A urea dust recycling system and method

Abstract

The application provides a urea dust circulation recovery system and method, the urea dust circulation recovery system comprises a dust collecting device, a spraying device is arranged above the dust collecting device, a solution storage device is connected to the bottom of the dust collecting device, the solution storage device is connected to the spraying device through a reflux pipeline, so that urea circulates and flows among the spraying device, the dust collecting device and the solution storage device, and a liquid discharge pipeline is led out on the reflux pipeline. The urea dust circulation recovery system provided by the application not only realizes recycling and reuse of urea solution, but also saves water resources, improves urea yield, reduces production cost, can automatically control the circulation amount and concentration of urea solution according to actual needs, has high automation degree and saves operation and maintenance cost.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of urea prilling dust recovery, and relates to a urea dust recycling system and method. BACKGROUND

[0002] The prilling tower is a key equipment in urea particle production, and through natural ventilation or mechanical forced ventilation, molten urea is cooled and dried to form particles in the falling process. In this process, a large amount of urea dust is entrained in the exhaust gas at the top of the urea prilling tower. Most of these urea dusts fall on the ground nearby, corrode roads and buildings, harm the growth of some crops, and pollute the surrounding environment. The urea dust entrained causes product waste and increases production cost consumption. The dust emission of the urea prilling tower is a technical problem that has long plagued urea production enterprises.

[0003] There are many treatment methods for the dust generated by urea high tower prilling in the industry, such as electric dust removal, electric bag composite dust removal, and wet scrubbing. With the increasingly stringent environmental protection requirements, the dry bag type dust removal process, which was previously considered unfeasible, has been upgraded and has made significant breakthroughs. Compared with other urea high tower prilling dust recovery processes, the dry bag type dust removal process is more energy-saving and environmentally friendly, and has a larger dust treatment capacity. Most of the urea dust recovered by the dry bag type dust removal process of urea high tower prilling falls in the urea prilling interval, and a small part falls on the urea solution pipeline, thereby causing the pipeline to bear pressure; in addition, the urea dust recovered by the dry bag type dust removal process of urea high tower prilling is in the form of dust, not urea particles, which does not meet the requirements of urea manufacturing process for urea particles. Therefore, it is urgent to process the urea dust recovered by the dry bag type dust removal process of urea high tower prilling. SUMMARY

[0004] In view of the deficiencies in the prior art, the present application provides a urea dust recycling system and dust recovery method. The urea dust recycling system provided by the present application not only recycles and reuses urea solution, but also saves water resources, improves urea yield, and reduces production cost. The circulation amount and concentration of urea solution can be automatically controlled according to actual needs, and the degree of automation is high, which saves operation and maintenance cost. The present application realizes the recycling of the collected urea dust through washing, dissolution and recycling.

[0005] To achieve this purpose, the present application adopts the following technical solutions:

[0006] In a first aspect, the present application provides a urea dust recycling system, which comprises a dust collecting device, a spraying device arranged above the dust collecting device, and a solution storage device connected to the bottom of the dust collecting device, wherein the solution storage device is connected to the spraying device through a reflux pipeline, so that urea circulates between the spraying device, the dust collecting device and the solution storage device; and a liquid discharge pipeline is arranged on the reflux pipeline.

[0007] The spraying device comprises a plurality of spraying ring pipes arranged in concentric circles, a plurality of nozzles are arranged on the spraying ring pipes in a circumferential direction, and the nozzles on adjacent two spraying ring pipes are arranged in a staggered manner.

[0008] Preferably, the urea dust recycling system further comprises a material receiving tray, a dust filtering device is arranged above the material receiving tray, and the dust cake formed after the dust is filtered by the dust filtering device falls and is collected on the material receiving tray; the material receiving tray is provided with an overflow port, so as to maintain a certain liquid level during spraying, dissolving and absorbing, and ensure that the dust can be fully dissolved.

[0009] Further, the dust filtering device is a filter box or a filter plate, or a filter cartridge or a filter bag.

[0010] Preferably, a dust filtering device is arranged above the spraying device; the dust filtering device comprises a box body, a partition plate is arranged transversely in the box body, the box body is divided into an upper air inlet chamber and a lower filter chamber by the partition plate, and an air inlet is arranged on the air inlet chamber; a plurality of air inlet holes are arranged on the partition plate to communicate the air inlet chamber and the filter chamber; a plurality of filter plates are arranged in the filter chamber, a fan is arranged on the outer wall of the filter chamber, and a liquid discharge port is arranged at the bottom of the box body; a moving plate is arranged transversely in the filter chamber, an even number of filter plates are arranged vertically between the partition plate and the moving plate, adjacent two filter plates form a group, a filter cavity is formed between adjacent two filter plates, and the top of the filter cavity corresponds to the position of the air inlet hole; the top edge of the filter plate is hinged to the edge of the corresponding air inlet hole, the bottom edge of the filter plate is hinged to a connecting piece, the edges of adjacent two connecting pieces are hinged to a point and movably connected to the hinge point of the moving plate; and a driving mechanism is connected to the moving plate, the driving mechanism is used to drive the moving plate to move in a vertical direction, and with the vertical movement of the moving plate, adjacent two connecting pieces are driven to rotate towards each other or away from each other around the hinge point, so as to respectively drive adjacent two filter plates to expand or contract.

[0011] Preferably, the bottom of the solution storage device is provided with a backflow port, which respectively independently leads out a first backflow branch and a second backflow branch, the outlet ends of the first backflow branch and the second backflow branch are connected to the backflow pipeline; a first regulating valve, a first filter, a first water pump and a first check valve are sequentially arranged on the first backflow branch along the material flow direction; a second regulating valve, a second filter, a second water pump and a second check valve are sequentially arranged on the second backflow branch along the material flow direction; the first regulating valve and the second regulating valve are controlled to switch the use of the first backflow branch or the second backflow branch; a liquid level sensor is arranged on the inner side wall of the solution storage device, and the liquid level sensor is electrically connected to a controller, which respectively independently feeds back the first regulating valve and the second regulating valve; when the liquid level of the urea solution in the solution storage device reaches a first preset height, the liquid level sensor sends a first control signal to the controller, the controller controls the first regulating valve or the second regulating valve to open, and the urea solution collected in the solution storage device enters the spraying device through the backflow pipeline.

[0012] Further, the outer side wall of the solution storage device is connected to a circulation pipeline, the inlet end of the circulation pipeline communicates with the bottom of the side wall of the solution storage device, and the outlet end of the circulation pipeline communicates with the top of the side wall of the solution storage device; a third regulating valve is arranged on the circulation pipeline, and the controller feeds back the third regulating valve; when the liquid level of the urea solution in the solution storage device reaches a second preset height, the liquid level sensor sends a second control signal to the controller, the controller controls the third regulating valve to open, and the urea solution collected in the solution storage device is externally circulated through the circulation pipeline; the second preset height is lower than the first preset height.

[0013] Preferably, the inside of the solution storage device is configured with a first concentration sensor for detecting the concentration of the urea solution in the solution storage device, and the first concentration sensor is electrically connected to the controller; a fourth regulating valve is arranged on the liquid discharge pipeline, and the controller feeds back the fourth regulating valve; when the concentration of the urea solution in the solution storage device reaches a preset urea concentration, the first concentration sensor sends a control signal to the controller, the controller controls the fourth regulating valve to open, and the urea solution collected in the solution storage device is discharged into a downstream client through the liquid discharge pipeline.

[0014] In another aspect, the urea dust recycling method comprises: a spraying device spraying an absorption liquid to a dust collecting device to dissolve urea dust collected on the dust collecting device and form a urea solution; the urea solution flows into a solution storage device, returns to the spraying assembly through a reflux pipeline to spray the urea dust again, and is discharged through a discharge pipeline after the concentration of the urea solution in the solution storage device reaches a standard.

[0015] Further, the urea dust recycling method further comprises:

[0016] The urea dust in the tail gas is captured through a dust filtering device, and the urea dust attached to the filter plate is shaken off to the dust collecting device, and the spraying ring pipe sprays the absorption liquid to the dust collecting device.

[0017] The dust capturing process comprises: starting a fan, the tail gas enters the air inlet chamber from the air inlet under the action of suction, is distributed into different filter cavities through each air inlet hole, is discharged after passing through the filter plate, and the dust in the tail gas is captured and intercepted by the filter plate; the driving mechanism drives the moving plate to move vertically, and with the vertical movement of the moving plate, the adjacent two connecting pieces are driven to rotate towards each other or away from each other around the hinge point, thereby driving the adjacent two filter plates to expand or contract respectively, generating a vibration and beating effect on the filter plate, so that the dust attached to the filter plate is crumbled and falls off.

[0018] Compared with the prior art, the present application has the following advantages:

[0019] 1. The urea dust collected on the dust collecting device is dissolved by the spraying device spraying the absorption liquid, and when the solution in the dust collecting device reaches a certain amount, it flows into the solution storage device, which is generally arranged in the prilling room, and if the space in the prilling room is insufficient, it can be arranged under the prilling tower. The urea solution in the solution storage device enters the spraying device again through the reflux pipeline to spray the urea dust again, forming a urea solution circulation.

[0020] 2. After the concentration of the urea solution in the solution storage device reaches a set value, the urea solution is sent to the customer end through the discharge pipeline.

[0021] 3. The urea dust recycling system provided by the present application not only realizes recycling and reuse of urea solution, but also saves water resources, improves urea yield, and reduces production cost.

[0022] 4. The present application can automatically control the circulation amount and concentration of the urea solution according to actual needs, has high automation degree, and saves operation and maintenance cost. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1A structure schematic diagram of a urea dust recycling system is provided for a specific embodiment of the present application.

[0024] Figure 2 A structure schematic diagram of a dust filtering device is provided for a specific embodiment of the present application.

[0025] Figure 3 A Figure 2 A state schematic diagram of a moving plate ascending process in the dust filtering device is provided.

[0026] Figure 4 A Figure 2 A state schematic diagram of a moving plate descending process in the dust filtering device is provided.

[0027] Figure 5 A structure schematic diagram of a spraying device is provided for a specific embodiment of the present application.

[0028] Wherein: 1-spraying device; 2-dust collecting device; 3-solution storage device; 4-backflow pipeline; 5-first backflow branch; 6-second backflow branch; 7-first regulating valve; 8-first filter; 9-first water pump; 10-first check valve; 11-second regulating valve; 12-second filter; 13-second water pump; 14-second check valve; 15-liquid discharge pipeline; 16-fourth regulating valve; 17-elution pipeline; 18-discharge pipeline; 19-fifth regulating valve; 20-circulation pipeline; 21-third regulating valve; 22-first concentration sensor; 23-second concentration sensor; 24-liquid level sensor; 25-dust filtering device; 26-box body; 27-air inlet chamber; 28-filtering chamber; 29-baffle; 30-air inlet hole; 31-filtering plate; 32-filtering cavity; 33-moving plate; 34-driving mechanism; 35-fan; 36-air inlet; 37-liquid discharge port; 38-spraying ring pipe. DETAILED DESCRIPTION

[0029] The technical solutions of the present application will be described in detail below with specific examples and their accompanying drawings. The examples described herein are specific embodiments of the present application, which are used to illustrate the concept of the present application; these descriptions are all explanatory and exemplary, and should not be understood as limiting the embodiments of the present application and the protection scope of the present application. In addition to the examples described herein, those skilled in the art can also employ other technical solutions that are obvious based on the content disclosed in the claims and the specification of the present application, which include technical solutions that make any obvious substitutions and modifications to the examples described herein.

[0030] The drawings of the specification are schematic and assist in the understanding of the concept of the present application, and schematically represent the shape of each part and the relationship therebetween. It should be understood that, in order to clearly show the structure of each component of the embodiments of the present application, the drawings are not drawn to the same scale, and the same reference numerals are used to indicate the same parts in the drawings. The technical solutions of the present application are further described below through specific embodiments.

[0031] It should be understood that, in the description of the present application, the orientations or positional relationships indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second", etc. can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0032] It should be noted that, in the description of the present application, unless otherwise explicitly specified and limited, the terms "provided", "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0033] The present application provides a dust recycling method of a urea dust recycling system, which is arranged with a water receiving tray on the upper layer of a prilling tower prilling room, a spray head coil pipe is arranged above the water receiving tray, and urea dust collected on the water receiving tray is dissolved by spraying solution through the coil pipe. When the solution in the water receiving tray reaches a certain volume, it will overflow to a urea collecting pool (which is generally arranged in the prilling room, and if the space of the prilling room is insufficient, it can be arranged under the prilling tower), and the solution in the collecting pool is sprayed again into the coil pipe on the water receiving tray by a circulating pump. In this way, a cycle is formed, and when the concentration of the solution in the urea collecting pool reaches a set value, the circulating pump sends the urea solution reaching the concentration value to a designated position of the owner, and then supplements the urea analysis water in the collecting pool again to form a new cycle.

[0034] The urea recovery liquid concentration can be controlled according to actual needs, and the recovery liquid with high concentration can save energy consumption.

[0035] Further, the urea dust recycling system comprises a dust collecting device, a spraying device is arranged above the dust collecting device, a solution storage device is connected to the bottom of the dust collecting device, the solution storage device is connected to the spraying device through a reflux pipeline, so that the urea circulates between the spraying device, the dust collecting device and the solution storage device; a liquid discharge pipeline is led out of the reflux pipeline. The spraying device comprises a plurality of spraying ring pipes arranged in concentric circles, a plurality of nozzles are arranged on the spraying ring pipes in the circumferential direction, and the nozzles on adjacent two spraying ring pipes are arranged in a staggered manner. The urea dust recycling system further comprises a material receiving tray, a dust filtering device is arranged above the material receiving tray, and the dust cake formed after the dust is filtered by the dust filtering device falls and is collected on the material receiving tray; the material receiving tray is provided with an overflow port, and a certain liquid level height is maintained during spraying, dissolution and absorption, so that the dust can be fully dissolved. The dust filtering device is a filter box or a filter plate, or a filter cartridge or a filter bag. In one specific embodiment, the urea dust recycling system comprises a dust collecting device 2, a spraying device 1 is arranged above the dust collecting device 2, a solution storage device 3 is connected to the bottom of the dust collecting device 2, the solution storage device 3 is connected to the spraying device 1 through a reflux pipeline 4, so that the urea circulates between the spraying device 1, the dust collecting device 2 and the solution storage device 3; a liquid discharge pipeline 15 is led out of the reflux pipeline 4. Figure 1

[0036] The urea dust collected in the dust collecting device 2 is dissolved by the spraying device 1 spraying the absorption liquid, and when the solution in the dust collecting device 2 reaches a certain amount, it flows into the solution storage device 3. The solution storage device 3 is generally arranged in a prilling room, and if the space in the prilling room is insufficient, it can be arranged below the prilling tower. The urea solution in the solution storage device 3 enters the spraying device 1 again through the reflux pipeline 4 to perform secondary spraying on the urea dust, forming a urea solution circulation. When the concentration of urea in the solution storage device 3 reaches a set value, the urea solution is sent to the customer end through the liquid discharge pipeline 15. The urea dust recycling system provided by the application not only realizes recycling and reuse of the urea solution, but also saves water resources, improves urea yield, reduces production cost, and can automatically control the circulation amount and concentration of the urea solution according to actual needs, so that the degree of automation is high and the operation and maintenance cost is saved.

[0037] In Figure 5 ​In the shown embodiment, the spraying device 1 comprises a plurality of spraying annular pipes 38 arranged in concentric circles, and a plurality of nozzles are arranged on the spraying annular pipes 38 in a circumferential direction, and the nozzles on adjacent two spraying annular pipes 38 are arranged in a staggered manner.

[0038] The plurality of spraying annular pipes 38 arranged in concentric circles can expand the spraying range of the spraying device 1, and the spraying amount of different spraying annular pipes 38 can be adjusted according to the urea dust distribution in different radius regions, so that the use of the absorption liquid can be effectively saved, and the utilization rate of the absorption liquid can be improved.

[0039] In the shown embodiment, Figure 2 , Figure 3 and Figure 4 In the shown embodiment, the upper part of the spraying device 1 is provided with a dust filtering device 25. The dust filtering device 25 comprises a box body 26, a partition plate 29 is arranged in the box body 26 in a transverse direction, the box body 26 is divided into an upper air inlet chamber 27 and a lower filtering chamber 28 by the partition plate 29, the air inlet chamber 27 is provided with an air inlet 36, a plurality of air inlet holes 30 are arranged on the partition plate 29 to communicate the air inlet chamber 27 and the filtering chamber 28, a plurality of filter plates 31 are arranged in the filtering chamber 28, a fan 35 is arranged on the outer wall of the filtering chamber 28, and a liquid outlet 37 is arranged at the bottom of the box body 26. A moving plate 33 is arranged in the filtering chamber 28 in a transverse direction, an even number of filter plates 31 are vertically arranged between the partition plate 29 and the moving plate 33, adjacent two filter plates 31 form a group, a filtering cavity 32 is formed between adjacent two filter plates 31, and the top of the filtering cavity 32 corresponds to the position of the air inlet hole 30.

[0040] The top edge of the filter plate 31 is hinged to the edge of the corresponding air inlet hole 30, the bottom edge of the filter plate 31 is hinged to a connecting piece, the edges of adjacent two connecting pieces are hinged to a point and movably connected to the hinge point of the moving plate 33. The moving plate 33 is connected to a driving mechanism 34, and the driving mechanism 34 is used to drive the moving plate 33 to move in a vertical direction, and with the vertical movement of the moving plate 33, adjacent two connecting pieces are driven to rotate towards each other or away from each other around the hinge point, so as to respectively drive adjacent two filter plates 31 to expand or shrink.

[0041] The dust filtering device 25 provided in the urea dust recycling system can realize the combination of dry recovery and wet recovery of urea dust in cooperation with the spraying device 1. The traditional dry recovery process often uses a filter bag as a filtering device, but the filter bag has the following disadvantages: on the one hand, the air resistance is large, which leads to high energy consumption and low filtering efficiency; on the other hand, if the filter bag is not cleaned in time for a long time, the dust will be attached to the surface of the filter bag and hardened, which will cause the filter holes of the filter bag to be blocked and the filtering effect to be reduced.

[0042] In order to solve the above problems of the filter bag, the traditional filter bag structure is replaced by the filter plate in the present application, and the relative rotation between the two adjacent filter plates is realized through the hinge between the moving plate 33 and the filter plate. On the one hand, the distribution state of the cross-sectional size of the filter cavity 32 between the two adjacent filter plates 31 in the vertical direction can be changed by the outward expansion or inward contraction of the two adjacent filter plates 31, so as to change the air intake or dust concentration to reduce the wind resistance. For example, when the exhaust gas flow is large or the dust content in the exhaust gas is high, if the conventional filter bag is used, the wind resistance is large and the filtration efficiency is low. At this time, if the dust filter device 25 provided by the present application is used, the moving plate 33 is driven by the driving mechanism 34 to rise in the vertical direction. With the rising of the moving plate 33, the two adjacent connecting pieces are driven to rotate away from each other around the hinge point, so as to drive the two adjacent filter plates 31 to expand outward, so that the cross section of the filter cavity 32 gradually increases in the vertical direction. When the exhaust gas enters the filter cavity 32, the flow cross section gradually increases as the exhaust gas flows downward, so that the exhaust gas flow rate decreases and the wind resistance decreases. Conversely, when the exhaust gas flow is small or the dust content in the exhaust gas is low, the moving plate 33 is driven by the driving mechanism 34 to descend in the vertical direction. With the descending of the moving plate 33, the two adjacent connecting pieces are driven to rotate towards each other around the hinge point, so as to drive the two adjacent filter plates 31 to contract inward, so that the cross section of the filter cavity 32 gradually decreases in the vertical direction. When the exhaust gas enters the filter cavity 32, the flow cross section gradually decreases as the exhaust gas flows downward, so that the exhaust gas flow rate increases, the filtration time is shortened, and the filtration efficiency is improved.

[0043] On the other hand, after the exhaust gas passes through the filter plate 31, the urea dust in the exhaust gas is intercepted by the filter plate 31 and adheres to the surface of the filter plate 31. Before spraying, the urea dust adhering to the surface of the filter plate 31 needs to be shaken off. If additional beating equipment is added, not only the equipment cost is increased, but also the internal space of the equipment is occupied. The present application utilizes the reciprocating movement of the moving plate 33 in the vertical direction to make the two filter plates 31 constantly expand outward or contract inward at high frequency, and utilizes the vibration of the filter plate 31 itself to shake off the urea dust adhering to the surface of the filter plate 31.

[0044] Therefore, the dust filter device 25 provided by the present application not only realizes the adjustment of the wind resistance, but also realizes the vibration cleaning of the filter plate 31, which achieves two goals at once.

[0045] In Figure 1 In the embodiment shown, the bottom of the solution storage device 3 is provided with a backflow port, and the first backflow branch 5 and the second backflow branch 6 are independently led out from the backflow port. The outlet ends of the first backflow branch 5 and the second backflow branch 6 are connected to the backflow pipeline 4.

[0046] The first return branch 5 is sequentially provided with a first regulating valve 7, a first filter 8, a first water pump 9 and a first check valve 10 along the material flow direction; the second return branch 6 is sequentially provided with a second regulating valve 11, a second filter 12, a second water pump 13 and a second check valve 14 along the material flow direction; the first regulating valve 7 and the second regulating valve 11 are controlled to switch the use of the first return branch 5 or the second return branch 6.

[0047] The inner side wall of the solution storage device 3 is provided with a liquid level sensor 24, which is electrically connected to a controller, and the controller independently feeds back the control of the first regulating valve 7 and the second regulating valve 11; when the liquid level of the urea solution in the solution storage device 3 reaches a first preset height, the liquid level sensor 24 sends a first control signal to the controller, and the controller controls the first regulating valve 7 or the second regulating valve 11 to open, and the urea solution collected in the solution storage device 3 enters the spraying device 1 through the return pipeline 4.

[0048] In Figure 1 In the embodiment shown, the outer side wall of the solution storage device 3 is connected to a circulation pipeline 20, the inlet end of the circulation pipeline 20 communicates with the bottom of the side wall of the solution storage device 3, and the outlet end of the circulation pipeline 20 communicates with the top of the side wall of the solution storage device 3.

[0049] The circulation pipeline 20 is provided with a third regulating valve 21, and the controller feeds back the control of the third regulating valve 21; when the liquid level of the urea solution in the solution storage device 3 reaches a second preset height, the liquid level sensor 24 sends a second control signal to the controller, and the controller controls the third regulating valve 21 to open, and the urea solution collected in the solution storage device 3 is circulated outside through the circulation pipeline 20.

[0050] The second preset height is lower than the first preset height.

[0051] In Figure 1 In the embodiment shown, the inside of the solution storage device 3 is configured with a first concentration sensor 22 for detecting the concentration of the urea solution in the solution storage device 3, and the first concentration sensor 22 is electrically connected to a controller; the drain pipeline 15 is provided with a fourth regulating valve 16, and the controller feeds back the control of the fourth regulating valve 16.

[0052] When the concentration of the urea solution in the solution storage device 3 reaches a preset urea concentration, the first concentration sensor 22 sends a control signal to the controller, and the controller controls the fourth regulating valve 16 to open, and the urea solution collected in the solution storage device 3 is discharged into the downstream client through the drain pipeline 15.

[0053] In Figure 1In the embodiment shown, the inside of the solution storage device 3 is also provided with a second concentration sensor 23 for detecting the gas concentration of carbon dioxide in the solution storage device 3, and the second concentration sensor 23 is electrically connected to the controller. Figure 1 In another embodiment corresponding to the embodiment shown, the urea dust circulation recovery system recovers urea solution and does not decompose the urea solution, but only uses the urea analysis water produced by the spray dissolution as analysis water for reuse, thereby saving clean water.

[0054] The solution storage device 3 is connected to an analysis pipeline 17 through which an analysis liquid is introduced into the solution storage device 3; the analysis pipeline 17 is connected to a discharge pipeline 18 at the outlet end of which a carbonic acid storage tank is connected, and the discharge pipeline 18 is provided with a fifth regulating valve 19 controlled by the controller.

[0055] When the concentration of the carbon dioxide gas solution in the solution storage device 3 reaches a preset value, the second concentration sensor 23 sends a control signal to the controller, and the controller controls the fifth regulating valve 19 to open, and the carbon dioxide gas generated in the solution storage device 3 is discharged through the discharge pipeline 15 and sent to the carbonic acid storage tank.

[0056] In another specific embodiment, the present application provides a urea dust circulation recovery method in the above-mentioned urea dust circulation recovery system, which comprises:

[0057] The spray device 1 sprays the absorption liquid to the dust collection device 2 to dissolve the urea dust collected on the dust collection device 2 and form a urea solution; the urea solution flows into the solution storage device 3 and returns to the spray assembly through the reflux pipeline 4 as the absorption liquid for secondary spraying and recovery of the urea dust; and the urea solution in the solution storage device 3 is discharged through the discharge pipeline 15 after the concentration of the urea solution reaches a standard for reuse.

[0058] In an optional embodiment, the urea dust circulation recovery method further comprises:

[0059] The urea dust in the tail gas is captured by the dust filter device 25 and the urea dust attached to the filter plate 31 is shaken off to the dust collection device 2, and the spray ring 38 sprays the absorption liquid to the dust collection device 2.

[0060] Specifically, the process of capturing dust comprises:

[0061] The fan 35 is turned on, the tail gas enters the air inlet chamber 27 from the air inlet 36 under the action of suction, and is distributed into different filter cavities 32 through each air inlet hole 30, and the tail gas is discharged after passing through the filter plate 31, and the dust in the tail gas is captured and intercepted by the filter plate 31;

[0062] The driving mechanism 34 drives the moving plate 33 to move vertically, and with the vertical movement of the moving plate 33, the adjacent two connecting pieces are driven to rotate towards each other or away from each other around the hinge point, thereby driving the adjacent two filter plates 31 to expand or shrink, respectively, to generate a vibrating beating effect on the filter plate 31, so that the dust attached to the filter plate 31 is broken and falls off.

[0063] In an optional embodiment, the urea dust recycling method further comprises: automatically controlling the reflux circulation, emission standard discharge and gas resolution process of the urea solution by the controller.

[0064] Specifically, the automatic control process specifically comprises the following steps:

[0065] The liquid level sensor 24 monitors the liquid level of the urea solution in the solution storage device 3 in real time, and when the liquid level of the urea solution in the solution storage device 3 reaches a first preset height, the liquid level sensor 24 sends a first control signal to the controller, and the controller controls the first regulating valve 7 or the second regulating valve 11 to open, and the urea solution collected in the solution storage device 3 enters the spraying device 1 through the reflux pipeline 4 to perform the circulating spraying of the urea solution.

[0066] When the liquid level of the urea solution in the solution storage device 3 reaches a second preset height, the liquid level sensor 24 sends a second control signal to the controller, and the controller controls the third regulating valve 21 to open, and the urea solution collected in the solution storage device 3 is externally circulated through the circulation pipeline 20.

[0067] The first concentration sensor 22 monitors the concentration of the urea solution in the solution storage device 3 in real time, and when the concentration of the urea solution in the solution storage device 3 reaches a preset value, the first concentration sensor 22 sends a control signal to the controller, and the controller controls the fourth regulating valve 16 to open, and the urea solution collected in the solution storage device 3 is discharged to the downstream client through the liquid discharge pipeline 15.

[0068] After the urea solution meeting the concentration standard is discharged, the resolving liquid is introduced into the solution storage device 3 through the resolving pipeline 17, so that the urea solution is decomposed to generate carbon dioxide gas, and the concentration of the carbon dioxide gas generated in the solution storage device 3 is monitored by the second concentration sensor 23, and when the concentration of the carbon dioxide reaches a preset value, the second concentration sensor 23 sends a control signal to the controller, and the controller controls the fifth regulating valve 19 to open, and the carbon dioxide gas generated in the solution storage device 3 is discharged to the carbonic acid storage tank through the liquid discharge pipeline 15.

[0069] Example 1

[0070] The embodiment provides a urea dust recycling system, which comprises a urea dust recycling system as described in the above embodiment. Figure 1As shown, it comprises a dust collecting device 2, a spraying device 1 is arranged above the dust collecting device 2, a solution storage device 3 is connected to the bottom of the dust collecting device 2, the solution storage device 3 is connected to the spraying device 1 through a reflux pipeline 4, so that the urea circulates between the spraying device 1, the dust collecting device 2 and the solution storage device 3; the reflux pipeline 4 leads out a liquid discharge pipeline 15.

[0071] As shown in the figure, Figure 5 The spraying device 1 comprises a plurality of spraying ring pipes 38 arranged in concentric circles, a plurality of spray heads are arranged on the spraying ring pipes 38 in the circumferential direction, and the spray heads on adjacent two spraying ring pipes 38 are arranged in a staggered manner.

[0072] As shown in the figure, Figure 1 The bottom of the solution storage device 3 is provided with a reflux port, the reflux port independently leads out a first reflux branch 5 and a second reflux branch 6, and the outlet ends of the first reflux branch 5 and the second reflux branch 6 are connected to the reflux pipeline 4. A first regulating valve 7, a first filter 8, a first water pump 9 and a first check valve 10 are sequentially arranged on the first reflux branch 5 along the material flow direction; a second regulating valve 11, a second filter 12, a second water pump 13 and a second check valve 14 are sequentially arranged on the second reflux branch 6 along the material flow direction; the opening and closing of the first regulating valve 7 and the second regulating valve 11 are controlled to switch the use of the first reflux branch 5 or the second reflux branch 6. A liquid level sensor 24 is arranged on the inner side wall of the solution storage device 3, and the liquid level sensor 24 is electrically connected to a controller, which independently feeds back controls the first regulating valve 7 and the second regulating valve 11, respectively. When the liquid level of the urea solution in the solution storage device 3 reaches a first preset height, the liquid level sensor 24 sends a first control signal to the controller, the controller controls the first regulating valve 7 or the second regulating valve 11 to open, and the urea solution collected in the solution storage device 3 enters the spraying device 1 through the reflux pipeline 4.

[0073] As shown in the figure, Figure 1 The outer side wall of the solution storage device 3 is connected to a circulation pipeline 20, the inlet end of the circulation pipeline 20 communicates with the bottom of the side wall of the solution storage device 3, and the outlet end of the circulation pipeline 20 communicates with the top of the side wall of the solution storage device 3; a third regulating valve 21 is arranged on the circulation pipeline 20, and the controller feedback controls the third regulating valve 21. When the liquid level of the urea solution in the solution storage device 3 reaches a second preset height, the liquid level sensor 24 sends a second control signal to the controller, and the controller controls the third regulating valve 21 to open, and the urea solution collected in the solution storage device 3 is circulated outside through the circulation pipeline 20.

[0074] As shown in the figure, Figure 1As shown, the inside of the solution storage device 3 is configured with a first concentration sensor 22 for detecting the concentration of the urea solution in the solution storage device 3, and the first concentration sensor 22 is electrically connected to the controller; the fourth regulating valve 16 is arranged on the liquid discharge pipeline 15, and the controller feedback controls the fourth regulating valve 16. When the concentration of the urea solution in the solution storage device 3 reaches the preset urea concentration, the first concentration sensor 22 sends a control signal to the controller, and the controller controls the fourth regulating valve 16 to open, and the urea solution collected in the solution storage device 3 is discharged through the liquid discharge pipeline 15 and sent to the downstream client.

[0075] As shown, Figure 1 As shown, the inside of the solution storage device 3 is also configured with a second concentration sensor 23 for detecting the gas concentration of carbon dioxide in the solution storage device 3, and the second concentration sensor 23 is electrically connected to the controller; the solution storage device 3 is connected with an analysis pipeline 17, and the analysis liquid is introduced into the solution storage device 3 through the analysis pipeline 17; the analysis pipeline 17 leads out a discharge pipeline 18, the outlet end of the discharge pipeline 18 is connected to the carbonic acid storage tank, and the fifth regulating valve 19 is arranged on the discharge pipeline 18, and the controller feedback controls the fifth regulating valve 19. When the concentration of the carbon dioxide gas solution in the solution storage device 3 reaches the preset value, the second concentration sensor 23 sends a control signal to the controller, and the controller controls the fifth regulating valve 19 to open, and the carbon dioxide gas generated in the solution storage device 3 is discharged through the liquid discharge pipeline 15 and sent to the carbonic acid storage tank.

[0076] Example 2

[0077] The embodiment provides a urea dust recycling method, which is carried out in the urea dust recycling system provided in the embodiment 1, and specifically includes the following steps:

[0078] (1) The spraying device 1 sprays the absorption liquid to the dust collecting device 2 to dissolve the urea dust collected in the dust collecting device 2, and forms the urea solution, and the urea solution flows into the solution storage device 3 from the bottom of the dust collecting device 2;

[0079] (2) With the injection of the absorption liquid, the liquid level height of the urea solution in the solution storage device 3 gradually rises, and the liquid level sensor 24 monitors the liquid level height of the urea solution in the solution storage device 3 in real time, when the liquid level of the urea solution in the solution storage device 3 reaches 30% of the highest liquid level threshold, the liquid level sensor 24 sends a control signal to the controller, and the controller controls the third regulating valve 21 to open, and the urea solution collected in the solution storage device 3 is circulated through the circulation pipeline 20;

[0080] (3) With the continuous injection of the absorption liquid, the inventory of the urea solution in the solution storage device 3 gradually increases, when the liquid level of the urea solution in the solution storage device 3 reaches 70% of the highest liquid level threshold, the liquid level sensor 24 sends a control signal to the controller, and the controller controls the first regulating valve 7 or the second regulating valve 11 to open, so that the urea solution collected in the solution storage device 3 enters the spraying device 1 through the reflux pipeline 4, the circulation spraying of the urea solution is carried out, and the secondary utilization of the urea solution is realized;

[0081] (4) In the circulation process of the urea solution, the first concentration sensor 22 monitors the concentration of the urea solution in the solution storage device 3 in real time, when the concentration of the urea solution in the solution storage device 3 reaches a preset value, the first concentration sensor 22 sends a control signal to the controller, and the controller controls the fourth regulating valve 16 to open, so that the urea solution collected in the solution storage device 3 is discharged into the downstream client through the liquid discharge pipeline 15;

[0082] (5) After the urea solution with the qualified concentration is discharged, the resolving liquid is introduced into the solution storage device 3 through the resolving pipeline 17, so that the urea solution is decomposed to generate carbon dioxide gas, the second concentration sensor 23 monitors the concentration of the carbon dioxide gas generated in the solution storage device 3, when the concentration of the carbon dioxide reaches a preset value, the second concentration sensor 23 sends a control signal to the controller, and the controller controls the fifth regulating valve 19 to open, so that the carbon dioxide gas generated in the solution storage device 3 is discharged into the carbonic acid storage tank through the liquid discharge pipeline 15.

[0083] Example 3

[0084] The embodiment provides a urea dust circulation recovery system, which is based on the urea dust circulation recovery system provided in embodiment 1, and a dust filtering device 25 is additionally arranged above the spraying device 1, and other structures are completely same as those in embodiment 1.

[0085] The structure of the dust filtering device 25 is shown in Figure 2 、 Figure 3 and Figure 4 , which comprises a box body 26, a partition plate 29 is arranged transversely in the inside of the box body 26, the partition plate 29 divides the inside of the box body 26 into an air inlet chamber 27 at the upper side and a filtering chamber 28 at the lower side, the air inlet chamber 27 is provided with an air inlet 36, and the inside of the air inlet chamber 27 is configured with the spraying device 1; a plurality of air inlet holes 30 are arranged on the partition plate 29, so as to communicate the air inlet chamber 27 and the filtering chamber 28; a plurality of filter plates 31 are arranged in the inside of the filtering chamber 28,

[0086] A fan 35 is arranged at the outer wall of the filtering chamber 28, and a liquid discharge port 37 is arranged at the bottom of the box body 26.

[0087] The inside of the filtering chamber 28 is transversely provided with a moving plate 33, and an even number of filtering plates 31 are vertically arranged between the baffle 29 and the moving plate 33, two adjacent filtering plates 31 form a group, and a filtering cavity 32 is formed between the two adjacent filtering plates 31, and the top of the filtering cavity 32 corresponds to the position of the air inlet hole 30.

[0088] The top edge of the filtering plate 31 is hinged to the edge of the corresponding air inlet hole 30, and the bottom edge of the filtering plate 31 is hinged to a connecting piece, and the edges of two adjacent connecting pieces are hinged to a point and movably connected to the hinge point of the moving plate 33.

[0089] The moving plate 33 is connected with a driving mechanism 34, and the driving mechanism 34 is used to drive the moving plate 33 to move in the vertical direction. As shown in Figure 3 , the driving mechanism 34 drives the moving plate 33 to rise in the vertical direction, and with the rising of the moving plate 33, the two adjacent connecting pieces are driven to rotate away from each other around the hinge point, thereby driving the two adjacent filtering plates 31 to spread out, respectively. As shown in Figure 4 , the driving mechanism 34 drives the moving plate 33 to descend in the vertical direction, and with the descending of the moving plate 33, the two adjacent connecting pieces are driven to rotate towards each other around the hinge point, thereby driving the two adjacent filtering plates 31 to retract, respectively. Through the reciprocating movement of the moving plate 33 in the vertical direction, the two adjacent filtering plates 31 are constantly spread out and retracted, thereby realizing the vibration and beating effect of the filtering plate 31, so as to shake off the dust agglomerated on the filtering plate 31, and facilitate recycling and cleaning.

[0090] Example 4

[0091] The embodiment provides a urea dust recycling method, and the urea dust recycling method is carried out in the urea dust recycling system provided in Embodiment 3, and the step (1)

[0092] of the urea dust recycling method provided in Embodiment 2 is increased with dust interception and cleaning of the filtering plate 31, and the specific operation steps are as follows:

[0093] (I) Start the fan 35, and the tail gas enters the air inlet chamber 27 from the air inlet 36 under the action of suction, and is distributed into different filtering cavities 32 from each air inlet hole 30, and the tail gas is discharged after passing through the filtering plate 31, and the dust in the tail gas is captured and intercepted by the filtering plate 31;

[0094] (II) As shown in Figure 3 , the driving mechanism 34 drives the moving plate 33 to rise in the vertical direction, and with the rising of the moving plate 33, the two adjacent connecting pieces are driven to rotate away from each other around the hinge point, thereby driving the two adjacent filtering plates 31 to spread out, respectively; as shown in Figure 4As shown, the driving mechanism 34 drives the moving plate 33 to descend along the vertical direction, and with the descent of the moving plate 33, the adjacent two connecting pieces are driven to rotate towards each other around the hinge points, thereby driving the adjacent two filter plates 31 to retract respectively; the moving plate 33 reciprocates in the vertical direction, so that the adjacent two filter plates 31 continuously expand and retract, thereby realizing the vibration and beating effect of the filter plates 31, so as to shake the caked dust on the filter plates 31 into the dust collecting device 2;

[0095] (III) In step (1) of the above embodiment 2, the spraying device 1 is opened to spray the absorption liquid to the urea dust shaken into the dust collecting device 2; the subsequent operation steps are completely the same as the urea dust recycling method provided in the embodiment 2, and will not be repeated here.

[0096] The applicant declares that the above description is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and it should be understood by those skilled in the art that any changes or replacements within the technical scope disclosed by the present application can be easily thought out by those skilled in the art, and all fall within the protection scope and disclosure scope of the present application.

Claims

1. A urea dust recycle system, characterized by, It includes dust collecting device, the upper part of the dust collecting device is provided with a spraying device, the bottom of the dust collecting device is connected with a solution storage device, the solution storage device is connected with the spraying device through a reflux pipeline, so that the urea circulates between the spraying device, the dust collecting device and the solution storage device; the reflux pipeline is connected with a liquid discharge pipeline; The spraying device comprises a plurality of spraying ring pipes arranged in concentric circles, a plurality of nozzles are arranged on the spraying ring pipes in a circumferential direction, and the nozzles on adjacent two spraying ring pipes are arranged in a staggered manner; the upper part of the spraying device is provided with a dust filtering device; The dust filtering device comprises a box body, a partition plate is arranged horizontally in the inside of the box body, the inside of the box body is divided into an air inlet chamber at the upper part and a filtering chamber at the lower part by the partition plate, and an air inlet is formed in the air inlet chamber; a plurality of air inlet holes are formed in the partition plate to communicate the air inlet chamber and the filtering chamber; a plurality of filter plates are arranged in the inside of the filtering chamber, a fan is arranged at the outer wall of the filtering chamber, and a discharge port is arranged at the bottom of the box body; a moving plate is arranged horizontally in the inside of the filtering chamber, an even number of filter plates are arranged vertically between the partition plate and the moving plate, adjacent two filter plates form a group, a filtering cavity is formed between adjacent two filter plates, and the top of the filtering cavity corresponds to the position of the air inlet hole; the top edge of the filter plate is hinged to the edge of the corresponding air inlet hole, the bottom edge of the filter plate is hinged to a connecting piece, the edges of adjacent two connecting pieces are hinged to a point and movably connected to the hinge point of the moving plate; the moving plate is connected with a driving mechanism, the driving mechanism is used to drive the moving plate to move in a vertical direction, with the vertical movement of the moving plate, adjacent two connecting pieces are driven to rotate towards each other or away from each other around the hinge point, so as to respectively drive adjacent two filter plates to expand or shrink; The bottom of the solution storage device is provided with a reflux port, the reflux port independently leads out a first reflux branch and a second reflux branch, and the outlet ends of the first reflux branch and the second reflux branch are connected with the reflux pipeline; a first regulating valve, a first filter, a first water pump and a first check valve are arranged on the first reflux branch in sequence along the material flow direction; a second regulating valve, a second filter, a second water pump and a second check valve are arranged on the second reflux branch in sequence along the material flow direction; the first regulating valve and the second regulating valve are controlled to switch the use of the first reflux branch or the second reflux branch; A liquid level sensor is arranged on the inner side wall of the solution storage device, the liquid level sensor is electrically connected with a controller, the controller respectively and independently feeds back the control of the first regulating valve and the second regulating valve, when the liquid level of the urea solution in the solution storage device reaches a first preset height, the liquid level sensor sends a first control signal to the controller, the controller controls the first regulating valve or the second regulating valve to be opened, and the urea solution collected in the solution storage device enters the spraying device through the reflux pipeline.

2. The urea dust recycle system of claim 1, wherein, The urea dust recycling system further comprises a receiving tray, a dust filtering device is arranged above the receiving tray, and the dust cake formed after the dust is filtered falls and is collected on the receiving tray; the receiving tray is provided with an overflow port, and a certain liquid level height is maintained during the spraying, dissolving and absorbing to ensure that the dust can be fully dissolved.

3. The urea dust recycle system of claim 2, wherein, The outer side wall of the solution storage device is connected with a circulating pipeline, an inlet end of the circulating pipeline is in communication with the bottom of the side wall of the solution storage device, and an outlet end of the circulating pipeline is in communication with the top of the side wall of the solution storage device; A third regulating valve is arranged on the circulating pipeline, and the controller feedback controls the third regulating valve; when the liquid level of the urea solution in the solution storage device reaches a second preset height, the liquid level sensor sends a second control signal to the controller, the controller controls the third regulating valve to be opened, and the urea solution collected in the solution storage device is externally circulated through the circulating pipeline; The second preset height is lower than the first preset height.

4. The urea dust recycle system of claim 3, wherein, The inside of the solution storage device is configured with a first concentration sensor for detecting the concentration of the urea solution in the solution storage device, and the first concentration sensor is electrically connected with the controller; a fourth regulating valve is arranged on the liquid discharge pipeline, and the controller feedback controls the fourth regulating valve; When the concentration of the urea solution in the solution storage device reaches a preset urea concentration, the first concentration sensor sends a control signal to the controller, the controller controls the fourth regulating valve to be opened, and the urea solution collected in the solution storage device is discharged through the liquid discharge pipeline and sent to a downstream client.

5. A urea dust circulation recovery method performed in the urea dust circulation recovery system according to any one of claims 1 to 4, characterized by, The urea dust recycling method comprises: The spraying device sprays the absorbing liquid to the dust collecting device to dissolve the urea dust collected on the dust collecting device and form a urea solution; the urea solution flows into the solution storage device and returns to the spraying assembly through the reflux pipeline as the absorbing liquid to spray and recycle the urea dust for a second time; and the urea solution in the solution storage device is discharged through the liquid discharge pipeline after the concentration of the urea solution reaches a standard and is reused.

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