Thorne installs fettling and dust extraction package at Fischer
02nd June 1996

J.B.Thorne of Leicester has just supplied six fettling benches with all associated dust extraction equipment and ducting to George Fisher of Lincoln, which operates one of Europe's most modern foundries. In a recently completed £25 million investment programme, Fischer has doubled production capacity at the Lincoln Site, where it produces SG and grey iron castings for major names in the international automotive industry. The company has installed other Thorne units in the past as part of its continuing drive to achieve the best possible internal and external environments at its works.

The six fettling benches supplied by Thorne are served by two reverse jet Autoflo units, with filters continuously cleaned by downblasted compressed air in 60-second cycles. The larger AFM 252 unit is sited outside the building, and is powered by an externally mounted fan which draws dust-laden air into the filter system.

Dust is then deposited through rotary valves into sealed bags, thus completely eliminating the risk of secondary contamination. Cleaned air is vented to atmosphere through vertical ducting.

A smaller AFC 162 Autoflo unit is sited inside the factory, serving the three smaller fettling stations, with metal dust deposited into bottom-mounted roll-out bins. This unit is fitted with a top-mounted high-efficiency particle arrestor (HEPA) giving a total system operating efficiency of 99.997% This means that cleaned warm air may be vented straight back into the factory area.

Both units feature filter media which is very effective in coping with problematical dusts such as those encountered at George Fischer. The filters used have been the subject of intensive research and development by J.B.Thorne. The design keeps system resistance losses to a minimum, resulting in higher efficiency an less power use. It also increases the interval between filter changes.

All equipment in the Autoflo range may be sited either externally or internally, and can be specified from small individual units to total turnkey systems. The Autoflo AFT/AFC series has been designed to use either tubular or cartridge filters in the same casing, a feature thorne believes to be a 'first' for the industry.

Because of its modular design, the new Autoflo offers much greater flexibility of size than existing units, while the cleaning system has been redesigned to make more effective use of compressed air.

By incorporating major modifications to the conventional system, the cleaning process drastically reduces the risk of overloading the cleaned filter, thus improving the life of the filter media.

Autoflo units are believed by the company to be unique in that they have an internationally patented failsafe dust filter seal, making it virtually impossible for dust to leak through, even when the seal is damaged.

J.B.Thorne can supply wet and dry dust extraction equipment for all dust problems. In addition, it designs systems of all sizes for external and internal use, from complete turnkey installations to individual units. It also supplies hoods, ducting, and a range of special work benches and laminar flow booths. All thorne systems meet current COSHH requirements, on which the company is qualified to give up-to-date advice. Thorne also carries out mandatory testing on installations when this service is required.