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ISSUE 04-05 / 2001 |
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| Bottle Making | BACK to contents |
FROM MINES TO MINERAL WATERS
Profile of a compressor manufacturer
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| Ateliers Francois of Liège, Belgium,offers a complete range of 40 to 45 bar oil-free 3-stage compressors with the Project Department also engineering compressor packages to suit special needs. | |
Ateliers François is a company that has really specialised in the manufacture of 40-bar compressors for the PET industry and has become one of the major suppliers in our business. They currently produce in excess of 100 machines per annum, of which 99 percent are destined for PET bottle blowing.
The privately owned company started in Liège in 1870, making pneumatic hammers for use in the local mining industry. The first oil-free reciprocating compressors were developed in the 1960s and proved very successful in the brewing, chemicals and food industries. It was in the early 80s, with the emergence of PET as a major new material in the packaging industry, that Ateliers François produced their first 40-bar oil-free piston compressors. Turnover is now some 22.5 million.
“L” shaped design
The PET compressors built by Ateliers François are all 3-stage compressors of the distinctive “L-shape” layout, with initial compression of 4 to 5 bar being carried out by one large, double-acting, vertically arranged piston. Stages 2 and 3 are carried out by two horizontal pistons mounted on the same piston rod, each of which is single acting, with the compression stroke of piston 3 on the outer end of the horizontally-arranged cylinder. All three pistons are driven by one centrally mounted crank-shaft which in turn is powered by an electric motor, of up to 500 kW where required. As explained by Georges Alard, Commercial Director of Ateliers François, having pistons 2 and 3 on the same piston rod means that the 40-bar stage (piston 3) does not require piston rod air packing seals between the 40-bar compressed air and atmosphere. The only packing required is on the horizontal piston rod, against the second stage piston compression of 14 to 15 bar, thus totally eliminating the 40 bar stage packing.
Georges Alard sees the uncomplicated design as a key reason for the success
of AF compressors. The “L” shaped layout makes it possible for the number
of moving parts to be reduced to a minimum. There are only two cross-head
assemblies with two piston rods and associated bearings. The fact that the
pistons at stages two and three are single-acting also means that a minimum
number of valves are required. The quantity of air delivered by the very large
diameter stage one piston allows the compressors to run at only about 500
rpm, helping to extend the life of the parts, and is regarded by Georges Alard
as a major advantage of this design. There is an “inter-cooler” with moisture
separator between each of the stages plus an “after-cooler” between stage
three and the air receiver. Smooth running of the oil-free compressors is
provided by PTFE compression and bearer rings which inevitably results in
some particulate deposits that are removed at each stage together with the
moisture. Air drawn off by the SBM machine finally passes through a stainless
steel refrigeration dryer which incorporates a 0.1 micron filter to remove
any solid particles which may remain. Compressors are installed on anti-vibration
mounts, which eliminates the need for special concrete foundations to be laid.
The current product range offers free air delivery from 192 m3 to 3000 m3 per hour.
Global expansion
The first major PET installation, supplied by AF 15 years ago, was for the Spa Monopole mineral water bottlers in Belgium. Since that time the 10,000 m2 plant in Liège has been completely rebuilt and modernised. Today Ateliers François has some 700 machines in operation around the globe and can number among its clients international soft drinks producers such as Coca-Cola, Pepsi-Cola and Perrier as well as the major blow moulding machinery manufacturers and container suppliers. The company has established subsidiaries in the USA, Mexico, Thailand, Tunisia, Malaysia and Russia to provide sales, parts and technical back-up to customers and distributors world wide, Currently employee numbers total around 100. As well as holding parts stocks at the subsidiary companies a separate parts supply operation has been set up in close proximity to the airport at Liège for rapid response to replacement parts requirements around the globe.
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