Dissolved air flotation machine

Abstract

The utility model discloses a dissolved air flotation machine which comprises a box body, a separation area and a mud scraping device are arranged in the box body, an auxiliary separation area and a dirt collecting area are arranged at the rear end of the separation area, the auxiliary separation area is located between the separation area and the dirt collecting area, the front end of the mud scraping device is located above the auxiliary separation area, and an auxiliary dirt removing device is arranged at the bottom of the auxiliary separation area. According to the scheme, the auxiliary separation area is additionally arranged, and the sludge scraping device is arranged above the auxiliary separation area, so that floccules formed by tiny bubble breakage caused by scraping and extruding scum above the sludge scraping device and the auxiliary separation area are deposited in the auxiliary separation area, and formation of a large number of flocculent flow states in the separation area is reduced; and secondary air flotation treatment is carried out on floccules generated in the auxiliary separation area, so that the floccules formed by tiny bubble breakage caused by scraping and squeezing of the sludge scraping device and scum above the auxiliary separation area can be subjected to secondary air flotation treatment to achieve solid-liquid separation.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, and in particular to a dissolved air flotation machine. Background Technology

[0002] With the increasing severity of water pollution, water resources have become extremely precious. To fully utilize water resources and reduce environmental pollution, wastewater needs to be treated and recycled. Water pollution treatment equipment mainly includes centrifuges, aerators, sludge dewatering machines, and dissolved air flotation (DAF) machines. Among these, the DAF machine uses a dissolved air system to generate a large number of microbubbles in water, causing air to adhere to suspended particles in the form of highly dispersed microbubbles, creating a density less than water. Utilizing the principle of buoyancy, these particles float on the surface, thus achieving solid-liquid separation. DAF machines are classified into ultra-efficient shallow DAF machines, vortex DAF machines, and horizontal flow DAF machines. They are used in water supply, industrial wastewater, and municipal sewage treatment. The advantages of DAF machines include low investment, small footprint, high degree of automation, and convenient operation and management. The dissolved air flotation machine consists of a flocculation zone, a flotation zone, a separation zone, a sludge collection zone, and a clear water zone, arranged sequentially from front to back. A sludge scraping device is located above the separation zone, scraping the scum from the separation zone into the sludge collection zone. In existing dissolved air flotation (DAF) machines, multiple scrapers alternately operate in the upper layer of the separation zone. The scrapers frequently scrape and squeeze the scum in the upper layer of the separation zone, causing the tiny bubbles on the scum to break and create a turbulent state. The flocculated material is discharged with the treated wastewater, resulting in poor solid-liquid separation effect of the DAF machine.

[0003] For example, Chinese Patent Publication No. CN216191515U, published on April 5, 2022, entitled "Dissolved Air Flotation Machine", includes a flotation machine, a first partition, a second partition, a filter plate, a dissolved air pipe, a container release device, a return pipe, a support, a frame, a first rotating roller, a first reducer, a first motor, a conveyor belt, and a connecting pipe. The flotation machine is internally equipped with chambers. The first partition, the second partition, and the filter plate divide the flotation machine chambers into a reaction chamber, a flotation contact chamber, a separation zone, a sludge zone, and a clear water zone. The reaction chamber is equipped with a stirring device, and the separation zone is equipped with a sludge scraping device. The dissolved air pipe is installed on the flotation machine, and the input end of the dissolved air pipe is connected to the output end of the dissolved air tank. The container release device is installed on the dissolved air pipe and is located in the flotation contact chamber. The return pipe is installed on the flotation machine and is connected to the clear water zone. The output end of the return pipe is connected to the input end of the dissolved air tank.

[0004] The drawback of the existing patent is that when the existing dissolved air flotation machine is in use, multiple scrapers alternately run in the upper layer of the separation zone. The scrapers frequently scrape and squeeze the scum in the upper layer of the separation zone, causing the tiny bubbles on the scum to break and form a turbulent state. The flocculated material is discharged with the treated wastewater, resulting in poor solid-liquid separation effect of the dissolved air flotation machine. Utility Model Content

[0005] The purpose of this invention is to improve the solid-liquid separation effect of dissolved air flotation machines by addressing the problem that frequent scraping and squeezing of the scum by the scraper in the separation zone causes the tiny bubbles on the scum to burst and form a turbulent state, which is then discharged with the treated wastewater, thereby reducing the solid-liquid separation effect. This invention provides a dissolved air flotation machine that reduces the floc content of the treated wastewater and improves the solid-liquid separation effect.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A dissolved air flotation (DAF) machine includes a housing with a separation zone and a sludge scraping device inside. An auxiliary separation zone and a sludge collection zone are located at the rear end of the separation zone, with the auxiliary separation zone situated between the separation zone and the sludge collection zone. The front end of the sludge scraping device is positioned above the auxiliary separation zone, and an auxiliary decontamination device is located at the bottom of the auxiliary separation zone. This DAF machine adds an auxiliary separation zone between the separation zone and the sludge collection zone, and positions the sludge scraping device above the auxiliary separation zone. This allows the sludge scraping device to scrape and compress the scum above the auxiliary separation zone, causing the microbubbles to burst and form flocculent material, which is then deposited within the auxiliary separation zone, reducing the formation of large amounts of turbulent flow within the separation zone. The bottom of the separation zone is connected to a clear water zone, through which treated wastewater from the lower part of the separation zone is drained. Most of the flocculent material formed during the operation of the sludge scraping device is deposited within the auxiliary separation zone, reducing the flocculent content within the separation zone and improving the solid-liquid separation effect of the DAF machine. The bottom of the auxiliary separation zone is equipped with an auxiliary decontamination device, which can help remove flocculent matter in the auxiliary separation zone, preventing excessive flocculent matter from flowing back into the separation zone, and further improving the solid-liquid separation effect of the dissolved air flotation machine.

[0008] Preferably, the sludge scraping device includes a sprocket and a chain mounted on the sprocket. The chain is equipped with several scrapers, and the scrapers that pass over the front end of the sludge scraping device via the chain are all located above the auxiliary separation zone. The sludge scraping device extends from front to back, and the scrapers scrape sludge from front to back.

[0009] Preferably, the upper surface of the separation zone is flush with the upper surface of the auxiliary separation zone.

[0010] Preferably, the auxiliary decontamination device includes a drain pipe located at the bottom of the auxiliary separation zone, the drain pipe being connected to the auxiliary separation zone, and a drain valve installed on the drain pipe. When the dissolved air flotation machine operates for an extended period, the flocculent material at the bottom of the auxiliary separation zone can easily flow back into the separation zone, resulting in excessively high flocculent material content in the wastewater. This leads to excessively high flocculent material content in the wastewater discharged from the dissolved air flotation machine, affecting the solid-liquid separation effect and causing the discharged wastewater to fail to meet standards. This technical solution uses a drain pipe and drain valve to discharge wastewater from the auxiliary separation zone, allowing the flocculent material deposited at the bottom of the auxiliary separation zone to be cleaned regularly, preventing excessive accumulation of flocculent material at the bottom of the auxiliary separation zone, and further improving the solid-liquid separation effect of the dissolved air flotation machine.

[0011] Preferably, the drain pipe connects the bottom of the auxiliary separation zone and the bottom of the sludge collection zone. When draining sludge from the auxiliary separation zone, the drain pipe connects to the bottom of the sludge collection zone, flushing the bottom of the sludge collection zone and cleaning it.

[0012] Preferably, the drain valve is connected to a drain valve controller, which includes a time-delay relay. The drain valve controller controls the interval operation time of the drain valve through the time-delay relay. The time-delay relay controls the interval operation time of the drain valve controller based on the amount of flocculent material deposited at the bottom of the auxiliary separation zone.

[0013] Preferably, the front end of the separation zone is provided with an air flotation zone, and the auxiliary decontamination device includes a return pipe connecting the bottom of the auxiliary separation zone and the bottom of the air flotation zone. The return pipe connects the bottom of the auxiliary separation zone and the bottom of the air flotation zone so that the turbulent flow generated at the bottom of the auxiliary separation zone can flow back into the air flotation zone for secondary air flotation treatment, preventing excessive deposition of flocculent matter in the auxiliary separation zone and further improving the solid-liquid separation effect of the dissolved air flotation machine.

[0014] Preferably, the front end of the flotation zone is provided with a flocculation zone, and the bottom of the flocculation zone is provided with a connecting pipe communicating with the flotation zone. The return sludge end of the return pipe communicating with the flotation zone is higher than the connecting pipe. The flocculent content of the wastewater in the auxiliary separation zone is much lower than that of the wastewater flowing into the bottom of the flotation zone from the flocculation zone. Directly impacting the wastewater in the auxiliary separation zone with the connecting pipe at the same height would cause the wastewater at the bottom of the flotation zone to be diluted and the flocculents to rise, which would affect the flotation efficiency to some extent. In this technical solution, by setting the return sludge end of the return pipe communicating with the flotation zone higher than the connecting pipe, the wastewater returning from the auxiliary separation zone is subjected to secondary flotation treatment without affecting the original flocculent flotation treatment.

[0015] Preferably, the return pipe is located on the outside of the housing, and a solenoid valve is provided on the return pipe.

[0016] Preferably, the auxiliary decontamination device includes an aeration disc disposed at the bottom of the auxiliary separation zone. In this technical solution, by adding an aeration disc at the bottom of the auxiliary separation zone, the flocculent material generated within the auxiliary separation zone undergoes secondary air flotation treatment. This allows the flocculent material formed by the rupture of tiny bubbles caused by the scraping and squeezing of the sludge by the sludge scraper and the scum above the auxiliary separation zone to undergo another air flotation treatment, achieving solid-liquid separation.

[0017] Therefore, this utility model has the following beneficial effects: An auxiliary separation zone is added, and the sludge scraping device is positioned above the auxiliary separation zone, so that the flocculent material formed by the scraping and squeezing of the scum above the auxiliary separation zone due to the rupture of tiny bubbles is deposited in the auxiliary separation zone, reducing the formation of a large amount of turbulent flow in the separation zone; the flocculent material generated in the auxiliary separation zone undergoes secondary air flotation treatment, so that the flocculent material formed by the scraping and squeezing of the scum above the auxiliary separation zone due to the rupture of tiny bubbles can be air flotated again to achieve solid-liquid separation. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of Embodiment 2 of this utility model.

[0019] Figure 2 This is a cross-sectional view of Embodiment 3 of this utility model.

[0020] Figure 3 This is a structural schematic diagram of Embodiment 3 of this utility model.

[0021] Figure 4 This is a cross-sectional view of Embodiment 4 of this utility model.

[0022] As shown in the picture:

[0023] Box 1, Flocculation Zone 1.1, Air Flotation Zone 1.2, Separation Zone 1.3, Auxiliary Separation Zone 1.4, Sludge Collection Zone 1.5

[0024] Sludge scraping device 2, scraper 2.1,

[0025] 3. Connecting pipe; 4. Sewage discharge pipe; 5. Sewage return pipe; 6. Aeration disc. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the utility model will be further described below in conjunction with the accompanying drawings and specific implementation methods.

[0027] Example 1: A dissolved air flotation machine includes a housing 1, which contains a separation zone 1.3 and a sludge scraping device 2. The rear end of the separation zone 1.3 is provided with an auxiliary separation zone 1.4 and a sludge collection zone 1.5. The auxiliary separation zone 1.4 is located between the separation zone 1.3 and the sludge collection zone 1.5. The front end of the sludge scraping device 2 is located above the auxiliary separation zone 1.4. An auxiliary decontamination device is provided at the bottom of the auxiliary separation zone 1.4.

[0028] With increasing water pollution, water resources have become extremely precious. To fully utilize water resources and reduce environmental pollution, wastewater needs to be treated and recycled. Water pollution treatment equipment mainly includes centrifuges, aerators, sludge dewatering machines, and dissolved air flotation (DAF) machines. Among these, DAF machines use a dissolved air system to generate a large number of microbubbles in water, causing air to adhere to suspended particles in the form of highly dispersed microbubbles. These microbubbles create a density less than water, allowing the particles to float on the surface using buoyancy, thus achieving solid-liquid separation. DAF machines are classified into ultra-efficient shallow DAF machines, vortex DAF machines, and horizontal flow DAF machines. They are used in water supply, industrial wastewater, and municipal sewage treatment. The advantages of DAF machines include low investment, small footprint, high degree of automation, and convenient operation and management. The dissolved air flotation (DAF) unit consists of, from front to back, a flocculation zone 1.1, a flotation zone 1.2, a separation zone 1.3, a sludge collection zone 1.5, and a clear water zone. A sludge scraping device 2 is installed above the separation zone 1.3. The scraper in the sludge scraping device 2 scrapes the scum above the separation zone 1.3 into the sludge collection zone 1.5. In existing DAF units, multiple scrapers alternately operate above the separation zone 1.3. The frequent scraping and compression of the scum by the scrapers causes the tiny air bubbles on the scum to burst, resulting in flocculation. The flocculent material is discharged with the treated wastewater, leading to poor solid-liquid separation efficiency.

[0029] To address the issue that frequent scraping and squeezing of the scum by the scraper in separation zone 1.3 causes the tiny air bubbles on the scum to burst and become turbulent, which is then discharged with the treated wastewater, thus reducing the solid-liquid separation effect of the dissolved air flotation machine, a dissolved air flotation machine that reduces the floc content of the treated wastewater and improves the solid-liquid separation effect is provided.

[0030] In the above embodiment, an auxiliary separation zone 1.4 is added between the separation zone 1.3 and the sludge collection zone 1.5 in a dissolved air flotation machine. A sludge scraper 2 is positioned above the auxiliary separation zone 1.4 so that the flocculent material formed by the rupture of microbubbles due to scraping and squeezing of the scum above the auxiliary separation zone 1.4 by the scraper 2 settles in the auxiliary separation zone 1.4, reducing the formation of a large amount of turbulent flow in the separation zone 1.3. The bottom of the separation zone 1.3 is connected to a clear water zone, and the treated wastewater in the lower part of the separation zone 1.3 is drained through the clear water zone. Most of the flocculent material formed during the operation of the sludge scraper 2 settles in the auxiliary separation zone 1.4, reducing the flocculent content in the separation zone 1.3 and improving the solid-liquid separation effect of the dissolved air flotation machine. An auxiliary decontamination device is provided at the bottom of the auxiliary separation zone 1.4. This device helps remove the flocculent material in the auxiliary separation zone 1.4, preventing excessive flocculent material from causing turbulent flow back into the separation zone 1.3, further improving the solid-liquid separation effect of the dissolved air flotation machine.

[0031] Specifically, the sludge scraping device 2 includes a sprocket and a chain mounted on the sprocket. The chain is equipped with several scrapers 2.1, which are located above the auxiliary separation zone 1.4 as they pass over the front end of the sludge scraping device 2. The sludge scraping device 2 extends from front to back, and the scrapers 2.1 scrape the sludge from front to back.

[0032] In this embodiment, the upper surface of the separation zone 1.3 is flush with the upper surface of the auxiliary separation zone 1.4.

[0033] Example 2, as Figure 1 The dissolved air flotation machine shown includes a housing 1, which contains a separation zone 1.3 and a sludge scraping device 2. The rear end of the separation zone 1.3 is provided with an auxiliary separation zone 1.4 and a sludge collection zone 1.5. The auxiliary separation zone 1.4 is located between the separation zone 1.3 and the sludge collection zone 1.5. The front end of the sludge scraping device 2 is located above the auxiliary separation zone 1.4. An auxiliary decontamination device is provided at the bottom of the auxiliary separation zone 1.4.

[0034] In this embodiment, as Figure 1 As shown, the auxiliary decontamination device includes a drain pipe 4 located at the bottom of the auxiliary separation zone 1.4, which is connected to the auxiliary separation zone 1.4. A drain valve is installed on the drain pipe 4. When the dissolved air flotation (DAF) machine operates for a long time, the flocculent material at the bottom of the auxiliary separation zone 1.4 can easily flow back into the separation zone 1.3, resulting in excessively high flocculent material content in the wastewater of the separation zone 1.3. This leads to excessively high flocculent material content in the wastewater discharged from the DAF machine, affecting the solid-liquid separation effect and causing the discharged wastewater to fail to meet standards. In this technical solution, the drain pipe 4 and the drain valve work together to discharge wastewater from the auxiliary separation zone 1.4, allowing the flocculent material deposited at the bottom of the auxiliary separation zone 1.4 to be cleaned regularly, preventing excessive accumulation of flocculent material at the bottom of the auxiliary separation zone 1.4, and further improving the solid-liquid separation effect of the DAF machine.

[0035] Further optimization of sewage pipe 4, such as Figure 1 As shown, the drain pipe 4 connects the bottom of the auxiliary separation zone 1.4 and the bottom of the sludge collection zone 1.5. When draining sludge from the auxiliary separation zone 1.4, the drain pipe 4 connects to the bottom of the sludge collection zone 1.5 to flush the bottom of the sludge collection zone 1.5, thus cleaning the sludge collection zone 1.5.

[0036] Further optimization of sewage pipe 4, such as Figure 1 As shown, the drain valve is connected to a drain valve controller, which includes a time-delay relay. The drain valve controller controls the interval operation time of the drain valve through the time-delay relay. The time-delay relay controls the interval operation time of the drain valve controller based on the flocculent deposition at the bottom of the auxiliary separation zone 1.4.

[0037] Specifically, such as Figure 1 As shown, the sludge scraping device 2 includes a sprocket and a chain mounted on the sprocket. Several scraper blades 2.1 are provided on the chain. The scraper blades 2.1 that pass over the front end of the sludge scraping device 2 via the chain are all located above the auxiliary separation zone 1.4. The sludge scraping device 2 extends from front to back, and the scraper blades 2.1 scrape sludge from front to back.

[0038] In this embodiment, as Figure 1 As shown, the upper surface of separation zone 1.3 is flush with the upper surface of auxiliary separation zone 1.4.

[0039] To address the issue of reduced solid-liquid separation efficiency in dissolved air flotation (DAF) caused by frequent scraping and compression of the scum by the scraper in separation zone 1.3, resulting in the rupture of microbubbles on the scum and subsequent flocculation that is discharged with the treated wastewater, this embodiment adds an auxiliary separation zone 1.4. The sludge scraping device 2 is positioned above the auxiliary separation zone 1.4, allowing the flocculent material formed by the rupture of microbubbles due to scraping and compression of the scum above the auxiliary separation zone 1.4 to deposit within the auxiliary separation zone 1.4, thus reducing the formation of excessive flocculation within separation zone 1.3.

[0040] Example 3, as Figure 2 , Figure 3 The dissolved air flotation machine shown includes a housing 1, which contains a separation zone 1.3 and a sludge scraping device 2. The rear end of the separation zone 1.3 is provided with an auxiliary separation zone 1.4 and a sludge collection zone 1.5. The auxiliary separation zone 1.4 is located between the separation zone 1.3 and the sludge collection zone 1.5. The front end of the sludge scraping device 2 is located above the auxiliary separation zone 1.4. An auxiliary decontamination device is provided at the bottom of the auxiliary separation zone 1.4.

[0041] In this embodiment, as Figure 2 , Figure 3As shown, the front end of the separation zone 1.3 is equipped with an air flotation zone 1.2. The auxiliary decontamination device includes a return pipe 5 connecting the bottom of the auxiliary separation zone 1.4 and the bottom of the air flotation zone 1.2. The return pipe 5 connects the bottom of the auxiliary separation zone 1.4 and the bottom of the air flotation zone 1.2 so that the turbid flow generated at the bottom of the auxiliary separation zone 1.4 can flow back to the air flotation zone 1.2 for secondary air flotation treatment, preventing excessive deposition of flocculent matter in the auxiliary separation zone 1.4 and further improving the solid-liquid separation effect of the dissolved air flotation machine.

[0042] Further optimization of return sewage pipe 5, such as Figure 2 , Figure 3 As shown, a flocculation zone 1.1 is located at the front end of the flotation zone 1.2. A connecting pipe 3, which communicates with the flotation zone 1.2, is located at the bottom of the flocculation zone 1.1. The return end of the wastewater return pipe 5, which communicates with the flotation zone 1.2, is higher than the connecting pipe 3. The flocculent content of the wastewater in the auxiliary separation zone 1.4 is much lower than that of the wastewater flowing from the flocculation zone 1.1 into the bottom of the flotation zone 1.2. Directly impacting the wastewater in the auxiliary separation zone 1.4 with the connecting pipe 3 at the same height would dilute the wastewater at the bottom of the flotation zone 1.2 and cause the flocculents to rise, thus affecting the flotation efficiency to some extent. In this technical solution, by setting the return end of the wastewater return pipe 5, which communicates with the flotation zone 1.2, higher than the connecting pipe 3, a secondary flotation treatment is performed on the wastewater returning from the auxiliary separation zone 1.4 without affecting the original flocculent flotation treatment.

[0043] The return sewage pipe 5 has been further optimized, such as... Figure 2 , Figure 3 As shown, the return pipe 5 is located on the outside of the housing 1, and a solenoid valve is installed on the return pipe 5.

[0044] Specifically, such as Figure 2 , Figure 3 As shown, the sludge scraping device 2 includes a sprocket and a chain mounted on the sprocket. Several scraper blades 2.1 are provided on the chain. The scraper blades 2.1 that pass over the front end of the sludge scraping device 2 via the chain are all located above the auxiliary separation zone 1.4. The sludge scraping device 2 extends from front to back, and the scraper blades 2.1 scrape sludge from front to back.

[0045] In this embodiment, as Figure 2 , Figure 3 As shown, the upper surface of separation zone 1.3 is flush with the upper surface of auxiliary separation zone 1.4.

[0046] To address the issue of reduced solid-liquid separation efficiency in dissolved air flotation (DAF) caused by frequent scraping and compression of the scum by the scraper in separation zone 1.3, resulting in the rupture of tiny bubbles on the scum and subsequent flocculation that is discharged with the treated wastewater, this embodiment adds an auxiliary separation zone 1.4. A sludge scraper 2 is positioned above the auxiliary separation zone 1.4, allowing the flocculent material formed by the rupture of tiny bubbles due to scraping and compression between the scraper 2 and the scum above the auxiliary separation zone 1.4 to settle within the auxiliary separation zone 1.4, thus reducing the formation of excessive flocculation in separation zone 1.3. The flocculent material generated in the auxiliary separation zone 1.4 undergoes secondary flotation treatment, enabling the flocculent material formed by the rupture of tiny bubbles due to scraping and compression between the scraper 2 and the scum above the auxiliary separation zone 1.4 to undergo further flotation treatment to achieve solid-liquid separation.

[0047] Example 4, as Figure 4 The dissolved air flotation machine shown includes a housing 1, which contains a separation zone 1.3 and a sludge scraping device 2. The rear end of the separation zone 1.3 is provided with an auxiliary separation zone 1.4 and a sludge collection zone 1.5. The auxiliary separation zone 1.4 is located between the separation zone 1.3 and the sludge collection zone 1.5. The front end of the sludge scraping device 2 is located above the auxiliary separation zone 1.4. An auxiliary decontamination device is provided at the bottom of the auxiliary separation zone 1.4.

[0048] In this embodiment, as Figure 4 As shown, the auxiliary decontamination device includes an aeration disc 6 installed at the bottom of the auxiliary separation zone 1.4. In this technical solution, by adding an aeration disc 6 at the bottom of the auxiliary separation zone 1.4, the flocculent material generated in the auxiliary separation zone 1.4 undergoes secondary air flotation treatment, so that the flocculent material formed by the scraping and squeezing of the scum above the auxiliary separation zone 1.4 by the sludge scraping device 2 can undergo air flotation treatment again to achieve solid-liquid separation.

[0049] Specifically, such as Figure 4 As shown, the sludge scraping device 2 includes a sprocket and a chain mounted on the sprocket. Several scraper blades 2.1 are provided on the chain. The scraper blades 2.1 that pass over the front end of the sludge scraping device 2 via the chain are all located above the auxiliary separation zone 1.4. The sludge scraping device 2 extends from front to back, and the scraper blades 2.1 scrape sludge from front to back.

[0050] In this embodiment, as Figure 4 As shown, the upper surface of separation zone 1.3 is flush with the upper surface of auxiliary separation zone 1.4.

[0051] To address the issue of reduced solid-liquid separation efficiency in dissolved air flotation (DAF) caused by frequent scraping and compression of the scum by the scraper in separation zone 1.3, resulting in the rupture of tiny bubbles on the scum and subsequent flocculation that is discharged with the treated wastewater, this embodiment adds an auxiliary separation zone 1.4. A sludge scraper 2 is positioned above the auxiliary separation zone 1.4, allowing the flocculent material formed by the rupture of tiny bubbles due to scraping and compression between the scraper 2 and the scum above the auxiliary separation zone 1.4 to settle within the auxiliary separation zone 1.4, thus reducing the formation of excessive flocculation in separation zone 1.3. The flocculent material generated in the auxiliary separation zone 1.4 undergoes secondary flotation treatment, enabling the flocculent material formed by the rupture of tiny bubbles due to scraping and compression between the scraper 2 and the scum above the auxiliary separation zone 1.4 to undergo further flotation treatment to achieve solid-liquid separation.

[0052] The specific embodiments described above are merely preferred embodiments of this utility model and are not intended to limit the specific scope of implementation of this utility model. All equivalent changes made to the shape and structure of this utility model should be included within the protection scope of this utility model.

Claims

1. A dissolved air flotation machine, comprising a housing, wherein the housing is provided with a separation zone and a sludge scraping device, characterized in that, The rear end of the separation zone is provided with an auxiliary separation zone and a sludge collection zone. The auxiliary separation zone is located between the separation zone and the sludge collection zone. The sludge scraping device is located above the auxiliary separation zone, and the bottom of the auxiliary separation zone is provided with an auxiliary decontamination device.

2. The dissolved air flotation machine according to claim 1, characterized in that, The sludge scraping device includes a sprocket and a chain mounted on the sprocket. The chain is equipped with several scrapers, and the scrapers that pass around the front end of the sludge scraping device via the chain are all located above the auxiliary separation zone.

3. A dissolved air flotation machine according to claim 1 or 2, characterized in that, The upper surface of the separation zone is flush with the upper surface of the auxiliary separation zone.

4. A dissolved air flotation machine according to claim 1 or 2, characterized in that, The auxiliary decontamination device includes a drain pipe located at the lower part of the auxiliary separation zone, the drain pipe being connected to the auxiliary separation zone, and a drain valve being provided on the drain pipe.

5. A dissolved air flotation machine according to claim 4, characterized in that, The sewage pipe connects the bottom of the auxiliary separation zone and the bottom of the sewage collection zone.

6. A dissolved air flotation machine according to claim 4, characterized in that, The drain valve is connected to a drain valve controller, which includes a time delay relay. The drain valve controller controls the interval operation time of the drain valve through the time delay relay.

7. A dissolved air flotation machine according to claim 1 or 2, characterized in that, The front end of the separation zone is provided with an air flotation zone, and the auxiliary decontamination device includes a return pipe connecting the bottom of the auxiliary separation zone and the bottom of the air flotation zone.

8. A dissolved air flotation machine according to claim 7, characterized in that, The front end of the flotation zone is provided with a flocculation zone, and the bottom of the flocculation zone is provided with a connecting pipe that communicates with the flotation zone. The return sludge end of the return sludge pipe that communicates with the flotation zone is higher than the connecting pipe.

9. A dissolved air flotation machine according to claim 7, characterized in that, The return pipe is located on the outside of the box, and a solenoid valve is installed on the return pipe.

10. A dissolved air flotation machine according to claim 1 or 2, characterized in that, The auxiliary decontamination device includes an aeration disc located at the bottom of the auxiliary separation zone.

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