Blocking member for process fluid flow measurement device

Abstract

A fluid flow blocking member for a process fluid flow measurement device is located in a fluid flow conduit and includes an upstream wall having a planar upstream surface and a downstream wall having a planar downstream surface coupled along a top to the upstream surface. The top includes a planar surface extending from an upstream top edge to a downstream top edge. The upstream top edge intersects the upstream wall and the downstream top edge intersects the downstream wall.

Description

Background Art

[0001] The present invention relates to industrial process control and measurement equipment. More particularly, the present invention relates to equipment for measuring fluid flow of process fluids.

[0002] Many industries use field devices (such as process variable transmitters) to remotely sense or control process variables. Such process variables are often associated with fluids (such as suspensions), liquids, vapors, gases, chemicals, pulp, petroleum, pharmaceuticals, food, and other fluid processing plants. Process variables may include pressure, temperature, flow, turbidity, density, concentration, chemical compensation, and other properties. Other examples of field devices include valves, actuators, heaters, and controllers.

[0003] Industrial process fluid flow measurement equipment usually requires multiple components. For example, a type of process fluid flow transmitter includes a fluid barrier device arranged in the fluid flow in the conduit. Then, the process flow transmitter measures the pressure difference before and after the fluid barrier device (such as an orifice plate, a V cone or an adjusting orifice plate) in the fluid conduit, and calculates the mass or volume flow of the fluid flowing through it. The fluid barrier device causes a pressure difference to be formed between the upstream side and the downstream side of the barrier, and the pressure difference is related to the flow velocity of the fluid. Then, the process variable fluid flow transmitter transmits the fluid flow information to a process controller, which can be a computer located in a control room, or can even be another field device installed on site.

[0004] Wedge flow meters are commonly used to measure the flow of abrasive, viscous and corrosive fluids. Wedge flow meters include two separate pressure ports that transmit high and low pressures on either side of a wedge-shaped fluid blocking device or element to restrict and generate a differential pressure (DP) signal across the valve core of the pipeline. The instrument branch typically transmits the differential pressure signal to a differential pressure transmitter through a remote seal. Summary of the invention

[0005] According to some aspects of the present specification, a fluid flow blocking device for a process fluid flow measurement device located in a fluid flow conduit includes an upstream wall having a planar upstream surface, a downstream wall having a planar downstream surface, the planar downstream surface being coupled to the upstream surface along a top portion. The top portion includes a flat surface extending from an upstream top edge to a downstream top edge. The upstream top edge intersects the upstream wall, and the downstream top edge intersects the downstream wall.

[0006] According to some aspects of the present specification, a method for constructing a fluid flow obstruction component located in a fluid flow conduit for a process fluid flow measurement device includes providing a wedge-shaped element having a planar upstream wall and a planar downstream wall intersecting the upstream wall at a first top. In addition, the wedge-shaped element is truncated to remove the first top and form a second top. The second top includes a flat surface extending from an upstream top edge to a downstream top edge. The upstream top edge intersects the upstream wall, and the downstream top edge intersects the downstream wall.

[0007] According to some aspects of the present specification, a system for measuring process fluid flow includes a fluid flow conduit having an inlet and an outlet, a fluid flow barrier component, and a differential pressure sensor configured to sense a process fluid pressure differential on either side of the fluid flow barrier component. The fluid flow barrier component includes an upstream wall having a planar upstream surface and a downstream wall having a planar downstream surface, the planar downstream surface being coupled to the upstream surface at a top. The top includes a flat surface extending from an upstream top edge to a downstream top edge, the upstream top edge intersecting the upstream surface, and the downstream top edge intersecting the downstream surface.

[0008] The purpose of providing this summary is to introduce a series of concepts in simplified form, which are further described in the detailed description below. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to assist in determining the scope of the claimed subject matter. The claimed subject matter is not limited to specific implementations that solve any or all disadvantages noted in the background technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A schematic diagram illustrating a process control system including a wedge-shaped flow meter having a fluid flow conduit with an inlet and an outlet and a differential pressure transmitter;

[0010] Figure 2 Example Figure 1 A cross-sectional view of a fluid flow conduit of a process control system of claim 1, wherein the fluid flow conduit has an internal wedge-shaped element as a fluid flow blocking member;

[0011] Figure 3 Example Figure 1 An implementation scheme of a differential pressure transmitter and a control room;

[0012] Figure 4 Example Figure 1 Simplified block diagram of a differential pressure transmitter;

[0013] Figure 5 Schematic diagram illustrating a fluid flow blocking member or wedge-shaped element arranged and mounted within the body of a fluid flow conduit;

[0014] Figure 6 A schematic diagram illustrating one embodiment of a fluid flow blocking member or wedge-shaped element arranged and mounted within the body of a fluid flow conduit;

[0015] Figure 7 Examples provided Figure 6 A schematic diagram of one embodiment of a fluid flow blocking member or wedge-shaped element;

[0016] Figure 8 A cross-sectional view illustrating one embodiment of a fluid flow conduit of a process control system, the process control system comprising Figure 7 wedge-shaped elements, such as Figure 3 The differential pressure transmitter and control chamber of the differential pressure transmitter and control chamber illustrated in;

[0017] Fig. 9 An enlarged embodiment of a truncated flat top and an enlarged circular top of equivalent top radius size are illustrated for comparison;

[0018] Fig.10 is a graph illustrating one embodiment of flow test results for a six inch Sch40 pipe wedge meter, wherein the six inch Sch40 pipe wedge meter has been flow tested with wedge elements having a round top and having an equivalent truncated flat top and having an h / D ratio of 0.20;

[0019] Fig.11 is a graph illustrating one embodiment of flow test results for a six inch Sch40 pipe wedge meter, wherein the six inch Sch40 pipe wedge meter has been flow tested with wedge elements having a round top and having an equivalent truncated flat top and having an h / D ratio of 0.60;

[0020] Fig.12 an enlarged schematic diagram illustrating one embodiment of a wear pattern on a truncated flat top;

[0021] Fig.13 An enlarged schematic diagram illustrating the wear pattern on a circular top;

[0022] Fig.14 is a graph illustrating one embodiment of flow test results for a two inch Sch40 pipe wedge meter, wherein the two inch Sch40 pipe wedge meter has been flow tested with wedge elements having a rounded top and having an equivalent truncated flat top, both having an h / D ratio of 0.40;

[0023] Fig.15 is a graph illustrating one embodiment of flow test results for a six inch Sch40 pipe wedge meter, where the six inch Sch40 pipe wedge meter has been flow tested with wedge elements having a rounded top and having an equivalent truncated flat top, both having an h / D ratio of 0.60; and

[0024] Fig.16 One embodiment of a method of constructing a fluid flow blocking device. DETAILED DESCRIPTION

[0025] The embodiments of the present disclosure will be described more fully below with reference to the accompanying drawings. Elements identified with the same or similar accompanying drawings represent the same or similar elements. In order to simplify the illustration, some elements may not be shown in every accompanying drawing.

[0026] The various embodiments of the present disclosure may be embodied in many different forms and should not be construed as limited to the specific embodiments set forth herein. Rather, these embodiments are provided to make this disclosure thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0027] The two most common wedge flow meter designs are the external wedge element and the internal wedge element. The external wedge element is usually made of an angle-bar and welded into a V-groove on the flow meter body. The advantage of the external wedge flow meter is that almost no specialized manufacturing equipment or tools are required. The dimensions of the external wedge element can be controlled by the dimensions of the V-groove and the dimensions of the angle bar used. The disadvantage of the external wedge flow meter is that the accuracy of the flow measurement may be reduced due to the tolerances of the geometric structures involved and welding distortion. In addition, the external wedge must be calibrated to achieve reasonable measurement accuracy.

[0028] The internal wedge element slides into the meter body and is anchored in place. The wedge element is typically manufactured with a cylindrical radius feature at the top of the wedge element, wherein the radius of curvature of the circular outer wall of the wedge element is slightly less than the radius of curvature of the inner diameter of the wedge meter conduit body to allow it to slide in. Due to the difficulty in fixing / holding the wedge element, the circular wedge shape of the internal wedge is not suitable for traditional machining methods, i.e., milling, computer numerical control (CNC), etc. Typically, the internal wedge is first constructed by turning the outer diameter of the rod on a lathe to match the inner diameter of the wedge gauge, and then using wire electric discharge machining (EDM) to cut the rod stock into a wedge shape. The advantage of an internal wedge made in this way is that it is more accurate than an external wedge due to improved manufacturing tolerances. The disadvantage of the internal wedge is that it is difficult to construct, which may include material waste, the wedge element is heavy and dense, requires a dedicated EDM process function, and large rod stock must be inventoryed and handled, thereby causing material handling risks.

[0029] Figure 1 A schematic diagram of an exemplary process control system 10 is shown, which includes a wedge-shaped flow meter or pipe spool meter 9 having a fluid flow conduit 5 such as a pipe with an inlet and an outlet, and a differential pressure transmitter 70. A fluid flow blocking device 1 embodied as a wedge-shaped element is arranged and mounted within a body 2 of the fluid flow conduit 5. Figure 1 As illustrated, fluid is shown flowing 6 in a direction from inlet 8A to outlet 8B of fluid flow conduit 5. The restriction caused by fluid flow blocking device 1 causes a pressure differential (DP) to form between each side of fluid flow blocking device 1. This pressure differential (DP) is related to flow rate and is measured by differential pressure (DP) transmitter 70 and converted into a flow rate measurement.

[0030] Figure 2 A cross-sectional view of a fluid flow conduit 5 of an exemplary process control system 10 having an internal wedge-shaped element as a fluid flow blocking device 1. Two or more DP branches or flanges 3 separate the main flow path of the pipe valve core and are configured to transmit a differential pressure signal to a differential pressure transmitter 70, i.e., a high pressure signal through connection 7A and a low pressure signal through connection 7B. Sensor 75 (see Figure 3 ) is arranged to sense high pressure signals (ie, pressure P1 ) and low pressure signals (ie, pressure P2 ) on either side of the wedge-shaped element 1 .

[0031] The wedge-shaped element 1 has a circular outer wall 30, an upstream wall 32, and a downstream wall 34, the radius of curvature or diameter of the circular outer wall corresponding to the inner radius of curvature or inner diameter of the valve core of the conduit 5, and the upstream wall and the downstream wall are at a ninety-degree angle to each other at the top 36 of the wedge-shaped element. The ratio of the throat opening height h below the wedge-shaped element or wedge-shaped opening to the meter valve core diameter D is called the h / D ratio. The size of the wedge-shaped element 1 formed as an internal wedge-shaped element in the fluid flow conduit 5 produces different h / D ratios, thereby producing different differential pressure signals for a given flow rate. In order to meet most variable requirements, most wedge-shaped flow meter manufacturers provide h / D ratios in increments of 0.05 or 0.10 between 0.20 and 0.60, while limiting iterations to finite values. Consider each flow application on a case-by-case basis to determine the optimal size of the wedge-shaped element. Factors that may be considered in determining the wedge element corresponding to a given differential pressure within a given internal fluid flow conduit 5 or pipe, diameter D may include: minimum Reynolds number, standard Reynolds number and maximum Reynolds number, permanent pressure loss, accuracy of flow rate measurement results, target differential pressure value at standard flow rate / maximum flow rate and transmitter differential pressure range. Fluid flowing through the wedge element 1 in a wedge flow meter experiences a pressure change as it is accelerated by the pipe restriction caused by the wedge element. Sensing this pressure change with a DP transmitter through the DP pressure branch 3 can facilitate flow measurement using an appropriate flow computer.

[0032] Figure 3 An example embodiment of a process control system 10 is illustrated, which includes a differential pressure (DP) transmitter 70 and a control room 72. The differential pressure transmitter 70 includes a sensor 75 that senses the pressure difference between the pressure P1 and the pressure P2 in the process fluid, and then forwards an electronic signal to the control room 72 through a control loop 73. In this example, the control room 72 also provides power to the differential pressure transmitter 70 from a power supply 71 through the control loop 73. The control loop 73 also enables a communication system 76 to communicate between the control room 72 and the differential pressure transmitter 70. In various embodiments, the control loop 73 is a 4mA to 20mA current loop or a process control industry standard 10A. In other embodiments, the differential pressure transmitter 70 and the control room 72 are connected by a two-wire communication circuit such as a field bus loop. In yet other embodiments, the output of the differential pressure transmitter 70 can be read by a handheld device connected to the differential pressure transmitter 70 in a wired or wireless manner.

[0033] The differential pressure transmitter 70 includes a transmitter circuit 77, a sensor 75, and an electronics housing 78. The transmitter circuit 77 is electrically connected to an electronics board 80 via wiring 79 for communication with the control loop 73. The transmitter circuit 77 includes components for transmitting the voltage signal generated by the pressure sensor 75 through the control loop 73 to the control room 72 or a local display such as an LCD screen 81, or both. The transmitter circuit 77 conditions the output of the sensor 75 into a format compatible with the control loop 73.

[0034] Sensor 75

[0035] The sensor module 86 includes isolation tubes 87A and 87B and isolation diaphragms 88A and 88B. The isolation tubes 87A and 87B include passages coupled to the sensor 75 at their first ends and to the isolation diaphragms 88A and 88B at their second ends. The isolation diaphragms 88A and 88B are connected to the process flange 83, which is typically bolted or fixed to the base of the sensor module 86.

[0036] Figure 4 is a simplified block diagram illustrating a DP transmitter 70. The DP transmitter 70 includes a sensor module 86 and an electronics board 80 coupled together by a data bus 66. The sensor module 86 includes sensor module electronics 67 and a sensor 75 that receives the pressures P1 and P2 of the process fluid and provides an output 58 related to the pressure differential to an analog-to-digital converter 82. An optional temperature sensor 89 that may be used for temperature compensation is illustrated along with a sensor module memory 90. The electronics board 80 includes a microcomputer system or microprocessor 74, an electronics module memory 91, a digital-to-analog signal converter 92, and a digital communications block 95.

[0037] Figure 4 Also illustrated are capillary or "fill" tubes 87A and 87B for coupling sensor 75 to the process fluid. Isolation diaphragms 88A and 88B receive pressures P1 and P2, respectively, from the process fluid, which is responsively applied to the fill fluid carried in capillaries 87A and 87B. Through this fluid fill, the pressure of the process fluid is applied to sensor 75.

[0038] Wedge flow meters are used in applications that may damage or destroy other types of flow meters, such as in applications with abrasive, viscous, plugging, and corrosive fluids. Exemplary fluids may quickly wear out flow element geometry such as orifice plates or vortex shedders, wear through non-metallic or thin pipe walls, clog pulse tubes, small passages or moving parts, and are not suitable for magnetic Coriolis flow meters or ultrasonic flow meters. Exemplary difficult fluids include fluids with entrained gravel or rock, asphalt, bottom residue, suspensions, paraffin. The flow path of difficult fluids entering the orifice plate exerts high friction due to flow acceleration and velocity vector changes on the sensitive, sharp edges of the orifice plate. The trapped solids, gravel, rocks, or bubbles can then quickly wear out the edges of the orifice plate.

[0039] Wedge-shaped flow meters are suitable for applications with many of these problems because the geometry of the wedge-shaped element is designed not to wear as quickly as competing technologies or primary elements, affecting flow measurement. It also has widely spaced differential pressure branches or taps that easily incorporate remote seals to inhibit impulse tube plugging. Wedge-shaped meters are less sensitive to wear than orifice plates because the path of flow around the wedge-shaped element barrier is less steep due to the gradual or inclined angles of the upstream and downstream faces.

[0040] Figure 5 Schematic diagram illustrating a fluid flow blocking component or wedge-shaped element 101 arranged and mounted within a body 102 of a fluid flow conduit 105 . Figure 5 The wedge-shaped element 101 in the figure illustrates another reason why a wedge-shaped meter is less sensitive to wear. Although the wedge-shaped element 101 has a circular outer wall 130, whose radius of curvature matches the valve core inner diameter or radius of curvature of the conduit 105, and an upstream face 132 and a downstream face 134, the upstream and downstream faces are at a ninety degree angle to each other, but the top 136 of the wedge element is rounded, rather than rounded like a circular wedge. Figure 1 and Figure 2 The rounded top 136 with a top radius will wear more slowly than a sharp edge, like a river rock in a stream or a knife that has become dull. The wedge-shaped meter provides a more consistent and accurate flow response over time and in problematic applications than other geometries of other types of flow meters.

[0041] However, as discussed above, wedge-shaped elements have been difficult to manufacture due to their shape and precision requirements. Figure 5As illustrated, forming the rounded top 136 may be more time consuming and machine intensive, requiring several passes of machining and interpolation on a CNC machine. The rounded top 136 is also difficult to align and tangent to both the upstream and downstream faces of the wedge-shaped element. Wire electrical discharge machining (EDM) can more easily construct the rounded top radius feature than conventional milling machines or CNCs, but EDM is expensive, bulky, and inefficient.

[0042] Figure 6 Schematic diagram illustrating one embodiment of a fluid flow blocking member or wedge-shaped element 201 arranged and mounted within the body 202 of a fluid flow conduit 205. The wedge-shaped element 201 has a circular outer wall 230 having a radius of curvature that matches the radius of curvature of the inner diameter of the conduit 205 (see also Figure 8 ). Wedge-shaped element 201 includes an upstream wall 232 having a planar upstream surface and a downstream wall 234 having a planar downstream surface that is coupled to the upstream surface along a top 236. Upstream wall 232, and therefore the planar upstream surface, is oriented at a perpendicular angle to downstream wall 234, and therefore the planar downstream surface. Top 236 has a truncated flat surface, rather than a rounded surface ( Figure 5 ) or with sharp or square edge top 36 ( Figure 1 and Figure 2 ). The truncated flat top 236 extends between an upstream top edge 241 and a downstream top edge 243. The upstream top edge 241 intersects the upstream wall 232, and the downstream top edge 243 intersects the downstream wall 234. The thickness or width 238 of this flat, straight top 236 is approximately uniform across the top of the wedge-shaped element or component 201. For example, the flat width or platform thickness 238 of the wedge-shaped element 201 is between 0.001 inches and 0.034 inches to correspond to the equivalent radius allowed by international wedge gauge management standards (such as ISO 5167-6). Such a flat width or platform thickness 238 is consistent with a truncated height 244 (0.001 inches to 0.017 inches). Figure 7 The upper limit of the truncated height 244 of 0.017 inches corresponds to an equivalent top radius 242 of 0.020 inches, which maximizes the pressure differential generated and minimizes the difference in discharge coefficient (C) between the truncated flat top 236 and the round top 136, as will be discussed in detail below.

[0043] Figure 7 A schematic diagram illustrating a fluid flow blocking component or wedge-shaped element 201 is shown. Figure 8 A cross-sectional view of one embodiment of a fluid flow conduit 205 of a process control system is illustrated, the fluid flow conduit including a wedge-shaped element 201. Figure 7As illustrated, top radius 242 is used to determine the overall size of wedge-shaped element 201, or in other words, how far upstream face 232 is from downstream face 234. As shown at 244, truncation of wedge-shaped element 201 occurs at or approximately below the perimeter of top radius 242 to form a truncated flat feature, which is a small, uniform, flat surface top 236 ( 244 ) on wedge-shaped element 201 having a platform thickness 238. Figure 6 ).

[0044] Wedge-shaped element 201 has upstream face 232 and downstream face 234 similar to wedge-shaped element 101, but the top is truncated to be flat rather than rounded. Fig. 9 By comparing wedge-shaped element 201 and wedge-shaped element 101 in the enlarged illustration of the truncated flat top 236 of wedge-shaped element 201 and the round top 136 of wedge-shaped element 101 in FIG. 1 , it is easily illustrated that both wedge-shaped element 101 and wedge-shaped element 201 have top radii 142 and 242 of equivalent size. Further and as shown Figure 8 As illustrated, the wedge-shaped element 201 is anchored to the inner surface of the catheter 205 by an anchor 250. This provides a truncated flat feature of the wedge-shaped element 201 to obtain a wedge opening height (h) 246 that is comparable in size to the wedge opening height of the circular top 136.

[0045] The truncated flat feature of the top 236 is easier to construct by conventional machining methods than the rounded radius feature of the top 136, resulting in more consistent construction results for various parts and more predictable flow calibration results for various meters. The setup requires fewer reference datums, the tooling is simpler, fewer machining times are required, less programming is required, and most importantly, the truncated flat feature of the top 236 is easier to manufacture consistently in both feature width or platform thickness 238 and wedge element height 240. These two factors are critical to reducing discharge coefficient variation for various wedge meters, thereby providing an uncalibrated product.

[0046] Another advantage of the truncated flat top 236 is that variations in feature size have less impact on flow properties than equivalent variations in the round top 136. This is important in repeatable manufacturing. Because of the improved predictable flow properties, the truncated flat top 236 is valuable even to manufacturers who are able to exceed the limitations of traditional machining by using EDM.

[0047] Generally speaking, the uncertainty of a wedge-shaped meter will never be less than 4% to 8% unless the meter is calibrated. The truncated flat top 236 allows for an uncalibrated wedge-shaped meter, which can be achieved by carefully controlling and tracking several factors that affect and characterize the expected discharge coefficient for a given iteration of the meter. Calibrating the meter increases the cost. Compared to the round top 136, the truncated flat top 236 reduces the flow response variation of various devices and enables the manufacture of uncalibrated meters.

[0048] Fig.10 is a graph 300 illustrating flow test results for a six inch Sch40 pipe wedge meter that has been flow tested with wedge elements having a round top 136 and having an equivalent truncated flat top 236, both having a truncated top of 0.020 inches and 0.040 inches top radius or equivalent top radius and an h / D ratio of 0.20. Fig.11 4 is a graph 400 illustrating flow test results for a six inch Sch40 pipe wedge meter that has been flow tested with a wedge element having a rounded top 136 and a wedge element having an equivalent truncated flat top 236, both having a truncated top of 0.020 inches and 0.040 inches top radius or equivalent top radius and an h / D ratio of 0.60. Fig.10 and Fig.11 As illustrated by the graphs in , some conclusions can be drawn. The truncated flat top and the round top do not show considerable differences from each other in the standard deviation (variance) of the calibration or the linearity of the calibration. In other words, from a flow performance perspective, the truncated flat top is as effective as the round top. A difference of 0.020 inches in the top radius or equivalent radius causes the emission coefficient (C) of the round top to shift by approximately 2 to 3 times that of the truncated flat top. Small differences between the truncated flat top values ​​have less impact on the emission coefficient (C) than equivalent small differences between the round top values. This data indicates that the round top is more sensitive to dimensional changes than the truncated flat top. In other words, the truncated flat top is more conducive to predicting emission coefficients in a production environment and is therefore a better choice for predictable and uncalibrated products in real-world environments.

[0049] Fig.12 An enlarged schematic diagram illustrating the wear pattern on the truncated flat top 236 of the wedge-shaped element 201, and Fig.13Schematic diagram of an enlarged view of the wear pattern on the rounded top 136 on the wedge-shaped element 101. Although the upstream top edge 241 and the downstream top edge 243 of the truncated flat top 236 are not rounded, they are not "sharp" because they are blunted. For example, each edge 241 and 243 of the truncated flat top 236 is at an angle 237 of approximately 135 degrees relative to the upstream wall 232 and the downstream wall 234, respectively, compared to the 90-degree square edge of the orifice plate. Figure 6 ). These dull edges wear more slowly than sharper edges. Fig.12 and Fig.13 As shown, the truncated flat top 236 is also less affected by edge wear than the round top 136. This was confirmed in flow testing. In addition, since the truncated flat top 236 wears or erodes in problematic applications, the truncated flat top 236 is first transformed into a round top feature ( Fig.12 ).

[0050] Fig.14 is a graph 500 illustrating flow test results for a two inch Sch 40 pipe wedge meter that has been flow tested using wedge elements having a rounded top 136 and having an equivalent truncated flat top 236, both having a top radius of 0.020 inches and an h / D ratio of 0.40. Fig.15 6 is a graph 600 illustrating flow test results for a six inch Sch40 pipe wedge meter that has been flow tested with wedge elements having a rounded top 136 and having an equivalent truncated flat top 236, both having a top radius of 0.020 inches and an h / D ratio of 0.60. Fig.14 and Fig.15 For many of the most common h / D ratios (h / D of 0.40 to 0.60) shown in FIG, there is little shift in the discharge coefficient for a 0.020 inch round top from that of an equivalently sized truncated flat top. This means that as the truncated flat top 236 wears to a round top, there is no shift in the discharge coefficient, and thus the wedge gauge maintains its base performance throughout the initial wear period.

[0051] In contrast, as the rounded top 136 wears, it becomes more rounded and causes the wedge-shaped element to lose height (see Fig.10 and Fig.11 The curve graph and Fig.15). Changes in roundness and wedge element height will cause the discharge coefficient to shift, although wedge meter geometry takes a considerable time to develop compared to competing flow measurement technologies such as orifice technology. As corrosion increases to the point of significant wear, the discharge coefficient will shift more dramatically relative to the effects of initial wear, regardless of the type of wedge element top, so changing the roundness of the radius and the wedge opening height (h) will make more sense.

[0052] Fig.16 In step 702, a wedge-shaped element such as wedge-shaped element 201 is provided, the wedge-shaped element having a planar upstream wall such as upstream wall 232 and a planar downstream wall such as downstream wall 234, the planar downstream wall intersecting the upstream wall at a first top, such as Figure 7 At step 704, a wedge-shaped element such as wedge-shaped element 201 is truncated to remove the first top and form a second top, such as having Figure 7 The top 236 of the flat surface shown. At step 706, at least one such Figure 8 The illustrated anchor 250 anchors a wedge-shaped element such as the wedge-shaped element 201 to a Figure 7 The interior of the fluid flow conduit 205 in the fluid flow conduit.

[0053] Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the description.

Claims

1. A fluid flow blocking component for a process fluid flow measurement device, the fluid flow blocking component being located in a fluid flow conduit and comprising: an upstream wall having a planar upstream surface; and a downstream wall having a planar downstream surface coupled to the upstream surface along a top portion; Wherein the top portion includes a planar surface extending from an upstream top edge to a downstream top edge, the upstream top edge intersecting the upstream wall and the downstream top edge intersecting the downstream wall.

2. A fluid flow blocking device according to claim 1, wherein the flat surface of the top is oriented at a first obtuse angle relative to the upstream surface of the upstream wall, and the flat surface of the top is oriented at a second obtuse angle relative to the downstream surface of the downstream wall.

3. The fluid flow blocking device of claim 2, wherein the first obtuse angle and the second obtuse angle are the same.

4. The fluid flow blocking device of claim 1, wherein the downstream surface is oriented at a perpendicular angle relative to the upstream surface.

5. The fluid flow blocking device of claim 1, further comprising a circular outer wall having a radius of curvature corresponding to an inner radius of curvature of the conduit and intersecting the upstream wall, the downstream wall and the top.

6. The fluid flow blocking device of claim 5, wherein the circular outer wall of the fluid flow blocking member is secured to the interior of the fluid flow conduit by at least one anchor.

7. The fluid flow blocking device of claim 6, wherein the top portion is spaced apart from the inner surface of the fluid flow conduit by a throat opening height (h).

8. The fluid flow blocking device of claim 7, wherein a ratio of the throat opening height to the inner diameter of the conduit (h / D) is in the range between 0.20 and 0.

60.

9. A method of constructing a fluid flow obstruction member in a fluid flow conduit for a process fluid flow measurement device, the method comprising: providing a wedge-shaped element having a planar upstream wall and a planar downstream wall intersecting the upstream wall at a first top; as well as The wedge-shaped element is truncated to remove the first top and form a second top, wherein the second top includes a flat surface extending from an upstream top edge that intersects the upstream wall to a downstream top edge that intersects the downstream wall.

10. The method of claim 9, wherein the planar surface of the second top portion is oriented at a first obtuse angle relative to an upstream surface of the upstream wall and is oriented at a second obtuse angle relative to a downstream surface of the downstream wall. The method of claim 10 , wherein the first obtuse angle and the second obtuse angle are the same.

12. The method of claim 9, wherein the downstream wall is oriented at a perpendicular angle relative to the upstream wall.

13. The method of claim 10, further comprising anchoring the wedge-shaped element to an interior of the fluid flow conduit with at least one anchor.

14. A system for measuring process fluid flow, the system comprising: a fluid flow conduit having an inlet and an outlet; A fluid flow blocking component, the fluid flow blocking component comprising: an upstream wall having a planar upstream surface; and a downstream wall having a planar downstream surface coupled to the upstream surface at a top; wherein the top portion comprises a planar surface extending from an upstream top edge to a downstream top edge, the upstream top edge intersecting the upstream surface and the downstream top edge intersecting the downstream surface; and A differential pressure sensor is provided to sense a differential pressure of the process fluid on either side of the fluid flow barrier.

15. The system of claim 14, wherein the planar surface of the top portion is oriented at a first obtuse angle relative to the upstream surface of the upstream wall, and the planar surface of the top portion is oriented at a second obtuse angle relative to the downstream surface of the downstream wall.

16. The system of claim 15, wherein the first obtuse angle and the second obtuse angle are the same.

17. The system of claim 14, wherein the downstream surface is oriented at a perpendicular angle relative to the upstream surface.

18. The system of claim 14, wherein the fluid flow blocking member further comprises a circular outer wall having a radius of curvature corresponding to an inner radius of curvature of the fluid flow conduit and intersecting the upstream wall, the downstream wall, and the top.

19. The system of claim 18, wherein the circular outer wall of the fluid flow blocking member is secured to the interior of the fluid flow conduit by at least one anchor.

20. A fluid flow blocking device according to claim 6, wherein the top is separated from the inner surface of the fluid flow conduit by a throat opening height (h), and the ratio of the throat opening height to the inner diameter of the conduit (h / D) is in the range between 0.20 and 0.60.

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