A cleaning system and method for scumming in a carbonation tower in soda production

Abstract

The application discloses a kind of for soda production in carbonization tower scab cleaning system and method, and cleaning system includes vacuum absorption tower, washing tower water pump, mother liquor storage barrel, multiple delivery pipelines and respectively access control valve of delivery pipeline;Vacuum absorption tower receives ammonia tower ammonia steam, mother I clear liquid and carries out cooling;Mother I clear liquid and ammonia tower ammonia steam carry out absorption in the absorption section of vacuum absorption tower, and the output of vacuum absorption tower washing mother liquor I;Vacuum absorption tower outlet end respectively through washing mother liquor I to cleaning tower pipeline, washing mother liquor I to mother liquor storage barrel pipeline and cleaning tower inlet end, mother liquor storage barrel communication;To be cleaned carbonization tower as cleaning tower receives cleaning gas and vacuum absorption tower washing mother liquor I and carries out washing tower operation;Cleaning tower outlet end passes through washing tower after washing mother liquor I to mother liquor storage barrel pipeline and accesses mother liquor storage barrel, and mother liquor storage barrel passes through mother liquor I to crystallization process pipeline and is communicated with crystallization process;The present application can reduce the energy consumption of cleaning system, improve cleaning efficiency.

Description

Technical Field

[0001] This invention belongs to the field of soda ash production technology, and particularly relates to a cleaning system and method for scaling inside the carbonation tower in soda ash production. Background Technology

[0002] In the production of soda ash, the carbonation process is a complex physicochemical process involving chemical reactions, energy conversion, solute transport and diffusion, and crystallization of supersaturated solutions. Simultaneously, solid, liquid, and gaseous states of matter coexist and react. The carbonation tower is the core equipment in the soda ash (sodium carbonate) manufacturing process. The main chemical reactions for soda ash production take place within the carbonation tower, and the ammonia-soda process is used to produce soda ash.

[0003] In the preparation of soda ash, sodium bicarbonate needs to be prepared using ammonia brine and carbon dioxide in a carbonation tower. Because sodium bicarbonate accumulates and forms scale inside the carbonation tower, prolonged neglect of cleaning will lead to blockage of the tower channels, thus reducing the carbonation effect. Therefore, periodic cleaning of the carbonation tower is necessary. One existing technical method involves using AⅡ solution (NH3, H2O, NaCl, NH4Cl, and a small amount of carbonate) from the crystallization section and low-pressure nitrogen from the air separation unit to clean the scale (NaHCO3, NH4HCO3, etc.) inside the carbonation tower. The cleaning principle of this method is that the NH3•H2O in the AⅡ solution reacts with the HCO3 in the crystallization components. - The reaction produces NH4 + and CO3 2- This process converts the low-solubility hydrocarbons into highly soluble carbonates, thus removing the scale. The introduced low-pressure nitrogen gas acts on the scale surface with its impact force, eroding the scale into fine particles, increasing contact with the AⅡ solution, and promoting a faster chemical reaction rate. The disadvantages of this method are: it requires a large amount of low-pressure nitrogen, and insufficient gas flow results in poor cleaning, especially under high production loads and intensities in the alkali production tower. Incomplete scale removal can lead to potential problems in the alkali production operation of the carbonation tower.

[0004] Existing Method Two: This method utilizes AⅡ liquid (NH3, H2O, NaCl, NH4Cl, and a small amount of carbonate) from the crystallization section along with cleaning gas (low-pressure nitrogen from the air separation unit and CO2 gas of appropriate concentration) to clean the scale buildup inside the carbonization tower. This method is an improvement on Method One, aiming to perform pre-carbonization of the carbonization reaction while cleaning the carbonization tower. It ensures effective cleaning of the carbonization tower while absorbing CO2 from the AⅡ liquid, thereby reducing the production intensity at the top of the carbonization tower and increasing the growth time for heavy alkali crystals, resulting in larger-particle heavy alkali. The disadvantage of this method is that increasing the CO2 concentration has a certain inhibitory effect on the cleaning process, while a lower CO2 concentration is insufficient to achieve the pre-carbonization purpose. Therefore, a reasonable CO2 concentration needs to be selected to balance these two requirements.

[0005] Existing technical method three: using hot ammonia I from the crystallization process and cleaning gas to clean the scale in the carbonization tower. The principle of this cleaning method is that hot ammonia I and the scale undergo a reverse reaction during the cleaning process, thereby accelerating the cleaning. The disadvantage of this method is that due to the large circulation volume of the system, it increases the energy consumption of transportation and the investment in equipment and pipelines, which is not conducive to the implementation of energy conservation and consumption reduction by enterprises.

[0006] Existing technical method four: After draining the material from the carbonization tower that needs to be cleaned, hot water is used for washing. This cleaning process utilizes the principle that scale is easily soluble in water at high temperatures to clean the scale, which is efficient and fast. The disadvantages of this method are: a large amount of steam is required to heat the wash water during the cleaning process, which increases energy consumption; the wash water has a high alkalinity after cleaning and cannot be discharged at will, making system recovery difficult, and there are dual problems of environmental protection and mother liquor expansion. Summary of the Invention

[0007] Technical problem solved: In view of the problems existing in the cleaning process of carbonation towers in the background art, the present invention provides a cleaning system and method for scaling inside carbonation towers in soda ash production, which reduces the energy consumption of the cleaning system and improves the cleaning efficiency.

[0008] Technical solution: The present invention provides a cleaning system for scaling inside the carbonation tower in soda ash production. The cleaning system includes a vacuum absorption tower, a tower washing water pump, a mother liquor storage tank, several conveying pipelines, and control valves connected to the conveying pipelines, all configured in conjunction with the carbonation tower to be cleaned.

[0009] The vacuum absorption tower includes at least one set of cooling sections and absorption sections connected in series. The cooling section includes a first cooler and a second cooler arranged along the height of the vacuum absorption tower. The inlet end of the first cooler is connected to the tail gas pipe at the top of the ammonia stripping tower to receive and cool the ammonia vapor from the ammonia stripping tower. The inlet end of the second cooler is connected to the washing mother liquor I pump to receive and cool the clarified mother liquor I. The clarified mother liquor I and the ammonia vapor from the ammonia stripping tower are absorbed in the absorption section of the vacuum absorption tower to produce ammonia-absorbing washing mother liquor I. The ammonia-absorbing washing mother liquor I is discharged from the vacuum absorption tower to form vacuum absorption tower washing mother liquor I.

[0010] The outlet of the vacuum absorption tower is connected to the inlet of the cleaning tower and the mother liquor storage tank via a washing mother liquor I to the cleaning tower pipeline and a washing mother liquor I to the mother liquor storage tank pipeline, respectively. The washing mother liquor I to the cleaning tower pipeline is connected to the washing tower water pump.

[0011] The carbonization tower to be cleaned serves as a cleaning tower, receiving cleaning gas and washing mother liquor I from the vacuum absorption tower for tower cleaning operations; the liquid outlet of the cleaning tower is connected to the mother liquor storage tank via a pipeline from the washing mother liquor I after the tower cleaning, and the mother liquor storage tank is connected to the crystallization process via a pipeline from the mother liquor I; the exhaust end of the cleaning tower transports the cleaning exhaust gas to the integrated recovery tower for treatment via a tail gas conveying pipeline.

[0012] Preferably, the vacuum absorption tower includes a cooling section A, an absorption section A, a cooling section B, and an absorption section B connected in series. The ammonia-absorbing washing mother liquor I produced from the absorption section A enters the cooling section B for heat exchange to produce heat-exchange washing mother liquor I. The heat-exchange washing mother liquor I enters the absorption section B and is absorbed by the ammonia vapor in the ammonia stripping tower to produce vacuum absorption tower washing mother liquor I.

[0013] Preferably, the shell sides of the multiple coolers installed in the cooling section A and cooling section B are respectively connected to the circulating water storage tank through the circulating water supply pipe and the circulating water return pipe.

[0014] Preferably, the pipeline from the washing mother liquor I to the mother liquor storage tank after the washing tower is connected to the washing tower water pump via a tee and the pipeline from the washing mother liquor I to the washing tower water pump. The residual washing mother liquor I in the washing tower is pumped into the mother liquor storage tank through the washing tower water pump and the pipeline from the washing tower water pump to the mother liquor storage tank, and the washing tower is converted into a carbonization tower to resume alkali production.

[0015] Preferably, the pipeline from the washing tower water pump to the cleaning tower is connected to the carbonation tower of other normal alkali production operations via a tee and the pipeline from the washing tower water pump to the carbonation tower.

[0016] Preferably, the pipeline from the washing tower water pump to the cleaning tower is connected to the mother liquor storage tank via a tee and the pipeline from the washing tower water pump to the mother liquor storage tank.

[0017] This invention also discloses a cleaning method for scale buildup inside the carbonation tower in soda ash production, the cleaning method comprising:

[0018] Step 1: Before cleaning, ensure that the following pipelines are closed: washing mother liquor I to the washing tower water pump, washing tower water pump to the cleaning tower, washing mother liquor I to the mother liquor storage tank, washing tower water pump to the mother liquor storage tank, and ammonia mother liquor II inlet pipeline. Ensure that the washing mother liquor I to the washing tower water pump and the washing tower water pump to the carbonization tower are connected. Start the washing tower water pump to sequentially send all the alkali-making liquid in the cleaning tower into the normally operating alkali-making tower for alkali production. After the residual alkali-making liquid in the cleaning tower is evacuated, turn off the washing tower water pump.

[0019] Step 2: During the cleaning operation, ensure that the pipelines from the washing tower water pump to the carbonization tower, the washing tower mother liquor I to the washing tower water pump, and the washing tower water pump to the mother liquor storage tank are closed; ensure that the pipelines from the washing mother liquor I to the washing tower water pump and the washing tower water pump to the cleaning tower are connected; start the vacuum absorption tower to receive the clarified mother liquor I and ammonia vapor from the ammonia stripping tower for absorption to produce vacuum absorption tower washing mother liquor I, and then start the washing tower water pump to pump the vacuum absorption tower washing mother liquor I; after the washing tower water pump starts, close the control valve connected to the pipeline from washing mother liquor I to the mother liquor storage tank to 50-80% to ensure that the flow rate of vacuum absorption tower washing mother liquor I delivered to the cleaning tower through the pipeline from the washing tower water pump to the cleaning tower is 200-300 m³ / h; and keep the pipeline from washing mother liquor I to the mother liquor storage tank connected after washing the tower, and the cleaning tower begins the cleaning operation.

[0020] Step 3: After the cleaning operation lasts for 18-24 hours, prepare to end the cleaning operation. Fully open the control valve of the pipeline connecting the washing mother liquor I to the mother liquor storage tank to ensure that after the cleaning stops, the washing mother liquor I of the vacuum absorption tower enters the mother liquor storage tank through the washing mother liquor I to mother liquor storage tank pipeline. Then connect the washing mother liquor I to the washing tower water pump pipeline to transport the remaining washing mother liquor I in the washing tower into the washing tower water pump. After connecting the washing mother liquor I to the washing tower water pump pipeline, shut off the washing mother liquor I to the washing tower water pump pipeline, the washing mother liquor I to the mother liquor storage tank pipeline, and the washing tower water pump to the cleaning tower pipeline. Then connect the washing tower water pump to the mother liquor storage tank pipeline to pump the remaining washing mother liquor I in the cleaning tower to the mother liquor storage tank for storage. Then shut off the washing tower water pump and shut off the washing mother liquor I to the washing tower water pump pipeline and the washing tower water pump to the mother liquor storage tank pipeline. The cleaning tower is now cleaned and can be used as a carbonization tower to resume the alkali production process.

[0021] Preferably, in step 2, the vacuum level inside the vacuum absorption tower is controlled at 25~35 kPa, and the flow rate of the clarified mother liquor is controlled at 200~500 m³ / s. 3 / h, the temperature of the mother I clarified liquid is controlled at 45~50℃ by the cooler in the vacuum absorption tower; the temperature of the ammonia vapor in the receiving ammonia stripping tower is controlled at 70~80℃, and the gas temperature is controlled at 55~65℃ after being cooled by the cooler.

[0022] Preferably, in step 1, cleaning gas is simultaneously introduced into the cleaning tower during the cleaning process. The cleaning gas includes N2, O2, and CO2, with the CO2 concentration not exceeding 5%, and the cleaning gas flow rate is controlled at 1000~1500 Nm³. 3 / h, pressure controlled at 0.32~0.4Mpa.

[0023] Preferably, during the cleaning process in step 2, the temperature of the washing mother liquor I in the vacuum absorption tower is controlled at 40~50℃ by adjusting the opening of the circulating water supply pipe and the circulating water return pipe and the circulating water flow rate.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The cleaning system for scale buildup inside the carbonization tower of the present invention can be used for cleaning operations of at least one carbonization tower in the existing alkali production process. On the one hand, it can increase the flow rate of the cleaning medium in the cleaning process of each carbonization tower by about 20% compared with the original cleaning process, which is beneficial to the cleaning of scale buildup. On the other hand, the temperature of the cleaning medium of the present invention is 3-8°C higher than that of the original cleaning medium without the need for external heating. The increased temperature is beneficial to the cleaning and reverse reaction, thereby improving the cleaning efficiency of the carbonization tower.

[0026] 2. This cleaning system improves the efficiency of alkali production in the carbonation tower process, enhancing product quality and yield. Because carbonation towers are more efficient at producing alkali, they increase the conversion rate of raw materials and reduce the equivalent mother liquor volume. This results in lower energy consumption and less equipment investment for the same output. It also solves the problem of scaling in the carbonation tower during soda ash production, achieving the goal of improving the production efficiency of the carbonation tower and reducing energy consumption during the cleaning process. Furthermore, it avoids the use of hot water boiling, thus reducing steam consumption and wastewater generation. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the cleaning process of the cleaning system for the scaling inside the carbonization tower of the present invention;

[0028] Figure 2 This is a schematic diagram showing the opening and closing states of each control valve in the cleaning system of the present invention before cleaning.

[0029] Figure 3 This is a schematic diagram showing the opening and closing states of various control valves in the cleaning system of the present invention during the cleaning process.

[0030] Figure 4 This is a schematic diagram showing the opening and closing states of each control valve in the cleaning system of the present invention after cleaning is completed.

[0031] Figure reference numerals: 1. Ammonia vapor from the ammonia stripping tower; 2. Ammonia vapor from heat exchange; 3. Clarified mother liquor I; 4. Ammonia absorption washing mother liquor I; 5. Washing mother liquor I from heat exchange; 6. Washing mother liquor I from the vacuum absorption tower; 7. Pipeline from washing mother liquor I to the cleaning tower; 8. Pipeline from washing mother liquor I after the washing tower to the mother liquor storage tank; 9. Pipeline from washing mother liquor I to the washing tower water pump; 10. Circulating water supply pipeline; 11. Circulating water return pipeline; 12. Cleaning gas; 13. Cleaning tail gas; 14. Ammonia washing tail gas; 15. Pipeline from mother liquor I to the crystallization process; 16. First control valve; 17. ... 18. Second control valve; 19. Third control valve; 20. Fourth control valve; 21. Fifth control valve; 22. Sixth control valve; 23. Seventh control valve; 24. Ammonia mother liquor II inlet valve; 25. Vacuum absorption tower; 26. Washing tower water pump; 27. Mother liquor storage tank; 28. Cleaning tower; 29. ​​Alkali production tower; 30. Washing mother liquor I to mother liquor storage tank pipeline; 31. Ammonia mother liquor II inlet pipeline; 32. Washing tower water pump to carbonization tower pipeline; 33. Washing tower water pump to cleaning tower pipeline; 34. Washing mother liquor I to washing tower water pump pipeline. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will be described in conjunction with the accompanying drawings. Figures 1-4 The technical solutions of the embodiments of the present invention are clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0033] Example 1: As Figure 1 As shown, the present invention provides a cleaning system for scaling inside a carbonation tower in soda ash production. The cleaning system includes a vacuum absorption tower 24, a tower washing water pump 25, a mother liquor storage tank 26, multiple conveying pipelines, and control valves connected to the conveying pipelines respectively.

[0034] The vacuum absorption tower 24 includes at least one set of cooling sections and absorption sections connected in series. The cooling sections include a first cooler and a second cooler arranged along the height of the vacuum absorption tower 24. The inlet end of the first cooler is connected to the tail gas pipe at the top of the ammonia stripping tower, receiving and cooling ammonia vapor 1 from the ammonia stripping tower. The inlet end of the second cooler is connected to the washing mother liquor I pump, receiving and cooling the clarified mother liquor I 3. The clarified mother liquor I 3 and the ammonia vapor 1 from the ammonia stripping tower are absorbed in the absorption section of the vacuum absorption tower 24 to produce ammonia-absorbing washing mother liquor I 4. The ammonia-absorbing washing mother liquor I 4 is discharged from the vacuum absorption tower 24 to form vacuum absorption tower washing mother liquor I 6. In a preferred embodiment, the vacuum absorption tower 24 includes a cooling section A, an absorption section A, a cooling section B, and an absorption section B connected in series. The shell sides of multiple coolers installed in cooling sections A and B are connected to a circulating water storage tank via a circulating water supply pipe 10 and a circulating water return pipe 11, respectively. The circulating water exchanges heat between cooling sections A and B to achieve cooling or heating of the circulating medium within them. Ammonia vapor 1 from the ammonia stripping tower flows through cooling section A to form heat-exchange ammonia vapor 2. Clarified mother liquor 3 flows through cooling and enters absorption section A to react with heat-exchange ammonia vapor 2 to form ammonia-absorbing washing mother liquor 14. After entering cooling section B, ammonia-absorbing washing mother liquor 14 undergoes heat exchange to produce heat-exchange washing mother liquor 15 and ammonia washing tail gas 14. Heat-exchange washing mother liquor 15 flows through absorption section B and further reacts with heat-exchange ammonia vapor 2 to produce vacuum absorption tower washing mother liquor 16, which meets the requirements for subsequent cleaning operations on the carbonization tower.

[0035] The outlet of vacuum absorption tower 24 is connected to the inlet of cleaning tower 27 and mother liquor storage tank 26 via washing mother liquor I to cleaning tower pipeline 7 and washing mother liquor I to mother liquor storage tank pipeline 29. Washing mother liquor I to cleaning tower pipeline 7 is connected to washing tower water pump 25 to form washing mother liquor I to washing tower water pump pipeline 34 and washing tower water pump to cleaning tower pipeline 33. A first control valve 16 is connected to washing mother liquor I to washing tower water pump pipeline 34, a second control valve 17 is connected to washing mother liquor I to mother liquor storage tank pipeline 29, and a third control valve 18 is connected to washing tower water pump to cleaning tower pipeline 33.

[0036] The alkali production system of this invention includes six carbonization towers. These carbonization towers (28) are prone to scaling during operation, thus requiring periodic cleaning to maintain their efficiency. In this invention, one carbonization tower (27) is cleaned using the cleaning system and method of this invention. The remaining five carbonization towers are cleaned using an AⅡ solution (NH3, H2O, NaCl, NH4Cl, and a small amount of carbonate) and cleaning gas 12 (low-pressure nitrogen from air separation and an appropriate concentration of CO2 gas) to remove the scaling. This cleaning method increases the flow rate of the cleaning medium (AⅡ solution and washing mother liquor) in each carbonization tower by approximately 20% compared to traditional cleaning methods, which is beneficial for scaling removal. Furthermore, the cleaning medium temperature of this invention is 3-8°C higher than the original cleaning medium temperature without external heating. Appropriately increasing the cleaning temperature facilitates cleaning and the reverse reaction, thus improving cleaning efficiency. Compared with hot AⅠ liquid cleaning, the cleaning system of the present invention consumes less energy and requires less equipment investment. It solves the problem of scaling in the carbonation tower during soda ash production, thereby improving the production efficiency of the carbonation tower and reducing energy consumption during the cleaning process.

[0037] The carbonization tower to be cleaned, acting as cleaning tower 27, receives cleaning gas 12 and mother liquor I6 from the vacuum absorption tower for cleaning operations. The outlet of cleaning tower 27 is connected to mother liquor storage tank 26 via a pipeline 8 from the post-cleaning mother liquor I to the mother liquor storage tank. Mother liquor storage tank 26 is connected to the crystallization process via a pipeline 15 from mother liquor I to the crystallization process. The pipeline 8 from the post-cleaning mother liquor I to the mother liquor storage tank is connected to the fourth control valve 19. The exhaust end of cleaning tower 27 transports cleaning exhaust gas 13 to the integrated recovery tower for treatment via a tail gas delivery pipeline. The pipeline 8 from the post-cleaning mother liquor I to the mother liquor storage tank is located upstream of the fourth control valve 19 and is connected to the cleaning pump 25 via a tee and a pipeline 9 from the post-cleaning mother liquor I to the cleaning pump. The pipeline 9 from the post-cleaning mother liquor I to the cleaning pump is connected to the fifth control valve 20, and the end of the pipeline 9 is located downstream of the first control valve 16. The washing tower water pump to cleaning tower pipeline 33 is located at the front end of the third control valve 18 and is connected to the mother liquor storage tank 26 via a tee and the washing tower water pump to mother liquor storage tank pipeline 30. The residual washing mother liquor I in the cleaning tower 27 is pumped into the mother liquor storage tank 26 through the washing tower water pump 25 and the washing tower water pump to mother liquor storage tank pipeline 30. The sixth control valve 21 is connected in the washing tower water pump to mother liquor storage tank pipeline 30, and the cleaning tower 27 is converted into a carbonization tower to resume alkali production operation.

[0038] The washing tower water pump to cleaning tower pipeline 33 is located upstream of the third control valve 18 and connects to other carbonization towers operating normally in alkali production via a tee and the washing tower water pump to carbonization tower pipeline 32. The washing tower water pump to carbonization tower pipeline 32 is connected to the seventh control valve 22. The cleaning tower 27 is also equipped with an ammonia mother II inlet valve 23. After the cleaning tower 27 completes cleaning, it is converted into an alkali production tower, and the alkali production operation can be started by controlling the ammonia mother II inlet valve 23.

[0039] Example 2: This invention also discloses a method for cleaning scale buildup inside the carbonation tower in soda ash production. The cleaning method includes:

[0040] (a) such as Figure 2 As shown, before the cleaning operation, ensure that the following pipes are closed: washing mother liquor I to washing tower pump 34, washing tower pump to cleaning tower 33, washing mother liquor I to mother liquor storage tank 8, washing tower pump to mother liquor storage tank 30, and ammonia mother liquor II inlet pipe 31; ensure that washing mother liquor I to washing tower pump 9 and washing tower pump to carbonization tower 32 are connected; start washing tower pump 25 to sequentially send all the alkali-making solution in cleaning tower 27 into the normally operating alkali-making tower 28 for alkali production; after the residual alkali-making solution in cleaning tower 27 has been evacuated, shut down washing tower pump 25. It should be noted that the shut-off or connection of the delivery pipes is controlled by the corresponding control valves connected to them.

[0041] (ii) such as Figure 3 As shown, during the cleaning operation, ensure that the following are the procedures: Pipeline 32 from the washing tower water pump to the carbonization tower, pipe 9 from the washing tower mother liquor I to the washing tower water pump, and pipe 30 from the washing tower water pump to the mother liquor storage tank are closed; ensure that pipes 34 from the washing mother liquor I to the washing tower water pump and pipe 33 from the washing tower water pump to the cleaning tower are connected; start the vacuum absorption tower 24 to receive the clarified mother liquor I 3 and ammonia vapor 1 from the ammonia stripping tower for absorption, producing vacuum absorption tower washing mother liquor I6; then start the washing tower water pump 25 to pump the vacuum absorption tower washing mother liquor I6; after the washing tower water pump 25 starts, close the control valve connected to the washing mother liquor I to the mother liquor storage tank pipe 29 to 50-80% to ensure that the flow rate of vacuum absorption tower washing mother liquor I6 delivered to the cleaning tower 27 through the washing tower water pump to the cleaning tower pipe 33 is 200-300 m³ / h. 3 / h; and keep the mother liquor I to mother liquor storage tank pipeline 8 connected after the washing tower, and the washing tower 27 starts the washing operation.

[0042] During the cleaning process, the vacuum degree inside the vacuum absorption tower 24 is controlled at 25~35 kPa, and the flow rate of the clarified mother liquor 3 is controlled at 200~500 m³ / s. 3 / h, the temperature of the mother liquor I clarified liquid 3 is controlled at 45~50℃ by the cooler inside the vacuum absorption tower 24; the temperature of the ammonia vapor 1 in the receiving ammonia stripping tower is controlled at 70~80℃, and the gas temperature is controlled at 55~65℃ after cooling by the cooler. It should be noted that the cooling capacity of each cooler in the vacuum absorption tower 24 is controlled by adjusting the opening of the circulating water supply pipe 10 and the circulating water return pipe 11 and the circulating water flow rate, so as to control the temperature of the produced vacuum absorption tower washing mother liquor I6 at 40~50℃. During the cleaning process, the cleaning tower 27 simultaneously introduces cleaning gas 12, which includes N2, O2, and CO2, with the CO2 concentration not exceeding 5%, and the flow rate of cleaning gas 12 is controlled at 1000~1500 Nm. 3 / h, pressure controlled at 0.32~0.4Mpa. It should be noted that the process parameters of this invention are all process control parameters, and their specific point values ​​have no practical significance in the actual production process. That is, the process parameters can be controlled at any value within the corresponding parameter range to meet the requirements.

[0043] (iii) If Figure 4 As shown, after the cleaning operation lasts for 18-24 hours, to prepare for the end of the cleaning operation, the control valve connecting the washing mother liquor I to the mother liquor storage tank 29 is fully opened to ensure that after the cleaning stops, the vacuum absorption tower washing mother liquor I6 enters the mother liquor storage tank 26 through the washing mother liquor I to mother liquor storage tank pipeline 29; then, the washing tower washing mother liquor I to washing tower water pump pipeline 9 is connected to transport the remaining washing mother liquor I in the washing tower 27 to the washing tower water pump 25; the washing tower washing mother liquor I to washing tower water pump pipeline 9 is connected to the washing tower water pump 25. After pipe 9, shut off the washing mother liquor I to washing tower water pump pipe 34, the washing mother liquor I after washing tower to mother liquor storage tank pipe 8, and the washing tower water pump to cleaning tower pipe 33, and connect the washing tower water pump to mother liquor storage tank pipe 30. Pump the residual washing mother liquor I in cleaning tower 27 to mother liquor storage tank 26 for storage. Then shut off the washing tower water pump 25 and shut off the washing mother liquor I after washing tower to washing tower water pump pipe 34 and the washing tower water pump to mother liquor storage tank pipe 30. The cleaning tower 27 completes the cleaning and resumes the alkali production process as a carbonization tower.

[0044] The cleaning method of this invention improves the efficiency of alkali production in the carbonation tower process, and enhances product quality and yield. Because the carbonation tower is more efficient in alkali production, it increases the conversion rate of raw materials and reduces the mother liquor equivalent. Under the same output conditions, it reduces energy consumption, offering advantages such as lower energy consumption and smaller equipment investment. It solves the problem of scaling in the carbonation tower during soda ash production, achieving the goal of improving the production efficiency of the carbonation tower and reducing energy consumption during the cleaning process. It avoids the use of hot water boiling technology, thereby reducing steam consumption and wastewater generation.

[0045] The above are preferred embodiments of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A cleaning system for scaling inside the carbonation tower in soda ash production, characterized in that, The cleaning system includes a vacuum absorption tower (24) that is installed in conjunction with the carbonization tower to be cleaned, a tower washing water pump (25), a mother liquor storage tank (26), several conveying pipelines, and control valves connected to the conveying pipelines respectively; The vacuum absorption tower (24) includes at least one set of cooling sections and absorption sections connected in series. The cooling section includes a first cooler and a second cooler arranged along the height of the vacuum absorption tower (24). The inlet end of the first cooler is connected to the tail gas pipe at the top of the ammonia stripping tower to receive and cool the ammonia vapor (1) from the ammonia stripping tower. The inlet end of the second cooler is connected to the washing mother liquor I pump to receive and cool the clarified mother liquor I. The clarified mother liquor I (3) and the ammonia vapor (1) from the ammonia stripping tower are absorbed in the absorption section of the vacuum absorption tower (24). Ammonia-absorbing washing mother liquor I (4) is produced. Ammonia-absorbing washing mother liquor I (4) is discharged from the vacuum absorption tower (24) to form vacuum absorption tower washing mother liquor I (6). The vacuum absorption tower (24) includes a cooling section A, an absorption section A, a cooling section B and an absorption section B connected in series. Ammonia-absorbing washing mother liquor I (4) produced from the absorption section A enters the cooling section B for heat exchange to produce heat exchange washing mother liquor I (5). Heat exchange washing mother liquor I (5) enters the absorption section B and is absorbed by ammonia vapor (1) from the ammonia stripping tower to produce vacuum absorption tower washing mother liquor I (6). The outlet of the vacuum absorption tower (24) is connected to the inlet of the cleaning tower (27) and the mother liquor storage tank (26) through the washing mother liquor I to the cleaning tower pipeline (7) and the washing mother liquor I to the mother liquor storage tank pipeline (29). The washing mother liquor I to the cleaning tower pipeline (7) is connected to the washing tower water pump (25). The carbonization tower to be cleaned serves as a cleaning tower (27) to receive cleaning gas (12) and vacuum absorption tower washing mother liquor I (6) for tower cleaning operations; the liquid outlet of the cleaning tower (27) is connected to the mother liquor storage tank (26) through the washing mother liquor I after the tower cleaning pipeline (8); the mother liquor storage tank (26) is connected to the crystallization process through the mother liquor I to the crystallization process pipeline (15); the exhaust end of the cleaning tower (27) transports the cleaning tail gas (13) to the comprehensive recovery tower for treatment through the tail gas conveying pipeline.

2. The cleaning system for scaling inside the carbonation tower in soda ash production according to claim 1, characterized in that, The shell sides of the multiple coolers installed in the cooling section A and cooling section B are respectively connected to the circulating water storage tank through the circulating water supply pipe (10) and the circulating water return pipe (11).

3. The cleaning system for scaling inside the carbonation tower in soda ash production according to any one of claims 1 to 2, characterized in that, The washing mother liquor I to mother liquor storage tank pipeline (8) after the washing tower is connected to the washing tower water pump (25) through a tee and the washing tower washing mother liquor I to washing tower water pump pipeline (9). The residual washing mother liquor I in the cleaning tower (27) is pumped into the mother liquor storage tank (26) through the washing tower water pump (25) and the washing tower water pump to mother liquor storage tank pipeline (30), and the cleaning tower (27) is converted into a carbonization tower to resume alkali production operation.

4. The cleaning system for scaling inside the carbonation tower in soda ash production according to claim 3, characterized in that, The washing tower water pump to the cleaning tower pipeline (33) is connected to the carbonation tower of other normal alkali production operations via a tee and the washing tower water pump to the carbonation tower pipeline (32).

5. The cleaning system for scaling inside the carbonation tower in soda ash production according to claim 4, characterized in that, The pipeline (33) from the washing tower water pump to the cleaning tower is connected to the mother liquor storage tank (26) via a tee and the pipeline (30) from the washing tower water pump to the mother liquor storage tank.

6. A method for cleaning scale buildup inside a carbonation tower in soda ash production, characterized in that, Using the cleaning system of claim 5, the cleaning method includes: Step 1: Before cleaning, confirm that the following pipelines are closed: washing mother liquor I to washing tower water pump (34), washing tower water pump to cleaning tower (33), washing mother liquor I to mother liquor storage tank (8), washing tower water pump to mother liquor storage tank (30), and ammonia mother liquor II inlet pipeline (31); confirm that washing mother liquor I to washing tower water pump (9) and washing tower water pump to carbonization tower (32) are connected; start washing tower water pump (25) to send all the alkali-making liquid in the cleaning tower (27) into the normally operating alkali-making tower (28) through washing mother liquor I to washing tower water pump (9) and washing tower water pump to carbonization tower (32) for alkali-making operation; after the residual alkali-making liquid in the cleaning tower (27) is evacuated, turn off washing tower water pump (25). Step 2: When performing the cleaning operation, confirm that the pipeline from the washing tower water pump to the carbonization tower (32), the pipeline from the washing tower mother liquor I to the washing tower water pump (9), and the pipeline from the washing tower water pump to the mother liquor storage tank (30) are closed; confirm that the pipeline from the washing mother liquor I to the washing tower water pump (34) and the pipeline from the washing tower water pump to the cleaning tower (33) are connected; turn on the vacuum absorption tower (24) to receive the clarified mother liquor I (3) and the ammonia vapor (1) from the ammonia stripping tower for absorption to produce the vacuum absorption tower washing mother liquor I (6), and then start the washing tower water pump (25) to pump the vacuum absorption tower washing mother liquor I (6); after the washing tower water pump (25) is started, close the opening of the control valve connected to the washing mother liquor I to the mother liquor storage tank (29) to 50~80% to ensure that the flow rate of the vacuum absorption tower washing mother liquor I (6) delivered to the cleaning tower (27) through the washing tower water pump to the cleaning tower pipeline (33) is 200~300m³. 3 / h; and keep the mother liquor I to mother liquor storage tank pipeline (8) connected after the washing tower, and the washing tower (27) starts the washing operation; Step 3: After the cleaning operation lasts for 18-24 hours, prepare to end the cleaning operation. Fully open the control valve of the pipeline connecting the washing mother liquor I to the mother liquor storage tank (29) to ensure that after the cleaning stops, the washing mother liquor I (6) of the vacuum absorption tower enters the mother liquor storage tank (26) through the washing mother liquor I to the mother liquor storage tank pipeline (29); then connect the washing mother liquor I of the washing tower to the washing tower water pump pipeline (9) to transport the remaining washing mother liquor I in the washing tower (27) into the washing tower water pump (25); connect the washing mother liquor I of the washing tower to the washing tower water pump pipeline (9) After that, shut off the washing mother liquor I to the washing tower water pump pipeline (34), the washing mother liquor I after washing tower to the mother liquor storage tank pipeline (8), the washing tower water pump to the cleaning tower pipeline (33), and connect the washing tower water pump to the mother liquor storage tank pipeline (30) to pump the residual washing mother liquor I in the cleaning tower (27) to the mother liquor storage tank (26) for storage. Then shut off the washing tower water pump (25) and shut off the washing mother liquor I after the tower to the washing tower water pump pipeline (34) and the washing tower water pump to the mother liquor storage tank pipeline (30). The cleaning tower (27) completes the cleaning and resumes the alkali production process as the carbonization tower.

7. The cleaning method for scale buildup inside the carbonation tower in soda ash production according to claim 6, characterized in that, In step 2, the vacuum degree inside the vacuum absorption tower (24) is controlled at 25~35 kPa, and the flow rate of the clarified mother liquor (3) is controlled at 200~500 m³ / s. 3 / h, the temperature of the mother liquor I clarified liquid (3) is controlled at 45~50℃ through the cooler inside the vacuum absorption tower (24); the temperature of the ammonia vapor (1) in the receiving ammonia stripping tower is controlled at 70~80℃, and the gas temperature is controlled at 55~65℃ after being cooled by the cooler.

8. The cleaning method for scale buildup inside the carbonation tower in soda ash production according to claim 6, characterized in that, In step 1, the cleaning tower (27) simultaneously introduces cleaning gas (12) during the cleaning process. The cleaning gas (12) includes N2, O2, and CO2, with the CO2 concentration not exceeding 5%. The flow rate of the cleaning gas (12) is controlled at 1000~1500 Nm. 3 / h, pressure controlled at 0.32~0.4Mpa.

9. The cleaning method for scale buildup inside the carbonation tower in soda ash production according to claim 6, characterized in that, During the cleaning process in step 2, the temperature of the washing mother liquor I (6) in the vacuum absorption tower is controlled at 40~50℃ by adjusting the opening of the circulating water supply pipe (10), the circulating water return pipe (11) and the circulating water flow rate.

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