High-wear-resistance ceramic ring pipeline for coal preparation plant

Abstract

The invention relates to the technical field of pipelines of coal preparation plants, in particular to a high-wear-resistance ceramic ring pipeline for a coal preparation plant, which comprises an armor layer consisting of a steel pipe and an expanded pipe, and a ceramic ring arranged on the inner wall of the armor layer, the ceramic ring adopts a gradient composite structure from the inner wall to the outer wall, the inner wall is an aluminum oxide or silicon carbide ceramic layer, and the outer layer is a metal-based ceramic composite material layer; the ceramic ring is prepared from a ceramic matrix added with nano-scale particles, and the nano-scale particles comprise nano tungsten carbide and nano titanium dioxide; the ceramic ring is divided into a plurality of independent small blocks, and the independent small blocks are spliced and mounted through a buckle type structure, a mortise and tenon joint structure or a threaded connection mode; compared with a traditional steel pipeline, the wear resistance of the high-wear-resistance steel pipeline is greatly improved, high-speed washing of particle materials in a solid-liquid mixture can be effectively resisted, and the high-wear-resistance steel pipeline is particularly suitable for strong-wear parts such as elbows and reducing parts of coal preparation plants.

Description

Technical Field

[0001] The invention relates to the technical field of coal preparation plant pipelines, in particular to a high-wear-resistant ceramic ring pipeline used in coal preparation plants. Background Art

[0002] In the production process of coal preparation plants, solid-liquid mixtures need to be transported through pipelines. The pipelines are subjected to long-term erosion and wear of materials. The entire pipeline system, including pressurized qualified medium pipes, mixing pipes, concentrated medium pipes, and pressurized dilute medium pipes, including straight pipes and pipe fittings (elbows, multi-passes, reducers), is more severely worn. Therefore, a high-wear-resistant ceramic ring pipeline for coal preparation plants is needed.

[0003] Traditional steel pipes have poor wear resistance and a short service life. Frequent replacement not only increases costs but also affects production efficiency. Although existing ceramic ring pipes can improve wear resistance to a certain extent, there are problems such as ceramic rings easily falling off, insufficient overall impact resistance, and inconvenient maintenance.

[0004] Therefore, those skilled in the art have proposed a high wear-resistant ceramic ring pipe for coal preparation plants to solve the above-mentioned problems. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is: poor wear resistance and short service life.

[0006] The above technical problems are solved by the following technical solution: The present invention proposes a high-wear-resistant ceramic ring pipe for a coal preparation plant, which comprises an armor layer consisting of a steel pipe and an expanded pipe, and a ceramic ring arranged on the inner wall of the armor layer; The ceramic ring adopts a gradient composite structure from the inner wall to the outer wall, the inner wall is an aluminum oxide or silicon carbide ceramic layer, and the outer layer is a metal-based ceramic composite material layer; The ceramic ring is made of a ceramic matrix with nano-scale particles added thereto, wherein the nano-scale particles include nano-tungsten carbide and nano-titanium dioxide; The ceramic ring is divided into a plurality of independent small pieces, and is assembled by means of a snap-fit structure, a mortise and tenon structure or a threaded connection; The surface of the ceramic ring is coated with a self-repairing coating or a friction-reducing coating.

[0007] As a preferred solution of the high wear-resistant ceramic ring pipe for coal preparation plant of the present invention, the alumina content of the alumina ceramic layer is ≥95%.

[0008] As a preferred solution of the high-wear-resistant ceramic ring pipe for a coal preparation plant of the present invention, the mass proportion of the nano-scale particles in the ceramic matrix is 1% to 5%.

[0009] As a preferred solution of the high-wear-resistant ceramic ring pipe for coal preparation plant of the present invention, the snap-fit structure includes a clamping block provided on one side of the ceramic ring and a clamping groove on the other side, and the clamping block and the clamping groove are buckled with each other.

[0010] As a preferred solution of the high-wear-resistant ceramic ring pipe for coal preparation plant of the present invention, the mortise and tenon structure includes a tenon provided on one side of the ceramic ring and a groove on the other side, and the tenon and the groove cooperate with each other and are clamped.

[0011] As a preferred solution for the high-wear-resistant ceramic ring pipe for coal preparation plants of the present invention, when the self-repairing coating is worn on the surface of the ceramic ring, it can automatically generate new material to fill the worn area under the conditions of temperature and pressure changes or chemical reactions with components in the material.

[0012] As a preferred solution of the high-wear-resistant ceramic ring pipeline for coal preparation plants of the present invention, the friction-reducing coating is a molybdenum disulfide coating or a graphene coating, which is used to reduce the friction coefficient between the ceramic ring and the material.

[0013] As a preferred solution of the high wear-resistant ceramic ring pipe for coal preparation plant of the present invention, wherein: in the metal-based ceramic composite material layer, the metal matrix is one of iron-based alloy and nickel-based alloy, and the ceramic phase is one of silicon carbide and aluminum oxide.

[0014] The beneficial effects of the high wear-resistant ceramic ring pipe for coal preparation plants of the present invention are as follows: The inner wall is made of alumina (content ≥95%) or silicon carbide ceramic layer with a hardness of up to HV1500 or above. Compared with traditional steel pipes, the wear resistance is greatly improved. It can effectively resist the high-speed erosion of particulate materials in solid-liquid mixtures. It is especially suitable for high-wear areas such as elbows and reducers in coal preparation plants. The outer layer is made of a metal-based ceramic composite material layer (iron-based / nickel-based alloy + silicon carbide / aluminum oxide). The toughness of the metal matrix buffers the impact of the material, and combined with the high hardness of the ceramic phase, the overall impact toughness of the ceramic ring is improved by more than 30%, avoiding the problem of fragmentation and falling off caused by impact of traditional single ceramic layers. The ceramic ring is divided into independent small pieces through snap-on, mortise and tenon or threaded connections. If a single piece is damaged, it can be quickly disassembled and replaced in a short time without replacing the entire pipeline. This greatly improves maintenance efficiency and reduces maintenance costs. The mechanical connection structure (such as the precise control of the mortise and tenon bite depth and the snap-on gap) ensures the splicing strength and prevents looseness and leakage at the connection parts. When wear occurs, the chemical reaction of the material triggers the rupture of the microcapsules in the coating, releasing repair agents (such as ceramic micropowder and binder) to automatically fill the wear pits. After repair, the surface roughness is restored, extending the service life of the ceramic ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings of the embodiments of the present invention. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention. Among them: Figure 1 This is a schematic diagram of the overall structure of high-wear-resistant ceramic ring pipes used in coal preparation plants.

[0016] Figure 2 This is a structural diagram of the snap-on ceramic ring pipeline.

[0017] Figure 3 for Figure 2 Exploded diagram.

[0018] Figure 4 This is a structural diagram of the mortise and tenon type ceramic ring pipe.

[0019] Figure 5 for Figure 4 Exploded diagram.

[0020] In the figure: 1. Block; 2. Slot; 3. Groove; 4. Tenon. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below with reference to specific embodiments and the accompanying drawings.

[0022] The terms used in the present invention are those commonly used in the art in view of the functions of the present invention, but these terms may vary according to the intentions of those skilled in the art, precedents, or new technologies in the art. In addition, specific terms may be selected by the applicant, and in such cases, their detailed meanings will be described in the detailed description of the present invention. Therefore, the terms used in the specification should not be understood as simple names, but rather as the meanings of the terms and the overall description of the present invention.

[0023] Example 1

[0024] Reference Figures 1 to 5 , which is the first embodiment of the present invention, provides a high wear-resistant ceramic ring pipe for a coal preparation plant, comprising an armor layer consisting of a steel pipe and an expanded pipe, and a ceramic ring arranged on the inner wall of the armor layer; The ceramic ring adopts a gradient composite structure from the inner wall to the outer wall. The inner wall is an aluminum oxide or silicon carbide ceramic layer, and the outer layer is a metal-based ceramic composite material layer. The ceramic ring is made of a ceramic matrix with nano-scale particles added, and the nano-scale particles include nano-tungsten carbide and nano-titanium dioxide; The ceramic ring is divided into multiple independent small pieces and assembled by snap-on structure, mortise and tenon structure or threaded connection; The surface of the ceramic ring is coated with a self-repairing coating or a friction-reducing coating.

[0025] When in use, the armor layer is made of Q235B carbon structural steel. The wall thickness of the steel pipe is designed to be 6-12mm according to the pipeline pressure level. The expansion pipe (used for pipeline connection) is stamped with the same material and welded to the steel pipe through gas shielded welding to form an overall support frame. For example, in a pipeline with a nominal diameter of DN100, the outer diameter of the steel pipe is 133mm and the expansion length is 1500mm. The overall pressure bearing capacity after welding is ≥10.0MPa; The inner wall layer of the ceramic ring is made of alumina ceramic or silicon carbide ceramic with a purity of ≥95%, produced by isostatic pressing process, with a density of ≥3.8g / cm³ and a hardness of ≥HV1500. The thickness accounts for 40%-60% of the total thickness of the ceramic ring (for example, when the total thickness is 20mm, the inner wall layer is 8-12mm thick), and is in direct contact with the material to resist erosion and wear. The outer layer of the ceramic ring is made of a metal-based ceramic composite material composed of an iron-based alloy (such as Fe-Cr-Ni alloy) or a nickel-based alloy and silicon carbide / alumina ceramic particles. The ceramic particles account for 30%-50% of the volume and are sintered through a powder metallurgy process. The thickness corresponds to the remaining part of the ceramic ring, and the elongation is ≥5%, which can absorb the impact energy of the material.

[0026] Example 2

[0027] Reference Figures 1 to 5 , which is the second embodiment of the present invention, is different from the previous embodiment in that the aluminum oxide content of the aluminum oxide ceramic layer is ≥95%.

[0028] The alumina ceramic layer is made into a green body through dry bag isostatic pressing (pressure 200MPa) and sintered at 1650℃ for 2 hours. The resulting ceramic has a density of ≥3.85g / cm³, a flexural strength of ≥300MPa, and a porosity of ≤0.5%, meeting the requirements of high hardness and wear resistance.

[0029] Specifically, the mass proportion of the nano-scale particles in the ceramic matrix is 1% to 5%.

[0030] Taking nano-tungsten carbide as an example, when the mass proportion is 3%, the wear resistance of the ceramic matrix is the best. During the preparation process, the nano-tungsten carbide particles and alumina powder are first dispersed in an ethanol medium by ultrasonic dispersion (power 200W, time 30 minutes), and then spray-dried (inlet air temperature 200°C, outlet air temperature 100°C) to obtain a composite powder. The subsequent molding and sintering process is the same as claim 1.

[0031] Furthermore, the snap-fit structure includes a snap-fit block 1 provided on one side of the ceramic ring and a snap-fit slot 2 on the other side, and the snap-fit block 1 and the snap-fit slot 2 are snap-fitted with each other.

[0032] The material of the clamping block 1 and the clamping slot 2 is alumina ceramics, which is the same material as the ceramic ring. They are formed by precision CNC machining and are connected by snap fasteners to form a continuous wear-resistant lining during installation.

[0033] The mortise and tenon structure includes a tenon 4 provided on one side of the ceramic ring and a groove 3 on the other side, and the tenon 4 and the groove 3 are engaged with each other.

[0034] The tenon 4 and the groove 3 are milled and formed using a five-axis linkage CNC machine tool. When splicing, after the tenon 4 is inserted into the groove 3, ceramic glue (such as aluminum dihydrogen phosphate adhesive) is injected at the interface and cured at room temperature for 24 hours. The bonding strength is ≥50MPa and can withstand the impact of a material flow rate of 60m / s.

[0035] Among them, when the self-repairing coating is worn on the surface of the ceramic ring, it can automatically generate new materials to fill the worn areas under conditions of temperature and pressure changes or chemical reactions with the components in the material.

[0036] The microcapsules rupture and the repair agent solidifies rapidly under the action of the material temperature to form a repair layer of a certain thickness.

[0037] Furthermore, the anti-friction coating is a molybdenum disulfide coating or a graphene coating, which is used to reduce the friction coefficient between the ceramic ring and the material.

[0038] Wherein, in the metal-based ceramic composite material layer, the metal matrix is one of an iron-based alloy and a nickel-based alloy, and the ceramic phase is one of silicon carbide and aluminum oxide.

[0039] During use, the metal matrix is made into a composite material through hot pressing and sintering, which is suitable for medium impact conditions. The metal matrix is clad on the outer layer of the ceramic ring using a laser cladding process to form a composite layer, which is suitable for high-temperature medium transportation scenarios (such as hot medium pipelines in coal preparation plants).

[0040] Example 3

[0041] Reference Figures 1 to 5 , which is the third embodiment of the present invention. Different from the previous embodiment, a method for using a ceramic ring pipe is provided: a pre-processed ceramic ring is embedded into the inner wall of a metal elbow by a special adhesive or mechanical means to form a wear-resistant lining. The ceramic ring wear-resistant pipe uses a ceramic ring (aluminum oxide content ≥ 95%) as a wear-resistant layer and a steel (Q235B) steel pipe and an expanded pipe as an armor layer.

[0042] Ceramic ring pipes have the characteristics of high hardness, good wear resistance, impact resistance, and corrosion resistance. They are suitable for conveying solid-liquid mixtures under any harsh working conditions. In heavy medium coal preparation plants, they are generally used for the entire pipeline system of pressurized qualified medium pipes, mixing pipes, concentrated medium pipes, and pressurized dilute medium pipes, including straight pipes and pipe fittings (elbows, multi-passes, reducers) and other pipe fittings.

[0043] It will be appreciated that in the development of any actual embodiment, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will, for those of ordinary skill having the benefit of this disclosure, be a routine undertaking of design, fabrication, and production without undue experimentation.

[0044] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A high wear-resistant ceramic ring pipe for a coal preparation plant, characterized by: include, an armor layer consisting of a steel pipe and an expanded pipe, and a ceramic ring disposed on the inner wall of the armor layer; The ceramic ring adopts a gradient composite structure from the inner wall to the outer wall, the inner wall is an aluminum oxide or silicon carbide ceramic layer, and the outer layer is a metal-based ceramic composite material layer; The ceramic ring is made of a ceramic matrix with nano-scale particles added thereto, wherein the nano-scale particles include nano-tungsten carbide and nano-titanium dioxide; The ceramic ring is divided into a plurality of independent small pieces, and is assembled by means of a snap-fit structure, a mortise and tenon structure or a threaded connection; The surface of the ceramic ring is coated with a self-repairing coating or a friction-reducing coating.

2. The high wear-resistant ceramic ring pipe for coal preparation plant according to claim 1, characterized in that: The aluminum oxide content of the aluminum oxide ceramic layer is ≥95%.

3. The high wear-resistant ceramic ring pipe for coal preparation plant according to claim 2, characterized in that: The mass proportion of the nano-scale particles in the ceramic matrix is 1% to 5%.

4. The high wear-resistant ceramic ring pipe for coal preparation plant according to claim 3, characterized in that: The snap-on structure comprises a snap-on block (1) provided on one side of the ceramic ring and a snap-on slot (2) on the other side, wherein the snap-on block (1) and the snap-on slot (2) are snap-on with each other.

5. The high wear-resistant ceramic ring pipe for coal preparation plant according to claim 4, characterized in that: The mortise and tenon structure comprises a tenon (4) provided on one side of the ceramic ring and a groove (3) provided on the other side, the tenon (4) and the groove (3) being engaged with each other.

6. The high wear-resistant ceramic ring pipe for coal preparation plant according to claim 5, characterized in that: When the surface of the ceramic ring is worn, the self-repairing coating can automatically generate new material to fill the worn area under the conditions of temperature and pressure changes or chemical reactions with components in the material.

7. The high wear-resistant ceramic ring pipe for coal preparation plant according to claim 6, characterized in that: The anti-friction coating is a molybdenum disulfide coating or a graphene coating, which is used to reduce the friction coefficient between the ceramic ring and the material.

8. The high wear-resistant ceramic ring pipe for coal preparation plant according to claim 7, characterized in that: In the metal-based ceramic composite material layer, the metal matrix is one of an iron-based alloy and a nickel-based alloy, and the ceramic phase is one of silicon carbide and aluminum oxide.

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