Design And Experiment Of Extrusion Type Apricot Stone Breaking Machine With Oblique Tooth And Counter Rollers

With increasing production of apricot,the development channels of the apricot industry are gradually widened,and the apricot kernels produced by dried apricot production are increased,many of which are not processed in time to become moldy or are discarded,resulting in waste of resources.In view of the problems of traditional apricot kernel shelling machinery such as low shell breaking rate,high kernel breaking rate or high cost of large and medium-sized production lines,high manpower and complicated operation,we developed an oblique tooth roller extrusion type apricot kernel shelling machine by conducting experimental research on the physical characteristics of apricot kernels and designing the key components of the machine.The results showed that the designed machine has the advantages of a high shell breaking rate and low kernel breaking rate.The main work and conclusions of this paper are as follows:(1)The effects of different thicknesses,moisture contents and loading rates on the mechanical properties of hull breaking such as hull breaking force and deformation were investigated with three varieties of apricot kernels: samite,black leaf and white apricot kernels.The results showed that the gap between the rolls should be controlled by the maximum deformation of the kernels of different grades of thickness minus the thickness of the kernels of the grade when shelling was carried out.The thickness of apricot kernels had a significant effect on the physical properties of shell breaking force and deformation.1mm was selected as the thickness grade difference,and 3 thickness grades were selected for samite and black leaf apricot kernels,and 4 thickness grades were selected for white apricot kernels.The physical characteristics of shell breaking force and deformation of apricot kernels were significantly influenced by the moisture content in a certain range,and the shell breaking force and deformation of three types of apricot kernels,namely,samite apricot kernels,black leaf apricot kernels and white apricot kernels,decreased and increased respectively with the increase of moisture content.In the loading rate range of5～100 mm/min,the effect of loading rate on the shell breaking force and whole kernel rate was not significant,and in the loading rate range of 100～400 mm/min,the shell breaking force and whole kernel rate decreased continuously.(2)The design and simulation analysis of the whole machine scheme and key working parts such as the shell-breaking roller of the oblique tooth-to-roller extrusion type apricot kernel shell-breaking machine were carried out.The conditions of apricot kernels entering the rollers and the shelling process were analyzed,the structural parameters of the pressure rollers were determined,and the modal analysis of the shelling rollers was carried out to ensure that the machine would not resonate;the design of the vibrating sieve holes was carried out according to the size of apricot kernels and almonds,and the motion analysis of the eccentric shaft crank linkage mechanism was carried out;the overall scheme of the transmission system was designed,the transmission ratio was calculated,and the type of motor was determined.The design and production of the prototype was finally completed.(3)A prototype was tested and experimental studies were carried out.The orthogonal test was carried out with hull breakage gap,feeding speed and differential speed ratio as the influencing factors,and hull breakage rate and kernel breakage rate as the evaluation indexes.The optimal combination of parameters was determined,i.e.,the shelling gap was 8.5 mm,the feeding speed was 350 kg/h,and the differential speed ratio was 1.75.The optimal combination of parameters was validated and the shelling rate of apricot kernels was 99.04% and the rate of broken kernels was 2.28%,which satisfied the requirements of shelling operation.