Water treatment equipment and air flotation pressure dissolved air tank thereof

Abstract

The utility model discloses a water treatment equipment and air floatation pressure dissolved air tank thereof, including tank body, water inlet system, compressed air system and dissolved air water discharge system. Tank body is provided with dissolved air zone and liquid phase area along gravity direction in proper order, and the liquid phase area is located the bottom of dissolved air zone, and the dissolved air zone gradually increases the cross section area in the direction of being close to the liquid phase area. The water inlet system includes water inlet pipeline and shower head, and the shower head is arranged in the dissolved air zone, and the water inlet pipeline is connected with the shower head by penetrating into the tank body. The compressed air system is used for providing compressed air to the tank body, and the dissolved air water discharge system is used for discharging the dissolved air water of the liquid phase area. The water treatment equipment and air floatation pressure dissolved air tank thereof have high control precision, high dissolved air efficiency, system has self -adaptation ability, reduces the liquid level variation amplitude in the tank, and the dissolved air water gas content in the tank is stable, improves the stability of air floatation dissolved air release area and air floatation separation effect.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, specifically to a water treatment device and its air flotation pressure dissolved air tank. Background Technology

[0002] Dissolved air flotation (DAF) is a highly efficient physicochemical water treatment technology. Its core principle involves introducing a large number of microbubbles into the water, causing them to adhere to suspended particles (such as oils, colloids, or fibers), forming a "bubble-particle" composite with a density less than water. This composite then rapidly floats to the surface under buoyancy, achieving solid-liquid or liquid-liquid separation. This process is widely used in oily wastewater, food processing wastewater, and papermaking wastewater treatment. Common forms include dissolved air flotation (DAF) and vortex flotation, and it features small footprint, high separation efficiency, and low sludge production.

[0003] The dissolved air pressure tank is the core equipment in dissolved air flotation (DAF) treatment. Its core function is to create high-pressure saturated dissolved air water by forcibly dissolving air in the returned treated water within a sealed, pressurized container. During operation, air from the air compressor and returned water from the wastewater or the DAF equipment are thoroughly mixed and contacted within the tank through a packing layer. The large contact surface area greatly improves the mass transfer efficiency of the gas, allowing a large amount of air to dissolve stably in the water. Subsequently, when this high-pressure dissolved air water enters the DAF tank through the release device, the pressure drops sharply, causing the supersaturated air to precipitate out in the form of extremely fine and uniform bubbles, providing a crucial medium for the subsequent adhesion and flotation separation of pollutants.

[0004] However, existing dissolved air flotation pressure tanks suffer from inflexible adjustment of dissolved air volume and low dissolved air efficiency due to the intermittent start and stop of the air compressor, the frequent changes in the water volume and air source pressure, the large fluctuations in the liquid level inside the tank, the inflexible adjustment of dissolved air volume, and the frequent changes in dissolved air volume and air source pressure. Utility Model Content

[0005] Therefore, it is necessary to provide a water treatment device and its air flotation pressure dissolved air tank to address the problems of large fluctuations in the liquid level inside the tank, inflexible adjustment of the dissolved air volume, and low dissolved air efficiency in existing air flotation pressure dissolved air tanks.

[0006] An air flotation pressure dissolved air tank, comprising: The tank body has a gas-dissolving zone and a liquid phase zone arranged sequentially along the direction of gravity. The liquid phase zone is located at the bottom of the gas-dissolving zone, and the cross-sectional area of ​​the gas-dissolving zone gradually increases towards the liquid phase zone. The water inlet system includes an inlet pipe and a spray head. The spray head is located in the dissolved air zone, and the inlet pipe passes through the tank body and is connected to the spray head. A compressed air system is used to supply compressed air into the tank; and A dissolved air water discharge system is used to discharge the dissolved air water from the liquid phase zone.

[0007] In the aforementioned dissolved air flotation pressure tank, water from the inlet pipe enters the tank and is sprayed down in a cone shape through the spray head, greatly increasing the air-water contact area and mass transfer rate. The dissolved air zone of the tank has a shape that is smaller at the top and larger at the bottom, similar to the shape of the spray mist cone.

[0008] The working liquid level in the dissolved gas tank fluctuates between high and low levels. When the liquid level is high, it intercepts a portion of the spray mist cone's volume, reducing the mass transfer time. At this time, the amount of gas absorbed by the water is less than the amount of gas entering the dissolved gas tank, causing the gas space to expand and the liquid level to drop. Conversely, when the liquid level reaches a low level, the mist cone's volume is at its maximum, the water's ability to absorb gas becomes stronger, and as the gas space contracts, the liquid level slowly rises again.

[0009] In one embodiment, a level gauge for displaying the liquid level inside the tank is installed outside the tank.

[0010] In one embodiment, a pressure gauge is installed on the tank for detecting the pressure inside the tank.

[0011] In one embodiment, the liquid phase region of the tank is cylindrical or a frustum-shaped structure with a radius that gradually increases away from the dissolved gas region.

[0012] In one embodiment, the water inlet system further includes a booster pump installed on the water inlet pipe for pressurizing the water in the water inlet pipe.

[0013] In one embodiment, the compressed air system includes a compressed air pipeline and a flow meter. The compressed air pipeline is connected to the tank for supplying compressed air to the dissolved air zone, and the flow meter is installed on the compressed air pipeline.

[0014] In one embodiment, the compressed air pipe is connected to the water inlet pipe.

[0015] In one embodiment, the dissolved gas water discharge system includes a dissolved gas water discharge pipe and a pressure control valve. The dissolved gas water discharge pipe is connected to the tank for discharging the dissolved gas water in the liquid phase zone, and the pressure control valve is installed on the dissolved gas water discharge pipe.

[0016] In one embodiment, the axis of the tank has an angle of 0-45° with the direction of gravity, and the spray head is located on the axis of the tank.

[0017] A water treatment device, comprising: As described in any of the above-mentioned air flotation pressure dissolved air tanks.

[0018] The above-mentioned water treatment equipment and its dissolved air flotation pressure tank have at least the following advantages: 1. Non-submerged water intake reduces additional resistance consumption in the pipeline system.

[0019] 2. High dissolved air efficiency reduces the problems of short residence time and poor buffering capacity caused by low liquid level in the tank, and prevents dissolved air water from carrying air bubbles into the subsequent tank and affecting the air flotation separation effect when the liquid level is low.

[0020] 3. High control precision and adaptive capability: Even if the water volume and gas source pressure change frequently, the liquid level can be dynamically adjusted adaptively to reduce the fluctuation range of the liquid level in the tank.

[0021] 4. No need to install a monitoring level gauge inside the tank, and no need to install an air vent valve on the top of the tank, saving costs.

[0022] 5. The dissolved air content in the tank is stable, which improves the stability of the dissolved air release zone and the air flotation separation effect. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of this utility model, the accompanying drawings used in the specific embodiments will be briefly described below. In all the drawings, the elements or parts are not necessarily drawn to scale.

[0024] Figure 1 This is a schematic diagram of the structure of an air flotation pressure dissolved air tank in one embodiment; Figure 2 for Figure 1 A schematic diagram showing that the liquid phase region of the middle tank is truncated cone-shaped; Figure 3 This is a schematic diagram showing that both the dissolved gas zone and the liquid phase zone of the tank have tapers with opposite taper directions; Figure 4 This is a schematic diagram showing that the dissolved gas zone and liquid phase zone of the tank are both ellipsoidal and symmetrically arranged.

[0025] Figure label: 10-Tank body, 11-Dissolved gas zone, 12-Liquid phase zone, 13-Level gauge, 14-Pressure gauge, 20-Water inlet system, 21-Water inlet pipe, 22-Spray head, 23-Pressure pump, 30-Compressed air system, 31-Compressed air pipe, 32-Flow meter, 40-Dissolved gas water discharge system, 41-Dissolved gas water discharge pipe, 42-Pressure control valve. Detailed Implementation

[0026] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0027] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0029] One embodiment of the water treatment apparatus includes, for example: Figure 1 The air flotation pressure dissolved air tank shown is specifically designed to include a tank body 10, a water inlet system 20, a compressed air system 30, and a dissolved air water discharge system 40.

[0030] Tank 10 is used to contain water and compressed air, and to dissolve the compressed air in water under a certain pressure to form dissolved air water. Tank 10 is generally made of pressure-resistant and corrosion-resistant materials, such as stainless steel.

[0031] The tank body 10 is provided with a dissolved gas zone 11 and a liquid phase zone 12 in sequence along the direction of gravity, with the liquid phase zone 12 located at the bottom of the dissolved gas zone 11. In one embodiment, the axial direction of the tank body 10 coincides with the direction of gravity, that is, the dissolved gas zone 11 and the liquid phase zone 12 are arranged in sequence along the axial direction of the tank body 10, with the dissolved gas zone 11 located in the upper half of the tank body 10 and the liquid phase zone 12 located in the lower half of the tank body 10.

[0032] In one embodiment, the cross-sectional area of ​​the dissolved gas region 11 gradually increases towards the liquid phase region 12. This can be considered as the radius of the dissolved gas region 11 gradually increasing towards the liquid phase region 12, resulting in a shape that is smaller at the top and larger at the bottom. In one embodiment, the shape of the dissolved gas region 11 can be a frustum. Of course, the shape of the dissolved gas region 11 can also be a semi-ellipsoid, or even a prism, as long as the cross-sectional area of ​​the dissolved gas region 11 gradually increases towards the liquid phase region 12.

[0033] In one embodiment, a level gauge 13 is installed on the outside of the tank 10. The level gauge 13 is used to display the liquid level inside the tank 10. The level gauge 13 can be a transparent connecting pipe that connects the liquid at the bottom of the tank 10 to the gas at the top, thus displaying the liquid level. A pressure gauge 14 is also installed on the tank 10 to detect the pressure inside the tank 10. The pressure gauge 14 can be installed on the top of the tank 10.

[0034] In one embodiment, the shape of the liquid phase zone 12 of the tank 10 can be specifically designed according to actual needs, as long as the dissolved air water residence time is 5-120 seconds. An excessively large diameter will result in material waste and increase the workload of transportation and installation.

[0035] For example, such as Figure 1 As shown, the liquid phase region 12 of the tank 10 can be cylindrical, and the radius of this cylinder is the same as the maximum radius of the dissolved gas region 11. Alternatively, as... Figure 2 As shown, the liquid phase region 12 is a frustum shape with its radius gradually increasing away from the dissolved gas region 11. The minimum radius of the liquid phase region 12 is the same as the maximum radius of the dissolved gas region 11, and the entire tank 10 is a relatively long frustum shape. Figure 3 and 4 As shown, or perhaps the liquid phase region 12 and the dissolved gas region 11 have similar shapes, but their taper directions are opposite.

[0036] Please refer to it again. Figure 1 The water inlet system 20 is used to supply water to the tank 10. The water source can be sewage or return water from air flotation. In one embodiment, the water inlet system 20 includes an inlet pipe 21 and a spray head 22. The spray head 22 is located in the dissolved air zone 11. The inlet pipe 21 passes through the tank 10 and is connected to the spray head 22. Water in the inlet pipe 21 can be sprayed out through the spray head 22.

[0037] The water sprayed from the spray head 22 is in a cone shape, which greatly increases the gas-water contact area and mass transfer rate. The dissolved gas zone 11 of the tank body 10 is shaped like a cone, which is smaller at the top and larger at the bottom, similar to the shape of the spray mist cone, thus increasing the gas-water contact area.

[0038] In one embodiment, the axis of the tank 10 forms an angle of 0-45° with the direction of gravity, and the spray head 22 is located on the axis of the tank 10. The centrally positioned spray head 22 maximizes the range of the circular mist it sprays and ensures uniform water distribution, thereby guaranteeing dissolved air efficiency. In this embodiment, the angle between the axis of the tank 10 and the direction of gravity is 0 degrees, meaning the axis of the tank 10 coincides with the direction of gravity, to ensure uniform water distribution and that the liquid phase zone 12 has a substantially uniform depth.

[0039] In one embodiment, the water inlet system 20 further includes a pressure pump 23, which is installed on the water inlet pipe 21 and is used to pressurize the water in the water inlet pipe 21.

[0040] The compressed air system 30 is used to inject compressed air into the tank 10. In one embodiment, the compressed air system 30 includes a compressed air pipe 31 and a flow meter 32. The compressed air pipe 31 is connected to the tank 10, and external compressed air is introduced into the dissolved air zone 11 of the tank 10 through the compressed air pipe 31.

[0041] Specifically, the compressed air pipeline 31 is connected to the top of the tank 10 to increase the contact time between the compressed air and water. A flow meter 32 is installed on the compressed air pipeline 31 and is used to detect the flow rate of the compressed air in the compressed air pipeline 31.

[0042] It is understood that in other embodiments, the compressed air pipe 31 may also be connected to the water inlet pipe 21, and the compressed air first enters the water inlet pipe 21 and then enters the tank 10 along with the water.

[0043] The dissolved air water discharge system 40 is used to discharge the dissolved air water in the tank 10, specifically into the flotation unit. In one embodiment, the dissolved air water discharge system 40 includes a dissolved air water discharge pipe 41 and a pressure control valve 42. The dissolved air water discharge pipe 41 is connected to the tank 10 and is used to discharge the dissolved air water in the liquid phase zone 12 of the tank 10.

[0044] Specifically, the dissolved air water discharge pipe 41 is connected to the liquid phase zone 12 of the tank 10, so that the dissolved air water can enter the dissolved air water discharge pipe 41 and be discharged into the air flotation machine. The pressure control valve 42 is installed on the dissolved air water discharge pipe 41 to control the pressure of the dissolved air water discharged from the dissolved air water discharge pipe 41.

[0045] The working principle of the above-mentioned water treatment equipment and its dissolved air flotation pressure tank is as follows: After the return water enters the tank 10 through the pipeline, it is sprayed down in a cone shape through the spray head 22, which greatly increases the air-water contact area and mass transfer rate. The dissolved air zone 11 of the tank 10 has a shape that is smaller at the top and larger at the bottom, which is similar to the shape of the spray mist cone.

[0046] The working liquid level inside tank 10 fluctuates between high and low levels. When the liquid level is high, it intercepts a portion of the spray mist cone's volume, reducing the mass transfer time. At this time, the gas absorbed by the water is less than the gas entering tank 10, causing the gas space to expand and the liquid level to drop. Conversely, when the liquid level reaches a low level, the mist cone's volume is at its maximum, the water's ability to absorb gas becomes stronger, and as the gas space contracts, the liquid level slowly rises again.

[0047] The aforementioned water treatment equipment and its dissolved air flotation pressure tank have high control precision, high dissolved air efficiency, and the system has self-adaptive capabilities. Even if the treated water volume and gas source pressure change frequently, the liquid level can automatically and dynamically adapt, reducing the fluctuation range of the liquid level in the tank. Moreover, the dissolved air content in the tank is stable, which improves the stability of the dissolved air release zone and the air flotation separation effect.

[0048] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.

Claims

1. An air float pressure dissolved air tank characterized by, include: The tank body has a gas-dissolving zone and a liquid phase zone arranged sequentially along the direction of gravity. The liquid phase zone is located at the bottom of the gas-dissolving zone, and the cross-sectional area of ​​the gas-dissolving zone gradually increases towards the liquid phase zone. The water inlet system includes an inlet pipe and a spray head. The spray head is located in the dissolved air zone, and the inlet pipe passes through the tank body and is connected to the spray head. A compressed air system for supplying compressed air into the tank; and A dissolved air water discharge system is used to discharge the dissolved air water from the liquid phase zone.

2. The pressure dissolved gas tank with air floatation according to claim 1, characterized in that, A level gauge is installed on the outside of the tank to display the liquid level inside the tank.

3. The pressure dissolved gas tank with air floatation according to claim 1, characterized in that, The tank is equipped with a pressure gauge for detecting the pressure inside the tank.

4. The pressure dissolved gas tank with air floatation according to claim 1, characterized in that, The liquid phase region of the tank is cylindrical or a frustum-shaped structure with a radius that gradually increases away from the dissolved gas region.

5. The pressure dissolved gas tank with air floatation according to claim 1, characterized in that, The water inlet system also includes a booster pump, which is installed on the water inlet pipe to pressurize the water in the water inlet pipe.

6. The pressure dissolved gas tank with air floatation according to claim 1, characterized in that, The compressed air system includes a compressed air pipeline and a flow meter. The compressed air pipeline is connected to the tank for supplying compressed air to the dissolved air zone, and the flow meter is installed on the compressed air pipeline.

7. The pressure dissolved gas tank with air floatation according to claim 6, characterized in that, The compressed air pipe is connected to the water inlet pipe.

8. The pressure dissolved gas holder according to claim 1, wherein The dissolved gas water discharge system includes a dissolved gas water discharge pipe and a pressure control valve. The dissolved gas water discharge pipe is connected to the tank body to discharge the dissolved gas water in the liquid phase zone, and the pressure control valve is installed on the dissolved gas water discharge pipe.

9. The pressure dissolved gas holder according to claim 1, wherein The axis of the tank has an angle of 0-45° with the direction of gravity, and the spray head is located on the axis of the tank.

10. A water treatment apparatus, characterized by, include: The air flotation pressure dissolved air tank as described in any one of claims 1-9.

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