JPH0369727A - Excavating suction port - Google Patents

Abstract

PURPOSE:To improve excavating and dredging efficiency by opening an excavating gas jetting port in a space in an excavating wall formed on the periphery of a suction nozzle, and by connecting the suction nozzle to a negative pressure forming means. CONSTITUTION:A dredging device 1 is composed of a suction port 8 consisting of a suction pipe 6 for sucking up the sludge 4 or the like of the sea bottom 3 through a suction nozzle 5, and an excavating means 7 set near the suction nozzle 5, and a dehydrating means 9 for dehydrating the slurry of the sludge 4. After that, a negative pressure forming means 2 is composed of a pressing pump 11 for pressing the water of a storage water tank 10, a jetting nozzle 13 for jetting to a jetting pipe 12, a negative pressure forming pipe 14, and a negative pressure feeding port 15. After that, on the periphery of the suction nozzle 5 of the lower end opening of the suction pipe 6, an excavating surround ing wall 17 is formed, and is closed with a helmet-shaped hood 18 in an air-tight state, and in the excavating surrounding wall 17, the excavating means 7 is formed. Then, the interior of the excavating surrounding wall 17 is filled up with gas jetted from an excavating gas jetting port 29, and exposed sludge is excavated.

Description

[Detailed description of the invention] [Industrial application field]

The present invention mainly relates to an excavation suction port used when dredging and removing sludge on the seabed in ports and waste materials accumulated at the bottom of ponds, lakes, etc.

[Conventional technology]

When removing sludge, conventionally, a suction nozzle of a suction pipe connected to a negative pressure generating means is located on the lake bed or ocean floor where sludge accumulates, and the negative pressure generating means sucks up and removes the sludge. However, sludge is made up of many different substances, and its hardness varies depending on the amount and depth of the deposits, so there is a problem in that sludge cannot be removed reliably by simply suctioning it. there were. In order to deal with these problems, conventional excavation means have been provided with a downwardly opening nozzle for injecting high-pressure jet water for excavation near the suction port.

[Problem to be solved by the invention]

When excavating sludge deposited on the ocean floor or the bottom of a lake using high-pressure jet water for drilling from a spout, the momentum of the high-pressure jet water for drilling that is jetted from the spout is rapidly attenuated by the viscosity of the surrounding water. There was a problem that a sufficient excavation effect could not be obtained. Moreover, most of the sludge excavated with high-pressure jet water scatters and floats around the area, causing the problem that water with low sludge content is sucked in from the suction port, significantly reducing dredging efficiency. there were. Therefore, the present invention was proposed in view of the above problems.
The purpose is to provide a suction port with high excavation and dredging efficiency.

[Means to solve the problem]

In order to achieve the above object, the excavation suction port according to the present invention forms an excavation enclosure wall with a closed upper part around the suction nozzle, and excavates an excavation gas outlet in the space within the excavation enclosure wall. It is characterized in that it is opened toward the lower end opening of the surrounding wall, and a suction nozzle is connected to a negative pressure forming means.

[Operation] First, the excavation suction port is sunk into the seabed or lakebed to be dredged, and the opening periphery of the excavation wall is buried in the sludge to isolate the inside of the excavation wall from the outside surrounding it. do. Next, when high-pressure gas is injected from the excavation gas outlet toward the lower injection opening while suctioning water and hemolyte in the excavation enclosure from the suction nozzle using the negative pressure forming means, the gas injected from the outlet is The excavation wall is gradually filled from above. In this way, when the sludge is exposed to the gas filling the excavation enclosure, this exposed part is excavated by the high-pressure gas injected from the excavation gas outlet, and is scattered inside the excavation enclosure. The sludge scattered inside is sucked out from the suction nozzle by the negative pressure forming means and removed. At this time, since the sludge sucked from the suction nozzle contains a lot of gas and has a light specific gravity, the sludge sucked upward from the suction nozzle due to the synergistic effect of this gas with the air lift effect.

【Example】

Embodiments according to the present invention will be described below based on the drawings. [Embodiment 1] <Refer to FIGS. 1 and 2> FIG. 1 is a partially cutaway side view showing a schematic configuration of a dredging device, and the reference numeral 1 in the figure indicates the dredging device as a whole. This dredging device 1 includes a negative pressure forming means 2, a suction pipe 6 that sucks sludge 4, etc. from the seabed 3 through a suction nozzle 5 at the lower end using the negative pressure formed by the negative pressure forming means 2, and a portion near the suction nozzle 5. It is equipped with a suction port 8 consisting of a provided excavation means 7, and a dewatering means 9 for dewatering the sludge slurry sucked up through the suction pipe 6. The negative pressure forming means 2 includes a pressurizing pump 11 that pressurizes water in a water storage tank 10, an injection nozzle 13 that injects pressurized high-pressure water into an injection pipe 12, and a jet water stream injected from this injection pipe 12. It is composed of a jet pump MJP equipped with a large-diameter negative pressure forming pipe 14 for generating negative pressure and a negative pressure supply port 15 for extracting the negative pressure inside the negative pressure forming pipe 14. An intake hole 16 is formed on the side of the nozzle 13 to prevent the momentum of the high-pressure water injected from the injection nozzle 13 from attenuating. As shown in the drawing, the suction port 8 formed at the lower end of the suction pipe 6 forms a short cylindrical excavation surrounding wall 17 around the suction nozzle 5 at the lower end opening of the suction pipe 6. 17 has a cap-like top between its upper end and the suction tube 6! The excavation means 7 is formed inside the excavation wall 17, which is closed airtightly by the excavation wall 1B. This excavation means 7 divides the internal space of the excavation wall 17 into an air chamber 20 and an excavation chamber 21 with a partition wall 19 through which the suction nozzle 5 portion penetrates the middle part of the canopy-shaped top IE1B. is formed so that compressed air (excavation gas) is supplied by the combrefser 22 via the supply pipe 23, and the compressed air supplied to the air chamber 20 is injected toward the sludge 4 on the seabed 3. The excavation chamber 21 is configured with an air outlet (excavation gas outlet) 29 projecting downward into the excavation chamber 21 . In addition, a dewatering means 9 for the slurry-like sludge sucked up through the suction pipe 6 and discharged from the negative pressure forming pipe 14 of the die-bond pump MJP is provided with a filter that is rotatably driven by a drive device (not shown) in the slurry tank 24. The drum 25 is pivoted with most of it immersed in the slurry 26, and the inside of the filter drum 25 is made negative pressure by a vacuum pump 27, and the sludge adhering to the circumferential surface of the filter drum 25 is scraped off. A doctor blade 28 is provided tangentially. Next, the operation of the suction port 8 will be explained through the dredging device 1 configured as described above. First, the suction pipe 6 is drawn from the sea surface 38 of the seabed 3 to be dredged.
is lowered so that the lower end opening 31 of the excavation wall 17 is buried in the sludge 4 deposited on the seabed 3, thereby cutting off the inside of the excavation wall 17 from the surrounding outside. At this time, if the suction pipe 6 is difficult to sink due to the buoyancy due to the volume of the air chamber 20 or the excavation chamber 21, a suitable weight may be provided on the circumferential surface of the excavation wall 17, or the suction pipe 6 may be moved with a pushing device (not shown). It is forcibly pushed in from above the sea level 38. Next, the water and sludge 4 in the excavation chamber 21 are sucked in from the suction nozzle 5 by driving the JIE'7 pump MJP, and at the same time, high-pressure air compressed by the compressor 22 is supplied from the air outlet 29 to the excavation chamber 21. When sprayed inward,
This air gradually fills the excavation chamber 21, and the excavation wall 17
The sludge 4 in the excavation chamber 21 partitioned by is gradually exposed to the air. When the sludge 4 is exposed to the air inside the excavation chamber 21, this exposed part is excavated by the high pressure air injected from the air outlet 29 and scattered inside the excavation chamber 21, and this excavation chamber 2
The sludge scattered inside is sucked by the negative pressure forming means 2 from the suction nozzle 5 through the suction pipe 6 to the negative pressure forming pipe 14 of the jet pump MJP. At this time, the sludge sucked into the negative pressure forming tube 14 from the suction tube 6 contains a large amount of air injected from the air jet port 29, and has a low specific gravity, making it easy to rise. Due to the synergistic effect with the air lift effect, the inside of the negative pressure forming tube 14 can be lightly sucked upward. Incidentally, the specific gravity of the sludge sucked into the negative pressure forming tube 14 from the middle tube 6 can be variously changed by adjusting the amount of air injected from the air jet port 29. The slurry-like sludge discharged from the negative pressure forming pipe 14 of the jet pump MJP along with the jet water stream is stored in the slurry tank 24, and is adsorbed to the circumferential surface of the filter drum 25 by the suction force of the vacuum pump 24. The water is discharged into the sea via a vacuum pump 27. Here, the water separated from the slurry sludge by the vacuum pump 27 can also be made to flow back to the water storage tank 24. When the solid mass adsorbed and dehydrated on the circumferential surface of the filter drum 25 by the suction force of the vacuum pump 27 is scraped off from the circumferential surface of the filter drum 25 by the doctor blade 28, it becomes cake-like with almost no moisture. In this first embodiment, the negative pressure forming means 2 injects high pressure water pressurized by a pressure pump 11 into an injection pipe 12 equipped with an intake hole 16, and further jets water from the injection pipe 12 to a negative pressure forming pipe 14. The jet pump MJP is configured to form a negative pressure in the injection pressure forming pipe 14 by injecting the It can also be used as a regular jet pump. (Example 2) (See Figures 3 and 4) A dredging device 1 equipped with a suction port 8 according to this example has a vacuum pump 32 as the negative pressure forming means 2 in Example 1, and A solid mass separating means 34 is interposed between the vacuum pump 32 and the suction pipe 6, and the excavation wall 17 of the suction port 8 is formed into a square shape. This excavation surrounding wall 17 has a substantially square shape in plan view or bottom view, and has a picture wall 19 at each corner to form an air chamber 20 at the corner. The air jet ports 31 are formed to protrude into the excavation chamber 21 with different angles. Forming the suction port 8 in a rectangular shape in plan view has the advantage that even the corners rising from the seabed 3 can be dredged neatly. When a plurality of sets of air jet ports 31 are formed protruding from the excavation chamber 21, there is an advantage that the sludge 4 exposed in the excavation chamber 21 can be excavated widely and effectively. Further, the solid lump separation means 34 merges the suction pipe 6 into the middle of a cylindrical separation pipe 37 whose lower end is formed larger than the diameter of the suction pipe 6 whose lower end is buried in water 36 stored in the settling tank 35. , the upper end of the cylindrical separation tube 34 is connected to the vacuum pump 32, and as in the steam embodiment 1, the sludge sucked into the cylindrical separation tube 34 from the suction tube 6 is supplied from the air outlet 29. It contains a large amount of injected air and has a light specific gravity, and due to the synergistic effect with the air lift effect of the air, it is sucked upward at a high flow rate inside the negative pressure forming tube 14. The flow velocity of the slurry-like sludge sucked into the cylindrical separation tube 34 from the suction tube 6 is buffered here, and during this time heavy solid matter falls into the settling tank 35 and is separated. Other operations are the same as in Example 1. The solid lump separation means 34 may be replaced with the dewatering means 9 in the first embodiment, or a cyclone type solid lump separation device may be used. Also, as shown by the imaginary arrow A in Fig. 4, the suction port 8
If it is made rotatable, it can be made to follow the side wall rising from the seabed, and it also has the advantage of being able to dredge cleanly. Furthermore, if the sludge to be dredged contains a lot of solid matter that cannot pass through the suction pipe 6, a strainer 39 is installed in the lower end opening 30 of the suction port 8 as shown in FIG. Of course, it is okay to do so. In addition, in each of the above embodiments, the air outlet 29 is positioned above the lower end of the excavation wall 17, but as shown by the imaginary line B in FIG. It goes without saying that it may be positioned so as to protrude below the section. Moreover, if the compressed air used as the drilling gas is turned into high-temperature steam, for example, if the composition of the sludge 4 contains a lot of oil such as pitch or tar, it can be softened by the heat and the drilling efficiency can be increased. If flammable gas such as methane gas is generated from the sludge, dredging can be carried out safely by injecting non-flammable gas from the air outlet without causing any accidents such as ignition. Incidentally, it goes without saying that a mechanical excavation device may be added to the suction port 8 of the above embodiment.

【Effect of the invention】

As explained above, the present invention fills the excavation wall with gas injected from the excavation gas outlet, exposes the accumulated sludge in the gas, and then injects the excavation gas from the excavation gas outlet. Since the exposed sludge is excavated with high-pressure gas, the momentum of the high-pressure gas injected from the excavation gas outlet is not attenuated, and the sludge can be excavated powerfully, increasing the excavation effect. It has the advantage of being able to significantly improve In addition, the sludge excavated by the high-pressure gas injected from the excavation gas outlet is separated by the excavation wall and does not scatter to the outside, but is sucked through the excellent suction nozzle.
Another advantage is that dredging efficiency can be significantly improved.

[Brief explanation of drawings]

The drawings show embodiments of the present invention, and FIGS. 1 and 2 relate to Embodiment 1. FIG. 1 is a partially cutaway side view showing a schematic configuration of a dredging device equipped with a suction port, and FIG. is a suction port; FIGS. 3 and 4 relate to Embodiment 2, and FIG. 3 is a partially cutaway side view showing a schematic configuration of a dredging device equipped with a suction port;
Figure 4 shows the suction port. 2... Negative pressure forming means, 5... Suction nozzle, 8...
Excavation suction port, 14... Negative pressure forming pipe, 17... Excavation wall, 29, 31... Excavation gas outlet, 30...
17 lower end opening: solid mass separation means.

Claims (3)

[Claims] (1) An excavation enclosure whose upper part is closed is formed around the suction nozzle, and an excavation gas outlet is opened in the space within the excavation enclosure toward the lower end opening of the excavation enclosure, and suction is performed. An excavation suction port characterized in that a nozzle is connected to negative pressure forming means. (2) The negative pressure forming means is configured to inject high pressure fluid into the negative pressure forming pipe and supply the negative pressure formed in the negative pressure forming pipe to the suction nozzle. Excavation suction port described in scope 1. (3) The excavation suction port according to claim 1 or 2, characterized in that a solid matter separating means is interposed between the negative pressure forming means connected to the suction nozzle.