KR100848623B1 - A Method and Apparatus for Collection and Analysis of the Hydrogen Element contained in Molten Metal of the Furnace - Google Patents

Abstract

According to the present invention, hydrogen generated by the charging of scrap metal during the process of refining steel and iron containing a large amount of carbon and impurities produced in a steelworks furnace has a possibility of deterioration of the toughness of the metal, brittle fracture and crack generation. High and up to now, in the domestic industry, the analysis of hydrogen content in the river is dependent on manual operation, and the device and method for analyzing the hydrogen content in real time in real time.

In order to solve the above problems, a probe for collecting hydrogen in the molten steel, a lance and a lifting drive device for depositing it in the molten steel, a nitrogen supply device for supplying nitrogen for collecting, and analyzing the hydrogen content in the bubbles in the collected molten steel Combining devices such as gas collection and composition analysis device with the function of transmitting the analysis data to other controllers, electric control device for transmitting the analysis data to the upper level, and driver's terminal that allows the operator to check the analysis data directly By developing the method of analyzing the hydrogen component, ultimately, the hydrogen component in molten steel is collected and analyzed in real time without the intervention of the operator or the separate test equipment, and used in the operation process to improve the productivity and establish various operating standards. Can be.

Description

A Method and Apparatus for Collection and Analysis of the Hydrogen Element contained in Molten Metal of the Furnace}

FIG. 1: Steelmaking Refining Operation Configuration Using Electrode in Steel Mill Related to the Present Invention

2: Flowchart of conventional hydrogen component analysis method

3 is a block diagram of the main device of the present invention

4 is a schematic diagram of a hydrogen component collecting device and method of the present invention

Figure 5: Flow chart of the hydrogen analysis work method of the present invention

6: Probe deposition step and position configuration diagram of the molten steel of the present invention

7 is a configuration diagram of sensor installation for position control device of the present invention

8: Analysis result of actual hydrogen content in steel using the present invention

According to the present invention, a probe for collecting hydrogen in molten steel, a lance and a lowering driving device for depositing it in the molten steel, a nitrogen supply device for supplying sampling nitrogen, and a hydrogen component in the bubbles in the molten steel collected are analyzed. And gas collection and composition analysis device with the function of transmitting the analysis data to other controllers, electric control device for transmitting the analysis data to the upper level, and driver's terminal that the operator can check the analysis data directly. The combination of these results in the improvement of productivity as well as the establishment of various operating standards by developing a method and a device that allows the investigator to collect and analyze the hydrogen content of molten steel in real time without the intervention of an operator or separate test equipment. The purpose is.

In the present invention, the LF (LADLE FURNACE) operation is a type of refurbishment in the molten iron pretreatment process that is operated for the purpose of removing various impurities contained in the molten iron in steel mills. Impurity removal process characterized by performing so-called submerged arc refining, which adds synthetic iron and stirs with argon (Ar) gas while maintaining a strong reducing atmosphere in the ladle. It is the refining process performed in a state. (Refer FIG. 1).

The molten steel refining method is easy to raise the temperature of molten steel, and easy composition of components such as dephosphorization and desulfurization can be combined with not only an electric furnace but also a converter which is a post process.

Hydrogen is generated in the river during this operation due to the following reasons.

In the case of secondary raw materials used in steel making, especially quicklime (CaO), water generation is inevitable during storage, and hydrogen in steel is caused by moisture in various raw materials and ferroalloys that are put into molten steel treatment to improve the cleanliness of molten steel and improve the mechanical properties of steel. The components are generated and their chemical reactions are as follows:                         

H42O (g) = 42H + O

Hydrogen generated at this time affects the quality of steel as follows.

Hydrogen has a very small atomic radius, and it is solid-solution in the form of N, C among the Fe lattice. Hydrogen has a faster diffusion rate than other factors. Such hydrogen remains in the metal structure and causes various defects such as deterioration of toughness, brittle fracture and cracking of beads under welding.

Hydrogen embrittlement is a phenomenon in which hydrogen easily penetrates the metal under high temperature and high pressure to act as carbon and become carbonic, and the metal is easily broken. The chemical reaction is as follows.

Fe3C + 42H42 = CH4 + 3Fe

In particular, if the place of use is extreme, there is a high possibility that HIC, which is a phenomenon that a crack occurs in the metal by inclusions in the steel and hydrogen, is generated. (HIC: HYDROGEN INDUCED CRACK, Hydrogen organic crack phenomenon)

Hydrogen generated by this cause is BREAK OUT during molten steel casting operation due to hydrogen content in steel. Here, break out refers to an operation interruption due to bursting of steel film when solidification is not completed during continuous casting of molten steel.

In order to analyze the hydrogen component that causes the above problems, the conventional work was carried out by the following method. The analysis procedure of the hydrogen component by the conventional method is shown in FIG.                         

First, the operator prepares a liquid nitrogen storage container for storing hydrogen specimens for the analysis of hydrogen content in steel (step ② of FIG. 2). Next, the operator directly receives a certain amount of liquid nitrogen at the liquid nitrogen storage place (step ③ of FIG. 2). At this time, when receiving liquid nitrogen and storing the container, there is a problem of frostbite due to skin contact (nitrogen temperature: -190 ° C) by direct work by an operator.

In the next work, a worker uses a conventional ladle-shaped collector to deposit it into molten steel to directly collect a sample (steel), and then stores it in a prepared sample storage container (step ④ of FIG. 2). In this process, the worker is directly exposed to high temperature and dusty places and works in a very dangerous environment.In addition, due to the function of the collector during sampling, the variation of the integrity of the specimen occurs and the emission of some hydrogen in the cooling process during the cooling of the specimen. Problems such as reduced reliability of analysis value occur.

Next, the operator requests the collected sample container to the test analysis room, and the test analysis room extracts the hydrogen content in the river through the sample analysis using the test analyzer and simultaneously notifies the operator in writing of the analysis result. Process) In this process, administrative work for requesting unnecessary specimen analysis occurs, and it is difficult to quickly respond to the operation due to excessive time required for sample analysis and final confirmation in the test and analysis room (more than 1 day), and operate the analysis data as a result. There was an issue that was difficult to apply at once.

According to the present invention, hydrogen generated by the charging of scrap metal during the high-purity steel manufacturing process, which is a process of refining a carbon steel and a large amount of impurities produced in a steelworks furnace, causes a decrease in toughness of the metal, brittle fracture, and cracks. To date, the analysis of hydrogen content in rivers in Korea has been dependent on manual work, and the method for automatic analysis of hydrogen content is devised, especially in the process of collecting, analyzing, transmitting and using hydrogen analysis process automatically and in real time. It is to provide a method and apparatus for analysis.

The present invention is to solve the above problems, the inner tube 33 is formed so that the bubbling tube 44 for supplying nitrogen gas into the molten steel and the bubble collecting tube 45 for collecting the bubbles are installed through the lance (42), a drive motor (39) for raising and lowering the lance (42), and a porosbell (47) mounted on the tip of the inner tube (33) of the lance (42) for collecting bubbles. It is characterized in that it comprises a probe 31 and the analysis device for analyzing the bubbles collected through the bubble collection tube (45).

In addition, the lance is coupled to the elevating device support 71 is raised and lowered, the elevating device support 71 is a detection sensor (72, 73, 74, 75, so that the lance 42 is raised and lowered by a predetermined depth) 76) is attached.

On the other hand, the method of collecting and analyzing the hydrogen component, the step of injecting nitrogen gas into the molten steel, the hydrogen in the molten steel is diffused into the nitrogen gas injected into the molten steel to generate a bubble mixed with nitrogen and hydrogen, and the nitrogen And a step of collecting bubbles mixed with hydrogen and analyzing the collected bubbles. The bubbles mixed with nitrogen and hydrogen are collected by a probe 31 having a poros bell attached thereto.

Hereinafter, the operation of the present invention will be described in more detail with reference to the accompanying drawings.                     

As shown in FIG. 5, in order to analyze the hydrogen component in the molten steel, the operator gives an operation start instruction for the hydrogen analysis operation using the operation screen in the driver terminal 36 (FIG. 5 ②). The operation screen has a structure that can indicate the level 1, level 2, level 3, level 4 position and the operation of lifting and lowering the lance lifting device. At this point, the operator attaches the probe to the lance in advance before starting work. The work order is transmitted to the lance elevating device 32 and the gas collecting and gas analyzing device 34 via the electric control device 35 and nitrogen is supplied from the nitrogen supply device 33 to the lance.

At this time, nitrogen is nitrogen that is commonly used in factories, and nitrogen supply has a structure that can supply, cut off and shut off by using a valve installed inside the nitrogen supply device.

At this point, the lance elevating device starts to descend and descends to a predetermined height, and is deposited in the river. ③ step). The depth of deposition of the probe in molten steel is determined according to the actual height of molten steel. For this purpose, the screen is configured to deposit by selecting 4 levels of depth in the operator's terminal equipment, and the operator selects the stage to determine the depth of deposition in the molten steel. Therefore, the lance raising and lowering device is lowered by a predetermined depth. In order to detect the lowering position, the elevating driving motor 39 and the position detecting sensor 38 are attached to the rear end of the motor.

The lance elevating device is divided into four stages from the first stage to the fourth stage, and the descending position, the depth of deposition in the molten steel, and the details of each stage are shown in FIG. 6.                     

As shown in Fig. 6, the first stage is FL + 5400MM, the second stage is FL + 5150MM, the third stage is FL + 4900MM, the fourth stage is FL + 4650MM, and the operator operates according to the actual molten steel height. It is possible to select from a personal terminal device.

In addition, the emergency lifting device is installed in the Lance lifting device so that the user cannot move up or down below a certain depth and height in case of an emergency. The operation method thereof will be described with reference to FIG. 7. First, when the elevating device reaches a predetermined position during the lowering, the lowering speed reducing sensor (limit sensor) 72 is provided on the elevating device support 71 to reduce the lowering speed. ), The lance lifting device detects this when it descends, decelerates the rotational speed of the lance drive motor, reduces the descending speed, descends by the desired depth, and the emergency sensor (73) detects this immediately when descending above the lower limit. The lance drive motor stops working.

In addition, even when the lifting device is raised, the rising speed is decreased by the detection of the rising speed detecting sensor 74, and the lifting device is stopped by the detection of the rising stop sensor 75 when the target point is reached. If an abnormality occurs and rises above the upper limit, the upper limit emergency sensor 76 is configured to stop the driving motor immediately upon detecting it.

In this case, the installation position and the operation determination point of the actual sensors for each case are shown in detail at the bottom of FIG.

A method of collecting hydrogen gas in the steel will be described in detail with reference to the accompanying drawings. First, the consumable probe is deposited to a certain depth in the molten steel and forcibly injects nitrogen gas into the molten steel through a bubbling tube 44 in an inner tube installed in the lance by a nitrogen supply device 33 which is a nitrogen injector (FIG. 5). ④ step)

Hydrogen dissolved in molten steel diffuses into the injected nitrogen bubbles, which are automatically collected by the bubble collecting device (step ⑤ in FIG. 5).

The collected intragas bubbles (nitrogen + hydrogen) are now sent to the gas collection and gas analyzer (34) through the collection tube (45, Sunction Tube), which is a passage in the lance tube, Separate nitrogen and hydrogen, and analyze the hydrogen component automatically. (⑥ step of Figure 5)

In this device, if the hydrogen partial pressure diffused and measured by the nitrogen gas in the molten steel becomes equal to the hydrogen partial pressure in the molten steel, no further injection of nitrogen gas is lost at this point, the nitrogen supply is stopped from the nitrogen supply device, and the lance lifting device Rises and the analysis of hydrogen content in the river takes place.

The analyzed hydrogen component data is transmitted to a communication system (RS42342 method) via a wired cable to the electric control device 35, which is a high level system, and the operator confirms the analysis data directly (step ⑦ of FIG. Hydrogen analysis data is automatically acquired in the driver terminal device 36, which gives an instruction to make it, and is displayed in real time on the screen (step ⑧ in FIG. 5).

When the analysis of hydrogen content in the steel is completed through the above process, the worker can use the hydrogen content data, and use it in a post process or a related process, and can perform efficient work.

In addition, the local elec- tric control device 37 with a switch is installed so that the elevating device cannot be raised or lowered due to an abnormal occurrence of the lance elevating device or can be manually operated by a switch operation for maintenance work or emergency.

The actual hydrogen component analysis result of the present invention is shown in FIG.

As shown in FIG. 8, it can be seen that the hydrogen component analysis in the steel proceeds stably as time passes. Therefore, the present invention eliminates the possibility of human injury that may occur during the storage and operation of the sample collected during the retreat of the molten steel sample depending on the manual operation of the operator, and the degradation of the analysis degree due to the working deviation between the operators, the sample analysis time and Excessive time required for final confirmation can solve problems that make it difficult to respond quickly to the operation and apply the analysis results, and the effects of stable operation of the operation equipment and ultimately do not involve the intervention of the operator or separate test equipment for the hydrogen content of molten steel. It is effective in improving productivity as well as establishing various operation standards by collecting and analyzing in real time without using it in the operation process.

Claims (5)

An inner tube 43 is formed so that a bubbling tube 44 for supplying nitrogen gas to the molten steel and a bubble collecting tube 45 for collecting bubbles are formed therethrough, and are coupled to the elevating device support 71 to raise and lower. Lance 42, A drive motor 39 configured to operate the lance 42 up and down, A probe 31 mounted to a tip of the inner tube 43 of the lance 42 and having a porosbell 47 for collecting bubbles; Hydrogen collecting analysis device in the molten steel, characterized in that consisting of an analysis device for analyzing the bubbles collected through the bubble collecting pipe (45). delete The method of claim 1, The elevating device support (71) is a hydrogen collecting analysis device, characterized in that the detection sensor (72, 73, 74, 75, 76) is attached so that the lance 42 is raised and lowered by a predetermined depth. Injecting nitrogen gas into the molten steel; Hydrogen in the molten steel is diffused into the nitrogen gas injected into the molten steel to generate bubbles in which nitrogen and hydrogen are mixed; Collecting the bubbles of nitrogen and hydrogen mixed by a probe bell attached to the probe 31; The method of collecting hydrogen gas in the molten steel, characterized in that consisting of the step of analyzing the collected bubbles. delete

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