Chemical injection device

Abstract

To disclose one example of a chemical liquid injection device that can restrain a chemical liquid concentration from becoming nonuniform regardless of a flow rate of flowing water.SOLUTION: A chemical liquid injection device 1 comprises a chemical liquid distribution regulator 7 capable of injecting chemical liquid discharged from a pump 5 into flowing water, and returning the chemical liquid into a chemical liquid tank 3, and capable of regulating a distribution ratio between a chemical liquid amount to be injected into the flowing water and a chemical liquid amount to be returned into the chemical liquid tank 3. Thereby, the chemical liquid amount to be injected into the flowing water can be regulated by the chemical liquid distribution regulator 7 in the chemical liquid injection device 1. Therefore, a chemical liquid concentration can be restrained from becoming nonuniform because a required injection amount can be secured without being greatly affected by a discharge amount of the pump 5.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a chemical liquid injection device that injects a chemical liquid into flowing water. [Background technology]

[0002] A chemical liquid injection device is a device that injects an oxidizing agent such as sodium hypochlorite into flowing water as a chemical liquid, as described in Patent Document 1. The amount of chemical liquid injected into the flowing water needs to be determined according to the flow rate of the flowing water.

[0003] For this reason, the invention described in Patent Document 1 uses a "positive displacement pump in which the amount of chemical solution discharged per one reciprocating movement of the shaft is fixed." Specifically, the invention described in Patent Document 1 uses a diaphragm pump with a reciprocating motor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-98136 Summary of the Invention [Problem to be solved by the invention]

[0005] In the invention described in Patent Document 1, the amount of chemical solution discharged when the shaft moves back and forth once (hereinafter referred to as the discharge amount) is fixed, so the amount of chemical solution injected into the flowing water (hereinafter referred to as the injection amount) is adjusted by changing and controlling the number of movements per unit time, i.e., the frequency of current flow to the coil.

[0006] For this reason, in the invention described in Patent Document 1, when the injection amount decreases, the injection timing interval of the drug solution, i.e., the period of the current frequency, must inevitably increase. In other words, the drug solution is injected discontinuously compared to a continuous flow rate.

[0007] Therefore, when observing the flowing water discharged from the chemical injector microscopically, there may be areas with high chemical concentration and areas with almost no chemical. This "non-uniformity in chemical concentration" becomes more pronounced as the discharge rate decreases.

[0008] In contrast, if a pump with a small discharge volume is used, the occurrence of "uneven drug concentration" is less likely. However, if the injection volume becomes large, a pump with a small discharge volume may not be able to secure the necessary injection volume.

[0009] In view of these points, the present disclosure discloses an example of a chemical solution injector that can prevent the chemical solution concentration from becoming non-uniform, regardless of the flow rate of flowing water. [Means for solving the problem]

[0010] A chemical liquid injection device that injects a chemical liquid into flowing water preferably includes at least one of the following components: a chemical liquid tank (3) that stores the chemical liquid, a pump (5) that pumps out the chemical liquid stored in the chemical liquid tank (3), and a chemical liquid distribution regulator (7) that can inject the chemical liquid discharged from the pump (5) into the flowing water and return the chemical liquid to the chemical liquid tank (3), and that can adjust the distribution ratio between the amount of chemical liquid injected into the flowing water and the amount of chemical liquid returned to the chemical liquid tank (3).

[0011] As a result, the chemical solution injection device can adjust the amount of chemical solution injected into the flowing water using the chemical solution distribution regulator 7. Therefore, the necessary injection amount can be secured without being significantly affected by the discharge rate of the pump 5, and therefore, uneven chemical solution concentration can be prevented regardless of the flow rate of the flowing water.

[0012] Incidentally, the symbols in each of the parentheses above are examples showing the correspondence with the specific configurations, etc. described in the embodiments described below, and the present disclosure is not limited to the specific configurations, etc. shown by the symbols in the parentheses above. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram showing a chemical liquid injector according to a first embodiment. [Figure 2] 1 is a diagram showing a chemical solution distribution regulator according to a first embodiment. FIG. [Figure 3] FIG. 2 is a diagram showing a pressure regulator according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] The following "embodiments of the invention" are examples of embodiments that fall within the technical scope of the present disclosure. In other words, the invention-specific matters described in the claims are not limited to the specific configurations and structures shown in the following embodiments.

[0015] Note that arrows and diagonal lines indicating directions in each figure are provided to facilitate understanding of the relationship between the figures and the shapes of each component or part. Therefore, the invention disclosed in this disclosure is not limited to the directions indicated in each figure. Diagonal lines do not necessarily indicate cross-sectional views.

[0016] At least one of each member or portion described with a reference numeral is provided unless otherwise specified, such as "one." In other words, unless otherwise specified, two or more members may be provided. The liquid injector disclosed in the present disclosure includes at least the components, such as the members or portions, described with reference numerals, and the structural portions shown in the drawings.

[0017] (First embodiment) <1. Overview of the chemical injection device> In this embodiment, an example of a chemical liquid injection device according to the present disclosure is applied to a pump device that supplies well water. As shown in Fig. 1, the chemical liquid injection device 1 according to this embodiment includes at least a chemical liquid tank 3, a pump 5, a chemical liquid distribution regulator 7, a pressure regulator 9, and a control unit 11.

[0018] The well water is pumped by a pump device (not shown) through a connecting pipe 13. The chemical liquid injection device 1 injects a chemical liquid into the well water (hereinafter referred to as flowing water) flowing inside the connecting pipe 13.

[0019] The chemical tank 3 is a tank that stores the chemical liquid (sodium hypochlorite in this embodiment). The pump 5 pumps out the chemical liquid stored in the chemical tank 3. The pump 5 in this embodiment is a positive displacement pump that pumps out a fixed amount of the chemical liquid in one operation (in this embodiment, a pump of the same type as the pump described in Patent Document 1).

[0020] The operation and stopping of the pump 5 is controlled by the control unit 11. That is, the chemical liquid injector 1 according to this embodiment also includes a flow rate sensor 15. The flow rate sensor 15 is a sensor that can continuously detect the flow rate of the flowing water circulating inside the connecting pipe 13.

[0021] The detection signal of the flow sensor 15 is input to the control unit 11. Then, the control unit 11 increases the power supply frequency to the pump 5 in response to an increase in the flow rate detected by the flow sensor 15, and decreases the power supply frequency in response to a decrease in the detected flow rate.

[0022] The control unit 11 according to this embodiment is configured by a microcomputer having a CPU, a ROM, a RAM, etc. Software for controlling the above-mentioned energization frequency is pre-installed in a non-volatile storage unit such as a ROM.

[0023] The chemical liquid distribution regulator 7 is a distribution regulator that can inject the chemical liquid discharged from the pump 5 into the flowing water and return the chemical liquid to the chemical liquid tank 3. The chemical liquid distribution regulator 7 adjusts the distribution ratio between the amount of chemical liquid injected into the flowing water and the amount of chemical liquid returned to the chemical liquid tank 3.

[0024] The pressure regulator 9 is a pressure compensator that adjusts the pressure difference between the flowing water side pressure P1 and the chemical tank side pressure P2 so that the pressure difference is equal to or less than a predetermined value.

[0025] The flowing water side pressure P1 refers to the pressure at the chemical solution outlet connected to the flowing water (connecting pipe 13) side among the chemical solution outlets of the chemical solution distribution regulator 7. The chemical solution tank side pressure P2 refers to the pressure at the chemical solution outlet connected to the chemical solution tank 3 side among the chemical solution outlets of the chemical solution distribution regulator 7.

[0026] <1.1 Details of the chemical distribution regulator> 2, the chemical liquid distribution regulator 7 is configured to have a valve body 7A, a valve element 7B, etc. The valve body 7A is provided with a chemical liquid injection path 7C and a return path 7D as paths for the chemical liquid.

[0027] The chemical liquid injection path 7C is a flow path that extends from the discharge side of the pump 5 to the side of the flowing water (connecting pipe 13). In this embodiment, the flow path that is bent approximately 90 degrees toward the tip side of the valve body 7B in Fig. 2 is the chemical liquid injection path 7C.

[0028] The return path 7D is a path that branches off from the chemical solution injection path 7C midway (at a location bent at approximately 90 degrees in this embodiment) and leads to the chemical solution tank 3. The valve body 7B is a valve member that adjusts the communication state of the return path 7D.

[0029] The valve element 7B according to this embodiment increases or decreases the opening area Sd of the return passage 7D by displacing in the left-right direction on the paper. Specifically, when the valve element 7B displaces toward the liquid chemical inlet (left side on the paper), the opening area Sd decreases, and when the valve element 7B displaces in a direction away from the liquid chemical inlet (right side on the paper), the opening area Sd increases.

[0030] The valve element 7B according to this embodiment is a screw-type conical tapered valve that is screwed to the valve body 7A. The opening area Sd of the return passage 7D is adjusted by an operator by rotating the valve element 7B.

[0031] In this embodiment, a check valve (not shown) is provided on the outflow side of the chemical injection path 7C and the outflow side of the return path 7D. Each check valve prevents the chemical flowing out of the chemical distribution regulator 7 from flowing back toward the pump 5.

[0032] <1.2 Pressure Regulator Details> 3, the pressure regulator 9 is configured to have at least a valve body 9A, a valve element 9B, a pressure guiding portion 9H, etc. The valve body 9A is provided with a chemical liquid flow path 9C. The chemical liquid flow path 9C is a flow path that leads from the chemical liquid distribution regulator 7 to the chemical liquid tank 3.

[0033] The valve element 9B adjusts the flow path area Sp of the chemical liquid flow path 9C. Note that the valve element 9B according to this embodiment is made of resin such as rubber. The valve seat portion 9D is made of metal. The valve seat portion 9D is provided on the valve body 9A, and is the portion that comes into contact with the valve element 9B when the valve opening 9E is closed, and is the portion that forms the outer edge of the valve opening 9E.

[0034] Valve port 9E is an opening that connects the upstream side (portion 9F of chemical distribution regulator 7) and downstream side (portion 9G leading to chemical tank 3) of chemical flow path 9C. In other words, valve element 9B adjusts the communication area of ​​valve port 9E, thereby adjusting the flow path area Sp of chemical flow path 9C.

[0035] The pressure of the liquid chemical flowing out of the liquid chemical distribution regulator 7, i.e., the pressure of portion 9F (hereinafter referred to as the valve opening pressure), acts on the valve element 9B with a force that increases the flow path area Sp. The pressure guiding portion 9H has the function of guiding the static pressure of the flowing water to the back surface of the valve element 9B.

[0036] The back surface of the valve element 9B refers to the part of the valve element 9B on which pressure acts in the direction opposite to the valve-opening pressure. Therefore, the static pressure of the flowing water acting on the back surface of the valve element 9B acts on the valve element 9B as a pressure that reduces the flow path area Sp (hereinafter referred to as the valve-closing pressure).

[0037] In this embodiment, the static pressure of the flowing water is guided to the pressure guiding portion 9H via the pressure guiding tube 9J (see FIG. 1). Incidentally, in FIG. 3, the spring 9K is a spring for suppressing vibration (chattering) of the valve body 9B. Therefore, the valve closing force is approximately equal to the force due to the static pressure of the flowing water.

[0038] <2. Operation of chemical distribution regulators and pressure regulators, etc.> 2.1 Operation of the pressure regulator The valve opening pressure acting on valve element 9B of pressure regulator 9 is the pressure of the chemical solution discharged from chemical solution distribution regulator 7 to pressure regulator 9. The valve closing pressure acting on valve element 9B is the static pressure of the flowing water guided to pressure guiding part 9H via pressure guiding pipe 9J.

[0039] The valve element 9B is displaced so that the valve-opening pressure and the valve-closing pressure are balanced, and the valve-closing force is approximately equal to the force due to the static pressure of the flowing water. Therefore, the pressure regulator 9 adjusts the pressure difference between the flowing water-side pressure P1 and the chemical solution tank-side pressure P2 so that the pressure difference is equal to or less than a predetermined value.

[0040] In this embodiment, the static pressure of the flowing water is introduced to the back surface of the valve body 9B, so the pressure on the upstream side of the chemical solution flow path 9C (part 9F of the chemical solution distribution regulator 7) is approximately the same as the static pressure of the flowing water. In other words, the pressure at the inlet of the pressure regulator 9 is approximately the same as the static pressure of the flowing water.

[0041] <2.2 Operation of the chemical distribution regulator> The flow rate Q1 of the chemical liquid flowing through the chemical liquid injection path 7C of the chemical liquid distribution regulator 7 is a function value of the "flow path cross-sectional area So of the chemical liquid injection path 7C" and the "pressure difference ΔP1 between the discharge pressure of the pump 5 and the static pressure of the flowing water", i.e., "Q1 = f(So, ΔP1)".

[0042] The flow rate Q2 of the chemical liquid flowing through the return path 7D of the chemical liquid distribution regulator 7 is a function value of the "opening area Sd" and the "pressure difference ΔP2 between the discharge pressure of the pump 5 and the pressure at the inlet of the pressure regulator 9," i.e., "Q2 = f(Sd, ΔP2)."

[0043] In other words, the ratio of Q1 to Q2, i.e., the distribution ratio between the amount of chemical solution Q1 injected into the flowing water and the amount of chemical solution Q2 returned to the chemical solution tank 3, is a function value of the ``flow path cross-sectional area So,'' ``opening area Sd,'' ``pressure difference ΔP1,'' and ``pressure difference ΔP2.''

[0044] Therefore, when at least one of the "flow path cross-sectional area So," "opening area Sd," "pressure difference ΔP1," and "pressure difference ΔP2" is changed, the distribution ratio is changed. In this embodiment, the "flow path cross-sectional area So" is a constant value (fixed value). Furthermore, since the pressure at the inlet of the pressure regulator 9 is approximately the same as the static pressure of the flowing water, the "pressure difference ΔP1" and the "pressure difference ΔP2" have the same value.

[0045] Therefore, in this embodiment, when the "pressure difference ΔP1 between the discharge pressure of the pump 5 and the static pressure of the flowing water" is constant, the distribution ratio between the amount of chemical solution Q1 injected into the flowing water and the amount of chemical solution Q2 returned to the chemical solution tank 3 is essentially a function value of only the "opening area Sd."

[0046] Therefore, the person in charge of the chemical liquid injection device 1 (hereinafter referred to as the "administrator") can adjust the distribution ratio between the amount of chemical liquid Q1 injected into the flowing water and the amount of chemical liquid Q2 returned to the chemical liquid tank 3 by rotating the valve body 7B of the chemical liquid distribution regulator 7.

[0047] 3. Features of the Chemical Solution Injector According to the Present Embodiment In the chemical solution injector 1 according to this embodiment, the amount of chemical solution injected into the flowing water can be adjusted by the chemical solution distribution regulator 7. Therefore, the necessary injection amount can be secured without being significantly affected by the discharge rate of the pump 5, and therefore, uneven chemical solution concentration can be prevented regardless of the flow rate of the flowing water.

[0048] In other words, if the discharge rate of pump 5 is larger than the required injection rate, the amount of chemical solution Q2 returned to chemical solution tank 3 can be increased and the amount of chemical solution Q1 injected into the flowing water can be reduced, thereby preventing the period of the current flow frequency from becoming larger, and thereby preventing the chemical solution concentration from becoming uneven.

[0049] Furthermore, if the discharge rate of the pump 5 is small compared to the required injection rate, the amount of chemical Q2 returned to the chemical tank 3 can be reduced (including the case where Q2 is set to 0) to increase the amount of chemical Q1 injected into the flowing water. Therefore, the cycle of the current frequency can be reduced, which can prevent the chemical concentration from becoming uneven regardless of the flow rate of the flowing water.

[0050] The liquid chemical injector 1 is equipped with a pressure regulator 9 that can adjust the pressure difference between the flowing water side pressure P1 and the liquid chemical tank side pressure P2 so that the pressure difference is equal to or less than a predetermined value. As a result, as described above, the distribution ratio is essentially a function value of only the "opening area Sd," and therefore, the administrator can easily adjust the distribution ratio.

[0051] (Other embodiments) The liquid injector according to the above-described embodiment is configured to include the pressure regulator 9. However, the present disclosure is not limited to this. That is, the present disclosure may be configured, for example, such that the pressure regulator 9 is eliminated.

[0052] In the above-described embodiment, the distribution ratio is substantially a function value of only the "opening area Sd," and therefore the distribution ratio is adjusted by rotating the valve body 7B of the chemical solution distribution regulator 7. However, the present disclosure is not limited to this.

[0053] That is, the disclosure may be, for example, a configuration for adjusting the "opening area Sd" and the "pressure difference ΔP2," or a configuration for adjusting only the "pressure difference ΔP2." Note that the configuration for adjusting the "pressure difference ΔP2" may be a "configuration for adjusting the valve closing pressure acting on the back surface of the valve element 9B," or a "configuration for adjusting the opening area of ​​the valve port 9E with the valve element 9B."

[0054] In the above-described embodiment, the valve element 7B is configured to be adjusted by an administrator. However, the present disclosure is not limited to this. That is, the present disclosure may be configured, for example, so that at least one of the valve elements 7B and 9B is driven by an actuator such as an electromagnetic solenoid or a reciprocating motor, and the power supply frequency to the actuator is controlled according to the flow rate of the flowing water.

[0055] The pump 5 according to the above-described embodiment is a positive displacement pump that delivers a fixed amount of liquid medicine in one operation. However, the present disclosure is not limited to this. That is, in the present disclosure, for example, the pump 5 may be configured as a non-positive displacement pump that delivers liquid medicine by rotating an impeller.

[0056] In the above-described embodiment, the chemical liquid distribution regulator 7 and the pressure regulator 9 are separate components. However, the present disclosure is not limited to this. That is, the present disclosure may be, for example, a chemical liquid distribution regulator in which the chemical liquid distribution regulator 7 and the pressure regulator 9 are integrated, or a configuration in which the pressure regulator 9 is eliminated.

[0057] Furthermore, the present disclosure is not limited to the above-described embodiments as long as it conforms to the spirit of the disclosure described in the above-described embodiments. Therefore, the present disclosure may be a configuration in which at least two of the above-described embodiments are combined, or a configuration in which any of the components illustrated or the components described with reference numerals in the above-described embodiments are eliminated. [Explanation of symbols]

[0058] 1. Chemical injection device 3... Chemical tank 5... Pump 7... Chemical distribution regulator 9... Pressure regulator 11... Control section 13…Connecting pipe 15... Flow sensor

Claims

1. In a chemical injection device that injects a chemical solution into flowing water, a chemical tank in which a chemical solution is stored; a pump that pumps out the chemical solution stored in the chemical solution tank; a chemical liquid distribution regulator capable of injecting the chemical liquid discharged from the pump into the flowing water and returning the chemical liquid to the chemical liquid tank, the chemical liquid distribution regulator being capable of adjusting the distribution ratio between the amount of chemical liquid injected into the flowing water and the amount of chemical liquid returned to the chemical liquid tank; When the pressure at the chemical solution outlet connected to the flowing water side among the chemical solution outlets of the chemical solution distribution regulator is defined as the flowing water side pressure, and the pressure at the chemical solution outlet connected to the chemical solution tank side among the chemical solution outlets of the chemical solution distribution regulator is defined as the chemical solution tank side pressure, a pressure regulator capable of adjusting a pressure difference between the flowing water side pressure and the chemical solution tank side pressure so that the pressure difference is equal to or less than a predetermined value; The pressure regulator is a valve element that adjusts a flow path area of ​​a chemical liquid flow path from the chemical liquid distribution regulator to the chemical liquid tank, the valve element being displaced in a direction that increases the flow path area when pressure of the chemical liquid flowing out from the chemical liquid distribution regulator is received; and a pressure guiding section that guides the static pressure of the flowing water to the back surface of the valve body, the pressure guiding section causing the static pressure of the flowing water to act on the valve body as a force in a direction that reduces the flow path area; A chemical liquid injection device having the same.

2. A chemical liquid injection device that injects a chemical liquid into a connecting pipe through which water (hereinafter referred to as flowing water) delivered by a pump device flows, a chemical tank in which a chemical solution is stored; a pump that pumps out the chemical solution stored in the chemical solution tank; a chemical liquid distribution regulator capable of injecting the chemical liquid discharged from the pump into the flowing water and returning the chemical liquid to the chemical liquid tank, the chemical liquid distribution regulator being capable of adjusting the distribution ratio between the amount of chemical liquid injected into the flowing water and the amount of chemical liquid returned to the chemical liquid tank; The chemical solution distribution regulator includes: A valve body provided with a chemical injection path extending from the discharge side of the pump to the flowing water side, and a return path branching from the chemical injection path to the chemical tank side; a valve body for adjusting the communication state of the return passage; When the pressure at the chemical solution outlet connected to the flowing water side among the chemical solution outlets of the chemical solution distribution regulator is defined as the flowing water side pressure, and the pressure at the chemical solution outlet connected to the chemical solution tank side among the chemical solution outlets of the chemical solution distribution regulator is defined as the chemical solution tank side pressure, a pressure regulator capable of adjusting a pressure difference between the flowing water side pressure and the chemical solution tank side pressure so that the pressure difference is equal to or less than a predetermined value; Furthermore, the pressure regulator a valve element that adjusts a flow path area of ​​a chemical liquid flow path from the chemical liquid distribution regulator to the chemical liquid tank, the valve element being displaced in a direction that increases the flow path area when pressure of the chemical liquid flowing out from the chemical liquid distribution regulator is received; and a pressure guiding section that guides the static pressure of the flowing water to the back surface of the valve body, the pressure guiding section causing the static pressure of the flowing water to act on the valve body as a force in a direction that reduces the flow path area; A chemical liquid injection device having the same.

3. 3. The chemical liquid injector according to claim 1, wherein the pump is a positive displacement pump that delivers a fixed amount of chemical liquid in each actuation.

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