Tracer particle as well as preparation method and application thereof

Abstract

The invention provides tracer particles as well as a preparation method and application thereof. The tracing particles comprise 45 parts of polyethylene, 20-35 parts of a lead-containing material, 2-12 parts of a cross-linking agent and 0.9-2.0 parts of a foaming agent. The polyethylene, the cross-linking agent and the foaming agent are matched and can cooperate with one another, so that the density of the prepared tracer particle can reach 0.9-1.1 g / cm < 3 >, the density is close to the water density, it can be guaranteed that when the tracer particle is applied to water flow field information monitoring, the floating or settling phenomenon cannot occur, and the tracer particle has the excellent water flow following performance. In addition, a lead-containing material is introduced into the tracer particles, so that the tracer particles can be further ensured to be detected by X rays. Tests show that when the tracer particle provided by the invention is used for water flow field information detection, the tracer particle has good water flow field following performance, can be detected by X rays, and can stay in water for three days without obvious expansion and deformation.

Description

Technical Field

[0001] The present invention belongs to the technical field of tracer particles, and particularly relates to a tracer particle, a preparation method and an application thereof, and more particularly to a tracer particle detectable by X-ray, a preparation method and an application thereof. Background Art

[0002] Generally, by performing multiple exposure imaging on tracer particles in a flow field, correlated tracer particle images are obtained, and information on the measured flow field can be obtained after processing the particle images using software. For tracer particles used in a water flow field, it is generally required that they are insoluble in water, non-corrosive, and have stable chemical properties.

[0003] In addition, some studies have pointed out that if the density of the tracer ions is less than that of water, the particles will float on the surface of the water and cannot achieve the purpose of tracking the flow field; conversely, when the density is greater than that of water, due to the action of the gravitational field, the particles will settle. Therefore, for tracer particles in water, their density should be as close as possible to the density of water (1 g / cm 3 ) to ensure that the particles have accurate followability.

[0004] Currently, hollow glass microspheres with a silver coating on the surface are usually used as tracer particles for a water flow field, and when the diameter is 5 - 20 μm, they are considered to have good followability in the water flow field. However, the process of manufacturing such fine and single-density hollow glass microspheres is very complex. At the same time, hollow glass microspheres with a silver coating on the surface are usually expensive and not convenient for use in general experiments. Therefore, it is necessary to develop a tracer particle for a water flow field with low cost and good performance indicators. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a tracer particle, a preparation method and an application thereof. The tracer particle has good followability in a water flow field and can stay in water for three days without significant swelling or deformation.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] In the first aspect, the present invention provides a tracer particle, and the preparation raw materials include, by weight:

[0008]

[0009]

[0010] Preferably, the polyethylene includes low-density polyethylene.

[0011] Preferably, the density of the low-density polyethylene is 0.91 - 0.94 g / cm 3 .

[0012] Preferably, the lead-containing material includes lead powder.

[0013] Preferably, the mesh number of the lead powder is 200-400 mesh.

[0014] Preferably, the crosslinking agent includes dicumyl peroxide.

[0015] Preferably, the foaming agent includes AC foaming agent.

[0016] More preferably, by weight, the preparation raw materials of the tracer particles include:

[0017]

[0018] Preferably, the density of the tracer particles is 0.9-1.1 g / cm 3 .

[0019] In a second aspect, the present invention provides a method for preparing the above-mentioned tracer particles, including the following steps:

[0020] Mix polyethylene, lead-containing material, crosslinking agent and foaming agent in proportion, and then obtain tracer particles through melting and extrusion.

[0021] Preferably, the mixing is carried out according to the following steps:

[0022] Mix polyethylene for 2-5 minutes in proportion, then successively add the lead-containing material and mix for 3-6 minutes, add the crosslinking agent and mix for 1-4 minutes, and add the foaming agent and mix for 5-10 minutes.

[0023] Preferably, the temperature of the mixing is 130-145 °C, the mixing is carried out under rotational conditions, and the rotational speed is 40-80 rpm.

[0024] Preferably, the melting and extrusion are carried out in a twin-screw extruder, and the working temperature of the twin-screw extruder is 140-180 °C.

[0025] In a third aspect, the present invention provides an application of the above-mentioned tracer particles in water flow field testing.

[0026] Preferably, during the application process, X-ray is used to detect the tracer particles.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] The present invention provides a tracer particle for a water flow field. The tracer particle comprises: 45 parts of polyethylene, 20 - 35 parts of a lead-containing material, 2 - 12 parts of a crosslinking agent, and 0.9 - 2.0 parts of a foaming agent. Among them, the polyethylene serves as the base material of the tracer particle, which can ensure that the tracer particle has a certain shape, size, and mechanical strength. The crosslinking agent and the foaming agent respectively play the roles of crosslinking and forming pores by foaming. The present invention uses a combination of polyethylene, a crosslinking agent, and a foaming agent, which can cooperate with each other, so that the prepared tracer particle can reach a density of 0.9 - 1.1 g / cm 3 The density is close to the density of water, which can ensure that when the tracer particle is applied to the monitoring of water flow field information, there will be no floating or sedimentation phenomenon, and it has excellent water flow following performance. In addition, the present invention introduces a lead-containing material into the tracer particle, which can further ensure that the tracer particle can be detected by X-ray.

[0029] Through testing, when the tracer particle provided by the present invention is used for water flow field information detection, it has good water flow field following performance, can be detected by X-ray, and can stay in water for three days without significant swelling or deformation. Detailed implementation manners

[0030] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0031] Aiming at the problem that the prior art usually uses hollow glass microspheres with silver plating on the surface, which are expensive and have a complex preparation process, as tracer particles for water flow fields, the present invention provides a tracer particle. Calculated by weight parts, the preparation raw materials include:

[0032]

[0033] In the present invention, for the tracer particle, calculated by weight parts, the preparation raw materials include 45 parts of polyethylene (abbreviation: PE). The polyethylene serves as the base material of the tracer particle, which can ensure that the tracer particle has a certain shape, size, and mechanical strength, and at the same time can be combined with other substances to accurately control the density of the tracer particle.

[0034] In some embodiments of the present invention, the polyethylene is preferably low-density polyethylene, and the density of the low-density polyethylene is 0.91 - 0.94 g / cm 3 , which is more conducive to controlling the density of the tracer particle to 0.9 - 1.1 g / cm 3 , ensuring that it is close to the density of water.

[0035] The present invention has no particular limitation on the source of the above polyethylene, and general commercially available products can be used.

[0036] In the present invention, for the tracer particles, by weight, the preparation raw materials include 20 - 35 parts of a lead-containing material, such as 20 parts, 22 parts, 25 parts, 28 parts, 30 parts, 32 parts or 35 parts, etc., preferably 25 - 30 parts. The lead-containing material is mainly used as an "X-ray non-transparent" material to ensure that the prepared tracer particles can be detected by X-ray during subsequent applications, so as to obtain the motion state of the medium to be traced.

[0037] In the present invention, the lead-containing material is preferably lead powder. To ensure that the density of the prepared tracer particles meets the requirements, the mesh number of the lead powder preferably used in the present invention is 200 - 400 mesh.

[0038] In the present invention, for the tracer particles, by weight, the preparation raw materials include 2 - 12 parts of a crosslinking agent, such as 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts or 12 parts, etc., preferably 2 - 8 parts. The crosslinking agent causes the polyethylene to form a certain degree of crosslinking, which is beneficial to forming a certain pore structure during the extrusion process, so as to achieve the required density.

[0039] In some embodiments of the present invention, the crosslinking agent is preferably dicumyl peroxide (abbreviation: DCP).

[0040] In the present invention, for the tracer particles, by weight, the preparation raw materials include 0.9 - 2.0 parts of a foaming agent, such as 0.9 parts, 1.0 parts, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts or 2.0 parts, etc., preferably 0.9 - 1.2 parts. The foaming agent can form certain air holes, which is beneficial to regulating the density of the tracer particles.

[0041] It should be noted that the polyethylene, crosslinking agent and foaming agent have a synergistic effect, which can make the prepared tracer particles have a density of 0.9 - 1.1 g / cm 3 , close to the density of water. If any component is missing or replaced, it cannot be guaranteed that the tracer particles can still reach the above density.

[0042] The above-listed point values are only for listing purposes, and other point values within the numerical range are applicable. To avoid complexity, they will not be elaborated one by one.

[0043] In some embodiments of the present invention, the foaming agent includes AC foaming agent.

[0044] The present invention has no particular limitation on the sources of the above crosslinking agent and foaming agent, and general commercially available products can be used.

[0045] The present invention also provides a method for preparing the above-mentioned tracer particles, comprising the following steps:

[0046] According to a ratio, polyethylene, a lead-containing material, a cross-linking agent, and a foaming agent are mixed, and then melted and extruded to obtain the tracer particles.

[0047] In the present invention, the above mixing is preferably carried out in a mixer at 130-145 °C, more preferably 135-140 °C. The rotation speed of the mixer is 40-80 rpm, preferably 50-70 rpm, and more preferably 55 rpm.

[0048] Specifically, in some embodiments of the present invention, the mixing is preferably carried out according to the following method:

[0049] First, heat the mixer to 130-145 °C, keep the rotation speed of the mixer at 40-80 rpm, add polyethylene particles according to the ratio and mix for 2-5 min, preferably 3 min, add the lead-containing material and mix for 3-6 min, preferably 4 min, then add the cross-linking agent (preferably DCP) and mix for 1-4 min, preferably 2 min, and then add the foaming agent (preferably AC) and mix for 5-10 min, preferably 8 min, and then stop.

[0050] The above mixing sequence can make the components mix more uniformly to ensure that the obtained tracer particles have a density closer to that of water.

[0051] After mixing, according to the present invention, the obtained mixture sample is melted and extruded to obtain the tracer particles. The melting and extrusion are carried out in a twin-screw extruder, and the working temperature of the twin-screw extruder is 140-180 °C, preferably 150-160 °C.

[0052] Specifically, in some embodiments of the present invention, the mixture sample is cut into small pieces and added to a twin-screw extruder at 140-180 °C to obtain the tracer particles.

[0053] Among them, the diameter and length of the tracer particles can be set as needed. For example, the diameter can be 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, etc.; the length can be 1.3 mm, 1.5 mm, 1.8 mm, 2.0 mm, etc.

[0054] In some specific embodiments of the present invention, it is preferably to set the diameter of the die opening of the twin-screw extruder to 1 mm and cut the tracer particles into a length of 1.5 mm.

[0055] It can be seen that the method for preparing the tracer particles provided by the present invention is simple and convenient, easy to implement, and can be obtained through blending, melting, and extrusion, without the need for complex and expensive equipment. Compared with the prior art, the preparation process of the tracer particles is greatly simplified, which is conducive to realizing large-scale production or industrial production.

[0056] The present invention also provides an application of the above-mentioned tracer particles in the water flow field test. During the application process, X-ray is used to detect the tracer particles.

[0057] After testing, it is found that the tracer particles provided by the present invention can be detected by X-ray, have good water flow field following performance, and the density is 0.9 - 1.1 g / cm 3 , and can stay in water for three days without significant swelling or deformation. It can be seen that the tracer particles provided by the present invention can be well used for detecting water flow field information.

[0058] To further illustrate the present invention, the following detailed description is provided through the following examples. The polyethylene (PE) used in the following examples of the present invention is low-density polyethylene, with a density of 0.91 - 0.94 g / cm 3 ; the mesh number of the lead powder is 200 - 400 mesh.

[0059] Example 1

[0060] Weigh 45 parts by weight of polyethylene (PE), add it to the mixing chamber of the internal mixer with a temperature of 134 - 136 °C, keep the rotation speed of the internal mixer at 55 rpm, mix for 3 min, add 25 parts by weight of lead powder and mix for 4 min, then add 6 parts by weight of dicumyl peroxide (DCP) and mix. After 2 min, add 0.9 part by weight of blowing agent (AC). After 8 min, the mixing stops. The sample is taken out, cut into small pieces, added to a twin-screw extruder with a temperature of 150 °C, the die diameter is 1 mm, and after extrusion, it is cut into particles about 1.5 mm.

[0061] Example 2

[0062] Weigh 45 parts by weight of polyethylene (PE), add it to the mixing chamber of the internal mixer with a temperature of 134 - 136 °C, keep the rotation speed of the internal mixer at 55 rpm, mix for 3 min, add 28 parts by weight of lead powder and mix for 4 min, then add 2 parts by weight of dicumyl peroxide (DCP) and mix. After 2 min, add 1.0 part by weight of blowing agent (AC). After 8 min, the mixing stops. The sample is taken out, cut into small pieces, added to a twin-screw extruder with a temperature of about 150 °C, the die diameter is 1 mm, and after extrusion, it is cut into particles about 1.5 mm.

[0063] Example 3

[0064] Weigh 45 parts by weight of polyethylene (PE), add it to the mixing chamber of a kneader with a temperature of 134 - 136 °C, keep the rotation speed of the kneader at 55 rpm, mix for 3 min, add 30 parts by weight of lead powder and mix for 4 min, then add 8 parts by weight of dicumyl peroxide (DCP) and mix. After 2 min, add 1.2 parts by weight of blowing agent (AC). After 8 min, stop mixing. Take out the sample, cut it into small pieces, add it to a twin-screw extruder at 150 °C with a die diameter of 1 mm, and cut it into particles about 1.5 mm after extrusion.

[0065] Comparative Example 1

[0066] Weigh 45 parts by weight of polyethylene (PE), add it to the mixing chamber of a kneader with a temperature of 134 - 136 °C, keep the rotation speed of the kneader at 55 rpm, mix for 3 min, add 25 parts by weight of lead powder and mix for 4 min, then add 6 parts by weight of dicumyl peroxide (DCP) and mix. After 2 min, add 0.5 parts by weight of blowing agent (AC). After 8 min, stop mixing. Take out the sample, cut it into small pieces, add it to a twin-screw extruder at 150 °C with a die diameter of 1 mm, and cut it into particles about 1.5 mm after extrusion.

[0067] Comparative Example 2

[0068] Weigh 45 parts by weight of polyethylene (PE), add it to the mixing chamber of a kneader with a temperature of 134 - 136 °C, keep the rotation speed of the kneader at 55 rpm, mix for 3 min, add 28 parts by weight of lead powder and mix for 4 min, then add 1 part by weight of dicumyl peroxide (DCP) and mix. After 2 min, add 1.5 parts by weight of blowing agent (AC). After 8 min, stop mixing. Take out the sample, cut it into small pieces, add it to a twin-screw extruder at about 150 °C with a die diameter of 1 mm, and cut it into particles about 1.5 mm after extrusion.

[0069] Comparative Example 3

[0070] Weigh 45 parts by weight of polyethylene (PE), add it to the mixing chamber of a kneader with a temperature of 134 - 136 °C, keep the rotation speed of the kneader at 55 rpm, mix for 3 min, add 30 parts by weight of lead powder and mix for 4 min, then add 10 parts by weight of dicumyl peroxide (DCP) and mix. After 2 min, add 0.5 parts by weight of blowing agent (AC). After 8 min, stop mixing. Take out the sample, cut it into small pieces, add it to a twin-screw extruder at 150 °C with a die diameter of 1 mm, and cut it into particles about 1.5 mm after extrusion.

[0071] Performance Test

[0072] The densities of the particles obtained in Examples 1 - 3 and Comparative Examples 1 - 3 are shown in Table 1 below.

[0073] The water flow field tests were conducted on the particles obtained in Examples 1 to 3 and Comparative Examples 1 to 3. The test method is as follows:

[0074] The particles obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were prepared and placed into one end of a pipeline. As water flowed through the pipeline, information on the measured flow field was obtained by using an X-ray instrument to measure the flow of the particles in the water.

[0075] The test results are shown in Table 1:

[0076] Table 1

[0077]

[0078] As can be seen from the data in Table 1, the tracer particles provided by the present invention have good water flow field followability, can be detected by X-ray, and have a density of 0.9 to 1.1 g / cm 3 , and can stay in water for three days without significant swelling or deformation.

[0079] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A tracer particle, characterized in that: By weight, the raw materials for preparation include:

2. The tracer particle according to claim 1, characterized in that: The polyethylene includes low-density polyethylene; The density of the low-density polyethylene is 0.91-0.94 g / cm 3 .

3. The tracer particle according to claim 1 or 2, characterized in that: The lead-containing material includes lead powder; The lead powder has a mesh size of 200 to 400 meshes.

4. The tracer particle according to any one of claims 1 to 3, characterized in that The cross-linking agent includes dicumyl peroxide; The blowing agent includes an AC blowing agent.

5. The tracer particle according to any one of claims 1 to 4, characterized in that: The tracer particles are prepared from the following raw materials in parts by weight:

6. The tracer particle according to any one of claims 1 to 5, characterized in that The density of the tracer particles is 0.9-1.1 g / cm 3 .

7. A method for preparing tracer particles according to any one of claims 1 to 6, characterized in that: The following steps are involved: Polyethylene, lead-containing material, cross-linking agent and foaming agent are mixed in proportion, melted and extruded to obtain tracer particles.

8. The preparation method according to claim 7, characterized in that: The mixing is carried out according to the following steps: According to the proportion, mix the polyethylene for 2 to 5 minutes, then add the lead-containing material and mix for 3 to 6 minutes, add the cross-linking agent and mix for 1 to 4 minutes, and add the foaming agent and mix for 5 to 10 minutes; The mixing temperature is 130-145°C, and the mixing is carried out under rotation conditions at a rotation speed of 40-80 rpm; The melting and extrusion are carried out in a twin-screw extruder, and the working temperature of the twin-screw extruder is 140-180°C.

9. Use of the tracer particles according to any one of claims 1 to 6 or the tracer particles prepared according to the preparation method according to claim 7 or 8 in water flow field testing.

10. The use according to claim 9, characterized in that: During the application process, X-rays are used to detect tracer particles.

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