升降式网箱装置

为了发展海水养殖，提高网箱的抗风浪能力，日本最近研制了一种升降式网箱装置。升降式网箱是一个直径十五米、高七米的类似圆筒状的结构。网衣采用金属材料制成，网箱上部装有浮子。网箱四周有四个绞绳滚筒，滚筒上分别由钢索与沉着海底的沉子相连。从而使网箱固定在水中，网箱的升降由海上渔船遥控，     

广东深水网箱养殖，重新起航——深水网箱养殖显活力

希望在路上，梦想在前方。 在国内深水网箱发展史上，广东创造了好几个引以为傲的全国第一：第一个引进国外升降式抗风浪深水网箱成功进行养殖．率先研制出第一组国产升降式抗风浪深水网箱．第一个利用深水网箱养殖的活鱼成功出口香港……     

科技之窗

正"具有类三角形浮管框架的深水网箱"获国家实用新型专利授权日前,由中国水产科学研究院南海水产研究所郭根喜、胡昱、陶启友等人完成的"具有类三角形浮管框架的深水网箱"获得国家实用新型专利授权。该实用新型公开了一种具有类三角形浮管框架的深水网箱,包括浮管框架和网衣,浮管框架包括由三根主浮管连接组成的类三角形浮管外框、三根中心区     

日本钢结构升降式大型深水网箱结构原理介绍

1日本钢结构升降式深水网箱的结构和作用 日本钢结构升降式大型深水网箱主要是由网箱本体系统和锚泊固定系统二大部分组成。其结构原理如图1。     

美国式钢质升降式大型深水网箱结构原理的研究探讨

目前国际上的网箱形式多种多样，网箱分类的方式也有多种多样，根据网箱的使用性质和使用海域，可将网箱分为浮式网箱和升降式网箱两大类。     

抗风浪深水网箱用连接件的开发

抗风浪深水网箱主要由框架系统、网衣系统、固迫系统、配重系统等组成，其中框架系统是整个深水网箱抗风浪的关键设备，它既要产生浮力，又要能经受住风浪的袭击。目前框架系统主要是采用HDPE材料制作，由2根或3根浮管、连接件、立柱和扶手管组成，其中连接件是用于连接2根浮管，     

俄罗斯钢结构升降式大型深水网箱的结构原理

目前国际上的网箱形式多种多样,网箱分类的方式也有多种多样,根据网箱的使用性质和使用海域,可将网箱分为浮式网箱和升降式网箱两大类。     

升降式抗风浪深水网箱充气系统原理及参数计算

近年来网箱养殖业发展迅速 ,浙江省网箱养殖的发展速度和力度处在全国的前列。无论是近海的传统形式的网箱或从国外引进的大型深水网箱 ,以及在国外网箱基础上国产化的深水网箱 ,都已在浙江省渔区逐步推广使用。大型抗风浪深水网箱 ,浙江省近年来开发的主要形式有 :高强度聚乙烯 (ＨＤＰＥ)框架的园形浮式网箱、钢结构框架多边形浮式网箱和钢结构框架的锥形 (飞蝶形 )升降式网箱。几种网箱都有各自的特点 ,可根据不同的海区状况加以选用。由于升降式网箱具有在台风来临时沉入海中 ,避免因风浪的撞击而损坏 ,待台风过后升到水面的升降功能 ,…     

近海浮绳式网箱养鱼

所谓近海浮绳式网箱养鱼，就是在港湾外的近海较深水域设置浮绳式的网箱，选择优质的鱼类，进行高密度、集约化的养殖。它是在内湾传统式网箱养鱼的基础上发展起来的一种优质、高产、高效的网箱养殖模式。 为了发展浮绳式网箱养鱼产业，介绍一下有关近海浮绳式网箱养鱼的技术。主要包括养殖场地的选择、网箱的制作与设置、鱼种的培育和投放、饲料的种类及投喂和饲养管理。 一、养殖场地的选择 首先介绍一下近海浮绳式网箱养殖场地的选定。由于这种养殖模式的网箱是设置在港湾外的近海，虽然它的结构是具有一定抗风浪能力的柔韧结构，但是也…     

“具有对称翼型剖面的网箱系统”和“对虾育苗用推卵装置”获得国家发明专利授权

正2017年7月,由中国水产科学研究院南海水产研究所王绍敏、陶启友、胡昱等发明的"具有对称翼型剖面的网箱系统"获得国家发明专利授权,专利号为ZL201510014514.7。该专利公开了一种具有对称翼型剖面的网箱系统,包括浮管框架和网衣。网衣的顶部连接浮管框架、底部边沿系挂有多个网衣重砣,以形成横截面形状与浮管框架相适配的养殖空间;浮管框架设     

HDPE倾角入水式大型深水升降网箱的研究

为抵御强风暴袭击和躲避赤潮灾害对深水网箱结构和养殖鱼类的危害，研究设计了一种HDPE倾角入水式深水升降网箱，并在海上进行了自然放气与手动调控2种排气方式下网箱的沉浮试验，利用手动控制方式实现了网箱的成功升降。结果显示，试验网箱的平均沉降时间14min，平均上浮时间10min，其特点是沉浮操作比较简便、网箱配重小、换网快、隐患少、维护方便；并解析了试验中风、浪、流等海洋环境因素对网箱沉浮过程的作用与影响，解释了自然放气方式下网箱不能完全沉入水中的原因。     

用数值法计算圆形沉浮式深海网箱的下潜水深

应用一系列力学关系,给出了深海沉浮式养殖网箱的运动方程组,在网箱下潜深度的研究中采用绕射理论和Morison方程进行了波浪力分析,讨论了网箱的下潜深度随波浪的波高、波长及周期的变化情况,得出下潜水深比较小时深海网箱的波力变化快,当达到某一个下潜深度以后,波力的变化趋于平缓,从而为深海网箱选用最佳工况提供了一种参考方法。     

不同培育方式对赤点石斑鱼成熟、产卵和孵化的影响

在深水网箱、传统小网箱和室内水泥池三种培育方式下,采用埋植外源激素的方法诱导赤点石斑鱼提前完成性转化,获得功能性雄鱼,并用所得雄鱼和人工驯化培育而成的雌鱼进行了亲鱼培育、产卵和孵化试验研究。结果表明:雌鱼性腺成熟以深水网箱培育为最好,室内水泥池培育次之,传统小网箱培育最差;转性效果深水网箱与室内水泥池培育相差无几,转性率分别为97.0%和94.6%,传统小网箱较差,转性率仅65.9%;自然雄鱼以深水网箱为最多。其中,2004年共获得亲鱼246 ind,施行转性手术100 ind,转性率达87.9%,先后获受精卵230.5×104粒,平均受精率22.4%,孵出仔鱼80×104ind,平均孵化率34.7%。     

Microbial mineralization of organic matter in sinking particles,bottom sediments and seawater in a coastal fish culturing area

Microbial mineralization rates in sinking particles, bottom sediments and seawater were determined in a coastal fish (red sea bream Pagrus major) culturing area to clarify the mineralization process of organic matter (OM) in the entire water column. The mineralization rates of ¹⁴C‐labelled glutamate and glucose per unit volume were highest in the sinking particles and were 131–572 and 7–49 times higher than those of the seawater and bottom sediments respectively. The turnover time of glutamate tended to be shorter than that of glucose at all three sites of the water column. Bacteria appeared to prefer amino acids to monosaccharides because amino acids could be utilized as both energy and nitrogen sources. The sedimentation rate of particulate organic carbon (POC) derived from phytoplankton accounted for 9–61% of the total POC, and it was particularly high in early summer (61% and 50% at fish cage and non‐cage stations respectively). The present study clearly shows that sinking particles serve as an important site of microbial mineralization process of OM within the water column, and that phytoplankton production was another serious cause of organic pollution of the seafloor in addition to the organic wastes directly discharged from fish farms.     

A simple and inexpensive spawning and egg collection system for fish with pelagic eggs

A spawning and egg collecting system for fish with pelagic eggs is described and discussed. The spawning unit is a 175 m³ submersible plastic pen supported by a polyethylene floating collar. The eggs are collected by rotating the water column in the pen and placing a net in the rotating water. The system is inexpensive and easy to operate. Temperature and illumination control are feasible.The quantity collected in the 1981 spawning season was 138 million eggs. Obtained eggs were of good quality. The theoretical spawning potential of the brood stock was 271 million eggs. This difference was mainly ascribed to suboptimal collection, but also to incomplete spawning and sinking of unfertilized and dead eggs.     

水流作用下重力式网箱浮架结构的动力响应研究

近年来深水网箱养殖设施得到了广泛的应用,浮架作为网箱结构的重要组成部分,其安全性对网箱的设计至关重要。基于有限单元法采用SHELL单元建立了浮架结构的荷载-变形数值模型,对水流作用下浮架的应力和变形进行了数值模拟,并开展物理模型试验对该数值模型进行验证。结果表明,该数值模型可以准确模拟浮架的变形,采用该数值模型,分析了不同流速条件下浮架的变形和应力,数值模拟结果显示:随着流速的增加,浮架的变形和应力逐渐增加。相同流速条件下,注水下潜后,浮架的应力和变形能够显著减小;因此,在强流条件下,可以采用浮架注水的方式,使浮架处于下潜状态,以改善浮架结构的变形和应力分布。     

Automatic submerging and surfacing performances of model submersible fish cage system operated by air control

An automatic, submersible fish cage system using air control was developed and a set of model experiments were conducted to examine the automatic submerging characteristics of the cage. The components of the fish cage consist of a rigid frame assembly with 6 variable ballast tanks and 6 fixed ballast tanks. The variable ballast tanks were used to change the buoyancy characteristics of the system by air control so that the fish cage can either be placed at the surface or submerged. The cage is free to move vertically within a water column by adjusting the weight and the buoyancy with an air control system. The model of this system, with dimensions of 2.20 m in diameter and length and 1.04 m in net cage depth, was constructed to be 1/10 the size of the full-scale system. In the model experiments, the submerging and surfacing characteristics of the cage were regulated with measurements from a water-pressure gauge and a gyroscope incorporated into the automatic control system. Model tests were performed in a still water tank and a large wave tank to develop the algorithm required to control the cage system and to verify the ability of the automatic submersion mechanism to function. The control system was designed so that when the variable ballast tanks were flooded with water, the model descended. To raise the system, compressed air is injected into the tanks by opening the main evacuation valve on the manifold. After the required amount of compressed air is supplied, the main evacuation valves can be shut and as a result, the fish cage becomes buoyant. Measured performance results in a still water tank are then compared with calculations from a previously developed numerical technique. The submerging and surfacing characteristics of the fish cage were relatively similar to the measurements obtained with the physical model experiments using air control. The cage was submerged to a target depth when incidence wave heights were higher than the critical wave height and raised when little wave actions were detected in a wave tank. On the other hand, the cage was placed at the surface when incidence wave heights were the same as the critical wave height or lower.     

HDPE圆形重力式网箱受力变形特性的数值模拟

该研究旨在综合探讨不同网箱周长、浮管管径、网衣高度及网目大小对整体网箱受力变形的影响,为网箱的科学合理选型提供数据参考。设定的网箱周长40—80m,浮管管径250～630mm,网衣高度6～20m,网目大小45～115mm。通过数值模拟方法对4种规格高密度聚乙烯圆形网箱在不同组合条件下网箱锚绳受力、波流力以及容积损失率进行了数值计算。结果表明,大规格网箱的锚绳受力、波流力更大,容积损失率更小,锚绳数量的增加可以大大降低锚绳受力。相比浮管管径,网衣高度和网目大小对网箱受力变形的影响更显著。整体网箱的受力变形随着网衣高度的增加而增大,随网目的增大而减小。     

圆柱形大型抗风浪养殖网箱网衣结构与装配技术

大型沉浮式抗风浪养殖网箱是近几年在引进国外先进技术的基础上,根据我国各沿海地区的实际情况加以创新并应用于海水养殖业的一项高新技术项目.本文主要介绍近年来开展大型抗风浪养殖网箱的研制中,关于圆柱形大型抗风浪网箱的网衣设计依据、结构与规格、制作工艺与装配技术及养殖过程中的注意事项.     

Numerical simulation of deformations and forces of a floating fish cage collar in waves

The dynamic behavior of a fish cage collar in waves was investigated using a numerical model based on the finite element method. The floating collar and mooring system were divided into a series of line segments modeled by straight massless model segments with a node at each end. To verify the validity of the numerical model, research data from other authors were cited and compared with the simulated results, the comparison of results showed a good agreement. The numerical model was then applied to a dynamic simulation of a floating cage collar in waves to analyze its elastic deformation and mooring line tension. The simulated results indicated that the greatest deformation of the collar taken place in the position of the mooring line connection point when incident waves were in the same direction. An increase in the length of mooring line would help to decrease the mooring line tension of the collar. Furthermore, the effects of collar dimension, including collar circumference, pipe diameter in cross-section, and pipe thickness, on the dynamic behavior of the floating collar were discussed. The results of this study provided a better understanding of the dynamic behavior of the fish cage collar.