Study On Experiment Of The Method Of Cracking Walnut Shell In Gas Explosion Type

Walnut planting is an important part of Xinjiang agriculture.it is necessary to take the road of walnut deep processing to develop the walnut industry, and one of the key technology is the method of breaking walnut shell. Now there exists many kinds of walnut shell breaking machines and many shortcomings, such as the low rate of whole nucleolus after the shell broken, the serious damage in the nucleoli surface, the high nucleoli loss rate in the broken shell process, and user dissatisfaction. So the new principle of shell breaking is put forward, and the high pressure is applied to shell breaking to solve the above problems. At last the prototype is designed and the parameters are optimized.This paper starts with the Xinjiang three representative sample of walnut and statistical analysis of three physical characteristics walnut, such as walnut three-dimensional size, shell thickness, inner membrane area and thickness. We established a model for walnut according to the three physical characteristics of above. And by use of the finite element mechanics analysis method, drilling in the walnut three axis direction and applying high pressure gas through hole inside, we have done force analysis of walnut shell. The software analysis indicates that:when high pressure gas load is applied in the B direction and C direction of walnut shell, surface vertex force change fierce mainly concentrated in the short axis direction, walnut shell rupture can only in the surface near the apex. The burst mouth is too small remove the shell of walnut kernel; When high pressure gas load in the A direction of walnut shell the place where the force is larger concentrates in the C direction of the surfaces and along the A direction on the surface. These broken shells is more, cracking length is longer and burst open walnut kernel from shell is easy. The separation rate and the complete kernel rate is relatively high. So applied load in the direction of A is the best way.We have designed and manufactured a shell breaking machine. It has some characteristics:Through the material dialing disc walnut is allocated one by one from the feeding hopper to the transport roller. A pair of conveying roller is composed of two rolls. This pair of rollers rotates in the opposite direction. It can not only convey walnuts to breaking shell position, but also adjust the position of walnut. The long axis of walnuts is oriented to parallel with roll axis of conveying roller. We also have designed the pressing mechanism, which would release walnuts before the high pressure loaded through the cooling drill. After the design of experiments the parameters are further optimized to obtain the optimal parameter combination.