Research On The Effect Of Material Flow On Accuracy Of Electronic Belt Scale

As a kind of automatic continuous weighting device,electronic belt scale is used to measure mass flow of the bulk solid material transported by conveyor belt,and is widely adopted in modern industrial product process.As a dynamic weighing device,its measurement accuracy and durability has always been a matter of concern.This paper is aimed at this problem,and to explore the effective method of improve the electronic belt scale measurement accuracy.Firstly,this paper summarizes the development of electronic belt scale at home and abroad,the results achieved,and the problems exist.Based on the weighing principle of the electronic belt scale,introduced the components of the electronic belt scale.Analysis the selection of load cell and speed sensor,the influence of the method of the speed sensor mounting on the weighing error.And analysis the response curves of several common scale structures,explains the advantages and disadvantages of various scale structures from the response curves of different scale structures.Secondly,analysis many factors that affect the precision of electronic belt scale.Of all these factors,the belt effect is the main one that result in measurement error."Belt effect" refers to the tension of the conveyor belt,the non-collimation of the weighing roller,the stiffness of the conveyor belt and other factors caused by the gravitational error.In order to analysis the influence of "belt effect" on the measurement precision of electronic belt scale,the conveyor belt is considered as the beam,and mechanical analysis of the measuring section conveyor belt.Based on the principle of minimum potential energy,established the weighing force error model among the weighing force error,conveyor belt tension,weighing roller non-collimation,conveyor belt stiffness and weighing load,and obtion the formula of gravity error.Through analysis the formula of the weighing force error model,the additional error force caused by the belt effect is an independent item,which does not affect the size of the material gravity.Therefore,the problem of belt effect can be solved by using the calculation method to eliminate the error force,Real-time compensation of the electronic belt scale gravitational error,from the root to eliminate the error of the electronic belt scale.Finally,this paper propose two kinds of calculation elimination method,dynamic compensation method based on calculated tension and dynamic compensation method with double weighing unit.Through theoretical analysis,data simulation and experimental verification,it is found that there are many limitations in the application of dynamic compensation of calculate tension method.It is difficult to obtain practical effect.The error compensation method of double weighing unit electronic belt scale is verified by theoretical analysis,data simulation and experiment.This method can real-time calculation compensation on the "Belt effect" caused by the weighing error,improve the electronic belt scale weighing accuracy and durability.