Detection Method And Device Of Mud Content In Base Sand By Turbidity Method

The amount of mud in the base sand is one of the important indicators to characterize the quality of the base sand.It directly or indirectly affects the performance of the sand with the base sand as the backbone material,which ultimately affects the quality of the sand casting.Therefore,one of the keys to controlling the quality of castings is to solve the problem of quickly and easily testing the mud content of the base sand.At present,the detection of mud content in base sand is based on the traditional principle of detecting mud content in base sand,and the national standard detection method is adopted.The operation process is cumbersome and time consuming,and it is not suitable for on-site inspection of sand in foundry.In this paper,the mud sand was firstly separated by vortex washing.Then,according to the law that the turbidity of the mud-sand mixture changes with the change of the mud content of the base sand,the turbidity of the mud turbid liquid after sand vortex washing is proposed to quantitatively measure the mud content.That is,the turbidity sensor is used to measure the turbidity of the original turbid liquid after vortex washing,and the determination of the mud content of the base sand is completed by the correspondence between the established turbidity and the mud content.Finally,based on this principle,a rapid detection device with a short measurement cycle and high degree of automation was developed.The equipment can directly test the mud content of the foundry sand in a short time,thereby eliminating the repeated siphoning water and the final drying process in the standard method.According to the method of detecting the turbidity of turbid liquid by turbidity sensor in related fields,overall shape design of the device for detecting the mud content of base sand by turbidity method are carried out.The STC89C52 MCU is selected as the main control unit,and the sensor,A/D converter,LCD display and buzzer are connected with the single-chip hardware.The design program can meet the functions of timing detection,automatic calculation and automatic display.The influence of the turbidity detection result on the turbidity optimizes and determines the optimal position of the sensor: the horizontal coordinates of the probe is at the geometric center of the sand washing cup,and the vertical coordinates is 50 mm above the bottom of the sand washing cup.By the experimental device was calibrated to determine the mathematical relationship between the mud content and the turbidity voltage: x(28)-1.022y(10)1.022k(x is mud content,y is turbidity voltage,k is clear water voltage),and compare the turbidity method with the national standard test show that the turbidity test time can be reduced by 90%.It is proved by T test that the turbidity method and the national standard test method are close to 99%.The equipment is suitable for rapid detection of the content of the base sand slurry used in the foundry production site.