CS242524B1 - Viscosity measuring container - Google Patents

Abstract

The solution concerns a container for measuring viscosity at low temperatures. According to the solution, the measuring container is arranged in such a way that a tube is led out from the side of the measuring container, which allows the placement of a thermometer directly into the sample and at the same time serves as an aeration tube. The measuring capillary is placed concentrically. The container can be used in the field of oil and oil products and also wherever viscosity is measured at low temperatures.

Description

The solution relates to a container for measuring the viscosity at low temperatures. According to the invention, the measuring cup is arranged such that a tube is led out of the side of the measuring cup, which allows the thermometer to be placed directly in the sample and at the same time serves as an aeration tube. The capillary is placed concentrically. The container may be in the field of oil and petroleum products, and wherever low temperature viscosity is measured.

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The subject of the invention is a container for measuring the viscosity at low temperatures.

One of the most important characteristics of oil is viscosity. In general, capillary viscometers, gauze viscometers or rotational viscometers are used to measure viscosity.

The internationally recognized SAE J 300 SEP 80 oil viscosity classification includes viscosity measurements at 100 ° C and low shear conditions, low temperature viscosity measurements from -5 ° C to -30 ° C under high shear conditions, 105 to 106 s -1 and measuring viscosity under low shear conditions of 0 to 103 s-1 in a temperature range of -5 ° C to -35 ° C. While the viscosity measurement at 100 ° C and the high shear slope measurement are not quite problematic, viscosity measurement at low temperatures and a small shear gradient presents a number of problems.

Rotational viscometers are usually used to measure viscosity under low shear conditions and below 0 ° C. These devices are quite complicated and expensive and usually require the use of calibration fluids. Therefore, it is desirable to measure the low temperature viscosity and the small shear gradients by using simpler capillary viscometers, where the viscosity can be calculated from the dimensions of the capillary and from the measured quantities directly, e.g.

The low temperature viscosity measuring apparatus and the small shear gradient are usually arranged such that the liquid does not flow out of the capillary due to the force of gravity, but rather the liquid is sucked into the capillary under pressure of a defined value.

Low temperature viscosity measurement poses a problem of accurate tempering and increased operating costs for cold production, as the test lasts more than 16 hours.

Typical are two ways of arranging the measuring apparatus: In the Deward vessel, only the sample is tempered in the coolant while the capillary is not tempered. This method is only applicable at low temperatures, up to about -10 ° C, and with low viscosity fluids, where the time required for filling;

Claims (2)

SUBJECT Vessel for measuring viscosity at temperatures below 0 ° C, characterized in that the capillary tube (2) extending from the side of the measuring vessel (1) is relatively short, up to approximately 60 sec. For more viscous liquids, or at temperatures below -10 ° C, the capillary filling time is so long that the temperature of the liquid to be measured changes in the capillary space, thereby distorting the measured viscosity value. Such an arrangement of the apparatus is described e.g. in UAE SP 418, p. 34th A second way of arranging the apparatus is that the entire measuring apparatus is located in the cooling chamber. Such an arrangement is described e.g. in Wear, Vol. 56, No 1, 1979, p. 25 or in the National Petroleum Refiners Association FL 78-83, p. 20. Although such an arrangement allows perfect tempering, it is quite large and its operation requires increased production costs for the cold. These disadvantages can be overcome if a measuring vessel according to the invention is used to measure the viscosity. It is an object of the present invention to provide a vessel for measuring viscosity at temperatures below 0 [deg.] C. having a side tube for temperature and aeration, and a measuring capillary connected through an airtight seal. The container is shown in FIG. 1. The overall arrangement of the measuring apparatus is shown in FIG. Second The measuring vessel 1 has a tube 2 on its side, into which a thermometer 3 is placed, extending directly into the sample space 4. The measuring tube 1 is connected concentrically to the measuring vessel 1 via an airtight seal. The advantage of the measuring vessel 1 is that it allows such an arrangement of the apparatus that it is possible for the entire measuring apparatus, i. j. immerse both the measuring vessel 1 with sample 4 and the measuring pipette 5 in the tempering liquid. The tube 2 for placing the thermometer 3 protrudes above the surface of the tempering liquid, thereby allowing the space above the level of the sample to be measured to be aerated. The design of the measuring vessel is unpretentious and operation, due to the small volume of the tempering fluid, is less energy intensive. OF THE INVENTION intended for temperature measurement and aeration and a measuring capillary (5) is connected through an airtight seal.