A granulation tower dust removal device and method

Abstract

The present invention discloses a dust removal device and method for a granulation tower, which relates to the technical field of granulation towers and includes a substrate. A purification structure is cooperatively mounted on the substrate through a first support frame. By introducing sodium chloride solution into a second atomizing nozzle and a first atomizing nozzle through a second jet pipe and a first jet pipe respectively, dust reduction of solid particles can be achieved, small urea dust can be settled, and at the same time, the carried ammonia can be absorbed. Ammonia reacts with sodium chloride to produce ammonium chloride and hydrogen. Ammonium chloride can be recycled as a production material for urea, which can improve the utilization efficiency of nitrogen elements. By providing an inverted conical rotating cylinder, the dust-containing gas rotates downward, which can increase the gas flow rate and better contact and react with the atomized sodium chloride solution. At the same time, during the acceleration reaction process, the accumulation of the dust-containing gas on the inner wall of the rotating cylinder can be avoided, which can reduce the complicated cleaning process, improve the self-cleaning ability of the equipment, and reduce the maintenance cost.

Description

Technical Field

[0001] The present invention relates to the technical field of granulation towers, and particularly relates to a dust removal device and method for a granulation tower. Background Art

[0002] Urea is an organic compound composed of carbon, nitrogen, oxygen, and hydrogen. It is a colorless or white needle-shaped or rod-shaped crystal. Industrial or agricultural products are white solid particles with a slightly reddish color, odorless and tasteless, and it is a neutral fertilizer. A urea granulation tower is an important device for producing granular urea. Its main working principle is to heat the urea solution or liquid urea and then spray it into the tower through a nozzle. The urea droplets contact with hot air in the tower, and after the drying and crystallization processes, granular urea is finally collected at the bottom of the tower. When the urea solution is heated to a molten state in the granulation tower, if the temperature of the melt is too high, the decomposition will be more intense, and thus more dust will be formed. These fine urea dusts are extremely easy to suspend in the air, forming a dust-containing gas, which needs to be dust-removed through a dust removal device.

[0003] A urea granulation tower is generally an upright cylindrical reinforced concrete structure, with characteristics such as high operating temperature, strong medium corrosiveness, long continuous operation period, and high maintenance difficulty. In order to prevent urea dust from polluting the environment, a filter or a water spray wet dust removal device is installed at the top of the granulation tower. At the same time, since urea is highly corrosive to cement, the inner wall of the tower usually has a protective layer, such as polyurethane, epoxy resin, etc., to protect the tower body from corrosion.

[0004] For example, application number: CN 108465437 A. The present invention discloses a tower granulation tail gas dust removal device and its dust removal method. It includes a mechanical part and a control part. The mechanical structure part includes a granulation tower, and the top of the granulation tower is connected to a dust removal system. The dust removal system includes a dust removal housing. A bag dust removal area is provided inside the dust removal housing. A cleaning area is provided above the bag dust removal area. A bag dust removal device is provided inside the bag dust removal area. A pulse cleaning device is installed on the dust removal housing at the top of the bag dust removal device. A plurality of induced draft fans are provided on the circumferential edge at the top of the dust removal housing. The control part includes a PLC control system. The signal input ends of the PLC control system are respectively connected to a first pressure sensor, a second temperature sensor, and a second pressure sensor. The signal output ends of the PLC control system are respectively connected to the induced draft fans and the pulse cleaning device. It can effectively solve the problems of tailing and short operation time of the bag dust removal equipment, and has the advantage of reducing the dust content of the dust-containing gas at the outlet to less than 10 mg / Nm3.

[0005] Based on the retrieval of the above patents and the discovery of equipment in the prior art, it is found that when operating in a urea granulation tower, the dust-containing gas generated is generally treated by a bag filter. The bag filter is designed to handle solid particles and cannot effectively absorb and utilize the volatilized ammonia. Secondly, the self-cleaning ability of the bag filter is poor, requiring regular maintenance. Moreover, with use, the dust removal effect decreases, affecting the dust removal efficiency. Summary of the Invention

[0006] The purpose of the present invention is to provide a dust removal device and method for a granulation tower, which solves the following technical problems: when treated by a bag filter, the bag filter is designed to handle solid particles and cannot effectively absorb and utilize the volatilized ammonia. Secondly, the self-cleaning ability of the bag filter is poor, requiring regular maintenance. Moreover, with use, the dust removal effect decreases, affecting the dust removal efficiency. The present invention uses the form of rotating eddy currents, which can reduce dust through spraying and can absorb the ammonia released during the urea operation at the same time. At the same time, the dust removal structure of this solution has strong self-cleaning ability and can effectively carry out dust removal operations for a long time.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] A dust removal device for a granulation tower, including a base plate, on which a purification structure is supported and installed through a first support frame.

[0009] Purification structure, the purification structure includes a rotating cylinder, the middle position of the rotating cylinder is an inverted conical structure, a vortex motor is installed at the top of the rotating cylinder, the output shaft of the vortex motor penetrates the top side wall of the rotating cylinder, a connecting rod is installed on the output shaft of the vortex motor, and a spiral vortex rod is suspended at the bottom of the connecting rod.

[0010] Rotating cylinder, a protective cover is sleeved outside the rotating cylinder, and a heating wire is spirally installed between the inner wall of the protective cover and the outer wall of the rotating cylinder.

[0011] Second atomizing nozzles and first atomizing nozzles, a group of second atomizing nozzles and a group of first atomizing nozzles are respectively installed on the inner wall of the rotating cylinder in an annular array. The second atomizing nozzles are connected in series through a second spray pipe, and the first atomizing nozzles are connected in series through a first spray pipe. The second atomizing nozzles are located above the first atomizing nozzles.

[0012] Shunt structure, a shunt structure for purification is arranged above the base plate.

[0013] Treatment structure, a treatment structure for secondary treatment of waste gas is connected to the outer side of the bottom of the rotary cylinder. Under the atomizing spray action of the second atomizing nozzle and the first atomizing nozzle, dust reduction of solid particles can be achieved, small urea dust can be settled, and at the same time, the carried ammonia can be absorbed. Ammonia reacts with sodium chloride to produce ammonium chloride and hydrogen. Ammonium chloride can be recycled as a production material for urea, and the use efficiency of nitrogen elements can be improved.

[0014] As a further solution of the present invention: The purification structure further includes an intake pipe. An air inlet is provided at the top of the rotary cylinder, and the intake pipe is connected to the air inlet. The intake pipe is connected to the exhaust port of the granulation tower. A first pressure sensor is installed at the top of the rotary cylinder, and a second pressure sensor is installed at the bottom of the rotary cylinder. By setting the first pressure sensor and the second pressure sensor, the operating pressure of the dust-containing gas in the rotary cylinder during the dust removal process can be monitored to ensure operating safety.

[0015] As a further solution of the present invention: The diversion structure includes a support column. A diversion ring is fixed to the top of the support column, and a diversion tray is fixed to the middle of the support column. A storage tank is installed at an eccentric position inside the diversion tray. A rotary motor is installed on the outer side of the storage tank, and a rotary filter disk is installed at the output end of the rotary motor. The surface of the rotary filter disk is covered with a filter film. The rotary filter disk is arranged at the bottom port of the rotary cylinder. The distance between the top surface of the rotary filter disk and the bottom port of the rotary cylinder is 1-10 cm. The storage tank is located below the rotary filter disk. The storage tank and the central axis of the rotary cylinder are on the same straight line. The liquid of the solid-liquid mixture flows into the storage tank through the rotary filter disk. The main content of the liquid flowing into the storage tank is ammonium chloride, which can be recycled and used for the production of urea, improving the utilization rate of materials. The solid impurities remaining on the surface of the rotary filter disk film are driven by the rotary filter disk to rotate. With the scraping cooperation of the scraper, the solid impurities can move along the inner arc wall of the scraper and are discharged through the diversion holes. The impurities converge in the discharge chute body for treatment.

[0016] As a further solution of the present invention: The bottom of the storage tank is connected to a diversion pipe, and the diversion pipe penetrates through the side wall of the diversion tray. An outlet pipe is connected to the diversion tray, which can cooperate to divert each diverted liquid for the recycling and utilization of materials.

[0017] As a further solution of the present invention: Diversion holes are provided on the circumferential wall of the diversion ring. An arc-shaped scraper is fixed to the inner wall of the diversion ring, and the scraper is located at the port position of the diversion hole. The bottom side of the notch of the diversion hole is parallel to the top side of the rotary filter disk. An outlet chute body is fixed to the outside of the diversion ring, and the outlet chute body is located outside the diversion hole.

[0018] As a further solution of the present invention: The treatment structure includes a combustion cylinder, which is supported and fixed on the top side of the substrate by a second support frame. An outward-expanded flared opening is provided at the top of the combustion cylinder, and an igniter is installed on the inner wall of the bottom of the flared opening. An ignition controller is connected to the igniter. An air inlet motor is fixed at the bottom of the combustion cylinder, and a vortex fan is installed at the output end of the air inlet motor.

[0019] As a further solution of the present invention: The treatment structure further includes a flow guide cover. A flow guide air hole is opened at the bottom of the rotating cylinder, and the flow guide cover is buckled on the flow guide air hole. A cooling pipe is spirally wound around the middle outer side of the flow guide pipe. A heat preservation sleeve is sleeved outside the flow guide pipe, and the heat preservation sleeve wraps outside the cooling pipe. The two ends of the cooling pipe are respectively connected with a water inlet pipe. The flow guide pipe is inclined, and the connection position between the flow guide pipe and the flow guide cover is set lower. A hydrogen concentration sensor is installed on the flow guide pipe. The gas passes through the upward flow guide pipe, and at the same time, cooling water is introduced into the heat preservation sleeve through the flow guide pipe to realize the cooling treatment of the flow guide pipe, which can better condense the liquid in the gas. The condensed gas not only reduces the water content of the gas, but also improves the dust removal efficiency. The condensed liquid slides down through the flow guide pipe and falls on the rotating filter disk through the rotating cylinder. The remaining gas is mixed with oxygen, and when discharged, under the cooperation of the igniter, the remaining gas is ignited. The hydrogen burns to form water vapor. After the gas content substances are burned, dust-free treatment is also realized, and the dust removal can be more thorough.

[0020] A granulation tower dust removal method includes the following steps:

[0021] S1: The cold air from the granulation tower exchanges heat with the urea solution particles from the granulation nozzle to form a dust-containing gas.

[0022] S2: Under the action of an induced draft fan, the dust-containing gas in S1 enters the purification structure through the air inlet pipe. After the dust-containing gas enters the rotating cylinder, it is conveyed downward in a rotating manner. During the conveying process, by spraying sodium chloride solution, the settlement of the dust gas can be realized, and at the same time, ammonia in the waste gas is absorbed. When sodium chloride and ammonia react, water, ammonium chloride and hydrogen are produced. Ammonium chloride is a toxic liquid, showing white light brown. The chemical inequality equation of the reaction is as follows: 2NaCl + 2NH3 → 2NH4Cl + H2↑.

[0023] S3: Monitor the pressure value and the formed pressure difference inside the rotary cylinder in real time through the first pressure sensor at the top of the rotary cylinder and the second pressure sensor at the bottom of the rotary cylinder, and determine the operating power of the induced draft fan based on the above pressure value and pressure difference. The pressure difference between the first pressure sensor and the second pressure sensor is 800 Pa - 1000 Pa. When the pressure difference between the first pressure sensor and the second pressure sensor is greater than 1000 Pa, the PLC control system of the granulation tower adjusts the operating power of the induced draft fan.

[0024] S4: Complete the dust removal of the dust-containing gas and the absorption operation of ammonia in S2. Filter the spray liquid through the shunt structure, and at the same time realize the recovery of the absorption liquid, which can achieve the dust removal effect, and at the same time absorb and purify the waste gas in urea production. The generated ammonium chloride can be recycled through purification and used in the production of urea.

[0025] S5: For the gas generated in S2, drain it through the diversion pipe in the treatment structure. After condensation and dehumidification, supplement and mix in oxygen, and ignite the tail gas through the igniter to realize the secondary purification of the purified gas.

[0026] S6: A hydrogen content sensor is provided at the port of the diversion pipe. According to the hydrogen content, the operating power of the inlet air motor can be adjusted, oxygen can be mixed in proportion, and the full combustion of hydrogen can be realized.

[0027] Advantages of the present invention:

[0028] In order to better treat the dust-containing gas, the dust-containing gas enters the rotary cylinder through the intake pipe under the action of the induced draft fan. Sodium chloride solution is introduced into the second atomizing nozzle and the first atomizing nozzle through the second spray pipe and the first spray pipe respectively, which can achieve the dust removal of solid particles, settle small urea dust, and at the same time absorb the carried ammonia. Ammonia reacts with sodium chloride to produce ammonium chloride and hydrogen. Ammonium chloride can be recycled as a production material for urea, which can improve the utilization efficiency of nitrogen elements.

[0029] By setting a conical rotary cylinder, the dust-containing gas rotates and moves downward, which can increase the gas flow rate and better contact and react with the atomized sodium chloride solution. At the same time, during the acceleration reaction process, the accumulation of dust-containing gas on the inner wall of the rotary cylinder can be avoided, which can reduce the complicated cleaning process, improve the self-cleaning ability of the equipment, and reduce the maintenance cost.

[0030] After the dust-containing gas has settled, the liquid of the solid-liquid mixture flows into the storage tank through the rotary filter disk. The main component of the liquid flowing into the storage tank is ammonium chloride, which can be recycled and used in the production of urea to improve the utilization rate of materials. To maintain the effectiveness of the rotary filter disk filtration, through the rotation of the rotary filter disk, the remaining solid impurities can be cleaned. At the same time, the rotary filter disk realizes circulation, avoiding the blockage of the filter holes, and can ensure the separation effect of the solid-liquid mixture. The shunt tray is used to receive the liquid that has not completed the solid-liquid mixing, reducing material waste and avoiding the random discharge of chemical substances, thus enhancing the safety of the dust removal operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described below with reference to the accompanying drawings.

[0032] Figure 1 is the overall first three-dimensional structure schematic diagram of the present invention.

[0033] Figure 2 is the overall second three-dimensional structure schematic diagram of the present invention.

[0034] Figure 3 is the top view structure schematic diagram of the present invention.

[0035] Figure 4 is Figure 4 the sectional view structure schematic diagram along A-A in

[0036] Figure 5 is the overall purification structure schematic diagram.

[0037] Figure 6 is the internal structure display diagram of the purification structure.

[0038] Figure 7 is the sectional view schematic diagram of the purification structure.

[0039] Figure 8 is the eddy current rod structure schematic diagram.

[0040] Figure 9 is the shunt structure schematic diagram.

[0041] Figure 10 is the processing structure schematic diagram.

[0042] Figure 11 is the sectional view schematic diagram of the processing structure.

[0043] In the figure: 1. Substrate, 2. Purification structure, 3. Treatment structure, 4. First support frame, 5. Shunt structure, 6. Second support frame, 21. Air inlet pipe, 22. Eddy current motor, 23. Rotating cylinder, 24. First jet pipe, 25. Second jet pipe, 26. Protective cover, 27. Connecting rod, 28. Eddy current rod, 29. First atomizing nozzle, 210. Second atomizing nozzle, 211. Electric heating wire, 31. Combustion cylinder, 32. Igniter, 33. Eddy current fan, 34. Air inlet motor, 35. Heat preservation sleeve, 36. Cooling pipe, 37. Diversion pipe, 38. Diversion cover, 39. Water inlet pipe, 51. Support column, 52. Shunt tray, 53. Shunt ring, 54. Rotating filter disc, 55. Scraper, 56. Diversion hole, 57. Discharge chute body, 58. Discharge pipe, 59. Rotating motor, 510. Storage tank, 511. Shunt pipe. Specific embodiments

[0044] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the protection scope of the present invention.

[0045] Please refer to Figure 1-8 As shown in the figure, the present invention is a dust removal device for a granulation tower, with a substrate 1, and a purification structure 2 is supported on the substrate 1 through cooperation with a first support frame 4.

[0046] Purification structure 2, the purification structure 2 includes a rotating cylinder 23, the middle position of the rotating cylinder 23 is an inverted conical structure, an eddy current motor 22 is installed at the top of the rotating cylinder 23, the output shaft of the eddy current motor 22 penetrates the top side wall of the rotating cylinder 23, a connecting rod 27 is installed on the output shaft of the eddy current motor 22, and a spiral eddy current rod 28 is suspended at the bottom of the connecting rod 27.

[0047] Rotating cylinder 23, a protective cover 26 is sleeved outside the rotating cylinder 23, and an electric heating wire 211 is spirally installed between the inner wall of the protective cover 26 and the outer wall of the rotating cylinder 23.

[0048] Second atomizing nozzle 210 and first atomizing nozzle 29, a group of second atomizing nozzles 210 and a group of first atomizing nozzles 29 are respectively installed on the inner wall of the rotating cylinder 23 in an annular array. The second atomizing nozzles 210 are connected in series through a second jet pipe 25, the first atomizing nozzles 29 are connected in series through a first jet pipe 24, and the second atomizing nozzles 210 are located above the first atomizing nozzles 29.

[0049] Shunt structure 5, a shunt structure 5 for purification and shunt is arranged above the substrate 1.

[0050] Treatment structure 3, a treatment structure 3 for secondary treatment of waste gas is connected to the outer side of the bottom of the rotary cylinder 23. The urea granulation tower is an important device for producing granular urea. Its main working principle is to heat the urea solution or liquid urea and then spray it into the tower through a nozzle. The urea droplets contact with hot air in the tower and go through the processes of drying and crystallization, and finally granular urea is collected at the bottom of the tower. The urea solution is heated to the molten state in the granulation tower. If the temperature of the melt is too high, the decomposition will be more intense, and thus more dust will be formed. These fine urea dusts are extremely easy to suspend in the air to form dust-containing gas, which needs to be dust-removed through a dust-removing device. The dust-containing gas contains ammonia. In order to better treat the dust-containing gas, the dust-containing gas enters the rotary cylinder 23 through the intake pipe 21 under the action of an induced draft fan. With the operation cooperation of the eddy current motor 22, the eddy current motor 22 drives the connecting rod 27 to rotate, realizing the rotation of the eddy current rod 28, which can make the dust-containing gas rotate downward. During the downward movement of the dust-containing gas, sodium chloride solution is introduced into the second atomizing nozzle 210 and the first atomizing nozzle 29 through the second jet pipe 25 and the first jet pipe 24 respectively. Under the atomizing spray action of the second atomizing nozzle 210 and the first atomizing nozzle 29, the dust reduction of solid particles can be realized, the small urea dust can be settled, and at the same time, the carried ammonia can be absorbed. Ammonia reacts with sodium chloride to produce ammonium chloride and hydrogen. Ammonium chloride can be recycled as a production material for urea, which can improve the utilization efficiency of nitrogen elements.

[0051] By setting the inverted conical rotary cylinder 23, the downward rotation movement of the dust-containing gas can be realized, the gas flow rate can be increased, and better contact reaction with the atomized sodium chloride solution can be achieved. At the same time, during the acceleration reaction process, the accumulation of the dust-containing gas on the inner wall of the rotary cylinder 23 can be avoided, the complicated cleaning process can be reduced, and the self-cleaning ability of the equipment can be improved. At the same time, an electric heating wire 211 is arranged between the rotary cylinder 23 and the protective cover 26, which can adjust the temperature in the rotary cylinder 23, avoid the crystallization and accumulation of urea particles in the dust-containing gas on the inner wall of the rotary cylinder 23, and at the same time avoid sodium chloride crystallization, which can better maintain the cleanliness of the dust-removing equipment and reduce the maintenance cost.

[0052] The purification structure 2 further includes an intake pipe 21. An air inlet is opened at the top of the rotary cylinder 23, and the intake pipe 21 is connected to the air inlet. The intake pipe 21 is connected to the exhaust port of the granulation tower. A first pressure sensor is installed at the top of the rotary cylinder 23, and a second pressure sensor is installed at the bottom of the rotary cylinder 23. The dust-containing gas can enter the rotary cylinder 23 through the intake pipe 21 for treatment. By setting the first pressure sensor and the second pressure sensor, the monitoring of the working pressure of the dust-containing gas in the rotary cylinder 23 during the dust-removing process can be realized to ensure the operation safety.

[0053] Please refer toFigure 4 , 9 As shown, the diversion structure 5 includes a support column 51, a diversion ring 53 is fixed to the top of the support column 51, a diversion tray 52 is fixed to the middle of the support column 51, a storage tank 510 is installed at an eccentric position inside the diversion tray 52, a rotating motor 59 is installed on the outer side of the storage tank 510, and a rotating filter disc 54 is installed at the output end of the rotating motor 59.

[0054] The surface of the rotating filter disc 54 is covered with a filter film, and the rotating filter disc 54 is arranged at the bottom port of the rotating cylinder 23. The top surface of the rotating filter disc 54 and the bottom port of the rotating cylinder 23 are spaced 1-10 cm apart. The storage tank 510 is located below the rotating filter disc 54. The storage tank 510 and the central axis of the rotating cylinder 23 are located on the same straight line. When working, after the dust-containing gas is settled, solid impurities will sink along the inner wall of the rotating cylinder 23, and the solid-liquid mixture will fall on the film of the rotating filter disc 54, and the rotating motor 59 will be operated. The rotating filter disc 54 is driven to rotate. During the rotation of the rotating filter disc 54, the liquid of the solid-liquid mixture flows into the storage tank 510 through the rotating filter disc 54. The liquid flowing into the storage tank 510 mainly contains ammonium chloride, which can be recycled and used for the production of urea, thereby improving the utilization rate of materials. The solid impurities accumulated on the surface of the film of the rotating filter disc 54 are driven to rotate by the rotating filter disc 54. With the scraping cooperation of the scraper 55, the solid impurities can move along the arc inner wall of the scraper 55 and be discharged through the guide hole 56. The impurities gather in the discharge trough 57 for treatment.

[0055] The bottom of the storage tank 510 is connected to a shunt pipe 511, and the shunt pipe 511 passes through the side wall of the shunt tray 52. ​​The shunt tray 52 is connected to a discharge pipe 58. A guide hole 56 is opened on the circumferential wall of the shunt ring 53. An arc-shaped scraper 55 is fixed on the inner wall of the shunt ring 53, and the scraper 55 is located at the port position of the guide hole 56. The bottom side of the notch of the guide hole 56 is parallel to the top side of the rotating filter disc 54. A discharge trough body 57 is fixed on the outer side of the shunt ring 53, and the discharge trough body 57 is located on the outer side of the guide hole 56. When realizing solid-liquid separation, a large amount of liquid enters into the storage tank 510 after passing through the rotating cylinder 23, and is discharged through the diversion pipe 511. In order to maintain the effectiveness of the filtration of the rotating filter disc 54, the remaining solid impurities can be cleaned by the rotation of the rotating filter disc 54. At the same time, the rotating filter disc 54 realizes circulation to avoid clogging of the filter holes, which can ensure the separation effect of the solid-liquid mixture. The diversion tray 52 is used to receive the liquid that has not completed the solid-liquid mixture, thereby reducing the waste of materials, avoiding the random discharge of chemical substances, and improving the safety of dust removal operations.

[0056] See also Figures 10-11As shown, the processing structure 3 includes a combustion cylinder 31. The combustion cylinder 31 is supported and fixed on the top side of the substrate 1 by a second support frame 6. The top of the combustion cylinder 31 is provided with an outward-expanding flared opening. The inner wall of the bottom of the flared opening is equipped with an igniter 32, and an ignition controller is connected to the igniter 32. The bottom of the combustion cylinder 31 is fixed with an air inlet motor 34, and a vortex fan 33 is installed at the output end of the air inlet motor 34.

[0057] The processing structure 3 further includes a flow guide cover 38. A flow guide air hole is opened at the bottom of the rotating cylinder 23, and the flow guide cover 38 is buckled on the flow guide air hole. The middle outer side of the flow guide pipe 37 is spirally wound with a cooling pipe 36. A heat preservation sleeve 35 is sleeved outside the flow guide pipe 37, and the heat preservation sleeve 35 wraps outside the cooling pipe 36. The two ends of the cooling pipe 36 are respectively connected to the flow guide pipe 37. The flow guide pipe 37 is inclined, and the connection position of the flow guide pipe 37 and the flow guide cover 38 is set lower. A hydrogen concentration sensor is installed on the flow guide pipe 37. In order to achieve a more comprehensive dust removal effect, the solid-liquid mixture is discharged from the bottom of the rotating cylinder 23. Under the operation cooperation of the air inlet motor 34, an upward airflow is formed in the combustion cylinder 31, which can lead out gases such as hydrogen in the rotating cylinder 23 through the flow guide cover 38 and the flow guide pipe 37. The gas passes through the upward flow guide pipe 37. At the same time, cooling water is introduced into the heat preservation sleeve 35 through the water inlet pipe 39 to realize the temperature reduction treatment of the flow guide pipe 37, which can better condense the liquid in the gas. The condensed gas not only reduces the water content of the gas, but also improves the dust removal efficiency. The condensed liquid slides down through the flow guide pipe 37 and falls on the rotating filter disc 54 through the rotating cylinder 23. The remaining gas is mixed with oxygen. When discharged, under the cooperation of the igniter 32, the remaining gas is ignited. The hydrogen burns to form water vapor. After the gas content substances burn, the dust-free treatment is also realized, and the dust removal can be more thorough.

[0058] A granulation tower dust removal method includes the following steps:

[0059] S1: The cold air from the granulation tower exchanges heat with the urea solution particles from the granulation nozzle to form a dust-containing gas.

[0060] S2: Under the action of the induced draft fan, the dust-containing gas in S1 enters the purification structure 2 through the air inlet pipe 21. After the dust-containing gas enters the rotating cylinder 23, it is rotated and conveyed downward. During the conveying process, by spraying sodium chloride solution, the settlement of the dust gas can be realized, and at the same time, ammonia in the waste gas is absorbed. When sodium chloride and ammonia react, water, ammonium chloride and hydrogen will be produced. Ammonium chloride is a toxic liquid, showing white light brown. The chemical inequality equation of the reaction is as follows: 2NaCl + 2NH3 → 2NH4Cl + H2↑.

[0061] S3: The first pressure sensor at the top of the rotary cylinder 23 and the second pressure sensor at the bottom of the rotary cylinder 23 are used to monitor the pressure value and the formed pressure difference in the rotary cylinder 23 in real time. The operating power of the induced draft fan is determined based on the above pressure value and pressure difference. The pressure difference between the first pressure sensor and the second pressure sensor is 800 Pa - 1000 Pa. When the pressure difference between the first pressure sensor and the second pressure sensor is greater than 1000 Pa, the PLC control system of the granulation tower regulates the operating power of the induced draft fan.

[0062] S4: In S2, the dust removal of the dust-containing gas and the absorption of ammonia are completed. The filtration of the spray liquid is achieved through the shunt structure 5, and at the same time, the recovery of the absorption liquid is realized, which can achieve the effect of dust removal. At the same time, the waste gas in urea production is absorbed and purified. The generated ammonium chloride can be recycled through purification and used in urea production.

[0063] S5: For the gas generated in S2, it is led through the diversion pipe 37 in the treatment structure 3, condensed and dehumidified, and then oxygen is supplemented and mixed in. The tail gas is ignited by the igniter 32 to realize the re-purification of the purified gas.

[0064] S6: A hydrogen content sensor is provided at the port of the diversion pipe 37. According to the hydrogen content, the operating power of the intake fan motor 34 can be adjusted, oxygen can be mixed in proportion, and the full combustion of hydrogen can be realized.

[0065] Working principle: To better treat the dust-containing gas, the dust-containing gas enters the rotary cylinder 23 through the intake pipe 21 under the action of the induced draft fan. With the cooperation of the eddy current motor 22, the eddy current motor 22 drives the connecting rod 27 to rotate, realizing the rotation of the eddy current rod 28, which enables the dust-containing gas to rotate and move downward. During the downward movement of the dust-containing gas, sodium chloride solution is introduced into the second atomizing nozzle 210 and the first atomizing nozzle 29 through the second jet pipe 25 and the first jet pipe 24 respectively. Under the atomizing spray action of the second atomizing nozzle 210 and the first atomizing nozzle 29, the dust removal of solid particles can be realized, the small urea dust can be settled, and at the same time, the carried ammonia can be absorbed. Ammonia reacts with sodium chloride to produce ammonium chloride and hydrogen. Ammonium chloride can be recycled as a production material for urea, which can improve the utilization efficiency of nitrogen.

[0066] By providing an inverted cone-shaped rotating drum 23, the dust-containing gas can be rotated downward, the gas flow rate can be increased, and the gas can be better contacted and reacted with the atomized sodium chloride solution. At the same time, in the process of accelerating the reaction, the dust-containing gas can be prevented from accumulating on the inner wall of the rotating drum 23, which can reduce the complicated cleaning process and improve the self-cleaning ability of the equipment. At the same time, a heating wire 211 is provided between the rotating drum 23 and the protective cover 26, which can adjust the temperature in the rotating drum 23, prevent the urea particles contained in the dust from crystallizing and accumulating on the inner wall of the rotating drum 23, and prevent the crystallization of sodium chloride, so as to better maintain the cleanliness of the dust removal equipment and reduce the maintenance cost.

[0067] After the dust-laden gas is settled, solid impurities will sink along the inner wall of the rotating cylinder 23, and the solid-liquid mixture will fall on the film of the rotating filter disc 54. The rotating motor 59 will drive the rotating filter disc 54 to rotate. During the rotation of the rotating filter disc 54, the liquid of the solid-liquid mixture will flow into the storage tank 510 through the rotating filter disc 54. The liquid flowing into the storage tank 510 mainly contains ammonium chloride, which can be recycled and used for the production of urea, thereby improving the utilization rate of materials. The solid impurities accumulated on the surface of the film of the rotating filter disc 54 are driven to rotate by the rotating filter disc 54. With the scraping cooperation of the scraper 55, the solid impurities can move along the arc inner wall of the scraper 55 and be discharged through the guide hole 56. The impurities gather in the discharge trough 57 for treatment.

[0068] When realizing solid-liquid separation, a large amount of liquid enters into the storage tank 510 after passing through the rotating cylinder 23 and is discharged through the diverter pipe 511. In order to maintain the effectiveness of the filtration of the rotating filter disc 54, the remaining solid impurities can be cleaned by the rotation of the rotating filter disc 54. At the same time, the rotating filter disc 54 realizes circulation to avoid clogging of the filter holes, thereby ensuring the separation effect of the solid-liquid mixture. The diverter tray 52 is used to receive the liquid that has not completed the solid-liquid mixture, thereby reducing material waste, avoiding the random discharge of chemical substances, and improving the safety of dust removal operations.

[0069] To achieve a more comprehensive dust removal effect, the solid-liquid mixture is discharged from the bottom of the rotating cylinder 23. With the operation of the air inlet motor 34, an upward airflow is formed in the combustion cylinder 31, which can lead out gases such as hydrogen in the rotating cylinder 23 through the flow guide cover 38 and the flow guide pipe 37. The gas passes through the upward flow guide pipe 37, and at the same time, cooling water is introduced into the heat preservation sleeve 35 through the water inlet pipe 39 to cool the flow guide pipe 37, enabling better condensation of the liquid in the gas. The condensed gas not only reduces the water content in the gas but also improves the dust removal efficiency. The condensed liquid slides downward through the flow guide pipe 37 and falls on the rotating filter disk 54 through the rotating cylinder 23. The remaining gas is mixed with oxygen and, when discharged, is ignited by the igniter 32. The hydrogen burns to form water vapor, and after the gas content substances burn, dust-free treatment is also achieved, making the dust removal more thorough.

[0070] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A granulation tower dust removal device, characterized in that, It includes a substrate, on which a purification structure is cooperatively mounted through a first support frame; The purification structure includes a rotating cylinder. The middle position of the rotating cylinder is an inverted conical structure. An eddy current motor is installed at the top of the rotating cylinder. The output shaft of the eddy current motor penetrates the top side wall of the rotating cylinder. A connecting rod is installed on the output shaft of the eddy current motor. A spiral eddy current rod is suspended at the bottom of the connecting rod; A protective cover is sleeved outside the rotating cylinder, and a heating wire is spirally installed between the inner wall of the protective cover and the outer wall of the rotating cylinder; A second atomizing nozzle and a first atomizing nozzle. A group of second atomizing nozzles and a group of first atomizing nozzles are respectively installed on the inner wall of the rotating cylinder in an annular array. The second atomizing nozzles are connected in series through a second jet pipe, and the first atomizing nozzles are connected in series through a first jet pipe. The second atomizing nozzles are located above the first atomizing nozzles; Above the substrate, a flow splitting structure for purification is provided; The outer side surface of the bottom of the rotating cylinder is connected with a treatment structure for secondary treatment of waste gas; the treatment structure includes a combustion cylinder. The combustion cylinder is supported and fixed on the top side of the substrate through a second support frame. An outwardly expanding flared opening is provided at the top of the combustion cylinder, and an igniter is installed on the inner wall of the bottom of the flared opening; an air inlet motor is fixed at the bottom of the combustion cylinder, and an eddy current fan is installed at the output end of the air inlet motor; a diversion air hole is opened at the bottom of the rotating cylinder, a diversion cover is buckled on the diversion air hole, a cooling pipe is spirally wound on the middle outer side of the diversion pipe, a heat preservation sleeve is sleeved outside the diversion pipe, the heat preservation sleeve is wrapped outside the cooling pipe, and the two ends of the cooling pipe are respectively connected with a water inlet pipe. The diversion pipe is inclined, and the connection position between the diversion pipe and the diversion cover is set lower; the flow splitting structure includes a rotating filter disk, and the rotating filter disk is arranged at the bottom port of the rotating cylinder; through the diversion of the diversion pipe in the treatment structure, after condensation and dehumidification, oxygen is supplemented and mixed in, and the tail gas is ignited by the igniter.

2. A granulation tower dust removal device according to claim 1, characterized in that, The purification structure further includes an air inlet pipe. An air inlet is opened at the top of the rotating cylinder, and the air inlet pipe is connected to the air inlet. The air inlet pipe is connected to the exhaust port of the granulation tower. A first pressure sensor is installed at the top of the rotating cylinder, and a second pressure sensor is installed at the bottom of the rotating cylinder.

3. A granulation tower dust removal device according to claim 2, characterized in that, The flow splitting structure includes a support column. A flow splitting ring is fixed at the top of the support column. A flow splitting tray is fixed in the middle of the support column. A storage tank is installed at an eccentric position inside the flow splitting tray. A rotating motor is installed on the outer side surface of the storage tank, and a rotating filter disk is installed at the output end of the rotating motor.

4. A granulation tower dust removal device according to claim 3, characterized in that, The surface of the rotating filter disk is covered with a filter film. The distance between the top surface of the rotating filter disk and the bottom port of the rotating cylinder is 1-10 cm. The storage tank is located below the rotating filter disk, and the central axes of the storage tank and the rotating cylinder are on the same straight line.

5. A granulation tower dust removal device according to claim 4, characterized in that, The bottom of the storage tank is communicated with a diversion pipe, and the diversion pipe penetrates the side wall of the flow splitting tray. An outlet pipe is connected to the flow splitting tray.

6. A granulation tower dust removal device according to claim 5, characterized in that, Diversion holes are opened on the circumferential wall of the flow splitting ring. An arc-shaped scraping plate is fixed on the inner wall of the flow splitting ring, and the scraping plate is located at the port position of the diversion hole. The bottom side of the notch of the diversion hole is parallel to the top side surface of the rotating filter disk. An outlet trough body is fixed outside the flow splitting ring, and the outlet trough body is located outside the diversion hole.

7. A method for dedusting a granulation tower, characterized in that, Using a granulation tower dust removal device according to claim 1, the following steps are included: S1: The cold air from the granulation tower exchanges heat with the urea solution particles from the granulation nozzle to form a dust-containing gas; S2: Under the action of the induced draft fan, the dust-containing gas in S1 enters the purification structure through the intake pipe. After the dust-containing gas enters the rotating cylinder, it is transported downward in a rotating manner. During the transportation process, by spraying sodium chloride solution, the sedimentation of the dust gas can be realized, and at the same time, ammonia in the waste gas can be absorbed; S3: The pressure value and the formed pressure difference in the rotating cylinder are monitored in real time through the first pressure sensor at the top of the rotating cylinder and the second pressure sensor at the bottom of the rotating cylinder. The operating power of the induced draft fan is determined by the above pressure value and pressure difference. The pressure difference between the first pressure sensor and the second pressure sensor is 800 Pa - 1000 Pa; when the pressure difference between the first pressure sensor and the second pressure sensor is greater than 1000 Pa, the granulation tower PLC control system regulates the operating power of the induced draft fan; S4: In S2, the dust removal of the dust-containing gas and the absorption of ammonia are completed. The spraying liquid is filtered through the shunt structure, and at the same time, the absorption liquid is recycled, which can achieve the dust removal effect, and at the same time, the waste gas in urea production is absorbed and purified. The generated ammonium chloride is recycled through purification and used for urea production; S5: For the gas generated in S2, it is diverted through the diversion pipe in the treatment structure. After condensation and dehumidification, oxygen is supplemented and mixed in, and the tail gas is ignited by the igniter to realize the re-purification of the purified gas; S6: A hydrogen content sensor is provided at the port of the diversion pipe. According to the hydrogen content, the operating power of the intake fan can be adjusted, oxygen can be mixed in proportion, and the full combustion of hydrogen can be realized.

8. A granulation tower dust removal method according to claim 7, characterized in that: In S2, when sodium chloride and ammonia react, water, ammonium chloride and hydrogen are produced.

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