WO1993023993A1

WO1993023993A1 - A fish breeding farm

Info

Publication number: WO1993023993A1
Application number: PCT/DK1992/000167
Authority: WO
Inventors: Lauritz Nicolai Balslev Klausen
Original assignee: Klausen Lauritz Nicolai Balsle
Priority date: 1991-02-12
Filing date: 1992-05-27
Publication date: 1993-12-09
Also published as: DK23991D0; DK166984B1; DK23991A

Abstract

In order to achieve the best possible environment for fish which are cultivated in a plant with recirculating water, the basin according to the invention is configured as a pipe (1, 2) which extends between two basins (3, 4). By pumping water from the one basin (3) to the other basin (4) by means of an air pump (9) and a connection pipe (7, 8), the water (21) is made to flow through the pipe (1, 2) and an oxidization of the water is also effected. This ensures that the fish (22) can reside undisturbed in the basin, and at the same time they will conceive the flow as being a natural watercourse, which gives rise to a high standard of health and rate of growth. This ensures a high yield and quality with a very low consumption of water and energy.

Description

A FISH BREEDING FARM

Background of the invention

The invention relates to a plant for the breeding of fish in recirculating flowing water, and comprising a fish basin which extends from an inlet basin and ends in an outlet basin, and where the surface of the water at the inlet basin lies higher than at the outlet basin.

The breeding of fish by so-called aquaculture is of increasing importance now that traditional fishery may be limited out of regard for the preservation of the natural fish population in the seas, lakes and rivers.

Consequently, there is a great need for fish-breeding plants, but it is difficult to get such plants to function in practice. This is due to the many demands placed by the fish on the environment in the basins, namely and especially concerning adequate oxygen in the water, clean water and with regard to non-stressing conditions.

Hitherto-known plants normally consist of open basins in which the fish are kept, and where the water is recirculated after having been cleaned and treated.

Such a plant is known from Swedish patent publication no. 451,171, in that this comprises a number of open basins through which the water can flow.

Although the demands on the quality of the water can wholly or partially be fulfilled in this known plant, it has not succeeded to a sufficient degree in creating conditions which promote the development of the fish, but rather conditions which stress the fish and therewith weaken them to the detriment of health and fish production. This is due not least to the fact that the fish are not able to find an adequate degree of concealment, and are therefore stressed by the many influences to which they are exposed from the surroundings through the water.

Advantages of the invention

The plant according to the invention with a fish basin which consists of a pipe through which the water can flow has the advantage that it has shown to improve the environment for the fish in a decisive manner. This is because the fish regard the pipe and the water flow as a natural watercourse, and tests have shown that their development and thus their growth far exceed that which it has hitherto been possible to achieve in traditional open basins.

Moreover, it has proved surprisingly that the amount of fish per unit of water volume can be increased without causing the fish any inconvenience, merely providing that the quality of the water is in order.

To this can be added that the condition of health of the fish has proved to be suprisingly good, which is because the air-borne bacteria, fungus spore, germs and vira and similar disease-promoting elements cannot reach the water and therewith the fish, for reasons of the pipe basin which separates the water from the surrounding air.

As disclosed in claim 2, by allowing the pipe to extend in an arc, the basins can be placed up against each other, which has practical advantages.

As disclosed in claim 3, by leading air to an underlying connection pipe between the basins, the oxidation of the water is combined with a pumping which ensures the flow through the pipe with very low consumption of energy.

Finally, as disclosed in claim 4, it is expedient to further treat the water in a UV-0₃ reactor, hereby achieving clean and suitable water in the plant.

The drawing

In the following section, an example embodiment according to the invention will be described in more detail with reference to the drawing, where

fig. 1 shows a plant seen from above,

fig. 2 shows the plant seen in perspective from the one end,

fig. 3 shows the plant seen in the direction III-III in fig. 1, and

fig. 4 shows a side view of the plant in the ground.

Description of the example embodiment

The plant comprises a U-shaped pipe which, as shown, can consist of two similar pipe sections 1 connected at the end with a bend 2. As will be seen in figs. 2-4, the pipe extends in a declining manner, in that the one end is placed higher than the other end.

Each pipe end is connected to a vessel or basin, one of which is connected to the highest-lying pipe end and functions as water inlet basin 4, while the other functions as water outlet basin 3.

The diameter and the length of the pipe depends on the capacity of the plant. The pipes 1, 2 and the basins 3, 4 are preferably made of dark-coloured synthetic material which can be reinforced with glass fiber.

In order to be able to carry out an inspection of the plant, it can be provided with one or more inspection pipes 5 through which it is possible to see into the pipe 1, 2. Growth lights or UV lamps can possibly be mounted in one or more of these pipes.

In the example embodiment, the inlet and the outlet basins 3, 4 are square vessels with an inclining bottom 6 which opens out in a pipe stub.

Furthermore, removable covers 11 can be mounted over the basins 3, 4 and the pipes 5. The fish 22 in the water 21 are thus protected against being frightened and stressed, in that they will thus reside in the water completely without the ingress of light. Moreover, evaportation is hereby reduced to a minimum, and infection of the water and herewith the fish is prevented.

On the bottom stub in the outlet vessel 3 there is mounted a pipe 12 which can be connected to a not-shown cleaning plant, such as a sedimentation or cyclone separation plant, for the separation of the precipitational organic refuse products from the fish in the form of faeces and feedstuff remains.

A valve 13 can regulate the discharge 14 from the pipe 12.

In the outlet pipe 12 there is an underpressure from a pump 15 which pumps the water through a UV-0₃ reactor 16. This comprises an 0₃ generator 17 which is supplied with oxygen or air 8, and this enriched water is supplied in counter- flow to the inlet to a UV generator 19 which both sterilizes and cleans the water, especially of ammonia and urea.

The treated water is then led through a pipe 20 possibly via a pump 15 to a bottom stub in the inlet vessel 4, whereby the closed circuit in the plant for recirculating water is established.

For the further improvement of the environment, one or more flow-generating and oxidizing pipes can be mounted between the basins 3, 4. This pipe 7 extends from the side of the outlet basin 3 downwards to a depth of up to eight meters. The end of the pipe is provided with a bend, and there is also mounted an inlet pipe for air 10 which is applied to the water by means of an air pump 9.

The air will immediately rise up through the water in the pipe 8 which leads into the side of the inlet basin 4, which will occur under expansion up through the pipe 8, whereby the flow of water in the pipe will accelerate. The water is thus oxidized while at the same time it is given a considerable rate of flow, and herewith a flow from the outlet basin 3 to the inlet basin 4. This results in a flow of water 21 in the pipes 1, 2, whereby this is brought into movement so that the fish 22 will perceive it as a natural flow of water and will move naturally in the water. The fish will hereby develop their muscle tissue in a natural manner, thus promoting their condition of health and growth.

All depending on the species of fish, the velocity of flow can be adjusted to suit the relevant species and their stage of development. In fig. 4 is shown how a plant according to the invention can be placed under the earth 23. This has the advantage that the temperature in the plant can be held relatively constant, and also that the plant can be established under a greenhouse or the like where the separated organic waste can be used as a valuable fertilizer and earth improvement agent.

The plant can have a very high degree of recirculation, which contributes greatly towards the plant's low consumption of water and energy.

To this can be added the good state of health among the fish, and herewith the relativly high density of fish which the plant makes possible.

The result is a hitherto-unknown fast rate of growth and herewith high yield, plus the fact that the quality of the fish is exceptionally high, partly for reasons of their highly-developed muscle tissue and partly because they have a pure flavour when consumed, and which is due to the high oxygen content and the effective cleaning which the plant is able to maintain.

It lies within the scope of the invention to cultivate organisms other than fish in the plant, in that crustaceans, molluscs and other organisms can be cultivated in the plant with correspondingly good results.

Claims

C L A I M S

1. Plant for the breeding of fish in recirculating flowing water, and comprising a fish basin which extends from an inlet basin and ends in an outlet basin, and where the surface of the water at the inlet basin lies higher than at the outlet basin, c h a r a c t e r i z e d in that the fish basin consists of a pipe (1, 2) through which the water (21) can flow.

2. Plant according to claim 1, c h a r a c t e r i z e d in that the pipe (1, 2) extends in an arc between the basins (3, 4).

3. Plant according to claim 1 and 2, c h a r a c t e¬ r i z e d in that the outlet basin (3) and the inlet basin (4) are water-connected via one or more connection pipes (7, 8) which extend down under the basins (3, 4), and where air (10) is introduced at the bottom of the connection pipe (7, 8) for the generation of a pumping effect through the connection pipe (8).

4. Plant according to claims 1-3, c h a r a c t e r i z e d in that water cleaning and water processing takes place in a UV-0₃ reactor (16).