A high-efficiency aeration device for acidic mine wastewater

Abstract

This utility model belongs to the technical field of mining wastewater treatment equipment, and discloses a high-efficiency aeration device for acidic mining wastewater. The device includes an inlet cylindrical section, a conical contraction section, a cylindrical throat, a conical diffusion section, an outlet cylindrical section, an air inlet pipe, and a micro-orifice section. All liquid flow components are coaxially connected sequentially. The air inlet pipe connects to the micro-orifice section with micro-holes and penetrates the sidewall of the cylindrical throat. It utilizes the Venturi effect to create negative pressure at the throat to draw in air, achieving efficient gas-liquid mixing through the micro-orifice section. Furthermore, the inner walls of each liquid flow component are coated with polytetrafluoroethylene (PTFE) for acid corrosion resistance. This device solves the problems of low gas-liquid mixing efficiency and poor corrosion resistance in traditional aeration devices. It is suitable for the pretreatment aeration stage of acidic mining wastewater and has the advantages of high efficiency, acid resistance, and compact structure.

Description

Technical Field

[0001] This utility model belongs to the technical field of mining wastewater treatment equipment, specifically relating to a high-efficiency aeration device for acidic mining wastewater. Background Technology

[0002] Acidic mine wastewater (AMD) is a typical polluted wastewater generated during mining operations. It contains high concentrations of heavy metal ions (such as Fe2+). 2+ Mn 2+ The presence of Fe(II), sulfates, and low pH levels in acidic mine wastewater can cause serious pollution to soil and water bodies if directly discharged. Aeration is a crucial step in the pretreatment of acidic mine wastewater, as it can remove Fe(II) from the water. 2+ Oxidized to Fe 3+ This creates conditions for subsequent neutralization precipitation and heavy metal removal.

[0003] Existing aeration devices mostly employ mechanical aeration or simple blower aeration, which suffer from low gas-liquid mixing efficiency, poor acid corrosion resistance, and high energy consumption. Mechanical aeration equipment is complex and easily damaged by acidic wastewater corrosion; simple blower aeration, on the other hand, suffers from low oxidation efficiency due to large bubble size and insufficient contact with water. Therefore, there is an urgent need for an aeration device that can efficiently achieve gas-liquid mixing and is resistant to acid corrosion to meet the treatment requirements of acidic mining wastewater. Utility Model Content

[0004] Therefore, the purpose of this utility model is to provide a high-efficiency aeration device for acidic mine wastewater, which aims to solve the defects of existing acidic mine wastewater aeration devices, such as low gas-liquid mixing efficiency and poor corrosion resistance.

[0005] To achieve the aforementioned objectives of this utility model, the technical solution adopted is as follows: A high-efficiency aeration device for acidic mine wastewater includes an inlet cylindrical section, a conical contraction section, a cylindrical throat, a conical diffusion section, an outlet cylindrical section, an air inlet pipe, and a micro-orifice section. The inlet cylindrical section, conical contraction section, cylindrical throat, conical diffusion section, and outlet cylindrical section are coaxially connected sequentially to form a continuous flow path for the acidic mine wastewater. Water enters through the inlet cylindrical section, accelerates in the conical contraction section, creates negative pressure in the cylindrical throat, and then decelerates and stabilizes in the conical diffusion section before exiting through the outlet cylindrical section. The air inlet pipe connects to the micro-orifice section to form a gas channel, and the other end of the micro-orifice section penetrates the sidewall of the cylindrical throat, communicating with the internal channel of the cylindrical throat. The micro-orifice section is positioned within the negative pressure zone generated by the Churi effect in the cylindrical throat, utilizing the negative pressure to draw in air without additional blowing. The tiny orifices disperse the air into fine streams, which are then thoroughly mixed with the high-speed water flow.

[0006] As a further improvement of this utility model, in order to enhance acid corrosion resistance, the inner walls of the inlet cylindrical section, the conical contraction section, the cylindrical throat, the conical diffusion section, and the outlet cylindrical section are all coated with a layer of polytetrafluoroethylene, which can withstand the strong corrosive environment of acidic mine wastewater (pH 1.5-6.0).

[0007] As a further improvement of this utility model, the contraction angle of the conical contraction section is 15°-30° to achieve efficient acceleration of water flow.

[0008] As a further improvement of this utility model, the expansion angle of the conical diffusion section is 10°-20°, which makes the water flow slow down smoothly.

[0009] As a further improvement of this utility model, the ratio of the inner diameter of the inlet cylindrical section to the inner diameter of the cylindrical throat is 2-5, ensuring that the Venturi effect generates sufficient negative pressure to draw in air.

[0010] As a further improvement of this utility model, the micro-hole segment is a tubular structure with several micro-holes. The beneficial effects of this utility model are: 1. High-efficiency gas-liquid mixing: By utilizing the Venturi effect to create negative pressure in the cylindrical throat, air can be drawn in without additional blower equipment, achieving miniaturization. This not only reduces investment costs but also significantly reduces energy consumption and operating costs. The tiny pores in the micro-orifice disperse the air into fine streams, which mix violently with the high-speed water flow, greatly improving the gas-liquid contact area and oxidation efficiency.

[0011] 2. Excellent corrosion resistance: The acid-resistant design of the polytetrafluoroethylene layer can withstand all strong acids, strong alkalis, and strong oxidants, and does not react with various organic solvents. It can withstand the corrosion of acidic mine wastewater for a long time, extend the service life of the equipment, and reduce maintenance costs.

[0012] 3. Compact and efficient structure: The device adopts a coaxially connected Venturi tube structure, which is compact in layout, adaptable to the site restrictions of mine wastewater treatment, and has low energy consumption and stable operation.

[0013] 4. Simple operation and convenient maintenance: Compared with traditional aeration devices, this aeration device can reduce energy consumption by more than 30% under the same operating conditions, significantly reducing operating costs. Due to its design principle, the device is almost never clogged, and installation and maintenance are relatively simple and convenient, reducing the complexity and cost of maintenance. Attached Figure Description

[0014] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings: Figure 1This is a schematic diagram of the structure of this utility model.

[0015] In the diagram: 1. Inlet cylindrical section; 2. Conical contraction section; 3. Cylindrical throat; 4. Conical diffuser section; 5. Outlet cylindrical section; 6. Inlet pipe; 7. Micro-orifice section. Detailed Implementation

[0016] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0017] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0018] like Figure 1 As shown, a high-efficiency aeration device for acidic mine wastewater includes an inlet cylindrical section 1, a conical contraction section 2, a cylindrical throat 3, a conical diffuser section 4, an outlet cylindrical section 5, an air inlet pipe 6, and a micro-orifice section 7. The inlet cylindrical section 1, conical contraction section 2, cylindrical throat 3, conical diffuser section 4, and outlet cylindrical section 5 are coaxially connected in sequence to form a continuous flow path for acidic mine wastewater. After the water flows into the inlet cylindrical section 1, it is accelerated in the conical contraction section 2, a negative pressure is formed in the cylindrical throat 3, and then it is decelerated and stabilized in the conical diffuser section 4 before being discharged from the outlet cylindrical section 5. The air intake pipe 6 is connected to the micro-perforated segment 7 to form a gas channel. The micro-perforated segment 7 is a tubular structure with several micro-holes. The other end of the micro-perforated segment 7 penetrates the side wall of the cylindrical throat 3 and communicates with the internal channel of the cylindrical throat 3. The micro-perforated segment 7 is located in the negative pressure zone generated by the Churley effect in the cylindrical throat 3. Air can be drawn in without additional blowing by utilizing the negative pressure. The micro-holes disperse the air into fine streams, which are fully mixed with the high-speed water flow.

[0019] To improve acid corrosion resistance, the inner walls of the inlet cylindrical section 1, the conical contraction section 2, the cylindrical throat 3, the conical diffusion section 4, and the outlet cylindrical section 5 are all coated with a layer of polytetrafluoroethylene (PTFE). PTFE has extremely high chemical inertness and can resist the erosion of various strong acids, strong alkalis, and organic solvents, thus performing excellently in the treatment of acidic mine wastewater.

[0020] In this embodiment, the inlet cylindrical section 1 is a straight cylindrical tube, the diameter of the conical contraction section 2 gradually decreases to a conical shape, the cylindrical throat 3 is a straight cylindrical tube, and the diameter of the conical diffusion section 4 gradually increases from the diameter of the cylindrical throat 3 to the diameter of the outlet cylindrical section 5, which is also a straight cylindrical tube. The cylindrical throat 3 is equipped with an air inlet pipe 6 and a micro-orifice section 7. This embodiment utilizes the pressure change of the venturi tube to generate negative pressure, causing air to be drawn in through the air inlet pipe 6 and the micro-orifice section 7, accelerating gas-liquid mixing and generating bubbles along the flow direction. More microbubbles are generated through the cylindrical throat 3, achieving rapid aeration.

[0021] After pretreatment, the acidic mine wastewater is pressurized by a pump and enters the inlet cylindrical section 1 and the conical contraction section 2. Then, it passes through the cylindrical throat 3 to generate negative pressure, which attracts air into the system through the micro-hole section 7. The negative pressure effect allows the air to be drawn in and sent to the subsequent treatment process.

[0022] The cylindrical throat 3 is the narrowest part of the Venturi bubble generator. Due to the narrowing space, air and water merge to form a high-speed flowing mixture. The rapid increase in flow velocity leads to a decrease in pressure, thereby increasing the bubble breakage rate and probability. This helps to increase the gas-liquid contact area and enhance aeration efficiency.

[0023] The conical diffuser section 4 is the expansion part of the Venturi bubble generator, used to slow down the flow rate and further disperse and break up the bubbles, ensuring that more oxygen in the air can be evenly distributed throughout the water body, further accelerating the aeration efficiency.

[0024] The outlet cylindrical section 5 is a circular channel that carries the aerated acidic mine wastewater through the next treatment system for further processing.

[0025] The contraction angle of the conical contraction section 2 is 15°-30° to achieve efficient acceleration of the water flow.

[0026] The expansion angle of the conical diffuser section 4 is 10°-20°, which makes the water flow slow down smoothly.

[0027] The ratio of the inner diameter of the inlet cylindrical section 1 to the inner diameter of the cylindrical throat 3 is 2-5, ensuring that the Venturi effect generates sufficient negative pressure to draw in air.

[0028] The micropores on the micropore segment 7 have a diameter of 50μm to 200μm, and the micropores are evenly distributed along the circumference of the micropore segment 7 with a spacing of 1mm to 3mm.

[0029] First, the acidic mine wastewater undergoes pretreatment by adding appropriate chemical reagents to adjust its pH value to a suitable treatment range. Then, physical methods, such as sedimentation, are used to treat the wastewater, removing precipitable suspended solids, heavy metal ions, and other pollutants. Subsequent treatment steps are then performed, and biochemical methods can be employed, utilizing sulfuric acid-reducing bacteria to remove sulfides and heavy metals from the AMD (acid-dependent mineral wastewater). Finally, a pressure pump forces the pretreated acidic mine wastewater into a high-efficiency aeration device based on a Venturi tube, specifically relating to this invention.

[0030] This device utilizes the Venturi effect for rapid gas mixing and aeration, and its working principle is based on Bernoulli's law in fluid mechanics. When air passes through the narrow section (throat) of the Venturi tube, the flow velocity increases, leading to a decrease in pressure. This creates a vacuum at the inlet, drawing in air and breaking it into tiny bubbles, increasing the air-liquid contact area and accelerating aeration efficiency. When acidic mine wastewater passes through the cylindrical throat 3, due to the increased velocity and decreased pressure (the inlet pressure is lower than atmospheric pressure), air is drawn in through the air inlet pipe 6 and the micro-orifice section 7. The air is rapidly broken into tiny bubbles, which make full contact with the water, increasing the gas-liquid contact area and improving aeration efficiency.

[0031] In operation, wastewater (AMD) pumped from the pump enters the cylindrical throat 3 through the inlet cylindrical section 1. As the pipe passes through the conical contraction section 2, the pipe diameter gradually decreases, and the flow velocity gradually increases. The high-speed water flow creates negative pressure as it passes through the cylindrical throat 3. This negative pressure causes air to be drawn into the cylindrical throat 3 through the air inlet pipe 6 and the micro-orifice section 7, where it mixes with the pretreated acidic mining wastewater. The gas-liquid mixture is then discharged through the conical diffusion section 4. Due to the gradually increasing surface area, its velocity decreases, and its pressure increases, forming a powerful jet stream that agitates and oxygenates the acidic mining wastewater, turning it into fine bubbles. This facilitates the rapid dissolution of oxygen in the water. The increased dissolved oxygen concentration alters the oxidation-reduction potential of the water, which is beneficial for the neutralization of pollutants in the acidic mining wastewater. After aeration, the acidic mining wastewater flows into the next treatment system through the outlet cylindrical section 5.

[0032] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, component disassembly or combination, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A high-efficiency aeration device for acidic mine wastewater, characterized in that: It includes an inlet cylindrical section, a conical contraction section, a cylindrical throat, a conical diffusion section, an outlet cylindrical section, an intake pipe, and a micro-orifice section. The inlet cylindrical section, conical contraction section, cylindrical throat, conical diffusion section, and outlet cylindrical section are connected coaxially in sequence. The intake pipe is connected to the micro-orifice section to form a gas channel, and the other end of the micro-orifice section penetrates the side wall of the cylindrical throat and communicates with the internal channel of the cylindrical throat. The micro-orifice section is located within the negative pressure zone generated by the Churley effect in the cylindrical throat.

2. The high-efficiency aeration device for acidic mine wastewater according to claim 1, characterized in that: The inner walls of the inlet cylindrical section, the conical contraction section, the cylindrical throat, the conical diffusion section, and the outlet cylindrical section are all coated with a layer of polytetrafluoroethylene.

3. The high-efficiency aeration device for acidic mine wastewater according to claim 1, characterized in that: The contraction angle of the conical contraction section is 15°-30°.

4. The high-efficiency aeration device for acidic mine wastewater according to claim 1, characterized in that: The expansion angle of the conical diffusion section is 10°-20°.

5. The high-efficiency aeration device for acidic mine wastewater according to claim 1, characterized in that: The ratio of the inner diameter of the inlet cylindrical section to the inner diameter of the cylindrical throat is 2-5.

6. The high-efficiency aeration device for acidic mine wastewater according to claim 1, characterized in that: The micro-perforated segment is a tubular structure with several tiny holes.

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