WO2013081440A1

WO2013081440A1 - Turbine type flow metering device

Info

Publication number: WO2013081440A1
Application number: PCT/MY2011/000238
Authority: WO
Inventors: Hamdan OTHMAN
Original assignee: Prestasi Teknologi Sdn. Bhd.
Priority date: 2011-11-30
Filing date: 2011-11-30
Publication date: 2013-06-06

Abstract

The present invention relates to an improved turbine type flow metering device (10) for 5 measuring the flow of fluid from a source. The improved turbine type flow metering device (10) includes: a) a body (30) having an inlet port (32) and an outlet port (34), wherein the body (30) is aerodynamically shaped to reduce any cavitations or "bubble effect" within the body (30); b) a turbine assembly (50) housed within the body (30), wherein the turbine assembly (50) includes: i) a rotor chamber (51) plurality of 10 substantially nozzle shape inlet-ports (51a) which is adapted to create high velocity flows or "nozzle effect" within the chamber; ii) a rotor (52) having a series of radially projecting propeller blades (52a), wherein the propeller blades (52a) are of hyperbolic or twisted helical shape; iii) a rotary shaft (54) in communication with the rotor (52); iv) a nose cone (56) provided at turbine inlet projected from the rotor (52); v) a cover plate 15 (58) mated with the rotor chamber (51) to complete the turbine assembly (50); and c) a register (70) in communication with a rotor (52) through a rotary shaft (54).

Description

TURBINE TYPE FLOW METERING DEVICE

FIELD OF INVENTION The present invention relates to a flow metering device and more particularly to an improved turbine type flow metering device for measuring fluid flow.

BACKGROUND OF INVENTION Flow meters are usually used to measure the flow of fluids by converting kinetic energy of the flowing fluid to rotational blades. The volume of fluids which is taken from a source is usually supplied to the users by way of service pipe lines. In many developed countries, water meters are used at each residential and commercial building in a public water supply system. There are different types of water meter in the market and the selection of which are usually based on different flow measurement methods, required flow rates, type of end user as well as the accuracy requirements for selected application.

Generally, there are two basic types of water meter, i.e. positive displacement and velocity water meters. Each of these meters has variations, leading to several different kinds. The water meter which includes features of both positive displacement and velocity is known as compound meter. Unit measurement of the water meters is usually displayed in cubic meter (m³), cubic feet (ft³) or in US gallon depending on the usage of each individual country.

The positive displacement water meters, sometimes referred to as PD meters, are normally use for domestic or small-scale commercial water consumption measurement. The PD meters typically operate by repeating filling and emptying compartments by volume of liquid moves with the flow of water. The flow rate is calculated based on the number of times the compartments are filled and emptied. For example, a typical rotary piston meter, which is usually used for domestic water consumption measurement, is generally provided with a positive displacement moves with the water flow. Accordingly, the meter is provided with a chamber in which the chamber obstructing the flow is a rotary piston (FIG.1 a). The rotary piston oscillates in a circular chamber by a known volume of liquid moves with the water flow. The flow of water is measured for each rotation, and the motion is transmitted to a register through an arrangement gearing assembly.

The PD meter is sensitive to low flow to moderate flow rates and has high accuracy over a wide range of flow rates of typical residential and small commercial users. However, it has minimal "leakage" across the measuring chamber and therefore the meter requires clean water for accurate and efficient measurement. Because the PD meter sorely rely on the water flowing through the meter to urge the measuring element, it is generally not practical for the measurement of high flow rates in large commercial applications.

In addition, built-in strainer is usually required in the PD meter to protect the rotary piston and measuring element from particles or other debris trap in the chamber. The particles such as sand or rocks trapped in the chamber may eventually result in blockage of the rotary piston or breakage to the measuring element (FIG.1 b).

The velocity water meters on the other hand are excellent for high flow applications. The velocity water meters generally operate on the principle that the water passing through a known cross-sectional area with a measured velocity which can be equated into a volume of flow. The speed of the flow can then be converted into volume of flow for usage. There are several types of velocity meters for measuring the velocity of flow in determining the total usage. Typical velocity water meters include sinlge- or multi- jet meters, turbine meters, propeller meters and magnetic flow meters. These velocity water meters are responsive to high flow rates and have high accuracy over a wide range of flow rates of typical industrial and large-scale commercial users. However, the velocity water meters tend to under-registration at low flows. As such, any erroneous readings by the register may lead to significant loss of revenue to the water provider.

In view of these and other shortcomings of the prior art there is a need in the art for an improved flow metering device to provide an effective and accurate measurement over a wide flow range. Accordingly, it is an object of the present invention to provide an improved turbine type flow metering device which is simple, low-cost in construction and reliable to use, and yet adapted for use in low flow measurement with higher accuracy and repeatability. Moreover, the improved turbine type flow metering device adapted to prevent any erroneous readings of low flow rate, and thus eliminate significantly loss of revenue. These and other advantages of the invention as well as novel features will be apparent from the details description of the invention provided herein.

SUMMARY OF THE INVENTION

Accordingly, there is provided an improved turbine type flow metering device for measuring the flow of fluid from a source. The improved turbine type flow metering device includes: a) a body having an inlet port and an outlet port, wherein the body is aerodynamically shaped to reduce any cavitations or "bubble effect" within the body; b) a turbine assembly housed within the body, wherein the turbine assembly includes: i) a rotor chamber plurality of substantially nozzle shape inlet-ports which is adapted to create high velocity flows or "nozzle effect" within the chamber; ii) a rotor having a series of radially projecting propeller blades, wherein the propeller blades are of hyperbolic or twisted helical shape; iii) a rotary shaft in communication with the rotor; iv) a nose cone provided at turbine inlet projected from the rotor; v) a cover plate mated with the rotor chamber to complete the turbine assembly; and c) a register in communication with a rotor through a rotary shaft.

Preferably, the body is configured and shaped to follow contour of the nose cone of the turbine assembly.

In the preferred embodiment, the high velocity flows or "nozzle effect" created by the nozzle shape inlet-ports permits flow metering device to start registering at low flow rates. Accordingly, the high velocity flows or "nozzle effect" ensures a proper rotation of propeller blades in response to low flow water delivered from the inlet port. The nozzle shape inlet-ports rotor chamber is a rip adapted to act as a flow-strainghtener, giving straight-through flow path needed for high flow rates used in larger pipe diameters. It will be appreciated that the improved turbine type flow metering device further provided with a specific internal strainer element which serves to protect the nozzle shape inlet-ports from clogged, and to prevent swirling flows in the chamber. In accordance with the preferred embodiments, the propeller blades of the rotor are sufficiently twisted to insure a proper rotation of rotor in response to water delivered from the inlet port at low flow rates. The rotor and nose cone are securely mounted to the rotary shaft housed in between the rotor chamber and cover plate. Preferably, the rotor and rotary shaft are made of materials having a density substantially equal to or less than the density of water so as to provide frictionally free and hydro-dynamically balanced lifting buoyancy characteristics. Accordingly, the rotor is securely mounted to the rotary shaft which is suspendably coupled to a cover plate through a bearing assembly. It will be appreciated that the nose cone serves to restrict the flow path and to direct the flow entering into the nozzle shape inlet-ports at high velocity. The nozzle shape inlet- ports further boost the flow at higher velocity, enabling the flow metering device starts registering in the event that water delivered from the inlet port at low flow rates. Preferably, the improved turbine type flow metering device further provided with a nonreturn valve at the outlet port. The non-return valve operates to prevent back-flow from the outlet port.

In the preferred embodiments, the register can be any metering counter with an analog or digital display to indicate and record the volume of water that passes through the turbine assembly. The register is in communication with the rotor through a rotary shaft by appropriate gearing. Accordingly, the gearing include predetermined gear ratio to transmit rotational movement the rotary shaft to the register.

The present invention consists of several novel features and a combination of parts hereinafter fully described and illustrated in the accompanying description and drawings, it being understood that various changes in the details may be made without departing from the scope of the invention or sacrificing any of the advantages of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, wherein:

FIG. 1 a (Prior Art) illustrates general working principle of a typical positive displacement or semi-rotary piston water meter; FIG. 1 b (Prior Art) illustrates a common problem encountered by the positive displacement or semi-rotary piston water meter, wherein particles or debris are usually trap in a chamber, resulting in blockage of rotary piston or breakage to measuring element in the displacement meter; FIG. 2a illustrates a perspective view of an improved turbine type flow metering device in accordance with preferred embodiment of present invention;

FIG. 2b is a cross-sectional assembled view of the improved turbine type flow metering device of FIG. 2a;

FIG. 3a illustrates a side view of a rotor with propeller blades of hyperbolic shape design;

FIGS. 3b - 3c illustrate flow paths of the fluid passing through a rotor chamber in associate with a hydo-dynamically balanced rotor; FIG. 4 is an exploded perspective view of the improved turbine type flow metering device in accordance with preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to a flow metering device and more particularly to an improved turbine type flow metering device for measuring fluid flow. Hereinafter, this specification will describe the present invention according to the preferred embodiments of the present invention. However, it is to be understood that limiting the description to the preferred embodiments of the invention is merely to facilitate discussion of the present invention and it is envisioned that those skilled in the art may devise various modifications and equivalents without departing from the scope of the appended claims.

In accordance with the preferred embodiment of present invention, a newly high performance and small turbine type flow metering device is provided. The improved turbine type flow metering device has several characteristics that provide an excellent performance for various applications.

Accordingly, the improved turbine type flow metering device is very compact and lightweight compared to various other common type water flow meters. The improved turbine type flow metering device is suitable for use in domestic and small-scale commercial water consumption applications. In the preferred embodiments, the improved turbine type flow metering device adapted to provide an effective and accurate flow measurement over a wide flow range and it covers all possible flow rates from high flow to low flow measurements. With a high accuracy and good repeatability, the improved turbine type flow metering device is advantageous for use in residential or domestic applications. Any under-registration at low flows can be eliminated to avoid significant loss of revenue. In addition, the present invention also provides flow metering device which is simple, low-cost in construction, reliable to use and yet low maintenance cost. The foregoing characteristics of the improved turbine type flow metering device are achieved by various novel improvements to the flow metering device, and will be described herebelow.

In accordance with preferred embodiments of the present invention, various improvements have been made to the flow metering device. Accordingly, the improved turbine type flow metering device having a body which is aerodynamically shaped. The body generally includes a body front and body back, wherein the body is desirably configured and shaped to follow contour of a nose cone of a turbine assembly to reduce any cavitations at high flow.

The improvements also include an introduction to a unique flow profile by having a rotor chamber with plurality of substantially nozzle shape inlet-ports so as to create high velocity flows therewithin to ensure a proper rotation of propeller blades in response to low flow water delivered from inlet port. Thus, flow metering device to start registering at low flow rates.

The improvements also made to propeller blades of a rotor wherein propeller blades are of substantially hyperbolic shape. The hyperbolic shape of the propeller blades adapted to reduce the retarding forces i.e. drag due to secondary flow generated at blades tip as well as mechanical friction. The improvements also made to rotor and rotary shaft of the improved turbine type flow metering device, wherein the rotor and rotary shaft are desirably having a density substantially equal to or less than the density of water so as to provide frictionally free and hydro-dynamically balanced lifting buoyancy characteristics. The improved turbine type flow metering device according to the preferred embodiments of the present invention will now be described in more details in accordance to the accompanying drawings FIGS. 2a to 4, both individually and in any combination thereof. The improved turbine type flow metering device (10) generally includes a body (30), a turbine assembly (50) housed within the body (30), and a register (70) in communication with a rotor (52) through a rotary shaft (54).

In the preferred embodiments, the body (30) is of aerodynamically shaped, having an inlet port (32) to be connected to a water service pine line that communicates with a source of water from a local provider utility, and an outlet port (34) to be connected to a water pipe of an end user. If will be appreciated that the inlet port (32) and outlet port (34) of the body (30) may provided with protective cap (80, 90) to prevent any dirt, debris, insect and etc into the metering device (10) prior to packing or installation. The body (30) generally includes a body front (36) and body back (38) securely coupled one to another. A rubber O-ring (37) is provided in between body front (36) and body back (38) coupling so as to provide water seal fitting. In is to be noted that, the body front (36) is desirably configured and shaped follow contour of a nose cone (56) of the turbine assembly (50) so as to reduce any cavitations or "bubble effect" at high flow. The body (30) of the improved turbine type flow metering device (10) is preferably made of, but not limited to a light weight, robust reinforced plastic materials. It will be appreciated that the improved turbine type flow metering device (10) can be installed at any desired position of supply pipe line. Located within the body (30) between the body front (36) and body back (38) of the improved turbine type metering device (10) is a turbine assembly (50). In the preferred embodiments, the turbine assembly (50) collectively includes a rotor chamber (51 ), a rotor (52) accommodated within the rotor chamber (51 ), a rotary shaft (54), and a nose cone (56).

The rotor chamber (51 ) is provided with plurality of substantially nozzle shape inlet-ports (51 a), wherein the nozzle shape inlet-ports (51 a) is adapted to create high velocity flows or "nozzle effect" within the chamber. The high velocity flows or "nozzle effect" enables the flow metering device to start registering at low flow rates. In particular, said high velocity flows or "nozzle effect" ensures a proper rotation of propeller blades (52a) in response to low flow water delivered from the inlet port (32). As such, it eliminates any under-registration of the flow metering device at low flow rates. In is to be noted that, the improved turbine type flow metering device (10) can be very accurate at low flow rates due to the high velocity flows or "nozzle effect" created by the nozzle shape inlet-ports (51 a). The improved turbine type flow metering device (10) can also be used in larger scale applications since each rip at the nozzle shape inlet-ports (51 a) adapted to act as a f low-strainghtener, giving straight-through flow path needed for high flow rates used in larger pipe diameters. Preferably, the improved turbine type flow metering device (10) further provided with a specific internal strainer element (75) which serves to protect the nozzle shape inlet-ports (51 a) from clogged, and to prevent swirling flows in the chamber.

In the preferred embodiments, the rotor (52) having a series of radially projecting propeller blades (52a). Accordingly, the propeller blades (52a) of the rotor (52) are of substantially hyperbolic or twisted helical shape. The principle of the propeller blades (52a) to be specifically shaped hyperbolic is that to reduce any retarding forces, i.e. drag due to secondary flow generated at blades tip and mechanical friction. It will be appreciated that the propeller blades (52a) are sufficiently twisted to insure a proper rotation of rotor (52) in response to water delivered from the inlet port (32) at low flow rates.

The rotor (52) is securely mounted to the rotary shaft (54) which is suspendably coupled to a cover plate (58) through a bearing assembly (60). The bearing assembly (60) general includes a drive coupling (62) in associated with a guide bush (64) mounted at the cover plate (58). The rotor (52) and rotary shaft (54) are desirably made of, but not limited to plastic materials having a density substantially equal to or less than the density of water so as to provide frictionally free and hydro-dynamically balanced lifting buoyancy characteristics.

In the preferred embodiments, a nose cone (56) is preferably provided at turbine inlet. Accordingly, the nose cone (56) is centrally coupled to one end of the rotary shaft (54) projected from the rotor (52). A bush (55) is preferably provided in between the nose cone (56) and rotor (52) to ensure sufficient clearance therebetween. The purpose of the nose cone (56) is to restrict the flow path and to direct the flow entering into the nozzle shape inlet-ports (51 a) at high velocity (FIG. 3b). Increasing the velocity of the flow entering the rotor chamber is critical to turbines performance as the kinetic energy also increases proportionally. Moreover, the rotor chamber (51 ) with nozzle shape inlet- ports (51 a) further boost the flow at higher velocity, enabling the flow metering device starts registering in the event that water delivered from the inlet port (32) at low flow rates. It is to be noted that the appropriate shape design of the body front (36) and body back (38) in relation with the nose cone (56) of the turbine assembly (50) is also one of the aspect to be considered to form a hydro-dynamically balanced rotor (FIG. 3c).

The rotor chamber (51 ) is mated to the cover plate (58) to complete the turbine assembly (50). Accordingly, the rotor (52) and nose cone (56) are securely mounted to the rotary shaft (54) housed in between the rotor chamber (51 ) and cover plate (58). A non-return valve (65) is preferably provided at the outlet port (34) of the improved turbine type flow metering device (10). The non-return valve (65) operates to prevent back-flow or opposite flow from the outlet port (34). The non-return valve (65) also serves to prevent any turbulent flow within the body back (38) which may affect the reading of the register (70). The non-return valve (65) also prevents any illegal usage or abuse of the device.

The register (70) can be any conventional metering counter with an analog or digital display (71 ) to indicate and record the volume of water that passes through the turbine assembly (50) within the body (30) of the improved turbine type flow metering device (10). In the preferred embodiments, the register (70) is in communication with a rotor (52) through a rotary shaft (54) by appropriate gearing (72). The principle operation of the improved turbine type flow metering device (10) is that the flow velocity of the water passing through spacing of the propeller blades (52a) caused rotor (52) to spin in proportion to the volume flow rate. The rotational movement is transmitted to the register (70) by the gearing (72) with predetermined gear ratio through the rotary shaft (54).

The invention being thus described, it will be obvious that the same may be varied in many ways. It is to be understood that the present invention may be embodied in other specific forms and it is not limited to the sole embodiments described above. However, modification and equivalents of disclosed concepts such as those which readily occur to one skilled in the art are intended to be included within the scope of the claims which are appended thereto.

Claims

1 . An improved turbine type flow metering device (10) to measure the flow of fluid from a source, the improved turbine type flow metering device (10) includes: a) a body (30) having an inlet port (32) and an outlet port (34), wherein the body (30) is aerodynamically shaped to reduce any cavitations or "bubble effect" within the body (30);

b) a turbine assembly (50) housed within the body (30), wherein the turbine assembly (50) includes:

i) a rotor chamber (51 ) plurality of substantially nozzle shape inlet- ports (51 a) which is adapted to create high velocity flows or "nozzle effect" within the chamber;

ii) a rotor (52) having a series of radially projecting propeller blades (52a), wherein the propeller blades (52a) are of hyperbolic or twisted helical shape;

iii) a rotary shaft (54) in communication with the rotor (52);

iv) a nose cone (56) provided at turbine inlet projected from the rotor (52);

v) a cover plate (58) mated with the rotor chamber (51 ) to complete the turbine assembly (50);

c) a register (70) in communication with a rotor (52) through a rotary shaft (54).

2. An improved turbine type flow metering device (10) according to Claim 1 , wherein the body (30) is configured and shaped to follow contour of the nose cone (56) of the turbine assembly (50).

3. An improved turbine type flow metering device (10) according to Claim 1 , wherein the high velocity flows or "nozzle effect" permits flow metering device to start registering at low flow rates.

An improved turbine type flow metering device (10) accordingly to Claim 3, wherein the high velocity flows or "nozzle effect" ensures a proper rotation of propeller blades (52a) in response to low flow water delivered from the inlet port (32).

An improved turbine type flow metering device (10) according to Claim 1 , wherein the nozzle shape inlet-ports (51 a) is a rip adapted to act as a flow- strainghtener, giving straight-through flow path needed for high flow rates used in larger pipe diameters.

6. An improved turbine type flow metering device (10) according to Claim 1 , wherein the improved turbine type flow metering device (10) further provided with a specific internal strainer element (75) which serves to protect the nozzle shape inlet-ports (51 a) from clogged, and to prevent swirling flows in the chamber.

7. An improved turbine type flow metering device (10) according to Claim 1 , wherein the propeller blades (52a) are sufficiently twisted to insure a proper rotation of rotor (52) in response to water delivered from the inlet port (32) at low flow rates.

8. An improved turbine type flow metering device (10) according to Claim 1 , wherein the rotor (52) and nose cone (56) are securely mounted to the rotary shaft (54) housed in between the rotor chamber (51 ) and cover plate (58).

An improved turbine type flow metering device (10) according to Claim 1 , wherein the rotor (52) and rotary shaft (54) are made of materials having a density substantially equal to or less than the density of water so as to provide frictionally free and hydro-dynamically balanced lifting buoyancy characteristics.

10. An improved turbine type flow metering device (10) according to Claim 1 , wherein the rotor (52) is securely mounted to the rotary shaft (54) which is suspendably coupled to a cover plate (58) through a bearing assembly (60).

1 1. An improved turbine type flow metering device (10) according to Claim 1 , wherein the nose cone (56) serves to restrict the flow path and to direct the flow entering into the nozzle shape inlet-ports (51 a) at high velocity.

12. An improved turbine type flow metering device (10) according to Claim 1 1 , wherein the nozzle shape inlet-ports (51 a) further boost the flow at higher velocity, enabling the flow metering device starts registering in the event that water delivered from the inlet port (32) at low flow rates.

13. An improved turbine type flow metering device (10) according to Claim 1 , wherein the improved turbine type flow metering device (10) further provided with a non-return valve (65) at the outlet port (34).

14. An improved turbine type flow metering device (10) according to Claim 13, wherein the non-return valve (65) operates to prevent back-flow from the outlet port (34).

15. An improved turbine type flow metering device (10) according to Claim 1 , wherein the register (70) is any metering counter with an analog or digital display (71 ) to indicate and record the volume of water that passes through the turbine assembly (50).

16. An improved turbine type flow metering device (10) according to Claim 1 , wherein the register (70) is in communication with the rotor (52) through a rotary shaft (54) by appropriate gearing (72).

17. An improved turbine type flow metering device (10) according to Claim 16, wherein the gearing (72) include predetermined gear ratio to transmit rotational movement the rotary shaft (54) to the register (70).