Cleaning device for ammonia still

Abstract

The invention discloses a cleaning device for an ammonia still, which comprises: a filter screen arranged between the lowermost tower plate of the ammonia still and an ammonia still wastewater outlet, the filter screen being provided with a lead-out port; the scraping plate is rotatably arranged above the filter screen and is used for scraping the impurities filtered out by the filter screen to the lead-out opening; the cleaning box is arranged below the filter screen, the cleaning box is provided with a first opening and a second opening, the first opening is communicated with the lead-out opening and is used for receiving the impurities, and the second opening is communicated to the outside of the tower; and the rotating fin is rotatably arranged in the cleaning box and is used for transferring the impurities out of the tower through the second opening. The cleaning device can prevent the ammonia distillation wastewater outlet from being blocked due to deposition at the bottom of the tower.

Description

Technical Field

[0001] The present invention relates to an ammonia still tower, and more particularly to a cleaning device for an ammonia still tower. Background Art

[0002] The ammonia-soda process is one of the main methods for industrial production of soda ash. Its characteristics are that the raw materials are cheap and easy to obtain, ammonia can be recycled, and the loss is small. The ammonia evaporation tower is the key device for the recovery and recycling of ammonia. Because in the process of producing soda ash by the ammonia-soda process, ammonia does not participate in the product, but only participates in the chemical reaction as an intermediate medium, and is finally recovered through the distillation process of ammonia evaporation, thereby realizing recycling. In this process, ammonia is circulated in the form of ammonia gas and ammonia water. Ammonia is a colorless gas with a strong pungent smell. It is very soluble in water. The aqueous solution is called ammonia water. Specifically, the ammonia evaporation tower uses direct steam as a heating agent to release the ammonia dissolved in water. At the top of the tower, a mixture of ammonia vapor and water vapor will be obtained, and ammonia evaporation wastewater will be obtained at the bottom of the tower. Since the ammonia evaporation wastewater flowing out of the ammonia evaporation tower contains heavy oil and ammonium salts, these impurities will reduce the flow rate when flowing through the bottom of the ammonia evaporation tower, and most of them will accumulate at the bottom of the tower. When the impurities accumulate to a certain extent, the outlet of the ammonia evaporation wastewater is blocked, resulting in a decrease in heat exchange efficiency, thereby affecting the recovery of ammonia.

[0003] (Question 1) When the ammonia evaporation tower is in operation for a long period of time, impurities at the bottom of the tower will crystallize and deposit, causing the outlet of the ammonia evaporation wastewater to be blocked. This will cause the ammonia evaporation tower to be shut down for cleaning, affecting work efficiency.

[0004] (Question 2) The ammonia wastewater obtained at the bottom of the ammonia evaporation tower may contain insufficient contact between ammonia water and direct steam, and the ammonia gas is not completely evaporated, resulting in energy waste. Summary of the invention

[0005] In order to solve the above problems, the present invention aims to provide a cleaning device for an ammonia evaporation tower to reduce tower bottom blockage and improve ammonia recovery efficiency of the ammonia evaporation tower.

[0006] The present invention adopts the following technical solution.

[0007] The cleaning device for the ammonia distillation tower comprises: A filter screen is installed between the bottom tray of the ammonia evaporation tower and the outlet of the ammonia evaporation wastewater, and the filter screen is provided with a guide outlet; A scraper is rotatably disposed above the filter screen and is used to scrape impurities filtered out of the filter screen to the outlet; A cleaning box is arranged below the filter screen, the cleaning box is provided with a first opening and a second opening, the first opening is connected to the outlet for receiving the impurities, and the second opening is connected to the outside of the tower; The rotating fin is rotatably arranged in the cleaning box and is used for transferring impurities to the outside of the tower through the second opening.

[0008] Furthermore, the scraper is an S-shaped scraper.

[0009] Furthermore, a plurality of filter holes are provided on one side of the bottom of the cleaning box close to the second opening to allow the ammonia water to flow out.

[0010] Furthermore, the area at the bottom of the cleaning box where the filter holes are arranged accounts for 1 / 3 of the total area of ​​the bottom of the cleaning box.

[0011] Furthermore, one end of the rotating shaft of the rotating fin is connected to a motor outside the ammonia distillation tower to drive the rotation, and the other end of the rotating shaft is provided with a bevel gear. Another bevel gear is provided at the bottom of the rotating shaft of the scraper and meshes with the bevel gear of the rotating shaft for rotation.

[0012] Furthermore, the two bevel gears are arranged in a closed space.

[0013] Furthermore, the cleaning box is installed on the tower diameter, with a length of 1.7 to 1.75 m, a width of 330 to 340 mm, a height of 340 to 350 mm, a rotating fin height of 150 to 155 mm, a pitch of 246 to 250 mm, and a rotating shaft diameter of 40 mm.

[0014] Furthermore, the cleaning device also includes: The spiral fin heating tube is arranged at the bottom of the ammonia distillation tower and is used for stirring and heating the ammonia distillation wastewater at the bottom.

[0015] Furthermore, the outer diameter of the spiral fin heating tube is 195-205mm, the length of the heating tube is 2.85m, the pitch of the spiral fin is 300-305mm, and the rotation direction of the spiral fin is right-handed; a rotating rod rotatably connected to the bearing seat is provided at the end of the spiral fin rotating shaft, and the diameter of the rotating rod is 95-105mm and the length is 250-260mm; the height of the bearing seat is 510-520mm, the spiral fin heating tube is above the water outlet and the heating tube outlet on the tower body is staggered with the water outlet. Beneficial Effects

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention transfers the impurities such as sediment and tar generated in the ammonia evaporation tower through the cleaning device in the tower, and at the same time, adds a structure so that the ammonia evaporation wastewater at the bottom of the tower can be quickly discharged, reducing the residence time and preventing the accumulation of fine impurities. Then, the ammonia water at the bottom of the tower is further heated and fully evaporated through the heating and diversion device, while avoiding the flow dead zone at the bottom of the tower to accelerate the discharge of the ammonia evaporation wastewater. Finally, it is ensured that the ammonia evaporation tower does not need to perform regular slag discharge operation during operation, and the phenomenon of the ammonia evaporation tower being shut down due to blockage at the bottom of the tower will not occur, thereby ensuring the continuous and stable operation of the ammonia evaporation tower. Compared with the prior art, it can not only effectively discharge impurities in the tower, but also reduce cleaning costs, increase cleaning efficiency and reduce residues, and the addition of a spiral fin heating tube can not only effectively reduce the deposition at the bottom of the tower, but also further evaporate ammonia to reduce energy waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 2 is a structural diagram of a cleaning device according to an embodiment of the present invention.

[0018] Figure 2 This is a structural diagram of the cleaning device according to an embodiment of the present invention from another angle.

[0019] Figure 3 It is a front view of the rotating fins of the cleaning device.

[0020] Figure 4 A front view of the spiral finned heating tube of the cleaning device.

[0021] Figure 5 Schematic diagram of the spiral fin heating tube after installation at the bottom of the tower.

[0022] Figure 6 This is a schematic diagram of the cleaning device after it is installed at the bottom of the tower.

[0023] In the figure: 1. filter screen; 2. scraper; 3. cleaning box; 4. rotating fins; 5. spiral bevel gear; 6. filter hole; 7. cleaning dead zone; 8. bearing seat; 9. shell; 10. water outlet; 11. heating tube; 12. tower bottom; 13. spiral blade; 14. spiral rod. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with specific embodiments and drawings.

[0025] See also Figure 1-6 The embodiment of the present invention provides a cleaning device for an ammonia evaporation tower. The cleaning device is installed between the bottom tray of the ammonia evaporation tower and the outlet of the ammonia evaporation wastewater.

[0026] The cleaning device includes a filter screen 1, a cleaning box 3, a rotating fin 4, a spiral bevel gear 5, and an S-shaped scraper 2. Figure 1 The cleaning range diameter of the S-type scraper 2 is slightly smaller than the tower plate diameter.

[0027] The tower plate diameter of this embodiment is 3.2m, so the cleaning range diameter D1 of the S-shaped scraper 2 of the cleaning device is designed to be 3.15m to 3.18m. The diameter is smaller than the tower plate diameter to prevent the scraper 2 from rubbing against the tower body and damaging the device.

[0028] In this embodiment, the scraper 2 is in an 'S' shape, which not only speeds up the cleaning speed but also eliminates the cleaning dead zone 7. Because heavy oil and ammonium salt in the ammonia distillation tower are easily attached, it is difficult to clean the impurities at the rotating shaft of the ordinary scraper into the cleaning box 3, which may cause blockage and impurities to break and flow into the tower bottom 12 due to excessive stirring. Therefore, the S-shaped scraper 2 can make the impurities attached to the rotating shaft fall off along the scraper 2 during the rotation process to solve this problem.

[0029] A filter screen 1 is fixed on the upper layer of the cleaning device, and a cleaning box 3 is installed below it and connected to the tower body. A manhole is opened on the tower body, and a motor is connected to the outside of the manhole to drive the rotating fins 4. The rotating fins 4 drive the impurities and ammonia collected in the cleaning box 3 to move out of the tower. The bottom of the cleaning box 3 is designed to be closed for 2 / 3 of its length, and the remaining length is opened with smaller and more dense filter holes 6. Figure 2 As shown, this ensures that the impurities can quickly approach the outlet and that the ammonia water can normally flow into the tower bottom 12 and will not be carried out of the tower, while the collected impurities are discharged through the manhole.

[0030] The cleaning box 3 is installed on the tower diameter, its length L1 = 1.7 ~ 1.75m, width D1 = 330 ~ 340mm, height H = 340 ~ 350mm, the designed rotating fin 4 height H1 = 150 ~ 155mm, pitch M1 = 246 ~ 250mm, rotating shaft diameter 40mm, structure as follows Figure 3 As shown. A section of the rotating shaft away from the housing 9 is a spiral bevel gear, which meshes with the spiral bevel gear under the scraper 2. A separate closed space is provided for the spiral bevel gear 5 to prevent the entry of impurities and affect its meshing. The specific structure is as follows Figure 1 shown.

[0031] The ammonia evaporation wastewater flows to the bottom 12 of the tower through the filter screen 1, which also contains small particulate impurities. When there is too much wastewater at the bottom 12 of the tower, it may be deposited due to untimely discharge, and heavy oil and ammonium salt impurities are very easy to deposit in the dead zone of the flow at the bottom 12 of the tower. The water outlet 10 of the tower bottom 12 will be blocked for a long time and the tower needs to be shut down for maintenance. Installing a spiral fin heating tube 11 at the bottom 12 of the tower can not only effectively further heat the ammonia evaporation wastewater at the bottom 12 of the ammonia evaporation tower to further evaporate the ammonia and reduce ammonia waste, but also increase the kinetic energy of the fluid, increase the turbulence of the fluid, and reduce the sedimentation of particulate impurities at the bottom 12 of the tower. The style of the spiral fin heating tube is as follows Figure 4A bearing seat 8 is provided on the side of the tower bottom 12 away from the water outlet 10, and is connected to a section of the spiral finned heating tube with a spiral rod 14. The other end of the spiral heating tube is connected to a corresponding rotating heat exchange device outside the tower. Therefore, the spiral finned heating tube can be suspended on the tower bottom 12. The specific installation method is as follows: Figure 5 As shown. The outer diameter of the spiral fin heating tube D2 = 195 ~ 205mm, the length of the heating tube 11 is about 2.85m, the pitch of the spiral fin 13 M2 = 300 ~ 305mm, and the rotation direction of the spiral fin 13 is right-handed. The end of the rotating shaft is provided with a rotating rod rotatably connected to the bearing seat 8, the diameter of the rotating rod D3 = 95 ~ 105mm, the length L2 = 250 ~ 260mm; the height of the bearing seat 8 H2 = 510 ~ 520mm, to ensure that the spiral fin heating tube 11 is above the water outlet 10 and the outlet of the heating tube 11 on the tower body does not interfere with the water outlet 10.

[0032] The present invention finally forms a structure installation diagram of a tower bottom slag discharge and improved ammonia recovery efficiency as shown in the following figure Figure 6 shown.

[0033] The examples described in the present invention are merely descriptions of the preferred implementation modes of the present invention, and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made to the technical solutions of the present invention by engineers and technicians in this field should all fall within the protection scope of the present invention.

Claims

1. A cleaning device for an ammonia distillation tower, characterized in that: include: A filter screen is installed between the bottom tray of the ammonia evaporation tower and the outlet of the ammonia evaporation wastewater, and the filter screen is provided with a guide outlet; A scraper is rotatably disposed above the filter screen and is used to scrape impurities filtered out of the filter screen to the outlet; A cleaning box is arranged below the filter screen, the cleaning box is provided with a first opening and a second opening, the first opening is connected to the outlet for receiving the impurities, and the second opening is connected to the outside of the tower; The rotating fin is rotatably arranged in the cleaning box and is used for transferring impurities to the outside of the tower through the second opening.

2. The cleaning device according to claim 1, characterized in that: The scraper is an S-shaped scraper.

3. The cleaning device according to claim 1, characterized in that: A plurality of filter holes are arranged on one side of the bottom of the cleaning box close to the second opening to allow ammonia water to flow out.

4. The cleaning device according to claim 1, characterized in that: The area at the bottom of the cleaning box where the filter holes are arranged accounts for 1 / 3 of the total area of ​​the bottom of the cleaning box.

5. The cleaning device according to claim 1, characterized in that: One end of the rotating shaft of the rotating fin is connected to a motor outside the ammonia distillation tower to drive the rotation, and the other end of the rotating shaft is provided with a bevel gear. Another bevel gear is provided at the bottom of the rotating shaft of the scraper and meshes with the bevel gear of the rotating shaft to rotate.

6. The cleaning device according to claim 5, characterized in that: The two bevel gears are arranged in a closed space.

7. The cleaning device according to claim 1, characterized in that: The cleaning box is installed on the tower diameter, with a length of 1.7-1.75m, a width of 330-340mm, a height of 340-350mm, a rotating fin height of 150-155mm, a pitch of 246-250mm, and a rotating shaft diameter of 40mm.

8. The cleaning device according to claim 1, characterized in that: The cleaning device also includes: The spiral fin heating tube is arranged at the bottom of the ammonia distillation tower and is used for stirring and heating the ammonia distillation wastewater at the bottom.

9. The cleaning device according to claim 8, characterized in that: The outer diameter of the spiral fin heating tube is 195-205mm, the length of the heating tube is 2.85m, the pitch of the spiral fin is 300-305mm, and the rotation direction of the spiral fin is right-handed; a rotating rod rotatably connected to the bearing seat is provided at the end of the spiral fin rotating shaft, and the diameter of the rotating rod is 95-105mm and the length is 250-260mm; the height of the bearing seat is 510-520mm, the spiral fin heating tube is above the water outlet, and the heating tube outlet on the tower body is staggered with the water outlet.

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