VEREENIGING AND ZUIKERBOSCH

The Rand Water Chlorination Plants was a joint venture between PCI SA and civil engineering contractor Mndeni (Pty) Ltd for Rand Water, South Africa’s largest water utility company. The contract valued at R20 million was for the erection, supply and commissioning of three fully automatic liquid chlorine plants capable of treating a total combined plant capacity of 2990 Mℓ/day.

PCI was the lead partner in the joint venture and were responsible for the overall project management of the contract. The effective contract period was 24 months and was successfully completed in October 2007.

Each plant consisted of a drum-storage room (drum-room), evaporator room, chlorinator room and electrical control panel room.

Chlorine Drum Room
The chlorine drumroom is used for the storage of 1-ton chlorine drums. The storage area comprises of a dual bank (10 drums arranged in series) system erected on steel platforms that have load cells to monitor the mass of available chlorine. An advanced automatic drum shutoff system complete with pneumatically driven motors is installed and utilizes strategically positioned leak sensors for monitoring gas leaks.

Chlorine Evaporator Room
A water-bath evaporator system was installed for converting liquid chlorine into gas phase at 65C. Each evaporator system has a dedicated electrical control panel complete and remote water level and water-temperature sensing facilities.

Chlorinator Room
This room houses chlorinators for regulating the chlorine gas flowrate. The maximum capacity of each chlorinator is 40 kg/hr and can be operated in automatic or manual mode. A robust chlorine flow control system has been implemented and utilizes feedforward and feedback control loops. The feedback control system consists of PID settings complete with a tuning facility in the human machine interface (HMI).

Electrical Control Panel Room
The plant consists of a modular control panel with a HMI from which the complete plant status can be viewed and manipulated. The SCADA equipment was installed for remote viewing and control of the plant by station personnel.