Weardale

Location:

Clinker manufacture operational: 7/6/1965 to 9/8/2002

Approximate total clinker production: 22.2 million tonnes (19th)

Raw materials: quarry at 394400,536900 in the Carboniferous Limestone Stainmore Formation yielding (top to bottom)

Ownership:

Sometimes called Eastgate Works. It had the first of the new generation of larger Lepol kilns to be installed in Britain and Ireland, with similar kilns subsequently installed at Dunbar, South Ferriby and Cookstown. A1 was briefly the largest kiln, until overtaken later in 1965 by Westbury A2. Although a suspension preheater system was suitable for the raw materials, it would appear that a Lepol system was adopted because quality problems then being encountered at Plymstock were mistakenly attributed to that plant’s kiln system.

In contrast to other plants, the raw materials were ground at the quarry. This meant that there was no scope for use of kiln waste heat for raw material drying. The rawmill heat consumption was typically 0.40 MJ/kg. The standard combination of oil-heated Aerofall mill and “double rotator” regrind mill produced rawmix which was transferred from the hill-top quarry to the plant on a sloping belt conveyor. Blending then took place at the plant.

On the closure of Humber, Weardale took over the production of sulfate resisting clinker alongside ordinary clinker (1980-2002), resulting in a slight reduction in efficiency. It was the first dry process plant to attempt this. Tyres were used as a fuel supplement from 1985 onward.

Although remote, the densely populated areas of the Durham coalfield were within 25 km to the east. The plant had a rail link running only eastwards. The up-rating of Dunbar and Hope, the general market reduction by the end of the 20th century, and a comparatively small reserve of good raw material brought about the plant’s closure. The site has now been cleared.

Please contact me with any relevant information or corrections. I am particularly interested in firmer dates and statistics.

Power Supply

The plant was entirely electrically powered from the grid from the outset.

Rawmills

One 1350 kW Aerofall mill for coarse grinding and two Polysius 900 kW double-rotator mills for separator rejects regrind.

Two rotary kilns were installed:

Kiln A1

Supplier: Polysius
Operated: 07/06/1965 – 09/08/2002
Process: Semi-dry: Lepol 27.7×3.91 m grate
Location: Hot end 394670,538476: Cold end 394611,538464: entirely enclosed
Dimensions: Metric 60.00 × 3.916BC / 4.351D
Rotation (viewed from firing end): anti-clockwise
Slope: 3.5% (2.006°)
Speed: 1.1 rpm
Drive: 134 kW
Kiln profile: 0×3519: 911×3519: 1811×3916: 49036×3916: 52311×4351: 59011×4351: 59620×3640: 60000×3640: Tyres at 4700, 27200, 47700: Turning gear 44700.
Cooler: Recupol P 2019 grate
Fuel: coal, from 1990 up to 60% replaced with petcoke. These were supplemented with small amounts of liquid wastes from 1982 and tyres from 1984.
Coal mill: direct: PHI 75 kW MPS100 roller mill
Exhaust: two parallel Western Precipitation electrostatic precipitators before the ID fan.
Typical Output: 1965-1972 924 t/d: 1973-1983 1071 t/d: 1984-2002 1014 t/d
Typical Heat Consumption: 1965-1975 3.56 MJ/kg: 1976-1988 3.39 MJ/kg: 1989-2002 3.50 MJ/kg


Kiln A2

Operated: 14/10/1965 – 09/08/2002
Location: Hot end 394666,538493: Cold end 394607,538482: entirely enclosed
Typical Output: 1965-1972 914 t/d: 1973-1983 1063 t/d: 1984-2002 1037 t/d
Typical Heat Consumption: 1965-1975 3.53 MJ/kg: 1976-1988 3.40 MJ/kg: 1989-2002 3.50 MJ/kg
Identical in all other respects to A1.



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