Wet-process urea dust recovery equipment

Abstract

The utility model relates to the technical field of urea dust treatment, in particular to wet-process urea dust recovery equipment. In order to solve the problem that existing cloth bag filtering type urea dust recycling equipment has many defects, the novel wet-process urea dust recycling equipment is provided and comprises a dust remover, a dust removal fan, an emptying barrel, a washing circulating tank and a circulating pump, the dust remover comprises a dust removal bin, and a liquid blocking silk screen layer, a spraying layer and a filler layer are sequentially arranged in the dust removal bin from top to bottom. A dust removal discharging port of the dust removal bin is connected with a feeding port of the washing circulating tank, the washing circulating tank is provided with a liquid outlet and a liquid supplementing port, the liquid outlet is communicated with an inlet of the circulating pump, an outlet of the circulating pump is communicated with the multiple nozzles through a circulating pipeline, and the outlet of the circulating pump is further communicated with the granulation dissolving tank through a granulation dissolving pipeline. A dissolving valve is arranged on the granulation dissolving pipeline, the liquid supplementing port is connected with a liquid supplementing pipeline, and a liquid supplementing valve is arranged on the liquid supplementing pipeline. The equipment effectively saves the production cost.

Description

Technical Field

[0001] This utility model relates to the field of urea dust treatment technology, specifically a wet urea dust recovery device. Background Technology

[0002] During the urea production process, the finished urea granules need to go through screening, conveying, and bagging processes in the urea packaging section. During this process, a large amount of urea dust is generated due to collision and friction between the urea granules, which seriously affects the on-site environment.

[0003] In existing technologies, urea dust is recovered and treated using bag filter urea dust recovery equipment, such as... Figure 1 As shown, the bag filter urea dust recovery equipment includes a dust collector fan, a bag filter (the bag filter includes a dust collection chamber 1, filter bags 2, a hopper 3, and a dust discharge port 4; the filter bags 2 are located inside the dust collection chamber 1, the hopper 3 is used to collect filtered dust and is located below the dust collection chamber 1, and the dust discharge port 4 is located at the lower end of the hopper 3), a dust collector fan 5, and an venting cylinder 6. The side dust inlet of the bag filter is connected to various dust collection points in the urea packaging section through dust collection pipes. The outlet of the bag filter... The outlet is connected to the inlet of the dust collector fan, and the outlet of the dust collector fan is connected to the venting cylinder. After the dust collector fan is started, the urea dust from each dust collection point in the urea packaging section will be continuously drawn into the bag filter. The urea dust is filtered by the bag filter, and the clean air is discharged into the atmosphere through the venting cylinder. The urea dust filtered by the bag filter is collected into the silo, and then manually bagged after passing through the dust collector discharge port. It is then transported to the urea granulation section for dissolution with water and then returned to the system for re-granulation.

[0004] While this bag filter urea dust recovery equipment can effectively treat urea dust, the following drawbacks were found during use: 1) Due to urea's strong hygroscopicity, urea easily adheres to the pipe walls after absorbing moisture, leading to dust accumulation and pipe blockage, severely affecting the dust removal effect; 2) Frequent blockage of the dust removal pipes, especially during rainy summer weather, necessitates frequent dismantling and cleaning to maintain dust removal efficiency. This results in high labor costs and frequent PVC pipe blockage. Dismantling can easily damage the pipeline and affect its airtightness, making it easier for water to enter; 3) Urea dust filtered by the bag filter needs to be manually bagged after being collected in the silo, and then transported to the urea granulation section for water dissolution, and finally returned to the system for re-granulation. The manual dissolution and recycling work is labor-intensive; 4) The dust filtered by the bag filter easily absorbs moisture and sticks to the surface of the filter bag, and cannot be removed. At the same time, the deliquescence of urea can easily corrode the filter bag, shorten its service life, and require frequent replacement of the filter bag, which greatly increases the production cost. Summary of the Invention

[0005] This invention addresses the problems of excessive manual bagging, transportation, and dust dissolution in existing bag filter urea dust recovery equipment, as well as the frequent replacement of filter bags. Therefore, it provides a new wet urea dust recovery device.

[0006] This utility model is achieved using the following technical solution:

[0007] A wet urea dust recovery device includes a dust collector, a dust collector fan, an venting cylinder, a washing and circulation tank, and a circulation pump. The dust collector includes a dust collection chamber, which contains, from top to bottom, a liquid-blocking wire mesh layer, a spray layer, and a packing layer. The spray layer includes multiple nozzles evenly distributed above the packing layer. The dust collection chamber has a side dust inlet, which is connected to various dust collection points in the urea packaging section via dust collection pipes. The side dust inlet is positioned below the packing layer. The dust collection chamber has a top gas outlet, which is connected to the venting cylinder via the dust collector fan. The system is interconnected, with a dust removal inlet at the bottom of the dust removal chamber and a washing circulation tank located below the dust removal inlet. An inlet is located above the washing circulation tank. The dust removal inlet of the dust removal chamber is connected to the inlet of the washing circulation tank. The washing circulation tank has an outlet and a replenishment outlet. The outlet is connected to the inlet of the circulation pump. The outlet of the circulation pump is connected to multiple nozzles via a circulation pipe. The outlet of the circulation pump is also connected to the granulation and dissolution tank via a granulation and dissolution pipe. A dissolution valve is installed on the granulation and dissolution pipe. A replenishment pipe is connected to the replenishment outlet, and a replenishment valve is installed on the replenishment pipe.

[0008] During use, steam condensate is introduced into the replenishment pipe. Principle explanation: 1) By replacing the original dust collection bags in the dust collector chamber with a spray layer and a packing layer, urea dust is filtered out. A liquid-blocking mesh layer prevents gas from carrying the liquid phase out. 2) A washing circulation tank is designed to collect the urea solution after spraying. A circulation pump draws the low-concentration urea solution from the washing circulation tank to the spray layer, where it is evenly sprayed onto the packing layer. The washed urea solution is then returned to the washing circulation tank through the dust collector discharge port. Simultaneously, when the urea solution concentration in the washing circulation tank is too high, the dissolving valve is opened, and the high-concentration urea solution in the washing circulation tank is drawn into the granulation dissolving tank for regranulation. When the urea solution in the washing circulation tank is low, the replenishment valve is opened, and the liquid level in the washing circulation tank is replenished through the replenishment pipe to ensure normal spraying of the spray layer.

[0009] Furthermore, the device also includes a controller, a level gauge installed in the washing circulation tank, and an electric replenishment valve. The signal output terminal of the level gauge is connected to the signal input terminal of the controller, and the control port of the controller is connected to the signal interface of the replenishment valve. An interlock control is established between the replenishment valve and the liquid level in the washing circulation tank. When the liquid level in the washing circulation tank is ≤30%, the replenishment valve opens; when the liquid level in the washing circulation tank is ≥70%, the replenishment valve closes, achieving automatic replenishment.

[0010] Furthermore, the washing circulation tank is equipped with a densitometer for detecting the concentration of the urea solution. The dissolving valve is an electric valve. The signal output terminal of the densitometer is connected to the signal input terminal of the controller, and the control port of the controller is connected to the signal interface of the densitometer. The densitometer and the concentration of the urea solution in the washing circulation tank are interlocked. When the concentration of the urea solution is ≥45%, the dissolving valve opens; when the concentration of the urea solution is ≤40%, the dissolving valve closes.

[0011] Furthermore, each dust removal point in the urea packaging section is equipped with a flushing pipe, which is connected to the liquid replenishment pipe. Each flushing pipe is equipped with a flushing valve to facilitate flushing of the dust removal pipes at each dust removal point in the urea packaging section. This ensures that the urea dust adhering to the inner wall of the dust removal pipe can be dissolved in time by the flushing water (steam condensate). The dissolved urea solution is then drawn back into the dust removal chamber under negative pressure.

[0012] Furthermore, the packing layer is 1.5 meters high, and the packing used is Pall ring packing. Additionally, all pipes in the equipment are made of stainless steel to prevent ruptures and leaks, improving pipe sealing. Each section of pipe in the equipment is equipped with an inspection port for easy inspection and cleaning of the pipe interior.

[0013] The beneficial effects of this utility model are as follows: The equipment described in this utility model is mainly used in the centralized recycling of urea dust in the urea packaging section. It can directly recycle urea dust, avoiding the separate processes of manual cleaning, filling, transportation, and dust dissolution. At the same time, it avoids manual disassembly and cleaning after the dust removal pipe is blocked and the replacement of the filter bag, thus saving production costs. Attached Figure Description

[0014] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the present invention and, together with the description, serve to explain the principles of the present invention.

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of a bag filter-type urea dust recovery device.

[0017] Figure 2 This is a schematic diagram of the structure of the wet urea dust recovery equipment described in this utility model.

[0018] In the diagram: 1-Dust removal bin, 2-Filter bag, 3-Hoop, 4-Dust removal discharge port, 5-Dust removal fan, 6-Ventilation cylinder, 7-Washing circulation tank, 8-Circulation pump, 9-Liquid-blocking wire mesh layer, 10-Nozzle, 11-Packing layer, 12-Dust removal pipe, 13-Circulation pipe, 14-Pelletizing and dissolving pipe, 15-Dissolving valve, 16-Liquid replenishment pipe, 17-Liquid replenishment valve, 18-Density meter, 19-Level gauge, 20-Flushing pipe, 21-Flushing valve, 22-Controller. Detailed Implementation

[0019] To better understand the above-mentioned objectives, features, and advantages of this utility model, the solution of this utility model will be further described below. It should be noted that, unless otherwise specified, the embodiments and features of this utility model can be combined with each other.

[0020] In this description, it should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. It should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joint" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0021] Many specific details are set forth in the following description in order to provide a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the present invention, and not all embodiments.

[0022] The specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0023] like Figure 2As shown, a wet urea dust recovery device includes a dust collector, a dust collector fan 5, an venting cylinder 6, a washing and circulation tank 7, and a circulation pump 8. The dust collector includes a dust collection chamber 1, which contains, from top to bottom, a liquid-blocking wire mesh layer 9, a spray layer, and a packing layer 11. The spray layer includes multiple nozzles 10 evenly distributed above the packing layer 11. The dust collection chamber 1 has a side dust inlet, which is connected to various dust collection points in the urea packaging section via a dust collection pipe 12. The side dust inlet is positioned below the packing layer 11. The dust collection chamber 1 has a top gas outlet, which is connected to the venting cylinder 6 via the dust collector fan 5. The dust removal chamber 1 has a dust removal discharge port 4 at the bottom. The washing circulation tank 7 is located below the dust removal discharge port 4 and has a feed inlet above it. The dust removal discharge port 4 of the dust removal chamber 1 is connected to the feed inlet of the washing circulation tank 7. The washing circulation tank 7 has a liquid outlet and a liquid replenishment port. The liquid outlet is connected to the inlet of the circulation pump 8. The outlet of the circulation pump 8 is connected to multiple nozzles 10 through the circulation pipe 13. The outlet of the circulation pump 8 is also connected to the granulation and dissolution tank through the granulation and dissolution pipe 14. The granulation and dissolution pipe 14 is equipped with a dissolution valve 15. The liquid replenishment port is connected to a liquid replenishment pipe 16. The liquid replenishment pipe 16 is equipped with a liquid replenishment valve 17.

[0024] During use, steam condensate is introduced into the replenishment pipe 16. Principle explanation: 1. By replacing the original filter bags 2 in the dust collection chamber 1 with a spray layer and a packing layer 11, urea dust is filtered. A liquid-blocking mesh layer 9 prevents gas from carrying the liquid phase out. 2. A washing circulation tank 7 is designed to collect the urea solution after spray washing. A circulation pump 8 draws the low-concentration urea solution from the washing circulation tank 7 to the spray layer. The packing layer 11 is then uniformly sprayed and washed by the nozzles 10. The washed urea solution is then returned to the washing circulation tank 7 through the dust collection outlet 4. Simultaneously, when the concentration of the urea solution in the washing circulation tank 7 is too high, the dissolving valve 15 is opened, and the high-concentration urea solution in the washing circulation tank 7 is drawn by the circulation pump 8 to the granulation dissolving tank for regranulation. When the urea solution in the washing circulation tank 7 is low, the replenishment valve 17 is opened, and the liquid level in the washing circulation tank 7 is replenished through the replenishment pipe 16 to ensure normal spraying of the spray layer.

[0025] In practical implementation, the device also includes a controller. A level gauge 19 is installed inside the washing circulation tank 7. The replenishment valve 17 is an electric valve. The signal output terminal of the level gauge 19 is connected to the signal input terminal of the controller 22, and the control port of the controller 22 is connected to the signal interface of the replenishment valve 17. An interlock control is established between the replenishment valve 17 and the liquid level in the washing circulation tank 7. When the liquid level in the washing circulation tank 7 is ≤30%, the replenishment valve 17 opens; when the liquid level in the washing circulation tank 7 is ≥70%, the replenishment valve 17 closes, achieving automatic liquid replenishment.

[0026] In practice, the washing circulation tank 7 is equipped with a densitometer 18 for detecting the concentration of the urea solution. The dissolving valve 15 is an electric valve. The signal output terminal of the densitometer 18 is connected to the signal input terminal of the controller 22, and the control port of the controller 22 is connected to the signal interface of the densitometer 18. The densitometer 18 and the concentration of the urea solution in the washing circulation tank 7 are interlocked. When the concentration of the urea solution is ≥45%, the dissolving valve 15 opens; when the concentration of the urea solution is ≤40%, the dissolving valve 15 closes.

[0027] In practice, each dust removal pipe 12 at each dust removal point in the urea packaging section is equipped with a flushing pipe 20. The flushing pipe 20 is connected to the replenishment pipe 16. Each flushing pipe 20 is equipped with a flushing valve 21 to facilitate flushing of the dust removal pipe 12 at each dust removal point in the urea packaging section. This ensures that the urea dust adhering to the inner wall of the dust removal pipe 12 can be dissolved in time by the flushing water (steam condensate). The dissolved urea solution is then drawn back into the dust removal chamber 1 under negative pressure.

[0028] In this specific embodiment, the height of the packing layer 11 is 1.5 meters, and the packing used in the packing layer 11 is Pall ring packing. In this specific embodiment, all pipes in the equipment are stainless steel pipes to avoid rupture and leakage, and to improve the sealing performance of the pipes. Each section of pipe in the equipment is equipped with an inspection hole for easy inspection or cleaning of the inside of the pipe.

[0029] The above description is merely a specific embodiment of this utility model, enabling those skilled in the art to understand or implement it. Although detailed descriptions have been provided with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments, and all should be covered by the protection scope of the claims.

Claims

1. A wet urea dust recovery plant, characterized by, The dust collector includes a dust collector, a dust collector fan (5), an venting cylinder (6), a washing circulation tank (7), and a circulation pump (8). The dust collector includes a dust collection chamber (1). Inside the dust collection chamber (1), from top to bottom, there are a liquid-blocking wire mesh layer (9), a spray layer, and a packing layer (11). The spray layer includes multiple nozzles (10) evenly distributed above the packing layer (11). The dust collection chamber (1) has a side dust inlet, which is connected to each dust collection point in the urea packaging section through a dust collection pipe (12). The side dust inlet is arranged below the packing layer (11). The dust collection chamber (1) has a top gas outlet, which is connected to the venting cylinder (6) through the dust collector fan (5). The bottom of the dust collection chamber (1) is equipped with... The dust removal discharge port (4) and the washing circulation tank (7) are located below the dust removal discharge port (4). The washing circulation tank (7) is provided with an inlet above it. The dust removal discharge port (4) of the dust removal chamber (1) is connected to the inlet of the washing circulation tank (7). The washing circulation tank (7) is provided with an outlet and a replenishment port. The outlet is connected to the inlet of the circulation pump (8). The outlet of the circulation pump (8) is connected to multiple nozzles (10) through the circulation pipe (13). The outlet of the circulation pump (8) is also connected to the granulation and dissolution tank through the granulation and dissolution pipe (14). The granulation and dissolution pipe (14) is provided with a dissolution valve (15). The replenishment port is connected to a replenishment pipe (16). The replenishment pipe (16) is provided with a replenishment valve (17).

2. A wet urea dust recovery plant according to claim 1, characterized in that, The device also includes a controller, a level gauge (19) is installed in the washing circulation tank (7), the replenishment valve (17) is an electric valve, the signal output terminal of the level gauge (19) is connected to the signal input terminal of the controller (22), and the control port of the controller (22) is connected to the signal interface of the replenishment valve (17).

3. A wet urea dust recovery plant according to claim 2, characterized in that, The washing circulation tank (7) is equipped with a densitometer (18) for detecting the concentration of urea aqueous solution. The dissolving valve (15) is an electric valve. The signal output terminal of the densitometer (18) is connected to the signal input terminal of the controller (22). The control port of the controller (22) is connected to the signal interface of the densitometer (18).

4. A wet urea dust recovery plant according to claim 3, characterized in that, Each dust removal pipe (12) at each dust removal point in the urea packaging section is equipped with a flushing pipe (20). The flushing pipe (20) is connected to the replenishment pipe (16), and each flushing pipe (20) is equipped with a flushing valve (21).

5. The wet urea dust recovery equipment according to claim 4, characterized in that, The height of the packing layer (11) is 1.5 meters and the packing used in the packing layer (11) is Pall ring packing.

6. A wet urea dust recovery plant according to claim 5, characterized in that, All pipes in this equipment are made of stainless steel.

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