Patent Description:
Coriolis flow meters may be used to measure flow meter variables, for example mass flow rate, density, and volume flow rate, of a fluid. The fluid may comprise liquids, gases, combined liquids and gases, solids suspended in liquids, and liquids including gases and suspended solids.

<FIG> depicts an example flow meter <NUM>. Flow meter <NUM> comprises a meter assembly <NUM> and a meter electronics <NUM>. Meter assembly <NUM> responds to changes in a fluid flow. Meter electronics <NUM> receives raw data from meter assembly <NUM> via leads <NUM> and determines flow meter variables for the fluid under test, in addition to other information.

Meter assembly <NUM> includes manifold <NUM>, flanges <NUM> and <NUM>', a pair of parallel flow tubes <NUM> and <NUM>', driver <NUM>, and a pair of velocity pick-off sensors <NUM> and 170R. Flow tubes <NUM> and <NUM>' bend at two symmetrical locations along their length and are essentially parallel throughout their length. Brace bars <NUM> and <NUM>' serve to define an axis about which each flow tube oscillates.

When flanges <NUM> and <NUM>' are connected, via inlet end <NUM> and exit end <NUM>' into a process line (not shown) which carries the process material that is being measured, material entering inlet end <NUM> of the meter through flange <NUM> is conducted through manifold <NUM> to flow tube mounting block <NUM>. Within manifold <NUM> the material is divided and routed through flow tubes <NUM> and <NUM>'. Upon exiting flow tubes <NUM> and <NUM>', the process material is recombined in a single stream within manifold <NUM> and is thereafter routed to exit end <NUM>' connected by flange <NUM>' to the process line (not shown).

Both flow tubes <NUM> and <NUM>' are driven by driver <NUM> in opposite directions and at what is termed the first out-of-phase bending mode of the flow meter. This driver <NUM> may comprise any one of many well-known arrangements, such as a magnet mounted to flow tube <NUM>' and an opposing coil mounted to flow tube <NUM> and through which an alternating current is passed for vibrating both flow tubes. A suitable driver voltage is applied by meter electronics <NUM> to driver <NUM>.

Meter electronics <NUM> provides the drive signal to driver <NUM> to vibrate flow tubes <NUM> and <NUM>'. Meter electronics <NUM> receives the left and right velocity signals from velocity pick-off sensors <NUM> and 170R to compute the mass flow rate, volumetric rate, and/or density information for the flow passing through meter assembly <NUM>.

Flow meter <NUM> further comprises a case (not pictured) that protects the vibrating flow tubes. In the example of flow meter <NUM>, the case couples to the flow tube mounting blocks <NUM>, <NUM>'. However, in further embodiments the case may couple to other parts of flow meter <NUM>. For example, the case may couple to any other part of manifold <NUM>, or flanges <NUM>, <NUM>'.

While the example of flow meter <NUM> includes two curved flow tubes, those of skill will understand that other configurations of flow meter <NUM> are possible. For example, flow meter <NUM> may comprise one or any number of flow tubes, in straight or curved flow tube configurations.

Installing flow meter <NUM> by attaching flanges <NUM>, <NUM>' to a process line can apply clamping forces in the axial direction to the flow tubes. Flow tubes <NUM>, <NUM>' are sensitive to axial stress, which can change the natural frequency of the flow tubes <NUM>, <NUM>'. Changing the natural frequency of flow tubes <NUM>, <NUM>' can interfere with flow meter <NUM> measurements, creating errors in the flow meter data.

In prior embodiments, spacing between the inlet and outlet of a Coriolis flow meter was often maintained by positioning a spacer between manifolds as necessary. For example, <FIG> depicts flow meter 200A. Flow meter 200A includes a case <NUM>, within which the flow tubes (not pictured) are positioned. A stainless-steel spacer <NUM> is positioned between flanges <NUM>, <NUM>' to maintain the spacing of the flanges, thereby preventing clamping forces from the flanges <NUM>, <NUM>' from affecting the flow tubes within case <NUM>, which could increase the sensor error.

<FIG> depicts a further prior flow meter 200B. Flow meter 200B includes a case <NUM> that surrounds the flow tubes (not pictured) and a casing <NUM> that provides an integrated manifold and spacer component between flanges <NUM>, <NUM>'. The casing <NUM> maintains the spacing between flanges <NUM>, <NUM>', thereby preventing the clamping strain from affecting the spacing of the flow tubes.

More recently, in order to lower costs and reduce complexity, the spacer function has been incorporated into some flow meter cases. For example, <FIG> depicts a flow meter 200C that corresponds to a Micro Motion CMFS model flow meter. Flow meter 200C includes a case <NUM> that performs a spacer function between flanges <NUM>, <NUM>'. In some circumstances, however, case <NUM> can transfer just enough of the axial clamping forces to the flow tubes to interfere with sensitive activities, such as meter calibration activities. Therefore, in order to verify meter accuracy, it is desirable to remove the axial clamping force on the flow tubes prior to meter testing, or prior to use of the meter.

What is needed is a way to couple a flow meter to a process line or a test setup without transferring clamping forces to the meter flow tubes.

In a first aspect of the invention, a flow meter coupling system to reduce axial stress on a flow meter is provided according to claim <NUM>.

In a second aspect of the invention, a method for reducing axial stress when coupling a flow meter to a flow meter coupling is provided according to claim <NUM>.

In an embodiment, the flow meter coupling system may further comprise a first connector member rigidly coupled to the first process fluid member and the first flow meter flange.

In an embodiment, the first process fluid member may be an inlet and the second process fluid member may be an outlet for a fluid.

In an embodiment, the flow meter coupling system may further comprise a flow meter alignment apparatus comprising at least one hanger for suspending the flow meter by a flow meter case.

In an embodiment, the first connector member may further comprise a first connector process fluid member collar configured to be coupled to the first process fluid member at a first process fluid member end of the first connector member, and a first connector flow meter interfacing member configured to be coupled to the first flow meter flange at a flow meter end of the first connector member.

In an embodiment, the first connector member may further comprise a flow reducer/increaser coupled to the first connector process fluid member collar at an end opposing the process fluid member end and coupled to the first connector flow meter interfacing member at an end opposing the flow meter end.

In an embodiment, the second connector member may further comprise the second connector rigid interfacing member, a second connector conduit member, and a second connector slidable coupler configured to sealably couple the second connector conduit member to the second process fluid member.

Further preferential embodiments are disclosed according to claims <NUM>-<NUM>.

<FIG> and the following description depict specific examples to teach those skilled in the art how to make and use the best mode of the Application. For the purpose of teaching inventive principles, some conventional aspects have been simplified or omitted. Those skilled in the art will appreciate variations from these examples that fall within the scope of the Application. Those skilled in the art will appreciate that the features described below may be combined in various ways to form multiple variations of the Application. As a result, the Application is not limited to the specific examples described below, but only by the claims.

<FIG> depicts an example embodiment of flow meter coupling system <NUM>, depicted as coupled to a flow meter <NUM>. <FIG> depicts a detail of a second process fluid member <NUM> and a second connector member <NUM> of flow meter coupling system <NUM>, and <FIG> depicts a detail of a first connector member <NUM> and a first process fluid member <NUM> of flow meter coupling system <NUM>.

Flow meter coupling system <NUM> may be used to support normal process operations of flow meter <NUM>. Flow meter coupling system <NUM> may also be used to support testing, characterizing, and/or calibration of flow meter <NUM>. Flow meter coupling system <NUM> may be used to connect flow meter <NUM> to first process fluid member <NUM> and second process fluid member <NUM> in a manner that minimizes axial stress experienced at the flow meter <NUM>, allowing a fluid to be flowed between first process fluid member <NUM> and second process fluid member <NUM> in either direction, through flow meter <NUM>.

In the example embodiment of flow meter coupling system <NUM> depicted in <FIG>, flow meter <NUM> is coupled to first and second process fluid members <NUM>, <NUM>, which are head stocks. This is not intended to be limiting, however. In further examples, flow meter coupling system <NUM> may be used to couple flow meter <NUM> to a process pipeline, and first and second process fluid members <NUM> and <NUM> may comprise a first coupling end of the process pipeline and a second coupling end of the process pipeline.

In embodiments, flow meter <NUM> may comprise a dual, curved flow tube Coriolis flow meter like flow meters <NUM>, 200A, 200B, or 200C. In further embodiments, however, flow meter <NUM> may comprise a Coriolis flow meter including any number of flow tubes in any possible configuration.

Flow meter <NUM> comprises a first flange 314a and a second flange 314b. In embodiments, first flange 314a and second flange 314b may comprise any type of conduit coupler known to those of skill in the art.

Flow meter <NUM> comprises a flow meter case <NUM>. Much like case <NUM> depicted in <FIG>, which provides a spacer function for the flow meter manifolds within case <NUM>, case <NUM> also performs a spacer function between manifolds (not depicted) for flow meter <NUM>. In further embodiments, flow meter <NUM> may include any kind of flow meter case known to those of skill, including any variation of a flow meter case that does or does not provide a spacer function. In further embodiments, however, flow meter <NUM> may not comprise a case, but may comprise another structure to maintain the spacing between flow meter manifolds.

Flow meter coupling system <NUM> comprises first process fluid member <NUM> and second process fluid member <NUM>. first process fluid member <NUM> and second process fluid member <NUM> comprise inlets or outlets for fluid to be flowed through flow meter <NUM> during normal customer use of the meter, or during meter testing, calibration, characterization. First process fluid member <NUM> and second process fluid member <NUM> are stationary, meaning temporarily or permanently fixed. First process fluid member <NUM> and second process fluid member <NUM> fluidly connect flow meter <NUM> to one or more conduits or reservoirs of fluid to be measured by flow meter <NUM>.

First process fluid member <NUM> is configured to be coupled to the first flow meter flange 314a of the flow meter. Example first process fluid member <NUM> comprises a stationary vertical structure coupled to a band surrounding a fluid passageway. First flow meter flange 314a may be coupled to first process fluid member <NUM> using any type of coupling known to those of skill.

Second process fluid member <NUM> is configured to be coupled to the second flow meter flange 314b. Example second process fluid member <NUM> also comprises a stationary vertical structure coupled to a band surrounding a fluid passageway to which second flow meter flange 314b may be coupled using any type of coupling known to those of skill.

Flow meter coupling system <NUM> further comprises a second connector member <NUM>. An exploded view of second connector member <NUM> is depicted in <FIG>. Second connector member <NUM> couples the second flow meter flange 314b to the second process fluid member <NUM> by rigidly coupling at least one of the second flow meter flange 314b or the second process fluid member <NUM>, and coupled to another of the second flow meter flange 314b or the second process fluid member <NUM> in a manner that provides substantially no axial stress.

According to the invention, the second connector member <NUM> further comprises a second connector rigid interfacing member <NUM>, a second connector conduit member <NUM>, and a second connector slidable coupler <NUM> configured to sealably couple the second connector conduit member <NUM> to the second process fluid member <NUM>.

Second connector rigid interfacing member <NUM> rigidly couples the second connector conduit member <NUM> to the second flow meter flange 314b or the second process fluid member <NUM>. By rigidly coupled, what is meant is that the connector members are mechanically clamped in a manner that utilizes axial force. In the example of flow meter coupling system <NUM>, second connector ridged interfacing member <NUM> comprises a second connector flange 316a and a second connector clamp 316b. In embodiments, the second connector flange 316a may comprise a surface with apertures that match up with apertures in second flow meter flange 314b, thereby allowing fasteners to couple the flanges together. Second connector clamp 316b may comprise any method of rigidly joining second connector flange 316a to second connector conduit member <NUM> known to those of skill. In embodiments, second connector clamp 316b may comprise a sanitary clamp.

Second connector conduit member <NUM> comprises a conduit configured to be coupled rigidly at one end and in a manner that provides substantially no axial stress at a second end. In the embodiment of flow meter coupling system <NUM>, second connector conduit member <NUM> is a straight conduit with a small flange feature at one end.

Second connector slidable coupler <NUM> comprises a slidable coupler that provides a sealed connection between second process fluid member <NUM> and second connector conduit member <NUM>. Slidable coupler <NUM> may be coupled to any axial position along second connector conduit member <NUM> where slidable coupler <NUM> may be fully seated. Because the axial position where slidable coupler <NUM> and second connector conduit member <NUM> couple together is not restricted, this may substantially reduce the axial stress between flow meter coupling system <NUM> and flow meter <NUM>. In embodiments, slidable coupler <NUM> may substantially reduce the axial stress between flow meter coupling system <NUM> and flow meter <NUM> by <NUM>%, <NUM>% or <NUM>% over prior art setups with dual flange couplings.

<FIG> provides a detail cutaway view of a second connector slidable coupler <NUM>. As may be seen in the figure, second connector slidable coupler <NUM> further comprises seal seat <NUM> and an inflatable seal <NUM>. Inflatable seal <NUM> is configured to be positioned within the seal seat <NUM>, providing radial pressure to the second connector slidable coupler <NUM> to prevent fluid from leaking from second connector member <NUM>.

In the embodiment of flow meter coupling system <NUM>, seal seat <NUM> comprises a flange seal seat component 322a with an annular recess coupled to a seal seat cover component 322b with an annular recess. The annular recesses of flange seal seat component 322a and seal seat cover component 322b face one another to form an inner annular void within seal seat <NUM>.

Inflatable seal <NUM> comprises an annular-shaped expandable membrane configured to nest inside the inner annular void within seal seat <NUM>. Inflatable seal <NUM> can be expanded by adding pressurized fluid to the interior of inflatable seal <NUM> via an inlet/outlet valve (not depicted), such as, for example, a Schrader valve. In examples, inflatable seal <NUM> may comprise, for example, a rubber inner tube forming a <NUM>-durometer seal.

Second connector slidable coupler <NUM> further comprises a way to couple second connector slidable coupler <NUM> to one of second process fluid member <NUM> or second flow meter flange 314b. In the example of flow meter coupling system <NUM>, flange seal seat component 322a comprises one or more toggle levers 326b configured to engage hook-like elements 328b coupled to second process fluid member <NUM>. Other methods of rigidly coupling second connector slidable coupler <NUM> to one of second process fluid member <NUM> or second flow meter flange 314b are also possible, as will be understood by those of skill.

In embodiments, second connector rigid interfacing member <NUM> and second connector conduit member <NUM> may be formed from multiple sections that are coupled together. In further embodiments, however, second connector ridged interfacing member <NUM> and second connector conduit member <NUM> may be formed as an integrated part.

In the embodiment of flow meter coupling system <NUM>, second connector rigid interfacing member <NUM> is coupled to second flow meter flange 314b and second connector slidable coupler <NUM> is coupled to second process fluid member <NUM>. This is not intended to be limiting, however. In further embodiments, second connector rigid interfacing member <NUM> may be coupled to second process fluid member <NUM> and second connector slidable coupler <NUM> may be coupled to second flow meter flange 314b.

According to the invention, flow meter coupling system <NUM> further comprises a first connector member <NUM>. First connector member <NUM> couples first process fluid member <NUM> to first flow meter flange 314a. In embodiments, first connector member <NUM> may rigidly couple first process fluid member <NUM> to first flow meter flange 314a. In further embodiments, however first connector member <NUM> may couple first process fluid member <NUM> to first flow meter flange 314a in a manner that provides substantially no axial stress.

In embodiments, first connector member <NUM> may comprise a first connector process fluid member collar <NUM> and a first connector flow meter interfacing member <NUM>.

First connector process fluid member collar <NUM> may be configured to be coupled to first process fluid member <NUM> at a process fluid member end <NUM> of first connector member <NUM>. In embodiments, first connector process fluid member collar <NUM> may comprise a first flange-like or annular member coupled to one or more toggle levers 326a configured to engage hook-like elements 328a coupled to first process fluid member <NUM> to create a seal.

First connector flow meter interfacing member <NUM> may be configured to be coupled to first flow meter flange 314a at a flow meter end <NUM> of first connector member <NUM>. In embodiments, first connector flow meter interfacing member <NUM> may comprise a flange configured to be coupled to first flow meter flange 314a.

In further embodiments, first connector member <NUM> may further comprise a flow reducer/increaser configured to increase or decrease the diameter of the flow between first process fluid member <NUM> or first connector process fluid member collar <NUM>. Flow reducer/increaser <NUM> may be coupled to the first connector process fluid member collar <NUM> at an end opposing the process fluid member end <NUM> and coupled to first connector flow meter interfacing member <NUM> at an end opposing the flow meter end <NUM>.

In embodiments, flow reducer/increaser <NUM> may comprise a flange-like feature at opposing ends configured to allow flow reducer/increaser <NUM> to be coupled to first connector process fluid member collar <NUM> and first connector flow meter interfacing member <NUM>. First connector process fluid member collar <NUM> and first connector flow meter interfacing member <NUM> may also comprise flange-like features configured to be coupled to flow reducer/increaser <NUM> via clamps 342a and 342b. In embodiments, clamps 342a and 342b may comprise sanitary clamps, or any type of clamps known to those of skill.

In embodiments of flow meter coupling system <NUM>, first process fluid member <NUM> may comprise an inlet and second process fluid member <NUM> may comprise an outlet for a fluid. This may provide for less pressure on the second process fluid member <NUM> side of flow meter coupling system <NUM>, thereby applying less pressure on inflatable seal <NUM>.

In embodiments, flow meter coupling system <NUM> may further comprise a flow meter alignment apparatus (not depicted). The flow meter alignment apparatus comprises any method of holding flow meter <NUM> within flow meter coupling system <NUM> to align first flow meter flange 314a and second flow meter flange 314b with first process fluid member <NUM> and second process fluid member <NUM>.

In embodiments, flow meter alignment apparatus may support flow meter <NUM> within flow meter coupling system <NUM> via one or more hangers, which may be used to suspend the flow meter by flow meter case <NUM>. In embodiments, flow meter alignment apparatus may suspend flow meter case within flow meter coupling system <NUM> by supporting the section between first flow meter flange 314a and flow meter case <NUM>, and the section between flow meter case <NUM> and second flow meter flange 314b. The example embodiment of one or more hangers is not intended to be limiting, however. Those of skill will readily understand that the flow meter alignment apparatus may comprise any manner to align and/or support flow meter <NUM> known to those of skill.

<FIG> depicts method 400A, in accordance with the invention. Method 400A is executed to reduce axial stress when coupling a flow meter comprising a flow meter case, a first flow meter flange, and a second flow meter flange, to a flow meter coupling system comprising a flow meter alignment apparatus, a first process fluid member, a second process fluid member, a first connector member, and a second connector member. Method 400A is used to couple flow meter <NUM> to flow meter coupling system <NUM>.

Method 400A begins with step <NUM>. In step <NUM>, the flow meter case is positioned in the flow meter alignment apparatus of the flow meter coupling system. For example, flow meter case <NUM> may be supported by two hangers positioned in the section between first flow meter flange 314a and flow meter case <NUM>, and in the section between flow meter case <NUM> and second flow meter flange 314b, as described above.

Method 400A continues with step <NUM>. In step <NUM>, the second connector member is rigidly coupled to at least one of the second flow meter flange or the second process fluid member using the second connector member. For example, second connector member <NUM> may be coupled to second flow meter flange 314b, as described above and depicted in <FIG>.

In embodiments, step <NUM> may further comprise any combination of steps <NUM> and <NUM> of method 400B of <FIG>.

In step <NUM>, a second connector conduit member is coupled to a second connector rigid interfacing member. For example, second connector conduit member <NUM> may be coupled to second connector rigid interfacing member <NUM>, as described above and depicted in <FIG>.

In step <NUM>, the second connector rigid interfacing member is coupled to the at least one of the second flow meter flange or the second process fluid member. For example, second connector rigid interfacing member <NUM> may be coupled to second flow meter flange 314b, as described above and depicted in <FIG>.

Method 400A continues with step <NUM>. In step <NUM>, the second connector member is coupled to another of the second flow meter flange or the second process fluid member using the second connector member in a manner that provides substantially no axial stress. For example, second connector member <NUM> may be coupled to second process fluid member <NUM>, as described above and depicted in <FIG>.

In embodiments, step <NUM> may further comprise step <NUM> of method 400C of <FIG>. In step <NUM>, a second connector slidable coupler is slidably and sealably coupled to the second connector conduit member. For example, second connector slidable coupler <NUM> may be coupled to second connector conduit member <NUM>, as described above.

In embodiments, step <NUM> of method 400C may further comprise steps <NUM> and <NUM> of method 400C. In step <NUM>, a seal seat and an inflatable seal is threaded to position the seal seat and inflatable seal within the seal seat over the second connector conduit member. For example, seal seat <NUM> and inflatable seal <NUM> may be threaded over second connector conduit member <NUM>, as is best depicted in <FIG>.

In step <NUM>, the inflatable seal is inflated to provide radial pressure to the second connector conduit member. For example, inflatable seal <NUM> may be pressurized, as described above.

In embodiments, method 400A may further comprise step <NUM>. In step <NUM>, the first process fluid member may be rigidly coupled to the first flow meter flange with the first connector member. For example, first connector member <NUM> may be used to couple first process fluid member <NUM> rigidly to first flow meter flange 314a, as described above. Those of skill will readily recognize that step <NUM> is not intended to be limiting. In embodiments, first process fluid member <NUM> may alternatively be slidably coupled to first flow meter flange 314a similar to the way that second flow meter flange 314b is slidably connected to at least one of second flow meter flange 314b or second process fluid member <NUM>.

In embodiments, step <NUM> may further comprise any combination of steps <NUM>-<NUM> of method 400D of <FIG>. In step <NUM>, a first connector process fluid member collar may be coupled to the first process fluid member at a process fluid member end of the first connector member. For example, first connector process fluid member collar <NUM> may be coupled to first process fluid member <NUM>, as described above.

In step <NUM>, a first connector flow meter interfacing member may be coupled to the first flow meter flange at a flow meter end of the first connector member. For example, first connector flow meter interfacing member <NUM> may be coupled to first flow meter flange 314a, as descried above.

In step <NUM>, a flow reducer/increaser may be coupled to the first connector process fluid member collar at an end opposing the process fluid member end. For example, flow reducer/increaser <NUM> may be coupled to first connector process fluid member collar <NUM>, as described above.

In step <NUM>, the flow reducer/increaser may be coupled to the first connector flow meter interfacing member at an end opposing the flow meter end. For example, flow reducer/increaser <NUM> may be coupled to first connector flow meter interfacing member <NUM>, as described above.

<FIG> depicts axial clamping forces under a prior flow meter flow meter coupling system 500A including a rigidly coupled first process fluid member <NUM>, a flow meter <NUM>, and a rigidly coupled second process fluid member <NUM>. As may be seen in the figure, the rigid coupling between flow meter <NUM> and second process fluid member <NUM> generates a clamping force Fclamp and a reaction force Rclamp in the axial direction of the flow meter conduit. In embodiments, the reaction force Rclamp can place forces on flow meter <NUM> flow tubes, which may impact the flow meter data accuracy.

<FIG> depicts clamping forces under a flow meter flow meter coupling system 500B according to an embodiment of the Application. flow meter coupling system 500B comprises a rigidly coupled first process fluid member <NUM>, a flow meter <NUM>, and a second process fluid member <NUM> coupled in a manner that provides substantially no axial stress. As may be seen in the figure, the connection between flow meter <NUM> and second process fluid member <NUM> comprises substantially no axial clamping force Fclamp or reaction force Rclamp. Instead, the second process fluid member <NUM> comprises radial sealing forces Fseal from an inflatable seal in the radial direction of the flow meter conduit. Radial sealing forces Fseal are much less likely to bend or place any strain on the flow tubes of flow meter <NUM>, thereby maintaining the accuracy of flow meter <NUM>.

Claim 1:
A flow meter coupling system (<NUM>) to reduce axial stress on a flow meter (<NUM>) comprising a first flow meter flange (314a) and a second flow meter flange (314b), the flow meter coupling system (<NUM>) comprising:
a first process fluid member (<NUM>) configured to be coupled to the first flow meter flange (314a) of the flow meter (<NUM>);
a second process fluid member (<NUM>); and
a first connector member (<NUM>) and a second connector member (<NUM>) configured to be rigidly coupled to at least one of the second flow meter flange (314b) or the second process fluid member (<NUM>) and coupled to another of the second flow meter flange (314b) or the second process fluid member (<NUM>) in a manner that provides substantially no axial stress;
wherein the second connector member (<NUM>) further comprises:
a second connector rigid interfacing member (<NUM>);
a second connector conduit member (<NUM>);
a slidable coupler (<NUM>) configured to sealably couple the second connector conduit member (<NUM>) to the second process fluid member (<NUM>);
a seal seat (<NUM>); and
an inflatable seal (<NUM>) configured to be positioned within the seal seat (<NUM>), providing radial pressure to the second connector slidable coupler (<NUM>).