A method and device for detecting fluidity

Abstract

The present invention relates to the field of operation and transportation, and provides a fluidization detection method and detection device. The fluidization detection method obtains the permeability coefficient value and the degassing coefficient value of the material in the conveying pipeline, and detects and obtains the minimum fluidization velocity value in the fluidization pipeline. In this way, according to the real density value of different materials, the function curve in the fluidization conveying process and the function curve of the minimum fluidization velocity value can be obtained, and then it is easy to judge the position of the permeability coefficient value and the degassing coefficient value at the two function curves, so as to determine the corresponding conveying mode for conveying, that is, the plug-shaped dense phase conveying, the moving bed dense phase conveying or the dilute phase conveying mode, which ensures the efficiency and safety of the conveying and improves the practicality.

Description

Technical Field

[0001] The invention relates to the field of operation and transportation, and in particular to a fluidization detection method and a detection device. Background Art

[0002] Pneumatic conveying, also known as air flow conveying, uses the energy of air flow to convey granular materials in the direction of air flow in a closed pipe. It is a specific application of fluidization technology. The pneumatic conveying device has a simple structure and is easy to operate. It can be used for horizontal, vertical or inclined conveying. During the conveying process, it can also perform physical operations such as heating, cooling, drying and air flow classification of materials or certain chemical operations.

[0003] The pneumatic conveying device has a simple structure and is easy to operate. It can be used for horizontal, vertical or inclined conveying. This technology is widely used in coal-fired power plants and steel mills. Its reliability, economy, environmental protection and other advantages make this technology gradually become a general technology. Because the composition of coal-fired power plants and steel mills is relatively stable, the projects have a strong correlation and reference to each other. At present, the pneumatic conveying mode is mainly divided into dense phase conveying and dilute phase conveying. Dense phase conveying is divided into plug-shaped dense phase conveying and moving bed dense phase conveying.

[0004] When there is no reference for materials with unknown composition, it is necessary to conduct necessary analysis on the material properties and analyze the interaction between the material and the compressed gas to determine the pneumatic conveying method. Therefore, it is necessary to determine the degree of combination between the material and the compressed gas to determine which method to use for conveying. Different conveying methods can improve the working efficiency and protect the equipment. However, the existing equipment lacks pre-use detection, so there are certain safety risks for the transportation of materials with unknown composition, as well as unknown working efficiency, which leads to the problem of blind work. Summary of the invention

[0005] The purpose of the present invention is to provide a method for detecting fluidity, aiming to improve the problem that the existing pneumatic conveying equipment lacks guarantee for conveying efficiency and safety when switching to convey different materials.

[0006] To achieve the above object, the present invention adopts the following technical solution: A method for detecting fluidity, comprising the following steps:

[0007] In a closed fluidized pipe, the material to be tested is transported by air flow;

[0008] Obtain the material conveying speed and the pressure drop per unit height to obtain the material permeability coefficient value P f ;

[0009] Gradually increase the flow rate in the fluidized pipeline, and the pressure drop value per unit height will gradually increase until the volume flow value of the fluidized gas in the fluidized pipeline does not increase, and the minimum fluidization velocity value U in the fluidized pipeline is obtained. mf ;

[0010] After the fluidization pipeline is completely fluidized, the fluidization gas is turned off, and the degassing coefficient value A of the material is obtained based on the ratio of the degree of pressure difference drop to the degree of height difference change per unit time. f ;

[0011] Obtain the real density value of the material and the fluidized pipeline, obtain the function curve X1 of degassing and real density, and artificially set the comparison value of the function curve X1; and artificially set U mf Under the judgment value of mf Function curve X2 of value;

[0012] If the permeability coefficient is above the curve position of X2, and the ratio of the degassing coefficient value to the true density value is below the comparison value point of the X1 curve, the material is transported in plug-like dense phase or dilute phase;

[0013] If the permeability coefficient is below the curve position of X2, and the ratio of the degassing coefficient value to the true density value is above the comparison value point of the X1 curve, the material is transported in a moving bed dense phase or dilute phase;

[0014] If the permeability coefficient is below the curve position of X2, and the ratio of the degassing coefficient value to the true density value is below the comparison value point of the X1 curve, the material is conveyed in dilute phase.

[0015] Preferably, the air permeability coefficient value P f The detection steps are as follows:

[0016] Obtain the height change value of the material bed during the fluidization process to obtain the height difference ΔL, and obtain the volume flow value Q of the fluidizing gas according to the flow meter;

[0017] , V is the superficial velocity, S is the cross-sectional area of ​​the fluidized pipe;

[0018] , is the pressure difference, P d is the pressure drop value;

[0019] .

[0020] Preferably, the degassing coefficient value A f The calculation formula is:

[0021] , t is the time.

[0022] Preferably, the minimum fluidization velocity value It is 48mm / s~52mm / s.

[0023] Preferably, the comparison value is 0.0008 to 0.0013 m 3 ·s / kg.

[0024] The present invention also provides a fluidization detection device, which aims to improve the problem that the existing pneumatic conveying equipment lacks guarantee for conveying efficiency and safety when switching to convey different materials.

[0025] To achieve the above object, the present invention adopts the following technical solution: a fluidity detection device, used to perform the above fluidity detection method, comprising:

[0026] A fluidizing mechanism, on which a plurality of detection pipelines for detecting pressure differences are arranged at intervals, and a differential pressure device connected to the plurality of detection pipelines for detecting pressure differences;

[0027] An air source pipe, the air outlet end of which is connected to the air inlet of the fluidizing mechanism, and a flow meter is arranged on the air source pipe;

[0028] The controller is electrically connected to the flow meter and is arranged on the input end of the controller.

[0029] Preferably, the fluidizing mechanism comprises a fluidizing pipe, a fluidizer, and an air chamber connected to the inlet of the fluidizing pipe and the fluidizer, and the air outlet end of the air source pipe is connected to the air inlet end of the fluidizer.

[0030] Preferably, the plurality of detection pipelines are arranged at equal intervals along the height of the fluidizing tube, a first valve is provided on the detection pipeline, and a second valve is provided on the detection pipeline on the air chamber.

[0031] Preferably, the fluidizing tube is provided with a height scale and a dust exhaust fan, and the dust exhaust fan is arranged at the top of the fluidizing tube;

[0032] The fluidization mechanism is provided with a camera for acquiring video or image of the fluidization tube, and the camera is electrically connected to the controller.

[0033] Preferably, a flow regulating valve and a pressure device are provided on the gas source pipe, and the pressure device is electrically connected to the controller.

[0034] After adopting the above technical solution, the present invention has the following advantages compared with the background technology:

[0035] 1. By obtaining the permeability coefficient value and degassing coefficient value of the material in the conveying pipeline, and detecting the minimum fluidization velocity value in the fluidized pipeline, the function curve in the fluidized conveying process and the function curve of the minimum fluidization velocity value can be obtained according to the actual density value of different materials, and then it is easy to judge the position of the permeability coefficient value and the degassing coefficient value in the two function curves, so as to determine the corresponding conveying method for conveying, which ensures the efficiency and safety of conveying and improves practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a flowchart of the method for detecting fluidity of the present invention;

[0037] Figure 2 It is a schematic diagram of the fluidization detection device described in the present invention.

[0038] Description of reference numerals:

[0039] 10. Fluidizing mechanism; 101. Detection pipeline; 102. Differential pressure device; 103. Fluidizing tube; 104. Fluidizer; 105. Air chamber; 106. Camera;

[0040] 1011, first valve; 1031, height scale; 1032, dust exhaust fan; 1051, second valve;

[0041] 20, gas source pipe; 201, flow meter; 202, flow regulating valve; 203, pressure device;

[0042] 30. Controller. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0044] In addition, it should be noted that the terms "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element of the present invention must have a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0045] When an element is referred to as being “fixed to” or “disposed on” or “provided on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0046] Unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0047] Embodiment 1

[0048] Please refer to Figure 1 As shown, this embodiment provides a method for detecting fluidity, comprising the following steps:

[0049] S101. In a closed fluidized pipe, use airflow to transport the material to be tested.

[0050] Specifically, pneumatic conveying, also known as air flow conveying, utilizes the energy of air flow to convey granular materials in the air flow direction in a closed pipe. It can be conveyed in a horizontal, vertical or inclined direction (vertical conveying is used as an example for illustration in this embodiment). During the conveying process, physical operations such as heating, cooling, drying and air flow classification of materials or certain chemical operations can also be performed simultaneously. At present, pneumatic conveying modes are mainly divided into dense phase conveying and dilute phase conveying. Dense phase conveying is divided into plug-shaped dense phase conveying and moving bed dense phase conveying.

[0051] S102, obtaining the speed of conveying materials and the pressure drop per unit height, and obtaining the permeability coefficient value P of the material f .

[0052] Specifically, the air permeability coefficient value is used to evaluate the air permeability of the material, so as to determine which conveying method is suitable based on the actual density of the material.

[0053] The air permeability coefficient value P in this embodiment is f The detection steps are as follows: obtain the height change value of the material bed during the fluidization process to obtain the height difference ΔL, and obtain the volume flow value Q of the fluidizing gas according to the flow meter;

[0054] , V is the superficial velocity, S is the cross-sectional area of ​​the fluidized pipe;

[0055] , is the pressure difference, P d is the pressure drop value;

[0056] .

[0057] According to the above calculation formula, the required air permeability coefficient value P can be calculated.f The height difference ΔL can be calculated based on the scale, and the height difference can be obtained by the scale on the vertical fluidizing pipe. The cross-sectional area of ​​the fluidizing pipe is the pipe measurement value or standard value (the product specification standard value), which is a known value. In this way, the permeability coefficient value P can be accurately calculated. f .

[0058] S103, gradually increase the flow rate in the fluidized pipeline, the pressure drop value at a unit height will gradually increase, until the volume flow value of the fluidized gas in the fluidized pipeline does not increase, and obtain the minimum fluidization velocity value U in the fluidized pipeline mf .

[0059] Specifically, because the cross-sectional area of ​​the pipeline is a fixed value, the pressure drop per unit height will gradually increase as the volume flow value Q gradually increases through the flow control valve, that is, Q and P d As a result, due to the limitation of the pipeline, when Q increases, P d If it does not increase, then Formula, calculate the minimum fluidization velocity U mf (i.e. the minimum value of V), the specific minimum fluidization velocity value U mf It is 48mm / s~52mm / s.

[0060] S104. After the fluidization pipeline is completely fluidized, the fluidization gas is turned off, and the degassing coefficient value A of the material is obtained based on the ratio of the degree of pressure difference decrease to the degree of height difference change in unit time. f .

[0061] Specifically, the degassing coefficient value is the ability of the material to retain air after inflation. Therefore, it is necessary to determine the value of the pressure drop per unit time under the condition of complete fluidization, and then obtain the degassing coefficient value A of the material. f .

[0062] In this embodiment, the degassing coefficient value A f The calculation formula is:

[0063] , t is the time.

[0064] S105, obtaining the real density value of the material and the fluidized pipeline, obtaining the function curve X1 of the degassing property and the real density, and manually setting the comparison value of the function curve X1; and manually setting U mf Under the judgment value of mf Function curve X2 of the value.

[0065] The actual density of a specific material can be directly obtained by measurement, thus obtaining the corresponding function curve of degassing and actual density, and the comparison value is 0.0008~0.0013m 3 ·s / kg, preferably, the comparison value can be ; The judgment value can be 50mm / s, and then the calculated air permeability coefficient value P f and degassing coefficient value A f Make a comparison.

[0066] S106. If the permeability coefficient is above the curve position of X2, and the ratio of the degassing coefficient value to the true density value is below the comparison value point of the X1 curve, the material is transported in plug-like dense phase or dilute phase; if the permeability coefficient is below the curve position of X2, and the ratio of the degassing coefficient value to the true density value is above the comparison value point of the X1 curve, the material is transported in moving bed dense phase or dilute phase; if the permeability coefficient is below the curve position of X2, and the ratio of the degassing coefficient value to the true density value is below the comparison value point of the X1 curve, the material is transported in dilute phase.

[0067] Specifically, based on the above judgment, the method of transporting the material can be known to ensure the efficiency and safety of the transport and improve the practicality.

[0068] Embodiment 2

[0069] like Figure 2 As shown, the present embodiment provides a fluidization detection device for executing the fluidization detection method described in the first embodiment, including a fluidization mechanism 10, an air source pipe 20 and a controller 30. The fluidization mechanism 10 is provided with a plurality of detection pipelines 101 for detecting pressure differences at intervals, and a differential pressure device 102 connected to the plurality of detection pipelines 101 for detecting pressure differences; the air outlet end of the air source pipe 20 is connected to the air inlet of the fluidization mechanism 10, and a flow meter 201 is provided on the air source pipe 20; the differential pressure device 102 is electrically connected to the flow meter 201 and is provided on the input end of the controller 30. The controller 30 may be a single-chip microcomputer, MCU or PLC, such as a 51 single-chip microcomputer, Siemens S7-200, S7-300, S7-1200 and other series of PLCs, and the like.

[0070] Specifically, the fluidization mechanism 10 is designed as a vertical structure, and the detection pipeline 101 is installed at intervals along the height direction. The pressure drop value at a unit height is obtained through the differential pressure device 102, and the flow meter 201 can obtain the flow value on the gas source pipe 20. The controller 30 can obtain the corresponding permeability coefficient value and degassing coefficient value based on the corresponding information, and use the pipeline cross-sectional area as a fixed value. Therefore, when the volume flow value Q gradually increases the flow through the flow control valve 202, the pressure drop per unit height will gradually increase, that is, Q is positively correlated. In this way, due to the limitation of the pipeline, when Q does not increase during the increase process, the minimum fluidization velocity (that is, the minimum value of V) is calculated by the formula.

[0071] In this embodiment, the fluidization mechanism 10 includes a fluidization pipe 103, a fluidizer 104, and an air chamber 105 connected to the inlet of the fluidization pipe 103 and the fluidizer 104. The outlet end of the gas source pipe 20 is connected to the inlet end of the fluidizer 104. Specifically, the fluidization pipe 103 fluidizes the material in the pipeline by introducing corresponding gas for transportation. The fluidizer 104 is a flow-aiding element in the process of discharging powder materials out of the bin. It is installed at the bottom of the hopper to introduce air through the porous plate to fluidize the powder, increase its fluidity, prevent bridging, and enable the material to be discharged smoothly.

[0072] Furthermore, in this embodiment, a plurality of detection pipelines 101 are arranged at equal intervals along the height of the fluidizing tube 103, a first valve 1011 is arranged on the detection pipeline 101, and a second valve 1051 is arranged on the detection pipeline 101 on the air chamber 105. Specifically, the detection pipeline 101 is designed at equal intervals to facilitate the calculation of the pressure drop. At the same time, the design of the first valve 1011 and the second valve 1051 can form a detection pipeline 101 of a corresponding height for detection, that is, the pressure difference at the corresponding position is obtained through the differential pressure device 102.

[0073] In this embodiment, a height scale 1031 and a dust exhaust fan 1032 are provided on the fluidizing tube 103 (the fluidizing tube 103 can be a transparent tube, such as a glass or transparent plastic tube), and the dust exhaust fan 1032 is arranged on the top of the fluidizing tube 103; the fluidizing mechanism 10 is provided with a camera 106 for obtaining video or images of the fluidizing tube 103, and the camera 106 is electrically connected to the controller 30.

[0074] Specifically, the height of the material in the fluidizing tube 103 can be obtained in real time through the camera 106, and the corresponding height difference can be read through the value on the height scale 1031, so that the controller 30 can obtain the corresponding height difference. The dust exhaust fan 1032 can remove the dust in the pipe, for example, when changing materials or cleaning, the dust exhaust fan 1032 can be used to remove dust.

[0075] In this embodiment, the gas source pipe 20 is provided with a flow regulating valve 202 and a pressure device 203, and the flow device 201 and the pressure device 203 are electrically connected to the controller 30. Through the pressure device 203, the corresponding pressure value of the gas flow delivered by the gas source pipe 20 can be fed back to the controller 30; and through the flow device 201, the corresponding flow value of the gas flow delivered by the gas source pipe 20 can be fed back to the controller 30. The flow regulating valve 202 can adjust the delivery of the gas flow of the gas source pipe 20 to improve practicality.

[0076] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for detecting fluidity, characterized in that: The following steps are involved: In a closed fluidized pipe, the material to be tested is transported by air flow; Obtain the material conveying speed and the pressure drop per unit height to obtain the material permeability coefficient value P f ; Gradually increase the flow rate in the fluidized pipeline, and the pressure drop value per unit height will gradually increase until the volume flow value of the fluidized gas in the fluidized pipeline does not increase, and the minimum fluidization velocity value U in the fluidized pipeline is obtained. mf ; After the fluidization pipeline is completely fluidized, the fluidization gas is turned off, and the degassing coefficient value A of the material is obtained based on the ratio of the degree of pressure difference drop to the degree of height difference change per unit time. f ; Obtain the real density value of the material and the fluidized pipeline, obtain the function curve X1 of degassing and real density, and artificially set the comparison value of the function curve X1; and artificially set U mf Under the judgment value of mf Function curve X2 of value; If the permeability coefficient is above the curve position of X2, and the ratio of the degassing coefficient value to the true density value is below the comparison value point of the X1 curve, the material is transported in plug-like dense phase or dilute phase; If the permeability coefficient is below the curve position of X2, and the ratio of the degassing coefficient value to the true density value is above the comparison value point of the X1 curve, the material is transported in a moving bed dense phase or dilute phase; If the permeability coefficient is below the curve position of X2, and the ratio of the degassing coefficient value to the true density value is below the comparison value point of the X1 curve, the material is conveyed in dilute phase; The air permeability coefficient value P f The detection steps are as follows: Obtain the height change value of the material bed during the fluidization process to obtain the height difference ΔL, and obtain the volume flow value Q of the fluidizing gas according to the flow meter; , V is the superficial velocity, S is the cross-sectional area of ​​the fluidized pipe; , is the pressure difference, P d is the pressure drop value; 。 2. The method for detecting fluidity according to claim 1, characterized in that: The degassing coefficient value A f The calculation formula is: , t is the time.

3. The method for detecting fluidity according to claim 1, characterized in that: The minimum fluidization velocity value U mf It is 48mm / s~52mm / s.

4. The method for detecting fluidity according to claim 1, characterized in that: The comparison value is 0.0008 to 0.0013 m 3 ·s / kg.

5. A fluidity detection device, characterized in that: A method for detecting fluidity according to any one of claims 1 to 4, comprising: A fluidizing mechanism, on which a plurality of detection pipelines for detecting pressure differences are arranged at intervals, and a differential pressure device connected to the plurality of detection pipelines for detecting pressure differences; An air source pipe, the air outlet end of which is connected to the air inlet of the fluidizing mechanism, and a flow meter is arranged on the air source pipe; and a controller, wherein the differential pressure device is electrically connected to the flow meter and is arranged on the input end of the controller.

6. The fluidization detection device according to claim 5, characterized in that: The fluidizing mechanism comprises a fluidizing pipe, a fluidizer, and an air chamber connected to the inlet of the fluidizing pipe and the fluidizer. The air outlet end of the air source pipe is connected to the air inlet end of the fluidizer.

7. The fluidization detection device according to claim 6, characterized in that: The plurality of detection pipelines are arranged at equal intervals along the height of the fluidizing tube, a first valve is arranged on the detection pipeline, and a second valve is arranged on the detection pipeline on the air chamber.

8. The fluidization detection device according to claim 6, characterized in that: The fluidizing tube is provided with a height scale and a dust exhaust fan, and the dust exhaust fan is arranged on the top of the fluidizing tube; The fluidization mechanism is provided with a camera for acquiring video or image of the fluidization tube, and the camera is electrically connected to the controller.

9. The fluidization detection device according to claim 5, characterized in that: The gas source pipe is provided with a flow regulating valve and a pressure device, and the pressure device is electrically connected to the controller.

Images