Connection pipe and liquid medicine injection device

Abstract

To propose a connection pipe and a liquid medicine injection device capable of suppressing corrosion of metallic materials in the pipe caused by elevation of concentration of an injection liquid at a position set apart from an injection position of the liquid in the flow direction of the liquid.SOLUTION: A connection pipe 15 is provided with a measuring device 17 having a component 61 of a metallic material and a liquid injection part 42 for injecting, to a liquid flowing in the pipe, an injection liquid having a specific gravity larger than that of the liquid. It includes a measurement site 51a where the measuring device 17 is provided, and a liquid injection site 52a provided with the liquid injection part 42 at a secondary side in a flow direction of the liquid than the measurement site 51a. A stream center CA of the measurement site 51a is higher than a stream center of any site of a channel on the secondary side than the measurement site 51a, or a stream center CB of the liquid injection site 52a is lower than a stream center of any site of a channel on the primary side than the liquid injection site 52a.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a connecting pipe provided with a flow rate sensor and into which a chemical solution is injected, and a chemical solution injector. [Background technology]

[0002] When raw water such as well water is pressurized and pumped by a pump device, there are known techniques for injecting a chemical solution into the raw water flowing through a pipe to sterilize it, and techniques for oxidizing and precipitating iron contained in the raw water and filtering it in a filtration tank. For example, a chemical solution injection device is known as a technique for injecting a chemical solution into raw water, which is provided with a flow rate measuring device and a chemical solution injection section in a connecting pipe connected to a pipe or a pump, and determines the amount of chemical solution to be injected based on the flow rate (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-40463 A Summary of the Invention [Problem to be solved by the invention]

[0004] In such a chemical injection device, there is a risk that the chemical will be injected when the flow rate is zero or close to zero when the raw water transitions from a moving state to a stopped state. When a chemical with a higher specific gravity than the raw water is injected with the raw water stopped, the chemical will not diffuse instantly but will sink from the injection point to the bottom of the pipe and spread along the bottom of the pipe.

[0005] Generally, a flow measuring device uses at least a part of a metal material, and the injected chemical solution is often corrosive to the metal material used in the flow measuring device. Therefore, if the injected chemical solution remains in the pipe and the concentration of the chemical solution around the flow measuring device becomes significantly higher than the control value, there is a risk that the metal material of the flow measuring device will corrode.

[0006] For this reason, it is possible to use a metal material with high corrosion resistance for the flow rate detection device, but this would result in an increase in manufacturing costs.As described above, when the injection liquid with a high specific gravity accumulates in the liquid, the injection liquid concentration increases at a position in the pipe away from the injection position in the liquid flow direction, so a technology is required to suppress the increase in the injection liquid concentration at a position in the pipe away from the injection position in the liquid flow direction.

[0007] Therefore, an object of the present invention is to provide a connecting pipe and a chemical liquid injection device that can suppress corrosion of metal materials due to an increase in the concentration of the injected liquid at a position away from the liquid injection position in the pipe in the liquid flow direction. [Means for solving the problem]

[0008] According to one aspect of the present invention, a connecting pipe is provided with a measuring device having a metal material part and a liquid injection section that injects an injection liquid having a higher specific gravity than the liquid flowing inside the pipe, and the connecting pipe comprises a measurement site where the measuring device is provided, and a liquid injection site where the liquid injection section is provided on the secondary side of the measurement site in the direction of liquid flow, and the flow center of the measurement site is higher than the flow center of any part of the flow path on the secondary side of the measurement site, or the flow center of the liquid injection site is lower than the flow center of any part of the flow path on the primary side of the liquid injection site. Effect of the Invention

[0009] The present invention can provide a connecting pipe and a chemical liquid injection device that can suppress corrosion of metal materials due to an increase in the concentration of the injected liquid at a position away from the injection position in the pipe in the direction of liquid flow. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is an explanatory diagram illustrating a schematic configuration of a water treatment device using a chemical liquid injector according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a front view showing the configuration of the liquid injector, partially in cross section. [Diagram 3] FIG. 2 is a cross-sectional view showing a configuration of a connecting pipe of the liquid injector. [Figure 4] FIG. 4 is a cross-sectional view showing an example of a configuration of a packing used in the connecting pipe. [Diagram 5] FIG. 4 is a cross-sectional view showing the configuration of another example of a packing used in the connecting pipe. [Figure 6] FIG. 4 is a cross-sectional view showing the configuration of another example of a packing used in the connecting pipe. [Figure 7] FIG. 6 is a cross-sectional view showing a configuration of a connecting pipe of a chemical liquid injector according to a second embodiment of the present invention. [Figure 8] FIG. 11 is a cross-sectional view showing a configuration of a connecting pipe of a chemical liquid injector according to a third embodiment of the present invention. [Figure 9] FIG. 11 is a cross-sectional view showing a configuration of a connecting pipe of a chemical liquid injector according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A chemical liquid injector 1 according to a first embodiment of the present invention and a water treatment apparatus 100 using the chemical liquid injector 1 will be described below with reference to FIGS. 1 to 6. FIG.

[0012] Fig. 1 is an explanatory diagram showing a schematic configuration of a water treatment device 100 using a chemical liquid injector 1 according to one embodiment of the present invention. Fig. 2 is a front view showing the configuration of the chemical liquid injector 1, partially in cross section, and Fig. 3 is a cross-sectional view showing the configuration of a connecting pipe 15 of the chemical liquid injector 1. Figs. 4 to 6 are cross-sectional views showing different examples of the configuration of a packing 54 used in the connecting pipe 15.

[0013] 1 pumps raw water from a well W, etc., and sterilizes the raw water by injecting a chemical solution into the pumped raw water. The water treatment device 100 may be configured to precipitate iron and manganese in the raw water, and filter the precipitated iron and manganese together with impurities such as solids in the raw water.

[0014] The water treatment device 100 includes, for example, a water supply pump 104 and a sand filter 105 on the primary side of the chemical liquid injector 1. The water treatment device 100 connects the water supply pump 104 and the sand filter 105 to the chemical liquid injector 1 via a pipe T.

[0015] 2, the liquid injection device 1 includes a stand 11, a liquid tank 12, a piping unit 13, a liquid injector 14, a connecting pipe 15, a pressure sensor 16, a flow rate measuring device (measuring device) 17, and an electrical box 19. The liquid injection device 1 is connected, for example, to a water supply pump 104 on the primary side via a sand filter 105, and to a water supply destination H on the secondary side. The liquid injection device 1 injects a predetermined amount of sodium hypochlorite as an aerated liquid into the water flowing through the connecting pipe 15, for example, to disinfect the water supplied from the water supply pump 104 and precipitate iron and manganese contained therein.

[0016] The stand 11 supports the liquid tank 12, the liquid injector 14, the connecting pipe 15, and the electrical box 19. For example, the stand 11 supports the liquid tank 12 at a position higher than the liquid injector 14. As a specific example, as shown in Fig. 2, the stand 11 includes legs 11a to be placed on an installation surface, a first base 11b, a wall portion 11c, and a second base 11d. For example, the legs 11a, the first base 11b, the wall portion 11c, and the second base 11d are integrally formed.

[0017] Leg 11a is placed on a mounting surface of chemical liquid injector 1. First base 11b is provided integrally on leg 11a. Connecting pipe 15 is placed on the upper surface of first base 11b so as to be fixed thereto.

[0018] The wall portion 11c is provided, for example, on the upper portion of the first base 11b in the depth direction of the first base 11b. The wall portion 11c is formed, for example, in the shape of a rectangular frame or plate extending upward from the first base 11b and continuing to the second base 11d.

[0019] For example, the liquid injector 14 is fixed to the center of the wall portion 11c. For example, the wall portion 11c is formed so that the liquid injector 14 can be fixed thereto by a fastening member such as a bolt or a screw.

[0020] The second base 11d is provided on the upper edge of the wall portion 11c, and is formed so that the chemical liquid tank 12 can be fixed on its upper surface.

[0021] The chemical tank 12 is made of a resin material and is formed so as to be able to store a predetermined amount of chemical liquid therein. The chemical tank 12 is fixed to the upper surface of the second base 11d. The chemical tank 12 has a piping unit 13 connected to a part of its bottom 12a. The chemical tank 12 has a supply port 12b at its upper portion for supplying the chemical liquid to the inside, and a lid 12c for covering the supply port 12b.

[0022] The piping unit 13 fluidly connects the liquid chemical tank 12 and the liquid chemical injector 14. The piping unit 13 forms a flow path for the liquid chemical from the liquid chemical tank 12 to the liquid chemical injector 14. As a specific example, as shown in FIG. 2, the piping unit 13 includes a connection pipe 21, an exhaust tube 22, a connecting tube 23, and an on-off valve 24.

[0023] One end of the connection pipe 21 is connected to the chemical tank 12, and the other end is branched in two directions to be connected to the exhaust tube 22 and the connecting tube 23. Specifically, the connection pipe 21 is a bent pipe formed by bending into an L shape. The connection pipe 21 has a screw portion 31, a flange 32, and a nut 33 at one end connected to the chemical tank 12. The connection pipe 21 also has an upper branch portion 34 and a lower branch portion 35 at the other end, which branch off in two directions, upward and downward. The connection pipe 21 also has an attachment portion 36 for the on-off valve 24 formed at the bent portion.

[0024] The screw portion 31 is formed on one end of the connection pipe 21. The screw portion 31 is a male screw formed on the outer surface of one end of the connection pipe 21. The screw portion 31 is inserted into the chemical tank 12 through a hole formed in the bottom 12a of the chemical tank 12. The flange 32 abuts against the lower surface of the bottom 12a of the chemical tank 12 when the screw portion 31 is inserted through the hole in the bottom 12a. The flange 32 is also formed so that a packing can be attached to the abutting surface with the lower surface of the bottom 12a of the chemical tank 12.

[0025] The nut 33 is screwed into the threaded portion 31. When the nut 33 is fastened to the threaded portion 31 inside the chemical tank 12, the flange 32 and the nut 33 are fixed to the bottom portion 12a of the chemical tank 12.

[0026] The exhaust tube 22 is a transparent tube or a tube through which the chemical solution can be visually observed, one end of which is connected to the upper branch portion 34. The other end of the exhaust tube 22 is open to the atmosphere. The exhaust tube 22 constitutes, for example, a water level gauge formed so that the water level of the chemical solution in the exhaust tube 22 can be visually observed.

[0027] One end of the connecting tube 23 is connected to the downward branch portion 35, and the other end is connected to the chemical solution injector 14. The connecting tube 23 is flexible. For example, the connecting tube 23 is made of a resin tube or the like that is flexible and resistant to the chemical solution.

[0028] The on-off valve 24 is provided at a mounting portion 36 provided at a bent portion on the primary side of the upper branch portion 34 and the lower branch portion 35 of the connection pipe 21. The on-off valve 24 is formed so that the pipeline of the connection pipe 21 can be opened and closed manually.

[0029] The chemical liquid injector 14 is equipped with a volumetric pump 41 that can pressure-feed a constant amount of chemical liquid and inject it into the connecting pipe 15, and a chemical liquid injection section (liquid injection section) 42 that connects the volumetric pump 41 and the connecting pipe 15 and is configured to prevent backflow of the chemical liquid and well water injected into the connecting pipe 15.

[0030] The volumetric pump 41 is a liquid medicine injection pump that injects a liquid medicine. For example, a diaphragm pump is used as the volumetric pump 41. The volumetric pump 41 has a liquid medicine suction port 41b and a liquid medicine discharge port 41c that are provided in a pump casing 41a.

[0031] The suction port 41b is provided at the bottom of the pump casing 41a. The suction port 41b is connected to the connecting tube 23. The discharge port 41c is provided at the top of the pump casing 41a. The discharge port 41c is connected to the chemical solution injector 42. The discharge port 41c is formed, for example, of a branch pipe, one of which is connected to the chemical solution injector 42 and the other of which is provided with a plug 41d.

[0032] Such a volumetric pump 41 is fixed to the wall portion 11c, and is disposed below the upper surface of the bottom portion 12a of the chemical liquid tank 12. The volumetric pump 41 is fixed to the wall portion 11c by a fastening member.

[0033] The chemical solution injector 42 includes a connecting pipe 42a, a first check valve 42b provided on one end of the connecting pipe 42a, a nozzle 42c provided on the first check valve 42b and communicating with the connecting pipe 15, and a second check valve 42d provided on the nozzle 42c. The connecting pipe 42a is formed of, for example, a flexible resin tube, similar to the connecting tube 23.

[0034] The first check valve 42b regulates the flow of liquid from the nozzle 42c side to the volumetric pump 41. That is, the first check valve 42b prevents liquid from flowing back from the nozzle 42c side to the volumetric pump 41. The first check valve 42b has, for example, a ball and a spring. The first check valve 42b closes the pipeline when the ball is urged toward the primary side by the spring, and when the chemical liquid is supplied from the volumetric pump 41, the ball moves against the spring due to the pressure of the chemical liquid, opening the pipeline.

[0035] The nozzle 42c injects the chemical liquid, which is supplied from the volumetric pump 41 through the first check valve 42b, into the connecting pipe 15.

[0036] The second check valve 42d regulates the flow of liquid from the connecting pipe 15 to the nozzle 42c. That is, the second check valve 42d prevents the liquid flowing in the connecting pipe 15 from flowing back to the nozzle 42c. The second check valve 42d is formed, for example, in a cylindrical shape with a bottom, from an elastically deformable resin material, and a cross-shaped notch is formed at the tip opposite to the tip of the nozzle 42c. When the chemical liquid is supplied from the volumetric pump 41, the tip of the second check valve 42d expands due to the pressure of the chemical liquid, widening the cross-shaped notch and opening it, thereby supplying the chemical liquid to the connecting pipe 15.

[0037] The connecting pipe 15 is, for example, a pipe whose primary side is connected to the water supply pump 104 and whose secondary side is connected to the water supply destination H. For example, the connecting pipe 15 has a pressure sensor 16 attached to an end of the primary side, a chemical liquid injector 42 attached to an end of the secondary side, and a flow measuring device 17 attached between the pressure sensor 16 and the chemical liquid injector 42. The connecting pipe 15 is configured such that the flow center CA of the flow path at the site (measurement site) where the flow measuring device 17 is provided is higher than the flow center of any part of the flow path on the secondary side of the flow measuring device 17, or the flow center CB of the flow path at the site (liquid injection site) where the chemical liquid injector 42 is provided is lower than the flow center of any part of the flow path on the primary side than the chemical liquid injector 42. In this embodiment, the connecting pipe 15 has a wall portion 54b extending upward from the bottom surface in the flow path between the flow measuring device 17 and the liquid medicine injecting section 42, so that the flow center CB of the flow path at the portion (liquid injecting portion) where the liquid medicine injecting section 42 is provided is lower than the flow center CC of the flow path at the portion where the wall portion 54b on the primary side of the liquid medicine injecting section 42 is provided. Such a connecting pipe 15 will be specifically described below.

[0038] The connecting pipe 15 includes, for example, a main pipe 51 to which the flow rate measuring device 17 is attached, a first connecting pipe 52 to which the chemical liquid injecting section 42 is attached and connected to the secondary side of the main pipe 51, a second connecting pipe 53 to which the pressure sensor 16 is attached and connected to the primary side of the main pipe 51, a packing 54 provided between the main pipe 51 and the first connecting pipe 52, and a flange 55 provided at each end of the first connecting pipe 52 and the second connecting pipe 53 opposite to the main pipe 51. The mounting section 52a of the chemical liquid injecting section 42 of the connecting pipe 15 (the position where the chemical liquid is injected by the chemical liquid injecting section 42 in the pipe) and the mounting section 51a of the flow rate measuring device 17 of the connecting pipe 15 (the position where the flow rate measuring device 17 in the pipe is provided and measures the flow rate) are set at positions separated from each other in the flow direction of the raw water (liquid), for example, in the direction along the axial direction of the connecting pipe 15.

[0039] The main pipe 51 has an inner diameter that gradually decreases from the end of the primary side toward the secondary side, and the inner diameter is constant and smallest at the attachment portion 51a (measurement portion) where the flow rate measuring device 17 is attached, and the inner diameter gradually increases from the attachment portion 51a to the end of the secondary side. That is, the main pipe 51 is formed in a tapered shape such that the inner diameter becomes small on the attachment portion 51a side of the primary side and the secondary side of the attachment portion 51a. The distance from the end of the primary side to the attachment portion 51a of the main pipe 51 is shorter than the distance from the attachment portion 51a to the end of the secondary side. In other words, the attachment portion 51a is formed at a position on the end side of the primary side of the main pipe 51 and at a predetermined distance away from the end of the primary side of the main pipe 51. In addition, the main pipe 51 is formed, for example, with the same inner diameter at both ends. As a result, the inner shape of the main pipe 51 has a taper angle of the mounting portion 51a on the primary side relative to the central axis that is larger than the taper angle of the mounting portion 51a on the secondary side. The main pipe 51 has flange portions 51b on both ends that are connected to the first connecting pipe 52 and the second connecting pipe 53.

[0040] The mounting portion 51a is formed so that the flow measurement device 17 can be attached. For example, the mounting portion 51a includes a support portion 51a1 capable of supporting a rotating shaft 61 (described later) of the flow measurement device 17, and a fixing portion 51a2 capable of fixing a detection portion 64 (described later) of the flow measurement device 17. The support portion 51a1 is, for example, an uneven portion provided on the lower surface of the main pipe 51, and holds the rotating shaft 61. The fixing portion 51a2 is, for example, an opening formed on the upper surface of the main pipe 51, facing the support portion 51a1, and having a female thread.

[0041] The first connecting pipe 52 is connected to a flange portion 51b on the secondary side of the main pipe 51 via a packing 54. The first connecting pipe 52 is formed to have a constant inner diameter. For example, the inner diameter of the first connecting pipe 52 is formed to be the same as the inner diameter of the end portion on the secondary side of the main pipe 51. The first connecting pipe 52 has an attachment portion 52a (liquid injection portion) for attaching the chemical solution injection portion 42 at either the upper portion or between the upper portion and the side portion in the gravity direction. In addition, the first connecting pipe 52 has flange portions 52b on both ends that can be connected to the flange portion 51b and the flange 55 of the main pipe 51. The attachment portion 52a is, for example, an opening in which a female screw portion 52a1 is formed.

[0042] The second connecting pipe 53 is connected to the flange portion 51b on the primary side of the main pipe 51 via an O-ring or the like. The second connecting pipe 53 is formed to have a constant inner diameter. For example, the inner diameter of the second connecting pipe 53 is formed to be the same as the inner diameter of the end portion on the primary side of the main pipe 51. The second connecting pipe 53 has an attachment portion 53a for attaching the chemical solution injection portion 42 at either the upper portion or between the upper portion and the side portion in the gravity direction. In addition, the second connecting pipe 53 has flange portions 53b at both ends that can be connected to the flange portion 51b and the flange 55 of the main pipe 51. The attachment portion 53a is, for example, a cylindrical protrusion provided on the second connecting pipe 53 and having a female screw portion 52a1 formed thereon. In addition, the chemical solution injection device 1 may be configured not to have the pressure sensor 16, and in this configuration, the connecting pipe 15 may not have the second connecting pipe 53, and the flange 55 may be connected to the primary side flange portion 51b of the main pipe 51 via an O-ring or the like.

[0043] The packing 54 includes, for example, a seal portion 54a disposed between the flange portion 51b of the main pipe 51 and the flange portion 52b of the first connecting pipe 52, and a wall portion 54b formed integrally with the seal portion 54a and disposed above the lower end in the direction of gravity in the flow paths in the main pipe 51 and the first connecting pipe 52. The packing 54 is formed by integrally molding the seal portion 54a and the wall portion 54b using an elastically deformable resin material.

[0044] The seal portion 54a is formed in an annular shape and seals between the flange portion 51b and the flange 55. The wall portion 54b is formed integrally with the seal portion 54a. As shown in FIG. 3, the wall portion 54b protrudes upward from the bottom surface of the lower end of the water flow path formed inside the connecting pipe 15 on the primary side of the chemical liquid injection portion 42, and obstructs the flow of the chemical liquid injected from the chemical liquid injection portion 42 to the secondary side at the bottom of the flow path. That is, the wall portion 54b serves as a trap that suppresses the movement of the chemical liquid injected from the chemical liquid injection portion 42 to the secondary side when the water is stopped. The height of the wall portion 54b from the bottom surface of the connecting pipe 15 is set to a height that can ensure the specified water volume of the chemical liquid injection device 1, that is, a height that can ensure the specified water volume of the chemical liquid injection device 1 by the opening area (flow path cross-sectional area) formed by the inner circumferential surface of the connecting pipe 15 and the upper end surface of the wall portion 54b.

[0045] 3, even if the flow center CA of the mounting portion 51a (measurement portion) of the main pipe 51 where the flow measuring device 17 is provided and the flow center CB of the mounting portion 52a (liquid injection portion) of the first connecting pipe 52 where the liquid medicine injection section 42 is provided are at the same height, the flow center CC of the wall portion 54b is higher than the flow center CB of the first connecting pipe 52. That is, the wall portion 54b has a flow center that is higher than the first connecting pipe 52 in a part of the secondary side of the liquid medicine injection section 42.

[0046] The wall portion 54b has an upper end that extends linearly in the horizontal direction, for example, as shown in Fig. 4. The shape of the wall portion 54b is not limited to the shape shown in Fig. 4, and the upper end may be formed into a curved shape with a center of curvature located below the center of the seal portion 54a, as shown in Fig. 5, or may be formed into a curved shape with a center of curvature located above the center of the seal portion 54a, as shown in Fig. 6. In this way, the wall portion 54b is provided below the flow path between the flow measurement device 17 and the chemical solution injection portion 42 arranged on the secondary side of the flow measurement device 17, and prevents the chemical solution, which has a higher specific gravity than the water injected from the chemical solution injection portion 42 when the water is stopped, from moving to the primary side at the bottom surface of the connecting pipe 15.

[0047] The flange 55 is provided with pipes that are connected to the primary side and secondary side of the connecting pipe 15 .

[0048] The pressure sensor 16 is connected, for example, by a signal line to an electrical equipment box 19. The pressure sensor 16 outputs an electrical signal corresponding to the pressure of the fluid in the connecting pipe 15 to the electrical equipment box 19.

[0049] The flow rate measuring device 17 is connected to, for example, an electrical box 19 by a signal line. The flow rate measuring device 17 is an impeller-type flow rate sensor. The flow rate measuring device 17 transmits a signal corresponding to the detected flow rate to the electrical box 19. As a specific example, the flow rate measuring device 17 includes, for example, a rotating shaft 61 made of a metal material, a rotor 62 made of a resin material provided on the rotating shaft 61 and rotated by the flow of the fluid in the connecting pipe 15, a magnet 63 provided on the rotor 62, a detection unit 64 that detects the magnetic force of the magnet 63, and a transmission unit 65 that outputs an electric signal to the outside based on the magnetic force detected by the detection unit 64. The flow rate measuring device 17 detects the magnetic force of the magnet 63 that rotates with the rotation of the rotor 62 by the detection unit 64, and outputs an electric signal corresponding to the flow rate.

[0050] The electrical equipment box 19 controls, for example, the drive of the volumetric pump 41 to control the amount of liquid medicine injected from the volumetric pump 41 into the connecting pipe 15 .

[0051] The input unit is an input interface for receiving user input. The input unit is, for example, an operation panel including buttons. The input unit can input the concentration of the chemical liquid supplied to the chemical liquid tank 12.

[0052] The interface is connected to a pressure sensor 16 and a flow rate measuring device 17. The display unit has, for example, a display device such as a segment display, a liquid crystal display, or an organic EL display, or a lighting unit using an LED or the like.

[0053] The storage unit is a storage medium from which data can be read and written. The storage unit includes so-called memory and storage. The storage unit stores data as various parameters such as function parameters, internal parameters, and external parameters used by the control unit, as well as various data and programs used for controlling the volumetric pump 41 and calculating the water level of the chemical solution.

[0054] The interface is connected to an electrical equipment box 19 and a water supply pump 104. The interface can also electrically connect to other devices. That is, the interface is a terminal or a circuit to which various devices are electrically connected.

[0055] The control unit issues commands to the electrical equipment box 19 regarding the injection of chemical liquid during each operation of the water supply pump 104, based on various data and programs stored in the memory unit.

[0056] The chemical injection device 1 used in the water treatment device 100 configured in this manner has a wall 54b extending from the bottom surface of the flow path between the flow measurement device 17 and the chemical injection unit 42 arranged on the secondary side of the flow measurement device 17 in the water flow direction in the connecting pipe 15. Therefore, the wall 54b prevents the chemical solution, which has a higher specific gravity than the water injected from the chemical injection unit 42 when the water is stopped, from moving toward the primary side of the flow path on the bottom surface below the chemical injection unit 42. To explain this effect specifically, first, since the chemical injection device 1 determines the amount of chemical injection based on the flow rate, the chemical solution is injected when the flow rate is zero or close to zero, i.e., when the raw water transitions from a moving state to a stopped state. When a chemical solution having a higher specific gravity than the raw water is injected in a raw water stop state, the chemical solution does not instantly diffuse in the raw water but sinks from the chemical solution injection part 42, which is the injection point, to the bottom of the pipe and then spreads along the bottom surface of the connecting pipe 15, which in this embodiment is the bottom surface of the first connecting pipe 52. However, since the packing 54 having the wall 54b is disposed between the flange 51b of the main pipe 51 and the flange 52b of the first connecting pipe 52, the wall 54b is disposed on the secondary side of the chemical solution injection part 42.

[0057] The wall 54b extends upward from the lower end of the flow path in the connecting pipe 15, i.e., from the bottom surface inside the connecting pipe 15, and thus prevents the chemical solution spreading along the bottom surface of the first connecting pipe 52 from moving to the primary side beyond the wall 54b. Even if the height of the chemical solution staying toward the upper end of the wall 54b rises over time, the wall 54b takes time for the chemical solution to overcome the wall 54b, so that the raw water can be moved from a stopped water state to a moving water state before the chemical solution overcomes the wall 54b, or the time from the chemical solution overcoming the wall 54b in the stopped water state to the moving water state can be shortened. That is, the wall 54b can lengthen the time until the concentration of the chemical solution in the raw water is homogenized in the flow path in the attachment part 51a where the flow measuring device 17 is provided according to the law of entropy when the water is stopped. Therefore, the wall portion 54b can suppress the movement of the chemical solution to the location where the flow measuring device 17 is provided. In this manner, the connecting pipe 15 can suppress an increase in the concentration of the chemical solution at the location where the flow measuring device 17 is provided, which is separated in the raw water flow direction from the location where the chemical solution is injected by the chemical solution injector 42. Therefore, the connecting pipe 15 can suppress corrosion by the chemical solution of parts such as the rotating shaft 61 made of a metal material used in the flow measuring device 17.

[0058] In addition, since the wall portion 54b can prevent the liquid medicine from moving to the primary side, there is no need to use a metal material with high corrosion resistance for the flow measuring device 17, and therefore the liquid medicine injector 1 can be manufactured at low cost.

[0059] Furthermore, by providing the wall portion 54b on the packing 54, the height of the wall portion 54b can be adjusted to any height by selecting a packing 54 having a wall portion 54b with a different height.

[0060] As described above, according to the chemical liquid injection device 1 and water treatment device 100 of one embodiment of the present invention, it is possible to suppress an increase in the concentration of the chemical liquid, which is the injected liquid, at a position where the flow measuring device 17 is provided, which is away from the position where the chemical liquid is injected by the chemical liquid injection section 42 in the connecting pipe 15 on the secondary side.

[0061] The present invention is not limited to the above-mentioned configuration. For example, in the above-mentioned example, the chemical liquid injector 1 is provided with the packing 54 having the wall portion 54b in the connecting pipe 15, so that the chemical liquid injected from the chemical liquid injector 42 is prevented from moving to the flow rate measuring device 17 side when the water supply is stopped, and the chemical liquid concentration in the pipe in which the flow rate measuring device 17 is provided is prevented from increasing, but the present invention is not limited to this.

[0062] That is, the chemical solution injection device 1 may be configured so that the flow center CA of the flow path at the location where the flow measuring device 17 is installed, which is a location where it is desired to avoid an increase in the chemical solution concentration when the connecting pipe 15 is stopped, is higher than the flow center of the secondary side of the flow measuring device 17, or the flow center CB of the flow path at the location where the chemical solution injection section 42 for injecting the chemical solution is installed is lower than the flow center of the flow path on the flow measuring device 17 side rather than the chemical solution injection section 42, i.e., the primary side, or the flow path between the flow measuring device 17 and the chemical solution injection section 42 may be provided with a wall portion extending upward from the bottom surface.

[0063] 7, the upper end of the main pipe 51 may be shaped to extend in the axial direction, for example, horizontally, and the lower end may be shaped to be inclined in the axial direction, with the inner diameter gradually decreasing from the end of the primary side toward the secondary side, the inner diameter being constant and minimum at the mounting part 51a where the flow measuring device 17 is attached, and the inner diameter gradually increasing from the mounting part 51a to the end of the secondary side. By adopting such a shape, the center of the opening of the end of the secondary side of the main pipe 51 is coaxial with the flow center CB of the first connecting pipe 52, and the flow center CA of the mounting part 51a where the flow measuring device 17 is provided is disposed above the flow center CB of the first connecting pipe 52. Therefore, when the water flow is stopped, the chemical liquid injected from the chemical liquid injection section 42 is prevented from moving to the primary side due to the difference in height between the flow center CA of the mounting section 51a to which the flow measuring device 17 is attached and the flow center CB of the mounting section 52a to which the chemical liquid injection section 42 is attached, and an increase in the chemical liquid concentration in the mounting section 51a to which the flow measuring device 17 is attached can be suppressed.

[0064] Also, for example, as in the case of the connecting pipe 15 according to the third embodiment shown in FIG. 8, the inner diameter may be gradually reduced from the end of the primary side toward the secondary side, the inner diameter may be constant and minimum at the mounting part 51a to which the flow measuring device 17 is attached, and the inner diameter may be expanded from the mounting part 51a to the end of the secondary side, and the bottom surface adjacent to the mounting part 51a may be stepped to have a wall part 51c. In this case, the flow center CA at the mounting part 51a is set to a position higher than the flow center CB at the mounting part 52a (chemical liquid injection part 42) of the first connecting pipe 52. With this configuration, the chemical liquid injected from the chemical liquid injection part 42 when the water is stopped is prevented from moving to the primary side due to the difference in height between the flow center CA of the mounting part 51a to which the flow measuring device 17 is attached and the flow center CB of the mounting part 52a to which the chemical liquid injection part 42 is attached, and the wall part 51c, and the increase in the chemical liquid concentration at the mounting part 51a to which the flow measuring device 17 is attached can be prevented.

[0065] Also, for example, as in the connecting pipe 15 according to the fourth embodiment shown in FIG. 9, for example, the bottom surface of the first connecting pipe 52 facing the chemical liquid injection part 42 may be recessed within a predetermined range in the axial direction of the first connecting pipe 52. With such a configuration, the flow center CB of the flow path in which the chemical liquid injection part 42 of the first connecting pipe 52 is provided is located below the flow center CA of the mounting part 51a of the main pipe 51. Also, the end of the axial direction of the recess of the bottom surface of the first connecting pipe 52 constitutes the wall part 52c. With such a configuration, the chemical liquid injected from the chemical liquid injection part 42 when the water is stopped is prevented from moving to the primary side due to the height difference between the flow center CA of the mounting part 51a to which the flow measuring device 17 is attached and the flow center CB of the mounting part 52a to which the chemical liquid injection part 42 is attached, and the wall part 52c, and the increase in the chemical liquid concentration in the mounting part 51a to which the flow measuring device 17 is attached can be suppressed.

[0066] In each of the above-described embodiments, an example of the connecting pipe 15 used in the chemical liquid injection device 1 has been described, and an example in which the liquid injected into the raw water is the chemical liquid has been described, but the present invention is not limited to this. That is, the connecting pipe 15 may be configured to be used in a device that flows a liquid other than the chemical liquid injection device 1. That is, the liquid flowing through the connecting pipe 15 may be other than raw water, and the connecting pipe 15 can be configured to inject a liquid having a higher specific gravity than the liquid flowing through the connecting pipe 15, and the connecting pipe 15 can be used when it is desired to suppress an increase in the concentration of the injected liquid at a position away from the injection position of the injected liquid in the liquid flow direction.

[0067] In addition, in the above example, a configuration has been described in which a portion (measurement portion) where it is desired to suppress an increase in the concentration of the injected liquid is provided on the primary side of the injection position (liquid injection portion) of the injected liquid having a higher specific gravity than the liquid flowing inside the connecting pipe 15, but this is not limited to this, and the portion where it is desired to suppress an increase in the concentration of the injected liquid when the water is stopped may be provided on the secondary side of the liquid injection portion in the direction of liquid flow.

[0068] In the above example, the packing 54 is configured such that the seal portion 54a and the wall portion 54b are integrally molded, but the present invention is not limited to this. For example, the wall portion 54b may be made of a hard material different from that of the seal portion 54a, or a hard base material may be provided in the wall portion 54b by insert molding to suppress deformation due to the flow of raw water.

[0069] The present invention is not limited to the above-mentioned embodiment, and can be modified in various ways without departing from the gist of the present invention. The embodiments may be combined as appropriate, and in that case, the combined effect can be obtained. Furthermore, the above-mentioned embodiment includes various inventions, and various inventions can be extracted by combinations selected from the multiple components disclosed. For example, if the problem can be solved and the effect can be obtained even if some components are deleted from all the components shown in the embodiment, the configuration from which the components are deleted can be extracted as an invention. [Explanation of symbols]

[0070] 1...chemical injection device, 11...frame, 11a...legs, 11b...first base, 11c...wall, 11d...second base, 12...chemical tank, 12a...bottom, 12b...supply port, 12c...lid, 13...piping unit, 14...chemical injector, 15...connecting pipe, 16...pressure sensor, 17...flow rate measuring device, 19...electrical box, 21...connecting pipe, 22...exhaust tube, 23...connecting tube, 24...opening / closing valve, 31...screw portion, 32...flange, 33...nut, 34...upper branch portion, 35...lower branch portion, 36...mounting portion, 41...volumetric pump, 41a...pump casing, 41b...suction port, 41c...discharge port, 41d...plug, 42...chemical injection portion (liquid injection inlet portion), 42a...connecting pipe, 42b...first check valve, 42c...nozzle, 42d...second check valve, 51...main pipe, 51a...mounting portion (measurement portion), 51a1...support portion, 51a2...fixing portion, 51b...flange portion, 51c...wall portion, 52...first connecting pipe, 52a...mounting portion (liquid injection portion), 52a1...female thread portion, 52b...flange portion, 52c...wall portion, 53...second connecting pipe, 53a...mounting portion, 53b...flange portion, 54...packing, 54a...seal portion, 54b...wall portion, 55...flange, 61...rotating shaft, 62...rotating blade, 63...magnet, 64...detection portion, 65...transmitting portion, 100...water treatment device, 104...water supply pump, 105...sand filter.

Claims

1. A connecting pipe provided with a measuring device having a metal component and a liquid injection section for injecting an injection liquid having a specific gravity greater than that of the liquid flowing through the pipe, a measurement site where the measurement device is provided; The liquid injection part is provided on the secondary side of the measurement part in a flow direction of the liquid, A connecting pipe in which the flow center of the measurement site is higher than the flow center of any part of the flow path on the secondary side of the measurement site, or the flow center of the liquid injection site is lower than the flow center of any part of the flow path on the primary side of the liquid injection site.

2. A connecting pipe provided with a liquid injection part for injecting an injection liquid having a larger specific gravity than a liquid flowing inside the pipe, a liquid injection site in which the liquid injection section is provided; The liquid injection portion and a measurement portion separated in a flow direction of the liquid, A connecting pipe in which the flow center of the measurement site is higher than the flow center of any part of the flow path on the liquid injection site side, or the flow center of the liquid injection site is lower than the flow center of any part of the flow path on the measurement site side.

3. 3. The connecting pipe according to claim 1, further comprising a wall portion disposed between the measurement site and the liquid injection site and protruding upward from a bottom surface inside the pipe.

4. The connecting pipe according to claim 3 , wherein the wall portion has a height sufficient to ensure a specified water volume.

5. A main pipe in which the measurement site is provided; a connecting pipe provided with the liquid injection portion and connected to the main pipe; a packing having a seal portion disposed between the main pipe and the connecting pipe and the wall portion formed integrally with the seal portion; The manifold of claim 4 .

6. A connecting pipe according to claim 1 or 2; a liquid injector including a pump for pumping a liquid medicine having a specific gravity greater than that of raw water flowing through the connecting pipe, and a liquid injector connected to the pump for injecting the liquid medicine into the connecting pipe; A drug solution injection device comprising:

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