JP7811777B2 - Chemical injection device - Google Patents

Description

This disclosure relates to a chemical liquid injection device that injects a chemical liquid into flowing water.

A chemical liquid injection device, as described in Patent Document 1, is a device that injects an oxidizing agent such as sodium hypochlorite into flowing water as a chemical liquid. The amount of chemical liquid injected into the flowing water must correspond to the flow rate of the flowing water.

For this reason, the invention described in Patent Document 1 uses a "positive displacement pump in which a fixed amount of chemical solution is expelled with each reciprocating movement of the shaft." Specifically, the invention described in Patent Document 1 uses a diaphragm pump with a reciprocating motor.

Japanese Patent Application Laid-Open No. 2005-98136

In the invention described in Patent Document 1, the amount of chemical solution expelled per one reciprocating movement of the shaft (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) can be adjusted by changing and controlling the number of reciprocating movements per unit time, i.e., the frequency of current flow to the coil.

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

Therefore, when observing the flowing water discharged from the chemical injection device microscopically, there may be areas with high chemical concentration and areas with almost no chemical. This "uneven chemical concentration" becomes more pronounced as the discharge rate becomes smaller.

In contrast, if a pump with a small output is used, "uneven drug concentration" is less likely to occur. However, if a pump with a small output is used, it may not be possible to ensure the required injection volume when the injection volume becomes large.

In consideration of these points, this disclosure discloses an example of a chemical solution injection device that can prevent the chemical solution concentration from becoming uneven, regardless of the flow rate of the flowing water.

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

As a result, the chemical injection device can adjust the amount of chemical injected into the flowing water using the chemical distribution regulator (7). Therefore, the necessary injection volume can be secured without being significantly affected by the discharge volume of the pump (5), preventing the chemical concentration from becoming uneven regardless of the flow rate of the flowing water.

Incidentally, the symbols in 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. indicated by the symbols in parentheses above.

1 is a diagram showing a chemical liquid injector according to a first embodiment; 1 is a diagram showing a chemical solution distribution regulator according to a first embodiment. FIG. FIG. 2 is a diagram showing a pressure regulator according to the first embodiment.

The following "Embodiments of the Invention" are examples of embodiments within the technical scope of this disclosure. In other words, the invention-specific matters set forth in the claims are not limited to the specific configurations and structures shown in the following embodiments.

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

At least one component or part that is described with a reference number is provided, unless otherwise specified, such as "one." In other words, unless otherwise specified, such as "one," two or more components may be provided. The drug solution infusion device disclosed in this disclosure includes at least the components, such as components or parts, that are described with a reference number, as well as the structural parts shown in the drawings.

(First embodiment)
<1. Overview of the chemical liquid injection device>
In this embodiment, an example of a chemical liquid injection device according to the present disclosure is applied to a pump device for supplying 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.

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

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

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 within the connecting pipe 13.

The detection signal from the flow sensor 15 is input to the control unit 11. The control unit 11 then 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.

In this embodiment, the control unit 11 is configured as a microcomputer having a CPU, ROM, RAM, etc. The software for controlling the above-mentioned power frequency is pre-installed in a non-volatile memory unit such as ROM.

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

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 below a predetermined value.

Note that the flow-water-side pressure P1 refers to the pressure at the chemical outlet of the chemical distribution regulator 7 that is connected to the flow-water side (connecting pipe 13). The chemical tank-side pressure P2 refers to the pressure at the chemical outlet of the chemical distribution regulator 7 that is connected to the chemical tank 3 side.

<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.

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

The return flow path 7D is a flow path that branches off midway through the chemical injection path 7C (at a location where it bends approximately 90 degrees in this embodiment) and leads to the chemical tank 3. The valve body 7B is a valve member that adjusts the communication state of the return flow path 7D.

In this embodiment, the valve element 7B increases or decreases the opening area Sd of the return passage 7D by displacing left or right on the page. Specifically, when the valve element 7B displaces toward the chemical liquid inlet (left side of the page), the opening area Sd decreases, and when the valve element 7B displaces away from the chemical liquid inlet (right side of the page), the opening area Sd increases.

The valve element 7B in this embodiment is a screw-type conical tapered valve that is threadedly connected to the valve body 7A. The opening area Sd of the return passage 7D is adjusted by the operator by rotating the valve element 7B.

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.

1.2 Pressure Regulator Details
3, the pressure regulator 9 is configured to include at least a valve body 9A, a valve element 9B, and a pressure guiding portion 9H. 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.

The valve element 9B adjusts the flow path area Sp of the chemical liquid flow path 9C. In this embodiment, the valve element 9B 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 contacts the valve element 9B when the valve opening 9E is closed, and forms the outer edge of the valve opening 9E.

The valve port 9E is an opening that connects the upstream side (portion 9F of the chemical distribution regulator 7) of the chemical flow path 9C with the downstream side (portion 9G leading to the chemical tank 3). In other words, the valve body 9B adjusts the flow path area Sp of the chemical flow path 9C by adjusting the communication area of the valve port 9E.

The pressure of the chemical liquid flowing out of the chemical liquid 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.

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

In this embodiment, the static pressure of the flowing water is guided to the pressure guiding section 9H via the pressure guiding tube 9J (see Figure 1). Incidentally, in Figure 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.

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

The valve element 9B then displaces so that the valve-opening pressure and the valve-closing pressure are balanced, and the valve-closing force is approximately equal to the force caused by 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 tank side pressure P2 so that the pressure difference is equal to or less than a predetermined value.

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 flow path 9C (part 9F of the chemical 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.

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

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," that is, "Q2 = f(Sd, ΔP2)."

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."

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 changes. In this embodiment, the "flow path cross-sectional area So" is a constant (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" are the same value.

For this reason, 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."

Therefore, the person in charge of managing the chemical liquid injection device 1 (hereinafter referred to as the "manager") 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.

3. Features of the chemical liquid injector according to this 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.

In other words, if the discharge rate of pump 5 is greater than the required injection rate, increasing the amount of chemical Q2 returned to chemical tank 3 and decreasing the amount of chemical Q1 injected into the flowing water can prevent the period of the current frequency from increasing, thereby preventing the chemical concentration from becoming uneven.

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), and the amount of chemical Q1 injected into the flowing water can be increased. 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.

The chemical liquid injection device 1 is equipped with a pressure regulator 9 that can adjust the pressure difference between the flowing water side pressure P1 and the chemical liquid 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," allowing the administrator to easily adjust the distribution ratio.

(Other embodiments)
The chemical solution injector according to the above-described embodiment includes the pressure regulator 9. However, the present disclosure is not limited to this. That is, the present disclosure may include, for example, a configuration in which the pressure regulator 9 is eliminated.

In the above-described embodiment, the distribution ratio is essentially a function value of only the "opening area Sd," so 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.

In other words, the disclosure may be, for example, a configuration that adjusts the "opening area Sd" and the "pressure difference ΔP2," or a configuration that adjusts only the "pressure difference ΔP2." Note that the configuration that adjusts the "pressure difference ΔP2" may be a "configuration that adjusts the valve closing pressure acting on the back surface of the valve element 9B," or a "configuration that adjusts the opening area of the valve port 9E with the valve element 9B."

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 frequency of current supplied to the actuator is controlled according to the flow rate of the flowing water.

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

In the above-described embodiment, the chemical liquid distribution regulator 7 and the pressure regulator 9 were separate components. However, the present disclosure is not limited to this. That is, the present disclosure may also be directed to, 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.

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 constituent elements shown in the drawings or those described with reference numerals in the above-described embodiments are eliminated.

REFERENCE SIGNS LIST 1... Chemical liquid injector 3... Chemical liquid tank 5... Pump 7... Chemical liquid distribution regulator 9... Pressure regulator 11... Control unit 13... Connecting pipe 15... Flow rate sensor

Claims (3)

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 . 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 liquid injection path extending from the discharge side of the pump to the flowing water side, and a return path branching from the chemical liquid injection path to the chemical liquid tank side; and a valve body for adjusting the communication state of the return path ,
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. 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.