JP4565680B2 - Variable speed underwater electric stirrer - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a variable-speed submersible electric stirring apparatus used in a stirring tank having an unstable inflow condition and a large water level fluctuation range such as a flow rate adjusting tank of a water treatment facility.
[0002]
[Prior art and its problems]
Conventionally, an underwater electric mixer having a capacity sufficient to obtain sufficient agitation when the tank is full has been continuously operated at a rating. For this reason, in an agitation tank where the inflow conditions are unstable and the water level fluctuation range is large, such as a flow adjustment tank of a water treatment facility, the agitation flow rate in the tank gradually increases as the water level becomes lower, and the water level in the tank rises and the mixer suction port A large amount of air is sent to the treated water by sucking vortex from the air, etc., and the anaerobic stirring that is the original purpose cannot be performed, adversely affecting the anaerobic treatment of the next process, and vortex sucking from the mixer suction port As a result, abnormal vibration occurs, leading to a serious accident such as breakage of the shaft or guide ring. Further, when the water in the tank is increased, the stirring flow rate in the tank gradually becomes slower as the water level becomes higher, so that the functions of preventing sedimentation of the sediment and homogenizing the liquid quality are lost. In this way, a mixer with a constant rotational speed cannot keep the stirring flow rate constant with respect to fluctuations in the water level, which is wasteful in energy, inefficient, wasteful in terms of power consumption, and increases running costs. become.
[0003]
OBJECT OF THE INVENTION
The object of the present invention is to continuously operate at a rotational speed corresponding to the fluctuation of the water level even in the agitation tank having a large fluctuation range of the water level, so that the agitation flow rate in the tank can be kept almost constant, and energy waste is reduced. It is an object of the present invention to provide a variable speed underwater electric stirring device that is efficient, can reduce power consumption, and has a low running cost.
[0004]
[Structure of the invention]
In the variable speed underwater electric stirrer according to the present invention, a plurality of water level sensors arranged so as to detect stepwise fluctuations in the water level in the stirring tank, and one of these water level sensors that senses the water level in the tank. and it receives a signal transmitted from the water level sensor corresponds to the water level of the sensing speed approximate to always substantially corresponding point on the setting curve previously determined so as to maintain a constant stirring velocity in the tank a controller to obtain as an inverter for transmitting a control signal corresponding to the water level of the sensing, the inverter supplies the frequency power corresponding to the signal receiving a transmission control signal from the control device, from the inverter It has a submersible motor that receives power and is driven at a rotational speed corresponding to fluctuations in the water level in the agitation tank, and an agitating blade that is fitted to the tip of the rotating shaft leading out of the submerged motor and rotates.
[0005]
[Action]
When the control device receives a transmission signal from one water level sensor that senses fluctuations in the water level in the agitation tank, the inverter is operated so as to obtain a rotation speed that approximates the corresponding point on the predetermined setting curve of FIG. transmits a control signal corresponding to the water level sensing, the control signal received inverter supplies frequency power corresponding to the signal in water motor, the water level of the water motor in the stirred tank receives power supply It is driven by the number of rotations corresponding to the fluctuation to cause a stirring action in the tank. When the inside of the tank becomes a low water level, the frequency power corresponding to the signal from the lower water level sensor that detected the lowering of the water level is supplied to the submersible motor and the stirring action is weakened by the low-speed rotation. Then, the frequency power source corresponding to the signal from the upper water level sensor that detected the rise in the water level is supplied to the submersible motor and the stirring action is strengthened by the high-speed rotation, and the stirring flow rate in the tank is kept relatively constant at all times. Will be drunk.
[0006]
【Example】
Hereinafter, description will be made with reference to the drawings of the embodiments.
[0007]
In FIG. 1, 1 is a stirring tank, 2... 2 are a plurality of water level sensors arranged so as to detect the fluctuation of the water level in the stirring tank 1 step by step. The type is used. A control device 3 is interposed between each water level sensor 2... 2 and an inverter 5 described later, and receives a transmission signal from each water level sensor 2. rotational speed approximate to the appropriate point on the settings of Figure 2 curve had to the inverter 6 so obtained to transmit a control signal corresponding to the water level of the sensing. 6 is an inverter that receives a control signal from the control device 3 and supplies a frequency power supply corresponding to the control signal. The submersible motor is preferably a direct current type, but the present invention can be applied even if it is an alternating current type. Reference numeral 7 denotes a stirring blade that is fitted to the rotating shaft leading end portion of the submersible motor 6 and rotates.
[0008]
When the control device 3 receives a transmission signal from one water level sensor 2 that senses a fluctuation in the water level in the agitation tank 1, a rotational speed approximating a corresponding point on the preset setting curve of FIG. 2 can be obtained. transmits a control signal corresponding to the water level of the sensing to the inverter, the control signal received by the inverter 5 supplies the frequency power corresponding to the signal in the water motor 6, water motor 6 by receiving the power source Is driven at a rotational speed corresponding to the fluctuation of the water level in the stirring tank 1 as shown in FIG. When the inside of the tank becomes a low water level, a frequency power source corresponding to a signal from the lower water level sensor 2 that has detected the lowered water level is supplied to the submersible motor 6 so that the submersible motor 6 rotates at a low speed and the stirring action is weakened. In addition, when the inside of the tank reaches a high water level, a frequency power source corresponding to the signal from the upper water level sensor 2 that has detected the rising water level is supplied to the submersible motor 6 so that the submersible motor 6 rotates at high speed and has a stirring action. As can be seen in FIG. 3, the stirring flow velocity in the tank is kept relatively constant at all times.
[0009]
【The invention's effect】
According to the variable speed underwater electric stirring device of the present invention, the stirring flow rate in the tank can be kept almost constant at all times in a continuous operation even in a stirring tank having a large water level fluctuation range, and efficient stirring work can be performed. The average rotational speed is lower than that of rated operation, so power consumption can be saved and the wear of moving parts is reduced, enabling longer life. Further, as a derivative effect due to the low-speed rotation at the low water level, the vortex is less sucked than in the rated operation, and the rotating shaft, the guide ring and the like are not damaged due to abnormal vibration. Furthermore, air entrainment at a low water level is reduced, and the anaerobic treatment of the next process in the water treatment facility is not adversely affected. As described above, the running cost can be reduced by the efficient operation, the maintenance is excellent, and the rotation speed does not depend on the power supply frequency. Therefore, the stirring blade can be used in the 50 Hz / 60 Hz region, and thus the manufacturing cost and There is also an advantage that inventory can be reduced.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating an embodiment of the present invention.
FIG. 2 is a diagram of a setting curve illustrating the relationship between the water level in the tank and the motor rotation speed at which the agitation in the tank and the flow velocity are always substantially constant during operation of the variable speed submersible electric stirrer according to the present invention.
FIG. 3 is a diagram illustrating the relationship between the water level in the tank and the stirring flow rate at each motor rotation speed during operation of the variable speed submersible electric stirring apparatus according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Stirring tank 2 Water level sensor 3 Control apparatus 5 Inverter 6 Underwater motor 7 Stirring blade

Claims (1)

A plurality of water level sensors arranged to detect the fluctuation of the water level in the agitation tank step by step, and a signal transmitted from one of these water level sensors that senses the water level in the tank, and receives the above-mentioned detection in response to the water level of, corresponding to the water level of the sensing to the inverter so that the rotational speed is always approximated substantially to the corresponding point on the predetermined set had been constant curves to keep constant stirring velocity in the tank is obtained A control device that transmits a control signal, an inverter that receives a transmission control signal from the control device and supplies a frequency power source corresponding to the signal, and receives power from the inverter to respond to fluctuations in the water level in the agitation tank A variable-speed submersible electric stirrer comprising: a submersible motor that is driven by the number of rotations; and a stirring blade that is fitted to a rotating shaft leading end of the submersible motor and rotates.

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