Patent Description:
Dual-conduit Coriolis mass flowmeters operate by detecting the motion of a pair of vibrating conduits, or flow tubes, that contain a flowing material. Properties associated with the material in the conduit, such as mass flow, density and the like, can be determined by processing measurement signals received from pickoffs, or motion transducers, associated with the conduit.

Vibratory meters can include assemblies with straight or curved conduits. As material begins to flow through the conduits, Coriolis forces cause each point along the conduits to have a different phase. For example, the phase at the inlet end of the flowmeter lags the phase at the centralized driver position, while the phase at the outlet leads the phase at the centralized driver position. Pickoffs on the conduits produce sinusoidal signals representative of the motion of the conduits. Signals output from the pickoffs are processed to determine the time delay between the pickoffs. The time delay between the two or more pickoffs is proportional to the mass flow rate of material flowing through the conduits.

A meter electronics connected to the driver generates a drive signal to operate the driver, and to determine a mass flow rate and/or other properties of a process material from signals received from the pickoffs. The driver may comprise any one of many well-known arrangements; however, a magnet and an opposing drive coil are one of the most common formats. An alternating current is passed to the drive coil for vibrating the conduits at a desired conduit amplitude and frequency. The pickoffs often also comprise a magnet and coil arrangement, similar to the driver.

A dual-conduit Coriolis sensor splits the flow stream into two paths at an inlet manifold, providing one stream for each respective conduit, and then rejoins the stream at a second manifold before the outlet of the sensor. The convergence of the two flow paths at the second manifold before the outlet often occurs in a larger transition volume that matches the diameter of a process pipeline. When the two flow paths rejoin, they flow over a manifold splitter, the trailing edge of the manifold. Especially in the cases when a flow of a gas is being measured, the flow over the splitter can produce vortex shedding in the fluid flow. Vortex shedding is an oscillating flow that takes place when a fluid such as air or water flows past a blunt body at certain velocities, depending on the size and shape of the body. The vortex shedding may further result in vibrations and unwanted audible noise.

Accordingly, there is a need for a manifold for a Coriolis flow meter with reduced vortex shedding and acoustical noise.

Patent Document <CIT> describes a Coriolis flow meter comprising a manifold according to the prior art.

According to a first aspect, a manifold with reduced vortex shedding is provided in accordance with claim <NUM>.

The manifold comprises a first conduit section, a second conduit section, a splitter section, positioned between the first conduit section and the second conduit section, the splitter section including a first splitter face facing the first conduit section, and a first protrusion at least a portion of which is positioned on the first splitter face.

According to a second aspect, a method for manufacturing a manifold with reduced vortex shedding is provided in accordance with claim <NUM>.

The method comprises forming a first conduit section, forming a second conduit section, forming a splitter section positioned between the first conduit section and the second conduit section, the splitter section including a first splitter face facing the first conduit section, and forming a first protrusion at least a portion of which is positioned on the first splitter face.

In a further aspect, the first protrusion may have a round shape.

In a further aspect, the first protrusion may have an elongated shape.

In a further aspect, the first protrusion may comprise a depressed region.

In a further aspect, the first protrusion may extend beyond a lip of the splitter section.

In a further aspect, the splitter section may further comprise a second splitter face facing the second conduit section, and the manifold may further comprise a second protrusion, at least a portion of which is positioned on the second splitter face.

In a further aspect, the first protrusion may be a first size and the second protrusion may be a second size.

In a further aspect, the first protrusion may be a first shape and the second protrusion may be a second shape.

In a further aspect, the manifold may further comprise at least one additional protrusion positioned on at least one of the first splitter face or the second splitter face.

In a further aspect, a vibratory meter with a manifold according to the first aspect is provided. The vibratory meter may further comprise a first conduit, a second conduit, a pickoff coupled to at least one of the first conduit or the second conduit, and a driver coupled to at least one of the first conduit or the second conduit.

In a further aspect, the first protrusion may comprise a round shape.

In a further aspect, the splitter section may further comprise a second splitter face facing the second conduit section, and the method may further comprise forming a second protrusion positioned on the second splitter face.

In a further aspect, a method for manufacturing a vibratory meter comprising a manifold manufactured according to the second aspect is provided. The method may further comprise coupling the first conduit section of the manifold to a first conduit, coupling the second conduit section of the manifold to a second conduit, coupling a pickoff to at least one of the first conduit or the second conduit, and coupling a driver to at least one of the first conduit or the second conduit, the driver being configured to vibrate the first conduit and the second conduit.

The present Application describes a manifold with reduced vortex shedding, a vibratory meter including said manifold, and methods of manufacturing both the manifold and the vibratory meter.

<FIG> depicts a vibratory meter <NUM> with a manifold <NUM> in accordance with an example. As shown in <FIG>, the vibratory meter <NUM> comprises a meter assembly <NUM> and meter electronics <NUM>. The meter assembly <NUM> responds to the mass flow rate and density of a process material. The meter electronics <NUM> is connected to the meter assembly <NUM> via leads <NUM> to provide density, mass flow rate, and temperature information over communications path <NUM>, as well as other information. Information and commands may be further received at meter electronics <NUM> over communications path <NUM>.

A Coriolis flow meter structure is described, although this is not intended to be limiting. Those of skill will readily understand that the present Application could be practiced as a vibrating tube densitometer, tuning fork densitometer, or the like.

The meter assembly <NUM> includes a pair of manifolds <NUM> and <NUM>', flanges <NUM> and <NUM>', a pair of parallel first and second conduits <NUM> and <NUM>', driver <NUM>, a pair of pick-off sensors <NUM> and 170r, and a case <NUM>.

The first and second conduits <NUM>, <NUM>' bend at two symmetrical locations along their length and are essentially parallel throughout their length. Brace bars <NUM> and <NUM>' serve to define the axis (not visible) about which each first and second conduit <NUM>, <NUM>' oscillates. The legs of the first and second conduits <NUM>, <NUM>' are fixedly attached to manifolds <NUM> and <NUM>'. This provides a continuous closed material path through meter assembly <NUM>.

When flanges <NUM> and <NUM>' are connected to a process line (not shown) carrying the process material, material enters an inlet end <NUM> of the meter through an orifice in the flange <NUM> and is conducted through the manifold <NUM>. Within the manifold <NUM>, the material is divided and routed through the first and second conduits <NUM>, <NUM>'. Upon exiting the first and second conduits <NUM>, <NUM>', the process material is recombined in a single stream in the manifold <NUM>' and is thereafter routed to outlet end <NUM>' back to the process line (not shown).

A case <NUM> encloses at least a portion of the conduits <NUM>, <NUM>', the driver <NUM>, and the pick-offs <NUM>, 170r. Manifolds <NUM> and <NUM>' may be coupled to the case <NUM>.

The first and second conduits <NUM>, <NUM>' are selected to have substantially the same mass distribution, moments of inertia and Young's modulus about their bending axes, which are defined by the brace bars <NUM>, <NUM>'.

Both first and second conduits <NUM>, <NUM>' are driven by driver <NUM> in opposite directions about their respective bending axes and at what is termed the first out-of-phase bending mode of the flow meter. This driver <NUM> may comprise, for example, a magnet mounted to the first conduit <NUM>' and an opposing coil mounted to the second conduit <NUM>. An alternating current is passed through the coil to vibrate both the first and second conduits <NUM>, <NUM>'. A suitable drive signal is applied by the meter electronics <NUM>, via lead <NUM>, to the driver <NUM>.

The meter electronics <NUM> receives the left and right pickoff signals appearing on leads <NUM>, 165r, respectively. The meter electronics <NUM> provides a signal via lead <NUM> to vibrate first and second conduits <NUM>, <NUM>' via driver <NUM>. The left and right pickoff <NUM>, 170r signals are used by the meter electronics <NUM> to compute the mass flow rate and/or the density of the material passing through meter assembly <NUM>. This information, along with other information, may be transmitted by meter electronics <NUM> over communications path <NUM>.

While <FIG> depicts a single meter assembly <NUM> in communication with meter electronics <NUM>, those skilled in the art will readily appreciate that multiple sensor assemblies may be in communication with meter electronics <NUM>. Further, meter electronics <NUM> may be capable of operating a variety of different sensor types. Each sensor assembly, such as the meter assembly <NUM> in communication with meter electronics <NUM>, may have a dedicated section of a storage system within meter electronics <NUM>.

Meter electronics <NUM> may include various other components and functions, as will be understood by those of skill. These additional features may be omitted from the description and the figures for brevity and clarity.

<FIG> and <FIG> depict a manifold <NUM> according to prior methods, with <FIG> depicting a perspective view, and <FIG> depicting a cutaway view. As may be seen, manifold <NUM> includes a first conduit section <NUM>, a second conduit section <NUM>, a splitter section <NUM> between the first and second conduit sections <NUM>, <NUM>, and a combined flow section <NUM>. The first and second conduit sections <NUM> and <NUM> may each be coupled to a respective conduit <NUM>, <NUM>'. The combined flow section <NUM> is fluidly coupled to the first conduit section <NUM> and the second conduit section <NUM>.

Prior manifold splitter section <NUM> provides a smooth transition between the first and second conduit sections <NUM>, <NUM> and the combined flow section <NUM>. Prior splitter section <NUM> includes a lip <NUM> between the first and second conduit sections <NUM> and <NUM> with an edge radius and thickness that is uniform across the length of the splitter. The blunt edge of lip <NUM> may result in vortex shedding and flow noise, especially when manifold <NUM> is installed in a gas pipeline.

<FIG> depicts a cutaway view of manifold <NUM> according to an example of the Application. Manifold <NUM> also includes the first conduit section <NUM>, the second conduit section <NUM>, and the combined flow section <NUM>. Manifold <NUM> differs from manifold <NUM>, however, because it includes splitter section <NUM>, positioned between the first conduit section <NUM> and the second conduit section <NUM>. Splitter section <NUM> includes lip <NUM>.

Splitter section <NUM> includes a first splitter face 408a facing the first conduit section <NUM>. First splitter face 408a is a surface positioned on the first conduit section <NUM> side of the lip <NUM>. In examples, first splitter face 408a may comprise a cross section of a saddle-shaped surface. In further examples, first splitter face 408a may comprise a cross section of a cone, planar, or any other shape known to those of skill.

Manifold <NUM> further includes a first protrusion 412a, at least a portion of which is positioned on the first splitter face 408a. First protrusion 412a may help disturb or break up the flow of fluid at the splitter section <NUM>, providing for the separation of fluid into streams that produce fewer coherent vortices.

In examples, first protrusion 412a may comprise a round shape. For example depicted in <FIG> and <FIG>, first protrusion 412a comprises a cross-section of a sphere.

In examples, manifold <NUM> may be positioned at outlet end <NUM>' of meter assembly <NUM>. In further examples, manifold <NUM> may alternatively be positioned at other points in the process path where two flow paths join into a single flow path, such as a downstream edge of a Y-fitting where two flow paths converge. In further examples, however, manifold <NUM> may be positioned at inlet end <NUM>. Other positions for manifold <NUM> are also possible, as will be understood by those of skill.

In examples, as may be seen in <FIG>, the splitter section <NUM> of the manifold <NUM> may further comprise a second splitter face 408b facing the second conduit section <NUM>, and a second protrusion 412b positioned on the second splitter 408b face. Like first protrusion 412a, second protrusion 412b may also be round. In further embodiments, however, second protrusion 412b may be any shape operable to disturb the flow of fluid at splitter section <NUM>.

In examples, first and second protrusions 412a, 412b may be the same shape, or different shapes. In further examples, first and second protrusions 412a, 412b may be the same size or different sizes. By providing two different shapes or sizes of protrusion, it may be possible to further disrupt the flow of fluid over splitter section <NUM>.

In further examples, first protrusion 412a may be square, oval, irregular, or any other shape. For example, <FIG> depicts a perspective view of manifold <NUM>. Manifold <NUM> includes splitter section <NUM> and lip <NUM>. Splitter section <NUM> includes a first protrusion 612a, at least a portion of which is positioned on first splitter face 608a. The first protrusion 612a includes an elongated shape that is positioned so that the longest dimension is substantially parallel to the lip <NUM>. By providing an elongated first protrusion 612a, manifold <NUM> may further help disturb the flow of fluid over the splitter section <NUM>.

In examples, the first protrusion 612a may include a first depressed region 614a. The depressed region 614a may further help to reduce the formation of streams with the potential to produce coherent vortices in manifold <NUM>.

In examples, manifold <NUM> may further include a second protrusion 612b positioned on a second splitter face 608b. The second protrusion 612b may include a second depressed region 614b, also operable to reduce the formation of coherent vortices. In examples, the first and second protrusions 614a and 614b may form a saddle-shaped feature on splitter section <NUM>, as depicted in <FIG>.

<FIG> further depicts example manifold <NUM>, including a splitter section <NUM>. The splitter section <NUM> includes a first protrusion <NUM> positioned on a first splitter face <NUM>. The first protrusion <NUM> extends beyond a lip <NUM>, in the direction of the combined flow section <NUM>. Because first protrusion <NUM> extends beyond lip <NUM>, it may help disturb the flow of fluid on both sides of the splitter section <NUM>. In examples, manifold <NUM> may further include a second protrusion (not pictured).

While examples of one or two protrusions have been provided, those of skill will readily understand that manifold <NUM>, <NUM>, or <NUM> may comprise three, or any greater number of protrusions.

<FIG> depicts method <NUM>, which may be performed to manufacture a manifold with reduced vortex shedding.

Method <NUM> begins with steps <NUM> and <NUM>. In step <NUM>, a first conduit section <NUM> is formed, and in step <NUM>, a second conduit section <NUM> is formed.

Method <NUM> continues with step <NUM>. In step <NUM>, a splitter section <NUM>, <NUM>, <NUM> is formed, positioned between the first conduit section <NUM> and the second conduit section <NUM>, the splitter section <NUM>, <NUM>, <NUM> including a first splitter face 408a, 608a facing the first conduit section <NUM>.

Method <NUM> continues with step <NUM>. In step <NUM>, a first protrusion 412a, 612a, <NUM> is formed, positioned on the first splitter face 408a, 608a.

In examples, method <NUM> may further include step <NUM>. In step <NUM>, a second protrusion 412b, 612b may be formed, positioned on the second splitter face 408b, 608b.

In examples, any of first or second conduit sections <NUM>, <NUM>, splitter section <NUM>, <NUM>, <NUM>, first protrusion 412a, 612a, <NUM>, or second protrusion 412b, 612b may be formed by machining, casting, welding, three-dimensional printing, or any other manufacturing technique known to those of skill. In examples, manifold <NUM>, <NUM>, <NUM> may be formed as a single, integrated body, or any portion of first or second conduit sections <NUM>, <NUM>, splitter section <NUM>, <NUM>, <NUM>, first protrusion 412a, 612a, <NUM>, or second protrusion 412b, 612b may be formed separately and coupled together via welding, brazing, gluing, and so forth, to form manifold <NUM>, <NUM>, <NUM>.

<FIG> depicts method <NUM>, which may be executed to manufacture a vibratory meter comprising a manifold with reduced vortex shedding according to any of the steps of method <NUM>.

Method <NUM> begins with steps <NUM> and <NUM>. In step <NUM>, the first conduit section of the manifold is coupled to a first conduit. In step <NUM>, the second conduit section of the manifold is coupled to a second conduit. For example, first conduit section <NUM> may be coupled to first conduit <NUM>, and second conduit section <NUM> may be coupled to first conduit <NUM>. In examples, first or second conduits <NUM>, <NUM>' may be coupled to manifold <NUM>, <NUM>, <NUM> via welding, brazing, or gluing, as will be understood by those of skill.

Method <NUM> continues with step <NUM>. In step <NUM>, a pickoff is coupled to at least one of the first conduit <NUM> or the second conduit <NUM>'. For example, left and right pickoffs <NUM>, 170r may each be welded, brazed, glued, or otherwise attached to a respective first conduit <NUM> or second conduit <NUM>'.

Method <NUM> continues with step <NUM>. In step <NUM>, a driver <NUM> is coupled to at least one of the first conduit <NUM> or the second conduit <NUM>', the driver <NUM> being configured to vibrate the first conduit <NUM> and the second conduit <NUM>'. For example, the driver <NUM> may be welded, brazed, glued, or otherwise attached to the first conduit <NUM> and/or the second conduit <NUM>'.

The manifold, vibratory meter, and methods to manufacture both described herein may help reduce vortex shedding, thereby reducing audible noise and vibrations caused by fluid flow in a Coriolis flow meter.

Claim 1:
A manifold (<NUM>, <NUM>, <NUM>) for reduced vortex shedding, the manifold (<NUM>, <NUM>, <NUM>) comprising:
a first conduit section (<NUM>);
a second conduit section (<NUM>);
a splitter section (<NUM>, <NUM>, <NUM>) positioned between the first conduit section (<NUM>) and the second conduit section (<NUM>), the splitter section (<NUM>, <NUM>, <NUM>) including a first splitter face (408a, 608a, <NUM>) facing the first conduit section (<NUM>);
and being characterised in that it further comprises:
a first protrusion (412a, 612a, <NUM>), at least a portion of which is positioned on the first splitter face (408a, 608a, <NUM>), wherein the first protrusion (412a, 612a, <NUM>) disturbs or breaks up a flow at the splitter section, providing for the separation of fluid into streams that produce fewer coherent vortices.