Gas-entrained droplet removal device and method for desulfurization wastewater concentration systems

Abstract

The application discloses a desulfurization wastewater concentration system carrier wet gas phase mist droplet removal device, which comprises a separation cylinder, a demister, a first treatment zone and a second treatment zone. A carrier wet gas phase inlet is arranged at the bottom of the separation cylinder, and a purified gas phase outlet is arranged at the top of the separation cylinder. The carrier wet gas phase flows from bottom to top in the separation cylinder. The first treatment zone comprises a low-frequency sound source device, which is arranged at the lower part of the separation cylinder and above the carrier wet gas phase inlet. The low-frequency sound source device emits first sound wave fields to the separation cylinder to make liquid droplets coagulate. The demister is arranged above the first treatment zone. The second treatment zone is arranged in the area where the demister is arranged. The second treatment zone comprises a high-frequency sound source device, which is arranged on the side wall of the separation cylinder and beside the demister. The high-frequency sound source device increases the collision probability of submicron liquid droplets and the demister. The desulfurization wastewater concentration system carrier wet gas phase mist droplet removal device provided by the application realizes deep removal of mist droplets through the cooperation and coupling of sound waves and the demister.

Description

Technical Field

[0001] This invention relates to the field of high-salt wastewater treatment and gas-liquid separation technology, and particularly to a device and method for removing wet gas-phase droplets from a desulfurization wastewater concentration system. Background Technology

[0002] Desulfurization wastewater from coal-fired power plants is characterized by high hardness and high salinity. Currently, mainstream concentration technologies mainly employ multi-effect evaporation concentration, air-borne humidification evaporation concentration, or low-temperature flue gas concentration. During the vapor-liquid separation process, the humidified gas phase inevitably entrains some fine droplets, resulting in droplet entrainment. Since the droplets generated after high-rate concentration of desulfurization wastewater contain high concentrations of chloride and sulfate ions, even a small amount of entrained droplets can lead to high chloride or total dissolved solids levels in the subsequent condensate, severely degrading the condensate quality and hindering its high-quality reuse. Currently, desulfurization wastewater concentration systems commonly use wire mesh, baffle, or ridge-type demisters to purify the humidified gas phase; however, the removal efficiency of submicron droplets (below five micrometers) through inertial collision is generally significantly reduced. This is because submicron droplets have extremely small mass and an inertial parameter far less than one, making it difficult for them to escape the airflow and impact the collection surface. Consequently, a large number of high-salt droplets penetrate the demister and enter the downstream condensation system. Acoustic agglomeration technology, as an auxiliary means of aerosol purification, suffers from extremely low agglomeration efficiency due to the small inertial parameters of droplets in the submicron size range, making it difficult for them to collide effectively in the sound field. Consequently, existing demisters are inefficient at capturing submicron high-salt droplets, leading to deterioration of condensate water quality. Furthermore, existing acoustic agglomeration technology has low agglomeration efficiency for submicron droplets and lacks synergistic coupling with demisters, making it impossible to achieve deep droplet removal. Summary of the Invention

[0003] This invention is based on the inventor's discoveries and understanding of the following facts and problems: Current methods for removing mist droplets have low efficiency.

[0004] The present invention aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, embodiments of the present invention propose a wet gas phase droplet removal device for a desulfurization wastewater concentration system, comprising a separation cylinder, a demister, a primary treatment zone, and a secondary treatment zone. The separation cylinder has a wet gas phase inlet at its bottom and a purified gas phase outlet at its top. The wet gas phase flows upward within the separation cylinder. The primary treatment zone includes a low-frequency sound source device located at the bottom of the separation cylinder and above the wet gas phase inlet. The low-frequency sound source device emits a first sound wave field towards the separation cylinder to cause droplet aggregation. The demister is located above the primary treatment zone and is used to capture droplets in the wet gas phase. The secondary treatment zone is located in the area where the demister is located. The secondary treatment zone includes a high-frequency sound source device located on the side wall of the separation cylinder and beside the demister. The high-frequency sound source device emits a second sound wave field towards the demister to increase the collision probability between submicron droplets and the demister.

[0006] The desulfurization wastewater concentration system's humidified gas phase droplet removal device according to an embodiment of the present invention achieves deep droplet removal through the synergistic coupling of acoustic waves and a demister. By leveraging the mechanistic coupling of dual-stage acoustic waves and the demister, deep removal of humidified gas phase droplets is achieved, significantly improving the quality of downstream condensate and effectively alleviating demister clogging and scaling. This device is suitable for processes such as multi-effect evaporation of desulfurization wastewater, air-based humidified evaporation, and low-temperature flue gas concentration.

[0007] In some embodiments, the low-frequency sound source devices are multiple sets and uniformly arranged along the circumference of the separation cylinder, and the sound radiation force of the first sound wave field points towards the central axis of the separation cylinder.

[0008] In some embodiments, multiple sets of the high-frequency sound source devices are uniformly arranged along the circumference of the separation cylinder, and the sound radiation force of the second sound wave field is directed towards the central axis of the separation cylinder.

[0009] In some embodiments, the high-frequency sound source device is fixed on the outer wall of the separator cylinder at a position corresponding to the installation height of the demister. The sound wave emitting end of the high-frequency sound source device extends through the side wall of the separator cylinder into the area where the demister is located. The sound wave emission direction of the second sound wave field forms an angle of 60°-90° with the mainstream direction of the humid gas phase.

[0010] In some embodiments, the frequency of the first sound wave field is 100Hz-2kHz, and the sound pressure level is 140dB-160dB; the frequency of the second sound wave field is 10kHz-50kHz, and the sound pressure level is 120dB-150dB.

[0011] In some embodiments, a gravity settling space is provided between the primary acoustic treatment zone and the demister, the height of which is not less than 0.5m, for allowing some large droplets to settle and flow back under gravity.

[0012] In some embodiments, the demister is a wire mesh demister, which comprises multiple layers of woven wire mesh with a wire diameter of 0.1mm-0.3mm and 6-12 layers.

[0013] In some embodiments, the system further includes an upper pressure plate and a lower support grid, wherein the multi-layer woven wire mesh is located between the upper pressure plate and the lower support grid, and the interlayer spacing of the multi-layer woven wire mesh is 2mm-5mm.

[0014] An embodiment of the present invention provides a method for removing wet gas-phase droplets from a desulfurization wastewater concentration system, comprising the following steps: The wet gas phase generated by the desulfurization wastewater concentration system is introduced from the bottom of the separation cylinder, so that the wet gas phase flows from bottom to top in the separation cylinder. Pretreatment involves emitting a first acoustic wave field into the separation cylinder from the lower part of the cylinder using a low-frequency acoustic source device. This causes fine droplets with a diameter of 1μm-5μm in the humid gas phase to agglomerate under the effect of acoustic wake flow, forming larger droplets. Some larger droplets with a diameter greater than 20μm are removed by gravity sedimentation, while the remaining larger droplets rise with the airflow and enter the demister. The frequency of the first acoustic wave field is 100Hz-2kHz, and the sound pressure level is 140dB-160dB. The humid gas phase flows through the multi-layer woven mesh of the demister installed inside the separation cylinder. During the process of the humid gas phase passing through the multi-layer woven mesh, a high-frequency sound source device located on the side of the demister emits a second sound wave field into the area where the demister is located, causing the submicron droplets in the humid gas phase to oscillate in a controlled manner, increasing the probability of inertial collision between the submicron droplets and the collection surface of the multi-layer woven mesh. The frequency of the second sound wave field is 10kHz-50kHz and the sound pressure level is 120dB-150dB. The mist droplets in the moisture-carrying gas phase are captured and removed by the multi-layer woven wire mesh, and the purified moisture-carrying gas phase flows out from the top of the separation cylinder.

[0015] In some embodiments, the low-frequency sound source device is used to cause fine droplets with a particle size of 1μm-5μm to agglomerate into large droplets with a particle size greater than 20μm; the high-frequency sound source device is used to cause submicron droplets with a particle size of 0.1μm-1μm to generate controlled oscillations in the demister region.

[0016] This application offers the following advantages: By coupling and coordinating two-stage acoustic waves with a demister, deep removal of droplets of different sizes from the humid gas phase is achieved, improving condensate quality. Applying a second acoustic field to the demister region causes controlled oscillations in residual submicron droplets, directly increasing the probability of inertial collisions with the multi-layer woven mesh trapping surface, overcoming the physical bottleneck of insufficient inertial collision efficiency for submicron droplets in existing demisters. In the first-stage acoustic treatment zone, the acoustic wake effect agglomeration mechanism causes fine droplets to form agglomerated droplets and larger droplets. Some large droplets are removed by gravity settling, while the rest are more easily captured by the demister due to their increased size. This pre-emptively reduces the demister load and forms a synergistic removal mode of "agglomeration pretreatment + oscillation-enhanced trapping" with the second stage. This not only reduces the load of high-viscosity droplets entering the demister but also effectively extends the demister's clogging and scaling cycle. The reduced content of residual high-salt droplets in the humid gas phase improves the quality of downstream condensate, meeting the requirements for high-quality condensate reuse. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the wet gas phase droplet removal device in the desulfurization wastewater concentration system according to an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of the low-frequency sound source device and the high-frequency sound source device of the wet gas phase droplet removal device in the desulfurization wastewater concentration system according to an embodiment of the present invention.

[0019] Figure 3 This is a cross-sectional schematic diagram of the low-frequency sound source device and the high-frequency sound source device of the wet gas phase droplet removal device in the desulfurization wastewater concentration system according to an embodiment of the present invention.

[0020] Reference numerals: 1. Separation cylinder; 2. Demister; 3. Low-frequency sound source device; 4. High-frequency sound source device; 51. Fine droplets; 52. Agglomerated droplets; 53. Large droplets; 54. Submicron droplets. Detailed Implementation

[0021] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0022] This invention provides an embodiment of a desulfurization wastewater concentration system with a wet gas phase droplet removal device, comprising a separation cylinder 1, a demister 2, a primary treatment zone, and a secondary treatment zone. The separation cylinder 1 has a wet gas phase inlet at its bottom and a purified gas phase outlet at its top. The wet gas phase flows upward within the separation cylinder 1. The primary treatment zone includes a low-frequency sound source device 3, located at the lower part of the separation cylinder 1 and above the wet gas phase inlet. The low-frequency sound source device 3 emits a first sound wave field towards the separation cylinder 1 to cause droplet aggregation. The demister 2 is located above the primary treatment zone and is used to capture droplets in the wet gas phase. The secondary treatment zone is located in the area where the demister 2 is located. The secondary treatment zone includes a high-frequency sound source device 4, located on the side wall of the separation cylinder 1 and beside the demister 2. The high-frequency sound source device 4 emits a second sound wave field towards the demister 2 to increase the collision probability between submicron droplets and the demister 2.

[0023] As a vertical container, the vertical flow path of the humid gas phase makes gravity settling the removal mechanism for some large droplets 53 in the primary treatment zone. Some large droplets 53 fall off because their gravity settling velocity is greater than the rising flow of the humid gas phase. Under the action of the first acoustic field in the primary treatment zone, fine droplets 51 with a particle size of 1μm to 5μm in the humid gas phase co-aggregate under the acoustic wake effect, forming agglomerated droplets 52 with a particle size of 5μm to 20μm and large droplets 53 with a particle size greater than 20μm. The agglomeration process increases the particle size and inertial parameters of the fine droplets 51 that were originally difficult to be effectively captured by the demister 2, making them easier to be captured and removed by the demister 2. The removal of large droplets 53 by gravity can reduce the droplet load entering the demister 2 and prolong the clogging and scaling cycle of the demister 2. Demister 2 captures droplets with increased particle size. The secondary treatment zone processes droplets treated by the primary acoustic field, which increases the probability of inertial collisions between submicron droplets and the collection surface of demister 2. The two stages of acoustic waves work together to form a combination of pretreatment and oscillation enhancement. The two stages of acoustic waves are complementary in terms of particle size processing range. The primary acoustic wave processes fine droplets 51, while the secondary acoustic wave processes submicron droplets, achieving deep removal of droplets of different sizes.

[0024] In some embodiments, the low-frequency sound source device 3 is in multiple groups and is evenly arranged along the circumference of the separation cylinder 1, and the sound radiation force of the first sound wave field points towards the central axis of the separation cylinder 1.

[0025] Specifically, multiple sets of low-frequency sound source devices 3, evenly arranged along the circumference of the separation cylinder 1, create a uniform sound wave coverage surface on the cross-section of the separation cylinder 1, ensuring that all fine droplets 51 in the upward-flowing humid gas phase are subjected to the same intensity of sound waves, preventing some droplets from penetrating downstream due to uneven sound field distribution and insufficient agglomeration. The sound radiation force of the first sound wave field points towards the central axis, causing the fine droplets 51 in the humid gas phase to move towards the center of the cylinder under the effect of the acoustic wake effect and to collide and agglomerate. During their movement towards the central axis, the fine droplets 51 collide and adhere to each other, forming agglomerated droplets 52 and large droplets 53 with increased particle size. Some of the large droplets 53 are removed by gravity due to their increased particle size and gravity settling velocity exceeding the upward flow velocity of the humid gas phase. The remaining droplets with increased particle size are more easily captured and removed by the demister 2 located above the primary treatment zone due to their increased inertial parameters.

[0026] In some embodiments, multiple sets of high-frequency sound source devices 4 are uniformly arranged along the circumference of the separation cylinder 1, and the sound radiation force of the second sound wave field is directed towards the central axis of the separation cylinder 1.

[0027] Specifically, multiple sets of high-frequency sound source devices 4 are uniformly arranged along the circumference to form a uniform sound wave coverage surface across the entire cross-section of the area where the demister 2 is located. This ensures that all residual submicron droplets in the humidified gas phase are subjected to the same intensity of sound waves, preventing submicron droplets in some areas from penetrating the demister 2 and reaching the downstream condensation system due to uneven sound field distribution without effective oscillation. The acoustic radiation force of the second sound wave field is directed towards the central axis of the separation cylinder 1. In the demister 2 area, the acoustic radiation force pointing towards the central axis causes the submicron droplets to be subjected to a periodic acoustic wave force pointing towards the center of the cylinder. The submicron droplets generate transverse controlled oscillations, and their transverse oscillation displacement is on the same order of magnitude as the wire diameter of the woven mesh of the demister 2, increasing the probability of inertial collisions between the submicron droplets and the surface of the mesh fibers. Submicron droplets approach and collide with the wire mesh surface of the entire circumference area of ​​the demister 2 under the action of vibration, which avoids the local wire mesh area being overloaded while other areas are undercaptured, ensuring that the capture load of each part of the demister 2 is balanced and extending the overall service life of the demister 2.

[0028] Optionally, the high-frequency sound source device 4 is only arranged in a local area on the side wall of the separation cylinder 1 corresponding to the installation height of the demister 2, so that the sound wave energy is concentrated on the wire mesh collection area where the collection efficiency needs to be enhanced the most, rather than being wasted in the entire cylinder space.

[0029] In some embodiments, the high-frequency sound source device 4 is fixed on the outer wall of the separation cylinder 1 at a position corresponding to the installation height of the demister 2. The sound wave emitting end of the high-frequency sound source device 4 extends through the side wall of the separation cylinder 1 into the area where the demister 2 is located. The sound wave emitting direction of the second sound wave field forms an angle of 60°-90° with the mainstream direction of the humid gas phase.

[0030] Specifically, the high-frequency sound source device 4 is aligned with the demister 2 in the height direction to ensure that the second sound wave field generates the strongest sound wave effect within the spatial range of the demister 2 area. This avoids excessive attenuation of sound wave energy or partial deviation of the sound wave field from the demister 2 area due to height misalignment between the sound source and the demister 2. The sound wave emitting end of the high-frequency sound source device 4 extends through the side wall of the separation cylinder 1 into the interior of the demister 2 area, so that the second sound wave field is generated directly inside the demister 2 area and acts on the moisture-carrying gas phase passing through the multi-layer woven mesh. The residual submicron droplets are subjected to sound waves and generate controlled oscillations as they pass through the mesh, rather than having sound waves applied at a position far from the demister 2 and then allowing the submicron droplets to move with the airflow to the demister 2 area. This ensures that the sound wave energy does not undergo spatial attenuation or dissipation before acting on the submicron droplets.

[0031] The sound wave emission direction of the second sound wave field forms an angle of 60°-90° with the mainstream direction of the humid gas phase. Within this angle range, the sound wave emission direction and the mainstream direction form a large angular relationship. Under the action of the second sound wave field, the submicron droplets generate a lateral oscillation displacement, that is, the oscillation direction forms a large angle with the mainstream direction. This causes the submicron droplets to have a lateral motion component that deviates from the mainstream direction as they move upward with the airflow along the mainstream direction. This increases the collision probability of submicron droplets that are difficult to break away from the airflow streamline and collide with the wire mesh capture surface due to their small inertial parameters. If the angle between the sound wave emission direction and the mainstream direction is too small, the oscillation direction of the submicron droplets is close to the mainstream direction, and the lateral deviation component is insufficient, so the effect of increasing the collision probability is not significant. If the angle is 90°, that is, perpendicular to the direction, the lateral oscillation reaches its maximum, and the submicron droplets experience the maximum oscillation displacement deviating from the mainstream direction when passing through each layer of wire mesh.

[0032] In some embodiments, the frequency of the first sound wave field is 100Hz-2kHz, and the sound pressure level is 140dB-160dB; the frequency of the second sound wave field is 10kHz-50kHz, and the sound pressure level is 120dB-150dB.

[0033] Specifically, the frequency of the first sound wave field is 100Hz-2kHz. Within this frequency range, the fine droplets 51 vibrate to varying degrees in the sound field due to differences in particle size. Larger droplets have greater inertia and are less easily carried by sound waves, while smaller droplets are more easily moved by the vibration of the medium. As a result, relative motion and collisions occur between the large and small particles. The larger particles act as collecting nuclei, adhering the smaller particles that collide with them to their surface, thus enabling the fine droplets 51 to aggregate into aggregated droplets with a particle size of 5μm to 20μm. 52 and large droplets 53 with a particle size greater than 20 μm; the sound pressure level of the first sound wave field is 140 dB-160 dB. This high sound pressure level ensures that the first sound wave field has sufficient sound wave energy to drive the fine droplets 51 to generate relative motion velocity and collision frequency. If the sound pressure level is lower than 140 dB, the acoustic wake effect is insufficient to cause the fine droplets 51 to effectively aggregate within a limited time. If the sound pressure level is higher than 160 dB, it may cause the already aggregated large droplets 53 to undergo secondary breakup under excessively high sound wave energy.

[0034] The second acoustic field has a frequency of 10kHz-50kHz. Within this frequency range, submicron droplets have extremely small mass and inertial parameters much smaller than one, making effective collisional aggregation difficult in low-frequency acoustic fields. However, high-frequency acoustic waves induce controlled oscillations in submicron droplets synchronized with the acoustic frequency. The transverse oscillation displacement is on the same order of magnitude as the diameter of the multi-layered woven mesh, increasing the probability of inertial collisions between submicron droplets and the mesh's collecting surface. This controlled oscillation does not rely on collisional aggregation between submicron droplets, directly enhancing the interaction between droplets and the collecting surface. This overcomes the physical limitation of traditional acoustic aggregation technology's extremely low aggregation efficiency for submicron-level droplets. The sound pressure level of the second sound field is 120dB-150dB. This range is lower than that of the first sound field because the mechanism of the second sound field is not to drive collisions and aggregation between submicron droplets, but to induce controlled oscillations in the submicron droplets to increase their probability of colliding with the wire mesh. Therefore, a high sound pressure level as high as that of the first sound field is not required. However, if the sound pressure level is lower than 120dB, the oscillation amplitude of the submicron droplets is insufficient to make the lateral oscillation displacement reach the same order of magnitude as the wire diameter. If the sound pressure level is higher than 150dB, the droplets already captured on the surface of the wire mesh may be re-entered into the airflow under excessively high sound energy. The first acoustic field, with a lower frequency and a higher sound pressure level, achieves acoustic wake effect agglomeration of fine droplets 51 from 1μm to 5μm. The second acoustic field, with a higher frequency and a moderate sound pressure level, achieves controlled oscillation enhancement and capture of submicron droplets from 0.1μm to 1μm. The two acoustic fields completely cover the entire droplet size range that needs to be removed from the humid gas phase in terms of particle size processing, avoiding the limitations of a single frequency acoustic wave.

[0035] In some embodiments, a gravity settling space is provided between the primary acoustic treatment zone and the demister 2, and the height of the gravity settling space is not less than 0.5m, which is used to allow some large droplets 53 to settle and flow back under the action of gravity.

[0036] Specifically, the gravity settling space is located above the first acoustic treatment zone and below the demister 2 within the separation cylinder 1. This provides sufficient residence time for the large droplets 53 formed by agglomeration in the first acoustic field, allowing them ample time to settle and separate from the humid gas phase by gravity during their ascent. Some of the large droplets 53 have a particle size greater than 20 μm, and their gravity settling velocity is greater than the upward flow velocity of the humid gas phase. Therefore, they can be removed by gravity in the gravity settling space without continuing to rise with the airflow. Before entering the demister 2, some of the agglomerated large droplets 53 are pre-removed, reducing the droplet load on the demister 2. At the same time, it prevents the large droplets 53 from depositing on the wire mesh surface of the demister 2, which would cause wire mesh blockage and a sharp increase in pressure drop, thus extending the blockage and scaling cycle of the demister 2. If the height of the gravity settling space is less than 0.5m, the residence time of large droplets 53 within the gravity settling space is insufficient for them to completely detach from the humid gas phase by gravity settling. Some of the large droplets 53 that do not have time to settle will be carried by the airflow into the demister 2, increasing the load on the demister 2 and the risk of blockage. The gravity settling space serves as a physical partition between the first-stage acoustic treatment zone and the demister 2, preventing the first and second acoustic fields from directly overlapping in space and causing acoustic interference or mutual cancellation, ensuring that the two acoustic fields function independently and effectively in their respective areas. The height of the gravity settling space can be adjusted according to the upward flow velocity of the humid gas phase and the particle size distribution of the large droplets 53. When the upward flow velocity is high, the height of the gravity settling space can be appropriately increased to provide sufficient settling time; when the upward flow velocity is slow, the height can be appropriately reduced to optimize the equipment size.

[0037] In some embodiments, the demister 2 is a wire mesh demister 2, which includes multiple layers of woven wire mesh with a wire diameter of 0.1mm-0.3mm and 6-12 layers.

[0038] Specifically, the demister 2 is a wire mesh demister 2. The multi-layer woven wire mesh of the wire mesh demister 2 is located between the primary treatment zone and the purified gas phase outlet inside the separation cylinder 1. The wire diameter range of the multi-layer woven wire mesh is on the same order of magnitude as the transverse controlled oscillation displacement generated by submicron droplets under the action of the second sound wave field. This causes the submicron droplets to deviate from the airflow streamline due to oscillation when passing through the multi-layer woven wire mesh and directly impact the surface of the wire mesh fibers and be captured. If the wire diameter is less than 0.1 mm, the wire mesh fibers are too thin, the mechanical strength is insufficient, and fatigue fracture is likely to occur in the high sound pressure level sound wave field. If the wire diameter is greater than 0.3 mm, the wire mesh fibers are too thick, and the transverse oscillation displacement of the submicron droplets is too small relative to the wire diameter. Even if oscillation occurs, it is difficult to effectively collide with the surface of the thicker fibers. At the same time, the excessively thick wire diameter leads to a reduction in the number of wire mesh fibers per unit volume and insufficient capture area.

[0039] The number of layers in the multi-layer woven wire mesh ensures sufficient collection stages and collisions for the humid gas phase as it passes through the wire mesh demister 2. This allows droplets not captured by the first few layers to continue being intercepted and captured in subsequent layers. If there are fewer than 6 layers, the number of collection stages is insufficient, and some droplets, especially smaller droplets in agglomerates 52, may penetrate the demister 2 and enter the downstream. If there are more than 12 layers, the airflow resistance of the demister 2 will be too high, resulting in a significant increase in system pressure drop. Furthermore, the multi-layer woven wire mesh is prone to forming liquid bridges due to the captured droplets, which accelerates clogging. A finer wire diameter combined with more layers can provide higher collection efficiency and a larger collection area without significantly increasing the pressure drop. A coarser wire diameter combined with fewer layers can reduce pressure drop and reduce the risk of clogging, adapting to long-term stable operation under high dust conditions. For example, under conditions where the dust content of the flue gas is approximately 50 mg / m³, a coarser wire diameter configuration of 0.3 mm and 6 layers can be selected to reduce the risk of clogging. The filament diameter range of the multi-layered woven mesh allows the acoustic energy of the second acoustic field to effectively penetrate each layer without significant attenuation or reflection. This ensures that the mesh layer located downstream of the demister 2, near the purified gas phase outlet, also receives the effective acoustic effect of the second acoustic field. This allows submicron droplets to undergo controlled oscillation as they pass through each mesh layer, continuously enhancing the probability of collision and capture. The multi-layered woven mesh, acting as an intermediary structure connecting the humidified gas phase and the second acoustic field, performs both the interception and capture functions of the traditional demister 2 and serves as the propagation medium for the second acoustic field and the target surface for submicron droplet oscillation and collision, thus integrating acoustic energy with the capture function. The specific values ​​of filament diameter and number of layers can be selected and adjusted based on the droplet size distribution, airflow velocity, and the frequency and sound pressure level parameters of the second acoustic field. When the proportion of submicron droplets is high, a finer filament diameter and more layers are used to enhance the capture capacity of fine particles; under high dust or high viscosity conditions, a coarser filament diameter and fewer layers are used to prolong the clogging cycle.

[0040] Optionally, the wire diameters of each layer of the multi-layer woven mesh can not be exactly the same. The mesh layer near the inlet of the humidified gas phase uses a coarser wire diameter to capture larger droplets and serve as a pre-separation layer, while the mesh layer near the outlet of the purified gas phase uses a finer wire diameter to capture residual tiny droplets, forming a gradient filtration structure from coarse to fine, thus optimizing the balance between capture efficiency and pressure drop.

[0041] In some embodiments, the system further includes an upper pressure plate and a lower support grid, with a multi-layer woven wire mesh located between the upper pressure plate and the lower support grid, and the interlayer spacing of the multi-layer woven wire mesh being 2mm-5mm.

[0042] Specifically, the upper pressure plate and the lower support grid together clamp and fix the multi-layer woven wire mesh at a predetermined installation height inside the separation cylinder 1. Under the impact force of the humid gas phase from bottom to top and the acoustic vibration of the first and second acoustic fields, the multi-layer woven wire mesh maintains a stable spatial position and shape, avoiding displacement, deformation, or interlayer compression due to airflow impact or acoustic vibration. This ensures that the relative position and spacing between the layers of the multi-layer woven wire mesh do not change due to fluctuations in operating conditions. The interlayer spacing range of the multi-layer woven wire mesh ensures that the humid gas phase has sufficient space to undergo micro-turning of the flow direction and velocity redistribution when passing between adjacent wire mesh layers. This allows droplets not captured by the previous wire mesh to have different incident angles and collision conditions when reaching the next wire mesh layer, increasing the probability of droplets being captured by subsequent wire mesh layers. This avoids the formation of liquid bridges between adjacent wire mesh layers due to excessively small interlayer spacing, which would accelerate the blockage and pressure drop increase of the demister 2.

[0043] If the interlayer spacing is less than 2mm, the adjacent wire mesh layers are too close together, and the captured droplets are prone to form a continuous liquid film or liquid bridge between the layers, which rapidly reduces the effective capture area of ​​the multi-layer woven wire mesh and increases the airflow resistance sharply. If the interlayer spacing is greater than 5mm, the overall height of the demister 2 is too large, which increases the equipment manufacturing cost and the flow of the moisture-laden gas phase between adjacent wire mesh layers is too dispersed. Some droplets may bypass the wire mesh fibers in the interlayer space and not be effectively intercepted.

[0044] As the bottom support structure of the multi-layer woven wire mesh, the lower support grid can play a role in the initial uniform flow of the humid gas phase entering the demister 2 area. This allows the humid gas phase to achieve preliminary uniformity of airflow distribution at the lower support grid before entering the multi-layer woven wire mesh, thus avoiding excessively high local airflow velocity leading to droplet penetration or excessively low local airflow velocity leading to a decrease in collection efficiency.

[0045] An embodiment of the present invention provides a method for removing wet gas-phase droplets from a desulfurization wastewater concentration system, comprising the following steps: The wet gas phase generated by the desulfurization wastewater concentration system is introduced from the bottom of the separation cylinder 1, so that the wet gas phase flows from bottom to top in the separation cylinder 1. This flow direction causes the wet gas phase to pass through the first-stage acoustic treatment zone, gravity settling space, demister 2 and second-stage acoustic treatment zone in sequence during the rising process. At the same time, some of the large droplets 53 formed by agglomeration in the first acoustic field can be naturally removed by settling in the gravity settling space in the direction of gravity opposite to the airflow direction, without the need for additional power equipment.

[0046] In the pretreatment process, a first sound wave field is emitted into the separation cylinder 1 from the lower part using a low-frequency sound source device 3. This causes the fine droplets 51 with a particle size of 1μm-5μm in the humid gas phase to agglomerate under the effect of the acoustic wake flow, forming larger droplets. Some of the larger droplets 53 with a particle size greater than 20μm are removed by gravity sedimentation, while the remaining larger droplets are carried upward by the airflow into the demister 2. The frequency of the first sound wave field is 100Hz-2kHz, and the sound pressure level is 140dB-160dB. This frequency and sound pressure level range meet the agglomeration conditions of the fine droplets 51 with a particle size of 1μm-5μm in the humid gas phase.

[0047] The humid gas phase flows through the multi-layer woven mesh of the demister 2 located inside the separation cylinder 1. During the process of the humid gas phase passing through the multi-layer woven mesh, a high-frequency sound source device 4 located on the side of the demister 2 emits a second sound wave field into the area where the demister 2 is located, causing the submicron droplets in the humid gas phase to oscillate in a controlled manner, increasing the probability of inertial collision between the submicron droplets and the trapping surface of the multi-layer woven mesh. The frequency of the second sound wave field is 10kHz-50kHz and the sound pressure level is 120dB-150dB. The submicron droplets oscillate in a controlled manner, and their lateral oscillation displacement is on the same order of magnitude as the wire diameter of the multi-layer woven mesh, increasing the probability of inertial collision between the submicron droplets and the trapping surface of the mesh. At the same time, the second sound wave field causes the droplets already trapped on the mesh surface to accelerate and flow downward along the mesh fibers under the action of sound wave vibration, reducing the accumulation of trapped droplets on the mesh surface and the risk of secondary entrainment. The mist droplets in the humid gas phase are captured and removed by a multi-layer woven wire mesh, and the purified humid gas phase flows out from the top of the separation cylinder 1. Larger droplets (including droplets enlarged by the first-stage agglomeration and originally larger droplets) are captured by the wire mesh fibers through inertial collision, direct interception, and diffusion. Submicron droplets, whose collision probability is enhanced by a second acoustic field, frequently collide with the surface of the wire mesh fibers due to controlled oscillation and are effectively captured. The purified humid gas phase flows out from the top of the separation cylinder 1 and enters the downstream condensation system.

[0048] In some embodiments, the low-frequency sound source device 3 is used to cause fine droplets 51 with a particle size of 1μm-5μm to agglomerate into large droplets 53 with a particle size greater than 20μm; the high-frequency sound source device 4 is used to cause submicron droplets with a particle size of 0.1μm-1μm to generate controlled oscillations in the region of the demister 2.

[0049] Specifically, the low-frequency, high-intensity sound field causes the fine droplets 51 to co-aggregate under the acoustic wake effect. The larger droplets have greater inertia and are less likely to be carried by the sound waves, while the smaller droplets are more likely to move with the vibration of the medium. As a result, the large and small particles generate relative motion and collide. The large particles act as collecting nuclei, adhering the small particles that collide with them to their surface. Among the large droplets 53 formed by aggregation, some with a diameter greater than 20 μm are removed by natural settling due to gravity, as their settling velocity is greater than the rising velocity of the humid gas phase. The remaining droplets with larger diameters are more easily captured and removed by the multi-layer woven mesh of the demister 2 due to their significantly increased inertial parameters.

[0050] The high-frequency acoustic field induces controlled transverse oscillations in submicron droplets with extremely small mass and inertial parameters far less than one, synchronized with the acoustic frequency. The transverse oscillation displacement is on the same order of magnitude as the diameter of the multi-layered woven mesh, increasing the probability of inertial collisions between submicron droplets and the mesh fiber surface. The controlled oscillation mechanism does not rely on the mutual collisions and agglomeration between submicron droplets, but directly enhances the interaction between the droplets and the collecting surface. Therefore, it overcomes the physical limitation of the extremely low agglomeration efficiency of traditional acoustic agglomeration technology for submicron-level droplets. The low-frequency acoustic source device 3 agglomerates fine droplets 51 into large droplets 53, while the high-frequency acoustic source device 4 induces controlled oscillations in submicron droplets. Functionally, this complements the particle size processing range, jointly covering the entire range of droplet sizes that need to be removed from the humidified gas phase, without leaving any untreated intermediate particle size gaps.

[0051] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0052] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0053] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0054] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0055] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0056] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A device for removing wet gas-phase droplets from a desulfurization wastewater concentration system, characterized in that, include: The system comprises a separation cylinder, a demister, a primary treatment zone, and a secondary treatment zone. The separation cylinder has a humidified gas phase inlet at its bottom and a purified gas phase outlet at its top. The humidified gas phase flows upwards within the separation cylinder. The primary treatment zone includes a low-frequency sound source device located at the bottom of the separation cylinder and above the humidified gas phase inlet. This device emits a first sound wave field towards the separation cylinder to cause droplet aggregation. The demister is located above the primary treatment zone and is used to capture mist droplets in the humidified gas phase. The secondary treatment zone is located in the area where the demister is situated. This zone includes a high-frequency sound source device located on the side wall of the separation cylinder and beside the demister. This device emits a second sound wave field towards the demister to increase the collision probability between submicron droplets and the demister.

2. The wet gas phase droplet removal device for the desulfurization wastewater concentration system according to claim 1, characterized in that, The low-frequency sound source device consists of multiple sets and is evenly arranged along the circumference of the separation cylinder, and the sound radiation force of the first sound wave field points towards the central axis of the separation cylinder.

3. The wet gas phase droplet removal device for the desulfurization wastewater concentration system according to claim 1, characterized in that, Multiple sets of the high-frequency sound source devices are evenly arranged along the circumference of the separation cylinder, and the sound radiation force of the second sound wave field is directed towards the central axis of the separation cylinder.

4. The wet gas phase droplet removal device for the desulfurization wastewater concentration system according to claim 1, characterized in that, The high-frequency sound source device is fixed on the outer wall of the separator cylinder at a position corresponding to the installation height of the demister. The sound wave emitting end of the high-frequency sound source device extends through the side wall of the separator cylinder into the area where the demister is located. The sound wave emission direction of the second sound wave field forms an angle of 60°-90° with the mainstream direction of the humid gas phase.

5. The wet gas phase droplet removal device for the desulfurization wastewater concentration system according to claim 1, characterized in that, The first sound wave field has a frequency of 100Hz-2kHz and a sound pressure level of 140dB-160dB; the second sound wave field has a frequency of 10kHz-50kHz and a sound pressure level of 120dB-150dB.

6. The wet gas phase droplet removal device for the desulfurization wastewater concentration system according to claim 1, characterized in that, A gravity settling space is provided between the primary acoustic treatment zone and the demister. The height of the gravity settling space is not less than 0.5m, which is used to allow some large droplets to settle and flow back under the action of gravity.

7. The wet gas phase droplet removal device for the desulfurization wastewater concentration system according to claim 1, characterized in that, The demister is a wire mesh demister, which comprises multiple layers of woven wire mesh with a wire diameter of 0.1mm-0.3mm and 6-12 layers.

8. The wet gas phase droplet removal device for the desulfurization wastewater concentration system according to claim 7, characterized in that, It also includes an upper pressure plate and a lower support grid, wherein the multi-layer woven wire mesh is located between the upper pressure plate and the lower support grid, and the interlayer spacing of the multi-layer woven wire mesh is 2mm-5mm.

9. A method for removing wet gas-phase droplets from a desulfurization wastewater concentration system, utilizing the removal device according to any one of claims 1-8, characterized in that, Includes the following steps: The wet gas phase generated by the desulfurization wastewater concentration system is introduced from the bottom of the separation cylinder, so that the wet gas phase flows from bottom to top in the separation cylinder. Pretreatment involves emitting a first acoustic wave field into the separation cylinder from the lower part of the cylinder using a low-frequency acoustic source device. This causes fine droplets with a diameter of 1μm-5μm in the humid gas phase to agglomerate under the effect of acoustic wake flow, forming larger droplets. Some larger droplets with a diameter greater than 20μm are removed by gravity sedimentation, while the remaining larger droplets rise with the airflow and enter the demister. The frequency of the first acoustic wave field is 100Hz-2kHz, and the sound pressure level is 140dB-160dB. The humid gas phase flows through the multi-layer woven mesh of the demister installed inside the separation cylinder. During the process of the humid gas phase passing through the multi-layer woven mesh, a high-frequency sound source device located on the side of the demister emits a second sound wave field into the area where the demister is located, causing the submicron droplets in the humid gas phase to oscillate in a controlled manner, increasing the probability of inertial collision between the submicron droplets and the collection surface of the multi-layer woven mesh. The frequency of the second sound wave field is 10kHz-50kHz and the sound pressure level is 120dB-150dB. The mist droplets in the moisture-carrying gas phase are captured and removed by the multi-layer woven wire mesh, and the purified moisture-carrying gas phase flows out from the top of the separation cylinder.

10. The method for removing wet gas-phase droplets from a desulfurization wastewater concentration system according to claim 9, characterized in that, The low-frequency sound source device is used to cause fine droplets with a particle size of 1μm-5μm to agglomerate into large droplets with a particle size greater than 20μm; the high-frequency sound source device is used to cause submicron droplets with a particle size of 0.1μm-1μm to generate controlled oscillations in the demister region.

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