A dust recovery system for an evaporation prilling tower

Abstract

The utility model relates to urea production field especially, and more particularly to a kind of evaporation prilling tower dust recovery system, technical scheme: a kind of evaporation prilling tower dust recovery system, including outer layer connecting pipe and the preheating dehumidification connecting structure being set in outer layer connecting pipe, connecting structure includes the inner layer connecting pipe being sleeved in outer layer connecting pipe, the tail fan frame being sleeved in the outer wall of outer layer connecting pipe tail end, the outer layer first dust collecting hood being installed in outer layer connecting pipe head, the inner layer first dust collecting hood being sleeved in outer layer first dust collecting hood inner wall and the tail dust collecting hood being installed in outer layer connecting pipe tail end, the utility model is heated by the annular heating cavity formed by inner and outer layer connecting pipe cooperation heating electric wire and output fan, constructs full range around type heating circulation, while, the outer layer first dust collecting hood cooperation with the hot gas barrier formed by heating airflow, constructs double moistureproof, solved the problem that existing urea evaporation prilling tower dust recovery system is easily blocked in high humidity operating environment under conveying pipeline.

Description

Technical Field

[0001] This utility model belongs to the field of urea production, specifically relating to a dust recovery system for an evaporation granulation tower. Background Technology

[0002] Evaporation granulation towers are widely used in chemical, food, pharmaceutical, and environmental protection industries to convert liquid materials (such as solutions and slurries) into solid granular products through evaporation of water and granulation processes. However, during the granulation process, a certain amount of dust is generated due to factors such as airflow disturbance, particle breakage, and uneven drying of droplets. This dust not only causes product loss and environmental pollution but may also lead to safety risks such as equipment wear and dust explosions.

[0003] In existing technologies, traditional dust recovery systems for evaporation granulation towers are often susceptible to the effects of ambient humidity during urea production. This leads to urea dust absorbing moisture and forming a sticky liquid film that adheres to the inner walls of pipes and the surface of filter bags when humid air intrudes or flue gas condenses, causing pipe blockage and filter bag failure. This necessitates frequent system shutdowns for cleaning. Furthermore, traditional dust recovery systems often employ localized heating structures, such as heating only the ash hopper, leading to temperature drops at the pipe ends and dust condensation at the tail end, as well as high energy consumption. Therefore, this invention proposes an evaporation granulation tower dust recovery system to address the problems existing in the prior art. Utility Model Content

[0004] To overcome the problem that the existing urea evaporation granulation tower dust recovery system is prone to blockage in the conveying pipeline under high humidity operating conditions.

[0005] The technical solution of this utility model is as follows: an evaporation granulation tower dust recovery system, including an outer connecting pipe and a preheating and dehumidification connection structure disposed inside the outer connecting pipe. The connection structure includes an inner connecting pipe fitted inside the outer connecting pipe, a tail fan frame fitted on the outer wall of the tail end of the outer connecting pipe, an outer head dust collection hood installed at the head end of the outer connecting pipe, an inner head dust collection hood fitted on the inner wall of the outer head dust collection hood, and a tail dust collection hood installed at the tail end of the outer connecting pipe. Several sets of heating wires are evenly distributed on the outer wall of the inner connecting pipe.

[0006] Preferably, the upper center of the outer dust collection hood is provided with a first groove, and the upper end of the outer dust collection hood is provided with four sets of first connecting grooves that are equidistantly distributed around the outer wall of the first groove. The first groove is connected to the inner dust collection hood, and the first end of the inner connecting pipe is installed in the first groove.

[0007] Preferably, the lower edges of the outer and inner head dust collection hoods are connected by a dustproof mesh plate, and the channel between the outer and inner head dust collection hoods is interconnected with the four sets of first connecting slots.

[0008] Preferably, three sets of fan mounting brackets are installed through the outer wall of the tail fan frame, equidistantly distributed around the outer wall of the tail fan frame, and the output fan is installed inside the fan mounting bracket.

[0009] Preferably, a second groove is provided through the center of the upper and lower ends of the tail fan frame, and four sets of second connecting grooves are equidistantly distributed around the outer wall of the second groove through the upper end of the tail fan frame. The second connecting grooves are connected to the tail dust collection hood. A tail collar is installed in the second groove, and the tail end of the inner connecting pipe passes through the tail collar.

[0010] Preferably, the first end of the outer connecting pipe is installed on the outer wall of the upper exhaust port of the evaporation granulation tower body through the outer first dust collection hood, and the first end of the inner connecting pipe is installed on the inner wall of the upper exhaust port of the evaporation granulation tower body through the inner first dust collection hood. The evaporation granulation tower body is installed on the granulation tower support frame.

[0011] Preferably, the tail end of the inner connecting pipe passes through the tail collar and is installed at the air inlet of the anti-adhesion pulse bag dust collector body, and the anti-adhesion pulse bag dust collector body is installed on the dust collector support frame.

[0012] The beneficial effects of this utility model are: 1. An annular heating chamber is formed by the outer and inner connecting pipes. Combined with the heating wire and three sets of output fans, a full-process surround heating cycle is constructed, breaking through the limitations of traditional local heating. At the same time, the outer and inner dust collection hoods work together. 2. A physical seal is formed by the inner insert seal and the outer cover seal, while the heated airflow is guided to the outer wall of the exhaust port to form a slightly positive pressure heat barrier, thus constructing a double moisture barrier. Attached Figure Description

[0013] Figure 1 The diagram shown is a three-dimensional structural schematic of the dust recovery system of the evaporation granulation tower of this utility model. Figure 2 The diagram shown is a three-dimensional structural breakdown of the dust recovery system of the evaporation granulation tower of this utility model. Figure 3 The diagram shown is a three-dimensional disassembled view of the inner and outer connecting pipes of the dust recovery system of the evaporation granulation tower of this utility model. Figure 4 The diagram shown is a three-dimensional structural split view of the outer and inner head dust collection hoods of the dust recovery system of the evaporation granulation tower of this utility model. Figure 5 The diagram shown is a split view of the outer and inner dust collection hoods of the dust recovery system of the evaporation granulation tower of this utility model. Figure 6 The diagram shown is a three-dimensional disassembled schematic of the tail fan frame, output fan, and tail collar of the dust recovery system of the evaporation granulation tower of this utility model.

[0014] Explanation of reference numerals in the attached drawings: 1-granulation tower support frame, 2-evaporation granulation tower main body, 3-anti-adhesion pulse bag dust collector main body, 4-dust collector support frame, 5-outer connecting pipe, 6-inner connecting pipe, 7-heating wire, 8-tail dust collection hood, 9-outer head dust collection hood, 10-dustproof mesh plate, 11-first connecting groove, 12-first groove body, 13-inner head dust collection hood, 14-tail fan frame, 15-fan mounting bracket, 16-second connecting groove, 17-output fan, 18-tail collar, 19-second groove body. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0016] Please see Figures 1-6 This utility model provides an embodiment: an evaporation granulation tower dust recovery system, including an outer connecting pipe 5, and a preheating and dehumidifying connecting structure disposed within the outer connecting pipe 5. The connecting structure includes an inner connecting pipe 6 fitted inside the outer connecting pipe 5, a tail fan frame 14 fitted on the outer wall of the tail end of the outer connecting pipe 5, an outer head dust collection hood 9 installed at the head end of the outer connecting pipe 5, an inner head dust collection hood 13 fitted on the inner wall of the outer head dust collection hood 9, and a tail dust collection hood 8 installed at the tail end of the outer connecting pipe 5. The outer wall of the inner connecting pipe 6 is equipped with several sets of heating wires 7 evenly distributed.

[0017] The outer connecting pipe 5 and the inner connecting pipe 6 form an annular heating chamber. Together with the heating wire 7 and three sets of output fans 17, a full-process surrounding heating cycle is constructed, breaking through the limitations of traditional local heating. At the same time, the outer first dust collection hood 9 and the inner first dust collection hood 13 cooperate, and the inner insert seal and the outer cover seal form a physical seal. Meanwhile, the heated airflow is guided to the outer wall of the exhaust port to form a slightly positive pressure heat barrier, thus constructing a double moisture protection.

[0018] Please see Figures 4-5In this embodiment, a first groove 12 is formed through the center of the upper end of the outer dust collection hood 9. Four sets of first connecting grooves 11, equidistantly distributed around the outer wall of the first groove 12, are formed through the upper end of the outer dust collection hood 9. The first groove 12 communicates with the inner dust collection hood 13. The head end of the inner connecting pipe 6 is installed inside the first groove 12. The four sets of equidistantly distributed first connecting grooves 11 are key flow ports for the outer heating airflow, allowing the hot air generated by the heating wire and driven by the fan in the outer pipe to be evenly introduced into the channel between the outer and inner dust collection hoods, avoiding… Local hot air accumulation or uneven flow rate ensures uniform circumferential heating of the inner pipe and prevents dust from absorbing moisture and sticking due to local low temperature. The lower edges of the outer first dust collection hood 9 and the inner first dust collection hood 13 are connected by a dustproof mesh plate 10. The channel between the outer first dust collection hood 9 and the inner first dust collection hood 13 is interconnected with the four sets of first connecting grooves 11. The dustproof mesh plate 10 can intercept coarse urea dust discharged from the granulation tower and prevent it from entering the outer heating channel. At the same time, the mesh structure performs preliminary rectification of the dust-laden flue gas entering the inner pipe, reducing the impact of turbulence on heating efficiency.

[0019] Please see Figure 6 In this embodiment, three sets of fan mounting brackets 15 are installed through the outer wall of the tail fan frame 14, equidistantly distributed around the outer wall of the tail fan frame 14. Output fans 17 are installed inside the fan mounting brackets 15. The three sets of equidistantly distributed output fans 17 form a ring-shaped suction force, driving the heating airflow between the outer and inner pipes to circulate efficiently, ensuring that heat is evenly transferred to the entire inner pipe and avoiding temperature attenuation caused by localized heat dissipation. Second grooves 19 are provided through the center of both the upper and lower ends of the tail fan frame 14, and a second groove 19 is provided through the upper end of the tail fan frame 14. Four sets of second connecting slots 16 are equidistantly distributed around the outer wall of the second tank 19. The second connecting slots 16 are interconnected with the tail dust collection hood 8. A tail collar 18 is installed inside the second tank 19. The tail end of the inner connecting pipe 6 passes through the tail collar 18. The four sets of second connecting slots 16 introduce the outer layer heated airflow into the tail dust collection hood 8, forming a tail hot air buffer zone. Part of the hot air participates in the circulation of the outer layer pipe back to the head dust collection hood, completing the heating closed loop. Another part of the hot air can preheat the area near the dust collector inlet to avoid condensation caused by a sudden drop in temperature before the dust-laden flue gas enters the dust collector.

[0020] Please see Figures 2-6In this embodiment, the first end of the outer connecting pipe 5 is installed on the outer wall of the upper exhaust port of the evaporation granulation tower body 2 through the outer first dust collection hood 9, and the first end of the inner connecting pipe 6 is installed on the inner wall of the upper exhaust port of the evaporation granulation tower body 2 through the inner first dust collection hood 13. The evaporation granulation tower body 2 is installed on the granulation tower support frame 1. The two pipes are respectively connected to the inner and outer walls of the exhaust port, and together with the hot air barrier of the first dust collection hood, a dual moisture-proof system of physical sealing and hot air sealing is formed: the physical sealing reduces gaps through structural fit, and the hot air... The seal utilizes the slight positive pressure of the hot air barrier to block humid air, ensuring that the relative humidity of the air at the interface is consistently below the critical value for urea. The tail end of the inner connecting pipe 6 passes through the tail collar 18 and is installed at the air inlet of the anti-adhesion pulse bag dust collector body 3. The anti-adhesion pulse bag dust collector body 3 is installed on the dust collector support frame 4. The inner connecting pipe 6 is directly connected to the dust collector air inlet, allowing the pre-treated dust-laden flue gas to quickly enter the separation core area, reducing the temperature drop in the intermediate links and preventing dust from absorbing moisture at the end of the pipe due to temperature reduction.

[0021] When in use, first start the heating wire 7 on the outer wall of the inner connecting pipe 6, and at the same time turn on the three sets of output fans 17 on the tail fan frame 14. The output fans 17 generate a ring-shaped suction force, which drives the air between the outer connecting pipe 5 and the inner connecting pipe 6 to form a circulating airflow. After being heated by the heating wire 7, the airflow flows towards the head along the outer pipe. The heated airflow passes through the four sets of first connecting slots 11 on the outer head dust collection hood 9 and enters the closed channel between the outer head dust collection hood 9 and the inner head dust collection hood 13. Finally, an annular hot air barrier is formed on the outer wall of the exhaust port at the top of the granulation tower, completing the preheating and moisture protection preparation. Next, the dust-laden flue gas discharged from the main body 2 of the urea evaporation granulation tower enters the system through the exhaust port. The flue gas first comes into contact with the inner first dust collection hood 13, and most of the flue gas directly enters the inner connecting pipe 6. The outer wall of the inner pipe is wrapped by the outer circulating hot air flow. The flue gas is continuously heated during the transportation process, and the relative humidity is further reduced, keeping the urea dust in a dry state. A small amount of coarse dust particles are intercepted by the dustproof mesh plate 10 between the outer first dust collection hood 9 and the inner first dust collection hood 13, preventing them from entering the heating channel and blocking the airflow or abrading the equipment. The hot air barrier formed by the outer heated airflow can block the outside humid air from entering the inner pipe through the gap of the exhaust port, and at the same time dry the air around the port, consolidating the low humidity environment. After the heated airflow in the outer duct completes the construction of the heat barrier at the head, part of the airflow flows back to the tail with the suction of the output fan 17. The returned heated airflow enters the tail dust collection hood 8 through the four sets of second connecting slots 16 on the tail fan frame 14, forming a tail hot air buffer zone. Part of the airflow continues to flow back to the heating wire 7 for secondary heating to participate in the circulation of the outer duct, thereby completing the heating closed loop. Another part of the airflow preheats the air inlet port of the anti-adhesion pulse bag dust collector body 3 to prevent the dust-laden flue gas from condensing due to a sudden drop in temperature before entering the dust collector. At the same time, the dry dust-laden flue gas in the inner connecting pipe 6 is accurately introduced into the anti-adhesion pulse bag dust collector body 3 through the elastically sealed tail collar 18. Then, the main body 3 of the anti-adhesion pulse bag dust collector starts to perform gas-solid separation on the dust-laden flue gas. The urea dust is intercepted by the filter bag, and the separated clean tail gas is discharged through the dust collector exhaust port. The intercepted dry urea dust can be returned to the granulation tower for regranulation through a closed conveying device.

[0022] Through the above steps, an annular heating chamber is formed by the outer connecting pipe 5 and the inner connecting pipe 6. Together with the heating wire 7 and three sets of output fans 17, a full-process surrounding heating cycle is constructed, breaking through the limitations of traditional local heating. At the same time, the outer first dust collection hood 9 and the inner first dust collection hood 13 cooperate, and a physical seal is formed by the inner insert seal and the outer cover seal. Meanwhile, the heated airflow is guided to the outer wall of the exhaust port to form a slightly positive pressure heat gas barrier, constructing a double moisture protection, which solves the problem of easy blockage of the conveying pipeline in the existing urea evaporation granulation tower dust recovery system in high humidity operating environment.

[0023] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A dust recovery system for an evaporation granulation tower, comprising an outer connecting pipe (5), characterized in that: It also includes a preheating and dehumidification connection structure set inside the outer connecting pipe (5). The connection structure includes an inner connecting pipe (6) fitted inside the outer connecting pipe (5), a tail fan frame (14) fitted on the outer wall of the tail end of the outer connecting pipe (5), an outer head dust collection hood (9) installed at the head end of the outer connecting pipe (5), an inner head dust collection hood (13) fitted on the inner wall of the outer head dust collection hood (9), and a tail dust collection hood (8) installed at the tail end of the outer connecting pipe (5). The outer wall of the inner connecting pipe (6) is equipped with several sets of heating wires (7) evenly distributed.

2. The dust recovery system for the evaporation granulation tower according to claim 1, characterized in that: The upper center of the outer head dust collection hood (9) is provided with a first groove (12), and the upper end of the outer head dust collection hood (9) is provided with four sets of first connecting grooves (11) that are equidistantly distributed around the outer wall of the first groove (12). The first groove (12) is connected to the inner head dust collection hood (13), and the head end of the inner connecting pipe (6) is installed in the first groove (12).

3. The dust recovery system for the evaporation granulation tower according to claim 2, characterized in that: The lower edges of the outer head dust collection hood (9) and the inner head dust collection hood (13) are connected by a dustproof mesh plate (10), and the channel between the outer head dust collection hood (9) and the inner head dust collection hood (13) is interconnected with the four sets of first connecting slots (11).

4. The dust recovery system for the evaporation granulation tower according to claim 1, characterized in that: Three sets of fan mounting brackets (15) are installed through the outer wall of the tail fan frame (14), which are equidistantly distributed around the outer wall of the tail fan frame (14). An output fan (17) is installed inside the fan mounting bracket (15).

5. The dust recovery system for the evaporation granulation tower according to claim 1, characterized in that: The upper and lower ends of the tail fan frame (14) are provided with a second groove (19) through the center. The upper end of the tail fan frame (14) is provided with four sets of second connecting grooves (16) that are equidistantly distributed around the outer wall of the second groove (19). The second connecting grooves (16) are connected to the tail dust collection hood (8). The tail collar (18) is installed inside the second groove (19). The tail end of the inner connecting pipe (6) passes through the tail collar (18).

6. The dust recovery system for the evaporation granulation tower according to claim 1, characterized in that: The first end of the outer connecting pipe (5) is installed on the outer wall of the upper exhaust port of the evaporation granulation tower body (2) through the outer head dust collection hood (9), and the first end of the inner connecting pipe (6) is installed on the inner wall of the upper exhaust port of the evaporation granulation tower body (2) through the inner head dust collection hood (13). The evaporation granulation tower body (2) is installed on the granulation tower support frame (1).

7. The dust recovery system for the evaporation granulation tower according to claim 1, characterized in that: The tail end of the inner connecting pipe (6) passes through the tail collar (18) and is installed at the air inlet of the anti-adhesion pulse bag dust collector body (3). The anti-adhesion pulse bag dust collector body (3) is installed on the dust collector support frame (4).

Images