Air drying device matched with combustion tower

Abstract

The utility model discloses a combustion tower matched air drying device which comprises a combustion tower and two dryers, the bottom of each dryer is provided with an air inlet, the top of each dryer is provided with an air outlet, and the air inlets are connected with an air inlet main pipe through air inlet branch pipes. A prefilter, an air precooler, a water-steam separator and an induced draft fan are sequentially arranged on the air inlet main pipe in the airflow direction, a waste gas pipe is further arranged on the air inlet, the air outlet is connected with an air outlet main pipe through an air outlet branch pipe, and the air outlet main pipe is communicated with a burner of the combustion tower. A bypass pipe and a rear filter are sequentially arranged on the gas outlet main pipe in the gas flow direction, a heater is arranged at the end of the bypass pipe, a drying layer is arranged in the dryer, a gas distributor is arranged in the drying layer, and a gas guide pipe communicated with the gas distributor is arranged on the heater. According to the device, continuous combustion of the combustion tower can be guaranteed, the air drying effect can be improved, and the impurity content of air is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of phosphorus chemical production technology, specifically relating to an air drying device for a combustion tower. Background Technology

[0002] Phosphorus pentoxide is a commonly used raw material and reagent in the chemical industry, widely applied in various fields. High-quality phosphorus pentoxide can also be used to produce high-purity phosphoric acid of various concentrations, especially polyphosphoric acid. Currently, the industrial preparation of phosphorus pentoxide generally adopts the oxidative combustion method: using yellow phosphorus as raw material, the yellow phosphorus is heated and melted and then added to a combustion furnace. Dry air is introduced into the combustion furnace to react and burn with the yellow phosphorus, generating phosphorus pentoxide flue gas. The phosphorus pentoxide flue gas is then cooled and settled to produce the finished phosphorus pentoxide product. The combustion tower is a key piece of equipment in the production of phosphorus pentoxide. Currently, to improve combustion efficiency, air needs to be introduced into the combustion tower during phosphorus pentoxide combustion. In existing technologies, the air needs to be dried before entering the combustion tower to prevent phosphorus pentoxide from becoming damp upon contact. Currently used air dryers mostly employ activated carbon dryers. This type of dryer has a relatively simple structure. During use, the activated carbon has poor activity, and after a period of use, as the activity decreases, the drying effect becomes poor, requiring the combustion tower to be shut down and the activated carbon replaced. Secondly, the air dried with activated carbon contains certain impurities, which affect the production quality of phosphorus pentoxide after combustion in the combustion tower. Therefore, it is objectively necessary to develop a combustion tower-compatible air drying device with a reasonable structure, significant drying effect, and the ability to filter impurities. Summary of the Invention

[0003] The purpose of this invention is to provide an air drying device for a combustion tower that has a reasonable structure, significant drying effect, and can filter impurities.

[0004] The purpose of this utility model is achieved as follows: it includes a combustion tower and two dryers. Each dryer has an air inlet at the bottom and an air outlet at the top. The air inlet is connected to a main air inlet via an air inlet branch pipe, and an air inlet valve is installed on the air inlet branch pipe. Along the airflow direction, a pre-filter, an air precooler, a water vapor separator, and an induced draft fan are sequentially arranged on the main air inlet. An exhaust pipe with an exhaust valve is also installed on the air inlet. The air outlet is connected to an exhaust main pipe via an exhaust branch pipe, and the exhaust main pipe is connected to the burner nozzle of the combustion tower. Along the airflow direction, a bypass pipe and a post-filter are sequentially arranged on the exhaust main pipe. A bypass valve is installed on the bypass pipe, and a heater is installed at the end of the bypass pipe. A drying layer is provided inside the dryer, and a gas distributor is installed within the drying layer. A guide pipe connected to the gas distributor is installed on the heater, and a control valve is installed on the guide pipe.

[0005] Compared with existing technologies, this device has the following advantages: First, based on the existing dryer technology, this device adds a pre-filter, air pre-cooler, water vapor separator, and induced draft fan at the front end of the dryer. The pre-filter filters impurities in the air, removes particulate matter, and reduces the impurity content. The air pre-cooler cools the air, condensing moisture. The water vapor separator separates the condensed moisture, reducing the moisture content and lowering the processing burden on subsequent dryers. Second, the dryer structure is optimized, with two dryers arranged in an alternating manner. This device solves the problem of replacing the desiccant when the combustion tower stops working, ensuring continuous combustion. Furthermore, by using a heater and gas distributor in conjunction, the desiccant layer can be regenerated, avoiding repeated replacements and extending its lifespan. This reduces production costs and improves air drying efficiency. Additionally, the installed post-filter further filters the dried air, preventing any desiccant carried in the air from entering the combustion tower, effectively improving the quality of phosphorus pentoxide production. This device boasts advantages such as a reasonable structural design, excellent air drying effect, and low air impurity content, making it easy to promote and use. Attached Figure Description

[0006] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0007] Figure 2 This is a schematic diagram of the structure of the pre-filter 5 in this utility model;

[0008] In the diagram: 1-Combustion tower, 2-Dryer, 21-Inlet, 22-Outlet, 23-Upper grille, 24-Lower grille, 25-Desiccant, 26-Straight pipe, 27-Inclined pipe, 3-Inlet branch pipe, 4-Inlet main pipe, 5-Pre-filter, 51-Shell, 52-Top plate, 53-Mounting frame, 54-Filter screen, 6-Air precooler, 61-Tube sheet, 62-Heat exchange tube, 63-Medium inlet, 64-Medium outlet, 7-Water vapor separator, 8-Exhaust fan, 9-Outlet branch pipe, 10-Outlet main pipe, 11-Bypass pipe, 12-Post-filter, 13-Heater, 14-Guide pipe, 15-Exhaust gas pipe. Detailed Implementation

[0009] The present invention will be further described below with reference to the accompanying drawings, but this description is not intended to limit the present invention in any way. Any changes or improvements made based on the teachings of the present invention shall fall within the protection scope of the present invention.

[0010] like Figures 1-2 As shown, this utility model includes a combustion tower 1 and two dryers 2. The combustion tower 1 consists of two dryers 2. Each dryer 2 has an air inlet 21 at its bottom and an air outlet 22 at its top. The air inlet 21 is connected to an air inlet main pipe 4 via an air inlet branch pipe 3. An air inlet valve is installed on the air inlet branch pipe 3. Along the airflow direction, the air inlet main pipe 4 is sequentially equipped with a pre-filter 5, an air precooler 6, a water vapor separator 7, and an induced draft fan 8. The water vapor separator 7 and the induced draft fan 8 are structures used in the prior art. An exhaust pipe 15 is also installed on the air inlet 21. A waste gas valve is provided on the 15. The gas outlet 22 is connected to the main gas outlet 10 through the gas outlet branch pipe 9. The main gas outlet 10 is connected to the burner of the combustion tower 1. A bypass pipe 11 and a post-filter 12 are arranged sequentially along the airflow direction on the main gas outlet 10. A bypass valve is provided on the bypass pipe 11. A heater 13 is provided at the end of the bypass pipe 11. A drying layer is provided inside the dryer 2. A gas distributor is provided inside the drying layer. A gas guide pipe 14 connected to the gas distributor is provided on the heater 13. A control valve is provided on the gas guide pipe 14.

[0011] The working process of this device is as follows: When the combustion tower 1 is working, first open the inlet valve and outlet valve on one of the dryers 2, open the bypass valve on the bypass pipe 11, and start the induced draft fan 8. Under the action of the induced draft fan 8, the outside air enters the pre-filter 5 for air purification to remove particulate matter from the air. The purified air enters the air preheater 6. The air precooler 6 can cool the air, condensing the moisture in the air. The cooled air then enters the water vapor separator 7. The water vapor separator 7 can separate the condensed moisture in the air, reducing the moisture content in the air and reducing the processing load of the subsequent dryer 2. The air after water vapor separation will then pass through... The air intake branch pipe 3 enters one of the dryers 2. After the air passes through the drying layer in one of the dryers 2 for adsorption and drying, the moisture in the air is completely separated. The air dried by one of the dryers 2 then enters the main exhaust pipe 10 through the exhaust branch pipe 9. Part of the air entering the main exhaust pipe 10 enters the post-filter 12, which filters the dried air again to prevent the desiccant carried in the dried air from entering the combustion tower 1, effectively improving the production quality of phosphorus pentoxide. The other part of the dried air enters the heater 13 through the bypass pipe 11 for heating. When the drying layer in one of the dryers 2 needs to be dried... During regeneration, the inlet and outlet valves of one of the dryers 2 need to be closed, while the control valve on the air guide pipe 14 connected to one of the dryers 2 and the exhaust valve on the exhaust pipe 15 are opened. The air heated in the heater 13 enters the gas distributor within one of the dryers 2 through the air guide pipe 14. The gas distributor distributes the heated air within the drying layer of one of the dryers 2 for regeneration. The regenerated air is then discharged through the exhaust pipe 15. Simultaneously with the inlet and outlet valves of one dryer 2 closed, the inlet and outlet valves of the other dryer 2 also need to be opened. The air after water vapor separation enters through the inlet branch pipe 3. In another dryer 2, the air is dried and adsorbed. After being dried by the other dryer 2, the air enters the post-filter 12 through the outlet branch pipe 9 and the outlet main pipe 10 for filtration, and then enters the two combustion towers 1 for combustion. This allows the two dryers 2 to work alternately, which solves the problem of replacing the desiccant when the combustion tower 1 stops working. It can ensure continuous combustion in the combustion tower 1. In addition, by using the combustion tower and the gas distributor in conjunction, the drying layer can be regenerated, avoiding the phenomenon of repeated replacement of the drying layer, increasing the service life of the drying layer, reducing production costs, and improving the drying effect of the air.

[0012] Furthermore, to achieve better air filtration, the pre-filter 5 and post-filter 12 have the same structure, both including a housing 51 and a filter assembly detachably installed within the housing 51. For easy cleaning of the filter assembly, the filter assembly includes a top plate 52, a mounting frame 53, and a filter screen 54. The top of the housing 51 is machined with a mounting groove. There are 2-3 mounting frames 53, which are mounted on the bottom surface of the top plate 52. The filter screen 54 is installed within the mounting frames 53. The bottom of the housing 51 is machined with slots corresponding to the mounting frames 53. The bottom of the mounting frames 53 is provided with protrusions. The mounting frames 53 are movably installed within the housing 51 via the mounting grooves, and the protrusions... The top plate 52 is movably installed in the mounting slot and fixed to it by connecting screws. When the filter assembly needs to be cleaned, the connecting screws are loosened, and the top plate 52, mounting frame 53 and filter screen 54 can be removed from the housing 51. The filter screen 54 is then cleaned, and the particles inside the housing 51 are cleaned through the mounting slot. After cleaning, the top plate 52, mounting frame 53 and filter screen 54 are inserted into the housing 51 through the mounting slot, and the connecting screws are tightened. The mesh diameter of the filter screen 54 on the mounting frame 53 gradually decreases along the airflow direction, which can filter the particles in the air multiple times and further improve the air filtration effect.

[0013] Furthermore, the air precooler 6 has two tube sheets 61 symmetrically spaced inside, with multiple heat exchange tubes 62 evenly distributed and running through the two tube sheets 61. A medium inlet 63 and a medium outlet 64 are respectively provided on the air precooler 6 between the two tube sheets 61. Both ends of the air precooler 6 are provided with an air inlet and an air outlet connected to the main air intake 4. In use, filtered air flows within the heat exchange tubes 62, and a cooling medium can be introduced into the air precooler 6 through the medium inlet 63. The cooling medium can be cold air or cooling water. After entering the air precooler 6, the cooling medium can indirectly contact the air within the heat exchange tubes 62, cooling the air during this contact process. The cooled air then enters the water vapor separator 7. After the cooling medium's temperature rises from contact with the air, it is discharged from the air precooler 6 through the medium outlet 64. Preferably, to increase the contact area between the cooling medium and the air and improve the cooling effect, the heat exchange tubes 62 are finned tubes.

[0014] Furthermore, to improve the air drying effect, the drying layer includes an upper grid 23 and a lower grid 24, which are installed at a distance inside the dryer 2. A desiccant 25 is filled between the upper grid 23 and the lower grid 24. The desiccant is a molecular sieve used in the prior art. Air flows within the desiccant 25 between the upper grid 23 and the lower grid 24, allowing for sufficient contact with the desiccant 25, which is beneficial for improving the air drying effect.

[0015] Furthermore, the gas distributor includes a straight pipe 26 and inclined pipes 27. The straight pipe 26 is vertically installed inside the drying layer. The lower end of the straight pipe 26 is sealed by a base plate, and the upper end of the straight pipe 26 extends above the drying layer and connects to the air guide pipe 14. The inclined pipes 27 are staggered on the straight pipes 26 inside the drying layer. The ends of the inclined pipes 27 are equipped with air-permeable meshes. When the drying layer is regenerated, the heated air entering the air-carrying pipe 14 first enters the straight pipe 26, and then is evenly distributed in the drying layer through each inclined pipe 27. This can achieve uniform distribution of heated air and accelerate the regeneration speed of the drying layer.

Claims

1. A combustion tower air drying device, comprising a combustion tower (1) and a dryer (2), characterized in that: The dryer (2) is provided with an air inlet (21) at the bottom and an air outlet (22) at the top, the air inlet (21) is connected with an air inlet main pipe (4) through an air inlet branch pipe (3), the air inlet branch pipe (3) is provided with an air inlet valve, the air inlet main pipe (4) is sequentially provided with a pre-filter (5), an air pre-cooler (6), a water vapor separator (7) and an air induction fan (8) along the air flow direction, the air inlet (21) is further provided with a waste gas pipe (15), the waste gas pipe (15) is provided with a waste gas valve, the air outlet (22) is connected with an air outlet main pipe (10) through an air outlet branch pipe (9), the air outlet main pipe (10) is communicated with the combustion nozzle of the combustion tower (1), the air outlet main pipe (10) is sequentially provided with a bypass pipe (11) and a post-filter (12) along the air flow direction, the bypass pipe (11) is provided with a bypass valve, the end of the bypass pipe (11) is provided with a heater (13), the inside of the dryer (2) is provided with a drying layer, the drying layer is provided with a gas distributor, the heater (13) is provided with a gas guide pipe (14) communicated with the gas distributor, the gas guide pipe (14) is provided with a control valve.

2. A combustion tower air drying system according to claim 1, wherein: The pre-filter (5) and the post-filter (12) have the same structure and each include a shell (51) and a filter assembly detachably installed in the shell (51).

3. A combustion tower air drying system according to claim 2, wherein: The filter assembly includes a top plate (52), mounting frames (53) and filter screens (54), the top of the shell (51) is processed with mounting grooves, the mounting frames (53) are 2-3 in number, the mounting frames (53) are installed on the bottom surface of the top plate (52), the filter screens (54) are installed in the mounting frames (53), the bottom of the shell (51) is processed with insertion grooves corresponding to the mounting frames (53), the bottom of the mounting frame (53) is provided with a protruding block, the mounting frame (53) is movably installed in the shell (51) through the mounting grooves and the protruding block is inserted into the corresponding insertion groove, and the top plate (52) is movably installed in the mounting grooves and is fixedly connected therewith through connecting screws.

4. A combustion tower air drying system according to claim 3, wherein: The filter screen (54) on the mounting frame (53) has a gradually decreasing mesh diameter along the air flow direction.

5. A combustion tower air drying system according to claim 1, wherein: Two pipe plates (61) are symmetrically and interval installed in the air pre-cooler (6), a plurality of heat exchange pipes (62) are evenly and penetratively installed between the two pipe plates (61), a medium inlet (63) and a medium outlet (64) are respectively arranged on the air pre-cooler (6) between the two pipe plates (61), and air inlets and air outlets communicated with the air inlet main pipe (4) are arranged at the two ends of the air pre-cooler (6).

6. A combustion tower air drying system according to claim 5, wherein: The heat exchange pipe (62) is a finned tube.

7. A combustion tower air drying system according to claim 1, wherein: The drying layer includes upper and lower grilles (23, 24) which are interval installed in the inside of the dryer (2), and the drying agent (25) is filled between the upper and lower grilles (23, 24).

8. A combustion tower air drying system according to claim 1, wherein: The gas distributor comprises straight pipes (26) and inclined pipes (27), the straight pipes (26) are vertically installed in the drying layer, the lower end of the straight pipes (26) is sealed by a bottom plate, the upper end of the straight pipes (26) extends above the drying layer and is communicated with the air guide pipe (14), the inclined pipes (27) are staggered and installed on the straight pipes (26) in the drying layer, and the end of the inclined pipes (27) is provided with a gas permeable net.

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