Drug injection device

Abstract

The present invention provides a chemical supply device that can supply chemical solution to a target area within the water of a receiving tank without passing the chemical solution through the pump itself, and can maintain an appropriate concentration of the chemical solution. [Solution] The pump draws water from the water tank via a suction hose and returns it to the water tank via a discharge hose. The chemical solution container is filled with chemical solution and positioned so that its liquid level is lower than the water level in the water tank. The chemical solution nozzle is connected to the end of the discharge hose and has a chemical solution suction port that opens into the stored water in the water tank and also opens into a negative pressure section where the discharge flow generates negative pressure. The chemical solution hose has its end connected to the chemical solution suction port of the chemical solution nozzle and its rear end communicates with the chemical solution container. A check valve is provided in the chemical solution hose that communicates the chemical solution hose and the water tank via the chemical solution nozzle when the chemical solution container side becomes negative pressure compared to the water tank, and when there is a discharge flow. The check valve may also be provided at the discharge side opening of the pump.

Description

Technical Field

[0001] The present invention relates to a chemical solution injection device, and particularly to a device for injecting a chemical solution (sodium hypochlorite) into a receiving water tank of a water supply system.

Background Art

[0002] In an elevated water tank of an apartment or the like, it is necessary to periodically add a bactericide (sodium hypochlorite) to maintain the sterilization effect. The concentration to be maintained is an extremely small amount, for example, 0.1 ppm to 1 ppm. When the water is constantly used, the above concentration is originally the concentration of the bactericide contained in the tap water, and since the water will be consumed before it volatilizes, there is no particular need to additionally replenish the bactericide.

[0003] In the elevated receiving water tank of a school, during the summer vacation or the like, the receiving water tank may be in a full state and left unattended for a long time. In this case, the bactericide originally contained in the tap water often volatilizes and does not maintain the legal amount (0.1 ppm to 1 ppm).

[0004] Also, in an elevated receiving water tank of a factory or the like where the usage frequency is high during the day but significantly decreases at night, the problem of bactericide volatilization also occurs in the summer as described above.

[0005] The applicant of the present application has proposed a chemical solution dropping device that intermittently drops a bactericide by using a tube pump in Japanese Patent Application Laid-Open No. 2023-95857. By intermittently operating the tube pump for a predetermined time, it attempts to maintain the above predetermined concentration, and a certain effect has been obtained.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] As mentioned above, in elevated water tanks at schools, the tanks can become full during summer vacation and other periods, and be left unattended for extended periods. In such cases, the sodium hypochlorite originally present in tap water volatilizes, often resulting in a level that does not meet legal requirements (0.1 ppm to 1 ppm).

[0008] 1m 3 To achieve a concentration of 0.1 ppm by adding 12% sodium hypochlorite to the tank, 0.83 cc of sodium hypochlorite needs to be added. To maintain this concentration, it is desirable to add very small amounts of sodium hypochlorite periodically.

[0009] However, if, for example, 1 cc of solution needs to be dispensed every few hours, performing this task manually would require stationing workers at the site at all times, or having workers rotate to handle multiple locations. While it is possible to use the above-mentioned personnel arrangements or expensive equipment if cost is not a concern, the cost-effectiveness would be low, and the emergence of low-cost equipment is desirable.

[0010] Therefore, a system is proposed in which a tube pump is operated every few hours to supply small amounts of sodium hypochlorite to a water tank, as disclosed in Patent Document 1.

[0011] However, in a structure like that described in Patent Document 1, where sodium hypochlorite is directly passed through a tube pump to supply water to a receiving tank, sodium hypochlorite is drawn into the tube of the tube pump, and if maintenance is not performed frequently, the pump will be damaged.

[0012] Next, the chemical solution dripping device described in Patent Document 1 above is based on the premise that the chemical solution is dripped from above the water accumulated in the water tank. Therefore, the dripped chemical solution will float on the surface of the water accumulated in the tank.

[0013] The specific gravity of pure sodium hypochlorite is 1.25, but the sodium hypochlorite used in water tanks is generally 12%. If, for example, only 1cc of this concentration is intermittently dropped into the water tank, it will diffuse at the point of addition and its specific gravity will become almost the same as that of water. As a result, the sodium hypochlorite will float towards the top of the tank.

[0014] As a result, sodium hypochlorite evaporates more quickly during the summer months, requiring more frequent replenishment.

[0015] It seems that the above problem could be solved by having the hose supplying sodium hypochlorite open into the water stored in the receiving tank. However, in this structure, the water from the receiving tank enters the hose supplying the chemical solution up to the same level as the water in the receiving tank, and only a very small amount of the chemical solution is dripped out. Therefore, it will initially remain in the hose and will not immediately diffuse into the receiving tank after being dripped out, requiring a long time to form the desired concentration. Alternatively, it is possible that it will remain in the hose and not contribute to sterilization.

[0016] While it is possible to pre-adjust the pump during installation to ensure that the hose opening is filled with sodium hypochlorite before use, this pre-adjustment is necessary, and the sodium hypochlorite that accumulates in the hose, particularly near the hose outlet, will diffuse into the tank over time, creating a concentration higher than intended.

[0017] The present invention has been proposed in view of the above-mentioned conventional circumstances, and aims to provide a chemical supply device that can supply a chemical solution to a target area in the water of a receiving tank without passing the chemical solution through the pump itself, and can maintain an appropriate concentration of the chemical solution. [Means for solving the problem]

[0018] The pump sucks up water from the water receiving tank through the suction hose and returns it to the water receiving tank through the discharge hose. The chemical liquid container is filled with a chemical liquid and is arranged at a position having a liquid level lower than the water surface of the water receiving tank. The chemical liquid nozzle is connected to the tip of the discharge hose, opens into the stored water in the water receiving tank, and has a chemical liquid suction port that opens into a negative pressure section that generates a negative pressure by the discharge flow.

[0019] The chemical liquid hose has its tip connected to the chemical liquid suction port of the chemical liquid nozzle and its rear end communicating with the chemical liquid container. The check valve is provided in the chemical liquid hose that prevents backflow from the water receiving tank to the chemical liquid container when the negative pressure on the chemical liquid container side becomes lower than that of the water receiving tank, and communicates the chemical liquid hose and the water receiving tank via the chemical liquid nozzle when there is the discharge flow.

[0020] Instead of being provided in the chemical liquid hose, the check valve may be provided at the discharge side opening of the pump.

[0021] The pump is a control device and is driven for a predetermined number of seconds at predetermined time intervals.

Advantages of the Invention

[0022] With the above configuration, the chemical liquid can be supplied to the water receiving tank without passing the chemical liquid through the pump, and moreover, the chemical liquid can be supplied to the target site regardless of any part of the water receiving tank, and the chemical liquid concentration can be properly maintained.

Brief Description of the Drawings

[0023] [Figure 1] A diagram showing the outline of the present invention. [Figure 2] A diagram showing an embodiment of the chemical liquid nozzle. [Figure 3] A diagram showing another mounting position of the check valve. [Figure 4] A diagram showing an example of the pump.

Embodiments for Carrying Out the Invention

[0024] FIG. 1 is a diagram showing the outline of the present invention.

[0025] Since this invention aims to adjust the amount of disinfectant (sodium hypochlorite) to be added to a water receiving tank installed in a water supply system, it is naturally assumed that there is a water receiving tank 10 filled with a predetermined amount of water.

[0026] Pump 1 draws water from the water tank 10 via a suction hose 11 and returns it to the water tank 10 via a discharge hose 12. A chemical nozzle 20 is connected to the end of the discharge hose 12. The chemical nozzle 20 has a structure, such as a venturi, that generates negative pressure from the discharge flow from the pump 1. That is, as shown in Figure 2(a), the inner diameter of the chemical nozzle 20 decreases in the middle and returns to its original inner diameter at the discharge port. A chemical suction port 21 is provided on the pipe wall of the portion with a reduced inner diameter.

[0027] The chemical nozzle 20 is positioned so as to be submerged in the water stored in the water tank 10.

[0028] The chemical solution container 30 is filled with sodium hypochlorite, which is the chemical solution. It is positioned so that the liquid level is below the water level in the water tank 1, and the rear end of the chemical solution hose 31 is connected to it.

[0029] With this structure, when pump 1 is activated, water is drawn up from the water tank 10 through the suction hose 11 and discharged back into the water tank 10 via the chemical nozzle 20 at the end of the discharge hose 12. As water is discharged from the discharge hose 12 in this way, the chemical nozzle 20 has a venturi structure, so the chemical is drawn in from the chemical container 30 via the chemical hose 31 and the chemical suction port 21 and discharged into the water in the water tank 10.

[0030] The chemical nozzle 20 described above is not limited to the venturi structure shown in Figure 2(a), but may also be configured such that the chemical inlet 21 opens downstream of the orifice plate of an orifice structure, as shown in Figure 2(b). Furthermore, as shown in Figure 2(c), a configuration in which the chemical inlet 21 opens in the direction of the water flow in a pipe with a constant diameter through which the discharge flow passes is also conceivable.

[0031] In any case, when pump 1 is activated and a water flow is generated, it is sufficient to have a configuration in which sodium hypochlorite is drawn in by the negative pressure created by the water flow. Also, the opening position of the chemical nozzle 20 can be in the water stored in the water tank 1, but it is preferable that it be near the outlet 101 that communicates with the pumping pump 100. This will allow for preparation for occasional use, even when schools are on holiday or factories are operating at night.

[0032] The chemical solution container 30 is positioned such that its liquid level is lower than the water level in the water tank 10 (so that the water pressure on the chemical solution container side is lower than that on the water tank side), and a check valve 32 is provided near the chemical solution suction port 21 of the chemical solution hose 31 to prevent water from flowing back from the water tank 10 side to the chemical solution container side.

[0033] When there is a discharge flow from the pump 1, a negative pressure is created in the venturi of the chemical nozzle 20, causing the check valve 32 to open and sodium hypochlorite to be injected into the water tank 10. Conversely, when there is no discharge flow from the pump 1, water attempts to flow back into the chemical container 30 through the chemical nozzle 20, but the check valve 32 closes, preventing water from flowing back from the water tank 10 to the chemical container 30.

[0034] Since the water attempting to flow back will always pass through the chemical nozzle 20, the check valve 32 may be installed at the tip of the chemical nozzle 20, as shown in Figure 3.

[0035] The above-mentioned pump 1 can be any pump that operates intermittently at predetermined time intervals to generate the water flow described above, but the amount of sodium hypochlorite injected in a single operation is extremely small, ranging from 1cc to a few cc. The following describes the case using a tube pump.

[0036] Figure 4 shows the main parts of the pump 1 used in the present invention.

[0037] The motor-driven rotor 41 has protrusions 12 at equal angular intervals (180 degrees in this case), and a retaining wall 43 is provided to surround the upper half of the rotor 41. A flexible hose 44 is sandwiched between the retaining wall 43 and the rotor 41, and the hose 44 is pressed against the retaining wall 43 in a constricted state at the portion of the protrusions 42.

[0038] As described above, the suction side of hose 44 is connected to the suction hose 11, and its tip is immersed in the water stored in the water tank 10. The discharge side of hose 44 is connected to the discharge hose 12 and opens to the water stored in the water tank 10 via the chemical nozzle 20.

[0039] In this state, when the rotor 41 is rotated, a specific protrusion 42 rotates while pressing against the retaining wall 43. At this time, the hose 44 at the point where the protrusion 42 passes constricts, and this constriction moves downstream with the rotation. Therefore, the water filled downstream in the direction of rotation is discharged into the water tank 10 from the chemical nozzle 20 connected to the end of the discharge hose 42. On the other hand, the hose upstream of the protrusion 42 in the direction of rotation expands again and draws up a predetermined amount of water from the water tank 10. Therefore, a volume of water corresponding to the rotation angle of the protrusion 42 is drawn up from the water tank 10 and returned to the water tank 10.

[0040] At this time, water returns to the water tank 10 via the chemical nozzle 20, causing a negative pressure in the negative pressure section of the chemical nozzle 20, which opens the check valve 32, drawing in sodium hypochlorite, and releasing it into the water tank 10 along with the water.

[0041] Since the sodium hypochlorite is released from the opening of the chemical nozzle 20, i.e., into the water, the evaporation of the injected sodium hypochlorite is suppressed.

[0042] By operating pump 1 for 1 to several seconds at predetermined time intervals (for example, every few hours), the concentration of sodium hypochlorite in the water that remains in the water tank 10 for a long period of time is maintained. The predetermined time intervals and the operating time of pump 1 will vary depending on the size and usage of the water tank, but naturally, the control device is responsible for managing these times.

[0043] While various pumps other than the aforementioned tube pump can be used for pump 1, using a tube pump makes it easier to adjust the discharge volume, and therefore the amount of sodium hypochlorite suctioned, which is proportional to the discharge volume.

[0044] As explained above, since the present invention injects sodium hypochlorite into the water in the water tank, even when the water is stored in the water tank for a long period of time, the evaporation of sodium hypochlorite can be suppressed, reducing the amount of sodium hypochlorite used, and also reducing the number of times the device is operated, thereby reducing the management workload for workers. [Explanation of symbols]

[0045] 1. Pump 10. Water storage tank 11. Intake hose 12. Discharge hose 20. Chemical solution nozzle 21. Medication inlet 30. Chemical solution containers 31. Chemical solution hose 32. Check valve 41. Rotor 42 ··Convex part 43. Retaining wall 44. Flexible hose

Claims

1. A pump that draws water from a water tank via a suction hose and returns the drawn water to the water tank via a discharge hose, A chemical solution container filled with chemical solution, having a liquid level lower than the water level in the water tank, A chemical nozzle is connected to the end of the discharge hose, opens into the water stored in the receiving tank, and has a chemical suction port that opens into a negative pressure section where negative pressure is generated by the discharge flow. A chemical hose whose tip is connected to the chemical suction port of the chemical nozzle and whose rear end is connected to the chemical container, When the chemical solution container side becomes negative pressure compared to the water tank, a check valve is provided on the chemical solution hose that connects the chemical solution hose and the water tank via a chemical solution nozzle to prevent backflow from the water tank to the chemical solution container, and when there is a discharge flow, the check valve is provided on the chemical solution hose. A drug injection device characterized by being equipped with the following features.

2. The chemical injection device according to claim 1, wherein the check valve is provided at the discharge-side opening of the chemical nozzle instead of being provided in the chemical hose.

3. The drug injection device according to claim 1 or 2, further comprising a control device that drives the pump for a predetermined number of seconds at predetermined time intervals.

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