A dynamic fluidized bed system and dynamic fluidized sorting method

Abstract

The application discloses a dynamic fluidized bed system and a dynamic fluidized sorting method, and belongs to the technical field of sorting fluidized particle system measurement, and aims to solve the problem of poor detection precision of the mixed separation state of coal powder in the sorting process in the prior art. In the dynamic fluidized bed system, a pressure collection unit collects pressure signals of different positions of a bed layer in a vertical direction and transmits the pressure signals to a controller, the controller receives the pressure signals to calculate a pressure difference signal, converts the pressure difference signal into a density signal, processes the density signal to generate a Hilbert graph of particles in the bed layer, and judges whether the bed layer is in a mixed state or a separated state according to the Hilbert graph. The application can be used for dynamic fluidized sorting of raw coal.

Description

Technical Field

[0001] This invention belongs to the field of measurement technology for fluidized bed systems, and particularly relates to a dynamic fluidized bed system and a dynamic fluidized separation method. Background Technology

[0002] Gas-solid fluidization separation technology is one of the important dry coal preparation technologies. For the separation of fine coal particles, dynamic fluidized bed systems are mainly used for gas-solid fluidization separation.

[0003] In actual sorting processes, coal powder with a particle size of less than 0.5 mm will separate with the weighting medium, affecting the subsequent sorting effect. Therefore, detecting the mixing and separation state of coal powder with a particle size of less than 0.5 mm and the weighting medium is crucial for sorting. However, in the existing technology, the detection accuracy of the mixing and separation state of coal powder with a particle size of less than 0.5 mm is poor. Summary of the Invention

[0004] Based on the above analysis, the present invention aims to provide a dynamic fluidized bed system and a dynamic fluidized bed separation method to solve the problem of poor detection accuracy of the mixing and separation state of coal powder in the prior art during the separation process.

[0005] The objective of this invention is mainly achieved through the following technical solutions.

[0006] This invention provides a dynamic fluidized bed system, including a blower, a vibration table, a fluidizing chamber, a pressure acquisition unit, and a processor. The fluidizing chamber is placed on the vibration table, which drives the fluidizing chamber to vibrate. The blower's outlet is connected to the inner cavity of the fluidizing chamber. The data acquisition end of the pressure acquisition unit is located in the bed of the fluidizing chamber. The pressure acquisition unit acquires pressure signals at different positions of the bed in the vertical direction and transmits them to the controller. The controller receives the pressure signals, calculates the differential pressure signal, converts the differential pressure signal into a density signal, and processes the density signal to generate a Hilbert spectrum of the particles in the bed. Based on the Hilbert spectrum, it is determined whether the bed is in a mixed state or a separated state.

[0007] Furthermore, the pressure acquisition unit includes an upper pressure acquisition component, a middle pressure acquisition component, and a lower pressure acquisition component arranged sequentially from top to bottom. The upper pressure acquisition component is used to acquire two pressure signals at different positions in the vertical direction on the upper part of the bed, the middle pressure acquisition component is used to acquire two pressure signals at different positions in the vertical direction on the middle part of the bed, and the lower pressure acquisition component is used to acquire two pressure signals at different positions in the vertical direction on the lower part of the bed.

[0008] Furthermore, the upper pressure acquisition component, the middle pressure acquisition component, and the lower pressure acquisition component each include two tubes and a pressure sensor. The two tubes are detachably and fixedly connected. The pressure sensor has two data input ports. The tubes correspond one-to-one with the data input ports. The tubes are connected to the data input ports. The tubes are inserted into the bed and the two tubes are located at different positions in the bed in the vertical direction.

[0009] Furthermore, the height difference between the two tubes is 1.5 to 2.5 cm, and the inner diameter of the tubes is 3 to 5 mm.

[0010] Furthermore, the upper pressure acquisition component, the middle pressure acquisition component, and the lower pressure acquisition component also include a filter layer, which is fitted onto the air inlet of the pipe body.

[0011] Furthermore, the dynamic fluidized bed system also includes a flow regulating valve located on the pipeline connecting the air receiver and the fluidizing chamber.

[0012] Furthermore, the dynamic fluidized bed system also includes a flow meter installed on the connecting pipeline between the air manifold and the fluidizing chamber.

[0013] Furthermore, the dynamic fluidized bed system also includes an air distribution chamber, an air distribution plate, and an air distribution layer. The air distribution chamber is located at the bottom of the fluidization chamber and is connected to the fluidization chamber. The bottom end of the air distribution chamber is connected to the vibration table. The air distribution plate and the air distribution layer are located between the air distribution chamber and the fluidization chamber. The air inlet of the air distribution chamber is connected to the air outlet of the blower.

[0014] The present invention also provides a dynamic fluidized bed sorting method, which uses the above-mentioned dynamic fluidized bed system and includes the following steps:

[0015] Step 1: Set the sampling frequency and sampling time of the pressure acquisition unit, and select the vibration frequency, vibration amplitude, gas supply flow rate and coal sample flow rate;

[0016] Step 2: Turn on the vibration table and blower, and feed the coal sample into the fluidization chamber. The coal sample refers to a sample of raw coal.

[0017] Step 3: The pressure acquisition unit acquires pressure signals at different positions in the vertical direction of the bed and transmits them to the controller. The controller receives the pressure signals, calculates the differential pressure signal, converts the differential pressure signal into a density signal, and processes the density signal to generate the Hilbert spectrum of the particles in the bed.

[0018] Step 4: Determine whether the bed is in a mixed or separated state based on the Hilbert chart;

[0019] If the bed is in a mixed state, proceed to step 5;

[0020] If the bed is in a separated state, increase the vibration frequency, vibration amplitude and / or gas supply flow rate, and / or decrease the coal sample flow rate, and repeat step 3;

[0021] Step 5: Feed raw coal into the fluidization chamber and sort the raw coal according to the selected vibration frequency, vibration amplitude, gas supply flow rate and coal sample flow rate.

[0022] Furthermore, step 3 includes the following steps:

[0023] Step 31: The pressure acquisition unit acquires two sets of pressure signals from the upper part of the bed, two sets of pressure signals from the middle part, and two sets of pressure signals from the lower part, and transmits them to the controller.

[0024] Step 32: The controller receives the pressure signal and calculates the differential pressure signal at the top of the bed, the differential pressure signal in the middle of the bed, and the differential pressure signal at the bottom of the bed;

[0025] Step 33: Convert the differential pressure signal into a density signal using a conversion formula. The conversion formula needs to be generated after the pressure sensor is calibrated. The conversion formula is as follows:

[0026]

[0027] In the formula:

[0028] ρ is the bed density, g / cm³ 3 ;

[0029] g is the gravitational coefficient, N / kg;

[0030] h represents the height difference of the pipe body, in mm;

[0031] Step 34: Define the set of all ρ as the density signal, perform empirical mode decomposition on the density signal, and obtain several intrinsic mode functions according to the different density fluctuation frequencies;

[0032] Step 35: Perform Hilbert transform on each intrinsic mode function to obtain the analytic signal of each intrinsic mode function. Integrate the analytic signals of all intrinsic mode functions to obtain the Hilbert spectrum of the particles in the bed.

[0033] Compared with the prior art, the present invention can achieve at least the following beneficial effects:

[0034] The dynamic fluidized bed system provided by this invention has a pressure acquisition unit set in the bed layer of the fluidization chamber to collect pressure signals at different positions in the vertical direction of the bed layer. Based on the pressure signals, a Hilbert spectrum of the particles in the bed layer is generated. The Hilbert spectrum is used to determine whether the bed layer is in a mixed state or a separated state. This allows the state of the bed layer to be understood before formal sorting. By adjusting various parameters, the bed layer can be adjusted to a mixed state, which can better guide the subsequent formal sorting and improve the sorting effect.

[0035] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained through the embodiments described and the accompanying drawings, which are particularly pointed out. Attached Figure Description

[0036] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0037] Figure 1 This is a schematic diagram of the structure of the dynamic fluidized bed system provided by the present invention;

[0038] Figure 2 This is a schematic diagram of the air distribution chamber in the dynamic fluidized bed system provided by the present invention;

[0039] Figure 3 This is a schematic diagram of the air distribution plate in the dynamic fluidized bed system provided by the present invention;

[0040] Figure 4a This is a schematic diagram of the EMD breakdown of the upper part of the bed in Example 1;

[0041] Figure 4b This is a schematic diagram of the EMD breakdown of the middle part of the bed in Example 1;

[0042] Figure 4c This is a schematic diagram of the EMD breakdown of the lower part of the bed in Example 1;

[0043] Figure 5a The image shows the Hilbert plot of the upper part of the bed in Example 1;

[0044] Figure 5b The image shows the Hilbert plot of the middle section of the bed in Example 1.

[0045] Figure 5c The image shows the Hilbert plot of the lower part of the bed in Example 1;

[0046] Figure 6a This is an exploded view of the EMD structure above the bed in Example 2;

[0047] Figure 6b This is an exploded view of the EMD structure in the middle of the bed in Example 2;

[0048] Figure 6c This is an exploded view of the EMD at the bottom of the bed in Example 2;

[0049] Figure 7aThe Hilbert map of the upper part of the bed in Example 2;

[0050] Figure 7b The Hilbert map of the middle part of the bed in Example 2;

[0051] Figure 7c This is the Hilbert map of the lower part of the bed in Example 2.

[0052] Figure label:

[0053] 1-Blower; 2-Air receiver; 3-Flow meter; 4-Flow regulating valve; 5-Vibration table; 6-Fluidization chamber; 7-Air distribution chamber; 701-Inner telescopic sealing ring; 702-Outer telescopic sealing ring; 703-Inner pipe; 704-Outer pipe; 705-Air pump; 8-Air distribution plate; 9-Air distribution layer; 10-Pipe body; 11-Pressure sensor; 12-Controller; 13-Gange discharge port. Detailed Implementation

[0054] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0055] In a first aspect, the present invention provides a dynamic fluidized bed system, see [link to previous article]. Figure 1 The system includes a blower 1, an air receiver 2, a vibration table 5, a fluidizing chamber 6, a pressure acquisition unit, and a processor. The fluidizing chamber 6 is placed on the vibration table 5, which drives the fluidizing chamber 6 to perform periodic sinusoidal vertical vibration with a frequency of 0–50 Hz and an amplitude of 1–5 mm. The outlet of the blower 1 is connected to the inner cavity of the fluidizing chamber 6 through the air receiver 2, allowing airflow to enter the inner cavity of the fluidizing chamber 6. The airflow and vibration work together to drive the fluidization of particles within the fluidizing chamber 6. The fluidizing chamber 6 has a raw coal inlet and a gangue outlet 1313. Located on the top side of the fluidization chamber 6, the gangue discharge port 1313 is located on the bottom side of the fluidization chamber 6. The data acquisition end of the pressure acquisition unit is located in the bed of the fluidization chamber 6. The pressure acquisition unit acquires the pressure signals of the bed at different positions in the vertical direction and transmits them to the controller 12. The controller 12 receives the pressure signals, calculates the pressure difference signals, converts the pressure difference signals into density signals, and processes the density signals to generate Hilbert spectra of the particles in the bed. Based on the Hilbert spectra, it is determined whether the bed is in a mixed state or a separated state.

[0056] The specific judgment method is as follows:

[0057] In a Hilbert spectrum, the X-axis represents frequency, the Y-axis represents time, and the Z-axis represents density fluctuation amplitude. For a vibrating fluidized bed, 0–10 Hz represents the bubble frequency, and 20–30 Hz represents the vibration frequency. If the peak value of the density fluctuation amplitude in the 0–10 Hz range is less than or equal to the peak value of the density fluctuation amplitude in the 20–30 Hz range, it indicates that the bed is in a separated state; if the peak value of the density fluctuation amplitude in the 0–10 Hz range is greater than the peak value of the density fluctuation amplitude in the 20–30 Hz range, it indicates that the fluidized bed is in a mixed state.

[0058] Specifically, the pressure acquisition unit includes an upper pressure acquisition component, a middle pressure acquisition component, and a lower pressure acquisition component arranged sequentially from top to bottom. The upper pressure acquisition component is used to acquire two pressure signals at different positions in the vertical direction at the top of the bed, the middle pressure acquisition component is used to acquire two pressure signals at different positions in the vertical direction at the middle of the bed, and the lower pressure acquisition component is used to acquire two pressure signals at different positions in the vertical direction at the bottom of the bed. The difference between the two pressure signals is the differential pressure signal.

[0059] Compared with the prior art, the dynamic fluidized bed system provided by the present invention sets up a pressure acquisition unit in the bed layer of the fluidization chamber 6 to collect pressure signals at different positions of the bed layer in the vertical direction, and generates Hilbert spectra of particles in the bed layer based on the pressure signals. The Hilbert spectra are used to determine whether the bed layer is in a mixed state or a separated state, so as to understand the state of the bed layer before formal sorting. By adjusting various parameters, the bed layer can be adjusted to a mixed state, which can better guide the subsequent formal sorting and improve the sorting effect.

[0060] It should be noted that during implementation, raw coal enters the fluidization chamber 6 through the raw coal inlet, and airflow is supplied into the fluidization chamber 6. Inside the fluidization chamber 6, the raw coal is subjected to the combined force field of excitation force and airflow, and stratification occurs longitudinally within the fluidization chamber 6 based on density differences. The light-density coarse coal remains in the upper part of the fluidization chamber 6, the heavy-density gangue particles settle to the lower part of the fluidization chamber 6, and the intermediate-density materials (including the mixture of middlings and re-selected clean coal) are suspended in the middle position of the fluidization chamber 6, thereby achieving the separation of raw coal.

[0061] In order to regulate the gas flow rate supplied into the fluidizing chamber 6, the above-mentioned dynamic fluidized bed system also includes a flow regulating valve 4 located on the pipeline connecting the air receiver 2 and the fluidizing chamber 6, and the gas flow rate supplied into the fluidizing chamber 6 is regulated by the flow regulating valve 4.

[0062] In order to detect the gas flow rate in the fluidization chamber 6 in real time, the above-mentioned dynamic fluidized bed system also includes a flow meter 3 installed on the pipeline connecting the air receiver 2 and the fluidization chamber 6. The flow meter 3 detects the gas flow rate in the fluidization chamber 6 supplied by the air receiver 2 in real time.

[0063] To ensure stable connections between the various components, the blower 1 is connected to the air receiver 2, the air receiver 2 to the flow meter 3, the flow meter 3 to the flow regulating valve 4, and the flow regulating valve 4 to the fluidizing chamber 6 via pipelines. For example, the pipelines between the blower 1 and the air receiver 2, the air receiver 2 and the flow meter 3, and the flow meter 3 and the flow regulating valve 4 are rigid pipelines, while the pipeline between the flow regulating valve 4 and the fluidizing chamber 6 is a flexible pipeline to accommodate the vibration of the fluidizing chamber 6.

[0064] In order to ensure the throughput of the fluidizing chamber 6, for example, the inner diameter of the fluidizing chamber 6 is 350-450 mm (e.g., 400 mm), and the height of the fluidizing chamber 6 is 450-550 mm (e.g., 500 mm).

[0065] To ensure the stability of the airflow supplied into the fluidizing chamber 6, the aforementioned dynamic fluidized bed system further includes an air distribution chamber 7, an air distribution plate 8, and an air distribution layer 9. The air distribution chamber 7 is located at the bottom of the fluidizing chamber 6 and communicates with it, and the two are detachably connected by bolts. The bottom end of the air distribution chamber 7 is detachably connected to the vibration table 5 by bolts. The air distribution plate 8 and the air distribution layer 9 are located between the air distribution chamber 7 and the fluidizing chamber 6, and the air inlet of the air distribution chamber 7 is connected to the air outlet of the air receiver 2. In this way, the arrangement of the air distribution chamber 7, the air distribution plate 8, and the air distribution layer 9 can ensure the stability of the airflow supplied into the fluidizing chamber 6, thereby generating a stable bed.

[0066] For example, the air distribution plate 8 is a perforated steel plate with a thickness of 2.5 to 4 mm (e.g., 3 mm), a hole diameter of 2.5 to 3.5 mm (e.g., 3 mm), a center distance of 4.5 to 5.0 mm (e.g., 4.8 mm) between two adjacent air holes, and an opening ratio of 25 to 35% (e.g., 30%).

[0067] To ensure a sealed connection between the air distribution chamber 7 and the fluidization chamber 6, an elastic sealing gasket (e.g., a rubber gasket) is provided between the air distribution chamber 7 and the fluidization chamber 6.

[0068] To ensure the accuracy of pressure acquisition and reduce the impact of the pressure acquisition unit on the bed, the upper, middle, and lower pressure acquisition components have basically the same structure. They all include two tubes 10 (e.g., copper tubes) and a pressure sensor 11. The two tubes 10 are detachably and fixedly connected. The pressure sensor 11 has two data input ports, and each tube 10 corresponds to one of the data input ports. The tubes 10 are connected to the data input ports through connecting pipes (e.g., rubber hoses). The tubes 10 are inserted into the bed, and the two tubes 10 are located at different positions in the bed in the vertical direction.

[0069] For example, the height difference between the two tubes 10 is 1.5 to 2.5 cm (e.g., 2 cm), and the inner diameter of the tube 10 is 3 to 5 mm (e.g., 4 mm).

[0070] To prevent particles in the bed from entering the tube 10 and causing blockage, the upper pressure acquisition component, the middle pressure acquisition component and the lower pressure acquisition component also include a filter layer. The filter layer is fitted onto the air inlet of the tube 10 and is used to filter particles in the bed.

[0071] Secondly, the present invention provides another dynamic fluidized bed system, the structure of which is basically the same as that of the dynamic fluidized bed system provided in Embodiment 1, the difference being:

[0072] Considering that the gangue particles will move along the air distribution plate 8 to the gangue discharge port 13 for discharge, in order to adjust the discharge speed of the gangue particles, for example, one end of the air distribution plate 8 near the gangue discharge port 13 is rotatably connected to the fluidization chamber, and the other end of the air distribution plate 8 is a free end. By rotating the air distribution plate 8, the tilt angle of the air distribution plate 8 can be adjusted, thereby realizing the adjustment of the discharge speed of the gangue particles.

[0073] In order to utilize airflow to adjust the tilt angle of the air distribution plate 8, the structure of the air distribution chamber 7 is specifically described in [reference needed]. Figure 2 The air distribution chamber 7 includes an inner telescopic sealing ring 701, an outer telescopic sealing ring 702, an inner tube 703, and an outer tube 704 sleeved outside the inner tube 703, with a gap between the outer tube 704 and the inner tube 703. The air distribution plate 8 is divided into a central area and a surrounding area. The surrounding area has main air distribution holes, while the central area does not. The air outlet of the inner tube 703 covers the central area and is connected to the edge of the central area via the inner telescopic sealing ring 701. An air pump 705 is installed on the inner tube 703, and the air outlet of the outer tube 704 covers the surrounding area and is connected to the edge of the surrounding area via the outer telescopic sealing ring 702.

[0074] When there is no need to increase the tilt angle of the air distribution plate 8, only the outer pipe 704 supplies air to the fluidization chamber through the main air distribution hole. When it is necessary to increase the tilt angle of the air distribution plate 8, the suction pump 705 is turned on, and airflow is simultaneously introduced into the inner pipe 703 and the outer pipe 704, which increases the length of the inner telescopic sealing ring 701 and the outer telescopic sealing ring 702, causing the air distribution plate 8 to rotate clockwise and increase its tilt angle. In this way, through the cooperating inner pipe 703 and outer pipe 704, the air pressure can drive the air distribution plate 8 to rotate, thereby realizing the adjustment of the tilt angle of the air distribution plate 8 by airflow without the need for other additional air distribution plate 8 drive mechanisms.

[0075] Thirdly, the present invention provides a third type of dynamic fluidized bed system, the structure of which is basically the same as that of the dynamic fluidized bed system provided in Embodiment 1, the difference being:

[0076] For the structure of air distribution plate 8, see Figure 3 It includes an air distribution channel and a partition rib 802. The partition rib 802 is located in the air distribution channel and divides the air distribution channel into multiple air distribution sub-channels 801. Each air distribution sub-channel 801 has an air inlet hole at its bottom. The air distribution layer 9 covers the opening of the air distribution channel.

[0077] Fourthly, the present invention provides a dynamic fluidized bed sorting method, employing the dynamic fluidized bed system provided in the first, second, or third aspects, the sorting method comprising the following steps:

[0078] Step 1: Set the sampling frequency and sampling time of the pressure acquisition unit, and select the vibration frequency, vibration amplitude, gas supply flow rate and coal sample flow rate;

[0079] Step 2: Turn on the vibration table and blower, and feed the coal sample into the fluidization chamber. The coal sample refers to a sample of raw coal.

[0080] Step 3: The pressure acquisition unit acquires pressure signals at different positions in the vertical direction of the bed and transmits them to the controller. The controller receives the pressure signals, calculates the differential pressure signal, converts the differential pressure signal into a density signal, and processes the density signal to generate the Hilbert spectrum of the particles in the bed.

[0081] Step 4: Determine whether the bed is in a mixed or separated state based on the Hilbert chart;

[0082] If the bed is in a mixed state, proceed to step 5;

[0083] If the bed is in a separated state, increase the vibration frequency, vibration amplitude and / or gas supply flow rate, and / or decrease the coal sample flow rate, and repeat step 3;

[0084] Step 5: Feed raw coal into the fluidization chamber and sort the raw coal according to the selected vibration frequency, vibration amplitude, gas supply flow rate and coal sample flow rate.

[0085] Compared with the prior art, the beneficial effects of the dynamic fluidized bed separation method provided by the present invention are basically the same as those of the dynamic fluidized bed system provided by the first, second or third aspects, and will not be described in detail here.

[0086] Specifically, step 3 includes the following steps:

[0087] Step 31: The pressure acquisition unit acquires two sets of pressure signals from the upper part of the bed, two sets of pressure signals from the middle part, and two sets of pressure signals from the lower part, and transmits them to the controller.

[0088] Step 32: The controller receives the pressure signal and calculates the differential pressure signal at the top of the bed, the differential pressure signal in the middle of the bed, and the differential pressure signal at the bottom of the bed;

[0089] Step 33: Convert the differential pressure signal into a density signal using a conversion formula. The conversion formula needs to be generated after the pressure sensor is calibrated. The conversion formula is as follows:

[0090]

[0091] In the formula:

[0092] ρ is the bed density, g / cm³ 3 ;

[0093] g is the gravitational coefficient, N / kg;

[0094] h represents the height difference of the pipe body, in mm.

[0095] Step 34: Define the set of all ρ as the density signal x(t), perform Empirical Mode Decomposition (EMD) on the density signal x(t), and obtain several Intrinsic Mode Functions (IMFs) and a residual signal that can characterize the overall trend of density change according to the different density fluctuation frequencies. Each IMF represents the density fluctuation frequency of the density signal x(t) at different time scales, and obtain the EMD decomposition diagram of particles in the dynamic fluidized bed system (including separation state and / or mixing state).

[0096] Step 35: Perform Hilbert Transform on each intrinsic mode function to obtain the analytical signal of each intrinsic mode function. The analytical signal includes the frequency, amplitude, phase and time of the density signal. Integrate the analytical signals of all intrinsic mode functions to obtain the Hilbert spectrum of particles in the dynamic fluidized bed system (including separated state and / or mixed state).

[0097] In practical applications, empirical mode decomposition and Hilbert transform can be implemented based on the MATLAB platform, which will not be detailed here.

[0098] Specifically, in step 4 above, the method for determining whether the bed is in a mixed or separated state based on the Hilbert diagram is as follows:

[0099] If the peak value of the density fluctuation amplitude in the 0-10Hz range is less than or equal to the peak value of the density fluctuation amplitude in the 20-30Hz range, it indicates that the bed is in a state of separation.

[0100] If the peak value of the density fluctuation amplitude in the 0-10Hz range is greater than the peak value of the density fluctuation amplitude in the 20-30Hz range, it indicates that the fluidized bed is in a mixed state.

[0101] Example 1

[0102] This embodiment provides a dynamic fluidized bed sorting method, the details of which are described in the fourth aspect, and the parameters are as follows:

[0103] There are three pressure sensors, each corresponding to two copper tubes. The two copper tubes are bound together as a group. The three groups of copper tubes are inserted into the upper, middle and bottom of the fluidized bed, respectively. The sampling frequency of the pressure sensor is 200Hz and the sampling time is 20s. The pressure signal is intercepted from the 10th to the 15th second during analysis.

[0104] The vibration frequency of the vibration table is f = 25 Hz, the vibration amplitude of the vibration table is A = 1 mm, and the air inlet flow rate of the fluidization chamber is U. g =1.0U mfv The coal sample flow rate was 0.3 kg / s.

[0105] See the obtained intrinsic mode functions. Figures 4a to 4c (IMF-1, IMF-2, IMF-3, IMF-4, IMF-5, and IMF-6), see Hilbert diagrams. Figures 5a to 5c ,from Figures 4a to 4c It can be seen that the fluctuation patterns and amplitudes of IMF-1 in the upper, middle and lower parts are significantly different. As the bed depth increases, the fluctuations of IMF-1 become more regular and the amplitudes are also greater.

[0106] from Figures 5a to 5c It can be seen that there is a relatively obvious density fluctuation range of 0-10Hz in the upper part, while the density fluctuation range of 20-30Hz is weaker. There is a relatively obvious density fluctuation range of 25Hz in the middle and bottom parts, indicating that the bed is in a separated state and the density fluctuation range and distribution pattern of different areas of the bed are very different.

[0107] Example 2

[0108] This embodiment provides a dynamic fluidized bed sorting method, the details of which are described in the fourth aspect, and the parameters are as follows:

[0109] There are three pressure sensors, each corresponding to two copper tubes. The two copper tubes are bound together as a group. The three groups of copper tubes are inserted into the upper, middle and bottom of the fluidized bed, respectively. The sampling frequency of the pressure sensor is 200Hz and the sampling time is 20s. The pressure signal is intercepted from the 10th to the 15th second during analysis.

[0110] The vibration frequency of the vibration table is f = 25 Hz, the vibration amplitude of the vibration table is A = 2 mm, and the air inlet flow rate of the fluidization chamber is U. g =1.4U mfv The coal sample flow rate was 0.25 kg / s.

[0111] See the obtained intrinsic mode functions. Figures 6a to 6c See Hilbert's diagram. Figures 7a to 7c ,from Figures 6a to 6c It can be seen that the oscillation patterns, fluctuation amplitudes, and change patterns of the upper, middle, and lower IMF-1s tend to be consistent.

[0112] from Figures 7a to 7c It can be seen that there are relatively obvious density fluctuations of 0-10Hz in the upper, middle and lower parts, while the density fluctuation of 25Hz is not obvious, indicating that the bed is in a mixed state and the density fluctuation amplitude and distribution pattern of each region of the bed are not significantly different.

[0113] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A dynamic fluidized bed system, characterized in that, The system comprises a blower, a vibrating table, a fluidized cavity, a pressure acquisition unit and a processor; the fluidized cavity is arranged on the vibrating table, the vibrating table drives the fluidized cavity to vibrate, and an air outlet of the blower is communicated with an inner cavity of the fluidized cavity; The data acquisition end of the pressure acquisition unit is located in the bed layer of the fluidized cavity, the pressure acquisition unit acquires pressure signals at different positions in the vertical direction of the bed layer and transmits the pressure signals to the controller, the controller calculates a differential pressure signal according to the pressure signals, converts the differential pressure signal into a density signal, processes the density signal, generates a Hilbert graph of the particles in the bed layer, and judges whether the bed layer is in a mixed state or a separated state according to the Hilbert graph; the X-direction coordinate of the Hilbert graph is frequency, the Y-direction coordinate is time, and the Z-direction coordinate is the density fluctuation amplitude; if the peak value of the density fluctuation amplitude in the frequency of 0-10 Hz is less than or equal to the peak value of the density fluctuation amplitude in the frequency of 20-30 Hz, it indicates that the bed layer is in a separated state; if the peak value of the density fluctuation amplitude in the frequency of 0-10 Hz is greater than the peak value of the density fluctuation amplitude in the frequency of 20-30 Hz, it indicates that the fluidized bed is in a mixed state; The dynamic fluidized bed system further comprises a wind distribution chamber, a wind distribution plate and a wind distribution layer, the wind distribution chamber is located at the bottom of the fluidized cavity and communicated with the fluidized cavity, the bottom end of the wind distribution chamber is connected with the vibrating table, the wind distribution plate and the wind distribution layer are arranged between the wind distribution chamber and the fluidized cavity, and the air inlet of the wind distribution chamber is connected with the air outlet of the blower; One end of the wind distribution plate close to the gangue discharge port is rotationally connected with the fluidized cavity, and the other end of the wind distribution plate is a free end; the wind distribution chamber comprises an inner telescopic sealing ring, an outer telescopic sealing ring, an inner tube and an outer tube sleeved outside the inner tube, a gap is formed between the outer tube and the inner tube, the wind distribution plate is divided into a central region and a surrounding region around the central region, the surrounding region is provided with main air distribution holes, the central region is not provided with the main air distribution holes, the air outlet of the inner tube covers the central region and is connected with the edge of the central region through the inner telescopic sealing ring, and the outer tube is provided with an air outlet covering the surrounding region and connected with the edge of the surrounding region through the outer telescopic sealing ring.

2. The dynamic fluidized bed system of claim 1, wherein, The pressure acquisition unit comprises an upper pressure acquisition assembly, a middle pressure acquisition assembly and a lower pressure acquisition assembly arranged in sequence from top to bottom, the upper pressure acquisition assembly is used for acquiring two pressure signals at different positions in the vertical direction of the upper part of the bed layer, the middle pressure acquisition assembly is used for acquiring two pressure signals at different positions in the vertical direction of the middle part of the bed layer, and the lower pressure acquisition assembly is used for acquiring two pressure signals at different positions in the vertical direction of the lower part of the bed layer.

3. The dynamic fluidized bed system of claim 2, wherein, The upper pressure acquisition assembly, the middle pressure acquisition assembly and the lower pressure acquisition assembly each comprise two pipe bodies and a pressure sensor, the two pipe bodies are detachably fixedly connected, the pressure sensor has two data input ports, the pipe bodies and the data input ports are in one-to-one correspondence, the pipe bodies are connected with the data input ports, and the pipe bodies are inserted into the bed layer and the two pipe bodies are located at different positions in the vertical direction of the bed layer.

4. The dynamic fluidized bed system of claim 3, wherein, The height difference between the two pipe bodies is 1.5-2.5 cm, and the inner diameter of the pipe body is 3-5 mm.

5. The dynamic fluidized bed system of claim 3, wherein, The upper pressure acquisition component, the middle pressure acquisition component and the lower pressure acquisition component further comprise a filter layer, which is sleeved on the air inlet of the pipe body.

6. The dynamic fluidized bed system of claim 1, wherein, The dynamic fluidized bed system further comprises a flow regulating valve arranged on the pipeline connecting the air bag and the fluidized cavity.

7. The dynamic fluidized bed system of claim 1, wherein, The dynamic fluidized bed system further comprises a flow meter arranged on the pipeline connecting the air bag and the fluidized cavity.

8. A dynamic fluidization sorting method characterized by, The separation method comprises the following steps by using the dynamic fluidized bed system according to any one of claims 1 to 7: Step 1: setting the sampling frequency and sampling time of the pressure acquisition unit, selecting the vibration frequency, vibration amplitude, air supply flow and coal sample flow; Step 2: starting the vibration table and the air blower, and feeding the coal sample into the fluidized cavity, wherein the coal sample refers to the sample of raw coal; Step 3: the pressure acquisition unit acquires the pressure signals at different positions in the vertical direction of the bed layer and transmits them to the controller, the controller receives the pressure signals to calculate the differential pressure signals, converts the differential pressure signals into density signals, and processes the density signals to generate the Hilbert graph of the particles in the bed layer; Step 4: judging whether the bed layer is in a mixed state or a separated state according to the Hilbert graph; If the bed layer is in a mixed state, proceed to step 5; If the bed layer is in a separated state, increase the vibration frequency, vibration amplitude and / or air supply flow, and / or reduce the coal sample flow, and repeat step 3; Step 5: feeding the raw coal into the fluidized cavity, and separating the raw coal according to the selected vibration frequency, vibration amplitude, air supply flow and coal sample flow.

9. The dynamic fluidization sorting method of claim 8, wherein, The step 3 comprises the following steps: Step 31: the pressure acquisition unit acquires two groups of pressure signals at the upper part of the bed layer, two groups of pressure signals at the middle part of the bed layer and two groups of pressure signals at the lower part of the bed layer respectively, and transmits them to the controller; Step 32: the controller receives the pressure signals to calculate the differential pressure signals at the upper part of the bed layer, the differential pressure signals at the middle part of the bed layer and the differential pressure signals at the lower part of the bed layer; Step 33: converting the differential pressure signals into density signals by a conversion formula, wherein the conversion formula is formed after the pressure sensor is calibrated, and the conversion formula is as follows: In the formula, g is the gravity coefficient, N / kg; h is the height difference of the pipe body, mm; p is the bed density, g / cm 3 ; Step 34: defining the set of all ρ as the density signal, empirically mode decomposing the density signal, and obtaining a plurality of intrinsic mode functions according to the different density fluctuation frequencies; Step 35: performing Hilbert transform on each intrinsic mode function to obtain the analytical signal of each intrinsic mode function, integrating the analytical signals of all intrinsic mode functions to obtain the Hilbert graph of the particles in the bed layer. ​ ​

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