Sewage surface foam scum treatment device and method

Abstract

The invention discloses a sewage surface foam and scum treatment device and method. The sewage surface foam and scum treatment device comprises a pretreatment tank and an oxidation treatment tank, the pretreatment tank comprises a sewage area and a filter area, a water outlet is formed in the partition plate, an inclined scum discharge pipe with the upper end penetrating through the sewage area to be communicated with the outside is arranged at the water outlet, and the bottom of the scum discharge pipe is of a filter plate structure; the filtering area is communicated with the oxidation treatment tank; a foam scum discharging device is arranged at the upper end of the scum discharging pipe and comprises a driving rotary drum, a plurality of scraping plates are arranged on the outer surface of the driving rotary drum in the circumferential direction, the ends of the scraping plates are of an L-hook-shaped structure, a discharging groove is formed in the outer wall, beside the scraping plates, of the driving rotary drum, and the bottom face of the discharging groove is obliquely arranged; and the driving drum can rotate to drive the scraper to move to the outlet of the scum discharge pipe to remove foam scum. The water outlet structure of the pretreatment tank is improved, and meanwhile, the foam and scum discharging device with an improved structure is arranged, so that collection and defoaming treatment of foam and scum can be realized during scraping.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to a device and method for treating foam scum on the surface of sewage. Background Art

[0002] Before sewage is treated, its surface usually contains a large amount of foam, scum, grease and other substances. If it is not treated in the early stage, a lot of foam, scum, grease and other substances will be trapped on the surface of the biochemical pool, thereby hindering the entry of oxygen into the mixed liquid of the aeration tank, resulting in reduced oxygenation efficiency or increased suspended solids and COD in the effluent of the secondary sedimentation tank, increasing the operating pressure of deep treatment, affecting the pool surface sensory and stable effluent water quality to meet discharge standards.

[0003] Therefore, it is very necessary to treat the foam, scum, grease and other substances on the surface of sewage before it enters the oxidation treatment tank. The current conventional treatment method is to set a foam scraper at the water inlet between the pretreatment tank and the oxidation treatment tank to scrape it off, but the removal effect is poor, and additional structures are required to transport and collect the scraped foam and subsequently defoam it.

[0004] In view of this, this application is hereby filed. Summary of the invention

[0005] The technical problem to be solved by the present invention is that the existing means of treating foam scum, grease and the like is to set a foam scraper at the water inlet between the pretreatment tank and the oxidation treatment tank to scrape them off, but the removal effect is poor, and an additional structure is required to transport, collect and subsequently defoam the scraped foam. The purpose is to provide a device and method for treating foam scum on the surface of sewage, by improving the water outlet structure of the pretreatment tank and setting a foam scum discharge device with an improved structure, so that the foam scum can be collected and defoamed while being scraped off.

[0006] The present invention is achieved through the following technical solutions:

[0007] In a first aspect, the present invention provides a sewage surface foam scum treatment device, comprising a pretreatment tank and an oxidation treatment tank;

[0008] The pretreatment tank includes a sewage area and a filtration area separated by a partition, a water outlet is provided on the partition, a scum discharge pipe inclined upward is provided at the water outlet, the scum discharge pipe is located in the sewage area and the upper end passes through the sewage area and is connected to the outside, the bottom of the scum discharge pipe is a filter plate structure, and the water in the sewage area enters the filtration area after being filtered by the filter plate structure;

[0009] The filtration area is connected to the oxidation treatment tank;

[0010] A foam scum discharge device is arranged at the outlet of the upper end of the scum discharge pipe, and the foam scum discharge device includes a driving drum arranged parallel to the outlet of the scum discharge pipe, and a plurality of scrapers are arranged in sequence along the circumferential direction on the outer surface of the driving drum, and the ends of the scrapers are in an L-hook shape. A discharge groove is opened on the outer wall of the driving drum beside the scraper, and the bottom surface of the discharge groove is inclined along the axis direction of the driving drum; the driving drum can rotate around its own axis to drive the scraper to move to the outlet of the scum discharge pipe to remove the foam scum.

[0011] At present, a water inlet is set between the pretreatment tank and the oxidation treatment tank, and then an interception tank is set at the water inlet, and a scraper is set above the interception tank. The sewage moves along the interception tank, so that under the action of the movement direction, the surface foam scum and the sewage below are separated by the interception tank. The surface foam scum remains on the interception tank, and other sewage enters the oxidation treatment tank from below the interception tank. This structure has the problem of incomplete removal of foam scum, and the foam scum on the interception tank is also prone to reflux under the impact of the sewage flow.

[0012] The foam scum treatment device of the present invention sets the pretreatment tank into two areas, and uses the filter area as the transition area between the pretreatment tank and the oxidation treatment tank. The lower part of the sewage without foam scum passes through the filter plate structure below the scum discharge pipe and enters the filter area and then enters the oxidation treatment tank, thereby preventing the surface foam scum from entering the oxidation treatment tank along the water flow direction. The scum discharge pipe structure is inclined upward, and the filter plate structure is much lower than the upper end opening of the scum discharge pipe, so that the water surface height of the sewage can always be maintained at a position close to the upper end outlet of the scum discharge pipe. On the one hand, it is avoided that the water surface height at the filter plate structure causes the foam scum to cover the filter plate structure and affect the water flow effect. On the other hand, the inclined structure also limits the movement direction of the foam scum on the water surface in the scum discharge pipe from bottom to top, without downward impulse, which can ensure the independence of the scum foam movement and the bottom filter plate structure in the direction of movement, and ensure the full separation of sewage and foam scum.

[0013] Since the sewage continuously enters the pretreatment tank, the pretreated water surface can continuously fluctuate. Under the action of the water flow fluctuation, the foam scum can be discharged back and forth at the outlet of the scum discharge pipe, and the driving drum drives the scraper to rotate. When the L-hook structure at the end of the scraper rotates from bottom to top to the outlet of the scum discharge pipe, the foam scum and other materials can be scraped into the L-hook structure. The scraper continues to rotate upward, and the foam scum on the scraper can flow back along the scraper to the discharge trough, and then be discharged into the collection device from the inclined discharge trough. Multiple scrapers repeat the above operation, and the foam scum overflowing from the scum discharge pipe can be continuously scraped and collected. In the foam scum treatment device of the present invention, the scraper is completely separated and independent from the entire sewage, and the scraper is in contact with the foam scum only at the opening of the scum discharge pipe. Therefore, relatively speaking, the sewage will no longer generate a continuous impact on the scraper, and the foam scum will not flow back. From a macroscopic perspective, the foam scum in the pretreatment tank of the present application is stationary and always remains at a horizontal height, and will not impact the foam discharge device along with the water flow. From a microscopic perspective, the foam scum on the water surface will fluctuate under the action of the lower water body, thereby gushing out and retreating to the opening on the scum discharge pipe at intervals in a tidal manner, thereby achieving intermittent discharge of the foam scum.

[0014] In a specific embodiment, the scraper is a hollow structure, including a fixed plate and a movable plate. The fixed plate is vertically installed directly above the discharge groove, and one end of the movable plate is movably mounted on the fixed plate. The movable plate can be retracted or extended from the fixed plate along the radial direction of the driving drum under the action of its own gravity; the other end of the movable plate is an L-hook structure, and the end opening is connected to the discharge groove.

[0015] The present invention sets the scraper into a hollow structure, so that the foam scum can enter the interior from the end opening of the scraper, and then flow into the discharge groove along the internal hollow structure, that is, the foam scum is wrapped inside the scraper for transportation, so as to avoid flowing to other places during the rotation process; at the same time, the scraper is set into a double-section structure, when the scraper scrapes the foam scum and continues to move upward to the highest point, the movable plate can slowly and gradually slide into the fixed plate under the action of its own gravity to narrow the distance between the L-hook structure and the fixed plate, and when reaching the highest point, the movable plate completely slides into the fixed plate in an instant, and the impact force generated between the movable plate and the fixed plate can shake off the foam scum adhered to the inside of the movable plate, so that it is fully discharged, and then after the scraper continues to rotate to the lowest point, the movable plate is completely extended out of the fixed plate under the action of gravity to carry out the next scraping work. The present invention utilizes an ingenious rotating structure to enable the scraper to transport the foam scum to the collection device while scraping the foam scum without the need for an additional transport structure. At the same time, the self-gravity of the scraper with a double-layer telescopic structure can be used to efficiently discharge the foam scum, avoiding adhesion to the inside of the scraper and affecting the subsequent scraping and transportation of the foam scum. In addition, by setting the scraper as a hollow structure, the end face opening has a certain siphon effect, which can be more conducive to the adsorption of foam.

[0016] In a specific embodiment, the water outlet is in a horizontal long strip structure, the internal height dimension of the scum discharge pipe gradually decreases from the lower end to the upper end, and the inclination angle of the bottom plate of the scum discharge pipe is greater than the inclination angle of the top plate.

[0017] The present invention provides a scum discharge pipe structure with a larger bottom and a smaller top and a bottom inclination angle greater than the top inclination angle. Firstly, it can ensure that there is a sufficient height difference between the filter plate structure and the upper end of the scum discharge pipe. Secondly, the structure can buffer the impact of the foam scum during the fluctuation process, thereby controlling the overflow of the foam scum.

[0018] A cleaning pool is provided below the driving drum beside the upper end outlet of the scum discharge pipe, and the cleaning pool is filled with cleaning water.

[0019] The present invention arranges a cleaning pool below the foam scum discharge device. When the scraper moves to the bottom, its end can be extended into the water of the clean water pool for simple wetting and cleaning to remove a small amount of residual foam scum at the end, thereby preventing the foam scum subsequently scraped off by the scraper from aggregating and adsorbing with the previous residual foam scum, thereby affecting the discharge effect.

[0020] In a specific embodiment, the opening surface of the L-hook-shaped structure at the end of the moving plate is inclined, so that the end is a tapered structure. The present invention sets the opening surface of the L-hook-shaped structure to be an inclined structure. First, the inclined structure can increase the contact area between the L-hook-shaped structure and the foam scum, so that it can smoothly enter the internal hollow structure. Secondly, after the opening inclined surface is set to increase the area, the height of the inclined surface entrance can be designed to be relatively narrow. In this way, when the foam scum enters the opening inclined surface and reaches the entrance, the narrow entrance can play a certain defoaming role. At the same time, the siphon principle can be used to suck all the foam on the opening inclined surface into the interior to avoid remaining on the opening inclined surface.

[0021] In a specific embodiment, in the sewage area, a wave-pushing shaft is provided at the extension direction of the lower end of the slag discharge pipe, the wave-pushing shaft can rotate around its own axis, and a wave-pushing plate is vertically connected to the wave-pushing shaft.

[0022] In order to produce more regular waves on the water surface at the scum discharge pipe, the present application arranges a wave pushing shaft and a wave pushing board. When the wave pushing board moves toward the scum discharge pipe, the sewage below is pushed into the scum discharge pipe to generate an outward impact force, causing the foam scum to overflow from the scum discharge pipe outlet. When the wave pushing board moves away from the scum discharge pipe, the water surface in the scum discharge pipe retreats smoothly until the wave pushing board moves toward the scum discharge pipe again. The above operation is continued to generate waves at a certain frequency interval at the opening at the upper end of the scum discharge pipe, corresponding to multiple scrapers, to achieve continuous removal of foam scum.

[0023] In a specific embodiment, the wave-pushing plate has an arc-shaped structure, which can increase the contact area with the sewage and make the generated driving force more concentrated and stable.

[0024] In a specific embodiment, a spray pipe is provided above the upper end outlet of the scum discharge pipe, and the spray pipe can spray adsorption powder into the opening of the movable plate. The adsorption powder is polylactic acid-glycolic acid copolymer microspheres coated with magnesium aluminum silicate, which can be used to adsorb foam scum and grease to form a gel-like structure.

[0025] Foam, grease and other substances on the surface of sewage are all substances with strong adhesion, so a certain amount of grease and foam substances will still remain on the scraper. Therefore, the present invention sprays adsorption powder of polylactic acid-glycolic acid copolymer microspheres coated with magnesium aluminum silicate on the scraper. The outer layer of magnesium aluminum silicate has a very large specific surface area and a porous structure, and can adsorb oily substances many times its own weight. Therefore, after the foam and grease are scraped onto the scraper, the magnesium aluminum silicate can quickly adsorb the grease and foam to form a continuously thickening gel-like substance. The gel substance after adsorbing the grease and foam has good fluidity and can easily slide from the inner wall of the scraper into the discharge groove. The polylactic acid-glycolic acid copolymer is a low-molecular-weight degradable material with a fast degradation rate and no pollution to the environment, and also solves the subsequent foam defoaming problem.

[0026] The preparation method of magnesium aluminum silicate coated polylactic acid-glycolic acid copolymer microspheres is as follows: tetraethyl orthosilicate, hydrochloric acid and water are mixed and stirred to form a gel, a solution of aluminum sulfate and magnesium sulfate is added dropwise, stirred and mixed, and ammonia water is added dropwise to obtain magnesium aluminum silicate sol; then polylactic acid-glycolic acid copolymer microsphere powder is added to the magnesium aluminum silicate sol, stirred and mixed, aged, washed with clean water, calcined, and finally ball milled to obtain a powdered material.

[0027] In a specific embodiment, a buffer interface pipe is provided at the upper opening of the scum discharge pipe, and the buffer interface pipe is perpendicular to the outer wall of the pretreatment tank. By providing the buffer interface pipe to extend the length and angle of the upper opening of the scum discharge pipe, it is more conducive to the coordination and connection between the foam scum discharge and the scraping of the scraper.

[0028] In a specific embodiment, the buffer interface pipe is tilted downward to form an inverted V-shaped structure with the slag discharge pipe. The inclination angle of the upper plate of the buffer interface pipe is greater than the inclination angle of the lower plate, and the lower plate of the buffer interface pipe is hinged to the side wall of the pool at the outlet of the slag discharge pipe. The lower plate of the buffer interface pipe can contact the scraper and rotate upward driven by the scraper, and can freely fall to the original position after separation from the scraper.

[0029] The buffer interface tube of the present invention is arranged to be tilted downward, firstly, the movement path of the overflowing foam can be extended by tilting, and at the same time, the foam waste residue can directly "fall" into the scraper after moving through the tilted buffer interface tube; the structure of the buffer interface tube that is larger at the top and smaller at the bottom can buffer the impact force of the overflowing foam, so that it can fall onto the scraper in a concentrated manner with a smaller area; finally, the present invention arranges the lower plate of the buffer interface tube as a hinged structure, and when the scraper rotates upward to the lower plate, the foam waste residue falls from the buffer interface tube onto the scraper, and the scraper contacts the lower plate and drives it to rotate upward (it can also move to contact the end of the upper plate to close the buffer interface tube), so that a reverse driving force can be applied to the foam scum that is about to overflow the lower plate to make it return to the scum discharge pipe, and as the scraper continues to rotate, after separating from the lower plate, the lower plate falls back to its original position, and the next wave of scum foam overflows into the buffer interface tube and falls onto the next scraper.

[0030] In a second aspect, the present invention provides a method for treating foam scum on the surface of sewage, characterized in that it comprises the following steps:

[0031] (1) Continuously introduce sewage into the sewage area until the water surface is flush with the upper opening of the scum discharge pipe, control the water inlet and outlet speeds of the sewage area, keep the water surface height of the sewage area constant, and allow the sewage to enter the filter area through the filter plate structure, with the foam scum and grease on the surface of the sewage floating on the water surface of the sewage area;

[0032] (2) The driving drum of the foam scum discharge device is started, and the wave-pushing shaft is started at the same time. During the rotation process, the wave-pushing plate pushes the sewage at the bottom to move toward the scum discharge pipe, causing fluctuations on the water surface in the scum discharge pipe, and the foam scum and grease on the surface overflow to the outlet of the scum discharge pipe. The scraper rotating to the outlet of the scum discharge pipe takes away the overflowed foam scum and grease;

[0033] (3) The foam scum and grease enter the end opening of the scraper, and the scraper continues to move upward. The foam scum and grease in the scraper flow into the discharge groove along the internal hollow structure and are discharged and collected through the discharge groove;

[0034] (4) The scraper moves downward into the clean water pool to clean the residual waste residue on the surface. The scraper continues to move upward and repeats the above steps to discharge the foam scum.

[0035] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0036] 1. A sewage surface foam scum treatment device and method provided by an embodiment of the present invention, wherein a pretreatment tank is set up into two areas, and the lower part of the sewage without foam scum passes through the filter plate structure below the scum discharge pipe into the filter area and then enters the oxidation treatment tank, thereby preventing the surface foam scum from entering the oxidation treatment tank along the water flow direction, wherein the scum discharge pipe structure is arranged to be inclined upward, and the water surface height of the sewage can always be kept close to the upper end outlet of the scum discharge pipe, on the one hand, it is avoided that the water surface height at the filter plate structure causes the foam scum to cover the filter plate structure and affect the water flow effect, and on the other hand, the movement direction of the foam scum on the water surface in the scum discharge pipe is limited from bottom to top, without downward impulse, which can ensure the independence of the movement of the scum foam and the water flow of the bottom filter plate structure in the movement direction, and ensure the full separation of the sewage and the foam scum;

[0037] 2. A device and method for treating foam scum on the surface of sewage provided by an embodiment of the present invention, wherein foam scum is discharged back and forth at the outlet of the scum discharge pipe. When the L-hook structure at the end of the scraper rotates from bottom to top to the outlet of the scum discharge pipe, foam scum and other substances can be scraped into the L-hook structure. The scraper is completely separated and independent from the entire sewage, and the scraper contacts the foam scum only at the opening of the scum discharge pipe. Therefore, relatively speaking, the sewage will not generate a continuous impact on the scraper, and the foam scum will not flow back.

[0038] 3. A device and method for treating foam scum on the surface of sewage provided by an embodiment of the present invention. From a macroscopic perspective, the foam scum is stationary and always remains at a horizontal height, and will not impact the foam discharge device along with the water flow. From a microscopic perspective, the foam scum on the water surface will fluctuate under the action of the lower water body, and will flow out and retreat to the upper opening of the scum discharge pipe at intervals in a manner similar to the tide, thereby achieving the interval discharge of the foam scum.

[0039] 4. A device and method for treating foam scum on the surface of sewage provided by an embodiment of the present invention utilizes an ingenious rotating structure to enable a scraper to transport the foam scum to a collection device while scraping off the foam scum without the need for an additional transport structure. At the same time, the self-gravity of the scraper with a double-layer telescopic structure is utilized to efficiently discharge the foam scum, thereby preventing the foam scum from adhering to the inside of the scraper and affecting the subsequent scraping and transportation of the foam scum. At the same time, the scraper is configured as a hollow structure, and its end face opening has a certain siphon effect, which is more conducive to the adsorption of foam;

[0040] 5. An embodiment of the present invention provides a sewage surface foam scum treatment device and method, wherein the opening surface of the L-hook-shaped structure is set as an inclined surface structure. First, the inclined surface structure can increase the contact area between the L-hook-shaped structure and the foam scum, so that it can smoothly enter the internal hollow structure. Secondly, after the opening inclined surface is set to increase the area, the height of the inclined surface entrance can be designed to be relatively narrow. In this way, when the foam scum enters the opening inclined surface and reaches the entrance, the narrow entrance can play a certain defoaming role. At the same time, the siphon principle can be used to suck all the foam on the opening inclined surface into the interior to avoid remaining on the opening inclined surface.

[0041] 6. An embodiment of the present invention provides a device and method for treating foam scum on the surface of sewage. By spraying adsorption powder of polylactic acid-glycolic acid copolymer microspheres coated with magnesium aluminum silicate on a scraper, the outer layer of magnesium aluminum silicate has a large specific surface area and a porous structure, and can adsorb oily substances many times its own weight. Therefore, after the foam and grease are scraped onto the scraper, the magnesium aluminum silicate can quickly adsorb the grease and foam to form a continuously thickening gel-like substance. The gel substance after adsorbing the grease and foam has good fluidity and can easily slide from the inner wall of the scraper into the discharge groove. The polylactic acid-glycolic acid copolymer is a low molecular weight degradable material, which degrades quickly and does not pollute the environment, and also solves the subsequent foam defoaming problem. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0043] Figure 1 A three-dimensional schematic diagram of a sewage surface foam scum treatment device provided by an embodiment of the present invention;

[0044] Figure 2 A front cross-sectional view of a sewage surface foam scum treatment device provided by an embodiment of the present invention;

[0045] Figure 3 A partial front cross-sectional view of a sewage surface foam scum treatment device provided by an embodiment of the present invention;

[0046] Figure 4 A schematic diagram of the structure of a driving drum provided in an embodiment of the present invention;

[0047] Figure 5 A schematic diagram of a scraper structure provided by an embodiment of the present invention;

[0048] Figure 6 A schematic diagram of the working state structure of the driving drum provided by an embodiment of the present invention;

[0049] Figure 7 A schematic diagram of the structure of a buffer interface tube provided in an embodiment of the present invention.

[0050] Reference numerals and corresponding parts names:

[0051] 1-pretreatment tank, 2-oxidation treatment tank, 3-wastewater area, 4-filtration area, 5-water outlet, 6-scum discharge pipe, 7-driving drum, 8-scraper, 9-discharge trough, 10-fixed plate, 11-movable plate, 12-cleaning tank, 13-wave pushing shaft, 14-wave pushing plate, 15-spraying pipe, 16-buffer interface pipe, 17-partition. DETAILED DESCRIPTION

[0052] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0053] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is apparent to those of ordinary skill in the art that these specific details do not have to be employed to practice the present invention. In other embodiments, in order to avoid confusing the present invention, well-known structures are not specifically described.

[0054] Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment," "an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. In addition, it will be appreciated by those of ordinary skill in the art that the figures provided herein are for illustrative purposes and that the figures are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0055] In the description of the present invention, the directions or positional relationships indicated by terms such as “front”, “rear”, “left”, “right”, “up”, “down”, “vertical”, “horizontal”, “high”, “low”, “inside” and “outside” are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the scope of protection of the present invention.

[0056] Example 1

[0057] like Figure 1-Figure 7 As shown, the embodiment of the present invention provides a sewage surface foam scum treatment device and method, including a pretreatment tank 1 and an oxidation treatment tank 2;

[0058] The pretreatment tank 1 includes a sewage area 3 and a filter area 4 separated by a partition 17. The partition 2 is provided with a water outlet 5. The water outlet 5 is provided with a scum discharge pipe 6 inclined upward. The scum discharge pipe 6 is located in the sewage area 3 and the upper end passes through the sewage area 3 and is connected to the outside. The bottom of the scum discharge pipe 6 is a filter plate structure. The water in the sewage area 3 is filtered by the filter plate structure and then enters the filter area 4.

[0059] The filtration area 4 is connected to the oxidation treatment tank 2;

[0060] A foam scum discharge device is provided at the outlet of the upper end of the scum discharge pipe 6, and the foam scum discharge device includes a driving drum 7 arranged parallel to the outlet of the scum discharge pipe 6, and a plurality of scrapers 8 are arranged in sequence along the circumferential direction on the outer surface of the driving drum 7, and the ends of the scrapers 8 are in an L-hook shape. A discharge groove 9 is provided on the outer wall of the driving drum 7 beside the scraper 8, and the bottom surface of the discharge groove 9 is inclined along the axial direction of the driving drum 7; the driving drum 7 can rotate around its own axis to drive the scraper 8 to move to the outlet of the scum discharge pipe 6 to remove the foam scum.

[0061] At present, a water inlet is set between the pretreatment tank and the oxidation treatment tank, and then an interception tank is set at the water inlet, and a scraper is set above the interception tank. The sewage moves along the interception tank, so that under the action of the movement direction, the surface foam scum and the sewage below are separated by the interception tank. The surface foam scum remains on the interception tank, and other sewage enters the oxidation treatment tank from below the interception tank. This structure has the problem of incomplete removal of foam scum, and the foam scum on the interception tank is also prone to reflux under the impact of the sewage flow.

[0062] The foam scum treatment device of the present invention sets the pretreatment tank into two areas, and uses the filter area as the transition area between the pretreatment tank and the oxidation treatment tank. The lower part of the sewage without foam scum passes through the filter plate structure below the scum discharge pipe and enters the filter area and then enters the oxidation treatment tank, thereby preventing the surface foam scum from entering the oxidation treatment tank along the water flow direction. The scum discharge pipe structure is inclined upward, and the filter plate structure is much lower than the upper end opening of the scum discharge pipe, so that the water surface height of the sewage can always be maintained at a position close to the upper end outlet of the scum discharge pipe. On the one hand, it is avoided that the water surface height at the filter plate structure causes the foam scum to cover the filter plate structure and affect the water flow effect. On the other hand, the inclined structure also limits the movement direction of the foam scum on the water surface in the scum discharge pipe from bottom to top, without downward impulse, which can ensure the independence of the scum foam movement and the bottom filter plate structure in the direction of movement, and ensure the full separation of sewage and foam scum.

[0063] Since the sewage continuously enters the pretreatment tank, the pretreated water surface can continuously fluctuate. Under the action of the water flow fluctuation, the foam scum can be discharged back and forth at the outlet of the scum discharge pipe, and the driving drum drives the scraper to rotate. When the L-hook structure at the end of the scraper rotates from bottom to top to the outlet of the scum discharge pipe, the foam scum and other materials can be scraped into the L-hook structure. The scraper continues to rotate upward, and the foam scum on the scraper can flow back along the scraper to the discharge trough, and then be discharged into the collection device from the inclined discharge trough. Multiple scrapers repeat the above operation, and the foam scum overflowing from the scum discharge pipe can be continuously scraped and collected. In the foam scum treatment device of the present invention, the scraper is completely separated and independent from the entire sewage, and the scraper is in contact with the foam scum only at the opening of the scum discharge pipe. Therefore, relatively speaking, the sewage will no longer generate a continuous impact on the scraper, and the foam scum will not flow back. From a macroscopic perspective, the foam scum in the pretreatment tank of the present application is stationary and always remains at a horizontal height, and will not impact the foam discharge device along with the water flow. From a microscopic perspective, the foam scum on the water surface will fluctuate under the action of the lower water body, thereby gushing out and retreating to the opening on the scum discharge pipe at intervals in a tidal manner, thereby achieving intermittent discharge of the foam scum.

[0064] In a specific embodiment, the scraper 8 is a hollow structure, including a fixed plate 10 and a movable plate 11. The fixed plate 10 is vertically installed directly above the discharge groove 9. One end of the movable plate 11 is movably mounted on the fixed plate 10. The movable plate 11 can be retracted into or extended from the fixed plate 10 along the radial direction of the driving drum 7 under the action of its own gravity; the other end of the movable plate 11 is an L-hook structure, and the end opening is connected to the discharge groove 9.

[0065] The present invention sets the scraper into a hollow structure, so that the foam scum can enter the interior from the end opening of the scraper, and then flow into the discharge groove along the internal hollow structure, that is, the foam scum is wrapped inside the scraper for transportation, so as to avoid flowing to other places during the rotation process; at the same time, the scraper is set into a double-section structure, when the scraper scrapes the foam scum and continues to move upward to the highest point, the movable plate can slowly and gradually slide into the fixed plate under the action of its own gravity to narrow the distance between the L-hook structure and the fixed plate, and when reaching the highest point, the movable plate completely slides into the fixed plate in an instant, and the impact force generated between the movable plate and the fixed plate can shake off the foam scum adhered to the inside of the movable plate, so that it is fully discharged, and then after the scraper continues to rotate to the lowest point, the movable plate is completely extended out of the fixed plate under the action of gravity to carry out the next scraping work. The present invention utilizes an ingenious rotating structure to enable the scraper to transport the foam scum to the collection device while scraping the foam scum without the need for an additional transport structure. At the same time, the self-gravity of the scraper with a double-layer telescopic structure can be used to efficiently discharge the foam scum, avoiding adhesion to the inside of the scraper and affecting the subsequent scraping and transportation of the foam scum. In addition, by setting the scraper as a hollow structure, the end face opening has a certain siphon effect, which can be more conducive to the adsorption of foam.

[0066] In a specific embodiment, the water outlet 5 is in a horizontal long strip structure, the internal height dimension of the scum discharge pipe 6 gradually decreases from the lower end to the upper end, and the inclination angle of the bottom plate of the scum discharge pipe 6 is greater than the inclination angle of the top plate.

[0067] The present invention provides a scum discharge pipe structure with a larger bottom and a smaller top and a bottom inclination angle greater than the top inclination angle. Firstly, it can ensure that there is a sufficient height difference between the filter plate structure and the upper end of the scum discharge pipe. Secondly, the structure can buffer the impact of the foam scum during the fluctuation process, thereby controlling the overflow of the foam scum.

[0068] A cleaning pool 12 is provided below the driving drum 7 beside the upper outlet of the scum discharge pipe 6 , and the cleaning pool 12 is filled with cleaning water.

[0069] The present invention arranges a cleaning pool below the foam scum discharge device. When the scraper moves to the bottom, its end can be extended into the water of the clean water pool for simple wetting and cleaning to remove a small amount of residual foam scum at the end, thereby preventing the foam scum subsequently scraped off by the scraper from aggregating and adsorbing with the previous residual foam scum, thereby affecting the discharge effect.

[0070] In a specific embodiment, the opening surface of the L-hook-shaped structure at the end of the moving plate 11 is inclined, so that the end is a tapered structure. The present invention sets the opening surface of the L-hook-shaped structure to be an inclined structure. First, the inclined structure can increase the contact area between the L-hook-shaped structure and the foam scum, so that it can smoothly enter the internal hollow structure. Secondly, after the opening inclined surface is set to increase the area, the height of the inclined surface entrance can be designed to be relatively narrow. In this way, when the foam scum enters the opening inclined surface and reaches the entrance, the narrow entrance can play a certain defoaming role. At the same time, the siphon principle can be used to suck all the foam on the opening inclined surface into the interior to avoid remaining on the opening inclined surface.

[0071] In a specific embodiment, in the sewage area 3 , a wave pushing shaft 13 is provided at the extension direction of the lower end of the scum discharge pipe 6 , and the wave pushing shaft 13 can rotate around its own axis, and a wave pushing plate 14 is vertically connected to the wave pushing shaft 13 .

[0072] In order to produce more regular waves on the water surface at the scum discharge pipe, the present application arranges a wave pushing shaft and a wave pushing board. When the wave pushing board moves toward the scum discharge pipe, the sewage below is pushed into the scum discharge pipe to generate an outward impact force, causing the foam scum to overflow from the scum discharge pipe outlet. When the wave pushing board moves away from the scum discharge pipe, the water surface in the scum discharge pipe retreats smoothly until the wave pushing board moves toward the scum discharge pipe again. The above operation is continued to generate waves at a certain frequency interval at the opening at the upper end of the scum discharge pipe, corresponding to multiple scrapers, to achieve continuous removal of foam scum.

[0073] In a specific embodiment, the wave-pushing plate 14 is in an arc-shaped structure, which can increase the contact area with the sewage and make the generated driving force more concentrated and stable.

[0074] In a specific embodiment, a spraying pipe 15 is provided above the upper outlet of the scum discharge pipe 6, and the spraying pipe 15 can spray adsorption powder into the opening of the movable plate 11. The adsorption powder is polylactic acid-glycolic acid copolymer microspheres coated with magnesium aluminum silicate, which can be used to adsorb foam scum and grease to form a gel-like structure.

[0075] Foam, grease and other substances on the surface of sewage are all substances with strong adhesion, so a certain amount of grease and foam substances will still remain on the scraper. Therefore, the present invention sprays adsorption powder of polylactic acid-glycolic acid copolymer microspheres coated with magnesium aluminum silicate on the scraper. The outer layer of magnesium aluminum silicate has a very large specific surface area and a porous structure, and can adsorb oily substances many times its own weight. Therefore, after the foam and grease are scraped onto the scraper, the magnesium aluminum silicate can quickly adsorb the grease and foam to form a continuously thickening gel-like substance. The gel substance after adsorbing the grease and foam has good fluidity and can easily slide from the inner wall of the scraper into the discharge groove. The polylactic acid-glycolic acid copolymer is a low-molecular-weight degradable material with a fast degradation rate and no pollution to the environment, and also solves the subsequent foam defoaming problem.

[0076] The preparation method of magnesium aluminum silicate coated polylactic acid-glycolic acid copolymer microspheres is as follows: tetraethyl orthosilicate, hydrochloric acid and water are mixed and stirred to form a gel, a solution of aluminum sulfate and magnesium sulfate is added dropwise, stirred and mixed, and ammonia water is added dropwise to obtain magnesium aluminum silicate sol; then polylactic acid-glycolic acid copolymer microsphere powder is added to the magnesium aluminum silicate sol, stirred and mixed, aged, washed with clean water, calcined, and finally ball milled to obtain a powdered material.

[0077] In a specific embodiment, a buffer interface pipe 16 is provided at the upper opening of the scum discharge pipe 6, and the buffer interface pipe 16 is perpendicular to the outer wall of the pretreatment tank 1. By providing a buffer interface pipe to extend the length and angle of the upper opening of the scum discharge pipe, it is more conducive to the coordination and connection between the foam scum discharge and the scraping of the scraper.

[0078] In a specific embodiment, the buffer interface pipe is tilted downward to form an inverted V-shaped structure with the slag discharge pipe. The inclination angle of the upper plate of the buffer interface pipe is greater than the inclination angle of the lower plate, and the lower plate of the buffer interface pipe is hinged to the side wall of the pool at the outlet of the slag discharge pipe. The lower plate of the buffer interface pipe can contact the scraper and rotate upward driven by the scraper, and can freely fall to the original position after separation from the scraper.

[0079] The buffer interface tube of the present invention is arranged to be tilted downward, firstly, the movement path of the overflowing foam can be extended by tilting, and at the same time, the foam waste residue can directly "fall" into the scraper after moving through the tilted buffer interface tube; the structure of the buffer interface tube that is larger at the top and smaller at the bottom can buffer the impact force of the overflowing foam, so that it can fall onto the scraper in a concentrated manner with a smaller area; finally, the present invention arranges the lower plate of the buffer interface tube as a hinged structure, and when the scraper rotates upward to the lower plate, the foam waste residue falls from the buffer interface tube onto the scraper, and the scraper contacts the lower plate and drives it to rotate upward (it can also move to contact the end of the upper plate to close the buffer interface tube), so that a reverse driving force can be applied to the foam scum that is about to overflow the lower plate to make it return to the scum discharge pipe, and as the scraper continues to rotate, after separating from the lower plate, the lower plate falls back to its original position, and the next wave of scum foam overflows into the buffer interface tube and falls onto the next scraper.

[0080] In a second aspect, the present invention provides a method for treating foam scum on the surface of sewage, characterized in that it comprises the following steps:

[0081] 1. Continuously introduce sewage into the sewage area until the water surface is flush with the upper opening of the scum discharge pipe, control the water inlet and outlet speeds of the sewage area, keep the water surface height of the sewage area constant, and the sewage enters the filter area through the filter plate structure, and the foam scum and grease on the surface of the sewage float on the water surface of the sewage area;

[0082] 2. Start the driving drum of the foam scum discharge device and start the wave-pushing shaft at the same time. During the rotation of the wave-pushing plate, the sewage at the bottom is pushed to move toward the scum discharge pipe, causing fluctuations on the water surface in the scum discharge pipe. The foam scum and grease on the surface overflow to the outlet of the scum discharge pipe, and the scraper rotating to the outlet of the scum discharge pipe takes away the overflowed foam scum and grease;

[0083] 3. The foam scum and grease enter the end opening of the scraper, and the scraper continues to move upward. The foam scum and grease in the scraper flow into the discharge groove along the internal hollow structure and are discharged and collected through the discharge groove;

[0084] 4 The scraper moves downward to the clean water pool to clean the residual waste residue on the surface. The scraper continues to move upward and repeats the above steps to discharge the foam scum.

[0085] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A sewage surface foam scum treatment device, characterized in that: It comprises a pretreatment tank (1) and an oxidation treatment tank (2); The pretreatment tank (1) comprises a sewage area (3) and a filter area (4) separated by a partition (17); a water outlet (5) is provided on the partition (2); a scum discharge pipe (6) inclined upward is provided at the water outlet (5); the scum discharge pipe (6) is located in the sewage area (3) and the upper end thereof passes through the sewage area (3) and is connected to the outside; the bottom of the scum discharge pipe (6) is a filter plate structure; water in the sewage area (3) is filtered by the filter plate structure and then enters the filter area (4); The filtering area (4) is connected to the oxidation treatment tank (2); A foam scum discharge device is arranged at the outlet of the upper end of the scum discharge pipe (6), and the foam scum discharge device comprises a driving drum (7) arranged parallel to the outlet of the scum discharge pipe (6), a plurality of scrapers (8) are arranged in sequence along the circumferential direction on the outer surface of the driving drum (7), the ends of the scrapers (8) are in an L-hook-shaped structure, and a discharge groove (9) is provided on the outer wall of the driving drum (7) beside the scrapers (8), and the bottom surface of the discharge groove (9) is arranged obliquely along the axial direction of the driving drum (7); the driving drum (7) can rotate around its own axis to drive the scrapers (8) to move to the outlet of the scum discharge pipe (6) to remove the foam scum.

2. A sewage surface foam scum treatment device according to claim 1, characterized in that: The scraper (8) is of a hollow structure, comprising a fixed plate (10) and a movable plate (11); the fixed plate (10) is vertically mounted directly above the discharge groove (9); one end of the movable plate (11) is movably sleeved on the fixed plate (10); the movable plate (11) can be retracted into or extended from the fixed plate (10) along the radial direction of the driving drum (7) under the action of its own weight; the other end of the movable plate (11) is of an L-hook structure, and the end opening is connected to the discharge groove (9).

3. The sewage surface foam scum treatment device according to claim 1, characterized in that: The water outlet (5) is in a horizontal long strip structure, the internal height dimension of the scum discharge pipe (6) gradually decreases from the lower end to the upper end, and the inclination angle of the bottom plate of the scum discharge pipe (6) is greater than the inclination angle of the top plate.

4. The sewage surface foam scum treatment device according to claim 1, characterized in that: A cleaning pool (12) is provided below the driving drum (7) beside the upper outlet of the scum discharge pipe (6), and the cleaning pool (12) is filled with cleaning water.

5. The sewage surface foam scum treatment device according to claim 2, characterized in that: The opening surface of the L-hook structure at the end of the movable plate (11) is an inclined surface, so that the end has a conical structure.

6. The sewage surface foam scum treatment device according to claim 1, characterized in that: In the sewage area (3), a wave-pushing shaft (13) is provided at the extension direction of the lower end of the scum discharge pipe (6), the wave-pushing shaft (13) can rotate around its own axis, and a wave-pushing plate (14) is vertically connected to the wave-pushing shaft (13).

7. The sewage surface foam scum treatment device according to claim 2, characterized in that: The wave pushing plate (14) has an arc-shaped structure.

8. The sewage surface foam scum treatment device according to claim 2, characterized in that: A spraying pipe (15) is arranged above the upper outlet of the scum discharge pipe (6), and the spraying pipe (15) can spray adsorption powder into the opening of the movable plate (11). The adsorption powder is polylactic acid-glycolic acid copolymer microspheres coated with magnesium aluminum silicate, and can be used to adsorb foam scum and grease to form a gel-like structure.

9. The sewage surface foam scum treatment device according to claim 2, characterized in that: A buffer interface pipe (16) is provided at the upper opening of the scum discharge pipe (6), and the buffer interface pipe (16) is perpendicular to the outer side wall of the pretreatment tank (1).

10. A sewage treatment method based on the foam scum treatment device according to any one of claims 1 to 9, characterized in that: The steps include: (1) Continuously introduce sewage into the sewage area until the water surface is flush with the upper opening of the scum discharge pipe, control the water inlet and outlet speeds of the sewage area, keep the water surface height of the sewage area constant, and allow the sewage to enter the filter area through the filter plate structure, with the foam scum and grease on the surface of the sewage floating on the water surface of the sewage area; (2) The driving drum of the foam scum discharge device is started, and the wave-pushing shaft is started at the same time. During the rotation process, the wave-pushing plate pushes the sewage at the bottom to move toward the scum discharge pipe, causing fluctuations on the water surface in the scum discharge pipe, and the foam scum and grease on the surface overflow to the outlet of the scum discharge pipe. The scraper rotating to the outlet of the scum discharge pipe takes away the overflowed foam scum and grease; (3) The foam scum and grease enter the end opening of the scraper, and the scraper continues to move upward. The foam scum and grease in the scraper flow into the discharge groove along the internal hollow structure and are discharged and collected through the discharge groove; (4) The scraper moves downward into the clean water pool to clean the residual waste residue on the surface. The scraper continues to move upward and repeats the above steps to discharge the foam scum.

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