromise between having sufficient time to achieve enough plunger force, and a short enough time to avoid electrolyte deposits sticking to the plunger. There was no feedback on whether the crust was successfully broken, often resulting in alumina being poured on top of the crust and not entering the mixture, resulting in anode effects.
In response to these problems, manual checks were frequently required, with process staff having to lift heavy covers from the pots in order to monitor their condition. With 1100 feeders at the plant, needing one or two inspections every shift, this required a significant amount of man hours. These spot inspections were also relatively inefficient as there can be an anode effect just fifteen minutes after a feeder stops working.
Parker"s intelligent crust breaking cylinders have been one of the key enablers for Elkem to reduce the rate of anode effects per pot from one every second day to approximately one every 10 days.
For further information please visit: www.parker.com
