A housing formation

Abstract

A housing formation for a transducer (12) of a flowmeter (14), the housing formation including: a wall (16) extending into a fluid flow passageway (18) of a flowmeter body (20); a recess (22) defined in the wall (16) for receiving the transducer (12) therein; and an opening (24) defined in a side (26) of the wall (16) opposite the fluid flow passageway (18), the opening (24) leading into the recess (22) for enabling the transducer (12) to be inserted into the recess (22) from the side (26) of the wall (16).

Description

[0001] A HOUSING FORMATION

[0002] TECHNICAL FIELD

[0003] This invention relates to a housing formation. In particular, this invention relates to a housing formation for transducers of an ultrasonic flow meter used to measure fluid flow rates.

[0004] BACKGROUND

[0005] The inventor of the present invention is also the inventor of an earlier invention entitled “A Flowmeter” filed under PCT Patent Application No.: PCT / ZA2018 / 050062.

[0006] The earlier version of the flowmeter included a body defining a passageway for allowing fluid to flow therethrough, the passageway having inlet and outlet portions arranged at opposing end regions of an intermediate portion of the passageway, which intermediate portion was arranged at an angle relative to central axes of the inlet and outlet portions and had a reduced cross-sectional area compared to the inlet and outlet portions. The flowmeter included a sensing arrangement with a pair of sensors, which extended substantially inwardly from opposing end regions of the intermediate portion for sensing a flow of fluid therebetween along an axis which is substantially parallel to the intermediate portion.

[0007] In addition, the earlier version of the flowmeter included transducer housings which included openings which lead into the housings from within the fluid flow passageway. Once a transducer was inserted into the housing via the opening, the opening would be closed by a cap. Although great efforts were made to smooth the joint between the edges of the cap and the opening and to ensure an effective fit, it was found that after some time, the fluid flowing through the flowmeter would wear away material at the joint. Wearing away of material at the joint would lead to increased turbulence which could negatively affect measurement accuracy and / or to potential leakages of fluid into the housing which would cause component failure. The inventor believes that there are several significant design alterations which have the potential to further improve measurement accuracy, power consumption and ease of manufacturing of the flowmeter.

[0008] SUMMARY OF THE INVENTION

[0009] According to a first aspect of the invention, there is provided a housing formation for a transducer of a flowmeter, the housing formation including: - a wall extending into a fluid flow passageway of a flowmeter body; a recess defined in the wall for receiving the transducer therein; and an opening defined in a side of the wall opposite the fluid flow passageway, the opening leading into the recess for enabling the transducer to be inserted into the recess from the side of the wall.

[0010] The wall may be integrally formed with the flowmeter body. It is to be appreciated that the wall being integrally formed with the flowmeter body eliminates the possibility of fluid leaking into the recess from the fluid flow passageway and interfering with and / or damaging the transducer in use. It is to be appreciated further that the wall being integrally formed with the flowmeter body eliminates turbulence creating ridges which may result from joints between various components within the fluid flow passageway.

[0011] The wall may have a generally arcuate and / or streamlined form. In particular, a surface of the wall encountering fluid in the fluid flow passageway may be shaped, configured and / or treated to encourage laminar flow of fluid thereover. The surface of the wall may include any surface treatment of the group including polishing, hydrophobic coatings, hydrophilic coatings, riblets, liquid-infused surfaces, nanotextured surfaces, and surface cleaning. The wall may include a first portion on which the transducer may be mounted. The first portion of the wall may include an outer surface which may encounter fluid inside the fluid flow passageway of the flowmeter. The outer surface of the first portion may extend from the flowmeter body at an angle in the range of 90 degrees to 135 degrees, preferably extending from the flowmeter body at an angle in the region of 95 degrees. The angle at which the outer surface extends from the flowmeter body may coincide with the angle of an intermediate portion of the flow passageway relative to inlet and outlet portions of the fluid flow passageway. More particularly, the intermediate portion of the flow passageway may be angled in the range of 2 to 12 degrees, preferably in the region of 5 degrees, from central axes of the inlet and outlet portions. It is to be appreciated that the angle of the outer surface is significant as it allows the signal from the transducer to be transmitted and / or received along an axis substantially parallel to the intermediate portion to a downstream transducer. It is to be understood that the outer surface of the first portion is intended to be the surface on the inside of the flowmeter body. The first portion of the wall may have a thickness in the range of 2mm to 7mm.

[0012] The outer surface of the first portion may be shaped, configured, treated and / or coated to optimise signal transmission and / or receipt by the transducer through the fluid flow passageway of the flowmeter body. The outer surface of the first portion may have a smoothed, consistent and / or uniform profile for reducing signal reflection and / or scattering. In particular, the outer surface may be polished for reducing reflection and / or scattering as a result of irregularities in the surface. More particularly, the outer surface of the first portion may include a guiding formation for guiding, directing, and / or focusing the signal towards and / or onto a downstream transducer. The guiding formation may be in the form of a concave surface. It is to be appreciated that the guiding formation in the outer surface of the first portion may cause collimation of the signal or beam transmitted by the transducer thus reducing energy consumption and increasing battery life. The outer surface of the first portion may include an anti-reflective coating for reducing signal reflection at a boundary between the outer surface of the first portion and fluid in the flow passageway.

[0013] The outer surface of the first portion may include an acoustic matching material layer for improving signal transmission at a boundary between the outer surface of the first portion and fluid in the flow passageway. It is to be appreciated that the acoustic matching layer serves to reduce the difference in acoustic impedance between the first portion and the fluid which in turn reduces the amount of reflection of the signal back towards the transducer.

[0014] The first portion of the wall may include an inner surface located inside of the recess. The inner surface of the first portion may extend at an angle similar to that of the outer surface of the first portion, the inner surface of the first portion preferably extending substantially parallel to the outer surface of the first portion. The inner surface of the first portion may include a transducer support portion for allowing mounting and support of the transducer thereon. The transducer support portion may be formed integrally with the inner surface of the first portion. In particular, the transducer support portion may define a mounting surface for allowing mounting and support of the transducer thereon. The mounting surface may be substantially parallel to the outer surface of the first portion for allowing the transducer to transmit signals along an axis substantially parallel to the intermediate portion of the flow passageway towards a similarly, but oppositely orientated downstream transducer. The transducer support portion may have a thickness in the range of 2mm to 7mm, preferably being in the region of 4mm. The transducer support portion may include surface treatments for optimising the adhesion to the transducer. The surface treatment may include abrasion and / or chemical treatments. In particular, the surface treatment may include a light abrasion and chemical cleaning to optimise glue adhesion. The inner surface of the first portion may include an anti-reflective coating or member for reducing signal scatter. A receiving formation, preferably being in the form of a slot, notch, depression, or furrow, may be defined in the transducer support portion for receiving and allowing transducer connecting wires to lead away from the transducer from an interface region between the transducer and the transducer support portion. It is to be appreciated that the receiving formation serves to prevent the wires from interfering with the fit between the transducer and the transducer support portion.

[0015] A groove may be defined in the inner surface at a periphery of the transducer support portion. Preferably, the groove may be defined in the transducer support portion to counter the transducer support surface from taking on a pillow shape due to the water pressure on the outer surface of the first portion of the wall which would place the glue layer, holding the transducer, under severe stress. The groove may have a generally annular form and may surround the transducer support portion. The groove may define a deformation reducing formation in the first portion of the wall for reducing a degree of deformation of the transducer support portion as a result of vibrations experienced during activation of the transducers. The deformation reducing formation may be in the form of a thinner region of the first portion of the wall. The thinner region may have a thickness in the range of 0.5mm to 4mm, preferably being in the region of 3mm. It is to be appreciated that the thinner region acts as a hinge-like formation which, due to being thinner than the transducer support portion, deforms more easily thus taking up a majority of the deformation of the first portion and reducing the likelihood of damage to the transducer, cracking of glue between the transducer and the transducer support portion, and separation of the transducer and transducer support portion, all of which may lead to failure of the flowmeter. It is to be appreciated further that the thinner region of the first portion also aids in signal transmission and propagation as it allows the transducer support portion to vibrate more freely. It is to be appreciated yet further that the groove also provides a space in which excess glue may enter when mounting the transducer to the transducer support portion. The groove may be sized to ensure that the mounting surface of the transducer support portion is smaller than the transducer to promote the flow of excess glue into the groove. More particularly, the groove may be sized to ensure that the mounting surface has a diameter at least 0.5mm, preferably 1 mm, smaller than the transducer. The wall may include a second portion leading from the first portion. An outer surface of the second portion may be shaped, configured, treated and / or coated to encourage laminar flow of fluid thereover. The outer surface of the second portion may have an elongated and / or arcuate form for encouraging laminar flow thereover and reducing bubble formation. The outer surface of the second portion may have a smoothed, consistent and / or uniform profile for reducing turbulence of fluid flowing thereover. The outer surface of the second portion may include any surface treatment of the group including polishing, hydrophobic coatings, hydrophilic coatings, riblets, liquid-infused surfaces, nanotextured surfaces, and surface cleaning.

[0016] The transducer may be in the form of an ultrasonic transducer. In particular, the transducer may be in the form of a piezoelectric transducer. The transducer may have a generally disc-like shape.

[0017] A temperature sensor may be provided for measuring the temperature of fluid flowing through the passageway of the body. The temperature sensor may be mounted in a receiving zone defined in the wall. The temperature sensor may be in the form of a thermistor or a thermocouple.

[0018] The flowmeter may include a pair of housing formations as hereinbefore described. The pair of housing formations may be located at opposing ends and opposing sides of the flowmeter body. More particularly, each of the housing formations may extend from each of two body portions which may define the flowmeter body. The two body portions may be identical to each other. The two body portions may be rotated 180 degrees relative to each other and arranged in an end-to-end manner to define the flowmeter body.

[0019] The flowmeter body may be mounted in an outer casing such that inlet and outlet portions thereof extend beyond the casing for allowing interconnection between fluid carrying piping. The two body portions of the flowmeter body may include locking pin receiving formations for allowing retention in the end-to-end arrangement by a plurality of locking pins. It is to be appreciated that the outer casing serves to encase the flowmeter body along with a battery and any auxiliary electronic devices, wiring and / or circuitry. The electronic devices may include RF (Radiofrequency) enabled communication devices which may be utilised to control the flowmeter and / or to obtain readings therefrom remotely.

[0020] The flowmeter body, housing formations and / or casing may be manufactured from any suitable plastics, metallic or synthetic material, preferably being manufactured from a polymer. The polymer may be reinforced. The polymer may be in the form of a Glass Fiber Reinforced Polymer.

[0021] According to a second aspect of the invention, there is provided a flowmeter including: - a body defining a fluid flow passageway for allowing fluid to flow therethrough, the passageway having inlet and outlet portions arranged at opposing end regions of an intermediate portion of the passageway; and a pair of housing formations as hereinbefore described located at opposing end and side regions of the intermediate portion of the fluid flow passageway for receiving a pair of transducers therein.

[0022] The inlet portion may include a mounting formation for allowing a filtering member to be mounted at an inlet of the flowmeter body for reducing a likelihood of large particles from entering the fluid flow passageway. The filtering member may be in the form of a wire mesh or sieve-like member. The mounting formation may be in the form of a shoulder extending from an inner region of the inlet portion. The shoulder may be sized and / or shaped to permit mounting of the filtering member by friction fit. According to a third aspect of the invention, there is provided a method for mounting an ultrasonic transducer on a transducer support surface inside a housing formation as hereinbefore described, the method including the steps of: - applying an adhesive to the transducer; connecting the transducer to a power source; inserting the transducer into a recess of the housing formation via an opening defined in a side of the wall of the housing formation; aligning the transducer with the transducer support surface such that the adhesive faces the transducer support surface; displacing the transducer towards the transducer support surface thus bringing the adhesive into contact with the transducer support surface; activating the power source causing the transducer to vibrate; displacing the transducer further towards the transducer support surface until excess adhesive exits from between the transducer and transducer support surface from a periphery thereof; and allowing the adhesive to set.

[0023] The adhesive may be in the form of any suitable glue. Preferably, the glue may be applied in droplet form. The droplet of glue may have a diameter in the range of 1 mm to 5mm, preferably having a diameter in the region of 3mm.

[0024] The power source may be in the form of a low frequency power source for allowing the transducer to vibrate at a low frequency.

[0025] Displacing the transducer further towards the transducer support surface may include the step of twisting and / or pivoting the transducer simultaneously. Displacing the transducer further towards the support surface may cause excess adhesive to enter a groove defined at the periphery of the transducer support surface. It is to be appreciated that entrained air bubbles weaken the bond and attenuate the signal to be transmitted by the transducer, thus during manufacturing of the flowmeter body, typically moulding of the two portions of the flowmeter body, the portions are gently removed from the press, without pulling on the leads or wires and allow undisturbed curing for a period specified for the particular glue.

[0026] It is to be appreciated that vibrating, rocking and / or twisting the transducer while squashing the adhesive between the transducer and the transducer support surface encourages even and uniform spreading of the adhesive therebetween. It is to be appreciated further that the vibration is believed to force air out from between the contact surfaces thus improving adhesion and strength of the adhesive.

[0027] It is to be appreciated yet even further that the above method is specifically intended to facilitate automation of the transducer mounting process.

[0028] BRIEF DESCRIPTION OF THE DRAWINGS

[0029] A housing formation in accordance with the invention will now be described by way of the following, non-limiting examples with reference to the accompanying drawings.

[0030] In the drawings: -

[0031] Figure 1 is a side view showing a casing with a flowmeter mounted therein;

[0032] Figure 2 is an end view showing the casing of Figure 1 ;

[0033] Figure 3 is a sectioned underside view along line 3-3 in Figure 1 , showing the flowmeter and transducer housing formations thereof;

[0034] Figure 4 is a sectioned side view along line 4-4 in Figure 2, showing the flowmeter and transducer housing formations; Figure 5 is a three-dimensional sectioned view showing the configuration of flowmeter and casing;

[0035] Figure 6 is a three-dimensional schematic showing a body of the flowmeter without the casing;

[0036] Figure 7 is a three-dimensional schematic showing a second portion of the flowmeter body;

[0037] Figure 8 is a three-dimensional sectioned view along the line 8-8 in Figure 7, showing an inside of the second portion of the flowmeter body;

[0038] Figures 9 and 10 are sectioned and enlarged sectioned side views showing the housing formations of the flowmeter more clearly; and

[0039] Figure 1 1 is an enlarged schematic representation showing a groove surrounding a transducer support portion of a first portion of the wall of the housing formation.

[0040] DETAILED DESCRIPTION OF THE INVENTION

[0041] Referring now to the Figures, reference numeral 10 refers generally to a housing formation for a transducer 12 of a flowmeter 14, the housing formation including: a wall 16 extending into a fluid flow passageway 18 of a flowmeter body 20; a recess 22 defined in the wall 16 for receiving the transducer 12 therein; and an opening 24 defined in a side 26 of the wall 16 opposite the fluid flow passageway 18, the opening 24 leading into the recess 22 for enabling the transducer 12 to be inserted into the recess 22 from the side 26 of the wall 16.

[0042] The wall 16 is integrally formed with the flowmeter body 20. It is to be appreciated that the wall 16 being integrally formed with the flowmeter body 20 eliminates the possibility of fluid leaking into the recess 22 from the flow passageway 18 and interfering with or damaging the transducer 12. It is to be appreciated further that the wall 16 being integrally formed with the flowmeter body 20 eliminates turbulence creating ridges resulting from joints between various components within the fluid flow passageway 18. The wall 16 has a generally arcuate and streamlined form. In particular, a surface 28 of the wall 16 encountering fluid in the fluid flow passageway 18 is shaped, configured, or treated to encourage laminar flow of fluid thereover. The surface 28 of the wall 16 includes any surface treatment of the group including polishing, hydrophobic coatings, hydrophilic coatings, riblets, liquid-infused surfaces, nanotextured surfaces, and surface cleaning.

[0043] The wall 16 includes a first portion 30 on which the transducer 12 is mounted. The first portion 30 of the wall 16 includes an outer surface 32 which encounters fluid (not shown) inside the fluid flow passageway 18 of the flowmeter 14, in use. The outer surface 32 of the first portion 30 extends from the flowmeter body 20 at an angle in the range of 90 degrees to 135 degrees, typically extending from the flowmeter body 20 at an angle in the region of 95 degrees. The angle at which the outer surface 32 of the first portion 30 extends from the flowmeter body 20 coincides with the angle of an intermediate portion of the flow passageway 18 relative to inlet and outlet portions of the flow passageway 18. More particularly, the intermediate portion of the flow passageway 18 is angled in the range of 2 to 12 degrees, typically in the region of 5 degrees, from central axes of the inlet and outlet portions. It is to be appreciated that the angle of the outer surface 32 is significant as it allows the signal from the transducer 12 to be transmitted and received along an axis substantially parallel to the intermediate portion to a downstream transducer. It is to be understood that the outer surface 32 of the first portion 30 is intended to be the surface on the inside of the flowmeter body 20. The first portion 30 of the wall 16 has a thickness in the range of 2mm to 7mm.

[0044] The outer surface 32 of the first portion 30 is shaped, configured, treated, or coated to optimise signal transmission and receipt by the transducer 12 through the fluid flow passageway 18 of the flowmeter body 20. The outer surface 32 of the first portion 30 has a smoothed, consistent, and uniform profile for reducing signal reflection and scattering. In particular, the outer surface 32 is polished for reducing reflection and scattering as a result of irregularities in the surface. The outer surface 32 of the first portion 30 includes a guiding formation (not shown) for guiding, directing, or focusing the signal towards or onto a downstream transducer 12. The guiding formation (not shown) is in the form of a concave surface (not shown). It is to be appreciated that the guiding formation (not shown) may cause collimation of the signal or beam transmitted by the transducer 12 thus reducing energy consumption and increasing battery life.

[0045] The first portion 30 of the wall 16 includes an inner surface 34 located inside of the recess 22. The inner surface 34 of the first portion 30 extends at an angle similar to that of the outer surface 32 of the first portion 30, the inner surface 34 of the first portion 30 extending substantially parallel to the outer surface 32 of the first portion 30. The inner surface 34 of the first portion 30 includes a transducer support portion 36 for allowing mounting and support of the transducer 12 thereon. In particular, the transducer support portion 36 defines a mounting surface 37 for allowing mounting and support of the transducer 12 thereon. The mounting surface 37 is substantially parallel to the outer surface 32 of the first portion 30 for allowing the transducer 12 to transmit signals along an axis substantially parallel to the intermediate portion of the flow passageway 18 towards a similarly, but oppositely orientated downstream transducer 12. The transducer support portion 36 is formed integrally with the inner surface 34 of the first portion 30. The transducer support portion 36 has a thickness in the range of 2mm to 7mm, typically being in the region of 5mm. The transducer support portion 36 includes surface treatments for optimising the adhesion to the transducer. The surface treatment includes abrasion and chemical treatments. In particular, the surface treatment includes a light abrasion and chemical cleaning to optimise glue adhesion. The inner surface 34 of the first portion 30 includes an anti-reflective coating or member for reducing signal scatter.

[0046] A receiving formation, typically being in the form of a slot 38, is defined in the transducer support portion 36 for receiving and allowing transducer connecting wires 40 to lead away from the transducer 12 from an interface region between the transducer 12 and the transducer support portion 36. It is to be appreciated that the receiving formation 38 serves to prevent the wires 40 from interfering with the fit between the transducer 12 and the transducer support portion 36.

[0047] A groove 42 is defined in the inner surface 34 at a periphery of the transducer support portion 36. Typically, the groove 42 is defined in the transducer support portion 36 to counter the transducer support surface 36 from taking on a pillow shape due to the water pressure on the outer surface of the first portion of the wall which would place the glue layer, holding the transducer, under severe stress. The groove 42 has a generally annular form and surrounds the transducer support portion 36. The groove 42 defines a deformation reducing formation in the first portion 30 of the wall 16 for reducing a degree of deformation of the transducer support portion 36 as a result of vibrations experienced during activation of the transducers 12. The deformation reducing formation is in the form of a thinner region 44 of the first portion 30 of the wall 16. The thinner region 44 has a thickness in the range of 0.5mm to 4mm, typically being in the region of 2mm. It is to be appreciated that the thinner region 44 acts as an elastic hinge-like formation which, due to being thinner than the transducer support portion 36, deforms more easily thus taking up a majority of the deformation of the first portion 30 and reducing the likelihood of deformation and damage to the transducer 12, cracking of adhesive 46 between the transducer 12 and the transducer support portion 36, and separation of the transducer 12 and transducer support portion 36, all of which may lead to failure of the flowmeter 14. It is to be appreciated further that the thinner region 44 of the first portion 30 also aids in signal transmission and propagation as it allows the transducer support portion 36 to vibrate more freely. It is to be appreciated yet further that the groove 42 also provides a space in which excess adhesive 46 may enter when mounting the transducer 12 to the transducer support portion 36. The groove 42 is sized to ensure that the mounting surface of the transducer support portion is smaller than the transducer 12 to promote the flow of excess glue into the groove 42. More particularly, the groove is sized to ensure that the mounting surface has a diameter in the region of 1 mm less than the transducer The opposite side of the transducer support portion 36, i.e., the outer surface 32 of the first portion 30 of the wall 16, is in direct contact with fluid flowing through the flowmeter 14. Thus, it is exposed to the fluid pressure. Without the groove 42, the transducer support portion 36 would be forced upwards to form a minute bulge in the surface beneath the transducer 12. Initially the adhesive 46 between them is strong enough to deform the transducer 12 into a microscopic matching arcuate shape, but the adhesive 46 can fatigue and crack when exposed to a high shear stress plus a superimposed vibration, thus potentially destroying the bond and releasing the transducer 12 in part or completely. As a result, the transducer 12 output will wane and fail.

[0048] In an attempt to reduce the likelihood of the occurrence of the above-described scenario, the groove 42 around the transducer was introduced to lower the surface tension in the transducer support portion 36, and to lower the stress in the adhesive layer 46 that bonds the transducer 12 to the transducer support portion 36. The transducer support portion 36 is part of the wall 16 of the housing 10 and integrally formed with the flowmeter body 20, which is made of a particularly strong Glass Fiber Reinforced Polymer. The material thickness between the bottom of the groove 42 and the fluid is only about 3mm, but because of the high material strength, it is amply strong. Under pressure the thinner region 44 acts as a hinge-like formation which deforms locally and takes on the shape of a very flat cone, leaving a central core, onto which the transducer 12 is adhered, reasonably flat. Of more importance is that the shear stress in the adhesive 46 is kept below the failure stress. This type of design requires a detailed finite element analysis to ensure that the permissible shear stress in the adhesive 46 is not exceeded.

[0049] The wall 16 includes a second portion 48 leading from the first portion 30. An outer surface 50 of the second portion 48 is shaped, configured, treated, or coated to encourage laminar flow of fluid thereover. The outer surface 50 of the second portion 48 has an elongated and arcuate form for encouraging laminar flow thereover and reducing bubble formation. The outer surface 50 of the second portion 48 has a smoothed, consistent, and uniform profile for reducing turbulence of fluid flowing thereover. The outer surface 50 of the second portion 48 includes any surface treatment of the group including polishing, hydrophobic coatings, hydrophilic coatings, riblets, liquid-infused surfaces, nanotextured surfaces, and surface cleaning.

[0050] The transducer 12 is in the form of an ultrasonic transducer. In particular, the transducer is in the form of a piezoelectric transducer. The transducer 12 has a generally disc-like shape.

[0051] A temperature sensor (not shown) is provided for measuring the temperature of fluid flowing through the passageway 14 of the body 20. The temperature sensor (not shown) is mounted in a receiving zone 41 defined in the wall 16. The temperature sensor (not shown) is in the form of a thermistor or a thermocouple.

[0052] The flowmeter 14 includes a pair of housing formations 10 as hereinbefore described. The pair of housing formations 10 are located at opposing ends 52 and opposing sides 54 of the flowmeter body 20. More particularly, each of the housing formations 10 extend from each of two body portions 56 and 58 which define the flowmeter body 20. The two body portions 56 and 58 are identical to each other. The two body portions 56 and 58 are rotated 180 degrees relative to each other and arranged in an end-to-end manner to define the flowmeter body 20.

[0053] The flowmeter body 20 is mounted in an outer casing 60 such that inlet and outlet portions 62 and 64 thereof extend beyond the casing 60 for allowing interconnection between fluid carrying piping (not shown). The two body portions 56 and 58 of the flowmeter body 20 include locking pin receiving formations 65 for allowing retention in the end-to-end arrangement by a plurality of locking pins 66. It is to be appreciated that the outer casing 60 serves to encase the flowmeter body 20 along with any auxiliary electronic devices, wiring and circuitry (not shown). The electronic devices include an RF (Radiofrequency) enabled communication device which is utilised to control the flowmeter 14 or to obtain readings therefrom remotely.

[0054] The flowmeter body 20, housing formations 10 and casing 60 are manufactured from any suitable plastics, metallic or synthetic material, typically being manufactured from a polymer. The polymer is reinforced. The polymer is in the form of a Glass Fiber Reinforced Polymer.

[0055] The inlet portion 62 includes a mounting formation 68 for allowing a filtering member 70 to be mounted at an inlet of the flowmeter body 20 for reducing a likelihood of large particles from entering the passageway 18. The filtering member 70 is in the form of a wire mesh or sieve-like member (not shown).

[0056] A method is provided for mounting an ultrasonic transducer 12 on a transducer support surface 36 inside a housing formation 10 as hereinbefore described, the method including the steps of: - applying an adhesive 46 to the transducer 12; connecting the transducer 12 to a power source (not shown); inserting the transducer 12 into a recess 22 of the housing formation 10 via opening 24 defined in a side 26 of a wall 16 of the housing formation 10; aligning the transducer 12 with transducer support surface 36 such that the adhesive 46 faces the transducer support surface 36; displacing the transducer 12 towards the transducer support surface 36 thus bringing the adhesive 46 into contact with the transducer support surface 36; activating the power source (not shown) causing the transducer 12 to vibrate; displacing the transducer 12 further towards the transducer support surface 36 until excess adhesive 46 exits from between the transducer 12 and transducer support surface 36 from a periphery thereof; and allowing the adhesive 46 to set.

[0057] The adhesive 46 is in the form of a droplet of glue which has a diameter in the region of 3mm.

[0058] The power source (not shown) is in the form of a low frequency power source for allowing the transducer to vibrate at a low frequency.

[0059] Displacing the transducer 12 further towards the transducer support surface 36 includes the step of twisting or pivoting the transducer 12 simultaneously.

[0060] It is to be appreciated that vibrating, rocking and / or twisting the transducer 12 while squashing the adhesive 46 between the transducer 12 and the transducer support surface 36 encourages even and uniform spreading of the adhesive 46 therebetween. It is to be appreciated further that the vibration is believed to force air out from between the contact surfaces thus improving adhesion and strength of the adhesive 46.

[0061] It is to be appreciated yet even further that the above method is specifically intended to facilitate automation of the transducer mounting process.

[0062] During the mounting process, the transducer 12, with the adhesive 46 hanging from underneath it, is slowly lowered with a rocking and twisting motion to gradually bring the adhesive 46 into contact with the transducer support surface 36, in such a way that it is properly wetted by the adhesive 46, without air bubbles being entrained therein, and that the adhesive 46 that oozes out from underneath the transducer 12 typically does not contaminate the contact surfaces. The design allows for the excess adhesive 46 to flow into the groove 42 surrounding the transducer support surface 36. The thickness of the adhesive layer is important and must be controlled to produce the required long term frequency characteristics of the assembly.

[0063] A vibration absorbing member, typically in the form of a sponge layer 72, is provided for absorbing vibrations propagated away from the transducer support surface 36. The sponge layer 72 is typically mounted on the transducer 12 via an adhesive.

[0064] In order to improve the adhesive coverage between the transducer 12 and transducer support surface 36 it is desirable to temporarily connect the transducer 12 to a suitable low frequency power source (not shown) to create a low frequency vibrator, to evenly spread the adhesive 46 between the face of the transducer 12 and the transducer support surface 36, while forcing out air trapped between the faces, wetting the faces with adhesive 46 and finally leaving a bead of excess adhesive 46 around the periphery of the transducer 12. These steps are important if the tedious and risky manual gluing operation is to be automated.

[0065] It is, of course, to be appreciated that the housing formation 10 and flowmeter 14 in accordance with the invention is not limited to the precise constructional and functional details as hereinbefore described with reference to the accompanying drawings and which is varied as desired.

[0066] Although only certain embodiments of the invention have been described herein, it will be understood by any person skilled in the art that other modifications, variations, and possibilities of the invention are possible. Such modifications, variations and possibilities are therefore to be considered as falling within the spirit and scope of the invention and hence form part of the invention as herein described and / or exemplified. It is further to be understood that the examples are provided for illustrating the invention further and to assist a person skilled in the art with understanding the invention and is not meant to be construed as unduly limiting the reasonable scope of the invention.

[0067] ADVANTAGES

[0068] The inventor believes that the housing formation for a flowmeter in accordance with the present invention is advantageous for the following reasons. The recess through which the transducer is inserted into the housing is accessible via the opening in the side of the wall opposite the fluid flow passageway. The significance thereof is that the transducer may be inserted into position within the recess without interfering with inner surfaces of the fluid flow passageway. This allows a degree of smoothness of the inner surfaces of the fluid flow passageway to be maintained during manufacturing and / or assembly, which is crucial for reducing turbulence and achieving optimal measurement accuracy and longevity. In addition, the positions of the recess and opening through which the transducer is inserted eases the process of effectively mounting the transducer within the housing formation, aiding in potential automation of the manufacturing process. Easing the mounting process would lead to the ability to produce large quantities of flowmeters with greater consistency, in performance and construction. Yet even further, because no joints associated with the housing formation are located within the fluid flow passageway, the risk of leakages which could potentially cause component failure and decrease measurement accuracy is eliminated.

Claims

CLAIMS1. A housing formation for a transducer of a flowmeter, the housing formation including: - a wall extending into a fluid flow passageway of a flowmeter body; a recess defined in the wall for receiving the transducer therein; and an opening defined in a side of the wall opposite the fluid flow passageway, the opening leading into the recess for enabling the transducer to be inserted into the recess from the side of the wall.

2. A housing formation as claimed in claim 1 wherein the wall is integrally formed with the flowmeter body.

3. A housing formation as claimed in claim 1 or 2 wherein a surface of the wall encountering fluid in the fluid flow passageway is shaped, configured, or treated to encourage laminar flow of fluid thereover.

4. A housing formation as claimed in claim 3 wherein the surface of the wall includes any surface treatment of the group including polishing, hydrophobic coatings, hydrophilic coatings, riblets, liquid-infused surfaces, nanotextured surfaces, and surface cleaning.

5. A housing formation as claimed in any one or more of the preceding claims wherein the wall includes a first portion on which the transducer may be mounted, the first portion including an outer surface which encounters the fluid inside the fluid flow passageway of the flowmeter.

6. A housing formation as claimed in claim 5 wherein the outer surface of the first portion extends from the flowmeter body at an angle in the range of 90 degrees to 135 degrees.

7. A housing formation as claimed in claim 6 wherein the angle at which the outer surface extends from the flowmeter body coincides with an angle of an intermediate portion of the flow passageway relative to inlet and outlet portions of the fluid flow passageway.

8. A housing formation as claimed in any one or more of the claims 5 to 7 wherein the first portion of the wall has a thickness in the range of 2mm to 7mm.

9. A housing formation as claimed in any one or more of the claims 5 to 8 wherein the outer surface of the first portion is shaped, configured, treated, or coated to optimise signal transmission and receipt by the transducer through the fluid flow passageway of the flowmeter body.

10. A housing formation as claimed in any one or more of the claims 5 to 9 wherein the outer surface of the first portion has a smoothed, consistent, or uniform profile for reducing signal reflection and scattering.1 1. A housing formation as claimed in any one or more of the claims 5 to 10 wherein the outer surface of the first portion is polished for reducing reflection and scattering as a result of irregularities in the surface.

12. A housing formation as claimed in any one or more of the claims 5 to 1 1 wherein the outer surface of the first portion includes a guiding formation for guiding the signal towards and a downstream transducer.

13. A housing formation as claimed in claim 12 wherein the guiding formation is in the form of a concave surface.

14. A housing formation as claimed in any one or more of the claims 5 to 13 wherein the outer surface of the first portion includes an anti-reflective coating for reducing signal reflection at a boundary between the outer surface of the first portion and fluid in the flow passageway.

15. A housing formation as claimed in any one or more of the claims 5 to 14 wherein the outer surface of the first portion includes an acoustic matching material layer for improving signal transmission at a boundary between the outer surface and fluid in the flow passageway.

16. A housing formation as claimed in any one or more of the claims 5 to 15 wherein the first portion of the wall includes an inner surface located inside of the recess.

17. A housing formation as claimed in claim 16 wherein the inner surface of the first portion extends substantially parallel to the outer surface of the first portion.

18. A housing formation as claimed in claim 16 or 17 wherein the inner surface of the first portion includes a transducer support portion for allowing mounting and support of the transducer thereon.

19. A housing formation as claimed in claim 18 wherein the transducer support portion is formed integrally with the inner surface of the first portion.

20. A housing formation as claimed in claim 18 or 19 wherein the transducer support portion defines a mounting surface for allowing mounting and support of the transducer thereon.

21. A housing formation as claimed in claim 20 wherein the mounting surface is substantially parallel to the outer surface of the first portion for allowing the transducer to transmit signals along an axis substantially parallel to the intermediate portion of theflow passageway towards a similarly, but oppositely orientated downstream transducer.

22. A housing formation as claimed in any one or more of the claims 18 to 21 wherein the transducer support portion has a thickness in the range of 2mm to 7mm.

23. A housing formation as claimed in any one or more of the claims 18 to 22 wherein the transducer support portion includes surface treatments for optimising the adhesion to the transducer.

24. A housing formation as claimed in claim 23 wherein the surface treatment includes a light abrasion and chemical cleaning to optimise glue adhesion.

25. A housing formation as claimed in any one or more of the claims 16 to 24 wherein the inner surface of the first portion includes an anti-reflective coating or member for reducing signal scatter.

26. A housing formation as claimed in any one or more of the claims 18 to 25 wherein a receiving formation is defined in the transducer support portion for receiving and allowing transducer connecting wires to lead away from the transducer from an interface region between the transducer and the transducer support portion.

27. A housing formation as claimed in any one or more of the claims 16 to 26 wherein a groove is defined in the inner surface at a periphery of the transducer support portion.

28. A housing formation as claimed in claim 27 wherein the groove defines a deformation reducing formation in the first portion for reducing a degree of deformation of the transducer support portion as a result of vibrations experienced during activation of the transducers.

29. A housing formation as claimed in claim 28 wherein the deformation reducing formation is in the form of a thinner region of the first portion.

30. A housing formation as claimed in claim 29 wherein the thinner region has a thickness in the range of 0.5mm to 4mm.

31. A housing formation as claimed in any one or more of the claims 27 to 30 wherein the groove is sized to ensure that the mounting surface of the transducer support portion is smaller than the transducer to promote the flow of excess glue into the groove.

32. A housing formation as claimed in any one or more of the preceding claims wherein the wall includes a second portion leading from the first portion.

33. A housing formation as claimed in claim 32 wherein an outer surface of the second portion is shaped, configured, treated, or coated to encourage laminar flow of fluid thereover.

34. A housing formation as claimed in claim 32 or 33 wherein the outer surface of the second portion has an elongated and arcuate form for encouraging laminar flow thereover and reducing bubble formation.

35. A housing formation as claimed in any one or more of the claims 32 to 34 wherein the outer surface of the second portion has a smoothed, consistent, or uniform profile for reducing turbulence of fluid flowing thereover.

36. A housing formation as claimed in any one or more of the claims 32 to 35 wherein the outer surface of the second portion includes any surface treatment of thegroup including polishing, hydrophobic coatings, hydrophilic coatings, riblets, liquid- infused surfaces, nanotextured surfaces, and surface cleaning.

37. A housing formation as claimed in any one or more of the preceding claims wherein a temperature sensor is provided for measuring the temperature of fluid flowing through the passageway of the body, the temperature sensor being mounted in a receiving zone defined in the wall.

38. A method for mounting an ultrasonic transducer on a transducer support surface inside a housing formation as hereinbefore described, the method including the steps of: - applying an adhesive to the transducer; connecting the transducer to a power source; inserting the transducer into a recess of the housing formation via an opening defined in a side of the wall of the housing formation; aligning the transducer with the transducer support surface such that the adhesive faces the transducer support surface; displacing the transducer towards the transducer support surface thus bringing the adhesive into contact with the transducer support surface; activating the power source causing the transducer to vibrate; displacing the transducer further towards the transducer support surface until excess adhesive exits from between the transducer and transducer support surface from a periphery thereof; and allowing the adhesive to set.

39. A method as claimed in claim 38 wherein the adhesive is in the form of glue which is applied in droplet form.

40. A method as claimed in claim 39 wherein droplet of glue has a diameter in the range of 1 mm to 5mm.

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