| In the industries with improved Siemens method to produce polysilicon,because of various factors such as complicated transmission medium,working condition and personnel operation errors,the key devices alkali pumps in the waste gas and residual liquid treatment process of polysilicon production plate of Xinte Energy Co.,Ltd are prone to fail.These equipment failures bring about production system fluctuation,decline in product quality,environmental pollution and corrosion of the whole unit.The expense which the company uses to manage above-mentioned questions and equipment maintenance is as much as millions of yuan every year.The original lye circulating pump used in the unit is manufactured by Hangzhou lye Pump Co.,Ltd.and put into operation in July2013.The operation failure of the original purchased equipment is frequent,and the service life of the overcurrent parts is 7-14 days on average due to wear and corrosion.Therefore,the equipment technicians are required to conduct research,test and transformation to develop a new type of equipment,which is suitable for the operation conditions of the device and extends the service life of the overcurrent components of the equipment.After comprehensive consideration,the way to solve this problem is to study from the design and selection of equipment,design structure optimization and material selection of parts.According to the scour and wear mechanism of the solid-liquid two-phase flow pump materials on the flow passage parts,the lower the speed of the drive motor is,the better the wear resistance is.When selecting the drive motor,reducing the speed of the original drive motor by half of the original speed can effectively reduce the wear of the overcurrent components.Therefore,this paper mainly considers the design of appropriate equipment parameters at low speed to ensure that the output flow and head of the equipment meet the requirements of process medium transportation.The overflow parts of centrifugal pump include suction chamber,impeller,discharge chamber and other parts.Wear of any part of the above flow passage parts will directly or indirectly affect the power output of the pump;when the wear reaches a certain degree,serious faults such as leakage can occur.Impeller is the core part of the pump,and it is also the most seriously worn part in the flow passage component.In this paper,the solidliquid two-phase flow theory is used to calculate the impeller design in detail,and the main parameters of the impeller are designed to calculate the most favorable parameters for wear resistance.When selecting the material of the flow passage parts,two kinds of metal materials and two kinds of non-metal materials are selected with reference to the suggestions of material selection under similar working conditions at home and abroad.The actual corrosion resistance test shows that the four materials have good corrosion resistance in the solid-liquid two-phase flow mixture studied in this paper,so the main consideration is the influence of wear factors on the service life of the flow passage parts.Due to the high hardness of solid particles such as silicon powder,the particles cause great damage to the wear of flow passage parts.The wear resistance test shows that UHMWPE material has very low friction coefficient and good adhesion resistance,and good wear resistance,which is suitable for the working conditions and equipment studied in this paper.According to the principle of combination of theoretical research and practical application,the equipment designed and manufactured has been verified by experiments.The results show that: after inspection and test,all parameters of the selected motor are within the qualified range;performance test,continuous operation test and cavitation test are carried out for the equipment,and its head,flow,efficiency,NPSH,vibration,noise,etc.All meet the design requirements and industry standards.This is an example of the application of modern pump design theory in industrial engineering.It is also a specific form of joint R & D and design of equipment manufacturers and users,reflecting the advantages of combining theory with practice.It is also found that the damage and failure of over-current components can be reduced by optimizing the operation,maintenance and process control of the equipment.The author mainly demonstrates and analyzes the above aspects in detail,puts forward the targeted solutions,solves the technical problems for the company,and through the field engineering practice verification,the average service life of the overcurrent components reaches 104 days,the longest service life reaches 125 days,and the effect reaches the expected goal. |
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