Development and application of an intelligent experimental device with series-parallel double towers for absorption and desorption

As a core device for teaching experimental chemical engineering principles, absorption and desorption towers are irreplaceable for helping students understand mass transfer theories and master engineering operations. This study addresses the main problems facing traditional experimental absorption and desorption devices, including potential safety hazards caused by the use of toxic gas mixtures such as acetone and ammonia, single-experiment application owing to the single-tower design, low academic value that lags behind the needs of modern industry, and cognitive obstacles resulting from the non-transparency of stainless steel tower bodies. This research aims to develop a new type of multi-functional, intelligent experimental device that supports the training of future engineers capable of addressing complex engineering challenges within the context of emerging engineering education and to provide innovative methods for teaching experimental chemical engineering principles.

A university-enterprise joint research and development (R&D) model was used to construct a device structure with stainless steel as the frame and transparent organic glass as the tower body. The core design steps include selecting the carbon dioxide-air mixture as the non-toxic and environmentally friendly system to be absorbed, which conforms to green chemical engineering and the “carbon peaking and carbon neutrality” strategy; designing a water circulation system to realize the recycling of water resources and reduce experimental consumption; innovatively building two same-size tower bodies filled with Raschig rings and Pall rings, respectively, which can realize flexible switching between series and parallel connections through valve control; integrating the system with Internet of Things (IoT) and PID intelligent control technology, and matching it with equipment such as infrared detectors and electromagnetic flowmeters to realize part-process touch operation, real-time data display, and remote operation.

The device achieved breakthroughs in multiple dimensions: the transparent tower body resolves the non-transparency problem of traditional devices, enabling visualization of the internal structure and allowing students to observe the gas-liquid flow state; the series-parallel structure facilitates multi-scenario tasks such as parallel measurement of the packing performance and series mass transfer experiments, enriching the teaching content and improving the experimental efficiency; the non-toxic system and intelligent control eliminate potential safety hazards, conform to the characteristics of modern industrial technology, facilitate digital empowerment in experimental teaching, and provide possibilities for cross-regional teaching. This device has been operating stably at Zhejiang University of Technology for three years, with remarkable teaching effectiveness and recognition from certain universities and peers, and has been successfully promoted to six universities. This year, it also became the designated experimental operation device for the National Final and Northwest Division of the 8th National College Students' Chemical Engineering Experiment Competition.

The intelligent experimental device with series-parallel double towers for absorption and desorption effectively overcomes the limitations of traditional devices. Through visual presentation, multi-process design, safety upgrade, and intelligent control, it helps students deepen the cognitive connection between mass transfer theories and engineering applications, expands the breadth and depth of experimental teaching, and effectively cultivates students' comprehensive experimental design and data analysis ability, innovative engineering thinking, and ability to solve complex engineering problems. This device provides effective support for reforming the experimental teaching of chemical engineering principles against the background of emerging engineering education and provides a reference for optimizing and upgrading similar teaching equipment.