Orifice flowmeter for oxygen lance flow of electric furnace

Abstract

The utility model discloses a kind of orifice flowmeter applied to the hole plate flowmeter of electric furnace oxygen lance flow, it is related to flow class instrument measurement technical field. Including pipeline, first flange, second flange and orifice, two first pressure tapping holes that are communicated with pipeline are set on first flange, two first pressure tapping holes are respectively connected with first pressure tapping pipe, second pressure tapping pipe, two second pressure tapping holes that are communicated with pipeline are set on second flange, two second pressure tapping holes are respectively connected with third pressure tapping pipe, fourth pressure tapping pipe, first pressure tapping pipe and third pressure tapping pipe are communicated with the large range differential pressure transmitter of the range of 0kPa~100kPa by three valve groups, second pressure tapping pipe and fourth pressure tapping pipe are communicated with the small range differential pressure transmitter of the range of 0kPa~1kPa by three valve groups. The utility model can use large range differential pressure transmitter to accurately measure the specific differential pressure value when high flow value, simultaneously, small range differential pressure transmitter can also be used to accurately measure the specific differential pressure value when low flow value.

Description

Technical Field

[0001] This utility model relates to the field of flow measurement technology, specifically an orifice plate flow meter used for oxygen lance flow in electric furnaces. Background Technology

[0002] A standard orifice plate flow meter is a differential pressure throttling device used to measure the flow rate of fluids in pipelines. It is widely used in various industries such as petroleum, chemical, metallurgy, and power. When fluid filling a pipeline flows through an orifice plate, a local contraction occurs at the throttling point of the orifice plate, leading to an increase in flow velocity and a decrease in static pressure, thus creating a pressure difference before and after the orifice plate. According to the law of conservation of energy and the principle of flow continuity, there is a certain mathematical relationship between the fluid flow rate and the pressure difference. By measuring this pressure difference, the fluid flow rate can be calculated.

[0003] Currently, the main oxygen process requirements for electric arc furnace equipment in electric arc furnace plants are unique. Specifically, during normal production, a cluster oxygen lance inserted into the molten steel is used for high-power oxygen injection. At this time, the oxygen flow rate in the pipeline is very fast, and the maximum oxygen flow rate in the pipeline can reach (3200~3500) Nm³. 3 / h, a large pressure difference is generated before and after the orifice plate (when the maximum oxygen flow rate reaches 3500 Nm). 3 At a rate of / h, the pressure difference can reach approximately 19 kPa; when the electric furnace taps steel, the oxygen injection power of the oxygen lance needs to be reduced to ensure that oxygen is injected into the lance and that the lance nozzle is not blocked by molten steel. At this time, the oxygen flow rate in the pipeline will slow down, and the minimum oxygen flow rate in the pipeline will be reduced to 200 Nm³. 3 / h (corresponding to a differential pressure of approximately 60Pa), a small differential pressure is generated before and after the orifice plate. Therefore, during the switching between normal production and steel tapping processes, the calculated differential pressure before and after the orifice plate changes significantly. The optimal measurement range of the differential pressure transmitter is usually set within 1 / 3 to 2 / 3 of its range. At the same time, there is currently no single model differential pressure transmitter on the market that can guarantee both a differential pressure measurement accuracy of 60Pa and a precise measurement of the specific differential pressure value at 19kPa. Utility Model Content

[0004] The purpose of this invention is to provide an orifice plate flow meter for use in the oxygen lance of an electric furnace, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: an orifice plate flow meter for use in electric furnace oxygen lance flow measurement, comprising a pipe, a first flange, a second flange, and an orifice plate. The orifice plate is installed between the first flange and the second flange, and the orifice plate is sealed to both the first flange and the second flange. Pipes are fixedly connected to the other side of both the first flange and the second flange, and the pipes on both sides are connected through the first flange, the orifice plate, and the second flange. Two first pressure taps are provided on the first flange, communicating with the pipes. The two first pressure taps are respectively connected to a first pressure tap pipe and a second pressure tap pipe. The second flange... The device has two second pressure taps connected to a pipeline, and the two second pressure taps are respectively connected to a third pressure tap and a fourth pressure tap. A needle valve is installed on the first and third pressure taps, and the first and third pressure taps are connected to a large-range differential pressure transmitter via a three-valve assembly. The range of the large-range differential pressure transmitter is 0 kPa to 100 kPa. A needle valve is also installed on the second and fourth pressure taps, and the second and fourth pressure taps are connected to a small-range differential pressure transmitter via a three-valve assembly. The range of the small-range differential pressure transmitter is 0 kPa to 1 kPa.

[0006] Based on the above technical features, this utility model provides two first pressure taps on the first flange, which are connected to a large-range differential pressure transmitter via a first pressure tap and a third pressure tap. Two second pressure taps are provided on the second flange, which are connected to a small-range differential pressure transmitter via a second pressure tap and a fourth pressure tap. The large-range differential pressure transmitter has a range of 0 kPa to 100 kPa and can accurately measure the specific differential pressure value at high flow rates. The small-range differential pressure transmitter can accurately measure the specific differential pressure value at low flow rates (therefore, this utility model can be used to measure flow rates in the differential pressure range of 60 Pa to 20 kPa), thus adapting to the precise measurement of molten steel flow during normal production and the switching of the tapping process in electric arc furnace plants.

[0007] Preferably, this technical solution further includes a control system, which is electrically connected to both a large-range differential pressure transmitter and a small-range differential pressure transmitter. When the received differential pressure value from the small-range differential pressure transmitter reaches the range of 700 Pa to 800 Pa, the control system can automatically switch to the large-range differential pressure transmitter for differential pressure measurement; or, when the received differential pressure value from the large-range differential pressure transmitter reaches the range of 700 Pa to 800 Pa, the control system can automatically switch to the small-range differential pressure transmitter for differential pressure measurement. More preferably, the control system is a PLC control system.

[0008] Based on the above technical features, the PLC control system uses a high-range differential pressure transmitter and a low-range differential pressure transmitter to quickly switch according to the actual measured differential pressure value, so as to ensure the measurement accuracy of fluid flow rate. At the same time, the PLC control system adopts a modular design, which has high reliability and stability, and can ensure stable and continuous operation in the harsh environment of molten steel production in electric furnace plants.

[0009] In this technical solution, preferably, the orifice plate, the first flange, and the second flange are all made of stainless steel.

[0010] Preferably, in this technical solution, the first flange or the second flange may have a flow direction indicator indicating the flow direction of the fluid in the pipeline.

[0011] Preferably, this technical solution also includes connecting screws, and the three valve groups are all connected to a large-range differential pressure transmitter or a small-range differential pressure transmitter using connecting screws.

[0012] Preferably, in this technical solution, the positions of the two first pressure taps and the two second pressure taps are symmetrical about the orifice plate. More preferably, the first and third pressure taps have the same structure and diameter, and the second and fourth pressure taps have the same structure and diameter. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the orifice plate flowmeter in an embodiment of this utility model;

[0014] Figure 2 This is a schematic diagram of the integrated perforated plate device in an embodiment of this utility model;

[0015] Figure 3 This is a schematic diagram of the differential pressure transmitter in an embodiment of the present invention;

[0016] Figure 4 This is a schematic diagram of the needle valve in an embodiment of the present invention;

[0017] Figure 5 This is a schematic diagram of the three-valve assembly in an embodiment of the present invention.

[0018] In the diagram: 1. First flange; 2. Second flange; 3. Orifice plate; 4. First pressure tap; 5. Second pressure tap; 6. Third pressure tap; 7. Fourth pressure tap; 8. Needle valve; 9. Three-valve manifold; 10. Small-range differential pressure transmitter; 11. Large-range differential pressure transmitter; 12. Flow direction indicator; 13. Connecting screws. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] It should be noted that in the description of this utility model, the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0021] Furthermore, it should be understood that, for ease of description, the dimensions of the various components shown in the accompanying drawings are not drawn to actual scale; for example, the thickness or width of some layers may be exaggerated relative to other layers.

[0022] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined or described in one figure, it will not need to be discussed or described in detail in the description of the subsequent figures.

[0023] Before understanding this utility model, it is important to understand that the measurement principle of a standard orifice plate flowmeter is based on the law of conservation of energy and the principle of flow continuity (law of conservation of mass). When fluid filling a pipe flows through an orifice plate, a local contraction occurs at the throttling element of the orifice plate, leading to an increase in flow velocity and a decrease in static pressure. This creates a pressure difference across the orifice plate. Since flow rate is proportional to the square root of the pressure difference, the flow rate is calculated using this measured pressure difference. The optimal measured differential pressure for commercially available differential pressure transmitters is set within 1 / 3 to 2 / 3 of their range. Within this range, the error in the measured differential pressure is minimized, and the sensitivity and stability are optimal. Specifically, the most common differential pressure transmitters on the market are divided into three categories: micro differential pressure transmitters (i.e., small-range differential pressure transmitters, with a range of 0 kPa to 1 kPa), medium-range differential pressure transmitters (with a range of 0 kPa to 10 kPa), and large-range differential pressure transmitters (with a range of 0 kPa to 100 kPa). Among them, micro differential pressure transmitters, because their measurement range is less than 1 kPa, are more sensitive to the selection of the measurement range and should be controlled as close as possible to 1 / 3 to 2 / 3 of the range; otherwise, their accuracy is easily affected by environmental interference. In the electric furnace equipment mentioned in the background technology, the pressure difference in the pipeline during production can reach approximately 19 kPa, and during the tapping process, the fluid pressure difference in the pipeline can reach approximately 60 Pa. Therefore, using only a micro differential pressure transmitter or a medium-range differential pressure transmitter cannot meet the normal measurement needs of electric furnace equipment during the production process. While using only a large-range differential pressure transmitter can meet the normal measurement needs of electric furnace equipment during the production process, the fluid pressure difference in the pipeline can reach about 60Pa when measuring the electric furnace equipment during the steel tapping process, making it impossible to accurately measure it.

[0024] like Figures 1 to 5 As shown, this utility model provides a technical solution: an orifice plate flow meter for oxygen lance flow in electric furnaces, wherein the orifice plate flow meter includes a pipe, a first flange 1, a second flange 2 and an orifice plate 3, the orifice plate 3 is installed between the first flange 1 and the second flange 2, the orifice plate 3 is sealed with the first flange 1 and the second flange 2, the first flange 1 and the second flange 2 are fixedly connected to the pipe on the other side of the orifice plate 3, and the pipes on both sides are connected through the first flange 1, the orifice plate 3 and the second flange 2.

[0025] like Figures 1-2 As shown, the first flange 1 has two first pressure taps connected to the pipeline, and the two first pressure taps are respectively connected to the first pressure tap 4 and the second pressure tap 5. The second flange 2 has two second pressure taps connected to the pipeline, and the two second pressure taps are respectively connected to the third pressure tap 6 and the fourth pressure tap 7.

[0026] Furthermore, needle valves 8 are respectively installed on the first pressure tap 4 and the third pressure tap 6. The first pressure tap 4 and the third pressure tap 6 are connected to a large-range differential pressure transmitter 11 via a three-valve assembly 9. The range of the large-range differential pressure transmitter 11 is 0 kPa to 100 kPa. Needle valves 8 are respectively installed on the second pressure tap 5 and the fourth pressure tap 7. The second pressure tap 5 and the fourth pressure tap 7 are connected to a small-range differential pressure transmitter 10 via a three-valve assembly 9. The range of the small-range differential pressure transmitter 10 is 0 kPa to 1 kPa.

[0027] In the orifice plate flowmeter of this invention, a small-range differential pressure transmitter 10 and a large-range differential pressure transmitter 11 are mounted on the same integrated orifice plate device. Specifically, in practical applications, the small-range differential pressure transmitter 10 can be used to measure flow rates with a differential pressure range of 0 Pa to 800 Pa, making it suitable for measurement in electric furnace equipment during the steel tapping process. The large-range differential pressure transmitter 11 can be used to measure flow rates with a differential pressure range of 700 Pa to 20 kPa, making it suitable for measuring fluid flow rates in electric furnace equipment during the production process. Therefore, the orifice plate flowmeter of this invention can meet the measurement accuracy requirements of a large range of differential pressure changes before and after the orifice plate 3. The large-range differential pressure transmitter 11 can be used to accurately measure the specific differential pressure value at high flow rates, while the small-range differential pressure transmitter 10 can be used to accurately measure the specific differential pressure value at low flow rates.

[0028] In this invention, the orifice plate flowmeter is also equipped with a control system. The control system is electrically connected to a large-range differential pressure transmitter 11 and a small-range differential pressure transmitter 10. When the differential pressure value received from the small-range differential pressure transmitter 10 reaches the range of 700Pa to 800Pa, the control system can automatically switch to the large-range differential pressure transmitter 11 for differential pressure measurement; or, when the differential pressure value received from the large-range differential pressure transmitter 11 reaches the range of 700Pa to 800Pa, the control system can automatically switch to the small-range differential pressure transmitter 10 for differential pressure measurement.

[0029] Preferably, the control system can be a PLC control system, which quickly switches between the high-range and low-range differential pressure transmitters based on the actual measured differential pressure value. Specifically, in a practical application embodiment of this invention, when the received differential pressure value from the low-range differential pressure transmitter 10 is greater than 747 Pa, the PLC control system can automatically switch to the high-range differential pressure transmitter 11 for differential pressure measurement; or, when the received differential pressure value from the high-range differential pressure transmitter 11 is lower than 747 Pa, the PLC control system can automatically switch to the low-range differential pressure transmitter 10 for differential pressure measurement. Therefore, the low-range differential pressure transmitter 10 can be dedicated to measuring flow rates with a differential pressure range of 0 Pa to 747 Pa, and the high-range differential pressure transmitter 11 can be dedicated to measuring flow rates with a differential pressure range of 747 Pa to 20 kPa.

[0030] The aforementioned PLC control system can also automatically convert the differential pressure value measured by the differential pressure transmitter into a fluid flow rate value.

[0031] In the orifice plate flowmeter of this utility model, the orifice plate 3, the first flange 1, and the second flange 2 are all made of stainless steel. In other embodiments, for different fluids, the integrated orifice plate device composed of the orifice plate 3, the first flange 1, and the second flange 2 can be made of other materials, but no specific examples are given here. To facilitate the differentiation of fluid flow direction, the first flange 1 or the second flange 2 can be marked with a flow direction indicator 12. To facilitate the maintenance and replacement of the large-range differential pressure transmitter 11 or the small-range differential pressure transmitter 10, the three-valve group 9 is connected to the large-range differential pressure transmitter 11 or the small-range differential pressure transmitter 10 using connecting screws 13.

[0032] The first and second pressure taps can be formed by drilling. In order to ensure accurate measurement and stable pressure tapping, the positions of the two first pressure taps and the two second pressure taps are symmetrical about the orifice plate 3. The first pressure tap 4 and the third pressure tap 6 have the same structure and the same diameter. The second pressure tap 5 and the fourth pressure tap 7 have the same structure and the same diameter.

[0033] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An orifice plate flow meter for use in electric furnace oxygen lance flow measurement, comprising a pipe, a first flange (1), a second flange (2), and an orifice plate (3), wherein the orifice plate (3) is installed between the first flange (1) and the second flange (2), and the orifice plate (3) is sealed to the first flange (1) and the second flange (2), wherein the first flange (1) and the second flange (2) are both fixedly connected to pipes on the opposite side of the orifice plate (3), and the pipes on both sides are connected through the first flange (1), the orifice plate (3), and the second flange (2), characterized in that, The first flange (1) has two first pressure taps connected to the pipeline, and the two first pressure taps are respectively connected to the first pressure tap (4) and the second pressure tap (5). The second flange (2) has two second pressure taps connected to the pipeline, and the two second pressure taps are respectively connected to the third pressure tap (6) and the fourth pressure tap (7). Needle valves (8) are respectively provided on the first pressure tapping tube (4) and the third pressure tapping tube (6). The first pressure tapping tube (4) and the third pressure tapping tube (6) are connected to a large-range differential pressure transmitter (11) through a three-valve group (9). The range of the large-range differential pressure transmitter (11) is 0 kPa to 100 kPa. Needle valves (8) are respectively provided on the second pressure tapping tube (5) and the fourth pressure tapping tube (7). The second pressure tapping tube (5) and the fourth pressure tapping tube (7) are connected to the small range differential pressure transmitter (10) through a three-valve group (9). The range of the small range differential pressure transmitter (10) is 0 kPa to 1 kPa.

2. The orifice plate flowmeter according to claim 1, characterized in that, It also includes a control system, which is electrically connected to the large-range differential pressure transmitter (11) and the small-range differential pressure transmitter (10) respectively. When the differential pressure value received from the small-range differential pressure transmitter (10) reaches the range of 700Pa to 800Pa, the control system can automatically switch to the large-range differential pressure transmitter (11) for differential pressure measurement; or, when the differential pressure value received from the large-range differential pressure transmitter (11) reaches the range of 700Pa to 800Pa, the control system can automatically switch to the small-range differential pressure transmitter (10) for differential pressure measurement.

3. The orifice plate flowmeter according to claim 2, characterized in that, The control system is a PLC control system.

4. The orifice plate flowmeter according to claim 1, characterized in that, The orifice plate (3), the first flange (1), and the second flange (2) are all made of stainless steel.

5. The orifice plate flowmeter according to claim 1, characterized in that, The first flange (1) or the second flange (2) may have a flow direction indicator (12) indicating the flow direction of the fluid in the pipeline.

6. The orifice plate flowmeter according to claim 1, characterized in that, It also includes connecting screws (13), and the three valve groups (9) are all connected to the large range differential pressure transmitter (11) or the small range differential pressure transmitter (10) by connecting screws (13).

7. The orifice plate flowmeter according to claim 1, characterized in that, The positions of the two first pressure taps and the positions of the two second pressure taps are symmetrical about the orifice plate (3).

8. The orifice plate flowmeter according to claim 7, characterized in that, The first pressure tapping tube (4) and the third pressure tapping tube (6) have the same structure and the same diameter, and the second pressure tapping tube (5) and the fourth pressure tapping tube (7) have the same structure and the same diameter.

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