Clarification zone height detection device and thickener flocculant adding system

Abstract

The invention discloses a clarification zone height detection device which comprises a thickener and further comprises a support, a first gravity monitoring device and a second gravity monitoring device are installed on the support, a first pull rope is fixed to the first gravity monitoring device, a first weight is fixed to the other end of the first pull rope, and a second weight is fixed to the other end of the second pull rope. A second pull rope is fixed to the second gravity monitoring device, a second heavy object is fixed to the other end of the second pull rope, and the horizontal line where the first heavy object is located is arranged on the highest warning line of an interface a between the clarification area and the settling area; the horizontal line where the second weight is located is arranged on the lowest warning line of the interface a between the clarification area and the settling area. The adding amount of the flocculating agent is adjusted in real time according to the height of the clarification area and feeding parameters, and it is ensured that the effluent quality is stable and reaches the standard.

Description

Technical Field

[0001] The present invention relates to the fields of mineral processing and wastewater treatment, and in particular to a device for detecting the height of a clarification zone and a flocculant dosing system for a thickener. Background Art

[0002] A thickener, also called a concentrator, is a solid-liquid separation device based on gravitational sedimentation. A low-concentration slurry flows into the top feed inlet of the thickener. Utilizing the property that the density of mineral particles is greater than that of water and the flocculation effect of a flocculant, the mineral particles in the slurry continuously settle. Solid particles or flocs settle to the bottom of the thickener tank under the action of gravity. The rake slowly rotates in the high-concentration slurry, transports the precipitated material to the underflow discharge port, and squeezes out the water between the solid particles. The upper clarified water is collected through an overflow weir for recycling use to achieve the purpose of solid-liquid separation. During the actual sedimentation process of the thickener, when it reaches stable operation, there are generally four regions: a clarification zone, an interference sedimentation zone, a compression zone, and a rake movement zone.

[0003] The thickener plays an important role in the processes of mineral processing and wastewater treatment, and its performance directly affects the treatment efficiency and the quality of the effluent water. Traditional thickener operations mostly rely on manual monitoring and adjustment, which is not only greatly affected by manual experience and the operation techniques of operators, the data is not easy to be accurate, but also time-consuming and laborious, the data is relatively lagging, it is difficult to cope with the measurement of rapidly changing water quality conditions, it cannot detect special situations such as muddy water running in time, and it is also impossible to accurately know the distribution of the sedimentation layer and the mud layer.

[0004] With the development of automation technology, intelligent dosing systems have gradually been applied to the field of water treatment. By real-time monitoring of water quality parameters and automatically adjusting the dosing amount of the reagent, the accuracy and efficiency of water quality treatment have been greatly improved. The primary control target for the dosage of the flocculant is the thickness of the clarification zone. Currently, domestic thickeners also use fixed interface instruments to measure the clarification zone and the heavy mud layer, but the instrument failure rate is high, and the data stability and accuracy are poor. Patent CN104176800B discloses a method for detecting the flocculation sedimentation effect and controlling the addition of flocculant for a coal slime thickener. Three floats filled with liquids of different densities are respectively located at the interfaces between adjacent two of the clarification zone, the sedimentation zone, the compression zone, and the concentration zone. By respectively measuring the distance from the horizontal top plate of the float to the level gauge with three fixed level gauges, the heights of the clarification zone, the sedimentation zone, and the compression zone are calculated and the dosing amount of the flocculant is adjusted. This patent does not mention measures or structures for restricting the horizontal movement of the floats, and the length of the longest float pull rod can be up to several meters and is extremely easy to tilt. Once the float deviates from the corresponding level gauge due to horizontal offset or tilt, the measured value will deviate from the actual situation, resulting in inaccurate dosing amount of the flocculant. Therefore, for the automatic control system for dosing flocculant in a thickener, especially the automatic control system based on the height of the clarification zone, further research and optimization are still needed. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a clarifying zone height detection device for detecting whether the height of the clarifying zone is within a reasonable range.

[0006] The present invention also provides a thickener flocculant dosing system, which automatically adjusts the flocculant dosing amount according to the detected clarifying zone height and controls the clarifying zone height within a reasonable range.

[0007] To solve the above technical problems, the technical solution adopted by the present invention is:

[0008] A clarifying zone height detection device includes a thickener and also includes a bracket. A first gravity monitoring device and a second gravity monitoring device are installed on the bracket. A first pulling rope is fixed at the first gravity monitoring device, and the other end of the first pulling rope is fixed with a first heavy object. A second pulling rope is fixed at the second gravity monitoring device, and the other end of the second pulling rope is fixed with a second heavy object. The horizontal line where the first heavy object is located is set at the highest warning line of the interface a between the clarifying zone and the sedimentation zone, and the horizontal line where the second heavy object is located is set at the lowest warning line of the interface a between the clarifying zone and the sedimentation zone.

[0009] In the present invention, due to the different buoyancy forces of the first heavy object and the second heavy object in the clarifying zone and the sedimentation zone with different densities, the values measured by the first gravity monitoring device and the second gravity monitoring device change, thereby further monitoring the height of the clarifying zone.

[0010] The first heavy object and the second heavy object are preferably weights.

[0011] The bracket includes a vertical rod, and a sliding groove is installed on the vertical rod. One end of the horizontal rod is cooperatively installed with the sliding groove.

[0012] Preferably, the horizontal lines where the first heavy object and the second heavy object are located are respectively the horizontal lines where the centers of gravity of the first heavy object and the second heavy object are located.

[0013] In a preferred embodiment of the present invention, it includes a clarifying zone height detection device, and also includes an influent suspended solids concentration detection device, an influent flow rate detection device, an effluent suspended solids concentration detection device, and a pump. A flow meter is installed at the discharge port of the pump. The control system is electrically connected to the water suspended solids concentration detection device, the influent flow rate detection device, the effluent suspended solids concentration detection device, the pump, and the flow meter respectively; preferably, the control system includes a monitoring module and a control module. The monitoring module is electrically connected to the water suspended solids concentration detection device and the influent flow rate detection device respectively, and the control module is electrically connected to the effluent suspended solids concentration detection device, the pump, and the flow meter respectively.

[0014] The control system controls the pump and flowmeter by receiving and analyzing the detection results of the influent suspended solid concentration detection device, influent flow detection device, and effluent suspended solid concentration detection device, so as to control the height of the clarification zone within a reasonable range.

[0015] The clarification zone height detection device can adopt the clarification zone height detection device described in the present invention or the clarification zone height detection device in the prior art.

[0016] In a preferred embodiment of the present invention, a valve is installed at the bottom discharge port of the thickener, and the control system is electrically connected to the valve; the control module is electrically connected to the valve.

[0017] The control system controls the opening degree of the valve by receiving and analyzing the detection results of the influent suspended solid concentration detection device, influent flow detection device, and effluent suspended solid concentration detection device, so as to control the height of the clarification zone within a reasonable range.

[0018] In a preferred embodiment of the present invention, the control system includes the following control methods:

[0019] S1. The height range of the clarification zone and water quality parameters are obtained in real time through the monitoring module, and the water quality parameters include the influent suspended solid concentration n (g / L), influent flow Q (L / min), and effluent suspended solid concentration C (mg / L);

[0020] S2. Calculate the theoretical value q x (g / min) of the flocculant addition amount according to the influent water quality parameters:

[0021] q x =Q*n*k*10 -6 (1)

[0022] where k is the single consumption of flocculant addition (g / t);

[0023] S3. Under the normal and stable operation state of the thickening tank, when the first heavy object or the second heavy object is at different depths in the clarification zone, multiple sets of test values of the gravity monitoring device are obtained, and their average value is F q , and the minimum value is F qmin ; when the first heavy object or the second heavy object is at different depths in the sedimentation zone, multiple sets of test values of the gravity monitoring device are obtained, and their average value is F j , and the maximum value is F jmax ; the test value of the gravity monitoring device of the first heavy object at the highest warning line of the clarification zone height is F h ; the test value of the gravity monitoring device of the second heavy object at the lowest warning line of the clarification zone height is F l ;

[0024] The flocculant dosing correction coefficient is:

[0025] k x = [(F h + F l ) - (F q + F j )] / (F q + F j ) (2)

[0026] The theoretical value correction value Q of the flocculant addition amount x is:

[0027] Q x = q x * (1 - k x ) (3)

[0028] S4. When F h ≥ F qmin , and F l ≤ F jmax , that is, the height of the clarification zone is within the normal range of the interval, add according to the currently given flocculant dosage;

[0029] When F h ≤ F jmax , and F l ≤ F jmax , that is, the height of the clarification zone is less than the lowest warning value, calculate the correction coefficient k according to formula (2) x <0, it is necessary to slightly increase the flocculant dosage on the basis of the theoretical flocculant addition amount, and gradually add according to the theoretical value correction value Q of the flocculant addition amount x ;

[0030] When F h ≥ F qmin , and F l ≥ F qmin , that is, the clarification zone is greater than the highest warning value, calculate the correction coefficient k according to formula (2) x >0, that is, continuously slightly reduce the flocculant dosage on the basis of the existing flocculant dosage, and continuously add according to the theoretical value correction value Q of the flocculant addition amount x ;

[0031] The analysis process of the clarification zone height interval in S1 and the first or second heavy object in S3 located in the clarification zone or the sedimentation zone is as follows: The thickener is overflow water, that is, the liquid level of the pool is fixed; the solid concentration in the thickener increases from top to bottom, and there is a clear and obvious muddy water interface in the normally and stably operating thickener, that is, the interface a between the clarification zone and the sedimentation zone. The solid concentration in the clarification zone is significantly lower than that in the sedimentation zone. Therefore, F jmax and F jmaxTheoretical tensions on the heavy objects above and below the mud-water interface; the distances from the liquid surface to the first heavy object and the second heavy object are L1 and L2 respectively, which also correspond to the minimum warning value and the maximum warning value of the height h of the clarification zone; when F h ≥F qmin , and F l ≤F jmax , it indicates that the first heavy object and the second heavy object are respectively located in the clarification zone and the sedimentation zone, and the interface a between the clarification zone and the sedimentation zone is located between the first heavy object and the second heavy object, that is, L1≤h≤L2, and the height of the clarification zone is appropriate; when F h ≤F jmax , and F l ≤F jmax , it indicates that both the first heavy object and the second heavy object are located in the sedimentation zone, and the interface a between the clarification zone and the sedimentation zone is located above the first heavy object, that is, h≤L1, and the height of the clarification zone is too small; when F h ≥F qmin , and F l ≥F qmin , it indicates that both the first heavy object and the second heavy object are located in the clarification zone, and the interface a between the clarification zone and the sedimentation zone is located below the second heavy object, that is, h≥L2, and the height of the clarification zone is too large.

[0032] In S2, the theoretical value q of the flocculant addition amount is calculated by multiplying the dry ore amount of the thickener feed by the single consumption of flocculant addition x .

[0033] In a preferred embodiment of the present invention, in S4, when F h ≤F jmax , and F l ≤F jmax , increase the underflow discharge.

[0034] In a preferred embodiment of the present invention, in S4, when F h ≥F qmin , and F l ≥F qmin , increase the solid inventory and reduce the underflow discharge.

[0035] In a preferred embodiment of the present invention, in S3, when the first heavy object or the second heavy object is located in the clarification zone, the time interval of the test value of the gravity monitoring device is greater than 10 min.

[0036] In a preferred embodiment of the present invention, in S4, the range of increasing or decreasing the flocculant dosage is q x *(-k x ).

[0037] In a preferred embodiment of the present invention, in S4, when F h ≤F jmax , and Fl ≤F jmax , the amplitude of increasing the underflow discharge is 4 - 6%.

[0038] In a preferred embodiment of the present invention, in S4, when F h ≥F qmin , and F l ≥F qmin , the amplitude of reducing the underflow discharge is 4 - 6%.

[0039] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0040] Optimize the flocculation effect: Adjust the dosage of the flocculant in real time according to the height of the clarification zone and the feed parameters to ensure that the effluent quality meets the standards stably.

[0041] Improve the treatment efficiency: Through automatic control, the manual intervention is reduced, and the treatment efficiency of the thickener is improved.

[0042] Energy conservation and emission reduction: Reduce the waste of chemicals, lower the operating cost, and meet the requirements of energy conservation and emission reduction.

[0043] The device for monitoring the height range of the clarification zone has a simple structure, is easy to maintain, and is inexpensive. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic structural diagram of the thickener flocculant dosing system in an embodiment of the present invention.

[0045] Figure 2 It is a schematic control principle diagram of the thickener flocculant dosing system in an embodiment of the present invention.

[0046] Figure 3 It is a schematic structural diagram of the clarification zone height detection device in an embodiment of the present invention.

[0047] Figure 4 It is a graph showing the change of the effluent suspended solid concentration before and after using the system in an embodiment of the present invention.

[0048] In the figure:

[0049] 1-1 First heavy object, 1-2 First pulling rope, 1-3 Second pulling rope, 1-4 Second heavy object;

[0050] 2 Bracket, 2-1 Vertical rod, 2-2 Horizontal rod;

[0051] 3-1 Pump, 3-2 Flowmeter, 3-3 Control system, 3-4 Concentration detection device, 3-5 Inlet flow detection device. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0052] Such as Figures 1-3As shown in the figure, the flocculant dosing system consists of a monitoring module, a control module, and a dosing module. Among them, the monitoring module includes a device for monitoring the height range of the clarification zone and sensors for monitoring feed parameters (inlet suspended solid concentration, inlet flow rate, outlet suspended solid concentration); the control module takes the PLC as the core, receives the data from the monitoring module, and automatically adjusts the dosing amount of the flocculant according to the preset control logic; the dosing module includes a dosing pump and a metering device (flow meter, etc.) for accurately dosing the flocculant.

[0053] Preferably, the height detection device for the clarification zone includes a bracket 2, on which a first gravity monitoring device and a second gravity monitoring device are installed. A first pulling rope 1-2 is fixed at the first gravity monitoring device, and the other end of the first pulling rope 1-2 is fixed with a first heavy object 1-1. A second pulling rope 1-3 is fixed at the second gravity monitoring device, and the other end of the second pulling rope 1-3 is fixed with a second heavy object 1-4. The interface a between the clarification zone and the sedimentation zone is located between the horizontal lines where the first heavy object 1-1 and the second heavy object 1-4 are located. The first heavy object 1-1 and the second heavy object 1-4 are made of weights. The bracket 2 includes a vertical rod 2-1, and a chute is installed on the vertical rod 2-1. One end of the horizontal end 2-2 is installed in cooperation with the chute. When the first pulling rope 1-2 and the second pulling rope 1-3 are straightened, the first gravity monitoring device and the second gravity monitoring device can measure the tensile force received by the stainless steel weights. The connection relationship of the main components is: two groups of gravity monitoring devices 1 are installed at the height monitoring points of the clarification zone through the bracket 2 on the thickener tank wall.

[0054] The first heavy objects 1-1 and the second heavy objects 1-4 of the two groups of gravity monitoring devices 1 are respectively located at the highest warning line and the lowest warning line of the clarification zone height after the lengths of the pulling ropes 1-2 are adjusted. The measurement principle of the device for monitoring the height range of the clarification zone is: due to the different material densities in the clarification zone and the sedimentation zone, the buoyancy forces received by the first heavy object 1-1 in the clarification zone and the sedimentation zone are different, so the resultant forces received are different. According to the magnitude of the resultant force tested by the high-precision tensile force sensor, it can be judged whether the position where the first heavy object 1-1 is located is the clarification zone or the sedimentation zone. Since the upper interface of the clarification zone is flush with the water surface of the overflow port, according to the measurement values of the two groups of gravity monitoring devices, it can be judged the positions where the first heavy object 1-1 and the second heavy object 1-4 are located, and it can be judged whether the height of the clarification zone is appropriate, and further judge whether it is necessary to adjust the dosing amount of the flocculant.

[0055] Preferably, the bracket 2 is composed of a vertical rod 2-1 with a chute and a horizontal rod 2-2 whose end can move in the chute. By moving the horizontal rod 2-2 upward, the weight 1-1 can be removed from the water surface for cleaning and maintenance.

[0056] The concentration detection device 3-4 includes an inlet suspended solid concentration detection device and an outlet suspended solid concentration detection device.

[0057] The control principle and method of the system are as follows:

[0058] The primary control objective for the dosage of the flocculant is the thickness of the clarification zone. The control logic of the flocculant dosing system is to quantitatively control the flocculant based on the optimal thickness of the clarification zone, saving the dosage of the flocculant to the greatest extent.

[0059] For a certain sand and gravel quarry, the control technology of the flocculant dosing system for sand and gravel wastewater includes the following steps:

[0060] 1) Obtain the recommended single consumption of the flocculant addition k = 30 (g / t) from the flocculant manufacturer.

[0061] 2) Obtain the height range of the clarification zone and water quality parameters in real time through the monitoring module. The water quality parameters include the influent suspended solid concentration n (g / L), the influent flow rate Q (L / min), the effluent suspended solid concentration C (mg / L), etc.

[0062] 3) Calculate the theoretical value q x (g / min) of the flocculant addition according to the influent water quality and quantity, specifically calculated by multiplying the dry ore quantity of the thickener feed by the single consumption of the flocculant addition:

[0063] q x = Q * n * k * 10 -6 (1)

[0064] 4) Calculate the correction value Q of the theoretical value of the flocculant addition according to the height of the clarification zone and the effluent water quality parameters x

[0065] When the weight is located in the clarification zone, the average test value of the gravity monitoring device is F q = 9.80N, and the minimum value is F qmin = 9.79N; when the weight is located in the sedimentation zone, the average test value of the gravity monitoring device is F j = 9.19N, and the maximum value is F jmax = 9.73N; the test value of the gravity monitoring device of the weight at the highest warning line of the clarification zone height is F h ; the test value of the gravity monitoring device of the weight at the lowest warning line of the clarification zone height is F l .

[0066] The flocculant dosing correction coefficient is:

[0067] k x = ((F h + F l ) - (F q + F j )) / (F q + F j ) (2)

[0068] The theoretical value correction value Q of the flocculant dosage x The correction value is:

[0069] Q x = q x *(1 - k x ) (3)

[0070] When F h ≥ F qmin , and F l ≤ F jmax , that is, the clarification zone is within the normal range of the interval, add according to the current given flocculant dosage, and calculate the correction coefficient k according to formula (2) x l ≈ 0, that is, add basically according to the current theoretical flocculant dosage;

[0071] When F h ≤ F jmax , and F l ≤ F jmax , that is, the height of the clarification zone is less than the lowest warning value of 1 m, calculate the correction coefficient k according to formula (2) x < 0, that is, it is necessary to slightly increase the flocculant dosage on the basis of the theoretical flocculant dosage, and at the same time increase the underflow discharge in stages;

[0072] When F h ≥ F qmin , and F l ≥ F qmin , that is, the clarification zone is greater than the highest warning value of 1.5 m, calculate the correction coefficient k according to formula (2) x > 0, continuously slightly reduce the flocculant dosage on the basis of the existing flocculant dosage, increase the solid inventory, and reduce the underflow discharge in stages.

[0073] 5) The control module issues an instruction to the dosing module to adjust the frequency or on / off state of the dosing pump, so as to accurately control the dosage of the flocculant.

[0074] 6) When the height of the clarification zone is abnormal and the height of the clarification zone still cannot return to the normal range for a long time after the flocculant dosage is adjusted, a warning is displayed; when F h and F l and F qmin and jmax do not conform to the above description, a warning is displayed; when the concentration C of the suspended matter in the effluent exceeds the standard, a warning is displayed, indicating that manual control intervention is required.

[0075] In summary, through this technical solution, the monitoring of the thickener range can be realized, and the dosage of the flocculant can be flexibly adjusted according to the feed properties and the change of the height of the clarification zone, so as to realize the automatic and reasonable addition of the flocculant, thereby achieving the purpose of saving drug consumption and improving the refined management.

[0076] Example 1

[0077] For a certain sand and gravel quarry, the main pollutant in the sand and gravel wastewater is suspended solids, with a concentration of 40 g / L to 100 g / L, and the effluent requirement is that the suspended solids are less than 100 mg / L. The control technology of the flocculant dosing system includes the following steps:

[0078] 1) Obtain the recommended single consumption of the flocculant k = 35 (g / t) according to the flocculant manufacturer.

[0079] 2) Obtain the height range of the clarification zone and water quality parameters in real time through the monitoring module. The water quality parameters include the influent suspended solid concentration n (g / L), the influent flow rate Q (L / min), the effluent suspended solid concentration C (mg / L), etc.

[0080] 3) Calculate the theoretical value q x (g / min) of the flocculant addition amount according to the influent water quality and quantity, specifically calculated by multiplying the dry ore amount of the thickener feed by the single consumption of the flocculant:

[0081] q x = Q * n * k * 10 -6 (1)

[0082] 4) Calculate the correction value Q of the theoretical value of the flocculant addition amount according to the height of the clarification zone and the effluent water quality parameters x

[0083] When the weight is located in the clarification zone, the average test value of the gravity monitoring device is F q = 14.70 N, and the minimum value is F qmin = 14.69 N; when the weight is located in the sedimentation zone, the average test value of the gravity monitoring device is F j = 13.28 N, and the maximum value is F jmax = 14.60 N; the test value of the gravity monitoring device of the weight at the highest warning line of the clarification zone height is F h ; the test value of the gravity monitoring device of the weight at the lowest warning line of the clarification zone height is F l .

[0084] The flocculant dosing correction coefficient is:

[0085] k x = ((F h + F l ) - (F q + F j )) / (Fq + F j ) (2)

[0086] The theoretical value correction value Q of the flocculant addition amount x The correction value is:

[0087] Q x = q x *(1 - k x ) (3)

[0088] When F h ≥ F qmin , and F l ≤ F jmax , that is, the clarification zone is within the normal range of the interval, add according to the current given flocculant dosage, and calculate the correction coefficient k according to formula (2) x l ≈ 0, that is, add basically according to the current theoretical flocculant dosage;

[0089] When F h ≤ F jmax , and F l ≤ F jmax , that is, the height of the clarification zone is less than the lowest warning value of 1 m, calculate the correction coefficient k according to formula (2) x < 0, that is, it is necessary to slightly increase the flocculant dosage on the basis of the theoretical flocculant addition amount, and at the same time increase the underflow discharge in stages;

[0090] When F h ≥ F qmin , and F l ≥ F qmin , that is, the clarification zone is greater than the highest warning value of 1.5 m, calculate the correction coefficient k according to formula (2) x > 0, continuously slightly reduce the flocculant dosage on the basis of the existing flocculant dosage, increase the solid inventory, and reduce the underflow discharge in stages.

[0091] 5) The control module issues an instruction to the dosing module to adjust the frequency or on / off state of the dosing pump, so as to accurately control the addition amount of the flocculant.

[0092] 6) When the height of the clarification zone is abnormal and the height of the clarification zone still cannot return to the normal range for a long time after the flocculant dosage is adjusted, a warning is displayed; when the concentration C of the suspended solids in the effluent exceeds the standard, a warning is displayed, indicating that manual control intervention is required.

[0093] During the implementation process, the influent flow rate was measured to be 30000 L / min, the influent suspended solid concentration was 62.6 g / L, and the effluent suspended solid concentration was 80 mg / L at a certain time period. Calculate q according to formula (1) x= 65.1 g / min; The tensile forces on the first heavy object 1-1 and the second heavy object 1-4 are 14.70 KN and 14.69 KN respectively, meeting F h ≥ F qmin , and F l ≥ F qmin , that is, the clarification zone is greater than the highest warning value of 1.5 m. According to Equation (2), the correction coefficient is k x = 0.05 > 0. Continuously and slightly reduce the flocculant dosage on the basis of the existing flocculant dosage, increase the solid inventory, and gradually reduce the underflow discharge; Calculate k x according to Equation (2), and calculate Q x = 61.8 g / min. The control module issues an instruction to the dosing module to adjust the frequency of the dosing pump, thereby precisely controlling the flocculant dosage. Every 15 minutes, according to the monitored influent water quality and quantity data and the tensile forces on the first heavy object 1-1 and the second heavy object 1-4, repeat the above steps to adjust the flocculant dosage. After 1 hour, the effluent suspended solid concentration is monitored to be 91.5 mg / L, and the tensile forces on the first heavy object 1-1 and the second heavy object 1-4 are 14.70 N and 14.02 N respectively, meeting F h ≥ F qmin and F l ≤ F jmax situation, that is, the clarification zone is within the normal range of the interval, and then stop adjusting the flocculant dosage. This adjustment process is realized through automatic control, improving the processing efficiency of the thickener.

[0094] After using this system, the effluent suspended solid concentration of the sand and gravel wastewater reaches the standard stably, changing the situation of blindly increasing the flocculant dosage to ensure the effluent compliance during manual control, and the flocculant consumption is reduced by about 8%.

[0095] In summary, through this technical solution, it is possible to achieve the monitoring of the thickener range, flexibly adjust the flocculant dosage according to the feed properties and the change of the clarification zone height, realize the automatic and reasonable addition of the flocculant, and thus achieve the purpose of saving drug consumption and improving refined management.

Claims

1. A clarification zone height detection device, comprising a thickener, characterized in that: The invention also comprises a support (2), on which a first gravity monitoring device and a second gravity monitoring device are mounted, a first pull rope (1-2) is fixed to the first gravity monitoring device, a first weight (1-1) is fixed to the other end of the first pull rope (1-2), a second pull rope (1-3) is fixed to the second gravity monitoring device, a second weight (1-4) is fixed to the other end of the second pull rope (1-3), the horizontal line at which the first weight (1-1) is located is set at the highest warning line of the interface a between the clarification zone and the sedimentation zone, and the horizontal line at which the second weight (1-4) is located is set at the lowest warning line of the interface a between the clarification zone and the sedimentation zone.

2. A thickener flocculant dosing system, characterized in that: The invention comprises a clarification zone height detection device, an inlet suspended matter concentration detection device, an inlet flow detection device, an outlet suspended matter concentration detection device, and a pump (3-1); a flow meter (3-2) is installed at the discharge port of the pump (3-1); the control system (3-3) is electrically connected to the water suspended matter concentration detection device, the inlet flow detection device, the outlet suspended matter concentration detection device, the pump (3-1), and the flow meter (3-2); preferably, the control system (3-3) comprises a monitoring module, a control module, and a dosing module; the monitoring module is electrically connected to the water suspended matter concentration detection device and the inlet flow detection device, and the dosing module is electrically connected to the outlet suspended matter concentration detection device, the pump (3-1), and the flow meter (3-2).

3. The thickener flocculant dosing system according to claim 2, characterized in that: A valve is installed at the bottom flow outlet of the thickener, and the control system (3-3) is electrically connected to the valve; preferably, the control module is electrically connected to the valve.

4. The thickener flocculant dosing system according to claim 2, characterized in that: The control system (3-3) includes the following control method: S1. Obtain the height interval and water quality parameters of the clarification zone in real time through the monitoring module. The water quality parameters include the inlet suspended solids concentration n (g / L), the inlet flow rate Q (L / min), and the outlet suspended solids concentration C (mg / L); S2. Calculate the theoretical value of flocculant addition amount q according to the influent water quality parameters x (g / min): q x =Q*n*k*10 -6 (1) Where k is the unit consumption of flocculant addition (g / t); S3. When the thickening tank is in normal and stable operation, when the first weight or the second weight is located at different depths in the clarification zone, multiple groups of gravity monitoring device test values ​​are obtained, and the average value is F q , the minimum value is F qmin When the first weight or the second weight is located at different depths in the sedimentation zone, multiple groups of gravity monitoring device test values ​​are obtained, and the average value is F j , the maximum value is F jmax ; The test value of the gravity monitoring device of the first weight at the highest warning line of the clarification area is F h ; The test value of the second weight gravity monitoring device at the lowest warning line of the clarification area is F l ; The flocculant dosage correction factor is: k x =[(F h +F l )-(F q + F j )] / (F q + F j ) (2) Theoretical value correction value of flocculant addition Q x The correction value is: Q x = q x *(1- k x ) (3) S4, when F h ≥F qmin , and F l ≤F jmax , that is, the height of the clarification zone is within the normal range of the interval, and the flocculant dosage is added according to the current given dosage; When F h ≤F jmax , and F l ≤F jmax When the height of the clarification zone is less than the minimum warning value, the correction coefficient k is calculated according to formula (2) x <0, it is necessary to slightly increase the amount of flocculant added based on the theoretical amount of flocculant added, and gradually achieve the correction value Q according to the theoretical value of flocculant addition x to add; When F h ≥F qmin , and F l ≥F qmin , that is, the clearing area is greater than the highest warning value, and the correction coefficient is calculated according to formula (2) as k x > 0, that is, on the basis of the existing flocculant dosage, the flocculant dosage is continuously reduced slightly, and the theoretical value correction value Q of the flocculant dosage is continuously achieved. x to add.

5. The thickener flocculant dosing system according to claim 4, characterized in that: In S4, when F h ≤F jmax , and F l ≤F jmax , increase the bottom flow discharge.

6. The thickener flocculant dosing system according to claim 4, characterized in that: In S4, when F h ≥F qmin , and F l ≥F qmin , increase solid inventory and reduce underflow discharge.

7. The thickener flocculant dosing system according to claim 4, characterized in that: In S3, when the first weight or the second weight is located in the clarification area, the time interval of the test value of the gravity monitoring device is greater than 10 minutes.

8. The thickener flocculant dosing system according to claim 2, characterized in that: In S4, the increase or decrease of the amount of flocculant is q x *(-k x ).

9. The thickener flocculant dosing system according to claim 5, characterized in that: In S4, when F h ≤F jmax , and F l ≤F jmax , increase the bottom flow discharge range by 4 to 6%.

10. The thickener flocculant dosing system according to claim 5, characterized in that: In S4, when F h ≥F qmin , and F l ≥F qmin , reducing the amount of bottom flow discharge by 4 to 6%.

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