US3908468A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Storage tank leak detector
Assignee: Mitsubishi Heavy Industries Ltd
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Filing: 1974-03-11
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Granted: 1975-09-30
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Expires: 1994-03-11
Abstract
Abstract A storage tank for a low-temperature liquid comprising a tank shell, a heat insulation layer with which the tank shell is lined, a liquid-impervious layer sandwiching the heat insulation layer between itself and the tank shell and serving as a first barrier, a second barrier provided inside the heat insulation layer, and a lamination extended along the inner side of the second barrier and including a capacitor layer which in turn consists of at least two electrically conductive layers and an electrical insulation layer interposed therebetween, said electrically conductive layer provided inwardly of the electrical insulation layer being formed with a multiplicity of fluid passages, so that any leakage of the low-temperature liquid through the lining is detected from a change in the capacity meter reading of the capacitor layer with the penetration of the leaking liquid into the electrical insulation layer by way of the fluid passages.
Inventors
- 👤 Kihei Katsuta
- 👤 Chiaki Matsuyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:46
CPC Classifications
G; G01; G01M; G01M3/00; G01M3/02; G01M3/04; G01M3/16; G01M3/18; G01M3/186; F; F17; F17C; F17C13/00; F17C13/12; F17C13/126; F17C2201/00; F17C2201/01; F17C2201/0104; F17C2201/0109; F17C2201/0119; F17C2203/00; F17C2203/03; F17C2203/06; F17C2203/0602; F17C2203/0612; F17C2203/0626; F17C2203/0629; F17C2205/00; F17C2205/01; F17C2205/0153; F17C2205/018; F17C2209/00; F17C2209/22; F17C2209/228; F17C2223/00; F17C2223/01; F17C2223/0146; F17C2223/0153; F17C2260/00; F17C2260/03; F17C2260/035; F17C2260/037; F17C2260/038
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
148 words
A storage tank for a low-temperature liquid comprising a tank shell, a heat insulation layer with which the tank shell is lined, a liquid-impErvious layer sandwiching the heat insulation layer between itself and the tank shell and serving as a first barrier, a second barrier provided inside the heat insulation layer, and a lamination extended along the inner side of the second barrier and including a capacitor layer which in turn consists of at least two electrically conductive layers and an electrical insulation layer interposed therebetween, said electrically conductive layer provided inwardly of the electrical insulation layer being formed with a multiplicity of fluid passages, so that any leakage of the low-temperature liquid through the lining is detected from a change in the capacity meter reading of the capacitor layer with the penetration of the leaking liquid into the electrical insulation layer by way of the fluid passages.
Claim 2
Dependent Claim
148 words
A storage tank for a low-temperature liquid comprising a tank shell, a heat insulation layer with which the tank shell is lined, a liquid-impErvious layer sandwiching the heat insulation layer between itself and the tank shell and serving as a first barrier, a second barrier provided inside the heat insulation layer, and a lamination extended along the inner side of the second barrier and including a capacitor layer which in turn consists of at least two electrically conductive layers and an electrical insulation layer interposed therebetween, said electrically conductive layer provided inwardly of the electrical insulation layer being formed with a multiplicity of fluid passages, so that any leakage of the low-temperature liquid through the lining is detected from a change in the capacity meter reading of the capacitor layer with the penetration of the leaking liquid into the electrical insulation layer by way of the fluid passages.
Claim 3
Dependent Claim
37 words
A low-temperature-liquid storage tank as defined in claim 1 including a gas analyzer and wherein the electrical insulation layer is made of gas-permeable material which provides spaces in communication with said gas analyzer for detecting gas leakage.
Claim 4
Dependent Claim
30 words
A low-temperature-liquid storage tank as defined in claim 1 wherein the electrical insulation layer is made of a honeycomb treated with a mold releasing agent and packed with foam plastics.
Claim 5
Dependent Claim
53 words
A low-temperature-liquid storage tank as defined in claim 3 wherein the electrical insulation layer upon shrinkage with low temperature forms sufficient spaces between the honeycomb and the foam plastics filling its individual cells for circulation of an inert gas in circulatory systems, and a gas analyzer connected to each of the circulatory systems.
Claim 6
Dependent Claim
52 words
A low-temperature-liquid storage tank as defined in claim 1 wherein the capacitor layer is in the form of framed panels and each frame is provided with a plurality of ducts for establishing communication among the gas-permeable electrical insulation layers of the panels and thereby constituting a continuous insulation layer throughout the lining.
References Cited (Backward Citations)
US3489311A
Cited
US3721898A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |