Coriolis effect mass flowmeter

A method of determining the mass flow rate of material flowing through a pipe section which is an integral part of an existing pipe system devoid of material flow measurement conduit means, said method comprising the steps of:

• clamping said pipe section at a first and a second location spaced apart from each other to inhibit transverse motion of said pipe section at said first and second locations;
• affixing a first motion sensor to said pipe section at a third location between said first and second locations, said third location comprising a zero flow vibration node for a harmonic of the natural frequency of vibration of said pipe section;
• affixing a vibration driver to said pipe at a fourth location between said third location and said first location, said fourth location not comprising a vibration node of said pipe section at said harmonic frequency;
• said motion sensor and said vibration driver being attached only to said pipe section and being free from attachment to a non-movable object;
• and
• operating said driver to oscillate said pipe section at said harmonic frequency;
• and
• determining the mass flow rate of said material through said pipe section by measuring with said motion sensor the amplitude of transverse deflections of said third location of said pipe section in a direction perpendicular to the longitudinal axis of said pipe section;
• said transverse deflections of said third location being caused jointly by the Coriolis motion of pipe section due to said material flow and said oscillation of said pipe section.

A method of determining the mass flow rate of material flowing through a pipe section which is an integral part of an existing pipe system devoid of material flow measurement conduit means, said method comprising the steps of:

• clamping said pipe section at a first and a second location spaced apart from each other to inhibit transverse motion of said pipe section at said first and second locations;
• affixing motion sensor means to said pipe section between said first and second locations;
• affixing a vibration driver to said pipe section between said first and second locations;
• said motion sensor means and said driver being attached only to said pipe section and being free from attachment to a non-movable object;
• operating said driver to oscillate said pipe section at a harmonic of a natural frequency of vibration of said pipe section;
• and
• determining the mass flow rate of said material through said pipe section by measuring with said motion sensor means the transverse deflections of said of said pipe section caused jointly by the oscillation of said pipe section and the Coriolis motion of said pipe section due to the flow of material through said pipe section.

A Coriolis flowmeter for measuring the mass flow rate of material flowing in a pipe section;

• said flowmeter comprising:
• support means clamped to first and second spaced apart locations of said pipe section to inhibit transverse motion of said pipe section;
• motion sensors affixed to different locations of said pipe section intermediate said first and second locations for detecting transverse deflections of said pipe section;
• driver means affixed to said pipe section intermediate said first and second locations;
• said motion sensors and said driver means being clamped directly onto said pipe section and being free from attachment to a non-movable object;
• means for operating said driver means to oscillate said pipe section at a harmonic of the natural frequency of vibration of said pipe section;
• and
• said motion sensors being responsive to transverse deflections of said pipe section resulting jointly from the Coriolis motion of said pipe section due to said material flow and said oscillation of said pipe section caused by said driver means to generate output signals indicative of said deflections;
• means for applying said output signals of said motion sensors to measuring apparatus;
• and
• said measuring apparatus being responsive to the said application of said output signals for determining the mass flow rate of said material in said pipe section.

A Coriolis flowmeter for determining the mass flow rate of material flowing through a pipe section, said flowmeter comprising:

• support means attached to first and second spaced apart location of said pipe section to inhibit transverse motion of said pipe section;
• a first motion sensor affixed to said pipe section at a third location between said first and second locations, said third location comprising a zero flow vibration node for a harmonic of the natural frequency of vibration of said pipe section;
• a vibration driver affixed to said pipe section at a fourth location between said third location and said first location, said fourth location not being a vibration node of said pipe section at said harmonic frequency;
• said motion sensor and said driver being attached only to said pipe section and being free from attachment to a non-movable object;
• means for operating said driver to oscillate said pipe section at said harmonic frequency;
• and
• means for determining the mass flow rate of said material through said pipe section by measuring with said motion sensor the amplitude of the transverse deflections of said third location of said pipe section in a direction perpendicular to the longitudinal axis of said pipe section;
• said transverse deflections of said third pipe section location being caused jointly by the Coriolis motion of said pipe section due to said material flow and said oscillation of said pipe section.

A method of determining information including the mass flow rate of material flowing through a pipe section which is an integral part of an existing pipe system, said method comprising the steps of:

• affixing a motion sensor to a said pipe section;
• affixing a vibration driver to said pipe section;
• said motion sensor and said vibration driver being attached only to said pipe section and being devoid of attachment to a non-movable object;
• said vibration driver comprising a magnetostrictive transducer for oscillating said pipe section;
• applying a drive current to said magnetostrictive transducer to oscillate said pipe section by forcing a magnetostrictive element in said transducer to elongate and return to normal length according to the frequency of said drive current;
• adjusting said frequency of said drive current to operate said driver to drive said pipe section at said harmonic frequency;
• and
• determining the mass flow rate of said material flowing through said pipe section by measuring with said motion sensor the amplitude of a transverse deflection of said pipe section in a direction perpendicular to the longitudinal axis of said pipe section;
• said deflections being caused jointly by said oscillations and the Coriolis motion of said pipe section due to said material flow.