JPH0760015A - Sand sedimentation pond control based on fuzzy inference - Google Patents

Abstract

PURPOSE:To optimize the control of operation by deciding the time for operating sand sedimentation pond facilities and the operation cycle time by a fuzzy inference based on integrated discharge flow rate, average rainfall intensity, rainfall time and seasonal function as the phenomenal items of membership function. CONSTITUTION:The operating time 5a and operating cycle 6a of the screening equipment 1a of sand sedimentation pond facilities, and the operating time 5b and operating cycle time 6b of sand removal facilities 1b are decided by fuzzy inference means 2a, 2b of average rainfall intensity 3a, reinfall time 3b, seasonal function 3c and integrated discharge flow rate as phenomenal items. In addition, screening equipment 1a, sand removal facilities 1b are operated by respective controlled operating means 4a, 4b which are set by setting means 5a, 5b and 6a, 6b. Further, the operating times 5a, 5b for each facilities can be minimized by detecting (7a, 7b) the operating times 5a, 5b for each facilities and correcting the operating times by an integrated operating time obtained by integration (8a, 8b).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a settling basin control system for controlling a settling basin facility by a control device such as a process controller using fuzzy inference.

[0002]

2. Description of the Related Art A sand basin is a facility for removing sediment in sewage by gravity settling by slowing the flow velocity of inflowing sewage.

Generally, the substance that precipitates is 0.2 to 0.4.
Although it is an inorganic substance such as sand of about mm, the average flow velocity of the sedimentation basin is about 15 to 30 cm / sec although it depends on the specific gravity of the sedimentation substance. If it is too much, there is a problem that even an organic substance having a small specific gravity is precipitated, and it decomposes to give off an odor. Therefore,
Mechanical equipment of the sand basin includes :, Screen equipment for removing relatively large suspended matter such as floating dust, fibers, and sticks in the inflowing sewage, sedimentation material accumulated at the bottom of the sand basin There is sand removal equipment to remove the sand.

[0004]

However, in the conventional control method of the sand basin equipment, since the operating time of the equipment is fixedly determined in a predetermined time schedule, the following problems occur. There is.

The quality of the inflowing sewage is fixed because the operating time is fixed, although it varies depending on the rainfall.
The optimum removal of dust and sand cannot be performed.

The frequent time schedule operation can prevent the spoilage of the precipitated substance and the clogging of the screen, but it leads to the shortening of the life of the mechanical equipment and the increase of the power consumption. ， Infrequent time schedule operation causes spoilage of sedimentation substances and clogging of screen equipment, increasing qualitative load on the subsequent treatment process such as pump equipment, causing deterioration and inhibition of function, resulting in water quality. Increase the deterioration of.

The present invention has been made in view of such circumstances, and an object thereof is to obtain an optimum sand basin control system.

[0008]

Means and Actions for Solving the Invention The operation time and operation cycle operation time of the screen equipment and sand removal equipment of the sand basin are defined as the average rainfall intensity in the rainfall area of the rainwater flowing into the sand basin,
Rainfall time, seasonal function, accumulated discharge of sand basin, and accumulated operation time of each equipment are determined by fuzzy reasoning which is a phenomenon item of membership function.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic configuration diagram for implementing the sand basin control system of the present invention.

Reference numeral 1 denotes a sand basin, which is provided with an inflow port 13 into which sewage flows at both ends thereof, and a pump well 12 for temporarily storing the water for pumping it to a water treatment facility 11 at a subsequent stage by a pump facility 9. , A screen facility that is a sand basin facility 1
a and sand removal equipment 1b. 2a and 2b are fuzzy inference means for determining the operating time and operating cycle time of the screen equipment 1a and sand removal equipment 1b, and 3 is the average rainfall intensity 3a, rainfall time 3b, and seasonal function which are the phenomenon items of the membership function in the fuzzy inference. 3c is an operator setting means, and 4a and 4b are control operation means for controlling the operation of the sand basin equipment 1a, 1b by the operation time and the operation cycle time determined by the fuzzy inference means 2a, 2b. Further, 5a and 5b are control operation means 4
driving time setting means for setting the driving time to a and 4b, 6
Reference numerals a and 6b are operation cycle time setting means for setting the operation cycle time in the control operation means 4a and 4b.

And, 7a and 7b are sand basin facilities 1a and 1
It is a driving time detecting means for detecting the driving situation of b and using the cumulative driving time, which is the cumulative driving time, as the phenomenon item of the membership function in the fuzzy inference means 2a, 2b. Further, 10 is a member of the fuzzy inference means 2a, 2b which detects the discharge flow rate from the sand basin (pump well 12) by the pump 9a to the water treatment facility 11 at the subsequent stage by the flow rate detection means 9b, and integrates the discharge flow rate. The discharge flow rate integrating means is used as a phenomenon item of the ship function.

Next, the method of the present invention will be described with reference to the block diagram of the sand basin control shown in FIG. The amount of relatively large suspended matter removed by the screen facility 1a, which is a sand basin facility, is empirically determined by the inflow amount of sewage flowing into the sand basin 1 through the inflow channel 13 and its quantitative change amount. It is a thing. Further, the amount of the sedimentation substance removed by the sand removing facility 1b is also substantially determined by the inflow amount of the sewage flowing into the sand basin 1 and its quantitative change amount. Therefore, the amount of suspended solids and sedimented substances in the sand basin 1 can be inferred from the inflow amount of inflowing sewage and its quantitative change amount.
It is generally difficult to directly measure and observe these inflows and their quantitative fluctuations.

Therefore, according to the present invention, the inflow amount of the sewage flowing into the sand basin 1 is determined by the pump equipment 9 in the subsequent stage of the water treatment equipment 1.
Indirect judgment is made by the integrated discharge flow rate that integrates the discharge flow rate discharged to 1 and the quantitative fluctuation (change amount) of the inflow is determined by the average rainfall intensity, rainfall time, seasonal function, etc. in the rainfall area of the inflowing rainwater. It is determined indirectly from the situation.

Table 1 explains the fuzzy inference in the settling basin control method of the present invention, and Table 2 shows an example of the control rules.

As described above, the operating time (TA) and operating cycle time (S) of the screen equipment 1a of the sand basin equipment
A), and the operating time (TB) and operating cycle time (SB) of the sand removal facility 1b are the average rainfall intensity (AR),
Fuzzy inference means 2a, 2b based on phenomenon items such as rainfall time (AT), seasonal function (AK), and discharge integrated flow rate (FQ).
The screen equipment 1a and the sand removing equipment 1b are determined by the respective setting means 5a, 5b and 6a, 6b.
It is operated by the control operation means 4a, 4 set by.

Then, the operating time (T
A) and (TB) detect the operating time of each equipment (7a,
7b), integrated (8a, 8b) integrated operating time (T
It is possible to minimize the operating time by correcting the values according to S) and (TC).

[0017]

As described above, according to the settling basin control system by fuzzy reasoning according to the present invention, each facility is optimally operated according to the amount of suspended solids and settling in the settling basin. It has the following effects.

The load of the water treatment process downstream of the sand basin can be reduced and the quality of treated water can be improved.

, Prevention of odor due to putrefaction of the precipitated substance,
Accidents due to blockage of the pump can be prevented.

Since unnecessary operation of the settling basin equipment can be eliminated, it is possible to shorten the operating time and the number of times of operation from a macro perspective, and it is possible to extend the service life of the related equipment and save energy. .

By using fuzzy inference, a flexible algorithm can be constructed, and the rule can be easily changed or modified.

[Brief description of drawings]

FIG. 1 is a configuration diagram for implementing a sand basin control system of the present invention.

[Explanation of symbols]

 1: sand set basin 1a: screen equipment 1b: sand removal equipment 2a: fuzzy inference means for screen equipment movement 2b: fuzzy inference means for sand removal equipment movement 3: operator setting means 4a: screen equipment operation control operation means 4b: sand removal equipment Operation control operation means

Claims (2)

[Claims] 1. A sand basin control method for determining the operating time and operating cycle time of a sand basin facility by fuzzy inference means, wherein the integrated discharge flow rate of the sand basin and the average rainfall intensity in a rainy area of rainwater flowing into the sand basin, A sedimentation basin control system, characterized in that the rainfall time and the seasonal function are used as the phenomenon items of the membership function of the fuzzy inference means. 2. The sand basin control system according to claim 1, wherein the operation cumulative time of the sand basin equipment is added as a phenomenon item of the membership function of the fuzzy inference means.