Metropolitan

Location:

Clinker manufacture operational: 3/1937-4/1970

Approximate total clinker production: 7.8 million tonnes (44th)

Raw materials:

Ownership:

The Metropolitan Cement Company was established by a consortium of Vickers Armstrong and Balfour Beatty, with a view to supplying the latter with cement. A small site was obtained crammed into a corner of the Thurrock Chalk and Whiting Company’s quarry. The plant was acquired by Alpha while still under construction, and was re-organised with calcinators as favoured by Alpha. The plant shared its chalk supply with the adjacent Lafarge calcium aluminate cement plant, and the whiting company. Following the takeover of Alpha by the APCM / Tunnel consortium, Metropolitan was administered by Tunnel, the other Alpha plants being run by APCM. Tunnel used the plant as flexible capacity, shutting it completely in 1941, but re-opening it following air-raids on the West Thurrock plant. It was shut again during 1944-1946. Following APCM’s acquisition of Tunnel’s holding in Alpha in 1949, APCM assumed control. Kiln A1 was removed in 1952 and used as part of Magheramorne B3. This seems to have been part of the deal with Tunnel, to limit the plant’s output, but the remaining two kilns continued to be operated flat out, even in years when other plants were cutting back because of market conditions. Facilities for oil firing were installed in the 1960s, but never used. Closure followed the start-up of Northfleet. The plant had both rail and river transport from the outset. The site was cleared after closure and is now a trading estate. The wharf is still called Alpha Wharf.

Power supply

The entire plant was electrically driven, using power purchased from the grid from the outset.

Rawmills

Chalk brought by rail was inter-ground with clay slurry in two washmills and two screeners.

Three rotary kilns were installed:

Kiln A1

Supplier: Vickers Armstrong
Operated: 1/3/1937 - 1952
Process: Wet: calcinator
Location: hot end (cooler ports) 557217,178081: cold end 557214,178144: entirely enclosed.
Dimensions (from cooler ports): 208’0”× 10’6” (metric 63.40 × 3.200)
Rotation (viewed from firing end): clockwise
Slope: ?
Speed: ?
Drive: ?
Kiln profile (from cooler ports): -610×3200: 0×3200: 63398×3200: tyres at 6858, 29108, 51359: turning gear at 32156.
Cooler: Reflex “Recuperator” planetary coolers: 12 × 13’6” × 3’10½“ (metric 4.11 × 1.181)
Fuel: Coal
Coal mill: direct: ball mill
Exhaust: via cyclones and an ID fan to stack.
Typical Output: 355 t/d
Typical Heat Consumption: 6.85 MJ/kg


Kiln A2

Operated: Mid-1937 - 30/04/1970
Process: Wet: original calcinator removed 01/1961
Location: hot end (cooler ports) 557208,178080: cold end 557205,178143: entirely enclosed.
Typical Output: 1937-1961 342 t/d: 1961-1970 342 t/d
Typical Heat Consumption: 1937-1961 7.03 MJ/kg: 1961-1970 8.43 MJ/kg
Identical in all other respects to A1.


Kiln A3

Supplier: FLS
Operated: 1938 - 30/04/1970
Process: Wet: original calcinator removed 1957
Location: hot end 557197,178081: cold end 557194,178143: entirely enclosed.
Dimensions: Metric 61.67 × 3.600B / 3.300CD
Rotation (viewed from firing end): clockwise
Slope: ?
Speed: ?
Drive: ?
Kiln profile: 0×3600: 30175×3600: 32410×3300: 61671×3300: tyres at 8420, 19887, 36057, 53127: turning gear at 34239.
Cooler: FLS bucket grate
Fuel: Coal
Coal Mill: indirect: Tirax ball mill
Exhaust: via cyclones and an ID fan to stack.
Typical Output: 1938-1957 355 t/d: 1957-1970 359 t/d
Typical Heat Consumption: 1938-1957 7.03 MJ/kg: 1957-1970 8.41 MJ/kg



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