Importance of Small Coal

Abstract

WHEN Dr. F. S. Sinnatt addressed the Institution of Civil Engineers on “Some Major Problems in the Utilisation of Coal” on March 17, he gave first place to the choice of coal suitable in composition, properties and preparation for the purpose in view, and emphasised the importance of collecting such information. Quoting examples from the work of the Coal Survey, he showed the great diversity of properties, even in one seam, and over comparatively small distances. Until these variations are exactly established, progress in rational marketing will be hampered. The needs of the consumer change. Large coal is in less demand, and is to an increasing extent being actually broken. The technique of mining, which has been designed to conserve lump coal, may be radically altered in favour of machine mining, which is prone to produce more fine coal. The breakage of coal is becoming of paramount importance to the coal industry, and involves many problems still requiring solution, and these are chemical, physical and particularly engineering. The disposal of fine coal dust involves consideration of the combustion of pulverised fuel, which steadily extends, hitherto mainly in large units. For small units, coal can now be obtained ready pulverised, and the Fuel Research Station has developed a new burner with which it can be burnt with a short flame. The use of pulverised fuel in Lancashire boilers thus becomes practicable, with advantage to the performance. Apparently output of steam may be doubled without loss of efficiency. The development of firing with pulverised fuel in small units will call for means for retaining the emission of grit and sulphur, and although this has been solved so far as large power stations are concerned, there is still scope for plant suitable for smaller units.