Drypoint adds safety to aircraft manufacture

Citation

(2004), "Drypoint adds safety to aircraft manufacture", Aircraft Engineering and Aerospace Technology, Vol. 76 No. 1. https://doi.org/10.1108/aeat.2004.12776aab.006

Drypoint adds safety to aircraft manufacture

Drypoint adds safety to aircraft manufacture

Keywords: Aircraft, Manufacturing, Safety

China's largest commercial airline, China Southern, has purchased a Delta Tornado laser-cutting machine equipped with a Beak Dry point M Membrane dryer from MJ Technologies, of Coalville, Leicestershire, UK.

The laser cutter will be used to drill an array of tiny holes in aircraft components to enable them to maintain a stable temperature during the extremely high temperatures seen in service. The Dry point has been installed on the exterior of the Delta Tornado and extracts moisture from compressed air fed into the laser machine beam delivery – a vital part of maintaining its accuracy. The unit has now been shipped out to Shanghai (Plate 6).

The potential for huge losses and collateral damage from imperfections to manufactured components – particularly in the engineering of commercial aircraft has led the precision laser cutting industry to enforce strict regulations regarding the operation and maintenance of machinery.

Plate 6 Pictured is the Delta Tornado laser cutting machine from MJ Technologies, used to drill tiny holes in aircraft components to enable them to maintain a stable temperature during the extreme heats experienced in service. The Drypoint M has been installed on the exterior of the Delta Tornado and extracts moisture from the compressed air fed into the laser machine beam delivery

Particles are especially problematic and moisture entering the system aggravates the situation because particles are less easy to remove when damp.

With the Delta Tornado, removal of contamination particles is necessary to keep laser beam delivery optics clean. It is also important that no moisture is present within the work chamber as any particles created during drilling or cutting can become stuck to the dampened surface of the components. This could result in the component becoming scratched or damaged during production, a major problem in precision engineering.

A build-up of dust and particles within the works chamber can also, if not properly extracted by the machine's filters, cause contaminants to escape into the work place.

The Beak Dry point M reduces the moisture entering equipment from the compressed air supply, facilitating the removal of particles by other filters.

Beak Technologies explain that inside the Dry point M membrane dryer, filtered, moist compressed air inflows through a bundle of highly selective hollow-fibre membranes and, at the same time, the water vapour diffuses through the membranes to the outside. At the outlet of the Dry point M, a small part of the compressed-air flow is diverted and expanded for use as purge air. This purge air flows as a counter current over the outer surface of the hollow fibres. The difference in the water vapour concentration results in a constant migration of water molecules from the compressed air into the purge air.

The components of the Delta Tornado will work on complex aerofoil shapes – such as blades and nozzle guide vanes – that form part of the turbine section of the aircraft engine and are made of various nickel-alloy metals.

The purpose of the holes is to maintain the material in a stable temperature during the extremely high temperatures seen in service. Components are peppered with a myriad of tiny holes that vary in diameter between 0.3 and 3.0 mm, to facilitate the passage of vital cooling air. These holes have to be very accurate in shape, size, depth and angle.

Prior to the Dry point M being installed, MJ Technologies specified another make of dryer with its Delta Tornado. The Beak Dry point was primarily chosen due to performance and maintainability, although other benefits also included its smaller physical size, simplicity of design and its relative small cost.

Details available from: Beak Technologies Ltd. Tel: +44 (0) 1527 575778; Fax: +44 (0) 1527 575779; E-mail: beko@beko-uk.com; Web site: www.bekotechnologies.com