JP2007090144A - Filtering apparatus for ballast water - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a centrifugal filtering apparatus especially separating and removing high-specific-gravity foreign matter from ballast water. <P>SOLUTION: The centrifugal filtering apparatus 1 is used to separate and remove high-specific-gravity sludge, e.g. sludge, from ballast water taken. The cylindrical body 11 of the apparatus 1 is connected to an inlet conduit 12 in the lower part and to an outlet conduit 13 in the upper part, and ballast water W fed from the inlet conduit 12 is raised while swirling along the side surface 111 and discharged from the outlet conduit 13. A slit 6 intersecting with the side surface 111 in the swirling direction of the ballast water W is disposed. High-specific-gravity foreign matter, e.g. sludge, is released from the slit 16 out of the cylindrical body 11 by utilizing the centrifugal force produced by the swirling with ballast the water W and removed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a centrifugal type filtration apparatus that separates and removes high specific gravity foreign substances such as sludge from water taken in ballast water. The “high specific gravity foreign matter” referred to in the present invention means a foreign matter that has a higher specific gravity than ballast water (seawater) and can be physically separated from the ballast water by filtration.

  In a ship, in order to separate and remove foreign substances from the taken ballast water, a filtration device is interposed in the water intake path from the water intake to the ballast tank. In particular, high specific gravity foreign matters such as sludge (hereinafter represented by high specific gravity foreign materials) are desirably removed sufficiently because they reduce the volume of the ballast tank and cause rusting in the ballast tank. As a filtering device that separates and removes such a high specific gravity foreign substance, for example, as seen in Patent Document 1, there is a configuration in which a “strain net (screen filter)” is simply used. However, since the screen filter is easily clogged, the centrifugal separation type found in Patent Document 2 is preferable as a filtration device that separates and removes the high specific gravity foreign matter from the ballast water.

  Centrifugal type filtration device swirls ballast water sent to a substantially conical main body in the downward shape, collects high-specific gravity foreign substances on the side of the outer side in the radial direction by centrifugal force (centrifugal action), and ballast near the swivel center The high specific gravity foreign matter is separated from water. Since the substantially conical body has a downwardly drawn shape, the rotating high-specific gravity foreign matter settles while stalling and is removed from the bottom surface of the substantially conical body. The filtration device (cyclone separator) disclosed in Patent Document 2 makes it difficult to send ballast water from the substantially conical body by narrowing an outlet pipe (water supply pipe) extending from the substantially conical body to the ballast tank. The specific gravity foreign matter separation effect is enhanced.

Japanese Patent Laid-Open No. 05-116675 JP 05-124573 A

  The centrifugal filtration device separates the ballast water and the high specific gravity foreign substance inward and outward in the radial direction by a centrifugal separation action. In order to remove the high-specific gravity foreign matter, it is necessary to settle the swirling high-specific gravity foreign matter while stalling. However, the sedimentation of the high-specific gravity foreign matter in the ballast water is slow and may be mixed with the ballast water again. Although it is considered that the phrase “to increase the separation effect by making it difficult to send out the ballast water from which the high specific gravity foreign matter has been separated” as referred to in Patent Document 2, it is considered to mean the function of preventing the high specific gravity foreign matter from being sucked up when the ballast water is sent out. The removal of high specific gravity foreign substances relies on sedimentation. Therefore, a configuration or structure for reliably removing the high-specific gravity foreign matter after separating the high-specific gravity foreign matter was examined for a centrifugal filter device that separates and removes the high-specific gravity foreign matter from the ballast water.

  What was developed as a result of the study is a centrifugal type filtration device that separates and removes sludge and other high-density sludge from the collected ballast water. The cylindrical body has an inlet pipe on the bottom and an outlet pipe on the top. The ballast water sent from the inlet pipe is raised while swirling along the side surface, and is sent out from the outlet pipe. This is a ballast water filtration device that uses the centrifugal force generated by swirling the high specific gravity foreign material together with the ballast water to remove it from the slit to the outside of the cylindrical body. The high-specific gravity foreign matter that has left the outside of the cylindrical main body from the slit may be accumulated in, for example, a foreign matter reservoir attached to the cylindrical main body, and may be discarded as appropriate after accumulating a certain amount.

  The filtering device of the present invention separates and removes high specific gravity foreign substances gathering on the side surface that is radially outward due to the centrifugal separation action by separating them from the slit provided on the side surface to the outside of the cylindrical body. From this, it is desirable that the slit extends so as to intersect with the swirling direction of the ballast water, and preferably approximately perpendicular to the swirling direction. By using such separation / removal of high-specific gravity foreign matter by the slit, the filtration device of the present invention does not need to stall the high-specific gravity foreign matter separated from the ballast water and settle it, and the extended portion below the inlet pipe The size can be reduced by omitting. Further, since it is not necessary to stall the high specific gravity foreign substance, the apparatus main body is not a substantially conical main body but a cylindrical main body, so that a necessary and sufficient volume can be ensured while downsizing.

  In the filtering device of the present invention, which separates and removes high specific gravity foreign substances directly from the ballast water in the middle of turning, the inlet pipe is connected to the tangential direction of this side below the side of the cylindrical main body, and the outlet pipe is connected to the cylindrical main body. Connect to the top of the. This is different from a configuration in which a conventional centrifugal separator has a lower opening end of an outlet pipe than an inlet pipe. As a result, the ballast water rises while swirling, so that only the ballast water that does not contain high specific gravity foreign matter is present in the vicinity of the swivel center above the inside of the cylindrical body, and only the ballast water from which high specific gravity foreign matter has been separated is removed from the outlet pipe. Can be sent out.

  Moreover, in the filtration apparatus of this invention, it is possible to send out the swirling ballast water as it is. In this case, the inlet pipe is connected to the tangential direction of the side face below the side face of the cylindrical body, and the outlet pipe is connected to the tangential direction of the side face and opposite to the inlet pipe line above the side face. . Here, “connecting the outlet pipe in the opposite direction to the inlet pipe” means connecting the outlet pipe in a direction in which the ballast water fed from the inlet pipe is sent out as it is. Since the inlet pipe and the outlet pipe are separated from each other in the vertical direction, if the inlet pipe and the outlet pipe are connected to the side surface at the same position in the circumferential direction in plan view, they are aligned on the same straight line. If the inlet pipe and the outlet pipe are connected to the side face at a position 180 degrees apart in the circumferential direction, both extend in the same direction and in parallel.

  Although the high specific gravity foreign substance separates from the slit to the outside of the cylindrical main body due to centrifugal force, since it swirls along the side surface, there is a possibility that the ratio of passing through the slit increases due to the swirling speed. Therefore, the slit may be provided with a guide plate that protrudes inward in the radial direction along the vertical edge portion on the downstream side in the swirling direction of the ballast water. This guide plate collides with high specific gravity foreign matter swirling with the ballast water along the side surface in a range protruding in the radial direction so that the high specific gravity foreign matter does not pass through the slit. The guide plate has a function of guiding the collided high specific gravity foreign substance from the slit to the outside of the cylindrical main body. Such a guide plate can be provided simultaneously with the formation of the slits by cutting and raising the side surface of the cylindrical body.

  The guide plate projecting inward in the radial direction serves as a resistance to the ballast water that turns. Therefore, the slit may be provided with a guide plate protruding outward in the radial direction along the vertical edge portion on the upstream side in the swirling direction of the ballast water. This radially outward guide plate does not collide with high specific gravity foreign matter swirling with the ballast water along the side surface, but guides the high specific gravity foreign material from the side surface of the cylindrical body by utilizing centrifugal force. Prevent foreign matter with high specific gravity from passing through the slit.

  Here, when the turning speed of the ballast water is low (for example, when the ballast water starts to be fed), there is a possibility that sufficient centrifugal force does not act on the high specific gravity foreign substance and cannot be separated and removed from the slit. However, in this case, as in the conventional case, foreign bodies with high specific gravity stall and settle, so that the cylindrical main body is provided with a water-permeable lower filter section that separates the inner space and the bottom surface of the cylindrical main body through which the ballast water turns. It is preferable to deposit a high specific gravity foreign substance that settles upon stalling and separates it from the ballast water. The high specific gravity foreign matter deposited on the bottom is collected as appropriate. The present invention separates the bottom surface on which the sedimented high specific gravity foreign matter is accumulated by the inner space of the cylindrical body in which the ballast water swirls and the lower filter compartment, so that the high specific gravity foreign matter is wound up by the swirling of the ballast water, and again into the ballast water. Eliminate opportunities to mix.

  The lower filter section only needs to have water permeability within a range in which it is possible to prevent the high specific gravity foreign matter from being rolled up by the swirling ballast water while allowing the high specific gravity foreign matter to settle to pass therethrough. As a specific lower filter section, a screen filter made of punching metal or expanded metal can be exemplified. In this case, if the screen filter is provided immediately below the inlet pipe connected to the side surface of the cylindrical main body, the ballast water fed from the inlet pipe does not flow to the bottom surface side, and the flow direction is specified as the upward turning direction. There is.

  In addition, in order to prevent the high specific gravity foreign matter from being completely separated and removed from the ballast water, or if there is a high specific gravity foreign matter wound up in the ballast water, a cylinder is used to prevent the high specific gravity foreign matter from being fed into the outlet pipe. The main body may be provided with a water-permeable upper filter section that separates the internal space of the cylindrical main body through which the ballast water turns and the outlet pipe connected to the cylindrical main body. The upper filter section serves as a resistance when the ballast water is sent out from the outlet pipe, and has a function of enhancing the effect of separating high specific gravity foreign substances from the ballast water, as in Patent Document 2. As this upper filter section, a cylindrical filter made of a metal mesh can be exemplified.

  According to the present invention, it is possible to provide a centrifugal type filtration device that can reliably remove foreign substances such as sludge from ballast water after separation. This does not remove the high specific gravity foreign matter separated from the ballast water by sedimentation, but removes the high specific gravity foreign matter swirling with the ballast water from the side slit to the outside of the cylindrical body and removes the high specific foreign matter at the same time as the separation. It is an effect by doing. The effect of separating and removing the high specific gravity foreign substance from the slit is further enhanced by the guide plate provided for the slit. In addition, the foreign matter to be separated and removed from the slit is not limited to the high specific gravity foreign matter such as sludge, but extends to cysts and crustaceans. Therefore, the present invention also has an effect of contributing to prevention of ballast water contamination.

  The lower filter section isolates the high specific gravity foreign matter accumulated on the bottom surface of the cylindrical body from the internal space of the cylindrical main body where the ballast water swirls, and prevents the separated high specific gravity foreign matter from being mixed with the ballast water again. Further, the upper filter section has a function of separating and removing from the ballast water fed out from the outlet pipe, and separating and removing the high specific gravity foreign matter that could not be separated and removed by sedimentation. By combining such separation and removal from the slit, separation and removal by sedimentation across the lower filter section, and separation and removal by the upper filter section, the filtration device of the present invention achieves a high separation effect.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of a ballast water intake system incorporating the filtration device 1 of the present invention, FIG. 2 is a sectional view showing an example of the filtration device 1 of the present invention, and FIG. 4 is an enlarged view of the portion indicated by the arrow B in FIG. 3 showing the vicinity of the slit 16 in the filtration device 1 of this example, FIG. 5 is an enlarged view corresponding to FIG. 4 showing the vicinity of the slit 17 of another example, and FIG. FIG. 7 is a sectional view showing another example of the filtering device 6, and FIG. 7 is a sectional view taken along the line CC in FIG. 6.

  The filtration device 1 of the present invention is not used alone, but, for example, as shown in FIG. 1, a suction filtration device 3 for a water intake post and a ballast for removing fine foreign matters, that is, plankton having a diameter of 10 mm or less. A water purification system (secondary filtration device) 5 is used in combination to constitute a water intake system that takes in ballast water without foreign matter into a ballast tank (not shown). In the water intake system of this example, the suction filtration device 3 is interposed between a water intake (sea chest) 2 opened at the bottom of the ship and a ballast pump 4 for sucking and sending ballast water, and the ballast pump 4 and the ballast water purification are interposed. The filtration device 1 of this example is interposed between the device 5 and the device 5. This means that the filtration device 1 of the present example is a primary filtration device for the ballast water purification device 5, and is a protection device that prevents the ballast water purification device 5 from being damaged by taking in high-specific gravity foreign matter.

  As shown in FIGS. 2 and 3, in the filtering device 1 of this example, the cylindrical main body 11 connects the inlet pipe 12 from the tangential direction to the lower side surface 111, and is a flat upper surface above the cylindrical main body 11. An outlet pipe 13 is connected to 112 from the vertical direction. Ballast water W (represented by white arrows in each figure, the same applies hereinafter) connects the inlet pipe line 12 in the tangential direction of the side surface 111, thereby smoothly forming a swirling flow along the side surface 111. In this example, the opening end 121 of the inlet pipe 12 is brought close to the side surface 111 to form a kind of orifice. As a result, the momentum of the ballast water W fed from the inlet pipe 12 to the cylindrical main body 11 is increased, and the swirl flow along the side surface 111 is pushed up from the lower layer to raise the ballast water W.

  The cylindrical main body 11 is provided with a screen filter 14 as a lower filter section immediately below the inlet pipe line 12, and separates an internal space 115 of the cylindrical main body 11 from a funnel-shaped bottom surface 113 narrowed downward. The cylindrical main body 11 is provided with a cylindrical filter 15 as an upper filter section on the upper surface 112 of the cylindrical main body 11, and the internal space 115 of the cylindrical main body 11 and the outlet pipe line 13 are separated from each other. An outlet line 13 connects to the upper surface 112 in the upper filter compartment. The slit 16 for separating and removing the high specific gravity foreign substance to the outside of the cylindrical main body 11 opens in the side surface 111 in the vicinity of the middle between the inlet pipe 12 and the cylindrical filter 15 in the height direction.

  The screen filter 14 that is a lower filter section is made of a circular punching metal that is equal to the cross-sectional shape of the cylindrical main body 11. The punching metal constituting the screen filter 14 has a hole diameter of 10 mm to 12 mm as a guide. The screen filter 14 of this example is arranged directly under the inlet pipe 12 and restricts the ballast water W sent from the inlet pipe 12 from falling, and is affected by the swirling of the ballast water W. Since it is difficult, it is not particularly fixed to the cylindrical body 11, and only the peripheral edge is placed on the support protrusions 141 provided in the four directions. For this reason, the screen filter 14 of this example is detachable as necessary, and can be replaced with a punching metal or an expanded metal having a different hole diameter, or temporarily removed for maintenance.

  As described above, the screen filter 14 regulates the ballast water W sent from the inlet pipe 12 so as not to descend, and helps to form an upward swirling flow, and also the inner space 115 of the cylindrical body 11. And the bottom surface 113 have a function of preventing the high specific gravity foreign matter that has settled on the bottom surface 113 from being rolled up. High specific gravity foreign substances that have passed through the screen filter 14 and settled on the bottom surface 113 are sequentially deposited from the lowermost center of the funnel-shaped bottom surface 113 constricted downward. A bottom surface discharge port 114 connected to an open / close valve (not shown) is provided at the lowermost center of the bottom surface 113. The bottom discharge port 114 is normally closed by the opening / closing valve, and when a certain amount of high specific gravity foreign material has accumulated, the open / close valve is appropriately opened to collect the high specific gravity foreign material.

  A cylindrical filter 15 that is an upper filter section is a mesh cylinder 151 made of a metal mesh. In order to retain the shape of the mesh cylinder 151, a cylindrical frame 152 made of punching metal is placed inside the mesh cylinder 151. I'll accompany you. The mesh cylinder 151 has a role to prevent the high specific gravity foreign matter that could not be removed and removed from the slit 16 to be described later from exiting the outlet conduit 13, but a prefilter for the ballast water purification device 5 at the latter stage of the water intake system. Also plays a role. From this, it is desirable that the mesh cylinder 151 is made of a fine metal mesh so that even a small foreign object up to, for example, about 100 μm can be blocked.

  Further, unlike the screen filter 14 which is the lower filter section, the cylindrical filter 15 is affected by the swirling ballast water W, and therefore, a restraining protrusion 154 is attached to each of the cross support bars 153 provided on the cylindrical body 11, The lower surface is fitted into the restraining protrusion 154 to fix the position. The cylindrical frame 152 in the cylindrical filter 15 is intended only to retain the mesh cylinder 151 having the filter action, so the hole diameter of the punching metal may be large, and various steel materials may be used instead of the punching metal. You may comprise with the framework frame using. The high specific gravity foreign matter blocked from passing through the cylindrical filter 15 settles, passes through the screen filter 14 described above, accumulates on the bottom surface 113, and is collected.

  As shown in FIG. 4, the slit 16 separates high-specific gravity foreign substances such as sludge swirling with the ballast water W radially outward, drops them into the foreign substance reservoir 162 attached to the cylindrical body 11, and removes them. Collect from 162 as appropriate. The foreign matter reservoir 162 has a space below the slit 16 so that a sufficient amount of high specific gravity foreign matter can be deposited until it is collected. The slit 16 in this example is a substantially rectangular opening extending in a vertical direction substantially orthogonal to the swirling direction of the ballast water W, and a guide plate 161 that guides the high specific gravity foreign material to the outside of the cylindrical body 11 by colliding with the high specific gravity foreign matter. Are protruded inward in the radial direction along the vertical edge portion on the downstream side in the turning direction of the ballast water W. The guide plate 161 of this example is configured by cutting and raising the side surface 111 of the cylindrical main body 11 and simultaneously opening the slit 16.

  The sizes of the slit 16 and the guide plate 161 are determined in consideration of the size of the cylindrical body 11 and the speed of the swirling flow of the ballast water W. For example, in the case of the configuration of this example in which the guide plate 161 is cut and raised to form the slit 16, as a guide, the guide plate 161 having a protrusion amount T = 10 mm to 20 mm is provided for the slit 16 having a width D = 30 mm to 50 mm. As a result, only the high-specific gravity foreign matter moving along the side surface 111 collides with the guide plate 161 without causing the guide plate 161 to greatly disturb the turning of the ballast water W, and is removed from the slit 16 toward the foreign matter reservoir 162 and removed. it can. At the bottom of the foreign matter reservoir 162, a reservoir outlet 163 connected to an open / close valve (not shown) is provided. This reservoir discharge port 163 is normally closed by the opening / closing valve, and when a certain amount of high specific gravity foreign matter has accumulated, the open / close valve is appropriately opened to collect the high specific gravity foreign matter.

  If resistance to the swirling flow is a problem due to the size of the cylindrical body 11 and the flow velocity of the ballast water W fed from the inlet pipe 12, for example, as shown in FIG. Can be protruded radially outward along the vertical edge on the upstream side of the ballast water W in the turning direction. The guide plate 171 has a function of guiding the high specific gravity foreign material to the foreign material reservoir 162 and releasing it. From this point on, the high specific gravity foreign substance that has entered the foreign substance reservoir 162 without almost decelerating is decelerated only after colliding with the wall surface in the foreign substance reservoir 162, and settles in the foreign substance reservoir 162. When providing a plurality of slits, the guide plates provided in each slit may be of the same type or a combination of different types (see FIGS. 4 and 5).

The filtering device 1 of this example works as follows, and removes and collects high specific gravity foreign substances such as sludge from the ballast water W. First, the ballast water W taken by the ballast pump 4 (see FIG. 1) is similarly sent from the inlet pipe 12 to the cylindrical body 11 by the ballast pump 4. Here, as described above, since the opening end 121 of the inlet pipe 12 has a shape narrowed toward the side surface 111, the ballast water W fed into the cylindrical main body 11 has an increased flow velocity, as well as FIGS. As can be seen, a swirl flow along the side surface 111 is smoothly formed. Here, if the ballast pump 4 is capable of ^{2kg / cm 2 ~3kg / cm 2} , ballast water W fed to the cylindrical body 11 be pivoted at a flow rate of approximately 2m / sec~3m / sec it can. The high specific gravity foreign matter contained in the ballast water W starts to turn in accordance with the turning of the ballast water W.

  The high specific gravity foreign matter swirling with the ballast water W is concentrated on the side surface 111 due to the centrifugal force. Here, when the high specific gravity foreign substance reaches the slit 16, the side surface 111 that has resisted centrifugal force until then disappears. Further, when the high-specific gravity foreign object collides with the guide plate 161, the force in the turning direction is reduced or lost. As a result, only the centrifugal force acts on the high-specific gravity foreign substance, and as shown in FIG. 16, the high specific gravity foreign matter X is dropped into the foreign matter reservoir 162. If the length L of the slit 16 (see FIG. 2) is larger than the ascending pitch of the swirl flow of the ballast water W, the detachment of the high-specific gravity foreign substance through the slit 16 is repeated a plurality of times. The high-specific gravity foreign matter that swivels can be removed by removing almost all from the slit 16 to the foreign matter reservoir 162. In the filtration device 1 of the present invention, since the swirl flow of the ballast water W is pushed up by the swirl flow of the lower layer and rises, the ascending pitch is kept small, and the length L of the slit 16 is not very small. As long as the high specific gravity foreign matter is released through the slit 16, the separation occurs multiple times.

  High specific gravity foreign matter (including other foreign matter) that has not separated from the slit 16 reaches above the slit 16 but is blocked by the cylindrical filter 15 and does not reach the ballast water purification device 5 from the outlet line 13. The high specific gravity foreign matter colliding with the cylindrical filter 15 is stalled by the collision and settles down. Here, as shown in FIG. 3, since the cylindrical filter 15 is provided at the center of the cylindrical body 11, the high specific gravity foreign matter that has stalled and settled is less affected by the swirling flow of the ballast water W. It reaches the screen filter 14 without being received, passes through the screen filter 14 and deposits on the bottom surface 113. Even if the high specific gravity foreign matter that settles is caught in the swirling flow of the ballast water W, it is newly detached from the slit 16 and removed, or is again blocked by the cylindrical filter 15 and settles.

  The high specific gravity foreign matter accumulated on the foreign matter reservoir 162 or the bottom surface 113 of the cylindrical main body 11 is periodically discharged by opening an on-off valve connected to the bottom outlet 114 or the reservoir outlet 163. As described above, since the ballast water W is fed by applying pressure from the ballast pump 4, the inside of the cylindrical main body 11 is in a pressurized state. Accordingly, if the bottom discharge port 114 or the pool discharge port 163 is always open, the pressure is released, making it difficult to transfer the ballast water W using the pressurized state. Therefore, the bottom discharge port 114 or the pool discharge port 163 may be opened only when the high specific gravity foreign material is collected, and the accumulated high specific gravity foreign material may be discharged.

  Unlike the conventional centrifugal separation type filtration device, the filtration device of the present invention does not take out the ballast water from the center of the swirling flow of the ballast water in which the high specific gravity foreign matter settles, but directly removes the high specific gravity foreign matter in the swirling process. Since it is removed from the slit and removed, the outlet pipe 63 can be connected in the swirling direction of the ballast water W as seen in FIG. The filtering device 6 of this other example is the same as the above-described example (FIGS. 1 to 4) except that the cylindrical body 61, the inlet pipe 62, the slit 66 and the guide plate 661, and the screen filter 64 are the outlet pipe. 63 also differs in that it is connected from the tangential direction of the side surface 611.

  Specifically, as seen in FIG. 7, the inlet pipe 62 and the outlet pipe 63 that are vertically separated are connected to the side surface 611 in a positional relationship of 180 degrees in the circumferential direction in plan view. An inlet pipe 62 and an outlet pipe 63 extend in the same direction and in parallel. Further, in this other example of the filtering device 6, a screen filter 67 built in the open end 631 of the outlet pipe 63 is used as an upper filter section for the outlet pipe 63. Thereby, the internal space 615 of the cylindrical main body 61 can be made large, and the formation of a smoother swirling flow of the ballast water W is facilitated.

It is a block diagram which shows the whole structure of the ballast water intake system incorporating the filtration apparatus of this invention. It is sectional drawing which shows an example of the filtration apparatus of this invention. FIG. 3 is a cross-sectional view taken along the line AA in FIG. FIG. 4 is an enlarged view of a portion indicated by an arrow B in FIG. 3 showing the vicinity of a slit in the filtration device of this example. FIG. 5 is an enlarged view corresponding to FIG. 4 showing the vicinity of another slit. It is sectional drawing which shows the filtration apparatus of another example. It is CC sectional drawing in FIG.

Explanation of symbols

1 Filtration device
11 Cylindrical body
12 Inlet pipeline
13 Exit pipeline
14 Screen filter
15 Tubular filter
16 slits
161 Guide plate
17 Another slit
171 Other guide plate D Width of slit T Projection amount of guide plate L Length of slit W Ballast water X High specific gravity foreign material

Claims (9)

Centrifugal filter that separates and removes sludge and other high specific gravity sludge from the collected ballast water. The cylindrical body is connected to the inlet pipe on the lower side and the outlet pipe on the upper side. The ballast water that has been fed is raised while swirling along the side surface, and is sent out from the outlet pipe.A slit that intersects the swirling direction of the ballast water is provided on the side surface, and high-specific gravity foreign substances such as sludge are provided. A ballast water filtration device using centrifugal force generated by swirling together with ballast water to remove the ballast water from the slit to the outside of the cylindrical body. 2. The ballast water filtering device according to claim 1, wherein the inlet pipe is connected to a lower side of the side surface of the cylindrical body in a tangential direction of the side surface, and the outlet pipe is connected to the upper surface of the cylindrical body. The inlet pipe is connected to a tangential direction of the side surface below the side surface of the cylindrical body, and the outlet pipe is connected to the tangential direction of the side surface and in a direction opposite to the inlet pipe line above the side surface. The ballast water filtration device described. The ballast water filtering device according to any one of claims 1 to 3, wherein the slit is provided with a guide plate that protrudes inward in the radial direction along a longitudinal edge portion on the downstream side in the swirl direction of the ballast water. The ballast water filtering device according to any one of claims 1 to 3, wherein the slit is provided with a guide plate that protrudes radially outward along a vertical edge portion on the upstream side in the swirling direction of the ballast water. The ballast water filtering device according to any one of claims 1 to 5, wherein the cylindrical main body is provided with a water-permeable lower filter section that separates an inner space and a bottom surface of the cylindrical main body through which the ballast water turns. The apparatus for filtering ballast water according to claim 6, wherein the lower filter section is a screen filter made of punching metal or expanded metal. The ballast water filtration device according to any one of claims 1 to 6, wherein the cylindrical main body is provided with a water-permeable upper filter section that separates an internal space of the cylindrical main body through which the ballast water swirls and an outlet pipe connected to the cylindrical main body. . The apparatus for filtering ballast water according to claim 8, wherein the upper filter section is a cylindrical filter made of a metal mesh.

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