JPS601378Y2 - turbine meter - Google Patents

Description

[Detailed description of the invention] The present invention relates to a turbine meter, in which a blade is protected outside the rotation space of an impeller attached to the tip of an insertion tube inserted from a direction substantially perpendicular to the flow direction of the fluid to be measured. By providing a meter outer shell for the meter outer shell and forming a circumferential opening over almost the entire circumference of the circumferential portion of the meter outer shell that faces the impeller, dust, etc. in the fluid to be measured can be prevented from coming into contact with the impeller and the meter outer shell. It is an object of the present invention to provide a turbine meter that can effectively prevent adhesion between the parts.

For example, when measuring the flow rate of exhaust gas flowing through the exhaust gas flue of a boiler, a turbine meter is attached to the tip of the insertion tube, inserted into the flue, and the exhaust gas flow rate is measured from the rotation speed of the turbine meter's impeller. Sometimes.

However, in conventional turbine meters in which the impeller is attached to the tip of the insertion tube with the impeller exposed, when the insertion tube is inserted into a large-diameter pipe, the blades may come into contact with the inner wall of the flue and bend. For this reason, there have been drawbacks such as the installation work of the insertion tube being complicated and troublesome.

In contrast, there is a known turbine meter that has a meter outer shell that covers the rotation space of the impeller to protect the blades, but this meter does not collide with the blades as the impeller rotates. Dust, etc. in the measured fluid that is blown away by the meter adheres to the inner wall of the outer shell of the meter, and after long-term use, the dust that adheres and accumulates on the inner wall of the outer shell of the meter obstructs the rotation of the impeller, making it difficult to accurately measure the flow rate. It had the disadvantage that it became impossible to do so.

The present invention eliminates the above-mentioned drawbacks, and an embodiment thereof will be described below with reference to the drawings.

Fig. 1 is a vertical sectional view of an embodiment of the turbine meter according to the present invention applied to an insertion type turbine meter;
The figures show a side view and a rear view of the main parts, respectively.

In FIG. 1, a turbine meter 1 is attached to the tip of an insertion tube 2, and in this embodiment is inserted into a large diameter tube 3 such as an exhaust gas flue of a boiler.

The insertion tube 2 is inserted from a direction substantially perpendicular to the channel of the large-diameter tube 3, and is fixed to the side of the large-diameter tube 3 by flange connection.

As shown in Fig. 2.3, the impeller 4 of the turbine meter 1 has blades 4b, each twisted at a constant angle, installed at regular intervals on the circumferential surface of the body 4a. The body portion 4a is rotatably fitted onto the shaft 5.

Reference numeral 6 denotes an electromagnetic pickup coil embedded in the tip of the insertion tube, which electromagnetically detects passage of the blade 4b.

Reference numeral 7 denotes a meter outer shell, which in this embodiment is composed of a hollow cylindrical body that covers the rotation space of the impeller 4, and is fixed to the tip of the insertion tube 2.

Three pillars 8 are provided on the end surface of the back side of the meter shell 7, protruding from the outer periphery toward the center, and a support part 9 for supporting one end of the shaft 5 is formed at the intersection of each pillar 8. has been done.

The impeller 4 is fitted onto the shaft 5 from the front end face of the meter outer shell 7, and a conical cone member 10 is further attached to the front face thereof.

In addition, in the case of this embodiment, an air pipe (not shown) is provided through the insertion tube 2 and the meter outer shell 7, and the pressure is reduced to a predetermined pressure by the pressure reducing valve 11 through this air pipe. The structure is such that air is supplied to the end face of the body 4a of the impeller 4, and the impeller 4 can be rotated floating in the axial direction by this air.

Reference numeral 12 denotes an opening constituting the main part of the present invention, which is an opening that forms the main part of the meter outer shell 7.
In this embodiment, three belt-like holes are formed on the circumferential surface of the circumferential portion where the blades 4b of the impeller 4 face, excluding only the reinforcing portions corresponding to the respective pillars 8. It is.

Further, the opening 12 is formed in the central portion of the meter outer shell 7 in the axial direction, leaving annular protective portions at the front and rear of the meter outer shell 7 in the axial direction.

Note that the opening 12 has a width slightly larger than the width of the impeller 4 in the axial direction, and has a size that is necessary and sufficient to discharge dust scattered from the impeller 4 in the outer circumferential direction. An annular protective portion sufficient to protect the impeller 4 is left before and after the impeller 4.

Here, when the fluid to be measured flows through the large diameter pipe 3, a part of the fluid to be measured passes through the meter outer shell 7, and the impeller 4 rotates at a rotational speed corresponding to the flow velocity of the fluid to be measured. do.

Every time the blades 4b of the impeller 4 pass near the pickup coil 6, a pulsed current is induced in the pickup coil 6, and the rotational speed of the impeller 4, that is, the flow rate (flow rate) of the fluid to be measured, is determined from the number of pulses. be measured.

When the impeller 4 rotates within the meter outer shell 7, dust etc. in the fluid to be measured collides with the blades 4b and is blown outward.
These dusts flow out of the meter shell 7 through the opening 12 of the meter shell 7.

Therefore, in the turbine meter 1 having the above configuration, dust etc. in the fluid to be measured does not adhere to the inner wall of the meter outer shell 7, and therefore, the meter outer shell 7 does not adhere to the inner wall of the meter outer shell 7 as in conventional turbine meters.
There is no inconvenience such as dust or the like adhering to the inner wall obstructing the rotation of the impeller 4 and making it impossible to accurately measure the flow rate.

Further, since the turbine meter 1 having the above configuration is provided with the meter outer shell 7 covering the rotation space of the impeller 4, for example, when inserting the insertion tube 2 into the large-diameter tube 3, the turbine meter 1 has a large diameter. Even if the blades 4b of the impeller 4 hit the inner wall of the large-diameter tube 3, the blades 4b of the impeller 4 will not directly contact the inner wall of the large-diameter tube 3, thereby reliably preventing accidents such as breakage of the blades 4b.

In the above embodiment, the number of openings 12 formed in the meter outer shell 7 is not limited to three, and any number of openings 12 may be formed as long as it is at least one.

Further, in the above embodiments, it is not necessary to provide an air bearing.

As mentioned above, the turbine meter according to the present invention has a meter for protecting the blades installed outside the rotating space of the impeller, which is attached to the tip of the insertion tube inserted from a direction substantially perpendicular to the flow direction of the fluid to be measured. A shell is provided, and a circumferential opening with a width slightly larger than the axial width of the blade is provided over almost the entire circumference of the circumferential portion of the meter outer shell that faces the blade in the axial center portion. The dust scattered from the car can be efficiently discharged through the circumferential opening, and the problem of dust accumulating inside the meter outer shell and impeding the rotation of the impeller can be prevented.
Furthermore, since only a minimum number of openings are required in the circumferential direction, there is almost no loss of protection for the impeller, and the outer frame of the meter shell, excluding the openings, allows the impeller to come into contact with other components when installed in piping. It has features such as being able to reliably prevent accidents such as contact and damage, and thereby enabling accurate flow measurement at all times.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional view of an embodiment of the turbine meter according to the present invention applied to an insertion type turbine meter;
The figures are a side view and a rear view of the main parts, respectively. 1...Turbine meter, 3...Large diameter pipe, 4...
Impeller, 4b...Blade, 7...Meter outer shell, 12.
··Aperture.

Claims (1)

[Scope of utility model registration request] an insertion tube inserted into a pipe through which a fluid to be measured flows from a direction substantially perpendicular to the flow direction; and provided at a distal end of the insertion tube,
An impeller is supported on a rotating shaft orthogonal to the insertion tube, rotates according to the flow velocity of the fluid to be measured, and has a plurality of blades around it, and an impeller that surrounds the rotating space is placed outside the rotating space of the impeller. It consists of a hollow cylindrical meter outer shell that is provided concentrically so as to cover the whole area, and an annular protective portion is left at the front and rear of the axial direction of the hollow cylindrical meter outer shell, and the blade of the impeller is attached to the axially central portion of the hollow cylindrical meter outer shell. A turbine meter having a structure in which an opening for dust outflow having an axial width slightly larger than the axial width of the blade is provided over substantially the entire circumference of a circumferential portion facing the blade.