October 1, 1915. THE COLLIERY GUARDIAN 671 brown coal, peat, wood refuse, or practically any waste product having a reasonable fuel value. Kynoch Suction Gas Plants for Non-Bituminous Coal. The generator is fitted with a substantial cast iron base, with a water bottom constructed to hold a con- siderable quantity of water; this keeps the firebars cool, and reduces clinkering, besides generating steam quickly when the plant is being started up. Fig. 11 is a section of a Kynoch suction gas plant. The feeding hopper is provided with a sliding gate, and the cover is fitted with a ball and socket joint, through which a poker can be passed right down through the fuel to the fire grate, and the fire can thus be stirred while the plant is working. The firebrick lining is of a very simple shape, making renewals inexpensive and easy to fit. The vaporiser is external, and therefore not exposed to the fierce heat of the fire, thus eliminating all danger of its being burnt out. The water is vaporised by the heat taken from the gas on its way from the generator to the scrubber, so that no live heat is taken from the fire, which would reduce the efficiency of the generator. The water supply to the vaporiser and the generator base is controlled by a very simple semi-auto- matic arrangement, which supplies the correct quantity of water for all loads, and thus the vaporiser is always kept at the proper temperature. As the vaporiser is Fig. 10.—Section through “ Kynoch Cambridge” Bituminous Suction Gas Producer. Fig. 12.—Diagram of Duff Plant. external, it is easily dismantled for cleaning without interfering with the generator. Automatic arrangements are provided to prevent difficulties arising from expan- sion and contraction. The water sprayer in the scrubber is a star-shaped casting consisting of V-troughs, which are open at the top and provided with notches for spreading the water; the sprayer cannot get stopped up by rust, as happens when perforated tubes are used. The fan is provided with an oil bath, in which the gears run. For dealing with inferior fuel the generator has a water-luted bottom, and is fitted with rotating fire- bars. With this plant the ashes can be removed while working, and the plant can be worked for long periods without shutting down. A fire is lighted in the generator with wood and coal, and a strong draught is induced by means of the hand fan until the fuel has become incandescent. This takes from 15 to 20 minutes, according to the size of the plant. During this operation the waste cock is open to allow the waste products of combustion to escape into the air. These products, however, first pass through and heat the vaporiser sufficiently to vaporise the water necessary for the production of good gas. Immediately it is found that the gas burns steadily with a bluish flame ^3 Fig. IL—Section of Kynoch Suction Gas Plant. when ignited at the blow-off cock, it is ready for work, and the engine may be started, when the following operation takes place :— Air is drawn into the vaporiser through an inlet at the top of the vaporiser, by the suction or “ pull ” of the piston. The air thus drawn in becomes saturated with steam or water vapour, then passes underneath the fire grate, and through the fire. The steam when pass- ing through the incandescent fuel is decomposed, and the resultant oxygen in the air (combining with an excess of carbon) forms carbon monoxide. This gas and the hydrogen liberated by the decomposition of the steam form the combustible constituents of suction gas. The gas then passes from the generator by a connect- ing pipe down the centre of the vaporiser; this keeps the vaporiser at a uniform temperature, and at the same time partly cools the gas. It then passes to the coke scrubber, which cleans and cools it, and thence to the engine. As soon as the engine is started the fan is stopped, and the whole operation becomes automatic. Duff By-Product Producer. This plant is constructed by the Gas Power and By- Products Company Limited, Glasgow. The diagram- matic drawings (figs. 12 and 13), and the following brief description will explain the working of the plant. The fuel is brought to the plant, and emptied into hopper A. It is delivered to hopper C (which may hold sufficient for twelve hours’ continuous working) by con- veyor B. The fuel is fed into producer D, where it is gasified. The average rate of gasification in these pro- ducers is about 16 cwt. per hour; when required, how- ever, they will work up to 25 cwt., and still give good gas, but this slightly lowers the amount of by-products recovered. The gas enters the superheater E, which is so arranged that the hot gas is utilised in heating the air and steam blast on its way to the producer grate, where it is delivered under pressure. The gas, on leaving the superheater, travels along the gas main to the washing apparatus F. This is a large horizontal chamber, water- luted at the bottom, in which the gas is subjected to sprays of cold water. By this method most of the dust and tarry matters carried in the gas are deposited in the chamber, which is so designed as to permit of the removal of any deposit with the minimum of trouble. From the washing apparatus the gas passes to an acid washer (here shown as the tower G), in which it is treated with diluted sulphuric acid (passing continuously through the washer or tower), which combines with and fixes the ammonia in the gas. The liquor obtained from this washer or tower is run into tank K, and is ready for feeding into the evaporating pan L, where it is boiled down to solid sulphate of ammonia. This pan is of the vacuum type, and is heated by either live or exhaust steam, and may be continuous working. The box M on the bottom of the pan receives the salt crystals in a moist conditions, and is so arranged that on discharge of the box the crystals are delivered into the centrifugal drying machine N, which thoroughly dries the salt, and it is then ready for the market. The gas is passed from the washer or tower G to the tower H, where it meets a descending stream of cold Fig. 13.—Duff Rotary-top Producer. water, which further washes the gas, and cools it to any desired temperature. From here the gas is taken to the engines, stoves, furnaces, or where required. The heat absorbed by the water in cooling the gas is utilised in heating and saturating the air blast by the follow- ing method :—The hot water is pumped to the top of tower I, into which air under pressure is delivered by the blower J. The air rising up the tower meets the falling rain of hot water, which gives a hot air blast saturated with vapour, which is led into superheater E, and superheated as before described. The water on reaching the bottom of the tower is now considerably cooled, and is pumped back again to the tower H, and again heated. This method of heating and cooling the water is continually going on, and by its use a large amount of the steam required in the blast is produced. Where the quantity of fuel used is large enough to warrant it, the by-product plant may be extended to deal with the tar obtained from the washing apparatus. From this a large variety of oils, greases, dyes, disin- fectants, etc., can be obtained in paying quantities. Plants of this type have been erected at Messrs. William Beardmore and Company’s works at Glasgow, where 750 .tons of fuel are gasified per day. A plant capable of gasifying 225 tons of fuel a day has also been erected at Messrs. Vickers’s works at Sheffield, and a plant at Messrs. John Brown and Com- pany’s works at Sheffield, gasifying 175 tons of fuel per day. The by-products are recovered at all these plants. Summary. These descriptions do not by any means exhaust the number of gas producers now at work in this country. The nature of the fuel that it is desired to gasify is so varied that in almost every case some slight modifica- tions are necessary; consequently, it is essential to consider fully the varying circumstances of each case with one of the designers of such a plant as may seem most likely to be able to deal successfully with the particular fuel that is to undergo gasification. The writer will now conclude by giving a summary of what may be gathered from the information which he has collected :— Although low grade fuels are not being generally used in gas producer plants, it will be seen from the results attained that at the Shelton Iron, Steel, and Coal Com- pany’s and other plants a low grade fuel is capable of being gasified, and that the resulting gas can be sufficiently purified for heating and power purposes. At many collieries large quantities of ‘k batty ” coal are thrown back into the goaf, and in many cases where the coal at the top or the bottom of the seam is inferior, it is left in the mine; in fact, our coal seams are being worked in a wasteful manner, as if there were no end to the store of our mineral wealth. It will, no doubt, be said that coal owners are not going to reduce the output of good saleable coal by sending out rubbish, and that the present-day strenuous wish to increase the output will not allow of rubbish being got and sent out of the mine. It has, however, to be remembered that every tons of unsaleable coal gasified saves at least half a ton of good coal. The country cannot expect the coal owners -to increase the cost of getting the merchantable fuel in order to use up a low grade fuel now lost, but the country has a right to ask that our rapidly diminishing supply of fuel shall not be wasted, and that our mining engineers, our chemists, and our mechanical engineers shall work together for the prevention of this waste. In many parts of England there are seams of coal that are unsaleable at a profit at the present time, merely because they are unsuited to present-day requirements, but the gas producer and the gas engine are now making this class of fuel available for generating power at a wonderfully low cost. The art of utilising low grade fuel must be cultivated if we are to retain our great place in the world for generations to come. The designers of gas producer plants are actively engaged in meeting the many diffi- culties connected with the use of low grade fuels; but the mining engineers who advise our large colliery com- panies are slow -to advocate the erection of plant that may prove unsuitable for their special purposes, and so the advancement of science is checked. The Midvale Steel Company, of Philadelphia, has been sold, the identity of the purchaser being undisclosed. The price is said to approximate 19,000,000 dols. The company, it is stated, will be re-capitalised, with Mr. W. E. Coney (president of the United States Steel Company) at the helm. It employs 5,500 men at present, and makes armour plate exclu- sively for the United States Government. It is also reported that negotiations are going on for the purchase of the Cambria Steel Company and the Steel Connection, with works at Johnstown. There are rumours that the Midvale and Cambria plants will eventually become units in a big steel concern, which will take in a number of independent plants in the eastern part of the country, but this is not confirmed. In a pamphlet on the sulphate of ammonia market in 1914, the American Coal Products Company, of New York, estimate the world’s output of sulphate last year at between 1,300.000 and 1,350,000 metric tons, as compared with 1,409,000 tons in 1913. The production in the United States in 1914 was only 183,000 net tons of sulphate and its equivalent, less by 12,000 tons than in the year before. Of the 183,000 tons produced, 139,500, or 76 per cent., are chargeable to the by-product coke ovens. The addition to the by-product coke ovens for the year 1914 included 41 Semet-Solvay ovens at Indianopolis, 27 Gas Machinery Company’s ovena at Johns- town, Pa., 120 Koppers ovens at Sparrows Point, Md., and 118 Wilputte ovens at Joliet, Ill. Besides these, 224 Koppers ovens at the Bethlehem Steel Works and 56 for the La Clede Gas Company at St. Louis, went into operation, the former early in 1915. Construction of the 100 Otto ovens at Buffalo is held up by the war. An addition of 20 ovens to the Inland Steel Company’s plant at Indiana Harbour, Ind., went in during January 1915. New plants expected to come into operation during 1915 include the Chattanooga Gas and Coal Products Company, 12 Roberts ovens at Chattanooga, in July; the Youngstowm Sheet and Tube Company, 204 Koppers ovens at Youngstown, Ohio, about the end of the year: and the Minnesota Steel Company at Duluth. 90 Koppers ovens, already completed. Additions comprise 92 Koppers ovens to the Republic Iron and Steel Company’s plant at Youngstown. Ohio, and a re-construction of the 120 ovens at Glassport, Pa., for the Allegheny By-Product‘Coke Company. The latter will start operation in July, the former in November 1915.