Double-reflux dissolved air flotation machine

Abstract

The utility model belongs to the technical field of air floatation machines, and particularly discloses a double-reflux dissolved air floatation machine which comprises an air floatation machine body, a dissolved air water reflux pump, a dissolved air tank, a dissolved air releaser and an easily settled matter reflux pump, the air flotation machine body sequentially comprises a contact area, a separation area and a clear water area from the head end to the tail end; a water inlet is formed in the side wall of the bottom of the contact area; the contact area and the separation area share a wall, the separation area and the clear water area share a wall, and a dissolved air releaser is mounted at the bottom of the contact area and is communicated with a dissolved air tank; a first reflux inlet is formed in the bottom of the separation area, and the first reflux inlet is communicated with the water inlet through an easily settled object reflux pump; a second reflux inlet is formed in the bottom of the clear water area, and the second reflux inlet is communicated with the dissolved air tank through a dissolved air water reflux pump. The double-reflux dissolved air flotation machine is provided with the dissolved air water reflux pump and the easily settled matter reflux pump, and an uninterrupted double-reflux operation mode is used, so that the removal rate of particulate matters is improved, and the effluent quality of the air flotation machine is ensured.

Description

Technical Field

[0001] The utility model belongs to the technical field of air flotation machines, and particularly relates to a double - return dissolved air flotation machine. Background Technique

[0002] The current air flotation process is widely used in the water treatment industry. The dissolved air flotation machine is a water treatment equipment that uses the air flotation process to achieve solid - liquid separation. Through the dissolved air system, a large number of fine bubbles are generated in water, so that air adheres to the suspended matter particles in the form of highly dispersed tiny bubbles, creating a state with a density less than that of water. Using the buoyancy principle, it floats on the water surface, thereby separating solids from liquids. The dissolved air flotation machine mainly includes a contact zone, a separation zone, a clear water zone, a scum zone, etc. However, the existing dissolved air flotation machines also have certain defects, resulting in unsatisfactory use effects under certain working conditions, and further causing abnormal operation of the downstream air flotation process.

[0003] For example, when using the air flotation process to treat wastewater with a high content of easily - sedimented particles, with a certain amount of dissolved air water, the buoyancy of the micro - bubbles provided by the air flotation machine is limited. This leads to the situation that after the easily - sedimented particles and the light - weight particles come into contact with the micro - bubbles at the same time, the floating time of the easily - sedimented particles on the water surface is shorter than that of the light - weight particles. During the subsequent process of waiting to be scraped by the scum scraper in the separation zone, it is easier to lose the floating state, settle from the water surface to the bottom, and thus accumulate continuously at the bottom, ultimately affecting the effluent quality of the air flotation machine.

[0004] Again, when the air flotation process operates intermittently, due to the stop of the influent, the liquid level in the separation zone will decrease compared with the normal influent situation. The scum scraper cannot contact the scum on the water surface, so it cannot scrape the scum. After a long time, the original scum on the water surface will sink to the bottom due to the fragmentation of the micro - bubbles and the disappearance of buoyancy, losing the floating state and accumulating continuously at the bottom. When starting up again next time, the particulate matter accumulated at the bottom may flow out along the production water pipe, affecting the effluent quality of the air flotation machine. Summary of the Utility Model

[0005] To solve the problems raised in the above - mentioned background technique, the utility model provides a double - return dissolved air flotation machine.

[0006] To achieve the above purpose, the utility model provides the following technical solution: A double - return dissolved air flotation machine, including an air flotation machine body, a dissolved air water return pump, a dissolved air tank, a dissolved air release device, and an easily - sedimented matter return pump; the dissolved air tank is arranged outside the air flotation machine body;

[0007] The air flotation machine body successively includes a contact zone, a separation zone, and a clear water zone from the head end to the tail end; an inlet is arranged on the bottom side wall of the contact zone;

[0008] The contact area and the separation area share a common wall, and the top height of the common side wall of the contact area and the separation area is lower than the top height of the dissolved air flotation machine body;

[0009] The separation area and the clear water area share a common wall, and the top height of the common side wall of the separation area and the clear water area is higher than or equal to the top height of the dissolved air flotation machine body;

[0010] A water production collecting pipe is installed through the common side wall of the separation area and the clear water area, and the height of one end of the water production collecting pipe located in the clear water area is higher than the height of one end located in the separation area;

[0011] A dissolved air release device is installed at the bottom of the contact area, and the dissolved air release device is communicated with a dissolved air tank; a first return port is arranged at the bottom of the separation area, and the first return port is communicated with the water inlet through a sediment return pump;

[0012] A second return port is arranged at the bottom of the clear water area, and the second return port is communicated with the dissolved air tank through a dissolved air water return pump.

[0013] Furthermore, a scum area is arranged at the upper part of the tail end of the separation area, the top height of the scum area is lower than the top height of the dissolved air flotation machine body, and is higher than the top height of the common side wall of the contact area and the separation area;

[0014] A sliding track is installed longitudinally above the tops of the contact area and the separation area, and a slag scraper is slidably installed on the sliding track.

[0015] Furthermore, the bottom of the separation area includes an inclined bottom and a flat bottom which are connected to each other, the inclined bottom slopes downward from the side close to the contact area to the side close to the clear water area, one side of the flat bottom is connected to the inclined bottom, and the other side is connected to the bottom of the clear water area.

[0016] Furthermore, the first return port is arranged on the flat bottom.

[0017] Furthermore, the water production collecting pipe is installed vertically and includes a bent pipe and a straight pipe which are communicated with each other, one end of the bent pipe is located in the separation area, the other end is located in the clear water area, and the straight pipe is located in the clear water area.

[0018] Furthermore, a liftable water outlet weir plate is arranged at the tail end of the clear water area.

[0019] Compared with the prior art, in view of the defect that the water quality of the effluent of the existing dissolved air flotation machine deteriorates under certain working conditions, the utility model develops a new type of dissolved air flotation machine with wide applicability, stable operation and good effluent effect, and has the following beneficial effects:

[0020] 1. The double - reflux dissolved air flotation machine of the present utility model is provided with a dissolved air water reflux pump and a readily - sedimentable material reflux pump, achieving double reflux. The design of double reflux retains the dissolved air water reflux while adding the readily - sedimentable material reflux and optimizing the operation mode, that is, using an uninterrupted double - reflux operation mode to improve the removal rate of particulate matter, thereby ensuring the effluent water quality of the flotation machine.

[0021] 2. When using this double - reflux dissolved air flotation machine to treat wastewater with a high content of readily - sedimentable particles, the readily - sedimentable particles that settle to the bottom return to the contact zone through the way of readily - sedimentable material reflux. Together with the influent water, after contacting micro - bubbles again, they enter the separation zone and are scraped off by the slag scraper. Because the readily - sedimentable material reflux is a continuous process, even if a small amount of readily - sedimentable particles are not scraped off by the slag scraper within the limited floating time, they will eventually be scraped off along with the process of re - floating during each reflux, thus making the effluent water quality of the flotation machine better.

[0022] 3. When using this double - reflux dissolved air flotation machine for intermittent operation, the influent water stops but the double reflux continues. After the influent water stops, the liquid level in the separation zone drops, and the slag scraper cannot reach the floating scum on the water surface, so the floating scum cannot be scraped off. However, when the floating scum that has lost its floating state settles to the bottom, it will return to the contact zone through the way of readily - sedimentable material reflux, contact the micro - bubbles brought by the dissolved air water reflux, and float again in the separation zone, and this process is repeated continuously during the period when the influent water stops, so as to ensure that there is no accumulation of particulate matter at the bottom of the separation zone and it will not affect the effluent water quality of the flotation machine during the next startup. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a structural schematic diagram of the double - reflux dissolved air flotation machine of the present utility model;

[0024] In the figure: 1. Dissolved air water reflux pump; 2. Dissolved air tank; 3. Dissolved air release device; 4. Readily - sedimentable material reflux pump; 5. Contact zone; 6. Separation zone; 7. Clear water zone; 8. Influent water inlet; 9. Produced water collection pipe; 10. First reflux port; 11. Second reflux port; 12. Floating scum zone; 13. Sliding track; 14. Slag scraper; 15. Inclined bottom; 16. Flat bottom. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0026] Such as Figure 1As shown in the figure, a double - reflux dissolved air flotation machine provided by the present utility model includes a flotation machine body, a dissolved air water reflux pump 1, a dissolved air tank 2, a dissolved air release device 3, and a readily - sedimentable material reflux pump 4. The dissolved air tank 2 is arranged outside the flotation machine body.

[0027] The flotation machine body successively includes a contact zone 5, a separation zone 6, and a clear water zone 7 from the head end to the tail end; an inlet 8 is provided on the bottom side wall of the contact zone 5; the contact zone 5 and the separation zone 6 share a common wall, and the top height of the common side wall of the contact zone 5 and the separation zone 6 is lower than the top height of the flotation machine body; that is, the tops of the contact zone 5 and the separation zone 6 are interconnected.

[0028] In order to improve the water dispersion in the contact zone 5, a water distribution device can be arranged in the contact zone 5 to assist the diffusion of the wastewater to be treated.

[0029] The separation zone 6 and the clear water zone 7 share a common wall, and the top height of the common side wall of the separation zone 6 and the clear water zone 7 is higher than or equal to the top height of the flotation machine body; that is, the tops of the separation zone 6 and the clear water zone 7 are not interconnected.

[0030] A water production collection pipe 9 is installed through the common side wall of the separation zone 6 and the clear water zone 7, and the height of the end of the water production collection pipe 9 located in the clear water zone 7 is higher than the height of the end located in the separation zone 6; a dissolved air release device 3 is installed at the bottom of the contact zone 5, and the dissolved air release device 3 is communicated with the dissolved air tank 2; a first reflux port 10 is provided at the bottom of the separation zone 6, and the first reflux port 10 is communicated with the inlet 8 through the readily - sedimentable material reflux pump 4; a second reflux port 11 is provided at the bottom of the clear water zone 7, and the second reflux port 11 is communicated with the dissolved air tank 2 through the dissolved air water reflux pump 1.

[0031] A scum zone 12 is provided at the upper part of the tail end of the separation zone 6, the top height of the scum zone 12 is lower than the top height of the flotation machine body and higher than the top height of the common side wall of the contact zone 5 and the separation zone 6; a sliding track 13 is installed longitudinally above the tops of the contact zone 5 and the separation zone 6, and a scum scraper 14 is slidably installed on the sliding track 13. The scum scraper 14 can reciprocally slide along the tops of the contact zone 5 and the separation zone 6 to scrape the scum above the liquid surface into the scum zone 12.

[0032] The bottom of the separation zone 6 includes an inclined bottom 15 and a flat bottom 16 that are connected to each other. The inclined bottom 15 slopes downward from the side close to the contact zone 5 to the side close to the clear water zone 7. One side of the flat bottom 16 is connected to the inclined bottom 15, and the other side is connected to the bottom of the clear water zone 7. The first reflux port 10 is arranged on the flat bottom 16.

[0033] The water production collection pipe 9 is vertically installed and includes a bent pipe and a straight pipe that are interconnected. One end of the bent pipe is located in the separation zone 6, the other end is located in the clear water zone 7, and the straight pipe is located in the clear water zone 7.

[0034] One end of the elbow of the water production collection pipe 9 is located at a position slightly below the middle of the separation area 6, which is used to collect the clear water after solid-liquid separation. The height slightly below the middle and the water collection method with a downward bend can avoid collecting the sinking particulate matter as much as possible and ensure the quality of the clear water.

[0035] A liftable effluent weir plate is provided at the end of the clear water area 7.

[0036] When the double-return dissolved air flotation machine of the present utility model is operating normally, the working steps are as follows:

[0037] (1) The wastewater to be treated containing easily sedimentable particles and light particles enters the contact area 5 from the water inlet 8. The water distribution device can assist in evenly distributing the wastewater to be treated into the contact area 5, and contacts a large number of microbubbles generated by the dissolved air release device 3. Relying on the buoyancy brought by the microbubbles, it floats on the water surface, and a large amount of floating scum is formed above the contact area 5 and the separation area 6.

[0038] (2) Most of the floating scum can be scraped into the floating scum area 12 for temporary storage by the scum scraper 14 within a limited time, and then discharged outside the device through the external discharge port of the floating scum area 12; a small part of the floating scum formed by easily sedimentable particles sinks to the bottom after floating for a period of time under the influence of gravity.

[0039] (3) At the bottom of the separation area 6, the easily sedimentable particles flow along the inclined bottom 15 to the flat bottom 16, and are transported to the contact area 5 again under the action of the easily sedimentable matter return pump 4 through the first return port 10. Together with the influent water, they contact the microbubbles again and float above the water surface and enter the separation area 6, forming new floating scum to be scraped off by the scum scraper 14 to the floating scum area 12.

[0040] The return of easily sedimentable matter is a continuous process. Even if a small amount of easily sedimentable particles are not scraped off by the scum scraper 14 within the limited floating time, they will eventually be scraped off along with the process of floating again and again, so as to make the effluent quality of the flotation machine better.

[0041] (4) The effluent formed in the separation area 6 is collected into the clear water area 7 for temporary storage through the water production collection pipe 9, and is discharged from the clear water area 7 after the liquid level exceeds the effluent weir plate.

[0042] (5) In the clear water area 7, a part of the clear water enters the dissolved air tank 2 under the pressure of the dissolved air water return pump 1 through the second return port 11 at the bottom. The dissolved air tank 2 adjusts the injection amount of compressed air through the opening and closing of the automatic valve. The clear water in the dissolved air tank 2 is mixed with compressed air into dissolved air water under high pressure conditions, and finally discharged through the dissolved air release device 3 after decompression, which can provide enough microbubbles for the contact area 5.

[0043] During the normal operation process, the height of the effluent weir plate and the influent flow rate can be manually adjusted, so as to indirectly control the liquid level height in the separation area 6 and ensure that the contact surface between the scum scraper 14 and the floating scum is within a reasonable and appropriate range.

[0044] During intermittent operation, the working steps are as follows:

[0045] (1) The wastewater to be treated stops entering, and the sediment return pump 4 and the dissolved air water return pump 1 continue to operate. As the liquid level in the separation zone 6 gradually drops, the scum scraper 14 cannot contact the scum and cannot perform the scum scraping operation. After a period of time, the scum originally on the water surface will lose its buoyancy as the microbubbles burst, lose its floating state, and settle to the bottom.

[0046] (2) At this time, the bottom particulate matter is transported to the contact zone 5 by the sediment return pump 4, evenly dispersed through the water distribution device, enters the separation zone 6 again after contacting the microbubbles, and forms new scum.

[0047] During the period when the water inlet stops, the above process is repeated to ensure that there is no accumulation of particulate matter at the bottom. Since the dissolved air water return pump 1 continues to work, a continuous supply of clear water will enter the contact zone 5 through the dissolved air water return pump 1 and then enter the clear water zone 7 through the water production collection pipe 9. The liquid level height in the clear water zone 7 is stable enough to ensure that the dissolved air water return pump 1 keeps running. In addition, in the case of no new water inlet into the equipment, even if the scum remaining in the separation zone 6 is not scraped off temporarily, when it is returned by the sediment return pump 4, the total amount of particulate matter does not increase, and the buoyancy of the microbubbles provided by the dissolved air water return is sufficient to maintain the normal floating time, so it will not affect the quality of the clear water. When the equipment is restarted next time, the liquid level in the separation zone 6 returns to the normal state, and the scum can be normally scraped off.

[0048] In the present utility model, each device can be controlled through the control cabinet. The operating parameters of the double - return dissolved air flotation machine are determined in advance according to the characteristics of the wastewater to be treated and set on the control cabinet. The entire operation process is operated through the control cabinet. Whether the water inlet stops or not, the double - return mode of the flotation machine will not be interrupted, thus ensuring the continuous floating of particulate matter and the water quality effect in the clear water zone 7.

[0049] The present utility model optimizes the structure, configuration and operation mode of the existing flotation machine, overcomes the defect that the use effect of the existing flotation machine is not ideal under certain working conditions, realizes the improvement of the effluent water quality, avoids the accumulation of particulate matter at the bottom of the separation zone 6, reduces the workload of manual cleaning, expands the application scenarios and applicable working conditions of the flotation process, simplifies the operation, and reduces the failure rate. The present utility model can use a standardized design, skid - mounted modules, with a compact structure and low cost; it can also be customized differently according to the characteristics of the influent water quality, such as the equipment material, structural form, etc.; it can also directly perform a double - return transformation on the basis of the existing flotation machine, achieving a huge improvement in the overall process effect with a small transformation amplitude, not only saving a large amount of cost but also shortening the transformation period, which is of extremely high cost - effectiveness for customers who are using the flotation process in the market.

[0050] Although embodiments of the present utility model have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present utility model. The scope of the present utility model is defined by the appended claims and their equivalents.

Claims

1. A double reflux dissolved air flotation machine, characterized in that: It includes an air flotation machine body, a dissolved air water reflux pump, an air dissolving tank, a dissolved air releaser, and an easy-to-sink object reflux pump; the air dissolving tank is arranged outside the air flotation machine body; The air flotation machine body includes a contact area, a separation area and a clean water area from the head end to the tail end; a water inlet is provided on the bottom side wall of the contact area; The contact zone and the separation zone share a common wall, and the top height of the common side wall of the contact zone and the separation zone is lower than the top height of the air flotation machine body; The separation zone and the clean water zone share a common wall, and the top height of the common side wall of the separation zone and the clean water zone is higher than or equal to the top height of the air flotation machine body; A produced water collecting pipe is installed through the common side wall of the separation zone and the clean water zone, and the height of one end of the produced water collecting pipe located in the clean water zone is higher than that of the other end located in the separation zone; A dissolved air releaser is installed at the bottom of the contact zone, and the dissolved air releaser is connected to the dissolved air tank; a first reflux port is provided at the bottom of the separation zone, and the first reflux port is connected to the water inlet through a reflux pump for easily precipitated objects; A second reflux port is provided at the bottom of the clean water zone, and the second reflux port is connected to the dissolved air tank through a dissolved air water reflux pump.

2. The double reflux dissolved air flotation machine according to claim 1, characterized in that: A scum zone is provided at the upper part of the tail end of the separation zone, the top height of the scum zone is lower than the top height of the air flotation machine body, and higher than the top height of the common side wall of the contact zone and the separation zone; A sliding track is installed above the top of the contact area and the separation area along the longitudinal direction thereof, and a scraper is slidably installed on the sliding track.

3. The double reflux dissolved air flotation machine according to claim 1, characterized in that: The bottom of the separation zone includes an inclined bottom and a flat bottom connected to each other. The inclined bottom slopes downward from a side close to the contact zone to a side close to the clear water zone. One side of the flat bottom is connected to the inclined bottom, and the other side is connected to the bottom of the clear water zone.

4. The double reflux dissolved air flotation machine as claimed in claim 3, characterized in that: The first reflux port is arranged on the flat bottom.

5. The double reflux dissolved air flotation machine according to claim 1, characterized in that: The produced water collecting pipe is installed vertically and comprises an elbow and a straight pipe which are interconnected. One end of the elbow is located in the separation zone and the other end is located in the clean water zone. The straight pipe is located in the clean water zone.

6. The double reflux dissolved air flotation machine according to claim 1, characterized in that: A liftable water outlet weir plate is provided at the tail end of the clean water zone.

Images