Mechanical Design and Control System Development for a Scallop Shell-Opening Machine

DOI: https://doi.org/10.62517/jes.202602314

Author(s)

Jiahui Zou, Lin Zheng*, Hong Xiao, Jingcheng Wang, Bo Liu, Zhifei Pan, Feifan Xia

Affiliation(s)

College of Intelligent Manufacturing, Jingchu University of Technology, Jingmen, Hubei, China *Corresponding Author

Abstract

To address the problems of low efficiency in manual shell-opening, high breakage rates and difficulty of ensuring adductor muscle integrity for the industry, a fully automatic scallop shell-opening machine controlled by a Siemens S7-1200 PLC was designed. Based on the analysis of the manual shell-opening process, a general structure for an intermittent assembly line with five stations was proposed: feeding, shell grinding and cutting, upper shell removal, discharge, and weight sorting. The centre conveying device of this machine is a 08B single-row roller chain, and custom scallop clamps have been added to the chain. Pneumatic cylinders are used at each station to move and process the scallops precisely by means of automation. A grinding wheel is used at the shell-grinding station to pre-grind a notch, and a superelastic nickel-titanium shape-memory alloy blade is employed in the cutting station to cut through the adductor muscle and improve the integrity rate of the adductor muscle. The Siemens S7-1200 1215C DC/DC/DC serves as the central control unit of the control system, connected to the KTP700 HMI and V20 variable-frequency drive via PROFINET.It employs a hybrid programming approach combining Structured Text (SCL) and Ladder Diagrams to achieve full-process automatic integration and real-time monitoring. Prototype test results show that the equipment achieves a processing cycle rate of 15 units per minute with an adductor muscle integrity rate of ≥ 92%, making it suitable for processing scallops of various sizes.

Keywords

Scallop Shell-Opening Machine; Batch-Type Assembly Line Operation; Chain Drive; Pneumatic Control; PLC

References

[1] Chen W T, Zhang H L, Wang X Y, et al. Application of ultra-high hydrostatic pressure technology in shellfish processing. Journal of Fisheries Research, 2026, 48(2): 287-296. [2] Olsen T, Hansen L. Shipboard ultra-high pressure scallop processing system design and performance test. Aquacultural Engineering, 2021, 92: 102187. [3] Lakhal O, Belarouci A, Yang X R, et al. CoboShell Robot for Automatic Scallop Shelling Process: Concepts and Applications//2023 IEEE/ASME International Conference on Advanced Intelligent Mechatronics (AIM). IEEE, 2023: 1571-1576. [4] Wang H, Zhao B. Optimization of infrared radiation shell-opening parameters for bay scallops based on response surface methodology. Food and Machinery, 2025, 41(10): 89-95. [5] Kong D G, Jiang D, Wang J Z, et al. Design and test of heat treatment and shell opening device for bay scallop. Journal of Chinese Agricultural Mechanization, 2023, 44(2): 76-82. [6] Liu M, Zhou Y, Li H. Design of intermittent chain conveying mechanism for automatic aquatic product processing equipment. Machinery Design & Manufacture, 2024(7): 112-116. [7] Wei J Y, Yang L, Wang G J, et al. Research status of cutting machining NiTi shape memory alloys: a comprehensive review. Frontiers in Materials, 2024, 11: 1431992. [8] Zhang L, Wang T, Sun K. Hybrid SCL and Ladder Diagram Programming Based on Siemens S7-1200 for Food Processing Production Line. Industrial Automation Journal, 2022, 46(11): 45-49. [9] Chang K, Lin Y, Huang S, et al. Optimizing Bay Scallop (Argopecten irradians) Product Quality: Moderate Freezing as an Effective Strategy for Improving Adductor Muscle Gel Properties. Foods, 2025, 14(8): 1371. [10] Zhao Y, Li Q. Design and experiment of automatic shell-opening machine for bivalve shellfish based on PLC and pneumatic control. Transactions of the Chinese Society of Agricultural Engineering, 2024, 40(15): 110-118.