May 2, 1913. THE COLLIERY GUARDIAN 909 operated independently. The fine slack for the coke ovens is drained on a Baum draining band, and the clarification of the water is effected by circulating it over a large conical tower erected over the draining band by means of a turbine pump. A 120-horse piwer motor operates the draining and clarifying apparatus. Steam is produced by 29 Lancashire boilers, 30 ft. long by 8 ft. diameter, in four batteries, three of which are fitted with Green's economisers. The working pressure is 90 to 100 pounds per square inch. Eight of the boilers are fired by waste heat from the coke ovens, six are fired by coke- oven gas, and the remainder by producer gas. The rescue apparatus and ambulance room contains six full sets of Fleuss “ Proto” apparatus, an oxygen cylinder charging pump, smoke helmets, reviving apparatus, &c. There is also an Oldham gas-testing apparatus, used for demonstrating to underground officials the size of gas caps on the safety lamp flame in known percentages of gas. Producer Gas Plant. This plant was erected in 1910 by the Power Gas Corporation to provide gas for boiler firing and for driving gas engines to generate electricity for general power purposes. The plant consists of 13 Mond producers, 11 of which are of the dry-bottom type, fitted with a mechanical arrangement for the removal of ashes, whilst the remaining two are of the standard water-bottom type. The fuel is elevated into overhead bunkers capable of holding 320 tons. Each producer is capable of gasifying 20 tons of fuel per 24 hours, or a total for the plant of 260 tons. The ashes are removed from the dry-bottom producers by means of an electrically operated ash wagon running on a track beneath the producers. The blast is provided by means of two Roots type blowers, driven by single cylinder vertical engines by Samuelson, of Banbury, capable of delivering 10,000 cubic feet of air per minute against a water-gauge of 28 in. The air on its way to the producers is saturated in a horizontal hot-water vessel, fitted with revolving dashers electrically operated, and further by exhaust steam collected from the colliery winding engines and washery. Before entering the pro- ducers, the saturated blast is superheated by the heat from the gases leaving the producers. The gas from the producers passes into a large main and dust arrester, and then into a horizontal type washer fitted with electrically driven dashers, which fill the vessel with water spray and free the gas from the bulk of the dust. It then passes through a vertical spray arrester into an ammonia absorber. This vessel is of similar design to the first washer, and contains a weak solution of sulphuric acid. On leaving this vessel the gas passes through another vertical spray arrester into a third horizontal washer, and thence into two vertical cooling towers, which reduce it to atmospheric temperature. It then passes into a large main which supplies the boilers and gas engines. Gas for the engines is further cleaned by passing through centrifugal washers and sawdust scrubbers. The tar recovered from the plant is distilled in a specially designed vacuum still, the products obtained being pitch and a little creosote oil. The acid liquor from the absorber is conveyed into large storage tanks in the base of the sulphate factory. It is there evaporated in an apparatus of the Campbell and McLean type, and the sulphate of ammonia is finally dried in an electrically-driven centrifugal machine by Watson, Laidlaw and Co., of Glasgow. The Electrical Plant. The electrical supply consists of three-phase alternating currrent, generated at 2,500 volts, 60 cycles, and is con" veyed to various sub-stations on the colliery by means of overhead bare copper transmission lines, and also by over- head three-core solid bitumen-insulated cables, the general practice being to have as few cables in the ground as possible. Each sub-station contains stepdown transformers for reducing the pressure to 500 volts for the supply of small motor circuits, the larger units taking current direct from the 2,500 volt bus bars. There are two generating stations. The older . one contains three Beiliss and Morcom-Mather and Platt high- speed sets of 300 kilowatt capacity. There is also installed in this station a 75-kw. Westinghouse rotary converter for supplying direct current at 200 volts for the colliery lighting. The new power station contains three horizontal Korting two-cycle gas engines, driving alternators of 300 kw. capacity, the combined sets being by Messrs. Mather and Platt. An extension of this power station is in progress, and when completed will accommodate three 1,000 kw. alternators coupled direct to vertical “Duplex ” gas engines. The overhead transmission line from the east end of the new power house is for transmitting alternating current at a pressure of 12,000 volts to the collieries of Messrs. Robert Heath and Sons in the Biddulph Valley, and has a capacity of 1,000-horse power. The step-up trans- formers are contained in a house at the foot of the terminal poles. Electrical driving is used extensively on the colliery both above and below ground, nearly 100 motors being coupled up to the mains. Included amongst these are two very large pumping units, each consisting of a 750-horse power motor coupled to a Mather and Platt turbine pump capable of delivering 1,800 gallons per minute against 950 ft. head when running at 900 revolutions per minute. Coking and By-product Plants. There are two of these plants, the first of which was erected by Messrs. Simon-Carves Limited in 1909, consisting of 84 ovens, 60 of which are non-regenerative, or waste-heat type, and 24 regenerative type, with the complete by-product plant for the extraction of tar, ammonia and 65 per cent, crude benzol, as well as a distillery for the working up of the tar. Each oven takes a stamped charge of 8 tons of slack and yields about 5*5 tons of dry coke. The size of the oven is 32 ft. long, 6 j ft. high, 19| in. wide at the charging end, 20| in. wide at the discharging end. The slack is transported from the washer to the ovens by means of an aerial ropeway by Messrs. Ropeways Limited, capable of conveying 50 tons per hour. Storage bunkers are provided at opposite ends of the batteries, of 500 and 600 tons capacity respectively. The slack-stamping and coke- discharging machine is self-contained and is in duplicate. Messrs. Buchanan and Son, of Liverpool, are the makers. The machines are electrically operated, a 35-horse power motor being used for the charging and a 10-horse power motor for the stampers. The coke is discharged from the 60 non-regenerative ovens on to a sloping bench paved with cast iron plates, and passes through a Darby quencher hood to which water is supplied at a pressure of 80 lb. per square inch. The coke from the 24 regenerative ovens is discharged into a Goodall quenching, screening and loading machine, which consists of a quencher hood and a large cast iron table rotating clockwise and driven by an electric motor of 22-horse power, so arranged as to make two complete revolutions during the discharge of the oven. The coke, after quenching, is allowed to remain upon the table of the machine in order to allow its own heat to drive off as much of the moisture introduced during the process of quenching as possible. It is then loaded into the truck by rotating the table in the opposite direction and at the same time opening a large ploughshare gate, which directs the coke over a shaking screen into the truck. The breeze, which is thus separated from the coke, is collected in a b >x below and loaded into a separate truck. The ovens are heated by a series of 30 vertical flues. In the non-regenerative type the burning gases ascend 14 flues on either side of the centre of the oven, and descend into the waste heat flue by two downtakes in the centre of the oven. In the regenerative type the burning gases are carried up 15 vertical flues on one side, and descend 15 vertical flues on the opposite side into the regenerators. There are two regenerators filled with chequer brickwork for extracting the heat from the waste gases. These are alternately brought into use for periods of 30 minutes by a suitable arrangement for closing valves on the gas main and simultaneously operating the dampers. Three lines of tramways are laid upon the tops of the ovens, and three charging holes over each oven are provided for top-charging in case of a breakdown of the stamping machine. The volatile products are conducted from each oven by means of an ascension pipe, which is connected to a large U-shaped hydromain, through which a stream of tar is constantly flowing. The exhausters, three in number, are by Messrs. Bryan Donkin and Co., Chesterfield, and are operated by means of vertical single-cylinder steam engines working at a steam pressure of 70 lb. per square inch. The gases are drawn through vertical annular and horizontal serpentine coolers, where the temperature is reduced from about 240 to 25 degrees Cent., thus depositing the bulk of the tar, which is piped into a deposit tank below the level of the coolers. After passing through ,the exhausters, the gas is forced through tar extractors of the Pelouze and Audouin type, which satisfactorily remove all the tar fog. From these the gas passes through five vertical scrubbers for the extraction of ammonia and three vertical scrubbers for the extraction of benzol. From the last of these the gas is piped back to the ovens for heating purposes, and the surplus is used at the tar distillation plant and for steam raising. The liquor from the ammonia scrubbers is collected in a large low-level tank, whence it is pumped to a high-level tank on the top of the exhauster house, and thence into the stills in the ammonia house, where a concentrated ammonia liquor is made in a Brunner-Mond absorbing plant. The strength of the liquor varies from 15 to 17 per cent, of ammonia. The rich oil from the benzol scrubbers is also collected in a low-level tank, from which it is pumped through a still in another building for the manufacture of 65 per cent, crude benzol. The tar from both plants (Simon-Carves and Still) is treated in a distillery situated behind the Simon-Carves by-product plant. A certain amount of muriate of ammonia is obtained from some of the pitchy residues of the tar. The Still Coking and By-product Plant. The Still coke ovens, 72 in number, in two batteries of 36 each, are of the regenerative type. They were brought into use in October 1912. A complete by-product plant for the extraction of tar, ammonia and 65 per cent, crude benzol was also installed, and in addition plants for the rectifi- cation of the benzol and for the manufacture of carbolic and cresylic acids and pyridine were erected. Each oven takes a stamped charge of 9’5 tons of slack and yields about 6 6 tons of coke. The size of the oven is 33| ft. long, 7 ft. high, 19| in. wide at the charging end, and 21| in. wide at the discharging end. The ovens are supplied with slack from a bunker situated midway between the two batteries; this is of 1,100 tons capacity, and is supplied with slack from an aerial ropeway by Messrs. Bleicherts Limited capable of conveying 70 tons per hour. The arrangement of this is interesting, inasmuch as the slack is discharged from the buckets whilst in motion into a primary bunker, from which the slack is elevated on to a horizontal conveyor above the main bunker. The bunker, elevator and scraper conveyor are operated by a 45-horse power motor. The charging and coke discharging machines are by Hardtmann and Co., of Z seeks. They are electrically operated by means of a 45-horse power motor. They are singular in that a block is provided which ensures free space between the end of the cake and the oven door, this being designed to obviate black ends of coke, and to avoid the strain of withdrawing the peel against the even door. The coke is discharged into two Goodall quenching, screening and loading machines similar to the one previously described. The ovens are heated by a series of 30 vertical flues. The burning gases pass up 15 flues on the one side and down 15 flues on the opposite side into the regenerators, the course of these gases being altered every 30 minutes. The gases for heating enter at the base of the flues, and the pre- heated air for its combustion is admitted at two points in each flue—one at the bottom of the flue, and the other some distance above. This is designed to obviate a cutting heat at the base of the oven, and a more even disposition of the heat over the oven walls. Three lines of tramway are laid upon the tops of the ovens, and three charging holes over each oven are provided for use in case of necessity. The volatile products are conducted from each oven by means of an ascension pipe connected to two U-shaped bydromains for lighting and heating gas respectively, this being the first installation in this country so arranged. From the hydromain the gases pass through two foul mains situated on each side of the hydromains, and thence through six tubular open-topped water coolers for the extraction of the tar. Each cooler is divided into four sections. The flow of the water is effected by means of an electrically driven turbine pump, which maintains it in continuous circulation through the gas coolers and over an open-type cooling tower. The exhausters are of the Connellsville type, four in number, arranged in pairs—two for the lighting gas section, and two for the heating gas section. These together with the pumps are operated by means of a 60-horse power Korting two-cycle gas engine, a steam engine being provided as a stand-by. Vertical single-acting pumps are used for circulating the ammoniacal liquor and creosote oil, for the extraction of ammonia and benzol from the gases, as well as for lifting tar to the hydromain. Ten scrubbers are provided, six for the extraction of ammonia, and four for benzol. The tar from the coolers and the liquor for the scrubbers pass into two underground tanks of 35,000 gallons capacity each. From these tanks the ammonia liquor is lifted into an overhead tank, whence it flows by gravity to the sulphate of ammonia stills, and the tar is pumped to the distillation plant previously referred to. Storage tanks are provided in the basement of the exhauster house for the benzolated creosote and raw creosote. The former is pumped through the heaters and still in the benzol rectification house for the manufacture of 65 per cent, crude benzol. This, together with the crude benzol from the Simon-Carves plant, is worked up into 100 per cent, benzol, 90 per cent, benzol, toluol, xylol, solvent and heavy naphthas. The creosote residue from the rectification of crude benzol is worked up into whizzed naphthalene and clear creosote in a separate building. The waste acid from the benzol rectifica- tion plant is regenerated in a series of acid-proof pans, the regenerated acid being afterwards used in the sulphate of ammonia or pyridine plants. Storage is provided for over 100,000 gallons of benzol products by 12 large storage boilers, 30 ft. long by 8 ft. diameter. The purified products may be loaded either direct into railway tank wagons, holding 10 tons, or into drums of various sizes. The ammoniacal liquor is worked up into sulphate of ammonia in the usual way, the plant being in duplicate, each set consisting of a free ammonia still and fixed ammonia still. The saturators are totally enclosed, of the self-ejector type. The sulphate is whizzed to free it from moisture, the whizzers being of 4 cwt. capacity. The sulphate store is of large dimensions, capable of holding about 200 tons of sulphate. , The middle oil from the tar distillation plant is worked up into carbolic and cresylic acids and pyridene. The appa- ratus consists of the necessary agitators for washing, absorbers and still. Brickworks. This plant is situated at the east side of the colliery, and consists of a Bradley and Craven brick press capable of producing 10,000 bricks per day and a Hoffman continuous kiln which will burn 70,000 bricks per week. The marl is obtained near by.