1、BRITISH STANDARD BS 4591:1990 ISO 918:1983 Method for Determination of distillation characteristics of organic liquids (other than petroleum products)BS4591:1990 This British Standard, having been prepared under the directionof the Chemicals Standards Policy Committee, waspublished under the authori
2、tyof the Board of BSIandcomes into effect on 28February1990 BSI 11-1999 First published January 1971 Second edition February 1990 The following BSI references relate to the work on this standard: Committee reference CIC/54 Draft for comment 82/55423 DC ISBN 0 580 17676 2 Committees responsible for t
3、his British Standard The preparation of this British Standard was entrusted by the Chemicals Standards Policy Committee (CIC/-) to Technical Committee CIC/54, upon which the following bodies were represented: Chemical Industries Association Ministry of Defence Coopted members Amendments issued since
4、 publication Amd. No. Date of issue CommentsBS4591:1990 BSI 11-1999 i Contents Page Committees responsible Inside front cover National foreword ii 1 Scope and field of application 1 2 References 1 3 Definitions 1 4 Principle 1 5 Apparatus 1 6 Sampling 2 7 Procedure 3 8 Corrections to barometer readi
5、ngs 3 9 Temperature corrections 4 10 Expression of results 5 11 Test report 6 Figure 1 Assembly of distillation apparatus (5.1) 6 Figure 2 Distillation flask (5.1.1) 7 Figure 3 Distillation receiver (5.1.3) 8 Figure 4 Condenser (5.1.4) 9 Figure 5 Draught screen (5.1.5) 10 Table 1 Sampling temperatur
6、es 3 Table 2 Correction of barometer readings to0 C Fortin barometer with brass scale 4 Table 3 Correction of barometer readings to standard gravity 5 Publications referred to Inside back coverBS4591:1990 ii BSI 11-1999 National foreword This British Standard has been prepared under the direction of
7、 the Chemicals Standards Policy Committee. It is identical with ISO918:1983 “Volatile organic liquids for industrial use Determination of distillation characteristics”, prepared by Technical Committee TC47, Chemistry, of the International Organization for Standardization (ISO). This revision superse
8、des BS4591:1971which is withdrawn. The principal difference between this standard and the1971edition is that reference to “asbestos board” and “asbestos shelf” have been replaced by “heat-resistant board” and “heat-resistant shelf” throughout, as the use of asbestos is now deprecated, for health rea
9、sons. The references to ISO 3405 and ISO4626in clauses 2 and 3 constitute informative matter only and, since no requirement is involved, the validity of this British Standard is not affected. A British Standard related to ISO3405:1975is BS2000 “Methods of test for petroleum and its products”, Part12
10、3:1985 “Distillation of petroleum products”. With reference to the footnote on page 2, no International Standard for the sampling of liquid chemical products is yet available. However, attention is drawn to BS5309 “Methods of sampling chemical products”, Part3:1976 “Sampling of liquids”. Additional
11、information. Attention is drawn to the related British Standard BS2000“Methods of test for petroleum and its products” : Part195:1983 “Distillation range of volatile organic liquids”. This standard describes a method of test only and should not be used or quoted as a specification defining limits of
12、 purity. Reference to this standard should indicate that the method of test used is in accordance with BS4591:1990. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a B
13、ritish Standard does not of itself confer immunity from legal obligations. Cross-reference International Standard Corresponding British Standard ISO 31-3:1978 BS 5775 Specification for quantities, units and symbols Part 3:1979 Mechanics (Identical) Summary of pages This document comprises a front co
14、ver, an inside front cover, pages i and ii, pages1to10, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS4591:1990 BSI 11-1999 1 1 Scope and f
15、ield of application This International Standard specifies an apparatus and method for the determination of distillation characteristics of volatile organic liquids which (excluding petroleum products) having a boiling point in the range30to300 C approximately and are stable during distillation in at
16、mospheric conditions. 2 References ISO 3405, Petroleum products Determination of distillation characteristics. ISO 4626, Volatile organic liquids Determination of boiling range of organic solvents used as raw materials. 3 Definitions (see ISO 3405and ISO 4626) 3.1 initial boiling point the temperatu
17、re noted (corrected, if required) at the moment when the first drop of condensate falls from the tip of the condenser during a distillation carried out under standardized conditions 3.2 final boiling point the maximum temperature noted (corrected, if required) during the final phase of the distillat
18、ion of a sample carried out under standardized conditions 3.3 dry point the temperature noted (and corrected, if required) at the moment of vaporization of the last drop of liquid at the bottom of a flask, during a distillation carried out under standardized conditions 3.4 boiling range the temperat
19、ure interval between the initial boiling point and the dry point 4 Principle Distillation of a test portion, under carefully defined conditions in order to determine either 4.1 the temperatures corresponding to the condensate volumes defined in the International Standard for the product under test;
20、these temperatures shall be corrected as indicated in clause9, unless the nature of the product provides only for a difference of temperature between two volumes of condensate, (plotting temperature as a function of volume); or 4.2 the volume of condensate when the thermometer indicates each of the
21、distillation temperatures (previously adjusted as indicated in clause9) specified in the International Standard for the product under test (plotting volume as a function of temperature). 5 Apparatus Ordinary laboratory apparatus, and 5.1 Distillation apparatus, as shown in Figure 1 comprising 5.1.1
22、Distillation flask, available capacity100ml, of borosilicate glass, as shown in Figure 2. 5.1.2 Thermometer, of the mercury-in-glass type, graduated in0,2 C intervals, having a maximum error of 0,2 C and covering a range suitable for the products being tested. The distance between the top of the bul
23、b and the first graduation mark is at least100mm. The thermometer has no contraction chamber unless this is very close to the bulb or contained therein. The scale is calibrated for use at100mm immersion (or alternatively for total immersion). Additional requirements, in particular concerning the ran
24、ge of the thermometer, may be given in the International Standards for the products under test. 5.1.3 Receiver, 100ml capacity, graduated as shown in Figure 3. 5.1.4 Condenser of the Liebig/West type, of borosilicate glass, as shown in Figure 4. The inner tube shall have the following dimensions: Th
25、e inlet of the inner tube of the condenser shall be finished square with its axis and its outlet, smoothly ground at an angle of approximately45to the axis of the tube at that point, as shown in Figure 4. The length of the central straight portion of the water jacket shall be450 10mm, and its extern
26、al diameter35 3mm. 5.1.5 Draught screen, rectangular in cross-section and open at the top and bottom. It shall have the dimensions shown in Figure 5 and shall be made of sheet metal0,7mm thick. Internal diameter 14,0 1,0 mm Wall thickness 1,0 to 1,5 mm Length of straight portion of longer limb 600 1
27、0 mm Length of shorter limb 55 5 mm Angle included between longer andshorter limb 97 3BS4591:1990 2 BSI 11-1999 In each of the two narrower sides of the draught screen are two air-vent, holes25mm in diameter situated below the heat-resistant shelf, as shown in Figure 5. In each of the four sides of
28、the draught screen are three air-vent holes with their centre25mm above the base of the draught screen. These holes occupy the positions shown in Figure 5, the diameter of the holes situated centrally in the wider side being25mm, and the diameter of the remaining10holes12,5mm. At the middle of each
29、of the wider sides, a vertical slot for the side tube of the distillation flask, dimensioned as shown in Figure 5, is cut downwards from the top of the screen. A removable shutter, conforming to the dimensions in Figure 5, is provided for closing whichever vertical slot is not in use. A shelf of har
30、d heat-resistant board6mm in thickness and possessing a centrally cut circular hole110mm in diameter, is supported horizontally in the screen and fits closely to the sides of the screen, to ensure that hot gases from the source of heat do not come into contact with the sides or neck of the flask. Th
31、e supports for shelf may consist of triangular pieces of metal sheet firmly fixed to the screen at its four corners. In one of the narrower sides of the screen, a door is provided having the dimensions shown in Figure 5 and overlapping an opening in the screen by approximately5mm all round. In each
32、of the narrower sides of the screen, a mica window is placed centrally with the bottom of the window level with the top of the heat-resistant shelf. The dimensions and the positions of the windows are shown in Figure 5. 5.1.6 Heat-resistant board In addition to the heat-resistant shelf referred to i
33、n5.1.5, a heat-resistant board150mm square and6mm in thickness is required. It has a central hole of50mm diameter, unless otherwise stated in the specification for the material under test. 5.2 Assembly of the apparatus Assemble the distillation apparatus as shown in Figure 1. 5.2.1 Position of therm
34、ometer The thermometer shall be held in the neck of the flask by means of a well-fitting stopper of a material which is not attacked by the liquid under test. The junction of the capillary tube and the main bulb of the thermometer shall be maintained level with the lower edge of the joint between th
35、e side tube and the neck of the flask. The stopper shall project about10mm above the top of the neck of the flask. When the thermometer is fixed in position as indicated above, the immersion line on the thermometer will be in the neighbourhood of the top of the stopper holding the thermometer in pos
36、ition in the neck of the flask. 5.2.2 Support for flask The heat-resistant board (5.1.6) shall be placed on the top of the heat-resistant shelf of the draught screen so that the two holes are approximately concentric. The flask is then placed in position so as to close the hole in the heat-resistant
37、 board completely. 5.2.3 Connection of flask to condenser The flask shall be connected to the condenser so that the end of the side tube projects at least25mm into the condenser and is coaxial with it. 6 Sampling 1) Store the laboratory sample in a clean, dry and air-tight dark-glass flask, fitted e
38、ither with a ground glass stopper or with a screw cap containing an air-tight inert plastics seal. The bottle should be of such capacity that it is almost entirely filled by the sample. If it is necessary to seal the container, take care to avoid any contamination of the contents. If special precaut
39、ions are necessary, they shall be given in the appropriate International Standard test methods. To carry out the test specified in this International Standard, a laboratory sample of500ml is recommended. 1) The sampling of liquid chemical products for industrial use will form the object of a future
40、International Standard.BS4591:1990 BSI 11-1999 3 7 Procedure 7.1 Test portion Using the receiver (5.1.3) take100 1ml of the laboratory sample. If the expected distillation temperature lies below70 C, adjust the temperature of the sample, before taking it, to the appropriate value shown in Table 1. T
41、able 1 Sampling temperatures 7.2 Distillation WARNING Carry out the distillation in a well-ventilated fume cupboard. Transfer the test portion (7.1) as completely as possible to the distillation flask (5.1.1) and add a few small pieces of clean, dry porous pot. Place the flask and its contents, the
42、thermometer (5.1.2) and the receiver (5.1.3) in position and ensure that the condenser has a steady supply of water. NOTEFor materials expected to boil below70 C, the temperature of the water supply of the condenser and the temperature of the receiver should be adjusted to the values indicated in Ta
43、ble 1. In this case, immerse the receiver in a transparent cold water bath maintained at the values of temperatures indicated in Table 1. Light the burner and adjust the flame so that the first drop of distillate falls from the end of the condenser after5to10min for materials boiling below100 C, aft
44、er10to15min for materials boiling above100 C, or after any other interval, as indicated in the specification, for the material under test. Again adjust the flame so that the condensate is collected at the rate of3to4ml/min corresponding to approximately2drops per second, unless otherwise stated in t
45、he specification of the material under test. This can be achieved by adjusting the distance between the burner and the bottom of the flask so that the flame of minimum size only is necessary. Record, as appropriate, temperature as a function of volume (4.1); volume as a function of temperature (4.2)
46、. In addition, record the atmospheric pressure and the temperature of the barometer on taking the reading. 8 Corrections to barometer readings Atmospheric pressure is generally measured bymeans of a mercury barometer (Fortin type), havinga brass scale calibrated in millibars(mbar).A Standard atmosph
47、ere(atm)=1013,25mbar=101325Pa (see ISO31-3). NOTEIf the barometer is calibrated in millimetres of mercury, multiply the observed value by1,33289 (rounded up to1,333) in order to obtain the corresponding value in millibars. If, however, the pressure reading is given in pascals (Pa), note the followin
48、g equivalent values: 1 bar = 1000 mbar = 105 Pa =100kPa=0,1MPa (see ISO31-3). 8.1 Index correction Initially correct the observed barometer reading in accordance with the inspection certificate issued with the instrument. The reading thus corrected gives the atmospheric pressure as would be indicate
49、d by a correctly adjusted barometer at the temperature and at the latitude of the place of observation. 8.2 Temperature correction to0 C Correct the value obtained in8.1 to 0 C, taking into account the temperature at which the reading was taken and the type of barometer used. If the mercury barometer is of the Fortin type, or of any other type in which the mercury is set to a fiducial level when the barometric reading is taken, apply the correction given in Table 2. If the barometer used is of the Kew type, i.e. one in which
