Africa’s largest cement plant in Obajana, north central Nigeria, owned by the Dangote Group, produces up to 30, 000 tons of cement daily. It will now record a major milestone as GE has been commissioned to undertake a highly specialized maintenance job – a PTR or “partial tear down” of a LM 6000 gas turbine – only the second time such complex work has been done in Africa.
Since 2014, the Obajana plant has been powered by four GE LM6000 gas turbines with a combined capacity of approximately 200MW. The engines, which can run on natural gas or diesel, have provided reliable and efficient power in a country where the electricity supply can be erratic.
This year, one of the 51MW turbines developed a leakage. These gas turbines are huge – to put this in perspective, they are some 20 meters long and nearly 10 meters high, and weigh up to eight tons. Shipping the turbine to the GE depot in Houston, the United States – or just the combustion rear frame (CRF) section where the fault occurred – would have been a costly and time-consuming exercise.
As such, GE took the decision to repair the LM6000 engine in Nigeria, leveraging its worldwide network to assemble the people, parts and tools needed to undertake this skilled and delicate work. The turbine was transported to the southern Nigerian city of Port Harcourt, 438km from Obajana, where spare parts arrived from Houston and specialized tools from Norway and Singapore.
Wiebe Van der Werff, a GE expert field service engineer said that, excluding logistics, transportation and customs costs, such a repair would have amounted to $3,5-million if the turbine had been transported to Houston. But doing the repair in-country would cost less than $1-million. “We couldn’t do the repair in Obajana because it requires a standard overhead crane and a properly prepared environment. Obajana has just a standard crane and the workshop environment and air quality are not up to the required standard,” said Wiebe.
Wiebe added that this was a highly delicate operation, which is normally carried out at a depot. But given that there are specialist field service engineers working on the project, he was confident of the GE team’s ability to complete the repairs.
