Correction of coriolis flowmeter measurements due to multiphase flows
First Claim
1. A Coriolis flowmeter which measures densities of materials including combinations of gas and liquids, gas and solids, or solids and liquids, said flowmeter comprising:
- at least one flowtube;
a driver that vibrates said at least one flowtube at a fundamental frequency based on a drive signal, said fundamental frequency corresponding to a density of material flowing through said at least one flowtube;
pickoffs affixed to said at least one flowtube that generate pickoff signals responsive to said material flowing through said at least one flowtube; and
meter electronics configured to;
determine said density of said material flowing through said at least one flowtube based on at least one of said pickoff signals, monitor a drive gain in said at least one flow tube for a change in value to determine if said material flowing through said at least one flowtube comprises a multiphase flow, and if said material flowing through said at least one flowtube comprises a multiphase flow, then determine said density of said material flowing through said at least one flowtube based on a stored density value.
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Accused Products
Abstract
A Coriolis flowmeter is operable as a vibrating tube densitometer where a flowtube is driven to vibrate at a fundamental frequency from which density of the material flowing through the flowtube may be calculated. The drive gain is monitored as an indicator of multiphase flow including gas and liquid components where a substantial increase in drive gain indicates gas damping of the flowtube vibrations due to a transient bubble entering the flowtube. The gas damping effects of the transient bubble and the correspondingly reduced density readings are remediated by the use of historical density measurements corresponding to periods of flow when no transient bubble has entered the flowtube.
15 Citations
70 Claims
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1. A Coriolis flowmeter which measures densities of materials including combinations of gas and liquids, gas and solids, or solids and liquids, said flowmeter comprising:
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at least one flowtube;
a driver that vibrates said at least one flowtube at a fundamental frequency based on a drive signal, said fundamental frequency corresponding to a density of material flowing through said at least one flowtube;
pickoffs affixed to said at least one flowtube that generate pickoff signals responsive to said material flowing through said at least one flowtube; and
meter electronics configured to;
determine said density of said material flowing through said at least one flowtube based on at least one of said pickoff signals, monitor a drive gain in said at least one flow tube for a change in value to determine if said material flowing through said at least one flowtube comprises a multiphase flow, and if said material flowing through said at least one flowtube comprises a multiphase flow, then determine said density of said material flowing through said at least one flowtube based on a stored density value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of operating a Coriolis flowmeter to measure densities of materials, said method comprising the steps of:
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vibrating at least one flowtube of said Coriolis flowmeter at a fundamental frequency corresponding to a density of material flowing through said at least one flowtube;
generating pickoff signals that represent motion of said at least one flow tube as said material flows through said at least one flowtube;
determining said density of said material flowing through said at least one flowtube based on at least one of said pickoff signals;
monitoring a drive gain in said at least one flowtube for a change in value to determine if said material flowing through said at least one flowtube comprises a multiphase flow; and
if said material flowing through said at least one flowtube comprises said multiphase flow, then determining said density of said material flowing through said at least one flowtube based on a stored density value. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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19. A Coriolis flowmeter which measures mass flow rates of materials including combinations of gas and liquids, gas and solids, or solids and liquids, said flowmeter comprising:
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at least one flowtube;
a driver that vibrates said at least one flowtube at a fundamental frequency based on a drive signal;
pickoffs affixed to said at least one flowtube that generate pickoff signals responsive to said material flowing through said at least one flowtube; and
meter electronics configured to;
determine said mass flow rate of said material flowing through said at least one flowtube based on said pickoff signals, monitor a drive gain in said at least one flow tube for a change in value to determine if said material flowing through said at least one flowtube comprises a multiphase flow, and if said material flowing through said at least one flowtube comprises a multiphase flow, then determine said mass flow rate of said material flowing through said at least one flowtube based on a stored mass flow rate value. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27)
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28. A method of operating a Coriolis flowmeter to measure mass flow rates of materials, said method comprising the steps of:
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vibrating at least one flowtube of said Coriolis flowmeter at a fundamental frequency corresponding to a mass flow rate of material flowing through said at least one flowtube;
generating pickoff signals that represent motion of said at least one flow tube as said material flows through said at least one flowtube;
determining said mass flow rate of said material flowing through said at least one flowtube based on said pickoff signals;
monitoring a drive gain in said at least one flowtube for a change in value to determine if said material flowing through said at least one flowtube comprises a multiphase flow; and
if said material flowing through said at least one flowtube comprises said multiphase flow, then determining said mass flow rate of said material flowing through said at least one flowtube based on a stored mass flow rate value. - View Dependent Claims (29, 30, 31, 32, 33, 34)
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35. A flowmeter, comprising:
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at least one flowtube;
a driver that vibrates said at least one flowtube based on a drive signal;
pickoffs affixed to said at least one flowtube that generate pickoff signals comprising a vibrational response to said material flowing through said at least one flowtube; and
meter electronics configured to;
monitor said vibrational response for a change in value to determine if said material flowing through said at least one flowtube comprises a multiphase flow; and
substitute remediation data in place of a flowmeter measurement if said material flowing through said at least one flowtube comprises said multiphase flow. - View Dependent Claims (36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52)
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53. A method of operating a flowmeter, comprising:
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vibrating at least one flowtube of said flowmeter based on a drive signal;
monitoring a vibrational response in said at least one flowtube for a change in value to determine if said material flowing through said at least one flowtube comprises a multiphase flow; and
substituting remediation data in place of a flowmeter measurement if said material flowing through said at least one flowtube comprises said multiphase flow. - View Dependent Claims (54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70)
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Specification