An apparatus and method for monitoring the tendency of fouling of the inner wall of a metal pipe on-line

Abstract

The application discloses a device and method for monitoring the fouling and blocking trend of the inner wall of a metal pipe, comprising a micro-resistance measuring instrument, a wheel patrol controller, a segmented pipe conductive metal probe, and a measuring loop wire, wherein the segmented pipe conductive metal probe comprises an outer probe and an inner probe, one end of the inner probe is inserted into the center of the metal pipe through a metal pipe flange gap, the inner probe is in good contact with the liquid in the pipe, a sealing washer is arranged between the metal pipe flanges, and the inner probe is sealingly installed through the sealing washer. The application can provide data for users, intuitively reflect the fouling condition of the inner wall of each pipe section, and directly determine whether to maintain production, or directly determine which pipe section needs to be dredged, repaired or replaced, so that the operation and maintenance work can be carried out with a clear purpose, the production efficiency is improved, energy consumption is saved, the production efficiency is improved, the lines, elements and devices of the whole system are fixedly installed, and the cumbersome work of moving the mobile monitoring equipment of other various detection and blocking modes is avoided.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of pipeline transportation of fluid, and particularly relates to a device and method for monitoring the tendency of fouling and blockage of the inner wall of a metal pipeline. BACKGROUND

[0002] In various metallurgical, petrochemical, chemical and other industrial fields, there are a large number of processes that utilize pipelines to transport liquid or slurry fluid substances (hereinafter referred to as "fluids"). The composition of the fluid in the pipeline is complex, and different processes are composed of various types of acid / alkali / salt solutions, particulate suspended materials, molten slurry, and various minerals, etc. mixed together, and there are various working conditions such as low temperature, normal temperature, and high temperature.

[0003] The length of the transportation pipeline can be from several meters to tens of kilometers, and the pipeline arrangement has various structures such as single pipe, pipe bank, curved rotation, etc., and there is also a long-distance heat-insulated heating sleeve structure, with the inner pipe transporting the fluid, the outer pipe filled with steam or heat-conducting fluid, and the outer pipe wrapped with heat-insulating material.

[0004] The fluid in the pipeline will undergo more or less chemical reactions during the transportation process, and gradually deposit and form a layer of fouling on the inner wall of the pipeline, just like the formation of scale in a kettle that has been used for a long time. The fouling in the pipeline gradually thickens, causing the internal space of the pipeline to be occupied and narrowed, which can cause the transportation of the fluid in the pipeline to be blocked and even occluded, seriously affecting the normal operation of the process. Once the pipeline is blocked, especially for long-distance pipelines, it is difficult to determine the specific blockage location, and only the pipeline can be disassembled and inspected in sections and zones for dredging or replacement, which often causes the entire process to be shut down for a long time, and the maintenance workload is huge.

[0005] For example, the core process in an alumina production plant in the aluminum smelting industry is high-temperature pipeline leaching, which uses a sleeve with a total length of up to ten kilometers and a structure with multiple curved turns, with the inner pipe transporting a slurry fluid composed of aluminum-silicon ore powder, NaOH and Ca(OH)2 solution, and the outer pipe filled with steam above 230°C, continuously heating the inner fluid. The fluid in the inner pipe undergoes chemical reactions during the transportation process in a high-temperature environment, and finally leaches to form Al(OH)3 and red mud slurry containing silicon and calcium residues. A large number of pipelines in the alumina pipeline leaching process are prone to fouling and blockage of the inner wall during production. According to actual production experience, new pipelines generally form serious fouling in a few months, causing the flow rate and flow of the fluid in the pipeline to decrease, and even causing blockage and occlusion. At present, alumina plants can only use regular shutdown maintenance every 3 months to flush the entire pipeline with high-pressure water to flush out the fouling in the pipeline. For serious blockages, the pipeline has to be disassembled in sections to find the blockage point for dredging or replacement. This method has a long shutdown time, consumes a lot of water and energy, and has low maintenance efficiency and a huge workload. Each maintenance will take several days and require a large amount of manpower and material resources. SUMMARY

[0006] To address the aforementioned technical problems, the main objective of this invention is to propose a method and apparatus for measuring the comprehensive equivalent resistance of integrated materials in segmented pipelines, using the resistance change trend to determine the scale thickness on the inner wall of each pipeline segment, enabling real-time online monitoring of pipelines transporting fluids, accurately grasping the scale changes on the inner wall of each pipeline segment, and precisely determining the location of pipe blockages. This invention aims to solve the aforementioned technical problems.

[0007] The present invention is achieved through the following technical solutions.

[0008] This invention provides an online monitoring device for scaling and clogging trends on the inner wall of metal pipes, comprising a micro-resistance meter, a patrol controller, segmented pipe conductive metal probes, and measurement circuit wires. The segmented pipe conductive metal probes include an outer probe and an inner probe. One end of the inner probe is inserted into the center of the metal pipe through the gap of the metal pipe flange, ensuring good contact between the inner probe and the fluid inside the pipe. A sealing gasket is provided between the metal pipe flanges, and the inner probe is sealed and insulated from the metal pipe. The outer probe is welded to or electrically connected to the outer wall of the metal pipe. The micro-resistance meter is electrically connected to the patrol controller, and the patrol controller is electrically connected to the segmented pipe conductive metal probes through the measurement circuit wires.

[0009] It also includes a resistance value recording and analysis data server, on-site network communication equipment, trend model calculation and display and alarm interface software. The micro resistance meter sends resistance measurement data to the resistance value recording and analysis data server through the on-site network communication equipment. The resistance value recording and analysis data server analyzes the data and generates charts through the trend model calculation and display and alarm interface software. When the resistance value exceeds the set value, an early warning information is issued.

[0010] The patrol controller has multiple patrol circuits. The number of patrol circuits is set according to the number of metal pipe segments to be monitored. The timing conduction control of the patrol circuits is controlled by PLC or DCS automatic control equipment or by single-chip microcomputer electronic circuit board. Each patrol circuit corresponds to a separate pipe segment in the control system.

[0011] One end of the measuring circuit wire passes through the metal pipe flange, and a protective layer is provided on the outside of the measuring circuit wire.

[0012] The trend model calculation, display, and alarm interface software includes a computer HMI interface, a mobile APP or mini-program, an analysis model database, and a data transmission and communication module. The trend model calculation, display, and alarm interface software can be customized to develop various display models and alarm measures according to different user and process requirements, as well as develop functions for user login, authorized operation, and historical record query.

[0013] A method for online monitoring of scaling and clogging trends on the inner wall of metal pipes includes the following steps:

[0014] Step S1, install inner probe at the flange connection of each section of metal pipe, install outer probe at the outer wall of metal pipe, and connect the conductive metal probe of segmented pipeline with the wheel patrol controller through the measuring circuit wire, and the wheel patrol controller is connected with the micro-resistance measuring instrument;

[0015] Step S2, the micro-resistance measuring instrument measures the resistance value of the wheel patrol circuit one by one through the internal controller of the wheel patrol controller, and sends the measurement data to the resistance value record analysis data server through the field network communication equipment;

[0016] Step S3, the resistance value data is analyzed by the trend model operation display and alarm interface software in the resistance value record analysis data server, and a chart is generated, and a warning information is sent out when the resistance value exceeds the set value.

[0017] In step S3, the fouling thickness parameter of each section of metal pipe is accumulated according to the periodic time sequence, and these data points are fitted into a curve along the time axis to form a real-time change trend of the fouling thickness.

[0018] The trend model operation display and alarm interface software can develop various display models and alarm measures according to different users and process requirements, and can develop user login, authorization control and historical record query functions.

[0019] The beneficial effects of the present application are:

[0020] 1. The user can intuitively understand the inner wall fouling condition of each section of pipeline according to the fouling thickness trend of each section of pipeline, so as to determine whether to maintain production or directly determine which section of pipeline needs to be dredged, repaired or replaced, so as to carry out operation and maintenance work with a clear purpose and improve production efficiency;

[0021] 2. High energy consumption and high water consumption caused by blind flushing of the whole process line can be avoided, and sewage discharge can be reduced;

[0022] 3. The lines, elements and equipment of the whole system are fixedly installed, which is a one-time job, and the cumbersome work of moving the monitoring equipment of other various blocking methods is avoided;

[0023] 4. The monitoring is intuitive, accurate, real-time and efficient, and is accurate to each section of physical pipeline, so that the fault point and hidden point are minimized;

[0024] 5. Trend prediction, early warning and emergency alarm and other intelligent functions can be easily realized, and detailed historical records are provided, which provides reliable support for factory informatization and intelligentization. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is a schematic view of the cross section of the inner wall fouling pipeline;

[0026] Figure 2The schematic diagram of the equivalent resistance measurement principle of a pipeline is shown in the figure;

[0027] Figure 3 The schematic diagram of the overall structure of the device of the present application is shown in the figure.

[0028] In the figure: 1-micro resistance measuring instrument, 2-round patrol controller, 3-sectioned pipeline conductive metal probe, 4-resistance value recording and analysis data server, 5-site network communication equipment, 6-trend model operation display and alarm interface software, 7-measurement loop wire. DETAILED DESCRIPTION

[0029] The technical solutions of the present application are further described below, but the scope of protection is not limited to the description.

[0030] As shown in Figure 1 , Figure 2 , Figure 3 An online device for monitoring the fouling and clogging trend of the inner wall of a metal pipe, comprising a micro resistance measuring instrument 1, a round patrol controller 2, a sectioned pipeline conductive metal probe 3, and a measurement loop wire 7, wherein the sectioned pipeline conductive metal probe 3 comprises an outer probe and an inner probe, the inner probe is inserted into the center of the metal pipe through the gap between the flanges of the metal pipe, the inner probe is in good contact with the liquid in the pipe, a sealing washer is arranged between the flanges of the metal pipe, the inner probe is sealed and installed through the sealing washer, and the inner probe is insulated from the metal pipe, the outer probe is welded or in good conductive connection with the outer wall of the metal pipe, the micro resistance measuring instrument 1 is electrically connected with the round patrol controller 2, and the round patrol controller 2 is electrically connected with the sectioned pipeline conductive metal probe 3 through the measurement loop wire 7.

[0031] The micro resistance measuring instrument 1 and the round patrol controller 2 are arranged in a control room or a special control cabinet near the pipeline production system, the sectioned pipeline conductive metal probe 3 is installed in groups inside and outside the sectioned pipeline to be monitored, and is connected with the round patrol controller 2 through the measurement loop wire 7; the round patrol controller 2 is connected with the micro resistance measuring instrument 1, so that the micro resistance measuring instrument 1 can sequentially detect the resistance value between each group of sectioned pipeline conductive metal probes 3; the micro resistance measuring instrument 1 and the round patrol controller 2 are both connected with the resistance value recording and analysis data server 4 through the site network communication equipment 5, and the resistance values of each section of the pipeline measured at a certain interval are stored and operated in the resistance value recording and analysis data server 4 in real time, and are converted into the thickness ratio value of the fouling on the inner wall of the sectioned pipeline through trend model operation; the monitoring result of the fouling trend on the inner wall of the pipeline is displayed and alarmed to the supervisors and the information center through the display and alarm interface software.

[0032] The principle of the present application is that industrial pipelines are connected by segmented pipelines, the inside of each segmented pipeline is filled with liquid, and the inner wall has more or less scale during production, the comprehensive material of each pipeline is mainly composed of three materials of metal pipeline, scale and liquid, and the comprehensive resistance of each pipeline is the superposition resistance of the three materials. Among the three materials, the metal pipeline is made of conductive metal components such as steel, copper and aluminum alloy, and has a low resistivity, generally in the order of 10-6~10-8Ω·m; the liquid has certain acid, alkali and salt components, and also has a low resistivity, generally in the order of 10-4~10-5Ω·m; and the scale layer is mainly composed of silicon oxide, and has a high resistivity, reaching 10-1~102Ω·m, which is tens, hundreds or even thousands of times of the resistivity of the metal pipeline and the liquid. It is verified by actual test that the change of the comprehensive resistance of each pipeline is mainly caused by the change of the thickness of the scale layer, and the comprehensive resistance of the pipeline has a relatively obvious linear relationship with the thickness of the structure layer. According to this linear relationship, the change of the thickness of the structure layer can be calculated more accurately through the change of the comprehensive resistance value.

[0033] It also comprises a resistance value record analysis data server 4, a field network communication device 5, a trend model operation display and alarm interface software 6, the micro-resistance measuring instrument 1 sends the resistance measurement data to the resistance value record analysis data server 4 through the field network communication device 5, the resistance value record analysis data server 4 analyzes the data and generates a chart through the trend model operation display and alarm interface software 6, and sends a pre-warning information when the resistance value exceeds the set value. The resistance value record analysis data server 4 is placed in the main control room, information center or other positions of the production plant, after the micro-resistance measuring instrument 1 sends the data to the resistance value record analysis data server 4 through the field network communication device 5, the trend model operation display and alarm interface software 6 fits the data points into a curve along the time axis according to the scale thickness parameters of each metal pipe accumulated in a period of time, forms the real-time change trend of the scale thickness, can be displayed for relevant control personnel to watch, and pre-warns or alarms when exceeding the set alarm threshold.

[0034] The wheel patrol controller 2 is provided with a plurality of wheel patrol circuits, the number of the wheel patrol circuits is set according to the number of segmented metal pipes to be monitored, the time sequence conduction control of the wheel patrol circuits is controlled by PLC, DCS automatic control equipment or through a single-chip electronic circuit board, and each wheel patrol circuit corresponds to a pipeline in the control system. The micro-resistance measuring instrument 1 can measure the resistance value of the metal pipes one by one through the wheel patrol controller 2, so as to obtain the resistance value data of each pipeline, and draw a chart.

[0035] The measuring loop wire 7 passes through between the metal pipe flanges at one end, and a protective layer is arranged outside the measuring loop wire 7. The measuring loop wire 7 is soft and thin, can pass through a small gap such as a connecting flange joint, and can be provided with a high-temperature-resistant, corrosion-resistant sheath or protective layer. In some working conditions with an inner and outer sleeve structure, the present application can only monitor the inner pipe and is not affected by the shielding of the outer pipe.

[0036] The trend model operation display and alarm interface software 6 includes a computer HMI interface, a mobile phone APP or applet, an analysis model database, and a data transmission communication module. The trend model operation display and alarm interface software 6 is customized and developed according to different users and process requirements to develop various display models and alarm measures, and to develop user login, authorization control, and historical record query functions. The trend model operation display and alarm interface software 6 linearly converts the resistance values of each section of the pipeline into structural thickness according to the data information fed back by the micro-resistance measuring instrument 1, generates a change trend curve, and can be displayed for relevant control personnel to view. At the same time, pre-warning and alarm are performed when the resistance value exceeds the set alarm threshold.

[0037] A method for online monitoring of the fouling and blocking trend of the inner wall of a metal pipe, comprising the following steps:

[0038] Step S1, an inner probe is installed at the flange connection of each section of the metal pipe, an outer probe is installed on the outer wall of the metal pipe, and a measuring loop wire 7 is used to connect the segmented pipeline conductive metal probe 3 with the round-trip controller 2, and the round-trip controller 2 is connected with the micro-resistance measuring instrument 1, so that the micro-resistance measuring instrument 1 is in communication with the segmented pipeline conductive metal probe 3.

[0039] Step S2, the micro-resistance measuring instrument 1 measures the resistance value of each round-trip loop through the internal controller of the round-trip controller 2, and sends the measurement data to the resistance value recording and analysis data server 4 through the field network communication equipment 5. The resistance value of each section of the metal pipe is measured by the micro-resistance measuring instrument 1, and the data is transmitted to the resistance value recording and analysis data server 4 through the field network communication equipment 5 for analysis.

[0040] Step S3, the resistance value recording and analysis data server 4 analyzes the resistance value data and generates a chart through the trend model operation display and alarm interface software 6, which can be displayed for relevant control personnel to view, and pre-warning information is sent out when the resistance value exceeds the set value.

[0041] In step S3, the fouling thickness parameters of each section of the metal pipe are accumulated according to the periodic time sequence, the data points are fitted into a curve along the time axis, and the real-time change trend of the fouling thickness is formed, so that the staff can quantify the fouling condition and judge whether to clean the pipeline and distinguish the fouling conditions of different pipelines.

[0042] The trend model operation display and alarm interface software 6 develops various display models and alarm measures according to different users and process requirements, and develops user login, authorization control and historical record query functions, so as to facilitate different users to use and view the pipeline structure data.

Claims

1. A method for online monitoring of scaling and clogging trends on the inner wall of metal pipes, characterized in that: This method is based on an online monitoring device for scaling and clogging trends on the inner wall of metal pipes, including a micro resistance meter (1), a patrol controller (2), a segmented pipe conductive metal probe (3), and a measurement circuit wire (7). The segmented pipe conductive metal probe (3) includes an outer probe and an inner probe. One end of the inner probe is inserted into the center of the metal pipe through the gap of the metal pipe flange. The inner probe is in good contact with the fluid inside the pipe. A sealing gasket is provided between the metal pipe flanges. The inner probe is sealed by the sealing gasket and is kept insulated from the metal pipe. The outer probe is welded to or has a good conductive connection with the outer wall of the metal pipe. The micro resistance meter (1) is electrically connected to the patrol controller (2). The patrol controller (2) is electrically connected to the segmented pipe conductive metal probe (3) through the measurement circuit wire (7). The wheel controller (2) is equipped with multiple wheel circuits. The number of wheel circuits is set according to the number of metal pipe segments to be monitored. The timing conduction control of the wheel circuits is controlled by PLC or DCS automatic control equipment or by single-chip microcomputer electronic circuit board. Each wheel circuit corresponds to a pipe segment in the control system. The method for online monitoring of scaling and clogging trends on the inner wall of metal pipes includes the following steps: Step S1: Install an inner probe at the flange connection of each section of metal pipe, install an outer probe on the outer wall of the metal pipe, and connect the segmented pipe conductive metal probe (3) to the patrol controller (2) through the measurement circuit wire (7). The patrol controller (2) is connected to the micro resistance measuring instrument (1). Step S2, the micro resistance measuring instrument (1) measures the resistance value of each wheel circuit through the internal controller of the wheel controller (2), and sends the measurement data to the resistance value recording and analysis data server (4) through the field network communication device (5); Step S3: The resistance value record analysis data server (4) analyzes the resistance value data and generates charts through the trend model calculation and display and alarm interface software (6). When the resistance value exceeds the set value, an early warning message is issued. In step S3, the scale thickness parameters accumulated by each metal pipe in a periodic sequence are fitted into a curve along the time axis to form a real-time trend of scale thickness change.

2. The method for online monitoring of scaling and clogging trends on the inner wall of metal pipes as described in claim 1, characterized in that: It also includes a resistance value recording and analysis data server (4), a field network communication device (5), and a trend model calculation, display and alarm interface software (6). The micro resistance meter (1) sends resistance measurement data to the resistance value recording and analysis data server (4) through the field network communication device (5). The resistance value recording and analysis data server (4) analyzes the data and generates charts through the trend model calculation, display and alarm interface software (6). When the resistance value exceeds the set value, an early warning message is issued.

3. The method for online monitoring of scaling and clogging trends on the inner wall of metal pipes as described in claim 1, characterized in that: One end of the measuring circuit wire (7) passes through the metal pipe flange, and a protective layer is provided on the outside of the measuring circuit wire (7).

4. The method for online monitoring of scaling and clogging trends on the inner wall of metal pipes as described in claim 2, characterized in that: The trend model calculation display and alarm interface software (6) includes a computer HMI interface, a mobile APP or mini program, an analysis model database, and a data transmission communication module. The trend model calculation display and alarm interface software (6) is customized to develop various display models and alarm measures according to different user and process requirements, as well as develop functions for user login, authorized operation, and historical record query.

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