JP7186482B2 - Chemical injection device and chemical injection method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a chemical injection device, a dialysate manufacturing device, and a chemical injection method.

A dialysate manufacturing apparatus is known that manufactures a dialysate undiluted solution by dissolving a raw material powder (powder formulation) for a dialysate in water. A dialysate used for hemodialysis is generally prepared by diluting and mixing two kinds of undiluted dialysate solutions. Since the adjusted dialysate is used for hemodialysis, the undiluted dialysate must also be kept clean. Therefore, in the dialysate manufacturing apparatus, the internal piping and the like are disinfected with a disinfectant such as sodium hypochlorite after use.

When disinfecting internal pipes and the like, the undiluted solution of the disinfectant solution is injected into the pipes and then water is injected to obtain a disinfectant solution diluted to a preset target concentration. At this time, if the concentration of the diluted disinfectant solution becomes lower than the target concentration, there is a risk of insufficient disinfection. Further, when the concentration of the diluted disinfectant solution is higher than the target concentration, the disinfectant solution may not be washed away sufficiently, and the dialysate may be mixed with the disinfectant solution. Therefore, it is necessary to accurately control the injection amount of the undiluted disinfectant so that the concentration of the diluted disinfectant reaches the target concentration. In a conventional dialysate manufacturing apparatus, a high quantitative pump was used to inject the undiluted solution of the disinfectant.

JP 2011-177411 A

However, pumps with high quantitativeness are expensive and large in size. Therefore, it is not preferable to use a highly quantitative pump only for injecting the undiluted solution of the disinfectant. Therefore, even if a low-cost, relatively low-quantitative small piezoelectric pump or the like is used as a pump for injecting the undiluted solution of the disinfectant, it is possible to inject an accurate amount of the chemical solution such as the disinfectant. was desired.

Patent Literature 1 proposes a device that measures the flow rate of a chemical solution and performs feedback control so as to achieve a desired flow rate. However, this device requires a flow rate sensor and a mechanism for performing feedback control, which complicates the configuration of the device, resulting in an increase in the size and cost of the device.

Accordingly, an object of the present invention is to provide a compact chemical injection device, a dialysate manufacturing device, and a chemical injection method that can accurately control the injection amount of the chemical and can be realized with a simple device configuration.

An object of the present invention is to solve the above problems by providing a chemical liquid tank for storing a chemical liquid, an injection pipe for circulating the chemical liquid drawn from the chemical liquid tank, and a liquid chemical provided in the injection pipe for feeding the chemical liquid. A chemical pump, a detection mechanism capable of detecting that a predetermined section of the injection pipe is filled with the chemical, and a control unit that controls the driving of the chemical pump based on the detection result of the detection mechanism. The control unit controls the injection of the chemical liquid based on the driving start time of the chemical liquid pump and the detection time when the detection mechanism detects that the predetermined section of the injection pipe is filled with the chemical liquid. Provided is a chemical injection device that has an injection speed calculation unit that obtains a speed, and performs driving control of the chemical pump based on the obtained injection speed of the chemical.

Further, in order to solve the above problems, the present invention provides a dialysate manufacturing apparatus having a dissolution tank for dissolving a raw material powder of a dialysate in water to generate a dialysate undiluted solution, the apparatus comprising: a dialysate manufacturing apparatus, wherein the injection pipe is a pipe extending from the chemical tank to the dissolution tank.

Further, for the purpose of solving the above problems, the present invention stores a chemical solution in a chemical solution tank, circulates the chemical solution drawn out from the chemical solution tank into an injection pipe, and provides a chemical solution pump in the injection pipe. A method for injecting a chemical solution, in which a detection mechanism capable of detecting that a predetermined section of the injection pipe is filled with the chemical solution is provided, and the driving start time of the chemical solution pump and the detection mechanism detect the Based on the detection time when it is detected that the predetermined section of the injection pipe is filled with the chemical solution, the injection speed of the chemical solution is obtained, and the driving control of the chemical solution pump is performed based on the obtained injection speed of the chemical solution. An injection method is provided.

Advantageous Effects of Invention According to the present invention, it is possible to provide a compact chemical injection device, a dialysate manufacturing device, and a chemical injection method that can accurately control the injection amount of the chemical and that can be realized with a simple device configuration.

1 is a schematic configuration diagram of a chemical injector according to an embodiment of the present invention; FIG. 3 is a perspective view showing a configuration example of an electrode; FIG. (a), (b) is a schematic block diagram which shows the example of a changed completely type of the liquid injection apparatus of FIG. FIG. 2 is a schematic configuration diagram of a dialysate manufacturing apparatus using the chemical injector of FIG. 1; FIG. 4 is a flowchart of disinfection work in the dialysate manufacturing apparatus;

[Embodiment]
BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram of a liquid injector according to the present embodiment. As shown in FIG. 1, the chemical injector 1 includes a chemical tank 3 that stores a chemical 2, an injection pipe 4 that flows the chemical 2 drawn out from the chemical tank 3, and a chemical 2 that is provided in the injection pipe 4. , a detection mechanism 6 and a control unit 7 .

An injection pipe 4 is connected to the chemical tank 3 so that the chemical 2 stored in the chemical tank 3 is introduced into the injection pipe 4 . The chemical liquid 2 is a disinfecting liquid for disinfecting internal piping of the dialysate manufacturing apparatus 10, which will be described later, and is, for example, sodium hypochlorite, acetic acid, peracetic acid, citric acid, or the like. Here, a case where the chemical liquid 2 is a conductive liquid such as sodium hypochlorite or citric acid will be described.

The injection pipe 4 is a pipe for injecting the chemical solution 2 into the dialysate manufacturing apparatus 10 , and more specifically, a pipe from the chemical solution tank 3 to a tank or the like for diluting the chemical solution 2 . Therefore, the injection pipe 4 includes part of the internal pipe of the dialysate manufacturing device 10 . In the present embodiment, the injection pipe 4 includes a chemical solution line 41 that connects the chemical solution tank 3 and the water supply line 11 of the dialysate manufacturing apparatus 10, and a downstream side of the connection point of the chemical solution line 41 (water to be supplied). and a water supply line 11 on the downstream side in the flow of the water. The water supply line 11 is a pipe for introducing water 11a supplied from a water treatment device (not shown) into a dissolution tank, which will be described later. As the water treatment apparatus, for example, one having a reverse osmosis filtration apparatus that generates treated water with a reverse osmosis membrane is used. Flexible tubes such as silicone tubes can be used as the water supply line 11 and the chemical solution line 41 .

A chemical pump 5 for feeding the chemical 2 is provided in the chemical line 41 . In this embodiment, a small and inexpensive piezoelectric pump is used as the chemical pump 5 . A piezoelectric pump performs a pumping operation by utilizing a change in volume when a voltage is applied to a piezoelectric element attached to a diaphragm. Although it is possible to use a pump other than a piezoelectric pump as the chemical pump 5, it is preferable to use a pump as small and inexpensive as possible. Further, a chemical liquid line solenoid valve 8 for switching supply and stop of the chemical liquid 2 is provided in the chemical liquid line 41 on the downstream side of the chemical liquid pump 5 .

The chemical injection device 1 according to the present embodiment includes a detection mechanism 6 capable of detecting that a predetermined section of the injection pipe 4 is filled with the chemical 2, and based on the detection result of the detection mechanism 6, the chemical liquid pump 5 and a control unit 7 for controlling the driving of the.

In the present embodiment, the detection mechanism 6 includes a plurality of electrodes 61 provided at a plurality of locations of the injection pipe 4 so as to protrude into the injection pipe 4, and a continuity detection for detecting continuity between the electrodes 61. and a portion 62 . Here, the case of using two electrodes 61, a transmitting electrode 61a and a receiving electrode 61b, will be described, but three or more electrodes 61 may be used.

In the example of FIG. 1 , the transmitting electrode 61 a is provided at the connecting portion between the chemical solution line 41 and the water supply line 11 . Further, the receiving electrode 61b is provided in the water supply line 11 on the downstream side of the connecting portion between the chemical solution line 41 and the water supply line 11 . A section between the transmitting electrode 61a and the receiving electrode 61b in the injection pipe 4 is a section for detecting that the liquid medicine 2 is filled in the present embodiment.

In the present embodiment, a conductive liquid is used as the chemical solution 2. Therefore, when the space between the transmitting electrode 61a and the receiving electrode 61b is filled with the chemical solution 2, the transmitting electrode 61a and the receiving electrode 61b are electrically connected. conducts to By detecting electrical continuity between the transmission electrode 61a and the reception electrode 61b by the continuity detection unit 62, it is possible to detect that the medical solution 2 is filled in the section between the electrodes 61a and 61b.

A specific method for detecting continuity between the electrodes 61a and 61b by the continuity detection unit 62 is not particularly limited. For example, a predetermined voltage (for example, 5 V) is applied between the transmitting electrode 61a and the receiving electrode 61b, and the current flowing between the electrodes 61a and 61b is measured, and the current value of the measured current is equal to or greater than a preset threshold. The continuity detector 62 can be configured to detect continuity between the two electrodes 61a and 61b when .

FIG. 2 is a perspective view showing a configuration example of the electrode 61. As shown in FIG. As shown in FIG. 2, the electrode 61 may be provided integrally with a tube connector (joint) 63 . In the example of FIG. 2, the tube connector 63 has a body portion 63a formed in a substantially cylindrical shape, and pipes such as tubes (the water supply line 11 and the chemical solution line 41) are inserted and connected through openings at both ends thereof. . A rod-shaped electrode 61 is provided on the main body portion 63a so that the distal end thereof protrudes into the main body portion 63a and the base end thereof protrudes to the outside of the main body portion 63a. By configuring in this way, the electrode 61 can be provided so as to be in contact with the chemical solution 2 . However, the specific structure for installing the electrode 61 is not limited to this, and can be changed as appropriate.

Returning to FIG. 1 , the continuity detection section 62 and the control section 7 are mounted on the control device 9 . The continuity detection unit 62 and the control unit 7 include arithmetic elements such as a CPU (Central Processing Unit), memories such as RAM (Random Access Memory) and ROM (Read Only Memory), storage devices such as HDD (Hard Disk Drive), and software. , an interface, etc., in combination. The control unit 7 has an injection speed calculation unit 71 , a stop time calculation unit 72 and a pump drive control unit 73 .

The injection speed calculation unit 71 detects when the chemical liquid pump 5 starts to be driven, and when the detection mechanism 6 detects that a predetermined section of the injection pipe 4 (here, the section between the electrodes 61a and 61b) is filled with the liquid chemical 2. The injection speed of the chemical solution 2 is obtained based on the detection time when is detected. More specifically, the injection speed calculation unit 71 stores the drive start time and the detection time, and drives the chemical liquid pump 5 from these times until a predetermined section of the injection pipe 4 is filled with the chemical liquid 2. In addition to calculating the time, the injection speed of the chemical solution 2 is calculated based on the calculated drive time and the capacity (volume) of the section filled with the chemical solution 2 .

For example, when the radius of the injection pipe 4 between the electrodes 61a and 61b is 10 mm and the distance is 100 mm, the capacity of the injection pipe 4 between the electrodes 61a and 61b is 31.4 mL. When the driving time of the chemical liquid pump 5 is 31.4 seconds, 1 mL of the chemical liquid 2 is injected per second. In this case, the injection rate is 1 mL/sec.

The stop time calculation unit 72 stops the chemical pump 5 based on the injection speed of the chemical 2 obtained by the injection speed calculation unit 71, the preset target injection amount, and the stored drive start time of the chemical pump 5. Obtain the drive stop time. In the above example, if the target injection volume is set to 100 ml, the total driving time of the chemical pump 5 is 100 seconds. Therefore, the time when 100 seconds have elapsed from the start time of the driving of the chemical pump 5 is set as the time when the driving of the chemical pump 5 is stopped.

The pump drive control unit 73 performs drive control of the chemical liquid pump 5 and opening/closing control of the chemical liquid line electromagnetic valve 8 . The pump drive control unit 73 stops driving the chemical liquid pump 5 at the drive stop time obtained by the stop time calculation unit 72 and closes the chemical liquid line electromagnetic valve 8 . Further, when the chemical liquid pump 5 starts to be driven, the pump drive control unit 73 opens the chemical liquid line electromagnetic valve 8 and starts driving the chemical liquid pump 5 in accordance with the operator's instruction.

In this embodiment, it is assumed that the chemical solution 2 flows into the section between the two electrodes 61a and 61b immediately after the chemical solution pump 5 is driven. and the water supply line 11 (close to the chemical solution line solenoid valve 8), and the injection pipe upstream of the transmitting electrode 61a (upstream of the chemical solution line solenoid valve 8) 4 must be filled with the chemical solution 2 .

FIG. 1 shows the case where the chemical solution 2 is injected while the water supply line 11 is filled with water 11a. (the chemical solution 2 diffuses into the water 11a), and this effect may cause an error in the amount of the chemical solution 2 to be injected. Therefore, when using a chemical solution 2 that is easily mixed with the water 11a, as shown in FIG. , and it is more desirable to perform the injection work of the chemical solution 2 . In this case, since the chemical solution 2 is held in the injection pipe 4 by surface tension, the injection pipe 4 can be arranged along the vertical direction, and the degree of freedom of the pipe layout is improved.

Furthermore, as shown in FIG. 3B, an air introducing mechanism 42 for introducing air into the injection pipe 4 may be provided. In the example of FIG. 3B , the air introduction mechanism 42 is composed of a three-way electromagnetic valve 43 provided in the chemical line 41 between the chemical tank 3 and the chemical pump 5 . The three-way solenoid valve 43 is a valve that can switch between communicating the common port 43a and the first port 43b or communicating the common port 43a and the second port 43c. The chemical line 41 and the first port 43b are connected to the chemical line 41 on the side of the chemical tank 3, and the second port 43c is open to the atmosphere. Air can be introduced into the injection pipe 4 by driving the chemical liquid pump 5 while the three-way electromagnetic valve 43 is used to connect the common port 43a and the second port 43c. When the liquid medicine 2 is normally sent, the three-way electromagnetic valve 43 allows the common port 43a and the first port 43b to communicate with each other.

By providing the three-way electromagnetic valve 43 as the air introduction mechanism 42 , air can be introduced to a predetermined portion (between the chemicals 2 ) of the chemical liquid line 41 . In this case, the injection rate calculation unit 71 adds the capacity from the tip of the chemical solution line 2 (the position where the transmission electrode 61a is provided) to the air introduction point and the capacity between the two electrodes 61a and 61b, and adds the capacity is divided by the time from when the chemical pump 5 is driven until both electrodes 61a and 61b are electrically connected (not including the driving time when introducing air), the injection rate can be calculated. Here, since the actual injection amount of the chemical solution 2 into which air is introduced is small, the value obtained by subtracting the introduction amount of air from the above-mentioned added capacity is the injection amount of the chemical solution 2 when both electrodes 61a and 61b are conductive. becomes. Therefore, the stop time calculation unit 72 subtracts this injection amount from the target injection amount to obtain the remaining injection amount, obtains the remaining driving time of the chemical pump 5 from the remaining injection amount and the injection speed, and 5 can be calculated. The three-way solenoid valve 43 as the air introduction mechanism 42 is installed as close to the transmitting electrode 61a as possible so that the electrodes 61a and 61b are not electrically connected only by the chemical solution 2 accumulated between the three-way solenoid valve 43 and the transmitting electrode 61a. is desirable.

By providing the air introduction mechanism 42 as shown in FIG. 3B, it is possible to set the reference position for detection by the detection mechanism 6 by the introduced air without discharging the water 11a of the water supply line 11. become. Therefore, the loss of water 11a can be reduced, and the disinfection work can be performed in a short time. In the case of FIG. 3A, it can also be understood that air is introduced into the injection pipe 4 by discharging the water 11a. In this case, means for discharging the water 11 a from the water supply line 11 constitutes the air introduction mechanism 42 .

Furthermore, the installation positions of both electrodes 61a and 61b may be appropriately adjusted so that the amount of chemical solution 2 equal to the target injection amount is injected into water supply line 11 when both electrodes 61a and 61b are electrically connected. This makes it possible to omit the injection rate calculator 71 and the stop time calculator 72, thereby simplifying the device configuration. In this case, the pump drive control section 73 stops driving the chemical liquid pump 5 when both the electrodes 61a and 61b become conductive.

(Explanation of experimental results)
A piezoelectric pump was used as the chemical pump 5, and an experiment was conducted to examine whether the injection amount of the chemical 2 would change when the power supply voltage and the power supply frequency were changed. Prior to the experiment, the flow rate was obtained when the piezoelectric pump was driven at 85 V and 50 Hz (condition 1) and when the piezoelectric pump was driven at 110 V and 60 Hz (condition 2). As a result, while the flow rate was 24.31 mL/min under condition 1, the flow rate was 46.69 mL/min under condition 2, and it was confirmed that the flow rate fluctuated about twice.

In the experiment, water was discharged from the water supply line 11 as shown in FIG. Also, the target concentration was set to 256 ppm, and the capacity between both electrodes 61a and 61b was set to be half of the target injection amount. A stopwatch is used to measure the time from driving the chemical pump 5 until both electrodes 61a and 61b are electrically connected. The electromagnetic valve 8 was closed. After that, a set amount of water was injected for dilution, and the concentration of sodium hypochlorite after dilution was measured. The above experiments were performed in the same manner for the above-described conditions 1 and 2. Table 1 shows the results.

As shown in Table 1, in both conditions 1 and 2, the concentration of sodium hypochlorite (hypochlorite concentration) is very close to the target concentration of 256 ppm. As described above, with a piezoelectric pump, the flow rate varies greatly depending on driving conditions and the like. 2 can be accurately controlled. In this experiment, it is considered that an error with respect to the target concentration occurred because the time measurement and the work of closing the chemical solution line electromagnetic valve 8 were performed manually.

(Modified example of detection mechanism 6)
In the present embodiment, a plurality of electrodes 61 are used as the detection mechanism 6, and it is detected that the section between the electrodes 61 is filled with the chemical solution 2 by detecting the conduction of the electrodes 61. However, the detection mechanism 6 , can be appropriately changed according to the chemical solution 2 to be used. For example, when a non-conductive, colored liquid is used as the chemical liquid 2, a light emitter and a light receiver are placed at a plurality of locations in the longitudinal direction of the injection pipe 4, with the flow path through which the chemical liquid 2 flows, facing each other. It is also possible to provide optical sensors that are aligned with each other, and to detect that the chemical solution 2 is filled in a predetermined section based on a change in the amount of light received by the light receiver of each optical sensor.

Further, when the chemical solution 2 has no conductivity and is a colorless and transparent liquid, for example, a temperature adjusting means for heating or cooling the chemical solution 2 is provided to control the chemical solution 2 to a temperature different from the ambient temperature. In addition, temperature sensors may be provided at a plurality of locations in the longitudinal direction of the injection pipe 4, and based on the detection results of each temperature sensor, it is possible to detect that the chemical solution 2 is filled in a predetermined section. be.

Furthermore, when air is introduced into the injection pipe 4 as shown in FIGS. 3A and 3B, the medicinal solution 2 is It is also possible to detect that is satisfied in a predetermined interval. In this case, the detection mechanism 6 includes an ultrasonic generator that outputs ultrasonic waves in the injection pipe 4, and is arranged in the injection pipe 4 and faces the ultrasonic generator in the longitudinal direction of the injection pipe 4. and a receiver arranged to detect, based on the presence or absence of reception of ultrasonic waves by the receiver, that the section between the ultrasonic generator and the receiver is filled with the chemical solution 2. should be. In this case, as the injection pipe 4, it is necessary to use a material, such as a silicone tube, through which ultrasonic waves are difficult to propagate. By using an ultrasonic wave generator and a receiver together with the air introduction mechanism 42 as appropriate, it is possible to realize a highly versatile detection mechanism 6 that can be applied to any kind of chemical liquid 2 .

(Dialysate manufacturing device 10 using chemical injection device 1)
FIG. 4 is a schematic configuration diagram of a dialysate manufacturing apparatus 10 using the drug injection apparatus 1 of FIG. As shown in FIG. 4 , the dialysate manufacturing apparatus 10 includes a dissolution tank 12 that dissolves raw powder of the dialysate in water to generate a dialysate undiluted solution, and stores the dialysate undiluted solution generated in the dissolution tank 12 . and a storage tank 13 . Here, two dissolution tanks 12 and two storage tanks 13 are provided in order to prepare two types of undiluted dialysate called liquid A and liquid B. As shown in FIG. Hereinafter, the dissolving tank 12 and storage tank 13 for manufacturing liquid A are referred to as first dissolving tank 12a and first storage tank 13a, and the dissolving tank 12 and storage tank 13 for manufacturing liquid B are referred to as second dissolving tank 12b and first storage tank 13b. called.

A water supply line 11 extending from a water supply port 111 is branched into two at a branch portion 112 and connected to the first and second dissolving tanks 12a and 12b, respectively. A first water supply line electromagnetic valve 14a is provided in the water supply line 11 closer to the first dissolving tank 12a than the branch portion 112 is. A second water supply line electromagnetic valve 14b is provided in the water supply line 11 closer to the second dissolving tank 12b than the branch portion 112 is. A chemical solution line 41 extending from the chemical solution tank 3 is connected to the water supply line 11 on the upstream side of the branch portion 112 . A water supply source electromagnetic valve 14 c is provided in the water supply line 11 on the upstream side of the connecting portion of the chemical line 41 .

A transmission electrode 61 a is provided at the connecting portion between the chemical solution line 41 and the water supply line 11 . A chemical liquid pump 5 and a chemical liquid line solenoid valve 8 are provided in order from the chemical liquid tank 3 side in the chemical liquid line 41 . Further, in the present embodiment, the receiving electrode 61b is provided in the water supply line 11 downstream of the first water supply line solenoid valve 14a. In the example of FIG. 4, the injection pipe 4 is a pipe (that is, part of the chemical solution line 41 and the water supply line 11) from the chemical solution tank 3 to the first and second dissolving tanks 12a and 12b.

Circulation channels 15a and 15b are provided in the first and second dissolving tanks 12a and 12b, respectively. Circulation pumps 16a and 16b are provided in the circulation flow paths 15a and 15b, respectively. Raw material containers 17a and 17b containing raw material powder of the dialysate are provided in the circulation flow paths 15a and 15b, respectively. It is sent to the first and second melting tanks 12a and 12b and melted. By configuring in this manner, scattering of the raw material powder can be suppressed as compared with the case where the raw material powder of the dialysate is directly charged into the dissolving tanks 12a and 12b.

The first and second dissolving tanks 12a, 12b and the first and second storage tanks 13a, 13b are connected by transfer lines 18a, 18b, respectively. The transfer lines 18a and 18b are provided with transfer valves 19a and 19b, respectively. The first and second storage tanks 13a and 13b are connected to supply lines 20a and 20b for supplying the undiluted dialysate stored in the first and second storage tanks 13a and 13b to a blood purification apparatus (not shown), respectively. It is The supply lines 20a and 20b are provided with supply pumps 21a and 21b for feeding the undiluted dialysate, respectively.

(Flow of disinfection work)
Next, the flow of disinfection work in the dialysate manufacturing apparatus 10 will be described with reference to FIG. As shown in FIG. 5 , first, in step S<b>1 , the pump drive control unit 73 opens the first water supply line electromagnetic valve 14 a and the chemical line electromagnetic valve 8 to drive the chemical pump 5 . After that, in step S2, the injection speed calculator 71 stores the current time as the drive start time of the chemical pump 5. FIG.

After that, in step S3, the continuity detection unit 62 determines whether the electrodes 61a and 61b are electrically connected. If NO is determined in step S3, step S3 is repeated. If the determination in step S3 is YES, the injection rate calculator 71 stores the current time as the detection time of the continuity detector 62 in step S4. After that, in step S5, the injection speed calculator 71 calculates the injection speed based on the driving start time of the chemical pump 5 and the detection time of the continuity detector 62. FIG.

After that, in step S6, the stop time calculation unit 72 calculates the total driving time of the chemical pump 5 based on the injection speed and the preset target injection amount, and starts driving the chemical pump 5 during the total driving time. By adding the time, the drive stop time of the chemical pump 5 is obtained. After that, in step S<b>7 , the pump drive control unit 73 determines whether or not the current time has reached the drive stop time of the chemical pump 5 . If the determination in step S7 is NO, step S7 is repeated. If YES is determined in step S7, the pump drive control unit 73 stops the chemical liquid pump 5 and closes the chemical liquid line electromagnetic valve 8 in step S8. After that, in step S9, the pump drive control unit 73 opens the water supply source electromagnetic valve 14c for a predetermined period of time to wash away the chemical solution 2 (disinfectant) in the water supply line 11 into the first dissolving tank 12a. After that, in step S10, the first water supply line electromagnetic valve 14a is closed.

After that, in step S<b>11 , the pump drive control unit 73 opens the second water supply line solenoid valve 14 b and the chemical liquid line solenoid valve 8 to drive the chemical liquid pump 5 . After that, in step S12, the pump drive control unit 73 determines whether or not the entire drive time of the chemical pump 5 obtained in step S6 has elapsed since the chemical pump 5 was driven. If NO in step S12, step S12 is repeated. If YES is determined in step S12, the pump drive control unit 73 stops the chemical liquid pump 5 and closes the chemical liquid line electromagnetic valve 8 in step S13. After that, in step S14, the pump drive control unit 73 opens the water supply source electromagnetic valve 14c for a predetermined period of time to flush the chemical solution 2 (disinfectant) in the water supply line 11 to the second dissolving tank 12b. After that, in step S15, the second water supply line electromagnetic valve 14b is closed.

Here, the case where the same amount of the chemical solution 2 as that in the first dissolving tank 12a is injected into the second dissolving tank 12b has been described, but if the capacity of the second dissolving tank 12b is different from that of the first dissolving tank 12a ( In other words, when the injection amount of water is different), the injection rate obtained in step S5 is used to obtain the total drive time of the chemical pump 5 at which the injection amount of the chemical liquid 2 is the desired amount. The total driving time may be used in the determination of step S6. When obtaining the total drive time of the chemical pump 5, it is not necessary to use the injection speed obtained in step S5. The injection rate may be calculated separately based on the time from the driving of the electrode 5 to the conduction between the electrode and the transmitting electrode 61a.

After that, in step S16, water is supplied to the first dissolving tank 12a. Although not shown, a liquid level sensor is provided in the first dissolving tank 12a. Water is supplied to the first dissolving tank 12a by opening the valve 14a. As a result, a predetermined amount of water is introduced into the first dissolving tank 12a to dilute the chemical solution 2 (disinfectant).

Thereafter, in step S17, water supply processing to the second dissolving tank 12b is performed. Although not shown, a liquid level sensor is provided in the second dissolving tank 12b. Water is supplied to the second dissolving tank 12b by opening the valve 14b. As a result, a predetermined amount of water is introduced into the second dissolving tank 12b to dilute the chemical liquid 2 (disinfectant).

After that, in step S18, each part of the dialysate manufacturing apparatus 10 is washed. That is, the circulation pumps 16a and 16b and the supply pumps 21a and 21b are appropriately driven to circulate the diluted chemical solution 2 (disinfectant) through each pipe and discharge it, and then introduce water and circulate the disinfectant solution in each pipe. is washed away. A specific procedure for cleaning each part is not particularly limited. Thus, the disinfection work of the dialysate manufacturing apparatus 10 is completed.

(Actions and effects of the embodiment)
As described above, in the chemical injection device 1 according to the present embodiment, the detection mechanism 6 capable of detecting that a predetermined section of the injection pipe 4 is filled with the chemical solution 2 and the detection result of the detection mechanism 6 are A control unit 7 for controlling the drive of the chemical pump 5 is provided.

As a result, even when an inexpensive piezoelectric pump or the like is used as the chemical pump 5, the injection amount of the chemical 2 can be controlled with high accuracy. As a result, there is no need to use an expensive and large-sized metering pump that has been used conventionally, and complicated control such as feedback control is no longer necessary, and a compact liquid injection device 1 that can be realized with a simple device configuration can be realized.

For example, it is conceivable to use an inverter to stabilize the pump power supply and stabilize the flow rate. Therefore, the injection amount of the chemical solution cannot be accurately controlled only by stabilizing the power supply with the inverter. It is also conceivable to provide a metering cylinder in the rear stage of the chemical liquid pump 5, for example, to measure the injection amount of the chemical liquid by the metering cylinder. In this embodiment, the detection mechanism 6 is configured to detect that the chemical solution 2 is filled in a predetermined section of the injection pipe 4, and the pipe itself is used as a means for measuring, so that the device can be miniaturized. is possible.

(Summary of embodiment)
Next, technical ideas understood from the embodiments described above will be described with reference to the reference numerals and the like in the embodiments. However, each reference numeral and the like in the following description do not limit the constituent elements in the claims to the members and the like specifically shown in the embodiment.

[1] A chemical tank (3) for storing the chemical (2), an injection pipe (4) for circulating the chemical (2) derived from the chemical tank (3), and the injection pipe (4) A chemical pump (5) provided for sending the chemical (2), a detection mechanism (6) capable of detecting that a predetermined section of the injection pipe (4) is filled with the chemical (2), A chemical injection device (1) comprising a control section (7) for controlling driving of the chemical pump (5) based on a detection result of a detection mechanism (6).

[2] The control unit (7) determines when the chemical pump (5) starts to be driven, and when the predetermined section of the injection pipe (4) is filled with the chemical (2) by the detection mechanism (6). an injection speed calculation unit (71) for obtaining the injection speed of the chemical solution (2) based on the detection time at which it was detected, the injection speed of the chemical solution (2) calculated by the injection speed calculation unit (71), and a stop time calculation unit (72) for obtaining the drive stop time of the chemical pump (5) based on the drive start time of the chemical pump (5); and the drive stop time obtained by the stop time calculation unit (72). and a pump drive control section (73) for stopping the driving of the chemical pump (5).

[3] The chemical solution (2) is a conductive liquid, and the detection mechanism (6) is provided at a plurality of locations of the injection pipe (4) so as to protrude into the injection pipe (4). The liquid injector (1) according to [1] or [2], which has a plurality of electrodes (61) arranged in a line and a continuity detection section (62) for detecting continuity of the plurality of electrodes (61).

[4] The detection mechanism (6) includes an ultrasonic generator that outputs ultrasonic waves in the injection pipe (4), and is arranged in the injection pipe (4), and the injection pipe ( 4) has a receiver arranged opposite to the ultrasonic generator (4) in the longitudinal direction, and based on the presence or absence of reception of ultrasonic waves by the receiver, the ultrasonic generator and the receiver The liquid injector (1) according to [1] or [2], which detects that the section between and is filled with the liquid medicine (2).

[5] The liquid injector (1) according to [4], comprising an air introduction mechanism (42) for introducing air into the injection pipe (4).

[6] The chemical injection device according to any one of claims 1 to 5, wherein the chemical pump (5) is a positive displacement pump.

[7] The chemical injection device (1) according to [1] to [6], wherein the chemical pump (5) is a piezoelectric pump.

[8] A dialysate manufacturing apparatus (10) comprising a dissolution tank (12) for dissolving a dialysate raw material powder in water to generate a dialysate undiluted solution, wherein any one of [1] to [7] is provided. A dialysate manufacturing apparatus (10) comprising the chemical injection device (1) according to item 1, wherein the injection pipe (4) is a pipe extending from the chemical tank (3) to the dissolution tank (12).

[9] The chemical solution (2) is stored in the chemical solution tank (3), the chemical solution (2) drawn out from the chemical solution tank (3) is circulated through the injection pipe (4), and the injection pipe (4) is supplied with the chemical solution (2). A chemical solution injection method in which a chemical solution pump (5) is provided to send a chemical solution (2), and a detection mechanism ( 6) is provided, and drive control of the chemical pump (5) is performed based on the detection result of the detection mechanism (6).

Although the embodiments of the present invention have been described above, the embodiments described above do not limit the invention according to the scope of claims. Also, it should be noted that not all combinations of features described in the embodiments are essential to the means for solving the problems of the invention.

The present invention can be appropriately modified and implemented without departing from the gist thereof. For example, in the above-described embodiment, the case where the chemical injection device 1 is applied to the dialysate manufacturing device 10 has been described, but the application of the chemical injection device 1 is not limited to this. and can also be used in disinfecting the dialysate circuit.

In addition, in the above-described embodiment, the case where only the ON/OFF of the chemical liquid pump 5 is controlled has been described. A pump voltage adjustment mechanism or the like for adjusting the applied voltage to the chemical pump 5 at the time may be provided. As a result, for example, when the total driving time is longer than a predetermined time threshold, it is possible to increase the voltage applied to the chemical pump 5 to shorten the injection time of the chemical 2 .

REFERENCE SIGNS LIST 1 chemical injector 2 chemical liquid 3 chemical tank 4 injection pipe 41 chemical line 42 air introduction mechanism 43 three-way electromagnetic valve 5 chemical pump 6 detection mechanism 61 electrode 62 continuity detection unit 7 control Part 10... Dialysate manufacturing device 11... Water supply line 11a... Water 12... Dissolving tank 13... Storage tank

Claims (10)

a chemical tank that stores the chemical;
an injection pipe for circulating the chemical solution drawn out from the chemical solution tank;
a chemical pump that is provided in the injection pipe and feeds the chemical;
a detection mechanism capable of detecting that a predetermined section of the injection pipe is filled with a chemical;
A control unit that controls driving of the chemical pump based on the detection result of the detection mechanism ,
The control unit obtains the injection speed of the chemical liquid based on the driving start time of the chemical liquid pump and the detection time when the detection mechanism detects that the predetermined section of the injection pipe is filled with the chemical liquid. having an injection speed calculation unit, and performing drive control of the chemical pump based on the obtained injection speed of the chemical;
Chemical injection device. The control unit
a stop time calculation unit that calculates a driving stop time of the chemical pump based on the chemical liquid injection speed obtained by the injection speed calculation unit and the driving start time of the chemical pump;
a pump drive control unit that stops driving the chemical pump at the drive stop time obtained by the stop time calculation unit;
The drug injection device according to claim 1. the chemical solution is a conductive liquid,
The detection mechanism includes a plurality of electrodes respectively provided so as to protrude into the injection pipe at a plurality of locations of the injection pipe, and a continuity detection unit that detects the continuity of the plurality of electrodes.
The drug injection device according to claim 1 or 2. The detection mechanism includes an ultrasonic generator that outputs ultrasonic waves into the injection pipe, and is arranged in the injection pipe and opposed to the ultrasonic generator in the longitudinal direction of the injection pipe. and a receiver, based on the presence or absence of reception of ultrasonic waves at the receiver, detects that the section between the ultrasonic generator and the receiver is filled with a chemical solution;
The drug injection device according to claim 1 or 2. Equipped with an air introduction mechanism for introducing air into the injection pipe,
The drug injection device according to claim 4. wherein the chemical pump is a positive displacement pump;
The liquid injector according to any one of claims 1 to 5. wherein the chemical pump is a piezoelectric pump;
The drug injection device according to claim 6. a chemical tank that stores the chemical;
an injection pipe for circulating the chemical solution drawn out from the chemical solution tank;
a chemical pump that is provided in the injection pipe and feeds the chemical;
a detection mechanism capable of detecting that a predetermined section of the injection pipe is filled with a chemical;
A control unit that controls driving of the chemical pump based on the detection result of the detection mechanism,
wherein the chemical pump is a positive displacement pump;
Chemical injection device. A dialysate manufacturing apparatus comprising a dissolution tank for dissolving a dialysate raw material powder in water to produce a dialysate undiluted solution,
A chemical injection device according to any one of claims 1 to 8 ,
The injection pipe is a pipe from the chemical tank to the dissolution tank,
Dialysate production equipment. The chemical solution is stored in the chemical solution tank,
circulating the chemical solution derived from the chemical solution tank to the injection pipe,
A chemical solution injection method in which a chemical solution pump is provided in the injection pipe and the chemical solution is sent,
A detection mechanism capable of detecting that a predetermined section of the injection pipe is filled with a chemical solution is provided,
Based on the driving start time of the chemical liquid pump and the detection time when the detection mechanism detects that the predetermined section of the injection pipe is filled with the chemical liquid, the injection speed of the chemical liquid is obtained. performing drive control of the chemical pump based on the injection speed ;
Chemical injection method.

Images