JP2023073720A - Water level detection device and chemical injection device - Google Patents

Abstract

To provide a water level detection device and a chemical injection device capable of detecting the water level even if chemical solutions have different concentrations.SOLUTION: Water level detection devices 18 and 19 for detecting the water level of a chemical solution stored in a chemical solution tank 12 of a chemical injection device 1, includes: at least two electrodes 18b; an electrode holder 18a holding two electrodes 18b; and an electrical component 19 that applies a voltage between the two electrodes 18b according to the concentration of the chemical solution.SELECTED DRAWING: Figure 6

Description

TECHNICAL FIELD The present invention relates to a water level detection device and a liquid injector for detecting a water level.

2. Description of the Related Art Conventionally, an electrode type water level detection device is known as a device for detecting a water level. Further, for example, there is known an electrode-type water level detection device of a constant voltage application method that realizes a continuous detection method by converting a current value flowing between electrodes of a known length into a voltage value and calculating the electrode immersion length. ing.

Further, for example, in Patent Document 1, a water level detection electrode pair whose longitudinal direction is arranged in the vertical direction, and a lower end at the same height as the lower end of the water level detection electrode pair, and a length of the water level detection electrode pair A water level sensor is described in which a short first electrode pair is sealed between two resin layers.

It is also conceivable that these electrode-type water level detectors are used in a chemical injection device for injecting sodium hypochlorite used for sterilization or the like.

Japanese Patent Application Laid-Open No. 2020-3308

For example, the sodium hypochlorite used in such a chemical injection device has a concentration of 5% in addition to the general 12% concentration of the undiluted solution. A situation of replenishment is also conceivable. However, if the conductivity of the liquid for detecting the water level is different, the constant voltage application type electrode type water level detection device cannot realize the continuous detection method.

In addition, in the case of a vaporizable liquid such as sodium hypochlorite, there is a problem that the current value flowing between the electrodes fluctuates due to the air bubbles generated by electrolysis adhering to the electrodes and changing the surface area of the electrodes. , the voltage had to be applied when the water level needed to be detected. Furthermore, it is necessary to reduce the chances of voltage application in order to obtain a simple detection circuit that applies only a positive voltage.

For example, conventional water level detection devices for chemical tanks that control the operation of chemical injection pumps are generally of the float switch type that uses reed switches, but in recent years, the pump control unit has been equipped with a communication function, making maintenance easier. Communication devices carried by workers are now required to have a function to transmit water level information and water shortage alarms in chemical tanks. However, the float switch type is mainly the type that detects ON/OFF signals at a low-cost fixed point water level. It has a complicated structure and has to be expensive.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a water level detection device and a chemical injection device that can detect the water level even if the chemical solutions have different concentrations.

According to one aspect of the present invention, a water level detection device is a water level detection device for detecting the water level of a chemical liquid stored in a chemical liquid tank, comprising at least two electrodes and an electrode holder holding the two electrodes. and an electrical component that applies a voltage between the two electrodes according to the concentration of the chemical solution.

INDUSTRIAL APPLICABILITY The present invention can provide a water level detection device and a chemical injection device that can detect the water level even if the chemical solutions have different concentrations.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram schematically showing the configuration of a water treatment apparatus using a chemical injector according to one embodiment of the present invention; The front view which shows the structure of the chemical|medical solution injection apparatus with a partial cross section. The block diagram which shows the structure of the electrical equipment box of the chemical injection device. Explanatory drawing which shows an example of each data when the water level of a chemical|medical solution differs. FIG. 5 is an explanatory diagram showing an example of each data when detecting a different water level of a chemical solution with a concentration different from that in FIG. 4 ; The flow chart which shows an example of control of the same chemical injection device.

A chemical injector 1 according to an embodiment of the present invention and a water treatment apparatus 100 using the chemical injector 1 will be described below with reference to FIGS. 1 to 6. FIG.

FIG. 1 is an explanatory diagram schematically showing the configuration of a water treatment device 100 according to one embodiment of the present invention. FIG. 2 is a front view showing a partial cross-section of the structure of the chemical injection device 1 used in the water treatment device 100. As shown in FIG. FIG. 3 is a block diagram showing the configuration of the electrical box 19 of the liquid injector 1. As shown in FIG. FIG. 4 is an explanatory diagram showing an example of each data when different water levels of the chemical solution are detected, and FIG. 5 is an explanatory diagram showing an example of each data when different water levels of the chemical solution with a concentration different from that of FIG. 4 are detected. It is a diagram. FIG. 6 is a flow chart showing an example of control of the liquid injector 1. As shown in FIG. In each figure, for the sake of explanation, the configuration is shown enlarged, reduced, or omitted as appropriate.

As shown in FIG. 1 , the water treatment device 100 includes a chemical injector 1 and a water supply device 2 that supplies water to the chemical injector 1 . The water treatment apparatus 100 supplies raw water from a water supply source 101 such as a well to a water supply destination by means of a water supply device 2, and injects a chemical solution into the raw water by means of a chemical injection device 1 to treat the raw water. The destination of the water supply is variously set depending on the application, such as a filtering device for removing iron and manganese from well water, a water tank for storing well water, and a faucet for a shower or the like. In the present embodiment, the water treatment device 100 has a filtration device 3, and will be described using an example in which raw water is subjected to sterilization, iron removal, manganese removal, and the like.

As shown in FIGS. 1 and 2, the chemical injector 1 includes a pedestal 11, a chemical tank 12, a piping unit 13, a chemical injector 14, a connecting pipe 15, a pressure sensor 16, and a flow rate sensor 17. , and an electrical box 19 . The chemical injection device 1 is connected to the water supply device 2 on the primary side and to the filtering device 3 on the secondary side. The chemical injection device 1, for example, injects a predetermined amount of sodium hypochlorite as a bubbly liquid into the water flowing through the connecting pipe 15, sterilizes the water supplied from the water supply device 2, and contains deposits iron and manganese.

The pedestal 11 supports the chemical bath 12 , the chemical injector 14 , the connecting pipe 15 and the electrical equipment box 19 . The pedestal 11 supports, for example, the chemical tank 12 at a position higher than the chemical injector 14 . As a specific example, as shown in FIG. 2, the gantry 11 includes a leg portion 11a to be placed on the installation surface, a first base 11b, a wall portion 11c, and a second base 11d. For example, the leg portion 11a, the first base 11b, the wall portion 11c and the second base 11d are integrally formed.

The leg portion 11 a is placed on the installation surface of the liquid injector 1 . The first base 11b is integrally provided on the leg portion 11a. A connection pipe 15 is mounted on the upper surface of the first base 11b and is formed so as to be fixed.

The wall portion 11c is provided, for example, above the first base 11b in the depth direction of the first base 11b. The wall portion 11c is formed, for example, in the shape of a rectangular frame or plate extending upward from the first base 11b and continuous with the second base 11d.

The chemical injector 14 is fixed at the center of the wall portion 11c, for example. For example, the wall portion 11c is formed so as to be able to fix the liquid injector 14 with a fastening member such as a bolt or a screw.

The second base 11d is provided on the upper edge of the wall portion 11c, and is formed so that the chemical liquid tank 12 can be fixed on the upper surface thereof.

The first base 11b and the second base 11d are connected by a wall portion 11c, and the upper surface of the second base 11d is arranged above the upper surface of the first base 11b. In addition, the upper surface of the second base 11d is located above the liquid injector 14 provided on the wall portion 11c.

The chemical liquid tank 12 is made of a resin material, and is formed so as to be able to store a predetermined amount of chemical liquid therein. The chemical bath 12 is fixed to the upper surface of the second base 11d. A piping unit 13 is connected to a portion of the bottom portion 12a of the chemical bath 12 . The chemical bath 12 includes a supply port 12b for supplying the chemical to the inside, and a lid 12c covering the supply port 12b.

The piping unit 13 fluidly connects the chemical bath 12 and the chemical injector 14 . The piping unit 13 forms a flow path for the chemical from inside the chemical tank 12 to the chemical injector 14 . As a specific example, as shown in FIG. 2, the piping unit 13 includes a connection pipe 21, an exhaust tube 22, a connection pipe 23, and an on-off valve 24.

The connection pipe 21 has one end connected to the chemical bath 12 and the other end branched in two directions and connected to an exhaust tube 22 and a connection pipe 23 . Specifically, the connection pipe 21 is a bent pipe formed by bending into an L shape. The connection pipe 21 includes a threaded portion 31 , a flange 32 and a nut 33 on one end side connected to the chemical bath 12 . In addition, the connection pipe 21 is provided with an upper branch portion 34 and a lower branch portion 35 branching in two directions, upward and downward, on the other end side. Further, the connecting pipe 21 is formed with a mounting portion 36 for the on-off valve 24 at its bent portion.

The threaded portion 31 is formed at one end of the connection pipe 21 . The threaded portion 31 is a male thread formed on the outer surface of one end of the connection pipe 21 . The screw portion 31 is inserted into the chemical bath 12 through a hole formed in the bottom portion 12 a of the chemical bath 12 . The flange 32 contacts the lower surface of the bottom portion 12a of the chemical tank 12 when the screw portion 31 is inserted through the hole of the bottom portion 12a. Moreover, the flange 32 is formed so that a packing can be attached to the contact surface with the lower surface of the bottom portion 12 a of the chemical bath 12 .

The nut 33 is screwed onto the threaded portion 31 . The flange 32 and the nut 33 are fixed to the bottom portion 12 a of the chemical tank 12 by fastening the nut 33 to the screw portion 31 in the chemical tank 12 .

The exhaust tube 22 is a tube whose one end is connected to the upper branch portion 34 and is transparent or through which the chemical solution can be visually recognized. The other end of the exhaust tube 22 is open so as to be open to the atmosphere. The exhaust tube 22 constitutes, for example, a water gauge formed so that the water level of the chemical liquid in the exhaust tube 22 can be visually recognized.

As a specific example, the exhaust tube 22 is fixed to the chemical tank 12 along the outer surface of the chemical tank 12 upward from the upper branch portion 34 . In addition, the exhaust tube 22 has a floating ball 38 floating in the chemical liquid provided inside, and a water level at which the capacity of the chemical liquid in the chemical tank 12 can be visually confirmed from the floating ball 38 floating in the chemical liquid in the exhaust tube 22 or the chemical liquid. It has scale 39 . For example, the water level scale 39 is formed by a waterproof seal or the like, and is a scale attached to the outer surface of the chemical tank 12, a scale printed on the exhaust tube 22, or a scale printed on the chemical tank 12 or formed by unevenness. such as a scale.

The connecting pipe 23 has one end connected to the lower branch portion 35 and the other end connected to the liquid injector 14 . The connecting pipe 23 has flexibility. For example, the connecting pipe 23 is made of a resin tube or the like that is flexible and resistant to chemicals.

The on-off valve 24 is provided at a mounting portion 36 provided at a bent portion on the primary side of the upper branch portion 34 and the lower branch portion 35 of the connection pipe 21 . The on-off valve 24 is formed so as to be able to manually open and close the pipe line of the connection pipe 21 .

The chemical injector 14 pumps a certain amount of chemical liquid and connects the volumetric pump 41 capable of injecting the chemical liquid into the connecting pipe 15, the volumetric pump 41 and the connecting pipe 15, and prevents the backflow of the chemical liquid injected into the connecting pipe 15 and the well water. and a drug solution injection part 42 formed to be preventable.

The volumetric pump 41 is a liquid injection pump that injects liquid medicine. A diaphragm pump, for example, is used as the volumetric pump 41 . For example, the positive displacement pump 41 includes a pump casing 41a, a diaphragm provided in the pump casing 41a, and a DC solenoid that is a motor that drives the diaphragm. The positive displacement pump 41 includes a chemical liquid suction port 41b and a chemical liquid discharge port 41c provided in a pump casing 41a.

The suction port 41b is provided at the bottom of the pump casing 41a. The suction port 41 b is connected to the connecting pipe 23 . The discharge port 41c is provided in the upper part of the pump casing 41a. The discharge port 41c is connected to the liquid injection part 42 . The discharge port 41c is configured by, for example, a branch pipe, one branch of which is connected to the liquid injection part 42, and the other branch of which is provided with a plug 41d.

Such a positive displacement pump 41 is fixed to the wall portion 11 c and arranged below the upper surface of the bottom portion 12 a of the chemical bath 12 . The displacement pump 41 is arranged with a solenoid, which is a motor, positioned inside the wall portion 11c. The positive displacement pump 41 is fixed to the wall portion 11c by a fastening member.

The chemical injection part 42 includes a connecting pipe 42a, a first check valve 42b provided at one end of the connecting pipe 42a, and a nozzle 42c provided in the first check valve 42b and communicating with the connecting pipe 15. and a second check valve 42d provided in the nozzle 42c. The connecting pipe 42a is formed of, for example, a flexible resin tube or the like, like the connecting pipe 23. As shown in FIG.

The first check valve 42b regulates the flow of liquid from the nozzle 42c side to the volumetric pump 41. As shown in FIG. That is, the first check valve 42b prevents the liquid from flowing back to the volumetric pump 41 from the nozzle 42c side. The first check valve 42b has, for example, a ball and a spring. The first check valve 42b closes the pipeline by urging the ball toward the primary side by a spring. The pipe is opened by the movement of the ball.

The nozzle 42 c injects into the connecting pipe 15 the chemical liquid supplied from the volumetric pump 41 through the first check valve 42 b.

The second check valve 42d regulates the flow of liquid from the connecting pipe 15 to the nozzle 42c. That is, the second check valve 42d prevents the liquid flowing through the connecting pipe 15 from flowing back to the nozzle 42c. The second check valve 42d is made of, for example, an elastically deformable resin material and has a bottomed tubular shape. The second check valve 42d expands at its tip due to the pressure of the liquid medicine when the liquid medicine is supplied from the volumetric pump 41, widens the cross-shaped notch, and opens to supply the liquid medicine to the connecting pipe 15.

The connecting pipe 15 is a pipe whose primary side is connected to the water supply device 2 and whose secondary side is connected to the filtering device 3 . The connecting pipe 15 has, for example, a mounting portion 15a to which the liquid injection portion 42 is connected at the secondary side end portion. Further, the connecting pipe 15 is provided with a pressure sensor 16 and a flow rate sensor 17 on the primary side of the mounting portion 15a.

The pressure sensor 16 is connected to the electrical box 19 by a signal line, for example. The pressure sensor 16 outputs an electrical signal corresponding to the pressure of the fluid inside the connecting pipe 15 to the electrical equipment box 19 .

The flow rate sensor 17 is connected to the electrical box 19 by a signal line, for example. The flow sensor 17 is an impeller-type flow sensor. The flow rate sensor 17 transmits a signal corresponding to the detected flow rate to the electrical equipment box 19 . As a specific example, the flow sensor 17 has, for example, a rotary blade that rotates due to the flow of the fluid in the connecting pipe 15, a magnet, and a transmitter that detects the magnetic force of the magnet and outputs an electric signal. An electrical signal corresponding to the flow rate is output based on the magnetic force detected along with.

The water level detection sensor 18 includes an electrode holder 18a and at least two electrodes 18b held by the electrode holder 18a. The water level detection sensor 18 is electrically connected to an electrical box 19, which is an electrical component, via a signal line or the like. The water level detection sensor 18 outputs a signal based on the water level to the electrical equipment box 19 as a voltage is applied between the two electrodes 18b by the electrical equipment box 19, which is an electrical component. That is, the water level detection sensor 18 and the electrical equipment box 19 constitute a water level detection device that detects the water level of the chemical solution in the chemical solution tank 12 .

The electrode holder 18a is fixed to the ceiling of the chemical bath 12 while holding two electrodes 18b.

One of the two electrodes 18b is set shorter than the other, for example. Note that the two electrodes 18b may have the same length. Two electrodes 18b, separated by a predetermined distance, in this embodiment 1.6 cm, and differing in length by 3 cm, are held in electrode holder 18a.

For example, when the electrode holder 18a is fixed to the ceiling of the chemical tank 12, the lower end of the short electrode 18b has a length that is at the same position as the water level, and the long electrode 18b is positioned lower than the water level. and the length is set to a position higher than the bottom portion 12 a of the chemical bath 12 . The drought water level is set at a position higher than the volumetric pump 41 , more preferably at a position higher than the suction port 41 b of the volumetric pump 41 .

The electrical equipment box 19 , for example, drives and controls the volumetric pump 41 to control the amount of the chemical liquid injected from the volumetric pump 41 into the connecting pipe 15 . Also, the electrical equipment box 19 detects the water level of the chemical solution in the chemical solution tank 12 .

As shown in FIG. 3, the electrical box 19 includes, for example, a communication unit 51, an input unit 52, an interface 53, a display unit 54, a storage unit 55, a DC voltage drive circuit 56, a drive unit 57, A control unit 58 is provided.

The communication section 51 is controlled by a control section 58 . The communication unit 51 uses a wired communication technology such as USB, Bluetooth (registered trademark) (for example, Bluetooth Low Energy standard (BLE standard)), Wi-Fi (registered trademark), near field communication such as NFC (Near Field Communication). Wireless communication technology, general-purpose wireless communication technology including mobile phone lines such as LTE (Long Term Evolution) (registered trademark), and long-distance wireless communication technology including dedicated wireless communication technology such as sigfox (registered trademark) Any communication interface capable of communicating with a communication terminal using technology. Here, the communication terminal is a communication device provided outside, which is different from the liquid injector 1 .

The communication unit 51 communicates with a communication terminal for inspection, for example, at the time of shipment or maintenance of the chemical injection device 1, and receives data as various parameters such as function parameters, internal parameters, and external parameters of the chemical injection device 1. , various programs for driving and controlling the displacement pump 41 and calculating the water level of the chemical solution, and change instructions for changing these data and programs, and transmit them to the storage unit 55 and the control unit 58 .

The input unit 52 is an input interface for accepting user input. The input unit 52 is, for example, an operation panel including buttons. The input unit 52 is a device that receives user input, such as a touch panel, keyboard, and mouse. The input unit 52 can input the concentration of the chemical liquid supplied to the chemical liquid tank 12 .

The interface 53 is connected with the pressure sensor 16 , the flow rate sensor 17 and the water level detection sensor 18 . In addition, the interface 53 can electrically connect other devices. That is, the interface 53 is a terminal or circuit to which various devices are electrically connected.

The display unit 54 has, for example, a display device such as a segment display, a liquid crystal display, or an organic EL display, or a lighting unit using an LED (Light Emitting Diode) or the like. In FIG. 2 of this embodiment, the display unit 54 is formed by an information panel having a three-digit segment display and a plurality of LEDs.

The storage unit 55 is a storage medium from which data can be read and written. The storage unit 55 includes so-called memory and storage. For example, the storage unit 55 includes a non-volatile memory such as EEPROM (Electrically Erasable Programmable Read-Only Memory) (registered trademark), ROM (Read only memory), RAM (Random Access Memory), or NAND flash memory. The storage unit 55 also includes an SSD (Solid State Drive) equipped with a flash memory. Note that the storage unit 55 is not limited to these, and various storage media can be used. In this embodiment, as shown in FIG. 3, the storage unit 55 has, for example, an EEPROM 55a and a RAM 55b.

The storage unit 55 stores data as various parameters such as functional parameters, internal parameters, and external parameters used by the control unit 58, various data and programs used for controlling the volumetric pump 41 and calculating the level of the chemical solution.

Here, the various data used for calculating the water level of the chemical are, for example, stored at the time of shipment, or the distance d (cm) between the two electrodes 18b, which is input by the input unit 52 when the water level detection sensor 18 is installed, The data includes the half circumference nD/2 (cm) of the electrode 18b, the voltage dividing resistance R1 (Ω), the cell constant determined by the surface area of the electrode 18b, the conductivity with respect to the concentration X (%) of the chemical solution, and the like. The concentration X of the chemical solution is input by the input unit 52 based on the chemical solution filled in the chemical tank 12 .

Further, the following arithmetic expressions (1) to (9) for calculating the electrode immersion length L are stored as a program used for detecting the water level of the chemical solution.

For example, the distance between the electrodes is d (cm), the chemical liquid contact area is A (cm ² ), the electrode half circumference is nD/2 (cm), the chemical concentration is X (%), the electrode immersion length is L (cm), The specific resistance is r (Ω cm), the electrical resistance is Rc (Ω), the voltage applied to the two electrodes 18b is V (V), the current during water conduction is I (mA), and the voltage dividing resistance is R1 (Ω). , the inter-electrode voltage during water conduction is Ve (V), and the detection voltage during water conduction is Vr (V).
A=πD/2×L (1)
Vr=V×R1/(r×d/(πd/2×I)+R1) (2)
Vr=V×R1/(r×d/A+R1) (3)
r=100000/((6666/12)×X) (4)
Rc=r×d/A (5)
V=10/X (6)
I=V/(Rc+R1)×1000 (7)
Ve=V×Rc/(Rc+R1) (8)
Vr=V×R1/(Rc+R1) (9)
becomes.

The storage unit 55 also stores, for example, operation data of the displacement pump 41 and a recommended replenishment water level L1, which is a water level higher than the drought water level and at which replenishment of the chemical solution is recommended. For convenience of explanation, the following description assumes that the water level is L2.

The DC voltage drive circuit 56 is a typical circuit that applies a voltage V between the two electrodes 18b of the water level detection sensor 18. As shown in FIG. The voltage V applied by the DC voltage drive circuit 56 is calculated and set from the concentration X (%) of the chemical liquid based on the above-described arithmetic expression (6).

The drive unit 57 is electrically connected to the DC solenoid, which is the motor of the volumetric pump 41, and the control unit 58 via signal lines. The drive unit 57 controls the number of strokes per unit time of the DC solenoid by varying the output frequency.

The controller 58 is a processor. The control unit 58 is, for example, a microcomputer. Note that the control unit 58 is not limited to a microcomputer, and may be a CPU (Central Processing Unit), FPGA (Field Programmable Gate Array), DSP (Digital Signal Processor), DSC (Digital Signal Controller), or other general-purpose or dedicated processor. may be Further, when a module including a processor is used for the communication unit 51 or the like, the control unit 58 may be the module.

The control unit 58 drives and controls the volumetric pump 41 based on various data and programs stored (stored) in the storage unit 55 . The controller 58 calculates the voltage V to be applied across the electrodes 18b based on the concentration X of the chemical, for example, and controls the DC voltage drive circuit 56 to apply the voltage V across the electrodes 18b. Here, the control unit 58 applies a voltage V inversely proportional to the concentration X of the chemical solution, that is, the electrical conductivity of the chemical solution, across the electrodes 18b.

As a result, for example, as shown in FIG. 4, if the concentration X of the chemical solution is 12%, the applied voltage V is 0.83 V. As shown in FIG. The applied voltage V becomes 10V.

In addition, the control unit 58 obtains the electrode immersion length L, which is the length of the electrode 18b immersed in the chemical solution, based on the calculation formulas (1) to (9), and from this electrode immersion length L, the inside of the chemical solution tank 12 is measured. Find the water level of the chemical solution. Here, the water level of the chemical solution in the chemical solution tank 12 is the sum of the length from the lower end of the electrode 18b to the bottom portion 12a of the chemical solution tank 12 and the immersion length L of the electrode.

Specifically, the control unit 58 detects the inter-electrode distance d, the cell constant, the specific resistance r that is the inter-electrode resistance per unit length calculated from the conductivity of the chemical solution, the applied voltage V, and the The immersion length L of the electrode 18b is calculated from the detection voltage Vr during water continuity, which is the voltage between the electrodes 18b.

That is, the control unit 58 calculates the immersion length L of the electrode 18b from the detection voltage Vr during water continuity, as shown in FIGS. The water level of the chemical bath 12 is calculated from the immersion length L of . The control unit 58 also displays the detected water level of the chemical tank 12 (detected water level) on the display unit 54 .

4 shows data when the electrode immersion length L is 30.0 cm and 1.0 cm when the concentration X of the chemical solution is 12%, and FIG. %, each data is shown when the electrode immersion length L is 30.0 cm and 1.0 cm.

Further, the control unit 58 applies the voltage V to the electrode 18b every first predetermined time t1 to detect the water level of the chemical solution. Here, the first predetermined time t<b>1 is, for example, one hour, is input in advance by the input unit 52 , and is stored in the storage unit 55 . The first predetermined time t<b>1 is set based on the consumption amount (injection amount) of the chemical liquid by the volume pump 41 . Here, the amount of chemical liquid consumed by the positive displacement pump 41 is much smaller than, for example, drinking water that is treated and stored in a water tank such as a water receiving tank, so frequent detection of the water level of the chemical liquid is not necessary. For this reason, by increasing the interval for applying the voltage V to the electrode 18b, such as one hour, the generation of bubbles due to the electrolysis of sodium hypochlorite, which is a chemical solution, and adhesion of the bubbles to the electrode 18b are suppressed. can do.

Also, for example, the control unit 58 applies the voltage V to the electrode 18b when a predetermined operation is performed by the input unit 52 . This function is used, for example, when the chemical solution is not depleted, but the volume pump 41 is stopped and the chemical solution is replenished. That is, when it is desired to acquire and display the latest water level data and, for example, the water level display button of the input unit 52 is pressed, the control unit 58 displays the data only once when the input unit 52 is operated. , a voltage V is applied to the electrode 18b to detect the water level.

In addition, the control unit 58 determines whether or not the detected water level of the chemical solution (detected water level) is the recommended replenishment water level L1. For example, the information of chemical solution replenishment recommendation is notified to the outside.

As a specific example, the control unit 58 controls the display unit 54 to display information on recommended chemical solution replenishment and/or controls the communication unit 51 to send an external signal to an external communication terminal or the like to indicate information on chemical solution replenishment recommendation. Perform processing to output as Further, the controller 58 applies the voltage V to the electrode 18b every second predetermined time t2. Here, the second predetermined time t2 is a time shorter than the first predetermined time t1, for example, 15 minutes, is input in advance by the input unit 52, and is stored in the storage unit 55. FIG.

The second predetermined time t2 is set based on the set recommended replenishment water level L1. In addition, the amount of chemical liquid consumed by the positive displacement pump 41 is very small compared to the drinking water that is treated and stored in a water tank such as a receiving tank, but the water level of the chemical liquid in the chemical liquid tank 12 is approaching the water shortage level L2. , and the second predetermined time t2 are set based on a suitable interval for informing the information of chemical solution replenishment recommendation.

Also, when the level of the chemical drops below the electrode 18b, which is the shortest of the two electrodes 18b, the detected voltage becomes 0 V, and the controller 58 determines that the level of the chemical is the water shortage level L2, ie, the water shortage. When the control unit 58 detects the shortage of liquid medicine, it applies a voltage V to the electrode 18b every third predetermined time t3 set shorter than the first predetermined time t1 and the second predetermined time t2 in preparation for the replenishment of the liquid medicine. do. Here, the third predetermined time t3 is, for example, one minute, is input in advance through the input unit 52, and is stored in the storage unit 55. FIG. Even if the voltage V is applied to the electrodes 18b at a high frequency until the chemical solution is replenished during a water shortage, no current flows between the two electrodes 18b. , the third predetermined time t3 is set shorter than the first predetermined time t1 and the second predetermined time t2.

As shown in FIG. 1, the water supply device 2 is installed in a well as a water supply source 101, for example, and is formed so as to be able to pump well water. The water supply device 2 includes, for example, a water supply pump 111, a suction pipe 112 connected to the water supply pump 111 and arranged in the water supply source 101, a discharge pipe 113 connected to the water supply pump 111 and the connecting pipe 15, and a discharge pipe 113. , a pressure tank 115 provided in the discharge pipe 113 , and a control panel 119 .

The water supply pump 111 has, for example, a pump and a motor. In the example shown in FIG. 1, the water supply pump 111 is a land pump, but the water supply pump 111 may be a submersible pump installed in well water.

The suction pipe 112 has, for example, a check valve 112 a that prevents water from flowing back from the water supply pump 111 to the water supply source 101 .

The detection sensor 114 includes, for example, a flow sensor 114a and a pressure sensor 114b.

The flow sensor 114a is, for example, a float switch. The flow rate sensor 114 a is connected to the control panel 119 via a signal line and outputs a detected flow rate signal to the control panel 119 . The flow rate sensor 114a detects only ON and OFF at a fixed point flow rate, for example. The flow rate sensor 114 a is configured to detect, for example, that the flow rate in the discharge pipe 113 is the stop flow rate of the water supply pump 111 and output a signal to the control panel 119 .

The pressure sensor 114b is formed to detect the pressure inside the discharge pipe 113 . The pressure sensor 114 b is connected to the control panel 119 via a signal line and outputs a signal of the detected pressure to the control panel 119 . The pressure sensor 114 b detects at least that the pressure in the discharge pipe 113 is the starting pressure of the water supply pump 111 and outputs a signal to the control panel 119 .

The control panel 119 drives and controls the motor of the water supply pump 111 . The control panel 119 starts the water supply pump 111 when the pressure in the discharge pipe 113 reaches the starting pressure, and stops the water supply pump 111 when the flow rate in the discharge pipe 113 reaches the stop flow rate.

The control panel 119 includes, for example, a communication section, an input section, an interface, a display section, a storage section, a drive section, and a control section. Note that these communication section, input section, interface, display section, storage section, drive section and control section are the communication section 51, input section 52, interface 53, display section 54, storage section 55, drive The configuration is similar to that of the unit 57 and the control unit 58, and detailed description thereof will be omitted.

The storage unit stores the start pressure and stop flow rate of the water supply pump 111 . The storage unit also stores data as various parameters such as functional parameters, internal parameters, and external parameters used by the control unit, various data and programs used for controlling the water supply pump 111, and the like. The control unit controls the water supply pump 111 based on various data and programs stored in the storage unit. The control unit starts the water supply pump 111 when the pressure detected by the pressure sensor 114b exceeds the starting pressure stored in the storage unit, and stops the water supply pump 111 when the flow sensor 114a detects the stop flow rate. .

The filtering device 3 removes iron and manganese contained in the treated water obtained by injecting the chemical solution into the raw water of the water supply source 101 by the chemical solution injector 1, and also removes solids such as sand present during the treatment. The filtering device 3 includes a tank main body 211 , a filtering material 212 , a suction pipe 213 and a water collecting pipe 214 . In addition, the filtering device 3 may be configured to be appropriately provided with a pumping device, an on-off valve, a water tank, a pipe, etc. so as to enable backwashing, cleaning, and the like.

The tank main body 211 accommodates the filtering material 212 . The tank main body 211 containing the filter media 212 forms a space above the filter media 212 in which the suction pipe 213 is arranged. A water collection pipe 214 is connected to the lower end of the tank main body 211 .

The filtering material 212 removes iron from the raw water into which the chemical solution is injected, for example. Also, the filtering material 212 removes manganese from the raw water into which the chemical solution is injected. Also, the filtering material 212 removes solids contained in the raw water.

The suction pipe 213 is connected to the connecting pipe 15 . One end of the water collection pipe 214 is provided inside the tank body 211 and the other end is connected to a water supply destination. Here, the water supply destination is, for example, a water tank, a water tap, or the like. For example, a filter is provided at the end of the water collecting pipe 214 inside the tank body 211 .

Next, an example of a control method for the chemical injector 1 of the water treatment apparatus 100 configured in this manner will be described with reference to the flowchart shown in FIG.

First, when the electric equipment box 19 of the liquid injector 1 is powered on, the electric equipment box 19 is turned on (step ST1), and enters a standby state. The control unit 58 determines whether or not the concentration X (%) of the chemical liquid filled in the chemical liquid tank 12 is set (step ST2). If the concentration X (%) of the chemical solution is not set (NO in step ST2), the control unit 58 waits until the operator operates the input unit 52 to input the concentration of the chemical solution in the chemical tank 12. do. At this time, the control unit 58 may control the display unit 54 and/or the communication unit 51 to inform the outside of the concentration input of the chemical solution.

When the concentration X (%) of the chemical solution is set (YES in step ST2), the control unit 58 applies the voltage V to the electrode 18b to detect the water level of the chemical solution (step ST3). It is determined whether or not the water level is higher than the recommended replenishment water level L1 (step ST4). When the detected water level is higher than the recommended replenishment water level L1 (YES in step ST4), the control unit 58 controls the display unit 54 to display the detected water level on the display unit 54 (step ST5). After the time t1 has passed (YES in step ST6), the process returns to step ST2.

If the detected water level is equal to or lower than the recommended replenishment water level L1 (YES in step ST4), the control unit 58 determines whether the detected water level is equal to or lower than the recommended replenishment water level L1 and higher than the drought water level L2. (Step ST7). That is, the control unit 58 determines whether or not the detection voltage Vr during water continuity is 0V. If the detected water level is equal to or lower than the recommended replenishment water level L1 and higher than the water shortage level L2 (YES in step ST7), the control unit 58 controls the display unit 54 to display the detected water level. (step ST8), and controls the display unit 54 and/or the communication unit 51 to output the information of chemical solution replenishment recommendation to the outside (step ST9). After the second predetermined time t2 has elapsed (YES in step ST10), the control unit 58 returns to step ST2.

If the detected water level is equal to or lower than the recommended replenishment water level L1 and equal to or lower than the water shortage level L2 (NO in step ST7), that is, if the detection voltage Vr during water conduction is 0 V, the controller 58 determines that there is a water shortage. Then, the display unit 54 is controlled to display information indicating a water shortage on the display unit 54, and the displacement pump 41 is stopped (step ST11). Then, the control unit 58 controls the display unit 54 and/or the communication unit 51 to output information on the water shortage to the outside (step ST12). After the third predetermined time t3 has elapsed (YES in step ST13), the control section 58 returns to step ST2. Then, the controller 58 repeats these steps until the liquid injector 1 is powered off.

According to the water level detection device, the chemical injection device 1 and the water treatment device 100 configured as described above, the concentration of the chemical solution is input through the input unit 52, and a voltage inversely proportional to the concentration (conductivity) of the chemical solution is applied to the electrode 18b. By applying the voltage, it is possible to detect the water level of the chemical solution in the chemical solution tank 12 even if the concentration of the chemical solution is different.

Further, the control unit 58 applies a voltage V to the electrode 18b and detects the level of the chemical solution every predetermined time (first predetermined time t1) or when a predetermined operation is performed on the input unit 52 . Therefore, even if the chemical solution is a vaporizable liquid such as sodium hypochlorite, by minimizing the time during which the current flows to detect the level of the chemical solution, air bubbles are generated in the chemical solution, and It is possible to prevent air bubbles generated in the chemical solution from adhering to the electrode 18b.

In addition, when the water level of the chemical solution reaches the recommended replenishment water level L1 or the water shortage level L2, the control unit 58 can notify the information to the outside by the communication unit 51 and/or the display unit 54, so that the chemical injection device 1 is installed. It is possible to grasp the replenishment of the chemical solution, etc.

As described above, according to the water level detection device, the chemical injection device 1, and the water treatment device 100 according to one embodiment of the present invention, the water level can be detected even with chemical solutions having different concentrations.

In addition, the present invention is not limited to the configuration described above. For example, in the above example, the liquid injector 1 has the pressure sensor 16 and the flow rate sensor 17, and the controller 58 controls the volumetric pump 41 according to the pressure and flow rate detected by the pressure sensor 16 and the flow rate sensor 17. Illustrated but not limited to.

For example, the chemical injection device 1 is configured without the pressure sensor 16 and/or the flow rate sensor 17, and the electrical equipment box 19 and the control panel 119 are wired by signal lines or by wireless communication by the communication unit 51. Transmission and reception may be possible, and based on the flow rate and pressure detected by the flow rate sensor 114 a and the pressure sensor 114 b of the water supply device 2 transmitted from the control panel 119 , the displacement pump 41 may be controlled. In this case, for example, an impeller-type flow sensor similar to the flow sensor 17 is used as the flow sensor 114a.

In addition, in the above-described example, a diaphragm pump was described as an example of the volumetric pump 41, but the volumetric pump 41 is not limited to this, and the volumetric pump 41 may be a plunger pump or another pump. good.

It should be noted that the present invention is not limited to the above-described embodiments, and can be variously modified in the implementation stage without departing from the gist of the present invention. Further, each embodiment may be implemented in combination as appropriate, in which case the combined effect can be obtained. Furthermore, various inventions are included in the above embodiments, and various inventions can be extracted by combinations selected from a plurality of disclosed constituent elements. For example, even if some constituent elements are deleted from all the constituent elements shown in the embodiments, if the problem can be solved and effects can be obtained, the configuration with the constituent elements deleted can be extracted as an invention.

DESCRIPTION OF SYMBOLS 1... Chemical injection apparatus 2... Water supply apparatus 3... Filtration apparatus 100... Water treatment apparatus 11... Mounting frame 11a... Leg part 11b... First base 11c... Wall part 11d... Second base 12... Chemical liquid tank 12a Bottom 12b Supply port 12c Cover 13 Piping unit 14 Chemical injector 15 Connecting pipe 15a Attachment 16 Pressure sensor 17 Flow rate sensor 18 Water level detection sensor (water level detection device) 18a Electrode holder 18b Electrode 19 Electrical box (electrical component, water level detector) 21 Connection pipe 22 Exhaust tube 23 Connection pipe 24 Opening and closing Valve 31 Threaded portion 32 Flange 33 Nut 34 Upper branch portion 35 Lower branch portion 36 Mounting portion 38 Floating ball 39 Water level scale 41 Volumetric pump 41a Pump Casing 41b Suction port 41c Discharge port 41d Plug 42 Chemical injection part 42a Connection pipe 42b First check valve 42c Nozzle 42d Second check valve 51 Communication Part 52... Input part 53... Interface 54... Display part 55... Storage part 55a... EEPROM 55b... RAM 56... DC voltage drive circuit 57... Drive part 58... Control part 101... Water source , 111... Water supply pump, 112... Suction pipe, 112a... Check valve, 113... Discharge pipe, 114... Detection sensor, 114a... Flow rate sensor, 114b... Pressure sensor, 115... Pressure tank, 119... Control panel, 211... Tank Main body 212 Filtering material 213 Suction pipe 214 Water collection pipe.

Claims (6)

A water level detection device for detecting the water level of a chemical liquid stored in a chemical liquid tank,
at least two electrodes;
an electrode holder that holds the two electrodes;
an electrical unit that applies a voltage between the two electrodes according to the concentration of the chemical solution;
A water level detector. When the concentration of the chemical liquid stored in the chemical liquid tank is X%, the voltage V applied to the electrode by the electrical equipment section is:
V=10/X
The water level detection device according to claim 1, wherein The electrical equipment section determines the 3. The water level detection device according to claim 1, wherein the immersion length of the electrode in the chemical solution is calculated. 4. The electrical component according to any one of claims 1 to 3, wherein the electrical component applies the voltage to the electrode every first predetermined period of time or when a predetermined operation is performed in the electrical component of the water level detection device. The water level detection device according to . In the electrical equipment unit, the detected immersion length of the electrode is higher than a water shortage level set in advance in the electrical equipment unit, and corresponds to the recommended replenishment water level set in advance in the electrical equipment unit to encourage replenishment of the chemical solution. When the length of the electrode is reached, it is notified to the outside that the recommended replenishment water level has been reached, and the voltage is applied to the electrode every second predetermined time shorter than the first predetermined time. Item 5. The water level detection device according to item 4. a chemical tank for storing the chemical;
a pump for injecting the chemical liquid stored in the chemical liquid tank into a pipe;
A water level detection device according to any one of claims 1 to 5;
A drug injection device.

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