JPH0632270B2 - Fry breeding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a breeding apparatus for fry after hatching, especially to juveniles.

[Prior art]

As is well known, it is difficult to secure clean water at an appropriate temperature as it becomes more popular to collect natural fish eggs to raise fishery resources and raise artificially hatched juveniles up to juveniles. New problems have arisen. Therefore,
For example, salmon and trout have rivers where salmon and trout can be expected to return. On the other hand, artificial hatching and breeding businesses are becoming popular.

By the way, in such an area, it is difficult to secure water having a preferable water quality, which is generally the most suitable temperature for breeding, of about 8 ° C. That is, the spring water in Hokkaido and the Tohoku region is about 8 ° C, but there is a limit in the area and the amount of spring water to obtain such spring water. Therefore, other water sources such as river water and underground water have been used. Even if the water quality of these waters is suitable, the average water temperature will be as low as around 4 ℃ during the cold season when fry salmon and trout, which will hinder the fry breeding in the farm. There is.

That is, since fry must be raised under running water, in addition to the enormous amount of heat required to heat the water at a temperature lower than the appropriate temperature to the appropriate temperature as described above, it is necessary to heat it. As a result, there is a problem that the amount of dissolved oxygen decreases and the biological system in the water changes due to heating.

Therefore, the present inventor radiates far-infrared rays into a fish pond instead of warming the water itself with a large amount of heat as a fish-culturing means capable of smoothly raising fry by artificial hatching even at water temperatures below these appropriate temperatures. Has developed a breeding method that allows smooth breeding of fry even under low water temperature.
It has already been proposed as 575 (Japanese Patent Publication No. 1-49688) and Japanese Patent Application No. 62-46679 (Japanese Patent Application Laid-Open No. 63-214126). In each of these inventions, far-infrared irradiation means is provided above or below the fish pond to raise the fish.

According to these means, the average water temperature during the breeding period is 1-2.
In the case of ℃, the period from hatching to the top required 120 days, but when the present invention was carried out, it could be significantly shortened to 50 to 52 days (30 days at a suitable temperature of 8 ° C), The growth status of the juveniles could be adjusted to the release time.

Moreover, juveniles (larvae) from hatching to the top of the hill have the habit of moving upstream in the fishpond if they are cultivated in cold water below a suitable temperature. However, according to the means of the previously proposed invention, such behavior does not appear, and it is possible to obtain a high breeding result with much less input energy than in the past.

By the way, it is estimated that migratory fish such as salmon and trout return to the hatched river at an extremely low rate. Therefore,
In order to effectively carry out the above-mentioned prior art, it is an important key to develop a far-infrared radiation device having high radiation efficiency with respect to input energy.

[Object of the Invention]

The present invention was made by focusing on the above problems,
In order to prevent fry that are raised in running water, especially fry from hatching to the top, to move in search of a suitable place, a fry breeding device that efficiently irradiates far infrared rays to raise fry is provided. It is intended to be provided.

[Means for Solving the Problems]

The fry breeding apparatus of the present invention for achieving the above object,
A far-infrared radiation device for fish farming is provided on the bottom of the aquarium, or the underside of the fish reef for fry, which allows water to flow down from one side to the other and hide fry on the bottom of the water. Is a metal casing having a flat heat-dissipating surface, a sheet-like heating element is arranged on the back side of the heat-dissipating surface, and a heat insulating layer is laminated on the back side of the sheet-like heat-dissipating surface. Is provided with a ceramic sprayed layer, which is parallel to the water surface of the water tank and is heated to a temperature at which visible light is not emitted.

The metal casing is a plate-shaped body processed,
The base material is not particularly limited as long as it is a material to which the sprayed ceramic layer firmly adheres. Further, it is preferable to use a flat heat dissipation surface in order to increase the heat dissipation surface and efficiently dissipate heat.

The far-infrared radiation device for fish farming of the present invention is mainly used by being installed on the upper surface of a water tank, but it may be submerged in water in some cases, but it is easy for water to enter the inside of the device. It is necessary to have a structure that does not easily corrode.

The ceramic forming the sprayed layer does not have to be one kind of raw material, and may be a composition in which various raw materials are mixed. There is no particular limitation on the raw material that can be used, it is possible to use the raw material used in the usual ceramic products, as the ceramics that emit a lot of far infrared rays, for example, zirconia, magnetite, alumina, zircon, iron, chromium,
Examples thereof include complex oxides such as manganese.

The spraying method is usually performed by a plasma spray gun,
The layer can be sprayed with a thickness of several μ or more, and if necessary, 20 mm or more. This plasma spray gun creates an ultra-high temperature plasma arc flame of 10,000 ° C or higher, feeds the powdered raw material into it, and melts it in a high-speed jet jet such as Mach 1-2 to spray the raw material onto the surface of the target base metal. A ceramic layer is formed by hitting. It should be noted that the spraying thickness is made more efficient in practice.

The above-mentioned structure of the present invention has a function of promoting the growth of fry and other plankton with a small input energy due to high far infrared radiation efficiency and fixing the plankton in the far infrared radiation region.
That is, the ceramic sprayed body itself plays the role of a converter to the far infrared wavelength. In particular, it acts to change the ceramic material into a radiator that emits far-infrared wavelength region peculiar to the material.

To efficiently radiate far infrared rays from the casing,
It is necessary to heat this casing to a predetermined temperature,
The heating means of this uses an electrically heating means, and the resistor used for this is a sheet-like one in which, in addition to metal low antibody, conductive particles such as carbon are dispersed in resin. Is preferably used in the form of a sheet heating element.

Although there is no limitation on the temperature of the radiation surface, if the temperature is high, the far-infrared radiation amount increases, but energy loss, for example, radiation of visible light, loss due to heat transfer, and the like, lowers energy efficiency. Especially for salmon and juveniles (larvae) after hatching of trout that need to be kept in the dark, the radiation surface temperature is preferably in the range of about 7 to 9 ° C.

The far-infrared radiation device for fish farming of the present invention, when used for rearing juveniles, especially from juveniles from hatching to the top, with the far-infrared radiation surface facing downward about 50 to 250 cm above the water surface of the breeding pond. Most preferably, it is arranged. However, far-infrared rays can be radiated from a position close to the juvenile by placing a fish reef for juvenile such as a stone for hiding the fish in the aquarium or an alternative member, and arranging it on the lower surface of the reef.

Hereinafter, the present invention will be described in detail with reference to one embodiment that is carried out by submerging the salmon and trout into the bottom of a fry pond after hatching.

FIG. 1 is a partially cutaway perspective view for explaining the far-infrared radiation device R for fish farming of this embodiment. In the figure, a casing 1 made of stainless steel is a flat box-like body which is provided with a flange portion 2 on the periphery and is watertightly sealed by a bottom plate 3, and a ceramic sprayed layer 5 is formed on a base material surface 4 (heat dissipation surface) of the casing. Is provided. The flange portion 2 is
It can also be provided facing inward.

The heating element 6 is a sheet-like long electric heater (trade name: PLAHEAT), which is made of a thermoplastic resin mixed with carbon particles, and has electrodes 7 on both ends of which copper wires are knitted in a ribbon shape is arranged. A heat insulating layer 8 made of a soft foamed resin that doubles as a backup is provided below the heat insulating layer 8.

The heating element 6 may use a metal resistance wire, and the heat insulating layer 7 may use another heat insulating material such as glass wool. Note that 9 is a watertight packing, and need not be used when the far-infrared emitting device R for fish farming is provided above the water surface.

The ceramic sprayed layer 5 is an important member as a means for efficiently radiating far infrared rays.
A plasma spray gun having the specifications was used, and the thickness was several μ in this example. The adhesive strength between the base material surface 4 and the ceramic sprayed layer 5 was extremely high.

FIG. 2 is an enlarged view of the ceramic sprayed layer 5 as a model of a cross section. In the figure, the sprayed layer 5 is composed of fine particles 10 constituting a ceramic.
0 is a space 11 between them is a normal ceramic sintered body,
For example, it is in a sparser state than ordinary ceramic products. That is, the density of the particles 10 formed by thermal spraying serves to enhance the far infrared radiation activity based on the ceramic raw material used.

FIG. 3 shows a fry breeding apparatus 12 according to the first embodiment, which is a rectangular water tank (or water channel) with a flat bottom having a width of about 1.8 m and a length of about 50 m and a water depth of about 50 cm. The plate-shaped far-infrared radiation device R shown in FIG. 1 was laid on the bottom 14 of the water, and a fish reef 16 for fry made of pebbles having a diameter of about 3.5 cm was laid on it. Then, in order to divide about 12 m in the longitudinal direction into a test section, a hard vinyl chloride pipe 18 having a diameter of about 2 cm was opened below the water surface at intervals of 10 cm, and a water supply weir 20 and a drainage weir 22 were arranged.

Further, FIG. 4 shows a second embodiment, in which the far-infrared emitting device R is hung by a hanging strap 15 at a place about 40 cm above the water surface instead of the first embodiment arranged on the water bottom 14. Other than that, the fry breeding apparatus 12 formed in the same manner as in Example 1 was used.

Further, in order to compare with the first and second embodiments, a fry breeding apparatus of a comparative example using a water tank of the same shape except that the far-infrared radiation device R is removed is prepared, and the fry breeding apparatuses are arranged in parallel. After placement, juveniles of salmon were bred from hatching to the top.

The breeding condition is that the sieve mesh surface is about 1 cm below the water surface.
At this point, 10,000 eggs of the invention were placed. The hatched larvae (not shown) pass through the net by themselves and fry for fry 1
I hid myself in 6.

As breeding water during the test period, river water having a water temperature of 0.3 to 2 ° C. was supplied to each fry breeding apparatus at a flow rate of 35 / min. The standard estimation is 80 / min when using spring water at an appropriate temperature of 8 ° C. In this way, Table 1 shows the results of comparing Examples 1 and 2 with Comparative Examples according to the number of days from the hatching to the absorption of the larvae from the larvae to the rising.
The glove thermometer in the lower space of the far-infrared radiation device R of Example 2 was controlled at 7 to 8 ° C.

It takes 65 days from hatching to the top of the salmon larvae raised in the spring water at a suitable water temperature of 8 ° C until hatching, whereas in the first embodiment, the total number of days until the top is 90 days, In the second example, the total number of days to reach the top was 70 days, whereas in the comparative example, the total number of days to reach the top was 150 days, clearly indicating that the fry breeding apparatus 12 of the present invention is excellent. It shows a bird.

That is, as described above, the larva has a habit of moving in search of a preferable environment at an appropriate temperature or lower, but in the first and second embodiments, even if the water temperature is lower than the appropriate temperature, the larva is in the far infrared radiation region. It can be fixed, unnecessary physical strength can be eliminated, and growth can be promoted.

Further, the following results show that the same breeding result can be obtained even when the far infrared radiation device without the ceramic sprayed layer 5 is used, but the ceramic sprayed layer 5 is provided for the same far infrared radiation amount. INDUSTRIAL APPLICABILITY The fry breeding apparatus of the present invention requires less electric power, can greatly reduce the economical efficiency when artificially hatching salmon in large quantities, and can provide a large economic benefit.

In the first embodiment, for example, a base is prepared on the bottom of a fry breeding tank, and then a heat insulating layer made of foamed resin and other heat insulating materials and a heating element are sequentially arranged, and for example, 2 to 3 cm. The epoxy resin layer is provided in the thickness of and the far infrared ray radiator such as a steel plate or aluminum plate on which ceramic is sprayed before the resin is hardened is adhered to the surface to form an integrated structure with the fry breeding tank. Can be carried out.

Further, the means for suspending the far-infrared radiation device in the air in the second embodiment can make the watertight structure simpler, especially for the type used indoors. Becomes that much easier.

Reference example: Explaining the operating conditions that are actually used, the far-infrared radiation device is hung at a position of about 2 m from the water surface of the water tank, and the glove thermometer is installed at a position of about 1 m. The far infrared radiation device was controlled so that the globe temperature was 8 ° C when the temperature was 0 ° C. In this case, the temperature of the radiating surface was 23.6 ° C, the drying temperature in the room equipped with the fry breeding apparatus was 3.2 ° C, and the water temperature was 0.1 ° C. According to the fry breeding apparatus of the present invention even under such conditions,
A remarkable breeding effect could be obtained with a small amount of power consumption.

To devise this fact, the temperature of the water is extremely low at 0.1 ° C, and the far infrared rays are radiated to the fry by adjusting the temperature of the glove in the air to about 8 ° C. Can be given.

〔The invention's effect〕

The juvenile breeding apparatus according to the present invention is to allow water to flow down from one side to the other, and to provide a far-infrared radiation device for aquaculture on the top of an aquarium filled with fry reefs for hiding fry on the bottom of the water, or on the underside of fry reefs. In the far-infrared radiator for fish farming, a planar heating element is arranged on the back surface of the radiation surface of a metal casing having a flat radiation surface, and a heat insulating layer is laminated on the back surface of the planar heating element. Further, a ceramic sprayed layer is provided on the surface of the heat dissipation surface, and this ceramic sprayed layer is parallel to the water surface of the water tank and is heated to a temperature at which visible light is not emitted.

Therefore, it is not economically feasible to warm the juvenile fish to a proper temperature under running water by using water having a temperature below the proper temperature.

However, in the present invention, by irradiating far-infrared rays to a reef for fry using the far-infrared radiation device for fish farming having the above-mentioned configuration, fry, particularly larvae from hatching to the top of the fish, can be traced back to the flow. It can be hidden in a fish reef without unnecessary physical consumption and promote growth.For example, fry salmon and trout at a water temperature below the optimum temperature, and keep them in time for release. Is possible.

And since the planar ceramic sprayed layer can radiate far infrared rays evenly and efficiently, it reduces energy consumption when raising fry, especially larvae from hatching to the top, and salmon trout etc. A large amount of fry can increase the economic efficiency of artificial breeding.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of a far infrared radiation device for fish farming according to one embodiment, and FIG. 2 is an enlarged cross-sectional view of the ceramic sprayed layer of FIG. FIG. 3 is a sectional view for explaining the outline of the fry breeding apparatus of the present invention according to the first embodiment, and FIG. 4 is a sectional view for explaining the outline of the fry breeding apparatus of the present invention according to the second embodiment. Is. 1 ... Casing, 4 ... Base material surface, 5 ... Ceramic sprayed layer, 6 ... Heating element, 12 ... Fryer, 14 ...
Water bottom, 16 …… Fish reef, R …… Far infrared radiation device.

Claims (1)

[Claims] 1. A far-infrared radiation device for fish farming is provided at the upper part of a water tank filled with fish reefs for fry that allows water to flow down from one side to the other to hide fry on the bottom of the water, or on the lower surface of the fish reef for fry. The far-infrared radiator for use disposes a sheet heating element on the back surface of the heat radiating surface of a metal casing having a plate-shaped heat radiating surface, and a heat insulating layer is laminated on the back surface of the sheet heating element. A fry breeding apparatus, wherein a ceramic sprayed layer is provided on the surface of the heat dissipation surface, the ceramic sprayed layer being parallel to the water surface of the water tank and being heated to a temperature at which visible light is not emitted.