Patent ID: 7730779
Filing Date: 2010-06-08
Classification: G01F

Abstract:
1. A multiphase-liquid level sensing system for sensing a layer depth and thickness of a liquid of a first phase that floats on a liquid of a different second phase, comprising: a. an elongated stem having a top end and an opposite bottom end, a top retainer disposed adjacent the top end and a bottom retainer disposed adjacent the bottom end, the elongated stem defining an elongated cavity therein; b. a first float disposed coaxially around the elongated stem, a portion of the first float exhibiting a sensible property, the first float having a negative buoyancy relative to the liquid of the first phase and a positive buoyancy relative to the liquid of the second phase; c. a level sensor disposed within the cavity defined by the elongated stem that senses the sensible property of the portion of the first float, the level sensor configured to indicate a second phase liquid distance from the first float to the bottom end of the stem based on where the sensible property is sensed on the level sensor; d. an overburden sensor extending downwardly from the bottom end of the stem, the overburden sensor configured to sense a property indicative of a total liquid thickness of the liquid of the first phase and the liquid of the second phase above the overburden sensor; and e. a computational circuit, responsive to a first signal from the level sensor, a second signal from the overburden sensor, that is configured to calculate a layer thickness of the liquid of the first phase wherein the layer thickness of the liquid of the first phase equals a pressure exerted on the overburden sensor by the liquid of the first phase on the overburden sensor times a pressure increase per unit depth of the liquid of the second phase times a specific gravity of the liquid of the first phase.