Design And Experimental Study Of Algae Detection System For Ocean Ship Ballast Water

With the development of world trade,ship contacts and transport has nowadays become gradually frequent.Problems caused by ship ballast water like marine ecology and biological invasion have been more and more serious,and the later one has been determined by GEF to be one of the four threats for the global marine ecological environment.Algae detection system for oceangoing ship ballast water could help reduce ecological problems caused by biological invasion and meanwhile lessen pace times of our oceangoing ships in foreign ports,and then improve work efficiency by testing algae's types and numbers in ballast xwater.Presently,research on algae detection technology and its equipment is still relatively blank,yet foreigners are refusing to public their own technology.Therefore,research on that field is quite practical and meaningful for ship manufacturing industry.Problems in designing rotary tube separator are studied in this paper by conducting overall design of algae detection system.The main achievements are as follows:1)Research and feasibility analysis on existing algae enrichment technology and detection method are conducted.2)Based on fluorescence spectra theory,combining technologies like physics.optics,machinery,computers,biochemistry,and control,overall design of algae detection system is finished.Systematical module division has been done to algae detection system by adopting mechatronics.According to independent requirements of each subsystem and the constraints of the entire system to each subsystem,independent design is conducted to each subsystem.3)Based on algae detection system requirements for enrichment subsystem and dynamic separation of rotary tube,explicit design indicators and important parameters,conduct modular design to algae enrichment subsystem,finish the different project designs on the core of enrichment subsystem-rotary tube separator according to different influent modes.4)Prototype of rotary tube separation is processed and prototype tests are conducted respectively to the tube side of water and the top tube water type,finally analyze the test results.Therefore the top tube water type rotary tube separator is selected as algae enrichment device of enrichment subsystem.5)Automatic control pattern of enrichment subsystem is studied.SCM AT89C51 is adopted as core processing and then automatic operation of the whole system is achieved.PWM speed mode is used for motor speed control and the speed of motor will be displayed on LCD.6)Numerical modeling and simulation for internal flow field of the tube side of water rotary tube separator is conducted by using FLUENT,then the distribution of pressure field and speed field under different speeds could be obtained,provide a scientific basis for improving the structure.