A flow rate control method for raising a flow rate performed in a flow control device having a first control valve, a second control valve downstream of the first control valve, and a pressure sensor for measuring a pressure between the first and the second control valves, comprises a step (a) of determining a pressure remaining downstream of the first control valve in a state of closing the second control valve, and a step (b) of controlling the pressure remaining downstream of the first control valve by adjusting the opening degree of the second control valve based on the output of the pressure sensor to flow the fluid downstream the second control valve at the first flow rate.

The present disclosure provides methods and devices for sample extraction.

A flow sensing device includes a first body member defining an inlet port, an upstream sensor port, and a first connecting port; a second body member defining an outlet port, a downstream sensor port, and a second connecting port; a flow restricting element defining a flow restricting passage and including a first end connection coupled to the first connecting port and a second end connection coupled to the second connecting port, such that the flow restricting passage is disposed between the inlet port and the outlet port, and between the upstream sensor port and the downstream sensor port; a first fluid sensor assembled with the upstream sensor port; and a second fluid sensor assembled with the downstream sensor port.

A ventilator apparatus includes a linear electro-mechanical actuator that interfaces with a self-inflating bag including an inlet configured to receive air and an outlet configured to expend the air. A three-way valve is coupled to the outlet via a first flowmeter, an ambient environment via a second flowmeter, and a patient via an endotracheal tube. The first and/or second flowmeters are coupled to pressure transducer(s). A control unit is coupled to the linear electro-mechanical actuator and the first and second flowmeters and includes a control panel, memory including programmed instructions stored thereon, and processor(s) configured to execute the stored programmed instructions to set an inhalation time and an exhalation time. A current inspiratory pressure and a current tidal volume are obtained from the pressure transducer(s) and/or the first flowmeter. A stroke of the linear electro-mechanical actuator is then controlled to facilitate inspiratory and expiratory phases of a respiratory cycle.

A flow measurement system is provided, which is configured to receive multiple flow rates; retrieve multiple physical properties for multiple pure gases; estimate multiple physical properties for a gas mixture; estimate multiple flow parameters for multiple channels of a flow splitter using a mathematical model, multiple physical properties for the gas mixture, and multiple pressure values from pressure sensors of multiple channels; and estimate multiple flow splits using multiple flow parameters for the multiple channels of the flow splitter.

An intelligent self-balancing downstream device (e.g., air fixture or diffuser) that can obtain accurate flow measurements that can be used to perform the self-balancing in situ and during operation to satisfy a set point. The downstream device may be controllable by a single software system or network accessible locally on site or remotely off site. The downstream device can operate in a single zone or be coupled with multiple like apparatuses for multi-zone operation. It is a high turndown ratio and self-balances, which can allow for continuous commissioning with built-in fault diagnostic systems and that may be used as a supply, return, or exhaust system, or a combination thereof. The downstream device can include multi-stage airflow control systems that operate progressively based on unique actuation mechanisms and/or algorithms that allow for precise flow control and feedback to self-balance and commission the system.

The LFFC technology allows for accurate measurement and metering of fluids in a HVAC system-based on parameters such as pressure, velocity, volume, particles, and temperature. A procedure in a processor allows for the calibration of the aperture devices thru various methods in real time based on the actual system performance. The fluid aperture device calibration curves can be developed in a lab environment, on calibrated flow stands and/or field calibration methods using adaptive learning software based on sensor data. The procedure can rely on calibration curves, characterizations, equations, predictive analysis, machine learning, artificial intelligence, simulation software, calibrated flow stands, duplicating environmental conditions, various sensor data and programming software executed by a processor or system software. Upstream and downstream reference points for temperature, flow, particles, and pressure can be used as additional data to auto calibrate/commission the system thru the software.

Apparatuses for controlling gas flow are important components for delivering process gases for semiconductor fabrication. These apparatuses for controlling gas flow frequently rely on flow restrictors which can provide a known flow impedance of the process gas. In one embodiment, a flow restrictor is disclosed, the flow restrictor constructed of a plurality of layers, one or more of the layers having a flow passage therein that extends from a first aperture at a first end of the flow restrictor to a second aperture at a second end of the flow restrictor.

A fire truck pump flow prediction system includes a pump, an inlet pipe connected to the pump, a discharge pipe connected to the pump, an intake pressure sensor connected to the inlet pipe, a discharge pressure sensor connected to the discharge pipe, a rotational sensor associated with the pump and a central processor connected to the intake pressure sensor, the discharge pressure sensor and the rotational sensor. The intake pressure sensor is configured to detect fire suppressant inlet pressure and the discharge pressure sensor is configured to detect fire suppressant discharge pressure. The rotational sensor configured to detect a rotational speed of the pump. The central processor configured to determine a flow through the pump and into the discharge pipe based on the inlet pressure, the discharge pressure and the rotational speed.

An intelligent self-balancing downstream device that can obtain accurate flow measurements (e.g., flow of a liquid or gas through a tube) that can perform the self-balancing in situ and during operation to satisfy a set point and without k factors or the use of TAB balancers. The downstream device may be controllable by a single software system or network. The downstream device can operate in a single zone or be coupled with multiple like apparatuses. It has a high turndown ratio and self-balances, which can allow for continuous commissioning with built-in fault diagnostic systems. A fluid metering device can include control systems that operate progressively based on unique actuation mechanisms and/or algorithms that allow for precise flow control and feedback to self-balance and commission the system.