MAN Diesel & Turbo South Africa, the compressor and turbine blade manufacturing subsidiary of European multinational MAN Diesel & Turbo SE, based in Augsburg, Germany and one of the world’s leading providers of large-bore diesel engines and turbo-machinery for use in marine and power station applications, has been gearing up to seamlessly transform the local operation into a Center of Excellence for turbine blade manufacture, while at the same time going beyond its usual markets and vigourously entering the power generation arena.
In 2004 MAN Turbo AG of Oberhausen, Germany opened up a South African subsidiary, in a deal facilitated by Ferrostaal. The investment in the manufacturing facility was linked to the industrial participation and offset investment commitments of the defence procurement programme. At the time Ferrostaal was an industrial services company in the MAN Group, and was the commercial partner in the German submarine consortium that supplied three U-209 submarines to the South African navy.
MAN Diesel & Turbo South Africa has seen progressive growth over the last ten years servicing the MAN fleet of compressors, expanders and steam turbines
MAN Diesel & Turbo South Africa manufacture a range of blades
Through various acquisitions and sell-offs MAN Turbo AG subsequently became MAN SE, and in 2009 the International Petroleum Investment Company (IPIC) of Abu Dhabi acquired over 70% of the shares of Ferrostaal AG from MAN AG. In March 2012 MAN SE sold the remaining shares in Ferrostaal.
The South African plant is situated in Elandsfontein, east of Johannesburg near the East Rand. The facilities include 3 000 m² of workshops and offices, 30 ton lifting capabilities, complete machining facility for blade production, service and repair, sandblast, shotblast and spray painting facilities.
At the time Rico Taxer, MAN Turbo South Africa’s managing director, said its turbine blade exports were worth about R40 million a year. Its long-term strategy was to increase these exports and the workforce. It has certainly done so if current expenditure on capital equipment is anything to go by.
Blades are manufactured for aircraft engines and power generating turbines
Laser-based refurbishment, based on laser cladding technology, is now available on the factory floor at MAN Diesel & Turbo South Africa
When the company opened in 2004, the installation of a new Deckel Maho DMU-100T 5-axis machining centre to manufacture the turbine blades in titanium and various other alloys, was the pride and joy of the modern facility. The installation included special software for machining of the blades, and combined with the NC swivelling head (B-axis) allows true constant surface speed, faster cycle times and increased tool life.
Other features of the machine included a laser type tool measuring system, a Renishaw infrared measuring inspection probe and a minimum lubrication system.
The versatility and flexibility of the Deckel Maho T-Series machines also allows for other complex machining of components, including large impellers and other related components used in both the turbine, aerospace, marine and related industries. The machine was commissioned by Retecon Machine Tools.
Such was the success of this machine and the growth in the company’s local and export business, MAN Diesel & Turbo South Africa invested in a further three Deckel Maho CNC machining centres, two Heller CNC machining centres and two Dah Li CNC machining centres. Further investment included a Leadwell CNC machining centre.
The company stocks a sizeable amount of bar which is cut to size on an Everising -H560 HA column type bandsaw supplied by First Cut
MAN Diesel & Turbo South Africa have invested in Deckel Maho CNC machining centres, Heller CNC machining centres, Dah Li CNC machining centres and a Leadwell CNC machining centre
The local operation manufactures in the region of 150 blades a day, which are used on new or refurbished compressors and turbines. Included on the machining side are spacers, which are used when there is no foot machined on a blade.
With the blades working in situations of up to 12 000 RPMs, all of them are machined from solid blocks. The blades manufactured locally are up to 700 mm in length.
The process starts off in the blocking department where imported material is cut to size and then rough machined on conventional milling machines. From there it moves to the high tech equipment where each individual blade has to be machined to 20µ tolerance, before moving through inspection and polishing.
The blades are then either exported back to the parent company in Germany, or used locally in the assembly of axial and centrifugal compressors and gas and steam turbines used in the power generation, refinery, blow furnace and sugar mill industries.
Further capital expansion has been put into the quality department. This includes acquiring a 7-axis Romer measuring arm. Looking after this department are Bryan Hollingshead and Derek West
A new Technifor laser etcher is used for marking and traceability
Other equipment included the investment in a DEA 3D Global coordinate measuring machine and other state of the art inspection equipment.
Where previously MAN Diesel & Turbo South Africa had to contract out for the dressing of shrouds and labyrinth seals when refurbishing large compressors and turbines, the company can now perform this machining function inhouse. The arrival on the floor, from the parent company, of a refurbished Heyligenstaedt CNC lathe, now performs this operation.
Also sent from the parent company at the same time was a refurbished special purpose 5-axis Starrag CNC machining centre that has five spindles and five heads. This machine is being used for the machining of the blade profiles and the transition area on the blade.
The company now has fourteen 3, 4 and 5-axis CNCs.
All this expansion meant that the company had to keep up in the design office, which is used mainly for the design of components for replacement when carrying out repairs, and for the interpretation of drawings from Germany.
Turbocharging turbine and turbo replacement component manufacturing
In recent years the company has built a thriving turbine and turbo machinery replacement component manufacturing operation. Requests for parts and complete replacement components stream in from South Africa’s power generation and chemical industries, either directly from the customer or via MAN PrimeServ, the division which the local operation falls under. But that’s not all.
MAN Diesel & Turbo South Africa have recently installed a DMG tool pre-setter supplied by Retecon Machine Tools
“The new Liechti Turbomill machine allows us to machine blades up to 1 350 mm in length, which is a big advantage. To give you a comparison, the blades used on the turbines at the Koeberg nuclear plant in the Western Cape are only 1 280 mm in length.”
Part sizes range from 25mm long to 1200mm long. Orders range from a few replacement blades to thousands, or for all of the turbine components needed to rebuild a massive steam or gas turbine. The equipment that needs to be repaired or rebuilt can be decades old. So frequently there are no drawings to work from. These are the conditions that the company deals with week in and week out.
Charles Swart, Production Manager for the turbine component manufacturing operation, said the company has learned to cope with these diverse challenges by investing heavily in the best available CNC manufacturing technology.
“The equipment is kept operating productively by using the advanced capabilities of Mastercam® CAD/CAM software. The CNC programs are written by one full-time Mastercam programmer and by myself. I estimate that the amount of work moving through my operation has increased by about 40% over the past five years. However, we have been able to keep up with the ever-increasing program generation requirements by relying on the flexible CAM software features that allow for ongoing improvement of CNC programming and manufacturing productivity,” explained Swart.
Charles said the engineering department has an exceptional level of proficiency in reverse engineering of worn or damaged turbine components, using scanned data as the basis for creating SolidWorks models that the programmers import into Mastercam as the starting point for CNC manufacturing programs. This information is then pulled off the server as an IGES or Parasolid file. Translating the model into Mastercam is always clean, so there is no need for further discussions with the engineers about design intent. Charles says this is a big time saver and keeps work moving forward.
MAN Diesel & Turbo South Africa Production Manager Charles Swart
Besides manufacturing and refurbishing blades, MAN Diesel & Turbo South Africa is capable of refurbishing complete systems for clients
With an eye toward transforming models into effective manufacturing programs as quickly as possible, Charles and his programmers have standardised their CAM programming process so that each always understands what the other has done. These standards ensure that CNC programming is efficient, machine utilisation is high, and CNC equipment operates at reasonably high cycles with barely any scrap.
Some of the principles the company has adopted to facilitate this high throughput CAM workflow include:
Pull toolpaths from parts with similar geometries: The part files contained on the MAN Diesel & Turbo file server contain hundreds of manufacturing programs that can be used as guides for programming parts with similar geometries. Toolpaths and other manufacturing strategies can be readily translated from an older manufacturing program to a new one.
Incorporate standard workholding fixtures: Most of the CNC programs written at MAN Diesel & Turbo incorporate standard work holding fixtures that are visible within Mastercam, allowing the program to be refined so that ideal clearances are visualised and established within the program. Parts in the manufacturing queue are set up in the fixtures ahead of time so that it is only a matter of minutes to snap the next one onto the CNC machine and keep cutting chips. Efficient setups dramatically improve productivity but put pressure on programmers to stay ahead of the manufacturing equipment.
Use tool libraries to reduce programming time: In more than 95% of the cases, the same special blade material is used. Hence the use of a tool library is beneficial. The library contains tested and proven speeds and feeds calculated for the specific tool. Keeping up-to-date information in tool libraries means that this information can be quickly entered into the program instead of having to use complicated formulas to calculate the best settings.
Always keep the CNC program in Mastercam: When simple changes come down from engineering, or tweaks are required to the program to improve a part’s manufacturability, it is tempting to change the CNC code at the machine’s controller. This is a temptation that Charles and his programmer avoid almost without exception. By always making manufacturing program changes within Mastercam, programmers have the option to post the program out to any machine in the shop, whereas programs that were modified at the code level can only be run on the machine at which the program was modified.
Pre-inspect processes and parts using simulation and STL-Compare: The two programmers routinely use simulation within Mastercam to identify tool and holder interferences and to make sure all of the material has been appropriately removed from the part. They also use Mastercam’s STL-Compare feature to compare the STL file generated by Mastercam to the actual part model. This high-resolution comparison is so realistic that it is possible to visually detect potential blemishes on the part’s surface just by looking at its image on the computer screen.
Eliminating air cutting: Traditional toolpaths can sometimes generate large amounts of “air cutting” due to inefficient tool movements or because the toolpath thinks there is material present where, actually, there is none. This is not much of a problem if there are only one or two parts to make. However, air cutting can greatly impede productivity if there are many of the same part in the manufacturing queue. When excessive air cutting is detected in a long part run, Charles goes back into Mastercam and uses simple graphic programming tools to define these areas on the part where it is occurring and refine tool movement to reduce it.
Get help for challenging process problems: The company’s maintenance license for Mastercam entitles it to free upgrades to the software and as-needed technical support from Mecad Systems, the nearby Mastercam Reseller. In most cases the programmers will get answers by phone or email to resolve programming issues within hours. Mecad has also collaborated with MAN to resolve more complex technical issues. For example, it helped the company devise a 5-axis cutting process for long, steeply curved blades that require long tools to reach deep surfaces. A unique cutting motion generated from within Mastercam improved the approach of the tool to minimize vibration and achieve high rates of productivity without sacrificing quality. “This was a very big success for us,” Charles said.
Growth through acquisition
In November 2013 the company entered into an agreement to acquire 100% of the shares in the family-owned Elca Engineering (Pty) Ltd.
At the time, the incumbent CEO of MAN Diesel & Turbo SE Dr. René Umlauft stated: “This acquisition underlines our growth strategy in Africa and enables us to offer an even broader range of services in the Sub-Saharan region.”
MAN Diesel & Turbo South Africa have employed Mastercam® CAD/CAM software to operate their CNC machines
MAN Diesel & Turbo South Africa have employed Mastercam® CAD/CAM software to operate their CNC machines
With a strong customer base, excellent reputation and more than 45 years of experience, Elca Engineering will keep on serving customers under its established brand name. Elca mainly provides repairs, servicing and overhaul of compressors, turbines, blowers and pumps, supported by a well-recognised team of field service engineers with experience throughout the entire African continent.
Company prepares to expand and further invest in turbine blade manufacturing – Adds cutting edge technology to its manufacturing capabilities in anticipation of increased demand
Holding company MAN Diesel & Turbo SE has now decided to invest in its blade manufacture operations in South Africa to support the three locations it currently occupies, which include Zurich, Switzerland and Oberhausen, Germany.
“We are very proud that our location in South Africa has been afforded such large investments, and will be considered on par with the locations around the world. This will entail setting up a Center of Excellence in Elandsfontein, Gauteng, which we are currently busy with and are scheduled to move into in mid 2015,” said Gary Muller, MAN Diesel & Turbo South Africa’s Sales and Operations Manager Blades.
“MAN Diesel & Turbo South Africa has seen progressive growth over the last ten years servicing the MAN fleet of compressors, expanders and steam turbines. To continue our growth in the blade manufacturing industry and secure further market share, we are constantly looking at new technologies and how to incorporate them into our production. We look for innovative features and processes that will improve our quality, reduce our delivery time and improve our flexibility,” Muller continued.
“As our market regions have grown and our customer requirements have changed. We see the need to increase our capacity, and at the same time reduce our costs before passing this benefit forward,” explained Muller.
New 3 500m² manufacturing facility
“Besides the new 3 500m² manufacturing facility that is being built adjacent to the current building, we have invested in a high-end Swiss made Liechti Turbomill 1400g CNC turning/milling machine. Our machine arrived in December 2014 and was commissioned and operational for the new production cycle in January 2015.”
“The Turbomill is a single spindle 5-axis machining centre for high precision machining at high feed rates. The machine is used for rough and finish machining of complex shapes as needed in the blade manufacturing environment.”
“The machine is highly specified with some notable capabilities. A high speed milling spindle, with integrated vector-controlled motor allows high-torque roughing with low spindle speeds, as well as finish cuts with high speeds and feed rates. The unique axis arrangement takes into consideration the different dynamical requirements for the various axis by appropriate mass distribution, so that the most dynamic axis has the lowest mass. The g-Double end part rotary drive uses a rotary drive instead of the tailstock to drive the tip end of the work piece. The drive is powered by a separate torque motor, which runs synchronous over the CNC control to the root end drive.”
“Our partnership with Liechti Engineering, which is now a GF Machining Solutions company, will help us achieve our goals and those of our customers. We will use the experience and knowledge from our Zurich and Oberhausen locations to ensure a successful setup of the Centre of Excellence.”
“It is envisaged that a further two 5-axis machining centres will be added to the shopfloor once we are in our new facility, and this will give us the capacity to manufacture in the region of 300 tons of blades annually. We currently have a capacity of about half that amount.”
“In addition, we have put further capital expansion into the other operations of blade manufacture. This includes acquiring a 7-axis Romer measuring arm, a DMG tool pre-setter and a laser etcher for marking and traceability.”
“Another exciting development has been the purchase of a 3D printer whereby we are now able to print a sample in three to four hours. Previously it took over a week to deliver a sample to a client.”
Power generation development – going beyond the usual markets
“Another new development is that we have started a drive to enter the 3rd party blade manufacturing arena with a particular emphasis on the power generation market. In this industry we need to ensure that we have suitable machining capabilities to service this market. We are confident that this first Turbomill with its maximum part length of 1 350mm will help us serve customers in this market.”
“The new Liechti Turbomill machine allows us to machine blades up to 1 350mm in length, which is a big advantage. To give you a comparison, the blades used on the turbines at the Koeberg nuclear plant in the Western Cape are only 1 280mm in length.”
“An example of how we have improved efficiencies since we introduced the one operation machine is that we have improved machining times by over 60%. Components that used to take us three hours of machining time have been reduced to one hour, and another one that took 40 minutes is now done in 15 minutes.”
Today the company employs approximately 140 staff in Elandsfontein, 150 in Vanderbijlpark where Elca Engineering are based, 40 in Cape Town and 10 in Durban. The company also has a branch in Kenya and will shortly be opening one in Namibia.
For further details contact MAN Diesel & Turbo South Africa on TEL: 011 842 0700 or visit www.mandieselturbo.com