Coal-fired boiler desulfurization device using pta inorganic sludge

Abstract

The utility model relates to a flue gas desulfurization technical field, it is a kind of coal powder boiler desulfurization device using PTA inorganic sludge, it includes including sludge pretreatment unit, sludge treatment unit, desulfurization slurry preparation tank, desulfurization tower, boiler, dust catcher and chimney, softening pool left side feed end fixed communication has a plurality of sewage inlet pipeline, softening pool discharge end and sedimentation tank feed end fixed communication has sedimentation tank feed pipeline;Sludge storage tank discharge end and between desulfurization slurry preparation tank fixed communication has slurry pipeline;Boiler exhaust end and dust catcher communication dust inlet pipeline;Dust catcher outlet and desulfurization tower lower part communication has dust after flue gas pipeline;Desulfurization slurry preparation tank discharge end and desulfurization tower upper part liquid inlet end between fixed communication has desulfurization slurry pipeline.The utility model is reasonable and compact in structure, convenient to use, its use PTA inorganic sludge has realized the desulfurization of boiler flue gas, and processing efficiency is high, and operating cost is low, with environmental protection, labour saving, simple, efficient characteristics.

Description

Technical Field

[0001] This utility model relates to the field of flue gas desulfurization technology, and is a desulfurization device for pulverized coal boilers that utilizes PTA inorganic sludge. Background Technology

[0002] Flue gas desulfurization (FGD) is a key technology for reducing sulfur dioxide (SO2) emissions. Several mainstream processes exist, including: Limestone-gypsum wet desulfurization: This process utilizes limestone slurry to react with SO2 in the flue gas, producing gypsum. Its disadvantages include high investment and operating costs, wastewater treatment, and large land area requirements, making it suitable for large power plants. Dry desulfurization: This process involves spraying a dry absorbent (such as sodium bicarbonate or lime powder) into the flue gas to react with SO2 and generate solid products. Its disadvantages include low desulfurization efficiency (70% to 90%), suitability for low-sulfur coal, low absorbent utilization, high operating costs, and difficulty in resource utilization of byproducts. Semi-dry desulfurization (spray drying, circulating fluidized bed): This process involves atomizing lime slurry and spraying it into a reaction tower to react with the flue gas and generate dry particulate matter. Its disadvantages include the need for proper treatment of byproducts, sensitivity to operating parameters, and lower absorbent utilization compared to wet processes. Ammonia desulfurization: This process uses ammonia water as the absorbent to generate ammonium sulfate. Its disadvantages are: ammonia is volatile and there is a risk of leakage; the equipment requires anti-corrosion treatment and the investment is high; and the cost of ammonia raw materials fluctuates greatly.

[0003] Therefore, designing a simple, efficient, and low-cost desulfurization process that is suitable for local conditions remains a challenge for power plant flue gas desulfurization. Summary of the Invention

[0004] This invention provides a desulfurization device for pulverized coal boilers that utilizes PTA inorganic sludge, overcoming the shortcomings of the existing technology. It can effectively solve the problems of high operating costs and numerous by-products in existing flue gas desulfurization.

[0005] The technical solution of this utility model is achieved through the following measures: A pulverized coal boiler desulfurization device utilizing PTA inorganic sludge, comprising: a sludge pretreatment unit, a sludge treatment unit, a desulfurization slurry preparation tank, a desulfurization tower, a boiler, a dust collector, and a chimney. The sludge pretreatment unit includes a softening tank and a sedimentation tank. The sludge treatment unit includes a sludge storage tank. Multiple wastewater inlet pipelines are fixedly connected to the left feed end of the softening tank, and a sedimentation tank inlet pipeline is fixedly connected to the discharge end of the softening tank and the feed end of the sedimentation tank. The sedimentation tank... A sedimentation tank discharge pipeline is fixedly connected between the discharge end and the sludge storage tank inlet end; a sludge slurry pipeline is fixedly connected between the sludge storage tank discharge end and the first inlet end of the desulfurization slurry preparation tank; a dust removal inlet pipeline is fixedly connected between the boiler exhaust end and the dust collector inlet end; a dust removal flue gas pipeline is fixedly connected between the dust collector outlet end and the lower inlet end of the desulfurization tower; a desulfurization slurry pipeline is fixedly connected between the desulfurization slurry preparation tank discharge end and the upper liquid inlet end of the desulfurization tower; and an exhaust pipeline is fixedly connected between the desulfurization tower exhaust end and the chimney.

[0006] The following are further optimizations and / or improvements to the above-mentioned utility model technical solution: The aforementioned sludge treatment unit also includes a filter press. A sludge slurry pipeline is fixedly connected to the feed end of the filter press, and a sludge discharge pipeline is fixedly connected to the discharge end of the filter press.

[0007] A sprayer is fixedly installed in the upper part of the desulfurization tower, and the feed end of the sprayer is connected to the desulfurization slurry pipeline.

[0008] The softening tank is fixedly connected to a softening agent feeding pipeline at the top feed end, and the desulfurization slurry preparation tank is fixedly connected to a supplementary agent feeding pipeline at the second feed end.

[0009] The aforementioned wastewater inlet pipelines include a PTA wastewater pipeline, a desalination station sewage discharge pipeline, and a boiler island desulfurization wastewater pipeline. The first feed end on the left side of the softening tank is fixedly connected to the PTA wastewater pipeline, the second feed end on the left side of the softening tank is fixedly connected to the desalination station sewage discharge pipeline, and the third feed end on the left side of the softening tank is fixedly connected to the boiler island desulfurization wastewater pipeline. A slurry pump is fixedly installed on the sludge slurry pipeline between the filter press and the desulfurization slurry preparation tank, and a desulfurization slurry pump is fixedly installed on the desulfurization slurry pipeline.

[0010] This utility model has a reasonable and compact structure and is easy to use. It utilizes PTA inorganic sludge to achieve desulfurization of boiler flue gas, with high treatment efficiency and low operating cost. It turns waste into treasure, meets the environmental protection requirements for flue gas emissions, and has the characteristics of being environmentally friendly, labor-saving, simple, and efficient. Attached Figure Description

[0011] Appendix Figure 1 This is a schematic diagram of the process flow of this utility model.

[0012] The codes in the attached diagram are as follows: 1 is softening tank, 2 is sedimentation tank, 3 is sludge storage tank, 4 is desulfurization slurry preparation tank, 5 is desulfurization tower, 6 is boiler, 7 is dust collector, 8 is chimney, 9 is filter press, 10 is PTA wastewater pipeline, 11 is desalination station sewage pipeline, 12 is boiler island desulfurization wastewater pipeline, 13 is sedimentation tank feed pipeline, 14 is sedimentation tank discharge pipeline, 15 is sludge slurry pipeline, 16 is dust collector air inlet pipeline, 17 is flue gas pipeline after dust removal, 18 is desulfurization slurry pipeline, 19 is sprayer, 20 is exhaust pipeline, 21 is sludge filter press pipeline, 22 is sludge discharge pipeline, 23 is softening agent feeding pipeline, 24 is supplementary agent feeding pipeline, 25 is mud pump, and 26 is desulfurization slurry pump. Detailed Implementation

[0013] This utility model is not limited to the following embodiments, and the specific implementation method can be determined according to the technical solution of this utility model and the actual situation.

[0014] Unless otherwise specified, all equipment and devices used in this invention are existing, publicly known, and commonly used equipment and devices in the field.

[0015] In this utility model, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as the positional relationships of front, back, top, bottom, left, and right, which are based on the instructions attached. Figure 1 The orientation of the layout is determined by the direction of the map.

[0016] The present invention will be further described below with reference to the embodiments and accompanying drawings: Example 1: As shown in the attached document Figure 1 As shown, the pulverized coal boiler desulfurization device utilizing PTA inorganic sludge includes a sludge pretreatment unit, a sludge treatment unit, a desulfurization slurry preparation tank 4, a desulfurization tower 5, a boiler 6, a dust collector 7, and a chimney 8. The sludge pretreatment unit includes a softening tank 1 and a sedimentation tank 2. The sludge treatment unit includes a sludge storage tank 3. Multiple sewage inlet pipelines are fixedly connected to the left feed end of the softening tank 1. The discharge end of the softening tank 1 is fixedly connected to the feed end of the sedimentation tank 2 via a sedimentation tank feed pipeline 13. A fixed connection is made between the discharge end of the sedimentation tank 2 and the feed end of the sludge storage tank 3. A sedimentation tank discharge pipeline 14 is connected; a sludge slurry pipeline 15 is fixedly connected between the discharge end of the sludge storage tank 3 and the first feed end of the desulfurization slurry preparation tank 4; a dust removal air intake pipeline 16 is fixedly connected between the exhaust end of the boiler 6 and the air intake end of the dust collector 7; a dust removal flue gas pipeline 17 is fixedly connected between the exhaust end of the dust collector 7 and the lower air intake end of the desulfurization tower 5; a desulfurization slurry pipeline 18 is fixedly connected between the discharge end of the desulfurization slurry preparation tank 4 and the upper liquid inlet end of the desulfurization tower 5; and an exhaust pipeline 20 is fixedly connected between the exhaust end of the desulfurization tower 5 and the chimney 8.

[0017] The above-mentioned desulfurization device for pulverized coal boilers utilizing PTA inorganic sludge can be further optimized and / or improved according to actual needs: Example 2: Its difference from Example 1 is as follows: (See attached) Figure 1 As shown, the sludge treatment unit also includes a filter press 9, a sludge slurry pipeline 15 is fixedly connected to the feed end of the filter press 9 via a sludge filter pipeline 21, and a sludge discharge pipeline 22 is fixedly connected to the discharge end of the filter press 9.

[0018] Example 3: Its difference from Examples 1 to 2 is as follows: (See attached) Figure 1 As shown, a sprayer 19 is fixedly installed in the upper part of the desulfurization tower 5, and the feed end of the sprayer 19 is connected to the desulfurization slurry pipeline 18.

[0019] Example 4: Its difference from Examples 1 to 3 is as follows: (See attached) Figure 1 As shown, the top feed end of the softening tank 1 is fixedly connected to the softening agent feeding pipeline 23, and the second feed end of the desulfurization slurry preparation tank 4 is fixedly connected to the supplementary agent feeding pipeline 24.

[0020] Example 5: It differs from Examples 1 to 4 in that, as shown in the appendix... Figure 1 As shown, the wastewater inlet pipeline includes a PTA wastewater pipeline 10, a desalination station sewage pipeline 11, and a boiler island desulfurization wastewater pipeline 12. The first feed end on the left side of the softening tank 1 is fixedly connected to the PTA wastewater pipeline 10, the second feed end on the left side of the softening tank 1 is fixedly connected to the desalination station sewage pipeline 11, and the third feed end on the left side of the softening tank 1 is fixedly connected to the boiler island desulfurization wastewater pipeline 12.

[0021] Example 6: It differs from Examples 1 to 5 in that a mud pump 25 is fixedly installed on the sludge slurry pipeline 15 between the filter press 9 and the desulfurization slurry preparation tank 4, and a desulfurization slurry pump 26 is fixedly installed on the desulfurization slurry pipeline 18.

[0022] As required, valves and instruments that enable the desulfurization device for pulverized coal boilers utilizing PTA inorganic sludge are fixedly installed on each pipeline to ensure its normal operation.

[0023] The pretreatment unit of PTA wastewater treatment involves homogenization and softening of the incoming water, using a lime and soda ash softening + coagulation sedimentation process. This process generates a large amount of inorganic sludge (mainly composed of calcium carbonate and magnesium hydroxide), which requires treatment. This invention utilizes this sludge to achieve desulfurization of flue gas from a pulverized coal boiler. The specific process is as follows: Wastewater collected within the plant area includes RO concentrate from the PTA wastewater treatment plant, wastewater from the desalination station, and desulfurization wastewater from Boiler Island 6. This mixed wastewater is high in salinity and has high hardness. To prevent scaling in the subsequent membrane treatment section, the wastewater undergoes softening and hardness removal treatment in the pretreatment section. The three wastewater streams are introduced into softening tank 1 through PTA wastewater pipeline 10, desalination station wastewater pipeline 11, and boiler island desulfurization wastewater pipeline 12, respectively. Softening and hardness removal are typically achieved by adding a softening agent to softening tank 1. Afterward, flocculation and sedimentation occur in sedimentation tank 2. The inorganic sludge generated after sedimentation in sedimentation tank 2 is transported to sludge storage tank 3. The inorganic sludge is then pumped to desulfurization slurry preparation tank 4 via sludge pump 25. Excess inorganic sludge can be dewatered to a moisture content of 60% by filter press 9 before being transported off-site for disposal. In the desulfurization slurry preparation tank 4, limestone or water is added to the inorganic sludge slurry through the additive feed pipeline 24 to adjust the slurry density, resulting in a desulfurization slurry with a density between 1100 kg / m³ and 1200 kg / m³ and a pH value between 5.0 and 5.5. Then, the desulfurization slurry is pumped to the desulfurization tower 5 by the desulfurization slurry pump 26, and the amount of desulfurization slurry added is adjusted according to the slurry density, pH value, and environmental parameters.

[0024] The flue gas discharged from boiler 6 is pressurized and enters dust collector 7 for electrostatic precipitator. After dust removal, the flue gas then enters desulfurization tower 5. The flue gas rises through the spray zone, where desulfurization slurry suspension droplets sprayed downwards from the spray pipe group inside the desulfurization tower 5. The flue gas and droplets come into countercurrent contact, undergoing mass transfer and absorption reactions. Calcium carbonate and magnesium hydroxide in the desulfurization slurry remove SO2, SO3, HCl, and HF from the flue gas. The desulfurized flue gas is then discharged through chimney 8.

[0025] This invention transforms inorganic sludge into a valuable resource by modifying the inorganic sludge and flue gas desulfurization process. This reduces sludge treatment costs and desulfurization operating costs, lowering overall energy and material consumption while ensuring environmentally friendly emissions. For a 1.2 million-ton PTA production system, this pulverized coal boiler desulfurization device utilizing PTA inorganic sludge can save approximately 4.8 million yuan in sludge treatment costs and reduce desulfurizing agent costs by 2.4 million yuan annually.

[0026] In summary, this utility model utilizes PTA inorganic sludge to achieve desulfurization of boiler flue gas, with high treatment efficiency, low operating cost, and the ability to turn waste into treasure. It meets the environmental protection requirements for flue gas emissions and features environmental protection, labor saving, simplicity, and high efficiency.

[0027] The above technical features constitute various embodiments of this utility model, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. A desulfurization device for pulverized coal boilers utilizing PTA inorganic sludge, characterized in that... The system includes a sludge pretreatment unit, a sludge treatment unit, a desulfurization slurry preparation tank, a desulfurization tower, a boiler, a dust collector, and a chimney. The sludge pretreatment unit includes a softening tank and a sedimentation tank. The sludge treatment unit includes a sludge storage tank. Multiple sewage inlet pipelines are fixedly connected to the left feed end of the softening tank. A sedimentation tank feed pipeline is fixedly connected to the feed end of the softening tank and the feed end of the sedimentation tank. A sedimentation tank discharge pipeline is fixedly connected to the feed end of the sedimentation tank and the feed end of the sludge storage tank. A sludge slurry pipeline is fixedly connected to the first feed end of the desulfurization slurry preparation tank. A dust collector inlet pipeline is fixedly connected to the boiler exhaust end and the dust collector inlet end. A post-dust removal flue gas pipeline is fixedly connected to the lower inlet end of the desulfurization tower. A desulfurization slurry pipeline is fixedly connected to the discharge end of the desulfurization slurry preparation tank and the upper liquid inlet end of the desulfurization tower. An exhaust pipeline is fixedly connected to the exhaust end of the desulfurization tower and the chimney.

2. The desulfurization device for pulverized coal boilers utilizing PTA inorganic sludge according to claim 1, characterized in that... The sludge treatment unit also includes a filter press. A sludge slurry pipeline is fixedly connected to the feed end of the filter press, and a sludge discharge pipeline is fixedly connected to the discharge end of the filter press.

3. The desulfurization device for pulverized coal boilers utilizing PTA inorganic sludge according to claim 1 or 2, characterized in that... A sprayer is fixedly installed in the upper part of the desulfurization tower, and the feed end of the sprayer is connected to the desulfurization slurry pipeline.

4. The desulfurization device for pulverized coal boilers utilizing PTA inorganic sludge according to claim 1 or 2, characterized in that... The top feed end of the softening tank is fixedly connected to a softening agent feeding pipeline, and the second feed end of the desulfurization slurry preparation tank is fixedly connected to a supplementary agent feeding pipeline.

5. The desulfurization device for pulverized coal boilers utilizing PTA inorganic sludge according to claim 3, characterized in that... The second feed end of the desulfurization slurry preparation tank is fixedly connected to a supplementary feed pipeline.

6. The desulfurization device for pulverized coal boilers utilizing PTA inorganic sludge according to claim 1, 2, or 5, characterized in that... The wastewater inlet pipeline includes the PTA wastewater pipeline, the desalination station sewage pipeline, and the boiler island desulfurization wastewater pipeline. The first feed end on the left side of the softening tank is fixedly connected to the PTA wastewater pipeline, the second feed end on the left side of the softening tank is fixedly connected to the desalination station sewage pipeline, and the third feed end on the left side of the softening tank is fixedly connected to the boiler island desulfurization wastewater pipeline.

7. The desulfurization device for pulverized coal boilers utilizing PTA inorganic sludge according to claim 3, characterized in that... The wastewater inlet pipeline includes the PTA wastewater pipeline, the desalination station sewage pipeline, and the boiler island desulfurization wastewater pipeline. The first feed end on the left side of the softening tank is fixedly connected to the PTA wastewater pipeline, the second feed end on the left side of the softening tank is fixedly connected to the desalination station sewage pipeline, and the third feed end on the left side of the softening tank is fixedly connected to the boiler island desulfurization wastewater pipeline.

8. The desulfurization device for pulverized coal boilers utilizing PTA inorganic sludge according to claim 4, characterized in that... The wastewater inlet pipeline includes the PTA wastewater pipeline, the desalination station sewage pipeline, and the boiler island desulfurization wastewater pipeline. The first feed end on the left side of the softening tank is fixedly connected to the PTA wastewater pipeline, the second feed end on the left side of the softening tank is fixedly connected to the desalination station sewage pipeline, and the third feed end on the left side of the softening tank is fixedly connected to the boiler island desulfurization wastewater pipeline.

9. The desulfurization device for pulverized coal boilers utilizing PTA inorganic sludge according to claim 2, characterized in that... A slurry pump is fixedly installed on the sludge slurry pipeline between the filter press and the desulfurization slurry preparation tank, and a desulfurization slurry pump is fixedly installed on the desulfurization slurry pipeline.

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