Automatic feeding device and method for defoaming agent

Abstract

The invention discloses an automatic defoaming agent feeding device which comprises a liquid level measuring device, a feeding device and a control device. The foam measuring device comprises a detection module and an analysis processing module, the detection module is used for detecting the foam height, the input end of the analysis processing module is connected with the output end of the detection module and the output end of the liquid level measuring device, and the analysis processing module receives and processes data transmitted by the detection module and the liquid level measuring device so as to determine the actual foam height; and the controller is in communication connection with the liquid level measuring device and the foam measuring device and is used for determining the feeding amount of the defoaming agent and the water supplementing amount. The invention further discloses an automatic feeding method of the defoaming agent. The device has the beneficial effects that the liquid level measuring device and the foam measuring device are arranged to realize accurate measurement of the water level and the foam height of the nitrification tank, and meanwhile, the water replenishing amount and the feeding amount of a defoaming agent are automatically controlled according to the measurement result, so that excessive feeding of the defoaming agent can be avoided, and the production efficiency is also improved.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to an automatic dosing device and method for a defoaming agent. Background Art

[0002] The nitrification tank of the sewage treatment plant is prone to produce a large amount of foam under the action of aeration. If the foam accumulates, it will cause pollution. The main defoaming methods currently include spraying water, adding chemicals, shortening the sludge retention time, and adding carriers to the aeration reactor. However, these methods all have certain problems: although spraying water is simple to operate, the defoaming effect is limited; although adding chemicals can solve the foam problem in a short time, most of them are manually observed based on video images, and then the defoaming agent is manually added after visual judgment. This method is likely to lead to excessive defoaming agent input. Excessive use of chemicals will have a greater impact on the quality of the effluent water, and other equipment needs to be installed to deal with the remaining substances, which greatly increases the cost. Summary of the invention

[0003] In order to solve the above problems, the object of the present invention is to provide an automatic dosing device and method for defoaming agent.

[0004] The present invention provides an automatic dispensing device for a defoaming agent, the device comprising:

[0005] Liquid level measuring device, used to detect the liquid level height of the liquid in the nitrification tank;

[0006] The foam measuring device comprises a detection module and an analysis and processing module, wherein the detection module is used to detect the foam height of the liquid in the nitrification tank, and the input end of the analysis and processing module is connected to the output end of the detection module and the output end of the liquid level measuring device, and receives and processes the data transmitted by the detection module and the liquid level measuring device to determine the actual height of the foam;

[0007] The controller is connected to the liquid level measuring device and the foam measuring device for determining the amount of defoaming agent input according to the actual height of the foam and determining the amount of water replenishment according to the liquid level.

[0008] As a further improvement of the present invention, the detection module is composed of a plurality of sensors, and each of the sensors is composed of a ground electrode and a plurality of measuring electrodes.

[0009] As a further improvement of the present invention, the analysis and processing module includes a current conversion circuit, a processor, and a digital-to-analog conversion circuit, wherein the input end of the current conversion circuit is connected to the output end of the liquid level measuring device, the input end of the processor is connected to the output end of the current conversion circuit and the output end of the detection module, the input end of the digital-to-analog conversion circuit is connected to the output end of the processor, and the output end of the digital-to-analog conversion circuit is connected to the controller.

[0010] As a further improvement of the present invention, the controller is interlocked with the dosing pump and the water replenishment circulation pump.

[0011] As a further improvement of the present invention, the device also includes an electric control box, which is in communication connection with the controller and controls the start and stop of the dosing pump and the water replenishment circulation pump.

[0012] As a further improvement of the present invention, a spray pipe is provided in the nitrification tank, which is connected to the dosing pump and the water replenishment circulation pump respectively.

[0013] As a further improvement of the present invention, the liquid level measuring device adopts a immersion type static pressure liquid level gauge.

[0014] The present invention also provides a method for automatically delivering a defoaming agent, the method comprising:

[0015] Obtain the liquid level and foam height of the liquid in the nitrification tank;

[0016] Based on the foam height and the liquid level height, determining the actual foam height of the liquid surface in the nitrification tank;

[0017] Determining the amount of defoamer to be added based on the actual foam height to eliminate the foam in the nitrification tank;

[0018] Based on the liquid level, it is determined whether to replenish water to the nitrification tank so that the adjusted liquid level is within a target range.

[0019] As a further improvement of the present invention, the method further comprises: based on the amount of defoamer input, adding defoamer to eliminate foam in the nitrification tank, comprising:

[0020] Determine the current flow rate of the dosing pump;

[0021] Determine the dosing time according to the defoamer input amount and the flow rate of the dosing pump;

[0022] The on / off of the dosing pump is controlled based on the dosing time.

[0023] As a further improvement of the present invention, the determining whether to replenish water to the nitrification tank based on the liquid level height includes:

[0024] When the liquid level height is less than the liquid level threshold, the water replenishment circulation pump is turned on to replenish water, and the water replenishment pump is turned off after the water replenishment amount reaches the target value;

[0025] When the liquid level height is greater than or equal to the liquid level threshold, the controller increases the reading frequency of the liquid level height.

[0026] The beneficial effects of the present invention are as follows: by setting a liquid level measuring device and a foam measuring device, accurate measurement of the water level and foam height of the nitrification tank is achieved, and the amount of water replenishment and the amount of defoaming agent input are automatically controlled according to the measurement results, which not only avoids excessive input of defoaming agent, but also reduces manual operations and improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor.

[0028] Figure 1 It is a structural schematic diagram of an automatic defoaming agent delivery device according to an exemplary embodiment of the present invention;

[0029] Figure 2 A circuit diagram of a current conversion circuit of a foam measuring device in an automatic defoaming agent dispensing device according to an exemplary embodiment of the present invention;

[0030] Figure 3 The present invention is a circuit diagram of a digital-to-analog conversion circuit of a foam measuring device in an automatic defoaming agent dispensing device according to an exemplary embodiment of the present invention.

[0031] In the figure,

[0032] 1. Liquid level measuring device; 2. Foam measuring device; 3. Controller; 4. Dosing pump; 5. Water replenishment circulation pump; 6. Spray pipe; 7. Electric control box. DETAILED DESCRIPTION

[0033] 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.

[0034] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0035] In addition, in the description of the present invention, the terms used are only for illustrative purposes and are not intended to limit the scope of the present invention. The terms "include" and / or "comprise" are used to specify the existence of the elements, steps, operations and / or components, but do not exclude the existence or addition of one or more other elements, steps, operations and / or components. The terms "first", "second" and the like may be used to describe various elements, do not represent the order, and do not limit these elements. In addition, in the description of the present invention, unless otherwise specified, the meaning of "multiple" is two and more than two. These terms are only used to distinguish one element from another element. In conjunction with the following drawings, these and / or other aspects become apparent, and it is easier for a person of ordinary skill in the art to understand the description of the embodiments of the present invention. The accompanying drawings are used to describe the embodiments of the present invention for illustrative purposes only. Those skilled in the art will easily recognize from the following description that, without departing from the principles of the present invention, alternative embodiments of the structures and methods shown in the present invention can be adopted.

[0036] like Figure 1 As shown, an automatic defoaming agent delivery device according to an embodiment of the present invention comprises:

[0037] The liquid level measuring device 1 is used to detect the liquid level height of the liquid in the nitrification tank;

[0038] The foam measuring device 2 includes a detection module and an analysis and processing module. The detection module is used to detect the foam height of the liquid in the nitrification tank. The input end of the analysis and processing module is connected to the output end of the detection module and the output end of the liquid level measuring device 1, and receives and processes the data transmitted by the detection module and the liquid level measuring device 1 to determine the actual height of the foam.

[0039] The controller 3 is connected to the liquid level measuring device 1 and the foam measuring device 2 for communication, and is used to determine the amount of defoaming agent input according to the actual height of the foam, and to determine the amount of water replenishment according to the liquid level height.

[0040] When the device of the present application is used for work, the analysis and processing module receives and processes the liquid level signal detected by the liquid level measuring device 1 to obtain liquid level height data information. The detection module detects the change signal of the electrical parameters in the nitrification tank and transmits it to the analysis and processing module. The analysis and processing module processes the change signal to obtain the foam height data information, and at the same time, the actual foam height data can be determined in combination with the liquid level height data information. The controller 3 determines the input amount of the defoaming agent and the amount of water replenishment according to the received data (the actual foam height data and the liquid level height data) to control the water replenishment and / or defoaming in the nitrification tank. Among them, the foam height covers the liquid level height below the foam, and the change signal of the electrical parameter includes but is not limited to the resistance change signal, the capacitance change signal and the potential difference change signal.

[0041] The liquid level measuring device 1 and the foam measuring device 2 are arranged to detect the liquid level height and the foam height of the liquid in the nitrification tank, which not only provides important basic data for the entire automatic delivery device, but also is conducive to automatically controlling the amount of water replenishment and the amount of defoaming agent input, thereby avoiding excessive input of defoaming agent, avoiding waste of defoaming agent while ensuring the defoaming effect, reducing manual operation, lowering the fault tolerance rate, and improving production efficiency.

[0042] Preferably, the liquid level measuring device 1 and the foam measuring device 2 are arranged at the top of the nitrification tank.

[0043] In one embodiment, the detection module is composed of a plurality of sensors, each of which is composed of a ground electrode and a plurality of measuring electrodes to detect the change signal of the electrical parameter in the nitrification tank. The measuring electrodes of each sensor are preferably 4-8 to fully cover the area of ​​the liquid in the nitrification tank detected by the sensor. The number of sensors and measuring electrodes can be determined according to the size of the actual nitrification tank, and this application does not limit it.

[0044] The detection principle is as follows: the presence of foam will affect the conductive path between the electrodes. For example, as the foam height increases, the measuring electrode contacts the foam, and the conductive path becomes unblocked, causing the resistance between the measuring electrodes to decrease. At this time, the change signal of the electrical parameter is a resistance change signal, and the foam height can be indirectly obtained by measuring the resistance change signal. The dielectric constant of foam is different from that of liquid and air. The change of foam height will also change the capacitance value between the electrodes. Assuming that the dielectric constant of foam is smaller than that of liquid and the capacitance is inversely proportional to the dielectric constant, when the foam height increases, the capacitance between the measuring electrodes will decrease. At this time, the change signal of the electrical parameter is a capacitance change signal, and the foam height can be indirectly obtained by measuring the capacitance change signal.

[0045] Preferably, both the measuring electrode and the grounding electrode are partially placed in the foam. This placement method allows the electrode to directly contact the foam, so as to have a more acute perception of changes in the foam height. When the foam height changes, the proportion of the electrode immersed in the foam and the liquid below changes, thereby changing the electrical characteristics between the electrodes. Taking the change signal of the electrical parameter as a resistance change signal as an example, when the foam height increases, the proportion of the conductive path between the electrodes through the foam increases, thereby causing the resistance between the electrodes to increase.

[0046] It is understandable that the measuring electrode and the grounding electrode may be placed separately, that is, one is placed in the foam and the other is placed in the liquid, or both the measuring electrode and the grounding electrode may be suspended in the air near the foam. When the measuring electrode and the grounding electrode are placed separately, the difference in electrical properties between the foam and the liquid may be utilized to improve the accuracy and sensitivity of the detection. When the measuring electrode and the grounding electrode are both suspended in the air near the foam, some adverse effects of the foam on the electrodes may be avoided, thereby improving the reliability and stability of the detection. The placement positions of the measuring electrode and the grounding electrode may be set according to actual conditions, and this application does not make specific limitations on this.

[0047] In one embodiment, the analysis and processing module includes a current conversion circuit, a processor, and a digital-to-analog conversion circuit, wherein the input end of the current conversion circuit is connected to the output end of the liquid level measuring device 1, the input end of the processor is connected to the output end of the current conversion circuit and the output end of the detection module, the input end of the digital-to-analog conversion circuit is connected to the output end of the processor, and the output end of the digital-to-analog conversion circuit is connected to the controller 3.

[0048] like Figure 2As shown, the current conversion circuit is used to receive the 4-20mA current signal (liquid level signal) transmitted by the liquid level measuring device 1 and convert it into a voltage signal. Among them, the resistor R1 is a sampling resistor, which is used to convert the current signal into a voltage signal; ZV1 is a voltage stabilizing diode, which is connected in parallel with the resistor R1. When the input current is too large, the voltage can be clamped at a lower value to protect the operational amplifier and prevent the problem of causing large-scale damage to the internal components of the instrument due to lightning or misconnection to a voltage higher than the required voltage; the resistor R2, the capacitor C1 and the resistor R3, the capacitor C3 form an RC filter circuit for optimizing the circuit; the diodes D1 and D2 are connected in series to form a high potential and a low potential clamping circuit, which helps to prevent transient voltage from damaging the components and improves the anti-interference performance of the input signal; the operational amplifier is designed as a voltage follower, making full use of the characteristics of high input impedance and low output impedance of the operational amplifier to achieve signal isolation. The ideal operational amplifier has an infinite input impedance, so that no current flows into the input end, that is, it presents a "virtual disconnection" state, which can effectively avoid the subsequent processing circuit from affecting the signal. Furthermore, since the output voltage of the operational amplifier will not exceed its power supply voltage, the operational amplifier can be used as a voltage clamp to provide overvoltage protection for the processor, thereby preventing the output signal from being too large and exceeding the processor's tolerance and damaging the processor.

[0049] The processor receives the electrical parameter change signal output by the detection module, performs photoelectric isolation processing, and then amplifies it to obtain foam height data information. At the same time, the processor also receives and processes the voltage signal output by the current conversion circuit to obtain liquid level height data information. Then, the actual foam height data is obtained based on the foam height data information and the liquid level height data information.

[0050] The digital-to-analog conversion circuit is used to convert the discrete actual foam height data into continuous actual foam height data and transmit it to the controller 3. Figure 3As shown, the operational amplifier uses a single-power rail-to-rail operational amplifier OPA333, whose operating voltage is 2.7-5.5V, offset voltage is 10uV, minimum output is 30uV, and maximum output is VCC-30uV, with extremely high accuracy and stability. DACOUT is connected to the output end of the processor, firstly, the digital noise field is filtered by capacitor C25, then enters the operational amplifier for 1:1 buffering, and then passes through transistor Q2 for current amplification, forming a detection voltage on R7, capacitor C17 performs de-jittering processing, and the 4-20mA signal is output by resistor RL. Among them, capacitor C25 is at the input end of the operational amplifier and plays a filtering role; the operational amplifier is connected to the base of transistor Q2, and the emitter of transistor Q2 is fed back to the negative input end of the operational amplifier, together forming a constant current source, thereby forming a stable current output; resistor R7 and capacitor C17 form an RC filter loop to make the negative feedback signal more stable; resistor R14 and resistor RL are connected in series on the collector side of transistor Q2.

[0051] Among them, the current in the load forms a voltage drop on the resistor R7, and after feedback from the operational amplifier, Vdacout=Vr7=I*R7, that is, I=Vdacout / R7. When Vdacout changes between 400mV and 2000mV, an output of 4-20mA can be obtained. By changing the size of resistor R7, the required range of DACOUT can be changed. In this circuit, there will be a bias voltage of about 0.7V between the base and emitter of transistor Q2, so Vb[MAX]=2V+0.7V=2.7V, which is just within the output range of the operational amplifier OPA333. Resistor R14 is used as the current limiting current at the output end, so that the maximum output current Imax of the output end is Icc / (R7+R14), which can avoid the problem that the resistor R7 is burned out or the temperature is too high, causing the resistance value of the resistor R7 to change significantly. For example: if Vcc is 6V, then Imax=6V / 200O=30mA. If there is no R14, the maximum current may be 60mA. At this time, the power dissipation on R7 is 0.06*0.06*100=0.36W. If 0805 chip resistor is used, R7 will burn out, or the temperature rise will cause the resistance value of R7 to change too much, causing a large deviation in the output. After adding R14, the maximum power dissipation on R7 is: 0.03*0.03*100=0.09W, which is within the normal range.

[0052] In one embodiment, the controller 3 is interlocked with the dosing pump 4 and the water replenishment circulation pump 5 to realize automatic control of the water replenishment amount and the defoaming agent input amount. The controller 3 determines whether to start the water replenishment circulation pump 5 and the dosing pump 4 according to the received liquid level height data and the actual foam height data.

[0053] When the controller 3 detects that the liquid level is lower than the liquid level threshold, the water replenishment circulation pump 5 is controlled to be turned on, and the controller 3 detects that the liquid level is greater than or equal to the liquid level threshold and then turns off. When the controller 3 detects that the actual foam height is greater than the preset foam height threshold, the dosing pump 4 is controlled to be turned on, and the defoaming agent is added to eliminate the foam in the nitrification tank, and ... off when the controller 3 detects that the actual foam height is less than or equal to the foam height threshold.

[0054] Among them, the defoaming agent includes but is not limited to chlorine and oxidants, coagulants and vegetable oils, etc. The present application does not specifically limit the type of the defoaming agent.

[0055] Preferably, both the dosing pump 4 and the water replenishment circulation pump 5 are provided with a cut-off valve and a check valve at their pump outlets to facilitate maintenance and avoid backflow.

[0056] In one embodiment, the device further comprises an electric control box 7, which is in communication connection with the controller 3, and can control the start and stop of the dosing pump 4 and the water replenishment circulation pump 5 through corresponding buttons, and the inspector can also switch the control mode through the switch button of the electric control box 7. Among them, the control mode includes automatic mode and manual mode, the automatic mode is used in normal production operation, and the manual mode is mainly used in abnormal conditions such as on-site debugging and maintenance.

[0057] The automatic dosing device is initially set to the automatic mode. In the automatic mode, the controller 3 controls the water replenishment and / or defoaming in the nitrification tank according to the detection data (liquid level height and actual foam height). When the detection personnel switches the automatic mode to the manual mode through the electric control box 7, the detection personnel observes the video images and determines whether to turn on or off the dosing pump 4 and the water replenishment circulation pump 5.

[0058] Preferably, the electric control box 7 is installed on-site in the nitrification tank, so as to observe the situation in the nitrification tank in real time when controlling water replenishment and / or defoaming in manual mode.

[0059] Preferably, the electric control box 7 is provided with a display screen to display the data transmitted from the controller 3 to the electric control box 7. This allows the inspector to control the start and stop of the dosing pump 4 and the water replenishment circulation pump 5 in real time according to the detection data during manual control, which is convenient for the operator to operate and monitor the operating status.

[0060] In one embodiment, a spray pipe 6 is provided in the nitrification tank, which is connected to the dosing pump 4 and the water replenishment circulation pump 5 respectively.

[0061] Among them, the spray pipe 6 is arranged at the top of the nitrification tank, which can not only realize the defoaming function and water replenishing function of the device, but also be used as spray water for defoaming while replenishing water, thereby reducing the input amount of defoaming agent.

[0062] Preferably, the spray pipe 6 is a stainless steel pipe covered with small holes, and it can also be a plastic pipe. The present application does not specifically limit the material of the spray pipe.

[0063] Preferably, two rows of spray pipes 6 are provided, respectively arranged at the top and bottom ends inside the nitrification tank, wherein the defoaming agent is only injected from the spray pipe 6 located at the top, and supplementary tap water can be injected from the spray pipe 6 located at the top or from the spray pipe 6 located at the bottom.

[0064] When both water replenishment and defoaming agent need to be added for defoaming, the defoaming agent can be added through the spray pipe 6 at the top, and tap water can be injected through the spray pipe 6 at the bottom to perform defoaming and water replenishment at the same time; or tap water can be injected through the spray pipe 6 at the top first, and it can be used as spray water for defoaming while replenishing water, until the defoaming agent is added for defoaming after the liquid level height meets the requirements.

[0065] Similarly, when the actual height of the foam is high, you can also use the top spray pipe 6 to inject tap water to use it as spray water for defoaming. After the foam is reduced, add defoaming agent to reduce the amount of defoaming agent, further reduce the impact of the defoaming agent on water quality, and save costs. Among them, when using spray water for defoaming, it is necessary to pay attention to the liquid level in the nitrification tank must not exceed the maximum value of the liquid level. When the controller 3 detects that the liquid level is greater than the maximum value of the liquid level, it is forced to close the water replenishment circulation pump 5 and turn on the water outlet pump at the same time until the liquid level drops to the liquid level threshold.

[0066] In one embodiment, the liquid level measuring device 1 adopts an immersion-type static pressure level gauge. The immersion-type static pressure level gauge is inserted from the top of the nitrification tank and can be installed without damaging the wall of the nitrification tank, which greatly simplifies the installation process. At the same time, since the immersion-type static pressure level gauge is directly immersed in the liquid, the influence of foam on the detection result is reduced, and the accuracy requirement of the nitrification tank liquid level measurement is met. Moreover, the measurement of the immersion-type static pressure level gauge has no dead zone, and its range can be arbitrarily selected within a certain range. It can not only fully cover the liquid level measurement range in the nitrification tank, ensure the accuracy and completeness of the measurement results, but also better adapt to the liquid level measurement requirements of different nitrification tanks.

[0067] The present invention also provides a method for automatically delivering a defoaming agent, the method comprising:

[0068] Obtain the liquid level and foam height of the liquid in the nitrification tank;

[0069] Based on the foam height and the liquid level height, determining the actual foam height of the liquid surface in the nitrification tank;

[0070] Determining the amount of defoamer to be added based on the actual foam height to eliminate the foam in the nitrification tank;

[0071] Based on the liquid level, it is determined whether to replenish water to the nitrification tank so that the adjusted liquid level is within a target range.

[0072] The liquid level height and the foam height are obtained by a liquid level measuring device and a foam measuring device respectively, and the liquid level height being within a target range means that the liquid level height is between a liquid level threshold value and a liquid level maximum value.

[0073] In one embodiment, the method further comprises: based on the amount of defoamer input, adding a defoamer to eliminate foam in the nitrification tank, comprising:

[0074] Determine the current flow rate of the dosing pump 4, which is related to the valve opening. The larger the valve opening, the greater the flow rate. The relationship between the valve opening and the flow rate can be obtained in advance. For example, when the valve is set to open 30%, the corresponding flow rate is a 1 ; When the valve is opened 50%, the corresponding flow rate is a 2 ; When the valve is opened 80%, the corresponding flow rate is a 3 ; When the valve is 100% open, the corresponding flow rate is a 4 , a 1 2 3 4 When determining the flow rate of the dosing pump 4, the corresponding flow rate can be selected according to the amount of defoaming agent input. For example, when the amount of defoaming agent input is small, a 1 As the flow rate of the dosing pump 4, at this time, when the dosing pump valve is opened, only 30% of the valve opening should be controlled. This application does not limit how to determine the flow rate of the dosing pump.

[0075] The dosing time is determined according to the amount of defoaming agent input and the flow rate of the dosing pump 4 .

[0076] The on / off of the dosing pump 4 is controlled based on the dosing time.

[0077] In the automatic control mode, the controller 3 can first select the flow rate of the dosing pump 4, for example, select a 3 As the flow rate of the dosing pump 4, after the dosing time is calculated, the controller 3 controls to open 80% of the dosing pump valves, and starts the countdown synchronously, until the countdown ends and the dosing pump 4 is closed. In the manual control mode, the controller 3 transmits the defoaming agent input amount to the electric control box 7 and displays it on the electric control box display screen. The inspection personnel can control the opening and closing of the dosing pump 4 according to the defoaming agent input amount and the video image.

[0078] In one embodiment, the determining whether to replenish water to the nitrification tank based on the liquid level height includes:

[0079] ​​​When the liquid level height is less than the liquid level threshold, the water replenishment circulation pump 5 is turned on to replenish water, and the water replenishment pump 5 is turned off after the water replenishment amount reaches the target value. The liquid level height should be continuously detected during the water replenishment process so that the water replenishment circulation pump 5 can be turned off in time when the liquid level height is greater than or equal to the liquid level threshold.

[0080] When the liquid level height is greater than or equal to the liquid level threshold, the controller 3 increases the reading frequency of the liquid level height, so as to promptly start the outlet pump to discharge excess liquid in the nitrification tank when the liquid level height is greater than the maximum liquid level value.

[0081] In the automatic control mode, when the controller 3 detects that the liquid level is less than the liquid level threshold, the water replenishment circulation pump 5 is controlled to be turned on, and the controller 3 detects that the liquid level is greater than or equal to the liquid level threshold and is turned off. In the manual control mode, the controller 3 transmits the liquid level to the electric control box 7 and displays it on the display screen of the electric control box. The inspector can control the start and stop of the water replenishment circulation pump 5 according to the liquid level and the video image.

[0082] Among them, when defoaming and / or replenishing water for the nitrification pool, it is not only possible to replenish water first and then defoam. At this time, the controller 3 first controls to open the water replenishment circulation pump 5 so that it is injected into the nitrification pool through the spray pipe 6 located at the top, and defoaming can be achieved while replenishing water, until the liquid level is detected to be greater than or equal to the liquid level threshold and then the water replenishment circulation pump is controlled to be closed. Then the actual foam height is re-acquired by the controller 3. If the actual foam height is still greater than the foam height threshold at this time, the controller 3 recalculates the defoaming agent input amount and the dosing time, controls the dosing pump 4 to be turned on, and the defoaming agent is added to eliminate the foam in the nitrification pool until the controller 3 detects that the actual foam height is less than or equal to the foam height threshold and is closed. On the contrary, if the actual foam height is less than the foam height threshold at this time, the controller 3 no longer performs the defoaming operation, thereby reducing the input amount of the defoaming agent, reducing the impact of the defoaming agent on the water quality, and saving costs. It is also possible to defoam first and then replenish water, and the controller 3 controls to turn on the dosing pump 4 and the water replenishment circulation pump 5 in sequence to defoam and replenish water. The present application does not specifically limit the order of defoaming and water replenishment.

[0083] Preferably, the method further comprises: the controller 3 delays for 2-10 seconds before starting and closing the dosing pump 4 and / or the water replenishment circulation pump 5 to prevent the problem of misjudgment.

[0084] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0085] Furthermore, persons of ordinary skill in the art will appreciate that although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features from different embodiments is meant to be within the scope of the present invention and to form different embodiments.

[0086] It will be appreciated by those skilled in the art that, although the present invention has been described with reference to exemplary embodiments, various changes may be made and its elements may be replaced with equivalents without departing from the scope of the present invention. In addition, many modifications may be made to adapt specific situations or materials to the teachings of the present invention without departing from the essential scope of the present invention.

Claims

1. An automatic defoaming agent delivery device, characterized in that: The device comprises: Liquid level measuring device, used to detect the liquid level height of the liquid in the nitrification tank; The foam measuring device comprises a detection module and an analysis and processing module, wherein the detection module is used to detect the foam height of the liquid in the nitrification tank, and the input end of the analysis and processing module is connected to the output end of the detection module and the output end of the liquid level measuring device, and receives and processes the data transmitted by the detection module and the liquid level measuring device to determine the actual height of the foam; The controller is connected to the liquid level measuring device and the foam measuring device for determining the amount of defoaming agent input according to the actual height of the foam and determining the amount of water replenishment according to the liquid level.

2. The automatic delivery device according to claim 1, characterized in that: The detection module is composed of a plurality of sensors, and each of the sensors is composed of a ground electrode and a plurality of measuring electrodes.

3. The automatic delivery device according to claim 1, characterized in that: The analysis and processing module includes a current conversion circuit, a processor, and a digital-to-analog conversion circuit, wherein the input end of the current conversion circuit is connected to the output end of the liquid level measuring device, the input end of the processor is connected to the output end of the current conversion circuit and the output end of the detection module, the input end of the digital-to-analog conversion circuit is connected to the output end of the processor, and the output end of the digital-to-analog conversion circuit is connected to the controller.

4. The automatic delivery device according to claim 1, characterized in that: The controller is interlocked with the dosing pump and the water replenishment circulation pump.

5. The automatic delivery device according to claim 4, characterized in that: The device also includes an electric control box, which is in communication connection with the controller and controls the start and stop of the dosing pump and the water replenishment circulation pump.

6. The automatic delivery device according to claim 4, characterized in that: The nitrification pool is provided with a spray pipe which is respectively connected with the dosing pump and the water replenishment circulation pump.

7. The automatic delivery device according to claim 1, characterized in that: The liquid level measuring device adopts an immersion type static pressure liquid level gauge.

8. An automatic delivery method using the automatic delivery device for defoaming agent according to any one of claims 1 to 7, characterized in that: The method comprises: Obtain the liquid level and foam height of the liquid in the nitrification tank; Based on the foam height and the liquid level height, determining the actual foam height of the liquid surface in the nitrification tank; Determining the amount of defoamer to be added based on the actual foam height to eliminate the foam in the nitrification tank; Based on the liquid level, it is determined whether to replenish water to the nitrification tank so that the adjusted liquid level is within a target range.

9. The automatic delivery method according to claim 8, characterized in that: The method further includes: based on the amount of defoamer input, adding a defoamer to eliminate foam in the nitrification tank, including: Determine the current flow rate of the dosing pump; Determine the dosing time according to the defoamer input amount and the flow rate of the dosing pump; The on / off of the dosing pump is controlled based on the dosing time.

10. The automatic delivery method according to claim 8, characterized in that: The determining whether to replenish water to the nitrification pool based on the liquid level height includes: When the liquid level height is less than the liquid level threshold, the water replenishment circulation pump is turned on to replenish water, and the water replenishment pump is turned off after the water replenishment amount reaches the target value; When the liquid level height is greater than or equal to the liquid level threshold, the controller increases the reading frequency of the liquid level height.

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