External circulation spouted fluidized bed for integrated desulfurization, decarbonization and particle separation and operation method of external circulation spouted fluidized bed

Abstract

The invention relates to an integrated desulfurization and decarburization particle separation external circulation spouted fluidized bed and an operation method, and belongs to the technical field of flue gas desulfurization and decarburization. An air inlet is formed in the bottom of the fluidized bed, a miniature cyclone separator is arranged in the fluidized bed, the air inlet of the spouted bed is communicated with an exhaust port of the fluidized bed, and an exhaust port of the miniature cyclone separator is communicated with the exhaust port of the fluidized bed; the bottom of the micro cyclone separator is communicated with the outside; a calcium oxide feeding port is arranged at the lower end of the spouted bed, the top of the spouted bed is communicated with an air inlet of the cyclone separator, an air outlet of the cyclone separator is communicated with an inlet of the calcining furnace, and a carbon dioxide discharge pipe is arranged on the calcining furnace. A calcium hydroxide slurry inlet is formed in the top of the intermittent fluidized bed, a calcium oxide feeding port is provided with a sealing cover, a calcining furnace outlet is communicated with a calcium oxide powder discharge pipe or a guide pipe inlet, and a guide pipe outlet is communicated with the lower end of the spouted bed; a liquid inlet is formed in the top of the continuous fluidized bed, the calcium oxide feeding port is an opening, an outlet of the calcining furnace is communicated with an inlet of the material guide pipe, and an outlet of the material guide pipe is communicated with the fluidized bed.

Description

Technical Field

[0001] The invention belongs to the technical field of flue gas desulfurization and decarbonization, and particularly relates to an external circulation spouted fluidized bed for integrated desulfurization and decarbonization particle separation and an operation method thereof. Background Art

[0002] At present, coal is usually utilized by combustion, which will produce a large amount of sulfuric acid dioxide gas and carbon dioxide greenhouse gas, which has a great negative impact on the environment and people's lives. Therefore, desulfurization and decarbonization technology came into being.

[0003] There are many desulfurization technologies, which can be divided into three categories: dry desulfurization, semi-dry desulfurization and wet desulfurization. Among them, the semi-dry desulfurization process is widely used due to its advantages such as low investment, small footprint, low operating cost and no wastewater discharge. In terms of decarbonization technology, it mainly includes absorption separation, adsorption separation, membrane separation and low-temperature separation. The integrated desulfurization and decarbonization removal technologies include: flue gas cascade desulfurization and decarbonization technology, flue gas combined desulfurization and decarbonization technology, etc. Factories often use flue gas cascade desulfurization and decarbonization technology, and desulfurization and decarbonization equipment has also developed accordingly. The general types can be divided into: fluidized bed, spouted bed, spouted-fluidized bed and spray tower. These technologies and equipment can effectively solve some desulfurization and decarbonization problems, but the desulfurization and decarbonization efficiency still needs to be further improved.

[0004] Among the integrated desulfurization and decarbonization equipment available so far, some use the method of removing sulfur dioxide and carbon dioxide together. However, sulfur dioxide and carbon dioxide will compete with each other during the removal process, thereby reducing the desulfurization and decarbonization efficiency. Summary of the invention

[0005] In response to the problems existing in the prior art, the present invention provides an external circulation spouted fluidized bed and operation method for integrated desulfurization and decarbonization particle separation, which solves the problem of competition in the integrated desulfurization and decarbonization, and at the same time recovers and reuses the generated powder with high purity. This process is still carried out in one device, thereby improving the desulfurization and decarbonization efficiency.

[0006] The present invention is achieved through the following technical solutions: The integrated intermittent desulfurization and decarbonization particle separation external circulation spouted fluidized bed includes a fluidized bed, a micro cyclone separator, a spouted bed and a calcining furnace: The bottom of the fluidized bed is provided with an air inlet, the top of the fluidized bed is provided with a calcium hydroxide slurry inlet, the micro-cyclone separator is installed inside the fluidized bed, the air inlet of the spouted bed is connected to the exhaust port of the fluidized bed, the exhaust port of the micro-cyclone separator is connected to the exhaust port of the fluidized bed, and the bottom of the micro-cyclone separator is connected to the outside; The lower end of the spouted bed is provided with a calcium oxide feeding port, which is equipped with a sealing cover. The top of the spouted bed is connected to the air inlet of the cyclone separator, and the exhaust port of the cyclone separator is connected to the inlet of the calcining furnace. The calcining furnace is provided with a carbon dioxide exhaust pipe, and the outlet of the calcining furnace is connected to the calcium oxide powder discharge pipe or the inlet of the guide pipe. The outlet of the guide pipe is connected to the lower end of the spouted bed, and the outlet of the guide pipe is lower than the inlet of the guide pipe.

[0007] Preferably, the fluidized bed, micro-cyclone separator and spouted bed are vertically distributed and their central axes coincide, the cyclone separator and calcining furnace are vertically distributed, the calcining furnace is a tubular structure, the calcium oxide powder discharge pipe is located at the extension of the lower pipe mouth of the calcining furnace and the inner diameters of the two are the same, the lower pipe mouth of the calcining furnace is higher than the bottom of the spouted bed, and the inlet of the guide pipe is connected to the lower pipe mouth of the calcining furnace.

[0008] Further, the fluidized bed comprises a first cylindrical section and a first truncated cone section, the upper end surface of the first truncated cone section is smoothly connected to the lower end surface of the first cylindrical section, the height of the first cylindrical section is 4 to 6 times that of the first truncated cone section, a distributor with a screen structure is horizontally arranged near the first truncated cone section of the first cylindrical section, silica particles are placed on the distributor, the inner diameter of the bottom of the first truncated cone section is smaller than the upper end, the bottom of the first truncated cone section is externally connected to a horizontally distributed air inlet pipe, and the inlet of the air inlet pipe is an air inlet; The spouted bed comprises a second cylindrical section and a second truncated cone section, the upper end surface of the second truncated cone section is smoothly connected to the lower end surface of the second cylindrical section, the height of the second cylindrical section is 1 to 1.2 times that of the second truncated cone section, the bottom inner diameter of the second truncated cone section is smaller than the upper end portion, the micro-cyclone separator comprises a third truncated cone section and a fourth truncated cone section, the upper end surface of the fourth truncated cone section is smoothly connected to the lower end surface of the third truncated cone section, the bottom inner diameter of the third truncated cone section is 0.95 to 0.99 times that of the upper end portion, the micro-cyclone separator air inlet is symmetrically arranged on both sides of the third truncated cone section, the micro-cyclone separator air inlet is spaced from the inner wall of the first cylindrical section, and the height of the third truncated cone section is 0.15 to 0.2 times that of the fourth truncated cone section; The upper end surface of the third frustum segment is provided with a first circular through hole, the upper end surface of the first cylindrical segment is provided with a second circular through hole, the upper end surface of the third frustum segment is fitted on the top of the inner wall of the first cylindrical segment, the bottom of the second frustum segment is the air inlet of the spouted bed, the lower end surface of the second frustum segment is fitted on the upper end surface of the first cylindrical segment, and the outer edges of the lower end surface of the second frustum segment are respectively aligned with the edges of the first circular through hole and the edges of the second circular through hole.

[0009] Furthermore, the bottom of the fourth truncated cone section is externally connected with a vertically distributed discharge pipe, which passes through the distributor, the first cylindrical section, the first truncated cone section and the air inlet pipe in sequence and then penetrates into the collection tank.

[0010] Furthermore, a feeding pipe is installed on one side of the height center of the second truncated cone section, the pipe opening of the feeding pipe is the calcium oxide feeding opening, and a valve is installed at a position of the feeding pipe near the calcium oxide feeding opening.

[0011] Furthermore, the cyclone separator includes a third cylindrical section, a fifth conical section and a tubular connecting section, the upper end surface of the fifth conical section is smoothly connected to the lower end surface of the third cylindrical section, the height of the fifth conical section is 1.5 to 2.0 times that of the third cylindrical section, the upper end surface of the third cylindrical section is flush with the upper end surface of the second cylindrical section, the third cylindrical section is connected to the second cylindrical section through a rectangular pipe, the upper end of the connecting section is connected to the bottom of the fifth conical section, the lower end of the connecting section is connected to the inlet of the calcining furnace, and the connecting section is inclined.

[0012] Furthermore, a heating wire is wound around the outer wall of the calcining furnace, and a plurality of mutually staggered and parallel baffles are fixed on the inner wall of the calcining furnace, each baffle has the same inclination, the upper end of the baffle at the top is located at the opening of the calcining furnace, the inclination of the baffle at the top is the same as that of the connecting section, a space is left between the upper end of each baffle and the lower end of the previous baffle, and a space is left between the lower end of each baffle and the inner wall of the calcining furnace, and a plurality of carbon dioxide exhaust pipes are evenly arranged on the outer wall of the calcining furnace from top to bottom, and a filter is installed in each carbon dioxide exhaust pipe.

[0013] The operation method of the integrated intermittent desulfurization and decarbonization particle separation external circulation spouted fluidized bed comprises the following steps: S1, mixed flue gas containing carbon dioxide and sulfur dioxide enters the fluidized bed from the air inlet, calcium hydroxide slurry enters the fluidized bed from the calcium hydroxide slurry inlet to react with sulfur dioxide to generate calcium sulfite powder, and the calcium sulfite powder enters the micro cyclone separator along with the flue gas, and falls into the outside from the bottom of the micro cyclone separator to achieve the separation of sulfur dioxide; S2, the mixed flue gas separated from sulfur dioxide is discharged from the exhaust port of the cyclone separator through the exhaust port of the fluidized bed into the spouted bed, the calcium oxide powder enters the spouted bed from the calcium oxide feeding port, and then the sealing cover is closed, the calcium oxide powder reacts with carbon dioxide to generate calcium carbonate powder, and then the calcium carbonate powder enters the cyclone separator with the air flow for gas-solid separation, the mixed gas is discharged from the top of the cyclone separator, and the calcium carbonate powder enters the calcining furnace during the falling process, and generates calcium oxide powder and carbon dioxide gas after high-temperature calcination. The calcium oxide powder generated by the reaction enters the spouted bed through the guide pipe under the action of gravity, and the carbon dioxide gas is recovered through the carbon dioxide discharge pipe; S3, the calcium oxide powder generated by the reaction is used to separate and recover the carbon dioxide in the mixed flue gas used to separate sulfur dioxide in the spouted bed according to the process of S2. When the calcium oxide powder added in S2 becomes ineffective, the calcium oxide powder generated by the reaction is discharged from the calcium oxide powder discharge pipe, and calcium oxide powder is added again from the calcium oxide feeding port, and intermittent desulfurization, decarbonization and particle separation are carried out according to the processes of S2 and S3.

[0014] An integrated continuous desulfurization and decarbonization particle separation external circulation spouted fluidized bed is based on any of the above-mentioned integrated intermittent desulfurization and decarbonization particle separation external circulation spouted fluidized bed, the calcium hydroxide slurry inlet is replaced by a liquid inlet, the calcium oxide feeding port is open, the outlet of the calcining furnace is connected to the inlet of the feed guide pipe, and the outlet of the feed guide pipe is connected to the fluidized bed.

[0015] The operation method of the external circulation spouted fluidized bed for integrated continuous desulfurization and decarbonization particle separation comprises the following steps: S1, the mixed flue gas containing carbon dioxide and sulfur dioxide enters the fluidized bed from the air inlet, and the calcium hydroxide slurry enters the fluidized bed from the liquid inlet to react with sulfur dioxide to generate calcium sulfite powder. The calcium sulfite powder enters the micro-cyclone separator along with the flue gas, and falls into the outside from the bottom of the micro-cyclone separator to achieve the separation of sulfur dioxide; S2, the mixed flue gas separated from sulfur dioxide is discharged from the exhaust port of the cyclone separator through the exhaust port of the fluidized bed into the spouted bed, and the calcium oxide powder enters the spouted bed from the calcium oxide feeding port, and the calcium oxide powder reacts with carbon dioxide to form calcium carbonate powder, and then the calcium carbonate powder enters the cyclone separator with the air flow for gas-solid separation, and the mixed gas is discharged from the top of the cyclone separator; S3, the calcium carbonate powder enters the calcining furnace during its falling process, and generates calcium oxide powder and carbon dioxide gas after high-temperature calcination. The carbon dioxide gas generated by the reaction is recovered through the carbon dioxide exhaust pipe. The calcium oxide powder enters the fluidized bed through the guide pipe under the action of gravity, and then water is added from the liquid inlet. The water and calcium oxide powder react to generate calcium hydroxide slurry for desulfurization in S1, and then continuous desulfurization, decarbonization and particle separation are carried out according to the processes of S2 and S3.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: The invention discloses an external circulation spouted fluidized bed for the separation of integrated intermittent desulfurization and decarbonization particles. The flue gas mixed with carbon dioxide and sulfur dioxide enters the fluidized bed from the air inlet. Calcium hydroxide slurry enters the fluidized bed from the feeding port to react with sulfur dioxide to generate calcium sulfite powder. The calcium sulfite powder enters the micro-cyclone separator inside the fluidized bed with the gas for gas-solid separation. The calcium sulfite powder falls to the outside under the action of gravity for collection. The micro-cyclone separator can effectively separate the calcium sulfite powder to avoid the adverse effect of the calcium sulfite powder on decarbonization. The micro-cyclone separator is placed in the fluidized bed to prevent the high-temperature powder from rewetting and adhering to the wall surface to cause blockage when it encounters the micro-cyclone separator; the airflow is discharged from the exhaust port of the cyclone separator, enters the spouted bed through the exhaust port of the fluidized bed, and reacts with the calcium oxide powder entering from the calcium oxide feeding port with carbon dioxide at high temperature to generate calcium carbonate. The calcium carbonate enters the cyclone separator with the airflow for gas-solid separation. The mixed gas is discharged from the top of the cyclone separator, and the calcium carbonate powder enters the calcining furnace during the falling process. It is calcined at high temperature to generate calcium oxide powder. The calcium oxide powder generated by the reaction enters the spouted bed through the guide pipe under the action of gravity. At the same time, the carbon dioxide discharge pipe can recycle carbon dioxide gas. When the added calcium oxide powder is ineffective, the calcium oxide powder generated by the reaction is discharged from the calcium oxide powder discharge pipe, and the calcium oxide powder is added again from the calcium oxide feeding port. Intermittent desulfurization, decarbonization and particle separation can be carried out for a long time, and the desulfurization and decarbonization processes can be effectively separated. The two processes are still completed in one device, avoiding the competitive relationship between desulfurization and decarbonization in other equipment in the past, and solving the problem of mutual inhibition between desulfurization and decarbonization in one time and efficiently, which significantly improves the efficiency of desulfurization and decarbonization. After the external circulation spouted fluidized bed of the present invention stops running, a small amount of calcium carbonate will be produced, and carbon dioxide, calcium sulfite and calcium carbonate can be recovered with high purity. Calcium carbonate is calcined at high temperature to generate calcium oxide powder and high-concentration carbon dioxide. Calcium carbonate becomes an intermediate product of the whole process, and the final products are calcium sulfite and high-concentration carbon dioxide, which simplifies the equipment process and reduces the total investment.

[0017] The external circulation spouted fluidized bed for integrated continuous desulfurization and decarbonization particle separation of the present invention has the same technical effect as the external circulation spouted fluidized bed for intermittent desulfurization and decarbonization particle separation, except that the implementation means are slightly different. However, the first time, like the intermittent external circulation spouted fluidized bed, calcium hydroxide slurry is added from the liquid inlet to react with sulfur dioxide until calcium carbonate powder is generated. At this time, the liquid inlet begins to switch to water, and the water and calcium oxide powder are mixed into calcium hydroxide slurry to carry out the above-mentioned desulfurization process. Correspondingly, calcium oxide is added to the calcium oxide feeding port again to carry out a second decarbonization reaction to achieve continuous desulfurization, decarbonization and particle separation. The desulfurization and decarbonization processes can also be effectively separated, and the two processes are still completed in one device, avoiding the competitive relationship during desulfurization and decarbonization in other equipment in the past, and efficiently solving the problem of mutual inhibition of desulfurization and decarbonization at one time, significantly improving the efficiency of desulfurization and decarbonization. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a structural diagram of the external circulation spouted fluidized bed for intermittent desulfurization and decarbonization particle separation of the present invention.

[0019] Figure 2 for Figure 1 Structural diagram of the calcining furnace.

[0020] Figure 3 This is a structural diagram of the external circulation spouted fluidized bed for continuous desulfurization and decarbonization particle separation according to the present invention.

[0021] Figure 4 for Figure 3 Structural diagram of the calcining furnace.

[0022] Figure 5 for Figure 1 Top view of a multi-stage calcining furnace.

[0023] Figure 6 Schematic diagram of the structure of the baffle.

[0024] In the figure: air inlet 1; fluidized bed 2; distributor 3; SiO2 particles 4; calcium hydroxide slurry inlet 5; micro cyclone separator 6; discharge pipe 7; collecting tank 8; spouted bed 9; calcium oxide feeding port 10; cyclone separator 11; baffle 12; first valve 13; calcium oxide powder discharge pipe 14; exhaust port 15; heating wire 16; micro cyclone separator air inlet 17; micro cyclone separator exhaust port 18; second valve 19; sealing cover 20; carbon dioxide discharge pipe 21; filter screen 22; calcining furnace 23; guide pipe 24; liquid inlet 25; CaSO3 powder 26; Ca(OH)2 slurry 27; CaCO3 particles 28; CaO particles 29; water 30. DETAILED DESCRIPTION

[0025] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described below. The purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly and comprehensively understood.

[0026] Implementation Method 1 The present invention is an integrated intermittent desulfurization and decarbonization particle separation external circulation spouted fluidized bed, the structure of which is shown in FIG. Figure 1 , including a fluidized bed 2, a micro cyclone separator 6 (mainly for separating calcium sulfite), a spouted bed 9 (mainly for decarbonization), a cyclone separator 11 (mainly for discharging mixed gas and separating calcium carbonate powder) and a calcining furnace 23 (multi-stage structure, mainly producing high-concentration carbon dioxide and calcium hydroxide powder).

[0027] An air inlet 1 is provided at the bottom of the fluidized bed 2, and the flue gas enters from the air inlet 1 and reaches the fluidized bed 2. A calcium hydroxide slurry inlet 5 is provided at the top of the fluidized bed 2 to facilitate the downward flow of the calcium hydroxide slurry to remove sulfur dioxide. A micro cyclone separator 6 is installed inside the fluidized bed 2, and the exhaust port 18 of the micro cyclone separator is connected to the exhaust port of the fluidized bed 2. The air inlet of the spouted bed 9 is connected to the exhaust port of the fluidized bed 2, and the bottom of the micro cyclone separator 6 is connected to the outside world. The lower end of the spouted bed 9 is provided with a calcium oxide feeding port 10, and the calcium oxide feeding port 10 is provided with a sealing cover 20. The top of the spouted bed 9 is connected to the air inlet of the cyclone separator 11, and the top of the cyclone separator 11 is equipped with an exhaust port 15 by welding. The exhaust port of the cyclone separator 11 is connected to the inlet of the calcining furnace 23. The calcining furnace 23 is provided with a carbon dioxide exhaust pipe 21. The outlet of the calcining furnace 23 is connected to the inlet of the guide pipe 24 or the calcium oxide powder exhaust pipe 14 through the first valve 13. The outlet of the guide pipe 24 is connected to the lower end of the spouted bed 9, and the outlet of the guide pipe 24 is lower than the inlet of the guide pipe 24. Specifically, during installation, the fluidized bed 2, the micro-cyclone separator 6 and the spouted bed 9 are vertically distributed and the central axes coincide, and the cyclone separator 11 and the calcining furnace 23 are vertically distributed. The calcining furnace 23 is designed as a tubular structure. The calcium oxide powder discharge pipe 14 is located at the extension of the lower pipe opening of the calcining furnace 23 and the inner diameters of the two are the same. The lower pipe opening of the calcining furnace 23 is higher than the bottom of the spouted bed 9. The first valve 13 is located at the lower pipe opening of the calcining furnace 23. The inlet of the guide pipe 24 is connected to the lower pipe opening of the calcining furnace 23. The lower end (outlet) of the guide pipe 24 is close to the bottom of the spouted bed 9. The first valve 13 is controlled to control whether the powder enters the spouted bed 9 from the guide pipe 24 or is discharged from the calcium oxide powder discharge pipe 14.

[0028] The fluidized bed 2 specifically includes a first cylindrical section and a first truncated cone section. The upper end face of the first truncated cone section is smoothly connected to the lower end face of the first cylindrical section. The height of the first cylindrical section is 4 to 6 times that of the first truncated cone section. A distributor 3 with a screen structure is horizontally welded near the first truncated cone section. Silica particles 4 are placed on the distributor 3. Then, the silica particles 4 will circulate with the gas to improve the mass transfer efficiency. The bottom inner diameter of the first truncated cone section is smaller than its upper end. The bottom of the first truncated cone section is externally connected to a horizontally distributed air inlet pipe, so the air inlet 1 is the entrance of the air inlet pipe. The spouted bed 9 specifically includes a second cylindrical section and a second truncated cone section. The upper end face of the second truncated cone section is smoothly connected to the lower end face of the second cylindrical section. The height of the second cylindrical section is 1 to 1.2 times that of the second truncated cone section. The bottom inner diameter of the second truncated cone section is smaller than its upper end. The micro-cyclone separator 6 specifically includes a third frustum section and a fourth frustum section, the upper end face of the fourth frustum section is smoothly connected to the lower end face of the third frustum section, the inner diameter of the bottom of the third frustum section is 0.95 to 0.99 times that of the upper end, and the micro-cyclone separator air inlet 17 is symmetrically arranged on both sides of the third frustum section, which is spaced from the inner wall of the first cylindrical section, and the height of the third frustum section is 0.15 to 0.2 times that of the fourth frustum section; the upper end face of the third frustum section is provided with a first circular through hole, and the upper end face of the first cylindrical section is provided with a first circular through hole. Two circular through holes, the upper end face of the third truncated cone segment is welded to the top of the inner wall of the first cylindrical segment, so as to facilitate the airflow to be discharged into the spouted bed 9 while reducing the loss of silica particles 4, the bottom of the second truncated cone segment is the air inlet of the spouted bed 9, the lower end face of the second truncated cone segment is welded to the upper end face of the first cylindrical segment, the outer edges of the lower end face of the second truncated cone segment are respectively aligned with the edges of the first circular through hole and the edges of the second circular through hole and then welded, and the airflow enters the spouted bed 9 through the formed through hole.

[0029] The present invention is externally connected to a vertically distributed discharge pipe 7 at the bottom of the fourth truncated cone section. The discharge pipe 7 needs to sequentially pass through the distributor 3, the first cylindrical section, the first truncated cone section and the air inlet pipe and then go deep into the collection tank 8, so as to collect the calcium sulfite powder generated by the reaction of the calcium hydroxide slurry and sulfur dioxide. Vertical feeding can avoid blockage. A feeding pipe is welded on one side of the height center of the second truncated cone section. The pipe mouth of the feeding pipe is a calcium oxide feeding port 10. A sealing cover 20 is hinged on the calcium oxide feeding port 10. A second valve 19 is installed at the feeding pipe near the calcium oxide feeding port 10 for intermittent feeding.

[0030] The cyclone separator 11 specifically includes a third cylindrical section, a fifth truncated cone section and a tubular connecting section. The upper end surface of the fifth truncated cone section is smoothly connected to the lower end surface of the third cylindrical section. The height of the fifth truncated cone section is 1.5 to 2.0 times that of the third cylindrical section. The upper end surface of the third cylindrical section is flush with the upper end surface of the second cylindrical section. The third cylindrical section is connected to the second cylindrical section through a rectangular parallelepiped pipe. The upper end of the connecting section is connected to the bottom of the fifth truncated cone section. The lower end of the connecting section is connected to the inlet of the calcining furnace 23. The connecting section is inclined. The outer wall of the calcining furnace 23 is wrapped with a heating wire 16 to heat the calcining furnace 23. Figure 2 and Figure 5 As shown, the inner wall of the calcining furnace 23 is fixed with a plurality of mutually staggered and parallel baffles 12 by welding. The structure of the baffles 12 is as shown in FIG. Figure 6 As shown, the upper end of the baffle 12 at the top is located at the opening of the calcining furnace 23, the inclination of each baffle 12 is the same, the inclination of the baffle 12 at the top is the same as that of the connecting section, the upper end of each baffle 12 is spaced apart from the lower end of the previous baffle 12, and the lower end of each baffle 12 is spaced apart from the inner wall of the calcining furnace 23. The calcium carbonate powder is heated in the process of descending, and the baffle 12 slows down the downward speed of the powder, thereby increasing the residence time of calcination, so that the calcium carbonate can be fully decomposed at high temperature. The outer wall of the calcining furnace 23 is evenly provided with a plurality of carbon dioxide exhaust pipes 21 from top to bottom, and the concentration of carbon dioxide gas is different at different heights. A filter screen 22 is installed in each carbon dioxide exhaust pipe 21, and high-concentration carbon dioxide can be collected step by step from the pipe mouth of the carbon dioxide exhaust pipe 21 after filtration.

[0031] The operation method of the external circulation spouted fluidized bed for integrated intermittent desulfurization and decarbonization particle separation specifically comprises the following steps: Step 1, the mixed flue gas containing carbon dioxide and sulfur dioxide enters from the air inlet 1, passes through the distributor and enters the fluidized bed 2 filled with silicon dioxide particles 4, the calcium hydroxide slurry enters the fluidized bed from the calcium hydroxide slurry inlet 5 to react with sulfur dioxide to generate calcium sulfite powder, the calcium sulfite powder enters the micro cyclone separator 6 along with the flue gas, and falls into the collection tank 8 from the bottom of the micro cyclone separator 6 to achieve the separation of sulfur dioxide.

[0032] Step 2, the mixed flue gas and silicon dioxide particles 4 separated from sulfur dioxide are discharged from the exhaust port 18 of the cyclone separator through the exhaust port of the fluidized bed 2 into the spouted bed 9, and the calcium oxide powder enters the spouted bed 9 from the calcium oxide feeding port 10, and then the sealing cover 20 is closed, and the calcium oxide powder reacts with carbon dioxide to generate calcium carbonate powder.

[0033] Step 3, after that, the airflow carrying the silicon dioxide particles 4, calcium oxide and calcium carbonate powder ascends to the top of the spouted bed 9, and then enters the cyclone separator 11 for gas-solid separation. The mixed gas is discharged from the exhaust port 15 at the top of the cyclone separator 11. The calcium carbonate powder enters the calcining furnace 23 during the falling process, and generates calcium oxide powder and carbon dioxide gas after high-temperature calcination. The inclined baffle increases the residence time of the calcium carbonate powder, so that the calcium carbonate reacts fully. The calcium oxide powder and silicon dioxide particles 4 generated by the reaction enter the spouted bed 9 through the guide pipe 24 under the action of gravity for circulation, and the carbon dioxide gas is recovered through the carbon dioxide discharge pipe 21.

[0034] In step 4, the calcium oxide powder generated by the reaction is used to separate and recover the carbon dioxide in the mixed flue gas from which sulfur dioxide is separated in the spouted bed 9 according to the processes of steps 2 and 3. When the calcium oxide powder added in step 2 becomes ineffective, the calcium oxide powder generated by the reaction is discharged from the calcium oxide powder discharge pipe 14, and calcium oxide powder is added again from the calcium oxide feeding port 10, and intermittent desulfurization, decarbonization and particle separation are carried out according to the processes of steps 2 to 4.

[0035] Implementation Method 2 The present invention provides an integrated continuous desulfurization and decarbonization particle separation external circulation spouted fluidized bed, such as Figure 3 As shown, the basic structure is basically the same as the external circulation spouted fluidized bed for intermittent desulfurization and decarbonization particle separation. Figure 4 The particle composition and Figure 2 The same, but the distribution is inevitably different at runtime, so we draw it again Figure 4 , there are three differences: First, replace the calcium hydroxide slurry inlet 5 with the liquid inlet 25, add the calcium hydroxide slurry first, and then add only water; Second, the calcium oxide feeding port 10 is an opening, and there is no need to hinge the sealing cover 20 on the calcium oxide feeding port 10; Third, the outlet of the calcining furnace 23 is only connected to the inlet of the material guide pipe 24, and the outlet of the material guide pipe 24 is connected to the fluidized bed 2, but not to the spouted bed 9. Therefore, there is no requirement that the first valve 13 is located at the lower pipe outlet of the calcining furnace 23, and the lower end (outlet) of the material guide pipe 24 is close to the bottom of the spouted bed 9.

[0036] The present invention provides an operation method of an external circulation spouted fluidized bed for integrated continuous desulfurization and decarbonization particle separation, which specifically comprises the following steps: Step 1, the mixed flue gas containing carbon dioxide and sulfur dioxide enters the fluidized bed 2 from the air inlet 1, and at this time, the calcium hydroxide slurry is added to the fluidized bed from the liquid inlet 25 to react with sulfur dioxide to generate calcium sulfite powder. The calcium sulfite powder enters the micro cyclone separator 6 along with the flue gas, and falls into the collection tank 8 from the bottom of the micro cyclone separator 6 to achieve the separation of sulfur dioxide.

[0037] Step 2, the mixed flue gas and silicon dioxide particles 4 separated from sulfur dioxide are discharged from the exhaust port 18 of the cyclone separator through the exhaust port of the fluidized bed 2 into the spouted bed 9, and the calcium oxide powder enters the spouted bed 9 from the calcium oxide feeding port 10. The calcium oxide powder reacts with carbon dioxide to form calcium carbonate powder. Then, the airflow carries the silicon dioxide particles 4, calcium oxide and calcium carbonate powder upward to the top of the spouted bed 9, and then enters the cyclone separator 11 for gas-solid separation. The mixed gas is discharged from the exhaust port 15 at the top of the cyclone separator 11.

[0038] In step 3, the calcium carbonate powder enters the calcining furnace 23 during its falling process, and generates calcium oxide powder and carbon dioxide gas after high-temperature calcination. The inclined baffle increases the residence time of the calcium carbonate powder to allow the calcium carbonate to fully react. The carbon dioxide gas generated by the reaction is recovered through the carbon dioxide exhaust pipe 21. The calcium oxide powder and the silicon dioxide particles 4 enter the fluidized bed 2 through the guide pipe 24 under the action of gravity for circulation. At this time, water needs to be added from the liquid inlet 25. The water and calcium oxide powder react to generate calcium hydroxide slurry for desulfurization in step 1, and then continuous desulfurization, decarbonization and particle separation are carried out according to the processes of steps 2 and 3.

[0039] The above description is only for the best embodiment of the present invention, but it should not be understood as limiting the claims. The present invention is not limited to the above embodiments, and its specific structure is allowed to be changed. However, all changes made within the protection scope of the independent claims of the present invention are within the protection scope of the present invention.

[0040] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

Claims

1. An external circulation spouted fluidized bed for integrated intermittent desulfurization and decarbonization particle separation, characterized in that: The invention comprises a fluidized bed (2), a micro cyclone separator (6), a spouted bed (9) and a calcining furnace (23): The bottom of the fluidized bed (2) is provided with an air inlet (1), the top of the fluidized bed (2) is provided with a calcium hydroxide slurry inlet (5), the micro-cyclone separator (6) is installed inside the fluidized bed (2), the air inlet of the spouted bed (9) is connected to the exhaust port of the fluidized bed (2), the exhaust port (18) of the micro-cyclone separator is connected to the exhaust port of the fluidized bed (2), and the bottom of the micro-cyclone separator (6) is connected to the outside; The lower end of the spouted bed (9) is provided with a calcium oxide feeding port (10), and the calcium oxide feeding port (10) is provided with a sealing cover (20). The top of the spouted bed (9) is communicated with the air inlet of the cyclone separator (11), and the exhaust port of the cyclone separator (11) is communicated with the inlet of the calcining furnace (23). The calcining furnace (23) is provided with a carbon dioxide discharge pipe (21), and the outlet of the calcining furnace (23) is communicated with the calcium oxide powder discharge pipe (14) or the inlet of the guide pipe (24). The outlet of the guide pipe (24) is communicated with the lower end of the spouted bed (9), and the outlet of the guide pipe (24) is lower than the inlet of the guide pipe (24).

2. The integrated intermittent desulfurization and decarbonization particle separation external circulation spouted fluidized bed according to claim 1 is characterized in that: The fluidized bed (2), micro-cyclone separator (6) and spouted bed (9) are arranged vertically and their central axes coincide with each other. The cyclone separator (11) and calcining furnace (23) are arranged vertically. The calcining furnace (23) is a tubular structure. The calcium oxide powder discharge pipe (14) is located at the extension of the lower pipe opening of the calcining furnace (23) and the inner diameters of the two are the same. The lower pipe opening of the calcining furnace (23) is higher than the bottom of the spouted bed (9). The inlet of the guide pipe (24) is connected to the lower pipe opening of the calcining furnace (23).

3. The integrated intermittent desulfurization and decarbonization particle separation external circulation spouted fluidized bed according to claim 2 is characterized in that: The fluidized bed (2) comprises a first cylindrical section and a first truncated cone section, the upper end surface of the first truncated cone section is smoothly connected to the lower end surface of the first cylindrical section, the height of the first cylindrical section is 4 to 6 times that of the first truncated cone section, a distributor (3) with a screen structure is horizontally arranged near the first truncated cone section, silicon dioxide particles (4) are placed on the distributor (3), the inner diameter of the bottom of the first truncated cone section is smaller than the upper end, the bottom of the first truncated cone section is externally connected to a horizontally distributed air intake pipe, the inlet of the air intake pipe is the air intake port (1); The spouted bed (9) comprises a second cylindrical section and a second truncated cone section, the upper end surface of the second truncated cone section is smoothly connected to the lower end surface of the second cylindrical section, the height of the second cylindrical section is 1 to 1.2 times that of the second truncated cone section, the bottom inner diameter of the second truncated cone section is smaller than the upper end portion, the micro-cyclone separator (6) comprises a third truncated cone section and a fourth truncated cone section, the upper end surface of the fourth truncated cone section is smoothly connected to the lower end surface of the third truncated cone section, the bottom inner diameter of the third truncated cone section is 0.95 to 0.99 times that of the upper end portion, the micro-cyclone separator air inlets (17) are symmetrically arranged on both sides of the third truncated cone section, the micro-cyclone separator air inlet (17) is spaced from the inner wall of the first cylindrical section, and the height of the third truncated cone section is 0.15 to 0.2 times that of the fourth truncated cone section; The upper end surface of the third truncated cone segment is provided with a first circular through hole, the upper end surface of the first cylindrical segment is provided with a second circular through hole, the upper end surface of the third truncated cone segment is fitted on the top of the inner wall of the first cylindrical segment, the bottom of the second truncated cone segment is an air inlet of the spouted bed (9), the lower end surface of the second truncated cone segment is fitted on the upper end surface of the first cylindrical segment, and the outer edge of the lower end surface of the second truncated cone segment is aligned with the edge of the first circular through hole and the edge of the second circular through hole respectively.

4. The integrated intermittent desulfurization and decarbonization particle separation external circulation spouted fluidized bed according to claim 3 is characterized in that: The bottom of the fourth truncated cone section is externally connected to a vertically distributed discharge pipe (7), which passes through the distributor (3), the first cylindrical section, the first truncated cone section and the air inlet pipe in sequence and then penetrates into the collection tank (8).

5. The integrated intermittent desulfurization and decarbonization particle separation external circulation spouted fluidized bed according to claim 3 is characterized in that: A feeding pipe is installed on one side of the height center of the second truncated cone section, the pipe opening of the feeding pipe is a calcium oxide feeding opening (10), and a valve is installed at a position of the feeding pipe close to the calcium oxide feeding opening (10).

6. The integrated intermittent desulfurization and decarbonization particle separation external circulation spouted fluidized bed according to claim 3 is characterized in that: The cyclone separator (11) comprises a third cylindrical section, a fifth truncated cone section and a tubular connecting section, the upper end surface of the fifth truncated cone section is smoothly connected to the lower end surface of the third cylindrical section, the height of the fifth truncated cone section is 1.5 to 2.0 times that of the third cylindrical section, the upper end surface of the third cylindrical section is flush with the upper end surface of the second cylindrical section, the third cylindrical section is connected to the second cylindrical section via a rectangular parallelepiped pipe, the upper end of the connecting section is connected to the bottom of the fifth truncated cone section, the lower end of the connecting section is connected to the inlet of the calcining furnace (23), and the connecting section is inclined.

7. The integrated intermittent desulfurization and decarbonization particle separation external circulation spouted fluidized bed according to claim 6 is characterized in that: The outer wall of the calcining furnace (23) is wound with a heating wire (16), and the inner wall of the calcining furnace (23) is fixed with a plurality of mutually staggered and parallel baffles (12), each of which has the same inclination, and the upper end of the baffle (12) located at the top is located at the opening of the calcining furnace (23), and the inclination of the baffle (12) at the top is the same as that of the connecting section, and the upper end of each baffle (12) is spaced from the lower end of the previous baffle (12), and the lower end of each baffle (12) is spaced from the inner wall of the calcining furnace (23), and the outer wall of the calcining furnace (23) is evenly provided with a plurality of carbon dioxide exhaust pipes (21) from top to bottom, and a filter screen (22) is installed in each carbon dioxide exhaust pipe (21).

8. The method for operating the external circulation spouted fluidized bed for integrated intermittent desulfurization and decarbonization particle separation according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, a mixed flue gas containing carbon dioxide and sulfur dioxide enters the fluidized bed (2) from the air inlet (1), and the calcium hydroxide slurry enters the fluidized bed from the calcium hydroxide slurry inlet (5) to react with sulfur dioxide to generate calcium sulfite powder. The calcium sulfite powder enters the micro cyclone separator (6) along with the flue gas, and falls into the outside from the bottom of the micro cyclone separator (6), thereby achieving the separation of sulfur dioxide; S2, the mixed flue gas from which sulfur dioxide is separated is discharged from the exhaust port (18) of the cyclone separator through the exhaust port of the fluidized bed (2) into the spouted bed (9), the calcium oxide powder enters the spouted bed (9) from the calcium oxide feeding port (10), and then the sealing cover (20) is closed, the calcium oxide powder reacts with carbon dioxide to generate calcium carbonate powder, and then the calcium carbonate powder enters the cyclone separator (11) with the air flow for gas-solid separation, the mixed gas is discharged from the top of the cyclone separator (11), and the calcium carbonate powder enters the calcining furnace (23) during the falling process, and after high-temperature calcination, calcium oxide powder and carbon dioxide gas are generated, the calcium oxide powder generated by the reaction enters the spouted bed (9) through the guide pipe (24) under the action of gravity, and the carbon dioxide gas is recovered through the carbon dioxide discharge pipe (21); S3, the calcium oxide powder generated by the reaction is used to separate and recover the carbon dioxide in the mixed flue gas from which the sulfur dioxide is separated in the spouted bed (9) according to the process of S2. When the calcium oxide powder added in S2 becomes ineffective, the calcium oxide powder generated by the reaction is discharged from the calcium oxide powder discharge pipe (14), and calcium oxide powder is added again from the calcium oxide feeding port (10), and intermittent desulfurization, decarbonization and particle separation are carried out according to the processes of S2 and S3.

9. An external circulation spouted fluidized bed for integrated continuous desulfurization and decarbonization particle separation, characterized in that: Based on the external circulation spouted fluidized bed for integrated intermittent desulfurization and decarbonization particle separation as described in any one of claims 1 to 7, the calcium hydroxide slurry inlet (5) is replaced by a liquid inlet (25), the calcium oxide feeding port (10) is open, the outlet of the calcining furnace (23) is connected to the inlet of the guide pipe (24), and the outlet of the guide pipe (24) is connected to the fluidized bed (2).

10. The method for operating the external circulation spouted fluidized bed for integrated continuous desulfurization and decarbonization particle separation according to claim 9, characterized in that: The following steps are involved: S1, a mixed flue gas containing carbon dioxide and sulfur dioxide enters the fluidized bed (2) from the air inlet (1), and the calcium hydroxide slurry enters the fluidized bed from the liquid inlet (25) to react with the sulfur dioxide to generate calcium sulfite powder. The calcium sulfite powder enters the micro-cyclone separator (6) along with the flue gas, and falls from the bottom of the micro-cyclone separator (6) to the outside, thereby achieving the separation of sulfur dioxide; S2, the mixed flue gas from which sulfur dioxide is separated is discharged from the exhaust port (18) of the cyclone separator through the exhaust port of the fluidized bed (2) into the spouted bed (9), and the calcium oxide powder enters the spouted bed (9) from the calcium oxide feeding port (10), and the calcium oxide powder reacts with carbon dioxide to form calcium carbonate powder. The calcium carbonate powder then enters the cyclone separator (11) along with the air flow for gas-solid separation, and the mixed gas is discharged from the top of the cyclone separator (11); S3, during the falling process, the calcium carbonate powder enters the calcining furnace (23), and after high-temperature calcination, calcium oxide powder and carbon dioxide gas are generated. The carbon dioxide gas generated by the reaction is recovered through the carbon dioxide discharge pipe (21). The calcium oxide powder enters the fluidized bed (2) through the guide pipe (24) under the action of gravity, and then water is added from the liquid inlet (25). The water and calcium oxide powder react to generate calcium hydroxide slurry for desulfurization in S1, and then continuous desulfurization, decarbonization and particle separation are carried out according to the processes of S2 and S3.

Images