Twentieth century handbook for steam engineers and electricians, with questions and answers; a practical nontechnical treatise on the care and management of steam engines, boilers and electric machinery (1922)
Swingle, Calvin Franklin, 1846- [from old catalog] · Chicago, F. J. Drake & company · leaf 265
back,about 3 thick, made of hard iron. These wearing backswill last from 10 to 18 months, and are quickly replacedwhen worn out, and can be replaced without interferiug 252 Steam Engineering •with the working of the conveyor, and at trifling cost.Patented fittings with interchangeable wearing back… … Fig. 100exhauster set driven by direct current motor can be readily seen on looking into a conveyor pipe inoperation. This fact prevents serious wear on the pipe, and fromobservation of plants in use up to two and one-half years,shows that an ordinary steel pipe, handling ashes, will lastfor years.…
