JPH0318892Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The present invention relates to a detection end of a rod-shaped electromagnetic current meter used, for example, when measuring the amount of water discharged through a discharge pipe in a dam. A rod-shaped member inserted into a fluid transport pipe through a through-hole formed in a peripheral wall of the pipe has a magnet for generating a magnetic field installed at the insertion side end thereof, and the direction is perpendicular or almost perpendicular to the flow line direction in the pipe. A detection section is fixedly arranged in a state in which a pair of detection electrodes facing each other are exposed to the outside, and at least a portion of the detection section located upstream of the pair of electrodes is arranged in the direction of the flow line in the pipe and The present invention relates to a detection end of a rod-shaped electromagnetic current meter for fluid in a pipe, which has a tapered shape that becomes gradually narrower toward the upstream side when viewed in a direction perpendicular to the electrode facing direction.

[Conventional technology]

The detection end of this type of rod-shaped electromagnetic current meter for fluid in a pipe can be installed without stopping fluid transport within the pipe by inserting it through a valve attached to the peripheral wall of the pipe, as will be explained in the examples below. For example, it has the advantage of superior workability compared to a structure in which the magnet and electrode are attached to a pipe inserted in the middle of a transport pipe. As in the conventional detection end shown in FIG. 1, the insertion end of the rod-shaped member 4 is configured in a ring shape whose axis coincides with the flow line direction inside the tube, and electrodes 6 are provided at locations facing each other in the diametrical direction.
When the detection unit 7' having six pairs is fixedly connected, the transport fluid is
In the case of a fluid that contains foreign matter such as wood chips or dirt, the foreign matter tends to get caught in two spaced apart locations on the ring-shaped detection section, and as a result, excessive disturbance acts on the detection section, making measurement impossible. Moreover, the disadvantage is that the flow path resistance increases and clogging is likely to occur. Therefore, in order to eliminate the above-mentioned drawbacks, it has been proposed that the detection section is formed into a streamlined shape and electrodes are provided on both the left and right sides of the detection section (for example,
123767, Japanese Patent Application Laid-Open No. 156563/1983).

[Problem to be solved by the invention] However, when measuring the flow velocity in a pipe with the above configuration, the flow in the pipe is not only a flow in the axial direction of the pipe, but also a flow substantially along the radial direction of the pipe, etc. Turbulent flow may occur in a direction different from the axial direction of the tube, and such flow in a direction other than the axial direction of the tube becomes a disturbance, making it difficult to accurately measure the flow velocity in the axial direction of the tube. was difficult.

The purpose of the present invention is to overcome these conventional drawbacks.

[Means to solve the problem]

A characteristic configuration of the detection end of the rod-shaped electromagnetic current meter for pipe fluid according to the present invention, which was taken to achieve the above object, is that the mounting surface of each electrode is provided with a groove along the flow line direction, and the electrode is inserted into the groove. The functions of the present invention having such features and configurations are as follows.

[Effect]

In other words, since the mounting surface of each electrode is provided with a groove along the streamline direction, only the flow along the axial direction of the tube passes through the groove, and the electrode is installed in the groove. Therefore, the flow in the groove can be accurately detected by the electrode, and it is also possible to prevent foreign matter in the transport fluid from getting caught in the detection part.

〔Effect of the invention〕

Therefore, the present invention can reduce detection errors caused by turbulent flow in pipes by making very simple structural modifications such as devising the shape of the detection part, and as a whole, it is possible to reduce detection errors caused by turbulent flow in pipes. We were able to provide a detection end for a rod-shaped electromagnetic current meter for fluid in a pipe that can very accurately measure the flow velocity setting in a pipe.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the drawings.

Using Faraday's law of electromagnetic induction, which states that when a conductor moves in a magnetic field, a voltage is generated between the electrodes, and the generated voltage is proportional to the speed at which the conductor moves, This is an electromagnetic current meter that measures the flow velocity of a conductive fluid such as water flowing in a transport pipe A. This is an electromagnetic current meter that is inserted into the fluid transport pipe A and has a detection end 1 that extracts the flow velocity as a voltage, and a measuring device. It consists of 2.

The detection end 1 is located on the pipe peripheral wall a of the fluid transport pipe A.
An electromagnetic coil 5 for generating a magnetic field ( An example of a magnet) is installed inside, and
A detection part 7 made of synthetic resin is provided in a state in which a pair of detection electrodes 6, 6 facing each other in a direction perpendicular to the flow line direction in the pipe and the longitudinal direction (insertion direction) of the rod-shaped member 4 are exposed to the outside. At the same time, the electrodes 6, 6 pairs are arranged in a fixed manner on the outer end side of the rod-shaped member 4, and the position of the detection 7 around the 4-axis axis of the rod-shaped member makes the electrodes 6, 6 pairs face each other in a direction perpendicular to the flow line direction in the pipe. The operating handle 8, which also serves as a detector position detector, is in a position along the flow line direction in the pipe, that is, the longitudinal direction of the pipe, and the voltage lead-out line and electromagnetic coil led out through the space inside the rod-shaped member 4. A terminal 9 for connecting the power supply line to the measuring device 2 is also provided.

The means for attaching the detection end 1 to the tube circumferential wall a includes the rod-shaped member 4 attached to the tube circumferential wall a in an open state.
A gate valve 10 that can be inserted through the gate valve 10 is installed concentrically with the through hole 3, and the rod-shaped member 4 is slidably inserted into the inlet side of the gate valve 10.
An annular seal that is configured to a size that allows the detection section 7 to be installed inside, and that is deformed to reduce its diameter when pressed from the axial direction, thereby making the insertion portion of the rod-like member 4 watertight and fixing the rod-like member 4. A gland flange 12 equipped with a seal material 11 is attached, and a member 13 for pressing the seal material 11 is attached to this gland flange 12. In this state, the gland flange 12 with the rod-shaped member 4 inserted therein is attached to the gate valve 10, and then the gate valve 10 is opened and the rod-shaped member 4 is slid so that the detection part 7 is located at a predetermined position in the pipe A. Thereafter, the sealing material 11 is pressed by the pressing member 13.

A portion 7A of the detection unit 7 located upstream of the pair of electrodes 6, 6 is located on the upstream side when viewed in a direction perpendicular to the in-pipe flow line direction and the electrode facing direction, that is, when viewed in the longitudinal direction of the rod-shaped member 4. The electrodes 6, 6 are configured in a tapered shape that gradually becomes narrower as the width increases.
The portion 7B located on the downstream side of the pair has a tapered shape that gradually becomes narrower toward the downstream side when viewed in the longitudinal direction of the rod-like member, and has a tapered shape that gradually becomes narrower toward the downstream side, and
The pair of mounting surfaces have grooves 14, 1 along the streamline direction.
4 are formed, and the electrodes 6, 6 are attached to the bottoms of these grooves 14, 14.

The portion of the rod-shaped member 4 that is inserted into the tube A is
As shown in FIG. 4, the front and rear portions are tapered.

Reference numeral 15 is a stopper for regulating the insertion amount of the rod-shaped member 4.

According to the configuration of the above embodiment, since both the detection part 7 and the rod-shaped member 4 are configured in a so-called streamlined shape that tapers back and forth, the flow path resistance increases due to the insertion of the detection end 1 into the pipe A. It is possible to suppress the flow disturbance as much as possible, and also to prevent foreign substances in the fluid from getting caught in the detection unit 7 and the rod-shaped member 4. Moreover, the grooves 14, 14 along the flow line direction in the detection part 7
are formed, and the electrodes 6,
6, it is possible to prevent impurities from coming into contact with the electrodes 6, 6.

Incidentally, in the present invention, as shown in FIG.
The portion 7A on the upstream side of the electrodes 6, 6 is configured to have a tapered shape that gradually becomes narrower toward the upstream side when viewed in the electrode opposing direction, and the portion 7B on the downstream side of the electrodes 6, Also when viewed in the opposite direction, it may be configured to have a tapered shape that becomes gradually narrower toward the downstream side. In this case, it is desirable that each of the portions 7A and 7B has a rounded shape when viewed in the streamline direction, such as a spindle shape.

Further, when implementing the present invention, the rod-shaped member 4 may be connected to the detection section 7 on the downstream side of the electrode 6. In this case, disturbance of the flow near the electrode 6 due to the rod-shaped member 4 can be prevented.

In addition, although the drawings show the detection section 7 which is asymmetrical in the front and back, the detection section 7 may be symmetrical in the front and back.

[Brief explanation of drawings]

Figures 1 to 4 show examples, with Figure 1 being a longitudinal sectional view, Figure 2 being an enlarged side view of the main parts, Figure 3 being an enlarged front view of the main parts, and Figure 4 being the main parts. FIG. 5 is an enlarged cross-sectional plan view, and FIG. 5 is an enlarged side view of main parts showing another embodiment. FIG. 6 is a perspective view of main parts showing a conventional example. A... Fluid transport pipe, a... Pipe peripheral wall, 3... Through hole, 4... Rod-shaped member, 5... Magnet, 6... Electrode,
7...detection section, 7A...upstream detection section, 7B...
...Downstream detection part, 14...Groove.

Claims (1)

[Scope of utility model registration request] A rod-shaped member 4 is inserted into the conductive fluid transport pipe A through a through-hole 3 formed in the pipe peripheral wall a, and a magnet 5 for generating a magnetic field is installed inside the insertion side end of the rod-shaped member 4, which is inserted into the conductive fluid transport pipe A through a through-hole 3 formed in the pipe peripheral wall a. A detection section 7 is fixedly arranged in a manner to expose a pair of detection electrodes 6, 6 facing to the outside in a direction perpendicular or almost perpendicular to the detection section 7, and at least the pair of electrodes 6, 6 of the detection section 7 A rod-shaped electromagnetic current meter for fluid in a pipe, in which a portion 7A located upstream of the pipe has a tapered shape that becomes gradually narrower toward the upstream side when viewed in a direction perpendicular to the flow line direction in the pipe and the electrode facing direction. The detection end is provided with grooves 14, 14 along the streamline direction on the mounting surfaces of the electrodes 6, 6, respectively, and the grooves 1
4, 14 is a detection end of a rod-shaped electromagnetic current meter for fluid in a pipe in which the electrodes 6, 6 are installed.