Flow measuring device

Abstract

This application discloses a flow measurement device, including a material conveying pipe, a detection cell, and a spectral acquisition probe. The first end of the material conveying pipe is connected to a material conveying pipeline. The inlet and outlet ends of the detection cell are connected to the sidewalls of the material conveying pipe via a feed pipe assembly and a discharge pipe assembly, respectively. The feed pipe assembly receives material from the material conveying pipeline and conveys it to the detection cell. The discharge pipe assembly discharges the material from the detection cell back into the material conveying pipe. The feed pipe assembly and discharge pipe assembly are arranged near the first and second ends of the material conveying pipe, respectively. The spectral acquisition probe irradiates the material in the detection cell and transmits the collected material signal to an external spectrometer for spectral analysis. This device can enrich polypropylene particles and acquire high-quality spectra in a flowing state, realizing automatic online measurement of the properties of flowing polypropylene materials, improving detection efficiency and reducing measurement errors.

Description

Technical Field

[0001] This application belongs to the field of petrochemical technology, and specifically relates to a flow measurement device. Background Technology

[0002] Polypropylene is the second largest general-purpose synthetic resin, accounting for about 30% of total synthetic resin consumption, and is the most promising of the five major synthetic resins. It is widely used in the production of clothing, blankets and other fiber products, medical devices, automotive and bicycle parts, pipelines, chemical containers, and also in food and pharmaceutical packaging. In recent years, China's polypropylene production capacity has continued to grow rapidly. For example, in 2020, domestic polypropylene production reached 25.8159 million tons, a significant increase compared to previous years. With new capacity continuously coming online, polypropylene production is expected to continue to increase in the coming years.

[0003] In polypropylene (PP) products, quality indicators are the main factors affecting product grade and price. Among these indicators, melt flow index (MFI) is a crucial measure of PP flow properties, significantly impacting processing and applications. A higher MFI indicates better melt flow properties, lower average molecular weight, and superior processing performance. Conversely, a lower MFI indicates poorer flow properties. Currently, PP MFI is typically obtained through routine laboratory analysis, which consumes significant manpower and resources. Furthermore, conventional analytical methods often result in data lag, failing to reflect real-time production status or anticipate potential risks. Additionally, traditional offline PP testing techniques require manual on-site sampling, leading to infrequent sampling, poor representativeness, high labor intensity, and delayed laboratory data. Summary of the Invention

[0004] The purpose of this application is to provide a flow measurement device to solve the technical problems of low efficiency and large error in traditional offline polypropylene detection technology.

[0005] To achieve the above objectives, this application provides a flow measurement device, comprising: Material conveying pipe; The detection pool has its inlet and outlet ends connected to the side wall of the material conveying pipe via a feed pipe assembly and a discharge pipe assembly, respectively. The feed pipe assembly is used to receive the material in the material conveying pipe and convey it to the detection pool. The discharge pipe assembly is used to discharge the material that has been detected in the detection pool into the material conveying pipe. The feed pipe assembly and the discharge pipe assembly are arranged close to the first end and the second end of the material conveying pipe, respectively. A spectral acquisition probe is used to irradiate the material in the detection cell, and the spectral acquisition probe sends the acquired material signal to an external spectrometer for spectral analysis.

[0006] In some embodiments, the spectral acquisition probe includes a probe body, a reference plate, a collecting beam mirror, and two light sources installed within the probe body. The probe body has a viewing window, the reference plate is located between the viewing window and the first end of the collecting beam mirror, the second end of the collecting beam mirror is connected to the spectrometer via an optical fiber, and the two light sources are arranged at intervals and symmetrically distributed about the collecting beam mirror. The light emitted by the light sources can pass through the viewing window to illuminate the material in the detection cell.

[0007] In some embodiments, the included angle between the two light sources is 20 to 40°.

[0008] In some embodiments, the detection pool includes: The detection pool body has a cover at both the top and bottom. The top cover has a material inlet, and the bottom cover has a material outlet. The detection pool body has windows on both sides along the width direction, and each window has a window slat embedded therein. The detection pool body has a blower panel on both sides along the length direction, and each blower panel is connected to an external air blowing device through an air inlet. The external air blowing device is used to clean the inside of the detection pool body.

[0009] In some embodiments, the ratio of the cross-sectional area of ​​the material inlet end face to the material outlet end face of the detection pool is in the range of 1:1 to 3:1.

[0010] In some embodiments, the feed pipe assembly includes a feed pipe and a feed ball valve disposed on the feed pipe. The feed pipe includes a straight section and a curved section. The feed ball valve is located between the straight section and the curved section. The feed end of the straight section is obliquely connected to the outer peripheral wall of the material conveying pipe. The discharge end of the curved section is vertically connected to the inlet end of the detection pool.

[0011] In some embodiments, the inclination angle between the feed end of the straight pipe section and the outer peripheral wall of the material conveying pipe is in the range of 40-50 degrees.

[0012] In some embodiments, the discharge pipe assembly includes a discharge pipe and a discharge valve disposed on the discharge pipe, one end of the discharge pipe being perpendicularly connected to the outlet end of the detection pool, and the other end being connected to the material conveying pipe.

[0013] In some embodiments, the flow measurement device further includes a sampling tube connected to the side wall of the material conveying pipe, the sampling tube being provided with a sampling valve, and the end of the sampling tube opposite to the material conveying pipe being connected to an external sampling device.

[0014] In some embodiments, an observation window is provided on the side wall of the material conveying pipe.

[0015] Through the above technical solution, the inlet and outlet ends of the detection pool are connected to the sidewall of the material conveying pipe via a feed pipe assembly and a discharge pipe assembly, respectively. The feed pipe assembly receives the material in the material conveying pipe and conveys it into the detection pool, while the discharge pipe assembly discharges the material from the detection pool back into the material conveying pipe. The feed pipe assembly and the discharge pipe assembly are arranged near the first and second ends of the material conveying pipe, respectively. A spectral acquisition probe is used to irradiate the material in the detection pool, and the probe sends the acquired material signal to an external spectrometer for spectral analysis. This device can enrich polypropylene particles and acquire high-quality spectra in a flowing state, realizing automatic online measurement of the properties of flowing polypropylene materials, improving detection efficiency and reducing measurement errors.

[0016] Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the following detailed description to explain the embodiments of this application, but do not constitute a limitation on the embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without any inventive effort. In the drawings: Figure 1 This is a schematic diagram of the flow measurement device of this application; Figure 2 This is an exploded structural diagram of the detection cell in the flow measurement device of this application; Figure 3 This is a cross-sectional schematic diagram of the detection cell in the flow measurement device of this application; Figure 4 This is a schematic diagram of the spectral acquisition probe in the flow measurement device of this application; Figure 5 This is a partial structural schematic diagram of the spectral acquisition probe in the flow measurement device of this application.

[0018] Explanation of reference numerals in the attached figures Detailed Implementation

[0019] The specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this application.

[0020] The flow measuring device according to this application, which can be used to measure polypropylene materials, is described below with reference to the accompanying drawings.

[0021] like Figure 1 As shown, this application provides a flow measurement device, including a material conveying pipe 10, a detection cell 20, and a spectral acquisition probe 30. The inlet and outlet ends of the detection cell 20 are connected to the side wall of the material conveying pipe 10 through a feed pipe assembly and a discharge pipe assembly, respectively. The feed pipe assembly is used to receive the material in the material conveying pipe 10 and convey it to the detection cell 20. The discharge pipe assembly is used to discharge the material that has been detected in the detection cell 20 back into the material conveying pipe 10. The feed pipe assembly and the discharge pipe assembly are arranged close to the first and second ends of the material conveying pipe 10, respectively. The spectral acquisition probe 30 is used to irradiate the material in the detection cell 20 and sends the collected material signal to an external spectrometer 40 for spectral analysis.

[0022] In this embodiment, polypropylene material enters from the top of the material conveying pipe 10 and flows within it towards the outlet. When it is necessary to measure the polypropylene flowing within the material conveying pipe 10, the feed pipe assembly is opened to receive the material and transport it to the detection tank 20. The polypropylene in the detection tank 20 is irradiated by the spectral acquisition probe 30 to collect material signals. An external spectrometer 40 analyzes the material signals to obtain the corresponding material property indicators, thereby calculating the melt flow index of the polypropylene. After the analysis is completed, the polypropylene in the detection tank 20 can be recycled back to the material conveying pipe 10 through the outlet pipe assembly. This application can enrich polypropylene particles and acquire high-quality spectra in a flowing state, realizing automatic online measurement of polypropylene in a flowing material state, improving detection efficiency and reducing measurement errors.

[0023] like Figure 4 and Figure 5 As shown, the spectral acquisition probe 30 includes a probe body 31, a reference plate 32, a beam collecting mirror 33, and two light sources 34 installed in the probe body 31. A viewing window 35 is provided on the probe body 31. The reference plate 32 is located between the viewing window 35 and the first end of the beam collecting mirror 33. The second end of the beam collecting mirror 33 is connected to the spectrometer 40 through an optical fiber 70. The two light sources 34 are arranged at intervals and symmetrically distributed about the beam collecting mirror 33. The light emitted by the light sources 34 can pass through the viewing window 35 to illuminate the material in the detection cell 20.

[0024] In this embodiment, the reference plate 32 is also connected to a motor 36 that drives its movement. When the motor 36 drives the reference plate 32 to the center position, the light spot of the light source 34 illuminates the reference plate 32, and the generated reflected light signal is collected by the collecting mirror 33 below the reference plate 32. The reference plate 32 is a circular flat gold-plated plate, which can reflect the light signal with maximum efficiency and has a reflectivity greater than 95%. When the motor 36 drives the reference plate 32 to the off-center position, the angle between the two light sources 34 is 30 degrees, and the emitted light passes through the viewing window 35 to illuminate the material in the detection cell 20 with maximum efficiency. The viewing window 35 is made of sapphire material produced by the bubble wrap method, which has a transmittance greater than 86% and no abnormal absorption peaks. The reflected light signal is collected by the beam-collecting mirror 33. The front end of the beam-collecting mirror 33 has a long tube with a diffuse reflection Lambertian black matte oxide finish on the inner wall. The inner diameter of the tube is 18mm, which can shield stray light signals. The beam-collecting mirror 33 is coupled to the optical fiber 70, which transmits the signal to the spectrometer 40. After entering the spectrometer 40, the light first passes through a slit, which filters out noise signals before illuminating the concave mirror 41. The concave mirror 41 converges the light to the collimating lens 42, and the collimated light signal then illuminates the grating 43 for spectral dispersion. The dispersed signal passes through the concave mirror 41 to the detector 44. The detector 44 transmits the spectral data from the spectrometer 40 to the computer for calculation via a data conversion module. The computer software calculates the absorption spectrum of the material using Beer-Lambert's law. After the spectrum is processed, it is entered into a database for calculation, and the corresponding material property indicators are analyzed. The results and trend graphs are displayed in the software. The system updates the reference data periodically and will continuously monitor the flow unless the stop button is triggered, thus realizing online measurement of polypropylene flow. It should be noted that the mathematical expression of Beer-Lambert's law in the existing technology is as follows: A = lg(1 / T) where A is absorbance and T is transmittance. T = I / I0, which means the intensity of the emitted light (I) is greater than the intensity of the incident light (I0). In some embodiments, the included angle between the two light sources 34 is 20~40°. In this embodiment, the two light sources 34 are symmetrically installed, and the included angle between the two light sources 34 is preferably 30 degrees, which can maximize the efficiency of irradiating the material in the detection cell 20 and maximize the excitation of the absorption signal of the material.

[0025] like Figure 2 and Figure 3As shown, the detection pool 20 includes a detection pool body 21. The top and bottom of the detection pool body 21 are provided with a cover 22. The top cover 22 has a material inlet 23 and the bottom cover 22 has a material outlet 24. The detection pool body 21 has windows on both sides along the width direction. Each window has a window slat 25. The detection pool body 21 has a purge panel 26 on both sides along the length direction. Each purge panel 26 is connected to an external air blowing component through an air inlet 27. The external air blowing component is used to blow air to clean the inside of the detection pool body 21.

[0026] In this embodiment, the upper end face of the detection pool body 21 is fitted with the upper cover of the detection pool 20, and the lower end face is fitted with the lower cover of the detection pool 20. The left and right sides of the detection pool 20 are provided with circular stepped holes for mounting window plates 25. The window plates 25 have a T-shaped structure, which ensures that the interior of the detection pool 20 is a pure plane. The front window plate 25 pressure plate is installed to the front of the detection pool 20 with screws. A gold-plated plate is placed at the rear end of the rear window plate 25 of the detection pool body 21, and the gold-plated plate pressure plate is installed to the rear side of the detection pool 20 with screws. Circular holes are reserved at the left and right ends of the detection pool 20 for installing purge panels 26. The upper purge panel 26 is installed at the right end of the detection pool 20, and the upper air inlet 27 is installed at the upper purge panel 26 to purge the upper part of the window plates 25. The lower purge panel 26 is installed at the left end of the detection pool 20, and the lower air inlet 27 is installed at the lower purge panel 26 to purge the lower parts of the left and right side window plates 25. The blowing holes of the upper and lower blowing panels 26 are air knife structures distributed at 90 degrees, with an air outlet gap of only 0.5mm. The air inlet 27 and the concave surface of the blowing panel 26 form a sealed chamber. When high-pressure gas enters, the gas can quickly blow away the dust and impurities on the window slats 25 from the air outlet.

[0027] This device does not require external power to drive the material flow. It uses the gravity of the polypropylene particles themselves to drive the particles to flow, while solving the stability and density of the material flow and improving the repeatability of spectral acquisition.

[0028] The light emitted by the spectral acquisition probe 30 on the left side of the detection cell 20 illuminates the material inside through the viewing window 35 and the window plate 25 of the detection cell 20. The signal light passing through the material is then reflected by the gold-plated plate. The returned light carrying material information is collected by the collecting beam mirror 33 of the spectral acquisition probe 30 and transmitted to the optical fiber 70. The optical fiber 70 conducts the light to the spectrometer 40, where it is used for online measurement of polypropylene flow. After the system has been running for a period of time, the feed ball valve 53 is closed, and the purging device is activated to purge the gas inside the detection cell body 21. The window plate 25 is cleaned through the upper and lower purging panels 26.

[0029] In some embodiments, the area ratio of the material inlet 23 end face to the material outlet 24 end face of the detection pool 20 is 1:1 to 3:1. During continuous detection operation, by setting the variable diameter relationship between the material inlet 23 end face and the outlet end face of the detection pool 20, it is possible to ensure that the material flows densely and uniformly within the detection pool 20. The dense material exhibits better spectral repeatability, thereby improving detection accuracy.

[0030] In some embodiments, the feed pipe assembly includes a feed pipe and a feed ball valve 53 disposed on the feed pipe. The feed pipe includes a straight section 51 and a curved section 52. The feed ball valve 53 is located between the straight section 51 and the curved section 52. The feed end of the straight section 51 is obliquely connected to the outer peripheral wall of the material conveying pipe 10, and the discharge end of the curved section 52 is vertically connected to the inlet end of the detection pool 20.

[0031] In this embodiment, during operation, the polypropylene granules are intercepted by the straight section 51 of the feed pipe after entering the material conveying pipe 10. By tilting the straight section 51 and the material conveying pipe 10, the material collection area can be increased to obtain more representative material samples. The material then flows into the detection pool 20 through the feed ball valve 53 and the curved section 52 to await testing. Furthermore, by making the outlet end of the curved section 52 perpendicular to the inlet end of the detection pool 20, it can be ensured that the material can enter the detection pool 20 more smoothly, improving the detection efficiency.

[0032] In some embodiments, the inclination angle between the feed end of the straight pipe section 51 and the outer peripheral wall of the material conveying pipe 10 is in the range of 40-50 degrees, which ensures smooth material flow while facilitating manufacturing and processing.

[0033] In some embodiments, the discharge pipe assembly includes a discharge pipe 55 and a discharge valve disposed on the discharge pipe 55. One end of the discharge pipe 55 is vertically connected to the outlet end of the detection tank 20, and the other end is obliquely connected to the material conveying pipe 10. The discharge valve can be a discharge ball valve 54, a solenoid-controlled valve, or other discharge valve capable of automatic control. In this embodiment, after detection, the material in the detection tank 20 enters the discharge pipe 55 from the outlet end. When the discharge ball valve 54 is opened, the discharge pipe 55 and the material conveying pipe 10 are connected, allowing the material in the discharge pipe 55 to enter the material conveying pipe 10, thereby achieving material recycling.

[0034] In some embodiments, the flow measurement device further includes a sampling tube 60 connected to the side wall of the material conveying pipe 10. One end of the sampling tube 60 communicates with the interior of the material conveying pipe 10, and a sampling valve 61 is provided on the sampling tube 60. The end of the sampling tube 60 facing away from the material conveying pipe 10 is connected to an external sampling device. It should be noted that the sampling tube 60 is used for sampling and testing needs other than material property measurement. By opening the sampling valve 61, a material sample is extracted from the sampling tube 60 through the external sampling device for other sample testing. The sampling tube 60 can be selected according to sampling needs and is not limited here.

[0035] In some embodiments, an observation window 11 is provided on the side wall of the material conveying pipe 10 to facilitate observation of the material condition inside the material conveying pipe 10.

[0036] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0037] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0038] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0039] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A flow measurement device, characterized in that, include: Material conveying pipe (10); The inlet and outlet of the detection pool (20) are connected to the side wall of the material conveying pipe (10) through the feed pipe assembly and the discharge pipe assembly, respectively. The feed pipe assembly is used to receive the material in the material conveying pipe (10) and convey it to the detection pool (20). The discharge pipe assembly is used to discharge the material that has been detected in the detection pool (20) into the material conveying pipe (10). The feed pipe assembly and the discharge pipe assembly are arranged close to the first end and the second end of the material conveying pipe (10), respectively. A spectral acquisition probe (30) is used to irradiate the material in the detection cell (20). The spectral acquisition probe (30) sends the acquired material signal to an external spectrometer (40) for spectral analysis.

2. The flow measurement device according to claim 1, characterized in that, The spectral acquisition probe (30) includes a probe body (31), a reference plate (32), a beam collector (33), and two light sources (34) installed in the probe body (31). A viewing window (35) is provided on the probe body (31). The reference plate (32) is located between the viewing window (35) and the first end of the beam collector (33). The second end of the beam collector (33) is connected to the spectrometer (40) through an optical fiber (70). The two light sources (34) are arranged at intervals and symmetrically distributed about the beam collector (33). The light emitted by the light sources (34) can pass through the viewing window (35) and illuminate the material in the detection cell (20).

3. The flow measurement device according to claim 2, characterized in that, The included angle between the two light sources (34) is 20~40°.

4. The flow measuring device according to claim 1, characterized in that, The detection pool (20) includes: The detection pool body (21) has a cover (22) at both the top and bottom. The cover (22) at the top has a material inlet (23) and the cover (22) at the bottom has a material outlet (24). The detection pool body (21) has windows on both sides along the width direction. Each window has a window piece (25) embedded in it. The detection pool body (21) has a blower panel (26) on both sides along the length direction. Each blower panel (26) is connected to an external air blowing device through an air inlet (27). The external air blowing device is used to clean the inside of the detection pool body (21).

5. The flow measurement device according to claim 1, characterized in that, The ratio of the area of ​​the material inlet (23) end face and the material outlet (24) end face of the detection pool (20) is in the range of 1:1 to 3:

1.

6. The flow measuring device according to any one of claims 1 to 5, characterized in that, The feed pipe assembly includes a feed pipe and a feed ball valve (53) disposed on the feed pipe. The feed pipe includes a straight section (51) and a curved section (52). The feed ball valve (53) is located between the straight section (51) and the curved section (52). The feed end of the straight section (51) is inclinedly connected to the outer peripheral wall of the material conveying pipe (10). The discharge end of the curved section (52) is vertically connected to the inlet end of the detection pool (20).

7. The flow measurement device according to claim 6, characterized in that, The inclination angle between the feed end of the straight pipe section (51) and the outer peripheral wall of the material conveying pipe (10) is in the range of 40-50 degrees.

8. The flow measuring device according to any one of claims 1 to 5, characterized in that, The discharge pipe assembly includes a discharge pipe (55) and a discharge valve disposed on the discharge pipe (55). One end of the discharge pipe (55) is vertically connected to the outlet end of the detection pool (20), and the other end is connected to the material conveying pipe (10).

9. The flow measuring device according to any one of claims 1 to 5, characterized in that, The flow measurement device also includes a sampling tube (60) connected to the side wall of the material conveying pipe (10), the sampling tube (60) is provided with a sampling valve (61), and the end of the sampling tube (60) away from the material conveying pipe (10) is connected to an external sampling device.

10. The flow measuring device according to any one of claims 1 to 5, characterized in that, The side wall of the material conveying pipe (10) is provided with an observation window (11).

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