JP4846666B2 - Automatic dust remover - Google Patents

Description

  TECHNICAL FIELD The present invention relates to rake standby position stop control in an automatic dust remover, and in particular, the structure of an automatic dust remover is simplified by eliminating the need for a structure to which a limit switch or proximity switch is attached, and the switch power supply, control wiring, and switches. The present invention relates to an automatic dust remover that can eliminate the need for maintenance.

There is an automatic dust remover as a facility for removing dust (sediment) contained in inflow sewage in a sand basin of a sewage treatment plant or a pumping station.
This automatic dust remover includes an intermittent type with one rake and a continuous type with multiple rakes depending on the number of rakes.

Depending on the installation conditions, the automatic dust remover does not always operate the rake, but operates according to an “operation command” when necessary.
In such an intermittent automatic dust remover, when the rake is not operated, the rake is kept at a standby position in the air.
This is because if the rake is kept in the water, there is a problem that dust is caught on the rake or the water flow is obstructed.

In this way, in the intermittent automatic dust remover, the rake is kept in the air when the device is stopped, but this standby position is always constant, and the position is called “fixed position”. .
In order to stop the rake moving up and down along the guide rail at this fixed position, conventionally, the position of the rake 2 is detected by using the mechanical limit switch 11 and the striker 12 shown in FIG. 8 or the proximity switch. As shown in the flowchart of FIG. 6B, control for stopping the rake was performed.

  However, in such a conventional automatic dust remover, the structure is complicated to attach a mechanical limit switch and proximity switch, and the power supply and control wiring of the switch are also required. There is a problem that a special structure having corrosion resistance is required, which is relatively expensive and requires a long delivery time, and also requires maintenance of switches.

  In view of the problems of the conventional automatic dust remover, the present invention simplifies the structure of the automatic dust remover by eliminating the need to attach a limit switch or a proximity switch, as well as the switch power supply, control wiring, and switches. An object of the present invention is to provide an automatic dust remover that can eliminate maintenance.

  In order to achieve the above object, an automatic dust remover according to the present invention is an automatic dust remover in which an annular rake is moved up and down along a bar screen and the residue captured by the bar screen is scraped up. Detects fluctuations in current, power, or power factor due to fluctuations in the load of the motor that drives the rake, and determines whether the rake is on the up side or down side based on the detected fluctuations in the current, power, or power factor. A rake fixed position stop device is provided that stops the rake at a fixed position for standby on the basis of a point in time when it is confirmed that the shift has been made to the descending side.

  In this case, the rake fixed position stopping device can stop the rake after a predetermined time has elapsed since it was confirmed that the rake has shifted from the ascending side to the descending side.

  According to the automatic dust remover of the present invention, in the automatic dust remover that raises and lowers the circulatory rake along the bar screen so as to lift up the residue captured by the bar screen, the motor for driving the rake is provided. Detects current, power, or power factor fluctuations due to load fluctuations, and determines whether the rake is on the upside or downside based on the detected current, power, or power factor fluctuations, and the rake shifts from the upside to the downside. Since it is equipped with a rake fixed position stop device that stops the rake at a fixed position for standby on the basis of confirming that it has been confirmed, an automatic dust remover eliminates the need for mechanical limit switches, proximity switches, and structures for attaching them. Simplifies the structure of the switch, eliminates the need for switch power supply, control wiring, and switch maintenance. Equipment used to output such a general-purpose products, are readily available at relatively low cost and short delivery time.

  In addition, the rake fixed position stop device can easily stop the rake at the fixed position in the standby state by stopping the rake after a predetermined time has elapsed from the time when it is confirmed that the rake has shifted from the rising side to the lowering side. .

  Embodiments of an automatic dust remover according to the present invention will be described below with reference to the drawings.

1 to 7 show an embodiment of the automatic dust remover of the present invention.
This automatic dust remover lifts and lowers a rake 2 that circulates around the rack 4 along the bar screen 1 and scrapes the residue captured by the bar screen 1.
And this automatic dust remover detects the fluctuation | variation of the electric current by the fluctuation | variation of the load of the electric motor 10 which drives the rake 2, determines whether the rake 2 is the rising side or the lowering side by the detected fluctuation of the current, Is provided with a rake fixed position stop device (not shown) for stopping the rake 2 at the standby fixed position A with reference to the time point when it is confirmed that the rake has shifted from the rising side to the lowering side.
Here, instead of the current fluctuation of the electric motor 10, the fluctuation of the electric power or the power factor is detected, and it is also possible to determine whether the rake 2 is the rising side or the lowering side based on the detected fluctuation of the electric power or power factor. it can.

  The automatic dust remover is not particularly limited, but a bar screen 1 in which strip-shaped steel bars are arranged and fixed at a predetermined interval is attached to the inflow side of the sand basin, and is arranged at the front stage of the bar screen 1. A rack 4 for raising and lowering the rake is provided on the guide frame 8 provided, and a drive pinion 5 is provided so as to mesh with the rack 4.

The drive pinion 5 is attached to both ends of the rake shaft 7 attached to the first arm 6 of the rake 2 so as to be driven by the electric motor 10.
A second arm 9 is connected to the first arm 6, and a rake 2 having rake teeth 3 inserted into the screen eyes of the bar screen 1 is attached to the tip of the second arm 9.

  When the rake 2 moves up and down with the drive pinion 5 meshed with the rack 4, the rake teeth 3 are inserted into the screen of the bar screen 1 when the rake 2 is raised, and are captured by the bar screen 1. The residue is lifted up, and on the contrary, the rake teeth 3 are lowered and separated from the screen of the bar screen 1 when lowered.

On the other hand, the rake fixed position stop device comprises a current (power, power factor) detector, sequencer, etc., as shown in FIGS. 6 (a) and 7, without using mechanical limit switches or proximity switches, This is a system in which the position of the rake 2 is detected only by electrical control and stopped at a fixed position A.
The rake 2 has its own weight of about 300 kg depending on the specifications of the automatic dust remover, and the motor load at the time of ascent and descent is different.
When the rake 2 is raised, power for raising its own weight is required, but when it is lowered, it is lowered by its own weight, so the power becomes smaller.
In this way, a change in current (power, power factor) due to a difference in required power at the time of ascent and descent is detected, and it is determined whether the position of the rake 2 is on the ascending side or the descending side.

  In addition, since the fixed position A of the rake 2 is normally the upper part on the lowering side, when it is confirmed that the rake 2 has shifted from the rising side to the lowering side, more specifically, in the present embodiment, FIG. As shown in FIG. 6A and FIG. 7, when the current value of the motor 10 is equal to or higher than the set value H, it can be confirmed (determined) that the rake 2 is rising, and the current value of the motor 10 is set to the set value. Since it can be confirmed (determined) that the rake 2 has shifted from ascending to descending by lowering to L or less, the time when the current value of the electric motor 10 has decreased to the setting value L or less (even in the case of fluctuations in power or power factor) Similarly, the motor 10 is stopped after a predetermined time t (specifically, about several seconds to 20 seconds) measured by a timer from when the value falls below a preset value), and the rake 2 is set to a predetermined value. Stop at position A.

  Thus, the automatic dust remover of the present embodiment is an automatic dust remover in which the rake 2 that circulates in an annular shape is moved up and down along the bar screen 1 and the residue captured by the bar screen 1 is lifted up. , A change in current, power, or power factor due to a change in load of the motor 10 that drives the rake 2 is detected, and it is determined whether the rake 2 is on the rising side or the lowering side based on the detected change in current, power, or power factor. Since it is equipped with a rake fixed position stop device that stops the rake 2 at the standby fixed position A on the basis of confirming that the shift from the ascending side to the descending side is performed, a mechanical limit switch, a proximity switch, and these are provided. The structure of the automatic dust remover is simplified by eliminating the need for mounting, and the switch power supply, control wiring, and switch maintenance are not required. Rukoto can also equipment used in the current detection, etc. are general-purpose products, are readily available at relatively low cost and short delivery time.

  Further, the rake fixed position stop device stops the rake 2 at a fixed position for standby easily by stopping the rake 2 after a predetermined time has elapsed since it was confirmed that the rake 2 has shifted from the ascending side to the descending side. be able to.

As mentioned above, although the automatic dust remover of the present invention has been described on the basis of the embodiments thereof, the present invention is not limited to the configurations described in the above embodiments, and the configuration is appropriately changed without departing from the spirit thereof. can do.
For example, in the present embodiment, the rake is circularly rotated by the rack and the drive pinion, but the rake can also be circularly rotated by the sprocket and the chain.

  The automatic dust remover of the present invention has the characteristics that the structure of the automatic dust remover is simplified by eliminating the need for a limit switch or proximity switch mounting structure, and the switch power supply, control wiring, and switch maintenance are not required. Therefore, it can be used widely and suitably for, for example, an automatic dust remover for sewers.

It is sectional drawing which shows one Example of the automatic dust remover of this invention. It is sectional drawing which shows the upper part of the automatic dust remover. It is sectional drawing which shows the lower part of the automatic dust remover. It is a front view which shows the lower part of the automatic dust remover. It is a top view which shows the bar screen and rake of the automatic dust remover. Rake fixed position stop control is shown, (a) is a flowchart showing the control of the rake fixed position stop device of the present invention, (b) is a flowchart showing the conventional control. It is a schematic diagram which shows the fluctuation | variation of the electric current of the electric motor in the automatic dust remover. The conventional automatic dust remover is shown, (a) is a top view which shows a limit switch and a striker, (b) is the same front view.

Explanation of symbols

1 Bar screen 2 Rake 3 Rake teeth 4 Rack 5 Drive pinion 6 First arm 7 Rake shaft 8 Guide frame 9 Second arm 10 Motor A Fixed position

Claims (2)

  In an automatic dust remover that raises and lowers a rake that circulates in an annular shape along a bar screen and scrapes the residue collected by the bar screen, the current, power, or power factor due to the fluctuation of the load of the motor that drives the rake As a reference, it is determined whether the rake is on the rising side or the lowering side based on the detected current, power, or power factor fluctuation, and confirming that the rake has shifted from the rising side to the lowering side. An automatic dust remover provided with a rake fixed position stop device for stopping the rake at a fixed position for standby.   2. The automatic dust remover according to claim 1, wherein the rake fixed position stop device stops the rake after a predetermined time has elapsed since it was confirmed that the rake has shifted from the rising side to the lowering side.

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