JP2975933B1 - Foam removal device - Google Patents

Abstract

An object of the present invention is to provide a foam removing device capable of suctioning and removing a layer of foam floating on a water surface such as an aeration tank. SOLUTION: A suction pipe 15 having a closed end and a slit 16 provided on a side face is connected to a suction pipe 8 of a blower 9 in a vertical direction at a height at which a lower end of the slit 16 is immersed in the water surface of an aeration tank 3. In addition, stable suction can be performed even if the water surface has ripples. When the continuous foam layer 7 is formed around the suction pipe 15, the foam layer 7 can be drawn from a wide area of the water surface and sucked by the adhesive force of the foam itself. Foam layer 7
Contains a putrefactive suspension, such as protein residue generated by aeration of aquatic animal breeding water,
A bubble separator 11 is provided on the way to remove the bubbles and prevent the blower 9 from being contaminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foam removing apparatus for sucking and removing a layer of foam floating on a water surface, and more particularly to a foam removing apparatus for sucking and removing protein residue generated in an aeration tank for aquatic animal breeding water.

[0002]

2. Description of the Related Art Bubbles which are hard to disappear are generated at places where water containing proteins, surfactants and the like falls or is aerated, and a foam layer is formed on the water surface. When this layer of foam becomes an obstacle, foam removal processing such as watering is performed,
If it is necessary to remove or recover the foam, it is desirable that only the foam can be separated from the water. As an example of removing bubbles, removal of protein residue generated in an aeration tank for aquatic animal breeding water will be described.

[0003] In breeding tanks such as aquariums for breeding aquatic animals, the water in the breeding tank is circulated and the predetermined water quality is maintained without changing the seawater. Therefore, in order to maintain a predetermined water quality, the water must be aerated to maintain dissolved oxygen in the water and to remove pollutants in the water. Pollutants are waste products mainly composed of proteins, such as residues of feed and excrement from breeding animals. If left untreated, they become ammoniated and increase water pollution. Therefore, as the water circulation treatment, following the aeration treatment in the aeration tank, the removal of suspended solids by a filtration device, etc., the decomposition of soluble organic substances by microorganism treatment, and the nitrification and nitration of ammonia are performed. Will be

[0004] As a filtering device, a biological filtering device is generally used, which is formed of a porous filtering material on which microorganisms such as activated carbon are likely to grow, and performs not only filtration but also microbial treatment at the same time. Is often used in combination with ozone treatment. When the water before biological filtration is treated with ozone, a part of the soluble organic matter is precipitated to form a form that can be filtered,
The organic matter can be decomposed into a form that can be easily treated by microorganisms, and the treatment efficiency of the biological filtration device can be improved. When the water after biological filtration is treated with ozone, nitrous acid harmful to aquatic animals can be converted into harmless nitrate simultaneously with sterilization of the water.

Most of the waste products containing protein as a main component are suspensions suspended in water, and many of these waste materials float together with air bubbles during the aeration process and contain protein on the water surface of the aeration tank. A foam layer (protein residue) is formed. In particular, when the breeding water is seawater, since the bubble diameter formed by aeration is about 1 mm, which is smaller than the bubble diameter of 4 to 5 mm in the case of fresh water, a foam layer having a high protein concentration is formed on the water surface. Therefore, by removing the foam layer formed on the water surface of the aeration tank, it is possible to remove a considerable amount of the suspended matter which is a source of water pollution, thereby reducing the burden of subsequent filtration, microbial treatment, and ozone treatment. Can be reduced.

[0006] The circulation treatment of aquatic animal breeding water and the removal of protein residue as described above are described in JP-A-6-46.
No. 719 discloses this in detail. As means for removing bubbles, in the container for transporting live fish described in JP-A-5-176657, aeration is performed on one side wall of the fish tank, and a bubble intake port is provided at a height near the water surface on the other side wall. The foam is moved to the other side wall by the water flow generated by the aeration, the foam is taken into the foam outlet together with the water, the foam and the water are separated at the water blocking wall, the foam is stored in the foam tank, and the water is stored in the fish tank. I'm back. Further, in the non-renewable water breeding apparatus described in Japanese Patent Application Laid-Open No. Hei 7-255321, a suspended foam discharger that is rotationally driven by a water flow above the water surface of an aeration tank is provided, and only the foam is discharged to a container.

[0007]

In the above-mentioned container for transporting live fish, when the foam is separated from the water that has flowed into the foam inlet, the foam is stored in the foam tank, and the separated water is returned to the fish tank. During the separation process, some of the foam is broken and the resulting suspension is returned to the fish tank again. Further, when the tank is full due to foam, no more foam can be accumulated. In addition, as in the above-mentioned non-renewable water culture device, a foam discharger that moves above the water surface of the aeration tank becomes a large-scale device when provided in a large aeration tank, and such a foam discharger has a Cannot be attached to an aeration tank equipped with a mechanical surface aerator.

[0008] As described above, various attempts have been made to remove bubbles generated in the aeration tank. However, in the case of circulating water in a large tank for migratory fish, sharks, and sea animals (dolphins, whales, etc.). Requires a large aeration tank, and the amount of bubbles generated by aeration, ie, protein residue, becomes large. Therefore, it is desired that only the bubbles can be efficiently separated from the water surface of the aeration tank.

In a flotation separation device or an oil separation device for separating dregs or oil floating on the water surface of a large water tank, the dregs or oil floated on a quiet water surface of the water tank is immersed in a scrap with its lower end submerged. I'm scraping with a parchment. Even if this scraping plate is applied to an aeration tank where the water surface is wavy, it is not possible to efficiently separate only bubbles.

[0010] Further, it is conceivable that the suction port of the suction pipe is positioned near the water surface and only the bubbles are suctioned and removed from the water surface as in a vacuum cleaner. The suction of the foam will stop or the water will be sucked.

An object of the present invention is to provide a foam removing apparatus for sucking and removing a layer of foam floating on the water surface.

[0012]

The foam removing apparatus of the present invention comprises:
According to the first aspect of the present invention, a suction tube having a closed end and a slit formed on a side surface is vertically moved at a height at which the lower end of the slit is immersed in the water surface. To the suction pipe connected to the suction source.

Air and bubbles are sucked from a vertically long slit whose lower end is immersed in the water surface. Even if the height of the water surface slightly fluctuates due to the ripples, most of the slits are on the water surface, and the suction is stable. Can be continued. Because the slits do not suck water, bubbles scattered on the water surface cannot be drawn and sucked, but when the bubbles gather and a continuous foam layer is formed around the suction tube, due to the adhesive force of the bubbles themselves, A layer of foam can be drawn and sucked from a wide area of the water surface.

According to the second aspect of the present invention, the opening area of the slit and the inner diameter of the suction tube are set to a size such that a predetermined air velocity can always be obtained in the suction tube by the suction air.

The bubbles sucked from the slit are partially broken and become droplets in the process of being transferred through the suction pipe. However, sufficient air is sucked regardless of the amount of sucked bubbles, and If the predetermined pipe wind speed is always maintained in the suction pipe, it is possible to transfer the heavy foam including the droplets. Even if the thickness of the foam layer is larger than the length of the slit, the foam layer is drawn into the slit together with the air in a thinly stretched state. Air for the work can be secured.

According to the third aspect of the present invention, a centrifugal blower is used as a suction source. Since the centrifugal blower has a lower static pressure than the positive displacement blower, even if the entire slit is submerged due to the large undulation of the water surface, it does not suck up water like a pump, and the centrifugal blower is compared to the positive displacement blower. Easy handling and low noise during operation.

According to the fourth aspect of the present invention, a foam separator having a watering space and a liquid outlet is provided in the middle of the suction pipe.
If the foam to be sucked contains suspended matter, water can be sprinkled in the middle of the suction pipe to break the foam, and the waste liquid containing the suspended matter can be discharged to the outside. It is desirable from the viewpoint of preventing scattering.

According to the fifth aspect of the present invention, the horizontal portion of the suction pipe has a downward slope toward the foam separator. Thereby, the transfer of the water containing the suspended matter generated by the breakage of the foam in the suction pipe can be promoted.

According to the sixth aspect of the present invention, the inside of the foam separator is partitioned into an inflow side space and an outflow side space which communicate with each other at a lower portion by the partition plate.

Since the U-shaped flow path is formed by the partition plate inside the bubble separator to be sprayed, bubbles and splashes flowing at high speed together with air from the suction pipe on the aeration tank side are blocked by the partition plate. It does not flow to the suction pipe on the blower side due to a short circuit.

According to a seventh aspect of the present invention, the foam layer to be removed is a protein residue generated in an aeration tank for aquatic animal breeding water.

The foam removing device of the present invention can efficiently aspirate and remove only bubbles together with air from the wavy water surface of the aeration tank. Therefore, by removing protein residue, a large proportion of contaminants in aquatic animal breeding water can be removed. And the load of the subsequent filtration and microbial treatment can be reduced.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS.
An embodiment of the present invention will be described. FIG. 1 is a flow sheet of a circulating water treatment facility for aquatic animal breeding water, and FIG. 2 is a flow sheet of a foam removing apparatus of the present invention.

The breeding aquarium 1 shown in FIG. 1 is a dolphin breeding aquarium. Seawater is first sent from the bottom of the breeding aquarium 1 to the aeration tank 3 by the circulation pump 2 to perform aeration. An air diffuser 4 is provided at the bottom of the aeration tank 3, and the air supplied from the air supply device 5 is released into the water as fine bubbles by the air diffuser 4. Bubble 6
In the process of floating, water is supplied with oxygen, and at the same time, a fine suspension floating in the water is taken in and floated to form a foam layer (protein residue) 7 containing the suspension on the water surface. The aeration tank 3 is provided with a foam removing device 10 of the present invention for sucking and removing the foam layer 7 by a blower 9 via a suction pipe 8, and a foam separator 11 is provided in the suction pipe 8. I have.

The water aerated in the aeration tank 3 is returned to the breeding aquarium 1 through the activated carbon filtration device 12. Activated carbon filter 12
Is a biological filtration device that simultaneously performs a filtration process and a microbial treatment, and uses an ozone treatment (not shown) in combination.
These descriptions are omitted.

FIG. 2 shows the details of the foam removing apparatus 10 of the present invention. The planar shape of the aeration tank 3 is a square surrounded by a tank wall 13 having one side of 3 m. In the aeration tank 3, a circulating water flow that rises at the center, spreads around, and descends along the tank wall 13 due to the rising of the air bubbles 6 released from the diffuser 4 installed at the center of the tank bottom. Is formed. Therefore, the bubbles 6 that have taken up the suspended matter and floated on the water surface 14 spread around the circulation flow, and gather inside the tank wall 13 to form a foam layer 7.

The blower 9 for sucking the foam layer 7 has a static pressure of 100 mmA.
q (0.98 KPa), centrifugal blower with air volume of 1 m ³ / min, inner diameter 50
A suction pipe 15 that is directed vertically inside the tank wall 13 of the aeration tank 3 is connected to a suction end of the suction pipe 8 of mm. Suction tube
Reference numeral 15 denotes a tube having an inner diameter of 50 mm having a closed end and a slit 16 having a width of 5 mm and a length of 100 mm formed on both side surfaces. The lower end of the slit 16 is slightly immersed in the water surface 14 of the aeration tank 3. It is connected to a suction pipe 8.

A bubble separator 11 is provided in the middle of the suction pipe 8,
The bubbles sucked from the slit 16 are separated to prevent the blower 9 from being contaminated. The foam separator 11 is a rectangular container having a V-shaped bottom plate 17 at the bottom, the upper surface of which is covered with a cover 18 that can be opened, and a liquid outlet 19 is provided at the center of the bottom plate 17. The inside of the container is provided with an inflow side space 21 communicating with the
a and an outflow side space 21b to form a U-shaped flow path. The suction pipe 8a on the aeration tank side is connected to the upper part of the space 20a, the suction pipe 8b on the blower side is connected to the upper part of the space 20b, and the water spray nozzles 22a and 22b are provided in the respective spaces 21a and 21b. The suction pipe 8a has a downward slope α toward the foam separator 11, and facilitates the transfer of the water containing the suspension formed by the breakage of the foam to the foam separator 11.

The foam removing apparatus 10 of the present invention is operated continuously in accordance with the operation of the aeration tank 3, and sucks the foam layer 7 floating on the water surface of the aeration tank together with air from a vertically long slit 16. Therefore, the suction can be continued even if the water surface 14 of the aeration tank 3 is wavy. Since the slit 16 does not suck water, bubbles scattered on the water surface 14 cannot be attracted. However, when the bubbles gather inside the tank wall 13 and the continuous foam layer 7 is formed around the slit 16, Due to its own tackiness, the foam layer 7 can be drawn and sucked from a wide area of the water surface 14.

The bubbles sucked from the slit 16 are partially broken and become droplets in the process of being transferred through the suction pipe 8a, so that the opening area of the slit 16 and the inner diameter of the suction pipe 8a are determined by suction air. A size that can always maintain a predetermined pipe wind speed within 8a is set so that heavy foam including droplets can be transferred to the foam separator 11. Even when the thickness of the foam layer 7 is larger than the length of the slit 16,
Since the foam layer 7 is thinly stretched near the slit 16 and is sucked together with the air, the air for promoting the transfer can be secured regardless of the amount of the sucked foam. Further, as mentioned above,
Since the suction pipe 8a is provided with the downward gradient α toward the foam separator 11, even if the foam is further broken during the transfer and the water containing the suspension increases, the suction pipe 8a is transferred to the foam separator 11. .

Since a centrifugal blower with a low static pressure is used as the blower 9, even if the water surface 14 of the aeration tank 3 has a large wave and the entire slit 16 is submerged, the blower 9 does not suck water. Also, the centrifugal blower is easier to handle and has less noise during operation than the positive displacement blower.

The foam sucked from the slit 16 is transported together with the air at a predetermined wind speed in the suction pipe 8a on the aeration tank side and flows into the foam separator 11. Since a U-shaped flow path is formed by the partition plate 20 inside the foam separator 11, the suction pipe 8a
The bubbles and splashes flowing at high speed together with the air are blocked by the partition plate 20, are short-circuited to the suction pipe 8b on the side of the blower and are not sucked, and the cross-sectional area of the flow path in the U-shaped flow path is increased. As a result, the flow velocity of the air is reduced, so that the splash generated by the water spray accompanies the air and the suction pipe 8b on the blower side.
Will not be sucked into.

Most of the foam flowing into the foam separator 11 from the suction pipe 8a hits the partition plate 20 and descends in the inflow-side space 21a, and is mostly broken by water spray from the water spray nozzle 22a. When the water passes through the lower portion and flows into the outflow side space 21b, the remaining bubbles are further broken by watering from the watering nozzle 22b, and the water thus sprinkled is discharged from the liquid outlet 19. Since the water discharged from the liquid outlet 19 is wastewater containing putrefactive suspension, it is sent to a wastewater treatment device for treatment or discharged to a sewer.

As a foam separator having a watering space and a liquid outlet, various devices other than the above-described foam separator 11 can be used. In the case where bubbles containing suspended matter such as protein residue are removed. A simple structure having a small amount of suspended solids is preferred. In the above foam separator 11, since the bottom plate 17 is washed by the water spray from the water spray nozzles 22a and 22b, there is no accumulation of suspended matter, and the dirt on other portions stops the blower 8 and stops the upper cover 18 It can be easily cleaned by opening it.

In the process of circulating the water in the dolphin breeding aquarium 1, a foam removing device 10 of the present invention is provided to remove the foam layer 7 formed on the water surface of the aeration tank 3 by suction to remove the activated carbon filter. Twelve washing cycles could be extended about twice.

The foam removing apparatus 10 of the present invention can be applied not only to the aeration tank 3 of the aeration type as described above, but also to a surface aeration tank which scatters water on the water surface to perform aeration. In addition, even when the height of the water surface fluctuates greatly, such as in an aeration tank provided with a floating type aerator, the height of the slit 16 with respect to the water surface can be increased by connecting the intake pipe 15 to the float so that it can move up and down. Can always be held at a predetermined height. When the aeration tank is larger or divided into a plurality of tanks, the suction pipe 8a on the aeration tank side may be branched and suction pipes 15 may be provided at a plurality of locations to suck the bubbles.

[0037]

As described above, the foam separation apparatus of the present invention
A suction pipe with a closed end and a slit formed on the side is connected to a suction pipe extending vertically to a blower at the height where the lower end of the slit is submerged in the water surface, creating a wave like an aeration tank. Bubbles can be stably removed even on the water surface. When the foam to be removed by suction is a foam containing a putrefactive suspension such as a protein residue, a foam separator by water sprinkling can be provided in the middle of the suction pipe to prevent contamination of the blower and the like. .

Further, since the foam removing device of the present invention is not a mechanical device such as a scraper, it can be easily attached to any type of tank without modifying the aeration tank or the like. Maintenance is easy. In addition, the foam removing device of the present invention can be efficiently attached to a portion of a waterway where bubbles are collected, such as an aeration tank or a fermentation tank, in addition to a water tank in which bubbles are formed, so that only the bubbles can be efficiently sucked.

[Brief description of the drawings]

FIG. 1 is a flow sheet of an aquatic animal breeding water circulation treatment facility.

FIG. 2 is a flow sheet showing the foam removing device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Aquatic animal breeding aquarium 2 ... Circulation pump 3 ... Aeration tank 4 ... Aeration device 5 ... Air supply device 6 ... Bubbles 7 ... Foam layer (protein residue) 8) Suction pipe 9 ... Blower 10 ... Bubble removal device 11 ... Bubble separator 12 ... Activated carbon filtration device 13 ... Tank wall 14 ... Water surface of aeration tank 15 ...・ Suction pipe 16 ・ ・ ・ Slit 17 ・ ・ ・ Bottom plate 18 ・ ・ ・ Top cover 19 ・ ・ ・ Liquid outlet 20 ・ ・ ・ Partition plate 21a, 21b ・ ・ ・ Internal space 22a, 22b ・ ・ ・ Sprinkling nozzle

Claims (7)

(57) [Claims] 1. A foam removing device for sucking and removing a layer of foam floating on a water surface, wherein a suction tube having a closed end and a slit formed on a side face is vertically moved at a height at which a lower end of the slit is submerged in the water surface. A foam removal device connected to a suction pipe leading to a suction source. 2. The bubble removing device according to claim 1, wherein the opening area of the slit and the inner diameter of the suction pipe are set to a size such that a predetermined air velocity in the pipe can always be obtained in the suction pipe by the suction air. 3. The method according to claim 1, wherein the suction source is a centrifugal blower.
A foam removal device as described. 4. The foam removing device according to claim 1, further comprising a foam separator having a water sprinkling space and a liquid outlet provided in the suction pipe. 5. The foam removing device according to claim 4 , wherein a horizontal portion of the suction pipe is inclined downward toward the foam separator. 6. The foam removing device according to claim 4, wherein the inside of the foam separator is partitioned into an inflow side space and an outflow side space which communicate with each other at a lower portion by a partition plate. 7. The foam removing device according to claim 1, wherein the foam layer is a protein residue generated in an aeration tank for aquatic animal breeding water.