Abstract:
Abstract: By analyzing and investigating the system of random sampling for bottom sowing offspring seed of patinopecten yessoensis in Dalian Zhangzidao, a new type of high-efficiency and reasonable grading and counting device for scallop seedling was designed. In order to prove the rationality of its structure, comparison tests were executed on the island of Xiao Changshan and the scallop seedlings were collected from this island. Scallop grading specifications were <30, 30?35, >35?40 and ≥40 mm. Mesh specifications were 38, 33 and 28 mm. There were 2 phases for the experiment. In the first phase, the orthogonal experiment analyzed the critical influencing factors of grading and counting statistical accuracy, and determined the optimum technological parameters of grading and counting device for scallop seedling. In the second phase, based on actual production situation, the tests lasted for 1 month (from October 5th to November 4th, 2014) and 4 groups of comparative tests were executed in which 1 group of test was executed within 1 week. Each group of test was repeated by 3 times, and each time grading and counting was finished for one box which stored 20 kg scallops. The interval time between each time was one hour. Grading and counting tests were completed by manual labor and machine respectively. At the end of each day, calculate the statistical deviation rate of scallops, the lower activity rate, the total number of workers and the total time. Through optimizing technological parameters of grading and counting device, the input of scallop seedling grading was finally determined to be 2.5 kg/min, the mesh size increment was -2 mm, the screen motor speed was 130 r/min, the angle between screen surface and horizon was 2°, the screen length was 1.2 m, the input of scallop per unit time in counting was 2 kg/min, the queueing baffle positional relationship was that the angle of upper baffle and conveying direction was 45° and the angle of under baffle and conveying direction was 30°, and belt motor speed was 115 r/min. The results showed that the deviation rates of grading and counting between mechanical and manual manner were 2.82%, 2.33%, 2.28% and 2.90% respectively in the 4 tests for the ≥40 mm group, 3.05%, 4.26%, 4.38% and 3.66% respectively for the >35?40 mm group, 2.26%, 1.75%, 2.10% and 2.29% respectively for the >30?35 mm group, and 9.04%, 11.44%, 7.63% and 9.23% respectively for the <30 mm group. The deviation rates of grading and counting for the 4 specifications between mechanical and manual manner were not significantly different (P>0.05). Working efficiency of mechanical manner was increased by 3.54 times and employed workers were reduced by 6 compared with manual manner. Labor intensity was significantly reduced, and exposing time of scallop seedling was also reduced, which ensured the activity of bottom sowing scallop seedling. It had remarkable economic benefit, and the grading and counting device for scallop seedling could save investment cost by 62.512 ten thousand yuan per year. This method meets the development needs of green industry.