JPH08192003A - Filter pond cleaning control device - Google Patents

Abstract

(57) [Summary] [Purpose] A filtration pond washing control device that can disperse the washing time of each filtration pond in consideration of the turbidity at the outlet of the sedimentation pond and perform the washing efficiently without burdening the filtration pond. I will provide a. [Structure] A turbidity signal is input to a filtration resistance interval determination means 1 from a water quality meter 28 provided at an outlet of a sedimentation basin 30, and a filtration resistance interval is obtained. In the cleaning planning means 2, when each filter basin is separated into a group created based on the filtration resistance interval and a plurality of filter basins are included in the same group, filtration of a filter basin other than the filter basin having the slowest cleaning sequence. The resistance threshold is corrected to decrease based on the filtration resistance interval and the filtration resistance value. In the order in which the filtration resistance value reaches the corrected filtration resistance threshold value, the cleaning requests are made in the filtration pond cleaning sequence means 4
Is output to

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter pond cleaning control device used for cleaning a filter pond provided in a water supply facility.

[0002]

2. Description of the Related Art Generally, in a water supply facility (water purification plant), raw water taken from a dam-type reservoir or river is supplied to consumers through a process of coagulation, precipitation and filtration.

[0003] In this process, the filtration basin that plays the role of filtration is usually composed of a plurality of basins, and the filtration treatment is performed according to the water demand. Since the filtration capacity of this filter basin decreases when it is used for a long time due to water turbidity, it is necessary to wash the filter basin in order to recover the filter capacity.

Conventionally, a filter basin is provided with a preset filtration resistance threshold value or a filtration continuation time upper limit value,
The ponds that have reached these values are washed in order. However, in this method, multiple filter basins have individual characteristics, and the deterioration of the filtration capacity is not uniform, so that multiple filter basin cleanings may be concentrated. In the water supply facility, the cleaning capacity is limited, which eventually makes it difficult to operate within the equipment rating of the filter, and in this case, the operator manually intervenes, based on empirical knowledge, , The final cleaning timing for each filter is finalized.

Further, since the operation method of the filter basin varies depending on the water supply facility, it is difficult to provide a control device having a general-purpose mechanism capable of coping with a plurality of water supply facilities with a fixed algorithm.

Further, although cleaning includes surface cleaning and reverse cleaning, conventionally, each cleaning time is constant irrespective of the conditions at the time of cleaning, which makes economical cleaning difficult.

As described above, when a preset filtration resistance threshold value or a filtration continuation time upper limit value is set and washing is performed in order from the ponds that reach these values, the washing of a plurality of filtration ponds is concentrated. Then, there is a problem that automatic control of cleaning becomes difficult.

The present invention has been made in view of the above points, and provides a filter basin cleaning control device capable of performing appropriate cleaning control even when cleaning of a plurality of filter basins is concentrated. With the goal.

[0009]

According to the first aspect of the present invention,
Within the group created based on the filtration resistance interval determination means that determines the filtration resistance interval based on the turbidity signal from the water quality meter installed at the outlet of the sedimentation basin and the filtration resistance interval determined by the filtration resistance interval determination means , Each filtration basin having a filtration resistance value is classified, and when multiple filtration basins are included in the same group, the standard filtration with the slowest cleaning order is determined from the plurality of filtration basins in order of longer filtration duration. Obtain the filtration resistance threshold value of the filtration basin based on the filtration resistance value and the filtration resistance interval of each filtration basin from the basin to the filtration basin, and request cleaning in the order that the filtration resistance value reaches the corresponding filtration resistance threshold value. A filter pond cleaning control device comprising: a cleaning plan means for outputting the cleaning plan means, and a filtering pond cleaning sequence means for outputting a cleaning command for the target filtering pond based on a signal from the cleaning plan means. That.

According to the second aspect of the present invention, the regular cleaning start determining means determines the regular cleaning mode when the previous cleaning time of the filter is concentrated, and the regular cleaning start determining means determines the regular cleaning mode. In this case, the cleaning cycle is determined based on the average value of the filtration duration of each filtration tank, and the periodic cleaning planning means for outputting the current cleaning request in descending order of the filtration resistance value is provided. It is a cleaning control device.

[0011]

According to the first aspect of the present invention, when the filtration resistance interval is determined by the filtration resistance interval determination means, and a plurality of filtration ponds are included in the group determined based on the filtration resistance interval by the cleaning planning means, Correct the filtration resistance thresholds of the filtration basins other than the filtration basin with the latest washing order so as to decrease based on the filtration resistance value and filtration resistance interval of each filtration basin, and the filtration resistance value after the correction The cleaning requests are output in the order of reaching. The filter basin cleaning sequence means outputs a cleaning command for the target filter basin based on the cleaning request from the cleaning planning means.

According to the second aspect of the present invention, the regular cleaning start determining means determines the regular cleaning mode when the previous cleaning time of the filter basin is concentrated, and determines the regular cleaning mode when the regular cleaning mode is determined. The cleaning planning unit determines the cleaning cycle based on the previous average value of the filtration duration times of the respective filtration basins, and outputs the current cleaning request in descending order of the filtration resistance value.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 4 are views showing an embodiment of a filter pond cleaning control device according to the present invention.

As shown in FIG. 1, in the water purification plant, the treated water from the sedimentation basin 30 which has been treated through the coagulation / precipitation process is flowed into the filtration basin 11, filtered by the filtration basin 11 and stored in the water purification basin 12. . The purified water stored in the purified water reservoir 12 is the purified water reservoir 1.
It is supplied from 2 to the demand groups and general households through the water pump 21. If the filtration is continued for a long time, the filtration capacity of the filtration basin 11 is lowered, and cleaning is required to recover the filtration capacity.

At the start of cleaning, the clean water tank 12 and the waste water tank 1
The water level of No. 3 is monitored, and when the water level of the water purification pond 12 is below the set value or when the water level of the wastewater pond 13 is above the set value, the interlock is applied and the washing is not performed.

For cleaning the filtration basin 11, purified water stored in the water purification basin 12 is used, and a surface cleaning pump (surface cleaning pump) 22 is used.
And the backwash pump (backwash pump) 23 for the filter 1
The cleaning is performed from the surface opposite to the surface of No. 1. The wastewater discharged when cleaning the filter tank 11 is stored in the wastewater tank 13 and returned to the coagulation / precipitation process by the return pump 24. In addition, a head loss meter 25 is installed in each filtration basin 11 to monitor the degree of reduction in filtration capacity.

Further, a water quality meter 28 is provided on the outlet side of the sedimentation basin 30, and the turbidity of the water on the outlet side of the sedimentation basin 30 detected by the water quality meter 28 is filtered by the filtration basin cleaning controller 8 via the process interface 8a. It is taken into the resistance range determining means 1.

Next, each component of the filter basin cleaning control device 8 will be described. The filtration resistance interval determination means 1 determines the filtration resistance interval based on the detected turbidity so that each filter basin can be cleaned at an appropriate cleaning interval. The cleaning planning means 2 plans the cleaning order and cleaning time of each filter basin based on the filtration resistance interval determined by the filtration resistance interval determination means 1, and when cleaning is concentrated, precedent cleaning is performed. Disperse the cleaning time of each filter. The filter basin cleaning sequence means 4 monitors the water level of the wastewater basin 13 and the water level of the purified water basin 12, and if the respective water levels are within the set range, for the filter basin judged by the cleaning plan means 2 to be the cleaning time, Outputs a cleaning command. In addition, filter pond cleaning control device 8
Has a filter basin condition monitoring means 3 for monitoring the condition of each filter basin.

Further, the filter basin cleaning control device 8 has a regular cleaning start determination means 9 for determining the regular cleaning mode when a periodic concentration of cleaning time occurs, and a regular cleaning planning means 10 is further provided. The cleaning cycle and the cleaning filtration basin, which will be described later, are determined by. In this embodiment, the filtration resistance interval determining means 1, the cleaning planning means 2, the regular cleaning start determination means 9, and the regular cleaning planning means 10 are configured by an expert system.

Further, the filter pond cleaning control device 8 has a cleaning time determining means 5, and the cleaning time determining means 5 determines the cleaning time for the surface cleaning and the back cleaning according to the filtration resistance at the start of cleaning.
Correcting the cleaning time.

Further, the filter pond cleaning control device 8 is connected to the CRT through the interface 6.

Next, the operation of this embodiment having such a structure will be described.

First, the detected value detected by the water quality meter 28 on the outlet side of the sedimentation tank 30 is taken into the filtration resistance interval determining means 1 as the sedimentation tank outlet turbidity. In the filtration resistance interval determination range 1, the filtration resistance interval is determined as follows from the taken turbidity detection value at the outlet of the sedimentation basin. Δr (i) = F (d, r (i), s) (1) In the equation (1), d: turbidity detection value at the outlet of the sedimentation pond [degree] s: turbidity threshold at the outlet of the sedimentation pond [Degree] r (i): actual filtration resistance value of the i-th filter basin [m water column] Δr (i): filtration resistance interval of the i-th filter basin [m water column]. Further, in the equation (1), if d <s, then F = const. If d> s, F = F (d, r (i)) and a preset function for each filter, or F = F (d) and a preset function.

Next, based on the filtration resistance interval Δr (i) for each filter pond determined by the filtration resistance interval determination means 1 or the average value Δr of the filtration resistance intervals, the cleaning planning means 2 uses each filtration pond. Schedule the cleaning time for the following.

That is, in FIG. 2, each filter is divided into filter resistance intervals Δr from the filter tank having the lowest actual filtration resistance value.

Next, for each of the filtration basins, in order from the lowest filtration resistance value or the longest filtration duration, the kth, (k-1)
No., No. (k-2), ..., No. 1 (k: number of operating filtration basins) and the cleaning order are determined.

At this time, as shown in FIG. 2, the filtration resistance value of the m pond may be concentrated in a certain filtration resistance interval. (A
Pond, B pond, C pond: m = 3) Among them, the washing order of each filtration pond is the order of the longest filtration duration (in the case of Fig. 2, the length of the filtration duration is A pond> B pond> C pond The washing order is determined as (), and the slowest washing order is the filtration tank (standard filtration tank) (C tank)
Based on the filtration resistance value of each filtration reservoir and the filtration resistance interval of each filtration reservoir as a reference, the filtration resistance threshold of each filtration reservoir is corrected as follows.

Rsv−Δr ′ (B) = Rsv−Max [0, {Δr (B) −Max (0, r (B) −r (C))}] (2) Rsv−Δr ′ (A) = Rsv−Max [0, {Δr (A) + Δr (B) −Max (0, r (A) −r (C))}] …… (3) Rsv: Filter pond equipment Filtration resistance threshold value [m water column] Δr ′ (i): Filtration resistance threshold correction value [m] of the i-th pond
Water column] r (i): Actual filtration resistance value of the i-th pond [m water column] Δr (i): Filtration resistance interval of the i-th pond [m water column] The cleaning plan means 2 has the actual filtration resistance value of the above formula. If the filtration resistance threshold value corrected in step 1 has been reached, a cleaning request is output to the filter pond.

If there is a filter pond whose actual filtration resistance value or actual filtration continuation time value has reached the filtration resistance threshold value before correction or the upper limit value of filtration continuation time, the filtration is performed. An interruption request is output to the pond.

The filter basin cleaning sequence means 4 outputs a cleaning command to the filter basin for which the cleaning plan means 2 has requested cleaning. At this time, the following interlock conditions work according to the detection values of the water purification pond water level meter 26 and the wastewater pond water level meter 27.

The interlock conditions of the filter basin cleaning sequence means 4 are as follows. The water level detection value of the purified water is not below the set value. The water level in the wastewater pond is not above the set value.

If this condition is not satisfied, the filter basin cleaning sequence means puts the filter basin for which a cleaning is requested into a cleaning standby state, and when the interlock condition is released, issues a cleaning command to the standby filter basin for cleaning. Output.

As described above, according to this embodiment,
In the operation of the filter at the water purification plant, if the filter is washed intensively, the washing is dispersed so that it is washed earlier than the preset filtration resistance threshold, and the filter is overloaded. It is possible to operate the filter basin efficiently and comprehensively.

Next, the operation of the regular cleaning start judging means 9 and the regular cleaning planning means 10 will be described. First, as shown in FIG. 1, the previous cleaning start time is input to the regular cleaning start determination means 9 from the filter basin state monitoring means 3. Next, as shown in FIG. 3, using the current time Tn as a reference, (Tn-To)
When the previous cleaning time of all N ponds is concentrated between Tn and Tn, the regular cleaning start determination means 9 determines the regular cleaning mode and switches the control from the normal mode to the regular cleaning mode.

In this case, To is the regular cleaning determination time set value [time], Tn is the current time [hour], and N is the number of operating filtration basins [pond].

Next, the filtration duration time is input from the filter basin state monitoring means 3 to the regular cleaning planning means 10. If the regular cleaning start determination means 9 determines that the cleaning mode is the regular cleaning mode, the regular cleaning planning means 10 determines the cleaning cycle by the following equation.

[0038]

[Equation 1] In the equation (4), Ti: actual filtration duration time value of the i-th pond (i = 1, ...,
N) [S] Ts: Periodic cleaning cycle [S].

Next, the regular cleaning planning means 10 uses the cleaning cycle T.
For each s, the current cleaning request is output in order from the filter tank with the highest filtration resistance. The regular cleaning mode ends when all the operating filter tanks have been cleaned, and then automatically switches to the normal mode.

In the case of T'≤To, periodical cleaning concentration cannot be avoided even if the mode is switched to the regular cleaning mode. Therefore, the control mode is not changed as the uncontrollable range.

Next, the operation of the cleaning time determining means 5 will be described. The cleaning time determination means 5 determines the cleaning time based on the filtration resistance at the start of cleaning, and the amount of purified water used for cleaning the filter basin can be made variable to save the amount of cleaning water. The cleaning time is determined as follows (see FIG. 4).

First, the filtration resistance recovery target value rsv is set, and the cleaning time t (i) required for cleaning is calculated by the following equation from the deviation between the filtration resistance value r (i) at the start of cleaning and the filtration resistance threshold value Rsv. Change.

T (i) = G [T (i), r (i) -rsv, Rsv-rsv] (5) In the equation (5), T (i) is the standard cleaning time of the i-th pond [ s] r (i): Filtration resistance value at the start of washing [m water column] rsv: Filtration resistance recovery target value [m water column] t (i): i-th pond washing time [s] G is a preset function Then, for example, G = T
(I) * (r (i) -rsv) / (Rsv-rsv) ...
(6) The filter basin cleaning means 5 performs the above calculation on the filter basin to which the cleaning command is output, and outputs the calculated cleaning time to the filter basin cleaning interlocking sequence means 4. In this way, the amount of purified water used for washing the filter basin can be made variable, and the amount of washing water can be saved.

As described above, according to this embodiment,
When cleaning each filtration basin, determine the cleaning time based on the filtration resistance value of each filtration basin and perform filtration based on the filtration resistance interval and the filtration resistance value of each filtration basin obtained by considering the turbidity at the outlet of the sedimentation basin. Since the resistance threshold value is corrected to appropriately disperse the cleaning intervals of the filter basin, efficient cleaning can be performed without burdening the filter basin. In addition, when the concentration of cleaning in the filter basin occurs periodically, the mode is switched to the regular cleaning mode, and the filter basin is cleaned sequentially for each cleaning cycle determined based on the previous average value of the filtration duration time. Stable operation of the filter tank for a long period of time and the burden on the operator can be reduced.

[0045]

According to the first aspect of the present invention, when cleaning each filtration basin, the filtration resistance value is washed in the order in which it reaches the filtration resistance setting value, and the cleaning of each filtration basin is concentrated. In addition, the filtration resistance threshold is corrected based on the filtration resistance interval set by the turbidity at the outlet of the sedimentation basin and the filtration resistance value of each filtration basin to disperse the cleaning time, so that the filtration basin is burdened. Efficient cleaning is possible.

According to the second aspect of the present invention, when cleaning concentration in the filter pond occurs periodically, the mode is switched to the regular cleaning mode, and the cleaning is determined based on the previous average value of the filtration duration time. Since the filter basin is washed sequentially every cycle, stable operation of the filter basin over a long period of time and the burden on the operator can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of a filter pond cleaning control device according to the present invention.

FIG. 2 is a diagram showing an operation of correcting a filtration resistance threshold value in a cleaning planning means.

FIG. 3 is a diagram showing an operation of a regular cleaning start determination means.

FIG. 4 is a diagram showing an operation of a cleaning time determining unit.

[Explanation of symbols]

 1 Filtration Resistance Interval Determining Means 2 Cleaning Planning Means 3 Filter Pond Condition Monitoring Means 4 Filter Pond Cleaning Sequence Means 5 Cleaning Time Determining Means 6 Interface 7 CRT 8 Filter Pond Cleaning Control Equipment 9 Regular Cleaning Start Means 10 Regular Cleaning Planning Means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Futoshi Kurokawa 1st in Toshiba Fuchu, Fuchu-shi, Tokyo Inside the Fuchu factory, Toshiba Corporation (72) Michio Kanayama 1st in Toshiba-cho, Fuchu, Tokyo Toshiba Fuchu, Ltd. in the factory

Claims (3)

[Claims] 1. A filtration resistance interval determining means for determining a filtration resistance interval based on a turbidity signal from a water quality meter provided at an outlet of a sedimentation basin, and a filtration resistance interval determined by the filtration resistance interval determining means. Each filter basin having a filtration resistance value is classified into the specified group, and when multiple filter basins are included in the same group, the cleaning order is determined from the multiple filter basins in the order of longer filtration duration. The filtration resistance threshold value of the relevant filtration basin is calculated based on the filtration resistance value and the filtration resistance interval of each filtration basin from the slowest standard filtration basin to the relevant filtration basin, and the filtration resistance value becomes the corresponding filtration resistance threshold value. A filtration characterized by comprising: a cleaning plan means for outputting a cleaning request in the order of arrival and a filtration basin cleaning sequence means for outputting a cleaning command for the target filtration basin based on a signal from the cleaning planning means. pond Kiyoshi control device. 2. A regular cleaning start determination means for determining the regular cleaning mode when the previous cleaning time of the filter tank is concentrated, and each filtration when the regular cleaning mode is determined by the regular cleaning start determination means. A filtration pond cleaning control device comprising: a cleaning cycle that determines the cleaning cycle based on the average value of the filtration duration of the pond, and a periodic cleaning planning means that outputs the current cleaning request in descending order of filtration resistance. 3. The cleaning time determining means for determining the cleaning time of the filtration basin based on the filtration resistance value at the start of cleaning of each filtration basin, further comprising: The filtration pond cleaning control device described in 1.