Fluidized drying device and method with function of removing chloride ions in ammonia-process desulfurization circulating liquid

Abstract

The invention relates to a fluidized drying method and a fluidized drying device with a function of removing chloride ions in ammonia desulfurization circulating liquid. The fluidized drying method is characterized in that an ammonium sulfate solution is added into a fluidized drying area of the fluidized drying device. The fluidized drying device comprises a fluidized drying tower, an ammonium sulfate solution inlet and a wet material inlet are formed in the fluidized drying tower, wet material drying and solution drying are carried out in the same area in the fluidized drying tower at the same time, the equipment size is reduced, investment is saved, and energy consumption is reduced.

Description

Technical Field

[0001] The present invention relates to a fluidized drying device and method with the function of removing chloride ions from the circulating liquid of ammonia-based desulfurization. Background Art

[0002] Fluidized drying refers to the drying of powdery or granular materials in a boiling state by the introduced air flow. The wet material is added into the fluidized bed dryer by a feeder, and the heated air is sent into the bottom of the fluidized bed by a blower and contacts the solid material through a gas distributor plate to form a fluidized state for heat and mass exchange between gas and solid. After the material is dried, it is discharged from the discharge port, and the waste gas is discharged from the top and discharged into the air after the solid powder is recovered by a cyclone dust collector group and a bag filter.

[0003] The flue gas ammonia-based desulfurization technology has the advantages of circular economy, no secondary pollution, high desulfurization efficiency, high by-product value, etc. However, there are still some problems that have always troubled the entire industry in the ammonia-based desulfurization process. One of them is the corrosion problem of equipment, pipelines, etc. caused by the enrichment of Cl - and F - enrichment. Since the ammonia-based desulfurization device does not discharge wastewater, the concentration of chloride ions in the system will be enriched. At present, fluidized drying equipment can be used for the drying of ammonium sulfate, the product of ammonia-based desulfurization, but it cannot solve the problem of chloride ion enrichment in the circulating liquid.

[0004] Existing Technical Solutions

[0005] Patent application CN202323526216.5 discloses a fluidized bed drying equipment, including a fluidized drying tower body, a vibrating feeder arranged outside the fluidized drying tower body and communicated with the fluidized drying tower body, a gas distributor arranged in the fluidized drying tower body, and a scraping device arranged above the gas distributor. The scraping device is configured to scrape off the material adhered to the gas distributor during the fluidization process for re-fluidized drying, and can solve the problems of full dispersion and fluidization of the wet material to be fluidized dried. However, this device does not consider the problem of chloride ion enrichment in the circulating liquid.

[0006] CN104368231A discloses a method for controlling the chlorine / fluorine content in the flue gas desulfurization absorption liquid. This method directly sends the high-chlorine (fluorine) absorption liquid to the drying system for drying, and directly dries the chlorine (fluorine)-containing absorption liquid into a solid chlorine (fluorine)-containing desulfurization by-product. The drying system uses high-speed evaporation drying equipment such as spray drying, flash drying, fluidized bed drying, and flash drying. However, all ammonium sulfate products in this method are obtained by directly drying the solution, with high energy consumption.

[0007] CN108569708A discloses a method for balancing Cl - and F -Method and device for content, the device being an integrated drying tower for ammonium sulfate solution and wet material ammonium sulfate output from an ammonia-based desulfurization device, including a solution drying functional area, a wet material drying functional area, and a drying tail gas dust removal functional area. In the balance ammonia-based desulfurization circulating liquid of the present invention, Cl - , F - content is adjusted to balance the harmful substances such as fluorine and chlorine in the ammonia-based desulfurization device system, control the system water balance, and integrate the drying of ammonium sulfate solution and wet ammonium sulfate material, greatly alleviating system corrosion. However, in this invention, the solution drying functional area and the wet material drying functional area are separately arranged, requiring sufficient residence time and large equipment investment. Summary of the Invention

[0008] Technical problems to be solved and beneficial effects

[0009] To solve the problem of chloride ion enrichment in the ammonia-based desulfurization circulating liquid, this solution is improved on the basis of the fluidized bed drying equipment described in CN202323526216.5, enabling the fluidized bed drying equipment to be used for drying ammonium sulfate, the product of ammonia-based desulfurization, and economically and efficiently solving the problem of chloride ion enrichment in the circulating liquid.

[0010] The present invention also relates to the following implementation schemes:

[0011] 1. A fluidized bed drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid, characterized in that ammonium sulfate solution is added to the fluidized drying area of the fluidized bed drying device.

[0012] 2. The fluidized bed drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to implementation scheme 1, characterized in that the ammonium sulfate solution is an unsaturated ammonium sulfate solution.

[0013] 3. The fluidized bed drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to implementation scheme 1, characterized in that the ammonium sulfate solution is pretreated by a pretreatment system before being added to the fluidized bed drying device.

[0014] 4. The fluidized bed drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to implementation scheme 3, characterized in that the pretreatment system is selected from a solution dilution system, a heating system, or a filtration system.

[0015] 5. The fluidized bed drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to implementation scheme 1, characterized in that the ammonium sulfate solution contains solids, the ammonium sulfate solution is subjected to solid-liquid separation, and the obtained solid wet material and part of the solution are respectively fed into the fluidized bed drying device for drying.

[0016] 6. The fluidized drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to embodiment 5, characterized in that a part of the solution obtained by solid-liquid separation is heated and then fed into the fluidized drying device.

[0017] 7. The fluidized drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to embodiment 6, characterized in that the solution obtained by solid-liquid separation is heated by using the waste gas heat energy after fluidized drying.

[0018] 8. The fluidized drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to embodiment 1, characterized in that the ammonium sulfate solution is added into the fluidized drying device through a spray gun.

[0019] 9. The fluidized drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to embodiment 8, characterized in that the spray gun includes a nozzle.

[0020] 10. The fluidized drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to embodiment 9, characterized in that the nozzle preferably has a porous type.

[0021] 11. The fluidized drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to embodiment 9, characterized in that the spray gun further includes a gas inlet for introducing gas, and the gas is preferably air.

[0022] 12. The fluidized drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to embodiment 8, characterized in that the pressure of the ammonium sulfate solution entering the spray gun is controlled to be 0.25 - 1.0 MPA (gauge pressure), preferably 0.4 - 1.0 MPA (gauge pressure).

[0023] 13. The fluidized drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to embodiment 11, characterized in that the pressure of the gas entering the spray gun is controlled to be 0.25 - 1.0 MPA (gauge pressure), preferably 0.4 - 1.0 MPA (gauge pressure).

[0024] 14. The fluidized drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to embodiment 9, characterized in that the nozzle extends into the fluidized drying tower, and the distance from the inner wall of the fluidized drying tower is greater than or equal to 100 mm, preferably greater than or equal to 200 mm.

[0025] 15. The fluidized drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to embodiment 1, characterized in that the chloride ion concentration in the ammonium sulfate solution treated by this method decreases by at least 60%, preferably 70%, more preferably 80%.

[0026] 16. The fluidized drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to Embodiment 1 is characterized in that wet materials are further introduced into the fluidized drying area of the fluidized drying device, and the ammonium sulfate solution and the wet materials are dried in the same fluidized drying area.

[0027] 17. The fluidized drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to Embodiment 16 is characterized in that the ammonium sulfate solution and the wet materials are dried with the same hot air in the same fluidized drying area.

[0028] 18. The fluidized drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to Embodiment 16 is characterized in that the position of the ammonium sulfate solution inlet is lower than the position of the wet material inlet.

[0029] 19. The fluidized drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to Embodiment 16 is characterized in that the wet materials and the ammonium sulfate solution for fluidized drying are discharged from the dry material outlet after drying, and the waste gas is discharged from the top. After the solid powder is recovered by the cyclone separation equipment, it is discharged or used to heat the ammonium sulfate solution entering the fluidized drying device.

[0030] 20. A fluidized drying device with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid is characterized in that the fluidized drying device includes a fluidized drying tower, and an ammonium sulfate solution inlet is provided on the fluidized drying tower.

[0031] 21. The fluidized drying device with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to Embodiment 20 is characterized in that a wet material inlet is further provided on the fluidized drying tower.

[0032] 22. The fluidized drying device with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to Embodiment 21 is characterized in that the ammonium sulfate solution inlet and the wet material inlet are located in the same fluidized drying area.

[0033] 23. The fluidized drying device with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to Embodiment 21 is characterized in that the position of the ammonium sulfate solution inlet is lower than the position of the wet material inlet.

[0034] 24. The fluidized drying device with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to Embodiment 20 is characterized in that the fluidized drying device further includes a cyclone separation equipment.

[0035] 25. The fluidized drying device with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to Embodiment 20 is characterized in that the fluidized drying device further includes a pretreatment system for the pretreatment of the ammonium sulfate solution.

[0036] 26. The fluidized drying device with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to embodiment 25, wherein the pretreatment system is selected from a solution dilution system, a heating system or a filtration system.

[0037] 27. The fluidized drying device with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to embodiment 20, wherein the fluidized drying device further comprises a solid-liquid separation device, and the solid wet material outlet and the solution outlet of the solid-liquid separation device are respectively connected to the fluidized drying tower of the fluidized drying device.

[0038] 28. The fluidized drying device with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to embodiment 27, wherein part of the solution obtained by solid-liquid separation is passed through a heating system before being fed into the fluidized drying device.

[0039] 29. The fluidized drying device with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to embodiment 28, wherein the exhaust gas after fluidized drying is connected to the heating system.

[0040] 30. The fluidized drying device with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to embodiment 20, wherein the fluidized drying device further comprises a spray gun for adding ammonium sulfate solution.

[0041] 31. The fluidized drying device with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to embodiment 30, wherein the spray gun comprises a nozzle, and the distance between the nozzle and the inner wall of the fluidized drying tower is greater than or equal to 100 mm, preferably greater than or equal to 200 mm.

[0042] 32. The fluidized drying device with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to embodiment 30, wherein the spray gun further comprises a gas inlet for introducing gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The present invention will be further described below with reference to the schematic drawings by means of exemplary embodiments.

[0044] Wherein:

[0045] Figure 1 is a schematic structure of the fluidized drying device according to the present invention Figure 1 ;

[0046] Figure 2 is a schematic structure of the fluidized drying device according to the present invention Figure 2 ;

[0047] Figure 3 is a schematic structural diagram of the fluidized drying device according to the comparative example.

[0048] The reference numerals in the technical solution of this application are as follows:

[0049] 1. Fluidized drying tower; 2. Air inlet; 3. Air outlet; 4. Cyclone separation equipment; 5. Wet material inlet; 6. Wet material; 7-1. Lower gas distribution plate; 7-2. Upper gas distribution plate; 8-1. Lower paddle scraping plate; 8-2. Upper paddle scraping plate; 9. Dry material outlet; 10. Solution inlet; 11. Ammonium sulfate solution; 12. Pretreatment system; 13. Spray gun; 14. Pressurized air; 15. Motor; 16. Hot air; 17. Tail gas purification system; 18. Automatic discharge valve; 19. Steam heat exchanger; 20. Steam; 21. Ammonium sulfate solution containing solids; 22. Solid-liquid separation equipment. Detailed implementation manners

[0050] Figure 1 is a schematic structural diagram of a fluidized drying device according to the present invention. Figure 2 is another schematic structural diagram of a fluidized drying device according to the present invention. Figure 3 is a schematic structural diagram of a fluidized drying device according to the comparative example.

[0051] As Figure 1 and 2 shown, the fluidized drying device of the present invention includes a fluidized drying tower 1, a lower gas distribution plate 7-1 and an upper gas distribution plate 7-2 arranged in the fluidized drying tower 1, and a lower paddle scraping plate 8-1 and an upper paddle scraping plate 8-2 provided above the lower gas distribution plate 7-1 and the upper gas distribution plate 7-2. A vibrating feeder can also be provided outside the fluidized drying tower 1 and communicated with the fluidized drying tower 1, and the vibrating feeder is configured to disperse the material by vibration before the material enters the fluidized drying tower 1 through the wet material inlet 5. The lower paddle scraping plate 8-1 and the upper paddle scraping plate 8-2 are configured to scrape off the material adhering to the lower gas distribution plate 7-1 and the upper gas distribution plate 7-2 during the fluidization process for re-fluidized drying.

[0052] The middle section of the fluidized drying tower 1 is configured to be cylindrical, and the upper section and the lower section of the fluidized drying tower 1 are configured to be conical. An air inlet 2, an air outlet 3, a wet material inlet 5, a dry material outlet 9 and a solution inlet 10 are provided at the fluidized drying tower 1. The air inlet 2 is arranged at the lower section. The air outlet 3 is arranged at the top of the fluidized drying tower 1, especially at the top of the upper section. The wet material inlet 5 is arranged at the upper part of the middle section. The dry material outlet 9 is arranged at the lower section opposite to the air inlet 2. In other embodiments, the wet material inlet 5 can also be arranged at the upper section of the fluidized drying tower 1, for example, at the lower part of the upper section. A waste gas treatment system can be connected downstream of the air outlet 3, which includes a cyclone separation device 4, such as a cyclone dust collector, a bag filter or a tail gas scrubber.

[0053] The vibrating feeder leads to the wet material inlet 5 provided at the fluidized drying tower 1. The wet material inlet 5 is connected to the vibrating feeder through a connecting pipe, wherein the inclination angle of the connecting pipe with respect to the horizontal line is greater than or equal to 30 degrees. The inclination angle of the connecting pipe with respect to the horizontal line can be 45 - 90 degrees, preferably 60 - 90 degrees, especially 75 - 90 degrees.

[0054] The lower gas distribution plate 7 - 1 and the upper gas distribution plate 7 - 2 are configured as gas distribution plates, and the gas distribution plate is a porous flat plate. The lower gas distribution plate 7 - 1 and the upper gas distribution plate 7 - 2 are arranged at the middle section of the fluidized drying tower 1. In this embodiment, two lower gas distribution plates 7 - 1 and upper gas distribution plates 7 - 2 are provided, wherein the upper lower gas distribution plate 7 - 1 and the upper gas distribution plate 7 - 2 are arranged at the middle part of the middle section of the fluidized drying tower 1, and the lower lower gas distribution plate 7 - 1 and the upper gas distribution plate 7 - 2 are arranged at the transition area from the middle section to the lower section of the fluidized drying tower 1. As can be seen from Figure 1 and 2 in, in these two layers of lower gas distribution plates 7 - 1 and upper gas distribution plates 7 - 2, the upper lower gas distribution plate 7 - 1 and the upper gas distribution plate 7 - 2 are provided with a lower paddle scraping plate 8 - 1 and an upper paddle scraping plate 8 - 2, and the lower paddle scraping plate 8 - 1 and the upper paddle scraping plate 8 - 2 are arranged on the upper lower gas distribution plate 7 - 1 and the upper gas distribution plate 7 - 2. In other embodiments, additional lower gas distribution plates 7 - 1 and upper gas distribution plates 7 - 2 can also be arranged on the lower lower gas distribution plate 7 - 1 and the upper gas distribution plate 7 - 2. In other embodiments, more than two lower gas distribution plates 7 - 1 and upper gas distribution plates 7 - 2 can also be provided, wherein at least the shown lower gas distribution plates 7 - 1 and upper gas distribution plates 7 - 2 are equipped with a lower paddle scraping plate 8 - 1 and an upper paddle scraping plate 8 - 2. In some embodiments, all lower gas distribution plates 7 - 1 and upper gas distribution plates 7 - 2 are respectively equipped with a lower paddle scraping plate 8 - 1 and an upper paddle scraping plate 8 - 2.

[0055] As can be seen from Figures 1 to 3As can be seen, the lower paddle blade scraping plate 8-1 and the upper paddle blade scraping plate 8-2 include at least one paddle blade rotatably supported about the central axis of the fluidized drying tower 1 and a scraping plate indirectly mounted on the paddle blade. In a specific embodiment, three paddle blades are provided, and the three paddle blades are evenly arranged at the same angular interval from each other, that is, at an angular interval of, for example, 120 degrees from each other. In other embodiments, two paddle blades may also be provided, and the two paddle blades are separated from each other by an angular interval of 180 degrees. In other embodiments, n paddle blades (where n is greater than or equal to four) may also be provided, and these paddle blades are separated from each other by an interval of 360 degrees / n. By spacing the respective paddle blades at the same angular interval from each other, the force on the paddle blades during rotation can be made more balanced. Of course, in some embodiments, only one paddle blade may be arranged. To ensure that the paddle blade together with the scraping plate arranged on the paddle blade has as large a coverage range as possible for the area to be scraped and at the same time prevent the paddle blade from rubbing or colliding with the inner wall of the fluidized drying tower 1, the distance between the free end of the paddle blade and the inner wall of the fluidized drying tower 1 is not greater than 50 mm.

[0056] To drive the paddle blade to rotate, as Figures 1 - 3 shown, the paddle blade is driven by a motor 15 to rotate about the central axis of the fluidized drying tower 1. The motor 15 is centrally arranged at the bottom of the lower section of the fluidized drying tower 1. The motor 15 drives the paddle blade to rotate through a transmission shaft. The rotation speed of the motor 15 is constant. In some embodiments, the rotation speed of the motor 15 can be preset according to requirements.

[0057] In the embodiment of the present invention, the scraping plate is indirectly mounted on the paddle blade via a carrier plate. In other embodiments, the scraping plate may also be directly mounted on the paddle blade. In the case of mounting via a carrier plate, a groove may be provided on the carrier plate, for example, in the middle area of the carrier plate, and a corresponding rib is provided at the paddle blade, so that the carrier plate can be fixedly mounted on the paddle blade. Of course, in other embodiments, a groove may also be provided at the paddle blade, and a rib is provided at the corresponding part of the carrier plate. To ensure a dead zone-free arrangement of the scraping plate mounted on the paddle blade for the lower gas distribution plate 7-1 and the upper gas distribution plate 7-2 when the paddle blade rotates, the scraping plates directly mounted or mounted via a carrier plate are arranged staggeredly from each other on different paddle blades when viewed in the circumferential direction. In the case where the scraping plate is mounted on the paddle blade via a carrier plate, the scraping plates are arranged at intervals from each other on the carrier plate. In addition, the scraping plate is arranged at an angle relative to the paddle blade in a top view, wherein the extending direction of the scraping plate and the extending direction of the paddle blade enclose an angle between 10 degrees and 60 degrees, so as to ensure a larger coverage range of the scraping plate on the one hand and reduce the shear force on the paddle blade on the other hand. To ensure a good scraping effect, the scraping plates are evenly distributed on the corresponding paddle blades.

[0058] In order to ensure that there is no gap between the lower edge of the scraping plate and the lower gas distribution plate 7-1 and the upper gas distribution plate 7-2, the scraping plate is at least partially movably mounted on the carrier plate in the vertical direction. Through the at least partially vertically movable arrangement structure of the scraping plate, after the lower edge of the scraping plate is worn, the scraping plate will freely fall, so as to ensure that the lower edge of the scraping plate always lies on the lower gas distribution plate 7-1 and the upper gas distribution plate 7-2. In this embodiment, the vertical movability of the scraping plate is achieved by a long-shaped opening combined with a double-nut structure arranged through the opening. For this purpose, a long-shaped opening for enabling the scraping plate to move in the vertical direction is provided in the carrier plate, and the scraping plate is movably mounted on the carrier plate in the opening via a double-nut structure arranged through the opening. In other embodiments, other movable anti-loss fastening devices other than double nuts can also be used, such as a fixing structure combining a screw and a pin or a snap. In this embodiment, in the case of adopting a double-nut structure, the stud portion of the double-nut structure passes through the opening, the inner first nut among the nut portions of the double-nut structure is spaced apart from the side surface of the carrier plate or the scraping plate, and the outer second nut is in a tightened connection with the inner first nut, so that the scraping plate can be movably and anti-loss mounted on the carrier plate. The scraping plate can be fixedly connected to the bolt head or the screw of the double-nut structure. Here, the long-shaped opening can be an oblong hole. In other embodiments, the opening can also adopt other forms.

[0059] In order to prevent the scraping plate from rotating itself when falling, in the scraping plate, two long-shaped openings are respectively provided for each scraping plate, and the two long-shaped openings are arranged parallel to each other. Alternatively or additionally, the section of the fastening device cooperating with the opening has a rectangular cross-sectional shape, so as to also prevent the scraping plate from rotating itself when moving in the vertical direction.

[0060] The material of the scraping plate can be non-metal, such as plastic, especially thermosetting plastic, while the materials of the lower gas distribution plate 7-1 and the upper gas distribution plate 7-2 can be metal, thereby ensuring that the scraping plate wears out prior to the lower gas distribution plate 7-1 and the upper gas distribution plate 7-2. The scraping plate is configured to be detachable and replaceable, thereby reducing the maintenance workload.

[0061] In the technical solution of the present invention, the ammonium sulfate solution has the same meaning as the ammonia-based desulfurization circulating liquid, but the ammonium sulfate solution will also contain a small amount of ammonium sulfite, ammonium bisulfite, ammonium bisulfate, etc. In the technical solution of this application, the ammonium sulfate solution for solution drying is preferably the concentrated circulating liquid in the ammonia-based desulfurization circulating liquid or the solution obtained after solid-liquid separation of the concentrated circulating liquid. Preferably, the ammonium sulfate solution is an unsaturated ammonium sulfate solution.

[0062] In the technical solution of the present invention, the wet material 6 (also known as wet feed) is preferably solid ammonium sulfate with a water content of 3-10% wt.

[0063] Specifically, such as Figure 1 and 2 , the fluidized drying device includes a fluidized drying tower 1, with a cylindrical middle part and conical upper and lower parts. The cylindrical part is the main fluidized drying area of the fluidized drying tower 1, and the fluidized drying area is the area where the hot air 16 contacts the wet material 6 to evaporate moisture. The fluidized drying tower 1 is provided with an air inlet 2, an air outlet 3, a wet feed inlet 5, a dry feed outlet 9, and a solution inlet 10. The cylindrical part is provided with a gas distribution plate 7-1, which is a porous flat plate. A paddle scraper 8-1 is arranged on the gas distribution plate, and the paddle scraper rotates through the transmission of a motor 15.

[0064] Preferably, the gas distribution plate 7-1 is located at the bottom surface of the cylinder of the fluidized drying tower 1.

[0065] Preferably, two layers of gas distribution plates are provided, namely gas distribution plates 7-1 and 7-2, and corresponding paddle scrapers 8-1 and 8-2. The distance between the gas distribution plates 7-1 and 7-2 is greater than or equal to 800 mm.

[0066] The wet feed inlet 5 is located at the upper part of the fluidized drying tower 1 and is connected to the solid ammonium sulfate wet feed pipeline 6.

[0067] The solution inlet 10 is located in the middle part of the fluidized drying tower 1 and is connected to the ammonium sulfate solution (i.e., the circulating liquid of the ammonia desulfurization system) 11 pipeline. The distance between the solution inlet 10 and the gas distribution plate 7-1 is greater than or equal to 200 mm. Preferably, the solution inlet 10 is located between the gas distribution plates 7-1 and 7-2. To improve the drying effect, multiple layers of gas distribution plates can be provided. To improve the atomization effect, multiple solution inlets can be provided. The solution inlet 10 is connected to a spray gun, and the spray gun extends into the fluidized drying tower 1. To improve the drying effect, the nozzle of the spray gun is greater than or equal to 100 mm away from the inner wall of the fluidized drying tower 1.

[0068] Preferably, the ammonium sulfate solution can be pretreated by a pretreatment system 12, and the pretreatment system is selected from a solution dilution system, a heating system, or a filtration system. Through pretreatment, it can be ensured that the ammonium sulfate solution entering the spray gun is not easily blocked.

[0069] Preferably, before entering the fluidized drying tower 1, pressurized air 14 can be introduced into the ammonium sulfate solution to improve the atomization effect. Preferably, the pressure of the pressurized air is greater than or equal to 0.25 MPA (gauge pressure). The pressure of the ammonium sulfate solution entering the tower needs to be greater than the pressure of the pressurized air.

[0070] The air inlet 2 is located in the lower conical part and is connected to the hot air 16 pipeline, which is used to heat the material and evaporate moisture.

[0071] Preferably, the hot air 16 can be heated to an appropriate temperature by the steam heat exchanger 19.

[0072] The air outlet 3 is located at the top and is connected to the cyclone separation device 4. An automatic discharge valve 18 is provided at the bottom of the cyclone separation device 4 to collect ammonium sulfate solids. The air outlet of the cyclone separation device 4 is connected to the tail gas purification system 17.

[0073] The dry material outlet 9 is located in the lower conical part, vertically downward, and extends inward to the gas distribution plate 7-1.

[0074] Specifically, such as Figure 2 , compared with Example 1, the ammonium sulfate solution 21 containing solids first enters the solid-liquid separation device 22 for solid-liquid separation to obtain the wet material 6 and the ammonium sulfate solution 11. The pretreatment system 12 is a heating system. The tail gas is treated by the tail gas purification system 17 and then sent to the pretreatment system 12 as a heat source to heat the ammonium sulfate solution 11.

[0075] Since the drying of the wet material and the drying of the solution are carried out simultaneously in the same area of the fluidized drying tower, it not only improves the hot air heat transfer efficiency but also reduces the hot air consumption. The solution is sprayed into the fluidized drying area, which also reduces the discharge temperature of the dry material. By effectively utilizing the hot air energy, reducing the heat carried out by the material, the thermal energy utilization rate is improved, and energy consumption is saved. Moreover, the solution sprayed by the spray gun into the fluidized drying area will cause particle agglomeration, reduce the amount of fine powder, and improve the quality of the dried material.

[0076] Example

[0077] Example 1

[0078] Such as Figure 1 , the wet material 6 (solid ammonium sulfate with a water content of 3-10% wt) enters the fluidized drying tower 1 from the wet material inlet 5, falls onto the upper gas distribution plate 7-2, and is dispersed by the paddle scraping plate 8-2.

[0079] After the ammonium sulfate solution 11 passes through the pretreatment system 12, pressurized air 14 is introduced, and it enters the fluidized drying tower 1 from the solution inlet 10, and is sprayed into the fluidized drying tower 1 through the spray gun 13, contacts and exchanges heat with the hot air, and the gas evaporates to form solid ammonium sulfate.

[0080] The hot air 16 enters the fluidized drying tower 1 through the air inlet 2, passes through the lower gas distributor 7-1 for gas distribution, fluidizes and dries the material in the fluidized drying tower, the tail gas is discharged from the air outlet 3, then connected to the cyclone separation device 4, and the solid ammonium sulfate is collected through the automatic discharge valve 18. The tail gas is sent to the tail gas purification system 17 for treatment and then discharged. The tail gas purification system 17 includes a cyclone dust collector, a bag filter or a tail gas scrubber. The dried material (ammonium sulfate with a water content of 0.5-3% wt) is discharged through the dry material outlet 9.

[0081] Among them, the concentration of the ammonium sulfate solution is 25 - 40% wt, the flow rate of the ammonium sulfate solution is 0.4 - 0.8 m 3 / h, the flow rate of the wet ammonium sulfate is 4 t / h, the inlet temperature of the hot air 16 is 120 - 200 °C, and the flow rate is 30000 - 50000 Nm 3 / h. The diameter of the fluidized drying tower 1 is 4 m.

[0082] The chloride ion concentration in the circulating liquid of the ammonia desulfurization system ≤ 20000 mg / L. The steam consumption is 1.02 t / h.

[0083] Example 2

[0084] As Figure 2 , compared with Example 1, the ammonium sulfate solution 21 containing solids first enters the solid-liquid separation equipment 22 for solid-liquid separation to obtain wet materials 6 and solution 11. The pretreatment system 12 is a heating system. The tail gas is treated by the tail gas purification system 17 and then sent to the pretreatment system 12 as a heat source to heat the solution 11. Others are the same.

[0085] The chloride ion concentration in the circulating liquid of the ammonia desulfurization system ≤ 20000 mg / L. The steam consumption is 0.98 t / h.

[0086] Comparative Example 1: As Figure 3 , compared with Example 1, there is no solution inlet 10 and related equipment, and others are the same.

[0087] The chloride ion concentration in the circulating liquid of the ammonia desulfurization system ≥ 50000 mg / L. The steam consumption is 0.92 t / h. When the chloride ion concentration is greater than 50000 mg / L, it will cause serious corrosion of the metal components in contact with the solution, and the system cannot operate normally.

[0088] Comparative Example 2: Compared with Comparative Example 1, a set of conventional spray drying system is added, such as CN209475606U, to control the chloride ion concentration in the circulating liquid of the ammonia desulfurization system ≤ 20000 mg / L, and others are the same.

[0089] The steam consumption is 2.22 t / h. Both the investment and operating costs increase.

[0090] Note that the terminology used herein is for the purpose of describing particular aspects only and is not intended to limit the disclosure. As used herein, the singular forms "a" and "an" shall include the plural forms unless the context clearly dictates otherwise. It will be understood that the terms "comprising" and "including" and other similar terms, when used in the application, specify the presence of the stated operations, elements, and / or components, without precluding the presence or addition of one or more other operations, elements, components, and / or combinations thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. In the description of the figures, like reference numerals always denote like elements.

[0091] The thickness of the elements in the figures may be exaggerated for clarity. It will also be understood that if an element is referred to as being on, coupled to, or connected to another element, then the element may be directly formed on, coupled to, or connected to the other element, or there may be one or more intervening elements between them. Conversely, if the phrases "directly on", "directly coupled to", and "directly connected to" are used herein, then there are no intervening elements. Other words used to describe the relationship between elements should be interpreted similarly, such as "between" and "directly between", "attached" and "directly attached", "adjacent" and "directly adjacent", etc.

[0092] The terms such as "top", "bottom", "above", "below", "upper", "lower", etc. are used herein to describe the relationship of one element, layer, or region to another element, layer, or region as shown in the figures. It will be understood that these terms should also encompass other orientations of the device in addition to the orientations described in the figures.

[0093] It will be understood that although the terms "first", "second", etc. may be used herein to describe different elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Thus, a first element may be referred to as a second element without departing from the teachings of the inventive concept.

[0094] It can also be contemplated that all of the exemplary embodiments disclosed herein may be combined with each other arbitrarily. In addition, all of the individual technical features in this application may be combined with each other arbitrarily, provided that the combined technical features are not mutually contradictory. All technically feasible combinations of features are the technical content recited in this application.

[0095] Finally, it should be pointed out that the above embodiments are only used to understand the present invention and do not limit the protection scope of the present invention. For those skilled in the art, modifications can be made on the basis of the above embodiments, and these modifications do not depart from the protection scope of the present invention.

Claims

1. A fluidized drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid, characterized in that Add the ammonium sulfate solution to the fluidized drying area of the fluidized drying device.

2. The fluidized drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to claim 1, characterized in that The ammonium sulfate solution is an unsaturated ammonium sulfate solution.

3. The fluidized drying method with the function of removing chloride ions in the ammonia desulfurization circulating liquid according to claim 1, wherein The ammonium sulfate solution is pretreated by a pretreatment system before being added to the fluidized drying device.

4. The fluidized drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to claim 3, characterized in that The pretreatment system is selected from a solution dilution system, a heating system, or a filtration system.

5. The fluidized drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to claim 1, characterized in that The ammonium sulfate solution contains solids. The solid-liquid separation of the ammonium sulfate solution is carried out, and the obtained solid wet material and part of the solution enter the fluidized drying device for drying respectively.

6. The fluidized drying method having the function of removing chloride ions from the ammonia desulfurization circulating liquid according to claim 5, characterized in that The part of the solution obtained by solid-liquid separation is heated and then fed into the fluidized drying device.

7. The fluidized drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to claim 6, characterized in that Utilize the waste gas heat energy after fluidized drying to heat the solution obtained by solid-liquid separation.

8. The fluidized drying method with the function of removing chloride ions from the ammonia desulfurization circulating liquid according to claim 1, wherein Add the ammonium sulfate solution to the fluidized drying device through a spray gun.

9. The fluidized drying method with the function of removing chloride ions from the ammonia desulfurization circulating liquid according to claim 8, characterized in that The spray gun includes a nozzle.

10. The fluidized drying method with the function of removing chloride ions from the ammonia-based desulfurization circulating liquid according to claim 9, characterized in that The nozzle is preferably of a porous type.

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