Electronics switch pays off for Harco
15 Jan 2000
A £13 million expansion to its polyvinyl alcohol (PVA) plant has enabled Harlow Chemical (Harco) to move its control strategy away from pneumatic to electronic valve actuation, increasing production by 40 per cent.
The switch to electronics was facilitated by new control panels installed by Max Wright. Three zone1 explosion-proof panels control the hydrolysis plant, solvent extraction and product dryer respectively. These all report via intrinsically safe barriers into a main control panel housing pneumatic solenoid valves, bead reactor control and PLC.
According to Harco's site engineer, Anthony Colley, 'all the electrical hardware was produced competently by Max Wright but their real forte was the development of the PLC software.' A Toshiba EX100 PLC is used for sequence control on the plant.
