Method for uniformly washing activated carbon in a desulfurization tower

Abstract

The present application belongs to the field of waste gas desulfurization purification technology, and particularly relates to a method for uniformly washing activated carbon in a desulfurization tower, which comprises desulfurization tower partitioned washing control, real-time detection of the temperature of the filler layer, and interlocking control of the temperature change of the filler layer and the washing time to wash the tower process. The present application increases partitioned control valves in the washing process of the desulfurization tower, and the speed of the temperature change of the filler layer in the washing process is used to reflect the blocking and hardening of the filler layer in the desulfurization tower. The washing time of the abnormal area is prolonged, the desorption effect of the filler layer is improved, the blocking and hardening of the activated carbon caused by the washing of the adsorbent is prevented, and the uniformity of the washing is ensured.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of waste gas desulfurization purification technology, and particularly relates to a method for uniformly washing activated carbon in a desulfurization tower. BACKGROUND

[0002] At present, the large-scale activated carbon regeneration methods include thermal regeneration, solvent regeneration, electrochemical regeneration, supercritical fluid regeneration, ultrasonic regeneration, microwave radiation regeneration and TiO2 photocatalytic regeneration.

[0003] The activated carbon desulfurization process of coke oven waste gas generally selects the water washing desulfurization regeneration method. During the operation of the desulfurization tower, SO2, H2O and O2 in the flue gas are adsorbed in the pores of the activated carbon, and H2SO4 is generated by catalytic reaction. The sulfuric acid generated by the catalytic reaction is enriched in the carrier. When the pores are saturated after a period of desulfurization, the carrier is regenerated to release the active sites of the catalyst, and the desulfurization capacity of the catalyst is restored.

[0004] The packing layer of the desulfurization tower is uniformly sprayed and washed by the nozzles arranged at the top (the number of nozzles is related to the diameter of the tower, generally 100-200). During the water washing regeneration process, water is supplied to the nozzles at the top of the desulfurization tower by a water washing pump,

[0005] The water washing removes SO2 and other substances adsorbed by the activated carbon, forming dilute sulfuric acid.

[0006] After the activated carbon adsorbs SO2, H2O and O2 and other substances, the air permeability of the activated carbon changes. During the water washing process, some parts of the activated carbon layer are over-washed, and some parts are not washed to the desired degree. As a result, the desulfurization efficiency of the activated carbon decreases due to uneven water washing. The existing process has certain defects, i.e., there is no targeted solution after the activated carbon is blocked and segregated.

[0007] The activated carbon desulfurization is the current mainstream coke oven waste gas desulfurization process. The activated carbon desulfurization is currently mostly in the fixed bed mode, i.e., the desulfurizer is filled in the desulfurization tower, and the flue gas passes through the activated carbon layer, and the sulfur dioxide in the flue gas is adsorbed by the activated carbon to achieve the desulfurization effect. After the activated carbon as the desulfurizer works for a period of time, the sulfur capacity reaches saturation, and it needs to be regenerated to restore the desulfurization capacity. The present application relates to a method for uniformly washing the packing of the desulfurization tower, and belongs to a method for uniformly washing and regenerating the activated carbon. The present application adopts the water washing partition control measures of the desulfurization tower, detects the temperature of the activated carbon packing layer by adding new activated carbon, judges whether the water washing of the activated carbon packing layer is segregated according to the temperature change trend of the water washing process in different regions, and adjusts the water washing time of each partition to ensure the uniform water washing of the activated carbon packing layer, so that the activated carbon is uniformly regenerated and the desulfurization efficiency is restored. SUMMARY

[0008] The present application aims to provide a desulfurization tower activated carbon uniform water washing method, improve the water washing uniformity, prevent water washing segregation, prevent the desulfurization filler layer from being blocked and hardened due to uneven water washing. Ensure that the desulfurizer is washed more fully, and ensure the desulfurization efficiency.

[0009] The technical scheme of the present application:

[0010] A desulfurization tower activated carbon uniform water washing method, comprising the following steps:

[0011] (1) Desulfurization tower partition water washing control

[0012] After setting a "large partition" water washing electric valve at the top of the desulfurization tower, b "small partition" water washing spray valves are set under the "large partition"; under normal circumstances, the "small partition" water washing spray valve is always open, and the water washing is divided according to the large partition; under abnormal circumstances, the local water washing can be adjusted by opening and closing the "small partition" water washing spray valve; a is an integer greater than or equal to 3, and b is an integer greater than or equal to 2;

[0013] (2) Real-time detection of filler layer temperature

[0014] The internal filler layer structure of the desulfurization tower is that the bottom is cobblestone, the middle layer is activated carbon, and the upper part is cobblestone. The activated carbon filling layer is divided into a*b quadrants, and a temperature detection point is arranged in each quadrant to monitor the change trend of the activated carbon temperature in real time;

[0015] (3) Filler layer temperature change and water washing time interlocking control washing process

[0016] When the water washing detection temperature decreases by 50 DEG C, and the cooling time exceeds 15 minutes, the central control room L1 monitoring screen will prompt sound and light alarm, reminding that water washing segregation occurs, and the water washing program of the large partition or the small partition is increased according to the corresponding position.

[0017] According to the desulfurization tower activated carbon uniform water washing method, further preferably, the large partition is 3 partitions, the small partition is 9 partitions, a=3, b=3, and the desulfurization tower activated carbon uniform water washing method is specifically:

[0018] (1) Desulfurization tower partition water washing control

[0019] After increasing 3 "3 partition" water washing electric valves at the top of the desulfurization tower, 3 "9 partition" water washing spray valves are further increased; under normal circumstances, the "9 partition" water washing spray valve is always open, and the water washing is divided according to 3 partitions; under abnormal circumstances, the local water washing can be adjusted by opening and closing the "9 partition" water washing spray valve;

[0020] (2) Real-time detection of filler layer temperature

[0021] The packing layer structure in the desulfurization tower is that the bottom is cobblestone, the middle layer is activated carbon, and the upper part is cobblestone; the activated carbon filling layer is divided into nine quadrants, and one temperature detection point is arranged in each quadrant, so that the change trend of the activated carbon temperature can be monitored in real time;

[0022] (3) The packing layer temperature change and water washing time interlocking control tower washing process

[0023] When the water washing detection temperature decreases by 50 DEG C, and the temperature decreasing time is more than 15 minutes, the central control room L1 monitoring picture will prompt sound and light alarm, reminding that water washing occurs segregation, and the water washing program of 3 sub-areas or 9 sub-areas is added according to the corresponding position.

[0024] According to the activated carbon uniform water washing method of the desulfurization tower, preferably, when all the temperature detection points of the small sub-areas in one large sub-area alarm simultaneously in the water washing process, one large sub-area water washing program (for example, the water washing program setting time is 20 minutes) is added; after the water washing program is added, if the corresponding temperature measuring point decreases, it can be determined that the water washing of the activated carbon is sufficient and effective, if the temperature still alarms, the relevant equipment needs to be checked on site, and if Figure 3 .

[0025] When one or two temperature detection points in the small sub-area alarm in the water washing process, the water washing valve of the small sub-area without alarm is closed, the water washing valve of the small sub-area with alarm is opened, and one water washing program (for example, the water washing program setting time is 20 minutes) is added.

[0026] Further, the water washing spray valve is specifically installed at the front of the desulfurization tower, vertically corresponds to the area temperature measuring point, and is synchronous to the position of one-half tower radius.

[0027] Further, the temperature measuring point is installed in the side hole of the desulfurization tower, the temperature detection instrument is extended to the inside of the desulfurization tower through the side hole, the depth is 1 / 2r, and the relative angle between the two temperature detection points is 2 / 9pi (40 DEG).

[0028] Further, the desulfurization tower is a cylinder.

[0029] The present application can improve the desorption effect of the packing layer, prevent the activated carbon from being blocked and consolidated due to adsorption, and ensure the uniformity of water washing by increasing the partition control valve of the water washing process of the desulfurization tower, and the speed of temperature change of the packing layer in the water washing process reflects the blocking and consolidation of the packing layer of the desulfurization tower.

[0030] The desulfurization tower in the application implements partition water washing, ensures uniform water washing, and adjusts the water washing time of each partition according to the temperature change in the water washing process of the desulfurization tower filler layer, to ensure uniformity of water washing.

[0031] Compared with the prior art, the partition water washing is more uniform, and through the temperature detection mode added in the filler layer, the temperature change of the filler layer is monitored in real time and effectively, so that whether the filler in a certain area is blocked or consolidated can be determined, for example, if the temperature change of the filler in a certain partition is slow, the water washing time of the partition is increased, to ensure more uniform water washing, effectively prevent the filler layer from being blocked or consolidated, and maximize the desulfurization efficiency.

[0032] The application optimizes the water washing mode, detects the abnormality of the filler layer in time through temperature detection in the water washing process, performs targeted water washing on the abnormal area, improves the air permeability of the filler layer, makes the activated carbon water washing more uniform, and guarantees the desulfurization efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 It is a partition water washing control schematic diagram of the desulfurization tower.

[0034] Among them: 2 is a water washing main pipe, 3 is a "3 partition" electric valve, 4 is a "9 partition" electric valve, 5 is a top temperature measurement point, 6 is a temperature measurement point, and 7 is a bottom temperature measurement point.

[0035] Figure 2 It is a schematic diagram of the position of the temperature measurement point in the tower section. Among them: 1 is a temperature measurement point.

[0036] Figure 3 It is a partition plane distribution schematic diagram.

[0037] Figure 4 It is a data statistical diagram of the water washing temperature measurement point of the desulfurization tower in March.

[0038] Figure 5 It is a data statistical diagram of the water washing temperature measurement point of the desulfurization tower in April.

[0039] Figure 6 It is a data statistical diagram of the water washing temperature measurement point of the desulfurization tower in May.

[0040] Figure 7 It is a water washing cooling time statistical diagram of the D tower of the 5A furnace.

[0041] Figure 8 It is a water washing cooling time statistical diagram of the E tower of the 5B furnace. DETAILED DESCRIPTION

[0042] The method comprises the following steps of: controlling water washing of a desulfurization tower in sections, detecting temperature segregation of a material layer, and controlling a tower washing process through interlocking of temperature change of a filler layer and water washing time.

[0043] 1. Water washing valve section control

[0044] In the existing process, the structure of the desulfurization tower of the 5A, 6B, 7A and 7B furnaces is a cylinder with a diameter of φ9m, and the structure of the desulfurization tower of the 5B and 6A furnaces is a cylinder with a diameter of φ10m and a height of 6m. On the basis of the existing process, three “3-section” water washing electric valves are added at the top of the desulfurization tower, and then three “9-section” water washing spray valves are added. The specific installation positions of the “9-section” water washing spray valves are placed in front of the spray of the desulfurization tower, vertically correspond to the temperature measurement points of the corresponding regions, and are synchronously corresponded to the positions at one-half radius (the radius of the 5A, 6B, 7A and 7B furnaces is φ4.5m, and the radius of the 5B and 6A furnaces is φ5m), so as to ensure that the water washing is effective and sufficient, and the temperature measurement points can accurately and effectively monitor the temperature. Under normal circumstances, the “9-section” water washing spray valves are kept open, and the water washing is carried out according to three sections. Under abnormal circumstances, the local water washing can be adjusted through the opening and closing of the “9-section” water washing spray valves. For example Figure 1 as shown in

[0045] The “3-section” is selected as the main section, so that the desulfurization tower can be effectively water washed, and each “3-section” water washing spray valve can provide water required by the three “9-section” water washing spray valves. The “9-section” is selected as the secondary section, because there are nine temperature measurement points, and the water washing efficiency and related abnormal conditions can be more accurately reflected during water washing.

[0046] 2. Real-time detection of temperature of filler layer

[0047] The desulfurization tower is a cylinder, and the structure of the filler layer in the cylinder is that the bottom is goose egg, the middle is activated carbon, and the upper part is goose egg. The activated carbon filling layer is divided into nine quadrants, and one temperature detection is added in each quadrant, so as to monitor the change trend of the temperature of the activated carbon in real time.

[0048] The installation height of the temperature detection from the bottom of the desulfurization tower is 3m (the height of the activated carbon layer), and the temperature detection is installed in the installation hole on the side of the desulfurization tower. The temperature detection instrument is placed into the desulfurization tower through the installation hole on the side, and the depth is 1 / 2r (r is the radius) (the radius of the 5A, 6B, 7A and 7B furnaces is φ4.5m, and the radius of the 5B and 6A furnaces is φ5m). The relative angle between the two temperature detection points is 2 / 9π (40°). The temperature detection is transmitted to the L1 picture in the central control room through online networking. For example Figure 2 as shown in

[0049] 3. Interlocking control of tower washing process through temperature change of filler layer and water washing time

[0050] (1) According to the data statistics of the water washing temperature measuring point of the desulfurization tower from March to May, the correlation curve of the detection temperature and time is as follows: Figures 4-6

[0051]

[0052]

[0053] Note: The number is the number of "temperature measuring points" that meet the requirements of the previous cell (the time required for the measuring point to reduce the temperature by 50°C during water washing).

[0054] According to a large amount of experimental data, when water washing normally, the time required for the measuring point to reduce the temperature by 50°C is within 0-15 minutes, which accounts for more than 90%, therefore, according to the experimental results, the water washing detection temperature is reduced by more than 50°C within 15 minutes as the judgment basis.

[0055] (2) The time of one water washing is 20 minutes, and the temperature is generally reduced from 140°C (running temperature) to 70°C, and the present program records the temperature detection (1-9) from 130°C to 80°C (50°C interval), if the time of reducing the temperature from 130°C to 80°C is more than 15 minutes, the central control room L1 monitoring picture will prompt sound and light alarm, reminding the water washing segregation; as shown in Figure 3

[0056] (3) If the water washing process, according to the temperature of 3-5 points shown in the figure, the temperature alarm is prompted at the same time, then increase 1 time of three-zone water washing program (water washing program setting time is 20 minutes), after increasing the water washing program, the corresponding temperature measuring point is reduced, then it can be determined that the water washing of activated carbon is sufficient and effective, if the temperature alarm is still prompted, then the related equipment needs to be checked on site; as shown in Figure 3

[0057] (4) If the water washing process, there is 1 or 2 temperature alarms in the water washing three-zone, then close the water washing "9 zone" valve without alarm, keep the corresponding water washing "9 zone" valve open, and increase 1 time of water washing program (water washing program setting time is 20 minutes).

[0058] Specific application effect test example:

[0059] According to the experimental data of the temperature measuring point in the water washing process, for the two desulfurization towers with the most times of reducing the temperature from 130°C to 80°C (50°C interval) more than 15 minutes, the project experiment is carried out, and the related experimental data after installation are as follows:

[0060]

[0061] According to the related experimental data of 5A furnace D tower (see Figure 7 ​​​As can be seen, adding a water washing program at temperature measuring points 4, 6, 7, 8, and 9 resulted in a water washing time reduction of approximately 45.28% to 57.4% after several months of experimentation.

[0062]

[0063] Based on relevant experimental data from the 5B furnace E tower (see...) Figure 8 As can be seen, adding a water washing program at temperature measuring points 2, 8, and 9 resulted in a water washing time reduction of approximately 22.22% to 48.97% after several months of experimentation.

[0064] This invention will be used in the third and fourth phase coke oven flue gas purification project of Baosteel's ironmaking plant. It is expected to effectively guarantee the water washing effect of activated carbon and ensure the desulfurization effect of activated carbon.

[0065] Fixed-bed activated carbon desulfurization technology is currently widely used in the coking industry. However, previous steel plants using this technology have experienced insufficient water washing, leading to decreased desulfurization efficiency. If the regeneration effect of activated carbon for desulfurization can be improved with minor modifications, thereby increasing desulfurization efficiency, this will inevitably become the choice for steel plants. Therefore, the application prospects of this invention are very broad.

[0066] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for uniformly washing activated carbon in a desulfurization tower, characterized in that, Includes the following steps: (1) Desulfurization tower zoned water washing control A "large zone" water washing electric valve is installed at the top of the desulfurization tower, and b "small zone" water washing spray valves are installed below the "large zone". Under normal circumstances, the "small zone" water washing spray valves are kept open, and water washing is carried out separately according to the large zone. Under abnormal circumstances, the local water washing is adjusted by opening and closing the "small zone" water washing spray valves. a is an integer ≥3 and b is an integer ≥2. (2) Real-time monitoring of packing layer temperature The internal packing layer structure of the desulfurization tower consists of pebbles at the bottom, activated carbon in the middle, and pebbles at the top. The activated carbon packing layer is divided into a*b quadrants, and a temperature detection point is set in each quadrant to monitor the temperature change trend of the activated carbon in real time. (3) Interlocking control of packing layer temperature change and water washing time in the washing tower process If the water washing temperature drops by 50°C and the cooling time exceeds 15 minutes, the L1 monitoring screen in the central control room will issue an audible and visual alarm, indicating that water washing has segregated. Depending on the location, the water washing program will be increased to a larger or smaller zone.

2. The method for uniformly washing activated carbon in a desulfurization tower according to claim 1, characterized in that, The large partition consists of 3 partitions, the small partition consists of 9 partitions, a=3, b=3, and the specific method for uniformly washing the activated carbon in the desulfurization tower is as follows: (1) Desulfurization tower zoned water washing control After adding three "3-zone" water washing electric valves to the top of the desulfurization tower, three "9-zone" water washing spray valves are added. Under normal circumstances, the "9-zone" water washing spray valves are kept open, and water washing is carried out separately according to the three zones. Under abnormal circumstances, the local water washing is adjusted by opening and closing the "9-zone" water washing spray valves. (2) Real-time monitoring of packing layer temperature The internal packing structure of the desulfurization tower consists of pebbles at the bottom, activated carbon in the middle, and pebbles at the top. The activated carbon packing layer is divided into 9 quadrants, with a temperature detection point set in each quadrant to monitor the temperature change trend of the activated carbon in real time. (3) Interlocking control of packing layer temperature change and water washing time in the washing tower process If the water washing temperature drops by 50°C and the cooling time exceeds 15 minutes, the L1 monitoring screen in the central control room will issue an audible and visual alarm, indicating that water washing has segregated. Depending on the location, a 3-zone or 9-zone water washing program will be added.

3. The method for uniformly washing activated carbon in a desulfurization tower according to claim 1, characterized in that, If all the temperature detection points in a large zone alarm simultaneously during the washing process, then the large zone washing procedure will be added once.

4. The method for uniformly washing activated carbon in a desulfurization tower according to claim 1, characterized in that, If one or two temperature detection points in a small zone alarm during the washing process, the washing valve of the small zone without alarms will be closed, and the washing valve of the corresponding alarmed small zone will be opened, adding one more washing cycle.

5. The method for uniformly washing activated carbon in a desulfurization tower according to claim 1, characterized in that, The water washing spray valve is specifically installed in front of the desulfurization tower spray, vertically aligned with the temperature measurement point in the corresponding area, and synchronously located at half the tower radius.

6. The method for uniformly washing activated carbon in a desulfurization tower according to claim 1, characterized in that, The temperature measuring point is installed in the mounting hole on the side of the desulfurization tower. The temperature measuring instrument is extended into the desulfurization tower to a depth of 1 / 2r through the mounting hole on the side. The relative angle between the two temperature measuring points is 2 / 9π (40°). The temperature is transmitted to the L1 screen in the central control room via online network.

7. The method for uniformly washing activated carbon in a desulfurization tower according to claim 1, characterized in that, The desulfurization tower is cylindrical.

Images