JP2001137835A - Facility control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a facility control system for improving the control efficiency of a sedimentation tank, a cleaning facility, a sewage treatment facility, or the like. SOLUTION: A surface level is measured by a laser level meter, and treatment to be operated by various facilities is controlled based on the measured distances by the laser level meter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facility control system for controlling a sedimentation tank, a water purification facility, a sewage treatment facility, and the like.

[0002]

2. Description of the Related Art Water purification plants have water purification facilities such as sedimentation basins and filtration ponds. Raw water supplied to the water purification plant is purified through these water purification facilities.

FIG. 8 is a diagram showing a configuration example of a sedimentation basin.
In FIG. 8, the water guided to the sedimentation tank 1 is separated into the supernatant 2 and the sludge 3 when the water is kept stationary for a predetermined time. Sludge 3 accumulates at the bottom of sedimentation tank 1, and supernatant 2 is generated on sludge 3. The valve 4 is opened when removing the sludge 3 accumulated at the bottom of the settling tank 1. The motor 5 opens and closes the valve 4. The timer 6 is connected to the motor 5 and controls the time during which the valve 4 opens.

In the sedimentation basin of FIG. 8, since the sludge 3 is withdrawn by the timer control, the set withdrawal time is not an optimal time, and the supernatant may be withdrawn extra. For this reason, there is a problem that the load on the equipment for sludge concentration and dewatering is increased downstream of the settling tank 1.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and measures the interface level with a laser level meter and uses the distance measured by the laser level meter to settle the sedimentation tank. An object of the present invention is to realize a facility control system in which control efficiency of facilities is improved by controlling water purification facilities, sewage treatment facilities, and the like.

[0006]

The present invention is an equipment control system having the following configuration.

(1) In a facility control system for controlling the extraction of the sediment accumulated in the sedimentation tank, a laser beam is emitted from the upper part toward the sedimentation tank, and suspended or sediment particles existing in the sedimentation tank are used. A laser level meter that receives the reflected light and measures the vertical distance to the particles, and a distribution analysis unit that analyzes the vertical distribution of the particles based on the measurement distance of the laser level meter. The interface calculation means for calculating the level of the interface separating the sedimentary layer and the supernatant from the analysis results of the distribution analysis means, and the withdrawal of the sediment settled at the bottom of the settling tank based on the interface level obtained by the interface calculation means An equipment control system, comprising: a pull-out control unit for controlling.

(2) In a facility control system for controlling coagulant injection into a water purification plant, the system is installed at a plurality of measurement points along the flow direction of water in a sedimentation basin, and emits laser light from above to the sedimentation basin. A laser level meter that receives light reflected by suspended or sediment particles present in the sedimentation basin and measures a vertical distance to the particles, and a particle based on a measurement distance of each laser level meter. Distribution analysis means for analyzing the distribution in the vertical direction, and first calculation means for obtaining, for each measurement point, the highest level of the layer where the suspended matter exists based on the analysis result of the distribution analysis means; A second calculating means for calculating the sedimentation speed of the suspended matter based on the highest level obtained by the first calculating means; and a coagulant injection amount based on the sedimentation speed obtained by the second calculating means. And a third calculating means for determining Equipment control system characterized by having, an injection control means for controlling the injection of the coagulant based on the injection amount of coagulant obtained in calculation means.

(3) From the analysis result of the distribution analysis means,
When the particle distribution converges within a predetermined range, the interface level determination unit determines that the interface level measurement has become possible, and the interface calculation unit starts calculating the interface level according to the determination by the determination unit. The equipment control system according to (1), wherein

(4) From the analysis result of the distribution analysis means,
When the distribution of the particles converges within a predetermined range, it has a judging means for judging that the level measurement of the interface has become possible. The equipment control system according to (2), wherein the calculation is started.

(5) In a facility control system for controlling a batch tank of a sewage treatment facility, sewage is introduced into the batch tank, and aeration and agitation are applied to the sewage flowing in, and then light is emitted toward the batch tank. Then, the light reflected by the activated sludge particles present in the batch tank is received, the distance to the position where the activated sludge particles are present is measured, and a laser level meter that repeats this measurement is provided. Distribution analysis means for analyzing the distribution of particles based on the measurement distance, and supernatant discharge means for discharging the supernatant of the batch tank when the distribution of the particles determined by this distribution analysis means converges within a predetermined range. The equipment control system characterized by having.

(6) In the equipment control system for controlling the sewage treatment equipment or the wastewater treatment equipment, the light is emitted toward the sedimentation basin, the light reflected by the sedimentation basin is received, and the distance to the reflection position of the sedimentation basin is measured. A laser level meter for measuring the floating level, and a floating substance detecting means for detecting whether a floating substance is floating on the surface of the sedimentation tank based on the measurement distance of the laser level meter,
When the floating object detection means determines that there is a floating object,
A trough control means for setting a trough in a position where water does not flow out of the sedimentation basin and, when it is determined that there is no suspended matter, setting a trough in a posture where water flows out of the sedimentation basin. Control system.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a configuration diagram showing one embodiment of the present invention. 1 that are the same as those in FIG. 8 are given the same reference numerals. FIG.
The laser level meter 10 emits a laser beam from the upper part toward the sedimentation tank 1, receives light reflected by suspended or sediment particles existing in the sedimentation tank 1, and receives light in a vertical direction up to the particles. Measure the distance. The laser level meter 10 repeatedly performs distance measurement.

The distribution analyzing means 11 includes a laser level meter 10
The distribution of particles in the vertical direction is analyzed based on the measured distance.
The determination means 12 determines from the analysis result of the distribution analysis means 11 that the level measurement of the interface has become possible when the distribution of the particles has converged within a predetermined range. The interface calculation means 13
The level of the interface 14 is calculated based on the measurement distance of the laser level meter. The interface calculation means 13 starts calculation when the determination means 12 determines that measurement is possible. The interface calculating means 13 may start the calculation after the water in the sedimentation tank 1 is stopped for a certain time without depending on the judgment of the judging means 12.
The extraction control means 15 controls the opening and closing of the valve 4 based on the interface level obtained by the interface calculation means 13 and controls the extraction of the sludge 3 sinking to the bottom of the settling tank 1.

FIG. 2 is a diagram showing an example of the distribution of particles analyzed by the distribution analysis means 11. In FIG. 2, the horizontal axis represents time, and the vertical axis represents the position of particles. As shown in FIG. 2, since the water in the sedimentation basin is not separated into supernatant and sediment at the beginning of the measurement, the positions of the particles are dispersed. As time elapses, the particles are separated into a supernatant and a precipitate, so that the positions of the particles converge near the interface. The judging means 12 judges that the level measurement of the interface has become possible when the distribution of the particles has converged within the predetermined range d.

FIG. 3 is a block diagram showing another embodiment of the present invention. In FIG. 3, a flocculant is injected into water guided to the chemical mixing pond 20, and is stirred by the stirrer 21. The injected coagulant forms particles together with dust and the like in the raw water. These particles are called flocs. The tank 22 stores a flocculant. When the valve 23 is opened, the coagulant in the tank 22 is injected into the chemical mixing pond 20. In the floc formation pond 24, a water wheel called a flocculator is running. Flock formation pond 2
The water passing through 4 is guided to the sedimentation basin 16. In the sedimentation basin 16, flocs are settled. The supernatant of the settling basin 16 is supplied to a filtration basin (not shown). As a result, dust and the like mixed in the raw water are removed.

Two laser level meters 10a and 10b are provided. The laser level meters 10a and 10b are installed at measurement points along the flow direction of the water in the sedimentation basin 16, emit laser light from above to the sedimentation basin 16, and float or sediment existing in the sedimentation basin 16. The light reflected by the particles is received, and the vertical distance to the particles is measured. The distribution analyzers 11a and 11b analyze the distribution of particles in the vertical direction based on the measurement distance of each laser level meter.
The determining means 12a and 12b determine that the level measurement of the interface has become possible when the particle distribution converges within a predetermined range. The first calculation means 17a, 17b obtains the highest level 25 of the layer in which the suspended matter exists in the sedimentation basin 16 for each measurement point based on the analysis results of the distribution analysis means 11a, 11b. The first calculation means 17a, 17b starts calculation when the determination means 12a, 12b determines that level measurement is possible. Note that the first calculation means 17
The calculations a and 17b may be started after standing still for a certain time without depending on the judgment of the judgment means 12a and 12b.
The second calculating means 30 includes first calculating means 17a, 17b
The sedimentation velocity of suspended matter is calculated based on the highest level obtained in the above. The third calculating means 31 calculates the amount of coagulant to be injected based on the sedimentation speed calculated by the second calculating means 30. The injection control means 32 controls the injection of the coagulant based on the coagulant injection amount obtained by the third arithmetic means 31. Note that three or more laser level meters may be provided.

In the embodiment shown in FIG. 3, the injection amount of the flocculant into the chemical mixing pond 20 is controlled to an optimum value according to the sedimentation velocity of the sedimentation pond 16.

Here, how to determine the sedimentation velocity will be described. FIG. 4 is a diagram showing a state of sedimentation in a sedimentation basin. Water flows through the settling basin 16 from left to right. V
And FIG. 4A is a diagram showing a case where the sedimentation speed is optimal. In this case, the sedimentation velocity V = V0. V0
Is the optimum speed of sedimentation, V0 = Q / A (Q is the volume flow rate of water, A is the sedimentation area of the sedimentation basin 16). Due to the water flow velocity v and the sedimentation velocity V, the highest level 25 of the layer in which the suspended matter exists in the sedimentation basin 16 is inclined. This inclination is defined as a settling gradient. The sedimentation gradient can be detected by measuring the highest level of each measurement point using the laser level meters 10a and 10b provided at a plurality of measurement points. In the case of FIG. 4A, the sedimentation gradient is optimal.

FIG. 4B shows the case where the sedimentation speed is lower than the optimum speed (when V <V0). In this case, since the sedimentation velocity V is smaller than the flow velocity v of the water, the sedimentation gradient becomes gentler than the optimum gradient. As shown in the figure,
The sedimentary layer increases by the amount of carryover. Suspended matter and sediment may be contaminated when the supernatant is collected.
Therefore, in the case of FIG. 4B, the injection amount of the coagulant is increased.

FIG. 4C shows the case where the sedimentation speed is higher than the optimum speed (when V> V0). In this case, since the sedimentation velocity V is higher than the water flow velocity v, the sedimentation gradient is steeper than the optimum gradient. In this case, the coagulant is used in excess. In this case, the injection amount of the coagulant is reduced.

FIG. 5 is a diagram showing the relationship between the flow velocity v of water and the sedimentation velocity V. Assuming that the angle of the settling gradient is θ, the settling velocity V is given by the following equation. V = vtan θ The flow velocity v of the water is a known value. The angle θ of the settling gradient can be detected by laser level meters provided at a plurality of measurement points.
Therefore, the sedimentation velocity V can be obtained from the equation. The injection amount of the flocculant is increased or decreased depending on whether the determined sedimentation velocity V is higher or lower than the optimum velocity V0. Then, the injection amount of the flocculant is controlled so that the sedimentation velocity V = V0.

FIG. 6 is a block diagram showing another embodiment of the present invention. Sewage flows into the batch tank 40 in the sewage treatment facility. Aeration and stirring are performed on the inflowing wastewater. afterwards,
When the sewage is kept stationary for a certain period of time, the sewage is separated into activated sludge 41 and supernatant 42. The activated sludge 41 has settled at the bottom.
The aeration / stirring device 43 is a device that aerates and agitates sewage flowing into the batch tank 40.

The laser level meter 44 emits light toward the batch tank 40, receives light reflected by the activated sludge particles present in the batch tank 40, and measures the distance to the position where the activated sludge particles are present. Measure. The laser level meter 44 repeats the measurement. The distribution analyzing means 45 includes a laser level meter 44.
The distribution of particles is determined based on the measurement distance. Control means 47
Operates the supernatant discharging device 48 when the particle distribution obtained by the particle distribution calculating means 46 converges within a predetermined range,
The supernatant of the batch tank 40 is discharged. The supernatant discharging device 48 draws the supernatant in a container and flows out of the batch tank 40. The valve 49 is provided for extracting activated sludge. The pull-out control means 50 controls opening and closing of the valve 49 to control the batch tank 40.
Of activated sludge at the bottom of the bed is controlled.

The operation procedure of the embodiment shown in FIG. 6 is as follows. Sewage flows into the batch tank 40. The aeration / stirring device 43 repeats the aeration by the aerobic treatment and the stirring by the anaerobic treatment for the inflowing wastewater. Keep the sewage stationary for a certain period of time. The distance to the activated sludge particles is measured by the laser level meter 44. The distribution of the measurement distance is obtained, and when the distribution converges within a predetermined range, it is determined that the sedimentation is completed. When the sedimentation is completed, the supernatant 42
To discharge. The valve 49 is opened to pull out excess activated sludge accumulated at the bottom of the batch tank 40. The removal amount is controlled according to the distance measured by the laser level meter.

FIG. 7 is a block diagram showing another embodiment of the present invention. In FIG. 7, the laser level meter 60 emits light toward the sedimentation basin 61, receives the light reflected by the sedimentation basin 61, and measures the distance to the reflection position of the sedimentation basin. The suspended matter detecting means 62 detects whether the suspended matter is floating on the surface of the sedimentation basin based on the measurement distance of the laser level meter 60. When a floating substance is floating on the water surface 64 of the water 63 stored in the sedimentation basin 61, the light emitted from the laser level meter 60 is reflected by the floating substance. When there is no suspended matter, use a laser level meter 6
The outgoing light of 0 is reflected at the bottom of the sedimentation basin 61. For this reason,
The measurement distance of the laser level meter 60 when the floating object is floating is shorter than the measurement distance of the laser level meter 60 when the floating object is not floating. From this, the presence or absence of suspended matter is identified.

The trough control means 65 includes the suspended matter detection means 6
When it is determined that there is a floating substance, the trough 66 is set to a position where the water 63 does not flow out, and when it is determined that there is no floating substance, the trough 66 is set to a position where the water 63 flows out. The trough 66 is a gutter-shaped member. By controlling the position of the trough in this manner, the water in which the floating material floats is settled in the sedimentation basin 61.
Outflow to the downstream side. Warning means 67
Generates an alarm when the floating object detection means 62 determines that there is a floating object. The sedimentation basin 61 here is a final sedimentation basin.

The laser level meter in FIGS. 1, 3, 6 and 7 is, for example, a phase difference detection type laser level meter. In this laser level meter, a laser beam subjected to amplitude modulation is emitted to an object to be measured, and a distance is detected based on a phase difference between light returned from the object to be measured and the original emitted light. Further, the laser level meter may detect the distance based on the time required from emitting the laser light to the object to be measured to returning the light reflected by the object to be measured. .

[0029]

According to the present invention, the following effects can be obtained.

According to the first aspect of the present invention, the level of the interface between the supernatant and the precipitate is measured by the laser level meter, and the extraction of the precipitate is controlled based on the measurement result of the laser level meter. For this reason, pull-out control can be performed based on the interface level measured with high accuracy. Thereby, it is possible to prevent extra water from being drawn out, and it is possible to reduce the load on the equipment for sludge concentration and dewatering on the downstream side of the sedimentation basin.

According to the invention of claim 2, since the injection of the flocculant is controlled based on the sedimentation gradient obtained from the measurement result of the laser level meter, the injection amount can be optimally controlled.

According to the third and fourth aspects of the present invention, the distribution of the particles of the precipitate is obtained from the measurement result of the laser level meter, and the level measurement is started when the distribution of the particles converges within a predetermined range. ing. Therefore, level measurement can be performed at an appropriate measurement timing.

According to the fifth aspect of the present invention, after the activated sludge is agitated and diffused into the supernatant, the particle distribution is obtained from the measurement result of the laser level meter, and the particle distribution converges within a predetermined range. The supernatant of the batch tank is discharged. Therefore, it is possible to take out the purified supernatant from the batch tank at an appropriate timing. Further, the timing at which the supernatant is discharged can be detected quickly, so that the processing efficiency is improved. In addition, the extraction of the activated sludge can be automated.

According to the invention of claim 6, the distance to the light reflection position in the sedimentation basin is measured by the laser level meter, and the presence or absence of suspended matter in the sedimentation basin is detected from the measured distance. Thereby, it is possible to prevent the water in which the suspended matter floats from flowing out of the sedimentation pond to the downstream side.

As described above, the present invention has realized a facility control system capable of efficiently performing water purification treatment.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention.

FIG. 2 is a diagram showing an example of particle distribution in a sedimentation tank.

FIG. 3 is a configuration diagram showing another embodiment of the present invention.

FIG. 4 is an explanatory diagram showing how to determine a sedimentation velocity.

FIG. 5 is an explanatory diagram showing how to determine a sedimentation velocity.

FIG. 6 is a configuration diagram showing another embodiment of the present invention.

FIG. 7 is a configuration diagram showing another embodiment of the present invention.

FIG. 8 is a diagram showing a configuration example of a sedimentation basin.

[Explanation of symbols]

 1,61 sedimentation tank 2 supernatant 3 sludge 10,10a, 10b, 44,60 laser level meter 14 interface 11,11a, 11b, 45 distribution analysis means 12,12a, 12b judgment means 13 interface calculation means 15,50 control means Reference Signs List 16 sedimentation basins 17a, 17b first calculation means 30 second calculation means 31 third calculation means 40 batch tank 41 activated sludge 42 supernatant 43 aeration and agitation device 47 control means 48 supernatant discharge device 62 suspended matter detection means 65 Trough control means 66 Trough

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C02F 1/52 C02F 1/52 Z 3/12 ZAB 3/12 ZABP G01B 11/00 G01B 11/00 B G01F 23/28 G01F 23/28 JF term (reference) 2F014 FA01 2F065 AA00 AA06 AA09 AA31 CC00 FF11 GG04 GG13 HH13 JJ05 JJ09 NN20 PP22 4D015 BA21 BA28 BB05 DC02 EA03 EA32 4D028 BB01 BA02 DC02 BA02

Claims (6)

[Claims] 1. An equipment control system for controlling extraction of sediment accumulated in a sedimentation tank, wherein a laser beam is emitted from an upper part toward the sedimentation tank and reflected by suspended or sediment particles existing in the sedimentation tank. A laser level meter that receives the measured light and measures a vertical distance to the particle; a distribution analysis unit that analyzes a vertical distribution of the particle based on a measurement distance of the laser level meter; Interface calculation means for calculating the level of the interface separating the sedimentation layer and the supernatant from the analysis results of the analysis means, and withdrawal of the sediment settled at the bottom of the sedimentation tank based on the interface level calculated by this interface calculation means And a pull-out control unit. 2. A facility control system for controlling coagulant injection in a water treatment plant, comprising: a plurality of measuring points installed along a flow direction of water in a sedimentation basin; A laser level meter that receives light reflected by suspended or sediment particles present in the sedimentation basin and measures a vertical distance to the particles; and a laser level meter based on a measurement distance of each laser level meter. Distribution analysis means for analyzing the distribution in the vertical direction; first calculation means for obtaining, for each measurement point, the highest level of the layer where the suspended matter exists, based on the analysis result of the distribution analysis means; A second calculating means for calculating the sedimentation speed of the suspended matter based on the highest level obtained by the first calculating means; and an injection amount of the flocculant based on the sedimentation speed obtained by the second calculating means. The third computing means to be sought, and the third performance An injection control means for controlling the injection of the flocculant based on the injection amount of the flocculant obtained by the calculating means. 3. A determination means for determining from the analysis result of the distribution analysis means that the level measurement of the interface is enabled when the particle distribution converges within a predetermined range, wherein the interface calculation means includes: 2. The equipment control system according to claim 1, wherein the calculation of the interface level is started according to the judgment of the judgment means. 4. A method according to claim 1, further comprising: judging means for judging from the analysis result of the distribution analyzing means that the level measurement of the interface becomes possible when the distribution of the particles converges within a predetermined range.
3. The equipment control system according to claim 2, wherein said calculating means starts calculation of the highest level according to the judgment of said judging means. 5. A facility control system for controlling a batch tank of a sewage treatment facility, wherein sewage flows into the batch tank, and aeration and agitation are applied to the sewage flowing into the tank, and then light is emitted toward the batch tank. A laser level meter that receives the light reflected by the activated sludge particles present in the batch tank, measures the distance to the position where the activated sludge particles are present, and repeats this measurement; and a measurement of the laser level meter. Distribution analysis means for analyzing the distribution of particles based on the distance, and supernatant discharge means for discharging the supernatant of the batch tank when the distribution of the particles determined by the distribution analysis means converges within a predetermined range, An equipment control system comprising: 6. An equipment control system for controlling a sewage treatment equipment or a wastewater treatment equipment, comprising: emitting light toward a sedimentation basin, receiving light reflected by the sedimentation basin, and determining a distance to a reflection position of the sedimentation basin. A laser level meter for measuring; a floating substance detecting means for detecting whether a floating substance is floating on the surface of the sedimentation basin based on a measurement distance of the laser level meter; and a floating substance detecting means for detecting the floating substance. If you decide,
A trough control means for setting a trough in a position where water does not flow out of the sedimentation basin and determining a trough in a posture where water flows out of the sedimentation basin when it is determined that there is no suspended matter. Control system.