| With the accelerated construction of different infrastructures such as highway, aerodrome and town planning, the equipments of road surface treatment are demanded. Especially, the equipments of road surface maintenance are demanded. But the equipments of road surface maintenance depend on importation from advanced country. The level movement shot blasting is one of the road surface treatment equipments that are used widely these days in other country. Shot blasting of the road surface treatment is one way which has been used in the road surface treatment in Occident in recent years. With the betterment of equipment of shot blasting and mature technique of shot blasting, shot blasting has been used in highway maintenance, bridge maintenance, aerodrome road maintenance and other areas in Occident. In developed county the level movement shot blasting not only can resume surface of concrete road and tunnel road enough but also can make bridge surface waterproof. In addition the level movement shot blasting can remove old coating of airport runway. But in our country this technique is seldom applied to these areas which this article mentions above. We only use it in some traditional items. With the market demand increasing, some section has given attention to the importance of the maintenance. In the area of removing old coating of airport runway, the level movement shot blasting is so predominant that other equipments can not substitute for it. Not only it removes old coating effectively, but also it works with high efficiency. And most important it dose not affect the use of airport runway at the time that it dose not work. So the market environment of application in road surface maintenance equipment is extending and can be anticipated that it will have better foreground in our country. To sum up, it is necessary not only now but also in the future that we do some theoretic researches in relation to practice. Now the exploitation and application of shot blasting machines which is used in traditional areas has been relative mature in our country. But the level movement shot blasting is relative strange for us. This paper is from a item The Exploitation And Application Of Level Movement Shot Blasting which is consigned by some company. In this background, I do some particular analysis about the mechanical structure and work principle of shot blasting machine. And I studied hard for finding out the factor that affect pills velocity at the time when the shot blasting machine shoots off them.Shot blasting machine has five section: shot blasting system, recovery chamber, seprator, ride-on system and control system (in addition dust collector being needed, and if necessary pills-pickup can being armed).The principle of shot blasting is that the machine translate pills'kinetic energy into impact force on the surface that is prepared for treatment. The electric machine of the shot blasting equipment drive the blast wheel to rotate rapidly. Then centrifugal force and wind power come from the rapidly rotating blast wheel. The velocity of pills is just been made by this centrifugal. The pills coming from the entering pipe will be accelerated by the rapidly rotating partitioning wheel. After that they will go though the accessory which make the pills at some direction. Then these pills after thrown out through the directional accessory's window will be picked up by the vanes of the rapidly rotating wheel and will be accelerated incessantly along the vanes at the extent direction and will be finally thrown out at the end of vanes. After being thrown out the pills which will have acquire the demanded velocity and will have formed fan figure bind will strike the prepared surface so that the surface will be cleared and will be intensified. And then the pills will rebound along with removed contaminants into recovery chamber. In the recovery chamber the high-power dust collector will remove contaminants which have been separated from the pills by the separated system. Very little abrasive is lost and the usable pills will be returned to the storage hopper for recirculation. In the dust collector these contaminants after being filtrated by the colander will be left on the colander and in the storage chamber. Automatic back flushing dust collector can clear up the colander intermittently by the back flushing air which provided by compressor. The efficiency of shot blasting is affected by amount, size, velocity impactive direction of the pills. The economical and technical performance is demanded by shot blasting system. Certainly the performance of the dust collector is also important. We can adapt three parameters to the different prepared surface. The parameters are the shape and size of the pills, the velocity of the equipment and the flux of the pills. That these parameters match each other can make the machine treat different surface and acquire different effect and also make sure that the surface is rough enough.In the exordium of paper, the domestic and foreign development of technology for shot blasting machine is introduced briefly, which indicates difference in mature technology with foreign country and the problem existing in scope and coverage of application. In addition, the characteristics and function of shot blasting machine developed in this project are introduced detailedly. In the end, the thesis describes the direction and main content of research.Shot blasting efficiency of cleaning lies on quantity, dimension, velocity, impact direction of bullet. Therefore, the economical and technical indexes of shot blasting cleaner depend on its function. Accordingly, the second chapter analyzes configuration and operational principle of shot blasting machine, and then presents abrator head, ball blast house and recovery-separation device in detail. Thereamong, the core equipment is mainly discussed which consists of shot blasting structure, theory of operation, design of structural parameters and the method of increasing fatigue of shot blaster. Finally, the noise factors effecting shot blasting machine are concluded and analyzed step by step, as result, the measurements of decreasing noise are put forward. In the third chapter, the mechanical models of bullet and blades are built, so deduce the solution formula about velocity of bullet. Aiming at the shot blasting machine, it is significant to study the bullet velocity because velocity of bullet is an important index. The chapter presents the process of analytical calculation when bullet coming into the window of impeller, and then gives out the condition of bullet only with radical velocity or circular velocity entering the window of impeller. The chapter not only analyzes the influence of the different shape of blades on bullet velocity and life of blades but also researches the relationship between friction and velocity of bullet. 3D model of shot blasting machine and dynamic simulation model of shot wheel are built and dynamic analysis theoretics about ADAMS are introduced.The forth chapter is the core part in this thesis, in which dynamic simulation of bullet used in shot blasting machine is analyzed. Meanwhile, the collision contact problem and dynamic friction simplied are researched. Furthermore, we introduce the bullet of shot blasting machine, present influence how bullet with different material has effect on casting, and then give out general expression which is multivariate function about effect of bullet cast. This chapter gives emphasis to effect of the key parameters of single impeller head of throwing machine on bullet velocity, and analyzes the design about double impeller of throwing machine as well as dynamic simulation about bullet in impeller head device. After comparing the simulation results to theory results minutely, we analyze the reason why deviation exists between two methods. According to discussing position about orientatied sleeve of opening corner, we put forward three optional plans and conclude the method of selecting position of orientatied sleeve based on the practical situation, . Finally, the chapter discusses the correlative factors that influence the casting and radial scattering angle.The fifth chapter is this article test portion, this article allexplanations all had full manifesting in this chapter, it has providedthe reality basis for this article all theory elaboration. In theactual work, may refer to this experiment to carry on the equipmentthe debugging.The sixth chapter shows the conclusion and prospect of this thesis. We summarize the work finished and conclusion deduced, and then point out the keystone in the next work. |
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