Control device, liquid processing system, control method, and control program

Abstract

The object of the present invention is to control the water level in a tank as a destination while eliminating pump clogging when a liquid to be treated is transferred using a pump. [Solution] The control device is equipped with a processor that samples the water level of a second tank to which the liquid to be treated stored in a first tank is transferred at predetermined intervals, statistically processes the sampled water level data over a predetermined period, and intermittently controls a pump that transfers the liquid to be treated based on the statistically processed value so that the on time width does not exceed a predetermined standard.

Description

[Technical Field]

[0001] The technology of the present disclosure relates to a control device, a liquid processing system, a control method, and a control program. [Background technology]

[0002] Patent Document 1 states, "The program installed in the delay control chip U4 is used to perform the delay control function. The specific delay control process is shown in FIG. 6. That is, when pin 7 of the delay control chip U4 receives a low level, pin 6 of the chip outputs a high level during the first preset time period T1 and has no output during the second preset time period T2. The first preset time period T1 and the second preset time period T2 are intermittent startup periods for the drainage pump. To exhaust most of the air in the working chamber of the impeller of the drainage pump, several intermittent startup periods may be set as necessary after the second preset time period T2. Thereafter, a high level is output during the third preset time period T3 to properly start and operate the drainage pump. When pin 7 of the delay control chip U4 switches from a low level to no input, pin 6 of the chip continues to output a high level during the preset fourth time period T4. After the fourth time period T4, pin 6 of the delay control chip U4 has no output." [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2016-513194 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventionally, when a pump is used to transfer a liquid to be treated (referred to as "liquid to be treated") from a source tank to a destination tank, there has been a problem of the pump becoming clogged. Also, there is a need to prevent the water level in the destination tank from deviating from a target water level.

[0005] Therefore, the present disclosure aims to provide an apparatus, system, method, and program that, when using a pump to transport a liquid to be treated, can control the water level in a tank to which the liquid is being transported while eliminating pump clogging. [Means for solving the problem]

[0006] A control device according to a first aspect of the present disclosure includes a processor that samples the water level of a second tank to which the liquid to be treated stored in a first tank is transferred at a predetermined period, statistically processes the sampled water level data over a predetermined period, and, based on the statistically processed values, intermittently controls a pump that transfers the liquid to be treated so that the on time width does not exceed a predetermined standard.

[0007] A control device according to a second aspect of the present disclosure is the control device according to the first aspect, wherein the processor intermittently controls the pump so that the on-time width is shorter than the period.

[0008] A control device according to a third aspect of the present disclosure is the control device according to the first or second aspect, wherein the processor executes the sampling and the statistical processing at least at a timing when the pump is turned off.

[0009] A control device according to a fourth aspect of the present disclosure is the control device according to any one of the first to third aspects, wherein the processor averages the water level data.

[0010] A liquid treatment system according to a fifth aspect of the present disclosure includes the first tank, the second tank, and the control device according to any one of the first to fourth aspects.

[0011] A liquid treatment system according to a sixth aspect of the present disclosure is the liquid treatment system according to the fifth aspect, wherein the liquid to be treated is wastewater, the first tank is a wastewater adjustment tank that temporarily stores the wastewater, and the second tank is a biological treatment tank that purifies the wastewater using microorganisms.

[0012] A liquid treatment system according to a seventh aspect of the present disclosure is the liquid treatment system according to the fifth or sixth aspect, wherein the second tank is provided with an air supply device.

[0013] A control method according to an eighth aspect of the present disclosure includes a computer sampling the water level of a second tank to which the liquid to be treated stored in a first tank is transferred at a predetermined period, statistically processing the sampled water level data over a predetermined period, and intermittently controlling a pump that transfers the liquid to be treated based on the statistically processed value so that the on time width does not exceed a predetermined standard.

[0014] A control program according to a ninth aspect of the present disclosure causes a computer to perform the following processes: sampling the water level of a second tank to which the liquid to be treated stored in a first tank is transferred at a predetermined period; statistically processing the sampled water level data over a predetermined period; and intermittently controlling a pump that transfers the liquid to be treated based on the statistically processed value so that the on time width does not exceed a predetermined standard.

[0015] According to the control device, liquid processing system, control method, and control program disclosed herein, when a pump is used to transfer a liquid to be processed, it is possible to control the water level in the destination tank while clearing blockages in the pump. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a diagram showing an example of a schematic configuration of a liquid processing system 1 according to the present embodiment. [Figure 2]1 is a diagram illustrating an example of a hardware configuration of a control device 100 according to the present embodiment. [Figure 3] 1 is a diagram illustrating an example of a functional configuration of a control device 100 according to the present embodiment. [Figure 4] FIG. 4 is a diagram showing an example of operation timing of the control device 100 according to the present embodiment. [Figure 5] FIG. 1 is a diagram showing a schematic configuration of a liquid treatment system 1′ according to the prior art. DETAILED DESCRIPTION OF THE INVENTION

[0017] An example of an embodiment of the technology of the present disclosure will be described below with reference to the drawings. Note that the same reference numerals are used to designate identical or equivalent components and parts in each drawing. Furthermore, the dimensional proportions of the drawings may be exaggerated for the sake of explanation and may differ from the actual proportions.

[0018] For the sake of convenience, the prior art will be described before disclosing the present embodiment. Note that, where the present embodiment and the prior art differ in function, configuration, or structure, the two will be distinguished by adding a "'" to the reference numeral in the description of the prior art.

[0019] 5 is a diagram showing an example of a schematic configuration of a liquid treatment system 1' according to the prior art. The liquid treatment system 1' includes a first tank 10, a second tank 20, a third tank 30, and a control device 100'.

[0020] Any liquid may be treated by the liquid treatment system 1'. Hereinafter, a case will be described as an example in which the liquid treatment system 1' is a circulating water treatment system that biologically treats domestic wastewater and circulates it as domestic water.

[0021] The first tank 10 is a storage tank that temporarily stores the liquid to be treated. Here, the first tank 10 is assumed to be a wastewater adjustment tank that temporarily stores wastewater.

[0022] A first pump 11' is provided in the first tank 10. The first pump 11' is a pump for transferring the liquid to be treated from the first tank 10 to the second tank 20. Here, the first pump 11' is a wastewater introduction peristaltic pump for introducing wastewater into the second tank 20. A peristaltic pump is a pump that transfers liquid by squeezing a soft tube made of silicon or the like with a roller.

[0023] The second tank 20 is a tank to which the liquid to be treated is transferred, and performs liquid treatment on the liquid to be treated transferred from the first tank 10. Here, the second tank 20 is assumed to be a biological treatment tank that purifies wastewater using microorganisms.

[0024] The second tank 20 is provided with a second pump 21, a water level indicator 22, and a blower 23. The second pump 21 is a pump for transferring the liquid in the second tank 20 as treated water from the second tank 20 to the third tank 30. Here, the second pump is assumed to be a membrane filtration pump that filters the biologically treated liquid by sucking it with the pump.

[0025] The water level gauge 22 measures the water level in the second tank 20. The water level gauge 22 may be of any type, and may be a contact type such as a pressure type, a capacitance type, or a float type, or a non-contact type such as a radio wave type or an ultrasonic type.

[0026] The blower 23 is a device that supplies air. Here, the blower 23 is assumed to be an aeration device that activates the microorganisms in the second tank 20 by sending air to supply oxygen. Since the blower 23 constantly supplies air, the liquid surface in the second tank 20 is wavy. Therefore, it is important to accurately grasp the water level in the second tank 20, as incorrect control of the water level can cause overflow.

[0027] The third tank 30 is a storage tank that temporarily stores the treated water. Here, the third tank 30 is assumed to be a treated water storage tank that temporarily stores the treated water.

[0028] A third pump 31 is provided in the third tank 30. The third pump 31 is a pump for transferring the treated water from the third tank 30 to the outside of the liquid treatment system 1'. Here, the third pump 31 is assumed to be a return pump that returns the treated water to the source of the domestic wastewater as domestic water.

[0029] The control device 100′ controls the entire liquid treatment system 1′. More specifically, the control device 100′ may be communicatively connected to the first pump 11′, the second pump 21, the water level gauge 22, the blower 23, and the third pump 31 via wired or wireless communication. The control device 100′ may control the blower 23 to control the amount of air supplied. The control device 100′ may sample the water level measured by the water level gauge 22, and when a drop in the water level in the second tank 20 is detected, the control device 100′ may control the first pump 11′ to transfer the liquid to be treated from the first tank 10 to the second tank 20. The control device 100′ may control the second pump 21 to transfer the treated water from the second tank 20 to the third tank 30. The control device 100′ may also control the third pump 31 to transfer the treated water from the third tank 30 to the outside.

[0030] In this liquid treatment system 1', control device 100' must accurately grasp the water level in second tank 20 and stop first pump 11', which is a transfer pump, when the target water level is reached. Here, in a conventional liquid treatment system 1', a small-capacity peristaltic pump with a flow rate of approximately 200 milliliters per minute was used as first pump 11'. Therefore, the water level in second tank 20, the transfer destination, rose slowly. Even if the water level fluctuated slightly due to blower 23, the water level could be accurately grasped through statistical processing.

[0031] Here, if moving average processing, for example, is used as the statistical processing, it is known that a certain number of water level samples are required, and the period required for this (for example, 1 sample / second x 60 seconds = 1 minute) can be sufficiently ignored in the case of transfers with small flow rates. Therefore, conventional technology was able to accurately detect the water level and stop the transfer pump at the appropriate time.

[0032] However, there has been a problem in that the inside of the pump tube becomes clogged due to viscous substances and debris contained in the wastewater. This problem is not limited to cases where the liquid to be treated is domestic wastewater, but can similarly occur when the liquid to be treated contains substances that can cause clogging. Furthermore, this problem is not limited to cases where the first pump 11' is a peristaltic pump, but can similarly occur when the momentum of the first pump 11' is insufficient to push out the substances that cause clogging.

[0033] Therefore, in this embodiment, a pump capable of suctioning at a high flow rate is employed as the transfer pump, and pump clogging is eliminated by forcefully suctioning the liquid to be treated. It is clear that when a high-flow pump is used, the second tank 20, which is the transfer destination, reaches the target water level in a shorter time than in conventional technology. As mentioned above, it is also necessary to accurately grasp the water level in the second tank 20, which is the transfer destination. However, for example, if a transfer pump of 10 to 100 liters per minute is used to transfer water instead of a 200 milliliters per minute peristaltic pump, the water level changes significantly during the water transfer, making it impossible to accurately measure the water level.

[0034] Therefore, in this embodiment, the transfer pump is intermittently controlled to eliminate blockages in the pump while controlling the water level in the destination tank. This will be described in detail.

[0035] 1 is a diagram showing an example of a schematic configuration of a conventional liquid treatment system 1' according to this embodiment. The differences from the conventional liquid treatment system 1' are that first pump 11' is changed to first pump 11 and that control device 100' is changed to control device 100. Other points may be the same as those of the conventional liquid treatment system 1', and therefore, redundant explanations will be omitted here.

[0036] The first pump 11 is a pump for transferring the liquid to be treated from the first tank 10 to the second tank 20. In the present disclosure, when the term "pump" is simply used, it may be interpreted as referring to the "first pump 11." Examples of types of the first pump 11 include liquid transfer devices such as peristaltic pumps, diaphragm pumps, dispensers, gear pumps, and piston pumps, as well as various types of pumps that transfer large volumes of liquid, such as submersible pumps, centrifugal pumps, axial pumps, and turbine pumps.

[0037] In this embodiment, it is particularly preferable to employ a large-capacity liquid transfer device as first pump 11. Note that "large capacity" here means a capacity that is relatively larger than that of first pump 11' employed in conventional liquid processing system 1'. Specifically, for example, a capacity of approximately 10 liters / minute to 100 liters / minute is preferable because it can suction with sufficient force to clear clogging of the pump.

[0038] The following description will be given as an example of using a submersible pump as the first pump 11. Therefore, in this figure, the first pump 11 is shown submerged in the liquid to be treated stored in the first tank 10.

[0039] The control device 100 controls the entire liquid treatment system 1. More specifically, the control device 100 may be communicatively connected to the first pump 11, the second pump 21, the water level indicator 22, the blower 23, and the third pump 31 via wired or wireless communication. The control device 100 may control the blower 23 to control the amount of air supplied. The control device 100 may sample the water level measured by the water level indicator 22, and when a drop in the water level in the second tank 20 is detected, the control device 100 may intermittently control the first pump 11 to transfer the liquid to be treated from the first tank 10 to the second tank 20. The control device 100 may control the second pump 21 to transfer the treated water from the second tank 20 to the third tank 30. The control device 100 may control the third pump 31 to transfer the treated water from the third tank 30 to the outside.

[0040] 2 is a diagram showing an example of the hardware configuration of the control device 100 according to this embodiment. The control device 100 includes a processor 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, a storage 104, a communication interface 105, and a user interface 106. These components are connected via a bus 109 so as to be able to communicate with each other.

[0041] The processor 101 executes various programs and controls each component. Here, the processor 101 is assumed to be a CPU (Central Processing Unit). The ROM 102 stores various programs and various data. The RAM 103 temporarily stores programs or data as a working area. The storage 104 is configured with an HDD (Hard Disk Drive) or an SSD (Solid State Drive), and stores various programs including an operating system and various data.

[0042] In the control device 100 according to this embodiment, a control program 107 is stored in the ROM 102 or the storage 104. In the present diagram, a case where the control program 107 is stored in the storage 104 is shown as an example. The processor 101 reads the control program 107 from the ROM 102 or the storage 104 and executes it using the RAM 103 as a working area, thereby controlling each component and performing various arithmetic processing in accordance with the control program 107.

[0043] The communication interface 105 is an interface through which the control device 100 communicates with other devices. The user interface 106 is an input / output interface through which the control device 100 exchanges information with a user. The user interface 106 may include input devices such as a mouse, keyboard, touch panel, and microphone, and output devices such as a monitor and speaker.

[0044] 3 is a diagram showing an example of the functional configuration of the control device 100 according to this embodiment. The control device 100 includes a sampling unit 110, a statistical processing unit 120, and a control unit 130. These functional configurations may be implemented in the processor 101 by the processor 101 reading out a control program 107 from the ROM 102 or the storage 104, loading the control program 107 into the RAM 103, and executing the program.

[0045] The sampling unit 110 samples the water level of the second tank 20 at a predetermined cycle. As an example, the sampling unit 110 may sample the water level of the second tank 20 measured by the water level gauge 22 at a rate of 1 sample per second.

[0046] The statistical processing unit 120 performs statistical processing on the water level data obtained by sampling the water level over a predetermined period. Below, an example will be described in which the statistical processing unit 120 averages the water level data. Examples of such averaging processing include moving average processing and approximation processing (smoothing processing). As an example, the statistical processing unit 120 may perform moving average processing on the water level data obtained by sampling the water level every second over a period of 60 seconds.

[0047] The control unit 130 controls the first pump 11 intermittently based on the statistically processed value so that the duration of the ON time does not exceed a predetermined standard.

[0048] 4 is a diagram showing an example of the operation timing of the control device 100 according to this embodiment. In this diagram, the horizontal axis represents time, and from the top to the bottom, the timing of sampling, the timing of statistical processing, and the timing of intermittent control are shown.

[0049] This figure shows an example of operation timing when the sampling period (predetermined period) is 1 second, the target period (predetermined period) for the moving averaging process is 60 seconds, the ON time width is 3 seconds, and the OFF time width is 57 seconds. Regarding the timing of the statistical process shown in the center of this figure, three cases are illustrated to explain that the target period for the moving averaging process can be a predetermined period starting from various time points. However, it is more preferable to perform the moving averaging process on water level data for a predetermined period (i.e., the predetermined period shown by the solid line in this figure) from the time when the first pump 11 can be switched from OFF to ON to the time when the first pump 11 can next be switched from OFF to ON (i.e., time T01 to time T11, time T11 to time T21, time T21 to time T31, etc. in this figure).

[0050] As shown in the figure, the processor 101 may intermittently control the first pump 11 so that the on-time width is shorter than a predetermined period. Also, as shown in the figure, the processor 101 may perform sampling and statistical processing at least at the timing when the first pump 11 is turned off. This will be described in detail.

[0051] The processor 101 controls the timing of water transfer based on the water level of the second tank 20, which is determined from values ​​obtained by statistically processing water level data (for example, moving average values). At this time, the number of times water is transferred by the first pump 11 is determined based on the immediately preceding water level. The duration of time that the first pump 11 is on may be fixed or variable. Here, the duration of time that the first pump 11 is on is assumed to be fixed at 3 seconds.

[0052] In this situation, it is assumed that the moving average value from time T01 to time T11 indicates that the water level in the second tank 20 is lower than the target water level. In this case, the processor 101 determines to turn on the first pump 11 at time T11 and operates the first pump 11. As a result, the first pump 11 is turned on for three seconds from time T11 to time T12, and then turned off for 57 seconds from time T12 to time T21. Next, it is assumed that the moving average value from time T11 to time T21 indicates that the water level in the second tank 20 is still lower than the target water level. In this case, the processor 101 determines to turn on the first pump 11 at time T21 and operates the first pump 11. As a result, the first pump 11 is turned on for three seconds from time T21 to time T22, and then turned off for 57 seconds from time T22 to time T31. Next, it is assumed that it is determined from the moving average value from time T21 to time T31 that the water level in the second tank 20 is still lower than the target water level. In this case, the processor 101 decides to turn on the first pump 11 at time T31 and operates the first pump 11. As a result, the first pump 11 is turned on for three seconds from time T31 to time T32, and then turned off for 57 seconds from time T32 to time T41 (not shown). Next, it is assumed that it is determined from the moving average value from time T31 to time T41 that the water level in the second tank 20 has reached the target water level. In this case, the processor 101 decides not to turn on the first pump 11 at time T41. As a result, the processor 101 intermittently controls the first pump 11 three times.

[0053] In this way, for example, the processor 101 controls the water level in the second tank 20 by controlling the operating time of the first pump 11. At this time, the processor 101 does not take into account the capacity of the first pump 11. In this way, by adopting a design that is not dependent on the capacity of the pump used, it is possible to control the water level without using a flow meter.

[0054] Here, the processor 101 limits the amount of liquid transferred at one time and transfers it in stages over multiple transfers, which means that the transfer takes longer than when the amount transferred at one time is not limited. However, when the second tank 20 to which the liquid is transferred is a biological treatment tank, it is known that purification using microorganisms takes time in the first place. Therefore, even if the liquid to be treated is transferred little by little in stages, as in this embodiment, no time is lost in the liquid treatment system 1 as a whole. Therefore, it can be said that the technology of this embodiment is particularly well suited to a liquid treatment system 1 that involves biological treatment.

[0055] Even when the first pump 11 is controlled intermittently in this manner, the processor 101 can perform sampling and averaging processing regardless of the timing of the intermittent control. That is, the processor 101 continues sampling and averaging processing not only when the first pump 11 is turned on but also when the first pump 11 is turned off. This provides a sufficient pump stop period before the next transfer, and this period can be used for sampling the water level and averaging processing. Therefore, the sufficient sampling period enables accurate water level detection and prevents deviation from the target water level.

[0056] In the above description, an example was given in which the sampling and averaging processes are performed when the first pump 11 is turned on. However, when the first pump 11 is turned on, the liquid level in the second tank 20, which is the transfer destination, may ripple. This may become more pronounced as the capacity of the first pump 11 increases.

[0057] Therefore, the processor 101 does not need to sample the water level of the second tank 20 when the first pump 11 is turned on. The processor 101 may then perform averaging processing, excluding the sample value when the first pump 11 is turned on. That is, the processor 101 only needs to perform sampling and statistical processing at least when the first pump 11 is turned off.

[0058] However, the present invention is not limited to this. Executing sampling and statistical processing when the first pump 11 is turned off is not an essential configuration in this embodiment, and the present invention does not exclude the execution of sampling and statistical processing only when the first pump 11 is turned on.

[0059] As an alternative to this embodiment, it is possible to control the first pump 11 based on instantaneous sample values ​​without performing averaging. However, this approach would result in the first pump 11 not being able to be stopped accurately, and the water level in the second tank 20 would deviate significantly from the target water level.

[0060] Another option is to shorten the sampling period, obtain multiple samples in a short period of time, and then perform averaging. However, with this option, the period of water level fluctuations is longer than the sampling period, making it impossible to obtain an accurate water level.

[0061] Therefore, based on these results, in this embodiment, a proposal was adopted in which the amount transferred at one time is limited and the amount is transferred in multiple batches.

[0062] In this manner, the control device 100 according to this embodiment samples the water level in the second tank 20 at predetermined intervals, statistically processes the sampled water level data over a predetermined period, and, based on the statistically processed values, intermittently controls the transfer pump so that the on-duration does not exceed a predetermined standard. This allows the control device 100 according to this embodiment to control the water level in the destination tank while eliminating pump blockages. Cases where it is difficult to grasp the liquid level include when the transfer rate per unit time is large, when rippling occurs due to water delivery at the destination (i.e., water delivery by the second pump 21), and when rippling occurs due to aeration at the destination (i.e., air supply by the blower 23). The control device 100 according to this embodiment can accurately grasp the water level and appropriately control the transfer rate in any of these cases.

[0063] The above-described processing can also be realized by dedicated hardware circuits. In this case, the processing may be performed by a single piece of hardware or by multiple pieces of hardware.

[0064] In addition, in the above explanation, the term "processor" refers to a processor in a broad sense, and includes general-purpose processors (e.g., CPU: Central Processing Unit, etc.) and dedicated processors (e.g., GPU: Graphics Processing Unit, ASIC: Application Specific Integrated Circuit, FPGA: Field Programmable Gate Array, programmable logic device, etc.).

[0065] Furthermore, the processor operations described above may not only be performed by a single processor, but may also be performed by multiple processors located at physically separate locations working together. Furthermore, the order of the processor operations is not limited to the order described above and may be changed as appropriate.

[0066] The above-mentioned program may be provided by a computer-readable non-transitory recording medium such as a USB (Universal Serial Bus) memory, a flexible disk, or a CD-ROM (Compact Disc Read Only Memory), or may be provided online via a network such as the Internet. In this case, the program recorded on the computer-readable non-transitory recording medium is typically transferred and stored in a memory or storage device. The program may be provided as standalone application software, or may be incorporated into the software of each device as a function of the device.

[0067] The above-described program can be provided as a program product. The program product includes any product for providing the program. For example, the program product includes a program provided over a network such as the Internet, and a non-transitory computer-readable recording medium such as a CD-ROM or DVD on which the program is stored.

[0068] The present disclosure is not limited to the above, and it goes without saying that various modifications can be made without departing from the spirit of the present disclosure. [Explanation of symbols]

[0069] 1 Liquid treatment system 10 First Tank 11 First Pump 20 Second tank 21 Second Pump 22 Water level gauge 23 Blois 30 Third Tank 31 Third Pump 100 control device 101 processors 102 ROM 103 RAM 104 Storage 105 Communication Interface 106 User Interface 110 Sampling section 120 Statistical Processing Unit 130 Control Unit

Claims

1. a processor, the processor comprising: sampling the water level of a second tank to which the liquid to be treated stored in the first tank is transferred at predetermined intervals; Statistically processing the sampled water level data over a predetermined period of time; intermittently controlling a pump that transports the liquid to be treated based on the statistically processed value so that the on-time width is shorter than the period; Control device.

2. the processor performs the sampling and the statistical processing at least at the timing when the pump is turned off. The control device according to claim 1 .

3. The processor averages the water level data. The control device according to claim 1 .

4. the first tank; the second tank; The control device according to any one of claims 1 to 3, Liquid handling systems.

5. the liquid to be treated is wastewater, the first tank is a wastewater adjustment tank that temporarily stores the wastewater, The second tank is a biological treatment tank that purifies the wastewater using microorganisms. The liquid treatment system according to claim 4 .

6. The second tank is provided with an air supply device. The liquid treatment system according to claim 5 .

7. The computer sampling the water level of a second tank to which the liquid to be treated stored in the first tank is transferred at a predetermined period; statistically processing the sampled water level data over a predetermined period of time; and intermittently controlling a pump that transports the liquid to be treated based on the statistically processed value so that the on-time width is shorter than the period. Control method.

8. On the computer, a process of sampling the water level of a second tank to which the liquid to be treated stored in the first tank is transferred at a predetermined period; a process of statistically processing the sampled water level data over a predetermined period of time; and performing a process of intermittently controlling a pump that transports the liquid to be treated based on the statistically processed value so that the on-time width is shorter than the period. Control program.

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