The present invention relates generally to sensors for measuring fluids, more particularly, to ultrasonic sensor assemblies.
Ultrasonic sensor assemblies have been used to measure properties of fluids. Such sensors typically include ultrasonic transceivers in operative communication across a flow of fluid, which are electrically coupled to electronics that assess transmission (transit times, phase or frequency shifts) to determine parameters of the fluid, such as fluid flow, density, viscosity, temperature, among others.
Flow sensors of such kind typically comprise the transceivers disposed across a conduit as measurement section. They require a well-defined flow profile through the measurement section for accurate measurement to allow extrapolation of results from a limited sample of the cross-section.
Although current approaches are generally effective, shortfalls exist. For example, in current approaches, it is required to position the measurement section downstream along a long, straight flow section, so that the flow velocity profile is stable and known as it passes through the measurement section. As such, such sensors are not desirable or effective, in applications that lack a long, straight flow section. To that end, a flow conditioner device is oftentimes positioned proximate to the entry to the cylindrical measurement section. Such accessories can be relatively expensive and cumbersome to install.
It should therefore be appreciated that there remains a need for an ultrasonic sensor assembly that addresses these concerns. The present invention fulfills these needs and others.
Briefly, and in general terms, the invention provides an ultrasonic sensor assembly comprising a sensor body having opposing open ends for enabling fluid flow therethrough. The body defines an interior measurement section therein. The body defines a plurality of spiral flow paths disposed about a longitudinal axis of the measurement section. The sensor assembly includes a pair of ultrasonic transceivers mounted to the tubular body in spaced longitudinal relationship across the measurement section. An electronics housing mounted to the body in a separable manner, when mounted, the electronics housing is operable communication with the pair of ultrasonic transceivers to measure fluid parameters within the measurement section.
In an independent aspect of the invention, a method of manufacture is provided for an ultrasonic sensor assembly utilizing a mold for the sensor body having an outer shell and a mold core, configured to result in a sensor body having opposing open ends for enabling fluid flow therethrough, in which the body defines an interior measurement section therein.
For purposes of summarizing the invention and the advantages achieved over the prior art, certain advantages of the invention have been described herein. Of course, it is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.
All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular preferred embodiment disclosed.
Embodiments of the present invention will now be described, by way of example only, with reference to the following drawings in which:
Referring now to the drawings, and particularly
In the exemplary embodiment, the spiral flow paths 16 are formed by curved interior walls 24 of the sensor body 14, curved vanes, extending through the measurement section 22. The interior wall initiates upstream from the measurement section and terminates downstream from the measurement section. The height profile of the interior walls include an upwardly sloping leading edge (24a), a maximum height region within the measurement section (24b), and a downwardly sloping trailing edge (24c). In the exemplary embodiment, the upwardly sloping leading edge initiates upstream from the measurement section, and the trailing edge terminates downstream from the measurements section. This configuration attributes to a desired flow within the measurement section, thereby aiding in accurate measurement.
The tubular body 14 includes four interior walls 24, curved vanes, having generally helical shape, twisting through the measurement section 22. The number and shape of the interior walls can vary in different embodiments without departing from the invention.
With continued reference to reference to
In the exemplary embodiment, transceivers 20 are piezo-disks attached to sensor cavities 26 is formed by the tubular body 14. The transceivers are operatively coupled using wires to electronics (not shown) within the housing 12. The piezo disks can be made from piezoelectric material like lead zirconium titanate, quartz crystal or piezoelectric polymer.
The body 14 provides four sensor cavities 26 positioned such that the transceivers are directed towards the measurement section, and so that corresponding transceivers can have a clear line of communication through the measurement section, unimpeded by interior walls 24. The sensor cavities protrude into the interior tubular region of the body proximate to respective interior walls 24. In other embodiments, the sensor cavities can be recessed relative to the interior tubular region of the sensor body. Having the sensor cavity wall terminate or partially obstruct separate flow paths helps fluid exchange between the channels and thus better mixing and averaging of the flow, enhancing the measurement accuracy.
With reference now to
With reference again to
With reference now to
In an exemplary method of manufacture, the mold 44 for the sensor body comprises an outer shell 46 and the mold core 40(A, B) positioned therein. The mold 44 is thereafter injected with a desired composition of thermoplastic material, preferably a commonly used piping system plastic like PVC, CPVD, PVDF, PP, PE or ABS. Other materials are feasible as well. As best seen in
Once the sensor body 14 is formed, the ultrasonic transceivers 20 are mounted within the corresponding sensor cavities 26 using an appropriate adhesive for the chosen plastic like Epoxy or Polyurethane resin. Wires connecting the transceivers (piezo disks) to the control electronics are soldered to the metallization of the piezo disks and then routed through the grooves of the spiral ridges 32 up to the electronics housing 12. The electronics housing 12 is disposed about the sensor body within recesses formed by the and locked with a snap feature.
After attaching the piezo disks, the sensor cavity is filled with epoxy resin or similar potting material. The reinforcing metal spring or fiber wrap (i.e., rigid structure 34) would be applied at this time
With reference now to
It should be appreciated from the foregoing that the present invention provides an ultrasonic sensor assembly comprising a sensor body having opposing open ends for enabling fluid flow therethrough. The body defines an interior measurement section therein. The body defines a plurality of spiral flow paths disposed about a longitudinal axis of the measurement section. The sensor assembly includes a pair of ultrasonic transceivers mounted to the tubular body in spaced longitudinal relationship across the measurement section. An electronics housing mounted to the body in a separable manner, when mounted, the electronics housing is in operable communication with the pair of ultrasonic transceivers to measure fluid parameters within the measurement section.
The present invention has been described above in terms of presently preferred embodiments so that an understanding of the present invention can be conveyed. However, there are other embodiments not specifically described herein for which the present invention is applicable. Therefore, the present invention should not to be seen as limited to the forms shown, which is to be considered illustrative rather than restrictive.