KR19990024122A - Water meter impeller - Google Patents

Abstract

In a water meter with an impeller, the shape of the plurality of blades provided in the impeller is varied, which is changed by extending the blades tangentially around the circumference of the impeller central axis. At this time, each blade has a constant distance from each other.

According to the shape of the blade, the angle between the blade and the fluid injected through the fluid injection nozzle is perpendicular to each other, and as the length of the blade extends in the tangential direction, the blade length is longer than the conventional blade length extending in the radial direction of the impeller central axis. It will be longer. Accordingly, it is possible to improve the torque of the blades for the same force. Therefore, the flow rate measurement property of a water meter can be improved more precisely.

Description

Water meter impeller

The present invention relates to a water meter connected to a water supply line for counting the amount of water used, and more particularly, to an impeller of a water meter that rotates in response to energy of water.

The water meter is largely divided into a method of measuring a certain amount of water, and is classified into a measurement equation mainly used for a test and an inference equation that measures an actual flow rate indirectly according to a flow rate or a rotation speed of an impeller. Here, the inferred equation is a single-pump type, in which the flow of water flows to the impeller through a single spout, and a double-pump type that imparts rotation to the impeller through a number of spouts formed in the lower inner shell. Meters).

As shown in FIG. 4, the impeller-type double-deck type water meter includes a main body 10 having an inlet 10a and an outlet 10c of water connected to a water supply line, and an upper portion of the main body 10. An upper cover 20 coupled to the upper casing, an upper casing (upper inner shell) 30 and a lower casing (lower inner shell) 40 installed inside the main body 10, and installed inside the upper and lower casings. It is composed of an impeller 35, and an integration display unit 60 that accumulates the passage amount of water by the rotation of the instrument gear 60a according to the rotation of the impeller 35.

In the impeller-type double-deck type water meter having the above-described configuration, it will be described below with reference to FIG. 5, which shows a conventional configuration of the upper and lower casings and the impeller in more detail.

A plurality of fluid injection nozzles 40a are formed at an outer lower end of the lower casing 40, at least one fluid discharge nozzle 40b is formed at an upper portion of the fluid injection nozzle 40a, and the lower casing 40 is formed. At the inner central portion of the support shaft 40c into which a ball is inserted is installed. The impeller 35 supported by the support shaft 40c is provided with a plurality of blades 35a (seven in the figure), each of which has a radius of the impeller central axis 35b. Extend in the direction.

Referring to the coupling relationship of the above components, on the support shaft 40c of the lower casing 40 which is located inside the main body 10 of the water meter, the hollow portion formed below the central axis 35b of the impeller 35 ( (Not shown) so that the impeller 35 is supported by the support shaft 40c, and then the upper casing 30 having a through hole 30a through which the central axis 35b of the impeller 35 passes. To the lower casing 40 to position the impeller 35 inside the upper and lower casings.

Next, the operation of the conventional water meter will be described with reference to FIGS. 4 and 5.

Water is introduced through the inlet 10a of the water meter in which the strainer 10b is installed, and the introduced water is discharged toward the fluid discharge nozzle 40b through a plurality of fluid injection nozzles 40a formed in the lower casing 40. Then, water is discharged through the outlet 10c formed in the main body 10. Here, the impeller 35 located between the lower casing 40 and the upper casing 30 is rotated by the water pressure of the water sprayed through the fluid injection nozzle 40a, and the impeller 35 is rotated by the impeller 35. The drive gear 35c integrally formed on the upper portion of the central axis 35b rotates, and the instrument gear 60a meshed with the drive gear 35c rotates. Accordingly, the amount of water passing through the water meter is displayed through the integration display unit 60.

The water meter having the above-described configuration has a structure in which the water passing through the fluid injection nozzle strikes the blade of the impeller so that the water injected through the fluid injection nozzle may hit the blade of the impeller. At this time, the flow rate, the fluid velocity, the angle at which the fluid strikes the blade, the shape of the fluid injection nozzle and the blade, etc. are important factors that determine the fluid's momentum transfer efficiency.

Physically, the maximization of the torsional moment is achieved when the angle of contact between the blade and the fluid with respect to the same working force is at right angles, and the length of the entire blade from the central axis to the end of the impeller is the longest. It is also well known that the kinetic energy of the fluid injected through the fluid injection nozzle is rapidly dissipated after passing through the outlet of the fluid injection nozzle.

As shown in FIG. 6, the impeller of the conventional water meter is formed by extending each blade 35a in the radial direction of the impeller central axis, so that the fluid W and the blade 35a are injected through the fluid injection nozzle 40a. Is an obtuse angle, and the point at which the fluid W and the blade 35a form a right angle is a point away from the fluid injection nozzle 40a by a predetermined distance.

Given that the flow of fluid is through the fluid injection nozzle, the transfer of fluid momentum occurs at a position close to the outlet of the fluid injection nozzle. In the conventional water meter, when the blade of the impeller is positioned near the outlet of the fluid injection nozzle, the angle formed by the fluid W and the blade 35a of the impeller 35 is an obtuse angle (103 °). This reduces the momentum of the fluid acting on the blade 35a of the impeller 35. Accordingly, there is a problem that the momentum of the fluid is not efficiently transmitted to the blade of the impeller, which means that the measurement performance of the water meter is reduced.

An object of the present invention is to change the blade shape of the impeller to maintain the injection angle of the blade and the fluid of the impeller at a right angle, and at the same time to allow the blade of the impeller to receive the action of the fluid in the position close to the outlet of the fluid injection nozzle The ultimate goal is to efficiently transfer the momentum of the fluid to the blade.

1 is an exploded perspective view showing a water meter with an impeller of the present invention.

2 is a perspective view of an impeller having a tangential blade of the present invention.

3 is a partial cross-sectional view showing the working relationship between the impeller and the fluid of the present invention.

Figure 4 is an exploded perspective view showing a water meter with a conventional impeller.

5 is an exploded perspective view showing a conventional impeller and upper and lower casings.

6 is a partial cross-sectional view showing a working relationship between a conventional impeller and a fluid.

Explanation of symbols for main parts of drawings

10: water meter body 30: upper casing

35, 50: impeller 35a, 50a: blade

40: lower casing 40a: fluid injection nozzle

40b: fluid discharge nozzle 50b: impeller central axis

60: integration display unit 60a: instrument gear

Referring to Figures 1 and 2 will be described the impeller configuration and operation of the water meter according to the present invention.

The main body 10 formed integrally with the inlet 10a and the outlet 10c of the water connected to the water supply line, the upper cover 20 is coupled to the upper portion of the main body 10, and the inside of the main body 10 The upper casing (upper inner shell) 30 and the lower casing (lower inner shell) 40 to be installed, the impeller 50 installed in the upper and lower casings, and the instrument according to the rotation of the impeller 50 In the water meter composed of an integration display unit 60 that accumulates the passage amount of water by the rotation of the gears (60a), a plurality of blades (50a) (7 in the figure shown) provided in the impeller 50 ), The shape is changed by extending the blades 50a in a tangential direction at the circumference of the impeller central axis 50b to which the blades 50a are integrally coupled. At this time, each of the blades have a constant distance from each other.

The operation of the impeller 50 in which the shape of the blade 50a is changed as described above is as follows.

Water is introduced through the inlet 10a of the water meter in which the strainer 10b is installed, and the introduced water is discharged toward the fluid discharge nozzle 40b through a plurality of fluid injection nozzles 40a formed in the lower casing 40. Then, water is discharged through the outlet 10c formed in the main body 10. Here, the impeller 50 located between the lower casing 40 and the upper casing 30 is rotated by the water pressure of the water sprayed through the fluid injection nozzle 40a, and the impeller is rotated by the impeller 50. The driving gear 50c integrally formed with the central shaft 50b on the upper portion of the central shaft 50b rotates, and the instrument gear meshed with the driving gear 50c by the rotation of the driving gear 50c. 60a) will rotate. Accordingly, the amount of water passing through the water meter is displayed through the integration display unit 60.

The above operation is the same as that of a conventional water meter. However, by changing the shape of the impeller blade 50a of the present invention, that is, extending tangentially from the circumference of the impeller central axis 50b to which the blades 50a are integrally coupled, the torque force of the blade for the same force can be improved. Will be. That is, as shown in FIG. 3, when the fluid W is injected through the fluid injection nozzle 40a, the angle at which the blades 50a of the impeller 50 and the fluid W contact each other is perpendicular to each other. As the overall blade length from the central axis to the end becomes longer, the torque force can be improved.

Hereinafter, the experimental results of the water meter employing the impeller of the present invention and the conventional impeller will be described in detail with reference to the embodiments described below.

Example 1

A water meter used in conjunction with a 13 mm diameter water pipe was selected as a model, and the flow rate of the fluid passing through the water meter was measured.

Measuring method is to pass the fluid corresponding to the convection flow rate (Qn) through the water meter to measure the indication amount by the water meter, and at the same time measure the actual flow rate passing through the water meter using a flow meter (Flow Meter) Then we adjusted the train (error). At this time, the train

Adjusted according to the formula. Here, WM is an indication amount of the water meter, that is, a measurement amount of the water meter, FM is a measurement amount of the flow meter, that is, a flow rate passing through the actual water pipe, and the unit of the flow rate is l / h. In addition, the experiments for passing a flow rate other than the convection flow rate (maximum flow rate, standard flow rate, transition flow rate, minimum flow rate, etc.) were based on a train adjusted according to Equation 1 above. The train between the meter reading and the meter reading was calculated.

The calculation result of the train for the impeller of the present invention is shown in Table 1 below, Table 2 shows the calculation result of the train for a conventional impeller.

The maximum flow rate (Qmax) is the flow rate through the water meter during the test under the condition that the pressure difference (loss pressure of the water meter) at the inlet and outlet according to KS regulations is 1 (kgf / cm ² ), and the standard flow rate (Qn) Is the flow rate through the water meter in the test with the pressure difference (loss pressure of water meter) of inlet and outlet in accordance with KS regulation 0.5 (kgf / cm ² ).

Therefore, according to KS 5301 Class 1 standard, the maximum flow rate (Qmax) is specified as 3000 (l / h) and the standard flow rate (Qn) as 2000 (l / h) for water meters used for 13 mm diameter water pipes. The convection flow rate (0.5Qn) is defined as 1000 (l / h). The transition flow rate Qt is also defined as 0.06 times the standard flow rate, i.e. 120 (l / h), and the minimum flow rate Qmin is defined as 0.01 times the standard flow rate, i.e. 20 (l / h).

As shown in Table 2, in the water meter to which the conventional impeller is applied, 0.7 (%) and 0.5 (%) of trains were generated at the maximum flow rate and the standard flow rate, respectively, and 0.3 (at the convection flow rate, the transition flow rate, and the minimum flow rate, respectively). %) And 0.5 (%) and -0.3 (%) trains.

In addition, as shown in Table 1, in the water meter to which the impeller with the tangential blade of the present invention is applied, trains of 0.4 (%) and 0.4 (%) were generated at the maximum flow rate and the standard flow rate, respectively, and the convection flow rate and the transition flow rate. And trains of 0.3 (%), 0.4 (%) and 0.9 (%) occurred at minimum flow rates, respectively.

As can be seen from the above results, the generation of trains in the water meter to which the impeller of the present invention is applied is significantly reduced in general, regardless of the flow rate of the conventional impeller. Therefore, the final result of this experiment can be seen to further improve the flow rate measurement.

By tangentially changing the blade of the impeller, the angle of injection of the fluid with the blade of the impeller can be maintained at a right angle, and at the same time, the blade of the impeller can receive the action of the fluid in a position close to the outlet of the fluid injection nozzle. . Accordingly, the momentum of the fluid can be efficiently transmitted to the blade of the impeller. Therefore, the torsional momentum (Torque) for the same force can be maximized, so that the water meter can be more precisely measured.

Claims (1)

A water meter having an impeller, wherein the plurality of blades formed in the impeller extend in a tangential direction from a circumference of the central axis of the impeller.