EP0214801A1
Expired / Lapsed
EP
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A method of monitoring the liquid contents of a container vessel, monitoring apparatus for use in such method, and an installation including such apparatus
Assignee: PARMADE INSTRUMENTS CC
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Filing: 1986-08-22
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Granted: —
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Expires: 2006-08-22
Abstract
Abstract Apparatus for monitoring the liquid contents of a container vessel 10 comprises a pair of pressure transducers 16.1, 16.2,120,192 arranged at different levels in the vessel or in an upright tube 114 leading from the vessel. The signals provided by the pressure transducers are processed in a processor 22,122 to provide an output signal corresponding to the value P 1 /|P 1 -P 2 |, where P 1 is the pressure sensed by the one pressure transducer and P 2 is the pressure sensed by the other pressure transducer. This corresponds to the level of the liquid in the vessel and is independent of the specific gravity of the liquid. In another embodiment two pressure values are obtained by a single pressure transducer 120 arranged at the bottom of an upright measuring tube 114 leading from the vessel. There is a solenoid operated valve 118 at the bottom of the tube and a solenoid operated valve 116 at the top of the tube. One pressure value is obtained with the pressure transducer subjected to the overall head of liquid in the vessel and in the measuring tube, and a second pressure value is obtained with the pressure transducer subjected to the head of liquid in the measuring tube only, the top of the measuring tube being vented to atmosphere. In yet a further embodiment, where the content of the vessel is subject to a varying gas pressure, a further pressure transducer 16.3 is provided to sense the gas pressure and to compensate for the effect which this has on the pressure measurements P, and P 2 .
Inventors
- 👤 Michael Dehane Cownley
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 07:17
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/14
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
165 words
A method of monitoring the contents of a container vessel (10, 70, 100, 180) which is partly filled with a liquid so that the liquid defines a liquid surface level within the vessel, wherein the pressure (P 1 ) at the bottom of a first column of the liquid is sensed to obtain a first signal corresponding to the pressure at the bottom of the first column, the first column extending from a first predetermined level with respect to the vessel to said liquid surface level; characterised in that the pressure (P 2 ) at the bottom of a second column of the liquid is sensed to obtain a second signal corresponding to the pressure at the bottom of the second column, the height of the second column, or the difference in height between the first and second columns, being a predetermined value; the first and second signals being processed to obtain an output signal as a predetermined function of the first and second signals.
Claim 2
Independent Claim
165 words
A method of monitoring the contents of a container vessel (10, 70, 100, 180) which is partly filled with a liquid so that the liquid defines a liquid surface level within the vessel, wherein the pressure (P 1 ) at the bottom of a first column of the liquid is sensed to obtain a first signal corresponding to the pressure at the bottom of the first column, the first column extending from a first predetermined level with respect to the vessel to said liquid surface level; characterised in that the pressure (P 2 ) at the bottom of a second column of the liquid is sensed to obtain a second signal corresponding to the pressure at the bottom of the second column, the height of the second column, or the difference in height between the first and second columns, being a predetermined value; the first and second signals being processed to obtain an output signal as a predetermined function of the first and second signals.
Claim 3
Dependent Claim
101 words
A method according to claim 1, wherein the difference in height between the first and second columns is a predetermined value, the second column extending from a second predetermined level with respect to the vessel to said liquid surface level, characterised in that the pressure at the bottom of the first column is sensed by a first pressure transducer (16.1, 120); and the pressure at the bottom of the second column is sensed by a second pressure transducer (16.2, 192) spaced vertically from the first pressure transducer, the vertical spacing between the first and second pressure transducers determining said predetermined value.
Claim 4
Dependent Claim
24 words
A method according to claim 2, characterised in that the first and second transducers (16.1, 16.2) are mounted at different levels on the vessel.
Claim 5
Dependent Claim
49 words
A method according to claim 2, characterised in that part of the liquid contents of the vessel is caused to flow into an upright measuring tube (114) leading from the vessel, and wherein the first and second transducers (120, 192) are mounted at different levels on the measuring tube.
Claim 6
Dependent Claim
43 words
A method according to claim 4, characterised in that the measuring tube (114) is opened from time to time at its end remote from the vessel (180), to cause displacement of the liquid in the measuring tube by fresh liquid from the vessel.
Claim 7
Dependent Claim
137 words
A method according to claim 1, wherein the height of the second column is a predetermined value characterised in that: part of the liquid contents of the vessel (100) is caused to flow from the vessel into an upright measuring tube (114) leading from the vessel; the first signal is obtained by sensing the pressure at a low end of the measuring tube while there is flow communication between the interior of the vessel and the measuring tube; and the second signal is obtained by sensing the pressure at the low end of the tube while flow communication between the interior of the vessel and the measuring tube is blocked off and a high end of the tube is vented, the height of the measuring tube between the low and high ends thereof determining said predetermined value.
Claim 8
Dependent Claim
22 words
A method according to claim 6, characterised in that the high end of the tube (114), when vented, is vented to atmosphere.
Claim 9
Dependent Claim
48 words
A method according to claim 6 or claim 7, characterised in that the first signal is obtained by a pressure transducer (120) mounted at said low end of the measuring tube (114), and wherein the second signal is obtained by the same pressure transducer at a different time.
Claim 10
Independent Claim
33 words
A method according to any one of the preceding claims, characterised in that said processing includes dividing one of the first and second signals by the difference between the first and second signals.
Claim 11
Independent Claim
71 words
A method according to any one of the preceding claims, characterised in that the pressure (P 3 ) in the vessel above said liquid surface level is sensed to obtain a third signal corresponding to the pressure in the vessel above the liquid surface level; and wherein said processing includes processing of the third signal to obtain said output signal as a predetermined function of the first, second, and third signals.
Claim 12
Dependent Claim
192 words
An installation which comprises a container vessel (10, 70, 100, 180) for containing a liquid partly filling the vessel so that the liquid defines a liquid surface level within the vessel, and monitoring apparatus (14) for monitoring the contents of the vessel, characterised in that the monitoring apparatus comprises: sensing means (16.1, 16.2, 120, 192) for sensing two pressures, namely the pressure at the bottom of a first column of the liquid to obtain a first signal corresponding to the pressure at the bottom of the first column, and the pressure at the bottom of a second column of the liquid to obtain a second signal corresponding to the pressure at the bottom of the second column, the arrangement being such that the first column extends from a first predetermined level with respect to the vessel to said liquid surface level, and that the height of the second column, or the difference in height between the first and second columns, is a predetermined value; and processing means (22, 52, 122) for processing the first and second signals to obtain an output signal as a predetermined function of the first and second signals.
Claim 13
Dependent Claim
192 words
An installation which comprises a container vessel (10, 70, 100, 180) for containing a liquid partly filling the vessel so that the liquid defines a liquid surface level within the vessel, and monitoring apparatus (14) for monitoring the contents of the vessel, characterised in that the monitoring apparatus comprises: sensing means (16.1, 16.2, 120, 192) for sensing two pressures, namely the pressure at the bottom of a first column of the liquid to obtain a first signal corresponding to the pressure at the bottom of the first column, and the pressure at the bottom of a second column of the liquid to obtain a second signal corresponding to the pressure at the bottom of the second column, the arrangement being such that the first column extends from a first predetermined level with respect to the vessel to said liquid surface level, and that the height of the second column, or the difference in height between the first and second columns, is a predetermined value; and processing means (22, 52, 122) for processing the first and second signals to obtain an output signal as a predetermined function of the first and second signals.
Claim 14
Dependent Claim
48 words
An installation according to claim 11, characterised in that the sensing means comprises a first pressure transducer (16.1, 120) arranged at said first predetermined level with respect to the vessel, and a second pressure transducer (16.2, 192) arranged at a second predetermined level with respect to the vessel.
Claim 15
Dependent Claim
136 words
An installation according to claim 11, characterised in that the monitoring apparatus further comprises: an upright measuring tube (114) leading from the vessel (100); a first valve (116) at a high end of the measuring tube, the first valve being arranged, in one condition thereof, to place the interior of the vessel in flow communication with the measuring tube and, in another condition thereof, to block off the interior of the vessel from the measuring tube; and a second valve (118) at a-low end of the measuring tube, the second valve being arranged, in one condition thereof, to close the low end of the tube and, in another condition thereof, to open the low end of the measuring tube; said sensing means comprising a pressure transducer (120) arranged at the low end of the measuring tube.
Claim 16
Dependent Claim
32 words
An installation according to claim 13, characterised in that the first valve (116) is arranged, in said other condition thereof, to vent the upper end of the measuring tube (114) to atmosphere.
Claim 17
Dependent Claim
87 words
An installation according to any one of claims 11 to 14, characterised in that it further comprises a third pressure transducer (16.3) for sensing the pressure in the vessel (70, 180) above said liquid surface level to provide a third signal (P 3 ) corresponding to the pressure in the vessel above said liquid surface level, the processing means (22, 122) being arranged to process the first, second, and third signals to obtain said output signal as a predetermined function of the first, second, and third signals.
Claim 18
Dependent Claim
100 words
Monitoring apparatus for monitoring the liquid contents of a container vessel (10, 70, 180), the apparatus comprising a first pressure transducer (16.1, 120) operative to provide a first signal corresponding to the pressure at the bottom of a first column of said liquid, characterised in that it further comprises: a second pressure transducer (16.2, 192) operative to provide a second signal corresponding to the pressure at the bottom of a second column of said liquid; and processing means (22, 52, 122) operative to divide one of the first and second signals by the difference between the first and second signals.
Claim 19
Dependent Claim
100 words
Monitoring apparatus for monitoring the liquid contents of a container vessel (10, 70, 180), the apparatus comprising a first pressure transducer (16.1, 120) operative to provide a first signal corresponding to the pressure at the bottom of a first column of said liquid, characterised in that it further comprises: a second pressure transducer (16.2, 192) operative to provide a second signal corresponding to the pressure at the bottom of a second column of said liquid; and processing means (22, 52, 122) operative to divide one of the first and second signals by the difference between the first and second signals.
Claim 20
Dependent Claim
46 words
Monitoring apparatus according to claim 16, characterised in that it further comprises a measuring tube (114) for connection in flow communication with the interior of the vessel (180), the first and second pressure transducers (120, 192) being mounted at longitudinally spaced positions on the measuring tube.
Claim 21
Dependent Claim
154 words
Monitoring apparatus for monitoring the liquid contents of a container vessel (100), characterised in that it comprises: a measuring tube (114) having a high end for connection in flow communication with the interior of the vessel, and a low end opposite the high end; a pressure transducer (120) for sensing the pressure in the tube at the low end thereof; a first valve (116) at the high end of the tube, the first valve being arranged, in one condition thereof, to place the interior of the vessel in flow communication with the measuring tube and, in another condition thereof, to block off the interior of the vessel from the measuring tube; and a second valve (118) at the low end of the tube, the second valve being arranged, in one condition thereof, to close the low end of the tube and, in another condition thereof, to open the low end of the measuring tube.
Claim 22
Dependent Claim
154 words
Monitoring apparatus for monitoring the liquid contents of a container vessel (100), characterised in that it comprises: a measuring tube (114) having a high end for connection in flow communication with the interior of the vessel, and a low end opposite the high end; a pressure transducer (120) for sensing the pressure in the tube at the low end thereof; a first valve (116) at the high end of the tube, the first valve being arranged, in one condition thereof, to place the interior of the vessel in flow communication with the measuring tube and, in another condition thereof, to block off the interior of the vessel from the measuring tube; and a second valve (118) at the low end of the tube, the second valve being arranged, in one condition thereof, to close the low end of the tube and, in another condition thereof, to open the low end of the measuring tube.
References Cited (Backward Citations)
GB1379554A
Cited
GB1429931A
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GB1583393A
Cited
EP0048589A1
Cited
DE3039210A1
Cited
EP0112105A1
Cited
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