Fish blocking system and technical introduction of blocking fish

Composition of fish blocking system

System features

1、Security

   ——The equipment adopts high strength insulation, so it can be touched;

   ——Main controller completely adopts the design of very large scale integration; the treating process of power supply changeover and boosted circuit completely adopts digital and micro treatment technology.

   ——The system adopts energy complement technology to make the operation noise of overall system less than 20db， which is inaudible.

   ——Zero passage technology and pulse bounce technology are adopted; when the equipment works without any interference and radiation for power grid.

   ——Working electrode pulse meets the safety index requirements of the State.

2、Reliability and stability

   ——Cold and hot spare structure and automated exchange technology are adopted to ensure the reliability for a long time service.

   ——The self-adaptation control, anti-shock structure and the design of military technology are adopted to maintain the stability for a long time service under severe environment.

3、Large area and remote control

   ——Integral type or sectional type can be controlled, and then the maximum control area can reach 10KM.

Method of fish blocking

1、Suspension type

Applied to river width less than 60m; the minimum position of horizontal steel wire rope shall be higher than 0.5m above maximum water level; the electrode array is hanged on the top of design section.

2、Floating type

For river width within 10 kilometer, the spacing of floating tank is less than 50m, and the minimum position of horizontal steel wire rope shall be slightly higher than water. The electrode array is connected with the floating tank that is fixed on the water of design section.

3、Ball float type

Adopted immersion node machine; particularly, applied to blocking downstream fish, the river width is 10 kilometer.

4、Stationary type

Applied to the place, such as intake, bridge floor, etc., that can fix the electrode; the electrode array is fixed on the location of design section.

Design Points

At present, blocking fish with electric screen is the one of main methods to prevent stocked fish in natural water from escaping. It is based on electric field in the water to stimulate fish, which has the reaction of preventing electric for the electric field in the water, thus to achieve the result of blocking fish.

1、t confirms the voltage, pulse frequency and pulse width of main machine power, according to the change of pulse frequency and width, signal strong and weak for different breeds of fish.

2、The best choice for blocking fish is small section of electric screen, and there is open water on the inside of horn location, which is more beneficial to fish migration after meeting electric yield. And the section of electric screen is not perpendicular to water direction.

3、For blocking upstream fish, the section of electric screen has enough electric yield to force fish to migrate after electrification; the section that saves raw material and is easy for construction can be applied. Generally, it is better to use double row electrode array.

4、For blocking downstream fish, 0.5-0.7m/S flow rate can be as the design standard of blocking downstream fish.

5、Confirm the spacing that electric screen is jointed with electrode , according to the conductivity of the local water quality and the size of the blocking fish.

6、The electrode material of electric screen shall have a suitable strength and good conductivity; generally 2-3 inch external diameter galvanized tube is as electrode, the length of electrode shall be higher than 0.5m maximum water level. 

7、Power bus of electric screen transmission high voltage pulse is multiplied copper stranded wire or duralumin bare stranded wire; the section of electric conduction shall not be less than 25mm2. Power bus is fixed by porcelain insulator on the cross arm of electrode top. Bus is connected with each electrode by multiplied flexible copper core insulated wire, which the rated voltage is not less than 500V; the section of electric conduction shall not be less than 4mm2.