NL2031369B1 - Escape-proof device suitable for fish collection and transportation system for dam - Google Patents

Abstract

The present invention provides an escape—proof device suitable for a fish collection. and. transportation. systenl for dam, wherein. a migration. passage well is provided. at one side of a dam. of a reservoir near the downstream, the migration passage well is in communication with a downstream water area, and a shaft is provided at one side of the migration passage well near the upstream; a plurality of escape—proof cages are provided in the migration passage well, two parallel first horizontal frames are provided at the upper and lower sides of the escape—proof cage, a blocking net fixed. between. the two first horizontal frames is provided near the upstream of the escape—proof cage; a trumpet— shaped escape—proof net cover is provided in the first horizontal frame, and a front end opening of the escape—proof net cover is connected to an opening of the blocking net. (+

Description

P1246 /NLpd

ESCAPE-PROOF DEVICE SUITABLE FOR FISH COLLECTION AND

TRANSPORTATION SYSTEM FOR DAM

TECHNICAL FIELD

The present invention relates to the technical field of water conservancy and environmental protection engineering, and more particularly, to an escape-proof device suitable for a fish col- lection and transportation system for dam.

BACKGROUND ART

The construction of river-blocking water conservancy project inevitably destroys the river connectivity, blocks the fish migra- tion passages and gene exchange, and causes the destruction of fish living environment and ecological diversity.

Fish pass facilities can be divided into up-going and down- going fish pass facilities according to fish migration direction, wherein, the fish collection and transportation system for up- going pass the dam is an artificial auxiliary system for trans- porting fish over the dam by means of fish luring, fish blocking, fish collecting, lifting and transferring, temporary raising, etc.

In the whole fish collection process, how to effectively prevent fish from escaping is the key to fish collection process and equipment design. On one hand, fish should be able to smoothly pass over the dam from the downstream water area to the upstream water area, on the other hand, fish should be prevented from es- caping as far as possible, so that fish can only travel upstream but not return to achieve efficient fish collection.

SUMMARY

In order to reduce the influence of dams on the ecology of fish, the present invention aims to provide an escape-proof device suitable for a fish collection and transportation system for a dam, in which fish in a dam can travel to a shaft near an upstream through an escape-proof cage of the device, fish can travel to a water storage area of a reservoir through the shaft, or it is con-

venient for us to focus on fishing and processing of fish in the shaft. The specific scheme is as follows: an escape-proof device suitable for a fish collection and transportation system for a dam, wherein a migration passage well is provided at one side of a dam of a reservoir near the migration passage well is in communication with a downstream water area, and a shaft is provided at one side of the migration passage well near the upstream, the upper end of the shaft is connected to a water outlet of the dam; the device is composed of several escape-proof cages connect- ed together end to end at the top and bottom and placed in the mi- gration passage well, the two parallel first horizontal frames are provided at the upper and lower sides of the escape-proof cage, the two first horizontal frames are fixedly connected via a sup- port vertical frame, a blocking net fixed between the two first horizontal frames is provided near the upstream of the escape- proof cage, and an opening with an adjustable width is reserved in the middle of the blocking net; a trumpet-shaped escape-proof net cover is provided in the first horizontal frame, the front end opening of the escape-proof net cover near the upstream is smaller than the rear end opening, and a front end opening of the escape-proof net cover is connected to an opening of the blocking net.

Further, the inner wall of the migration passage well is pro- vided with a vertical guide rail, and the frame of the escape- proof cage is provided with a rubber slide in rolling frictional contact with the vertical guide rail.

Further, the first horizontal frame is a rectangular frame, and the support vertical frame comprises a main support vertical frame connecting two sides of the upper and lower two rectangular frames together, and a longitudinal bracket for connecting corners of the upper and lower two first horizontal frames; a blocking net is fixed between two front edges of the upper and lower two rectangular frames near upstream, and two cross frames parallel to the front edges are further provided between the two rectangular frames, the blocking net is composed of an up- per blocking net fixed between the upper cross frame and the front edge of the upper rectangular frame, a lower blocking net fixed between the lower cross frame and the front edge of the lower rec- tangular frame, and a middle blocking net with an adjustable open- ing fixed between the two cross frames.

Further, the escape-proof net cover is provided with two trapezoidal net cover frames which can rotate horizontally, a ro- tating seat is installed on both ends of the rear sides of the up- per and lower two rectangular frames, a sliding groove is provided on the rotating seat, a rear end vertical frame of the net cover frame is rotatably connected in the sliding grooves of the upper and lower two rotating seats, a front end vertical frame is fixed between two cross frames by means of screws, and a row of adjust- ing screw holes is provided on at least one cross frame; a rigid orifice plate is fixed in the area enclosed by each of the net cover frames, and a flexible netting is connected be- tween the two hypotenuse sides of the upper side and between the two hypotenuse sides of the lower side of the two trapezoidal net cover frames.

Further, the upper blocking net and lower blocking net are rigid orifice plates or nettings and the middle blocking net is formed from two pieces of nettings with adjustable spacing.

Further, one end of the main support vertical frame is pro- vided with a latch seat, and the other end is provided with a latch, and the upper and lower two escape-proof cages are connect- ed via the latch structure of the main support vertical frame.

The escape-proof cage of the present invention is placed in the migration passage well, the fish is driven by the migration habit to go upstream through the escape-proof cage into the shaft, and the trumpet opening with narrow front and wide back of the cage is designed to prevent fish from swimming back. The fish can travel through the shaft to the water storage area of the reser- voir, or it is convenient for us to focus on the fishing of the fish in the shaft. In addition, the opening width of the escape- proof cage is adjustable, so that we can choose the appropriate opening width according to the size of the fish body, and avoid the fish from swimming back as much as possible without affecting the fish swimming upward.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overall view of a fish collection and transpor- tation system for a dam according to the present invention;

FIG. 2 is a side view of the system of the present invention;

FIG. 3 is a partial top view of a dam showing the location of migration passage wells and shafts;

FIG. 4a is a perspective view of an escape-proof cage accord- ing to one embodiment of the present invention;

FIG. 4b is a rear view of the escape-proof cage;

FIG. 4c is a sectional view of A-A in FIG. 4b;

FIG. 4d is a schematic view of the main frame of the escape- proof cage;

FIG. 4e is a schematic view of the main frame of the escape- proof net cover;

FIG. ba is a perspective view of a lifting up fish collecting box in an embodiment;

FIG. 5b is a left side view of the fish collecting box;

FIG. 5c is a front view of the fish collecting box;

FIG. 5d is a top view of a fish collecting box;

FIGS. 6a-6b are side and top views of a sliding groove ac- cording to an embodiment;

FIG. 6c is a top view of a three sets of guide devices in the upstream and downstream direction of the sliding groove in one em- bodiment;

FIG. 6d is a perspective view of a temporary culture pond in one embodiment;

FIG. 6e is an embodiment wherein two baffles are set up in the first temporary culture area to further divide the first tem- porary culture area into three third temporary culture areas;

FIG. 6f is a schematic view showing an embodiment in which baffles are formed on both sides of the hierarchical grid and a row of water injection nozzles for injecting water toward the hi- erarchical grid;

FIGS. 6g-6h show top views of the grad bars of a hierarchical grid at two different spacing, respectively.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present invention provides a fish collection and trans- portation system suitable for use in a dam, the fish collection and transportation system being used to assist fish to transport 5 over the dam and be collected and transported. a migration passage well 201 is provided at one side of a dam 200 of a reservoir near the downstream, the migration passage well 201 is in communication with a downstream water area, and a shaft 202 is provided at one side of the migration passage well 201 near the upstream, the shaft 202 is connected to a water outlet of the dam; several es- cape-proof cages 100 are longitudinally arranged in the migration passage well 201, the escape-proof cage 100 is provided with a trumpet-shaped opening, the width of the front end of the trumpet- shaped opening close to the upstream opening is smaller, and the width of the rear end close to the downstream opening is larger; a lifting fish collecting box 300 is provided in the shaft 202, the lifting fish collecting box 300 can sink into the water of the shaft 202 and can be lifted to emerge from the water sur- face, the lifting fish collecting box 300 is provided with a fun- nel-shaped netting fish collecting groove 308 with narrow upper part and wide lower part, a water storage bucket 309 is installed at the bottom opening of the fish collecting groove 308, the water storage bucket 309 is provided with a knife gate valve 304 for connecting with a matching sliding groove 410 on the dam, and a multi-in-one fish luring device 302 is installed right above the fish collecting groove 308; the other end of the sliding groove 410 is connected to the classified temporary culture pond 420, and an upper side wall at one side of the temporary culture pond 420 is provided with a fish inlet 429 connected to a fish outlet at the other end of the slid- ing groove 420; the classified temporary culture pond 420 is di- vided into two temporary culture areas 421 and 422 by a first mesh baffle 428, a hierarchical grid 430 is installed in the temporary culture pond 420, the hierarchical grid 430 is provided with a grid bar 431 with a front end inclined downwards, one end of the grid bar 431 near the sliding groove is installed on the bottom surface of the fish inlet 429, and the other end is fan-shaped and fixed on the first mesh baffle 428; fish flowing out from the sliding groove 410 is transported to the temporary culture pond 420 via the hierarchical grid 430, small fish with a smaller vol- ume falls from the gap between the grid bars to the first tempo- rary culture area 421, and large fish slides on the hierarchical grid to the second temporary culture area 422, and the temporary culture pond of the classified temporary culture pond is provided with a fish suction valve 423, a submersible pump 427 and an oxy- genation device 424.

As shown in FIGS. 4a-4e, the escape-proof cage is further de- scribed below: two parallel first horizontal frames 101 and 106 are provided at the upper and lower sides of the escape-proof cage 100, the two first horizontal frames 101 and 106 are fixedly connected via a support vertical frame, a blocking net fixed between the two first horizontal frames is provided near the upstream of the escape- proof cage 100, and an opening with an adjustable width is re- served in the middle of the blocking net; a trumpet-shaped escape- proof net cover is provided in the first horizontal frame, the front end opening of the escape-proof net cover near the upstream is smaller than the rear end opening, and a front end opening of the escape-proof net cover is connected to an opening of the blocking net.

In an alternative embodiment, the first horizontal frames 101 and 106 are rectangular frames, and the support vertical frame comprises a main support vertical frame 109 connecting two sides of the upper and lower two rectangular frames together, and two longitudinal brackets 110 for connecting front end corners of the upper and lower two first horizontal frames 101 and 106. The con- nection between the two main support vertical frames 109 is rein- forced by a connecting truss 107. A blocking net is fixed between two front edges of the upper and lower two first horizontal frames 101 and 106 near upstream, and two cross frames 111 parallel to the front edges are further provided between the two rectangular frames, the blocking net is composed of an upper blocking net 102 fixed between the upper cross frame 111 and the front edge of the upper rectangular frame, a lower blocking 105 net fixed between the lower cross frame 111 and the front edge of the lower rectan- gular frame, and a middle blocking net 104 with an adjustable opening 115 fixed between the two cross frames 111.

In an alternative embodiment, the inner wall of the migration passage well 201 is provided with a vertical guide rail, and the escape-proof cage 100 frame is provided with a rubber slide 109a in rolling frictional contact with the vertical guide rail to act as a stop.

In an alternative embodiment, the escape-proof net cover is provided with two horizontally rotatable trapezoidal net cover frames 120. As further shown in FIG. 5, a rotating seat 113 is in- stalled on both ends of the rear sides of the upper and lower two rectangular frames, a sliding groove 114 is provided on the rotat- ing seat, a rear end vertical frame 121 of the net cover frame is rotatably connected in the sliding grooves 114 of the upper and lower two rotating seats 113, a front end vertical frame 122 is fixed between two cross frames 111 by means of screws 123; a row of adjusting screw holes 1lla is provided on at least one cross frame 111. With this design, one can adjust the width of the front opening of the net cover frame 120 and adaptably connect to the middle opening 115 of the middle blocking net 104.

As shown in FIGS. 4-5, a rigid orifice plate 124 is fixed in the area enclosed by each of the net cover frames, and a flexible netting 125 is connected between the two hypotenuse sides of the upper side and between the two hypotenuse sides of the lower side of the two trapezoidal net cover frames. Since the two net cover frames can rotate horizontally, in order to realize the rotation of the net cover frame 120 without affecting the integrity of the escape-proof net cover, we connect the upper and lower two hypote- nuse sides of the two net cover frames 120 with a flexible netting 125, avoiding the escape of fish while freely rotating the net cover frame 120.

In an alternative embodiment, the upper blocking net 102 and lower blocking net 105 are rigid orifice plates or rigid nettings, and the middle blocking net 104 is formed of two pieces of net- tings with adjustable spacing (either rigid or flexible netting).

It should be noted that, in practical applications, the open-

ing at the front end of the escape-proof cage 100 may be set so that the width of the opening is not adjustable, and accordingly, the blocking net at the front end of the escape-proof cage 100 and the net cover on the net cover frame 120 may both be set to be rigid, thereby facilitating installation.

In an alternative embodiment, one end of the main support vertical frame 109 is provided with a latch seat 112, and the oth- er end is provided with a latch 108; the latch seat 112 and the latch 108 are both provided with a latch hole; the upper and lower two escape-proof cages 100 are connected via the latch structure of the main support vertical frame 109; and the joints where the upper and lower two escape-proof cages 100 are connected can ro- tate, so that the device as a whole has a certain flexibility, fa- cilitating the sinking and lifting. In the actual installation process, we place the escape-proof cages 100 connected together in a chain type into the migration passage well 201 in a hoisting manner, and after installing one escape-proof cage 100, sinking a certain width, and then installing another escape-proof cage 100 on the uppermost side until the escape-proof cage 100 sinks to the bottom. The junction of the upper and lower adjacent escape-proof cages 100 can be rotated, so that when we lift off the water sur- face, the escape-proof cages 100 connected in one body have a cer- tain flexibility to avoid bending due to excessive length.

The escape-proof cage 100 is placed in the migration passage well, the fish is driven by the migration habit to go upstream through the escape-proof cage into the shaft, and the trumpet opening with narrow front and wide back of the cage is designed to prevent fish from swimming back. In addition, the opening width of the escape-proof cage is adjustable, so that we can choose the ap- propriate opening width according to the size of the fish body, and avoid the fish from swimming back as much as possible without affecting the fish swimming upward.

As shown in FIGS. 5a-5d, the lifting fish collection tank is further described below: vertical guide rails are provided on at least one set of op- posite sides of the inner wall of the shaft 202, and the fish col- lecting box is liftably installed in the shaft 202; The fish col-

lecting box is provided with a horizontal main frame 305, a guide wheel 303 in rolling friction contact with the guide rail is pro- vided on at least one pair of sides of the main frame 305, a fun- nel-shaped fish collecting groove 308 is fixed in the middle of the main frame 305, the fish collecting groove 308 is formed by splicing multiple mesh plates, a water storage bucket 309 is in- stalled on the bottom opening of the fish collecting groove 308, the bottom of the water storage bucket 309 is connected to a fish delivery pipeline 311 via a knife gate valve 304, and at least one group of fish luring devices 302 are installed on the main frame 305 above the fish collecting groove 308.

In an alternative embodiment, a brush 306 is secured to each side of the main frame 305 and contacts the inner wall of the shaft 202. When the fish collecting box is lifted and lowered, the organisms and moss attached on the inner wall of the shaft 202 can be scraped off by the brush 306, so as to clean the shaft 202.

In an alternative embodiment, the main frame 305 is composed of upper and lower two parallel rectangular frames 305a and 305b fixedly connected by a support truss 305c, and guide wheels 303 cooperating with guide rails in the shaft 202 are provided at each side of the upper and lower two rectangular frames. Preferably, four sides of the upper and lower two rectangular frames are each installed with a guide wheel 303 in rolling friction contact with the guide rail, part of the guide wheel 303 of the upper rectangu- lar frame is fixed on the upper rectangular frame 305a via a mounting inclined frame 301, and the height of the guide wheel 303 on the mounting inclined frame 301 is higher than that of the up- per rectangular frame. As can be seen from the figures, the pre- sent invention improves the rollover resistance by optimizing the arrangement positions of the upper sliding wheels, changing the arrangement positions of the four sliding wheels from the original side arrangement to an upward movement, and increasing the central moment torque of the upper and lower wheels.

In an alternative embodiment, two sets of fish luring device stainless steel support brackets 305d are connected between one set of opposite sides of the upper rectangular frame, and one set of fish luring device 302 is secured to each set of fish luring support brackets 305d. The fish luring device 302 needs to ensure a firm installation and fastening; the junction of power cord shall be waterproofed, and the outside shall be protected by flex- ible hose.

In an alternative embodiment, the fish luring device 302 com- prises an underwater fish luring lamp and/or a feeder. Preferably, the underwater fish luring lamp is installed in a place which is not easily damaged by the outside, the installation position does not affect the operation of field equipment and the normal opera- tion of personnel, and the irradiation direction of the underwater fish luring lamp can be flexibly adjusted. The feeder is mainly composed of a feed bin, a screw drive motor, a sprinkling plate and a control box, which can automatically and continuously feed bait into the fish collecting groove 308; the feeder can set time, turn on and off periodically, can be controlled remotely, and can adjust feeding speed.

The steel punched-plate arrangement extends to the bottom outlet, reducing sucking plane of some fish like echeneis nau- crates, and more easily flows out of the fish collecting box into the water storage bucket 309 under the impact of water flow. The position of the water storage bucket 309 is arranged close to the central position of the integral box, so as to facilitate the cen- tering of the centre of gravity of the integral box in the case of accumulated water and increase the stability in the lifting pro- cess. The water-facing area in the water-facing direction of the fish collecting box punched-plate is minimized so as to reduce the impact of the water flow on the box. In the arrangement of the multi-orifice plate, the fish is directed towards the side of the water storage bucket 309 close to the outlet opening, so that wa- ter is accumulated on the rear side of the fish shoal, which is advantageous for flushing the fish out when the water is released.

In addition, the water storage bucket 309 is further provided with a flushing device, and one end of a flushing pipeline of the flushing device is connected in the water storage bucket 309, and is used for drawing water to flush the water storage bucket 309, on one hand, flushing fish which does not flow out from the water storage bucket 309 into the fish delivery pipeline 311, and on the other hand, performing simple flushing cleaning on the water stor- age bucket 309.

Preferably, the water storage bucket 309 is a water tank with no cover plate at the top; considering that the bottom area of the water storage bucket is large, the resistance of the fish collect- ing box to sink in the water is large, so we have a flap valve which opens upward in one direction in the bottom plate, and when sinks in the water, the flap valve opens upward, so as to reduce the resistance from the water in the process of sinking, and fa- cilitate the fish collecting box to sink faster and stably at a constant speed. After the fish collecting box is lifted off the water surface, the flap valve is automatically closed under the gravity of the water to store water in the water storage bucket 309. A flap valve hole is provided on the bottom plate of the wa- ter storage bucket 309, one side of the flap valve hole is provid- ed with a hinge, and one side of the flap valve is fixedly con- nected to the hinge. In order to ensure the sealing, a sealing strip is provided on the side of the flap valve, so as to avoid excessive water flowing out of the water storage bucket when leav- ing the water too long, thereby affecting the survival of fish in the water storage bucket.

In an alternative embodiment, a lifting crane for lifting and controlling the lifting of the fish collecting box is provided on the working platform of the reservoir dam, and the lifting rope of the lifting crane is connected to the lifting lug 310 of the main frame 305 via a hook.

The lifting crane lowers the fish collecting box to a preset height of the lifting shaft by means of a lifting rope, and the fish collecting box is located below the water surface. The fish luring device 302 is turned on to lure fish, and the fish shoal is drawn to swim into the area enclosed by the main frame 305 by the light or feed. When it is the right time, the lifting crane verti- cally hangs the fish collecting box until leaving the water sur- face, and under the action of gravity, the fish shoal slides down to the water storage bucket 309 at the bottom of the fish collect- ing box 308, wherein a certain amount of water is stored in the water storage bucket 309 so as to prevent the fish shoal from squeezing and injuring each other, and at the same time, the sur- vival time of the fish when leaving the water can be extended, and the fish shoal can be temporarily cultivated in the water storage bucket 309. After the fish delivery pipeline is connected to the knife gate valve 304 at the bottom of the water storage hopper 309, the knife gate valve 304 is opened, and water and fish in the water storage bucket 309 slide down into the fish delivery pipe- line 311 under the action of gravity. The other end of the fish delivery pipeline can be connected to the water storage area of the dam, and the fish shoal is transported to the water temporary culture area of the other side of the dam to assist the fish shoal to cross the reservoir dam; alternatively, the other end of the fish delivery pipeline may be connected directly to a transport vehicle for temporary processing or transport of collected fish.

Finally, the flushing pipeline is opened to clean the water stor- age bucket 309.

As shown in FIGS. 6a-6h, the sliding groove and the classi- fied temporary culture pond are further described below:

The sliding groove 410 is a transport channel arranged obliquely, the sliding groove being provided with a counting de- vice 412. In an alternative embodiment, as shown in FIGS. 6a-6b, the sliding groove 410 is fixed to the ground by means of a brack- et, the bottom of which is fitted with universal wheels 413 to fa- cilitate our movement and assembly of the sliding groove 410, which is provided with a ladder 411 to facilitate our crossing of the sliding groove 410.

In an alternative embodiment, on the upper surface of the bottom plate of the sliding groove 410 and upstream of the count- ing device 412, a plurality of sets of guide devices distributed along the transport direction of the fish are provided, each set of guide devices having a plurality of separating strips 417 coin- ciding with the transport direction, the spacing of the separating strips of each set of guide devices gradually decreasing in the transport direction of the fish. FIG. 6c shows that three sets of guide devices 414, 415, 416 are provided on the bottom plate of the sliding groove 410, the arrow indicating the transport direc- tion of the fish in the sliding groove 410. When fish are trans-

ported in the sliding groove 410, the arrangement direction of the fish is different, and even some fish will overlap up and down, which will affect the counting accuracy of the counting device.

Therefore, we provide multiple sets of guide devices on the bottom plate of the sliding groove 410 upstream of the counting device, and when fish in various directions pass through the guide devic- es, the direction will be corrected to a uniform direction, and at the same time, the overlapping of multiple fish can be effectively avoided. Due to the large volume difference of some fish, if the spacing between the separating strips of the guide device is too large, it can not guide the small fish; if the spacing of the sep- arating strips of the guiding device is too small, the guiding ef- fect of large fish will be limited and the fish and water trans- mission efficiency will be reduced, and too many separating strips will increase the damage of fish to some extent. Therefore, in consideration of the above factors, the present invention prefera- bly solves the above-mentioned problems by providing a large spac- ing between the separating strips 417 of the upstream guide devic- es and a small spacing between the separating strips 417 of the downstream guide devices. The counting device comprises a light curtain counting sensor and a camera arranged directly above the sliding groove 410. The light curtain counting sensor generates a protective light curtain by emitting infrared rays, and when the light curtain is blocked by fish, the device sends out a shading signal so as to realize the technology; the camera implements counting and recording of fish species based on the mechanism of image recognition.

As shown in FIG. 6d, a fish inlet 429 is provided at one side of the temporary culture pond 420, and the fish inlet 429 is con- nected to the outlet of the sliding groove 410; the temporary cul- ture pond 420 is divided into a first temporary culture area 421 and a second temporary culture area 422 by a first mesh baffle 428; the temporary culture pond 420 is provided with a fish suc- tion valve 423, a submersible pump 427 and an oxygenation device 424; and water pumped by the submersible pump 427 is delivered to the temporary culture pond 420 via a water discharge pipe 427a.

The hierarchical grid 430 is installed in the temporary culture pond 420; the hierarchical grid 430 is provided with several grid bars 431 with front ends (namely, one end away from the fish inlet 429) inclined downwards; one end of the grid bars 431 close to the sliding groove 410 is installed on the inner wall of the bottom surface of the fish inlet 429, and the other end is scattered and fixed in a fan shape on the first mesh baffle 428; the fish flow- ing out from the sliding groove 410 passes through the hierar- chical grid 430 and is transported into the temporary culture pond 420; small fish fall from the gap between the grid bars 431 to the first temporary culture area 421; and large fish slide on the hi- erarchical grid 430 to the second temporary culture area 422.

In an alternative embodiment, a row of first distance- adjusting jacks is provided on the bottom surface of the fish in- let 429, a row of second distance-adjusting jacks is provided on the first mesh baffle 428, two ends of each grid bar 431 are re- spectively inserted into the first distance-adjusting jacks and the second distance-adjusting jacks, and the total number of the grid bars 431 is less than or equal to the number of the first distance-adjusting jacks and/or the second distance-adjusting

Jacks; and according to practical requirements, an appropriate number of grid bars 431 is selected for installation, and then the spacing between the grid bars 431 can be adjusted, thereby con- trolling the volume of small fish falling into the first temporary culture area 421. FIGS. 6g-6h show a top view of the grid bars 431 of the hierarchical grid 430 in two different numbers in two em- bodiments, spacing of the grid bar 431 in FIG. 6h being signifi- cantly increased compared to the spacing of the grid bar 431 in

FIG. 6g, whereby the size of the fish falling into the first and second temporary culture areas can be controlled.

In an alternative embodiment, on the bottom plate of the tem- porary culture pond in the first temporary culture area 421, a plurality of mesh plates distributed in front and back are further erected, each mesh plate being located directly below the hierar- chical grid, and the first temporary culture area is further di- vided into a plurality of independent third temporary culture are- as by the mesh plates. As can be seen in FIG. 6e, since the grid bars 431 of the hierarchical grid 430 are in fan-shaped distribu-

tion, the farther away from the fish inlet 429 of the temporary culture pond 420, the larger the spacing between the grad bars 431. Two mesh plates 428a and 428b are set up in the first tempo- rary culture area 421, and the first temporary culture area 421 is divided into three third temporary culture areas 4211, 4212 and 4213. Fish of various volume sizes pass through the hierarchical grid 430 and fall into the temporary culture areas 4213, 4212 and 4211 in turn, so that classification according to the volume the separating temporary culture can be realized. The largest fish will continue to slide forward into the second temporary culture area 422 because they cannot fall through the gap between the grid bars 431.

In an alternative embodiment, the bottom plate of the tempo- rary culture pond 420 is inclined, and the side wall of the lower side of the temporary culture pond is provided with a fish outlet connected to the fish suction valve 423. The design of the slope at the bottom of the temporary culture pond 420 allows us to sub- sequently drain the fish from the temporary culture pond 420 more thoroughly. The first temporary culture area 421 or each third temporary culture area is provided with a communication valve con- nected to the second temporary culture area 422. When the valves are normally in a closed state, if we do not need to transfer the fish in each temporary culture area separately, all the communica- tion valves can be opened at the same time, then the fish suction valve 423 is opened, and the fish in the first temporary culture area 421 or each third temporary culture area is discharged through the second temporary culture area 422, and the fish in the temporary culture pond 420 is transferred without difference. If we need to transfer the fish in the second temporary culture area 422 and the first temporary culture area 421 in batches, we di- rectly open the fish suction valve 423 to transfer the large fish in the second temporary culture area 422, and in this process, supplement water to the temporary culture area 420 through the submersible pump 427, so as to ensure the survival of the fish in the first temporary culture area 421. And then successively open- ing a communication valve connected between each third temporary culture area and the second temporary culture area, and succes-

sively transferring same from each third temporary culture area to the outside.

In an alternative embodiment, as can be seen in FIG. 6f, the inner wall of the temporary culture pond 420 below the fish inlet 429 is provided with a row of water injection nozzles 432 for spraying water towards the hierarchical grid 430, so that the fish caught between the grid bars 431 can be flushed down, blocking of the fish caught in the gaps of the grid bars 431 can be avoided, and further damage of the fish can be reduced.

In an alternative embodiment, as shown in FIG. 6d, a water collection bucket 426 is installed at an outer side wall of the temporary culture pond 420, the water collection bucket is in com- munication with the temporary culture pond 420, and two overflow devices are provided in the water collection bucket 426, and the height of overflow ports of the two overflow devices is different.

With the two overflow devices of the water collection buckets, we can choose the appropriate water level of the temporary culture pond 420 depending on the scenario. When putting fish in the slid- ing groove 410, the water level of the temporary culture pond 420 needs to be kept a certain distance below the hierarchical grid 430, so as to avoid that the water level is too high to affect the falling of the fish. The water level of the temporary culture pond 420 can be maintained at a relatively high level to increase the living space of the fish when the fish releasing from the sliding groove 410 is finished. Vertical baffles 434 are provided on the left and right sides of the hierarchical grid 430 so that fish can only slide forward through the grid bars 431 to avoid falling from both sides without grading.

In an alternative embodiment, a water quality detection de- vice 425 is provided in the temporary culture pond 420, the water quality detection device is connected to an alarm device, the wa- ter quality detection device detects other water quality parame- ters affecting the survival of fish, such as oxygen content, and once an alarm threshold value is exceeded, an alarm is timely ac- tivated to notify maintenance personnel.

The steps for carrying out the present invention are specifi- cally as follows:

preparation: the escape-proof cage 100 is placed in the mi- gration passage well 201, and the lifting crane 330 lowers the fish collecting box 300 to a preset depth of the shaft 202 by means of a lifting rope, and the fish collecting box 300 is locat- ed below the water surface.

The fish is driven by the migration habit to go upstream through the escape-proof cage into the shaft 202, and the trumpet opening with narrow front and wide back of the cage is designed to prevent fish from swimming back. Preferably, we can provide a fish barring electrode at the drainage port connected to the shaft 202, which generates a weak electric field when power on, thereby con- centrating the fish shoal in the shaft 202 and facilitating our centralized handling. The opening width of the escape-proof cage of the present invention is adjustable, so that we can choose the appropriate opening width according to the size of the fish body, and avoid the fish from swimming back as much as possible without affecting the fish swimming upward.

The fish luring device 302 is turned on to lure fish, and the fish shoal is drawn to swim into the area enclosed by the main frame 305 by the light or feed. When it is the right time, the lifting crane 330 vertically hangs the fish collecting box 300 un- til leaving the water surface, and under the action of gravity, the fish shoal slides down to the water storage bucket 309 at the bottom of the fish collecting box 308, wherein a certain amount of water is stored in the water storage bucket 309 so as to prevent the fish shoal from squeezing and injuring each other, and at the same time, the survival time of the fish when leaving the water can be extended, and the fish shoal can be temporarily cultivated in the water storage bucket 309. After the fish collecting box 300 reaches the designated height, and the fish delivery pipeline 311 is connected to the knife gate valve 304 at the bottom of the wa- ter storage hopper 309, the knife gate valve 304 is opened, and water and fish in the water storage bucket 309 slide down into the fish delivery pipeline 311 under the action of gravity.

The other end of the fish delivery pipeline 311 is connected to the sliding groove 410, and the fish passing through the guide device on the bottom plate of the sliding groove 410 will be cor-

rected into a uniform direction, so as to facilitate the counting device to count the quantity. Fish flowing out from the sliding groove 410 is then transported to the temporary culture pond 420 via the hierarchical grid 430. Small fish with a smaller volume falls from the gap between the grid bars 431 to the first tempo- rary culture area 421, and large fish slides on the hierarchical grid 430 to the second temporary culture area 422.

After all the fish in the water storage bucket 309 is trans- ferred to the temporary culture pond 420, we connect the fish col- lecting pipeline of the transfer car 500 with the fish suction valve 423 of the temporary culture pond 420, and then open the fish suction valve 423 to transfer the fish in the temporary cul- ture pond 420 to the transfer car 500, and the migratory fish is transferred to the upstream suitable water area by the transfer car 500. The transfer car 500 is used to transfer the migratory fish to the upstream waters because: migratory fish need a certain flow of water as they go upstream to help them find the right di- rection; However, due to the blocking action of the reservoir dam 200, the water flow in the water storage area near the reservoir dam 200 is slow, and if fish directly enters the water storage ar- ea, migratory fish may not find a direction. Therefore, we use the transfer car 500 to transfer the migratory fish to the upstream water area with appropriate flow velocity, so as to avoid the loss of direction of the fish due to the slow water velocity in the process of swimming upstream.

Claims (5)

CONCLUSIONS Escape proof device suitable for a fish collection and transport system for a dam, characterized in that a migration passage well is provided on one side of a dam of a reservoir near the downstream part, the migration passage well communicating with a downstream water area, and wherein a shaft is provided on one side of the migration passage well near the upstream side, the top of the shaft being connected to a water outlet of the dam; the apparatus being composed of several escape-proof cages connected end to end at the top and bottom and placed in the migration passageway, the two parallel first horizontal frames being arranged at the top and bottom of the escape-resistant cage, the two first horizontal frames being fixedly connected via a supporting vertical frame, a blocking net fixed between the two first horizontal frames being arranged near the upstream side of the escape-resistant cage, and an opening with a adjustable width is reserved in the center of the blocking net; wherein a trumpet shaped net cover is mounted in the first horizontal frame, the front opening of the breakaway net cover near the upstream side is smaller than the aft end opening and a front opening of the breakaway net cover is connected to an opening of the blocking network. The escape-proof device for a fish collection and transport system for a dam according to claim 1, characterized in that the inside wall of the migration passage pit is provided with a vertical guide rail and the frame of the escape-proof cage is provided with a rubber slide in rolling frictional contact with the vertical guide rail. The escape-proof device for a dam fish collecting and transporting system according to claim 1, characterized in that the first horizontal frame is a rectangular frame, and the vertical supporting frame includes a supporting vertical main frame connecting two sides of the upper and connecting lower two rectangular frames together, and a longitudinal bracket for connecting corners of the upper and lower two first horizontal frames; wherein the blocking net is mounted between two front edges of the upper and lower two rectangular frames near the upstream side, and further two transverse frames are arranged parallel to the front edges between the two rectangular frames, the blocking net consisting of an upper blocking net fixed between the upper cross frame and the front edge of the upper rectangular frame, a lower blocking net fixed between the lower cross frame and the front edge of the lower rectangular frame, and a middle blocking net with a adjustable opening that is fixed between the two cross frames. A break-proof device for a fish collecting and transporting system for a dam according to claim 3, characterized in that the break-proof net cover has two trapezoidal net cover frames which can pivot horizontally, with a rotating seat installed at both ends of the back sides. of the upper and lower two rectangular frames, with a sliding groove provided on the rotating seat, a vertical frame of the net cover frame provided at the rear end being pivotally connected in the sliding grooves of the upper and lower two rotating seats, with a vertical frame provided at the front end is fixed by means of screws between two cross frames and a row of set screw holes is provided on at least one cross frame; in the area enclosed by each of the net cover frames a rigid orifice plate is mounted and between the two hypotenuse sides of the top and between the two hypotenuse sides of the bottom of the two trapezoidal net cover frames a flexible net is connected; wherein one end of the vertical frame of the main support is provided with a latch seat, the other end is provided with a latch, and the upper and lower two escape-proof cages are connected through the latch structure of the vertical frame of the main support . The escape-proof device for a dam fish collection and transport system according to claim 4, characterized in that the upper blocking net and the lower blocking net are rigid apertured plates or nets, and the middle blocking net is formed of two pieces of nets with adjustable spacing.