The Mechanical Handling and Storing of Material

WORM OR ARCHIMEDEAN SCREW CONVEYORS 51 In one of the largest cement works on the lower Thames, where miles of these worms are in use, the practice is as follows: 10-in. continuous worms fitted in 11-in. troughs with the bearings 10 ft. apart with a pitch of 7 in. and a speed of 80 revs. These worms convey 7, 14 and sometimes even 21 tons of fine cement per hour. As they Fig. 50. Worm Bearing in Halves. Fig. 51. Cross Section of Worm Conveyor Bearing. aie all driven by electric motors the actual horse power consumed was easily obtainable, and from a number of readings the average power was 1 B.H.P. for every 35 ft. of conveyor when handling 7 tons of cement. The intermediate bearings are similar to Figs. 51 and 52, from which it will be seen that the space between the adjacent sections of the 10-in. worm is very small, only H in. J this is a great advantage, as the break of the blades at the junction is very small and therefore prevents accumulations of the stuff. These bearings have also the further advantage that the working portions are quite away from the injurious influence of the cement.