A detection device for preventing excessive liquid from chemical oxygen demand

Abstract

The present invention relates to a detection device for preventing excessive liquid of chemical oxygen demand. The fixed sleeve is a semicircular arc plate. Two groups of fixed sleeves are arranged as mirror images to form a circular ring. A clamping groove for clamping a capacitor plate is arranged inside the fixed sleeve. Clamps are arranged above and below the fixed sleeve respectively. The clamps are retracted and released by locking bolts. The capacitor plate is an arc plate, slightly smaller than a semicircle. The two groups of capacitor plates form a capacitor C0. One end of the capacitor C0 is connected to a high-frequency oscillator, and the other end is connected to an operational amplifier circuit. The operational amplifier circuit is connected to an analog switch. The analog switch is connected to an amplifying filter circuit. The amplifying filter circuit is connected to a digital-to-analog converter ADC. The ADC is connected to a controller. The ADC is respectively connected to the analog switch and the high-frequency oscillator. The capacitor plate is clamped in the fixed sleeve. The fixed sleeve is sleeved on a liquid guide tube. The clamp fixes the fixed sleeve on the liquid guide tube by a locking bolt. The liquid guide tube is located between a meter and a peristaltic pump. The present invention can detect excessive liquid in time, is easy to use, easy to disassemble and assemble, automatically detects excessive liquid state, and avoids failure to detect excessive liquid.

Description

Technical Field

[0001] The present invention relates to the technical field of water quality monitoring equipment, in particular to a detection device for timely detecting excessive liquid, convenient use, convenient assembly and disassembly, automatic detection of excessive liquid state, and prevention of excessive liquid by preventing chemical oxygen demand from failing to detect excessive liquid. Background Art

[0002] Before digestion, online water quality monitoring equipment such as COD needs to measure the liquid added to the digester. The peristaltic pump drives the liquid suction and controls the switch of the multi-way valve at the same time. One of the liquid storage bottles is selected, and the liquid in the liquid storage bottle is sucked into the multi-way valve, and then enters the meter for measurement. After the measurement is completed, the peristaltic pump reverses and presses the liquid in the meter into the multi-way valve. Through the switch selection of the multi-way valve, the liquid is pressed into the digester for digestion and detection. The meter detects whether the liquid level has been reached through the light detector. The principle is that the emitting end of the light detector emits light through the metering tube of the meter. When liquid enters the metering tube, it absorbs light. The receiving end of the light detector is used to receive light to determine whether liquid has reached the metering position. Two groups of light detectors are generally set. In actual use, when the concentration of liquid in the metering tube is too high, it will completely block the light. The receiving end of the light detector cannot receive light, which will lead to a misjudgment that no liquid has reached the metering tube, and the peristaltic pump will not be stopped by the controller. To prevent this, a liquid collection bottle will be installed at one end of the peristaltic pump. Once the liquid cannot be detected, the liquid pumped by the peristaltic pump will enter the liquid collection bottle. During the liquid overflow, whether there is liquid in the liquid collection bottle is determined by humans, which is very inconvenient and needs to be checked at any time.

[0003] Capacitive level sensors use the principle of electrostatics. The measurement of this sensor usually includes a plate of a capacitor, and the outside of the plate is the appearance of the sensor shell. This external measurement is usually close to the container of the device. When the liquid rises and falls, the internal conductor is covered by the liquid, and the dielectric constant of the capacitor changes, so the capacitance changes, and the state of the circuit connected to the measuring head also changes, so the switch can be controlled to open or close.

[0004] A detection device is needed that can detect excessive liquid in time, is easy to use, easy to assemble and disassemble, automatically detects the excessive liquid state, and avoids the failure to detect the chemical oxygen demand of excessive liquid to prevent excessive liquid. Summary of the invention

[0005] The purpose of the present invention is to provide a detection device for timely detecting excessive liquid, which is easy to use, easy to assemble and disassemble, and can automatically detect the excessive liquid state and avoid the detection of chemical oxygen demand to prevent excessive liquid.

[0006] A detection device for preventing excessive liquid from chemical oxygen demand, comprising:

[0007] A fixing sleeve, the fixing sleeve is a semicircular arc plate, two sets of fixing sleeves are arranged in mirror image to form a ring, a clamping groove for clamping the capacitor plate is arranged on the inner side of the fixing sleeve, clamps are arranged on the upper and lower sides of the fixing sleeve, and the clamps are retracted and released by locking bolts, the capacitor plate is an arc plate, slightly smaller than a semicircle, and the two sets of capacitor plates form a capacitor C0;

[0008] One end of the capacitor C0 is connected to a high-frequency oscillator, and the other end is connected to an operational amplifier circuit, the operational amplifier circuit is connected to an analog switch, the analog switch is connected to an amplifying filter circuit, the amplifying filter circuit is connected to a digital-to-analog converter ADC, the ADC is connected to a controller, and the ADC is connected to the analog switch and the high-frequency oscillator respectively;

[0009] The capacitor plate is clamped in the fixing sleeve, the fixing sleeve is sleeved on the liquid guiding tube, the clamp fixes the fixing sleeve on the liquid guiding tube through the locking bolt, and the liquid guiding tube is located between the meter and the peristaltic pump.

[0010] A support platform is provided at the bottom of the fixing sleeve. The two ends of the fixing sleeve are concave and then bent inward to form a smooth arc surface, and the smooth arc surface fits the catheter.

[0011] An interface is arranged in the middle of the capacitor plate, and the interface of the capacitor plate passes through the fixing sleeve.

[0012] The clamp is in a circular shape, with locking heads at both ends, and the bottom of the locking bolt cooperates with a nut.

[0013] The high-frequency oscillator, ADC and controller are integrated in one MCU.

[0014] The third interface of the amplifier U1 of the operational amplifier circuit is respectively connected to the resistor R5 and the capacitor C0, the first interface of the amplifier U1 is respectively connected to the second interface of the amplifier U1 and the resistor R3, the resistor R3 is connected to the third interface of the amplifier U2, the second interface of the amplifier U2 is respectively connected to the resistor R1, the resistor R2, and the capacitor C1, the resistor R1 is grounded, and the first interface of the amplifier U2 is respectively connected to the capacitor C1 and the resistor R2;

[0015] The analog switch is U3, the 8th interface, the 1st interface and the 14th interface of U3 are grounded respectively, the 7th interface of U3 is connected to -VCC, the 16th interface of U3 is connected to VCC, and the 5th interface and the 12th interface of U3 are connected to the 1st interface of the amplifier U2 respectively;

[0016] The first interface of the amplifier U4 of the amplifying and filtering circuit is connected to the third interface of U3, the fourth interface of the amplifier U4 is connected to the thirteenth interface of U3, the sixth interface of the amplifier U4 is grounded, the eighth interface of the amplifier U4 is connected to VCC, the fifth interface of the amplifier U4 is connected to -VCC, the seventh interface of the amplifier U4 is connected to the resistor R4, the resistor R4 is respectively connected to the capacitor C2 and the ADC interface of the MCU, and the capacitor C2 is grounded;

[0017] The PWM interface of the MCU is connected to capacitor C0, the A interface of the MCU is connected to the 10th interface of U3, the B interface of the MCU is connected to the 9th interface of U3, and the INH interface of the MCU is connected to the 6th interface of U3.

[0018] The liquid in the catheter passes through the fixed sleeve, the capacitance of the capacitor C0 changes, and the oscillating voltage signal emitted by the high-frequency oscillator becomes an oscillating current signal after passing through the changed capacitor C0. The oscillating current signal is converted into a voltage signal through the operational amplifier circuit. The voltage signal passes through the analog switch and the amplification and filtering circuit to take the absolute value and then is filtered, and then sent to the digital-to-analog converter ADC, organized into a digital signal and sent to the controller for processing. The controller controls the high-frequency oscillator, and the controller detects the change of the digital signal, and then controls the peristaltic pump to stop.

[0019] The output waveform of the high-frequency oscillator is a sawtooth wave, and the controller adjusts the output wave of the high-frequency oscillator by setting the duty cycle and / or the frequency.

[0020] The liquid guide tube is arranged between the peristaltic pump and the meter, the meter is connected to a multi-way valve, the multi-way valve is respectively connected to a plurality of liquid storage bottles and a digester, the digester is connected to a liquid storage bottle, and two light detectors are arranged on the meter.

[0021] Grooves cooperating with the clamp are respectively arranged on the upper and lower outer sides of the fixing sleeve.

[0022] The fixing sleeve of the present invention is a semicircular arc plate, two groups of fixing sleeves are mirrored to form a circular ring, a clamping groove for clamping a capacitor plate is arranged on the inner side of the fixing sleeve, clamps are arranged on the upper and lower sides of the fixing sleeve respectively, the clamps are retracted and released by locking bolts, the capacitor plate is an arc plate, slightly smaller than a semicircle, and the two groups of capacitor plates form a capacitor C0; one end of the capacitor C0 is connected to a high-frequency oscillator, and the other end is connected to an operational amplifier circuit, the operational amplifier circuit is connected to an analog switch, the analog switch is connected to an amplifying filter circuit, the amplifying filter circuit is connected to a digital-to-analog converter ADC, the ADC is connected to a controller, and the ADC is respectively connected to the analog switch and the high-frequency oscillator; the capacitor plate is clamped in the fixing sleeve, the fixing sleeve is sleeved on the liquid guide tube, the clamp fixes the fixing sleeve on the liquid guide tube by a locking bolt, and the liquid guide tube is located between a meter and a peristaltic pump. The present invention can detect excessive liquid in time, is easy to use, easy to disassemble and assemble, automatically detects excessive liquid state, and avoids failure to detect excessive liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a front view of the fixing sleeve of the present invention;

[0024] Figure 2 is a cross-sectional view of the fixing sleeve of the present invention;

[0025] Figure 3 is a top view of the clamp of the present invention;

[0026] Figure 4 It is the control relationship diagram of the present invention;

[0027] Figure 5 is a circuit diagram of the present invention;

[0028] Figure 6 is a waveform comparison diagram of the present invention;

[0029] Figure 7 It is a schematic diagram of the use state of the present invention;

[0030] Figure 8 It is a schematic diagram of the use state of the present invention under the prior art;

[0031] In the figure: 1. fixing sleeve, 2. capacitor plate, 3. clamp, 4. locking bolt, 5. liquid guide tube, 7. peristaltic pump, 9. meter, 10. multi-way valve, 11. liquid storage bottle, 12. digester, 13. photodetector, 14. excess liquid collection bottle. DETAILED DESCRIPTION

[0032] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0033] A detection device for preventing excessive liquid in chemical oxygen demand comprises: a fixing sleeve 1, which is a semicircular arc plate, two groups of fixing sleeves 1 are arranged in mirror image to form a ring, a clamping groove for clamping a capacitor plate 2 is arranged on the inner side of the fixing sleeve 1, clamps 3 are respectively arranged on the upper and lower sides of the fixing sleeve 1, and the clamps 3 are retracted and released by locking bolts 4, the capacitor plate 2 is an arc plate, slightly smaller than a semicircle, and the two groups of capacitor plates 2 form a capacitor C0; one end of the capacitor C0 is connected to a high-frequency oscillator, and the other end is connected to an operational amplifier circuit, the operational amplifier circuit is connected to an analog switch, the analog switch is connected to an amplifying filter circuit, the amplifying filter circuit is connected to a digital-to-analog converter ADC, the ADC is connected to a controller, and the ADC is respectively connected to the analog switch and the high-frequency oscillator; the capacitor plate 2 is clamped in the fixing sleeve 1, the fixing sleeve 1 is sleeved on a liquid guiding tube 5, the clamp 3 fixes the fixing sleeve 1 on the liquid guiding tube 5 by means of locking bolts 4, and the liquid guiding tube 5 is located between a meter 9 and a peristaltic pump 7.

[0034] A support platform is provided at the bottom of the fixing sleeve 1. The two ends of the fixing sleeve 1 are concave and bent inward to form a smooth arc surface, which fits the catheter 5. An interface is provided in the middle of the capacitor plate 2, and the interface of the capacitor plate 2 passes through the fixing sleeve 1. The clamp 3 is annular, with locking heads at both ends, and the bottom of the locking bolt 4 cooperates with the nut.

[0035] The high-frequency oscillator, ADC, and controller are integrated in one MCU. The third interface of amplifier U1 of the operational amplifier circuit is connected to resistor R5 and capacitor C0 respectively, the first interface of amplifier U1 is connected to the second interface of amplifier U1 and resistor R3 respectively, resistor R3 is connected to the third interface of amplifier U2, the second interface of amplifier U2 is connected to resistor R1, resistor R2, and capacitor C1 respectively, resistor R1 is grounded, and the first interface of amplifier U2 is connected to capacitor C1 and resistor R2 respectively; the analog switch is U3, the eighth interface, the first interface, and the fourteenth interface of U3 are grounded respectively, the seventh interface of U3 is connected to -VCC, the sixteenth interface of U3 is connected to VCC, the fifth interface and the twelfth interface of U3 are connected to amplifier U 2; the 1st interface of the amplifier U4 of the amplifying and filtering circuit is connected to the 3rd interface of U3, the 4th interface of the amplifier U4 is connected to the 13th interface of U3, the 6th interface of the amplifier U4 is grounded, the 8th interface of the amplifier U4 is connected to VCC, the 5th interface of the amplifier U4 is connected to -VCC, the 7th interface of the amplifier U4 is connected to the resistor R4, the resistor R4 is respectively connected to the capacitor C2 and the ADC interface of the MCU, and the capacitor C2 is grounded; the PWM interface of the MCU is connected to the capacitor C0, the A interface of the MCU is connected to the 10th interface of U3, the B interface of the MCU is connected to the 9th interface of U3, and the INH interface of the MCU is connected to the 6th interface of U3.

[0036] The liquid in the catheter 5 passes through the fixed sleeve 1, the capacitance of the capacitor C0 changes, and the oscillating voltage signal emitted by the high-frequency oscillator becomes an oscillating current signal after passing through the changed capacitor C0. The oscillating current signal is converted into a voltage signal through the operational amplifier circuit. The voltage signal is filtered after taking the absolute value through the analog switch and the amplification and filtering circuit, and then sent to the digital-to-analog converter ADC, which is organized into a digital signal and sent to the controller for processing. The controller controls the high-frequency oscillator, detects the change of the digital signal, and then controls the peristaltic pump 7 to stop.

[0037] The output waveform of the high-frequency oscillator is a sawtooth wave, and the controller adjusts the output wave of the high-frequency oscillator by setting the duty cycle and / or frequency. The liquid guide tube 5 is arranged between the peristaltic pump 7 and the meter 9, the meter 9 is connected to the multi-way valve 10, the multi-way valve 10 is respectively connected to a plurality of liquid storage bottles 11 and a digester 12, the digester 12 is connected to a liquid storage bottle 11, and two light detectors 13 are arranged on the meter 9. The outer side of the fixing sleeve 1 is provided with grooves matching with the clamp 3 at the top and bottom.

[0038] The capacitor plate 2 is stuck in the fixing sleeve 1 and fixed. Then the two sets of fixing sleeves 1 are set as mirror images to form a ring, which is put on the catheter 5. Then the fixing sleeve 1 is fixed to the catheter 5 by the clamp 3 through the locking bolt 4 to complete the installation. When it needs to be disassembled, it can be removed by reverse operation, which is convenient for use and disassembly. The capacitor plate 2 is an arc-shaped plate, slightly smaller than a semicircle. The two sets of capacitor plates 2 form a capacitor C0, so that the capacitor plates 2 are mirror images of each other and do not touch each other, which is convenient for positioning.

[0039] The oscillating voltage signal emitted by the high-frequency oscillator changes into an oscillating current signal after passing through the variable capacitor C0. After passing through the amplifier U1 of the operational amplifier circuit, the oscillating current signal changes into a voltage signal. The voltage signal is amplified by the amplifier U2 and then sent to the analog switch. The positive part of the curve of the voltage signal is a smooth curve that is inclined downward to the right and concave, and the negative part is a smooth curve that is inclined upward to the right and concave. The analog switch is controlled by the controller to select the switching time, specifically: the A interface of the MCU is connected to the 10th interface of U3, the B interface of the MCU is connected to the 9th interface of U3, the INH interface of the MCU is connected to the 6th interface of U3, the INH interface of the MCU is an enable interface that controls whether U3 works or not, and the A interface of the MCU and the B interface of the MCU control whether the X0 interface, Y0 interface, X1 interface, and Y1 interface of U3 are turned on and the turn-on time. When the voltage signal is positive, the X0 interface and Y0 interface of U3 are turned on, and the output values ​​of the XCOM interface and YCOM interface of U3 are positive, that is, X0-Y0. When the voltage signal is negative, the X1 interface and Y1 interface of U3 are turned on, and the output values ​​of the XCOM interface and YCOM interface of U3 are positive, that is, X1-Y1. The output values ​​of the XCOM interface and YCOM interface of U3 are amplified by U4, filtered by RC, and sent to the analog-to-digital converter ADC. The converted digital signal is sent to the controller for processing.

[0040] The output waveform of the high-frequency oscillator is a sawtooth wave. The controller adjusts the output wave of the high-frequency oscillator by setting the duty cycle, which can be set as needed. The liquid guide tube 5 is arranged between the peristaltic pump 7 and the meter 9. The meter 9 is connected to the multi-way valve 10. The multi-way valve 10 is respectively connected to multiple liquid storage bottles 11 and a digester 12. The digester 12 is connected to a liquid storage bottle 11. Two light detectors 13 are arranged on the meter 9. Grooves that cooperate with the clamp 3 are respectively arranged on the upper and lower outer sides of the fixed sleeve 1. There is no need to install the excess liquid collection bottle 14, which saves materials, and realizes the excess liquid emergency stop to prevent the corrosive liquid from flowing out and causing harm, thereby ensuring safety. When liquid passes through the liquid guide tube 5, the controller detects the liquid and controls the peristaltic pump 7 to stop, so as to realize timely detection of excess liquid, automatic detection of excess liquid state, and avoid failure to detect excess liquid.

[0041] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A detection device for preventing excessive liquid from chemical oxygen demand, characterized in that: include: A fixing sleeve (1), wherein the fixing sleeve (1) is a semicircular arc-shaped plate, two sets of fixing sleeves (1) are arranged in mirror images to form a circular ring, a clamping groove for clamping the capacitor plate (2) is arranged on the inner side of the fixing sleeve (1), clamps (3) are respectively arranged on the upper and lower sides of the fixing sleeve (1), and the clamps (3) are retracted and released by locking bolts (4), the capacitor plate (2) is a circular arc-shaped plate, slightly smaller than a semicircle, and the two sets of capacitor plates (2) form a capacitor C0; One end of the capacitor C0 is connected to a high-frequency oscillator, and the other end is connected to an operational amplifier circuit, the operational amplifier circuit is connected to an analog switch, the analog switch is connected to an amplifying and filtering circuit, the amplifying and filtering circuit is connected to a digital-to-analog converter ADC, the digital-to-analog converter ADC is connected to a controller, and the digital-to-analog converter ADC is connected to the analog switch and the high-frequency oscillator respectively; The capacitor plate (2) is clamped in the fixing sleeve (1), the fixing sleeve (1) is sleeved on the liquid guiding tube (5), the clamp (3) fixes the fixing sleeve (1) on the liquid guiding tube (5) through a locking bolt (4), and the liquid guiding tube (5) is located between the meter (9) and the peristaltic pump (7).

2. A chemical oxygen demand detection device for preventing excessive liquid according to claim 1, characterized in that: A support platform is provided at the bottom of the fixing sleeve (1), and the two ends of the fixing sleeve (1) are concave and then bent inwards to form a smooth arc surface, and the smooth arc surface fits the catheter (5).

3. A chemical oxygen demand detection device for preventing excessive liquid according to claim 1, characterized in that: An interface is provided in the middle of the capacitor plate (2), and the interface of the capacitor plate (2) passes through the fixing sleeve (1).

4. A chemical oxygen demand detection device for preventing excessive liquid according to claim 1, characterized in that: The clamp (3) is in the shape of a ring and has locking heads at both ends, and the bottom of the locking bolt (4) cooperates with a nut.

5. A chemical oxygen demand detection device for preventing excessive liquid according to claim 1, characterized in that: The high-frequency oscillator, the digital-to-analog converter ADC, and the controller are integrated into one MCU.

6. A chemical oxygen demand detection device for preventing excessive liquid according to claim 5, characterized in that: The third interface of the amplifier U1 of the operational amplifier circuit is respectively connected to the resistor R5 and the capacitor C0, the first interface of the amplifier U1 is respectively connected to the second interface of the amplifier U1 and the resistor R3, the resistor R3 is connected to the third interface of the amplifier U2, the second interface of the amplifier U2 is respectively connected to the resistor R1, the resistor R2, and the capacitor C1, the resistor R1 is grounded, and the first interface of the amplifier U2 is respectively connected to the capacitor C1 and the resistor R2; The analog switch is U3, the 8th interface, the 1st interface and the 14th interface of U3 are grounded respectively, the 7th interface of U3 is connected to -VCC, the 16th interface of U3 is connected to VCC, and the 5th interface and the 12th interface of U3 are connected to the 1st interface of the amplifier U2 respectively; The first interface of the amplifier U4 of the amplifying and filtering circuit is connected to the third interface of U3, the fourth interface of the amplifier U4 is connected to the thirteenth interface of U3, the sixth interface of the amplifier U4 is grounded, the eighth interface of the amplifier U4 is connected to VCC, the fifth interface of the amplifier U4 is connected to -VCC, the seventh interface of the amplifier U4 is connected to the resistor R4, the resistor R4 is respectively connected to the capacitor C2 and the digital-to-analog converter ADC interface of the MCU, and the capacitor C2 is grounded; The PWM interface of the MCU is connected to capacitor C0, the A interface of the MCU is connected to the 10th interface of U3, the B interface of the MCU is connected to the 9th interface of U3, and the INH interface of the MCU is connected to the 6th interface of U3.

7. A chemical oxygen demand detection device for preventing excessive liquid according to claim 1, characterized in that: The liquid in the catheter (5) passes through the fixed sleeve (1), and the capacitance of the capacitor C0 changes. The oscillating voltage signal emitted by the high-frequency oscillator changes into an oscillating current signal after passing through the changed capacitor C0. The oscillating current signal changes into a voltage signal after passing through an operational amplifier circuit. The voltage signal passes through an analog switch and an amplifying and filtering circuit to take an absolute value and then is filtered. The voltage signal is then sent to a digital-to-analog converter ADC, which is converted into a digital signal and sent to a controller for processing. The controller controls the high-frequency oscillator. The controller detects the change in the digital signal and then controls the peristaltic pump (7) to stop.

8. A chemical oxygen demand detection device for preventing excessive liquid according to claim 1, characterized in that: The output waveform of the high-frequency oscillator is a sawtooth wave, and the controller adjusts the output wave of the high-frequency oscillator by setting the duty cycle and / or the frequency.

9. A chemical oxygen demand detection device for preventing excessive liquid according to claim 1, characterized in that: The liquid guide tube (5) is arranged between the peristaltic pump (7) and the meter (9); the meter (9) is connected to a multi-way valve (10); the multi-way valve (10) is respectively connected to a plurality of liquid storage bottles (11) and a digester (12); the digester (12) is connected to a liquid storage bottle (11); and two light detectors (13) are arranged on the meter (9).

10. A chemical oxygen demand detection device for preventing excessive liquid according to claim 1, characterized in that: Grooves cooperating with the clamp (3) are respectively arranged on the upper and lower sides of the outer side of the fixing sleeve (1).

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