The Mechanical Handling and Storing of Material

WORM OR ARCHIMEDEAN SCREW CONVEYORS 47 Table giving Diameter, Pitch, and Capacity of the Open-Bladed ok Spiral Conveyor for Heavy as well as for Light Work. Diameter of Spiral. Pitch of Spiral. Diameter of Solid Shaft. Section of Spiral. Speed for Heavy1 Materials. Revs, per Minute. Capacity for Heavy- Materials in Cubic Feet per Hour. Speed for Light 2 Materials. Revs, per Minute. Capacity for Light Materials in Cubic Feet per Hour. Inches. Inches. Inches. Inches. 4 4 H to I| li x A 100 40 130 6<> 6 5 U 90 120 120 150 8 6 15 to 2 If xi 80 230 110 300 10 7 2 ,, 2JL 2f x i 70 350 100 500 12 8 2 ,, 2^ 2Jx| 60 550 90 800 14 9 ,, 3 2| xi 60 700 80 1,100 16 10 •2i ,, 3 3 xi 50 950 70 1,400 | 18 11 2i ,, 3 3 j x i 40 1,100 60 1,700 20 12 2| „ 3 35 1,300 50 1,900 22 13 3 ,, 3|x£ 30 1,500 40 2,100 24 14 3 „ 3| 3W 25 1,600 35 2,300 Table giving Diameter, Pitch, and Capacity of Paddle Worms Diain. of Worm. Pitch of ■ Worm. Outer Diam. of Hollow Spindle. Diam. of Inter- mediate Bear- ings and End Gudgeons. Diam. of Shank of Blade. Speed for Heavy1 Materials. Revs, per Minute. Capacity for Heavy- Materials in Cubic Feet per Hour. Speed for Light 2 Materials. Revs, per Minute. Capacity for Light Materials in Cubic Feet per Minute. 5 Inches. Inches. Inches. Inches. Inches. 4 4 If 1 r er 85 26 ]‘2O . 40 5 5 1 -® 11 85 65 120 90 6 6 1H "8 S') 110 110 170 7 7 u 80 175 110 260 8 8 Iri 11 70 220 100 330 •» 9 2 '2' 70 320 100 470 10 10 2 1 60 400 90 600 11 1J 2f 2} 60 500 90 750 12 12 & 60 600 90 900 14 14 2 is. 21 . 55 1,000 80 1,300 1(5 16 U 3 5 50 1,350 70 1.800 18 18 3 * 50 1,800 60 2,200 Experiments with “Paddle” and “Spiral” Worm Conveyors.—In order to ascertain the respective merits of spiral-worm and paddle-worm conveyors, the author carried out a series of experiments in March 1889, which point to the fact that when running at a slow speed the paddle worm is of greater efficiency, while with a high speed the advantage is on the side of the spiral worm. At a speed—for 4-in. worms—of 150 revs, per minute the efficiency of both is about equal, while if run at higher speeds the spiral worm increases and the paddle worm decreases in capacity. The following is a summary of the results of the experiments. The material experi mented with was sawdus.t. 1 Heavy materials include fine coal, cement, sand, ground minerals, fine gravel, plaster of Paris, oxide of iron, etc. 2 Light materials include grain, seeds, sugar, flour, meal, bran, ice, sawdust, rice, etc.