Recently, ISME have supplied a batch of process instruments and control panels for a water treatment plant in Sabah. The treatment plant is part of the initiative by the Sabah’s government to solve water supply shortage and cope with the increasing demand for clean water supply in Kota Kinabalu and the surrounding areas.
Given the nature of the temporary plant’s purpose as an emergency capacity expansion, there are several special requirements imposed on the plant design necessitating a design that requires us to think out of the box.
Requirements
- The proposed plant is developed as a temporary plant for emergency capacity demand expansion to boost water supply.
- Conventional clarifier and sand filter plant is not favourable due to its temporary nature and land scarcity.
- A compact plant with a unique DAF (Dissolved Air Flotation) system coupled with UF (ultrafiltration) system is selected as the final design of the plant.
- Both systems enable the treatment plant to meet the required plant capacity of 10MLD while reducing the environmental footprint.
- As a temporary plant, the design is required to be dismantled and transported easily for future recommissioning.
Solutions
- The 10MLD capacity of the plant is split into 4 trains of 2.5MLD each which ensures that the plant can be modular and be transported out easily.
- Each individual train control system is designed as an individual plant with its own control panel inclusive of PLC and HMI control system.
- At the heart of the system is a master control panel with another set of PLC and HMI to synchronize the entire plant operations across the 4 trains.
- Various process instrumentation is utilized to realize the fully automatic control of the water treatment plant:
- Electromagnetic flow meters are used to regulate the output and measure the throughput of the entire plant.
- Level sensors such as ultrasonic level sensor and electrode level sensors are deployed to allow the control system to control the level of water inside various tanks, preventing unnecessary overflow that leads to wastage.
- Digital pressure switches are deployed to ensure compressed air pressure is sufficient to actuate the pneumatic valves of the system. Digital pressure switches are also installed on blower lines to ensure there is proper aeration inside the UF tanks.
- Pressure transmitters are installed to monitor the performance of the UF and allows the system to perform automatic backwash when the TMP (trans-membrane pressure) is too high. Backwash carried out at the proper interval and TMP setpoint ensures the UF system is kept at the optimum operating condition and improves the lifespan of the UF membranes.
- REMOX monitoring system is also installed to enable the plant to be monitored and controlled from a remote location. This feature is much needed as the plant is situated in a rural area and is a couple of hours away from a major town.
- The monitoring system also enables our engineers to assist the client on troubleshooting the system without being physically present at the plant.
- Remote system maintenance and software upgrade is also possible using the REMOX monitoring system supplied.
- All critical process data logged at the HMI can be retrieved from a remote location, allowing engineers to create reports and analyze the plant performance without attending the site, saving precious travelling time.
