Sittingbourne

Location:

Clinker manufacture operational: 1858-11/1970

Approximate total clinker production: 6.8 million tonnes

Raw materials:

Ownership:

Also known as Smeed & Dean’s and Murston Works. Smeed, Dean and Co. were a horizontally-integrated company producing cement, lime, bricks, fruit and jam. The company was the largest producer of London Stock bricks, and the brick plant at Sittingbourne, at one time Britain’s largest, continues in business today. Currently owned by Weinerberger, it is still called Smeed Dean Plant. The stock brick process used both clay and chalk, and Portland cement making was started as a sideline in 1858, with wet process bottle kilns. By 1876 there were eight of these, making around 220 t/week. Another 12 had been added by 1898, giving a total capacity of 550 t/week. Around the turn of the century, the plant's capacity was greatly expanded by installation of Batchelor kilns. During 1900-1902, the bottle kilns were replaced with three blocks of six Batchelor kilns (581 t/week). During 1906-1909 a range of 23 more was added (607 t/week). Davis’ 1907 capacity of 600 t/week is an underestimate; it was 740 t/week by the end of 1906. A further range of 15 was added in 1911 (312 t/week), and another 16 were added in 1921 (422 t/week), the latter being among the last chamber kilns to be installed in Britain. These remained in operation until the rotary kilns were installed, continuing the practise of 6-day working until 1924. The renovation of the plant by FLS began with installation of new cement silos and packing plant in 1921, and the rotary kilns, complete with power plant, coal handling and finish mills, from 1926. The plant was shut down during WWII from 9/1941 to 1945. The original coolers (dimensions unknown) were replaced with recycled Wouldham (Essex) kilns in 1940 and 1948. The plant never had a rail link, and used the increasingly silted Milton creek for water transport originally. Available reserves were nearly exhausted by 1970 and the plant was one of those earmarked for replacement by Northfleet. The cement plant site was cleared in 1973 and redeveloped. The clay pits are flooded, and the chalk quarries are waste land.

Power supply

The original plant was entirely direct-driven by steam engine, and this continued until the re-build in 1926, when the plant was largely electrified (other than the chalk quarry washmills, still driven by steam), using power from a 2 MW turbo-generator. From 1946, grid power was used, and the chalk quarry was electrified.

Rawmills

There were two washmills and two screeners at the first chalk quarry producing chalk slurry that was pumped by 3.1 km pipeline to the plant. A similar but larger system was subsequently installed in the second quarry. Chalk slurry was stored at the plant site in the original slurry backs, and it was combined with clay in a further washmill and screener.

Two rotary kilns were installed.

Kiln A1

Supplier: FLS
Operated: 5/1926-30/11/1970
Process: Wet
Location: Hot end 591909,164746: Cold end 591956,164796: entirely enclosed.
Dimensions, metric:

Rotation (viewed from firing end): ?
Slope: 1/25 (2.292°)
Speed: ?
Drive: ?
Kiln profile:

Cooler: rotary 59’6”× 6’3½” (metric 18.14 × 1.918) beneath kiln: second-hand (ex Wouldham kiln), installed 1940: previously ? (Note 1)
Cooler profile: 0×2235: 1168×2235: 1778×1918: 18136×1918: Tyres at 3048, 13919
Fuel: Coal
Coal mill: semi-indirect: ball mill
Exhaust: initially direct to stack: ID fans were installed in 1936, and around 1964, two parallel Unit Precipitators were installed after the fan.
Typical Output: 1925-1936 140 t/d: 1936-1950 165 t/d: 1950-1970 232 t/d
Typical Heat Consumption: 1925-1936 8.28 MJ/kg: 1936-1950 7.85 MJ/kg: 1950-1970 7.40 MJ/kg


Kiln A2

Operated: 9/1927 to 30/11/1970
Location: Hot end 591917,164738: Cold end 591964,164789: entirely enclosed.
Cooler: as Kiln A1 - original replaced in 1948.
Typical Output: 1927-1936 140 t/d: 1936-1950 159 t/d: 1950-1970 227 t/d
Typical Heat Consumption: 1927-1936 8.16 MJ/kg: 1936-1950 7.87 MJ/kg: 1950-1970 7.44 MJ/kg
Identical in all other respects to A1



Sources:

Note 1. Ihave been unable to establish for certain the nature of the original coolers. The contemporary FLS installations of West Thurrock No.3, Billingham No.1, Lewes and Bevans No.4 were all Unax, and the replacement of the kiln nose with a cone, complete with tyre, presumably by Vickers Armstrong, also suggests this. On the other hand, the arrangement of tyres and the possibilities for clinker handling suggest the earlier concentric rotary cooler design. Maybe someone knows, but the details were not retained at Dunstable for some reason. Also undiscovered is the reason for the timing of the replacement during WWII, when major projects were not usually undertaken. It might have been a desperate response to bomb damage, but the plant shut down anyway in 1941. I have found nothing in newspapers, but such news tended to be suppressed.