Research On Countercurrent Steep Simulation System For Maize Wet-milling

Domestic and foreign investigations on the material changes in the maize steeping process and the migration of mycotoxins in the wet-milling process are mainly divided into direct factory sampling and laboratory-scale simulation experiments.The plant sampling method has the problems of uneven raw material mycotoxin levels,large scale and difficult to accurately sample,limited adjustment of process parameters,and lack of raw material samples with high mycotoxin levels,which makes it difficult to obtain mycotoxin migration patterns that can cover high,medium and low mycotoxin levels,and different process conditions.The static steeping method in the laboratory is different from the factory steeping process and cannot simulate the material exchange in the steeping process,which makes it difficult to obtain a reliable migration model.In this paper,a 5 kg level maize counter-current steeping device was developed to simulate the counter-current steeping process commonly used in plants by using an automated program for process control and online monitoring of relevant parameters during the steeping process using p H,conductivity and temperature sensors.And a preliminary investigation of the migration of mycotoxins in the counter-current steeping process was carried out.The main research contents of this paper include:1.By analyzing the counter-current steeping process in corn wet milling,a counter-current steep system consisting of steeping tank,thermostatic monitoring box,solenoid valve,filter,magnetic pump and corresponding piping was designed;the online monitoring sensors were selected and calibrated;the data acquisition board was designed and fabricated to integrate the sensors and interface lines;the load control line and signal acquisition were built using PLC and relay.2.Program the microcontroller to realize p H,temperature,solids data acquisition and Modbus/TCP communication;program the PLC to realize PID temperature control and relay management;write the local server to realize data communication,pouring tank logic and data processing function;write the user interface to realize data display and user interaction function.3.The difference between the steep system built in this paper and the plant steeping was evaluated in terms of effluent concentration,effluent p H,corn moisture,and wet milling main and by-product yields.The effluent p H,effluent concentration,and corn moisture after steeping of the designed equipment can reach the actual production level of the plant,and the migration of deoxynivalenol,zearalenone,and aflatoxin in the counter-current steeping process was initially investigated.