Urea production system

Abstract

The utility model provides a urea production system. The urea production system comprises a granulation tower; the trapping and purifying all-in-one machine is arranged at the top of the prilling tower, is used for receiving gas from the prilling tower and is provided with a reaction space and a demisting device, ammonia gas in the gas from the prilling tower reacts with a reaction solvent in the reaction space, and the demisting device is arranged at the top of the reaction space; the absorption chamber is used for receiving gas from the reaction space and absorbing a dispersion medium in the gas; and the deamination tower is connected with the trapping and purifying all-in-one machine and is used for receiving the reaction solvent which comes from the trapping and purifying all-in-one machine and reacts with the ammonia gas and recovering the ammonia gas in the reaction solvent. The trapping and purifying all-in-one machine can remove liquid and solid particles in the gas, so that the content of ammonia gas and urea dust in the discharged gas is effectively reduced. In addition, the ammonia gas absorbed by the reaction solvent is recycled by the deamination tower, so that the recycling of raw materials is facilitated.

Description

Technical Field

[0001] The utility model relates to the technical field of urea production, in particular to a urea production system. Background Art

[0002] In the urea production process, urea solution is typically prepared first and then transported to a prilling tower. The urea solution is sprayed from the top of the prilling tower as droplets, which fall freely. As they fall, they come into contact with countercurrent air, cooling and solidifying them into urea granules. The countercurrent air is then discharged from the top of the prilling tower into the atmosphere. However, this countercurrent air carries with it some urea dust and ammonia into the atmosphere, causing environmental pollution and resulting in raw material loss. Utility Model Content

[0003] One object of the utility model is to provide a urea production system capable of reducing the dust and ammonia contents in the gas discharged from a prilling tower.

[0004] In particular, the present invention provides a urea production system, comprising:

[0005] granulation tower;

[0006] a capture and purification integrated machine, which is arranged at the top of the granulation tower, for receiving the gas from the granulation tower, and is provided with a reaction space and a demisting device, wherein the ammonia in the gas from the granulation tower reacts with the reaction solvent in the reaction space, and the demisting device is arranged at the top of the reaction space, for receiving the gas from the reaction space and absorbing the dispersion medium in the gas; and

[0007] The deamination tower is connected to the capture and purification integrated machine and is used to receive the reaction solvent after the reaction with ammonia from the capture and purification integrated machine and recover the ammonia in the reaction solvent.

[0008] Optionally, the capture and purification integrated machine is provided with a spraying device and a recovery pool. The spraying device is arranged in the reaction space for spraying the reaction solvent into the reaction space. The recovery pool is arranged at the bottom of the reaction space for receiving the falling reaction solvent. The recovery pool is connected to the deamination tower so that the deamination tower receives the reaction solvent in the recovery pool.

[0009] Optionally, the capture and purification integrated machine is provided with a circulation pump, the spraying device includes a first spraying device, and the circulation pump connects the recovery tank and the first spraying device to transport the reaction solvent in the recovery tank to the first spraying device.

[0010] Optionally, the urea production system includes a delivery pump, the spraying device includes a second spraying device, and the delivery pump connects the deamination tower and the second spraying device to deliver the deammoniation-treated reaction solvent in the deamination tower to the second spraying device.

[0011] Optionally, the second spray device is arranged at a higher position than the first spray device.

[0012] Optionally, a filler is provided in the reaction space, and the filler is located below the spraying device.

[0013] Optionally, at least one flow balancing plate is provided in the reaction space, the flow balancing plate is located below the spraying device, and the flow balancing plate is provided with a plurality of through holes.

[0014] Optionally, a plurality of equalizing plates are provided in the reaction space, the plurality of equalizing plates are distributed in the longitudinal direction, the equalizing plates are arranged obliquely in the reaction space, and the inclination directions of two adjacent equalizing plates are opposite.

[0015] Optionally, the demisting device includes a plurality of electrode plates, each of which is passed with current so as to utilize electrostatic adsorption to absorb the dispersion medium in the gas.

[0016] Optionally, the integrated capture and purification machine further includes a fan, which is arranged on the top of the integrated capture and purification machine and is used to drive the gas to flow out of the integrated capture and purification machine.

[0017] The urea production system of the present invention is provided with a capture and purification integrated unit at the top of the granulation tower, so that the gas from the granulation tower can react with the reaction solvent in the reaction space of the capture and purification integrated unit, thereby reducing the ammonia in the gas. The gas after the reaction with the reaction solvent is then processed by a demisting device to remove liquid and solid particles in the gas before being discharged into the atmosphere, thereby effectively reducing the content of ammonia and urea dust in the exhaust gas and helping to protect the environment. In addition, the deamination tower receives the reaction solvent after the reaction and recovers the ammonia absorbed by the reaction solvent, which helps to recycle the raw materials and the reaction solvent, thereby reducing costs.

[0018] Based on the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings, those skilled in the art will become more aware of the above and other objects, advantages and features of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings:

[0020] Figure 1 is a schematic diagram of a urea production system according to one embodiment of the present utility model;

[0021] Figure 2 This is a schematic diagram of a capture and purification integrated machine in a urea production system according to one embodiment of the present utility model;

[0022] Figure 3 This is a schematic diagram of a capture and purification integrated machine and a deamination tower in a urea production system according to one embodiment of the present utility model;

[0023] Figure 4 is a schematic diagram of a capture and purification integrated machine in a urea production system according to another embodiment of the present utility model;

[0024] Figure 5 This is a schematic diagram of a capture and purification integrated machine in a urea production system according to another embodiment of the present invention. DETAILED DESCRIPTION

[0025] Those skilled in the art should understand that the embodiments described below are only a portion of the embodiments of the present invention, rather than all of the embodiments of the present invention. These embodiments are intended to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Based on the embodiments provided by the present invention, all other embodiments obtained by those skilled in the art without creative effort should still fall within the scope of protection of the present invention.

[0026] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0027] Furthermore, it should be noted that, in the description of this utility model, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections, indirect connections through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0028] like Figures 1 to 4As shown, in one embodiment, the urea production system includes a granulation tower 100, a capture and purification integrated machine 200 and a deammonification tower 300. The capture and purification integrated machine 200 is arranged at the top of the granulation tower 100, and is used to receive the gas from the granulation tower 100. The capture and purification integrated machine 200 is provided with a reaction space 201 and a demisting device 210. The ammonia in the gas from the granulation tower 100 reacts with the reaction solvent in the reaction space 201. The demisting device 210 is arranged at the top of the reaction space 201, and is used to receive the gas from the reaction space 201 and absorb the dispersion medium in the gas. The deammonification tower 300 is connected to the capture and purification integrated machine 200, and is used to receive the reaction solvent from the capture and purification integrated machine 200 after reacting with ammonia and recover the ammonia in the reaction solvent.

[0029] Reference Figures 1 to 4 As shown, the prilling tower 100 is used to produce urea granules. Specifically, the prepared urea solution is transported to the prilling tower 100. The urea solution is sprayed from the top of the prilling tower 100 as droplets that fall freely. During their fall, the droplets come into contact with countercurrent air, cooling and solidifying into urea granules. The countercurrent air, carrying some urea dust and ammonia, flows out of the prilling tower 100 and enters the reaction space 201 of the integrated capture and purification unit 200. A reaction solvent is sprayed inside the integrated capture and purification unit 200. The gas from the prilling tower 100 reacts with the reaction solvent in the reaction space 201, and the reaction solvent absorbs the ammonia carried by the gas.

[0030] Reference Figures 1 to 4 As shown, the gas after reacting with the reaction solvent continues to flow upward, passing through the demister 210, where liquid and solid particles in the gas are removed, and finally discharged into the atmosphere. The deamination tower 300 is connected to the capture and purification integrated unit 200. The reaction solvent after absorbing ammonia can be transported to the deamination tower 300. Within the deamination tower 300, carbon dioxide reacts with the reaction solvent to precipitate ammonia in the reaction solvent, thereby obtaining a reaction solvent-lean solution that can be further used to absorb ammonia.

[0031] In the solution of this embodiment, by arranging a capture and purification integrated machine 200 at the top of the granulation tower 100, the gas from the granulation tower 100 can react with the reaction solvent in the reaction space 201 of the capture and purification integrated machine 200, thereby reducing the ammonia in the gas. And the gas after the reaction with the reaction solvent is processed by the demisting device 210 to remove the liquid and solid particles in the gas before being discharged into the atmosphere, thereby effectively reducing the content of ammonia and urea dust in the exhaust gas, which helps to protect the environment. In addition, the deammonification tower 300 receives the reaction solvent after the reaction and recovers the ammonia absorbed by the reaction solvent, which helps to recycle the raw materials and the recycling of the reaction solvent, thereby reducing costs.

[0032] It should be noted that the urea production system is configured such that the operating pressure of the deamination tower 300 is higher than the operating pressure of the capture and purification integrated machine 200 .

[0033] like Figures 1 to 4 As shown, the integrated capture and purification unit 200 is equipped with a spray device 220 and a recovery tank 202. The spray device 220 is disposed within the reaction space 201 and is used to spray the reaction solvent into the reaction space 201. The recovery tank 202 is disposed at the bottom of the reaction space 201 and is used to receive the falling reaction solvent. The recovery tank 202 is connected to the deamination tower 300, so that the deamination tower 300 receives the reaction solvent from the recovery tank 202.

[0034] Reference Figures 1 to 4 As shown, specifically, the spray device 220 sprays the reaction solvent into the reaction space 201. During the falling process, the spray device 220 encounters the upward flowing gas, thereby reacting with the gas, absorbing ammonia in the gas, and finally falling into the recovery tank 202. A recovery pump 400 is provided between the recovery tank 202 and the deamination tower 300. The recovery pump 400 transports the reaction solvent in the recovery tank 202 to the deamination tower 300.

[0035] like Figures 1 to 4 As shown, in some embodiments, the capture and purification integrated machine 200 is provided with a circulation pump 230, and the spraying device 220 includes a first spraying device 221. The circulation pump 230 connects the recovery tank 202 and the first spraying device 221 to transport the reaction solvent in the recovery tank 202 to the first spraying device 221.

[0036] Reference Figures 1 to 4 As shown, that is, the circulation pump 230 can transport the reaction solvent in the recovery tank 202 to the first spraying device 221, and the first spraying device 221 sprays it into the reaction space 201. The reaction solvent sprayed into the reaction space 201 by the first spraying device 221 will fall into the recovery tank 202 again.

[0037] Because the reaction solvent and the gas may not react fully after a single contact, a circulation pump 230 is used to transport the reaction solvent that has fallen into the recovery tank 202 to the first spray device 221. The first spray device 221 then sprays it back into the reaction space 201, thereby helping to ensure a full reaction between the reaction solvent and the ammonia in the gas. Furthermore, this arrangement allows the reaction solvent in the recovery tank 202 to be transported to the deamination tower 300 for deamination treatment after the saturation level of the reaction solvent in the recovery tank 202 reaches the required level, thereby reducing power consumption.

[0038] like Figures 1 to 4As shown, the urea production system includes a delivery pump 500 , and the spraying device 220 includes a second spraying device 222 . The delivery pump 500 connects the deamination tower 300 and the second spraying device 222 to deliver the deammoniation-treated reaction solvent in the deamination tower 300 to the second spraying device 222 .

[0039] Reference Figures 1 to 4 As shown, after the reaction solvent that has absorbed ammonia in recovery tank 202 is transported to deamination tower 300, ammonia is precipitated in deamination tower 300, resulting in a lean reaction solvent solution that can be further used to absorb ammonia. A delivery pump 500 transports the lean reaction solvent solution to second spray device 222, which sprays it into reaction space 201. The reaction solvent sprayed into reaction space 201 by second spray device 222 then falls back into recovery tank 202.

[0040] It will be understood by those skilled in the art that the reaction solvent that has undergone deamination treatment in the deamination tower 300 is transported to the second spraying device 222 by using the delivery pump 500, and then sprayed into the reaction space 201 again by the second spraying device 222, so that the reaction solvent can be recycled and the circulation can be made more timely and efficient.

[0041] like Figures 1 to 4 As shown, the second spray device 222 is arranged at a higher position than the first spray device 221. That is, the reaction solvent in the deamination tower 300 that has undergone deamination treatment is sprayed into the reaction space from a spray position higher than the spray position of the circulating reaction solvent directly from the recovery tank 202.

[0042] Because the ammonia content of the reaction solvent that has been deaminated in the deammoniation tower 300 is lower, and the ammonia content of the circulating reaction solvent directly from the recovery tank 202 is relatively high, the circulating reaction solvent directly from the recovery tank 202 is sprayed into the reaction space 201 at a lower spray position, and the reaction solvent that has been deaminated in the deammoniation tower 300 is sprayed into the reaction space 201 at a higher spray position, so that the circulating reaction solvent directly from the recovery tank 202 contacts the gas first, and the ammonia content of the gas is the highest at this time, which can ensure that the circulating reaction solvent directly from the recovery tank 202 can also absorb part of the ammonia, that is, preliminarily absorb the ammonia in the gas, and then the gas meets the reaction solvent that has been deaminated and absorbs the ammonia in the gas again. Therefore, it can ensure that the reaction solvents sprayed by the first spray device 221 and the second spray device 222 can both achieve a good absorption effect, thereby effectively reducing the ammonia content in the gas.

[0043] It should be noted that the gas from the granulation tower can enter the reaction space from the side of the capture and purification integrated machine.

[0044] It should be noted that, in some other embodiments, the spraying device may only spray the reaction solvent that has undergone deammoniation treatment.

[0045] like Figures 1 to 4 As shown, a packing 240 is provided within the reaction space 201 and is located below the spraying device 220. Specifically, the reaction solvent sprayed by the spraying device 220 can fall onto the packing 240, and the upward-flowing gas can meet and react with the reaction solvent on the packing 240. The packing 240 can increase the contact area between the gas and the reaction solvent, thereby ensuring a more complete reaction.

[0046] like Figures 1 to 4 As shown, the demisting device 210 includes a plurality of plates, each of which is passed with current to utilize electrostatic adsorption to absorb the dispersion medium in the gas. The electrostatic adsorption effect is better and helps to fully absorb the liquid and dispersion medium in the gas.

[0047] like Figures 1 to 4 As shown, the capture and purification integrated machine 200 further includes a fan 250, which is disposed on the top of the capture and purification integrated machine 200 and is used to drive the gas out of the capture and purification integrated machine 200. The provision of the fan 250 helps to improve gas fluidity and prevent gas deposition in the reaction space.

[0048] like Figure 5 As shown, in one embodiment, two equalizing plates 260 are provided in the reaction space 201, with the plurality of equalizing plates 260 distributed longitudinally. The equalizing plates 260 are located below the spray device 220 and are provided with a plurality of through holes 261. The equalizing plates 260 are tilted relative to the reaction space 201, with adjacent equalizing plates 260 tilted in opposite directions.

[0049] like Figure 5 As shown, specifically, the lower current equalizing plate 260 of the two current equalizing plates 260 is tilted from the lower left to the upper right, and the higher current equalizing plate 260 is tilted from the lower right to the upper left, and the lowest point of the higher current equalizing plate 260 is higher than the highest point of the lower current equalizing plate 260. The reaction solvent sprayed by the spray device 220 can fall on the current equalizing plate 260 and diffuse on the current equalizing plate 260. At the same time, the gas flowing upward needs to pass through the through holes 261 of the current equalizing plate 260, so as to be dispersed by the multiple through holes 261 of the current equalizing plate 260. In this way, the dispersed gas and the diffused reaction solvent meet and react on the surface of the current equalizing plate 260. The current equalizing plate 260 can increase the contact area between the gas and the reaction solvent, thereby making the reaction more sufficient.

[0050] In addition, by arranging multiple flow equalizing plates 260 in the reaction space 201 and making the inclination directions of two adjacent flow equalizing plates 260 opposite, the flow equalizing plates 260 can guide the flow of the gas, so that the gas flows in a reciprocating bend flow path in the reaction space 201, thereby extending the flow path of the gas in the reaction space 201, helping to give the gas and liquid more reaction time in the reaction space 201, thereby further improving the fullness of the reaction between the gas and the reaction solvent.

[0051] It should be noted that, in some other embodiments, one, three or more flow equalizing plates may be provided in the reaction space, that is, at least one flow equalizing plate may be provided in the reaction space. In addition, the flow equalizing plate may also be placed horizontally in the reaction space.

[0052] At this point, those skilled in the art should recognize that, although multiple exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications consistent with the principles of the present invention can be directly determined or deduced from the contents disclosed herein without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and deemed to cover all such other variations or modifications.

Claims

1. A urea production system, characterized in that: include: granulation tower; a capture and purification integrated machine, which is arranged at the top of the granulation tower, for receiving the gas from the granulation tower, and is provided with a reaction space and a demisting device, wherein the ammonia in the gas from the granulation tower reacts with the reaction solvent in the reaction space, and the demisting device is arranged at the top of the reaction space, for receiving the gas from the reaction space and absorbing the dispersion medium in the gas; and The deamination tower is connected to the capture and purification integrated machine and is used to receive the reaction solvent after the reaction with ammonia from the capture and purification integrated machine and recover the ammonia in the reaction solvent.

2. The urea production system according to claim 1, characterized in that: The capture and purification integrated machine is provided with a spraying device and a recovery pool. The spraying device is arranged in the reaction space and is used to spray the reaction solvent into the reaction space. The recovery pool is arranged at the bottom of the reaction space and is used to receive the falling reaction solvent. The recovery pool is connected to the deamination tower so that the deamination tower receives the reaction solvent in the recovery pool.

3. The urea production system according to claim 2, characterized in that: The capture and purification integrated machine is provided with a circulation pump, the spraying device includes a first spraying device, and the circulation pump connects the recovery tank and the first spraying device to transport the reaction solvent in the recovery tank to the first spraying device.

4. The urea production system according to claim 3, characterized in that: The urea production system includes a delivery pump, the spray device includes a second spray device, and the delivery pump connects the deamination tower and the second spray device to deliver the deammoniation-treated reaction solvent in the deamination tower to the second spray device.

5. The urea production system according to claim 4, characterized in that: The second spray device is arranged at a higher position than the first spray device.

6. The urea production system according to claim 2, characterized in that: A filler is provided in the reaction space and is located below the spraying device.

7. The urea production system according to claim 2, characterized in that: At least one flow balancing plate is provided in the reaction space. The flow balancing plate is located below the spray device and is provided with a plurality of through holes.

8. The urea production system according to claim 7, characterized in that: A plurality of equalizing plates are provided in the reaction space, and the plurality of equalizing plates are distributed in the longitudinal direction. The equalizing plates are arranged obliquely in the reaction space, and the inclination directions of two adjacent equalizing plates are opposite.

9. The urea production system according to claim 1, characterized in that: The demisting device includes a plurality of electrode plates, each of which is passed with current so as to utilize static electricity to adsorb the dispersion medium in the gas.

10. The urea production system according to claim 1, characterized in that: The capture and purification integrated machine further includes a fan, which is arranged on the top of the capture and purification integrated machine and is used to drive the gas to flow out of the capture and purification integrated machine.

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