Acid-containing sewage treatment system

Abstract

The utility model relates to the technical field of acid-containing sewage treatment, in particular to an acid-containing sewage treatment system. The acid-containing sewage treatment system comprises a pre-mixing tank and an alkali liquor preparation tank, the pre-mixing tank is connected with a product filter through a reaction kettle, the product filter is connected with an acid liquor treatment tank through a reverse filter, the acid liquor treatment tank is connected with an evaporation kettle through a flocculation reaction tank, the evaporation kettle is connected with a filtering conveying belt, and the filtering conveying belt is connected with the alkali liquor preparation tank. And the alkali liquor preparation tank is connected with the acid liquor treatment tank through a pipeline. According to the system, the cooling sleeve of the alkali liquor preparation tank is connected with the temperature control coil pipe of the reaction kettle, so that heat generated in the preparation process of calcium hydroxide is recycled. After absorbing redundant heat, the cooling sleeve of the alkali liquor preparation tank transmits the heat to the temperature control coil pipe of the reaction kettle through the temperature control pipeline, so that the reaction temperature in the reaction kettle is maintained, extra energy consumption is reduced, and the energy utilization rate is improved.

Description

Technical Field

[0001] This utility model relates to the field of acidic wastewater treatment technology, specifically to an acidic wastewater treatment system. Background Technology

[0002] Humic acid is a widely distributed organic macromolecule found in nature, abundant in soil, lakes, and coal such as lignite, weathered coal, and peat. It is primarily composed of fulvic acid and hematitic acid. In agriculture, it optimizes soil structure, improves soil fertility, and enhances fertilizer utilization efficiency. In industrial production, it can be used to prepare drilling fluids and ceramic additives, improving product performance. In environmental protection, it has a good adsorption effect on heavy metal ions in wastewater, contributing to wastewater purification. With the increasing demand for humic acid across various industries, its production scale continues to expand.

[0003] The production of humic acid generates a large amount of acidic wastewater. Currently, most plants use calcium hydroxide for neutralization in the acid treatment stage. However, the preparation of calcium hydroxide releases a large amount of heat, which is often not effectively utilized, resulting in energy waste. Moreover, the acid solution lacks pretreatment before entering the treatment tank, and impurities in it react with calcium hydroxide to form calcium sulfate, leading to excessively high calcium sulfate impurity content in the subsequent product, failing to meet commercial standards and seriously affecting product quality and market competitiveness. Simultaneously, calcium sulfate precipitation is ineffective; traditional processes struggle to achieve rapid and complete precipitation and separation, limiting wastewater treatment efficiency and product purity. Utility Model Content

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide an acidic wastewater treatment system that connects a cooling jacket of an alkali solution preparation tank to a temperature control coil of a reaction vessel to recover heat generated during calcium hydroxide preparation. After absorbing excess heat, the cooling jacket of the alkali solution preparation tank transfers it to the temperature control coil of the reaction vessel via a temperature control pipe, maintaining the reaction temperature inside the reaction vessel, reducing additional energy consumption, and improving energy utilization efficiency.

[0005] This utility model is achieved using the following technical solution:

[0006] The acidic wastewater treatment system includes a premixing tank and an alkali preparation tank. The premixing tank is connected to a product filter via a reaction vessel. The product filter is connected to an acid treatment tank via a reverse filter. The acid treatment tank is connected to an evaporation vessel via a flocculation reaction vessel. A filter conveyor belt is connected to the evaporation vessel. The alkali preparation tank is connected to the acid treatment tank via a pipeline.

[0007] The premixed tank is connected to a sulfuric acid inlet pipe and has a solid raw material inlet. The reactor is equipped with a reactor temperature control coil. This coil precisely controls the reaction temperature, providing a suitable environment for the reaction of humic acid and sulfuric acid, promoting a complete reaction, and increasing product yield.

[0008] The alkaline solution preparation tank is equipped with an alkaline solution preparation tank cooling sleeve on its outside, and the alkaline solution preparation tank cooling sleeve is connected to the temperature control coil of the reaction vessel through a temperature control pipe.

[0009] The reverse filter has a filter plate inside, and a rotating scraper driven by a drive motor is located below the filter plate. The upper edge of the rotating scraper is tangent to the lower edge of the filter plate.

[0010] The evaporator is connected to the condenser via an internal airflow channel. The condenser has a condenser coil inside and an outer recovery sleeve outside the internal airflow channel.

[0011] The outer recovery sleeve is connected to the condenser recovery unit, but not to the evaporator.

[0012] The external recovery sleeve is connected to the flocculant preparation tank via a connecting pipe. The flocculant preparation tank is connected to the flocculation reaction tank via a flocculant inlet pipe. The flocculation reaction tank utilizes the flocculant to flocculate and precipitate impurities such as calcium sulfate, thereby improving the calcium sulfate precipitation effect and reducing the impurity content of the product.

[0013] The working principle of this utility model is as follows:

[0014] Premixing stage: Solid raw materials are added to the premixing tank through the solid raw material inlet, while sulfuric acid flows into the premixing tank through the sulfuric acid inlet pipe. The stirring speed is set to 300 r / min, and the mixing time is controlled at 15 min, so that the solid raw materials and sulfuric acid can initially contact and react, removing some impurities.

[0015] Reaction stage: The premixed materials are introduced into the reactor, and the temperature control coil is turned on to stabilize the temperature inside the reactor at 60℃. The reaction time is 2 hours to ensure that the humic acid and sulfuric acid react completely.

[0016] Acid treatment stage: After the reaction, the material is initially filtered through the product filter to remove larger particulate impurities before entering the reverse filter. In the reverse filter, a rotating scraper, driven by a motor, continuously scrapes away impurities from the filter plate to prevent clogging. The filtered acid then enters the acid treatment tank. Meanwhile, the prepared alkali solution from the alkali preparation tank flows into the acid treatment tank at a rate of 20 L / min for acid-base neutralization, adjusting the pH of the acid to 7.

[0017] Flocculation and sedimentation stage: The material in the acid treatment tank enters the flocculation reaction tank. The flocculated solution prepared in the flocculation preparation tank using the liquid phase of the condenser is added to the flocculation reaction tank through the flocculation inlet pipe at a flow rate of 15 L / min. The stirring speed in the flocculation reaction tank is 200 r / min, and the reaction time is 30 min, which promotes the full flocculation and sedimentation of impurities such as calcium sulfate.

[0018] Evaporation and Separation Stage: After flocculation and sedimentation, the material enters the evaporation kettle, where the temperature is raised to 90°C to evaporate the water. The water vapor generated by evaporation enters the condenser through the internal airflow channel, where it is condensed into a liquid phase for recycling by the condenser coils. The remaining material in the evaporation kettle undergoes solid-liquid separation via a filter conveyor belt. The solid phase is the processed product, while the liquid phase undergoes further processing.

[0019] Compared with the prior art, the beneficial effects of this utility model are:

[0020] (1) The cooling jacket of the alkali preparation tank is connected to the temperature control coil of the reactor to recover the heat generated during the preparation of calcium hydroxide. After absorbing excess heat, the cooling jacket of the alkali preparation tank is transferred to the temperature control coil of the reactor through the temperature control pipeline to maintain the reaction temperature in the reactor, reduce additional energy consumption, and improve energy utilization.

[0021] (2) Before entering the treatment tank, the acid solution is pretreated by a premixing tank and other devices to effectively remove some impurities. The added flocculation reaction tank, using a special flocculant, greatly improves the precipitation effect of calcium sulfate, significantly reduces the impurity content of calcium sulfate, makes the product meet the standards for external sales, and enhances the market value of the product.

[0022] (3) The liquid phase of the condenser is used to prepare flocculant, reducing water waste and production costs. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the acidic wastewater treatment system of this utility model;

[0024] In the diagram: 1. Premixing tank; 2. Reactor; 3. Acid treatment tank; 4. Flocculation reaction tank; 5. Evaporator; 6. Filter conveyor belt; 7. Product filter; 8. Reverse filter; 9. Alkali preparation tank; 10. Condenser; 11. Sulfuric acid inlet pipe; 12. Reactor temperature control coil; 13. Filter plate; 14. Rotating scraper; 15. Flocculant preparation tank; 16. Alkali preparation tank cooling jacket; 17. Temperature control pipe; 18. Condenser coil; 19. External recovery jacket; 20. Internal airflow channel; 21. Flocculant inlet pipe; 22. Connecting pipe. Detailed Implementation

[0025] To make the objectives and technical solutions of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0026] Example 1

[0027] like Figure 1 As shown, the acidic wastewater treatment system includes a premixing tank 1 and an alkali preparation tank 9. The premixing tank 1 is connected to a product filter 7 via a reaction vessel 2. The product filter 7 is connected to an acid treatment tank 3 via a reverse filter 8. The acid treatment tank 3 is connected to an evaporation vessel 5 via a flocculation reaction vessel 4. A filter conveyor belt 6 is connected to the evaporation vessel 5. The alkali preparation tank 9 is connected to the acid treatment tank 3 via a pipeline. A sulfuric acid inlet pipe 11 is connected to the top of the premixing tank 1, and a solid raw material inlet is provided on the premixing tank 1. The reaction vessel 2 is equipped with a reaction vessel temperature control coil 12. An alkali preparation tank cooling sleeve 16 is provided on the outside of the alkali preparation tank 9, and the alkali preparation tank cooling sleeve 16 is connected to the reaction vessel temperature control coil 12 via a temperature control pipe 17. The reverse filter 8 is equipped with a filter plate 13 inside, and a rotating scraper 14 driven by a drive motor is provided below the filter plate 13. The upper edge of the rotating scraper 14 is tangent to the lower edge of the filter plate 13. The filter plate 13 and rotating scraper 14 inside the reverse filter 8 work together to prevent the filter plate 13 from clogging, ensuring continuous and stable filtration and improving filtration efficiency. The evaporator 5 is connected to the condenser 10 above the internal airflow channel 20. The condenser 10 has a condenser coil 18 inside, and an outer recovery sleeve 19 is located outside the internal airflow channel 20. The outer recovery sleeve 19 is connected to the condenser 10 but not to the evaporator 5. The outer recovery sleeve 19 is connected to the flocculant preparation tank 15 via a connecting pipe 22. The flocculant preparation tank 15 is connected to the flocculation reaction tank 4 via the flocculant inlet pipe 21. The flocculation reaction tank 4 uses the flocculant to flocculate and precipitate impurities such as calcium sulfate, improving the calcium sulfate precipitation effect and reducing the impurity content of the product.

[0028] The above-mentioned acidic wastewater treatment system includes the following steps during operation:

[0029] (1) Solid raw materials are added to premix tank 1 through solid raw material inlet, while sulfuric acid flows into premix tank 1 through sulfuric acid inlet pipe 11. The stirring speed is set to 300 r / min, and the mixing time is controlled at 15 min to allow the solid raw materials to initially contact and react with sulfuric acid, removing some impurities. The premixed material enters reactor 2, and the reactor temperature control coil 12 is turned on to stabilize the temperature in reactor 2 at 60℃. The reaction time is 2 h to ensure that humic acid and sulfuric acid react fully. (2) The reacted material is initially filtered through product filter 7 to remove larger particulate impurities before entering reverse filter 8. The rotating scraper 14 in reverse filter 8 continuously scrapes impurities on filter plate 13 under the drive of the drive motor to prevent blockage. The filtered acid solution enters acid treatment tank 3, and the alkaline solution prepared in alkaline solution preparation tank 9 flows into acid treatment tank 3 at a flow rate of 20 L / min to carry out acid-base neutralization reaction and adjust the pH value of the acid solution to 7. (3) The material in the acid treatment tank 3 enters the flocculation reaction tank 4. The flocculation solution prepared in the flocculation solution preparation tank 15 using the condenser 10 is added to the flocculation reaction tank 4 through the flocculation solution inlet pipe 21 at a flow rate of 15 L / min. The stirring speed in the flocculation reaction tank 4 is 200 r / min, and the reaction time is 30 min, which promotes the full flocculation and precipitation of impurities such as calcium sulfate. The flocculated and precipitated material enters the evaporation kettle 5. The evaporation kettle 5 is heated to 90℃ to evaporate the water. The water vapor generated by evaporation enters the condenser 10 through the internal airflow channel 20 and is condensed into a liquid phase for recycling under the action of the condenser coil 18. The remaining material in the evaporation kettle 5 undergoes solid-liquid separation through the filter conveyor belt 6. The solid phase is the processed product, and the liquid phase is further processed.

Claims

1. An acid-containing wastewater treatment system, characterized by, The application relates to a production device for producing a product, which comprises a premixing tank (1), an alkali solution preparation tank (9), the premixing tank (1) is connected with a product filter (7) through a reaction kettle (2), the product filter (7) is connected with an acid solution treatment tank (3) through a reverse filter (8), the acid solution treatment tank (3) is connected with an evaporation kettle (5) through a flocculation reaction tank (4), the evaporation kettle (5) is connected with a filter conveying belt (6), and the alkali solution preparation tank (9) is connected with the acid solution treatment tank (3) through a pipeline.

2. The sour wastewater treatment system of claim 1, wherein, The premixing tank (1) is connected with a sulfuric acid inlet pipeline (11), the premixing tank (1) is provided with a solid raw material feeding port, and the reaction kettle (2) is internally provided with a reaction kettle temperature control coil pipe (12).

3. The sour water treatment system of claim 2, wherein, The alkali solution preparation tank (9) is externally provided with an alkali solution preparation tank cooling jacket (16), the alkali solution preparation tank cooling jacket (16) is connected with the reaction kettle temperature control coil pipe (12) through a temperature control pipeline (17).

4. The sour water treatment system of claim 1, wherein, The reverse filter (8) is internally provided with a filter plate (13), the filter plate (13) is provided below with a rotary scraper (14) driven by a driving motor, and the upper edge of the rotary scraper (14) is tangent to the lower edge of the filter plate (13).

5. The sour water treatment system of claim 1, wherein, The evaporation kettle (5) is connected above with a condensing recovery device (10) through an inner airflow channel (20), the condensing recovery device (10) is internally provided with a condensing recovery device coil pipe (18), and the outer side of the inner airflow channel (20) is provided with an outer recovery jacket (19).

6. The sour water treatment system of claim 5, wherein, The outer recovery jacket (19) is connected with the condensing recovery device (10) and does not communicate with the evaporation kettle (5).

7. The sour water treatment system of claim 5, wherein, The outer recovery jacket (19) is connected with a flocculation liquid preparation tank (15) through a connecting pipeline (22), and the flocculation liquid preparation tank (15) is connected with the flocculation reaction tank (4) through a flocculation liquid inlet pipeline (21).

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