Productivity takes off at aerospace plant thanks to coolant centrifuging

Productivity takes off at aerospace plant thanks to coolant centrifuging from LUBRISERV LTD

By: LUBRISERV LTD  25/01/2011
Keywords: machining, filtration, industrial lubricants

By using an Alfa Laval high speed centrifuge has helped the Airbus plant at Broughton, Flintshire eliminate coolant fouling and improve productivity.

In the UK, AlfaPure Z3 coolant treatment systems have helped the Airbus plant at Broughton, Flintshire eliminate coolant fouling and improve productivity.

Assembling wings for Airbus family
Airbus’s Broughton site assembles wings for the whole Airbus family of aircraft. Crucial to the construction process are alu-minium stringers which provide strength and flexibility. From 15 – 21 metres long, these are machined from solid billets on a Dorries Scharmann CNC machine. Most of the aluminium is removed in large sections, until only the strong, flexible core material remains. Typically, component tolerances are accurate to +0 -150 microns on the horizontal surface and +3 mm on a 21 metre length of material.

Tramp oils entrained in the coolant
Machining a 15 metre billet of 20/26 aluminium takes approximately 4.5 hours. 27,000 litres of water-based Castrol Alusol. A coolant cascade continuously over the workpiece to maintain the operation at the correct temperature. However, tramp hydraulic oils can become entrained in the coolant along with swarf and other metal fines. The two are separated in a series of settling tanks but, although this decontaminates the swarf and the solid scrap, it does not clean the coolant itself. In the past, this contaminated coolant caused severe problems.
 Tramp oil tended to leave a film on the cylinders inside the CNC machine which allowed foreign objects to adhere to them. Dealing with these problems was both time and labour intensive. Airbus’s stringent Health & Safety rules meant that the whole line had to be shut down to enable the interior to be manually cleaned, resulting in a significant loss of production.

AlfaPure Z3 cleaning system from Alfa Laval
Airbus engineers initially solved the problem by replacing the coolant at frequent intervals. Thanks to coolant costs and the need to employ specialist contractors to handle the waste, this proved to be expensive. Consequently, they evaluated several different coolant-recovery methods before settling on the AlfaPure Z3 cleaning system from Alfa Laval.

Unscheduled downtime eliminated
The AlfaPure Z3 is a compact unit that uses high speed centrifugal force to separate liquids and solids. The machine in Airbus’s stringer manufacturing shop continuously cleans 3,000 litres of Alusol A coolant per hour and returns it to the production line. Since it was installed they have eliminated the problem of bacterial growth and, most important of all, any unscheduled breaks for clean-up operations. In the two years the AlfaPure Z3 has been operating,
Airbus has had to purchase coolant only to top up fluid lost to atmosphere or on workpieces or scrap.
A second AlfaPure Z3 module is also in operation in the wing spar production plant, where it is used to clean and recycle a water-based coolant, Cimstar 560, which cools an Ingersoll machining centre, the largest of its kind in the world.

Lubriserv are the UK Distributor for Alfa Laval mobile centrifuges
Please visit us for more information:
Tel: 01302 723131

Keywords: CNC coolant, Coolant Centrifuge, Coolant Cleaning, coolant recycling, Coolants, filtration, industrial lubricants, machining, Metalworking Fluids