CN116817018B

CN116817018B - Arrangement and construction method of long-distance pipeline refractory lining

Info

Publication number: CN116817018B
Application number: CN202310706555.7A
Authority: CN
Inventors: 付艳鹏; 金锋; 程立
Original assignee: Sinosteel Equipment and Engineering Co Ltd
Current assignee: Sinosteel Equipment and Engineering Co Ltd
Priority date: 2023-06-14
Filing date: 2023-06-14
Publication date: 2025-11-07
Anticipated expiration: 2043-06-14
Also published as: CN116817018A

Abstract

The invention discloses an arrangement and construction method of a long-distance pipeline refractory lining, which belongs to the technical field of refractory pipeline construction and comprises the following steps of prefabricating a pre-installed pipeline in a segmented mode to form a plurality of pipeline sections, reinforcing the pipeline sections, namely installing fixing bolts on the outer parts of steel bodies at two ends of each pipeline section, filling castable materials, namely installing steel plate linings in each pipeline section, filling refractory castable materials in the pipeline sections, conducting primary baking, conducting refractory brick masonry on the pipeline sections subjected to primary baking, conducting secondary baking, conducting on-site splicing, conducting single-sided beveling on the pipeline sections subjected to secondary baking, installing a cushion plate under the beveling, conducting hoisting splicing, and conducting full penetration welding on the pipeline sections subjected to on-site splicing. The invention can reduce the construction difficulty, shorten the construction period and ensure the construction quality.

Description

Arrangement and construction method of long-distance pipeline refractory lining

Technical Field

The invention belongs to a high Wen Naicai pipeline used in the technical production fields of metallurgy, chemical industry, garbage incineration and the like, and particularly relates to an arrangement and construction method of a long-distance pipeline refractory lining.

Background

Currently, the recognized carbon reduction technology in the metallurgical industry is a gas-based shaft furnace direct reduction process. That is, iron ore is charged from the top of the shaft furnace, the ore is reduced in the furnace, and the reduced iron is discharged from the bottom of the furnace. Reducing gas is blown in from a nozzle in the middle of the furnace body, and escapes from the furnace top after reaction. A circulating cooling gas is provided in the lower portion of the furnace to cool the reduced iron. The furnace body inlet and outlet are respectively provided with a dynamic sealing device, and can be continuously charged and discharged, and the generated mixture of the metallic iron and gangue is commonly called as Direct Reduced Iron (DRI). Direct Reduced Iron (DRI) is a pure raw material for smelting excellent and special steel by reducing iron ore into metallic iron under the solid state condition, and can also be used as an iron-containing raw material for casting, ferroalloy, powder metallurgy and other processes. The direct reduction process does not use coke, the raw materials can use cold-pressed pellets, pellet blocks or lump ores, and sintering ores are not used, so that the direct reduction process is a new process with high quality, low consumption and low pollution for iron making, and is one of leading edge technologies of ferrous metallurgy worldwide.

The flow of the direct reduction process mainly comprises a reduction gas preparation part, a reduction shaft furnace part and a waste heat recovery part 3. The preparation of ① reducing gas comprises the steps of pressurizing and feeding about 70% of purified CO+H2 into a mixing chamber, mixing with equivalent natural gas, feeding into a heat exchanger for preheating, then feeding into a reaction tube with a nickel-based catalyst at about 1100 ℃ for catalytic cracking reaction, converting into 4% -36% CO, 60% -70% H2, 3% -6% CH4 and 870 ℃ reducing gas, wherein a ② reducing shaft furnace is circular in section and is divided into a preheating section, a reducing section and a cooling section, furnace burden stays for 4-6H (total time is about 10H) in the reducing section above 800 ℃, the operating pressure of the shaft furnace is 0.2-0.3 MPa, and ③ waste heat recovery is carried out, so that waste heat of the furnace roof gas can be directly recovered, energy consumption is reduced, and the purposes of energy conservation and emission reduction are achieved. Meanwhile, the waste heat recovery system can improve the efficiency of the whole furnace body, the top gas enters the waste heat recovery device through purification and pressurization, and the recovered waste heat can heat combustion air and reducing gas through a heat exchanger.

The development of gas-based direct reduction shaft furnaces is now well completed, and because of the process characteristics of the shaft furnace bodies, the gas pipelines which are vertical to the shaft furnace bodies and serve as high-temperature (850-1050 ℃) gas pipelines for reduction work need to be arranged parallel to the shaft furnace. Because of the high temperature requirement, the refractory lining is required to be poured or built in advance in the pipeline, so that the working gas is loaded and insulated. However, the pipe cavity has a small diameter (< 1.0 m) and a large length (30 m or more), and thus the pipe cavity needs to be constructed in sections. Under the premise of ensuring engineering quality, ensuring construction efficiency, reducing construction difficulty, shortening construction period, ensuring long-service life of a pipeline and improving safety coefficient, the construction method with high efficiency, stability and science is found to be a necessary requirement for engineering quality.

Disclosure of Invention

The invention aims to provide an arrangement and construction method of a long-distance pipeline refractory lining, which can reduce construction difficulty, shorten construction period, ensure construction quality and ensure that equipment functions meet technological design requirements.

In order to achieve the above purpose, the invention provides an arrangement and construction method of a long-distance pipeline refractory lining, which comprises the following steps:

A prefabrication segmentation step, namely prefabricating the pre-installed pipeline in segments to form a plurality of pipeline sections;

the pipe section reinforcing step, namely fixing bolts are additionally arranged at the outer parts of the steel bodies at the two ends of each pipe section;

filling the castable, namely adding a steel plate lining into each pipe section, and then filling refractory castable into the pipe sections;

a primary baking step, namely carrying out primary baking treatment on the pipe section filled with the castable according to a baking system;

a step of building refractory bricks, in which the refractory bricks of the working layer are built on the pipe section subjected to primary baking treatment;

a secondary baking step, namely performing secondary baking on the built pipe section;

The on-site splicing step is that a single-sided groove of a beveling machine is adopted for the pipe section subjected to the secondary baking, a cushion plate is additionally arranged below the groove, and then hoisting and splicing are carried out;

and full penetration welding, namely performing full penetration welding on the pipe sections spliced on site.

Further, in the prefabricating step, the length of the pipe section is 6m.

Further, the casting material filling step specifically comprises the step of adding a steel plate lining on the inner side of the steel body cylinder wall and the splicing head of each pipe section.

Further, in the castable filling step, the refractory castable includes an insulating layer castable and a permanent layer castable.

Further, the on-site splicing step specifically comprises the step of polishing a V-shaped groove on the steel cylinder body of each pipe section by adopting a beveling machine, wherein the angle of the V-shaped groove is 45-60 degrees.

Further, in the full penetration welding step, different welding rods are adopted for welding corresponding to steel body materials of different pipe sections.

Further, when the steel body material of the welded pipe section is Q235B, the welding is performed by adopting a J422 welding rod, and when the steel body material of the welded pipe section is Q345B, the welding is performed by adopting a J506 welding rod.

Further, when the steel body material of the welded pipe section is Q345B, welding by adopting a J506 welding rod comprises the steps of firstly preheating the J506 welding rod to 300 ℃, preserving heat for 2 hours, then performing carbon dioxide arc welding, and finally performing surface irradiation welding by adopting welding rod arc welding or submerged arc welding.

Further, in the full penetration welding step, the full penetration welding method adopts one or more of Shielded Metal Arc Welding (SMAW), submerged Arc Welding (SAW), gas Tungsten Arc Welding (GTAW) and Gas Metal Arc Welding (GMAW).

Further, the on-site splicing step further comprises the steps of cleaning the groove after the groove is manufactured, and performing appearance and nondestructive detection.

Compared with the prior art, the method for arranging and constructing the lining of the long-distance pipeline refractory material comprises the steps of carrying out segmented prefabrication on the pipeline, carrying out bolt reinforcement on each pipeline section, additionally arranging a steel plate lining in each pipeline section, and then filling refractory material into the pipeline section. By adopting a full penetration welding mode, the construction period of a high-temperature gas pipeline with the length of 100m can be shortened to be within 50 days, and the full penetration welding method has good popularization and assistance significance for high-temperature small-inner-diameter gas pipelines with refractory liners in the industries of gas-based direct reduced iron, COREX furnaces, garbage incinerators, petrochemical industry and the like.

Drawings

FIG. 1 is a schematic diagram of a full penetration weld of an arrangement and construction method of a long distance pipeline refractory lining of the present invention;

FIG. 2 is a schematic view of a single groove angle of the present invention;

FIG. 3 is a shrimp bend view of the arrangement and construction method of the long-distance pipeline refractory lining of the present invention;

FIG. 4 is a schematic sectional view of an arrangement and construction method of a long-distance pipeline refractory lining of the present invention;

FIG. 5 is a schematic illustration of a segmented pipeline containing tile supporting plates for the arrangement and construction method of the long-distance pipeline refractory lining of the present invention;

FIG. 6 is a schematic view of a conventional segmented steel cylinder of the inventive arrangement and construction method of a long-distance pipeline refractory lining;

FIG. 7 is a schematic diagram of a full penetration weld of a seal dislocation of a refractory lining strip of a long distance pipeline refractory lining arrangement and construction method of the present invention;

FIG. 8 is a schematic diagram of a 5mm mortar joint filling, splicing and full penetration welding for the arrangement and construction method of the long-distance pipeline refractory lining of the invention;

FIG. 9 is a schematic diagram of a fully penetration welded spliced added refractory pipeline of the inventive arrangement and construction method of a long-distance pipeline refractory lining;

Fig. 10 to 13 are schematic diagrams of full penetration welding of a core furnace molten gas pipeline and a related pipeline structure of the method for arranging and constructing a long-distance pipeline refractory lining according to the present invention.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The terms "first," "second," "third," "fourth" and the like in the description and in the claims and in the above drawings, if any, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the invention described herein may be implemented in sequences other than those illustrated or otherwise described herein.

It should be understood that, in various embodiments of the present invention, the sequence number of each process does not mean that the execution sequence of each process should be determined by its functions and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

It should be understood that in the present invention, "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements that are expressly listed or inherent to such process, method, article, or apparatus.

It should be understood that in the present invention, "plurality" means two or more. "and/or" is merely an association relationship describing the association object, and means that three relationships may exist, for example, and/or B, and that three cases of a alone, a and B together, and B alone may exist. The character "/" generally indicates that the context-dependent object is an "or" relationship. "comprising A, B and C", "comprising A, B, C" means that all three of A, B, C are comprised, "comprising A, B or C" means that one of A, B, C is comprised, "comprising A, B and/or C" means that any 1 or any 2 or 3 of A, B, C are comprised.

It should be understood that in the present invention, "B corresponding to a", "a corresponding to B", or "B corresponding to a" means that B is associated with a, from which B can be determined. Determining B from a does not mean determining B from a alone, but may also determine B from a and/or other information. The matching of A and B is that the similarity of A and B is larger than or equal to a preset threshold value.

As used herein, "if" may be interpreted as "at" or "when" depending on the context, "or" in response to a determination "or" in response to a detection.

The technical scheme of the invention is described in detail below by specific examples. The following embodiments may be combined with each other, and some embodiments may not be repeated for the same or similar concepts or processes.

In the actual construction operation, the refractory pipeline with larger pipe diameter can accommodate human turnover, and the steel is generally processed and manufactured, and then a supporting frame is built in the pipeline for pouring or bricking. Thus, the integrated integrity of the equipment is ensured, and the stability of the working layer is ensured. The high-temperature pipeline of the gas-based shaft furnace has smaller inner diameter, adopts a three-layer structure (heat preservation layer casting material, permanent layer casting material and working face brick), has the length of more than 100m and also has a shrimp bending structure, so that the method of manual construction, formwork supporting, formwork removing, mechanical construction and the like cannot be satisfied. Even if the device can be additionally arranged, the device can be operated in a narrow closed limited space, has huge potential safety hazards, and can not meet the requirements of construction period.

In order to ensure the engineering quality design requirements and meet the engineering requirements, a method for arranging and constructing a long-distance pipeline refractory lining is provided, as shown in fig. 1, according to the preferred embodiment of the invention, the method for arranging and constructing the long-distance pipeline refractory lining comprises the following steps:

The embodiment of the invention is realized by adopting a mode of splicing the pipeline by segment construction and full penetration welding of an external steel body. The long-distance pipeline is divided into natural sections which are convenient to implement in the pipe section without holes or with other devices, the length of each pipe section is about 6m generally, and fixing bolts are additionally arranged outside the steel body at two ends of each natural section or shrimp bending section for fusion welding, centering and reinforcing during splicing.

In one embodiment of the invention, the pouring material filling step specifically comprises the step of adding a steel plate lining to the inner side of the steel body cylinder wall and the splicing head of each pipe section.

In an embodiment of the present invention, in the castable filling step, the refractory castable includes a heat insulating layer castable and a permanent layer castable.

In one embodiment of the invention, the field splicing step specifically comprises the step of polishing a V-shaped groove on the steel cylinder body of each pipe section by adopting a beveling machine, wherein the angle of the V-shaped groove is 45-60 degrees, as shown in fig. 2.

Whether welding method is used for full penetration welding of four general welding methods such as shielded arc welding (SMAW), submerged Arc Welding (SAW), tungsten arc welding (GTAW) and Gas Metal Arc Welding (GMAW), the specific steel cylinder material and working condition requirements are combined, and the penetration welding is an equal-strength welding seam, and adopts equal strength of a node and a base metal. In one embodiment of the present invention, in the full penetration welding step, different welding rods are used for welding corresponding to steel body materials of different pipe sections. If deep penetration welding is performed, a special welding rod is adopted to obtain welding with a large penetration bead. When welding and cutting operation is performed, firstly, a gas cylinder meeting the requirements of relevant national standards and regulations is used, and safety operation regulations are strictly adhered to in the links of storage, transportation, use and the like of the gas cylinder. The pipelines for conveying the combustible gas and the combustion-supporting gas are installed, used and managed according to the regulations, and special safety technical training is carried out on operators and inspectors.

In one embodiment of the invention, the welding is performed by using a J422 welding rod when the steel body material of the welded pipe section is Q235B, and the welding is performed by using a J506 welding rod when the steel body material of the welded pipe section is Q345B. When the steel body material of the welded pipe section is Q345B grade, welding by adopting a J506 welding rod comprises the steps of firstly preheating the J506 welding rod to 300 ℃, preserving heat for 2 hours, then performing carbon dioxide arc welding, and finally performing surface irradiation welding by adopting welding rod arc welding or submerged arc welding.

In an embodiment of the present invention, in the full penetration welding step, the full penetration welding method uses one or more of Shielded Metal Arc Welding (SMAW), submerged Arc Welding (SAW), gas Tungsten Arc Welding (GTAW), and Gas Metal Arc Welding (GMAW).

In one embodiment of the invention, the field splicing step further comprises the steps of cleaning the groove after the groove is manufactured, performing appearance and nondestructive detection, and setting aside heavy welding until the flaw detection is qualified after the flaw detection is failed.

According to the embodiment of the invention, as shown in fig. 1 to 6, the lining pipes with the refractory are basically constructed on site for the steel cylinder body with the small ultra-long diameter, and are divided into a plurality of groups to be constructed simultaneously. According to the working condition of the actual pipeline, the cutting and dividing design is carried out, the special positions such as the brick supporting plate position, the temperature measuring hole position, the observing hole position and the like are avoided, and after the refractory filling construction is finished, the full penetration welding is carried out. After pouring the heat-insulating layer and the permanent layer castable, drying according to a baking system, building the refractory bricks of the working layer after baking, and performing secondary baking after building, wherein the next step is an important splicing procedure. In the field welding process, a single-sided groove of a beveling machine is adopted, and a backing plate is added below the groove. And cleaning up hanging slag, greasy dirt, dust, floating rust and the like on the groove after finishing the groove.

After the arrangement and construction method of the long-distance pipeline refractory lining are designed, the high-temperature gas pipeline with long distance, small inner diameter, long service life and inner refractory lining is subjected to full penetration welding according to the working condition of the site and the direct gas-based reduction process requirement, as shown in fig. 7 and 8, one is the casting of the lining refractory, the butt joint dislocation step is reserved during the construction, the centering and the splicing are convenient, and the sealing of high-temperature gas is convenient, and the other is the plane butt joint. Mortar is reserved for joint filling by 5mm in any welding, and bolts are additionally arranged on the outer body and are used for centering welding, steel body lining and full V-shaped groove. If the full penetration welding mode is not adopted, the construction period of a high-temperature gas pipeline with the length of 100m is more than 80 days, and the construction period can be shortened to be within 50 days after the mode is adopted, wherein the method comprises twice baking, flaw detection and acceptance, hoisting and splicing, and has good popularization and assistance significance on the gas pipeline with the high-temperature small-inner diameter and refractory lining in the industries of gas-based direct reduced iron, COREX furnaces, garbage incinerators, petrochemical industry and the like.

In one embodiment of the present invention, the arrangement and construction method of the long-distance pipeline refractory lining of the present invention has been implemented and applied to the high-temperature gas pipeline of the maximum direct reduced iron production process in China. The whole pipeline is constructed in 23 sections with the total length exceeding 100m, and the construction period is 52 days, as shown in fig. 3,4, 5, 6 and 9.

In one embodiment of the invention, the arrangement and construction method of the long-distance pipeline refractory lining of the invention are implemented and popularized on a melting process gas pipeline of a shaft furnace section of a COREX furnace. The whole pipeline is constructed in 15 sections with the total length exceeding 30m, and the service life and the application effect of the refractory are doubled compared with the original pipeline, as shown in figures 10 to 13.

According to the arrangement and construction method of the long-distance pipeline refractory lining, the pipeline is prefabricated in sections, each pipe section is reinforced by bolts, a steel plate lining is added in each pipe section, then refractory castable is filled in the pipe section, the technical scheme further comprises two times of baking, the pipe section subjected to the two times of baking is subjected to single-sided groove of a beveling machine, a cushion plate is added under the groove, and full penetration welding is carried out on the pipe section subjected to field splicing. The construction difficulty can be reduced, the construction period can be shortened, the construction quality can be ensured, and the equipment function can be ensured to meet the technical design requirement of the process. Has good popularization and assistance significance for high-temperature small-inner-diameter refractory lining gas pipelines in the industries of gas-based direct reduced iron, COREX furnaces, garbage incinerators, petrochemical industry and the like.

The foregoing descriptions of specific exemplary embodiments of the present invention are presented for purposes of illustration and description. It is not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application to thereby enable one skilled in the art to make and utilize the invention in various exemplary embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims and their equivalents.

Claims

1. A construction method for arranging refractory linings for long-distance pipelines, characterized by comprising the following steps:

Prefabrication segmentation process: The pre-installed pipeline is prefabricated into segments to form several pipe sections;

Pipe section reinforcement steps: Install fixing bolts on the outside of the steel body at both ends of each pipe section;

Refractory filling steps: Install steel plate linings on the inner side of the steel cylinder wall of each pipe section and at the joint, and then fill the pipe section with refractory castable; when filling the refractory castable, the refractory castable at one joint of two adjacent pipe sections is recessed inward, and the refractory castable at the joint of the other pipe section is protruding outward; and a butt seal chamfer and mortar joint are formed between the insulation castable at the joint of the two pipe sections.

One baking step: The pipe section filled with refractory is baked once according to the baking regime;

Refractory bricklaying steps: Lay the working layer of refractory bricks on the pipe section that has undergone one baking treatment.

Secondary baking step: The completed pipe section is then baked a second time;

On-site splicing steps: The pipe section that has undergone secondary baking is beveled on one side using a beveling machine, and a pad is installed under the bevel before hoisting and splicing.

Full penetration welding procedure: Perform full penetration welding on the pipe sections after they are spliced on site.

2. The construction method for arranging refractory linings for long-distance pipelines according to claim 1, characterized in that, in the prefabrication segmentation step, the length of the pipe segment is 6m.

3. The construction method for arranging refractory linings for long-distance pipelines according to claim 1, characterized in that, in the refractory filling step, the refractory refractory includes insulation layer refractory and permanent layer refractory.

4. The construction method for arranging refractory linings for long-distance pipelines according to claim 1, characterized in that the on-site splicing step specifically includes: using a beveling machine to grind a V-shaped bevel around the steel cylinder of each pipe section, wherein the angle of the V-shaped bevel is 45-60°.

5. The construction method for arranging refractory linings for long-distance pipelines according to claim 1, characterized in that, in the full penetration welding step, different welding rods are used for welding according to the steel material of different pipe sections.

6. The construction method for arranging refractory linings for long-distance pipelines according to claim 5, characterized in that, when the steel material of the pipe section to be welded is Q235B, J422 welding rods are used for welding; when the steel material of the pipe section to be welded is Q345B, J506 welding rods are used for welding.

7. The construction method for arranging refractory linings for long-distance pipelines according to claim 6, characterized in that, when the steel material of the pipe section to be welded is Q345B, welding with J506 welding rods includes: firstly, preheating the J506 welding rods to 300°C and holding for 2 hours, then performing carbon dioxide shielded welding, and finally performing face-to-face welding with shielded metal arc welding or submerged arc welding.

8. The construction method for arranging refractory linings for long-distance pipelines according to claim 1, characterized in that, in the full penetration welding step, the full penetration welding method adopts one or more of the following: shielded metal arc welding (SMAW), submerged arc welding (SAW), gas tungsten inert welding (GTAW), and gas metal arc welding (GMAW).

9. The construction method for arranging refractory linings for long-distance pipelines according to claim 1, characterized in that the on-site splicing step further includes: cleaning the bevel after the bevel is manufactured, and performing visual and non-destructive testing.