Buckland Paper Mill - Blowdown Vessel

Buckland Paper Mill, situated on Dover''s River Dour in Kent, originated in 1770.

It is now one of a number of mills owned by Arjo Wiggins Fine Papers Ltd, part of the Arjo Wiggins Appleton conglomerate. Buckland Mill produces 25,000 tons of fine quality paper from two paper machines, principally for its prestigious Conqueror brand of business stationery.

In 1994 Arjo Wiggins and Scottish Hydro-Electric, working together, designed and constructed a gas turbine powered Combined Heat & Power Plant. The Plant is used to generate electricity and steam for the papermaking process. Surplus power is exported to the National Grid.

The CHP Plant uses raw water from on-site wells to cool the boiler blowdown vessel. Within seven months of operation, up to 1½" of scale had accumulated on all surfaces in contact with the cooling water. Initially, the vessel was manually descaled which proved to be laborious and very time-consuming. Looking for an efficient and economical means of resolving the problem, CHP Engineer Alex Fraser examined a variety of other options.

Water treatment equipment was considered. However, the initial capital expenditure, together with additional costs and environmental considerations of using chemicals for regeneration, along with difficulties of plant layout, made this unattractive. Chemical descaling, another option, was also found to be too expensive and was not in accord with Buckland Mill's BS7750 accreditation.

ENiGMA technology appeared to provide Alex with a cost-effective solution and a two-month trial was arranged. The trial unit was installed on to the 1½" cooling water line to the blowdown vessel. A small area within the vessel was cleaned and the remainder left scaled-up to demonstrate the unit's ability to reduce existing scale in addition to preventing its formation. Regular inspections were carried out during the trial period and record photographs taken. It was noted that not only had the ENiGMA system halted the scaling process but it was also actively descaling the vessel.

Buckland Mill has now purchased the ENiGMA and is considering other applications. Alex Fraser commented: "We are extremely pleased with the ENiGMA system and the claims made by Environmental Treatment Concepts Ltd are quite correct. We are delighted to have found an environmentally-friendly means of treating what was an undesirable and labour-intensive problem".