Sludge discharge method and system

Abstract

The invention relates to the technical field of water treatment, in particular to a sludge discharge method and system.The discharge method comprises the following steps that S1, detection light rays are emitted to a sludge interface through a light ray casting unit, and the detection light rays form a detection pattern on the sludge interface; s2, acquiring the detection pattern through a pattern acquisition unit; s3, judging whether a sludge discharge condition is met or not according to the detection pattern; if so, entering step S4; otherwise, entering the step S2; and S4, controlling a sludge discharge valve group to discharge sludge. According to the sludge discharge method provided by the invention, the sludge discharge is controlled by using the optically measured sludge condition, so that the accuracy and timeliness of sludge condition judgment are ensured, and the accuracy of sludge discharge is further ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and particularly to a sludge discharge method and system. Background Art

[0002] In the existing water treatment process, various water treatment methods need to achieve solid-liquid separation through a sedimentation process. In the sedimentation process, sludge is generated at the bottom of the sedimentation tank. To ensure the normal progress of water treatment, after the sludge reaches a certain amount, it is necessary to discharge the sludge in a timely manner.

[0003] The rate of sludge generation mainly depends on the pollutant concentration of the influent water and the amount of water to be treated, and the changes in these two factors will also cause the rate of sludge generation to be non-uniform. Many water treatment sites adopt a periodic timed discharge method, resulting in a lot of waste and abnormal water treatment. If the discharge time is too early, a large amount of dilute sludge or even clear water will be discharged, wasting the treated water volume and increasing the cost of sludge treatment. If the discharge time is too late, it may lead to excessive sludge accumulation in the sedimentation tank, affecting the sedimentation of subsequent precipitates and even causing serious consequences such as "pool overturning".

[0004] In view of this, how to accurately control sludge discharge is a technical problem that needs to be solved urgently at present. Summary of the Invention

[0005] To solve the problem of difficult accurate control of sludge discharge in the prior art, the present invention provides a sludge discharge method. This sludge discharge method emits a detection light beam to the sludge interface, determines the sludge height according to the change of the detection pattern formed by the detection light beam on the sludge interface, and then controls the sludge discharge according to the sludge height, improving the accuracy of sludge height detection and further improving the accuracy of sludge discharge, thus solving the problem of difficult accurate control of sludge discharge in the prior art.

[0006] The technical solution adopted by the present invention to solve its technical problems is as follows: A sludge discharge method, comprising the following steps: S1: Emitting a detection light beam to the sludge interface through a light projection unit, and the detection light beam forms a detection pattern on the sludge interface; S2: Obtaining the detection pattern through a pattern acquisition unit; S3: Judging whether the sludge discharge condition is satisfied according to the detection pattern; if so, proceeding to step S4; otherwise, proceeding to step S2; S4: Controlling a sludge discharge valve group to discharge sludge.

[0007] Optionally, judging whether the sludge discharge condition is satisfied according to the detection pattern includes: S31: Obtaining the size of the detection pattern; S32: Obtain the installation height of the light projection unit; S33: According to the size of the detection pattern and the installation height of the light projection unit, use trigonometric functions and calibration algorithms to calculate the detection height of the sludge interface; S34: Compare the detection height with a preset sludge height, and determine whether the detection height is greater than the preset sludge height. If so, the sludge discharge condition is satisfied.

[0008] Optionally, determining whether the sludge discharge condition is satisfied according to the detection pattern includes: S301: Obtain the size of the detection pattern; S302: Compare the size of the detection pattern with a preset size, and determine whether the size of the detection pattern is smaller than the preset size. If so, the sludge discharge condition is satisfied.

[0009] Optionally, controlling the sludge discharge valve group to discharge includes: obtaining the flatness of the sludge interface according to the detection pattern, and then determining the discharge time of each sludge valve in the sludge discharge valve group according to the flatness of the sludge interface.

[0010] Optionally, the detection pattern is a checkerboard.

[0011] Optionally, the detection pattern is a single line.

[0012] Another object of the present invention is to provide a sludge discharge system, including a light projection unit, a pattern acquisition unit, a sludge discharge valve group, a sedimentation tank, and a control unit; The light projection unit emits detection light to the sludge interface; The pattern acquisition unit is used to capture the detection pattern formed by the detection light on the sludge interface; The sludge discharge valve group is used to discharge the sludge in the sedimentation tank; Both the light projection unit and the pattern acquisition unit are installed in the sedimentation tank; The sludge discharge valve group is installed at the bottom of the sedimentation tank; The light projection unit, the pattern acquisition unit, and the sludge discharge valve group are all communicatively connected to the control unit; The control unit controls the opening and closing of the sludge discharge valve group according to the sludge discharge method described above to achieve sludge discharge.

[0013] Optionally, the light projection unit is a projector.

[0014] Optionally, the pattern acquisition unit is a camera.

[0015] Optionally, it further includes an installation unit; the light projection unit and the pattern acquisition unit are both installed below the water surface through the installation unit.

[0016] The beneficial effects of the present invention are: The sludge discharge method provided by the present invention controls sludge discharge by utilizing optically measured sludge conditions, thereby ensuring the accuracy and timeliness of sludge condition judgment and further ensuring the accuracy of sludge discharge. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0018] Figure 1 It is a schematic diagram of the process of the sludge discharge method of the present invention; Figure 2 It is a simplified structural diagram of the sludge discharge system in the present invention; Figure 3 It is a schematic diagram of the detection pattern under different sludge interface conditions in the present invention; Figure 4 It is a schematic diagram of dynamic mud level detection in the present invention.

[0019] In the figure: 1-light projection unit; 2-pattern acquisition unit; 3-mud discharge valve group; 4-sedimentation tank. DETAILED DESCRIPTION

[0020] The present invention is now further described in detail. The embodiments described below are exemplary and intended to be used to explain the present invention, but cannot be understood as limiting the present invention. All other embodiments obtained by ordinary technicians in this field without creative work based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0021] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0022] In order to solve the problem that it is difficult to accurately control sludge discharge in the prior art, the present invention provides a sludge discharge method, see Figure 1 As shown, the sludge discharge method comprises the following steps: S1: emitting detection light to the sludge interface through the light projection unit 1, and the detection light forms a detection pattern on the sludge interface; S2: Acquire a detection pattern through the pattern acquisition unit 2; S3: judging whether the sludge discharge conditions are met according to the detection pattern; if so, proceeding to step S4; otherwise, proceeding to step S2; S4: Control the sludge discharge valve group to discharge sludge.

[0023] Specifically, the optical projection unit 1 emits detection light towards the sludge interface. After the detection light irradiates the sludge interface, it is reflected to form a pattern with a certain shape, denoted as the detection pattern. The pattern acquisition unit 2 is used to capture the pattern formed by the detection light on the sludge interface. Since the shape and size of this pattern are related to the flatness and height of the sludge interface, it is possible to obtain the sludge situation in the sedimentation tank based on the detection pattern captured by the pattern acquisition unit 2, and then determine whether the sludge discharge condition is met according to this sludge situation.

[0024] The sludge discharge method provided by the present invention uses the optically measured sludge situation to control sludge discharge, ensuring the accuracy and timeliness of sludge situation judgment, and thus ensuring the accuracy of sludge discharge.

[0025] Whether sludge discharge can be accurately controlled is one of the important factors affecting the water treatment effect. During the water treatment process, it is usually judged whether sludge discharge is required by the sludge level, that is, the height of the sludge at the bottom of the sedimentation tank. Therefore, to achieve accurate control of sludge discharge, it is necessary to accurately measure the sludge height.

[0026] The technical solution provided by the present invention is based on the optical principle. When the installation positions of the light projection unit 1 and the pattern acquisition unit 2 relative to the bottom of the sedimentation tank remain unchanged, as the height of the sludge interface increases, the size of the detection pattern captured by the pattern acquisition unit 2 becomes smaller. That is to say, when the sludge level is higher, the size of the detection pattern is smaller; when the sludge level is lower, the size of the detection pattern is larger.

[0027] Based on this, the process of judging whether the sludge discharge condition is met according to the detection pattern in the present invention can be carried out as follows: S31: Obtain the size of the detection pattern; S32: Obtain the installation height of the light projection unit; S33: According to the size of the detection pattern and the installation height of the light projection unit, use trigonometric functions and calibration algorithms to calculate the detection height of the sludge interface; S34: Compare the detection height with the preset sludge height, and judge whether the detection height is greater than the preset sludge height. If so, the sludge discharge condition is met.

[0028] The preset sludge height can be set according to requirements such as sludge properties and water treatment requirements; when the detected height is greater than the preset sludge height, it is determined that the sludge discharge condition is met, and then the sludge discharge starts; the stop of the discharge can be controlled by the sludge discharge amount or the sludge discharge time; for example, according to the size of the sedimentation tank and water treatment requirements, etc., the sludge discharge time is set, and when the set sludge discharge time is reached, the discharge stops; or the sludge discharge amount is set, and when the detected sludge discharge amount reaches the set sludge discharge amount, the discharge stops, and then the detection continues according to the above steps.

[0029] Alternatively, in the present invention, determining whether the sludge discharge condition is met according to the detected pattern can also be carried out according to the following process: S301: Obtain the size of the detected pattern; S302: Compare the size of the detected pattern with the preset size, and determine whether the size of the detected pattern is smaller than the preset size. If so, the sludge discharge condition is met.

[0030] The preset size is determined according to the sludge height suitable for sludge discharge, that is, the preset sludge height; when the size of the detected pattern is smaller than the preset size, the sludge height at the bottom of the sedimentation tank is greater than the preset sludge height, and it is determined that the sludge discharge condition is met, and then the sludge discharge starts; the stop of the discharge can be controlled by the sludge discharge amount or the sludge discharge time; for example, according to the size of the sedimentation tank and water treatment requirements, etc., the sludge discharge time is set, and when the set sludge discharge time is reached, the discharge stops; or the sludge discharge amount is set, and when the detected sludge discharge amount reaches the set sludge discharge amount, the discharge stops, and then the detection continues according to the above steps.

[0031] In the existing methods for measuring the sludge height, one type is to predict the sludge production based on information such as the influent water volume, water quality, and flocculant dosage, or to linearly predict the sludge production using historical data. For this type of prediction method, due to the quantity and quality problems of the training samples, the measurement error is relatively large and the effect is not satisfactory. Another type is to detect through corresponding instruments. For example, the sludge interface meter uses the ultrasonic reflection method to obtain the sludge level height. In this method, the sensor immersed in water emits ultrasonic waves downward. Since there is a density difference at the interface between the clean water and the sludge, an ultrasonic reflection signal will be formed. The sludge interface meter can calculate the current sludge level by detecting the time difference between the emission and reception. Or through the detection of the sludge concentration distribution, the light transmittance detection device is installed on the winding machine, and the light transmittance data is obtained by adjusting the depth of the light transmittance detection device in the water and sludge through winding, so as to obtain the sludge level information. This type of detection method can obtain the sludge level information, but they all belong to single-point detection and can only obtain the sludge level data near the installation position. The detection result has low accuracy and large errors. When the sedimentation tank is large and the sludge settling rate is different at different positions, resulting in non-uniform sludge level distribution, using the single-point sludge level information to control the sewage discharge cannot achieve the optimal sludge discharge control.

[0032] The present invention actually measures the sludge level through an optical method rather than predicting the sludge level. Therefore, the accuracy of sludge level measurement is greatly improved. At the same time, in the present invention, the sludge level is measured through a pattern, and the sludge level within the area where the pattern is located is measured instead of a single-point sludge level, which helps to further improve the accuracy of sludge level measurement and thus helps to accurately discharge sludge according to actual needs.

[0033] To further improve the accuracy of sludge discharge, the present invention preferably controls the sludge discharge valve group for discharge, including: obtaining the flatness of the sludge interface according to the detected pattern, and then determining the discharge time of each sludge valve in the sludge discharge valve group according to the flatness of the sludge interface.

[0034] Specifically, since the specific shape of the detected pattern is related to the flatness of the sludge interface, the higher the flatness of the sludge interface, the more uniform the distribution of each line in the detected pattern. For the case where the sludge interface is uneven, the line distribution in the detected pattern is uneven, and the higher the sludge level at the sludge interface, the greater the density of the line distribution in the detected pattern. On the contrary, the lower the sludge level, the smaller the density of the line distribution in the detected pattern. Therefore, the discharge time of the sludge valve at the corresponding position can be controlled according to the line distribution density at different positions in the detected pattern. By appropriately extending the discharge time of the sludge valve at the position with a larger line distribution density, on the one hand, it helps to improve the flatness of the sludge interface, and on the other hand, the sludge discharge time can be determined according to the sludge level height at different positions, further realizing sludge discharge on demand and improving the accuracy of sludge discharge.

[0035] The present invention preferably uses a checkerboard pattern as the detected pattern; see Figure 3As shown, when the sludge interface is a flat interface, the detection pattern formed by the detection light irradiating on the sludge interface is a grid of vertical and horizontal lines with the same distance spacing. When the sludge level is relatively high, the size of the checkerboard is smaller; when the sludge level is relatively low, the area of the checkerboard is larger, and the distance between adjacent projection lines is farther. Therefore, by using trigonometric functions and a calibration algorithm, the distance from the sludge interface to the light projection unit 1 can be calculated based on the size of the checkerboard obtained by the pattern acquisition unit 2. Then, with the installation position of the light projection unit 1, the information of the actual sludge level can be obtained, and thus it can be determined whether the sludge discharge condition is met.

[0036] It should be noted that the detection pattern of the "five-segment line checkerboard" described above is only a special case of the implementation method. By increasing the number of checkerboard projection lines, more detailed information about the height of the sludge interface can be obtained. Depending on the installation depth of the light projection unit 1 and the pattern acquisition unit 2, the measurable sludge level range is also different. In practical applications, a larger area can be covered by increasing the number of installations, or a mobile sludge suction vehicle can be used to cover the entire sedimentation tank.

[0037] In addition, as shown in Figure 4 the light projection unit 1 can also be dynamic, emitting only a single "linear" light beam, changing the emission angle using an optical structure, scanning the sludge interface to be detected, and simultaneously using the pattern acquisition unit 2 to obtain the reflected light at different emission angles, thereby calculating the sludge height information and determining whether the sludge discharge condition is met.

[0038] Another object of the present invention is to provide a sludge discharge system. As shown in Figure 2 the sludge discharge system includes a light projection unit 1, a pattern acquisition unit 2, a sludge discharge valve group 3, a sedimentation tank 4, and a control unit. The light projection unit 1 emits detection light towards the sludge interface. The pattern acquisition unit 2 is used to capture the detection pattern formed by the detection light on the sludge interface. The sludge discharge valve group 3 is used to discharge the sludge in the sedimentation tank 4. The light projection unit 1 and the pattern acquisition unit 2 are both installed in the sedimentation tank 4. The sludge discharge valve group 3 is installed at the bottom of the sedimentation tank 4. The light projection unit 1, the pattern acquisition unit 2, and the sludge discharge valve group 3 are all communicatively connected to the control unit. The control unit controls the opening and closing of the sludge discharge valve group 3 according to the sludge discharge method described above to achieve sludge discharge.

[0039] The sludge discharge system provided by the present invention measures the sludge level through an optical method rather than predicting it. Therefore, the accuracy of sludge level measurement is greatly improved. At the same time, in the present invention, the sludge level is measured through a pattern, and the sludge level in the area where the pattern is located is measured rather than a single-point sludge level, which helps to further improve the accuracy of sludge level measurement and thus helps to accurately discharge sludge according to actual needs.

[0040] In the present invention, it is preferred that the light projection unit 1 is a light projector; it is preferred that the pattern acquisition unit 2 is a camera; since the pattern acquisition unit 2 needs to be installed and operate below the water surface and is likely to be affected by attached sediment, thus affecting the pattern acquisition effect, the present invention further preferably selects the camera as a self-cleaning camera to ensure the clarity and accuracy of the pattern.

[0041] To facilitate the installation of the light projection unit 1 and the pattern acquisition unit 2, the present invention preferably further includes an installation unit (not shown in the figure) in this sludge discharge system; both the light projection unit 1 and the pattern acquisition unit 2 are installed below the water surface through the installation unit.

[0042] The installation unit installs the light projection unit 1 and the pattern acquisition unit 2 at the designated positions according to the detection requirements. The specific structure of the installation unit can select the corresponding existing technologies according to the detection requirements, and the present application does not limit the specific structure of the installation unit; for example, to improve the accuracy of detection, the present invention preferably installs the light projection unit 1 and the pattern acquisition unit 2 below the water surface in the sedimentation tank; and, to facilitate the pattern formed by the light projected by the light projection unit 1 to be photographed by the pattern acquisition unit 2, the present invention sets an installation cross bar. On the one hand, the light projection unit 1 and the pattern acquisition unit 2 are installed below the water surface in the sedimentation tank through the installation cross bar, and on the other hand, it is convenient to adjust the relative position between the light projection unit 1 and the pattern acquisition unit 2, so that the pattern formed by the light projected by the light projection unit 1 can be obtained by the pattern acquisition unit 2.

[0043] The present invention preferably further includes an installation vertical bar in the installation unit; the installation cross bar is perpendicularly connected to the installation vertical bar, and the installation cross bar is connected to the sedimentation tank through the installation vertical bar.

[0044] To expand the applicable range of the installation unit so that the installation unit can be applicable to sedimentation tanks of different sizes, the present invention preferably selects the installation vertical bar as a structure with adjustable length. Specifically, it is preferred that the installation vertical bar includes a first vertical bar and a second vertical bar that are inserted into each other, so as to facilitate adjusting the length of the installation vertical bar by adjusting the insertion length of the two.

[0045] Among them, one structural form of the installation vertical bar is that the first vertical bar and the second vertical bar are connected by threads, that is, external threads are provided on the outer side of the first vertical bar, and internal threads adapted to the external threads are provided inside the second vertical bar. Thus, the connection between the first vertical bar and the second vertical bar can be realized by rotation, and moreover, the length of the second vertical bar can be adjusted by adjusting different screwing lengths.

[0046] Another structural form of the installation vertical rod can be that at least two first installation holes are provided on the first vertical rod; second installation holes adapted to the first installation holes are provided on the second vertical rod; the installation vertical rod further includes an installation pin adapted to the first installation holes and the second installation holes, and the connection between the first vertical rod and the second vertical rod is realized by sequentially inserting the installation pin into the second installation hole and the first installation hole; and the length of the installation vertical rod is adjusted by selecting first installation holes at different positions.

[0047] The sludge discharge valve group 3 in the present invention includes at least two sludge discharge valves. Based on the sludge discharge system provided by the present invention, the sludge levels at different positions can be actually measured instead of a single-point sludge level. Therefore, the sludge discharge valves at different positions can be controlled according to the sludge levels at different positions for targeted sludge discharge, further improving the accuracy of sludge discharge.

[0048] Inspired by the above ideal embodiments according to the present invention, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A sludge discharge method, characterized in that: The steps include: S1: emitting a detection light to the sludge interface through a light projection unit, wherein the detection light forms a detection pattern on the sludge interface; S2: Acquire the detection pattern by a pattern acquisition unit; S3: judging whether the sludge discharge conditions are met according to the detection pattern; if so, proceeding to step S4; Otherwise, proceed to step S2; S4: Control the sludge discharge valve group to discharge sludge.

2. The sludge discharge method according to claim 1, characterized in that: Judging whether the sludge discharge conditions are met according to the detection pattern includes: S31: Obtain the size of the detection pattern; S32: Obtaining the installation height of the light projection unit; S33: calculating the detection height of the sludge interface using trigonometric functions and a calibration algorithm according to the size of the detection pattern and the installation height of the light projection unit; S34: Compare the detected height with the preset sludge height to determine whether the detected height is greater than the preset sludge height, and if so, the sludge discharge condition is met.

3. The sludge discharge method according to claim 1, characterized in that: Judging whether the sludge discharge conditions are met according to the detection pattern includes: S301: Obtain the size of the detection pattern; S302: Compare the size of the detection pattern with a preset size to determine whether the size of the detection pattern is smaller than the preset size. If so, the sludge discharge condition is met.

4. The sludge discharge method according to claim 1, characterized in that: Controlling the mud discharge valve group to discharge includes: obtaining the flatness of the mud interface according to the detection pattern, and then determining the discharge time of each mud valve in the mud discharge valve group according to the flatness of the mud interface.

5. The sludge discharge method according to any one of claims 1 to 4, characterized in that: The detection pattern is a checkerboard.

6. The sludge discharge method according to any one of claims 1 to 4, characterized in that: The detection pattern is a word line.

7. A sludge discharge system, characterized in that: It comprises a light projection unit (1), a pattern acquisition unit (2), a mud discharge valve group (3), a sedimentation tank (4) and a control unit; The light projection unit (1) emits detection light to the sludge interface; The pattern acquisition unit (2) is used to photograph the detection pattern formed by the detection light on the sludge interface; The sludge discharge valve group (3) is used to discharge the sludge in the sedimentation tank (4); The light projection unit (1) and the pattern acquisition unit (2) are both installed in the sedimentation tank (4); The mud discharge valve group (3) is installed at the bottom of the sedimentation tank (4); The light projection unit (1), the pattern acquisition unit (2) and the mud discharge valve group (3) are all communicatively connected to the control unit; The control unit controls the opening and closing of the sludge discharge valve group (3) according to the sludge discharge method according to any one of claims 1 to 6, so as to achieve sludge discharge.

8. The sludge discharge system according to claim 7, characterized in that: The light projection unit (1) is a light projector.

9. The sludge discharge system according to claim 7, characterized in that: The pattern acquisition unit (2) is a camera.

10. The sludge discharge system according to claim 7, characterized in that: It also comprises a mounting unit; the light projection unit (1) and the pattern acquisition unit (2) are both mounted below the water surface via the mounting unit.

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