JP2009028624A - Liquid chemical injection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid injection apparatus Y which can be manufactured at a relatively low cost even when the level of the planned maximum flow rate in a liquid feeding pipe 101 is designed high, and can stably inject the liquid chemical of an amount proportional to the flow rate ranging from the small flow to the large flow of liquid flowing inside the liquid feed pipe 101. <P>SOLUTION: The liquid injection apparatus Y, which injects the liquid chemical with an injection pump 9 into the liquid flowing inside the liquid feed pipe 101, is provided with a plurality of liquid flow pipes 13, 14 for branching the liquid flow in the liquid feed pipe 101 in the course of the pipe 101; and a flow rate sensor 16 detecting the flow rate of the liquid in one optional liquid flow pipe 14. The liquid chemical injection operation of the injection pump 9 is controlled on the basis of the signals detected by the flow rate sensor 16. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a chemical liquid injector that injects a chemical liquid into a liquid flowing in a liquid feeding pipe.
For example, by pumping up ground water and injecting chemicals into it, it can be used by installing it in water supply facilities to sterilize bacteria such as Escherichia coli contained in water and supply it to living space as high-quality water Is.

  For example, Patent Documents 1 to 3 exist as the chemical solution injector.

  The chemical liquid injectors disclosed in Patent Documents 1 to 3 are configured to detect a flow rate sensor that detects a flow rate of a liquid in a liquid feeding pipe and generates a detection signal, an injection pump, and a detection signal emitted from the flow rate sensor to detect the flow rate sensor. A control unit that generates a control signal based on the signal, and an injection pump that operates to inject a chemical liquid in an amount proportional to the liquid flow rate in the liquid supply pipe into the liquid in the liquid supply pipe based on the control signal. Yes.

  Since the flow rate sensor used here directly detects the liquid flow rate in the liquid supply pipe, it must have a detection capability corresponding to the maximum flow rate of the liquid supply pipe. As the planned flow rate increases, its size increases and its price is relatively high.

JP 2006-68681 A Japanese Patent Laid-Open No. 11-19653 JP-A-62-245113

  In the above chemical injection device, even if the planned maximum flow rate in the liquid delivery pipe is large, if the liquid flow rate in the liquid delivery pipe can be detected by using a small flow sensor with a relatively small detection capability, the price of the flow sensor Therefore, even if the chemical solution injection device is designed to have a large planned maximum flow rate in the liquid delivery pipe, it can be provided to the market relatively inexpensively.

  Under such circumstances, the present invention can be manufactured relatively inexpensively with respect to the size of the planned maximum flow rate in the liquid feeding pipe and is proportional to the flow rate from a small flow rate to a large flow rate of the liquid flowing in the liquid feed tube. It is an object of the present invention to provide a chemical liquid injector capable of stably injecting an amount of chemical liquid.

  In order to achieve the above object, a chemical injection device according to the present invention is a chemical injection device for injecting a chemical with an injection pump into a liquid flowing in a liquid supply tube, as described in claim 1. Provided with a plurality of liquid passing pipes for dividing the liquid flow in the liquid feeding pipe in the middle of the length, and provided with a flow rate sensor for detecting the flow rate of the liquid in the arbitrary one liquid passing pipe, The chemical solution injection operation of the injection pump is controlled based on the detection signal of the flow sensor.

  The present invention may be embodied as follows. That is, as described in claim 2, 2 for dividing the liquid flow in the liquid feeding pipe in the middle of the length of the liquid feeding pipe. A liquid passage pipe is provided, and one of the liquid passage pipes has a smaller passage diameter than the other, and detects the flow rate of the liquid in the liquid passage pipe having a smaller diameter passage. A flow rate sensor is provided, and a chemical solution injection operation of the injection pump is controlled based on a detection signal of the flow rate sensor.

  In these inventions, a liquid flow having a smaller flow rate than that in the liquid feed pipe is generated in each liquid flow pipe. The flow rate of the liquid flow can be arbitrarily set by changing the cross-sectional area of the liquid flow path of the liquid flow pipe. Can be made with size. Therefore, the flow rate sensor can detect the flow rate of the liquid flow arbitrarily made smaller than the flow rate in the liquid feeding pipe, and the flow rate of the liquid flow in the liquid feeding pipe at the time of detection is determined based on the detection signal of the flow rate sensor. The injection pump injects an amount of the chemical solution corresponding to the flow rate in the liquid feeding pipe into the liquid in the liquid feeding pipe.

The invention described in claim 2 can be further embodied as follows.
That is, as described in claim 3, the liquid passage having a larger diameter of the liquid passage has a passage cross-sectional area at a portion in the middle of its length than a passage cross-sectional area at another portion of the liquid passage. It is assumed that a narrowing portion for reducing the size is formed. In this way, the flow resistance in the liquid flow pipe having the larger liquid flow path is increased and the flow rate of the liquid flow in the liquid flow pipe is decreased, while the flow rate detected by the flow sensor is reduced. The flow rate of the liquid flow in the liquid pipe is increased.

  According to a fourth aspect of the present invention, the injection position of the chemical liquid is in the fluid passage of the fluid passage where the restrictor is formed and upstream of the restrictor. In this way, the vortex generated in the vicinity of the upstream side and the downstream side of the throttle portion is effectively used to promote the mixing and stirring of the liquid and the chemical in the liquid passage.

  Furthermore, as described in claim 5, the upstream liquid contact surface of the narrow portion of the throttle portion is positioned so that a point on the surface is displaced upstream as the point on the surface moves radially outward. And the radius of the partial spherical surface is approximately the radius of the maximum passage cross-sectional area of the liquid passage tube in which the throttle portion is formed, and the size is in the range of 0.5 to 1.0 times. The configuration is as follows. In this way, the partial spherical surface inverts part of the liquid flow smoothly and induces vortex flow toward the upstream side, thereby accelerating turbulent flow constantly.

According to the present invention, the following effects can be obtained.
That is, according to the first aspect of the present invention, a part of the liquid flowing in the liquid feeding pipe flows in each of the liquid feeding pipes, and the flow rate sensor of the liquid in any one of the liquid feeding pipes to which the flow sensors are attached. The flow rate is detected, and based on the detected flow rate, the flow rate of the liquid in the liquid feeding pipe is grasped. Therefore, even if the planned liquid flow rate in the liquid feeding pipe is relatively large, By appropriately reducing the cross-sectional area of the flow path of the flow pipe provided with the flow sensor, the flow sensor can have a relatively small detection capability, and the manufacturing cost occupied by the flow sensor is greatly reduced. Therefore, the product of the present invention can be provided to the market at a relatively low cost.
Further, as the flow sensor is downsized, the so-called minimum detectable flow rate of the flow sensor is correspondingly reduced, so that the product of the present invention detects the flow rate of a part of the liquid in the water pipe. Even with a method of grasping the flow rate in the pipe, the detection accuracy of the flow rate can be the same as when the flow rate sensor is provided directly in the water supply pipe.

  According to the invention described in claim 2, since the effect of the invention described in claim 1 can be obtained by providing two liquid pipes, it is simpler and less expensive than the case where three or more liquid pipes are provided. The cross-sectional area of the flow path of one liquid flow pipe can be the same as that of the liquid feed pipe, and the connection between the liquid feed pipe and the liquid flow pipe of the present invention is different. There is no need to use a diameter joint pipe or the like.

  According to the invention described in claim 3, the following effect is obtained in addition to the effect of the invention described in claim 2, that is, the liquid passage has a large diameter due to the presence of the throttle portion. While the flow resistance in the liquid flow pipe is increased and the flow rate of the liquid flow in the liquid flow pipe is decreased, the flow rate of the liquid flow in the liquid flow pipe detected by the flow rate sensor can be increased. In addition, by changing the degree of the degree of restriction of the restricting portion, it is possible to arbitrarily change the flow rate of the liquid flow in the liquid flow pipe whose flow rate is detected by the flow rate sensor. Therefore, the flow rate in the liquid feeding pipe can be accurately detected by the same flow rate sensor even if the type of the liquid is arbitrarily changed by providing the throttle portion according to the properties of the liquid flowing in the liquid feeding pipe. In addition, it is possible to reduce the energy loss of the liquid by increasing the efficiency of the liquid flow in the liquid passing pipe.

  According to the invention described in claim 4, in addition to the effect of the invention described in claim 3, the following effect is obtained, that is, the pressure rises due to the blocking effect by the throttle portion. The chemical solution is injected into the liquid, and the infusion pump has a more accurate amount of the chemical solution than the case where the chemical solution is injected into the liquid at a position where negative pressure may occur (for example, the position near the downstream side of the throttle). In addition, eddy currents are prominent in the vicinity of the upstream side and downstream side of the throttle part, but the chemical solution is injected in the vicinity of the upstream part of the throttle part. First, the mixing and stirring of the liquid and the chemical solution in the liquid flow pipe is promoted by the vortex, and further, after passing through the throttle part, the mixing and stirring of the liquid and the chemical liquid in the liquid flow pipe again by the vortex flow that stops near the downstream side of the throttle part Infused chemicals and fluid delivery pipes are promoted It can be mixed in the liquid evenly and quickly.

  According to the invention described in claim 5, in addition to the effect of the invention described in claim 4, the following effect can be obtained, that is, the liquid in the liquid passage in which the throttle portion is formed. Since part of the flow direction can be smoothly reversed by the guiding action of the partial spherical surface and directed toward the upstream side, turbulence of the liquid flow in the vicinity of the upstream side of the throttle portion is steadily promoted, and the injection pump The mixing and stirring of the injected chemical liquid and the liquid in the flow pipe can be steadily promoted, and the upstream liquid contact surface of the flesh portion of the throttle section crosses the center line of the flow pipe. When compared with a flat surface (when there is no partial spherical surface), the turbulent flow of the liquid flow near the upstream side of the throttle part becomes steady, and the upstream side in the liquid passage due to the blocking action of the throttle part The pressure rise is stabilized, and the flow rate sensor detects the flow rate in the liquid delivery pipe. It is possible to improve the degree.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a perspective view of a chemical injection device according to the present invention, FIG. 2 is a front view of the chemical injection device, FIG. 3 is a plan view of the chemical injection device, and FIG. 4 is a side view of the chemical injection device.

  Reference numeral 1 denotes a base made of a metal material such as a stainless steel plate in a flat rectangular parallelepiped shape. Reference numeral 2 denotes a synthetic resin material placed on the upper surface 1a of the base 1 and fixed by a bolt 3 or a coupling plate 4. It is a chemical tank.

  The upper surface of the base 1 is a single plane. For example, the lengths of the vertical and horizontal sides are both about 600 mm and the height is about 120 mm. On the other hand, the liquid chemical tank 2 has a vertically long rectangular parallelepiped shape, the capacity is about 50 to 100 liters, the size in plan view is substantially matched with that of the base 1 and the height is about 700 mm, for example. The upper surface 2a is formed with a relatively large opening 5 that is releasably closed by a lid member 5a, and the right side surface 2b is a liquid level gauge for confirming the liquid level of the medicine contained therein. 6 is formed, and the front surface 2c is formed with a hollow space portion a1 in which a relatively wide portion within the lower half range is greatly recessed toward the rear surface side. The attached chemical solution outlet 8 is formed.

  The hollow space a1 is formed by cutting out the left and right side portions b2 and b2 of the chemical liquid tank 2 from the front side while enclosing the lower surface with a front projecting bottom surface b1 of the chemical liquid tank 2 and the left and right side portions. The upper surface portion is surrounded by an inclined front wall b4 extending in an inclined manner from the upper front wall b3 of the chemical tank 2 toward the lower back side, and the rear surface portion is defined from the lower edge of the inclined front surface b3. It is surrounded by a rear front wall b5 that extends vertically downward.

  Reference numeral 9 denotes an infusion pump which is disposed in the hollow space part a1 and is fixed to the upper surface of the front projecting bottom surface part b1 with a bolt, and is constructed by assembling the pump part 10, the drive part 11 and the control part 12 integrally. . At this time, the pump unit 10 is a diaphragm pump that functions as a metering pump, and the drive unit 11 is configured to reciprocate an output member linked to the diaphragm of the diaphragm pump 10 with an electric motor. The unit 12 controls the electric motor of the drive unit 11.

  2A is a cover member made of a transparent synthetic resin material that covers most of the front and left and right sides of the hollow space b1, and is fixed to the front surface 2c of the chemical tank with a screw member (not shown). A portion between the lower edge of the cover member 2A and the lower surface of the hollow space portion b1 serves as an opening for opening the hollow space portion outward, and has a height of about 10 cm to 20 cm.

  5 and 6 are views showing a liquid passage unit U in which two liquid passage pipes 13 and 14 are integrally assembled. The liquid passage unit U is fixed to the base 1. One of the liquid passage pipes 13 and 14 has a smaller diameter in the liquid passage than the other one 13. Specifically, for example, when one of the liquid passing pipes 13 is formed of a pipe member having a nominal diameter of 50A, the other liquid passing pipe 14 is formed of a pipe member having a nominal diameter of 32A, or one of the liquid passing pipes is formed. When the liquid pipe 13 is formed of a pipe member having a nominal diameter of 40A, the other liquid passage pipe 14 is formed of a pipe member having a nominal diameter of 32A.

  A chemical injection port 15 is provided in the middle of the length of the liquid passage 13 having the larger nominal diameter, and flows in the liquid passage 14 in the middle of the length of the liquid pipe 14 having the smaller nominal diameter. A flow sensor 16 for detecting the flow rate of the liquid is provided. The flow rate sensor 16 includes an impeller 16a that is in contact with the liquid flowing in the liquid passage 14 and is rotated in proportion to the flow rate of the liquid, and as an electric signal representing the liquid flow rate, the rotation time of the impeller 16a is one rotation time. It is supposed to generate a pulse at a time interval corresponding to. This pulse is transmitted to the control unit 12 of the infusion pump 9 through the transmission line 17, and the control unit 12 reciprocates the output member of the drive unit 11 based on the pulse transmitted thereto, as will be described later. Yes.

  The appearance of the liquid flow pipe unit U actually used is as shown in FIG. One liquid passing pipe 13 is formed by connecting different diameter cheeses 18a and 18b, straight pipe members 19a and 19b, and flange joint parts 20 in series, and the other liquid passing pipe 14 is a straight pipe member 21a. 21b, 90-degree bent pipes 22a and 22b, a threaded straight pipe member 23, a union joint part 24, and a main body frame 16A of the flow sensor 16 are connected in series.

  The flange joint portions 20, 20 of the fluid passage pipe 13 of the fluid passage unit U are disposed outside the foundation base 1 through the through holes c 1 formed in the left and right side surfaces 1 a of the foundation base 1 and the flange joint portions 20. , 20 are arranged at the inner side of the base 1 and fixed to the inner surface of the base 1 via U bolts.

  As shown in FIG. 2, the liquid suction port 10a of the pump unit 10 and the liquid outlet of the on-off valve 7 are communicated with each other via a hose connector by a suction hose 25 made of a synthetic resin material. The discharge port 10b and the chemical solution injection port 15 are communicated with each other through a hose connector by a discharge hose 26 made of a synthetic resin material that has passed through a through hole d2 formed in the front surface 1c of the base 1.

  Then, in the middle of the length of the liquid passage 13 and downstream of the chemical liquid inlet 15 and between the inlet 14a and outlet 14b of the liquid passage 14, as shown in FIG. A restricting portion 27 is formed to make the cross-sectional area of the flow passage at this location smaller than the cross-sectional area of the flow passage at other locations of the flow-through pipe 13. FIG. 7 is a cross-sectional view showing a specific structure around the diaphragm 27. In order to easily form the narrowed portion 27, a donut-shaped orifice plate 27A is inserted into the upstream receiving port of the different-diameter cheese 18b and brought into contact with the stepped portion e1 of the receiving port. The downstream end is fitted into the receiving port and pressed against the upstream end face of the orifice plate 27A. These members 18b, 19b, and 27A are bonded with an adhesive.

Next, usage examples and operations of the above-described chemical liquid injector will be described.
For example, as shown in FIG. 2, in a water supply facility that pumps groundwater with a pumping pump 100 and supplies sanitary water to a living space 102 through a water supply pipe 101, the present invention is in the middle of the water supply path of the water supply pipe 101. A chemical injection device Y is installed.
Specifically, the downstream end of the water supply pipe 101 upstream of the chemical liquid injector Y is communicated with the flange joint 20 on the upstream side of the liquid pipe 13, and the upstream end of the water pipe 101 downstream of the chemical liquid injector Y is connected. The passage is communicated with the flange joint 20 on the downstream side of the liquid pipe 13.

  The liquid supply system of the chemical injection device Y has a maximum operating pressure of about 0.5 MPa, and the maximum flow rate is about 200 liters per minute when the nominal diameter of the water pipe 101 is 40 A. When the nominal diameter is 50 A, it is about 400 liters per minute.

  Then, a 12% sodium hypochlorite solution is introduced into the chemical liquid tank 2 from the opening 5, and thereafter, each part is brought into an operable state.

  Under this condition, the pump 100 operates to automatically pump up groundwater so that the pressure in the water pipe 101 on the outlet side of the pump is maintained within a predetermined pressure range. Such operation is not different from the conventional one. Now, when the water in the water pipe 101 flows out from the faucet 102a of the living space 102 and the pressure in the water pipe 101 decreases, the pump 100 is automatically activated in connection with this, and the ground water is pumped up and sent. Feed into the water pipe 101. At this time, water equivalent to the amount of water consumed flows through the two liquid flow pipes 13 and 14 of the chemical liquid injector Y.

  During this flow, water flows in each of the flow-through pipes 13 and 14 at a flow rate related to the pressure drop per unit length. In this example, the nominal diameter of the liquid pipe 13 is made to match that of the water pipe 101 for the convenience of the connection between the water pipe 101 and the liquid pipe 13, but in this way, no measures should be taken. In this case, it is expected that the flow rate of the liquid flow pipe 14 becomes smaller than that of the liquid flow pipe 13 and it is difficult to accurately detect the flow rate by the flow rate sensor 16. The orifice 27A is for coping with this, and the flow resistance applied by the orifice 27A is preferably determined so as to be minimized within a range where the flow rate detection by the flow rate sensor 16 is accurately performed. If determined in this way, the application of excessive flow resistance is avoided, and the water flow in the two liquid-passing pipes 13 and 14 becomes efficient. The flow rate in each of the liquid flow pipes 13 and 14 is, for example, approximately proportional to the cross-sectional area of each liquid flow path.

  The flow of water in the liquid flow pipe 14 rotates the impeller 16a of the flow sensor 16, and the flow sensor 16 outputs, for example, the same number of pulses as the rotation speed of the impeller 16a to output the liquid flow pipe 14. Detects the water flow rate inside. This pulse is transmitted to the control unit 12 through the transmission line 17, and the control unit 12 counts each pulse transmitted to the control unit 12 to measure the flow rate of water in the water supply pipe 101 (specifically, the liquid flow pipe 13 and the liquid flow pipe). 14).

Figure 8 is with respect to a change in the pressure difference Δh of Tsuekikan 14, the flow rate _{Q 1} and water liquid passing pipe 13, and the flow rate _{Q 2} of the water liquid passing pipe 14, the two liquid passage pipe 13 and 14 it is a graph showing the change of the flow rate Q ₃ of water inside. Here, the pressure difference Δh is the difference between the pressure at the position p1 near the inlet 14a of the fluid passage 14 and the pressure at the position p2 near the outlet 14b of the fluid passage 14 in FIG. In FIG. 8, s1 is a line indicating a change in the flow rate to Q ₁ Tsuekikan in 13, s2 is a line indicating a change in water flow rate Q ₂ of Tsuekikan in 14, s3 are two liquid passing The sum of the flow rates Q ₁ and Q ₂ in the pipes 13 and 14 is a line indicating the change in the flow rate Q ₃ of the water in the water pipe 101.

  The pressure difference Δh changes depending on a change in the operating environment of the pumping pump 100 and also changes depending on a change in the flow rate of water in the water pipe 101 due to a change in water consumption in the living space 102. In addition, it is already known that the relationship between the pressure difference Δh and the flow rate of water in the liquid flow pipes 13 and 14 based on the pressure difference Δh is expressed by the following equations (1) and (2).

Δh = λ ₁ · v ₁ ² / (2 · g) (1)
Δh = λ ₂ · v ₂ ² / (2 · g) (2) where λ ₁ is a constant of the liquid passage 13, λ ₂ is a constant of the liquid passage 14, and v ₁ is in the liquid passage 13. The flow rate of water, v _2, is the flow rate of water in the liquid passage 14.

Therefore, the flow velocity in each of the liquid flow pipes 13 and 14 is expressed by the following equations (3) and (4).
v ₁ = k ₁ · (Δh) ^1/2 ··· (3) equation
v ₂ = k ₂ · (Δh) ^1/2 ··· (4) where k ₁ is a constant of the liquid passage 13, and k ₂ is a constant of the liquid passage 14.

Based on the above formulas (3) and (4), the flow rates Q ₁ and Q ₂ of the water in each of the liquid flow pipes 13 and 14 are expressed by the following formulas (5) and (6).
Q ₁ = v ₁ · s ₁ = k ₃ · (Δh) ^1/2 ··· (5)
Q ₂ = v ₂ · s ₂ = k ₄ · (Δh) ^1/2 ··· (6)

8, line s1 are obtained from equation (5), line s2 are obtained from equation (6), the line s3 by summing the water flow rate Q _1, the water flow rate Q ₂ obtained It is what
Based on the relationship of these lines s1, s2, s3, two water by passing liquid pipe 13 of the flow (water flow in the water pipe 101) _{Q 3} is a flow _{Q 2} of water Tsuekikan 14 It will be uniquely identified. The relationship between water flow rate Q ₂ and the water flow rate Q ₃ are can also be determined from the theoretical, it is determined easily by experiment.

The control unit 12 relationships and between the flow rate Q ₂ and the flow rate Q _3, information relating to the relationship between the chemical quantity to be injected the flow rate Q ₃ is inputted in advance. The control unit 12 includes the information and the flow rate (amount of water passing through the flow sensor 16) flow rate grasped by the transmitted pulse from the sensor 16 Q ₂ and two of the flow rate of liquid passing pipe 13, 14 on the basis of the ( identify the amount of water) Q ₃ which passes through the two liquid passage pipe 13 and 14, driving the amount of chemical solution to address this flow Q ₃ to inject the water passing liquid pipe 13 from inside the chemical liquid tank 2 Actuate part 11.

  The operation at this time will be described in more detail. When a pulse generated from the flow sensor 16 for each rotation of the impeller 16a is transmitted to the control unit 12, the control unit 12 sequentially adds the pulses. The output member of the drive unit 11 is set so that the diaphragm pump of the pump unit 10 is reciprocated once when the added value matches the numerical value set in advance by operating the adjustment member of the control unit 12. Operate. As a result, the pump unit 10 operates to suck a certain amount of the chemical liquid guided from the chemical liquid tank 2 to the liquid suction port 10a through the suction hose 25, and then discharges it from the liquid discharge port 10b. A certain amount of chemical solution is injected into the water in the liquid passage 13 through the hose 26 and the chemical solution injection port 15.

  The addition value is reset to zero when the injection of the fixed amount of the chemical solution is completed, and the control unit 12 sequentially adds pulses transmitted from the flow sensor 16 again after the return. The same operation as described above is repeated. As a result, a predetermined amount of a chemical solution is injected into the water in the water supply pipe 101 after passing through the two liquid supply pipes 13 and 14 every time a predetermined amount of water passes, and the water supply pipe The water in 101 has a planned chemical concentration regardless of changes in the flow rate in the water pipe.

  During such use, when it is desired to increase the concentration of the chemical supplied to the living space 102, the adjustment member of the control unit 12 is operated to decrease the number of pulses for operating the drive unit 11. . As a result, a certain amount of chemical solution, which is the same amount as before, is discharged from the pump unit 10 with respect to a smaller amount of water than before, and the concentration of the chemical solution in the water supply pipe 101 after passing through the liquid flow pipe 13 is increased. The Conversely, when it is desired to reduce the chemical concentration of the water supplied to the living space 102, the adjustment member is operated to increase the value of the number of pulses for activating the drive unit 12, which is higher than before. A certain amount of chemical solution, which is the same amount as the previous amount, is discharged from the pump unit 10, and the concentration of the chemical solution in the water supply pipe 101 after passing through the liquid passage pipe 13 is reduced.

  The chemical liquid guided from the chemical liquid injection port 15 into the liquid flow pipe 13 is injected into the water in the vicinity of the upstream side of the orifice 27A, whereby the chemical liquid is submerged by the vortex generated intensively in the vicinity of the upstream side of the orifice 27A. In addition, even after passing through the orifice 27A, the mixture is evenly mixed by the vortex generated intensively in the vicinity of the downstream side of the orifice 27A.

A modified example of the chemical liquid injector Y will be described.
(1) FIG. 9 is a cross-sectional view showing a modified example of the diaphragm portion 27. A turbulent flow promoting portion 28 for constantly promoting turbulent flow is formed in the vicinity of the upstream side of the throttle portion 27. Specifically, the liquid contact surface g1 on the upstream side of the flesh portion of the throttle portion 27 is formed as follows, that is, the virtual point moves on the liquid contact surface g1 outward in the liquid passage radial direction. The partial spherical surface has a shape that is displaced to the upstream side with the movement, and the radius of the partial spherical surface is the maximum flow passage cross-sectional area of the liquid passage 13 in which the throttle portion 27 is formed. Is approximately the size within a range of 0.5 to 1.0 times the radius of. In this way, the water flow that has flowed from the upstream side toward the orifice 27A in the liquid passage 13 is smoothly redirected in the direction of the arrow h1 and reverses, so that turbulent flow in the vicinity of the upstream side of the orifice 27A is generated. Promoted.

  At this time, the shape of the terminal portion on the most upstream side of the partial spherical surface g1 is the shape of the terminal portion and the radial surface (a plane including the liquid passage center line O1 and an arbitrary specific radial line around the center line O1). It is assumed that the intersection line approaches the liquid passage center line o1 as the cross line is displaced to the upstream side of the liquid passage 13. In this way, the water flow whose direction is changed as indicated by the arrow h1 in FIG. 8 is further smoothly changed as indicated by the arrow h2 toward the liquid passage center line o1, so that the vortex is formed by the partial spherical surface g1. Is promoted, and turbulent flow is more effectively promoted. As a result, the chemical concentration of the groundwater after passing through the liquid passage is quickly equalized.

(2) In the above-described example, the two liquid-passing pipes 13 and 14 having different liquid passage cross-sectional areas are provided, but the respective liquid-passing pipes 13 and 14 are within a range where the effects of the present invention can be obtained. It is possible to have an arbitrary diameter, and it is possible to provide a configuration in which three or more liquid passage pipes are provided and the flow rate sensor 16 is provided in any one liquid passage pipe. In some cases, the orifice 27A may not be provided depending on the magnitude relationship between the flow resistances of the liquid flow pipes.

(3) In the above example, the case where the chemical solution is injected into the groundwater has been described. However, the present invention is not limited to this, and the present invention can also be used when two arbitrary kinds of liquids are mixed at a constant ratio.

It is a perspective view of the chemical injection device concerning the present invention. It is a front view of the said chemical injection device. It is a top view of the said chemical injection device. It is a side view of the said chemical injection device. It is sectional drawing which shows typically the liquid flow pipe unit which assembled | attached two liquid flow pipes integrally. It is a perspective view which shows the external appearance of the state which materialized the said liquid flow pipe unit. It is sectional drawing which shows the specific structure of an aperture | diaphragm | squeeze part periphery. It is a graph which shows the change of the flow volume of the water in a liquid flow pipe with respect to the change of the pressure difference in a liquid flow pipe. It is sectional drawing which shows the modification of the aperture | diaphragm | squeeze part of the said liquid flow pipe unit.

Explanation of symbols

Q ₂ Flow rate Y Chemical solution injection device g1 Partial spherical surface 9 Injection pump 13 Fluid passage tube 14 Fluid passage tube 16 Flow rate sensor 27 Throttle portion 101 Fluid delivery tube

Claims (5)

  In a chemical liquid injector for injecting a chemical liquid with an injection pump into the liquid flowing in the liquid supply pipe, a plurality of liquid flow pipes for dividing the liquid flow in the liquid supply pipe are provided in the middle of the length of the liquid supply pipe, and A liquid sensor for detecting a flow rate of the liquid in any one of the liquid flow pipes, and a chemical liquid injection operation of the injection pump is controlled based on a detection signal of the flow sensor. Injection device.   In the chemical liquid injection device that injects the chemical liquid into the liquid flowing in the liquid supply pipe with an injection pump, two liquid supply pipes for dividing the liquid flow in the liquid supply pipe are provided in the middle of the length of the liquid supply pipe, One of these liquid pipes has a smaller diameter passage than the other, and a flow rate sensor is provided for detecting the flow rate of the liquid in the liquid passage having the smaller diameter. A chemical solution injection device, wherein a chemical solution injection operation of the injection pump is controlled based on a detection signal of the flow sensor.   The flow passage pipe having the larger diameter of the liquid passage is formed with a throttle portion for making the passage cross-sectional area of the portion in the middle of its length smaller than the passage cross-sectional area of the other portion of the liquid passage pipe. The chemical injection device according to claim 2, wherein:   4. The chemical solution injection device according to claim 3, wherein the injection position of the chemical solution is in a flow path of the liquid flow pipe in which the throttle portion is formed and upstream of the throttle portion.   The upstream liquid contact surface of the flesh portion of the throttling portion is a partial spherical surface positioned so that a point on the surface is displaced upstream as the point on the radial direction of the liquid passage moves, and the radius of the partial spherical surface 5. The diameter of the maximum passage cross-sectional area of the liquid flow pipe in which the throttle portion is formed is approximately 0.5 to 1.0 times larger than the radius. The chemical injection device according to the description.

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