Distillation range testing apparatus

 Distillation range measurement method refers to the temperature at which a liquid is calibrated to the standard pressure [101.3kPa(760mmHg)], from the 5th drop from the beginning of the distillation, to the temperature at which the test product has only 3 to 4ml or a certain proportion of the volume is distilled A method of scope.

Some liquid medicines have a certain distillation range, and the determination of the distillation range can distinguish or check the purity of the medicine. A set of domestic 19 standard grinding mouth distillation equipment is used. A is a distillation flask; B is a condenser, the distillation range is below 130°C and water-cooled, and the distillation range is above 130°C with an air condenser; C is a 25ml graduated cylinder with a graduation of 0.5ml; D is a split immersion type with a graduation of 0.2°C The thermometer has been calibrated in advance. The upper end of the mercury bulb of the thermometer is aligned with the lower wall of the outlet branch pipe of the distillation flask; according to the different distillation range of the test product, different heaters can be selected. The liquid level shall not exceed the liquid level of the test product at all times), use direct flame or other electric heaters to heat when the temperature is above 80℃. Determination method Take 25ml of the test sample, transfer it to a drying distillation flask through a long-necked drying funnel, add a few pieces of clean, unglazed small porcelain pieces, plug in a thermometer with a ground mouth, and connect the lower end of the condenser tube to flow The tube is connected to a 25ml graduated cylinder as the receiver. If heating by direct flame, place the distillation flask on the small round hole in the center of the asbestos board (the asbestos board has a width of 12-15cm, a thickness of 0.3-0.5cm, and a diameter of 2.5-3.0cm). Closely fit to prevent the vaporized vapor from continuing to be heated, and then use direct flame heating to heat the test sample to boil, adjust the temperature to distill 2 to 3 ml per minute, pay attention to the reading when the 5th drop is distilled from the condenser tube When the test product is distilled with only 3 to 4ml or a certain proportion of the volume, the temperature range displayed on the thermometer is the distillation range of the test product.

When measuring, if the test product is required to distill no less than 90% within the distillation range, a 100ml distillation flask should be used, and 50ml of the test product should be measured, and a 50ml graduated cylinder should be used for the receiver.

When measuring, if the air pressure is above 101.3kPa (760mmHg), for every height 0.36kPa (2.7mmHg), 0.1℃ should be subtracted from the measured temperature; if it is below 101.3kPa (760mmHg), every lower 0.36kPa (2.7mmHg) , Should increase by 0.1℃.

Distillation range is an important quality index for evaluating the vaporization of liquid fuels. It can not only indicate the boiling point range of liquid fuel, but also judge the general content of the light and heavy components in the oil composition, which is of great significance to production, use, storage and other aspects. We usually use the distillation range apparatus to test this.

Measuring the distillation range can roughly see the amount of gasoline, kerosene, light diesel and other distillates in the crude oil, thereby determining the use and processing plan of a crude oil; in the refining unit, by controlling or changing the operating conditions, the product can reach the predetermined value. Indicators: To determine the distillation range of fuel, you can preliminarily determine the type of fuel according to different boiling point ranges; to determine the distillation range of engine fuels, you can identify its evaporability, so as to judge the suitability of the oil in use; regularly determine the distillation range. Understand the evaporation loss of fuel and whether it is mixed with other kinds of oil.