JPH05205A - Settled grit scraping-up machine - Google Patents

Abstract

PURPOSE:To eliminate the need for a worker and to prevent generation of overload in a turning device by performing elevating/lowering control so that the height of a scraping-up face is lowered until driving torque is raised larger than an intermediate torque level when a state wherein the driving torque is lowered smaller than a low torque level is continued for a specified time. CONSTITUTION:Driving torque of a turning device 6 is detected by a torque detector 7 and gradually lowered according to scraping-up of settled grit 31 by a bucket 2. When a state wherein driving torque is lower than a low torque level is continued for a specified time, an elevating/lowering controlling device 25 outputs a command signal of lowering to an elevating/lowering device 21. Therefore the height of a scraping-up face 3 is gradually lowered and the bucket 2 gradually bites into the settled grit 31 and driving torque is gradually raised. When the bucket 2 bites into grit 31 and driving torque is raised larger than an intermediate torque level, the controlling device 25 releases the command signal of lowering. Therefore, the elevating/lowering device 21 is stopped in this state and the driving torque of the turning device 6 is gradually lowered according to scraping up of settled grit 31. Thereafter this is automatically repeated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sand settler,
In particular, the present invention relates to a control method for a lifting device of a sand rake.

[0002]

2. Description of the Related Art In a sewage treatment plant, a pumping plant, etc., a bucket conveyor having a plurality of buckets mounted therein is arranged in a sand basin, and a rotating device for rotatably driving the bucket conveyor and a lifting surface of the bucket conveyor. A sand settling machine provided with an elevating device for driving the elevating and lowering device is used. This settling sand scooping machine lifts the height of the scraping surface gradually and scoops up the sand sediment by the lifting device while rotating the bucket conveyor by the rotating device. A level meter that detects the height and a limit switch that detects the upper and lower limits of the scooping surface are attached to the lifting device, and the leveling and the limit switch are monitored while taking into consideration the amount of sand settled on the day and the like. I was driving with the surface height gradually decreasing.

[0003]

The operation control of the above-mentioned conventional settling sand raker relies on a human can in the end, and therefore requires a worker, and sometimes the rake face is excessively lowered. , The bucket digs deep into the sand set and the motor output of the rotating device exceeds the rated value. As a result, the rotating device is stopped due to overload and the work of setting sand is interrupted or the rotating device is damaged. There was a fear. Therefore, an object of the present invention is to provide a sand raker that does not require an operator and does not overload the rotating device.

[0004]

The present invention has been made to achieve the above object, that is, a bucket conveyor having a plurality of buckets mounted therein is arranged in a sand basin and the bucket conveyor is rotatably driven. In a settling sand rake provided with a moving device and a lifting device that drives the height of the scraping surface of the bucket conveyor to move up and down, a torque detection device that detects the drive torque of the rotating device, and a detection by the torque detection device When the drive torque lower than the low torque level continues for a certain period of time, the height of the scraping surface should be lowered until the drive torque rises above the intermediate torque level higher than the low torque level. And a lifting control device for issuing a descending command signal to the lifting device.

[0005]

When the height of the scraping surface of the bucket conveyor is lowered until the driving torque of the rotating device detected by the torque detecting device indicates the intermediate torque level, the bucket bites into the set sand and lifts the set sand. The driving torque of the rotating device gradually decreases as the sand is lifted. When the state where the driving torque is lower than the low torque level continues for a certain period of time, the lifting control device issues a descending command signal to the lifting device, so that the height of the scraping surface gradually decreases and the bucket gradually sediments. Drive torque gradually increases. When the bucket gets into the settling sand to a certain extent and the driving torque rises above the intermediate torque level, the lifting control device releases the descending command signal issued to the lifting device.
In that state, the lifting device stops, and the driving torque of the rotating device gradually decreases as the sand is lifted. Hereinafter, the above process is automatically repeated until the height of the lifting surface of the bucket conveyor reaches the lower limit position, thus requiring no worker,
Moreover, it is possible to scoop up the sediment without causing an overload on the rotating device.

[0006]

The present invention will be described with reference to the drawings. FIG. 1 is a schematic vertical sectional view of an embodiment of the present invention. A bucket conveyor 1 having a plurality of buckets 2 mounted therein is arranged in a sand basin 30, and the bucket conveyor 1 includes a drive sprocket 5a and a driven sprocket. The drive sprocket 5a is wound around 5b to 5j and is rotationally driven by the rotating device 6, and the drive torque of the rotating device 6 is detected by the load cell 7.

A driving arm 10 and a driven arm 15 are rotatably mounted on the sand basin 30 by shafts 11 and 16, and an underwater shaft 12 is mounted on one end of the driving arm 10. The driven sprocket 5i and one end of the wire 20 are attached to the submersible shaft 12. The other end of the drive arm 10 is rotatably attached to one end of a link rod 14 via a pivot 13. A driven sprocket 5h is attached to one end of the driven arm 15, and the other end of the driven arm 15 is rotatably attached to the other end of the link rod 14 via a pivot 17. The other end of the wire 20 is wound around the elevating device 21, and when the wire 20 is unwound by the elevating device 21 in this way, the drive arm 10 is mainly driven by the gravity acting on the bucket conveyor 1 between the driven sprockets 5h and 5i. The submersible shaft 12 and the driven sprocket 5i descend in the clockwise direction, the link rod 14 moves in the right direction in the drawing, and the driven arm 15 rotates in the clockwise direction in the drawing to have a shape parallel to the driven arm 10. Keep the driven sprocket 5h
Is lowered, and the scraping surface 3 of the bucket conveyor 1 between the driven sprockets 5h and 5i is lowered. Lifting device 2
When the wire 20 is wound up by 1, the submersible shaft 12 rises and therefore the scraping surface 3 also rises.

A limit switch 22 is attached to the lifting device 21 so that the submersible shaft 12 can be wound down to lift the bucket 2.
The lower limit switch operates in a state of being in contact with the floor surface under the settling sand 31, and the upper limit switch operates in a state where the submersible shaft 12 is fully wound and all the buckets 2 are kept above the water surface 32. . On the other hand, the settling sand 31 in the settling basin 30 is scraped up by the bucket 2 of the bucket conveyor 1 and washed by the wash water supplied through the electric motor valve 35 for washing, and the wastewater settling conveyor 36, the settling sand discharge conveyor 37, and the settling hopper. It is carried out via the input conveyor 38.

The output signals of the load cell 7 attached to the rotating device 6 and the limit switch 22 attached to the lifting device 21 are supplied to the lifting control device 25, and the output signals of the lifting control device 25 are fed to the lifting device 21. Is being supplied. The value Q of the turning torque supplied from the load cell 7 is compared with the four comparison values in the elevation control device 25. The comparison value in order from high, excessive torque level Q _HH, a high torque level Q _H, the intermediate torque level Q _M, and low torque level Q _L. Of these, the overtorque level Q _HH is an emergency stop of the lifting device 21 when the turning torque Q exceeds the value Q _HH , and is not particularly related to the present invention.

2 and 3 show a control method of the lifting control device 25. When a start command is issued (a in FIG. 2), it is judged whether or not the start condition is satisfied (the same b), and the condition is not satisfied. Sometimes operation is not started (same as c). In this embodiment, the rotating device 6 is not overloaded, the lifting device 21 is not overloaded, the wire 20 is not loose, and the submersible shaft 12 is not at the lower limit position. When all of the above are satisfied, it is judged that the starting condition is satisfied. When it is determined that the starting condition is satisfied, the rotating device 6 is started to rotate the bucket conveyor 1 (at d), and the electric motor valve for cleaning 35 is opened (at e).
The sewage settling conveyor 36, the settling discharge conveyor 37, and the settling hopper loading conveyor 38 are activated (at f, g, and h).

Thereafter, a command is issued to the elevating device 21 to wind down the underwater shaft 12 (at i), whether the underwater shaft 12 reaches the lower limit position (at j), or the driving torque Q is an intermediate torque level Q.
_Continue unwinding until it becomes larger than _M (same k).
Since the submersible shaft 12 does not reach the lower limit position immediately, at the beginning of lowering, the drive torque Q is the intermediate torque level Q _M
When it becomes larger than the lower limit, the lowering is stopped (the same l). In this state, the driving torque Q while discharging the sediment 31
Elevated condition T ₂ seconds, for example, several than reduced state T ₁ minute, for example, whether to persist for several minutes (at m), the drive torque Q is high torque level Q _H than but low torque level Q _L It is monitored whether it lasts for 2 seconds (the same n). When the former occurs, it means that the settling sand 31 to be scooped up at the height of the submersible shaft 12 at the present time is short, so the submersible shaft 12 is rewound (the same i), and the submersible shaft 1 is rewound.
The lowering is continued until either 2 reaches the lower limit position (same j) or the drive torque Q becomes larger than the intermediate torque level Q _M (same k).

On the other hand, when the latter, that is, the state where the drive torque Q is higher than the high torque level Q _H is maintained for T ₂ seconds, the submersible shaft 12 is temporarily moved to avoid overload of the drive device 6.
When the driving torque Q becomes lower than the intermediate torque level Q _M (same p), the winding is stopped (same q), and the driving torque Q becomes lower than the low torque level Q _L again. It is monitored whether the state lasts for T ₁ minute (the same m) or whether the state where the driving torque Q rises above the high torque level Q _H lasts for T ₂ seconds (the same n). However, the driving torque Q may be higher than the high torque level Q _H (the same n) when the sand is being scooped just above the intermediate torque level Q _M (the same k) (the same n), and there is no particular circumstance. It does not occur as long as possible. That is, this step (the same n, o, p,
q) is a protection loop for safely lifting the sand sediment, and unlike the case of the above-mentioned overtorque level Q _HH , the suspension of sand sediment by stopping the drive device 6 does not occur. Sand set 3
Depending on the nature of 1 etc., this step (the same n, o, p, q)
Can be omitted.

[0013] The above manner When the drive torque Q is a state of being lower than the low torque level Q _L persists T ₁ minute (the same m), until the driving torque Q is greater than the intermediate torque level Q _M water shaft 12 The step of winding down (the same i, k,
Repeat l) to scoop up the sand 31. Submersible shaft 12
When the submersible shaft 12 reaches the lower limit position (the same j) during the lowering, the lowering is stopped (the same r), and the frying is continued for a certain period of time T ₃ , for example, for several tens of minutes. Thereafter (s in FIG. 3), the submersible shaft 12 is wound up (same t, t) until the submersible shaft 12 reaches the upper limit position (same u, v). Thereafter, the rotating device 6 is stopped to stop the rotation of the bucket conveyor 1 (the same w), the electric motor valve 35 for cleaning is closed (the same x), and after a fixed time T ₄ , for example, several tens of minutes have passed. (Same y), the waste water sedimentation conveyor 36, the sand sedimentation discharge conveyor 37, and the sand sedimentation hopper loading conveyor 38 are stopped (Same as z, aa, bb). Then, after a certain period of time T ₄ , for example, several tens of hours (the same cc), a start command is issued again (a in FIG. 2). This timer T ₄
Instead of setting a time interval, it is preferable to use, for example, one that operates at a fixed time every day. As described above, according to this settling sand scooping machine, it is possible to scoop up the settling sand 31 without requiring an operator and without overloading the rotating device 6.

[0014]

According to the present invention, no worker is required,
Moreover, there is provided a settling machine that does not overload the rotating device.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view of an embodiment of the present invention.

FIG. 2 is a partial view showing a control method of the embodiment.

FIG. 3 is a partial view following FIG.

[Explanation of Codes] 1 ... Bucket conveyor 2 ... Bucket 3
... Lifting surface 5a ... Drive sprocket 5b to 5j ... Followed sprocket 6 ... Rotating device 7 ... Load cell 10, 15 ... Arm 1
1, 16 ... Shaft 12 ... Underwater shaft 13, 17 ... Pivot 1
4 ... Link rod 20 ... Wire 21 ... Lifting device 2
2 ... Limit switch 25 ... Lifting control device 30 ... Sand basin 3
1 ... Settling sand 32 ... Water surface 35 ... Motor valve for cleaning 3
6 ... Wastewater settling conveyor 37 ... Settling discharge conveyor 38 ... Settling hopper loading conveyor

Claims (2)

[Claims] 1. A bucket conveyor, to which a plurality of buckets are attached, is arranged in a sand basin, and comprises a rotating device for rotating and driving the bucket conveyor, and a lifting device for lifting and lowering the height of the scraping surface of the bucket conveyor. In the settling sand rake provided, a torque detection device for detecting the drive torque of the rotating device, and a drive device when the state where the drive torque detected by the torque detection device is lower than the low torque level continues for a certain period of time. And a lifting control device for issuing a lowering command signal to the lifting device to lower the height of the scraping surface until the torque rises above an intermediate torque level higher than the low torque level. A characteristic settling machine. 2. The elevating / lowering control device issues the lowering command signal to the elevating / lowering device when the drive torque is lower than a low torque level for a certain period of time,
When the state where the driving torque is higher than the high torque level higher than the intermediate torque level lasts for a certain period of time,
2. The sand setting and lifting machine according to claim 1, wherein a lifting command signal for raising the height of the lifting surface is issued to the lifting device until the driving torque falls below the intermediate torque level.