ESKOM ROTEK INTERVIEW: “We're very excited about the millions of rands in savings that can be realized through our improved turbine maintenance practices.”

1)    Let’s start with some background of Eskom Rotek Industries – there is a proud history there.
Eskom Rotek Industries is a wholly owned subsidiary of Eskom Enterprises, which in turn forms part of Eskom Holdings. ERI came about as result of the amalgamation of three entities namely, Rotek Engineering, Roshcon and Rotran. Based in Rosherville, it has a national footprint in all major centres in South Africa.

In 2015 the companies were officially merged to form Eskom Rotek Industries SOC Ltd with the mission to provide high quality mission critical services to Eskom’s lines of business and evolving Africa Strategy. The organisation also provides services to both public and private commercial entities in the energy industry sphere.

2)    Tell us more about the services you provide in the utility sector on the continent?
Eskom Rotek Industries is known and respected for its high quality, mission-critical engineering services. Operating from our head office in Rosherville, we have a national footprint in the form of smaller regional and project site offices, extending our resources and expertise to meet the needs of even the most remote client.

Bulk Material Services offers a wide range of services: from the delivery of coal via road to power stations; to the provision and maintenance of coal conveyor operations; to ash and coal handling; to the operation and maintenance of bulk water schemes in the primary water supply; and first line electrical maintenance of Eskom power stations.

Construction Services specialises in both civil and electrical construction, from constructing conveyor systems at coal stock piles; to terracing and reticulation in preparation for building new power stations; to building and cabling sub-stations; to erecting towers for power lines. This allows delivery on power line, substation, cabling and mixed civil projects.

Logistics Services offers road transport, material handling, warehousing and logistics services to Eskom, as well as the other Eskom Rotek Industries product groups including: transporting boilers and turbines to and from power stations, transformers and switchgear from substations, poles and pylons to remote sites, as well as all power generation and distribution equipment. It boasts the largest multi-axle fleet in the Southern hemisphere.

Transformer and Switchgear Services offers modification, maintenance, refurbishment and repair services to transformers and switchgear, both on and off site, through its high tech workshop and on-site services. Its workshop and test facility is the most advanced in Africa, and the only facility that can repair and test transformers of sizes up to 920 MVA and 765 kV.

Turbo Gen Services focuses on the maintenance engineering of the Turbine Island, with a separate focus on heavy engineering to capitalise on available resources. Turbo Gen Services also refurbishes turbine equipment and generators during Eskom maintenance outages; either on-site, or in the Rosherville-based workshops. Turbo Gen Services is Eskom’s exclusive strategic major turbine generator maintenance service provider

3)    Which current projects that you are involved in at the moment are you particularly excited about?
We're very excited about the millions of rand in savings that can be realized through our improved turbine maintenance practices.

Background:
In the past major performance and vibration problems were experienced by clients following major outages.

Challenge:
Eskom Rotek Industries engineering department worked tirelessly with clients within the power utility sector to address vibration problems on turbines, which was leading to distortions on these rotating machines. The challenge was further aggravated by machine aging as well as general misalignment. Vibration problems had become a norm on these machines, following every outage (planned or unplanned).

It is quite normal for high temperature turbine cylinders to distort over time due to operational stress and age. During this period however it was observed that conventional cylinder alignment methods were proving to be unsuccessful during major turbine over haulage.

With many of these clients’ fleet operating on longer hours in a drive to meet customer’s energy demand, distortion becomes a major challenge and had been a major driver for higher maintenance costs as well as longer duration outages. The industry norm for power plants with similar conditions would be to replace the turbines or remove the distortion by machining or heat treatment. These options are very costly and time consuming and would often mean material life exhaustion of major components, which in turn would drive costs.

Solution:
An alternative solution was investigated and implemented by ERI (Eskom Rotek Industries). This solution involved retaining the distortion of the casing as it often is a function of the operational temperature distribution in the casings. Doing so improved the life expectancy of the assets’ major components, as the casing was retained for longer in the secondary creep zone cycle.

Graphic caption: Typical creep curve for steel
 
Furthermore the team went on and investigated solutions that were to ensure a reliable operational turbine without any vibrational or process problems. To this end, a method was designed to execute accurate cylinder alignment in the presence of distortion. The distortion causes cylinder components to move relative to each other during the assembly. These movements affect the small internal clearances and can lead to mechanical contact between rotating and stationary components which in turn may lead to major vibration and mechanical damage.

The Outcome:
The development of the new technology was completed within ERI and has been executed successfully on three units to date. By utilizing this method the turbines were refurbished, assembled, and returned to service successfully. The distortion compensation method will in future be the norm for cylinder alignment of cylinders with above normal distortion. One of the major advantages of the new method is that it can be executed within a shorter period than the conventional methods and tends to be much more accurate.

4)    Where in Africa are you active?
In various African countries with a good and strong footprint and working on expanding it.

5)    What is Eskom Rotek Industries’ vision for the energy sector on the continent?
Eskom Rotek Industries’ mission is to be a sustainable business, within the Eskom Enterprises group of companies, providing high quality mission critical services to Eskom’s lines of business and evolving Africa Strategy.

Guided by our values – Zero Harm, Integrity, Innovation, Sinobuntu, Customer Satisfaction and Excellence – this operating model and our strategy to shift performance and grow sustainably will realize our vision to be a world class energy industry services company.

6)    How excited are you about the role of renewables in the energy mix?
It’s an exciting period for all.

7)    Eskom has been a longstanding partner of African Utility Week over the years. Why the decision by Eskom Rotek Industries to be a platinum sponsor?
We intend to introduce our industry service offerings, designed to support our customers with a range services throughout the entire power generation value chain:



8)    What will be your message at African Utility Week in May?
We invite all participants to come and visit us to learn and know more about our various service offerings and engage us on how we can assist with their power generating plants operation and maintenance practices.

9)     Anything you would like to add?
Excited to be part of the AUW and hoping for fruitful engagements.