JPH0647102B2 - Red tide extinguishing device for aquaculture livestock - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a device for eliminating red tide, which has been seriously damaging the fishery industry in recent years, and particularly for protecting seafood during aquaculture from damage by the red tide. The present invention relates to a red tide extinguishing device for farm livestock.

(Prior art) The red tide is caused by a temporary increase in phytoplankton in seawater or lake water, but the cause has not been fully clarified. The reality is that it has not been set up.

Therefore, when a red tide occurs in a farm, the aquaculture live cage containing the seafood being cultivated is moved to a sea area where the red tide does not occur, or the red tide occurs only in a shallow area near the water surface. We are surpassing the situation by sinking stalks deep below the surface of the water, and by using seawater once filtered at factories that use seawater.

In addition, as what is currently proposed as a measure against red tide,
A device that sprays chemicals such as copper sulphate and clay onto the red tide in seawater to cause an electric current to disappear (Shokaisho 62-18163).
0), a device that irradiates ultraviolet rays to extinguish the red tide
2-189298) etc.

(Problems to be solved by the invention) Of the above, the method of spraying a drug or clay is too expensive to perform over a wide area of the sea, and kills fish and shellfish with the drug, It is not practical because it may cause secondary pollution such as pollution.

A device that passes an electric current through the seawater or irradiates ultraviolet rays may also kill the seafood along with the disappearance of the red tide, and in particular, cannot deal with the occurrence of red tide in the sea area of the farm,
Not valid.

The present invention has been made in view of the above points, does not adversely affect seafood, does not pollute the sea area,
It is intended to provide a red tide extinguishing device for aquaculture livestock that has no secondary pollution problem and is highly safe, and that can effectively extinguish the red tide in a limited sea area such as a farm. is there.

(Means for Solving Problems) The gist of the red tide extinction device of the present invention for achieving the above-mentioned object is to provide a pump device that generates ultrasonic waves of 50 kHz or less due to collapse of cavitation during operation,
Installed on a pontoon that floats above the water surface, the suction port and discharge port of the pump device are exposed to relatively shallow water below the water surface, and a net-like member for preventing inflow of water floating matter and fish is attached to the suction port. At the same time, the outlet is provided with a fan-shaped red tide invasion prevention fence that gradually expands to a fish and shellfish farm.

(Operation) According to the present invention, in response to the red tide generated in the sea area or the lake area that is sucked into and collected in the pump device, bubbles due to cavitation generated in the pump device during operation collapse and ultrasonic waves of 50 kHz or less are generated. And the ultrasonic waves kill or stop the growth of phytoplankton such as Horneria and Shutnera, which are the main causative organisms of the red tide. Especially, when seawater or lake water containing red tide passes through a narrow space (between the impeller and the casing) in the pump device, ultrasonic waves are intensively applied and turbulent flow occurs when seawater or the like passes through the pump device. By being
Planktonic death or growth arrest is effectively achieved.

In this way, the dead plankton is discharged to the bottom of the water by forcibly discharging and supplying seawater or lake water, from which harmful plankton has already been killed or where plankton growth has been completely suppressed, from the pump device. The red tide disappears as the concentration of the red tide in the livestock settles down. In addition, it is possible to eliminate the red tide from the vicinity of the live fish by forcing the treated water to flow into the live fish, and to protect the live fish from the sea area and lake area where the red tide has occurred, or In the live fish, the red tide disappears in the cultured live fish by sucking seawater or lake water in which red tide has occurred into the pump device and continuously discharging it to the cultured live fish while circulating the seawater or lake water while killing plankton. Can be made.

(Example) Hereinafter, the red tide extinction method and its apparatus of the present invention will be described based on FIGS. 1 to 3 showing an example of the apparatus.

In the figure, this device A is basically a so-called horizontal axial flow pump, and here, a red tide is generated mainly as a device for inflowing seawater in which the red tide has been extinguished into the livestock of a farm. It is composed of a seawater suction part 1, a pump device body 2 as an ultrasonic wave generation means, and a seawater discharge part 3 in which red tide has disappeared.

The suction part 1 includes a substantially cylindrical net-like suction cage 1a for preventing fish inflow, and a suction pipe 1b connected to the cage 1a.
And a float 6 for floating the cage 1a near the sea surface. The suction cage 1a has a structure in which a metal, plastic or fibrous net is stretched around a frame.

The suction pipe 1b is a steel pipe, a riming pipe having a plastic lining or the like on the inner surface of the steel pipe, or a plastic pipe, and the seawater sucked from the inside of the suction cage 1a with the suction port of the suction pipe 1b facing below the sea surface. Send water to 2.

The device body 2 is mounted on a hollow box-shaped pedestal 4, and as shown in FIG. 3, a suction adjusting valve 2a is provided on the suction port side thereof. In the device body 2, the external drive device 2c (first
An impeller 2b rotated via a shaft 2d is provided by the drawing (see the drawing), and a vacuum pump 5 is connected to a casing around the impeller 2b. The pontoon 4 is connected to mooring lines 4a and is held at a fixed position in the sea area.

By the way, the impeller 2b is different from a general pump device, and in particular, so that a large amount of cavitation occurs, the angle of depression of the impeller 2b with respect to the suction water is made larger or smaller than a normal value of a general pump device. I am doing it. In addition, a baffle plate 2e is provided in the high-speed basin in the pipe line on the downstream side of the impeller 2b.
The action also causes cavitation. Further, the opening degree of the suction adjusting valve 2a is normally narrowed down and made smaller than the pumping capacity of a general pump device to promote the occurrence of cavitation. In other words, the pump device A according to the present invention is provided with high flow velocity and low pressure portions at various places so that a large amount of cavitation is generated. The energy consumed to generate cavitation in the entire pump device is set to about 10 to 50% of the pump input. Further, since cavitation is more likely to occur when the rotation speed of the pump is higher, a high speed rotation pump may be used. Since a large amount of cavitation is generated in the pump device A of the present invention, the pump casing, the impeller, and the like are made of materials such as stainless steel, titanium, monel, and various types of materials that can sufficiently withstand the erosion action that occurs when the cavitation disappears. It is preferably manufactured using ceramics. Further, the vacuum pump 5 sucks the seawater sucked from the suction section 1 to the impeller 2b at the time of starting the operation,
Used for so-called priming.

The discharge part 3 includes a discharge pipe 23a, a red tide intrusion prevention fence 3b which is connected to the discharge pipe 3a and gradually expands in the discharge direction, and a float 7 for floating the red tide intrusion prevention fence 3b near the sea surface. , The open end of the red tide intrusion prevention fence 3b is connected to the aquaculture livestock B. The red tide intrusion prevention fence 3b is made of a material such as metal, rubber, waterproof fiber material, or plastic.

Next, a specific aspect of the red tide extinction method of the present invention when the pump device A configured as described above is used will be described.

In Fig. 1 and Fig. 2, by operating the pump device, seawater near the sea surface in the red tide generation sea area is prevented from flowing into the water surface suspended matter and fish by the suction cage 1a, and passes through the suction pipe 1b. After being sucked up to the impeller 2b in the apparatus main body 2, it is discharged from the discharge pipe 3a to the red tide intrusion prevention fence 3b. In the device body 2, a large amount of cavitation is generated when seawater passes, and ultrasonic waves are generated when the bubbles are collapsed due to the cavitation. Therefore, plankton in the red tide is mainly killed by receiving ultrasonic waves of 10 to 50 kHz or Seawater containing plankton that has stopped growing and has died is discharged from the pump device, and then the red tide intrusion prevention fence
It flows into live B along 3b. In addition, a part of the ultrasonic waves generated in the device body 2 is prevented from entering the red tide through the discharge pipe 3a.
Since it also diffuses into the seawater in 3b, it prevents the plankton from growing in the red tide that has invaded the red tide intrusion prevention fence 3b. In this way, only the seawater containing dead plankton is sent to the aquaculture livestock B, the carcasses of plankton settle to the seabed, and the red tide in the aquaculture livestock B gradually diminishes to produce red tide. It disappears and seafood is protected.

In the above embodiment, the axial flow pump, which has the advantage that the pump capacity is less likely to decrease even if the amount of cavitation generated is large, is used as the pump device, but other types of pumps such as mixed flow pumps and centrifugal pumps are used. Can also be used. Further, the number of pump devices to be used is not limited to one, and the number of pump devices to be used may be appropriately determined according to the size of the seawater area to which the red tide countermeasure is applied.

(Effect) As is clear from the above description, the method and apparatus for extinguishing red tide of the present invention have the following effects.

(1) Ultrasonic waves generated when bubbles are collapsed by cavitation generated in the pump device, mainly 10 to 50 kHz ultrasonic waves, kill or stop the growth of plankton such as Horneria in the red tide. By continuously using the method of the invention in a body of water,
Plankton, the organism responsible for the occurrence of red tide, is killed, and the carcasses of the plankton settle to the bottom of the water, allowing the red tide to disappear.

(2) By performing the method of the present invention in a specific sea area or lake area before the occurrence of red tide, the occurrence of red tide can be prevented.

(3) The ultrasonic waves are generated inside the pump device, and the effect of the ultrasonic waves emitted from the pump device to the outside is usually only about a few meters, so the ultrasonic waves are in seawater or lake water. There is no danger of adversely affecting
There is no concern about secondary pollution caused by ultrasonic waves.

(4) The seawater and lake water in which red tide is generated are intensively irradiated with ultrasonic waves of 50 kHz or less, which is effective for killing plankton in the red tide, in a narrow space inside the pump device (usually between the impeller and the casing). Therefore, the ultrasonic waves effectively act on the plankton in the red tide, and the turbulent flow region generated when seawater or the like passes through the pump device also has the effect of killing the plankton in the red tide and stopping the proliferation. In addition, since the pump device forcibly circulates the seawater or the lake water to lower the water temperature, it is effective in preventing the occurrence of red tide. For this reason,
It is extremely effective as a countermeasure against red tides in a sea area and lake area within a predetermined range such as aquaculture livestock, and the cost required for the countermeasure is relatively low.

[Brief description of drawings]

The drawings show an embodiment of the red tide extinguishing device of the present invention. Fig. 1 is a front view of the entire device, Fig. 2 is a plan view of the same, and Fig. 3 is a partially enlarged sectional view of a pump device body. 1 ... Suction part, 1a ... Suction cage, 1b ... Suction pipe, 2 ... Device body, 2a ... Suction adjustment valve, 2b ... Impeller, 2e ... Baffle plate, 3 ... Discharge part, 3a ... … Discharge pipe, 3b
…… Red tide intrusion prevention fence, 4 …… Boat, A …… Pump device,
B: Cultured live fish.

Claims (1)

[Claims] 1. A cavitation collapse during operation causes 50
A pump device that generates ultrasonic waves of kHz or less is installed on a pontoon that floats above the water surface, and the suction port and discharge port of the pump device are exposed to relatively shallow water below the water surface. A red tide for aquaculture livestock, characterized in that a net-like member for preventing inflow of suspended solids and fish is attached, and a fan-shaped red tide invasion prevention fence that gradually expands to the aquaculture livestock for fish and shellfish is attached to the discharge port. Disappearing device.