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US 6,684,716 B2Granted
Coriolis flowmeter
AssigneeNone recorded
InventorsKazumasa Ohnishi, Yoshiro Tomikawa
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AssigneeNone recorded
InventorsKazumasa Ohnishi, Yoshiro Tomikawa
Estimating the term…
A sensitivity of a Coriolis flowmeter, which is also utilizable as a density meter, composed of a straight conduit through which a fluid to be measured flows, and two counter straight rods that are aligned on both sides of the conduit in parallel, in which one end of the conduit and each one end of the counter rods are fixed to a common support block and another end of the conduit and each another end of the counter rods are fixed to another common support block, is improved by providing to each of the conduit and counter rods a vibration generator for generating vibrations in such manner that the conduit and the counter rods vibrate in opposite phase, and by fixing both support blocks onto a rigid substrate.
A Coriolis flowmeter which vibrates in a mode of three-forked plate vibration comprising a straight conduit through which a fluid to be measured flows and which has a predetermined resonance frequency and a sensor attached thereto, and two counter straight rods that have the same resonance frequency as the resonance frequency of the straight rod conduit and are aligned on both sides of the conduit in parallel space, one end of the conduit and each one end of the counter rods being fixed to a common support block and another end of the conduit and each another end of the counter rods being fixed to another common support block, in which each of the conduit and counter rods has a vibration generator attached thereto for generating vibrations in such manner that the conduit and the counter rods vibrate in opposite phase, and both support blocks are fixed onto a rigid substrate.
A density flowmeter which vibrates in a mode of three-forked plate vibration comprising a straight conduit through which a fluid to be measured flows and which has a predetermined resonance frequency and a sensor attached thereto, and two counter straight rods that have the same resonance frequency as the resonance frequency of the straight conduit and are aligned on both sides of the conduit in parallel with a space, one end of the conduit and each one end of the counter rods being fixed to a common support block and another end of the conduit and each another end of the counter rods being fixed to another common support block, in which each of the conduit and counter rods has a vibration generator attached thereto for generating vibrations in such manner that the conduit and the counter rods vibrate in opposite phase, and both support blocks are fixed onto a rigid substrate.
Dependencies are inferred from the claim text.
From the US filing history. Foreign family members aren’t listed.
Means for influencing the flowmeter's motional or vibrational behaviour, e.g., conduit support or fixing means, or conduit attachments: motion or…
Vibrating measuring conduits: having straight measuring conduits
Measuring volume, volume flow, mass flow or liquid level
Term ended 21 Sep 2021 (estimated)
The invention relates to a Coriolis flowmeter and further relates to a density meter utilizing the Coriolis flowmeter.
The Coriolis flowmeter is known as a direct mass flowmeter which is designed to work under the known principle that when a conduit through which a fluid to be measured flows is vibrated, a Coriolis force which is proportional to the mass flow rate is generated to give a certain effect to the movement of vibrating fluid. Generally, the Coriolis force is detected in terms of an elastic deformation or distortion of the conduit.
Since the Coriolis force is small as compared with the applied vibration force, it is required to provide a force measurement system to accurately detect the generated Coriolis force with high sensitivity. Therefore, a representative Coriolis flowmeter is designed to have a U-shaped conduit so that an enlarged deformation can be detected. However, the U-shaped conduit has a disadvantageous feature in that the fluid flowing through the U-shaped conduit is apt to undergo a pressure loss. Accordingly, most of the U-shaped conduits have not enough measurement accuracy. Moreover, it is necessary to provide a relatively large space for encasing the U-shaped conduit in a flowmeter.
FIG. 1 is a schematic view of a Coriolis flowmeter according to the invention.
FIG. 2 is a plane view of the Coriolis flowmeter of the FIG. 1, in which vibration generators and a sensor are illustrated.
FIG. 3 is a schematic view of a three-forked vibrator which explains the principles of the Coriolis flowmeter of the invention.
The present invention is further described by referring to the figures given in the attached drawing.
FIG. 1 is a schematic view of a Coriolis flowmeter according to the invention, and FIG. 2 is a plane view, in which vibration generators and a sensor are illustrated.
The flowmeter comprises a straight conduit 3 through which a fluid to be measured flows, and two counter straight rods (in the form of a hollow tube) 4a, 4b that are aligned on both sides of the conduit 3 in parallel with a space. One end of the conduit 3 and each one end of the counter rods 4a, 4b are fixed to a common support block 2a, and another end of the conduit 3 and each another end of the counter rods 4a, 4b are fixed to another common support block 2b. The fluid conduit 3 is connected to outer fluid-flowing systems by means of a flange 1.