In the more recent Simon-Carqs ovens the fireplace and grate are dispensed with, and the oven is fired exclusively with the gases escaping condensation, these entering the lower flue at the place where the hearth used to be, while air is forced in through an annular pipe. being previously heated to or by being brought in contact with the hot flutes ing the spent gases away from the ovens. The two lower flues are thrown into one, and at the bettom flue, where the greatest is sustained, the walls are lined with fire-briek. The heated air admitted into the bottom flue is purposely insufficient for complete combustion of the gas introduced there, the further supply of hot air luting obtained through the side-flues of the ()yen, the amount thus admitted being controlled by dampers. These ovens are made 23 ft. long. 6 ft. high, and 19} in. wide. Their capacity is about 5 tons of coal per charge, the time of coking lasting 48 hours. The cost of a oven to work about 480 tons per year. which is the capacity of an ordinary beehive oven, is $845, complete. with the coolers and all appliances, An ordinary beehive oven of this capacity costs but $280. AI Dyson & Bear Colliery (Durham, England), according to S. A. Tuska. iu an article "The (published by the author), a battery of 50 ovens cokes about 9(10 tons of (quid per week. The analysis of this coal is as follows: Volatile matter, per cent : fixed earl Mal, per cent ; sulphur, '77 per cent nsh, per (Tilt. The yield in coke was per cent : sulphate of ammonia. 9 tons per week, equivalent to anononiaeal water, 10 per cent of the coal, and of tar to 74 gals. per ton of cold. The cost of labor for coking and collecting by-products is estimated at 4S cents per ton of coke for a battery of 50 ovens, producing 107.5 tons of coke per 24 hours. A force of 33 men is required to operate a plant of this size.
The Coke-Oven (Fig. 5) is very similar to the ordinary beehive oven, but it has a fireplace and grate, and the gases are carried to an upper collecting tube a, and returned to the bottom flue b, where they are fired with solid fuel. The Jameson Coke-Oven (Fig. 6) is an improve ment on the ordinary beehive oven. Channels are made in the bottom of the oven, covered with per forated tiles, b, b', b", connected outside the oven with pipes leading to an apparatus, c, e', for produc ing a slight suction, and for discharging the by products when required. This is a very shnple and inexpensive oven, and is said to have given very good results. According to Mills and Rowan (Chemical Technology, Fuel and its Applications, p. 185), a series of trials showed an average yield of 56.1- per cent coke, the average yield of ammonium sulphate and tarry oil being 63 lbs. and gals. per ton (2,240 lbs.), respectively.
The Liirmann Coke-Oven (Fig. 7) consists of a large chamber, a, opening into which are a number of coking-chambers, 1).11, into which fine coal is fed continuously from hoppers by a piston-feed, worked : by a crank. The gaseous products pass into the chamber a, and, if required to be collected, are drawn off at an aperture at the top, and thence conducted into the spaces c. c', tinder the re torts b, b', where they are burned by means of air admitted for the purpose. The coke, as it falls from the ends of b.11 is received in the chamber a, and is re moved at intervals. This oven is continu ous - working, and yields good, compact coke, It is very sim ple in construction, requiring no special fire-bricks, and is com paratively inexpen sive.
The Batter Coke Oven (Fig. 8), which has been used with satisfactory results in France and Scotland, consists of alternate coke and regenerator chambers arranged side by side in a doub le row, while main flues for the combus tion gases run along the tops of the cham bers near the front, and discharge into chimneys placed in convenient positions. The coking-chamber E. with
a charging opening at the top, a curved back and base, and large discharge opening in front, communicates at the sides through openings f f arranged at various heights. with the combustion-chamber (I-, where the gases are mixed with air admitted from the outside through passages H, forming a combustible gas of high heating power, which, by way of passage h, is conducted to the channel j below and along the back of the coking-chamber, and then through i into the upper chambers GI, heating by their combustion the upper part of the walls of the coking-chamber 1? before they are discharged through the passages l l into the main title The air before it mixes with the retort gases is heated by passing through long passages in contact with the heated walls, and the amount of air can be carefully regulated by slides. Additional air inlets with valves are provided near the top of the ovens it 11 I, and the coin bUStiOn gases can be also retarded in their flow to the chimney by valves at Fig. 1 is a cross-section through the combustion, and Fig. 2, through the coking-chambers. Forty of these ovens were erected at the works of the Carlton Iron Co., Ltd., in 1888 (Engineering and Mining Journal, I, 72). To obtain actual results of their work special trials were made in April, 1890, 124 tons of coal being used, of which 65 tons 16 cwt. was washed East Howie coal (fairly good coking coal), and 58 tons 4 cwt. unwashed coal from various collieries, varying considerably in quality and containing a large amount of volatile matter. Out of a total fixed carbon and ash of 69•G5 in the coal, 69.44 per cent was returned as coke, the time required for coking being 24 hours. The proportion of large to small coke was satisfactory, there being only about 6 tons of small in a total of 86 tons of coke obtained from 124 tons of coal. This proportion of small coke is, however, considerably reduced, it is stated, in places where the traveling belt is used for the transit of the coke from the ovens to the trucks. The traveling belt consists of an endless metallic chain, supported on rollers and so arranged that it travels slowly in front of the discharge opening of the ovens. When the door of a chamber is opened the coke runs, owing to the shape of the coking-chamber, with but very little assistance from the attendant, on to the traveler, where it is quenched by water-sprays. The belt discharges the coke, practically without handling, into the trucks: thus a great saving of labor is effected, a foreman with three laborers attending to a group of 40 ovens. The experience so far gained seems to show that, owing to the high temperature obtained in the regenerative flues by burn ing the gases with a suitable admixture of atmospheric air, coals of almost any composition can either by themselves or as mixtures he used to produce sound hard coke suitable for blast furnace work, and, since none but the volatile gases are utilized to produce the necessary heat, nearly the whole of the fixed carbon is converted into coke, while in addition any of the vola tile gases not required for the coking process may be condensed and utilized for by-products. Dr. von Bauer, the inventor of this oven, has found that about 16 per cent of gases is neces sary for the combustion.