JPS593315A - Rod-type detection terminal for measuring flow speed of fluid - Google Patents

Abstract

PURPOSE:To improve characteristics for general purpose and durability, by providing the 1st and 2nd sensors on the part inserting into a fluid transport pipe of a rod-type member which is pushed into a streamline of the pipe and transmitting detected signals of total pressure of the 1st sensor and static pressure of the 2nd sensor to the outside of the pipe. CONSTITUTION:The plural number of the 1st pressure/electric current transmitter S1 for total pressure detection and the 2nd pressure/electric current transmitter S2 for static pressure detection are provided to an insertion part 2A of a rod-type member 2 vertically by a streamline in a fluid transport pipe 1. It is constituted so that each electric current of both transmitters S1, S2 is transmitted from the part 2A to the outside of the pipe 1 through the member 2.

Description

[Detailed Description of the Invention] The present invention is mainly necessary when calculating the flow rate of various fluids such as liquids such as tap water and sewage water, gases for combustion, and gases such as air for pricking. This invention relates to a detection end for measuring fluid flow velocity.

As a detection end for the fluid velocity meter side, ■ When the fluid is a conductor, VC uses the fact that the electromagnetic induction of the fluid changes depending on the change in the flow velocity of the fluid to insert a rod-shaped member pushed into the fluid transport pipe. An electromagnetic type in which a sensor for detecting the electromagnetic induction of the fluid is attached to the part °, @ a rod-shaped member pushed into the fluid transport pipe is inserted into the part, and a wheel rotated by the fluid VC and its rotation speed. There have been single-type turbine blades and pitot-tube types that are equipped with a sensor that detects TH.

However, when using the vjjL magnetic type in (■), the range of use is narrow because it measures the flow velocity of a non-conductive fluid, and the sensor structure is not only complicated but also large. , which obstructs fluid flow, and the sensors are expensive and power-hungry.
The drawback is that manufacturing costs and running costs (inspection and maintenance costs) are very low. When using a single type turbine blade, it lacks durability because wear of the rotating part of the impeller is unavoidable, and it also suffers from not only changes in fluid flow speed but also changes in fluid viscosity and foreign matter contamination. Since the rotational speed of the impeller changes due to the change in the rotation speed of the impeller, measurement accuracy is low, and the balls and impeller act as fluid flow resistance and impede fluid flow. When using the Pitot tube type for θ, the measurement accuracy is low due to clogging with water scale, etc. in the impulse tube that guides the total pressure and static pressure to the outside of the tube, foreign matter entering the impulse tube, air adhesion, etc. Moreover, in order to introduce the total pressure and static pressure to the outside of the pipe, an im- lag occurs in the measurement VC3t, and in particular, when the fluid is water, there is a drawback that the water in the impulse pipe freezes.

The present invention has an object to eliminate the conventional drawbacks detailed above.

The A-type detection end for fluid flow rate measurement according to the present invention has a first detection end that detects the total pressure as an electric signal at the part of the rod-shaped member pushed into the pipe in a position perpendicular to the flow line or almost on duty in the fluid transport pipe. A sensor and a second sensor that detects static pressure as an electric signal are attached, and the detection signals of both sensors are transmitted from the insertion part inside the pipe to the outside of the pipe via the rod-shaped member. do.

According to such features of the present invention, (1) the flow velocity of the fluid is detected from the VC total pressure and static pressure, similar to the Pitot tube type; therefore, even if the fluid is non-conductive, the flow velocity of the fluid can be detected; It can be measured and has the same versatility as above, ■ There are no adhesive parts such as impellers, etc., and since it is rod-shaped, it is difficult to get dirty, so durability and maintainability can be improved. Since the first sensor f- for detection and the @2 sensor for static pressure detection are housed, measurement time lag can be completely eliminated, and the pressure-receiving surface of the sensor comes into direct contact with the fluid, allowing the fluid to cleanse the sensor pressure-receiving surface. By synergistically, it is possible to measure the flow velocity stably and with high accuracy regardless of disturbances such as fluid viscosity and foreign matter. Since a small and inexpensive pressure/current tonometer can be used for this purpose, manufacturing costs and running costs can be significantly reduced, and the detection signals of both sensors can be transmitted from the insertion part inside the pipe to the outside of the pipe via a rod-shaped member. There is an advantage that the fluid flow resistance can be reduced due to the fact that the only member pushed into the pipe is a rod-shaped member equipped with a sensor.

Embodiments of the present invention will be described below based on the drawings.

Calculate the flow velocity (V) from the total 1f (Pl) and static pressure (Pli),
This is a detection end for a flow meter that determines the flow rate from the flow velocity (v), and this is a rod-shaped member inserted into the fluid transport pipe [11 in a position perpendicular to the streamlines (the part pushed into the pipe of 21)]. 2A)
[, A plurality of @l pressure/current transmitters (Sl) for total pressure lateral pressure are embedded in the rod-shaped member (2) at appropriate intervals in the longitudinal direction, and the pressure/current transmitters (Sl) for total pressure and lateral pressure are installed in an embedded state at appropriate intervals, and A plurality of second pressures/currents for detection 2
Smitters (St)... are spaced appropriately in the longitudinal direction of the rod-shaped member (2). both types of transmitter (81) configured to be housed in an embedded abutment;
(S2)... is configured to transmit the current from the intra-tube insertion part 0 (2A) to the outside of the tube via the inside of the rod-shaped member (2).

As a means for transmitting the current of the transmitter (S+), (s2)@・ via the rod-shaped member (2), there can be mentioned a means of embedding a transmission wire in the rod-shaped member (2). .

The pressure-receiving surfaces of both types of transmitters (Sl) and (S2) are each a diaphragm (peas may be used) (al) that does not protrude beyond the surface of the rod-shaped member (2),
(Illusion) It is composed of...

The rod-shaped member (2) is attached to a fluid transport pipe 111K!jy through a loose 7 flange (3) and a stop valve (Vl). Built-in calculation circuit that calculates the average value of the total pressure detected by the first transmitter (S,), the average value of the static pressure detected by the second transmitter (S2), and the flow velocity and flow rate. At the same time, a flow meter (7) equipped with a flow rate II* indicator (4), an integrated flow rate display meter t51, and a connector (6) for outputting a flow rate signal is attached.

+81 is an arrow mark attached to the flowmeter 171 K, which indicates the direction of the diaphragm (al) in the first sensor (Sl).

Therefore, by attaching the rod-shaped member (2) to the pipe tjl vc so that the arrow mark 18) can be turned to the upstream side, the first
The sensor (Sl) can be positioned in a total pressure detection position.

Between the above flow rates, the flow rate tQl is calculated by the following formula: Pl-
Total pressure, P2=quiet pressure, p=density of fluid, 8-11i cross-sectional area in the pipe, ■=average flow velocity in the pipe, R=specific m difference of flowmeter (coefficient determined by experiment). Seed sensor (
SL).

A plurality of sensors (S2) are provided for each sensor (Sl).

(S2) Calculate the flow velocity using the average value t of the detected values.
It is possible to correct disturbances in the flow velocity distribution within the interior, improve detection accuracy, and also prevent snow (1
It is possible to easily carry out installation and removal for maintenance etc. without stopping the flow of fluid within the tube 1 and without spouting the fluid outside the tube.

Also, when installing the rod-shaped member (2), the posture is Flow+wl! It is possible to allow a posture tilted by about 8 in both the front and rear with respect to the vertical posture with respect to the VC.

In addition, the number of both sensors (Sl) and (Sri) may be at least one. For example, in the case of small diameter (100 to 200) (1), Vci, one each, large diameter (2oo' or more) case[
d, a plurality of pieces, etc., is determined based on the diameter of the pipe 111, the type of fluid, the required detection accuracy, etc., and the length of the part (2A) of the rod-shaped member (2) inserted into the pipe is f
It is determined based on the caliber of ill.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of the device in use, and FIG. 2 is a perspective view.

Claims (1)

[Claims] ■ A portion of the rod-shaped member (2) pushed into the fluid transport pipe fil in a position perpendicular or almost perpendicular to the streamline (
2A) vc, the total pressure is output as an electrical signal (the first sensor (Sl) that outputs, and the static pressure is detected as an electrical signal @2
Attach the sensor (S2) and both these sensors (Sl). (S2) A rod-shaped detection sensor for fluid flow rate measurement, characterized in that it is configured to transmit the detection signal 87 from the inside of the pipe push-in part (2A) to the outside of the pipe through the inside of the rod-shaped member (2). Both sensors (Sl) and (Ss) are both VC
A rod-shaped detection element for fluid flow rate measurement according to claim 0, wherein a plurality of rod-shaped detection elements are provided.