October 2010 Update

 Hello and welcome to our October Update,

We are celebrating our 16th year in business and we are happy to say that things just keep getting better! Our team and capabilities are constantly expanding and we are excited about the opportunities ahead of us.  Read on to find out more of the projects and events we have been involved with in recent months. You can click on the headings below to go directly to the articles in the newsletter.

We are thrilled about our recent BOP Exporter of the Year win and are pleased that our international business is continuing to grow. We are involved in several exciting international projects in the coming months - watch this space!  Members of our team have just returned from Australia after providing engineering services at the Visy Pulp and Paper site.

The AIE team is growing, and in the last 2 months we have filled several vacancies across the organisation. Click on the links below to see our new team member profiles.

Our business capabilities have expanded in recent years with increasing demand from the power generation sector.  In August we assisted our customer in a plant shutdown of the Kawerau Geothermal Power Station. We were recently involved in the re-design and refurbishment of a G4 Vertical Turbine.  We also performed major works on the Southdown Steam Turbine located in Auckland.  Click on the links below to read more.

Allied Industrial Engineering is a community-focussed organisation and supports a wide range of individuals, groups and charities. Over the years AIE has encouraged the growth and development of various individuals and groups which benefits the wider community. This month we supported Loud Shirt Day, which raises funds for hearing impaired children. We also supported the Kawerau Woodfest and National Woodskills Competition. You can see more details on our sponsorship and community page on our website.  

I hope you enjoy reading this update, and we look forward to working with you in the future.

Mark Lovegrove

Refurbish of Components for a New Zealand Steel Mill
Repair of Turbine Diaphragms and Rotor Machining
Maintenance Shutdown at an Australian Pulp and Paper Site
G4 Vertical Turbine Overhaul
Maintenance and Inspection Shut at Kawerau Geothermal Plant
The AIE Team is Growing!
Loud Shirt Day at AIE
Kawerau Woodskills and National Woodskills Competition

Refurbish of East Fan Impeller and Suction Cones for a Steel Mill
AIE were recently commissioned by BlueScope to refurbish their KOBM East Secondary Vent Fan Impeller and Suction Cones during their planned outage period.

The East Induced Draught Fan components were showing typical signs of wear after over 2 years in operation at BlueScope's Glenbrook steel mill. BlueScope's fully integrated steel mill produces a range of flat steel products for both domestic and export markets. Around 90% of New Zealand's annual steel requirements are produced at the Glenbrook Mill, with production of about 600,000 tonnes per year.

The purpose of the Induced Draught fans is to eliminate the fume laden air that is emitted during the charging of the KOBM and from the Iron and Steel making ladles during the steel manufacturing process.

The iron is delivered by a kress carrier from the melters in a steelmaking ladle weighing approximately 125 ton. The ladle of iron is then processed at the Vanadium recovery unit (The VRU) in preparation for charge. The 70 ton of molten iron is then charged with a percentage of scrap steel into the Oxygen Steelmaking furnace (The KOBM). After approximately 25 minutes the steel is then tapped from the KOBM furnace into a Casting Ladle and is transferred to the Ladle treatment station (The LTS). Here the steel is then refined inside the ladle before being lifted up onto the turret for casting through the Continuous slab casting machine.

AIE was the preferred choice for this work as our team had built a trusted relationship with BlueScope during previous projects at the Glenbrook Mill. Previously, AIE had manufactured the East and West ID Fans, as well as other components such as fan shafts and hub assemblies for the Steel Mill.

AIE manufactured a complete new impeller for the ID Fan. The impeller was manufactured using a proven design that was developed by AIE on a previous rebuild. The re-design that was carried out by the AIE design team included developing a 3D model for FEA analysis that was then verified by an external third party. The re-design gave better operating efficiencies and with the application of a wear resistant metal spray in high wear areas, it is hoped that an extend service life beyond the current 24 month period can be achieved.

The Suction Eye Cones were beyond repair and needed a full replacement. We manufactured the cones in our workshops and metal sprayed the high wear zones to ensure an extended service life is achieved.

On final assembly, the fan had wear resistant deflector plates installed around the hub and mounting flange with all of the high wear areas of the fan finally being metal sprayed to increase the life expectancy.

The fan runner was then balanced in our workshops to ISO 1940 G1 (980rpm), and departed our workshop on time, within budget and met our customers expectations.

Bruce Byrom from BlueScope Steel says "I was very impressed with the finished product we received from AIE and am quite confident that the metal spray will extend the life of the impeller well past the current 24 months".

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Repair of Southdown Turbine Diaphragms and Rotor Machining
AIE were recently engaged to perform repairs to the steam turbine and associated diaphragms from the Southdown power station. The Southdown plant is a 175MW natural gas-fuelled, co-generation station capable of producing 1400GWh of electricity a year. At Southdown there are 3 gas turbines, 2 of which have an HRSG, the third is an open cycle unit. The gas turbines each drive a generator, which produces electricity. Heat recovery boilers capture the energy in the gas turbine exhaust gases to produce steam, which drives the steam turbine. The steam is then made available to the local industrial area near the station.

The scope of work included machining out the existing seals in the diaphragms, and then rolling, machining and fitting replacement seal strip carriers. This operation required AIE to develop specialised welding procedures in conjunction with an independent inspection organisation, and subsequent qualification of several members of our specialised welding team to these procedures.

The split line faces of the diaphragms were then machined in our CNC machining centre to ensure an acceptable fit of the mating surfaces was achieved. Following this, the diaphragms were assembled and set up in our vertical lathe to finish machine the new seal strip carriers.

After this process was completed, the new seal strips were caulked into the diaphragms, using a purpose made tool. The diaphragms were then reassembled on our vertical lathe to finish machine the new seal strips.

As our specialised welders had been qualified to the weld procedures, AIE was requested to perform on-site repairs to the turbine casing at the Southdown power station, south of Auckland.

During the refurbishment of the diaphragms, AIE received a call from our customer asking if we could assist with the repair of the steam turbine rotor as a crack had been discovered during the course of the non-destructive testing. Once the rotor had arrived at AIE's workshops, it was setup in our Super-Lathe, and an inspection was undertaken by the OEM Works Engineer to verify the severity of the crack and to determine the remedial work requirements.

The repair procedure required progressive machining of the rotor followed by in-house NDT verification and technical analysis by the OEM engineers at each stage of the machining process. This measured approach to the repair was used to ensure the integrity and performance of the rotor was not compromised. It became apparent that the crack in the rotor was far more significant than originally thought, and the decision was made to completely remove the third stage disc from the turbine rotor.

The repairs to the diaphragms and rotor were successful and our customer has reported that after machining the disc off, the expected power loss was not seen and apart from a slight efficiency loss, output remained as before.
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Maintenance Shutdown at an Australian Pulp and Paper Site
A team of AIE staff trades people travelled to Tumut in NSW, Australia to provide engineering maintenance services for the Visy Pulp and Paper Plant Digester Washer and Diffuser. The AIE team performed thorough maintenance checks to ensure the mechanical and operational integrity of the Upgraded Diffuser Washer. The Outlet Device and Top Separator were replaced on the Digester, and the internal screens were opened up for inspection and cleaning.  A skilled and experienced AIE crew of over 30 men worked in shifts around the clock for 9 days to minimise downtime for our customer.  AIE was the preferred contractor for this work because of our ability to provide competitive technical solutions, and a high standard of maintenance.  Our advantage is that we have a large manufacturing capability at our fingertips to produce or refurbish components within a limited time frame.

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G4 Turbine Overhaul
After the successful refurbishment of the G3 horizontal turbine at North Power's Wairua Falls site, McRaes Engineering again asked for AIE to be involved in the re-design and refurbishment of the G4 vertical turbine. The main issue that had been making this turbine very difficult to obtain operational reliability was silt seizing the wicket gates in the bearing pots on the bottom ring. This in turn was causing the external regulating ring to distort during operation. There was no access to the bottom ring bearing pots without dismantling the bottom of the scroll casing.

North Power's instructions for this project were:

• Provide a sealing arrangement for the top and bottom rings to prevent silt entering the bearing pots
• Provide a lubrication system to the bearing pots
• Design and build a regulating ring that is internal to the wicket gate spindles
• Design a linkage system that allows for easy adjustment of the guide vane position to ensure sealing strips contact one another
• Incorporate into the linkage system a mechanism to prevent damage to the guide vanes if there is an obstruction when trying to close

Together McRaes Engineering and Allied Industrial Engineering successfully undertook a complete redesign of the regulating ring, linkage and lubrication systems. Draft designs were continuously updated as we created fresh ideas to include reliability coupled with ease of maintenance.

The highlights of the final design were:

Externally removable bearing pots:

• There is no longer any need to dismantle the turbine to service the bearing pots. Each individual bearing pot can be extracted by the removal of three bolts.
• The bearing pots were fitted with high pressure seals where previously these were not in existence.
• The bearing itself has a drain, which ensures that any silt that bypasses the seal is expelled by grease during lubrication. The drain is a clear tube which allows the operator to see what is being expelled when lubricating the bearing pot.

A new regulating ring assembly was designed and subjected to Finite Element Analysis (FEA)

• The static ring was spiggoted to the top cover to ensure repeatable location
• The rotating ring had LG2 bushes cast and fitted to provide better reliability from any contamination.

Linkages were designed to provide a same plane direct transfer of energy from the hydraulic ram that actuates the regulating ring through to the guide vane spindles. There was no chance of distortion from cantilevered fixtures.

• Shear pins were designed and calculated to prevent any damage to obstructed wicket gates.
• Eccentric pins were supplied to aid in seal strip alignment

AIE were also asked to inspect and subsequently machine the runner shaft to improve alignment of the runner within the machine. Throughout the redesign of the turbine clearances were re-calculated between the runner and top and bottom rings to provide a more efficient water path.

The turbine was installed and then commissioned in October.
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Maintenance and Inspection Shutdown at Kawerau Geothermal Plant
In August we assisted our customer in a planned plant maintenance shut at their Kawerau Geothermal Power Station.  The purpose of the 7 day shutdown was to conduct the Risk Based Inspections (RBI) and PECPR inspections of pressure vessels, piping and other equipment. Also a number of Preventative Maintenance routines were carried out as part of their ongoing maintenance program.  AIE were engaged to oversee the complete shut process, which involved the co-ordination of third party inspection personnel and the management of approximately 25 subcontractors to ensure timely access to the plant items that required inspection. AIE also provided a detailed confined space hazard and rescue plan procedure for the shut, as well as the confined space personnel. In addition to this, AIE supplied Health and Safety personnel to carryout on-site audits for the duration of the shut.
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The AIE Team is growing!
The AIE team is constantly growing! In the last 2 months we have filled several vacancies across the organisation. Click on the roles below to see our new staff profiles:
Production Planner
Finance and Administration Manager
Engineering Estimator
Project Engineer
Sales Engineer

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Loud Shirt Day at AIE
Several of the AIE team took up the challenge to wear their loudest and craziest shirts to work in support of Loud Shirt Day. The aim of Loud Shirt Day is to raise funds for hearing impaired children in New Zealand. Loud Shirt Day was a fun way for the AIE team to support children with hearing difficulties, and substantial funds were raised.
  
Click here to view our community and sponsorship page

Kawerau Woodfest and National WoodSkills Competition
The Woodfest and National Woodskills Competition was recently held in Kawerau, and the National Woodskills Competition is recognized as New Zealand's premier event for carvers and turners.  AIE sponsored the College Age Category in the Woodskills Competition, which had many impressive entries from entrants aged up to 18 years. 

AIE also entered 2 teams into the 'Big Dig' challenge.  The Big Dig challenge involved 3 team members who had to shovel 3 cubic metres of woodchips into a large bin in the shortest time. Eight local businesses took part in the Big Dig challenge and the competition was fierce! The two AIE teams did well and placed second in the competition, but conceded that next year they would need to start training early for the event! Back to Top