Research On High Pressure Water Jet Cleaning Technology For Tank Truck

As an important carrier of highway transportation,automobile tanker is widely used in petroleum,chemical and other transportation fields.As a kind of mobile pressure vessel,automobile tank truck needs periodic inspection according to relevant regulations.In order to ensure the accuracy of magnetic particle inspection,wall thickness measurement and the safety of inspection personnel,it is necessary to clean the inside of tank in advance.The dirt of liquefied petroleum gas tank truck is difficult to clean because of its complex composition,high viscosity and strong adhesion.The largest,so this paper mainly focuses on the LPG tank car cleaning technology research.According to market and literature research,there are two main cleaning methods for LPG tank owners at present,i.e.manual bottom tank cleaning and three-dimensional tank washer washing.The former has low cleaning efficiency and bad working conditions,but good cleaning effect and universality;the latter has short cleaning time and high automation,but poor cleaning quality,high water consumption and high cleaning cost.Therefore,in order to give full play to the advantages of the above two cleaning methods,this paper proposes a new cleaning method which combines high-pressure water jet cleaning with mechanical brushing cleaning,and integrates mobile mechanism technology into the platform of cleaning mechanism,integrates a car tank car wall-climbing jet cleaning car,and uses theoretical derivation,numerical simulation,simulation calculation and experimental test.The related cleaning technology,executing equipment,jet parameters and mechanical characteristics of high-pressure water jet cleaning technology for automobile tankers are deeply studied by means of demonstration and other methods.The main contents of this paper include:(1)Study on operating parameters of high pressure water jet cleaning.Combining fouling characteristics of tank inner wall and fouling removal mechanism of jet brush combined cleaning,the optimum hydraulic parameters of jet cleaning are established.The internal and external flow field of cleaning nozzle is simulated and analyzed by FLUENT fluid simulation software.Through the study of static and dynamic pressure distribution on target surface,the optimum distance and incidence angle of jet which can obtain the maximum effective cleaning coverage area are given for subsequent cleaning.Research and development of washing equipment and optimization of performance parameters provide theoretical basis.(2)Research and development of tank car cleaning equipment and optimization of performance parameters.The overall structure of cleaning system of automobile tank car is built.Combining with the internal space structure of tank body and cleaning conditions,the solid works software is used to design the body structure and build a full scale three-dimensional model.Then the differential equation of rotation of the spray mechanism is derived.Then the factors affecting the speed of the spray mechanism,such as the tightening force of the steel wire brush,the radius of rotation of the nozzle and brush,the roughness of the wall and the starting time are analyzed.The optimal speed and the optimal combination of influencing parameters are given.Finally,the motion simulation of the car’s brush trajectory is carried out by ADAMS software,and the maximum travel speed of the brush trajectory under complete traversal is given.(3)Study on mechanical characteristics of wall-climbing jet cleaning trolley.The static and dynamic models of the cleaning car are established,and the minimum adsorption force equation for the car under three failure modes,i.e.preventing sliding along the wall,longitudinal overturning and lateral overturning,and the minimum driving moment equation under two operation modes of straight-line driving and differential steering are derived.Then,the numerical simulation of different wall inclination angles and different wall roughness is compared and analyzed.The results show that the qualitative test results are in good agreement with the numerical analysis results.The validity of mechanical model and theoretical analysis method of cleaning car is verified.