Load adaptive circulating fluid bed reactor and exhaust gas treatment system and method

Abstract

The application discloses a load-adaptive circulating fluidized bed reaction tower and a waste gas treatment system and method. The load-adaptive circulating fluidized bed reaction tower comprises a fluidized bed, a Venturi tube, a first air inlet pipe and a first air outlet pipe, and further comprises an adjuster arranged in a diffusion pipe of the Venturi tube. The load-adaptive circulating fluidized bed reaction tower waste gas treatment system comprises the load-adaptive circulating fluidized bed reaction tower, a cyclone dust collector, a bag-type dust collector and an induced draft fan. The circulating fluidized bed reaction tower and the waste gas treatment system can adapt to different waste gas inlet loads, effectively prevent the fluidized bed from collapsing, can adjust the height of the fluidized bed, enhance the residence time of the fluidized medium in the tower and the turbulent flow effect between the gas and the solid, and improve the removal efficiency of the pollutants in the waste gas. The waste gas treatment method can automatically adapt to different waste gas inlet loads, can normally operate in a wide waste gas flow range, and has wide adaptability.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fluidized bed reactors, in particular to a load adaptive circulating fluidized bed reactor tower and waste gas treatment system and method. BACKGROUND

[0002] Fluidized bed is a kind of reactor that uses gas or liquid to pass through the granular solid layer to make the solid particles in suspended motion state and carry out gas-solid phase reaction process or liquid-solid phase reaction process, which is widely used in chemical industry, petroleum, metallurgy and environmental protection fields.

[0003] In the use process of the existing fluidized bed, the operation is complex and the flexibility is low, and the upward flow speed of the gas or liquid can only be changed in a narrow range. When the gas flow is too large, the fluidized medium is impacted by the strong gas flow and is washed out of the fluidized bed, which reduces the treatment effect and causes material waste; when the gas flow is too small, the fluidized medium cannot be suspended, which reduces the treatment effect. Moreover, when the fluidized bed stops working, the bed collapse phenomenon is easy to occur, which affects the production efficiency.

[0004] In addition, due to the violent impact and friction of the solid fluidized medium in the flow process, the fluidized medium is accelerated to be pulverized, and combined with the explosion and high-speed movement of the bubbles at the top of the bed layer, a large amount of fine particle fluidized medium is taken out of the fluidized bed, which causes obvious loss of fluidized medium and reduces the waste gas treatment efficiency. SUMMARY

[0005] In view of the problems existing in the prior art, the purpose of the present application is to provide a load adaptive circulating fluidized bed reactor tower and waste gas treatment system and method, which can adapt to different waste gas inlet load, can normally operate in a wide range of waste gas flow, and effectively prevents the bed from collapsing; at the same time, the internal circulation of the reaction tower enhances the residence time of the fluidized medium in the tower and the turbulent flow effect between the gas and the solid, strengthens the mass transfer effect, improves the removal efficiency of pollutants in the waste gas, and has wide adaptability.

[0006] In order to achieve the above purpose, the technical scheme is adopted as follows.

[0007] In a first aspect, a load adaptive circulating fluidized bed reactor tower comprises a fluidized bed, a Venturi tube, a first air inlet pipe and a first air outlet pipe; the fluidized bed comprises a first shell and a fluidized medium arranged in the first shell; a feed pipe is arranged on the left side of the lower side wall of the first shell, and a valve is arranged on the feed pipe; the Venturi tube comprises a converging pipe, a throat pipe and a diffuser pipe connected in sequence from bottom to top, the lower part of the converging pipe is provided with a discharge pipe, and the discharge pipe is provided with a valve; the first air inlet pipe is connected with the lower end of the converging pipe; the diffuser pipe is connected with the lower end of the first shell, and the upper end of the first shell is connected with the first air outlet pipe; further comprising a regulator arranged in the diffuser pipe, the regulator is used to open or close the gas passage at the connection between the throat pipe and the diffuser pipe.

[0008] Preferably, the regulator is divided into an upper half and a lower half along the middle horizontal plane; the upper half is hemispherical or conical; and the lower half is a streamlined body with a gradually decreasing radius from the middle to the lower end.

[0009] Preferably, the upper half of the regulator is conical, and the lower half is inverted conical.

[0010] Preferably, the upper half and the lower half of the regulator are detachably connected, the upper half has a cavity with a lower opening, the lower half has a cavity with an upper opening, and the regulator further comprises a counterweight that can be loaded into the upper half and the lower half.

[0011] Preferably, the counterweight is a plurality of metal balls.

[0012] Preferably, the fluidized bed further comprises an internal circulation adjustment device, which is arranged in the middle of the inner side of the first shell; the internal circulation adjustment device is a hollow inverted circular table with openings on both upper and lower end faces, and the side upper part of the internal circulation adjustment device is fixedly connected to the inner wall of the first shell in a circumferential direction.

[0013] Preferably, the fluidizing medium is limestone particles.

[0014] A load-adaptive circulating fluidized bed reactor tower waste gas treatment system, comprising the load-adaptive circulating fluidized bed reactor tower, a cyclone dust collector, a bag dust collector, and an induced draft fan; the cyclone dust collector comprises a second shell, the lower end of the second shell is provided with a first hopper, the bottom of the first hopper is provided with a first discharge pipe, and the first discharge pipe is provided with a first valve; the upper part of the side wall of the second shell is provided with a second air inlet, and the top middle is provided with a second air outlet; the bag dust collector comprises a third shell and a filter screen arranged in the third shell, the lower end of the third shell is provided with a second hopper, the bottom of the second hopper is provided with a second discharge pipe, and the second discharge pipe is provided with a second valve; the lower part of the side wall of the third shell is provided with a third air inlet, and the upper part of the side wall is provided with a third air outlet; the first air outlet pipe is connected to the second air inlet through a connecting pipe, the second air outlet is connected to the third air inlet through a connecting pipe, and the third air outlet is connected to the air inlet of the induced draft fan through a connecting pipe.

[0015] Preferably, the right side of the first shell is provided with a return pipe, the return pipe is provided with a third valve; the system further comprises an air conveying pipe and an air compressor, the left end of the air conveying pipe is in communication with the return pipe, and the right end is connected to the air outlet of the air compressor; the lower ends of the first discharge pipe and the second discharge pipe are respectively in communication with the air conveying pipe.

[0016] In the second aspect, a waste gas treatment method based on the load-adaptive circulating fluidized bed reactor tower waste gas treatment system is provided, comprising the following steps:

[0017] Step 1: Close the first valve, the second valve, and the third valve, and send the waste gas into the first air inlet pipe;

[0018] Step 2, the regulator floats upward, the exhaust gas rises from the four sides of the regulator to the inside of the fluidized bed, reacts with the fluidizing medium to remove the droplets and sulfides, and then enters the cyclone through the connecting pipe from the first air outlet;

[0019] Step 3, the cyclone performs the first stage of dust removal, and the exhaust gas after the first stage of dust removal enters the bag filter through the connecting pipe from the second air outlet;

[0020] Step 4, the bag filter performs the second stage of dust removal, and the exhaust gas after the second stage of dust removal is discharged from the third air outlet by the induced draft fan through the connecting pipe;

[0021] Step 5, when the first air inlet pipe stops sending in the exhaust gas, the first valve, the second valve and the third valve are opened; the fluidizing medium dust in the first ash bucket enters the air conveying pipeline from the first unloading pipe; the fluidizing medium dust in the second ash bucket enters the air conveying pipeline from the second unloading pipe; the air compressor is started, and the fluidizing medium dust is conveyed to the first shell through the air conveying pipeline.

[0022] Compared with the prior art, the beneficial effects of the present application are:

[0023] The load-adaptive circulating fluidized bed reaction tower and the exhaust gas treatment system can adapt to different exhaust gas inlet loads, can normally operate within a wide range of exhaust gas flow, and effectively prevents the fluidized bed from collapsing; the height of the fluidized bed can be adjusted, and the internal circulation of the reaction tower enhances the residence time of the fluidizing medium in the tower and the turbulent flow effect between the gas and the solid, strengthens the mass transfer effect, and improves the removal efficiency of the pollutants in the exhaust gas.

[0024] The load-adaptive circulating fluidized bed reaction tower exhaust gas treatment method can automatically adapt to different exhaust gas inlet loads, can normally operate within a wide range of exhaust gas flow, and has wide adaptability. BRIEF DESCRIPTION OF DRAWINGS

[0025] The present application will be further described in detail below in combination with the drawings and specific embodiments.

[0026] Figure 1 It is a structural schematic view of the load-adaptive circulating fluidized bed reaction tower;

[0027] Figure 2 It is a structural schematic view of the Venturi tube and the regulator;

[0028] Figure 3 It is a structural schematic view of the regulator;

[0029] Figure 4 It is a structural schematic view of the load-adaptive circulating fluidized bed reaction tower exhaust gas treatment system;

[0030] The reference signs are: 1. fluidized bed, 2. venturi, 3. first air inlet pipe, 4. first air outlet pipe, 5. regulator, 6. circulating fluidized bed reaction tower, 7. cyclone, 8. bag filter, 9. induced draft fan, 10. air conveying pipe, 11. first shell, 12. fluidized medium, 13. internal circulation regulating device, 21. convergent pipe, 22. throat pipe, 23. divergent pipe, 51. upper half, 52. lower half, 53. counterweight, 71. second shell, 72. first hopper, 81. third shell, 82. second hopper, 101. air compressor. DETAILED DESCRIPTION

[0031] The embodiments of the present application will be described in detail below with reference to the examples, but those skilled in the art will understand that the following examples are only for illustration of the present application and should not be regarded as limiting the scope of the present application.

[0032] (I), Reference Figure 1 , is a structural schematic diagram of the load-adaptive circulating fluidized bed reaction tower of the present application. The load-adaptive circulating fluidized bed reaction tower comprises a fluidized bed 1, a venturi 2, a first air inlet pipe 3 and a first air outlet pipe 4; the fluidized bed 1 comprises a first shell 11 and a fluidized medium 12 arranged in the first shell 11, and a feeding pipe is arranged on the left side of the lower side wall of the first shell 11 for adding the fluidized medium 12 into the fluidized bed 1, and a valve is arranged on the feeding pipe; the venturi 2 comprises a convergent pipe 21, a throat pipe 22 and a divergent pipe 23 connected in sequence from bottom to top, and a discharge pipe is arranged at the lower part of the convergent pipe 21 for discharging waste, and a valve is arranged on the discharge pipe; the first air inlet pipe 3 is connected with the lower end of the convergent pipe 21; the divergent pipe 23 is connected with the lower end of the first shell 11, and the upper end of the first shell 11 is connected with the first air outlet pipe 4; further comprising a regulator 5 arranged in the divergent pipe 23, and the regulator 5 is used for opening or closing the gas passage at the connection between the throat pipe 22 and the divergent pipe 23.

[0033] In the present embodiment, the fluidized medium is limestone particles.

[0034] Reference Figure 2 , is a structural schematic diagram of the venturi and the regulator. The convergent pipe 21 of the venturi 2 can reduce the pressure of the waste gas flow and increase the flow rate of the waste gas flow, and the high-speed waste gas flow enters the divergent pipe 23, thereby enhancing the gas flow circulation inside the fluidized bed.

[0035] Reference Figure 3 , is a structural schematic diagram of the regulator. The regulator 5 is divided into an upper half 51 and a lower half 52 along a middle horizontal plane; the upper half 51 is hemispherical or conical; and the lower half 52 is a streamlined body with a gradually decreasing radius from the middle to the lower end. Preferably, the upper half 51 of the regulator 5 is conical, and the lower half 52 is inverted conical.

[0036] The upper half 51 and the lower half 52 of the regulator 5 are detachably connected, the upper half 51 has a lower open cavity, the lower half 52 has an upper open cavity, and the regulator further comprises a counterweight 53 which can be loaded into the upper half 51 and the lower half 52. In this embodiment, the counterweight 53 is a plurality of metal balls.

[0037] The fluidized bed 1 further comprises an inner circulation adjusting device 13 which is arranged in the middle of the inner side of the first shell 11. The inner circulation adjusting device 13 is a hollow inverted circular table which is open at both upper and lower ends. The angle between the generatrix of the hollow inverted circular table and the axis is 30-60 degrees, preferably 45 degrees. The upper side of the inner circulation adjusting device 13 is fixedly connected with the inner wall of the first shell 11 in the circumferential direction. The inner circulation adjusting device 13 enhances the residence time of the limestone particles in the tower and the turbulent flow effect between the gas and the solid, thereby strengthening the mass transfer and improving the pollutant removal efficiency.

[0038] The regulator 5 is made of light anti-corrosion wear-resistant material. When there is no waste gas entering the venturi 2, the regulator 5 is clamped on the upper pipe opening of the throat pipe 22 under the action of gravity, thereby closing the gas passage at the connection between the throat pipe 22 and the diffuser pipe 23 and preventing the fluidized medium 12 in the fluidized bed part 1 from collapsing.

[0039] When the waste gas enters the venturi 2, the regulator 5 floats up under the action of the waste gas, thereby opening the gas passage at the connection between the throat pipe 22 and the diffuser pipe 23. The regulator 5 can automatically rise and fall when the waste gas flow changes, thereby changing the waste gas flow entering the fluidized bed by controlling the waste gas flow area. When the waste gas flow increases, the regulator 5 automatically rises, and when the waste gas flow and the height of the regulator 5 are balanced, the regulator no longer rises. When the waste gas flow decreases, the regulator 5 automatically falls, and when the waste gas flow and the height of the regulator 5 are balanced, the regulator no longer falls.

[0040] When the waste gas flow greatly increases and the height of the regulator 5 is too high, the regulator 5 is opened, and spherical metal particles are loaded into the lower half 51 as counterweight components, thereby increasing the weight of the regulator and adapting to the high waste gas flow.

[0041] Working principle:

[0042] The waste gas enters the venturi from the first air inlet pipe, and the flow rate of the waste gas increases after the pressure of the waste gas flow decreases after passing through the converging pipe. The flow rate is the largest at the throat pipe, and the high-speed waste gas flow enters the diffuser pipe. The regulator floats up, the waste gas flow enters the fluidized bed, and the waste gas flow reacts with the limestone particles to remove liquid droplets and gaseous pollutants. When the inlet load of the waste gas changes, the regulator moves up and down to adjust the height of the fluidized bed, guide the flow, equalize the flow, and generate turbulence. According to the principle of gas-solid two-phase flow, the inner circulation adjusting device in the fluidized bed can enhance the residence time of the limestone particles in the tower and the turbulent flow effect between the gas and the solid, thereby strengthening the mass transfer and improving the pollutant removal efficiency.

[0043] Reference Figure 4 , a load adaptive circulating fluidized bed reactor tower waste gas treatment system structure diagram. A load adaptive circulating fluidized bed reactor tower waste gas treatment system, including the above-mentioned load adaptive circulating fluidized bed reactor 6, cyclone 7, bag filter 8 and induced draft fan 9;Cyclone 7 includes the second shell 71, the first hopper 72 is arranged at the lower end of the second shell 71, the first discharge pipe is arranged at the bottom of the first hopper 72, and the first valve is arranged on the first discharge pipe;The upper part of the second shell 71 is provided with a second air inlet, and the top is provided with a second air outlet;The bag filter 8 includes a third shell 81 and a filter screen arranged inside the third shell 81, and the second hopper 82 is arranged at the lower end of the third shell 81, and the second hopper 82 has a second discharge pipe at the bottom, and the second valve is arranged on the second discharge pipe;The lower part of the third shell 81 is provided with a third air inlet, and the upper part of the third shell 81 is provided with a third air outlet;The first air outlet pipe 4 is connected with the second air inlet through the connecting pipe, and the second air outlet is connected with the third air inlet through the connecting pipe;The third air outlet is connected with the air inlet of the induced draft fan 9 through the connecting pipe.

[0044] As an improvement of the present application, the first shell 11 is provided with a return pipe on the right side, and the return pipe is provided with a third valve;It also includes an air conveying pipe 10 and an air compressor 101, the left end of the air conveying pipe 10 is communicated with the return pipe, and the right end is connected with the air outlet of the air compressor 101;The lower end of the first discharge pipe and the second discharge pipe is communicated with the air conveying pipe 10 respectively.

[0045] The load adaptive circulating fluidized bed reactor tower waste gas treatment system of the present application has both external circulation of the system and internal circulation of the fluidized bed, and the internal circulation adjusting device in the fluidized bed enhances the residence time of limestone particles in the reactor and the turbulent flow effect between gas and solid, so as to strengthen mass transfer and improve the efficiency of pollutant removal;And it can adapt to the fluctuation of waste gas inlet load, and still work normally when the waste gas flow changes.

[0046] The load adaptive circulating fluidized bed reactor tower waste gas treatment system of the present application can be used for paint mist treatment and gaseous pollutant treatment in coating, chemical and other industries.

[0047] (II) waste gas treatment method based on load adaptive circulating fluidized bed reactor tower waste gas treatment system, including the following steps:

[0048] Step 1, close the first valve, the second valve and the third valve, and the first air inlet pipe sends in waste gas;

[0049] Step 2, the regulator floats upward, the exhaust gas rises from around the regulator to the inside of the fluidized bed, reacts with the fluidizing medium to remove droplets and sulfides, and then enters the cyclone through the connecting pipe from the first air outlet;

[0050] The exhaust gas enters the Venturi tube from the first air inlet pipe, and after passing through the convergent pipe, the exhaust gas flow pressure decreases and the flow rate increases. The flow rate is maximum at the throat, and the high-speed exhaust gas flow enters the diffuser pipe, and the regulator floats upward. When the exhaust gas inlet load changes, the regulator moves up and down to adjust the height of the fluidized bed. At the same time, the internal circulation adjustment device in the fluidized bed enhances the residence time of limestone particles in the tower and the turbulent flow effect between gas and solid, which strengthens mass transfer and improves the efficiency of pollutant removal. When the height of the regulator and the exhaust gas inlet load reach a balanced state, the height of the regulator remains unchanged. The gas enters the fluidized bed and reacts with the limestone particles to remove droplets and gaseous pollutants in the exhaust gas, and then the exhaust gas is discharged from the first air outlet.

[0051] Step 3, the cyclone performs the first stage of dust removal, and the exhaust gas after the first stage of dust removal enters the bag filter through the connecting pipe from the second air outlet;

[0052] The exhaust gas containing the dust of the fluidizing medium enters the tangential inlet of the cyclone, rotates at high speed in the second shell to generate centrifugal force, and the larger particles of the fluidizing medium dust are separated from the exhaust gas and fall into the first hopper at the lower end of the second shell. The gas after the first stage of dust removal enters the bag filter through the connecting pipe from the second air outlet.

[0053] Step 4, the bag filter performs the second stage of dust removal, and the exhaust gas after the second stage of dust removal is discharged from the third air outlet through the connecting pipe by the induced draft fan;

[0054] The exhaust gas after the first stage of dust removal still contains fine particles of the fluidizing medium dust. After entering the bag filter, the filter screen filters the remaining fine particles of the fluidizing medium dust, and the filtered fine particles of the fluidizing medium dust fall into the second hopper at the lower end of the third shell. The gas after the second stage of dust removal enters the induced draft fan inlet through the connecting pipe from the third air outlet, and is discharged by the induced draft fan.

[0055] Step 5, when the first air inlet pipe stops sending in the exhaust gas, the first valve, the second valve and the third valve are opened; the fluidizing medium dust in the first hopper enters the air conveying pipeline from the first unloading pipe; the fluidizing medium dust in the second hopper enters the air conveying pipeline from the second unloading pipe; the air compressor is started, and the fluidizing medium dust is conveyed into the first shell through the air conveying pipeline.

[0056] The limestone particles collected by the cyclone and the bag filter enter the fluidized bed through the air conveying pipeline, realizing the recycling of the limestone particles.

[0057] While the application has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. It is therefore intended that whatever lies within the scope of the application be covered by the appended claims.

Claims

1. A load-adaptable circulating fluidized bed reactor column, characterized in that, The utility model relates to a fluidized bed, a venturi, a first air inlet pipe and a first air outlet pipe, the fluidized bed comprises a first shell and a fluidizing medium arranged in the first shell, the first shell is provided with a feeding pipe on the left side of the lower side wall, and a valve is arranged on the feeding pipe, the venturi comprises a converging pipe, a throat pipe and a diffuser pipe connected in sequence from bottom to top, the converging pipe is provided with a discharge pipe at the lower part, and the discharge pipe is provided with a valve, the first air inlet pipe is connected with the lower end of the converging pipe, the diffuser pipe is connected with the lower end of the first shell, the upper end of the first shell is connected with the first air outlet pipe, and an adjuster is arranged in the diffuser pipe, the adjuster is used for opening or closing the gas passage at the connection position between the throat pipe and the diffuser pipe. The adjuster is divided into an upper half and a lower half along a middle horizontal plane, the upper half is semispherical or conical, the lower half is a streamlined body with a gradually decreasing radius from the middle to the lower end, the upper half of the adjuster is conical, and the lower half is inverted conical. The upper half and the lower half of the adjuster are detachably connected, the upper half has a cavity with an opening at the lower part, the lower half has a cavity with an opening at the upper part, and a counterweight is arranged in the upper half and the lower half, the counterweight comprises a plurality of metal balls. The fluidized bed further comprises an internal circulation adjusting device arranged in the middle of the inner side of the first shell, the internal circulation adjusting device is a hollow inverted circular table with openings on the upper and lower end faces, and the upper part of the side face of the internal circulation adjusting device is fixedly connected with the inner wall of the first shell in the circumferential direction.

2. The load-adaptive circulating fluid bed reaction column according to claim 1, characterized in that The fluidizing medium is limestone particles.

3. A load-adaptive circulating fluidized bed reactor off-gas treatment system, characterized in that, The load adaptive circulating fluidized bed reactor tower (6), the cyclone (7), the bag filter (8) and the induced draft fan (9) are comprised; the cyclone (7) comprises a second shell (71), the lower end of the second shell (71) is provided with a first ash bucket (72), the bottom of the first ash bucket (72) is provided with a first discharge pipe, and the first discharge pipe is provided with a first valve; the upper part of the second shell (71) is provided with a second air inlet, and the top is provided with a second air outlet; the bag filter (8) comprises a third shell (81) and a filter screen arranged in the third shell (81), the lower end of the third shell (81) is provided with a second ash bucket (82), the bottom of the second ash bucket (82) is provided with a second discharge pipe, and the second discharge pipe is provided with a second valve; the lower part of the third shell (81) is provided with a third air inlet, and the upper part is provided with a third air outlet; the first air outlet pipe (4) is connected with the second air inlet through a connecting pipe, the second air outlet is connected with the third air inlet through a connecting pipe, and the third air outlet is connected with the air inlet of the induced draft fan (9) through a connecting pipe.

4. The load-adaptive circulating fluid bed reactor effluent treatment system of claim 3, wherein, The first shell (11) is provided with a return pipe on the right side, the return pipe is provided with a third valve; further comprising an air conveying pipe (10) and an air compressor (101), the left end of the air conveying pipe (10) is communicated with the return pipe, and the right end is connected with the air outlet of the air compressor (101); the lower ends of the first discharge pipe and the second discharge pipe are communicated with the air conveying pipe (10) respectively.

5. A method for treating exhaust gas of a circulating fluidized bed reactor tower according to any one of claims 3 or 4, characterized in that The following steps are comprised: Step 1, the first valve, the second valve and the third valve are closed, and the first air inlet pipe sends in waste gas; Step 2, the regulator floats upwards, the waste gas rises from the periphery of the regulator to the inside of the fluidized bed, reacts with the fluidized medium to remove droplets and sulfides, and then enters the cyclone through the connecting pipe from the first air outlet; Step 3, the cyclone carries out the first stage of dust removal, and the waste gas after the first stage of dust removal enters the bag filter through the connecting pipe from the second air outlet; Step 4, the bag filter carries out the second stage of dust removal, and the waste gas after the second stage of dust removal is discharged by the induced draft fan through the connecting pipe from the third air outlet; Step 5, when the first air inlet pipe stops sending in waste gas, the first valve, the second valve and the third valve are opened; the fluidized medium dust in the first ash bucket enters the air conveying pipe from the first discharge pipe; the fluidized medium dust in the second ash bucket enters the air conveying pipe from the second discharge pipe; the air compressor is started, and the fluidized medium dust is conveyed into the first shell through the air conveying pipe.

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