JPS6126402B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for discharging sludge collected in a sludge collection tank of a coagulation-sedimentation device, and more particularly to a structure for preventing clogging of sludge.

First, the prior art will be explained with reference to FIGS. 1 and 2. As shown in FIG. 1, raw water to be treated stored in a raw water tank 1 is sent into a coagulation sedimentation device 3 via a pipe 14 by a pump 2. A sludge collection tank 4 is provided at the bottom of the coagulation and sedimentation device 3. Sludge 6 is collected in the sludge collection tank 4 by a flight conveyor 15, etc., and pipes 7 and 8 are collected by a sludge drawing pump 5. Sludge is discharged through.
As shown in FIG. 2, an air pinch valve 9 is provided in the discharge side piping 8 of the sludge drawing pump 5, and compressed air is supplied to the air pinch valve 9 from the compressor 12 via the air piping 11 and the solenoid valve 10. The air pinch valve 9 is configured to close when the compressed air is supplied, and to open when the solenoid valve 10 is switched to discharge the compressed air to the outside of the system. When the sludge drawing pump 5 is operated, the air pinch valve 9 is opened, and when the pump 5 is stopped, the air pinch valve 9 is closed.

In such a coagulation-sedimentation device, as long as there is sludge in the device 3, if left as is, sludge clogging will occur in the sludge collecting tank 4 and the suction side piping 7 of the sludge withdrawal pump 5 due to the compaction effect of the sludge. do. In order to prevent this sludge clogging, the sludge drawing pump 5 and air pinch valve 9 are automatically operated by a timer or the like while the coagulation-sedimentation device 3 is in operation, so that the sludge is automatically discharged. However, since the sludge discharge also stops after the treatment operation is stopped, the sludge may solidify and cause clogging.

Therefore, some conventional coagulation-sedimentation apparatuses are equipped with a device for removing clogging in the sludge even if it occurs, but this has the disadvantage that the structure becomes complicated.

Furthermore, after the processing operation has been stopped, it is possible to manually operate the sludge drawing pump 5 continuously to discharge the sludge, but the remaining sludge can only be discharged from the vicinity of the sludge collection tank 4. Since the sludge located away from the sludge collection tank 4 is collected by the flight conveyor 15 or the rake, it takes time to reach the sludge collection tank 4, and the sludge cannot be continuously discharged. Moreover, there is a problem that the work burden on the operator increases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a sludge discharge device for a coagulation-sedimentation device that can solve the above-mentioned problems and can efficiently discharge sludge after the processing operation is stopped and prevent clogging due to sludge.

A feature of the present invention is that it is equipped with a post-processing operation timer that starts operating from the time when the processing operation of the coagulation-sedimentation device is stopped, and that the sludge withdrawal pump is operated intermittently during the set time of the post-processing operation timer. There is a particular thing.

The details of the present invention will be explained below with reference to the drawings. Third
The figure is a circuit diagram showing an embodiment of the present invention, and 5.
10 is the sludge drawing pump and solenoid valve described above, 16 is a changeover switch for the sludge drawing pump, 17 is a manual relay that is energized in manual mode, MX1 to MX3 are its contacts, 18 is an automatic relay that is energized in automatic mode, AX1 ~AX3 is its contact, 19 is a pump stop timer that sets the pump stop time _T2 , T2 is its time-limited operation contact, 20
is the pump operation timer that sets the pump operation time T ₁ , T1 is its time-limit operation contact, 21, 22 are auxiliary relays, X11, X12 and X21, X22 are these contacts, 23 is the operation timer after processing is stopped, T
3 is its time-limited operating contact.

In this circuit, when the changeover switch 16 is now operated to the manual (M) side, the manual relay 17 is energized, so the contact MX1 closes, and the sludge drawing pump 5 and the solenoid valve 10 are activated.
The air pinch valve 9 is opened, and the changeover switch 1 is opened.
6 is turned OFF, the contact MX1 is opened, the sludge drawing pump 5 is stopped, the solenoid valve 10 is restored, and the air pinch valve 9 is closed.

On the other hand, when the selector switch 16 is operated to the automatic (A) side, the automatic relay 18 is energized, so the contact
AX1 closes. The pump stop timer 19 is energized via the contact X22 of the auxiliary relay 22,
When the set time _T2 elapses, the contact T2 closes, so the pump operation timer 20 starts operating, and the auxiliary relay 21 is energized to close the contact X12.The auxiliary relay 22 is energized, so the contact
1 is closed, the sludge drawing pump 5 is operated, and the air pinch valve 9 is opened by the operation of the solenoid valve 10. At this time, the pump operation timer 20 is maintained in an operating state by the contact X11 of the auxiliary relay 21, and the operation of the auxiliary relay 21 is maintained via the contact T1 of the timer 20. When the set time _T1 of the pump operation timer 20 has elapsed, the contact T1 opens, so the auxiliary relay 21 is demagnetized and the contact X12 opens.
opens and the auxiliary relay 22 is also demagnetized, so the contact X21 opens and the sludge drawing pump 5 is stopped, and the solenoid valve 10 is restored and the air pinch valve 9 is activated.
closes. At the same time, the contact X22 closes, and the pump stop timer 19 starts operating. Therefore, in the automatic mode, as shown in FIGS. 4a and 4b, the sludge drawing pump 5 is repeatedly activated and stopped, and the air pinch valve 9 is opened and closed in synchronization with this.

Next, the operation after the processing operation is stopped will be explained.
When the changeover switch 16 is turned off (OFF),
By closing both contacts MX3 and AX3,
After the process is stopped, the operation timer 23 starts operating. Contact T3 of the timer 23 indicates the set time from the start of operation.
It remains closed during T ₃ . On the other hand, the timers 19, 20 and the auxiliary relays 21, 22 repeat the on-off operation as described above, and the contact X2
1 opens and closes at each set time T ₂ and T ₁ of the timers 19 and 20. Therefore, as shown in Figure 4C,
Processing operation stop time t ₀ to processing operation stop timer 2
During the set time T ₃ of 3, the sludge drawing pump 5
The air pinch valve 9 will be operated intermittently.

In this manner, by intermittently operating the sludge drawing pump 5 even after the treatment operation is stopped, it is possible to wait until the sludge is deposited in the sludge collection tank 4 and then discharge it efficiently and automatically.

FIG. 5 shows another embodiment of the present invention, in which, during automatic operation, the level switch 13 provided in the raw water tank 2 shown in FIG.
When LS closes and processing operation stops, contact LS
The post-processing operation timer 23 starts from the time when
starts the operation of the timer 23, and the set time T ₃ of the timer 23 is set.
Inside, as shown in FIG. 4C, the sludge drawing pump 5 and the solenoid valve 10 (air pinch valve 9) are operated intermittently. That is, when the contact LS of the level switch 13 closes while the changeover switch 16 is operated to the A side, the post-processing operation timer 23 starts operating, and the contact T3 closes for the set time _T3 . Since the timers 19 and 20 and the auxiliary relays 21 and 22 operate, the contact X2
1 opens and closes, and the sludge drawing pump 5 and solenoid valve 10 (air pinch valve 9) operate intermittently.

According to this embodiment, the treatment operation is automatically started and stopped by the level switch 13, and the sludge can be discharged without any effort at all.

The present invention has been described above with reference to examples, but when carrying out the present invention, the operation of the after-processing stop operation timer is started due to the operation or phenomenon of the component equipment caused by the stoppage of the processing operation of the coagulation-sedimentation apparatus, or the stoppage of the processing operation. It is only necessary to cause this to occur by an operation or phenomenon that causes this, and it is also possible to realize a circuit that has both the functions of the circuits shown in FIGS. 3 and 5.

As described above, according to the present invention, the sludge withdrawal pump is automatically operated intermittently after the processing operation of the coagulation sedimentation device is stopped, so that the sludge is efficiently discharged even after the processing operation is stopped, and the sludge is It is possible to prevent clogging. Further, the present invention has the advantage that it can be realized easily and inexpensively by adding simple parts, and that it does not increase the workload of the operator.

[Brief explanation of the drawing]

Fig. 1 is a treatment system diagram of a general coagulation sedimentation device, Fig. 2 is an enlarged view of its sludge extraction section, Fig. 3 is a circuit diagram showing an embodiment of the present invention, Fig. 4 is its operation chart, FIG. 5 is a circuit diagram showing another embodiment of the present invention. 1...Raw water tank, 3...Coagulation sedimentation device, 4...Sludge collecting tank, 5...Sludge drawing pump, 16...Sludge drawing pump changeover switch, 19...Pump stop timer, 20...Pump operation timer ,2
3...Timer activated after processing is stopped.

Claims (1)

[Scope of Claims] 1. In a device for discharging sludge from a sludge collection tank of a coagulation and sedimentation device using a sludge drawing pump, a pump operation that sets the pump operating time when the sludge drawing pump is operated intermittently at fixed time intervals. A timer and a pump stop timer for setting a pump stop time are provided, and a post-processing stop operation timer that starts operating from the time when the processing operation of the coagulation-sedimentation apparatus is stopped, and during the set time of the post-processing stop operation timer, the above-mentioned A sludge discharge device for a coagulation sedimentation device, characterized in that a sludge drawing pump is configured to operate intermittently. 2. The sludge coagulation and sedimentation apparatus according to claim 1, characterized in that the operation of the post-processing stop operation timer is started by turning off the sludge withdrawal pump changeover switch. Ejection device. 3. The operation of the post-processing stop timer is configured to start when a level switch installed in the raw water tank that stores raw water to be sent to the mud collection tank detects a drop in the water level. A sludge discharge device for a coagulation-sedimentation device according to claim 1.