Method of determination of the point of the disappearance of the crystals of products petroleum as well as a device for implementing this process

摘要

A sample is held in a horizontal tubular measuring cell (4) with a laser emitter (6) and a longitudinal optical receiver (7) at opposite ends, all in a cryostatic chamber (1). The temperature is lowered until crystallisation is complete or the sample is opaque, and then raised while recording transmitted light intensity against temperature, thus giving the point at which the crystals disappear The cryostatic chamber (1) has a temperature gauge (2) connected to a cooler and temperature controller so the optical beam (8) emitted by the laser is aligned along the longitudinal axis of the measuring cell and on the longitudinal optical receiver. The temperature gauge, the cooler, the temperature controller and the optical receiver are connected to a programmable calculating and recording device. A diaphragm (12) is mounted directly downstream of the laser emitter so the optical beam is fine enough to exclude all reflection from the walls of the measuring cell. Upstream of the measuring cell a polarizer is mounted so it is not able to transmit the beam directly emitted from the laser. The sample to be analyzed is placed in the cell. A lateral optical receiver (13) is placed near the measuring cell at its upstream part and is connected to the means of calculation and recording and the opacity against temperature curve recorded and used to analyze the temperature when crystallisation is complete, that is when the variation in temperature should be reversed. An Independent claim is included for a device for carrying out this process, where the optical beam is transmitted to the optical receivers via light guides acting with lenses which concentrate the optical beam. The measuring cell is metallic, in particular aluminum with ports allowing the optical beam to pass through. The cooler and temperature controller are a Stirling cycle refrigeration unit. The device is compact and portable.