122 THE COLLIERY GUARDIAN. January 15, 1915. which is always maintained at the overflow, thus ensuring a constant head of water for the washing units. The main pump which delivers to this tank is of the centrifugal type, and is driven by a 60-horse power motor. The used water from all parts of the washery is delivered into a clarifying basin in which the particles of slurry gradually settle to the bottom, and the clarified water' is used over again. The slurry from this basin is run off by means of valves and troughs to a series of three slurry drying basins outside the washery, from which the dry slurry is raised in trams by an electric hoist and delivered to the colliery boilers. The hoist is driven by a 10-horse power motor. The centrifugal pump for dealing with the drainage water is driven by a 15-horse power motor. From the storage hoppers at the washery the small coal, or the required proportion of it, is delivered by scraper conveyor to the boot of the elevator at the disintegrators. The disintegrators are of the Carr type, and are installed in duplicate, being driven by a 170-horse power motor. From the disintegrators the crushed coal is raised by an elevator- passed over an Avery automatic weigher and totalise!’, and delivered principle of operating this type of oven is well known. Every battery of ovens has two main collecting galleries BB1, and two regenerating galleries A A1. The latter- are connected on one end with the main collecting galleries, and on the other with a vertical reversing valve V. This valve can either connect the regenerating gallery with the chimney or with the fan provided for introducing into the battery the air which has to be heated before being mixed up with the gas. At Coedely, the fan-house is below the 1,000 tons ferro-concrete bunker, and contains three Sturtevant fans, each driven by a 7|-horse power motor. One of these sets acts as a stand-by. In this fan-house are placed also the levers for the reversing of the gases and air, as will be explained further on. Under each carbonising chamber is a sole flue. The uneven numbers S (fig. 3) and even numbers S' are connected to the two main collecting galleries B and Bl respectively. By this arrangement, it can easily be seen that, according to the position of the reversing valve, the burnt gases are drawn through the even- number sole flues, when the air for the combustion previously heated is blown through the uneven-number of the gas affects only one-tenth of the side wall of the oven, and thus, owing to the short distance which the hot gas has to travel, the difference in temperature between the upcast and downcast flues is very small. The oven is consequently kept at an even temperature throughout its length. Another important feature of the Coppee oven is the special arrangement of the regenerator, by which the air is made to pass through the whole length of the regenerator, and is thus heated to a uniform temperature before entering the flues of each oven side wall. If for any accidental reason one oven has a tendency to cool down, the cooling down cannot take place, as the loss of heat is compensated for by the heat drawn from all the other ovens of the battery. This advantage permits of a very regular and even working of the ovens. Each battery of ovens is served by an independent electrically-driven charging and discharging machine, but the arrangement is such that any one unit can be made to serve either or both batteries. Provision is also made for charging the ovens from the top, by means of charging dandies, in case of accident to the com- pressors, and in 'lr l tote! wife 1*1 i I'X.„ I' lit Sulphate Factory. into the crushed coal storage bunker, which is placed between the two batteries of ovens. This bunker, which is built in ferro-concrete, has a height of 105 ft. from foundation level, and a holding capacity of 1,000 tons. From this bunker the coal is fed into a service bunker for feeding duplicate compressing machines (each of which is driven by a 10-horse power motor), by a scraper conveyor. The elevator delivering from the dis- integrators, and the automatic weigher into the crushed coal bunker, are driven by a 30-horse power motor. The shale from all parts of the washery is delivered by trough and water to a shale basin, from which the water overflows back to the washery, the shale being elevated to a shale bunker of 440 tons capacity, which is common to both washery and colliery, and from which it is conveyed by a Bleichert aerial ropeway, of a carrying capacity of 60 tons per hour, to the tip on top of the mountain. This ropeway is about 4,300 ft. long. The Coking Plant. The ovens, of which the sizes are—length, 33 ft.; height, 8 ft. 2-J in.; and mean width, 1ft. 8 in., of the Coppee regenerative type, are in two batteries of 30. The construction is shown in figs. 2, 3 and 4. The sole flues and vice versa. Each side wall contains 30 vertical flues divided into five chambers of six vertical flues each (fig. 2). The first three vertical flues (a) of each chamber are connected with the uneven-number sole flues S1, the three others (o) being connected with the even-number soles S1. During one period the gas is delivered by the gas distributor 3 on fig. 3 to vertical flues (a), and to the other set (o) during the following period by the distri- butors 4. The air blown by the fan passes through the regenerating gallery A (fig. 4), thence through the collecting gallery B, which is connected with the uneven-number sole flues S. Through the openings (7t) the hot air is brought in contact with the gas coining from the distributor 3 (fig. 3) at the bottom of the vertical flues (a). The combustion takes place in the first set of flues (a), the burnt gases being drawn down- wards through the other set (o). From these sole flues the gases enter the collecting main flue B1 and thence through the regenerating flue A1 to the chimney. After each period of about half-an-hour the position of the reversing valve is changed and the travel of the air and fresh and burnt gases is reversed. The reversing require stamping. The capacity of each oven is 10 tons, and the time of coking is approximately 32 hours. The battery stack is 171ft. high from sole plate of ovens, and has a diameter of 7 ft. at the top. The coke is discharged on to a sloping bench through a quencher, and the quenching water is supplied at 801b. pressure by duplicate Eureka tandem compound pumps, which are controlled by Fisher governors. The bench of each battery of ovens is provided with catch pits for the interception of the coke breeze. The surplus water, after flowing through a series of settling basins, is returned to the pump sump to be used over again. The gases from the ovens are led into a common main 27| in. in diameter. This is of exceptional length, so as to take the fullest possible advantage of air-cooling effect in order to avoid any deposit of pitch, and dips into a pitch cistern for the interception of the condensate. The gases pass through three series of serpentine coolers, which are so disposed that any one unit of either or the complete cooler can be cut out for cleaning or repairs without interfering with the continuity. Under each cooler a seal pot is provided for the collection of condensate.