For a long time, mankind has tried to find a simple and easy-to-use source of heat, light and fuel.At first, such as were common wood and straw, later people learned to make and use the peat.Then mankind has made a significant breakthrough in science and technology in general - and in the fuel sector in particular began to use kerosene.
It is a mixture of hydrocarbons boiling at a temperature of 150-250 ° C.It is a clear, oily, flammable liquid obtained by the distillation of crude oil.Depending on the processing method and the chemical composition may include paraffin saturated hydrocarbons of the aliphatic type, naphthenic compounds, bicyclic compounds, a variety of impurities of oxygen, sulfur or nitrogen elements.
main stage in the application of domestic kerosene associated with the invention in 1823 of an oil unit.And since 1950, when she became actively develop turboprop and jet aircraft, launched the production of other of its kind, called "jet fuel".Get and he and the other types of kerosene oil by distillation.During primary distillation of crude oil is purified of various impurities and water (it should be noted that the density lower than the density of water kerosene).Then, already purified composition is subjected to direct distillation, in which the boiling point hydrocarbon oil fraction is released and the residual oil.
The average density of kerosene is about 0,78-0,85 grams per cubic centimeter, and flash point ranges from 28 to 72 ° C.The density of combustible liquid used for domestic purposes, is 830 kg per cubic meter, and the temperature of its outbreak is about 35-40 ° C.This is the most common indicators.Density kerosene used for lighting in mines and small vessels is 860 kg per cubic meter.The flashpoint of the liquid form may be up to 90 ° C.The density of the kerosene is not less than 780 kg per cubic meter.Such kerosene intended for use in aircraft samples subsonic aircraft.
Under the implied value of the density of kerosene, which is determined by the ratio of the mass of the fuel to its volume.Determine the density of the flammable liquid using a pycnometer - instrument specifically designed to determine the density of various liquids and solids.
for the analysis required pycnometer thermostat capable of maintaining a temperature of 20 ° C, vacuum pump, vacuum desiccator, thermometer and kerosene.The procedure itself is calculating its density is divided into several stages.First, thoroughly washed and dried pycnometer weighed.Then it is filled graphite and reweighed.Then the flask was poured kerosene (half volume), and it was placed in a dessicator where held for about one hour.
In the second stage of analysis pycnometer taken out of the desiccator and completely filled with kerosene, placed for one hour in an oven.After a certain time the appliance is removed from the oven, and its weight was measured.Then, in the same pycnometer, but already well-washed and dry rubbed, poured kerosene and doing all the same, but without the addition of graphite.Similar actions are carried out, filling in the pycnometer normal distilled water.
Calculate the density of kerosene by the following formula: density of water multiplied by the difference between the mass of the pycnometer with kerosene and graphite and weight are absolutely empty pycnometer, and the result is divided by the difference in mass of the pycnometer with water and the mass of the empty pycnometer.
discrepancy allowed between the results of two determinations carried out in parallel must not exceed 0.01-0.02 g / cc.
