Development Of Automatic Detection Instrument For Sulfitation Intensity In Sugar Refinery

Sugarcane juice clarification is an important part of the sugarcane process, the sulfur dioxide generated by food-grade sulfur combustion is often used to clarify the sugarcane juice in Sulfitation Sugar Mill. Sulfitation intensity is used to indicate the number of sulfur dioxide which is absorbed in the sugarcane juice clarification. The low sulfitation intensity will affect the clarification, when the high will make the residual sulfur dioxide high in sugar, affect sucrose quality. Therefore, sulfitation intensity is an important parameter to detect in the process of Sugarcane juice clarification. Currently, manual titration as a traditional detection method, which has some defects, such as large operating strength and intermittence, is the main method to detect sulfitation intensity; It is also difficult to meet the real-time adjustment needs and results in inconsistent quality of the product.In this paper, an online titration instrument to detect sulfitation intensity has been designed, which in based on color sensor, and the reference of traditional detection methods as well as related instruments. The instrument simulates the traditional manual titration method, and uses the starch as indicator, and takes a known concentration of standard iodine solution to titrate the juice. The system takes the STM32F407 as central controller, migrates embedded real-time operating system Free RTOS, selects the stepper motor driven syringe pump as titration equipment, and uses a color sensor TCS3200 to detect the endpoint of the titration. This measurement system is divided into a microprocessor module, system communication module, human-computer interaction module, power module, stepper motor drive module and color sensor module. CAN communication system of communication module facilitates the control room monitoring. Serial screen included by human-computer interaction module provide a friendly interactive interface on-site.The Detection system can properly run after the debugging of hardware and software. Precision of syringe pump meets the testing requirement of titration. The color sensor can identify the titration endpiont well. After the simulation sugarcane juice for testing, titration detection system has higher precision, good reproducibility and smaller error than current manual titration method. After a long time online testing, the instrument meets the requirements of sulfitation intensity detection.