11) and the expansion zone (E), and/or between the converging zone (C) and the outlet (12), which can help stabilize pressure sensing. In the illustrated embodiment, the manifold (3) is located within a middle portion of the plateau (X) located between the expansion zone (E) and the converging zone (C) and the manifolds (2 and 4) are located in additional plateaus (X) adjoining the expansion zone (E) and the converging zone (C) at respective upstream and downstream locations. The direction of flow of the fluid can be established by one or more fan(s) (not shown). The fluid can be any fluid, including a gas such as air, a liquid such as water, or a gas with entrained liquid droplets.

The areas (A1-A3) can be measured perpendicular to the flow direction of the internal flow path (F). The internal flow path (F) at or near the inlet (11) (e.g., immediately downstream of the inlet (11) and/or immediately upstream of the area (A1)) can have a substantially constant area, which in some embodiments can be substantially equal to the area (A1). The internal flow path (F) at or near the outlet (12) (e.g., immediately upstream of the outlet (12) and/or immediately downstream of the area (A3)) can have a substantially constant area, which in some embodiments can be substantially equal to the area (A3). In the illustrated embodiment, area (A2)>area (A1) and area (A2)>area (A3). The downstream area (A3) can be smaller than the inlet area (A1) but not by more than approximately thirty percent, such that A3≥0.70·A1. A minimum area (Amin) between the inlet (11) and outlet (12) can, in some embodiments, satisfy the relationship Amin≥AR·(A1), where, for example, AR≥0.70 or AR≈1. For example, in an embodiment where the area A3 is the minimum area (Amin), then A3≥AR·(A1), where AR≥0.70. In some embodiments, A1≈A3≈Amin.

In contrast to conventional single-zone Venturi-type devices, the measurement zone (M) of the illustrated embodiment includes two discrete measurement zones—one located within the expansion zone (E) and another within the converging zone (C). Each zone defines a distinct pressure-sensing region that can be independently sampled or differentially compared to derive flow characteristics. This dual-zone arrangement allows the device (1) to characterize both the rise and fall of static pressure within the same structure, providing additional measurement fidelity and diagnostic flexibility without altering the overall flow sequence or geometry described above.

As the working fluid moves through the internal flow path (F), it enters region (P1) at the inlet (11), expands through the expansion zone (E) to region (P2), and then contracts through the converging zone (C) to region (P3) near the outlet (12). Each of these regions corresponds respectively to manifolds (2-4), which can sample local static pressure at areas (A1-A3). The measured pressures can then be transmitted through ports (5-7) for differential-pressure measurement as described below. In the illustrated embodiment, the port (5) is fluidically connected to the manifold (2), the port (6) is fluidically connected to the manifold (3), and the port (7) is fluidically connected to the manifold (4). Moreover, in the illustrated embodiment, the ports (5 and 7) and the manifolds (2 and 4) are low pressure ports and manifolds, and the port (6) is a high-pressure port and the manifold (3) is a high-pressure manifold.

A differential pressure transducer or sensor (850) can have a high-pressure port or connection (851) and a low-pressure port or connection (852). In some embodiments, the high-pressure port (851) can be connected to port (6) and the low-pressure port (852) can be connected to either port (5) or (7), or to a composite formed by averaging pressures from ports (5) and (7) as depicted in FIG. 1A. As illustrated, the ports (5) and (7) are connected together to form a composite low-pressure signal delivered to the low-pressure port (852). The fluid connections are shown schematically and can be formed using flexible pneumatic tubing or other suitable tube or conduit structure(s). A composite average of the ports (5 and 7) can be provided fluidically (e.g., pneumatically) by fluidically coupling their corresponding tubes or the like with a t-fitting or other manifold for delivery to the low-pressure portion (852) with a common delivery tube or the like. This configuration enables the transducer (850) to measure the differential pressure AP across selected regions of the flow path (F), which can be correlated to the instantaneous volumetric flow (Q). Accordingly, differential-pressure measurements can be obtained between any combination of the defined sensing regions, including between (A2, A3), (A2, A1), or a composite of (A2, A1⊕A3). In some embodiments, ports can be present in the device (1) that are unused, or sealed off, or alternatively ports that are not needed for desired measurements can be omitted entirely. The transducer (850) can have an output interface to output a differential pressure measurement or signal, such as to transmit an electronic signal to another component or device.

In some embodiments, two transducers (850) can be used to independently monitor separate portions of the flow path (F). For example, a first transducer can measure the pressure rise between ports (5) and (6), while a second transducer measures the pressure drop between ports (6) and (7). These signals can be processed individually or combined to provide enhanced flow resolution, noise/turbulence rejection, or redundancy. Although a single transducer (850) is illustrated, any number of transducers can be implemented to measure differential pressures across one or more of the defined sensing positions (P1-P3).

Pressure sampling can be achieved using annular or discrete pickup configurations that are flush or recessed relative to the internal surface of the flow path (F), minimizing protrusions that could disrupt laminar flow or collect debris. The internal flow path (F) can have a circular, rectangular (including square and non-square shapes), non-circular elliptical, oval/elliptical, polygonal (including irregular polygonal shapes), obround, asymmetric or non-axisymmetric, or other cross-section, and equivalent geometric relationships can be defined in terms of area (A) or hydraulic diameter (Dh). Different regions of the internal flow path (F) along the flow direction can have different perimeter shapes in some embodiments. For example, in some embodiments the internal flow path can include transitions between circular and rectangular perimeter shapes along the flow direction, such as between any of the areas (A1, A2, and/or A3).

In some embodiments, a damper (16), such as a blade mounted on a shaft (8) in a butterfly valve configuration, can be actuated (e.g., rotated) by an actuator (9) supported by a mount (10). In further embodiments, the damper (16) can be configured as a sliding plate damper, a flapper, an iris-type damper, a proportional valve, or have any other suitable configuration. The actuator (9) can include or be communicatively coupled to a controller configured to receive a differential-pressure signal from the transducer (850), determine a corresponding flow rate, and adjust the damper (16) to regulate airflow and room pressurization. The controller can implement proportional, integral, or model-based control logic to maintain a target flow or pressure setpoint. Although the damper assembly and controller can enhance automation, the device (1) can also operate in passive or manually adjusted configurations where such control elements are omitted.

The device (1) provides two measurement zones within a single flow passage that enable accurate differential-pressure sensing with minimal to no permanent pressure loss. The example geometry shown demonstrates how expansion followed by contraction in sequential measurement zones allows precise, energy-efficient flow measurement distinct from conventional single-zone Venturi and other existing devices.

FIG. 1C illustrates an embodiment in which a single differential-pressure transducer or sensor (850) is connected to the device (1) to measure pressure across a portion of the expansion side. In this configuration, the low-pressure port (5) of the device (1) is pneumatically coupled to the low-pressure connection (852) of the transducer (850), and the high-pressure port (6) of the device (1) is pneumatically coupled to the high-pressure connection (851) of the transducer (850). The connections are shown schematically and can be formed using flexible pneumatic tubing or other suitable tube or conduit structure(s).

FIG. 1D illustrates an embodiment in which a single differential-pressure transducer or sensor (850) is connected to the device (1) to measure pressure across a portion of the contraction side. In this configuration, the high-pressure port (6) of the device (1) is pneumatically coupled to the high-pressure connection (851) of the transducer (850), and the low-pressure port (7) of the device (1) is pneumatically coupled to the low-pressure connection (852) of the transducer (850). The connections are shown schematically and can be formed using flexible pneumatic tubing or other suitable tube or conduit structure(s).

FIG. 1E illustrates an embodiment in which two differential-pressure transducers or sensors (850A, 850B) are connected to the device (1) to measure separate pressure relationships within the flow path. Transducer 850A is configured to measure pressure across a portion of the expansion side and is pneumatically coupled between ports (5) and (6) of the device (1) through its respective low-pressure and high-pressure connections (852A, 851A). Transducer 850B is configured to measure pressure across a portion of the contraction side and is pneumatically coupled between ports (6) and (7) of the device (1) through its respective high-pressure and low-pressure connections (851B, 852B). Port (6) serves as a common pressure tap and is pneumatically tied to both transducers (850A, 850B). The connections are shown schematically and can be formed using flexible pneumatic tubing or other suitable tube or conduit structure(s). In the illustrated embodiment, a composite or average static pressure can be determined electronically by combining or otherwise processing differential pressure signals from the separate pressure transducers (850A and 850B).

FIG. 2A is a three-dimensional cutaway view of device (1) illustrating its internal manifolds (2-4) where one or more of the manifolds (2-4) include a pressure-averaging channel that is open to the interior of the flow path (F) along the perimeter of the region corresponding to its associated sensing plane. In the illustrated embodiment, the channel is generally U-shaped, although other shapes are possible. The pressure-averaging channel can extend fully or partially around the perimeter (e.g., hydraulic diameter) of the flow path (F). The channel can be configured to remain recessed or otherwise shielded from the principal flow direction of the internal flow path (F), with a relatively short width in the direction of fluid flow along the flow path (F) so that the channel communicates static pressure uniformly from the sampled region while minimizing local turbulence or disturbance of the main flow stream as shown in FIG. 2AA Detail. The pressure-averaging channel can be substantially devoid of discrete openings facing the flow path (F), in some embodiments; instead, the channel can provide direct fluid communication between the internal flow path (F) and the corresponding manifold cavity. The cross-sectional area of the channel is excluded from the area (A1-A3), with the areas (A1-A3) and the channels measured at the openings to those channels. In various embodiments, the channel can be continuous or segmented, such as circumferential or as a partial arc segment along a circumference, and may be formed by molding, machining, or other suitable processes. The open configuration permits uniform pressure sampling across the measured region while maintaining a smooth, obstruction-free internal surface and reducing the potential for fouling or debris accumulation. In that way, the presence of the channel allows a given manifold (2-4) to have as few as a single outlet port connected to a sensing device, while having an open inlet face that allows the manifold to effectively collect and combine fluid from multiple different perimeter regions at a given position (P1-P3).

In FIG. 2A one or more pressure-averaging channels may be employed independently or in combination. These embodiments are not limiting and may be adapted to various geometries, including circular, rectangular, square, or asymmetric cross-sections, to achieve equivalent static-pressure measurement performance within the measurement zone (M) of device (1).

FIG. 2B is a three-dimensional cutaway view of an alternative embodiment of the device (1′), showing example configurations of pressure-sensing structures positioned along the measurement zone of the internal flow path (F).

In the embodiment of FIG. 2B, one or more pressure-sensing openings (13A-13C) of the device (1′) are distributed around the circumference or perimeter of the flow path (F) at regions corresponding respectively to areas (A1′-A3′). Each set of openings communicates through a wall of the valve body to the associated manifold (2′-4′) and corresponding external pressure port (5′-7′). The openings (13A-13C) can be flush, recessed, or of minimal protrusion relative to the internal surface, providing circumferential or perimeter-averaged pressure sampling without introducing significant flow disturbances or fouling points. Axial placement of the openings may be within substantially constant-area plateaus, such as those described with respect to FIG. 1, to promote stable and repeatable static-pressure measurement. In some embodiments, the openings are produced by laser drilling, punching, machining, molding, or other suitable manufacturing methods, and may include multiple openings per ring or segmented array. Optional purge fittings or balancing restrictors may be provided externally in the manifolds (2′-4′) while maintaining a smooth internal flow surface.

FIG. 2BA shows an enlarged portion of the manifold region of FIG. 2B, illustrating the local geometry of a representative flush pressure-sensing opening and its interface with the manifold.

FIG. 2C is a three-dimensional cutaway view of another embodiment of device (1), illustrating a pressure-averaging manifold (3′″) that includes a channel configured as an open-face trough extending along a portion of the perimeter of the internal flow path (F).

In this embodiment, the channel of the manifold (3′″) is canted at an angle (μ) relative to a reference line that is substantially perpendicular to a longitudinal axis of the device (1). The angle (μ) can satisfy the relationship 90°>μ>0°, such as 15°>μ>5°, in some embodiments. Unlike the recessed, static-pressure-oriented channel configurations shown in FIGS. 2A and 2B, the canted orientation of the channel in FIG. 2C causes the associated manifold (3′″) to receive a pressure signal comprising static pressure together with a controlled component of velocity pressure resulting from the reverse-facing orientation of the open trough configuration. By positioning the sampling region within a zone in which the flow naturally accelerates and by canting the open channel partially toward the incoming fluid flow, the device can produce an increased differential pressure between the upstream manifold (3′″) and the downstream manifold (4). This increased differential pressure can, in certain embodiments, provide increased resolution when correlating differential pressure to flow rate, while maintaining a smooth internal surface and without introducing intrusive flow-disturbing structures.

FIG. 2CA shows an enlarged detail view of the canted channel region of FIG. 2C, illustrating the geometry of the open-face channel of the manifold (3′″) and the angle (μ) at which the trough surface is canted relative to a reference line that is substantially perpendicular to the longitudinal axis of the device (1).

As depicted in the detail, the channel is recessed into the valve-body wall and presents an open inlet face that is canted forward toward the incoming flow. The angle (μ) defines the degree of forward cant and enables controlled admission of a velocity-pressure component while preserving continuity of the surrounding internal surface. The enlarged view shows an example embodiment of the local channel geometry, including the transition between the internal contour and the canted channel inlet, a local body wall thickness, and a fluid-communication interface opening between the channel of the manifold (3′″) and a converging zone (C) of the flow path (F). This configuration supports embodiments in which the device is configured to sense a combination of static pressure and velocity pressure at at least one position along the flow path (F), thereby enabling improved flow-measurement performance under various operating conditions.

The illustrated embodiments discussed above highlight the internal pressure-sampling architectures that enable uniform static-pressure collection while maintaining smooth, low-disturbance flow. The embodiments shown illustrate design flexibility between discrete openings and continuous pressure-averaging channels, each supporting accurate, low-fouling operation suited to cleanroom, healthcare, laboratory, and other environments.

FIG. 3 illustrates the pressure operation of the disclosed fluid-flow measurement device (1). The device includes ports (5-7) connected through flexible lines (14A-14C) to U-tube manometers (200) containing working fluids (205, 206). Each manometer represents a differential-pressure relationship between corresponding sensing regions within the measurement zone (M). The configuration establishes two distinct pressure relationships, one across the expansion zone (E), and another across the converging zone (C), providing dual measurement regions within a single flow passage. In comparison, the prior art Venturi valve (300) shown in FIG. 10 defines only a single pressure relationship across its contraction zone, characterized by a throat diameter (D₁) that is smaller than its inlet and outlet diameters (D₂). The resulting constriction in the venturi generates the differential pressure used for flow measurement in the Venturi arrangement and causes a permanent static pressure drop.

FIG. 4 illustrates the device (1) installed between representative upstream and downstream duct sections equipped with pressure taps (600A, 600B) for measuring total static-pressure loss. A manometer (200D) is shown connected via flexible lines (14D, 14E) across the assembly to indicate any permanent static-pressure difference. In this illustration, no measurable static-pressure loss is shown within manometer fluid (205C), as the disclosed geometry does not constrict the airflow below the inlet area. By contrast, as referenced in FIG. 11, conventional Venturi valves exhibit a permanent static-pressure drop between comparable pressure taps (402, 403), resulting from the throat restriction defined by diameters D₁and D₂that generates the required differential pressure. FIG. 4 therefore illustrates the improvement of generating two distinct measurable pressure regions while eliminating the inherent pressure loss associated with prior art Venturi configurations.

FIGS. 5A-FIG. 8 illustrate an alternative embodiment of the fluid-flow measurement device (500) having an asymmetrical cylindrical body geometry. At least a portion of the body geometry can be asymmetrical with respect to the flow direction of the internal flow path (F) and/or with respect to a centerline of the internal flow path (F) connecting centers of the inlet (11) and the outlet (12). A working fluid enters the inlet (11), flows along the internal flow path (F), and exits the outlet (12). In this embodiment, the body expands from the inlet region (A1″) to an intermediate region (A2″) and reconverges toward a downstream region (A3″), forming two distinct potential measurement zones (encompassing zones C or E) within the measurement zone (M). The device (500) otherwise operates according to the same principles described with respect to FIGS. 1A-1B, including the generation of differential pressure signals between the defined regions.

Manifolds (2″-4″) are coupled to corresponding pressure ports (5″-7″) and communicate with internal openings (13A″-13C″) as shown in FIG. 6. The openings may be discrete or continuous and are configured to sample local static pressure without substantial protrusion into the flow path. In other embodiments, the manifolds can employ pressure-averaging channels of the type described in FIG. 2A, which provide open communication with the sensing region while maintaining uniform sampling around the perimeter or hydraulic diameter. Pneumatic coupling to one or more transducers can provide differential-pressure signals representative of flow rate.

FIG. 7 and FIG. 8 illustrate the asymmetrical cylindrical embodiment of the fluid-flow measurement device (500) in multiple orientations. FIG. 7 highlights the overall body geometry, including the asymmetrical expansion region and subsequent reconverging section. FIG. 8 depicts a longitudinal side profile and an end-on view through the outlet, showing the unobstructed internal flow path.

This figure shows the general configuration and proportional relationships of the asymmetrical body rather than specific component details. The sequence of expansion followed by contraction along the internal flow path (F) is clearly visible, demonstrating the multi-zone measurement concept described with respect to device (1) in FIGS. 1A-1B.

Although the illustrated embodiment employs an asymmetrical form, other embodiments may adopt symmetrical, rectangular, polygonal, or other cross-sectional geometries. Equivalent configurations may include curved or offset body contours while preserving the fundamental principle of first expanding and then reconverging the flow to establish two distinct measurement zones within the measurement region.

The asymmetrical body geometry shown in FIGS. 5A-8 demonstrates that the disclosed dual-zone measurement principle is not limited to symmetrical or axis-uniform forms. Curved or non-uniform wall contours may be used to achieve desired flow characteristics, maintain measurement linearity, or accommodate spatial or manufacturing constraints, while retaining the functional relationship among the sensing regions (A1″-A3″). The inclusion of optional control components illustrates compatibility with active flow or pressure regulation.

FIG. 9 illustrates yet another embodiment of the fluid-flow measurement device (900) configured in a rectangular or polygonal form. A working fluid enters the inlet (11), flows through the internal path (F), and exits the outlet (12). In this embodiment, the internal passage expands from the inlet region (A901) to an intermediate region (A902) and reconverges toward a downstream region (A903), forming two distinct measurement zones within the measurement region.

Manifolds (902, 903, 904) are coupled to corresponding external ports (905, 906, 907) and communicate internally through openings (913A, 913B, 913C), which permit static-pressure sampling at each respective region. The openings may be discrete or continuous, configured to provide representative pressure averaging across the flow area without significant protrusion into the flow path. In other embodiments, the manifolds can incorporate pressure-averaging channels of the type described with respect to FIG. 2A, allowing open communication with the sensing region while maintaining uniform sampling around the perimeter or hydraulic diameter. Pneumatic coupling to one or more transducers can transmit these signals for differential-pressure measurement.

The embodiment shown in FIG. 9 demonstrates that the disclosed dual-zone flow-measurement geometry is not limited to cylindrical constructions. The rectangular or polygonal form shown may be fabricated from sheet metal or other planar construction methods while preserving the flow path sequence of expansion followed by contraction.

FIG. 9 highlights the adaptability of the design to alternate geometries and fabrication methods while still providing multiple possible sequential measurement zones-providing accurate, low-loss differential-pressure sensing across a wide range of system configurations.

Although three representative sampling regions are illustrated in each of the embodiments of the devices (900), the number, position, and configuration of manifolds and ports can vary to suit application requirements.

The disclosed device may be integrated into control systems at various levels to measure and/or regulate fluid flow. In a measurement-only configuration, one or more differential-pressure signals may be generated for monitoring, logging, diagnostics, or verification purposes. In control configurations, the measured signals may be processed by an embedded or external controller—operating with or without an operating system—to modulate a damper, valve, actuator, or other flow-modulating element in accordance with a specified condition. Such control may be implemented in open-loop form, where actuation is based on a fixed or predetermined command, or in closed-loop form, where the measured flow, pressure, or other process variable is continuously compared to a setpoint and corrected in real time. Control objectives may include maintaining constant flow, volumetric offset, adjusting to a programmed trajectory, or meeting dynamic or safety-related requirements. The device may function as a stand-alone controller receiving a direct setpoint and modulating flow accordingly, or it may operate as part of a building automation system (BAS) exchanging signals via standard protocols such as BACnet, Modbus, or LON. Output signals may also be utilized for energy management, compliance monitoring, or operational optimization within larger facility networks. These modes of operation are representative and not limiting, and the device may be employed in other process or environmental control systems requiring accurate flow measurement and regulation.

Pressure-sensing ports of the device may be coupled to a wide variety of transducers or other measurement technologies. These may include dead-ended designs, which prevent through-flow contamination, or flow-through types. Transducers may employ silicon or metallic diaphragms, MEMS elements, optical, ultrasonic, capacitive, thermal-anemometric, or laser-Doppler sensing principles. The sensing devices may provide outputs in analog form (such as voltage or current) or in digital form (such as SPI, I²C, or other serial communication protocols). Alternative methods of measuring differential pressure, velocity, or volumetric flow may also be employed without departing from the scope of the invention. Future or yet-to-be-commercialized sensing technologies may likewise be incorporated to achieve the desired measurement accuracy and reliability.

The flow-modulating element may take many forms and may be configured to increase or decrease the flow rate through the device. In some embodiments, the element may include a damper, valve, or other throttling mechanism having blades or vanes of cylindrical, rectangular, elliptical, butterfly, iris, or other geometries. Other embodiments may incorporate louvers, sliding plates, iris mechanisms, or comparable mechanical arrangements suitable for adjusting flow. The flow-modulating element may also employ emerging or future flow-control technologies not yet commercially available, without departing from the scope of the invention.

The disclosed device may be applied across a broad range of airflow, liquid flow, and mixed-phase flow systems. Representative applications include fume hoods, fume snorkels, negative or positive isolation rooms, biosafety laboratories (BSL-