KR20090025978A - Control system for sewage treatment system - Google Patents

Abstract

A control system for sewage treatment facilities is provided to prevent shutdown of operation cased by overloading of a motor and to control the amount of necessary medicines. A control system for sewage treatment facilities comprises the followings: a flux measuring unit including a grid sensor of first optical fiber; a water level detecting unit including the grid sensor of second optical fiber; a motor temperature measuring unit(400) including the grid sensor of third optical fiber measuring temperature of the motor; a controller controlling operation of sewage treatment facilities according to measured information after measuring a flux of fluid, the water level of a water tub(10) and the temperature of the motor.

Description

Control system for Sewage treatment system

The present invention relates to a control system of a water treatment plant, and more particularly, to a control system of a water treatment plant for calculating a flow rate, a water level of a water tank, and a temperature of a motor using an optical fiber grating sensor and operating the water treatment plant accordingly. It is about.

In general, when the sewage and wastewater discharged from homes and restaurants, such as sewage and domestic sewage is discharged into the river as it is a cause of water pollution, a lot of means have been developed to discharge it after purification treatment.

The conventional water treatment facility includes a tank into which wastewater and waste water flow from the outside, and various tanks such as a settling tank, anoxic tank, and aeration tank for purifying the wastewater stored in the tank. In each tank, various kinds of pollutants contained in the sewage are precipitated, or oxygen is supplied to induce the biodegradation by microorganisms. Then, the pollutants are precipitated in the discharge tank, and the purified clean water is the overflow block of the discharge tank. The sewage was purified by overflowing through.

However, the amount of sewage and wastewater discharged from homes and restaurants, etc., varies greatly depending on time and time, so if a large amount of wastewater is introduced at a time, If the residence time is short and moved to the next step not properly treated, or if too little amount of waste water is introduced, there was a problem that the microorganisms die due to nutritional imbalance due to the lack of organic material as a source of microorganisms.

In addition, it is necessary to operate the water treatment facility by appropriately checking the temperature of the motor so as not to overload each motor for driving, and to control the sewage filling in each tank for purification does not exceed the limit level of the tank.

However, the flow meter, the water level sensor, and the motor thermometer used in the conventional water treatment facility have difficulty in calculating the measured value quickly and accurately.

For example, in the case of a flow meter, a differential pressure flow meter has no moving or moving parts due to its simple structure among various types of flow meters, and has abundant measurement characteristics and experimental data. It is mainly used as a water meter in a water treatment plant because of the advantage of measuring accuracy and the relatively low price compared to other flow meters.

However, the conventional differential pressure flow meter is difficult to precisely measure pressure in the case of pressure sensors for measuring pressure, and to compensate for this, when the sensitivity to pressure is increased, the pressure measuring range becomes very narrow, and a wide range of pressure is to be measured. In the case of poor sensitivity, it was not easy to calculate the correct flow rate.

In addition, the water level meter also had a difficulty in quickly checking the change in the flow rate of the fluid filled in the tank, the thermometer of the motor also had a difficulty in detecting the temperature change of the motor quickly.

Thus, in the conventional water treatment facility, it was difficult to maintain the efficient purification treatment function of the water treatment facility because the flow rate of the sewage, the water level of the water tank, and the temperature of the motor could not be measured quickly and accurately.

The present invention has been made to solve the above problems, and to provide a control system of a water treatment facility that can maintain an efficient and stable purification treatment by measuring the exact flow rate of sewage, the water level of the tank and the temperature of the motor. There is this.

The control system of the water treatment facility according to the present invention for achieving the above object is a water treatment facility having a sewage treatment unit including a water collection tank and an anaerobic tank, aeration tank, sedimentation tank, pressure flotation tank, concentration tank, measuring the flow rate through the pressure of the fluid A flow rate measuring means comprising a first optical fiber grating sensor installed on a pipe line interconnecting the water tanks so as to measure the pressure of the fluid, and a pressure of the fluid filled in the water tank installed on the inner bottom of the water tanks. The water level sensing means comprising a second optical fiber grating sensor for detecting the water level through the; and the temperature of the motor through the phase difference of the optical signal generated by the deformation of the motor is attached to the motor for driving the water treatment facility Motor temperature measuring means comprising a third optical fiber grating sensor for measuring and the sense of the first to third optical fiber grating sensor It is provided with a controller for receiving the ground information to calculate the flow rate of the fluid, the water level of the tank and the temperature of the motor, and to adjust the operation of the water treatment plant according to the calculated information.

The flow rate measuring means has an internal space through which fluid can flow, and an optical fiber pressure installed at each of upper and lower sides of the main body having an throttle portion having a narrow inner cross-sectional area, and installed at upper and lower sides of the throttle portion. A sensor and control means for receiving the pressure measured by the optical fiber pressure sensor as an electrical signal to calculate and display a flow rate of the fluid passing through the main body by using the pressure difference between the respective points. First and second pressure outlets are respectively formed on the upstream side and the downstream side around the shaft, and the first and second pressure detection tubes communicating with the inside of the main body from the first and second pressure outlets, respectively. The optical fiber pressure sensor is fixedly coupled to enter the predetermined depth into the first and second pressure detection tube, coupled to the main body to surround the first and second pressure outlet, It is preferable to further include a housing in which the control means is installed.

In addition, the main body has third and fourth pressure outlets formed on the upstream side and the downstream side of the throttle part, respectively, and the inner and outer spaces of the body are formed in the body in which the third and fourth pressure outlets are formed. A thin film having an elastic force is formed and partitioned according to the pressure of the fluid, and the optical fiber pressure sensor is mounted on the upper surface of the thin film so that the pressure of the fluid can be measured through the deformation amount of the thin film expanding according to the pressure of the fluid. May be combined.

The water level detecting means is installed on the inner bottom surface of the water tank, and has a body in which deformation occurs according to the hydraulic pressure of the fluid filled in the water tank, and the first optical fiber grating sensor is installed in the body of the fluid It is formed to measure the deformation amount of the main body generated by the hydraulic pressure in accordance with the filling amount, the motor temperature measuring means is attached to one side of the motor so that the heat generated by the drive of the motor can be transferred, The third optical fiber grating sensor is preferably installed inside the main body so as to measure the amount of deformation of the main body due to heat generated from the motor.

The control system of the water treatment plant according to the present invention accurately measures the flow rate of water supplied or returned to each tank for the purification of sewage, the water level of the sewage filled in each tank, and the temperature of the motors to effectively clean the sewage. It is possible to control the amount of added water and the tank filling of sewage, and to minimize the time and cost damages caused by downtime and replacement of the motor due to the overload of the motor.

Referring to the drawings in more detail the control system of the water treatment plant according to the present invention.

1 shows a schematic diagram of a water treatment plant 100 according to the invention.

The water treatment facility 100 includes a water collecting tank 10 that primarily stores inflow water, a first processing unit 20 for firstly treating wastewater supplied from the water collecting tank 10, and a first purification unit 20. And a second treatment section for secondary purification of the collected wastewater.

The first processing unit 20 includes an anaerobic tank 21, an aeration tank 22, and a settling tank 23. The anoxic tank 21 converts nitrate contained in the sewage supplied from the collection tank 10 into nitrogen and blows it into the air. Throw away. Sewage from which nitrate is removed is sent to the aeration tank 22.

The aeration tank 22 promotes oxidation and digestion by aerobic bacteria through an operation of blowing air into the water or spraying water into the air to sufficiently contact the water and the air. Microorganisms extinguish carbon dioxide, hydrogen sulfide, and methane gas. In other words, aeration in the sewage, microorganisms to purify the water.

The purified water in the aeration tank 22 is transferred to the settling tank 23. When the nitrate is not sufficiently removed, the water is returned to the anoxic tank 21 again.

In the settling tank 23, sludge contained in the sewage is precipitated. Precipitated sludge is sent to the concentration tank 46 by the sludge pump 24, and the sludge-removed primary purified water is transferred to the primary treatment tank 30.

The primary treatment water tank 30 supplies the primary purified water to the secondary treatment unit 40, and maintains the supply amount at a constant level so that the supply amount does not become excessive.

The secondary treatment unit 40 includes a chemical treatment unit 41, a pressurized floatation tank 45, and a concentration tank 46.

The chemical treatment unit 41 performs chemical treatment on the primary purified water, and includes a reaction tank 42, a neutralization tank 43, and a coagulation tank 44.

In the reaction tank 42, an inorganic polymer flocculant (PAC) is added, and in the neutralization tank 43, sodium hydroxide is added. The reaction is performed with the PAC added in the reaction tank 42 to produce aluminum hydroxide. Agglomerates the colloidal components of. In the coagulation tank 44, the polymer is further added, and the chemicals added in the reaction tank 42, the neutralization tank 43, and the coagulation tank 44 respectively activate the aggregation of contaminants in the primary purified water.

The chemically treated water in the chemical processing unit 41 is transferred to the pressure flotation tank 45.

The pressurized floatation tank 45 is compressed by dissolving air in the water tank using the pressurizing tank 48 and the pressurizing pump 49, and when it is opened in the air, when the dissolved air is bubbled and flies into the air, This removes suspended solids by reducing the specific gravity of the pollutants in the water and allowing them to float above the water.

The contaminants removed from the pressure flotation tank 45 are transferred to the concentration tank 46, and the concentration tank 46 concentrates the sludge supplied from the settling tank 23 and the pressure flotation tank 45. The concentrate is treated after removing water by the dehydrator 47, and the secondary treated water is discharged to the outside through the discharge tank 50 through the pressure flotation tank 45.

The flow rate measuring means for measuring the flow rate supplied to each tank in the process of the wastewater treatment is installed on the conveying pipe.

In the present embodiment, the flow rate measuring means includes a first flow meter 200a for measuring the supply flow rate of the raw water supplied to the oxygen-free tank 21, and a second flow rate for measuring the conveyance amount conveyed to the oxygen-free tank 21 and the aeration tank 22. , The third flow meter (200b, 200c), the first and fifth flow meters (200d, 200e), and the chemical treatment unit 41 for measuring the supply amount of the first purified water and the supply flow rate to the chemical treatment unit 41, respectively Sixth to eighth flow meters (200f, 200g, 200h) for measuring the flow rate of the chemical supplied to the water tank of the ninth flowmeter (200i) for measuring the flow rate of the purified water discharged through the secondary processing unit 40 It includes.

Each flow meter 200 has the same structure as the differential pressure flow meter 200, the flow meter 200 is shown in FIG.

Referring to FIG. 2, the flow meter 200 includes a main body 210 connected to a transfer pipe through which fluid is transferred, first and second optical fiber pressure sensors 217 and 218 installed on the main body 210, and a main body 210. The housing 219 is coupled to the outside of the control unit, and the control means 220 for calculating the flow rate using the pressure value measured by the optical fiber pressure sensor and displaying it.

The main body 210 is provided at both ends with a connecting portion 211 which can be connected to the transfer pipe through the screw coupling, the throttle portion 212 is narrow is formed on the inner flow path through which the fluid moves. A first pressure outlet 213 and a second pressure outlet (not shown) are respectively formed on the upstream side and the downstream side of the main body 210 around the throttle part 212.

The first and second pressure outlets 213 are inserted into the first and second pressure detection pipes 215 and 216 so as to extend into the inner space of the main body 210. The first and second pressure detection pipes 215 and 216 are installed. ) Is open so that the lower end is opened so that the hydraulic pressure can be transferred into the first and second pressure detection pipes 215 and 216 according to the pressure of the fluid.

The first and second optical fiber pressure sensors 217 and 218 are respectively installed inside the first and second pressure detection pipes 215 and 216. When the hydraulic pressure of the fluid is transmitted, a mold deformation according to the hydraulic pressure occurs to measure the pressure.

The first and second optical fiber pressure sensors 217 and 218 have first and second optical fibers through which optical signals are transmitted from the same light source, and include photodetectors for detecting optical signals transmitted from the first and second optical fibers.

The first optical fiber transmits the same optical signal to the photodetector regardless of the application of the external pressure, and the second optical fiber changes the refractive index or the length of the optical fiber according to the application of the external pressure. Therefore, when an external pressure is applied, a phase difference occurs between the optical signals detected by the photodetectors in the first and second optical fibers, and the magnitude of the hydraulic pressure applied by the phase difference can be measured.

Based on the pressure measurement values measured by the first and second optical fiber pressure sensors 217 and 218, the control unit 220 converts the flow rate into a flow rate and displays it.

The control means 220 includes a calculation unit 221 for calculating the flow rate, and a display unit 222 for numerically displaying the converted flow rate.

The calculation unit 221 calculates the flow rate based on the pressure measurement values measured by the first and second optical fiber pressure sensors 217 and 218 using the continuous law and the Bernoulli equation.

When the flow rate is calculated in the calculator 221, the flow rate is transmitted to the display unit 222 as an electrical signal, and the display unit 222 displays the numerical value through the liquid crystal display 223 so that the manager can easily recognize the flow rate.

The housing 219 is installed on the main body 210 to protect the first and second optical fiber pressure sensors 217 and 218, and the liquid crystal display 223 of the display unit 222 is coupled to the outside through the upper surface. .

3 shows another embodiment of a flow meter 230.

The flowmeter 230 of the present embodiment includes a main body 231, third and fourth optical fiber pressure sensors 237 and 238 coupled to the main body 231, a housing 239 coupled to the main body 231, and control means 240. ).

The main body 231 is provided with a connecting portion 232 that can be connected to the transfer pipe at both ends, and the throttle portion 233 is narrow on the inner flow path is provided.

In the main body 231 on the upstream side and the downstream side centering on the throttle part 233, the 3rd and 4th pressure relief openings 234 and 235 of predetermined area which communicate the exterior and the inside of the main body 231 are formed, respectively.

The outer circumferential surface of the main body 231 is attached with a thin film 236 for closing the third and fourth pressure outlets 234 and 235. Since the thin film 236 is an elastic material, when the fluid moves through the body 231, the thin film 236 expands upward by the pressure of the fluid.

Third and fourth optical fiber pressure sensors 237 and 238 are installed on the thin film 236, and when the thin film 236 expands by hydraulic pressure, the third and fourth optical fiber pressure sensors 237 and 238 are also attached thereto. Deformation occurs and the pressure can be measured.

Since the pressure measuring principles of the third and fourth optical fiber pressure sensors 237 and 238 are the same as those of the first and second optical fiber pressure sensors 217 and 218, detailed description thereof will be omitted.

Based on the measured values measured by the third and fourth optical fiber pressure sensors 237 and 238, the calculation unit 241 calculates a flow rate and displays it on the display unit 242 so that an administrator can identify it.

Figure 4 shows an embodiment of the water level detecting means for measuring the level of filthy water filled in the tank.

As shown in FIG. 1, the water level for measuring the water level of the scum storage tank 51 storing scum removed from the water collecting tank 10, the primary purification water tank 30, the concentrating tank 46, and the pressure flotation tank 45. Sensors 300a, 300b, 300c, and 300d are installed inside each tank.

Referring to FIG. 4, the water level sensor 300 will be described in detail. The water level sensor 300 is installed inside the body 310 and the inside of the body 310. A second optical fiber grating sensor 320 is provided.

When the second optical fiber grating sensor 320 is attached to the inside of the main body 310 to fill the water tank 301 with fluid, the second optical fiber grating sensor 320 detects the deformation amount of the main body 310 deformed by the pressure of the fluid. Since the flow rate of the fluid varies depending on the level of the water tank 301, the hydraulic pressure applied to the main body 310 is changed. Therefore, it is possible to convert the water level of the water tank 301 according to the size of the hydraulic pressure, the second optical fiber grating sensor 320 based on this by measuring the amount of hydraulic pressure applied to the main body 310 through the deformation amount of the main body 310 The water level of the tank 301 can be calculated.

Deformation measurement of the second optical fiber grating sensor 320 is performed as follows.

The reference optical fiber 321 and the measurement optical fiber 322 are installed in the second optical fiber grating sensor, and the reference optical fiber 321 transmits a constant optical signal without being affected by the deformation of the main body 310. On the other hand, the optical fiber 322 for measuring transmits an optical signal having a phase difference with the optical signal of the reference optical fiber while changing the length and refractive index according to the deformation of the main body 310. The optical signals of the reference optical fiber 321 and the measuring optical fiber 322 are connected to the controller 500 to be described later in a state wrapped in the protective cable 323 to transmit the optical signal to the controller 500, the controller 500 ), The amount of deformation of the body 310 can be known through the phase difference between the reference optical fiber 321 and the measurement optical fiber 322.

5 shows a motor thermometer 400 for measuring the temperature of the motor 401.

Although not shown, the motor thermometer 400 includes a motor 401 for driving a blower 52 for supplying air to the water tank as shown in FIG. 1, but is operated for the operation of a water treatment facility such as a pump and a stirrer. To measure the temperature of 401.

The motor thermometer 400 includes a main body 410 attached to the outer circumferential surface of the motor housing 402 of the motor 401 and a third optical fiber grating sensor 420 installed inside the main body 410. ).

When the temperature rises according to the driving of the motor 401, the main body 410 receives heat through the motor housing 402, thereby causing deformation.

According to the shape deformation of the main body 410, the third optical fiber grating sensor 420 installed inside the main body 410 is changed in length and refractive index of the optical fiber for measurement, and thus has a phase between the optical signal transmitted from the optical fiber for measurement and the reference optical fiber. There is a car.

The phase difference depends on the mold deformation amount of the main body 410, and since the mold deformation amount of the main body 410 depends on the temperature of the motor 401, the phase difference between the reference fiber and the measurement optical fiber and the temperature of the motor 401 are different. By analyzing the correlation through the experimental data, it is possible to measure the temperature of the motor 401 using the third optical fiber grating sensor 420.

Measurement information of the flow meters 200, the water level sensor 300, and the motor thermometer 400 are transmitted to the controller 500. In the case of the flowmeter 200, since the flowmeter 200 has a calculation unit for converting the flow rate based on the pressure values measured by the optical fiber pressure sensors, the flow rate 200 can be converted into its own flow rate and displayed to the outside. To the controller 500.

In the case of the water level sensor 300 and the motor thermometer 400, the deformation amount of each of the main bodies 310 and 410 is calculated by the controller 500 based on the phase difference transmitted from the second and third optical fiber grating sensors 320 and 420. The water level of the water tank 301 and the temperature of the motor 401 are calculated.

In the controller 500, when the measured information is higher than the set value, for example, if the flow rate is greater than the set flow rate, the controller 500 adjusts the valve to reduce the flow rate through the transfer pipe, and the water level of the water tank 301 exceeds the threshold. In this case, the proper level of the water tank 301 is maintained by blocking the fluid supply to the water tank 301 or by discharging the fluid.

In addition, when the temperature of the motor 401 is out of the set level, the power switch is operated to stop the driving of the motor 401, and when the temperature of the motor 401 is lowered to the normal level, it is driven again.

In addition, the controller 500 displays the manager so that the manager can check the flow rate, the water level of the tank and the temperature of the motor through the management monitor. To be checked.

Since the controller 500 can control the flow rate of the fluid, the water level of the tank and the temperature of the motor in this way, it is possible to grasp the exact flow rate of the sewage and to adjust the amount of the chemical added to the chemical accordingly, and the most efficient for the purification of the sewage. Quantity can be stored in the tank.

In addition, in the operation of the motor 401 for operating the respective devices, the motor 401 is overloaded, the operation of the entire water treatment plant 100 is stopped or the time and cost according to the replacement of the failed motor 401 Damage can be minimized.

1 is a schematic view of a water treatment plant according to the present invention,

2 is a partially exploded perspective view showing a flow meter installed in the water treatment facility of FIG.

3 is a sectional view showing another embodiment of the flow meter,

Figure 4 is a partially cut perspective view showing one example of the water level sensor;

Figure 5 is a partial excerpt perspective view showing an embodiment of a motor thermometer,

6 is a block diagram showing the operation of the controller.

<Explanation of symbols for the main parts of the drawings>

100; Water treatment facility

10; Sump 20; First processing unit

30; Primary treatment tank 40; Secondary processing unit

50; Discharge tank

200; Flow meter 210; main body

217; First optical fiber pressure sensor 218; 2nd optical fiber pressure sensor

220; Control means

300; Water level detector 320; 2nd optical fiber grating sensor

400; Motor thermometer 420; 3rd optical fiber grating sensor

500; controller

Claims (6)

A water treatment facility comprising a sewage treatment unit including a sump tank, an anaerobic tank, aeration tank, sedimentation tank, pressurized floatation tank, and concentration tank, Flow rate measuring means including a first optical fiber grating sensor installed on a pipe line interconnecting the water tanks to measure the flow rate through the pressure of the fluid and measuring the pressure of the fluid; Water level sensing means including a second optical fiber grating sensor installed on the inner bottom surfaces of the tanks and sensing the water level through the pressure of the fluid filled in the tank; A motor temperature measuring means attached to a motor for driving the water treatment facility and including a third optical fiber grating sensor for measuring a temperature of the motor through a phase difference of an optical signal generated by deformation of the motor; And And a controller configured to receive sensing information of the first to third optical fiber grating sensors, calculate a flow rate of a fluid, a water level of a tank, and a temperature of a motor, and adjust the operation of a water treatment facility according to the calculated information. Control system of a water treatment plant. The method of claim 1, The flow rate measuring means includes a main body having an internal space through which the fluid can flow, and an throttle having an narrow internal cross section; An optical fiber pressure sensor installed at an upper side and a downstream side of the throttle to detect a pressure of a fluid inside the main body; And control means for receiving the pressure measured by the optical fiber pressure sensor as an electrical signal, calculating a flow rate of the fluid passing through the main body by using the pressure difference between the respective points, and displaying the calculated flow rate. system. The method of claim 2, The main body has first and second pressure outlets formed on the upstream side and the downstream side of the throttle part, respectively, and communicates with the inside of the main body from the first and second pressure outlets. The detection tube is extended, respectively, and the optical fiber pressure sensor is fixedly coupled to enter a predetermined depth into the first and second pressure detection tube, And a housing coupled to the main body to surround the first and second pressure outlets, the housing having the control means installed therein. The method of claim 2, The main body is provided with third and fourth pressure outlets on the upstream side and the downstream side around the throttle part, respectively. The body having the third and fourth pressure outlets is provided with a thin film having an elastic force that partitions the inner space and the outside of the body and is deformed according to the pressure of the fluid. And the optical fiber pressure sensor is coupled to an upper surface of the thin film so as to measure the pressure of the fluid through the deformation amount of the thin film expanding according to the pressure of the fluid. The method of claim 1, The water level detecting means is installed on the inner bottom surface of the tank, and has a body in which deformation occurs in accordance with the hydraulic pressure of the fluid filled in the tank, The first optical fiber grating sensor is installed inside the main body, the control system of the water treatment facility, characterized in that formed to measure the deformation amount of the main body generated by the hydraulic pressure in accordance with the filling amount of the fluid. The method of claim 1, The motor temperature measuring means has a main body attached to one side of the motor so that the heat generated by the driving of the motor can be transferred, The third optical fiber grating sensor is installed in the interior of the main body so as to measure the amount of deformation of the main body due to the heat generated from the motor.

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