← Back to Patent Explorer
US3933030A Expired / Lapsed US ⏱️ 0.0 years remaining

System for continuous monitoring of the density of cryogenic liquids via dielectric constant measurements

Assignee: ExxonMobil Technology and Engineering Co
•
Filing: 1974-09-09
•
Granted: 1976-01-20
•
Expires: 1994-09-09
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A system has been invented for the continuous determination of density of cryogenic liquids such as LPG and LNG to within +/- 0.1% or better using differential capacitance measurements. This system would allow the detection of incipient density inversions in storage tanks and the accurate determination of quantities transferred from ship to shore to customers.

Inventors

  • 👤 Eric O. Forster
  • 👤 William R. L. Thomas

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 08:30
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/22; G01N27/221; G01N9/00

Claims Analysis

Total Claims: 17
Claim 1
Independent Claim 126 words
A process for obtaining continuous and simultaneous multiple density measurements of cryogenic liquids at temperatures between -40° to -215°C. in storage tanks yielding an accurate density profile of the cryogenic liquid stored in the tanks to avoid rollover and obtain accurate billing data consisting of the steps of making numerous simultaneous measurements of the dielectric constant and temperature of the cryogenic liquid by means of numerous probes spaced vertically in the tank at some predetermined interval, determining the density using the dielectric constant in a single step independent of knowledge of the absolute material composition of the cryogenic liquid, continuously monitoring the density profile and triggering a pump or circulation system upon monitoring density stratification or inversion in the tank to avoid the occurrence of rollover.
Claim 2
Dependent Claim 126 words
A process for obtaining continuous and simultaneous multiple density measurements of cryogenic liquids at temperatures between -40° to -215°C. in storage tanks yielding an accurate density profile of the cryogenic liquid stored in the tanks to avoid rollover and obtain accurate billing data consisting of the steps of making numerous simultaneous measurements of the dielectric constant and temperature of the cryogenic liquid by means of numerous probes spaced vertically in the tank at some predetermined interval, determining the density using the dielectric constant in a single step independent of knowledge of the absolute material composition of the cryogenic liquid, continuously monitoring the density profile and triggering a pump or circulation system upon monitoring density stratification or inversion in the tank to avoid the occurrence of rollover.
Claim 3
Dependent Claim 132 words
A process for obtaining continuous and sequential density measurements of cryogenic liquids at temperatures between -40° to -215°C in storage tanks yielding an accurate continuous density profile of the contents of the tank to avoid rollover and obtain accurate billing data consisting of the steps of making numerous sequential measurements of the dielectric constant and temperature of the cryogenic liquid by means of a moving probe which probe moves vertically through the cryogenic liquid at no more than 10 feet per minute, calculating the density using the dielectric constant in a single step independent of knowledge of the absolute material composition of the cryogenic liquid, continuously monitoring the density profile and triggering a pump or circulation system upon monitoring density stratification or inversion in the tank to avoid the occurrence of rollover.
Claim 4
Dependent Claim 132 words
A process for obtaining continuous and sequential density measurements of cryogenic liquids at temperatures between -40° to -215°C in storage tanks yielding an accurate continuous density profile of the contents of the tank to avoid rollover and obtain accurate billing data consisting of the steps of making numerous sequential measurements of the dielectric constant and temperature of the cryogenic liquid by means of a moving probe which probe moves vertically through the cryogenic liquid at no more than 10 feet per minute, calculating the density using the dielectric constant in a single step independent of knowledge of the absolute material composition of the cryogenic liquid, continuously monitoring the density profile and triggering a pump or circulation system upon monitoring density stratification or inversion in the tank to avoid the occurrence of rollover.
Claim 5
Dependent Claim 162 words
A process for obtaining continuous and simultaneous multiple density measurement of cryogenic liquids at temperatures between -40° to -215°C. in storage tanks yielding an accurate density profile of cryogenic liquids stored in tanks to avoid rollover and obtain accurate billing data consisting of the steps of making numerous simultaneous measurements of the dielectric constant and temperature of the cryogenic liquid by means of numerous probes spaced vertically in the tank at some predetermined interval, determining the actual density to an accuracy of at least ±0.1% using the dielectric constant in a single step independent of knowledge of the absolute material composition of the cryogenic liquid, continuously monitoring the density profile, wherein the individual density measurement making up the continuously monitored density profile are reproduceable to an accuracy of ±0.01% of the relative density of the cryogenic liquid in the tank, and triggering a pump or circulation system upon monitoring density stratification or inversion in the tank to avoid the occurrence of rollover.
Claim 6
Dependent Claim 162 words
A process for obtaining continuous and simultaneous multiple density measurement of cryogenic liquids at temperatures between -40° to -215°C. in storage tanks yielding an accurate density profile of cryogenic liquids stored in tanks to avoid rollover and obtain accurate billing data consisting of the steps of making numerous simultaneous measurements of the dielectric constant and temperature of the cryogenic liquid by means of numerous probes spaced vertically in the tank at some predetermined interval, determining the actual density to an accuracy of at least ±0.1% using the dielectric constant in a single step independent of knowledge of the absolute material composition of the cryogenic liquid, continuously monitoring the density profile, wherein the individual density measurement making up the continuously monitored density profile are reproduceable to an accuracy of ±0.01% of the relative density of the cryogenic liquid in the tank, and triggering a pump or circulation system upon monitoring density stratification or inversion in the tank to avoid the occurrence of rollover.
Claim 7
Dependent Claim 170 words
A process for obtaining continuous and sequential density measurements of cryogenic liquids at temperatures between -40° to -215°C in storage tanks yielding an accurate continuous density profile of the contents of the tank to avoid rollover and obtain accurate billing data consisting of the steps of making numerous sequential measurements of the dielectric constant and temperature of the cryogenic liquid by means of a moving probe which probe moves vertically through the cryogenic liquid at no more than 10 feet per minute, calculating the actual density to an accuracy of at least ±0.1% using the dielectric constant in a single step independent of knowledge of the absolute material composition of the cryogenic liquid, continuously monitoring the density profile wherein the individual density measurements making up the continuously monitored density profile are reproducible to an accuracy of ±0.01% of the relative density of the cryogenic liquid in the tank and triggering a pump or circulation system upon monitoring density stratification or inversion in the tank to avoid the occurrence of rollover.
Claim 8
Dependent Claim 170 words
A process for obtaining continuous and sequential density measurements of cryogenic liquids at temperatures between -40° to -215°C in storage tanks yielding an accurate continuous density profile of the contents of the tank to avoid rollover and obtain accurate billing data consisting of the steps of making numerous sequential measurements of the dielectric constant and temperature of the cryogenic liquid by means of a moving probe which probe moves vertically through the cryogenic liquid at no more than 10 feet per minute, calculating the actual density to an accuracy of at least ±0.1% using the dielectric constant in a single step independent of knowledge of the absolute material composition of the cryogenic liquid, continuously monitoring the density profile wherein the individual density measurements making up the continuously monitored density profile are reproducible to an accuracy of ±0.01% of the relative density of the cryogenic liquid in the tank and triggering a pump or circulation system upon monitoring density stratification or inversion in the tank to avoid the occurrence of rollover.
Claim 9
Dependent Claim 12 words
A process according to claim 1 wherein the cryogenic liquid is LNG.
Claim 10
Dependent Claim 12 words
A process according to claim 1 wherein the cryogenic liquid is LPG.
Claim 11
Dependent Claim 12 words
A process according to claim 1 wherein the cryogenic liquid is ethane.
Claim 12
Dependent Claim 12 words
A process according to claim 1 wherein the cryogenic liquid is propane.
Claim 13
Dependent Claim 12 words
A process according to claim 1 wherein the cryogenic liquid is butane.
Claim 14
Dependent Claim 68 words
A process for obtaining continuous and simultaneous multiple dielectric constant measurement of cryogenic liquids at temperatures between -40° to -215°C. in a tank which comprises making numerous simultaneous measurements of the dielectric constant of the cryogenic liquid by means of numerous probes spaced vertically in the tank at some predetermined interval which measurements are accurate to within 0.05% of actual dielectric constant and are reproduceable to within ±0.0002.
Claim 15
Dependent Claim 68 words
A process for obtaining continuous and simultaneous multiple dielectric constant measurement of cryogenic liquids at temperatures between -40° to -215°C. in a tank which comprises making numerous simultaneous measurements of the dielectric constant of the cryogenic liquid by means of numerous probes spaced vertically in the tank at some predetermined interval which measurements are accurate to within 0.05% of actual dielectric constant and are reproduceable to within ±0.0002.
Claim 16
Dependent Claim 77 words
A process for obtaining continuous and sequential multiple dielectric constant measurements of cryogenic liquids at temperatures between -40° to -215°C in a tank which comprises making numerous sequential measurements of the dielectric constant of the cryogenic liquid by means of a moving probe which probe moves vertically through the cryogenic liquid at no more than 10 feet per minute, which measurements are accurate to within 0.05% of actual dielectric constant and are reproducible to within ± 0.0002.
Claim 17
Dependent Claim 77 words
A process for obtaining continuous and sequential multiple dielectric constant measurements of cryogenic liquids at temperatures between -40° to -215°C in a tank which comprises making numerous sequential measurements of the dielectric constant of the cryogenic liquid by means of a moving probe which probe moves vertically through the cryogenic liquid at no more than 10 feet per minute, which measurements are accurate to within 0.05% of actual dielectric constant and are reproducible to within ± 0.0002.

References Cited (Backward Citations)

US3010319A Cited
US3222918A Cited
US3276214A Cited
US3638442A Cited
US3633372A Cited
US3665209A Cited
US3728897A Cited
US3813924A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1979-01-19 1979-07-21 1980-01-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1983-01-19 1983-07-21 1984-01-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1987-01-19 1987-07-21 1988-01-20 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag