Air stirring hydraulic circulation pollutant slow sinking and discharge assisting system

Abstract

The invention discloses an air stirring hydraulic circulation pollutant slow sinking and discharge assisting system which comprises an air supply device, an air main pipe, an air branch pipe, an air vertical pipe and an air small branch pipe. One end of the air main pipe is connected with an air supply device, the other end of the air main pipe is connected with an air branch pipe which is transversely arranged, the air branch pipe is connected with the upper ends of a plurality of air vertical pipes which are longitudinally arranged, the lower end of each air vertical pipe is connected with a transverse small air branch pipe, and air outlet holes for spraying air are formed in the small air branch pipes. After the air supply device is started, air sequentially passes through the air main pipe, the air branch pipe, the air vertical pipe and the air small branch pipe and is sprayed out from the air outlet holes, so that suspended matters in inlet water float in a water inlet space above the filter layer as much as possible in a suspended state, the time of the suspended matters accumulated on the surface of the filter layer is delayed, and the inlet water is kept to pass through the filter layer with small water loss. The water layer above the filter medium is fully utilized as a pollutant holding space, so that the effective utilization rate of the filter tank can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment, is a scheme for delaying filter layer pollution for a filter unit, and particularly relates to an air-stirring hydraulic circulation pollutant slow-sinking and drainage-aiding system. Background Art

[0002] In sewage treatment, the filter tank is a key process section for deep treatment, which can further remove suspended matter in sewage and residual organic matter and pollutants adsorbed on it, ensuring that the suspended matter in the effluent meets the standards.

[0003] In a downward flow gravity filter, the area above the filter layer is the water inlet space. During the gravity flow of water in the water inlet space, suspended matter in the water is retained on the surface of the filter layer, and clean water passes through the filter layer, thereby removing the suspended matter. As the suspended matter retained above the filter layer continues to accumulate, the loss required for water to pass through the filter layer will gradually increase, causing the water output of the filter to decrease. If too much pollutant accumulates in the filter layer, it may even penetrate the filter bed and affect the quality of the effluent.

[0004] Therefore, after the filter has been running for a period of time, it is necessary to backwash it in time. Frequent backwashing will not only occupy the normal working time of the filter, but also require the use of a part of the filtered water, increase the self-water consumption of the system, and thus increase the actual water inlet design scale. The reduction of the actual online operation time will also increase the design scale of the filter. The increase in the design scale of the filter will bring about a series of problems such as increased floor space, increased civil engineering investment and equipment investment, and increased ancillary equipment, thus affecting its economic and practical performance. Therefore, in actual operation, it is extremely important to minimize the frequency of backwashing and increase the online operation time of the filter for the effective use of the filter. Summary of the invention

[0005] The purpose of the present invention is to provide an air-stirring hydraulic circulation pollutant slow-settling and drainage system, by introducing an air-stirring system into the water inlet space above the filter layer, so that the solid matter in the water continues to remain in a suspended state, delaying the time of its deposition in the filter layer, thereby slowing down the pollution of the filter layer.

[0006] To achieve the above purpose, the technical solution provided by the present invention is as follows:

[0007] An air-stirring hydraulic circulation pollutant slow-sinking and drainage-aiding system comprises an air supply device, an air main pipe, an air branch pipe, an air riser, and an air small branch pipe;

[0008] One end of the main air pipe is connected to the air supply device, and the other end is connected to a transversely arranged air branch pipe. The air branch pipe is connected to the upper ends of several longitudinally arranged air risers. The lower end of each of the air risers is connected to a transverse small air branch pipe, and the small air branch pipe is provided with an air outlet hole for air jet.

[0009] Wherein, the air supply device is a blower.

[0010] There are two air branch pipes, which are arranged at the top of the filter tank. Both air branch pipes are connected to the air main pipe and are arranged along the length of the tank close to the tank walls on both sides.

[0011] Among them, several air risers are evenly spaced along the length of the pool.

[0012] Wherein, each of the air risers extends above the filter layer inside the filter tank.

[0013] Wherein, the small air branch pipes are two small air branch pipes with the same length and opposite directions, and the lower end of the air riser is connected to the two small air branch pipes.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] By introducing an air stirring system at a suitable position above the filter layer, after turning on the air supply device, the gas will pass through the air main pipe, air branch pipe, air riser, and air small branch pipe in sequence, and spray out from the air outlet, so that the suspended matter in the incoming water will float in the water inlet space above the filter layer as much as possible in a suspended state, delaying the time for it to accumulate on the surface of the filter layer, and keeping the incoming water passing through the filter layer with less water loss. By making full use of the water layer above the filter medium as a pollution receiving space, the effective utilization rate of the filter tank can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The figure shows a cross-sectional schematic diagram of an air-stirring hydraulic circulation pollutant slow-sinking and drainage-aiding system provided in an embodiment of the present application;

[0017] Figure 2 Shown is a schematic diagram of hydraulic flow in an embodiment of the present application;

[0018] In the figure, there is a self-blower 1, an air main pipe 2, an air branch pipe 3, an air riser 4, a small air branch pipe 5, a control valve 6, air bubbles 7, solid impurities 8, inlet water 9, filtered water after passing through the filter layer 10, an inlet trough 11, and an inlet pipe and an inlet tank 12. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0021] In the description of this patent, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "set" should be understood in a broad sense, for example, it can be fixedly connected, set, or detachably connected, set, or integrally connected, set, and can refer to direct connection or indirect connection. For ordinary technicians in this field, the specific meanings of the above terms in this patent can be understood according to specific circumstances.

[0022] like Figure 1 The structure of the embodiment provided by the present invention is shown in FIG.

[0023] The present embodiment provides an air-stirring hydraulic circulation pollutant slow-sinking and drainage-aiding system, comprising an air supply device, an air main pipe 2, an air branch pipe 3, an air riser 4, and an air small branch pipe 5;

[0024] One end of the main air pipe 2 is connected to the air supply device, and the other end is connected to a transversely arranged air branch pipe 3. The air branch pipe 3 is connected to the upper ends of several longitudinally arranged air risers 4. The lower end of each of the air risers 4 is connected to a transverse small air branch pipe 5. The small air branch pipe 5 is provided with an air outlet hole for air jet.

[0025] It should be noted that the air stirring system is introduced into the water inlet space above the filter layer and at a suitable position above the filter layer. After the air supply device is turned on, the gas will pass through the air main pipe, air branch pipe, air riser, and air small branch pipe in sequence, and spray out from the air outlet, so that the solid matter in the water continues to remain in a suspended state, delaying its deposition time in the filter layer, thereby reducing the pollution of the filter layer. The water inlet space is also used as a pollutant receiving space. During the backwashing process, the suspended pollutants are discharged along with the backwashing water.

[0026] Among them, keeping solid particles suspended on the upper part of the filter bed can increase the filter layer's ability to intercept suspended matter, helping to minimize the filter head during operation. At the same time, the air stirring system can also increase the filter's solid load capacity, cope with high-concentration solid particles and impact load conditions, and make the filter have a wider range of applications.

[0027] Wherein, the air supply device is a blower 1.

[0028] There are two air branch pipes 3, which are arranged at the top of the filter tank. Both air branch pipes 3 are connected to the air main pipe 2 and are arranged near the tank walls on both sides along the tank length direction.

[0029] Among them, several air risers 4 are evenly spaced along the length of the pool. With this structure, the air volume can be evenly distributed to each area in the pool.

[0030] Each of the air risers 4 extends above the filter layer inside the filter tank. A control valve 6 is provided on the air riser 4.

[0031] The small air branch pipes 5 are two small air branch pipes with the same length and opposite directions, and the lower end of the air riser 4 is connected to the two small air branch pipes 5 .

[0032] like Figure 2 As shown, it can be seen from the hydraulic flow diagram that the raw water (inlet water 9) falls into the inlet trough 11 through the inlet pipe and the inlet box 12, and then falls into the space above the filter material layer of the filter tank through the inlet trough. The solid impurities 8 in the raw water are intercepted by the filter material layer. After the filtered water passes through the filter material layer, the filtered water 10 after passing through the filter layer is collected at the bottom of the filter tank and discharged. The hydraulic flow direction is in the form of gravity from top to bottom. An air stirring system is provided on the upper part of the filter layer. The air bubbles 7 can make the solid matter in the water on the upper part of the filter layer suspended, slowing down the time for it to be intercepted in the filter material layer, thereby delaying the fouling cycle of the filter material layer; at the same time, the air stirring system is set at a suitable position to help the inlet water form a local circulation flow on the upper part of the filter layer.

[0033] In addition, in the design of the air-agitation hydraulic circulation pollutant slow sedimentation and drainage system, the total air volume required to maintain the air-agitation hydraulic circulation state, the number and layout positions of air branch pipes, and the number and direction of air release outlets are all key design factors. The above parameters are determined by comprehensive consideration so that the supplied air volume can enter the filter tank evenly, which helps to form the flow state of hydraulic circulation and enable the solid pollutants in the incoming water to remain evenly suspended in the entire upper space of the filter layer.

[0034] Among them, the total amount of air required is determined according to the length of the filter tank to ensure that the hydraulic suspension state is evenly achieved in the entire filter layer space. The amount of air required for air stirring is related to the number of pools, the pool length, the number of air branches arranged in each pool, and the empirical air volume required for stirring per unit pool length and unit number of mud branches. This air volume needs to comprehensively consider the suspended matter and other pollutants carried in the raw water in a suspended state under this air volume, and can stir up some of the trapped pollutants in the filter cake layer on the surface of the filter material, while not affecting the sand particles in the filter material layer to avoid filter material loss. Specifically, it can be calculated according to the following formula: Total air stirring volume = number of pools * pool length * number of branch pipes per pool * 0.116 (m 2 / min). For example, in a shallow sand filter tank of a certain project, there are three tank bodies, each tank body is 7.6m long and 3.7m wide. Two branch pipes are designed for each tank. The total amount of air required for mixing is: 3*7.6*2*0.116=5.29m 3 / min.

[0035] In order to make the air release help the water to form a circulating flow pattern, the small air branch pipes are arranged on both sides of the filter tank near the pool wall, with a distance of about 200mm from the pool wall. The number of small air branch pipes varies according to the pool width. When the pool width is ≤3.7m, two air branch pipes are arranged, and accordingly, two rows of small air branch pipes are formed; when the pool width is ≥4.9m, three air branch pipes are arranged to form three rows of small air branch pipes. This is mainly based on the influence range of the circulating flow pattern caused by the air stirring intensity.

[0036] The number of air release outlets is determined based on experiments and practical application experience, based on the number of openings on a single meter of pipe length, to ensure that within this length range, the gas can be released evenly and help the water to form a circulation. The direction of the air release outlets is arranged obliquely downward, with an angle of about 20° to 30°, and the holes are facing the pool wall. In this way, the air comes out of the hole, is blocked by the wall during the upward movement, and turns toward the pool, thus being consistent with the direction of the water inlet in the pool, forming the same circulation direction, and keeping the suspended matter in a suspended state.

[0037] In addition, the air stirring system used has a daily operating time related to the solid pollution concentration in the influent water. It can be automatically started and stopped by setting a liquid level sensor to monitor the liquid level in the influent area above the filter layer. When it is lower than the set liquid level, the air stirring system will not be turned on; as the filtration resistance increases, the influent liquid level gradually increases. After reaching the set liquid level, the air stirring system is controlled to be turned on; although air stirring can slow down the blockage of the filter layer by pollutants, the suspended matter and other pollutants in the influent water to be filtered will continue to accumulate, so the resistance of the filter layer will gradually increase and the liquid level on the filter layer will gradually rise. When the high liquid level is reached, the system will automatically start backwashing to thoroughly clean and discharge the accumulated pollutants from the system. During the backwashing process, the system will automatically start the air stirring system for a certain period of time to cooperate with the backwashing, helping to quickly discharge the scum and foam in the backwashing water, improve the efficiency of the backwashing system, and reduce the backwashing time, thereby further reducing the system's own water consumption.

[0038] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. An air-stirring hydraulic circulation pollutant slow-sinking and drainage system, characterized in that: It comprises an air supply device, an air main pipe (2), an air branch pipe (3), an air riser (4), and an air small branch pipe (5); One end of the main air pipe (2) is connected to the air supply device, and the other end is connected to a transversely arranged air branch pipe (3). The air branch pipe (3) is connected to the upper ends of a plurality of longitudinally arranged air risers (4). The lower end of each of the air risers (4) is connected to a transverse small air branch pipe (5). The small air branch pipe (5) is provided with an air outlet hole for jetting air.

2. The air-stirring hydraulic circulation pollutant slow-sinking and drainage system according to claim 1 is characterized in that: The air supply device is a blower (1).

3. The air-stirring hydraulic circulation pollutant slow-sinking and drainage system according to claim 1 is characterized in that: There are two air branch pipes (3) arranged at the top of the filter tank. Both air branch pipes (3) are connected to the air main pipe (2) and are arranged along the tank length direction close to the tank walls on both sides.

4. The air-stirring hydraulic circulation pollutant slow-sinking and drainage system according to claim 1 is characterized in that: Several air risers (4) are evenly spaced and arranged along the length of the pool.

5. The air-stirring hydraulic circulation pollutant slow-sinking and drainage system according to claim 4 is characterized in that: Each of the air risers (4) extends above the filter layer inside the filter tank.

6. The air-stirring hydraulic circulation pollutant slow-sinking and drainage system according to claim 1 is characterized in that: The small air branch pipes (5) are two small air branch pipes of the same length and in opposite directions, and the lower end of the air riser (4) is connected to the two small air branch pipes (5).

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