RU2387993C1 - Method for determination of water content in liquid fuel in domestic conditions - Google Patents

Abstract

FIELD: measurement technique.

SUBSTANCE: rapid method for determination of water content in liquid fuel in domestic conditions. Method for determination of water content in liquid fuel in domestic conditions includes preparation of fuel samples by taking fuel sample into transparent measuring container and mixing in it. Testing is performed by freezing fuel sample at temperature below ice point. Then during freezing sample is visually inspected for presence of water in solid state in it. Further, after freezing completion, water amount collection is performed by filtering water crystals. Then water is defrosted, its volume is measured by weighing and percentage of water in the sample is calculated.

EFFECT: development of water content in fuel determination without using expensive equipment and special solvents.

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Description

The invention relates to mechanical engineering and can be used as an express method for determining the water content in fuel in a domestic environment.

A known method for determining the water content in fuel (prototype - GOST 2477-65) using apparatus according to GOST 1770-74. The method includes: preparing fuel samples by taking fuel into a measured tank, mixing a fuel sample in it, testing if these devices are available by heating a fuel sample with a water-insoluble solvent (for example, toluene, xylene, oil distillate, isooctane, nefras). Then, the amount of water is collected by condensation and its volume is measured, by which the percentage of water in the fuel sample is calculated.

The disadvantage of the method for determining the water content of the prototype is the need to use expensive equipment and special solvents (reagents).

The technical task is to create a method that allows you to determine the water content in the fuel without the use of expensive equipment and special solvents.

This task is achieved by a method of determining the water content in liquid fuel in domestic conditions, including the preparation of fuel samples by taking into a transparent measuring tank and mixing a fuel sample in it, conducting tests, collecting the amount of water and measuring its volume, which calculate the percentage of water in the sample in which, according to the invention, the tests are carried out by freezing a fuel sample at a temperature below freezing of water, during the freezing process, a visual inspection of the sample is carried out for the presence of Verdi state water, after freeze charge amount of water carried by sieving water crystals through a filter, defrost water is measured by weighing its volume and the percentage of the sample.

The present invention differs from the prototype in that the tests are carried out by freezing a fuel sample at a temperature below freezing of water, during the freezing process, a visual inspection of the sample is carried out for the presence of water in it in a solid state, after the end of freezing, the amount of water is collected by filtering out water crystals through a filter, water is thawed, its volume is measured by weighing and the percentage in the sample.

The method is as follows. Prepare for testing a fuel sample by taking fuel into a transparent measuring container, for example, into a clean, dry, colorless bottle. In this case, the measuring tank is filled into 2/3 of its volume, the fuel is thoroughly mixed by shaking for 2-3 minutes. Then the measured capacity is placed in the freezer until the water freezes (below 0 ° C) in the sample. Freezing is carried out for 2-3 hours. As practice shows, a freezing period of 2-3 hours is sufficient to freeze water in the freezer. During the first one or two hours of the freezing procedure, water, if it is in the fuel, begins to stand out from it in the form of droplets and / or ice cubes, which are visible through the transparent wall of the measuring container. Therefore, after 1-2 hours from the start of freezing, the sample is taken out of the freezer and inspected in the light. If water droplets and / or ice are not visually detected at this stage of the test, they conclude that there is no water in the fuel and the test is completed. When they are visually detected, they conclude that there is water in the fuel, and freezing is continued to turn all the water in the sample into ice. After freezing (after the specified 2-3 hours), the water in the sample fully crystallizes, while the fuel can remain liquid or solidify with water. If the fuel in the sample remains liquid, immediately begin to collect water by filtering the ice particles through the filter. Use, for example, a filter plug by attaching it to the neck of the container in which the test fuel is located. In the event of fuel freezing, the sample is thawed for 5-10 minutes, which is sufficient to turn the fuel into a liquid state. At the same time, the water remains in solid form due to the fact that the freezing temperature of water and fuel are different: the freezing temperature of water is 0 ° С, summer diesel fuel -10 ° С, winter diesel fuel -25 ° С, gasoline below -60 ° C, that is, the fuel thaws much faster than water. After thawing the fuel, they immediately begin to collect water by filtering its crystals through a filter. The sieved crystals are immediately placed in a clean measuring container and after complete thawing, the percentage of water is determined according to GOST 2477-65. The volume of water is recorded with an accuracy of one upper division of the occupied water in a measuring tank. The mass and volume fraction of water in percent is calculated according to GOST 2477-65 according to the formulas

X = V ₀ / m 100; X ₁ = V ₀ / V · 100,

where V ₀ is the volume of water in the measured capacity, cm ³ ;

m is the mass of the sample, g;

V is the sample volume, cm ³ .

Note. To simplify the calculation of the density of water at room temperature, it is taken as 1 g / cm ³ and the numerical value of the volume of water in cm ³ is taken as the numerical value of the mass of water in g; when the fuel mass is (100 ± 0.1) g, the volume of water collected in the measuring tank, in cm ^3, is taken as the mass fraction of water.

Example 1. A sample of summer diesel fuel was investigated (freezing temperature -10 ° C). The test sample of diesel fuel was poured into a clean, dry, colorless bottle of no more than 2/3 of the volume and thoroughly mixed by shaking for 2-3 minutes. Placed in the freezer for 2-3 hours. After 1-2 hours from the start of freezing, the sample was removed from the freezer and inspected in the light, water was present in the diesel fuel sample, which was collected in small drops at the bottom. After this, the sample was placed in the freezer until the end of freezing. Then the measured capacity was removed, after 5-10 minutes, after the diesel fuel thawed, the fuel was drained by filtration, the water remained at the bottom with pieces of ice. Thawed water, poured into a measuring container, determined by weighing its volume according to GOST 2477-65. The water concentration in the diesel sample was 0.1%.

Example 2. Investigated the water content in a sample of winter diesel fuel (freezing temperature -25 ° C). The tests were carried out according to the proposed method. After 1-2 hours from the start of freezing, a visual inspection of the sample was carried out and at this stage of the study, the presence of water in the sample was not detected. It is concluded that there is no water in the sample.

Comparative characteristics of the indicators of the method of the prototype and the proposed method are shown in the following table.

Table Indicators Prototype The proposed method The number of devices used to implement the method, pcs one 0 The number of special solvents used (reagents - toluene, xylene, petroleum distillate, isooctane, nephras), pcs one 0 The minimum water content in the fuel, which can be determined by the method,% 0.1 0.1 The convergence of the results,% 2 2 Reproducibility of results no more,% when the volume of water is from 1.0 to 10 cm ³ 10 10 with a water volume of more than 10 cm ³ 5 5

From the data of the table it can be seen that the proposed method allows to determine the water content in liquid fuel without the use of expensive equipment and special solvents without reducing the required accuracy.

The method was tested in the testing laboratory of the Federal State Institution "Saratov Center for Standardization, Metrology and Certification named. B.A.Dubikova ", according to the conclusion of the center for standardization, metrology and certification, this method allows you to determine the water content in the fuel, starting from 0.1% and above in domestic conditions (without AKOV devices) without reducing the required accuracy. For small amounts of water, you can make a scale of known amounts of water and then compare the test sample with the samples of the scale.

Claims (1)

A method for determining the water content in liquid fuel in domestic conditions, including the preparation of fuel samples by taking into a transparent measuring tank and mixing a fuel sample in it, conducting tests, collecting the amount of water and measuring its volume, by which the percentage of water in the sample is calculated, characterized in that the tests are carried out by freezing a fuel sample at a temperature below freezing of water, during the freezing process, a visual inspection of the sample is carried out for the presence of water in it in a solid state, after freezing collect water by filtering crystals of water through a filter, thaw water, measure its volume by weighing and the percentage in the sample.