JPH10151478A - Operation control method for aerating and stirring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continuously carry out proper water treatment by comparing standard data of normal operation of an aerating and stirring apparatus during a prescribed period with the aerating and stirring motive power data at the time of operation at real time and judging that a DO meter is abnormal and switching to a prescribed protective operation in the case the fluctuation width is the flowing-in load fluctuation or higher. SOLUTION: Proper aerating and stirring motive power data including the aeration time to the wastewater flowing-in amount is recorded as the standard data at the time of normal operation during a prescribed period in a control apparatus 5. The standard data and the measured data during a prescribed period are compared with each other at real time and in the case the fluctuation width is higher than the flowing-in load fluctuation, it is judged that abnormality due to a trouble of a DO meter 4 or a sensor 3 for the DO meter 4 occurs. Then, switching to the protective operation by a prescribed program is carried out and the protective operation is continuously carried out until normal operation is re-started by a recovering work. Consequently, highly reliable water treatment can be carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the operation of an aeration stirrer, and in particular, when the aeration stirrer is operated for water treatment based on a measured DO value, the DO meter may fail due to some effect such as failure. Also, the present invention relates to an operation control method of an aeration stirrer capable of detecting a failure of a DO meter at an early stage and performing an appropriate aeration process continuously even when an accurate DO value cannot be detected.

[0002]

2. Description of the Related Art Conventionally, in an aeration tank for performing biological treatment of sewage and the like, the sewage is aerated by an aeration agitator installed in the aeration tank, and the dissolved oxygen concentration in the sewage (in this specification,
It is called "DO value". ) To improve. In this aeration method, maintaining an appropriate DO value is a very important factor for effective biological treatment. For this reason, conventionally, a DO meter sensor is installed in the sewage to measure the DO value of the sewage, the measured value is compared with a preset DO value, and the measured value exceeds the upper limit of the set value. Has automatically performed an operation of stopping the aeration stirrer and operating the aeration stirrer when the value is lower than the lower limit, and continuously aerated the wastewater.

[0003]

In the above-mentioned method for controlling the operation of the conventional aeration stirrer, the measured DO value, which is a reference for the aeration operation control in the biological treatment of sewage, is measured by using one DO meter installed in the aeration tank. Since the measurement was performed by the sensor, this DO meter failed due to some influence, or the sensor membrane was damaged by sewage, and the sensor was damaged due to entanglement of impurities in the sewage. In some cases, accurate DO value measurement by the DO meter may not be possible. However, even when such accurate DO value measurement is not possible, the operation of the aeration stirrer is controlled based on the measured DO value during the period of automatic operation, so that appropriate water treatment is not performed. There was a problem. There is also a method of determining the failure of the DO meter using another sensor. However, this method cannot detect whether or not the other sensor has failed.
There has been a problem that it may not be possible to determine whether the DO meter is normal.

[0004] The present invention solves the above-mentioned problems of the conventional operation control method of the aeration stirrer, and detects a failure or the like of the DO meter at an early stage so that appropriate water treatment can be continuously performed. An object of the present invention is to provide an operation control method of a stirrer.

[0005]

In order to achieve the above object, a method for controlling the operation of an aeration stirrer according to the present invention is a method for controlling the operation of an aeration stirrer in which the aeration stirrer is operated based on a measured DO value. The aeration / stirring power data within a predetermined period in a normal operation state is recorded as reference data, and the reference data and the aeration / stirring power data during operation of the aeration stirrer are compared in real time. Is switched to the protection operation that is set in advance when the abnormality is detected.

Thus, the reference data within a predetermined period in the normal operation state of the aeration stirrer and the aeration / stirring power data (measurement data) during the actual operation of the aeration stirrer are compared in real time, and the fluctuation range is compared. If the fluctuation is larger than the inflow load fluctuation, it is determined that an abnormality has occurred due to a failure of the DO meter itself or a sensor of the DO meter, and the protection operation can be immediately switched to the predetermined protection operation, so that the water treatment can be appropriately performed.

In this case, after the abnormality is detected, the measurement D
The operation based on the O value can be switched to the protection operation based on a preset timer operation.

[0008] Thus, the aeration stirrer can be continuously operated without stopping, and the water treatment can be properly continued, and at the same time, the recovery operation can be performed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for controlling the operation of an aeration stirrer will be described below with reference to the drawings. An aeration agitator 2 for aerating sewage is installed in a circulation channel of an aeration tank 1 having a circulation channel. The type, the number of units, and the position of the aeration stirrer 2 are determined so that biological treatment by aeration of wastewater is properly performed. Therefore, the aeration stirrer 2
Is a screw type aerator in the illustrated embodiment, but may be any type.

Further, a DO meter 4 for detecting the DO value of sewage is installed in a circulation channel in the aeration tank 1. This D
The sensor 3 of the O meter 4 is provided in the circulation channel so that the DO value of the sewage in the aeration tank 1 can be measured. In this case, the sensor 3 is desirably installed at a position that is a half turn from the aeration stirrer 2 in the circulation channel, that is, a boundary position between the aerobic zone and the anaerobic zone. Then, the measured DO value measured by the sensor 3 is sent from the DO meter 4 to the control device 5 that controls the aeration stirrer 2.

Next, an operation method of the aeration stirrer will be described. In order to control the aeration stirrer 2 based on the DO value of the sewage, it is necessary to operate at a highly reliable DO value.
Further, it is necessary to immediately detect an abnormality in the DO value and perform an appropriate aeration operation. Therefore, the amount of wastewater inflow
As appropriate aeration stirring power data including the aeration time, a predetermined period, for example, for the past week or 10 days,
It is recorded in the control device 5 as reference data during normal operation.
The inflow amount is normally stored for each treatment plant.

During operation of the aeration stirrer, the DO value of the sewage in the aeration tank 1 is always measured by the sensor 3 and the measured DO value is sent from the DO meter 4 to the control device 5 for controlling the aeration stirrer 2. input.

That is, in this embodiment, the operation of the aeration stirrer 2 is controlled based on the DO value measured by the sensor 3 at the boundary position between the aerobic and anaerobic zones. 4 transmits a signal for stopping the operation of the aeration stirrer 2 when the measured DO value exceeds a predetermined DO value, and this signal is transmitted to the control device 5, from which the operation of each aeration stirrer 2 is stopped. When the measured DO value becomes smaller than the predetermined DO value after stopping the aeration stirrer 1, the aeration stirrer 2 is stopped.
A signal for starting the operation of the controller 5 is transmitted.
The operation of each aeration stirrer 2 is started from there. The present invention can be applied to intermittent operation of the aeration stirrer in addition to such zone operation.

The reference data and data measured within a predetermined period are compared in real time. If the fluctuation range is larger than the inflow load fluctuation, an abnormality due to a failure of the DO meter 4 itself or the sensor 3 of the DO meter 4 is detected. Is determined to have occurred. By the way, if an accurate DO value is not transmitted to the aeration stirrer 2,
Since the aeration stirrer 2 operates based on the inappropriate DO value, the aeration tends to be excessive or insufficient, and appropriate water treatment is hindered. To prevent this from happening, the control operation based on the DO value is switched to a protection operation according to a predetermined program, for example, switching to a timer operation to prevent the water treatment from being performed improperly. Activate an alarm bell, etc., to notify the administrator of the abnormality and promptly perform the recovery work. Since the inflow of sewage is normally stored for each treatment plant, the inflow load fluctuation can be easily grasped. Further, this protection operation is an emergency operation until restoration, and is continued until normal operation is resumed by the restoration work.

FIG. 2 shows a specific example of a method for determining a power change abnormality. [Case (1)] Aeration and stirring power is 130% of that of the previous day
If it is not less than 70% or less, it is determined to be abnormal, and the operation is switched to the protection operation. [Case (2)] When a state in which the aeration / stirring power rises or falls relatively large for two or three days continues, it is determined to be abnormal and the operation is switched to the protection operation. [Case (3)] When the state in which the aeration and stirring power gradually increases or decreases continues for 5 days, it is determined to be abnormal, and the operation is switched to the protection operation. [Case (4)] When the DO total 4 itself determines a failure, switch to the protection operation.

[0016]

According to the present invention, the aeration / stirring power data during a predetermined period in the normal operation state of the aeration / stirring machine and the aeration / stirring power data during the actual operation of the aeration / stirring machine are compared in real time. If the fluctuation width is larger than the inflow load fluctuation, it is determined that an abnormality has occurred due to a failure of the DO meter itself or a sensor of the DO meter, and the protection operation can be immediately switched to the predetermined protection operation, so that highly reliable water treatment is performed. be able to. In addition, when an abnormality is detected, the recovery operation can be performed by switching to the protection operation using a preset timer, so that the aeration does not become insufficient or excessive during the protection operation. Can be performed continuously.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of a facility for implementing an operation control method of an aeration stirrer of the present invention.

FIG. 2 is an explanatory diagram showing an example of a power change abnormality determination method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Aeration tank 2 Aeration mixer 3 DO sensor 4 DO meter 5 Control device

Claims (2)

[Claims] In an operation control method of an aeration stirrer in which the aeration stirrer is operated based on a measured DO value, aeration agitation power data within a predetermined period when the aeration stirrer is in a normal operation state is recorded as reference data, The reference data and the aeration / stirring power data at the time of operation of the aeration / stirring machine are compared in real time, and when an abnormality of the DO meter is detected from the fluctuation range, the protection operation is switched to a preset protection operation. Operation control method. 2. A method for controlling the operation of an aeration stirrer, comprising switching from operation based on a measured DO value to protection operation using a preset timer operation after an abnormality is detected.