Composite flow tube bushing for magnetic flowmeter

Abstract

A composite flow tube liner includes a cylindrical substrate and an inner layer. The cylindrical substrate includes a plurality of perforations and is configured to be installed in a flow tube assembly of a magnetic flow meter. The inner layer includes a fluoroelastomer and covers an inner surface of the substrate. The inner layer extends into the perforations of the cylindrical substrate, thereby fixing the fluoroelastomer to the cylindrical substrate.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to magnetic flow meters, and more particularly, to flow tube liners for use with magnetic flow meters. Background Art

[0002] Accurate and precise flow control is critical to a wide variety of fluid handling applications, including bulk fluid handling, food and beverage preparation, chemical and pharmaceutical, water and air dispensing, hydrocarbon extraction and processing, environmental control, and a range of manufacturing technologies that utilize materials such as thermoplastics, films, glues, resins, and other fluids. The flow rate measurement technology used in each specific application depends on the fluids involved and the associated process pressures, temperatures, and flow rates.

[0003] Exemplary flow rate measurement technologies include turbine devices that measure flow based on mechanical rotation, Pitot tube sensors and differential pressure devices that measure flow based on the Bernoulli effect or pressure drop across a flow restriction, eddy current and Coriolis devices that measure flow based on vibration effects, and mass flow meters that measure flow based on thermal conductivity. Magnetic flow meters differ from these technologies in that they characterize flow based on Faraday's law, which depends on electromagnetic interactions rather than mechanical or thermodynamic effects. Specifically, magnetic flow meters rely on the conductivity of the process fluid and the electromotive force (EMF) induced when the fluid flows through a magnetic field region.

[0004] A conventional magnetic flowmeter includes a sensor section, a transmitter section, and a flow tube assembly. The fluid flow to be measured travels through the pipe section of the flow tube assembly. A pair of electrodes is positioned to contact the flow. The electrodes extend through a non-conductive liner that electrically insulates the fluid from the pipe section and prevents the fluid from shorting between the electrodes and the pipe section.

[0005] The transmitter section includes a current generator that drives current through the coil of the sensor section to generate a magnetic field across the pipe section and the flow. The EMF or potential difference (voltage) induced by the magnetic field across the flow is proportional to the velocity of the flow. The magnetic flowmeter uses electrodes to measure the voltage difference and determines the flow velocity of the flow based on the measured voltage difference.

[0006] Conventional bushings are formed from polymers that are compatible with the process fluid.The rubber bushings may be adhesively bonded to the inner diameter and flange faces of the pipe sections of the flow tube assembly and then vulcanized to complete the installation.

[0007] The high chemical and temperature resistance of fluoroelastomers, such as FKM, make them ideal candidates for forming flow tube liners. Unfortunately, there are challenges in manufacturing flow tube liners using these materials. For example, fluoroelastomers can only be bonded during vulcanization and before full cure. However, the thermal mass of the flow tube assembly can hinder effective adhesive bonding and vulcanization of fluoroelastomers. Therefore, the benefits of using fluoroelastomer liners in flow tube assemblies have not yet been realized. Summary of the invention

[0008] Embodiments of the present disclosure relate to a composite flow tube liner for a flow tube assembly of a magnetic flow meter, a magnetic flow tube assembly including the composite flow tube liner, and a method of forming the composite flow tube liner. One embodiment of the composite flow tube liner includes a cylindrical substrate and an inner layer. The cylindrical substrate includes a plurality of perforations and is configured to be installed in a flow tube assembly of a magnetic flow meter. The inner layer includes a fluoroelastomer and covers an inner surface of the substrate. The inner layer extends into the perforations of the cylindrical substrate, thereby fixing the fluoroelastomer to the cylindrical substrate.

[0009] In one embodiment, the flow tube assembly includes a pipe segment and a coil configured to receive a coil current and generate a magnetic field across the pipe segment. The magnetic field induces an electromotive force (EMF) in a fluid flow traveling through an interior of the pipe segment. The composite flow tube liner is secured to the interior of the pipe segment.

[0010] In one embodiment of a method of forming a composite flow tube liner for a flow tube assembly of a magnetic flow meter, a cylindrical substrate including a plurality of perforations and an open interior is provided. A sheet comprising a fluoroelastomer is inserted into the interior of the cylindrical substrate. The sheet is pressed against the inner surface of the cylindrical substrate so that portions of the sheet extend into the perforations of the cylindrical substrate, thereby securing the fluoroelastomer to the cylindrical substrate.

[0011] According to another embodiment of the method, a substrate sheet having a plurality of perforations and a first surface and a second surface is provided. A lining sheet comprising a fluoroelastomer is applied to the first surface of the substrate sheet. The lining sheet is pressed against the first surface of the substrate sheet so that portions of the lining sheet extend into the perforations of the substrate sheet, thereby securing the lining sheet to the substrate sheet and forming a composite lining sheet. The composite lining sheet is formed into a cylinder. The second surface of the substrate sheet forms the exterior of the cylinder.

[0012] This summary is provided to introduce some concepts in a 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 help determine the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all of the disadvantages noted in the background technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a simplified diagram of an example of an industrial process measurement system according to an embodiment of the present disclosure.

[0014] Figure 2 is a schematic diagram of an example of a magnetic flow meter according to an embodiment of the present disclosure.

[0015] Figure 3 is a simplified cross-sectional diagram of an example of a magnetic flowmeter according to an embodiment of the present disclosure.

[0016] Figure 4 and Figure 5 are respectively taken along line 4-4 according to the embodiments of the present disclosure Figure 3 A simplified cross-sectional view of a composite flow tube liner and Figure 3 A simplified side plan view of a flow tube assembly.

[0017] FIG. 6A to FIG. 6C is a simplified side view of a portion of a cylindrical substrate of a composite bushing according to an embodiment of the present disclosure.

[0018] Figure 7 is a flow chart illustrating a method of forming a composite flow tube liner according to an embodiment of the present disclosure.

[0019] Figures 8 to 11 The flow tube liner according to the embodiment of the present disclosure is Figure 7 Simplified side cross-sectional views of various stages of the method.

[0020] Fig.12 and Fig.13 is a simplified side cross-sectional view showing installation of a composite flow tube liner into a flow tube assembly according to an embodiment of the present disclosure.

[0021] Fig.14 is a flow chart illustrating a method of forming a composite flow tube liner according to an embodiment of the present disclosure.

[0022] Figures 15 to 18 The flow tube liner according to the embodiment of the present disclosure is Fig.14 Simplified side cross-sectional views of various stages of the method. DETAILED DESCRIPTION

[0023] Embodiments of the present disclosure are described more fully below with reference to the accompanying drawings. Elements identified with the same or similar reference numerals refer to the same or similar elements. However, various embodiments of the present disclosure can be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure will be thorough and complete, and these embodiments will fully convey the scope of the present disclosure to those skilled in the art.

[0024] Specific details are given in the following description to provide a thorough understanding of the embodiments. However, it should be understood by those of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, circuits, systems, networks, processes, frameworks, supports, connectors, motors, processors, and other components may not be shown or may be shown in block diagram form to avoid obscuring the embodiments in unnecessary detail.

[0025] Figure 1 is a simplified diagram of an exemplary industrial process measurement system 100 according to an embodiment of the present disclosure. The system 100 may be used in the processing of materials (e.g., process media) to transform the materials from a less valuable state into a more valuable and useful product, such as pharmaceuticals, chemicals, paper, food, etc. For example, the system 100 may be used in an oil refinery that performs an industrial process that may process crude oil into gasoline, fuel oil, and other petrochemical products.

[0026] The system 100 includes a magnetic flow meter 102, which is configured, for example, to sense a flow rate of a process fluid flow 104, such as through a pipe section 106. The magnetic flow meter 102 includes a sensor section 108 and a transmitter 110. The sensor section 108 is generally configured to measure or sense a flow rate of the fluid flow 104. The transmitter 110 is generally configured to control the sensor section 108 to measure the flow rate, and optionally transmit the measured flow rate to an external computing device 112, such as a computerized control unit, which may be located remotely from the flow meter 102, such as in a control room 114 of the system 100.

[0027] The transmitter 110 can communicate with the external computing device 112 over a suitable process control loop. In some embodiments, the process control loop includes a physical communication link (such as a two-wire control loop 116) or a wireless communication link. Communications between the external computing device 112 and the transmitter segments over the control loop 116 can be performed according to conventional analog and / or digital communication protocols. In some embodiments, the two-wire control loop 116 includes a 4-20 mA control loop, wherein the process variable can be determined by the loop current I flowing through the two-wire control loop 116. L Exemplary digital communication protocols include, for example, The communication standard modulates the digital signal onto the analog current level of the two-wire control loop 116. Other purely digital technologies may also be used, including Foundation Fieldbus, Profibus, and Modbus communication protocols. Exemplary wireless versions of process control loops include, for example, wireless mesh network protocols such as (IEC 62591) or ISA 100.11a (IEC62734), or another wireless communication protocol such as WiFi, LoRa, Sigfox, BLE or any other suitable protocol.

[0028] The magnetic flow meter 102 may be powered from any suitable power source, such as an AC or DC power source. For example, the magnetic flow meter 102 may be powered entirely by the loop current I flowing through the control loop 116. L Power supply. The magnetic flow meter 102 may also be powered by one or more power sources, such as internal or external batteries. A generator (e.g., a solar panel, a wind turbine, etc.) may also be used to power the magnetic flow meter 102 or to charge a power source used by the magnetic flow meter 102.

[0029] The transmitter 110 may be directly attached to the sensor section 108, such as to a housing that houses the sensor section 108, or the transmitter 110 may be located remotely from the sensor section 108 (e.g., 10-1000 feet away therefrom). When the transmitter 110 is located remotely from the sensor section 108, electrical connections between the transmitter 110 and the sensor section 108 may be provided by one or more connecting cables or transmission lines 118, which may be formed by cables, wires, a data bus, a control bus, or other connections suitable for electrical and data communications.

[0030] Figure 2 1 is a simplified diagram of a magnetic flow meter 102 according to an embodiment of the present disclosure. The sensor section 108 may include a flow tube assembly 120 having a pipe section 122 through which the fluid flow 104 travels. The flow tube assembly 120 also includes an EMF sensor 123 having electrodes 124 (such as electrodes 124A and 124B), and the flow tube assembly 120 includes one or more excitation coils or coil wires 126, such as coils 126A and / or 126B. The electrodes 124A and 124B and the coils 126A and 126B may each be positioned on opposite sides of the pipe section 122, such as Figure 2 shown.

[0031] The digital processor 130 may represent one or more processors that control components of the magnetic flow meter 102 to perform one or more functions described herein in response to execution of instructions that may be stored in a non-transitory patent-qualified memory or computer-readable medium. In some embodiments, the digital processor 130 provides a control signal to the current generator 132 based on an operating set point of the magnetic flow meter 102 to generate a coil current I C , the coil current includes, for example, DC current pulses (eg, square wave current pulses) that alternate the direction through the coil 126. Other types of alternating coil currents may also be used.

[0032] In some embodiments, the current generator 132 includes a controller 140 and a power amplifier 142. The controller 140 may represent one or more processors that control components of the power amplifier 142 to perform one or more functions described herein, such as in response to control signals from the digital processor 130 and / or in response to the execution of instructions, which may be stored in a non-transitory patent-qualified memory or computer-readable medium represented by the controller 140.

[0033] The controller 140 controls the power amplifier 142 to generate the coil current I based on the set point level of the magnetic flow meter 102 C The controller 140 may periodically receive the coil current I from the current sampling circuit 143. C The current level measurement result is used as feedback to determine whether the coil current I C Adjustments are made to match the set point level of the magnetic flow meter 102, which is necessary for accurate flow rate measurement.

[0034] The current sampling circuit 143 may take any suitable form. For example, the current sampling circuit 143 may be operable to Figure 2 The position shown is sensed by the coil current I C The sampled voltage is converted into a digital signal using an analog-to-digital converter, which is presented to the controller 140 as a measured current level, for example. The controller 140 may adjust the coil current I based on the measured current level. C , in an attempt to make the coil current I C The current level matches the set point current level indicated by the operating set point of the magnetic flowmeter 102.

[0035] Coil current I C By appropriate electrical connections (such as Figure 1 and Figure 2The transmission line 118 shown in the figure is delivered to the excitation coil 126A and / or 126B of the flow tube assembly 120. This causes the coil 126A and / or 126B to generate a magnetic field across the pipe section 122, which changes direction at the desired excitation frequency. The process fluid flow 104 traveling through the interior 144 of the pipe section 122 acts as a moving conductor that induces an EMF in the fluid according to Faraday's law of electromagnetic induction. The electrodes 124A and 124B (which may include electrode components that provide capacitive coupling with the conductive process fluid or direct electrical coupling with the conductive process fluid) pick up the voltage present in the fluid flow 104. The voltage difference at the electrodes 124A and 124B is proportional to the velocity of the fluid flow 104.

[0036] Signal processor 128 of transmitter 110 is connected to electrodes 124A and 124B. Flow tube assembly 120 may be electrically grounded to pipe segment 122, a flange or pipe segment upstream or downstream of pipe segment 122, or another suitable ground connection. Digital processor 130 controls signal processor 128 using any suitable technique to sample the voltage difference between electrodes 124A and 124B and provide the measured voltage difference to digital processor 130. For example, this may involve converting an analog differential voltage signal to a digital value provided to digital processor 130. Digital processor 130 may perform further signal processing on the measured differential voltage to establish a flow rate measurement of the flow rate of process fluid stream 104. The measured flow rate may be transmitted to computing device 112 using communication interface 146, such as by one of the wired or wireless communication protocols discussed above.

[0037] Figure 3 1 is a simplified cross-sectional view of an example of a magnetic flowmeter 102 according to an embodiment of the present disclosure. In some embodiments, the magnetic flowmeter 102 includes a transmitter housing 150 that can house circuitry forming the transmitter 110, such as a signal processor 128, a digital processor 130, a communication interface 146, a controller 140, a power amplifier 142, and / or other components. A magnetics compartment 152 can surround the pipe segment 122 of the flow tube assembly 120 and house one or more excitation coils 126, electrodes 124, and / or other components. As described above, the excitation coils 126 (such as excitation coils 126A and 126B) can be positioned opposite each other on the outside of the pipe segment 122 (e.g., above and below the pipe segment 122).

[0038] The composite flow tube liner 160 of the flow tube assembly 120 formed according to one or more embodiments described herein seals the pipe segment 122 from the interior 144 through which the fluid stream 104 travels. The electrode 124 may extend through the tunnel 162 of the pipe segment 122 while being electrically insulated from the pipe segment 122. The electrode 124 and / or electrical connections to the electrode 124 may extend through the hole 164 of the liner 160 and into the interior 144 to contact the fluid stream 104. The hole 164 may be located on opposite sides of the liner 160, such as by Figure 2 As shown in the holes 164A and 164B in the liner 160. For example, the liner 160 may include additional holes 164 as needed to accommodate additional electrodes 124, such as a reference electrode. The liner 160 may provide a seal with the electrode 124 at the hole 164 to prevent fluid from penetrating into the pipeline segment 122.

[0039] Embodiments of composite flow tube liner 160 include a fluoroelastomer layer that provides high chemical resistance to process fluid stream 104. The fluoroelastomer layer of composite flow tube liner 160 also provides protection from process fluid penetration into pipe segment 122 during operation. This protects magnetic flow meter 102 from forming a short circuit between fluid stream 104, pipe segment 122, and electrode 124A or 124B, which would render magnetic flow meter 102 inoperable.

[0040] Figure 4 and Figure 5 are respectively taken along line 4-4 according to the embodiments of the present disclosure Figure 3 A simplified cross-sectional view of the composite flow tube liner 160 and Figure 3 14. A simplified side plan view of a liner 160 of FIG. 14. The features shown are not shown to scale. In some embodiments, the composite flow tube liner 160 includes a composite (e.g., multi-layer) cylindrical wall 166 having an open interior 168 that substantially surrounds the interior 144 of the pipe segment and receives the process fluid stream 104. The wall 166 includes an interior layer 170 and a cylindrical substrate 172 that may form an exterior layer of the liner 160. In one embodiment, the interior layer 170 is directly attached to the cylindrical substrate. Alternatively, embodiments of the liner 160 may include one or more intermediate layers (not shown) positioned between the interior layer 170 or a portion of the interior layer 170 and the cylindrical substrate 172.

[0041] In some embodiments, inner layer 170 includes a fluoroelastomer, such as FKM (which is a family of fluoroelastomer materials defined by the American Society for Testing and Materials (ASTM) standard D1418) or another suitable fluoroelastomer. Fluoroelastomer inner layer 170 provides for the flow of process fluid 104 ( Figure 1 )'s electrical insulation and chemical resistance.

[0042] The fluoroelastomer may form substantially 100% (eg, at least 98%) by weight of the interior layer 170. Alternatively, the fluoroelastomer may form at least 50%, at least 75%, at least 90%, and at least 95% by volume or weight of the interior layer 170.

[0043] The cylindrical substrate 172 may be formed of a metal. The metal may form substantially all (eg, greater than 90% by volume or weight) of the substrate 172. Examples of metals include aluminum, stainless steel, gold, copper, titanium, chromium, tantalum, vanadium, nickel, and metal oxides.

[0044] The fluoroelastomer inner layer 170 may be bonded to the inner side 173 of the cylindrical substrate 172 using one or more of the techniques described herein. In some embodiments, the cylindrical substrate 172 has a plurality of perforations 174 that facilitate bonding the fluoroelastomer inner layer 170 to the inner side 173 of the cylindrical substrate 172.

[0045] The perforations 174 can take various shapes. In one embodiment, the perforations 174 are generally circular, such as Figure 5 shown. FIG. 6A to FIG. 6C is a simplified side view of a portion of a cylindrical substrate 172 according to an embodiment of the present disclosure. In some embodiments, the through-holes 174 may have an elliptical shape, such as Fig. 6A as shown, or a rectangle, as Figure 6B In some embodiments, the cylindrical substrate 172 is formed of a wire mesh 176 having perforations 174 defined by openings through the wire mesh 176, such as Figure 6C shown.

[0046] As described in more detail below, the fluoroelastomer inner layer 170 can be pressed against the inner side 173 of the cylindrical substrate such that portions of the fluoroelastomer inner layer 170 extend at least partially into the perforations 174 of the cylindrical substrate 172. Heat can be used to cure the fluoroelastomer inner layer 170 in this configuration to securely bond the fluoroelastomer inner layer 170 to the cylindrical substrate 172 and form the composite flow tube liner 160.

[0047] Any suitable technique may be used to secure the outer surface 178 of the cylindrical substrate 172 within the interior 144 of the pipe segment 122. As described below, this may involve bonding (e.g., adhesively bonding or welding) the outer surface 178 to the inner surface 180 of the pipe segment and / or flaring the end 182 of the composite flow tube liner 160, such as Figure 3 shown.

[0048] Figure 7 is a flow chart illustrating a method of forming a composite flow tube liner 160 according to an embodiment of the present disclosure. Figures 8 to 11The flow tube liner 160 according to an embodiment of the present disclosure is Figure 7 Simplified side cross-sectional views of various stages of the method.

[0049] At 184 of the method, a cylindrical substrate 172 having a plurality of through-holes 174 and an open interior 185 is provided, such as Figure 8 In some embodiments, the cylindrical substrate 172 can be separated from the flow tube assembly 120 and the remaining steps of the method are performed to complete the manufacture of the flow tube liner 160 before installing it in the pipe section 122 of the flow tube assembly 120. Alternatively, the cylindrical substrate 172 is fixed in the pipe section 122 of the flow tube assembly 120 using any suitable technique (e.g., adhesive bonding, welding, flaring the end 182, etc.) before performing the remaining steps of the method described below.

[0050] At 186 of the method, one or more liner sheets 187 (hereinafter referred to as "sheets") comprising uncured fluoroelastomer are inserted into the interior 185 of the cylindrical substrate 172. The sheet 187 corresponds to the inner layer 170. The sheet 187 can be rolled into a circle so that it covers the inner side 173 of the cylindrical substrate 172, as shown in FIG. Fig. 9 shown.

[0051] At 188, the sheet 187 is pressed against the inner surface 173 of the cylindrical substrate 172. Any suitable technique may be used to perform this method step. In one embodiment, a forming mandrel 190 is inserted on the inner side 192 of the sheet 187, such as Fig.10 The mandrel 190 is then inflated to radially press the sheet 187 against the inner surface 173 to form the inner layer 170, as shown. Fig.11 As shown, and the pressing step 188 is completed.

[0052] The sheet 187 may be heated before, during, and / or after the pressing step 188. In one embodiment, the sheet 187 is initially heated to a flow temperature (e.g., a temperature of about 120° C. (248° F.)) at which the fluoroelastomer within the sheet 187 flows but does not begin to cure. This ensures that the fluoroelastomer is ductile and fills or at least partially extends into the perforations 174 during the pressing step 188, as shown in FIG. Figure 4 and Fig.11 shown.

[0053] Such heating of the sheet 187 may be performed by heating the mandrel 190 using a suitable heating device and / or applying heat directly to the sheet 187 and / or cylindrical substrate 172. When the cylindrical substrate 172 is secured within the pipe section 122 of the flow tube assembly 120 during step 188, the pipe section 122 may be heated to heat the cylindrical substrate 172 and sheet 187 to a flow temperature while being contained on the interior side of the substrate 172 and pressed against the surface 173.

[0054] After the pressing step 188, the pressed sheet 187 or inner layer 170 (having a portion extending at least partially into the perforation of the cylindrical substrate 172, such as Figure 4 The composite wall 166 formed by the inner layer 170 and the cylindrical substrate 172 may then be cooled. According to some embodiments, this allows the inner layer 170 to bond to the cylindrical substrate and may complete the formation of the composite flow tube liner 160.

[0055] When the completed flow tube liner 160 is separated from the flow tube assembly 120, it can be secured within the pipe segment 122 of the flow tube assembly 120 using a variety of techniques. In some embodiments, the pipe segment 122 includes a central axis 193, and the flow tube liner 160 is inserted into the pipe segment 122 such that it is substantially concentric with the central axis 193, such as Fig.12 The flow tube liner 160 may then be secured within the pipe segment 122 using any suitable technique, such as adhering or welding the outer surface 178 of the cylindrical substrate 172 to the inner surface 180 of the pipe segment 122 and / or flaring the end 182 of the flow tube liner 160, such as Figure 3 and Fig.13 shown.

[0056] The end 182 of the flow tube liner 160 may be expanded using a suitable tube expansion tool so that the end 182 extends away from the central axis 193, such as Figure 3 and Fig.13 The flared end 182 may be clamped between a flange 194 attached to the pipe segment 122 and a flange of a pipe segment adjacent to the pipe segment 122, such as Figure 1 Pipe segments 106 are shown) which may receive and discharge fluid streams 104 from these pipe segments. According to some embodiments, this secures the flow tube bushings 160 within the pipe segments 122 and may complete the formation of the flow tube assembly.

[0057] Fig.14is a flow chart illustrating a method of forming a composite flow tube liner 160 according to an embodiment of the present disclosure. Figures 15 to 18 The flow tube liner 160 according to an embodiment of the present disclosure is Fig.14 Simplified side cross-sectional views of various stages of the method.

[0058] At 200 of the method, a substrate sheet 202 having a plurality of through-holes 204, a first surface 206, and an opposing second surface 208 is provided. Fig.15 According to one or more embodiments described above, the substrate sheet 202 will be used to form the cylindrical substrate 172 of the composite flow tube liner 160. The through-holes 204 extend from the first surface 206 to the second surface 208 and may be formed according to the embodiments of the through-holes 174 described above.

[0059] At 210 of the method, a lining sheet 212 comprising a fluoroelastomer such as FKM is applied to the surface 206 of the substrate sheet 202. Fig.16 According to one or more embodiments described above, the liner sheet 212 is used to form the inner layer 170 of the composite flow tube liner 160 .

[0060] At 214 of the method, the bushing sheet 212 is then pressed against the surface 206, as shown. Fig.17 As shown. A plate, roller or other suitable member may be used to press the liner sheet 212 against the surface 206. This causes a portion of the liner sheet 212 to extend into the perforations 204. This secures the liner sheet 212 to the substrate sheet 202 and forms a composite liner sheet 216, such as Fig.18 shown.

[0061] At 218 of the method, the composite liner sheet 216 is formed into a cylinder to form the composite flow tube liner 160 ( Figure 4 and Figure 5 ), wherein the substrate sheet 202 forms the substrate cylinder 172 and the liner sheet 212 forms the inner layer 170. Thus, the second surface 208 of the substrate sheet 202 corresponds to the outer surface 178 of the cylindrical substrate 172. In some embodiments, the composite liner sheet 216 may be cut to a desired size before rolling the composite liner sheet 216 into a cylinder. The composite liner sheet 216 may also be formed large enough to allow multiple sections to be cut from the sheet 216, and each section is used to form the composite flow tube liner 160.

[0062] In some embodiments, the sheet 216 is rolled into a cylinder and the adjoining ends of the substrate sheet 202 are secured together using suitable techniques to form the flow tube liner 160, which is configured for subsequent installation into the duct segment 122 of the flow tube assembly 120. Heat may be applied to the sheet 212 to ensure that all seams are sealed by the sheet 212.

[0063] Alternatively, for example, the composite liner sheet 216 may be rolled into a cylinder, inserted into the pipe segment 122, and secured or bonded to the pipe segment 122 to form the flow tube liner 160 and flow tube assembly 120, as shown. Figure 3 In one embodiment, a surface 208 corresponding to the outer surface 178 of the substrate cylinder 172 may be adhered to the inner surface 180 of the pipe segment 122 using a suitable adhesive, and / or the end 182 may be flared to secure the flow tube liner 160 formed from the composite sheet 216 to the pipe segment 122.

[0064] In some embodiments of the method, the liner sheet 212 includes an uncured fluoroelastomer, and the method includes heating the liner sheet 212 before, during, and / or after the pressing step 214. In one embodiment, the liner sheet 212 is heated to a flow temperature before or during the pressing step 214, at which the fluoroelastomer is ductile or flowing. This enhances the extension of the portion of the liner sheet 212 into the perforations 204 of the substrate sheet 202 during the pressing step 214. The heating and pressing step 214 can be completed before or after the composite liner sheet 216 or the flow tube liner 160 formed using the composite liner sheet 216 is installed in the pipe segment 122 of the flow tube assembly. In some embodiments, the flow temperature is less than the cure temperature at which the fluoroelastomer of the liner sheet 212 cures.

[0065] After forming the composite liner sheet 216, the liner sheet 212 may be heated to at least the curing temperature of the fluoroelastomer to cure the liner sheet 216. This may be done before or after installing the composite liner sheet 216 or a flow tube liner 160 formed using the composite liner sheet 216 in a pipe segment 122 of a flow tube assembly.

[0066] Although embodiments of the present disclosure have 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 present disclosure.

Claims

1. A composite flow tube liner for a flow tube assembly of a magnetic flow meter, the composite flow tube liner comprising: a cylindrical substrate having a plurality of perforations and an open interior and configured for mounting within a flow tube assembly of a magnetic flow meter; as well as an inner layer comprising a fluoroelastomer and covering an inner surface of the substrate, wherein the inner layer extends into the perforations of the cylindrical substrate thereby securing the inner layer to the cylindrical substrate, Wherein, the composite flow tube liner is formed by the following method: providing the cylindrical substrate including the plurality of perforations and the open interior; inserting a sheet comprising a fluoroelastomer into the interior of the cylindrical substrate; pressing the sheet against the inner surface of the cylindrical substrate, wherein portions of the sheet extend into the perforations of the cylindrical substrate, thereby securing the fluoroelastomer to the cylindrical substrate, wherein pressing the sheet against the inner surface of the cylindrical substrate comprises: inserting a forming mandrel into the interior of the cylindrical substrate; and The mandrel is expanded against the inner surface of the sheet, thereby pressing the sheet against the inner surface of the cylindrical substrate.

2. The composite flow tube liner of claim 1, wherein the cylindrical substrate comprises a wire mesh.

3. The composite flow tube liner of claim 1, wherein the perforations have a shape selected from the group consisting of: circular, oval, and rectangular.

4. The composite flow tube liner of claim 1, wherein the cylindrical substrate comprises a metal selected from the group consisting of aluminum, stainless steel, gold, copper, titanium, chromium, tantalum, vanadium, nickel, and metal oxides.

5. A flow tube assembly for use with a magnetic flow meter to measure the flow rate of a fluid flow, the flow tube assembly comprising: Pipeline sections; a coil configured to receive a coil current and generate a magnetic field across the pipe segment, the magnetic field inducing an electromotive force (EMF) in a fluid flow traveling through an interior of the pipe segment; as well as The composite flow tube liner of claim 1, secured to said interior of said pipe segment.

6. The flow tube assembly of claim 5, wherein an outer surface of the cylindrical substrate is bonded to an inner surface of the pipe segment.

7. The flow tube assembly of claim 5, wherein: The duct section includes a central axis; and The composite flow tube liner includes opposing flared end portions positioned on an outside of the duct segment, the flared end portions extending away from the central axis.

8. The flow tube assembly of claim 5, further comprising a pair of electrodes exposed to an interior side of the pipe segment.

9. A magnetic flowmeter, comprising: The flow tube assembly according to claim 8; a power amplifier configured to generate a coil current; a signal processor configured to receive the voltages sensed by the electrodes and generate a digital voltage signal indicative of a voltage difference between the electrodes, the voltage difference being proportional to the EMF and a flow rate of the fluid flow; as well as A digital processor is configured to process the digital voltage signal and establish a flow rate of the fluid flow.

10. A method of forming a composite flow tube liner for a flow tube assembly for a magnetic flow meter, the method comprising: providing a cylindrical substrate including a plurality of perforations and an open interior; inserting a sheet comprising a fluoroelastomer into the interior of the cylindrical substrate; pressing the sheet against the inner surface of the cylindrical substrate, wherein portions of the sheet extend into the perforations of the cylindrical substrate, thereby securing the fluoroelastomer to the cylindrical substrate, wherein pressing the sheet against the inner surface of the cylindrical substrate comprises: inserting a forming mandrel into the interior of the cylindrical substrate; and The mandrel is expanded against the inner surface of the sheet, thereby pressing the sheet against the inner surface of the cylindrical substrate.

11. The method of claim 10, wherein the fluoroelastomer of the sheet is fully cured.

12. The method according to claim 10, wherein: The fluoroelastomer is uncured; The method includes heating the sheet; and Pressing the sheet against the inner surface of the cylindrical substrate includes pressing a heated sheet against the inner surface of the cylindrical substrate.

13. The method according to claim 12, wherein: Heating the sheet includes heating the sheet to a first temperature at which the fluoroelastomer flows but does not begin to cure; and The method includes curing the fluoroelastomer after pressing against the sheet, including heating the sheet to a second temperature greater than the first temperature.

14. The method of claim 10, further comprising forming a magnetic flow meter, comprising: supply: Pipeline sections; as well as a coil configured to receive a coil current and generate a magnetic field across the pipe segment, the magnetic field inducing an electromotive force (EMF) in a fluid flow traveling through an interior of the pipe segment; as well as The composite flow tube liner is secured within the interior of the pipe segment.

15. The method of claim 14, wherein securing the composite flow tube liner within the interior of the pipe segment comprises bonding an outer surface of the cylindrical substrate to an inner surface of the pipe segment prior to inserting and pressing the sheet against the sheet.

16. The method of claim 14, wherein: The duct section includes a central axis; and Securing the composite flow tube liner within the interior of the pipe segment includes flaring opposing ends of the composite flow tube liner positioned outside of the pipe segment away from a central axis.

17. A method of forming a composite flow tube liner for a flow tube assembly for a magnetic flow meter, the method comprising: providing a substrate sheet including a plurality of perforations and a first surface and a second surface; applying a liner sheet comprising a fluoroelastomer onto the first surface of the substrate sheet; pressing the liner sheet against the first surface of the substrate sheet, wherein portions of the liner sheet extend into the perforations of the substrate sheet, thereby securing the liner sheet to the substrate sheet and forming a composite liner sheet; and forming the composite liner sheet into a cylinder, wherein the second surface of the substrate sheet forms an exterior of the cylinder; in: The fluoroelastomer is uncured; The method includes heating the bushing sheet; and Pressing the liner sheet against the first surface of the substrate sheet includes pressing the heated sheet against the first surface of the substrate sheet; Heating the liner sheet includes heating the liner sheet to a first temperature at which the fluoroelastomer flows but does not begin to cure; and The method includes curing the fluoroelastomer after being pressed against the liner sheet, including heating the liner sheet to a second temperature greater than the first temperature.

18. The method of claim 17, wherein the fluoroelastomer of the bushing sheet is fully cured.

19. The method of claim 17, further comprising forming a magnetic flow meter, comprising: supply: Pipeline sections; as well as a coil configured to receive a coil current and generate a magnetic field across the pipe segment, the magnetic field inducing an electromotive force (EMF) in a fluid flow traveling through an interior of the pipe segment; as well as The composite flow tube liner is secured within the interior of the pipe segment.

20. The method of claim 19, wherein: The duct section includes a central axis; and Securing the composite flow tube liner within the interior of the pipe segment includes flaring opposing ends of the composite flow tube liner positioned outside of the pipe segment away from a central axis.

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