离心式滩涂贝类播苗装置设计与试验

Design and test of a centrifugal shellfish seeding device for tidal flat aquaculture

为解决滩涂贝类无专用机械化播苗装备,以及人工播苗效率低和均匀性差等问题,根据贝苗特性及播苗作业规范,以四角蛤蜊Mactra veneriformis苗为研究对象,设计离心式滩涂贝类播苗装置,通过对播苗装置及其运动过程进行分析,建立了在离心叶轮盘上运动的动力学模型,应用离散元颗粒仿真软件(EDEM)进行播苗过程的离散元仿真,基于Design-Expert软件进行播苗装置行进速度、叶轮盘叶片个数和叶轮盘转速对贝苗分布变异系数的响应曲面分析,优化播苗参数,并进行滩涂贝类播苗验证试验。结果表明:各因素对贝苗分布变异系数影响的主次顺序为叶片个数>叶轮转速>行进速度;叶片个数与叶轮转速的交互作用极显著影响贝苗分布变异系数(P<0.01),叶轮转速与行进速度的交互作用对贝苗分布变异系数的影响次之(P<0.05);经回归分析得到最优组合参数为叶片个数4、叶轮转速500 r/min、行进速度0.77 m/s,在此条件下,贝苗分布变异系数的离散元仿真值为8.53%,滩涂播苗装置的实测值为9.33%,仿真值与实测值的相对误差为8.46%,破碎率为2.17%。研究表明,基于离散元的仿真分析方法可用于离心式滩涂贝类播苗装置设计与参数优化,所设计的离心式播苗装置可为滩涂贝类机械化播苗装备设计提供参考。

In order to solve the problems of high labor intensity,low efficiency and poor uniformity of manual seedling,a centrifugal seeding device was designed for tidal flat culture of surf clam Mactra veneriformis,according to the characteristics of clam and the seedling operation specifications.The force and movement of the seedling process was analyzed and the dynamic moving model of the clam on impeller disc was established.Discrete element simulation of the seeding process by discrete element method(EDEM)and simulation orthogonal experiment based on Design-Expert software were carried out.The response surface analysis of variation coefficient of shellfish seedling distribution and the travel speed of seedling device,the number of impeller disc blades and the speed of impeller disc were investigated,and operational performance of the seeding device was demonstrated by site seeding.The regression analysis and tidal flat seeding approach revealed that the optimal operational performance of the seeding device was observed under the combined parameters of blade number of 4,the impeller disc revolving speed of 500 r/min,and the moving speed of 0.77 m/s in the ship,with the simulation value of 8.53%in the discrete element distribution variation,the measured value of 9.33%by the polycast seedling device,the relative error of the simulation value and the measured value of 8.46%,and the fragmentation rate of 2.17%.The findings indicate that the simulation analysis method based on discrete is feasible to use in the design and parameter optimization of the centrifugal shellfish seeding device,and provide reference for the beach equipments.