February 2020

28 | Plant & Works Engineering www.pwemag.co.uk February 2020 Energy, the Environment & Water Focus on: Boilers, Burners & Controls H aving been installed for well over 30 years, the original boiler feed pumps were showing signs of their age. The original design for the installation intended seven pumps to be in service while the remaining two offered reserve capacity that enabled maintenance to be completed without interrupting the boilers. The toll of time Unfortunately, several decades in service had taken their toll and worn seals, increased clearances, and a need to improve efficiency resulted in the engineering manager contacting Sulzer, a company he had worked with before. In fact, the situation had reached such a point that all nine pumps were required to be operating to keep up with demand from the boilers. Once the initial inspection had been completed, the results showed that six of the nine pumps had leakage figures of around 25 m3/hour. Manish Talwar, head of retrofits for pump services, Asia Pacific, commented: “The original pumps had performed remarkably well, but over the last few years, they have not been running anywhere near peak efficiency. It was clear that we could offer some immediate assistance as well as a plan for the long-term performance of the pumps.” The discussions with the plant engineering manager revealed that the original equipment manufacturer (OEM) had been contacted with a view to repairing or replacing all of the pumps. However, both the proposed costs and the projected lead times for this work were well beyond the expectations of the customer. Fast fixes The initial contract for Sulzer was to repair and upgrade two of the pumps so that they could operate close to their original performance figures. This involved installing mechanical upgrades to the coupling system, seal improvements and efficiency upgrades through non-metallic wear parts, before returning them to normal service. Given the cost of energy production at the power plant, Sulzer’s engineers were able to calculate the payback period of the overall upgrade project. Having been assessed in the company’s service centre in Singapore, it was concluded that the investment in the pump refurbishment would be paid off in less than three years. Advanced manufacturing The new parts were designed and Boiler feed pumps are essential pieces of equipment for power generation plants. High energy requirements mean they need to be efficient as well as reliable. For one liquified natural gas (LNG) plant in South East Asia, nine boiler feed pumps needed urgent attention and Sulzer was called in to deliver the most effective solution. PWE reports. New lease of life for boiler feed pumps CASE STUDY Sulzer’s repair and replacement program for the pumps will bring the plant back to original specification but with improved efficiency. The new pumps will offer a 5% increase in efficiency and have a lower power requirement delivering on-going cost savings.