Abb Research Ltd.

Asea Brown Boveri Inc.

Carnelian Cordless LLC

John Anthony Byatt

Daniel A Matter

Thomas Kleiner

Walter Ruegg

Ulrich Kogelschatz

Thomas Christen

Philippe Pr&ecirc;tre

Walter R&uuml;egg

Elias J&uuml;lke

Gunter Spanner

Walter Rüegg

A method and a sensor ( ) for oil-in-water measurement, in particular for the oil industry. In an electric measuring cell ( ) a capacitance is measured as a measure of an oil concentration in the water flowing through or in the accumulation filter ( ). In order to reduce the maintenance requirement, the measuring cell ( ) is automatically calibrated at recurring time intervals with clean water (FIG. ) and/or flushed with water, possibly oil-contaminated, in the back-flushing direction (FIG. ). Advantages of the invention are reduced signal drift, improved long-term reliability and a long service life without monitoring or filter exchange. Important exemplary embodiments relate to: a measuring cell ( ) with a long measuring and short flushing/calibration cycle, a measuring cell ( ) with a plurality of accumulation filters ( ) whose measuring cycles supplement one another in time, a cross-flow filter ( ) for oil enrichment upstream of the measuring cell ( ) and a compact, pressure-resistant cylindrical ring-type filter ( ) made from porous ceramic ( ) with measuring and flushing connections radially ( ) and axially ( ).

Method and device for oil-in-water measurement

The present invention discloses a capacitive filling-level sensor, which is suitable in particular for filling-level determination in oil separator tanks. The capacitive sensor includes a measuring probe with at least one sensor electrode. According to the invention, the measuring probe is at least partially sheathed with at least one outer layer of a fluorinated plastic and at least one inner layer of a mica-filled plastic. Important exemplary embodiments concern an outer layer of perfluoroethylene-perfluoropropylene copolymer (FEP), an inner layer of mica-coated glass fiber tape impregnated with epoxy resin and possibly silanized and an incompressible, thermally adapted filling of the measuring-probe pipe with silicone oil and glass spheres or glass polyhedrons and/or an inner rod of AlMgSi-filled epoxy resin. The sheathing is electrically insulating, chemically inert, hydrophobic, oleophobic, waterproof, mechanically robust and easy to produce.

Capacitive filling-level sensor with dielectric coating

The present invention relates to a method and a device for fluorescence measurement of oil residues in water. The core of the invention is to use a powerful, narrow-band excimer lamp to excite intensive fluorescence radiation to detect the latter with a photodiode or the like, and to determine the oil concentration therefrom. The excimer lamp can be designed as a flat radiator a hollow cylindrical inner radiator or a tubular radiator, and can be combined with a through-flow or free fall measuring cell. The excimer lamp is advantageously operated in a pulsed or modulated fashion, the fluorescence radiation is measured at a right angle to the exciting radiation, the emitted and/or transmitted exciting light is monitored with the detectors, and a redundant measuring arrangement with a plurality of excimer lamps and fluorescence detectors is provided. The sensor is distinguished by reliability, freedom from maintenance and a long service life.

Method and device for determining the oil concentration in liquids by means of fluorescence excitation with an excimer lamp

The subject matter of the present invention is the optimization of a capacitive liquid level sensor which is suitable, in particular, for determining the location of a boundary layer,between water,and oil,in a separator tank. The known sensor principle is based on measuring the environmentally dependent capacitance between neighboring electrodes,of a rod-shaped probe,. According to the invention, the probe,is designed such that large ionic double-layer capacitors occur on the electrodes,in the more conductive medium,, and small capacitors occur between electrodes,in the insulating medium,. For this purpose, the electrode height h is selected to be large, the ratio of the electrode height h to the electrode spacing a is preferably selected to be in the range of 1<h/a<6 and, in particular, the measuring frequency f is selected to be in the dielectric cut-off frequencies of the media,. As a result, it is possible to achieve a large jump in capacitance for a digital liquid level display and/or a largely continuous increasing capacitance for an analog liquid level display. Furthermore, the influence of more conductive and/or insulating dirt films,on the capacitance signal is eliminated by suitable measuring frequencies and/or by radially offsetting the electrodes

Capacitive level detector with optimized electrode geometry

A photoacoustic flow measuring cell (1a, 1b) for measuring oil residues in water including a photoacoustic sensor principle based on converting optical energy into acoustic energy by absorption of light on oil molecules in water. A measuring cell (1a, 1b) having contamination-free infeed optics (9, 10, 11, 21) is produced by providing a free fall stage (3) for a contactless feed (12) of light into an analyte (4). A sound detector (16) is an externally mounted piezoelectric transducer (16) or an optical interferometer (23) which measures vibrations of a liquid surface (6) without contacting the same. The photoacoustic free fall measuring cell (1a, 1b) provides a high level of detection, well into the ppm concentration range, low susceptibility to faults and is suitable, in particular, for use in high pressure separating tanks (28) for conveyance of crude oil.

Photoacoustic free fall measuring cell

In a method and a device for measuring the concentration of particles present in a gas, in which a gas stream is guided past a UV light source, the particles are ionized and filtered out and the resulting ionic current is measured, the gas flow required is produced by thermal convection using an internal or external heat source. A suitable internal heat source in this context is, for example, the UV lamp (2) itself, which heats the gas via a radiation absorber (5). The elimination of a mechanical pump reduces the space requirement, power consumption and susceptibility to faults of the measuring arrangement.

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Klingnau, Switzerland

John Anthony Byatt