Modern Gasworks Practice

VERTIC AL RETORTS AND CHAMBER O VENS 189 tons. Owing to the moderately sharp incline at which the chambers are set, the coke will in many cases discharge itself without any outside assistance, but in order that any tendency to hang up may be avoided, a light starting-ram is pr o vided to set the carbonized charge in motion. The discharger consists of a link-coiling . ram geared to an electric motor ; and the pusher, by means of suitable guides, is constrained to move in a straight line, following the angle of the oven which it enters. As a general rule the complete charge is dispatclied in about forty seconds. The oven doors, which are extremely massive, are raised by an electric hoisting motor, and the incandescent coke runs direct into a specially designed coke-quenching machine. The chamber door is then lowered, and automatically engages itself in a special fastener for ensuring a hermetical seal. In the Munich installation the coke-quenclier consists of a - mild-steel receiving hopper surmounted by a ferro-concrete skaft of square section for the purpose of conducting the steam to a con-siderable height before its escape into the air is permitted. After quenchmg has been partly carried out by means of a spray at the head of the hopper the coke goes into a swing-boat conveyor, cased with. steel plates, which scrapes it through, a bath of water and delivers it, fully quenched, to a de Brouwer conveyor. The coke is then carried on to a screening and sorting plant. Outside producers have in some instances been employed for h.eating the ovens ; but, in general, each beuch. of three is provided with a self-contained producer, the fuel consumption averaging from 14 to 15 per cent, of the coal carbonized. A feature of the producer is the water-cooled grate. Any dass of coal can be charged into the ovens so long as the lumps do not exceed 10 X 15 indies in size. Much depends, however, on the type of coke required. For a semi-coke the temperature of carbonization is kept down to 600° C. ; whilst for furnace coke the coal is ground extremely fine, carbonized at 1,100° C., and steamed in the bunkers with exhaust steam so as to add the reqmsite 10 per cent, of moisture. At the Tegel works, Berlin, there are eighty-one of these ovens at work, carbonizing 567 tons of coal per diem. An idea of the labour entailed can be gleaned from the faet that eighteen men are required for an output of 7,000,000 cubic feet in twenty-four hours. At the Moosah Gasworks, Munich., there are nearly a hundred o vens at work. The salient features of the Munich chamber system are given below Shape of chamber................ Slope............................ Length ............................ Mean width......................... Height............................ Coal carbonized per chamber per 24 hours Average yield of chamber per 24 hours Number of chambers set in a bed Duration of charge________________ Grate area of setting________________ Rectangulai' tapered. 40-42° with horizontal. 26 feet (actual length of sloping floor line). 1 foot 9 inches. 9 feet 10 inches. 2| to 8 tons, as desired. 100,000 cubic feet. 2, 3, 4, or 5. 24 hours. 8 to 16 square feet. Darwen Chamber Ovens These ovens (Kg. 104) are of fairly recent introduction in this country, and m