JP3214058B2 - Sand basin control method by fuzzy inference - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art A sedimentation basin is a facility that sediments and removes sediment in sewage by gravity sedimentation by reducing the flow rate of inflow sewage.

[0003] Generally, the substance that precipitates is 0.2-0.4.
mm, the average flow velocity of the sand basin depends on the specific gravity of the sedimentary substance, but is about 15 to 30 cm / sec. If it is too much, organic substances having a low specific gravity will precipitate, which will rot and give off an odor. Therefore,
The mechanical equipment of the sand basin includes: Screen equipment for removing relatively large suspended matter such as floating dust, fibers, rods, etc. in the inflow sewage, and sediment collected at the bottom of the sand basin. There is a sand removal facility for removing ash.

[0004]

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

[0005] Since the operating time is fixed despite the quality of the incoming sewage fluctuating due to rainfall conditions, etc.,
Optimum removal of sand and sediment cannot be achieved.

[0006] Frequent time-scheduled operation can prevent decay of the sedimented material and clogging of the screen, but causes a reduction in the life of the mechanical equipment and an increase in the amount of electric power used. , Infrequent time-scheduled operation may cause decay of sedimented substances and clogging of screen equipment, increase the qualitative load on the downstream treatment processes such as pump equipment, induce deterioration and inhibition of functions, and consequently water quality Exacerbate the deterioration.

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

[0008]

Means for Solving the Problems The operation time of the screen equipment and sand removal equipment of the sand basin and the operation cycle operation time are determined by the average rainfall intensity of the rainfall area flowing into the sand basin,
The rainfall time, the seasonal function, the integrated discharge rate of the sand basin, and the integrated operation time of each facility are determined by fuzzy inference as a phenomenon item of the membership function.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram showing the construction of a sand basin control system according to the present invention.

A settling basin 1 is provided with an inflow sewage 13 into which sewage flows in on both side ends thereof, and a pump well 12 which is temporarily stored by a pump facility 9 for pumping to a later-stage water treatment facility 11. , Screen equipment 1 that is a sand basin equipment
a and sand removal equipment 1b. 2a and 2b are fuzzy inference means for determining the operation time and operation cycle time of the screen equipment 1a, sand removal equipment 1b, and 3 are average rainfall intensity 3a, rainfall time 3b, and seasonal function which are phenomena of membership functions in fuzzy inference. Operator setting means for setting 3c, and control operating means 4a and 4b for controlling the operation of the sand basin equipment 1a and 1b based on the operation time and the operation cycle time determined by the fuzzy inference means 2a and 2b. 5a and 5b are control operation means 4
operating time setting means for setting the operating time to a, 4b, 6
Reference numerals a and 6b denote operation cycle time setting means for setting operation cycle times in the control operation means 4a and 4b.

And, 7a and 7b are sand basin facilities 1a and 1b.
This is a driving time detecting means for detecting the driving state of b and integrating the driving time to make the driving integrated time a phenomenon item of the membership function in the fuzzy inference means 2a, 2b. Reference numeral 10 denotes a flow rate detection means 9b which detects a discharge flow rate from a sand basin (pump well 12) by a pump 9a to a water treatment facility 11 at a subsequent stage, and calculates a discharge integrated flow rate obtained by integrating the detected discharge flow rate in the fuzzy inference means 2a, 2b. This is a discharge flow rate integrating means for setting 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. 1 as described above. The amount of relatively large suspended matter removed by the screen facility 1a, which is a sand basin facility, is empirically determined by the amount of sewage flowing into the sand basin 1 through the inflow channel 13 and its quantitative change. Things. Similarly, the amount of the sediment removed by the sand removal equipment 1b is also substantially determined by the amount of sewage flowing into the sand basin 1 and its quantitative change. Therefore, the amount of suspended matter and sediment in the sedimentation basin 1 can be inferred from the amount of inflow of sewage flowing in and its quantitative change,
It is generally difficult to directly measure and observe these inflows and their quantitative fluctuations.

In view of the above, the present invention relates to a method of controlling the amount of sewage flowing into
Indirect determination is made based on the integrated discharge flow rate obtained by integrating the discharge flow rate discharged to the first area, and the quantitative fluctuation (change amount) of the inflow rate is determined by the average rainfall intensity, rainfall time, seasonal function, etc. This is indirectly determined from the situation.

[0014]

As described above, the operation time (TA) and the operation cycle time (S) of the screen equipment 1a of the sand basin equipment
A) and the operation time (TB) and operation cycle time (SB) of the sand removal facility 1b are respectively 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 removal equipment 1b are respectively set by the respective setting means 5a, 5b and 6a, 6b.
It is operated by the control operation means 4a, 4 set by.

The operation time (T) of each of the facilities 1a and 1b
A) and (TB) detect the operation time of each facility (7a,
7b), the accumulated (8a, 8b) accumulated operation time (T
S) and (TC) make it possible to minimize the operation time.

[0017]

As described above, according to the sand basin control method based on the fuzzy inference according to the present invention, each facility is optimally operated according to the amount of suspended matter and sediment in the sand basin. The following effects are obtained.

[0018] 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 decay of the precipitated substance,
Accidents caused by blockage of the pump can be prevented.

Unnecessary operation of the sand basin equipment can be eliminated, so that the operation time and the number of operation times can be reduced macroscopically, and the service life and energy saving including the related equipment can be extended. .

Since fuzzy inference is used, a flexible algorithm can be constructed, and its rules can be easily changed or modified.

[Brief description of the drawings]

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

[Explanation of symbols]

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

Continuation of front page (56) References JP-A-3-166601 (JP, A) JP-A-3-91002 (JP, A) JP-A-3-184101 (JP, A) JP-A-1-246601 (JP) JP-A-3-91805 (JP, A) JP-A-4-98502 (JP, A) JP-A-2-131181 (JP, A) JP-A-3-134704 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B01D 21/00-21/34 G05B 1/00-21/02

Claims (1)

(57) [Claims] 1. A sediment provided with a screen facility and a sand removal facility.
The sewage of the sand pond is sent to the downstream equipment via the pump equipment, and
Fuzzy equipment, screen equipment and sand removal equipment
Control means for operating based on the output signal of the logical means
In those prior to detecting an operating condition of said screen and facilities removal sand facilities
Output to fuzzy inference means as phenomenon items
Operating time detecting means, and water
Detects and integrates the discharge flow rate of the oil and the phenomenon occurs in the fuzzy inference means.
Discharge flow integrating means for outputting as an item;
Phenomenon item of membership function in inference means
An operator that sets the average rain intensity, rain time, and seasonal function
Data setting means and each current input to the fuzzy inference means.
The operation cycle time is set using the
Operation system that outputs to each control
Cycle time setting means and the fuzzy inference means.
The operation time is set using the respective phenomenon items
During operation to output to each control and operation means of recirculation equipment and sand removal equipment
Sand basin control device characterized by comprising a space setting means
Place .