JPH03258312A - Automatic washing device for rapid filtration pool - Google Patents

Abstract

PURPOSE:To shift the real washing time of a rapid filtration pool by providing a prediction unit predicting the washing start time, a preceding washing decision unit advancing the time of washing, and a washing control unit. CONSTITUTION:The rapid filtration system is provided with plural rapid filtration pool unit 1, a control unit and a washing water pump 3. The time of washing is predicted based on the head loss, etc., of filtration water in the rapid filtration pool unit 1, and the time of washing of the rapid filtration pool unit 1 is decided and the washing process is started. The washing water pump 3 is energized, when a washing water pump driving signal is inputted, and the washing water is supplied to each rapid filtration pool part 1. Each rapid filtration pool unit 1 outputs the over-head-loss signal obtained by a differential pressure transmitter 7 and the operational state signal of a filtration valve 10 to the control unit 2, and the filtration process and the washing process are carried out thereby, and the treated water is stably supplied.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to an automatic cleaning device for a rapid filtration pond used in a water purification plant or the like using a rapid filtration basin.

(Conventional technology) At water purification plants, each rapid filtration tank is selected manually or automatically in sequence depending on the number of rapid filtration tanks, processing volume, etc., and the selected rapid filtration tanks are moved to the filtration process or to the filtration waiting process. We are doing water purification treatment to avoid any problems.

Furthermore, rapid filtration basins whose filtration concentration deteriorates during the filtration process and the filtration loss head pressure or suitable filtration time reaches the specified value are sequentially transferred to the cleaning process, and when the cleaning process is completed, they are transferred to the filtration waiting process again. .

(Problems to be Solved by the Invention) However, in most cases, such water purification plants only have the cleaning capacity of one pond in order to improve equipment efficiency.

For this reason, if rapid filtration ponds whose filtration operation time has reached a specified value occur simultaneously, the number of ponds waiting for cleaning occurs frequently, making it impossible to secure a predetermined filtration throughput.

In view of the above-mentioned circumstances, the present invention is capable of predicting the cleaning timing of each suitable area for rapid filtering, and if these overlap, performing preliminary cleaning and shifting the actual cleaning time of each suitable area for rapid filtering,
The object of the present invention is to provide an automatic cleaning device for a rapid filtration site that can stabilize the operation of the rapid filtration site and stabilize the supply of treated water through planned operation.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the automatic cleaning device for rapid filtration sites according to the present invention requires cleaning when each rapid filtration site that performs raw water filtration becomes necessary. In an automatic rapid filtration suitable area cleaning device that selects and performs cleaning by selecting a suitable rapid filtration area, the prediction unit detects the filtration state of each suitable rapid filtration area and predicts the cleaning start time, and When the cleaning start time of each rapid filtration suitable area overlaps, a pre-cleaning determining section which determines the one that satisfies the pre-cleaning conditions as the pre-cleaning target and advances the cleaning time; The present invention is characterized in that it is equipped with a cleaning control unit that performs preliminary cleaning of each suitable area for rapid filtration.

(Function) In the above configuration, the cleaning start time determination unit determines the cleaning start time of each suitable rapid filtration site so that the cleaning start timing of each suitable rapid filtration area obtained by the prediction unit does not overlap, and the cleaning control unit determines the cleaning start time of each suitable rapid filtration site. Have each rapid filtration site pre-cleaned in order based on content.

(Embodiment) First, the figure is a block diagram showing an example of a rapid filtration system using an embodiment of the automatic rapid filtration cleaning device according to the present invention.

The rapid filtration system shown in this figure has multiple rapid filtration suitable areas 1
, a control unit, and a washing water pump 3, and predicts the washing time based on the filtrate water loss head pressure etc. on the side of each rapid filtration suitable area 1, and adjusts each rapid filtration time to meet the water demand. The time for cleaning the filter suitable area 1 is determined and the process is moved to the cleaning process.

When the cleaning pump drive signal is supplied from the control section 2, the cleaning pump 3 is turned on and sends out cleaning water to supply it to each rapid filtration suitable soil section 1.

Each rapid filtration suitable area 1 has an overflow tank 4 that stores the supplied raw water, and a filter bed 5 that filters the raw water that overflows from the overflow tank 4.
a differential pressure transmitter 7 that detects the pressure difference between the upper and lower sides of the filter bed 5 and generates an excess head pressure signal indicating the degree of clogging; Overflow tank 4
a drain valve 8 for discharging the raw water stored in the water to the outside, and a waste water valve 9 for discharging the washing water when the rapid filtration suitable land 6 is washed.
Then, the water filtered by the rapid filtration site 6 is transferred to a distribution reservoir.
and a cleaning valve 11 that is opened when cleaning the rapid filtration suitable area 6 and sends the washing water sent from the washing water pump 3 to the lower side of the rapid filtration suitable area 6. ing.

Then, the excess water head pressure signal obtained by the differential pressure transmitter 7 and the operating state signal of the filtration lift 10 are supplied to the control section 2, and the control section 2 supplies the filtration valve drive signal and the cleaning valve drive signal, When the drain valve drive signal and the waste water valve drive signal are supplied, the filtration lift 10, the washing valve 11, the drain valve 8, and the waste water valve 9 are driven in response to the drain valve drive signal and the waste water valve drive signal to perform waste water treatment, filtration treatment, cleaning treatment, etc. In addition, the control section 2 includes a computing unit 12 and a cleaning control/sequence control section 13, and controls the filtration loss head pressure signal supplied from each rapid filtration suitable area section 1 and the operation of the filtration lift 10. The cleaning timing of each rapid filter suitable soil section 1 is predicted based on the status signal, the cleaning timing of each rapid filter suitable soil section 1 is determined to match the required amount of water demand, and the cleaning process is started.

The computing unit 12 supplies the operating state signal of the filtration lift 10 from each rapid filtration suitable soil section 1 to the cleaning control/sequence control section 13 every time the operating state signal of the filtration lift 10 is supplied from each rapid filtration suitable soil section 1. The filtration loss head pressure signal output from the
The change in the filtration loss head pressure value per hit is determined, and the filtration arrival time (time until the filtration loss head pressure reaches the set value) T, 1 is determined based on this calculation result.

As an arithmetic expression in this case, for example, the following expression is used.

However, Po (to +X), time to + Xte (7
) Mouth loss head pressure value PD(to): Time t. Filtration loss head pressure value Pos: Filtration loss head pressure value when it is necessary to perform cleaning. Then, when the calculation circuit 12 obtains this filtration arrival time T s +, it predicts this until the start of cleaning. The time is supplied to the cleaning control/sequence control section 13.

The cleaning control/sequence control unit 13 compares the integrated value of the operating time obtained based on the operating state signal of the filtration lift 10 supplied from the arithmetic circuit 12 with a preset operating limit time, and compares it with a preset operating limit time until the start of cleaning. Find the remaining time (appropriate setting time) Tpos.

Thereafter, the cleaning control/sequence control unit 13 starts cleaning the rapid filter suitable area 1 to be cleaned based on each filter arrival time T e l supplied from the arithmetic circuit 12 as shown in the flowchart of FIG. After finding the time (step 5
TI) Based on these cleaning start times, it is determined whether the number of areas 1 suitable for rapid filtration that must be simultaneously cleaned is greater than or equal to a set number (step 5T2).

Next, if the number of suitable rapid filtration areas 1 that must be simultaneously cleaned is equal to or greater than the set value, the cleaning control/sequence control unit 13 selects the suitable rapid filtration areas 1 to be cleaned based on a preset algorithm. Setting the suitable location for rapid filtration from the number in part 1 T6.
At the same time, the calculation shown in the following formula is performed to determine the appropriate setting time Tpos, the filter arrival time Tml,
It is determined whether the set value T1° satisfies the following relationship.

Tpos −T+m+≦T+wm (2) If this condition is satisfied, the cleaning control/sequence control unit 13 must perform cleaning based on a preset algorithm.
The cleaning order is determined, and based on the determination result, a cleaning command is issued to each rapid filter suitable area section 1 (step 5T3).

As described above, in this embodiment, the filtration arrival time T is determined from the change in the filtration loss head pressure indicated by the filtration loss head pressure signal supplied from each rapid filtration suitable area 1, and this filtration arrival time T s+ The cleaning start time of the rapid filtration suitable area 1 to be cleaned must be predicted and cleaned based on Since the cleaning of each suitable rapid filter area 1 is carried out at different intervals, the cleaning timing of each rapid filter suitable area 1 is predicted and if these overlap, the preliminary cleaning is performed and the cleaning of each rapid filter suitable area is performed. The actual cleaning time can be shifted, thereby making it possible to stabilize the operation of the rapid filtration suitable area section 1, and also to stabilize the supply of treated water through planned operation.

In addition, in this embodiment, the start timing of the preliminary cleaning is adjusted by the preliminary cleaning time T, .
The cleaning timing of each rapid filtration suitable area 1 can be determined in accordance with the required amount of water demand.

Further, in the above-described embodiment, the control unit 2 is provided near each rapid filtration suitable area 1, and the preliminary cleaning time T3. and the operation of
The order of cleaning of the suitable rapid filter areas 1 that must be cleaned is determined, but the control unit 2 is provided at a position away from each rapid filter suitable area 1, and the control unit 2 and each rapid filter are connected to each other. It is also possible to control each rapid location suitable location section 1 at a remote location by connecting the rapid location suitable location section 1 with a transmission device.

In addition, in the above-described embodiment, when the above formula (2) is satisfied, cleaning of the rapid filtration suitable area 1 is started, but the water quality etc. of the water filtered by the rapid filtration suitable area 6 is measured. However, the cleaning start time may be calculated based on this measurement result, and the cleaning timing for the rapid filtration suitable area may be determined based on this cleaning start time and the set suitable time TPDS.

In addition, in each of the embodiments described above, each rapid filter suitable area 1
The cleaning start time is predicted based on the side operating time, filtration head pressure loss, quality of filtered water, etc., and when these are in a predetermined relationship, advance cleaning of each rapid filtration suitable area 1 is performed. However, the preliminary cleaning may be performed when any one of these cleaning start times satisfies a predetermined condition.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to predict the cleaning timing of each suitable area for rapid filtering, and if these overlap, advance cleaning can be performed to shift the actual cleaning time of each suitable area for rapid filtering, This makes it possible to stabilize the operation of the rapid filtration site, and also to stabilize the supply of treated water through planned operation.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an example of a rapid filtration system using an embodiment of the automatic cleaning device for a suitable area for rapid filtration according to the present invention, and Fig. 2 is an example of filtration loss head pressure change in the area suitable for rapid filtration shown in Fig. 1. FIG. 3 is a flowchart showing an example of processing when deciding to start cleaning. 3...Washing water pump 6...Rapid filtration suitable area 7...Differential pressure transmitter 10...Filtration riser 11...Washing valve 12...Prediction section 13...Preliminary cleaning determination section, cleaning Control unit (cleaning control/sequence control unit)

Claims (1)

[Claims] (1) In an automatic rapid filtration basin cleaning device that selects and cleans the rapid filtration basin that requires cleaning when it becomes necessary to clean each rapid filtration basin that filters raw water, each of the above-mentioned rapid filtration When the prediction unit detects the filtration state of the pond and predicts the cleaning start time, and the cleaning start time of each rapid filtration basin obtained by this prediction unit overlaps, the one that satisfies the preliminary cleaning condition is targeted for preliminary cleaning. A rapid filtration basin characterized by comprising: a pre-cleaning determining unit that determines the timing and advances the cleaning time; and a cleaning control unit that performs preliminary cleaning of each rapid filtration basin based on the determination result of the preliminary cleaning determining unit. automatic cleaning equipment.