Seraya Chemicals has a cooling water intake station which takes in water from the sea to cool the plant facilities.
Soon after a shutdown, solid particles were found to be present. These solid particles may cause erosion of the pipelines over time and if left unattended, may compromise the entire cooling water system either when the pipeline becomes choked or eroded. Another shut down soon ensued and preliminary investigations showed that the problem originated from the cooling water intake station.
Entrusted with the task to solve the problem, divers were deployed to perform detailed inspection of the underwater structure of the station. Years of scouring resulting from destructive currents had deteriorated and weaken the base material of the sheet pile wall. Numerous openings on the base material created a vacuum beneath the concrete base, eventually leading to its partial collapse.
Working within a tight schedule, HSL performed the repair by installing thick steel plates next to sheet pile walls, which effectively cover the holes. Based on our study of the current movement, armor rocks were designed and placed in front of the steel plates to effectively mitigate erosion of the sloping seashore. Subsequently, filter stones were brought in to fill up the cavity and thick steel plates with cathodic protection were introduced to replace the concrete base. Finally, compartmentalization was done to allow partial shutdown of station.
Working within the tight schedule was a very big challenge which our cohesive and motivated team of experienced workers, project managers and supervisors overcame with zest and confidence. Shell was once again very pleased with our achievement on the job site and praised our creativity and industriousness. We had completed our project in a timely and efficient manner that draws praises from our accolades and other industrial partners. It may also be worthwhile to note that the cooling water intake station is still currently in operation since our works some years ago and is expected to be able to continue operating soundly before the station reaches the end of its equipment life.