The continuous weighing of the basic raw materials involved in quarrying operations, sand and gravel pits and cement/concrete/asphalt manufacture is considered to be important not only as an aid to quality control, but also to help management control production costs and stockpile levels, and also in connection with operator incentive schemes based on production figures. A report on belt weighers is presented which, by definition, are described as devices which automatically indicate the feed rate and totalize the weight of a loose bulk product as it passes along a conveyor belt. The incorporation of such devices into continuous processing lines is described, and information presented on the design and accuracy of such systems. Two example studies are described to illustrate the use of bulk weighers. The first example refers to a marine-gravel treatment plant where belt lines are used to feed raw sand and gravel aggregate from ship to stockpile, and where a system of weighers is employed to weigh up to 1600 tons/h to an accuracy of +0.5 per cent. The second example refers to the precise control of materials in a mass asphalt plant where weigh feeders have the task of exactly proportioning the various aggregates on a true weight basis. The complete feed system is controlled from a central control cabin where the aggregate, filler and binder proportions are selected on digital switches according to their percentage in the total mix. Reference is made to new developments in anticipation of new EEC regulations for belt weighers for trade use, and to the introduction of a weigher using nucleonic principles in which weighing is achieved by the measurement of gamma ray absorption. /TRRL/

  • Availability:
  • Corporate Authors:

    Embankment Press Limited

    Building 59, GEC Estate, East Lane
    Wembley, Middlesex HA9 7TQ,   England 
  • Authors:
    • Lockwood, F
  • Publication Date: 1978-2

Media Info

  • Features: Figures; Photos;
  • Pagination: p. 1215
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00178661
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Sep 27 1978 12:00AM