KR102314263B1 - System for continuously measuring suspended solids and turbidity - Google Patents

Abstract

The present invention relates to in providing a system for measuring an online turbidity and a suspended solid, wherein a water tank is equipped with a structure that allows the water to be measured to continuously pass, and enables, for water quality management, a concentration of the suspended solid and the turbidity solid in water to be accurately measured while being continuously measured by using a measuring sensor and the like that measures the concentration of the suspended solid and the turbidity solid in water using scattered light and transmitted light by an LED light source.

Description

Online turbidity and suspended solids measurement system {System for continuously measuring suspended solids and turbidity}

The present invention relates to an online turbidity and suspended matter measurement system, and more particularly, to an on-line turbidity and suspended matter measurement system that enables continuous measurement while accurately measuring the concentration of suspended substances and turbidity substances in water for water quality management will be.

In general, suspended matter in water refers to a substance that does not dissolve in water having a particle diameter of 2 μm or more, and turbidity in water is a substance having a particle diameter of less than 2 μm, and is used as an index indicating the quality of polluted water.

These suspended substances and turbidity substances are contained as organic and inorganic solids in wastewater, and when they are discharged into natural waters such as rivers, lakes, and seas, they increase the turbidity of the water, pollute its appearance, and reduce dissolved oxygen, which is an organic substance that can be decomposed by living things. It can cause water pollution.

Therefore, there is a need for a method for continuously measuring the concentrations of suspended substances and turbidity substances in water for water quality management.

Registered Patent Registration No. 10-0572370 (2006.04.12)

The present invention has been devised in view of the above points, and a water tank having a structure that can continuously pass water to be measured, and the concentration of suspended substances and turbidity substances in the water using scattered light and transmitted light by an LED light source An object of the present invention is to provide an online turbidity and suspended matter measurement system that enables continuous measurement while accurately measuring the concentration of suspended substances and turbidity substances in water for water quality management by using a measurement sensor that measures them.

In order to achieve the above object, the present invention provides: a water tank which is fixedly installed on a water tank support of a predetermined height, in which water to be measured is circulated; an inlet pipe connected to the bottom of one side of the water tank to supply water to be measured into the water tank; an outlet pipe connected to the other lower end of the water tank to discharge water after measurement; a first partition wall and a second partition wall of a predetermined height respectively mounted on one side and the other side inside the water tank to divide the inside of the water tank into a first room, a second room, and a third room; an openable and openable cover attached to the upper portion of the water tank so as to be open and closed; and a body part having a built-in driving circuit, and a measuring part including an LED light emitting device mounted on the lower part of the body part, a first light receiving element and a second light receiving element, and the body part is fastened to the opening and closing cover so as to be adjustable in height. a measuring sensor in which the measuring unit is immersed in the water filled in the second chamber to measure suspended matter or turbidity; It provides an online turbidity and suspended matter measurement system, characterized in that it comprises a.

The measuring circuit of the driving circuit of the measuring sensor includes: an EMI and RC filter connected to the first light receiving element and the second light receiving element to filter the scattered light and transmitted light signals, an operational amplifier for amplifying the filtered signal, and the amplified An analog-to-digital converter for converting a signal to digital, and a microprocessor for receiving the digital signal and calculating the concentration of suspended matter and turbidity in water (sample).

The driving circuit of the measuring sensor includes: a power supply circuit for applying power to a driving circuit other than the measuring unit circuit, a first insulating circuit for protecting the microprocessor from surge voltage, increasing the processing speed of the microprocessor, and operating error It is characterized in that it is configured to include an external clock and reset circuit for minimizing

Through the means for solving the above problems, the present invention provides the following effects.

According to the present invention, using a water tank having a structure that allows water to be measured to pass continuously, and a measurement sensor that measures the concentration of suspended substances and turbidity substances in water using scattered light and transmitted light by an LED light source, etc. For water quality management, it is possible to measure the concentration of suspended substances and turbidity substances in water continuously while accurately measuring them.

1 is a front view showing an online turbidity and suspended matter measurement system according to the present invention;
2 is a side view showing an online turbidity and suspended matter measurement system according to the present invention;
Figure 3 is a front view showing the measurement sensor of the online turbidity and suspended matter measurement system according to the present invention,
Figure 4 is an enlarged cross-sectional view showing the measurement part of the measurement sensor during the configuration of the online turbidity and suspended matter measurement system according to the present invention;
5 is a schematic diagram showing the measurement principle of the measurement sensor in the configuration of the online turbidity and suspended matter measurement system according to the present invention;
6 is a configuration diagram showing a circuit of a measurement unit of a driving circuit included in a measurement sensor among the configuration of an on-line turbidity and suspended matter measurement system according to the present invention;
7 is a configuration diagram showing the entire driving circuit included in the measurement sensor among the configuration of the online turbidity and suspended matter measurement system according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 and 2 show the on-line turbidity and suspended matter measurement system according to the present invention, Figure 3 is a front view showing the measurement sensor of the online turbidity and suspended matter measurement system according to the present invention.

As shown in FIGS. 1 and 2 , a water tank 10 is provided in which water to be measured is stored in a circulating manner in order to measure suspended or turbidity materials in water for 24 hours continuously, and the water tank 10 is a predetermined It is fixedly installed on the tank support 20 of the height.

An inlet pipe 22 for supplying water to be measured into the water tank is connected to the bottom of one side of the water tank 10, and an outlet pipe 24 for discharging water after measurement is connected to the other lower end of the water tank 10. do.

In addition, a first partition wall 11 and a second partition wall 12 of a predetermined height are formed on one side and the other side of the water tank 10, respectively, and the inside of the water tank 10 is a first chamber (1) and a second room (2) and a third room (3).

Accordingly, the inlet pipe 22 is connected to the first chamber 1 so that water can be supplied, and the outlet pipe 24 is connected to the third chamber 3 so that water can be discharged.

At this time, the reason for forming the first chamber 1 in the water tank 10 by using the first partition wall 11 is that water flows into the first chamber 1 from the inlet pipe 22 and bubbles when filled first. is generated and the particles are introduced together, so that when the water passes over the first partition wall 11, the bubbles are removed and the particles are filtered at the same time.

In other words, when air bubbles and particles are present in the water during the sensing operation of suspended substances or turbidity substances by the measurement sensor 100, the measurement value is disturbed and the measurement accuracy is lowered. ), when the water flows through the first partition wall 11 to the second chamber 2, air bubbles are removed and particles can be easily filtered.

Accordingly, since the water filled in the second chamber 2 is in a state in which air bubbles and particles are removed, the sensing operation of suspended substances or turbidity substances by the measurement sensor 100 can be precisely performed.

At this time, the second partition wall 12 allows the water after sensing of suspended matter or turbidity material to flow to the third chamber 3 at a constant speed, thereby connecting the outlet pipe 24 connected to the third chamber 3 . Water after measurement can be discharged at a constant rate.

On the other hand, an openable cover 13 is mounted on the upper portion of the water tank 10, and a measurement sensor 100 for measuring suspended substances or turbidity substances by being submerged in water in the water tank is inserted and fastened to the openable cover 13. .

Preferably, the water tank 10 is made of a sufficient thickness (about 10 mm) so that all six sides can block external light, and thus the measurement sensor 100 is not affected by an external interference effect for sensing, Accordingly, stable sensing of the measurement sensor 100 may be achieved.

In particular, as shown in FIG. 3 , the measurement sensor 100 includes a body part 110 , a connector 102 and a cable 104 connected to the upper end of the body part 110 , and a body part 110 . A measurement unit 120 that is mounted on the lower end of the body to substantially measure suspended or turbidity substances in a state submerged in water, and the connector 102 and the connector 102 so as to be electrically conductive and signal-transferable while being built into the body 110 . It is configured to include a driving circuit 130 to be.

The body part 110 of the measurement sensor 100 is manufactured in a cylindrical elongated shape using a SUS material that has good durability and is resistant to corrosion.

The cable 104 is connected to an indicator (not shown) of the control panel through online, and power provided from the indicator is supplied to the driving circuit 130 so that the sensing operation of the measurement sensor 100 can be performed.

Preferably, on the body portion 110 of the measurement sensor 100, a cradle 112 is mounted so as to be mounted on the outer periphery of the hole 14 formed in the opening/closing cover 13 of the water tank 10 so as to be adjustable in height. .

More preferably, the holder 112 is an acetal material and is fastened to the body portion 110 of the measurement sensor 100 in a screw manner to adjust the height, so that the measurement portion 120 of the measurement sensor 100 is located in the water tank. It can be adjusted so as to be sensibly submerged in the water filled in the second chamber (2).

Here, the configuration of the measurement sensor 100 will be described in more detail as follows.

4 is an enlarged cross-sectional view showing the measurement part of the measuring sensor in the configuration of the 24-hour continuous suspended matter measurement system according to the present invention, and FIG. It is a schematic diagram showing the measurement principle.

The measuring unit 120 of the measuring sensor 100 is a part that substantially measures the concentration of suspended substances and turbidity substances in the water using scattered light and transmitted light by the LED light source, and is mounted on the measuring block 124 with a central wavelength of 880 nm. It includes one LED light emitting device 121 and two first and second light receiving devices 122 and 123 as a light source having

In more detail, two or more rows of O-ring insertion grooves 125 are formed in the measuring block 124 of the measuring unit 120 to be press-fitted to the lower end of the body 110 at the upper portion, and water is formed at the bottom thereof. It is provided in a structure in which an inflow water inlet groove 126 is formed, and the LED light emitting device 121 as the light source is mounted on one side of the water inlet groove 126 under the measuring block 124 and receives the first light. The element 122 is mounted on the ceiling surface of the water inlet groove 126 at the lower part of the measurement block 124 to receive scattered light, and the second light receiving element 123 is located below the measurement block 124 to receive the transmitted light. It is mounted on the other side of the water inlet groove 126 in the.

At this time, the LED light emitting device 121 and the second light receiving device 123, which are the light sources, are arranged while maintaining a predetermined distance forming a straight line, and the first light receiving device 122 is the LED light emitting device 121 and the second light receiving device. They are arranged at an orthogonal position at 1/2 the distance between the elements 123 .

Preferably, based on a 1/2 position of the distance between the LED light emitting device 121 and the second light receiving device 123, the LED light emitting device 121, the first light receiving device 122, and the second light receiving device Reference numeral 123 maintains the same distance from each other, but as the same distance increases, signal sensitivity may be improved.

In addition, in order to prevent and protect the LED light emitting device 121, the first light receiving device 122, and the second light receiving device 123 from direct contact with the measurement object (sample), the LED light emitting device 121 ) and a sapphire window 127 is mounted in front of each of the first light receiving element 122 and the second light receiving element 123 .

At this time, the sapphire window 127 has a very good infrared wavelength light transmittance and a small refractive index, so it is a material frequently used in a precise IR spectrometer. However, due to the characteristics of the analysis method quantified by the ratio of scattered light and transmitted light signals, the effect is small, and there is no problem at all in measuring the concentration of suspended substances and turbidity substances in the water (sample) to be measured.

Meanwhile, as shown in FIG. 6 , the measuring circuit of the driving circuit 130 of the measuring sensor 100 is connected to the first light receiving element 122 and the second light receiving element 123 to provide scattered light and transmitted light signals. An EMI and RC filter 131 for filtering, an operational amplifier 132 for amplifying the filtered signal, an analog-to-digital converter 133 (ADC) for converting the amplified signal to digital, and a digital signal receiving the water It is configured to include a microprocessor 134 for calculating the concentrations of suspended solids and turbidity substances for (sample).

At this time, the microprocessor 134 controls the amount of light of the LED light emitting device 121 through the PWM control and constant current circuit 135, and the constant current circuit 135 controls the light amount of the LED light emitting device even when the voltage changes according to the temperature. It is controlled with a constant current so that it does not change.

In addition, the microprocessor 134 controls to increase the amplification ratio of the operational amplifier 132 according to the signal-to-noise ratio (S/N ratio). As the amplification ratio increases, the noise ratio also increases, but the EMI And noise may be sufficiently removed from the RC filter 131 .

On the other hand, as shown in FIG. 7 , the entire circuit of the driving circuit 130 of the measurement sensor 100 includes a power supply circuit 140 for applying power to the driving circuit 130 in addition to the measurement unit circuit, and a second It is configured to include a first insulation circuit 141, a second insulation circuit 142, and an RS-485 circuit 143, and the like.

Accordingly, the power circuit 130 distributes and applies power to the measuring circuit, etc., and the microprocessor 134 plays the most essential role in generalizing and controlling the entire driving circuit, so that the first insulation circuit 141 is is placed between the power circuit 140 and the microprocessor 134 to protect the microprocessor 134 from being shocked even when an instantaneous surge voltage is applied.

Also, although an internal clock is built into the microprocessor 134, using an external clock can increase processing speed (overclock), so a precise external clock and reset 144 (referring to an external clock and reset circuit) It is possible to increase the processing speed of the microprocessor 134 and minimize the operation error by using the .

In addition, the microprocessor 134 controls and generalizes the entire circuit of the measurement unit, and the RS-485 circuit 143 is communicatively connected to the upper interface for online communication with the outside.

At this time, since the RS-485 circuit 143 is connected with an external device and a wire for online, a high current may flow in reverse along this wire in an unstable environment, and this is the second insulation circuit 142 . will block

Here, the measurement process for the above-described online turbidity and suspended matter measurement system is as follows.

First, when water (sample) to be measured is supplied to the water tank 10 through the inlet pipe 22, water flows into the first chamber 1 in the water tank 10 and is first filled, and then the first partition wall ( 11) and passes to the second chamber (2), the air bubbles and particles contained in the water are filtered.

Subsequently, when the second chamber 2 is filled with water from which air bubbles and particles have been removed, the measurement unit 120 of the measurement sensor 100 mounted on the open/closeable cover 13 of the water tank 10 moves into the water. become asleep.

Accordingly, as the measuring unit 120 is submerged in water, the water inlet groove 126 formed in the measuring block 124 of the measuring unit 120 is also filled with water.

Next, the LED light emitting device 121 is operated to irradiate light to the measurement object (sample).

At this time, when the light source is selected, the ultraviolet (UV) wavelength has too much energy, and its emission distance is short, making it unsuitable for measurement, and the visible light wavelength has a disturbing effect on samples with chromaticity, so the near-infrared wavelength (λ = 880 nm) By using , the influence of sample chromaticity can be minimized, and since the wavelength in infrared is short, the energy is strong, so that the interference effect can be minimized and high sensitivity can be obtained.

Accordingly, light having a near-infrared wavelength from the LED light emitting device 121 may be irradiated to the measurement target (sample).

Subsequently, as the light having a near-infrared wavelength from the LED light emitting device 121 comes into contact with particles (suspended material and turbidity material particles) present in water (sample), scattered light is generated and transmitted light passing through the particles as they are is generated.

Accordingly, the first light receiving element 122 receives the scattered light and the second light receiving element 123 receives the transmitted light. It is input to the microprocessor 134 included in the to calculate the particle size and concentration of suspended substances and turbidity substances in water (sample).

For example, according to the Rayleigh scattering formula, the maximum size of a measurable particle can be calculated by Equation 1 below.

(Equation 1): x = 2πr/λ _I

In Equation 1 above, x is the particle size, and λ _I is the wavelength length of the incident light.

Accordingly, the particle size and concentration of suspended substances and turbidity substances in the water (sample) calculated as above are transmitted in real time from the microprocessor 134 to the outside through the RS-485 circuit 143 for communication with the upper interface. In the end, the particle size and concentration of suspended substances and turbidity substances in water (sample) can be monitored from the outside in real time 24 hours a day.

On the other hand, the measuring sensor 100, the LED light emitting device 121, the first light receiving device 122, and the second light receiving device 123 are coated with an anti-contamination coating composition to effectively prevent adhesion and removal of contaminants. An antifouling coating layer made of may be applied.

The antifouling coating composition contains citrate and diethylene glycol monobutyl ether in a molar ratio of 1:0.01 to 1:2, and the total content of citrate and diethylene glycol monobutyl ether is 1 to 10 based on the total aqueous solution. % by weight.

The citrate and diethylene glycol monobutyl ether preferably have a molar ratio of 1:0.01 to 1:2, and when the molar ratio is out of the above range, the measurement sensor 100, the LED light emitting device 121, and the first light receiving device ( 122), there is a problem in that the applicability of the second light receiving element 123 is lowered or the moisture adsorption on the surface increases after application, so that the coating film is removed.

The citrate and diethylene glycol monobutyl ether are preferably 1 to 10% by weight of the total aqueous solution of the composition, and when it is less than 1% by weight, the measurement sensor 100, the LED light emitting device 121, the first light receiving device 122, There is a problem in that the applicability of the second light receiving element 123 is deteriorated, and when it exceeds 10 wt%, crystal precipitation is likely to occur due to an increase in the thickness of the coating film.

On the other hand, as a method of applying the present antifouling coating composition to the measuring sensor 100, the LED light emitting device 121, the first light receiving device 122, and the second light receiving device 123, it is to apply by a spray method. desirable. In addition, the final coating film thickness of the measurement sensor 100, the LED light emitting device 121, the first light receiving device 122, and the second light receiving device 123 is preferably 700 ~ 2500Å, more preferably 900 ~ 2000Å am. If the thickness of the coating film is less than 700 Å, there is a problem in that it is deteriorated in the case of high-temperature heat treatment, and if it exceeds 2500 Å, there is a disadvantage that crystal precipitation on the coated surface is easy to occur.

In addition, the present antifouling coating composition may be prepared by adding 0.1 mol of citrate and 0.05 mol of diethylene glycol monobutyl ether to 1000 ml of distilled water and then stirring.

The reason why the ratio of the components and the thickness of the coating film were numerically limited as described above was that the present inventor repeated several failures and analyzed through the test results. As a result, the optimal antifouling coating effect was exhibited at the ratio.

In addition, an O-ring (not shown) is inserted into the O-ring insertion groove 125, and the raw material content ratio of the O-ring is 55% by weight of rubber, 7% by weight of 2-mercaptobenzothiazole, and 6% by weight of hexamethylenetetramine. , carbon black 21% by weight, 3C (N-PHENYL-N'-ISOPROPYL-P-PHENYLENEDIAMINE) 5% by weight, and 6% by weight of precipitated sulfur are mixed.

Carbon black is added to increase or improve abrasion resistance, thermal conductivity, etc., 2-mercaptobenzothiazole and hexamethylenetetramine are added to improve acceleration.

3C (N-PHENYL-N'-ISOPROPYL-P-PHENYLENEDIAMINE) is added as an antioxidant, and precipitated sulfur is added to act as an accelerator.

Therefore, according to the present invention, the elasticity, toughness, and rigidity of the O-ring are increased, so that durability is improved, and thus the life of the O-ring is increased.

The tensile strength of the rubber material is 150Kg/cm2.

The reason for limiting the rubber material constituents and constituents and limiting the numerical value of the mixing ratio is that the present inventor repeatedly failed several times and analyzed the test results to find the optimal effect in the composition and numerical limit ratio. indicated.

In addition, when the first partition wall 11 and the second partition wall 12 are formed inside the water tank 10 , the water tank 10 and the first partition wall 11 and the second partition wall 12 are formed in order to improve the adhesive force therebetween. ), an adhesion enhancer may be applied between them.

The adhesion enhancer may include 63 parts by weight of water, 16 parts by weight of N-hydroxymethylacrylamide, 15 parts by weight of sodium dodecylsulfonate, 4 parts by weight of ammonium persulfate, and 2 parts by weight of a buffer.

N-hydroxymethylacrylamide is added to improve adhesion, flexibility, water resistance, etc., sodium dodecylsulfonate acts as a surfactant, and ammonium persulfate acts as a catalyst.

The reason for limiting the constituent materials and constituents as described above and limiting the numerical value of the mixing ratio is that the present inventors repeatedly failed several times and analyzed the test results to obtain the optimal effect from the constituents and numerical limiting ratios. indicated.

1: Room 1 2: Room 2
3: Room 3 10: Aquarium
11: first bulkhead 12: second bulkhead
13: openable cover 14: hole
20: tank support 22: inlet pipe
24: outlet pipe 100: measuring sensor
102: connector 104: cable
110: body 112: cradle
120: measurement unit 121: LED light emitting device
122: first light receiving element 123: second light receiving element
124: measuring block 125: O-ring insertion groove
126: water inlet groove 127: sapphire window
130: driving circuit 131: EMI and RC filter
132: operational amplifier 133: analog-digital converter
134: microprocessor 135: constant current circuit
140: power circuit 141: first insulation circuit
142: second insulation circuit 143: RS-485 circuit
144: external clock and reset (external clock and reset circuit)

Claims (3)

a water tank 10 that is fixedly installed on the tank support 20 of a predetermined height, and in which water to be measured is circulated;
An inlet pipe 22 connected to the bottom of one side of the water tank 10 to supply water to be measured into the water tank;
an outlet pipe 24 connected to the other lower end of the water tank 10 to discharge water after measurement;
In order to divide the inside of the water tank 10 into a first chamber (1), a second chamber (2), and a third chamber (3), a predetermined portion mounted on one side and the other side of the water tank (10), respectively. The height of the first partition wall 11 and the second partition wall 12;
an opening/closing type cover 13 operably attached to the upper portion of the water tank 10; and
A body part 110 having a driving circuit 130 built therein, an LED light emitting device 121 mounted on a lower portion of the body part 110 , a first light receiving device 122 and a second light receiving device 123 are included. It is composed of a measuring part 120, and the body part 110 is height-adjustably fastened to the opening/closing cover 13, and at the same time, the measuring part 120 is submerged in the water filled in the second chamber 2, so that suspended matter It is configured to include a measurement sensor 100 to measure the turbidity material;
The measuring unit circuit of the driving circuit 130 of the measuring sensor 100 is:
An EMI and RC filter 131 connected to the first light receiving element 122 and the second light receiving element 123 to filter the scattered light and transmitted light signals, an operational amplifier 132 for amplifying the filtered signal, and the amplified an analog-to-digital converter 133 (ADC) for converting a signal to digital, and a microprocessor 134 for receiving the digital signal and calculating concentrations of suspended solids and turbidity substances in water (sample);
The driving circuit 130 of the measurement sensor 100 includes:
A power circuit 140 for applying power to the driving circuit 130 in addition to the measurement circuit, a first insulation circuit 141 for protecting the microprocessor 134 from a surge voltage, and the microprocessor 134 . An external clock and reset 144 circuit that increases processing speed and minimizes operation errors, an RS-485 circuit 143 for communication with an upper interface for online communication with the outside, and an RS-485 circuit 143 Online turbidity and suspended matter measurement system, characterized in that it comprises a second insulation circuit (142) for insulation. delete delete

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