JPH08252592A - Batch sewage treating device and sludge concentration measuring device - Google Patents

Abstract

PURPOSE: To improve the capacity of a batch sewage treating device and to efficiently and stably treat sewage. CONSTITUTION: The sludge concn. is measured by a device 12, excess sludge discharge means 8A and 8B are operated to discharge the excess sludge into a sludge concentration tank 3, and the operating time of a concd. sludge discharge means 10 is calculated from the integrated operating time of the discharge means to withdraw the concd. sludge. Consequently, the sludge concn. is kept at a target value, the concd. sludge is discharged in accordance with the amt. of the excess sludge stored and concentrated in the concentration tank, hence the sludge amt. is surely controlled, and the instability in the sludge discharge, sludge concn. and treated water quality is obviated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a batch type sewage treatment apparatus for improving the treatment capacity and an apparatus for measuring the concentration of activated sludge necessary for stable sewage treatment of the apparatus.

[0002]

2. Description of the Related Art In a batch type sewage treatment apparatus, inflow,
The steps of aeration and stirring, precipitation and discharge are sequentially performed in the same batch tank, and the surplus is discharged to the sludge concentrating tank in the discharge step in order to keep the concentration of the activated sludge at a predetermined value. This excess sludge is discharged by measuring the sludge concentration with a so-called throw-type densitometer and adjusting the operating time of the excess sludge extraction pump from management experience according to the detected activated sludge concentration. It was normal to do it. Also,
In some cases, the excess sludge extraction pump was automatically operated for a certain period of time.

Further, for the withdrawal of the concentrated sludge from the sludge thickening tank, the operating time of the concentrated sludge withdrawal pump is adjusted from experience in management according to the operating time and operating cycle of the surplus sludge withdrawing pump as described above. It was usually done artificially. The management of the amount of concentrated sludge is an important element for stable wastewater treatment, but the artificial method as described above makes the management complicated and the treatment capacity of the sludge thickening tank is not stable. Instability of the sludge thickening tank not only causes sludge outflow, but also causes an unexpected situation in which concentrated sludge is returned to the raw water tank along with desorbed liquid when sludge is concentrated, and further sludge concentration control does not function. There is a problem that it causes instability of wastewater treatment.

[0004]

SUMMARY OF THE INVENTION The applicant of the present invention has proposed to solve the above-mentioned problems by automatically measuring the excess sludge concentration in this type of batch-type sewage treatment apparatus. Although proposed by No. 351393, this proposal does not mention concentrated sludge, and it was found that the specific configuration should be further improved in order to improve the measurement accuracy. The present invention has been made for the purpose of solving the problems of conventional general apparatuses and realizing a batch type sewage treatment apparatus capable of more appropriately performing sewage treatment with higher performance than the above proposal. It is a thing.

[0005]

In order to achieve the above object, in the first invention relating to the batch type sewage treatment apparatus described in claim 1, each step of inflow, aeration stirring, precipitation and discharge is sequentially performed. The batch tank, measuring means for measuring the activated sludge concentration in the batch tank, surplus sludge discharging means for discharging the excess sludge in the batch tank, and the target sludge concentration according to the sludge concentration measured by the measuring means Control means for outputting an operation command to the excess sludge discharge means as obtained, a sludge thickening tank for storing and concentrating the discharged excess sludge, and a concentrated sludge discharge means for discharging the concentrated sludge in the sludge thickening tank, In the batch type wastewater treatment device provided with, the control means has a function of calculating the operating time of the concentrated sludge discharging means from the integrated value of the operating time of the excess sludge discharging means and outputting an operation command to the concentrated sludge discharging means. ing

In the second invention described in claim 2,
Similar to the above, batch tank, measuring means, discharging means, control means,
In a batch-type sewage treatment apparatus equipped with a sludge thickening tank, when a signal indicating that the inflow process has started according to a predetermined sequence is detected, measurement and operation of the excess sludge discharging means and the concentrated sludge discharging means are performed. Only when a signal indicating that the water level in the batch tank has reached the set upper limit is detected after starting the waiting time counting, the above measurement and the operation of the excess sludge discharge means and the concentrated sludge discharge means are executed. Equipped with control means.

Further, in the first invention relating to the sludge concentration measuring device in the batch type wastewater treatment device described in claim 3, sampling of the activated sludge mixed liquid to be supplied to the measuring means between the upper limit water level and the lower limit water level of the batch tank. Has a mouth. In this case, it is possible to provide a means for cleaning the sampling port within a time when the water level in the batch tank after the discharging step is lower than the sampling port.

Further, in the second invention relating to the sludge concentration measuring device described in claim 5, bubbles are collected by receiving bubbles rising from below at the lower part of the collection port of the activated sludge mixed liquid to be supplied to the measuring means. A bubble blocking plate is placed to prevent it from reaching the mouth.

Further, in the third invention described in claim 6,
A vacuum tank for collecting the activated sludge mixed liquid to be supplied to the measuring means by suction, and a liquid level sensor for detecting that a predetermined amount of liquid has been supplied into the vacuum tank, and the liquid level sensor On the other hand, a cleaning means for spraying cleaning water each time the measurement is completed is provided.

According to the fourth aspect of the present invention,
It is equipped with a vacuum tank that collects the activated sludge mixed liquid to be supplied to the measuring means by suction, and a liquid level sensor for detecting that a predetermined amount of liquid has been supplied into this vacuum tank. Cleaning means for supplying cleaning water into the vacuum tank to clean the vacuum tank and the liquid level sensor, and a detection signal from the liquid level sensor after supplying a predetermined amount of cleaning water or after suction collection of a predetermined amount of activated sludge mixed liquid Is detected, or abnormality detection means for determining an abnormality is detected when the detection signal from the liquid level sensor is detected when the residual water in the vacuum tank is discharged.

In this case, it is possible to arrange the second liquid level sensor above the above liquid level sensor and forcibly stop suction and cleaning by the operation of this second liquid level sensor. .

According to the fifth aspect of the present invention,
Cleaning means for directly injecting a cleaning fluid is provided inside the measuring means for measuring the sludge concentration by passing the collected activated sludge mixed solution.

Further, in the sixth aspect of the present invention, a sampling pipe for supplying the activated sludge mixed liquid to the measuring means,
The same pipe is also used as the discharge pipe for returning the collected activated sludge mixed liquid to the batch tank.

[0014]

In the invention of claim 1 relating to the batch type sewage treatment apparatus, since the concentrated sludge discharging means is operated according to the amount of the excess sludge discharged to the sludge thickening tank and stored / concentrated, the sludge amount can be controlled. It can be done more reliably, sludge outflow,
It is possible to prevent operational management failures such as sludge concentration and unstable treated water quality.

The operation of the batch type sewage treatment apparatus itself is managed by the facility management control apparatus, and the steps of inflow, aeration stirring, precipitation, and discharge are sequentially performed in accordance with a preset sequence, independently of the measurement of sludge concentration. Repeated. The start of the inflow process according to this predetermined sequence is performed by, for example, an inflow start signal from the facility management control device, a start signal of the sewage pump, a start signal of a switching valve for flowing sewage into the batch tank, a lighting signal of an inflow process display lamp, etc. Can be detected. Further, the fact that the water level in the batch tank has reached the set upper limit means that, for example, an inflow end signal from the facility management control device,
It can be detected by the upper limit signal from the water level meter of the batch tank, the stop signal of the sewage pump and the switching valve, the extinguishing signal of the inflow process indicator lamp, etc.

According to the second aspect of the present invention, these signals are used to measure and serve as a reference time point for operating the excess sludge discharging means and the concentrated sludge discharging means, and for detecting the actual operation time of each discharging means. To be done. Therefore, the sludge concentration is measured at a predetermined timing, and moreover, the measurement is performed only when the sewage has flowed into the batch tank to the upper limit and is in a state suitable for measurement, so the measurement accuracy is high, It is possible to properly control the sludge concentration.

In the invention of claim 3 relating to the sludge concentration measuring device, since the sampling port for the activated sludge mixed liquid is arranged between the upper limit water level and the lower limit water level of the batch tank, at the end of the discharging step, the sampling port is above the water surface. It is above. Therefore, it is possible to backwash the sampling port without water pressure, or to flush the cleaning port from the outside and wash it from the outside, so that clogging is less likely to occur and the frequency of maintenance can be reduced. , It becomes easy to collect the activated sludge in the completely mixed state. The end of the discharge process can be detected by, for example, a discharge end signal from the facility management control device, a lower limit signal from the water level gauge of the batch tank, a lower limit signal or a stop signal of the supernatant water discharge device, and a light-off signal of the discharge process display lamp. Moreover, since the sampling port is above the water surface immediately after the start of the inflow process, the above-described operation is possible.

According to the fifth aspect of the invention, since the bubble blocking plate is arranged below the collection port for the activated sludge mixture, the bubbles do not reach the collection port even during aeration and stirring, and the activity is not mixed with bubbles. The sludge mixed liquid can be collected and supplied to the measuring means, and the measurement accuracy in the aeration process is improved.

According to the sixth aspect of the present invention, it is possible to inject the cleaning water every time the measurement is completed to clean the liquid level sensor in the vacuum tank. Can detect faces.

According to the seventh aspect of the present invention, when a predetermined amount of the activated sludge mixed liquid is sucked and collected in the vacuum tank, the detection signal from the liquid level sensor cannot be sensed, so that it cannot be collected due to the clogging of the pipe or the like. It is possible to detect abnormalities and abnormalities in which cleaning cannot be performed due to interruption of cleaning water, etc., by not being able to detect the detection signal from the level sensor when cleaning the vacuum tank and the liquid level sensor. It is possible to detect abnormalities such as liquid level sensor failure and wire breakage. In addition, by detecting the detection signal from the liquid level sensor when the residual water is discharged from the vacuum tank, it is possible to detect abnormalities such as the liquid level sensor malfunctioning due to sludge accumulation, etc. be able to. That is, since the liquid level sensor is also used for detecting these abnormalities, it is not necessary to add a new sensor for detecting these abnormalities.

Further, the second liquid level sensor is arranged above the liquid level sensor, and when the second liquid level sensor is activated, the suction and the washing are forcibly stopped so that the suction pump can be operated. It is possible to prevent problems such as intrusion of water and sludge invasion of the solenoid valve for washing water.

According to the invention of claim 9, since the inside of the measuring means can be surely cleaned by directly injecting the cleaning fluid, normal measurement cannot be prevented by the attached sludge, The reliability of measured values can be improved and the frequency of maintenance and calibration can be reduced.

According to the tenth aspect of the invention, since the collecting pipe and the discharging pipe for the activated sludge mixed liquid are used as the same pipe, the pipe can be simplified and the number of valves used can be reduced. Moreover, the cleaning process can be simplified because the cleaning of the measuring means and the pipe and the backwash of the sampling port can be performed at the same time.

[0024]

EXAMPLE Next, an example of an apparatus having two batch tanks will be described. If there is only one batch tank,
It is sufficient to omit the part relating to one of the batch tanks from the apparatus and the processing procedure of this embodiment, and the description is omitted because it can be easily carried out.

In FIG. 1, 1 is a sewage adjusting tank, 2A and 2B are a pair of batch tanks, 3 is a sludge concentrating tank, 4 is a sludge storage tank, 5 is a sewage supply pump, and 6A and 6B are batch tanks 2 respectively.
A stirring device with an air supply function provided at the bottom of A, 2B,
7A and 7B are floating type supernatant water discharge devices provided in the batch tanks 2A and 2B, and 8A and 8B are batch tanks 2A and 2B.
The sludge withdrawing pumps 9A and 9B are water level gauges provided in the batch tanks 2A and 2B, and 10 is the concentrated sludge withdrawal pump provided in the sludge thickening tank 3.

As the stirring devices 6A and 6B, for example, a well-known structure having a structure in which an impeller provided in a casing sucks sewage from the lower portion and discharges it from the upper portion, and an air outlet is also provided is appropriate. It is used, and well-known structures are appropriately used for the supernatant water discharge devices 7A and 7B. It should be noted that although not shown because it is not directly related to the present invention, other various devices are appropriately provided in each tank as needed.

Reference numeral 11 is a controller, and 12 is a measuring device provided by the present invention. The controller 11 controls the operations of the measuring device 12 and various devices related to the present invention, and is provided with a microcomputer, for example. The measuring device 12 collects a sample of the activated sludge mixed solution from each batch tank 2A or 2B via the sampling / discharging pipe 13A or 13B according to a command from the controller 11, and automatically determines the concentration of the suspended activated sludge in the sample. After the measurement, the sample is returned to the original batch tank 2A or 2B via the sampling / discharging pipe 13A or 13B.
The operation of each process of inflow, aeration stirring, precipitation, and discharge of the batch type sewage treatment apparatus is controlled according to a sequence preset by a facility management control device (not shown).

14A and 14B are sludge collection ports, 15A
15B are cleaning nozzles for the sampling ports 14A and 14B. When the treated water is discharged from the batch tank 2A or 2B and the water level reaches the lower limit water level, in response to a command from the controller 11, the wash water is discharged from the measuring device 12 through the wash water pipe 16A or 16B at the same time as the next inflow of dirty water. Cleaning nozzle 15A,
It is configured such that it is jetted from 15B and the sampling port 14A or 14B is directly washed from the outside. The signal circuit is shown by a broken line or a chain line.

The apparatus of the embodiment has the above-mentioned structure.
The basic operation is the same as that conventionally known. That is, the wastewater to be treated once flows into the wastewater adjusting tank 1 from the inflow passage 17, and then a predetermined amount is passed through the switching valve 18 by the wastewater supply pump 5 from the supply passage 19A or 19B to the batch tank 2A.
Alternatively, the supply is stopped when the water level meter 9A or 9B senses that the water level has reached the upper limit.
When only the impellers of the stirring devices 6A and 6B are operated, anaerobic stirring is performed, and further aeration stirring is performed by ejecting air from the discharge port. The stirring may be started after the inflow is completed, but it is usually started at the same time as the inflow.

Upon completion of these agitation, the process proceeds to the precipitation step, and in the subsequent discharge step, the supernatant water of each batch tank 2A, 2B is discharged by the supernatant water discharge devices 7A, 7B. Further, the excess sludge generated in each batch tank 2A or 2B is discharged to the sludge thickening tank 3 via the sludge discharge passages 20A or 20B by the sludge drawing pumps 8A and 8B in the discharging process, and is concentrated, and then the concentrated sludge drawing pump 10 Is discharged to the sludge storage tank 4 via the concentrated sludge discharge pipe 21.

FIG. 2 is a sequence diagram showing the above basic operation. (a) is the case where only aeration and stirring is performed, (b)
Indicates the case where the steps of anaerobic stirring and aeration stirring are repeated a plurality of times, respectively. As shown in the drawing, the duration of each process is set in advance so that all of these processes are repeated 4 times a day for one cycle of 6 hours, for example.
The processing on the batch tank 2B side is similarly performed with a delay of 3 hours with respect to the processing on the A side. Note that these
(a) and (b) can be arbitrarily switched depending on how to use the stirring devices 5A and 5B, and both steps can be carried out by a device having exactly the same configuration.

In (a), the aeration process is started at the same time when the inflow process is started, and the aeration stirring process is continued even after the inflow process is completed. Further, in (b), at the same time when the inflow process is started, anaerobic agitation is started and aeration and anaerobic agitation are alternately performed, and the agitation process is continued even after the inflow process is completed.
The concentration measurement of the suspended activated sludge according to the present invention is carried out at the end of the aeration stirring step in (a) and at the end of the last anaerobic stirring step or aeration stirring step in (b), as shown by the arrow.

FIG. 3 is a flow chart showing the operation procedure of the entire apparatus for measuring the concentration and removing sludge.
The control by the controller 11 has a starting condition that a signal indicating the start of inflow of dirty water into each batch tank 2A or 2B is detected. For example, since the activation of the switching valve 18 is regarded as the start of operation of the batch type sewage treatment apparatus, that is, the start of inflow,
When the controller 11 detects the activation signal of the switching valve 18 in the standby state of step S1, the controller 11
Is activated to enter the measurement standby state, and the built-in timer of the controller 11 starts counting (step S2). The signal indicating the start of inflow is not limited to the activation signal of the switching valve 18, and various signals as described above can be used as appropriate.

Since the measurement needs to be carried out when the sewage has flowed to the upper limit of the batch tank, the measurement start condition is that the water level gauge 9A or 9B senses the liquid level and outputs the water level upper limit signal. When the water level upper limit signal is output up to the predetermined set count number in step S3, the controller 11 outputs a measurement start command signal to the measuring device 12, and the process proceeds to step S4 to measure the activated sludge concentration. Be seen. If it is determined to be abnormal during this measurement, an alarm signal is transmitted and the operation is stopped (step S9).

In the next step S5, the sludge drawing pump 7 is determined from the difference between the obtained measured value and the target value of the activated sludge concentration.
The operating time of A or 7B is calculated by the controller 11,
At the end of the discharge process in which the count reaches a predetermined set value, the pump 7A or 7B is operated to remove the excess sludge (step S6), whereby the concentration of the activated sludge is maintained at the target value. Further, the controller 11 integrates the operating times of the sludge drawing pumps 7A and 7B, and calculates the operating time of the concentrated sludge drawing pump 10 from the integrated value (step S7). Then, when the count reaches a predetermined set value, the concentrated sludge extraction pump 10 is operated to extract the concentrated sludge (step S8),
The management state of the sludge thickening tank 3 is kept stable.

When the activation signal of the switching valve 18 is not detected in step S1 and when the water level upper limit signal is not detected in step S3, the process returns to the standby state of step S1. That is, the water level WL1, WL2, WL3 of the wastewater adjusting tank 1 shown in FIG. 1 respectively corresponds to the amount of wastewater treated once, but is less than one time, but to the batch tank to prevent overflow of the wastewater adjusting tank 1. It corresponds to the amount of water that flows in and the amount of water that does not flow in, and the above-mentioned operation differs depending on these water levels. Further, as will be described later, even when an abnormal signal is output during measurement, the standby state of step S1 is restored.

For example, if the water level of the wastewater adjusting tank 1 is WL
When it is 1 or more, the sewage supply pump 5 is activated and the switching valve 1
Sewage flows into the batch tank 2A or 2B via 8. Then, the controller 11 detects that the switching valve 18 has actuated as an inflow start signal, and the controller 11 outputs a start signal to the measuring device 12. Next, when the controller 11 senses that the water level has reached the upper limit and the water level gauge 9A or 9B has detected this, the pump 5 and the switching valve 18 are stopped, and a command to start measurement is output to the measuring device 12. Of. The operation of the pump 5 and the switching valve 18 is controlled by a facility management control device (not shown).

In addition, the water level of the waste water adjusting tank 1 is WL2.
In the case of, the sewage supply pump 5 is started and the switching valve 1
Sewage flows into the batch tank 2A or 2B via 8 and the controller 11 senses the operation of the switching valve 18 and the measuring device 1
A command signal for starting the start is output to 2. However, since the inflow ends before the water level reaches the upper limit, a detection signal is not output from the water level gauge 9A or 9B, and the start start command is reset when a preset time elapses,
Return to the standby state.

When the water level is WL3, the sewage supply pump 5 and the switching valve 18 are not activated, so the measuring device 1
The start-up command for 2 is not output, and the standby state continues.

Next, the configuration of the measuring device 12 and the measuring operation corresponding to step S4 in FIG. 3 will be described. FIG. 4 is a system diagram showing an example of the configuration, FIG. 5 is a diagram showing a basic sequence of the measurement operation, and FIG. 6 is a flowchart showing an operation procedure. In FIG. 4, SS is a sensor unit and VT
Is a vacuum tank, P-1 is a vacuum pump, C-
1 is a small air compressor, MV-1 to MV-3 are motor valves, SV-1 to SV-6 are solenoid valves,
LS-1 is a commonly used liquid level sensor, LS-2 is an emergency second
Liquid level sensor of.

The specific connection is as shown in the figure. The motor valves MV-1 and MV-2 are connected to the sensor section SS and the sampling port 1.
4A and 14B are connected to the sampling / discharging pipes 13A and 13B, and the MV-3 is inserted to the sampling / discharging pipe 22 that connects the sensor unit SS and the vacuum tank VT. Once through the vacuum tank VT, after measurement, the original batch tank 2A or 2B
Is returned to.

Further, the solenoid valves SV-1, SV-
2 is to the washing water pipes 16A and 16B, SV-3 is to the pipe 23 connecting the sensor section SS and the compressor C-1, and SV-4.
SV-5 on the pipe 24 connecting the sensor unit SS and the washing water source.
Is inserted in the pipe 25 for opening the vacuum tank VT to the atmosphere, and SV-6 is inserted in the pipe 26 connecting the vacuum tank VT and the washing water source. Also, the pump P-1
A pipe 27 connects between the vacuum tank VT and the vacuum tank VT.

The left side of FIG. 5 shows the measurement sequence of the measuring device 12 during the wastewater treatment operation of the batch tank 2A, and the right side shows the measurement sequence of the measuring device 12 during the wastewater treatment operation of the batch tank 2B. Each sequence during the operation of the batch tanks 2A and 2B is controlled by the facility management control device and alternately performed. For example,
When the measurement is performed on the batch tank 2A, first, in step S2 of FIG. 3, the measuring device 12 receives a signal for starting the inflow process from the batch tank 2A, thereby starting the step of cleaning the sampling port.

That is, in this process, the valves MV-1 and SV-1, 3, 4 are opened, the compressor C-1 is operated, and the cleaning water and the cleaning air are collected through the respective pipes to the sampling port 14A.
Is supplied to the sensor unit SS, the sensor unit SS is cleaned. Further, the cleaning water is supplied to the cleaning nozzle 15A, but in the present invention, the sampling ports 14A and 14B are provided in the respective batch tanks 2A or 2B.
The water level is close to the lower limit in the initial stage of the inflow process started after the discharge process, because the water level is located between the upper and lower water levels. Therefore, the sampling port 14A is exposed to the atmosphere, and the sampling port 14A is backwashed with the cleaning air and cleaning water supplied from the sampling / exhaust pipe 13A and the cleaning nozzle 1
The cleaning water is sprayed from 5A to surely clean and maintain a sufficiently clean state (step S11).

Subsequently, in step S12, backwashing of the sampling port 14A is performed, and before and after this, it is judged that the liquid level sensor LS-1 is abnormal, and if it is off, the next step S1.
3, the measurement process shown in FIG. 5 is started.

That is, the pump P-1 is operated to exhaust the inside of the tank VT, and at the same time, the valves MV-1 and MV-3.
Opens. Therefore, a sample is taken from the batch tank 2A, passes through the sensor section SS, and enters the tank VT, at which time the concentration of activated sludge is measured. The result is controller 1
1, the average of the measured values is calculated and stored. When the liquid level sensor LS-1 detects that the liquid level of the tank VT has risen and has reached the predetermined water level, the discharging process of step S14 is performed. At this time, if the detection signal of the liquid level sensor LS-1 is not sensed even after the lapse of the set time, it is determined that there is an abnormality that the sample cannot be collected due to blockage of the pipe.

In the discharging process, the pump P-1 is stopped, the valve SV-5 is opened, the inside of the tank VT is opened to the atmospheric pressure, and the sample is collected / discharged by its own weight.
After passing through 3A, it is returned to the batch tank 2A. At this time, if the liquid level sensor LS-1 is ON, it is determined that the liquid level sensor LS-1 cannot be discharged due to blockage of the pipe or the liquid level sensor malfunctions due to sludge accumulation. Therefore, even when the detection signal of the liquid level sensor LS-1 is not sensed by the controller 11 even after the set time corresponding to the collected amount of the activated sludge mixed liquid has passed, or even when the discharging process is started, the liquid level sensor LS-1 is detected.
When the detection signal is detected by the controller 11, it is determined that the above-mentioned abnormality has occurred and, for example, an alarm is issued.

In the subsequent cleaning process, the compressor C-1
And the opening and closing of each valve are performed as shown (step S15). Then, the sensor unit SS, the tank VT, the liquid level sensor LS-1 and each pipe are washed, and after the set time has elapsed, if the liquid level sensor LS-1 is off, it is determined to be abnormal. After being discharged, the measurement of this time is completed, and the standby state of step S16 is entered. As described above, the important part including the sensor part SS is sufficiently cleaned by using the air cleaning and the back cleaning together. If it is determined to be abnormal, an abnormal alarm is issued and the operation is stopped (step S17).

In the present invention, the sampling pipe for supplying the sample of the activated sludge mixed liquid from the sampling ports 14A, 14B to the measuring device 12 is the same as the discharging pipe for returning the sample and the washing water after the measurement to the batch tank 2A or 2B. It is also used as the sampling / discharging pipe 13A or 13B. Therefore, the piping is simplified as compared with the case where the sampling and the discharge are performed by separate piping, the number of valves used is reduced, and the operation is simplified. In addition, the sensor unit SS and the vacuum tank V
T, the cleaning water for cleaning the piping in the middle of the sampling port 14A,
It is possible to make the backflow from 14B and also serve as the backwash, thereby reducing the procedure of the washing process.

Next, the arrangement of the sampling ports 14A and 14B will be described. In the conventional batch type sewage treatment apparatus, the collection port is arranged at a level below the lower limit water level of the batch tank in order to reliably suck the sewage. Therefore, backwashing becomes uncertain because water pressure is applied to the sampling port, and it is difficult to perform sufficient cleaning from the outside, which may cause trouble such as clogging of the sampling port. it was high.

On the other hand, in the present invention, the above-mentioned problems are prevented by disposing the sampling port between the upper limit water level and the lower limit water level of the batch tank. That is, FIG.
3 is a sectional view of the batch tank 2A or 2B showing the arrangement of the sampling ports 14A or 14B. As shown in the figure, the lower limit water level L. W. L. Up to h
1, upper limit water level W. L. Up to h2 and up to the sampling port H, the sampling port 14A is positioned so that h1 <H <h2.
And 14B are arranged.

According to this arrangement, since the sampling ports 14A and 14B are located on the surface of the sewage and no water pressure is applied after the discharging step, the backwashing can be surely performed by ejecting the washing water from the sampling port. Further, since it is possible to surely clean from the outside with the cleaning water 15a sprayed from the cleaning nozzles 15A and 15B, the sampling ports 14A and 14B can be cleaned each time measurement is performed. A fine cylindrical filter 31 is provided at the tips of the sampling ports 14A and 14B.
Since the filter 31 is arranged horizontally and the cleaning nozzles 15A and 15B are arranged on the upper part thereof, the cleaning water easily hits and the external cleaning is more reliably performed.

Therefore, the filter 31 is less likely to be clogged, the activated sludge in a completely mixed state can be collected, and the number of required maintenance operations is reduced. As described above, the water level gauge 9A or 9B
If the detection signal is not output from, measurement is not performed, so
When the inflow of dirty water is small and the sampling ports 14A and 14B are exposed above the water surface, the suction operation is not performed.

FIG. 8 shows an example of a sensor section SS for measuring by the light transmission method. A light source lamp SS-2 and a detector SS-3 are arranged to face each other with a measuring cell SS-1 in between, and a measuring cell SS-1. The activated sludge concentration is measured by the detection output of the detector SS-3 when the sample 32 of the activated sludge mixed liquid is passed through the inside. Therefore, if air bubbles 33 are mixed in the sample 32, the liquid phase becomes non-uniform, and normal measurement cannot be performed due to air bubbles in an optical detection method, for example, detection by transmitted light or scattered light, especially during the aeration process. May be difficult to measure. In addition to the light transmission method as illustrated, the sensor section SS may be of other types such as an ultrasonic type or an infrared type, and even in these cases, bubbles make it impossible to perform normal measurement. Is the same as the light transmission method.

Therefore, in the present invention, as shown in FIG. 7, a bubble blocking plate 34 is provided at the lower part of the sampling ports 14A and 14B so as to receive the bubbles rising from below and prevent the bubbles from reaching the sampling port. There is. 9 and 10 exemplify the shape of the bubble blocking plate 34. FIG. 9 shows a shape in which a semi-cylindrically curved plate is laid down, and FIG. 10 shows a plate bent obtusely. The shape is such that both edges are inclined so that both edges are low so that sludge does not accumulate on the upper surface.

Therefore, the sludge does not deposit on the bubble blocking plate 34 during the precipitation process, and the bubbles 33 form the bubble blocking plate 3.
Collection port 1 because it is received by 4 and rises from its surroundings
Never reach 4A, 14B directly. Therefore, even during the aeration process, bubbles are prevented from being sucked into the sensor section SS of the measuring device 12 together with the sample, and the measurement can be performed without any trouble. The bubble blocking plate 34 of the embodiment
Is attached by a support fitting 34a, and the sampling port 14
It has a structure that doubles as a support for A and 14B.

Since the activated sludge mixed solution is collected by the suction method as described above, the liquid level sensor LS-1 in the vacuum tank VT contacts the sludge and the sludge adheres or accumulates, and the amount of the sludge has passed with time. There is a possibility that the liquid level sensor increases and the normal operation of the liquid level sensor is hindered. Therefore, in the present invention, the liquid level sensor can be cleaned as shown in FIGS.

In FIG. 11, reference numeral 36 is a cleaning nozzle provided on the upper part of the inner surface of the vacuum tank VT to clean the tank VT by widely spraying the cleaning water 36a supplied from the pipe 26 into the tank VT. A part of the sprayed cleaning water 36a directly hits the surface of the liquid level sensor LS-1, and the sludge 37 adhering or accumulating is removed. This cleaning is performed every time measurement is performed in step S15 in the flowchart of FIG.
The function of the liquid level sensor is sufficiently ensured and the liquid level sensor always operates normally, so that malfunction of the sensor can be prevented and necessary maintenance frequency can be reduced.

The liquid level sensor LS-1 is a capacitance type,
Various sensors such as an electrode type and a float type can be used, and the cleaning water needs to be sprayed from a proper direction to a proper position according to each sensor. That is, FIG.
Is an example using a capacitance type sensor. In this case, washing water is applied to a position where the sludge 37 clinging to the surface is washed away, and in the example of FIG.
The cleaning water is applied to the position where the sludge 37 accumulated between the electrodes of the book is washed away. Further, in the example of FIG. 13 using the float type sensor, when the sludge 37 is accumulated on the upper part of the float, the switch is not turned on, and the sludge 37 is formed on the lower part of the float.
If water accumulates, the switch will not turn off, so wash water must be applied to the top and bottom of the float.

As described above, the state of adhesion and accumulation of the sludge 37 differs depending on the type of sensor, and even the same type of sensor varies depending on the shape of the float or the like and the method of sucking the sample. The position and the direction of the water must be changed. This change can be dealt with by changing the shape of the cleaning nozzle 36, adjusting the water pressure and the amount of water, etc. You may make it provide a washing nozzle separately.

The above-mentioned cleaning is performed in step S15 of FIG. 6 as described above, and the cleaning water is stored in the tank VT while cleaning the liquid level sensor LS-1 and the vacuum tank VT, and the cleaning water of the liquid level sensor LS-1 is stored. It activates when the water level is reached. When the controller 11 receives this detection signal, it stops the solenoid valve SV-6, and the motor valve MV
-3 is operated to discharge the wash water in the tank VT, but the above detection signal is not transmitted if there is an abnormality such as the wash water being cut off, the liquid level sensor LS-1 being broken, or the signal circuit being broken. .

Therefore, when the detection signal is not sensed by the controller 11 even after the lapse of the set time corresponding to the supply amount of washing water, it is judged that the above-mentioned abnormality has occurred and, for example, an alarm is issued. Thus, the liquid level sensor LS-1
Is used not only for simply detecting the water level in the vacuum tank VT, but also for detecting abnormalities such as sampling failure, detection failure, water cutoff, and other malfunctions and failures of each device.

Further, in this embodiment, as shown in FIG. 4, a second liquid level sensor LS-2 is provided in the vacuum tank VT as an emergency safety device, and the liquid level sensor LS-
It is located above the sensor LS-1 to operate at water levels higher than 1. That is, in step S13 of FIG. 6, the activated sludge mixed liquid is sucked into the vacuum tank VT for measurement, and also in step S13 of FIG.
In 15, by applying the cleaning water from the solenoid valve SV-6 to the vacuum tank VT and the liquid level sensor LS-1 for cleaning, the water level in the tank VT rises, but the water level reaches a predetermined value. Nevertheless, if the liquid level sensor LS-1 does not operate, the suction operation will be continued as it is, and water or sludge will enter the vacuum pump P-1, solenoid valves SV-5, SV-6, etc. It may damage the equipment.

The liquid level sensor LS-2 is configured to forcibly turn off the power switch 39 of the power source 38 when the liquid level is detected at such time, and when the liquid level sensor LS-1 or the controller 11 fails, the controller 11 and pump P-1
Emergency stop. As the liquid level sensor LS-2, various sensors such as a capacitance type, an electrode type and a float type can be used similarly to the liquid level sensor LS-1 described above.

In the case of various abnormalities as described above, the measurement of the sludge concentration according to the present invention, the sludge withdrawal and the concentrated sludge withdrawal based on the measurement are not performed, and the control is switched to the control by the timer. That is, reference numeral 41 in FIG. 1 is a timer for this purpose, and the signal circuits for the sludge withdrawal pumps 8A and 8B and the concentrated sludge withdrawal pump 10 shown by chain lines are switched from the controller 11 to the timer 41 side, and the pump is operated according to a preset program. 8A, 8B and 10 are operated.

Next, the internal cleaning of the sensor section SS will be described. In FIG. 14, the sample of the activated sludge mixed solution is measured cell SS- in a direction perpendicular to the paper surface through a pipe 22 or the like.
When the cleaning air or cleaning water is supplied through the pipe 22 or the like, the air pressure and the water pressure decrease until reaching the sensor unit, and the sludge 37 attached or accumulated on the inner surface of the cell SS-1 37 Cannot be reliably removed.

In the present invention, in order to solve such a problem, an injection nozzle 42 is provided in the measuring cell SS-1 and the pipe 23 from the compressor C-1 is connected to the measuring nozzle SS-1 so that the high pressure air 42a for cleaning is provided. It is designed to be directly injected into the measuring cell SS-1 from a direction different from the direction of the sample flow.
As a result, the cleaning efficiency is increased and the sludge 37 adhering to or accumulating on the inner surface of the cell SS-1 is sufficiently removed, and the frequency of maintenance and calibration of the sensor unit SS can be reduced. Become. The ejected fluid may be water or a mixture of water and air instead of air as in the embodiment, and is good when the cleaning fluid is ejected perpendicularly to the wall surface of the measuring cell SS-1. A good cleaning effect is obtained.

[0068]

As is apparent from the above description, the first invention relating to the batch type sewage treatment apparatus of the present application measures the excess sludge discharging means so as to obtain the target sludge concentration by measuring the sludge concentration. While operating, the excess sludge is discharged to the sludge thickening tank, and the operating time of the concentrated sludge discharging means is calculated from the integrated value of the operating time of the excess sludge discharging means to pull out the concentrated sludge. Therefore, storage in the sludge thickening tank
Since the concentrated sludge discharge means is operated according to the amount of concentrated excess sludge, the amount of sludge can be managed more reliably, and the operational management of sludge outflow, sludge concentration and unstable treated water quality, etc. It is possible to prevent failures.

A second invention relating to the same apparatus is to measure the start of the inflow of the treated wastewater into the batch tank and count the waiting time until the operation of the excess sludge discharge means and the concentrated sludge discharge means. The measurement and the operation of each discharging means are performed only when the water level in the batch tank reaches the set upper limit after the start. Therefore, the sludge concentration should be adjusted only when the timing is appropriate and the measurement is suitable for the operation of the batch type sewage treatment device which is repeated regardless of the sludge concentration measurement according to the preset sequence. Since the measurement is performed, high measurement accuracy can be obtained, and the sludge concentration can be appropriately controlled.

The first invention relating to the sludge concentration measuring device has a sampling port for the activated sludge mixed liquid to be supplied to the measuring means between the upper limit water level and the lower limit water level of the batch tank.
Therefore, at the end of the discharging process, the sampling port is above the water surface, and it is possible to backwash the sampling port without water pressure, or to spray cleaning water from the outside to clean the sampling port. It is hard to get up, the frequency of maintenance can be reduced, and it becomes easy to collect the activated sludge in a completely mixed state.

A second invention relating to the same device is a bubble for receiving bubbles rising from below at the lower part of the sampling port for the activated sludge mixed liquid to be supplied to the measuring means and preventing the bubbles from reaching the sampling port. A blocking plate is arranged. Therefore, it is possible to collect the activated sludge mixed liquid in which air bubbles are not mixed even during aeration and stirring and supply it to the measuring means, and the measurement accuracy in the aeration process is improved.

Further, a third invention relating to the same apparatus is for detecting a vacuum tank for collecting the activated sludge mixed liquid to be supplied to the measuring means by suction, and detecting that a predetermined amount of liquid has been supplied into this vacuum tank. The liquid level sensor is provided, and the liquid level sensor is provided with cleaning means for injecting cleaning water after each measurement. Therefore,
The liquid level sensor can always be kept clean, and accurate water level detection can be performed.

Further, in the fourth aspect of the apparatus, a vacuum tank for collecting the activated sludge mixed liquid to be supplied to the measuring means by suction, and a liquid surface for detecting that a predetermined amount of the liquid has been supplied into the vacuum tank. Equipped with a sensor,
Abnormality when the detection signal from the liquid level sensor cannot be detected when suctioning and collecting a predetermined amount of the activated sludge mixed liquid into the vacuum tank, or when the detection signal from the liquid level sensor is detected when the residual water is discharged from the vacuum tank. It was decided to judge. Furthermore, each time the measurement is completed, cleaning water is supplied into the vacuum tank to clean the vacuum tank and the liquid level sensor, and if a detection signal from the liquid level sensor cannot be sensed after supplying a predetermined amount of cleaning water, it is determined to be abnormal. It is something that is done. Therefore, it is possible to detect abnormalities such as poor sampling, defective discharge, washing water interruption, liquid level sensor failure, and wire breakage, and it is not necessary to add a new sensor for abnormality detection.

Further, in the case where the second liquid level sensor is arranged above the liquid level sensor and the suction and the cleaning are forcibly stopped when the second liquid level sensor is activated, Problems such as water entering the pump for cleaning and sludge entering the solenoid valve for washing water are prevented.

A fifth aspect of the apparatus is to provide a cleaning means for directly injecting a cleaning fluid into the inside of the measuring means for measuring the sludge concentration by passing the sampled activated sludge mixed solution. . Therefore, the inside of the measuring means is surely cleaned, and the adhered or accumulated sludge does not interfere with normal measurement, so that the reliability of measured values is improved and the frequency of maintenance and calibration can be reduced.

Further, in the sixth invention of the same apparatus, the sampling pipe for supplying the activated sludge mixed liquid to the measuring means and the discharge pipe for returning the sampled activated sludge mixed liquid to the batch tank are also used as the same pipe. Since the piping can be simplified and the number of valves used can be reduced, and the cleaning of the measuring means and the piping and the backwashing of the sampling port can be performed at the same time, the cleaning process is simplified.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention.

FIG. 2 is a sequence diagram showing an outline of a basic operation of the embodiment.

FIG. 3 is a flowchart showing a control procedure of the entire apparatus of the embodiment.

FIG. 4 is a system diagram showing an example of a configuration of a measuring device according to the same embodiment.

FIG. 5 is a sequence diagram showing a basic operation of the measuring apparatus.

FIG. 6 is a flowchart showing a control procedure of the measuring device.

FIG. 7 is a side view showing the arrangement of sampling ports in the measuring device.

FIG. 8 is an explanatory diagram of an operating state of a sensor unit in the measuring device.

FIG. 9 is a front view and a side view showing an example of a bubble blocking plate in the measuring device.

FIG. 10 is a front view and a side view showing another example of the bubble blocking plate in the measuring device.

FIG. 11 is a schematic side view showing an example of a liquid level sensor cleaning means in the measuring apparatus.

FIG. 12 is a schematic side view showing an example of another liquid level sensor cleaning means in the same measuring apparatus.

FIG. 13 is a schematic side view showing an example of another liquid level sensor cleaning means in the same measuring apparatus.

FIG. 14 is a cross-sectional view showing an example of a sensor unit cleaning means in the measuring apparatus.

[Explanation of symbols]

 2A, 2B batch tank 3 sludge thickening tank 8A, 8B sludge drawing pump 9A, 9B water level meter 10 concentrated sludge drawing pump 11 controller 12 measuring device 13A, 13B sampling / discharging pipe 14A, 14B sampling port 15A, 15B washing nozzle 32 sample 33 Air bubbles 34 Bubble blocking plate 36 Washing nozzle 36a Washing water 37 Sludge 42 Injection nozzle SS Sensor section VT Vacuum tank P-1 Vacuum pump C-1 Air compressor MV-1 to MV-3 Motor valve SV-1 to SV-6 Solenoid valve LS-1 Liquid level sensor LS-2 Second liquid level sensor SS-1 Measuring cell

Claims (10)

[Claims] 1. A batch tank for sequentially performing the steps of inflow, aeration and agitation, precipitation, and discharge, measuring means for measuring the concentration of activated sludge in the batch tank, and excess sludge discharge means for discharging excess sludge in the batch tank. And a control means for outputting an operation command to the excess sludge discharge means so as to obtain a target sludge concentration according to the sludge concentration measured by the measuring means, and a sludge concentration method for storing and concentrating the discharged excess sludge. In a batch type sewage treatment apparatus provided with a tank and a concentrated sludge discharging means for discharging the concentrated sludge in the sludge thickening tank, the control means controls the accumulated sludge discharging means from the integrated value of the operating time of the excess sludge discharging means. A batch type sewage treatment apparatus having a function of calculating an operation time and outputting an operation command to the concentrated sludge discharging means. 2. A batch tank for sequentially performing the steps of inflow, aeration and agitation, precipitation, and discharge, measuring means for measuring the concentration of activated sludge in the batch tank, and excess sludge discharge means for discharging excess sludge in the batch tank. And a control means for outputting an operation command to the excess sludge discharge means so as to obtain a target sludge concentration according to the sludge concentration measured by the measuring means, and a sludge concentration method for storing and concentrating the discharged excess sludge. In a batch type sewage treatment apparatus provided with a tank and a concentrated sludge discharging means for discharging the concentrated sludge in the sludge thickening tank, measurement and measurement are performed when a signal indicating that an inflow process is started in a predetermined sequence is detected. Start the counting of the waiting time until the operation of excess sludge discharge means and concentrated sludge discharge means, and then only when the signal indicating that the water level in the batch tank has reached the set upper limit is detected A batch type sewage treatment apparatus comprising: a control means for executing the operation of the excess sludge discharge means and the concentrated sludge discharge means. 3. A sludge concentration measuring device for a batch type sewage treatment device, wherein a sampling port for sampling the activated sludge mixed liquid to be supplied to the measuring means is disposed between the upper limit water level and the lower limit water level of the batch tank. 4. The sludge concentration measuring device of a batch type sewage treatment apparatus according to claim 3, further comprising means for cleaning the sampling port within a time when the water level of the batch tank after the discharging step is lower than the sampling port. 5. A bubble blocking plate is provided below the sampling port for the activated sludge mixed liquid to be supplied to the measuring means, the bubble blocking plate for receiving bubbles rising from below and preventing the bubbles from reaching the sampling port. Sludge concentration measuring device for batch type sewage treatment equipment. 6. A vacuum tank for collecting the activated sludge mixed liquid to be supplied to the measuring means by suction, and a liquid level sensor for detecting that a predetermined amount of liquid has been supplied into the vacuum tank, A sludge concentration measuring device for a batch type sewage treatment device, which is provided with a cleaning means for injecting cleaning water into the liquid level sensor after each measurement. 7. A vacuum tank for collecting the activated sludge mixed liquid to be supplied to the measuring means by suction, and a liquid level sensor for detecting that a predetermined amount of liquid has been supplied into the vacuum tank. , A cleaning means for supplying cleaning water into the vacuum tank after each measurement to clean the vacuum tank and the liquid level sensor, and after supplying a predetermined amount of cleaning water or after sucking and collecting the activated sludge mixed liquid, the liquid level sensor A batch type sewage treatment apparatus provided with an abnormality detecting means for judging an abnormality when the detection signal cannot be sensed or when the detection signal from the liquid level sensor is sensed when the residual water in the vacuum tank is discharged. Sludge concentration measuring device. 8. The safety device according to claim 6, wherein a second liquid level sensor is arranged above the liquid level sensor, and a safety device for forcibly stopping suction and cleaning by the operation of the second liquid level sensor is provided. Sludge concentration measuring device for batch type sewage treatment equipment. 9. A batch type sewage treatment apparatus comprising a cleaning means for directly injecting a cleaning fluid inside a measuring means for measuring the sludge concentration by passing the collected activated sludge mixed solution. Sludge concentration measuring device. 10. A batch type sewage treatment characterized in that the sampling pipe for supplying the activated sludge mixed liquid to the measuring means and the discharge pipe for returning the sampled activated sludge mixed liquid to the batch tank are also used as the same pipe. Sludge concentration measuring device.