RU230198U1 - BOTTOM SOIL SAMPLER - Google Patents

Abstract

A bottom soil sampler consisting of a sampler pipe, the top of which is equipped with a bypass valve, a hanger and a swivel fixed on a cable, and the lower part - with a petal valve; a stabilizer in the form of a massive section of pipe fixed on the upper part of the sampler pipe body with flat plates extended symmetrically in the axial direction. The technical result consists in obtaining a reliable sample of bottom soil of a strictly vertical structure of the required height, i.e. a technically achievable (along the length of the tube) long sample of a strictly vertical section of marine sedimentary rocks, allowing to obtain a reliable picture of bottom sediment deposits over time. The implementation of the technical solution will ensure a reliable entry of the sampler pipe, with the required force, into the seabed, strictly along the vertical axis, which allows to obtain the required size of the reliable sample column. The technical result is achieved by the fact that the stabilizer is made in the form of a hollow truncated cone with rounded edges of the larger base and is oriented with the larger base towards the oncoming flow of liquid that occurs when the sampler is immersed.

Description

AREA OF TECHNOLOGY

The proposed "Bottom Soil Sampler" is a device for collecting core type soil samples from the bottom of water bodies during scientific research, geological exploration and design and survey work. The sampler is especially relevant when working with silty types of bottom soils, the main goal here is to obtain a strictly vertical core sample of bottom soil of sufficient size for subsequent study of the structure of accumulation of bottom sediments over time. For this, it is necessary to ensure vertical entry of the sampler pipe into the soil. If the angle of entry of the pipe into the bottom changes, the sample is unreliable or the pipe collapses.

TECHNICAL LEVEL

A technical solution is known (patent for utility model RU 158011 U1, G01N 1/04; "Impact sampler for bottom sediments"; publication date 20.12.2015). The sampler is used in shallow water bodies, contains a core barrel and an impact mechanism with a striker. The device is lowered into the water on a metal cable, upon reaching the bottom soil, the pipe enters a certain depth of sediment, under the action of the sampler's own weight. A massive impact load is sent along the cable, which accelerates, reaches the pipe and drives the core barrel into the bottom soil of the reservoir. After that, the sample with the pipe, with the help of a metal cable, rises to the surface.

The disadvantage of the known technical solution is that during immersion the issue of strictly vertical entry of the sampler pipe into the bottom soil is not monitored and structurally resolved. The sampler pipe is not equipped with either a stabilizing element or an inertial load. Therefore, the sampler moves with a deviation from the vertical axis and does not penetrate the bottom soil strictly vertically and may even fall over without collecting samples. Further actions, when a messenger load of significant mass is sent along the cable, may lead to the sampler entering (penetrating) the bottom soil at a significant angle, or even tipping over. As a result, the resulting sample will not be reliable, or will not enter the sampler at all.

A device is known that uses a standard solution - placement of a tail stabilizer on a cylindrical sampler pipe (patent for invention RU 2045753 C1, G01N 1/02; "Bottom soil sampler", publication date 10.10.1995). In the known solution, the sampler pipe is equipped with an extended tail stabilizer in the form of four longitudinally arranged plates that occupy about 40% of the length of the sampler pipe. The stabilizing plates have a large area and should, according to the developers, stabilize the sampler in a vertical position when immersed.

The disadvantage of such a solution is the change in the center of mass of the tube and the violation of the conditions of the water flow around the plates randomly due to the thickness of the stabilizing plates, which leads to "swinging" of the tube relative to the center of mass, especially when the plates are not aligned with the longitudinal axis of the tube. The tail stabilizer, in fact, only cuts the oncoming flow, but does not stabilize the position of the sampler tube in space. The stabilizing plates have a large area and are exposed to underwater lateral currents that can change the orientation and trajectory of the sampler. This leads to a loss of stability of the tube when moving and contributes to the entry of the sampler tube into the ground at an angle. As a result, there is a high probability of collecting an unreliable sample or the collapse of the tube.

A technical solution is known - a shock straight-through soil tube, which is a core barrel with a petal valve designed to hold the soil core when extracting the tube from sediments and lifting it to the surface. To increase the mass of the tube, weights are used, fixed in the upper part of the structure (Smolov Yu.S. Equipment for sampling bottom sediments, work experience and prospects // Geology and useful minerals of the World Ocean. 2015. No. 1 P. 83.1).

Sampling with a straight-through impact soil tube is carried out from a vessel using a winch with a cable unwinding speed of at least 1 m/s or free running with the winch fully released. Before penetrating the bottom soil, the winch is stopped and the tube is suspended 40-50 m above the seabed. After the tube vibrations have calmed down for 2-5 minutes, the winch is released and the tube is dropped using the free running of the ship's winch, but with the cable secured to the tube. The tube accelerates and is penetrating the soil. The sampler is penetrating the soil massif due to the kinetic energy developed by the falling tube.

The disadvantage of this soil sampler device is the lack of design solutions for stabilizing the pipe during immersion and the resulting deviation from the vertical axis during immersion, which leads to an inclined entry of the pipe into the ground. The collapse of the pipe leads to poor-quality core sampling of bottom sediments from the seabed or to its absence altogether.

A technical solution is known (patent for invention RU 2668441 C2, G01N 1/16, G01N 1/20, "Marine geological pipe sampler", date of publication 28.11.2017). The device consists of a pipe, on the top of which an inertial impact mass and an impeller are fixed, significantly protruding beyond the dimensions of the sampler, and ensuring rotation of the pipe around its own axis during immersion, and the pipe is suspended on a swivel. When lowering the sampler from the side of the vessel, the presence of the swivel and impeller causes rotation of the pipe around the vertical axis. According to the authors of the technical solution, the presence of rotation helps to reduce the swinging of the pipe on a long cable, and the rotation of the pipe created by the impeller should, in fact, be a stabilizing factor ensuring high stability of the pipe from tipping over and deviating from the vertical axis when entering the seabed.

The disadvantages of this technical solution are that:

- the presence of a rotating impeller significantly increases the hydraulic resistance due to its large area, which reduces the speed of movement of the sampler pipe; which leads to a decrease in the force of entry of the sampler pipe into the seabed. At the same time, the magnitude of the force created by the tube during immersion depends to a greater extent on the speed of the sampler's fall than on whether the sampler rotates or not, therefore, in comparison with the loss of speed by the sampler pipe, the positive effect of the presence of rotation is greatly exaggerated;

- when submerged, the sampler pipe can pass through layers of sea water with different temperatures and salinities; strong currents are often encountered near the bottom, which, given the large area of the impeller and the rotation of the sampler pipe, can completely change the trajectory of the sampler pipe and its orientation in space.

The closest, in terms of approach to solving the problem of strictly vertical entry of the sampler pipe into the seabed, when collecting a sample, is the technical solution "Soil tube" (www.naeco.ru, devices for sampling; soil tube; soil tube TG-1/111). The soil tube consists of a sampler pipe, the top of which is equipped with a bypass valve, a hanger and a swivel fixed to a cable, and the lower part - a petal valve; a stabilizer in the form of a massive pipe section, fixed on the upper part of the sampler pipe body with flat plates elongated symmetrically in the axial direction. The implementation of the stabilizer in the form of a massive pipe section ensures the function of stabilizing the sampler during immersion and creates an inertial mass serving to accumulate kinetic energy. The placement of a cylindrical pipe section improves the conditions of hydraulic flow around the tube and serves to impart the necessary stability to the tube.

The disadvantage of the known solution is the insufficient stability of the tube when moving in water. When immersed, the stabilizer - a cylindrical section of the pipe, cuts a vertical column of liquid in the oncoming flow. However, this does not create a restoring moment. This can lead to the tube swinging relative to the center of mass, which, if it is located high, leads to the loss of stability of the tube on the trajectory and not strictly vertical entry of the tube into the ground. The stabilizer, in the form of a cylindrical massive section of the pipe, has a significant wall thickness and edges without rounding, which significantly increases hydraulic losses.

Thus, the review of devices and methods used for sampling bottom soil revealed a technical problem. The essence of the problem is the need to ensure reliable entry of the sampler pipe into the seabed, strictly along the vertical axis. This allows obtaining a reliable sample of the bottom soil.

DISCLOSURE OF THE ESSENCE OF THE UTILITY MODEL

The problem solved by implementing the utility model is to ensure a strictly vertical entry of the sampler into the bottom soil.

The technical result consists in obtaining a reliable sample of bottom soil, i.e. a technically achievable (along the length of the tube) long-length sample of a strictly vertical section of marine sedimentary rocks, which makes it possible to obtain a reliable picture of the deposition of bottom sediments over time.

The technical result is achieved by the fact that the stabilizer is made in the form of a massive section of pipe, in the form of a truncated cone with rounded edges on a larger base and ensures the performance of the functions of stabilization and inertial mass simultaneously. In this case, the stabilizer is placed with a larger base towards the oncoming flow of liquid that occurs when the sampler is immersed.

When analyzing known technical solutions from the state of the art, no solutions were identified that would have features that coincide with the distinctive features of the proposed technical solution "Bottom soil sampler", therefore the latter meets the condition of "novelty".

The possibility of using the proposed technical solution for sampling a strictly vertical section of marine sedimentary rocks, allowing us to obtain a reliable picture of bottom sediment deposits over time, allows us to conclude that it meets the condition of "industrial applicability".

IMPLEMENTATION OF A UTILITY MODEL

The preferred embodiment of the proposed technical solution is described below based on the drawings presented below, where:

Fig. 1 shows an axonometric image of the proposed bottom soil sampler, with a new design of the stabilizer.

Fig. 2 shows a bottom soil sampler, a) side view, b) a callout of a pipe type, with a rounded edge on a larger base, c) top view, d) bottom view.

In the graphic materials, the corresponding structural elements of the bottom soil sampler are designated by the following positions:

1. sampler pipe;

2. bypass valve;

3. petal valve attachment;

4. suspension;

5. flat plates;

6. stabilizer;

7. swivel;

8. cable,

9. petal valve,

10. Rounded edge.

The bottom soil sampler comprises: a sampler pipe 1, the top of which is provided with a bypass valve 2 and a suspension 4; flat plates 5, fixed on the pipe 1 and extended symmetrically in the axial direction; a suspension 4, fixed on the flat plates 5, and a holding swivel 7, suspended on a cable 8. The lower part of the sampler pipe 1 is provided with a petal valve 9, which is located in the attachment of the petal valve 3. A stabilizer 6 in the form of a massive section of pipe in the shape of a truncated cone, located on the flat plates 5, on the top of the pipe, with a large base oriented towards the oncoming flow arising during the immersion of the sampler, and having a rounded edge 10, a larger base of the cone.

The bottom soil sampler operates as follows during immersion.

The pipe of the sampler 1 is fixed on the cable 8 through the hanger 4 and the swivel 7. In this case, the ship's winch must have a free stroke or provide a descent speed of up to 5 m/s. The cable 8 is released and the pipe of the sampler 1 is submerged in a mode close to a free fall. In this case, the open valves - the bypass 2 and the petal 9 - freely pass water. The presence of the stabilizer 6, in the form of a conical pipe, placed with a large base towards the oncoming flow, increases the resistance of the tail section of the sampler and shifts the pressure center of the hydrodynamic forces to a point lying behind the center of mass. As a result, when an angle of attack occurs, i.e. the angle between the velocity vector of the center of mass of the sampler and its longitudinal axis, a restoring moment occurs, which tends to reduce the angle of attack. As a result, the pipe 1 moves along a trajectory close to the vertical axis. In this case, the liquid pressure drops when moving from a wide inlet to a narrow outlet section, and the speed and kinematic energy of the flow increase. Stabilizer 6 creates a confuser effect, i.e. compresses the liquid flow and increases its speed, creating a directed jet effect, as a result of which the position of the sampler is stabilized.

The sampler pipe 1 enters the bottom soil vertically, filling almost completely, since the stabilizer 6 is placed on the top of the pipe and no parts of the sampler interfere with the movement of the sampler pipe 1 deep into the bottom. In this case, the water displaced by the sample is ejected through the upper valve 2.

The moment when the sampler pipe 1 enters the bottom soil is determined by the cessation of the retrieval of the cable 8 from the winch of the vessel's launching device.

On the vessel, the winch of the launching and lifting device is switched on in the "lift" mode, due to which the selection of the cable 8 and, accordingly, the lifting of the sampler begin. At the same time, the petal valve 9 and the bypass valve 2 are closed, blocking the sample of the bottom soil in the pipe of the sampler 1. One of the variants of the petal valve operation is considered in detail in the description and in the drawings FIG. 3A and FIG. 3B - patent applications US 20190113419 A1, IPC G01N 1/08; "Piston sampler and method for collecting a soil sample"; publication date 18.04.2019. The bypass valve 2 is a known technical solution. It is a spring-loaded plug, usually made of silicone rubber. The power of the spring of the bypass valve 2 ensures its open state when moving the pipe 1 downwards and at the moment of taking a sample, and its closed state when moving the sampler upwards, to the surface. After lifting the pipe of the sampler on board the vessel, the sample is removed from the pipe 1 of the bottom soil sampler.

Thus, when using the proposed sampler, the reliability of the bottom soil sampling process increases, due to ensuring a strictly vertical entry of the sampler pipe 1 into the bottom. The conical stabilizer compresses the liquid flow and increases its speed, stabilizing the position of the sampler. The external shapes of the sampler parts (the sampler pipe and the stabilizer) have rounded shapes and therefore, lateral currents at depth do not change its axial orientation during immersion, as happens with a "feather" stabilizer.

Claims (1)

A bottom soil sampler consisting of a sampler pipe, the top of which is equipped with a bypass valve, a hanger and a swivel secured to a cable, and the lower part with a petal valve; a stabilizer in the form of a massive section of pipe secured to the upper part of the sampler pipe body with flat plates extended symmetrically in the axial direction, characterized in that the stabilizer is made in the form of a truncated cone with rounded edges of the larger base and is oriented with the larger base towards the oncoming flow of liquid that occurs when the sampler is immersed.

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