Mass flow meter systems and methods

A mass flow meter comprising:

• an inlet with a diameter and an outlet with a diameter;
• a flow restrictor having a restriction chamber and a pressure balancing system interposed between the inlet and outlet;
• the restriction chamber having a cylindrical restriction wall with a diameter less than the diameters of the inlet and outlet;
• a conical compression wall located upstream from the restriction wall;
• a variable orifice assembly, the variable orifice assembly having a deformable tube member having an internal surface defining an effective cross-sectional area of the restriction chamber;
• a compression wedge;
• a compression shim;
• first and second chevron members;
• and, a compression nut;
• whereby axial rotation of the compression nut displaces the nut towards the restriction wall, as the nut moves toward the restriction wall;
• the nut applies a force on the compression wedge through the first and second chevron members and compression shim and forces the compression wedge radially inwards deforming the deformable tube member and reducing the effective cross-sectional area of the restriction chamber;
• and,
• a pressure sensor and a temperature sensor upstream from the flow restrictor providing input to a meter circuit having calibration data;
• whereby the meter circuit generates a flow output signal based on the calibration data and the input from the pressure sensor and temperature sensor.

A mass flow control system comprising:

• a flow controller capable of controlling a flow rate through the mass flow control system;
• said controller connected in series with a mass flow meter;
• said mass flow meter comprising an inlet with a diameter and an outlet with a diameter;
• a flow restrictor having a restriction chamber and a pressure balancing system interposed between the inlet and outlet;
• the restriction chamber having a cylindrical restriction wall with a diameter less than the diameters of the inlet and outlet;
• and, a pressure sensor and a temperature sensor upstream from the flow restrictor providing input to a meter circuit having calibration data;
• whereby the meter circuit generates a flow output signal based on the calibration data and the input from the pressure sensor and temperature sensor;
• said mass flow meter is connected to a valve control feedback loop system;
• whereby the mass flow meter sends the flow output signal to the valve control feedback loop system and said feedback system compares the flow output signal with a predetermined flow rate to generate a flow control signal;
• said valve control feedback loop system is connected to the flow controller;
• whereby said feedback system sends the flow control signal to the flow controller to operate the flow controller to change the flow rate.

A mass flow control system comprising:

• a flow controller capable of controlling a flow rate through the mass flow control system;
• said controller connected in series with a mass flow meter;
• said mass flow meter comprising an inlet with a diameter and an outlet with a diameter;
• a flow restrictor having a restriction chamber and a pressure balancing system interposed between the inlet and outlet;
• the restriction chamber having a cylindrical restriction wall with a diameter less than the diameters of the inlet and outlet;
• a conical compression wall located upstream from the restriction wall;
• a variable orifice assembly, the variable orifice assembly having a deformable tube member having an internal surface defining an effective cross-sectional area of the restriction chamber;
• a compression wedge;
• a compression shim;
• first and second chevron members;
• and, a compression nut;
• whereby axial rotation of the compression nut displaces the nut towards the restriction wall, as the nut moves toward the restriction wall;
• the nut applies a force on the compression wedge through the first and second chevron members and compression shim and forces the compression wedge radially inwards deforming the deformable tube member and reducing the effective cross-sectional area of the restriction chamber;
• a pressure sensor and a temperature sensor upstream from the flow restrictor providing input to a meter circuit having calibration data;
• whereby the meter circuit generates a flow output signal based on the calibration data and the input from the pressure sensor and temperature sensor;
• said mass flow meter is connected to a valve control feedback loop system;
• whereby the mass flow meter sends the flow output signal to the valve control feedback loop system and said feedback system compares the flow output signal with a determined flow rate to generate a flow control signal;
• and,
• and said feedback system compares the flow output signal with a determined flow rate to generate a flow control signal;
• and,
• said valve control feedback loop system is connected to the flow controller;
• whereby said feedback system sends the flow control signal to the flow controller to operate the flow controller to change the flow rate.

A mass flow meter comprising:

• an inlet with a diameter and an outlet with a diameter;
• a flow restrictor having a restriction chamber and a mechanical pressure balancing system interposed between the inlet and the outlet;
• the restriction chamber having a cylindrical restriction wall with a diameter less than the diameters of the inlet and outlet;
• and,
• a pressure sensor and a temperature sensor upstream from the flow restrictor providing input to a meter circuit having calibration data;
• whereby the meter circuit generates a flow output signal based on the calibration data and the input from the pressure sensor and temperature sensor.