The Mechanical Handling and Storing of Material

COAL FACE CONVEYORS 169 Consumption and Cost of Compressed Air for Driving Reciprocating Coal Face Conveyors, or Rutschen System. Diameter of Motor Cylinder in Inches. Piessure in lbs. per Inch. Consumption of Air per Minute in Cubic Feet Cost of Compressed Air. Length of Trough in Feet. Incline of Seam in Degrees. Per Cubic Metre 1 at the Pressures given in Column 3. Per Ton of Coal Conveyed. Carlshiitte2- 8 68-75 70p •05 1-2 525 15 55 10 45 70 V •0375 •1375 131 20 Flottmann - 8 45-60 18 •25 1-0 262 3-20 5 > 10 75 •16 •025 •281 229 2-5 5 5 Hi 45-60 26 •187 '225 164 2-12 5) 1H 75-90 18 •1625 •2275 262 2-12 M 14 75-90 21 •1625 ‘2725 238 2-12 Würfel & Neuhaus 10 52 1-875 210 22 >5 55 12 45 •3125 •9 394 13 5 > 5 J 12 75 41 •125 •75 262 0-5 Eickhoff 9 38 18 •156 •46 295 0-15 Degenhard - 6:! 60 76 •187 1-5 328 0-10 Hinselmann 6|3 4 38 43 •156 •968 295 0-15 5 9 9 60 14 ■225 •2625 328 10 The variation of cost in the above table of compressed air per ton of coal handled is from ’1375 to 1'875 pence. In Germany it is considered that 5 pfennige or -625d. is a reliable average figure. Experience gained in German collieries shows that the life of a compressed air motor is about five to six times as long as that of the conveyor trough, whilst that of an electro motor is about ten times as long, so that the wear and tear of the motor may be calculated to be from Jd. to IJd. per ton of coal handled. From observations in the working of a large colliery, where many such conveyors are at work, it is safe to assume that:— A trough of 2 mm. 14 B.W.G. will handle 30,000 tons of coal and 18,000 tons of dirt. „ 3 ,, 11 „ „ 50,000 „ „ 30,000 ,, 4 ,, 9 „ ,, 70,000 ,, „ 40,000 „ 1 he dirt or spoil which is mentioned above is not of a cutting nature and the figures given are for the life of the trough. It is calculated that the cost of the wear on the trough works out at from |d. to Id. per ton of coal handled. I he working expenses tabulated from the above experiences with these conveyors in Germany, per ton of coal handled, are as follows :— Per Ton of Coal Handled. Driving power ----- Wear on motor - Wear on the trough - Lubricant - Repairs ------ Cost of erection and re-erection - '625 penny • -125 „ • -625 „ • 1 „ • 375 ,, '625 ,, 2'475 pence/ 1 1 cubic metre = 35'3166 cubic feet. 2 The motors are not of the latest type. 3 Twin motors. 4 Air not under pressure when measured.