Method enabling trawl net to vertically expand

Abstract

Disclosed is a method enabling a trawl net to vertically expand. Canvas is utilized for manufacturing flexible expanders. The method is characterized in that the flexible expander is made to be rectangular, the periphery of the expander is sewed with edges, and stamping eyelet rings are evenly distributed on a center line of each sewing edge; the flexible expander is tied on a middle position of an upper line or flexible expanders are respectively tied at the middle position of the upper line and the middle position of a lower line, the flexible expander tied on the middle position of the upper line is connected with a string of cork wire ropes of a deepwater trawl net, a rope ring at each of both ends of each cork wire rope is provided with an attack angle control line, two attack angle control lines of the flexible expander which is at the middle position of the upper line are respectively connected with the upper line on two sides of the flexible expander, the flexible expander which is tied on the middle position of the lower line is connected with a string of iron chains, an attack control line is installed at each of both ends of each iron chain, and two attack control lines of the flexible expander which is at the middle position of the lower line are respectively connected with the lower line on two sides of the flexible expander; and flexible expanders adjust an attack angle through adjustment to the lengths of the attack angle control lines. The method is suitable for the deepwater trawl net and a termocline trawl net.

Description

technical field [0001] The invention relates to a trawl attachment and a trawl vertical expansion technology. Background technique [0002] Trawl fishery occupies a large proportion in my country's marine fishery, and the vertical expansion performance of trawl net is one of the main evaluation criteria of trawl gear performance, and is the main factor affecting trawl output. At present, my country's trawl nets generally use plastic floats to bind the upper class to expand the net gear upwards, and use sinking materials (usually iron chains or multiple steel wire ropes) to tie the net mouth of the net gear to the lower class to expand downwards, thereby achieving The purpose of opening the mouth of the trawl in the vertical direction. With the decline of offshore resources, my country's trawling operations are developing towards large-scale deep-water and variable-water layer trawls. At present, the pressure-resistant water depth of plastic floats produced in my country is g...

AI Technical Summary

Problems solved by technology

With the decline of offshore resources, my country's trawling operations are developing towards large-scale deep-water and variable-water layer trawls. At present, the pressure-resistant water depth of plastic floats produced in my country is generally about 200 meters. The thickness is too large and the static buoyancy is small, so it is difficult to adapt to the operation requirements of mid-water trawl and deep-water trawl

The large size of the trawl net makes the weight added to the lower outline very heavy, which causes inconvenience to the operation and maintenance of the net gear

Countries with developed fisheries in the world also use sinking plates, hydrodynamic buoys, etc. to vertically expand the net mouth, but these devices are either complex in structure, high in cost, or heavy in themselves, inconvenient to operate, and have poor practical results. Trawling nets are not used in our country

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