Jet type spraying arm for ditching
By introducing vent pipes and air holes into the jet type injection arm, gas is injected to reduce hole effect, solving the problem of damage to the subsea trencher equipment, achieving lower replacement cost and higher trenching efficiency.
Patent Information
- Application Number
- CN202420691803.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-07
- Publication Date
- 2025-05-30
- Estimated Expiration
- 2034-04-07
AI Technical Summary
When the subsea jet trenching machine works in viscous sediment soil, cavitation can easily damage the nozzle and main pipeline, resulting in increased equipment damage and replacement costs.
A jet type injection arm is designed, adopting multiple injection parts and a vent pipe, and air holes are arranged on the surface of the vent pipe to inject gas to achieve controllable ventilation and corrosion reduction, and protect the injection part and the delivery pipe.
By reducing the impact of hole effects, the risk of equipment damage is reduced, the replacement cost and replacement cycle are reduced, and the directionally controllable corrosion reduction effect and optimized trench digging efficiency are achieved.
Smart Images
Figure CN222923828U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of underwater construction operations, and specifically relates to a jet flushing arm for trenching. Background Art
[0002] With the continuous exploration and development of marine resources by humans, submarine pipelines will become an important way for transporting submarine resources. The submarine cable power transmission project is an important part of the construction of the cross-sea networking project, and the national cable laying project has a great demand for stable and reliable trenchers.
[0003] Submarine jet trenching machines are suitable for cohesive sediment soils, and the process of soil breaking by water jets is very complex. During the process of water jets breaking the soil, the physical and chemical properties of the soil will also change accordingly. The main soil-breaking mechanisms include impact, shear, extrusion, water wedge, dynamic pressure failure, cavitation failure, and fatigue failure, etc. The function of one of the key components, the nozzle, is that the forward nozzle jet breaks the soil in front to meet the required trench depth; the lateral nozzle breaks the soil directly below the pipeline to form a trench; the rear nozzle transports the sediment accumulated during operation to the rear. However, due to the direction and mode of action, the impact and shear actions have little impact on the nozzle and the main conveying pipe. But in the case of cavitation, due to the lack of gas at the bottom of the water, the cavitation energy is likely to damage the nozzle and the main pipeline. Especially when operating on cohesive sediment, this cavitation energy mainly plays a destructive role rather than helping the trenching operation. Summary of the Utility Model
[0004] An embodiment of the utility model provides a jet flushing arm for trenching, which includes a conveying pipe main body, a plurality of spraying parts, a trailing part, and a tail nozzle. The plurality of spraying parts extend vertically downward on the surface along the center line of the conveying pipe main body. One or more ventilation pipes are fixedly arranged on the outer cylindrical surface of the conveying pipe main body, and a plurality of air holes are arranged on the surface of the ventilation pipe to spray gas toward the surface of the spraying part to achieve controllable ventilation and erosion reduction.
[0005] Further, two ventilation pipes are symmetrically and fixedly arranged on both sides of the spraying part along the outer cylindrical surface of the conveying pipe main body to spray gas toward the two side surfaces of the spraying part to achieve controllable ventilation and erosion reduction.
[0006] Further, the included angle between the plane formed by the center line of the ventilation pipe and the center line of the conveying pipe main body and the vertical plane is 0 - 30°, and the vertical plane is the plane formed by the center line of the conveying pipe main body and the extending direction of the plurality of spraying parts.
[0007] Further, the aperture of the air hole gradually increases from top to bottom.
[0008] Further, the air holes are inclined inwardly towards the injection part.
[0009] Further, the ventilation pipe is arranged on the plurality of injection parts, and the central axis of the ventilation pipe is parallel to the central axis of the conveying pipe main body.
[0010] Further, the central axis of the ventilation pipe is located at the middle position of the injection part.
[0011] According to another aspect of the present invention, two ventilation pipes are asymmetrically arranged on both sides of the injection part. The central axes of the two ventilation pipes are both parallel to the central axis of the conveying pipe main body, and the distances between the two ventilation pipes and the conveying pipe main body are different.
[0012] Further, at least one of the ventilation pipes is provided with air holes with different directions. Some of the air holes inject gas towards the injection part, and some of the air holes inject gas towards the conveying pipe main body.
[0013] Further, the injection holes are distributed along the central axis of the conveying pipe main body with gradually increasing density from top to bottom, so that the gas flux gradually increases from top to bottom.
[0014] The beneficial effects of the present invention include that it can reduce the damage of the cavitation effect to the excavation equipment during the trench digging process, reduce the replacement cost and replacement cycle, achieve a directionally controllable erosion reduction effect, and balance the optimized controllable erosion reduction effect and the optimized trench digging efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Through the following detailed description in conjunction with the accompanying drawings, the advantages of the present invention will become clearer and easier to understand. These drawings are only schematic and do not limit the protection scope of the present invention, wherein:
[0016] Figure 1 Shows a schematic structural diagram of a jet flushing arm for trench digging according to an embodiment of the present invention;
[0017] Figure 2 Shows the scope of the action of cavitation on silt / accumulation and on the conveying pipe main body and the injection part;
[0018] Figure 3 Shows Figure 1 A partial enlarged schematic diagram of the cavitation suppression structure of the jet flushing arm for trench digging according to an embodiment of the present disclosure in
[0019] Figure 4 Shows a schematic diagram of a variant structure of a jet flushing arm for trench digging according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0020] The technical solution of the present utility model will be described in detail below in conjunction with specific embodiments and their accompanying drawings. The embodiments described herein are specific specific embodiments of the present utility model and are used to illustrate the concept of the present utility model; these descriptions are all explanatory and exemplary and should not be construed as limiting the embodiments of the present utility model and the protection scope of the present utility model. Except for the embodiments described herein, those skilled in the art can also adopt other obvious technical solutions based on the content disclosed in the claims and the specification of this application. These technical solutions include technical solutions that make any obvious substitutions and modifications to the embodiments described herein.
[0021] The accompanying drawings of this specification are schematic diagrams to assist in explaining the concept of the present utility model and schematically show the shapes of various parts and their mutual relationships. It should be understood that in order to clearly show the structures of the various components of the embodiments of the present utility model, the accompanying drawings are not drawn in the same proportion, and the same reference numerals are used to represent the same parts in the drawings.
[0022] Non-limitingly, as Figure 1 shown, the jet flushing arm 100 for trenching according to an embodiment of the present application includes a delivery pipe main body 10, a plurality of jetting portions 11, a trailing portion 12, and a tail nozzle 13. Among them, the plurality of jetting portions 11 extend along the center line of the delivery pipe main body 10 on its surface in the vertically downward direction. The jetting portions 11 pressurize and output the high-pressure liquid (usually seawater or purified water) fed by the delivery pipe main body 10 to directionally remove accumulations such as silt through impact action to form a trench / ditch for burying cables, that is, to form a trench for accommodating the cable.
[0023] Non-limitingly, since the silt at the bottom of the water becomes firmer from shallow to deep, the diameter of the delivery pipe main body 10 is preferably designed to gradually decrease from top to bottom, so that the pressure of the fluid ejected by the same jetting portions 11 evenly distributed from top to bottom gradually increases, which is more conducive to cleaning the firm accumulations below; and / or, alternatively, without changing the diameter of the delivery pipe main body 10, but arranging a plurality of jetting portions 11 with different jet hole diameters along the delivery pipe main body 10 from top to bottom, so that the pressure (silt cleaning ability) of the fluid ejected by the jetting portions 11 closer to the bottom is stronger; it is easy to understand that the technical solutions of changing the diameter of the delivery pipe 10 and / or changing the jet hole diameter of the nozzles of the jetting portions 11 can be selected and used in combination with each other.
[0024] However, when the jet flushing arm 100 for trenching according to the embodiments of the present application operates on the seabed, high-speed liquid is ejected to form eddies and air cavities (i.e., Cavatition Effect), and this effect acts on the surfaces of the ejection part 11 and the conveying pipe main body 10 for a long time, combined with the electrochemical corrosion of seawater. It is easy to cause irreversible damage and failure under the action of Chemical Mechanical Friction. This situation is more obvious in seawater. Although an anti-corrosion layer can be formed on the surface of the flushing arm 100 and / or the ejection part 11 by methods such as coating, such a coating is extremely easy to be damaged under the combined action of a strong flushing effect and cavitation. And during the process of trenching some hard substrates, cavitation is beneficial to removing or activating some firm and difficult-to-remove accumulations. In other words, as Figure 2 shown, it is not desired to unilaterally eliminate cavitation, but only hope that cavitation occurs more within a range of a certain distance H from the front end of the ejection part 11, specifically acting on the silt / accumulations, effectively promoting the trenching operation but not having a negative cavitation effect on the flushing arm 100 and the ejection part 11.
[0025] Non-limitingly, it is desired to provide a mechanism / device that can not passively avoid or reduce cavitation. On the one hand, it can at least not weaken the positive effects of cavitation (promoting trenching, promoting the activation and loosening of accumulations, and destroying the structure of accumulations), and on the other hand, it can avoid damaging the surfaces of the flushing arm 100 and / or the ejection part 11. As Figure 1 and Figure 3 shown, according to the embodiments of the present application, the jet flushing arm 100 for trenching is provided with one or more air vent pipes 20 on the cylindrical surface of the conveying pipe main body 10 facing the silt. A plurality of air holes 21 are formed on the surface of the air vent pipe 20 facing the silt, so that the air holes 21 can eject gas towards the ejection part 11 generally along a direction perpendicular to the axis of the conveying pipe main body 10 (as shown by the arrow in Figure 1 ), thereby achieving the effect of controllable ventilation and erosion reduction.
[0026] Although the mechanism of ventilation and cavitation erosion reduction is not yet fully understood, the generally recognized theories in the engineering field for its effect include: introducing air into the water flow to reduce the local negative pressure in the water flow, thereby increasing its cavitation number, weakening the cavitation intensity or suppressing cavitation; the aerated water flow is fully mixed with the cavitation bubble flow, and the cavitation bubbles can become air-containing cavitation bubbles, reducing the energy released when the cavitation bubbles collapse; the cavitation bubbles are surrounded by a bubble cluster to form an air cushion, and part of the energy released when the cavitation bubbles collapse is absorbed by the bubbles. In other words, ventilation and cavitation erosion reduction are achieved by providing gas (air) to the surface of the injection part 11 and the surface of the conveying pipe main body 10 during the operation of the flushing arm 100, which is beneficial to controllably and directionally reducing the negative impact of cavitation on the surface of the injection part 11 and the surface of the conveying pipe main body 10.
[0027] Non-limitingly, due to the differences in the structure and design of the flushing arm 100 and the structure and design of the injection part 11 used for different seabed structures, the flow rate of the gas introduced into the ventilation pipe 20 should be tested and calibrated before use to determine the best ventilation and cavitation erosion reduction effect.
[0028] Non-limitingly, although not shown in the figure, the direction of the center line of the air hole 21 of the ventilation pipe 20 can be set to point to the injection part 11 or set to point to the vertical plane where the center line is located (i.e., inwardly inclined towards the injection part 11) to form protection for all or specific parts of the injection part 11. Preferably, the angle between the direction of the center line of the air hole 21 (injection direction) and the vertical plane where the center line of the conveying pipe main body 10 is located is 0 - 30°, that is, in Figure 3 the angle between the plane formed by the center line of the ventilation pipe 20 and the center line of the conveying pipe main body 10 and the plane perpendicular to the paper surface is 0 - 30°.
[0029] As Figure 3 shown, in the partial enlargement 200 of the jet flushing arm 100 for trenching according to the embodiment of the present invention, the air holes 21 on the ventilation pipe 20 are evenly and equidistantly distributed.
[0030] It should be understood that although Figure 1 and Figure 3 the ventilation pipe 20 shown is arranged on the cylindrical surface of the conveying pipe main body 10 by means of welding or the like, but in such as Figure 4In the variant 100A of the jet spray arm 100 for trenching according to the embodiment of the utility model, the vent pipe 20A can also be fixed to the injection portion 11 by welding or other forms and maintain a certain distance from the surface of the conveying pipe body 10, and at the same time make the center line of the vent pipe 20A parallel to the center line of the conveying pipe body 10; in this technical solution variant, although not shown, a plurality of air holes with different directions and distributed on both sides facing each other can be set on the surface of the vent pipe 20A, on the one hand, gas is sprayed toward the surface of the injection portion 11 to reduce the influence and damage of the cavitation effect on the injection portion 11 through ventilation cavitation reduction, and on the other hand, gas is sprayed toward the columnar surface of the conveying pipe body 10 to reduce the influence and damage of the cavitation effect on the conveying pipe body 10 through ventilation cavitation reduction.
[0031] It should be understood that in the above-mentioned embodiment of the jet spray arm 100 for trenching according to the utility model and its variant 100A, the air holes 21 arranged in the ventilation pipes 20 and 20A can be evenly and equidistantly distributed, but preferably, the distribution of these air holes 21 can be non-equidistant, and / or their aperture and spray angle, etc. can also be optimized. These optimization analysis processes can be calibrated according to different working environments, so as to achieve both optimized controllable erosion reduction effect and optimized trenching efficiency.
[0032] Preferably, the distribution density of the air holes 21 should gradually increase from the upper part of the jet spray arm 100 for trenching to the trailing part 12 and the tail nozzle 13 at the bottom, that is, the gas flow rate introduced should gradually increase, and / or, the aperture of the air holes distributed in the ventilation pipes 20 and 20A should gradually increase from top to bottom along the center line of the conveying pipe body 10 and 10A, so as to slow down the stronger cavitation effect at the bottom.
[0033] Preferably, in the above-mentioned embodiment of the jet spray arm 100 for trenching according to the utility model and its variant 100A, the ventilation pipes 20 respectively arranged on both sides of the injection part 11 can be independently controlled, so as to adjust the air flow rate of the air holes of each ventilation pipe 20 according to the actual working conditions.
[0034] Preferably, two ventilation pipes 20 or 20A are symmetrically fixedly arranged on the outer cylindrical surface of the delivery pipe body 10 along both sides of the injection portion 11 to inject gas toward the two side surfaces of the injection portion 11 to achieve controllable ventilation cavitation reduction.
[0035] Preferably, in the above-described embodiment of the jet flushing arm 100 for trenching according to the present invention and its variant 100A, the air holes on the air pipes 20 respectively provided on both sides of the jetting portion 11 may be independently and asymmetrically arranged. For example, the air holes 21 on one side of the air pipe 20 are arranged towards the jetting portion 11, while the air holes 21 on the other side of the air pipe 20 are arranged towards the surface of the conveying pipe main body 10.
[0036] Preferably, although not shown, two air pipes 20 and / or 20A are asymmetrically arranged on both sides of the jetting portion 11. The center lines of the two air pipes are both parallel to the center line of the conveying pipe main body, and the distances of the two air pipes from the conveying pipe main body 10 are different.
[0037] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples.
[0038] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents.
Claims
1. A jet-type spray arm for trenching, characterized in that: It includes a conveying pipe body, multiple injection parts, a trailing part, and a tail nozzle. The multiple injection parts extend vertically downward on the surface of the conveying pipe body along the center line of the conveying pipe body. One or more ventilation pipes are fixedly arranged on the outer cylindrical surface of the conveying pipe body. The surface of the ventilation pipe is provided with multiple air holes to spray gas toward the surface of the injection part to achieve controllable ventilation erosion reduction.
2. The jet-type spray arm for trenching according to claim 1, characterized in that: Two ventilation pipes are symmetrically fixedly arranged on the outer cylindrical surface of the conveying pipe body along the two sides of the injection part, so as to spray gas toward the two side surfaces of the injection part to realize controllable ventilation cavitation reduction.
3. The jet-type spray arm for trenching according to claim 1, characterized in that: The angle between the plane formed by the center line of the ventilation pipe and the center line of the delivery pipe body and the vertical plane is 0-30°, and the vertical plane is the plane formed by the center line of the delivery pipe body and the extending direction of the multiple injection parts.
4. The jet-type spray arm for trenching according to claim 1, characterized in that: The apertures of the pores gradually increase from top to bottom.
5. The jet-type spray arm for trenching according to claim 1, characterized in that: The air holes are arranged to be inclined inwardly toward the injection portion.
6. The jet-type spray arm for trenching according to claim 1, characterized in that: The ventilation pipe is arranged on the plurality of injection parts, and the center line of the ventilation pipe is parallel to the center line of the conveying pipe body.
7. The jet spray arm for trenching according to claim 6, characterized in that: The center line of the vent pipe is located in the middle of the injection portion.
8. The jet-type spray arm for trenching according to claim 1, characterized in that: Two ventilation pipes are asymmetrically arranged on both sides of the injection portion, the center lines of the two ventilation pipes are parallel to the center line of the delivery pipe body, and the distances between the two ventilation pipes and the delivery pipe body are different.
9. The jet-type spray arm for trenching according to claim 1 or 6, characterized in that: At least one of the ventilation pipes is provided with air holes in different directions, some of which spray gas toward the spraying part, and some of which spray gas toward the conveying pipe body.