Acid cleaning wastewater treatment device and method

Abstract

The invention relates to the technical field of industrial wastewater treatment, in particular to an acid cleaning wastewater treatment device and method.The device comprises a multi-layer rotational flow neutralizing tower, a self-adaptive inclined plate precipitation separation box and a combined rolling filter cartridge, and full-process intelligent regulation and control are achieved through a control system. 4-6 rotational flow reaction layers are arranged in the multi-layer rotational flow neutralization tower, each layer of spiral blade is of a three-dimensional curved surface structure and has variable screw pitches, the spiral directions of the adjacent layers are opposite, a neutralizer is sprayed by micropores at the tail end and is synergistically mixed with rotational flow centrifugal force, and the pH value of the wastewater is regulated and controlled to 6-8 within 30-60 seconds. The treatment method comprises the steps of real-time monitoring, rotational flow neutralization, self-adaptive precipitation and rolling filtration, the neutralization reaction efficiency is remarkably improved, meanwhile, the operation and maintenance cost is reduced, and the method is suitable for efficient acid wastewater treatment in the industries of metal surface treatment, electronic cleaning and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial wastewater treatment, in particular to an acidic cleaning wastewater treatment device and method. Background Art

[0002] In industrial production, acidic cleaning wastewater primarily originates from processes such as metal surface treatment, electronic component cleaning, and chemical raw material processing. Its typical characteristics include large fluctuations in water volume, extremely low pH values ​​(typically less than 3), high concentrations of suspended solids (SS), and the presence of heavy metal ions such as copper, nickel, and iron, as well as small amounts of organic pollutants. Direct discharge of this wastewater without proper treatment can not only corrode pipe networks and disrupt the acid-base balance of the water, but also lead to the accumulation of heavy metals in soil and organisms, posing a serious threat to the ecological environment and human health.

[0003] Traditional acidic wastewater treatment processes mostly use the "neutralization-sedimentation-filtration" process, in which there are significant technical bottlenecks in the neutralization process:

[0004] Neutralization reaction efficiency is low: it relies on flat stirring paddles or aeration mixing, the liquid-liquid contact area is limited, and the neutralizer (such as sodium hydroxide, calcium hydroxide) is not mixed evenly with the wastewater, resulting in a long reaction time (usually 5-10 minutes), high neutralizer consumption (excessive addition rate of 20%-30%), and local over-alkali easily generates hydroxide colloids, which increases the burden of subsequent precipitation.

[0005] With increasingly stringent environmental protection standards (such as the limit requirements for total copper, total nickel and other indicators in the "Electroplating Pollutant Emission Standard" GB21900-2008), the defects of traditional equipment in processing efficiency and cost control have become increasingly prominent, and there is an urgent need to improve processing efficiency through equipment structure innovation and intelligent control technology. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, a device and method for treating acidic cleaning wastewater are provided, which achieve efficient mixing through mechanical structure innovation, and solve the problem of low treatment efficiency of traditional devices.

[0007] The technical solution adopted by the present invention to solve the technical problem is: an acid cleaning wastewater treatment device, comprising a multi-layer cyclone neutralization tower, an adaptive inclined plate sedimentation separation box and a combined rolling filter cartridge connected in sequence from top to bottom, wherein the device realizes intelligent control of the entire process through a control system;

[0008] The multi-layer cyclone neutralization tower includes a neutralization tower body, the top and bottom of the neutralization tower body are respectively connected to a water inlet pipe and a transition connecting pipe, a hollow liquid guide cavity is provided inside the neutralization tower body, and is connected to a neutralization pipe, 4-6 cyclone reaction layers are provided in the neutralization tower body, each cyclone reaction layer includes a hollow blade support, the hollow blade support is connected to the inner wall of the neutralization tower body through an L-shaped support tube, and the L-shaped support tube connects the hollow blade support with the liquid guide cavity, the hollow blade support is evenly distributed with 6-8 spiral blades around the circumference, the spiral directions of the spiral blades of two adjacent layers are opposite, a micropore injection structure is provided at the end of the spiral blade, and the micropores are connected to the hollow blade support through a guide channel;

[0009] It also includes a support frame and a mounting seat. The support frame is fixed at the bottom of the neutralization tower body and is used to fix the neutralization tower body. The mounting seat is fixed at the bottom of the support frame and is used to connect external equipment.

[0010] Specifically, the spiral blade adopts a three-dimensional spiral curved surface structure, the angle between the spiral blade and the horizontal plane is 45°-60°, the pitch of the spiral blade decreases gradually from 200mm to 150mm along the axial direction of the neutralization tower body, the spiral blade is made of 316L stainless steel or polyvinylidene fluoride (PVDF), and the surface is sprayed with a nano-titanium dioxide super-hydrophilic coating, with a contact angle of <15°.

[0011] Specifically, the inclined plate in the adaptive inclined plate sedimentation separation box is connected to the side wall of the box through a hydraulic telescopic rod. A sludge concentration sensor is set below the inclined plate, and the sensor signal output end is electrically connected to the control end of the hydraulic telescopic rod;

[0012] The adaptive inclined plate settling and separation box's inclined plate angle automatically adjusts based on the sludge concentration sensor signal, with an adjustment range of 30°-60°. A conical sludge collection hopper is located at the bottom of the box, connected to a sludge discharge pipe with an electric sludge discharge valve. This valve (model: Z41H-16C) is linked to the sludge concentration sensor and automatically opens when the sludge in the hopper reaches half the bucket depth. A single sludge discharge takes 1-3 minutes, and the sludge moisture content is ≤90%, preventing long-term sludge retention and the resulting resolubility.

[0013] Specifically, the combined rolling filter cartridge is composed of 3-5 nested filter cartridges of different pore sizes, which are mounted on the equipment bracket through a bearing seat and driven by a motor to roll axially;

[0014] The filter cartridge pore sizes of the combined rolling filter cartridge are 500 μm, 200 μm, 50 μm and 10 μm from the inside to the outside, the motor drive speed is 0.5-2 revolutions per minute, and a transparent observation window is provided on the outer shell.

[0015] A method for treating acidic cleaning wastewater comprises the following steps:

[0016] Real-time monitoring: The flow sensor and pH sensor installed on the water inlet pipe obtain wastewater parameters, and the control system calculates and adjusts the amount of neutralizer added;

[0017] Cyclone neutralization: The wastewater is mixed with the neutralizer in the multi-layer cyclone neutralization tower by the centrifugal force generated by the spiral blades, and the pH value is initially adjusted to 6-8 within 30-60 seconds;

[0018] Adaptive sedimentation: After neutralization, the wastewater flows into the adaptive inclined plate sedimentation separation box. The inclined plate angle is dynamically adjusted according to the sludge concentration sensor data. The sedimentation time is 15-30 minutes.

[0019] Rolling filtration: The supernatant enters the combined rolling filter cartridge and is intercepted by filters of different pore sizes. The clean water meets the standards for discharge or reflux treatment. The clean water after filtration is tested in real time by an online turbidity meter (model: HACH2100Q). When the turbidity is greater than 10NTU, the solenoid valve of the reflux pipe (model: VQZ312) automatically opens to return the wastewater to the neutralization tower for reprocessing. The detection cycle is once every 2 minutes.

[0020] Specifically, in the vortex neutralization step, the neutralizer is transported in sequence through the neutralization tube, the liquid guide cavity, the L-shaped support tube, and the hollow blade bracket, and is sprayed out from the micropores through the internal guide channel of the spiral blade. The micropore diameter of the micropore injection structure is 0.5-1mm, evenly distributed along the spiral direction of the spiral blade, with a spacing of 10-15mm. The injection direction is consistent with the tangential direction of the blade, and the two adjacent layers of blades form a counter-vortex to enhance mixing.

[0021] Beneficial effects of the present invention:

[0022] Three-dimensional variable-pitch spiral blades enhance mixing: 4-6 layers of three-dimensional curved blades with opposite spiral directions are used to create a "counter-swirl" effect, which causes high-intensity turbulence in the wastewater in a short period of time. The liquid-liquid contact area is increased compared to traditional mixing, and the neutralization reaction time is shortened. The pitch decreases gradually from 200mm at the top of the tower to 150mm at the bottom of the tower, forcing the water swirl velocity to increase axially, further enhancing the mixing intensity in the high-concentration neutralization area in the lower layer, improving the utilization rate of the neutralizer, and reducing the neutralizer consumption in the wastewater. The microporous injection structure at the end of the spiral blade sprays the neutralizer in a tangential direction, synergizing with the centrifugal force of the swirl to achieve "shear-entrainment" efficient mixing of the neutralizer atomization and the wastewater, avoiding local oversaturation.

[0023] Structural innovation reduces operation and maintenance costs: Super hydrophilic coating and self-cleaning design. The nano-titanium dioxide coating on the surface of the spiral blades significantly reduces the adhesion of precipitates such as CaSO4 and Fe(OH)3. Combined with the 5°-8° self-cleaning inclination angle, the amount of solid residue on the blade surface is reduced, and the frequency of manual cleaning is reduced.

[0024] In summary, the present invention has achieved significant breakthroughs in treatment efficiency, neutralizer consumption, automation level and operation and maintenance costs, providing an efficient and reliable technical solution for the stable and standard-compliant treatment of acidic industrial wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described below with reference to the accompanying drawings and examples.

[0026] Figure 1 This is a schematic structural diagram of a multi-layer cyclone neutralization tower in the acidic cleaning wastewater treatment device provided by the present invention;

[0027] Figure 2 This is a cross-sectional view of a multi-layer cyclone neutralization tower in the acidic cleaning wastewater treatment device provided by the present invention.

[0028] In the figure: 1. Neutralization tower body; 2. Water inlet pipe; 3. Transition connecting pipe; 4. Support frame; 5. Mounting seat; 6. Neutralization pipe; 7. Liquid guide cavity; 8. L-shaped support pipe; 9. Hollow blade bracket; 10. Spiral blade. DETAILED DESCRIPTION

[0029] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific implementation methods.

[0030] like Figure 1-Figure 2 As shown, the multi-layer cyclone neutralization tower of the present invention includes:

[0031] The three-dimensional spiral surface structure adopts variable pitch spiral blades. The cross section of the spiral blades is a streamlined arc (wide at the leading edge and narrow at the trailing edge). The radius of curvature gradually increases along the radial direction, forming a spiral channel that is wide at the top and narrow at the bottom.

[0032] The inclination angle of the spiral blades is 45°-60° (preferably 55°) to the horizontal plane. This angle can ensure that the wastewater generates a strong vortex while avoiding a sharp increase in water flow resistance due to an excessively large angle.

[0033] The thickness of the spiral blade is 3-5mm, made of corrosion-resistant 316L stainless steel or polyvinylidene fluoride (PVDF), and the edge is rounded (R=2-3mm) to reduce water impact wear.

[0034] The spiral blades are staggered in multiple layers, with 6-8 blades arranged in each swirl reaction layer, evenly distributed along the circumference of the tower body. The spiral directions of the blades in the two adjacent layers are opposite (clockwise for the upper layer and counterclockwise for the lower layer), forming a "counter-swirl" to enhance the degree of liquid turbulence. The hollow blade bracket 9 of each swirl reaction layer is detachably connected to the inner wall of the neutralization tower body 1 through the L-shaped support tube 8, and is fixed with bolts to facilitate maintenance and replacement of blades; the vertical spacing between the two adjacent layers of blades can be flexibly adjusted within the range of 300-500mm by adjusting the length of the L-shaped support tube to adapt to different treatment flow rates (such as flow rate ≥100m 3 / h, the layer spacing is 300mm; flow rate ≤ 50m 3 / h, the layer spacing is 500mm).

[0035] The vertical spacing between two adjacent layers of blades is 300-500mm, which is adjusted according to the processing flow rate. The larger the flow rate, the smaller the layer spacing to ensure the stability of the swirl.

[0036] The blades are hollow for flow diversion, with a flow channel inside that connects to the annular nozzle. Neutralizer is injected through the port at the root of the blade and ejected through the internal channel from the micropores (0.5-1mm in diameter) at the end of the blade. The micropores are preferably 0.8mm in diameter and 12mm apart. The injection direction is at an angle of 15° to the blade tangent, ensuring that the neutralizer and swirling wastewater are mixed at a 45-degree angle, enhancing liquid-liquid mass transfer efficiency.

[0037] The micropores are evenly distributed along the spiral direction of the blade with a spacing of 10-15mm. The spray direction is consistent with the tangential direction of the blade, and the swirl kinetic energy is used to reduce the energy consumption of neutralizer atomization.

[0038] The pitch changes gradually, and the blade pitch decreases gradually from the top to the bottom of the tower (the upper pitch is 200mm, and the lower pitch is 150mm), so that the wastewater vortex speed increases along the axial direction of the tower body, and the mixing intensity of the high-concentration neutralization area in the lower layer is enhanced.

[0039] The super-hydrophilic coating, a nano-titanium dioxide (TiO2) coating sprayed on the blade surface, has a contact angle of less than 15°, reducing the adhesion of precipitates generated by neutralization reactions (such as CaSO4 and Fe(OH)3) and reducing the frequency of manual cleaning. The nano-titanium dioxide (TiO2) coating is produced using magnetron sputtering, with a thickness of 5-10μm. After sintering at 500°C, it forms a dense structure with a measured contact angle of ≤12°. Its adhesion resistance to precipitates such as CaSO4 and Fe(OH)3 is increased by over 60% compared to traditional coatings.

[0040] The self-cleaning inclination angle is 5°-8° larger between the inner side of the blade and the central axis of the tower body than the outer side, and the centrifugal force is used to make the attached solid particles automatically slide to the sludge collection area at the bottom of the tower.

[0041] During use: Incoming water is monitored and intelligently controlled in real time. Before entering the equipment, the acidic cleaning wastewater is monitored for flow and pH in real time via a flow sensor and pH sensor at the water inlet. The flow sensor uses an electromagnetic flowmeter (model: E+HPromagH, measurement accuracy ±0.5%), and the pH sensor uses a Mettler Toledo InPro3250 (response time <10 seconds). The control system hardware is a Siemens PLCS7-1200 equipped with a customized PID algorithm. The neutralizer dosage is adjusted in steps of 0.1 L / min, and data is transmitted to the control system. Based on a preset program and real-time monitoring data, the control system calculates and controls the opening degree of the electric regulating valve at the outlet of the neutralizer storage tank to ensure that the neutralizer is mixed with the wastewater in a precise proportion.

[0042] The highly efficient cyclonic neutralization reaction involves wastewater entering the neutralization tower body 1 through the water inlet pipe 2 at the top of the tower. Under the action of spiral blades 10, it rapidly descends in a spiral shape. Neutralizer is pumped into the liquid guide cavity 7 by the neutralization pipe 6 and transported along the L-shaped support pipe 8 and hollow blade bracket 9 to each spiral blade 10. Microporous injection structures at the ends of each layer of spiral blades 10 simultaneously spray neutralizer. Under the centrifugal force of the cyclonic flow, the wastewater and neutralizer are instantly and thoroughly mixed, causing a neutralization reaction. A high-precision pH sensor is installed at the water outlet at the bottom of the tower to monitor the pH value of the effluent in real time. Feedback is provided to the control system to dynamically adjust the neutralizer flow rate to ensure that the wastewater pH value reaches the initial control range of 6-8. The entire neutralization reaction process is completed efficiently and in a short period of time.

[0043] Intelligent sedimentation and separation: Neutralized wastewater flows through a transition pipe into the adaptive inclined plate sedimentation and separation tank. A sludge concentration sensor at the bottom of the sedimentation zone monitors sludge concentration in real time (sensor model: SC200, measurement range 0-20,000 mg / L). This data is transmitted to the control system every 5 seconds. When the sludge concentration exceeds 15,000 mg / L, a hydraulic telescopic boom adjusts the inclined plate angle to 60° within 30 seconds. When the concentration is less than 5,000 mg / L, the angle automatically adjusts to 30°, with an adjustment accuracy of ±2°. When the sludge concentration exceeds the set upper limit, the control system controls the hydraulic telescopic boom to increase the inclined plate angle to 50-60 degrees, accelerating sludge descent. When the sludge concentration falls below the set lower limit, the angle decreases to 30-40 degrees, extending sludge settling time and improving sedimentation efficiency. The settling time is dynamically adjusted by the control system within 15-30 minutes based on wastewater flow and water quality. The supernatant after sedimentation flows through the overflow weir and enters the combined roller filter cartridge below.

[0044] Stable rolling filtration and purification: the supernatant enters the inner cylinder of the combined rolling filter cartridge, and the motor is turned on to drive the filter cartridge to roll. During the rolling process, impurities in the wastewater are intercepted by filter screens of different apertures in turn. By regularly adjusting the motor speed and reverse rotation, the filter screen is effectively prevented from clogging. A differential pressure sensor (model: DP100) is installed on the inside of the transparent observation window (material: tempered glass, thickness 5mm). When the internal and external pressure difference is greater than 5kPa, the control system automatically starts the motor to rotate in the opposite direction (speed 1 rpm, for 5 minutes), and cooperates with the spray device to rinse the filter screen. The rinse water returns to the multi-layer cyclone neutralization tower through the return pipe for reprocessing. The filtered clean water flows out from the side outlet of the outermost filter cartridge and is reused in the cleaning process or discharged after testing to meet the standards. If the test does not meet the standards, it returns to the multi-layer cyclone neutralization tower through the return pipe for reprocessing.

[0045] Example: Treatment of acidic wastewater from a certain electroplating plant (pH = 2.5, SS = 300 mg / L, Cu 2 + = 50 mg / L), and the neutralizing agent is NaOH solution (concentration 10%):

[0046] Cyclone neutralization: The control system dynamically adds neutralizer according to the real-time pH value. The wastewater stays in the tower for 30 seconds and the pH value rises to 7.2.

[0047] Adaptive sedimentation: The initial angle of the inclined plate is 45°, which automatically adjusts to 55° when the sludge concentration rises to 12,000 mg / L. After 15 minutes of sedimentation, the supernatant SS drops to 50 mg / L.

[0048] Rolling filtration: The filter cartridge runs at 1 rpm, and the turbidity of the effluent is stable at 5 NTU, Cu 2 +Concentration < 0.5mg / L, meeting the limit requirements of "Electroplating Pollutant Emission Standard" GB21900-2008.

[0049] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above-described embodiments. The above-described embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An acidic cleaning wastewater treatment device comprising a multi-layer cyclone neutralization tower, an adaptive inclined plate sedimentation separation box, and a combined rolling filter cartridge connected sequentially from top to bottom. The device achieves full-process intelligent control through a control system, characterized in that: The multi-layer cyclone neutralization tower comprises a neutralization tower body (1), the top and bottom of the neutralization tower body (1) are respectively connected to a water inlet pipe (2) and a transition connecting pipe (3), a hollow liquid guide cavity (7) is provided inside the neutralization tower body (1), and is connected to a neutralization pipe (6), 4-6 cyclone reaction layers are provided inside the neutralization tower body (1), each cyclone reaction layer comprises a hollow blade support (9), the hollow blade support (9) is connected to the inner wall of the neutralization tower body (1) through an L-shaped support tube (8), and the L-shaped support tube (8) connects the hollow blade support (9) with the liquid guide cavity (7), 6-8 spiral blades (10) are evenly distributed around the circumference of the hollow blade support (9), the spiral directions of the spiral blades (10) of two adjacent layers are opposite, a micropore injection structure is provided at the end of the spiral blade (10), and the micropores are connected to the hollow blade support (9) through a guide channel; It also includes a support frame (4) and a mounting seat (5), wherein the support frame (4) is fixed to the bottom of the neutralization tower body (1) and is used to fix the neutralization tower body (1), and the mounting seat (5) is fixed to the bottom of the support frame (4) and is used to connect external equipment.

2. The acidic cleaning wastewater treatment device and method according to claim 1, characterized in that: The spiral blade (10) adopts a three-dimensional spiral curved surface structure, the angle between the spiral blade (10) and the horizontal plane is 45°-60°, the pitch of the spiral blade (10) decreases gradually from 200 mm to 150 mm along the axial direction of the neutralization tower body (1), the spiral blade (10) is made of 316L stainless steel or polyvinylidene fluoride, and the surface is sprayed with a nano-titanium dioxide super-hydrophilic coating, with a contact angle of less than 15°.

3. The acidic cleaning wastewater treatment device and method according to claim 1, characterized in that: The inclined plate in the adaptive inclined plate sedimentation separation box is connected to the side wall of the box through a hydraulic telescopic rod. A sludge concentration sensor is set below the inclined plate, and the signal output end of the sensor is electrically connected to the control end of the hydraulic telescopic rod. The inclination angle of the inclined plate of the adaptive inclined plate sedimentation separation box is automatically adjusted according to the sludge concentration sensor signal, and the adjustment range is 30°-60°. A conical sludge collection bucket is set at the bottom of the box, and the bottom of the bucket is connected to a sludge discharge pipe with an electric sludge discharge valve.

4. The acid cleaning wastewater treatment device and method according to claim 1, characterized in that: The combined rolling filter cartridge is composed of 3-5 nested filter cartridges with different pore sizes. The filter cartridge is mounted on the equipment bracket through a bearing seat and is driven by a motor to roll axially. The filter cartridge pore sizes of the combined rolling filter cartridge are 500 μm, 200 μm, 50 μm and 10 μm from the inside to the outside, the motor drive speed is 0.5-2 revolutions per minute, and a transparent observation window is provided on the outer shell.

5. A method for treating acidic cleaning wastewater based on the device according to any one of claims 1 to 4, characterized in that: The following steps are involved: Real-time monitoring: The wastewater parameters are obtained through the flow sensor and pH sensor provided on the water inlet pipe (2), and the control system calculates and adjusts the amount of the neutralizer added; Cyclone neutralization: The wastewater is mixed with the neutralizer in the multi-layer cyclone neutralization tower by the centrifugal force generated by the spiral blades (10), and the pH value is initially adjusted to 6-8 within 30-60 seconds; Adaptive sedimentation: After neutralization, the wastewater flows into the adaptive inclined plate sedimentation separation box. The inclined plate angle is dynamically adjusted according to the sludge concentration sensor data. The sedimentation time is 15-30 minutes. Rolling filtration: The supernatant enters the combined rolling filter cartridge and is intercepted by filters of different pore sizes. The clean water meets the standards for discharge or reflux treatment.

6. The method for treating acidic cleaning wastewater according to claim 5, wherein: In the vortex neutralization step, the neutralizer is sequentially transported through the neutralization tube (6), the liquid guide cavity (7), the L-shaped support tube (8), and the hollow blade bracket (9), and is ejected from the micropores through the internal guide channel of the spiral blade (10). The micropores of the micropore injection structure have a diameter of 0.5-1 mm and are evenly distributed along the spiral direction of the spiral blade (10) with a spacing of 10-15 mm. The injection direction is consistent with the tangential direction of the blade, and two adjacent layers of blades form a counter-vortex to enhance mixing.

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