Detecting liquid dry conditions for liquified compressed gases
US6643951B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 23, 2000 |
| Grant date | Nov 11, 2003 |
| Priority date | — |
| Expiry date | Jan 29, 2021 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF17C2270/0518
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A method and an apparatus are disclosed for detecting an occurrence of a liquid dry condition in a container containing a liquefied compressed gas while the gaseous phase of the liquefied compressed gas is being removed from the container over time. The apparatus includes a first sensor, a second sensor, and a computer, preferably a programmed logic controller (PLC). The first sensor senses temperature (T) inside the container and provides a signal indicative thereof. The second sensor senses pressure (P) inside the container and provides a signal indicative thereof. The computer receives signals from the first and second sensors, and determines the rates of change in the pressure (dP/dt) and the temperature (dT/dt) inside the container over time. The computer identifies an occurrence of a sudden increase in the rate of change in the temperature (dT/dt) inside the container and a substantial simultaneous occurrence of a sudden decrease in the rate of change in the pressure (dP/dt) inside the container, said substantially simultaneous occurrences indicating an occurrence of a liquid dry condition in the container. The preferred embodiment includes a third sensor for sensing ambient …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.