Dynamic fluidized bed system and dynamic fluidized separation method

Abstract

The invention discloses a dynamic fluidized bed system and a dynamic fluidized separation method, belongs to the technical field of fluidized particle separation system measurement, and aims to solve the problem of poor detection precision of a mixed separation state of pulverized coal in a separation process in the prior art. In the dynamic fluidized bed system, a pressure acquisition unit acquires pressure signals at different positions of a bed layer in the vertical direction and transmits the pressure signals to a controller, the controller receives the pressure signals, calculates pressure difference signals, converts the pressure difference signals into density signals, and processes the density signals to generate a Hilbert map of particles in the bed layer; and judging whether the bed layer is in a mixed state or a separated state according to the Hilbert spectrum. The method can be used for dynamic fluidized separation of raw coal.

Description

Technical Field

[0001] The invention belongs to the technical field of sorting fluidized particle system measurement, and in particular relates to a dynamic fluidized bed system and a dynamic fluidized sorting method. Background Art

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

[0003] In the actual sorting process, coal powder with a particle size of less than 0.5 mm will be stratified with the weighting material, affecting the subsequent sorting effect. Therefore, detecting the mixed separation state of coal powder with a particle size of less than 0.5 mm and the weighting material is very important for sorting. However, in the prior art, the detection accuracy of the mixed separation state of coal powder with a particle size of less than 0.5 mm is poor. Summary of the invention

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

[0005] The purpose of the present invention is mainly achieved through the following technical solutions.

[0006] The present invention provides a dynamic fluidized bed system, comprising a blower, a vibration table, a fluidizing chamber, a pressure collection unit and a processor; the fluidizing chamber is placed on the vibration table, the vibration table drives the fluidizing chamber to vibrate, and the air outlet of the blower is connected with the inner cavity of the fluidizing chamber; the data collection end of the pressure collection unit is located in the bed layer of the fluidizing chamber, the pressure collection unit collects pressure signals at different positions of the bed layer in the vertical direction and transmits them to a controller, the controller receives the pressure signal to calculate a pressure difference signal, converts the pressure difference signal into a density signal, and processes the density signal to generate a Hilbert spectrum 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 spectrum.

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

[0008] Furthermore, the upper pressure collection assembly, the middle pressure collection assembly and the lower pressure collection assembly each include two tube bodies and a pressure sensor, the two tube bodies are detachably fixedly connected, the pressure sensor has two data input ports, the tube bodies correspond to the data input ports one by one, the tube bodies are connected to the data input ports, the tube bodies are inserted into the bed layer and the two tube bodies are located at different positions in the bed layer 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 tube is 3 to 5 mm.

[0010] Furthermore, the upper pressure collection component, the middle pressure collection component and the lower pressure collection component also include a filter layer, and the filter layer is sleeved on the air inlet of the pipe body.

[0011] Furthermore, the dynamic fluidized bed system also includes a flow regulating valve arranged on the pipeline connecting the wind bag and the fluidizing chamber.

[0012] Furthermore, the dynamic fluidized bed system also includes a flow meter arranged on the pipeline connecting the wind bag 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 fluidizing chamber and is connected to the fluidizing 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 arranged between the air distribution chamber and the fluidizing 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 separation method, using the above-mentioned dynamic fluidized bed system, the separation method comprises 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 the blower to supply a coal sample into the fluidizing chamber, where the coal sample refers to a sample of raw coal;

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

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

[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 flow rate, and / or reduce the coal sample flow rate, and repeat step 3;

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

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

[0023] Step 31: The pressure acquisition unit respectively acquires two groups of pressure signals at the upper part of the bed, two groups of pressure signals at the middle part, and two groups of pressure signals at the lower part, and transmits them to the controller;

[0024] Step 32: The controller receives the pressure signal and calculates to obtain a pressure difference signal of the upper part of the bed layer, a pressure difference signal of the middle part of the bed layer, and a pressure difference signal of the lower part of the bed layer;

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

[0026]

[0027] Where:

[0028] ρ is bed density, g / cm 3 ;

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

[0030] h is the height difference of the tube, mm;

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

[0032] Step 35: Perform Hilbert transform on each intrinsic mode function to obtain the analytical signal of each intrinsic mode function, integrate the analytical 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 at least achieve the following beneficial effects:

[0034] The dynamic fluidized bed system provided by the present invention is provided with a pressure collection unit in the bed layer of the fluidizing chamber, which respectively collects pressure signals at different positions of the bed layer in the vertical direction, and generates a Hilbert spectrum of particles in the bed layer according to the pressure signals. It is judged according to the Hilbert spectrum whether the bed layer is in a mixed state or a separated state, so that the state of the bed layer can be understood before formal sorting, and the bed layer can be adjusted to a mixed state by adjusting various parameters, so as to better guide the subsequent formal sorting, which is conducive to improving the sorting effect.

[0035] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the embodiments of the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings are only for the purpose of illustrating specific embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0037] Figure 1 A schematic structural diagram of a dynamic fluidized bed system provided by the present invention;

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

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

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

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

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

[0043] Figure 5a is the Hilbert spectrum of the upper part of the bed in Example 1;

[0044] Figure 5b This is the Hilbert spectrum of the middle part of the bed in Example 1;

[0045] Figure 5c is the Hilbert spectrum of the lower part of the bed in Example 1;

[0046] Figure 6a This is a schematic diagram of the EMD decomposition of the upper part of the bed in Example 2;

[0047] Figure 6b This is a schematic diagram of EMD decomposition in the middle of the bed in Example 2;

[0048] Figure 6c This is a schematic diagram of the EMD decomposition of the lower part of the bed in Example 2;

[0049] Figure 7ais the Hilbert spectrum of the upper part of the bed in Example 2;

[0050] Figure 7b This is the Hilbert spectrum of the middle part of the bed in Example 2;

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

[0052] Reference numerals:

[0053] 1-blower; 2-wind bag; 3-flow meter; 4-flow regulating valve; 5-vibrating table; 6-fluidizing chamber; 7-air distribution chamber; 701-inner telescopic sealing ring; 702-outer telescopic sealing ring; 703-inner pipe; 704-outer pipe; 705-vacuum pump; 8-air distribution plate; 9-air distribution layer; 10-tube body; 11-pressure sensor; 12-controller; 13-gangue discharge port. DETAILED DESCRIPTION

[0054] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings 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 used to limit the scope of the present invention.

[0055] In a first aspect, the present invention provides a dynamic fluidized bed system, see Figure 1 , including a blower 1, an air bag 2, a vibration table 5, a fluidizing chamber 6, a pressure collection unit and a processor. The fluidizing chamber 6 is placed on the vibration table 5. The vibration table 5 drives the fluidizing chamber 6 to perform periodic sinusoidal vertical vibration. The vibration frequency is 0-50 Hz and the amplitude is 1-5 mm. The air outlet of the blower 1 is connected with the inner cavity of the fluidizing chamber 6 through the air bag 2, and airflow is introduced into the inner cavity of the fluidizing chamber 6. The airflow and vibration work together to drive the particles in the fluidizing chamber 6 to fluidize. The fluidizing chamber 6 is provided with a raw coal feed port and a gangue discharge port 1313. The raw coal feed port Located on the top side of the fluidizing chamber 6, the gangue discharge port 1313 is located on the bottom side of the fluidizing chamber 6, and the data acquisition end of the pressure acquisition unit is located in the bed of the fluidizing chamber 6. The pressure acquisition unit collects pressure signals at different positions of the bed in the vertical direction and transmits them to the controller 12. The controller 12 receives the pressure signal and calculates the pressure difference signal, converts the pressure difference signal into a density signal, and processes the density signal to generate a Hilbert map of the particles in the bed. According to the Hilbert map, it is judged whether the bed is in a mixed state or a separated state.

[0056] The specific judgment methods are as follows:

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

[0058] Specifically, the pressure collection unit includes an upper pressure collection component, a middle pressure collection component and a lower pressure collection component which are arranged in sequence from top to bottom. The upper pressure collection component is used to collect two pressure signals at different positions on the upper part of the bed in the vertical direction, the middle pressure collection component is used to collect two pressure signals at different positions in the middle part of the bed in the vertical direction, and the lower pressure collection component is used to collect two pressure signals at different positions on the lower part of the bed in the vertical direction. The difference between the two pressure signals is the pressure difference signal.

[0059] Compared with the prior art, the dynamic fluidized bed system provided by the present invention is provided with a pressure collection unit in the bed layer of the fluidizing chamber 6, which collects pressure signals at different positions of the bed layer in the vertical direction, and generates a Hilbert map of the particles in the bed layer according to the pressure signals. It is judged according to the Hilbert map whether the bed layer is in a mixed state or a separated state, so that the state of the bed layer can be understood before formal sorting, and the bed layer can be adjusted to a mixed state by adjusting various parameters, so as to better guide the subsequent formal sorting, which is conducive to improving the sorting effect.

[0060] It should be noted that, during implementation, the raw coal enters the fluidizing chamber 6 from the raw coal feed port, and the airflow is supplied into the fluidizing chamber 6; in the fluidizing chamber 6, the raw coal is subjected to the composite force field of the exciting force and the airflow, and stratification occurs in the longitudinal direction of the fluidizing chamber 6 according to the density difference. The light-density rougher clean coal stays in the upper part of the fluidizing chamber 6, and the heavy-density gangue particles sink to the lower part of the fluidizing chamber 6. The intermediate-density material (including the mixture of medium coal and re-selected clean coal) is suspended in the middle position of the fluidizing chamber 6, thereby realizing the sorting of the raw coal.

[0061] In order to be able to adjust the gas flow supplied into the fluidizing chamber 6, the above-mentioned dynamic fluidized bed system also includes a flow regulating valve 4 arranged on the pipeline connecting the wind bag 2 and the fluidizing chamber 6, and the gas flow supplied into the fluidizing chamber 6 is adjusted by the flow regulating valve 4.

[0062] In order to detect the gas flow rate supplied into the fluidizing chamber 6 in real time, the above-mentioned dynamic fluidized bed system also includes a flow meter 3 arranged on the pipeline connecting the wind bag 2 and the fluidizing chamber 6, and the flow meter 3 detects the gas flow rate supplied into the fluidizing chamber 6 by the wind bag 2 in real time.

[0063] In order to achieve stable connection between various components, the blower 1 and the wind bag 2, the wind bag 2 and the flow meter 3, the flow meter 3 and the flow regulating valve 4, and the flow regulating valve 4 and the fluidizing chamber 6 are all connected by pipelines. For example, the pipelines between the blower 1 and the wind bag 2, between the wind bag 2 and the flow meter 3, and between the flow meter 3 and the flow regulating valve 4 are rigid pipelines, and the pipeline between the flow regulating valve 4 and the fluidizing chamber 6 is a flexible pipeline to adapt to the vibration of the fluidizing chamber 6.

[0064] In order to ensure the processing capacity of the fluidizing chamber 6, illustratively, the inner diameter of the fluidizing chamber 6 is 350-450 mm (eg, 400 mm), and the height of the fluidizing chamber 6 is 450-550 mm (eg, 500 mm).

[0065] In order to ensure the stability of the airflow supplied into the fluidizing chamber 6, the above-mentioned 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 is connected to the fluidizing chamber 6. 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 arranged between the air distribution chamber 7 and the fluidizing chamber 6. The air inlet of the air distribution chamber 7 is connected to the air outlet of the wind bag 2. In this way, by setting the air distribution chamber 7, the air distribution plate 8 and the air distribution layer 9, the stability of the airflow supplied into the fluidizing chamber 6 can be ensured, so that a stable bed layer can be generated.

[0066] Exemplarily, the air distribution plate 8 is a porous steel plate with a thickness of 2.5 to 4 mm (for example, 3 mm), a pore size of 2.5 to 3.5 mm (for example, 3 mm), a center distance between two adjacent air holes of 4.5 to 5.0 mm (for example, 4.8 mm), and an opening rate of the air distribution plate 8 of 25 to 35% (for example, 30%).

[0067] In order to ensure the sealed connection between the air distribution chamber 7 and the fluidization chamber 6 , an elastic sealing gasket (for example, a rubber gasket) is provided between the air distribution chamber 7 and the fluidization chamber 6 .

[0068] In order to ensure the accuracy of pressure collection and reduce the impact of the setting of the pressure collection unit on the bed, the structures of the upper pressure collection assembly, the middle pressure collection assembly and the lower pressure collection assembly are basically the same, all of which include two tubes 10 (for example, copper tubes) and a pressure sensor 11. The two tubes 10 are detachably fixedly connected. The pressure sensor 11 has two data input ports. The tubes 10 correspond to the data input ports one by one. The tubes 10 are connected to the data input ports through a connecting tube (for example, a rubber hose). 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] Exemplarily, the height difference between the two tubes 10 is 1.5-2.5 cm (eg, 2 cm), and the inner diameter of the tube 10 is 3-5 mm (eg, 4 mm).

[0070] In order to prevent particles in the bed from entering the pipe body 10 and causing blockage of the pipe body 10, the upper pressure collection assembly, the middle pressure collection assembly and the lower pressure collection assembly also include a filter layer, which is sleeved on the air inlet of the pipe body 10 to filter the particles in the bed.

[0071] In a second aspect, the present invention provides another dynamic fluidized bed system, the structure of which is substantially the same as that of the dynamic fluidized bed system provided in Example 1, except that:

[0072] Taking into account that the gangue particles will move along the air distribution plate 8 to the gangue discharge port 13 for discharge, in order to be able to adjust the discharge speed of the gangue particles, illustratively, one end of the air distribution plate 8 close to the gangue discharge port 13 is rotatably connected to the fluidizing chamber, and the other end of the air distribution plate 8 is a free end. By rotating the air distribution plate 8 to adjust the inclination angle of the air distribution plate 8, the discharge speed of the gangue particles can be adjusted.

[0073] In order to adjust the inclination angle of the air distribution plate 8 by using the air flow, the structure of the air distribution chamber 7 is specifically described in detail. 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 peripheral area surrounding the central area. The peripheral area is provided with a main air distribution hole, and the central area is not provided with a main air distribution hole. The air outlet of the inner tube 703 covers the central area and is connected to the edge of the central area through the inner telescopic sealing ring 701. An air pump 705 is provided on the inner tube 703, and the air outlet of the outer tube 704 covers the peripheral area and is connected to the edge of the peripheral area through the outer telescopic sealing ring 702.

[0074] When there is no need to increase the inclination angle of the air distribution plate 8, only the outer tube 704 supplies air to the fluidization chamber through the main air distribution hole; when the inclination angle of the air distribution plate 8 needs to be increased, the air pump 705 is turned on, and airflow is introduced into the inner tube 703 and the outer tube 704 at the same time, so that the length of the inner telescopic sealing ring 701 and the outer telescopic sealing ring 702 increases, the air distribution plate 8 rotates clockwise, and the inclination angle of the air distribution plate 8 increases. In this way, the air distribution plate 8 can be driven to rotate by the pressure of the airflow through the inner tube 703 and the outer tube 704 that cooperate with each other, so as to realize the adjustment of the inclination angle of the air distribution plate 8 by airflow, without the need to equip other additional air distribution plate 8 driving mechanisms.

[0075] In a third aspect, the present invention provides a third dynamic fluidized bed system, the structure of which is substantially the same as that of the dynamic fluidized bed system provided in Example 1, except that:

[0076] For the structure of the air distribution plate 8, see Figure 3 , including an air distribution slot and a partition rib 802, the partition rib 802 is arranged in the air distribution slot, dividing the air distribution slot into a plurality of air distribution sub-slots 801, an air inlet hole is provided at the bottom of each air distribution sub-slot 801, and an air distribution layer 9 covers the slot of the air distribution slot.

[0077] In a fourth aspect, the present invention provides a dynamic fluidized separation method, using the dynamic fluidized bed system provided in the first aspect, the second aspect or the third aspect, the separation 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 the blower to supply a coal sample into the fluidizing chamber, where the coal sample refers to a sample of raw coal;

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

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

[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 flow rate, and / or reduce the coal sample flow rate, and repeat step 3;

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

[0085] Compared with the prior art, the beneficial effects of the dynamic fluidized separation method provided by the present invention are substantially the same as the beneficial effects of the dynamic fluidized bed system provided by the first aspect, the second aspect or the third aspect, and are not described in detail herein.

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

[0087] Step 31: The pressure acquisition unit respectively acquires two groups of pressure signals at the upper part of the bed, two groups of pressure signals at the middle part, and two groups of pressure signals at the lower part, and transmits them to the controller;

[0088] Step 32: The controller receives the pressure signal and calculates to obtain a pressure difference signal of the upper part of the bed layer, a pressure difference signal of the middle part of the bed layer, and a pressure difference signal of the lower part of the bed layer;

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

[0090]

[0091] Where:

[0092] ρ is bed density, g / cm 3 ;

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

[0094] h is the height difference of the tube, 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 a number of intrinsic mode functions (IMFs) and a residual signal that can characterize the overall density change trend according to the density fluctuation frequency. Each intrinsic mode function represents the density fluctuation frequency of the density signal x(t) on different time scales, and obtain an EMD decomposition diagram of the particles in the dynamic fluidized bed system (including separation state and / or mixing state);

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

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

[0098] Specifically, in the above step 4, the method for judging whether the bed is in a mixed state or a separated state according to the Hilbert spectrum is as follows:

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

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

[0101] Example 1

[0102] This embodiment provides a dynamic fluidized separation method. For specific methods, see the fourth aspect. The parameters are as follows:

[0103] There are three pressure sensors, each corresponding to two copper tubes, which are bound into a group. The three groups of copper tubes are respectively inserted into the upper, middle and bottom of the fluidized bed. The sampling frequency of the pressure sensor is 200 Hz, and the sampling time is 20 s. The pressure signal at the 10th to 15th second is captured 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 flow rate of the fluidization chamber is U g =1.0U mfv , the coal sample flow rate is 0.3kg / s.

[0105] The obtained intrinsic mode functions can be found in Figures 4a to 4c (IMF-1, IMF-2, IMF-3, IMF-4, IMF-5 and IMF6), Hilbert spectrum see Figure 5a to Figure 5c ,from Figures 4a to 4c It can be seen that the fluctuation forms and amplitudes of IMF-1 in the upper, middle and lower parts are obviously different. With the increase of bed depth, the fluctuation of IMF-1 becomes more regular and the amplitude becomes larger.

[0106] from Figure 5a to Figure 5c It can be seen that there is a more obvious 0-10Hz density fluctuation amplitude in the upper part, while the density fluctuation amplitude of 20-30Hz is weaker. There is a more obvious 25Hz density fluctuation amplitude in the middle and bottom, indicating that the bed is in a separated state, and the density fluctuation amplitude and distribution form of each area of ​​the bed are very different.

[0107] Example 2

[0108] This embodiment provides a dynamic fluidized separation method. For specific methods, see the fourth aspect. The parameters are as follows:

[0109] There are three pressure sensors, each corresponding to two copper tubes, which are bound into a group. The three groups of copper tubes are respectively inserted into the upper, middle and bottom of the fluidized bed. The sampling frequency of the pressure sensor is 200 Hz, and the sampling time is 20 s. The pressure signal at the 10th to 15th second is captured 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 flow rate of the fluidization chamber is U g =1.4U mfv , the coal sample flow rate is 0.25kg / s.

[0111] The obtained intrinsic mode functions can be found in Figures 6a to 6c , Hilbert graph see Figures 7a to 7c ,from Figures 6a to 6c It can be seen that the oscillation modes, fluctuation amplitude forms and change laws of the upper, middle and lower IMF-1 tend to be consistent.

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

[0113] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A dynamic fluidized bed system, characterized in that: It includes a blower, a vibrating table, a fluidizing chamber, a pressure acquisition unit and a processor; The fluidizing chamber is placed on a vibration table, the vibration table drives the fluidizing chamber to vibrate, and the air outlet of the blower is connected to the inner cavity of the fluidizing chamber; The data acquisition end of the pressure acquisition unit is located in the bed layer of the fluidizing chamber. The pressure acquisition unit collects pressure signals at different positions of the bed layer in the vertical direction and transmits them to the controller. The controller receives the pressure signal and calculates the pressure difference signal, converts the pressure difference signal into a density signal, and processes the density signal to generate a Hilbert map of the particles in the bed layer. According to the Hilbert map, it is judged whether the bed layer is in a mixed state or a separated state.

2. The dynamic fluidized bed system according to claim 1, characterized in that: The pressure collection unit includes an upper pressure collection component, a middle pressure collection component and a lower pressure collection component which are arranged in sequence from top to bottom. The upper pressure collection component is used to collect two pressure signals at different positions of the upper part of the bed in the vertical direction, the middle pressure collection component is used to collect two pressure signals at different positions of the middle part of the bed in the vertical direction, and the lower pressure collection component is used to collect two pressure signals at different positions of the lower part of the bed in the vertical direction.

3. The dynamic fluidized bed system according to claim 2, characterized in that: The upper pressure collection component, the middle pressure collection component and the lower pressure collection component each include two tubes and a pressure sensor, the two tubes are detachably fixedly connected, the pressure sensor has two data input ports, the tubes correspond to the data input ports one by one, the tubes are connected to the data input ports, the tubes are inserted into the bed layer, and the two tubes are located at different positions in the bed layer in the vertical direction.

4. The dynamic fluidized bed system according to claim 3, characterized in that: The height difference between the two tubes is 1.5-2.5 cm, and the inner diameter of the tube is 3-5 mm.

5. The dynamic fluidized bed system according to claim 3, characterized in that: The upper pressure collection component, the middle pressure collection component and the lower pressure collection component further include a filter layer, and the filter layer is sleeved on the air inlet of the pipe body.

6. The dynamic fluidized bed system according to claim 1, characterized in that: The dynamic fluidized bed system also includes a flow regulating valve arranged on a pipeline connecting the wind bag and the fluidizing chamber.

7. The dynamic fluidized bed system according to claim 1, characterized in that: The dynamic fluidized bed system also includes a flow meter arranged on the pipeline connecting the wind bag and the fluidizing chamber.

8. The dynamic fluidized bed system according to claim 1, characterized in that: 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 fluidizing chamber and is connected to the fluidizing chamber. The bottom end of the air distribution chamber is connected to a vibration table. The air distribution plate and the air distribution layer are arranged between the air distribution chamber and the fluidizing chamber. The air inlet of the air distribution chamber is connected to the air outlet of a blower.

9. A dynamic fluidized separation method, characterized in that: Using the dynamic fluidized bed system according to any one of claims 1 to 8, the separation method comprises the following steps: 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; Step 2: Turn on the vibration table and the blower to supply a coal sample into the fluidizing chamber, where the coal sample refers to a sample of raw coal; Step 3: The pressure acquisition unit collects pressure signals at different positions of the bed in the vertical direction and transmits them to the controller. The controller receives the pressure signal and calculates the pressure difference signal, converts the pressure difference signal into a density signal, and processes the density signal to generate a Hilbert map of the particles in the bed. Step 4: Determine whether the bed is in a mixed state or a separated state based on the Hilbert spectrum; If the bed is in a mixed state, proceed to step 5; If the bed is in a separated state, increase the vibration frequency, vibration amplitude and / or gas flow rate, and / or reduce the coal sample flow rate, and repeat step 3; Step 5: Feed raw coal into the fluidizing chamber and sort the raw coal according to the selected vibration frequency, vibration amplitude, gas flow rate and coal sample flow rate.

10. The dynamic fluidized separation method according to claim 9, characterized in that: The step 3 comprises the following steps: Step 31: The pressure acquisition unit respectively acquires two groups of pressure signals at the upper part of the bed, two groups of pressure signals at the middle part, and two groups of pressure signals at the lower part, and transmits them to the controller; Step 32: The controller receives the pressure signal and calculates to obtain a pressure difference signal of the upper part of the bed, a pressure difference signal of the middle part of the bed, and a pressure difference signal of the lower part of the bed; Step 33: Convert the differential pressure signal into a density signal through a conversion formula. The conversion formula needs to be formed after the pressure sensor is calibrated. The conversion formula is as follows: Where: ρ is bed density, g / cm 3 ; g is the gravity coefficient, N / kg; h is the height difference of the tube, mm; Step 34: define the set of all ρ as a density signal, perform empirical mode decomposition on the density signal, and obtain several intrinsic mode functions according to different density fluctuation frequencies; Step 35: Perform Hilbert transform on each intrinsic mode function to obtain the analytical signal of each intrinsic mode function, integrate the analytical signals of all intrinsic mode functions to obtain the Hilbert spectrum of the particles in the bed.

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