7119 (ISO International Standard INTE RNATIONAL ORGANIZATION FOR STANDARDIZATION MEXAYHAPOAHAA OPrAHW3AuH IO CTAHAAPTW3AUMGORGANISATION INTE RNATIONALE DE NORMALISATION ANsI IrexatDo Set Continuous mechanical handling equipment for loose bulk materials - Screw conveyors - Design rules for drive power - Transporteurs a vis - Regles pour le calcul de la puissance Engins de manutention continue pour produits en vrac - d'entrainement First edition - 1981-10-01 OCT 07 1 1981 UDC 621.867.4 Ref. No. ISO 7119-1981 (E) ISO /119-1981 (E) Descriptors : handling equipment, continuous handling, conveyors, screw conveyors, computation, power. Pricebased on 4pages nsefromIHS NotforResa Foreword Iso (the International Organization for Standardization) is a worldwide federation of national standards institutes (IsO member bodies). The work of developing Inter- national Standards is carried out through ISo technical committees. Every member body interested in a subject for which a technical committee has been set up has the right to be represented on that committee. International organizations, governmental and non-governmental; in liaison with iso, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the Iso Council. International Standard ISO 7119 was developed by Technical Committee ISO/TC 101, Continuous mechanical handling equipment, and was circulated to the member bodies in May 1980. Australia France Poland Belgium India Romania Chile Ireland Sweden United Kingdom Czechoslovakia Netherlands Norway Finland USSR The member bodies of the following countries expressed disapproval of the document on technical grounds : Austria Germany, F. R. This International Standard is based on the work carried out by "Section Il -- Con- tinous handling" of the European Mechanical Handling Confederation (FEM). @ International Organization for Standardization, 1981 Printed in Switzerland Copyright International Organization for Standardization from IHS ISO 7119-1981 (E) INTERNATIONAL STANDARD Continuous mechanical handling equipment for loose bulk Screw conveyors -- Design rules for drive materials - power Scope 1 Symbols and units This International Standard establishes a method for the calculation of drive power of screw conveyors. [Units] Symbol Designation A Working section of screw conveyor m2 2 Field of application D Nominal screw diameter m FH Main resistances N This International Standard only applies to a screw conveyor, FN Secondary resistances N used in a horizontal or inclined position (up to approximately Fst Resistances due to inclination N 20o), for a regular, controlled and continual supply of the buik materials. Acceleration due to gravity m/s2 g H Lifting height m Excluded from this International Standard are the special screws for the following special uses : t/ h IM Mass flow rate Iv Volume flow rate m3/h extracting screws 7 Conveying length m calibrating screws Number of screw r.p.m. r/min n p kw Total power mixing screws PH Power for material progress kw PN Power when operating at no load kw moistening screws Pst Power due to inclination kw inclined screw (above 200) s Screw pitch m Linear speed of material movement m/s vertical screws Trough fiHing coefficient Density of bulk material! t/m3 Q 3 Reference Progress resistance coefficient ISO2148, Continuous mechanical handling equipment Nomenclature. Calculation of the capacity of a screw Comments 6. 4 conveyor The necessary drive power and the rate of flow of the material which may be reached by a screw conveyor are interdepen- The nominal capacity to be considered is the capacity per hour of the maximum volume that may be reached by a screw dent. conveyor. Nevertheless, they also depend upon the operating conditions, The volume flow rate Iy is the product of : the nature of the product.conveyed and the design parameters, the most important