1、INTERNATIONAL STANDARD ISO 4262 Second edition 1993-09-15 Petroleum products - Determination of carbon residue - Ramsbottom method Produits p6 troliers - Dbtermination du r attempt to pass a 2,0 mm diameter drill rod through the capillary. Reject bulbs that do not permit the insertion of the smaller
2、 rod and those whose capillaries are larger than the larger rod. 4.2 Control bulb, for use in determining compliance of furnace characteristics with the Performance re- quirements (see clause 5). Made of stainless steel, containing a thermocouple and conforming to the tol- erances shown in figure 2.
3、 The control bulb shall be provided with a dull finish by heating in a furnace at a temperature of 850 “C to 900 “C for 30 min, and shall not be polished thereafter, as a polished bulb has different heating characteristics from one with a dull finish. Hemispherical inside rradius z 11 mm I I I I I Y
4、 1,4 m c / I I / t I : 1 ii 1 “y/ / / N / -a ,) 252 # 24,2 I Dimensions in millimetres - Capillary length 8 7 - 5 2,0 IS Capillary, free a-a of constrictions A suita ble th te mperature ermocouple pyrometer for within + 1 “C is also requ observ red. ing true Figure 1 - Glass coking bulb 4.3 Syringe,
5、 for test Portion charging. A 5 ml or IO ml glass hypodermic Syringe fitted with a needle of 1,5 mm outside diameter or a Serum needle of 1,45 mm to 1,47 mm outside diameter, for transfer of the test Portion to the glass coking bulb. NOTE 6 A Syringe having a needle which fits on the ground glass ti
6、p of the Syringe is not recommended, as it may be blown off when pressure is applied to the Syringe plunger. Locking-type syringes are more satisfactory, as the needle locks on the bottom of the Syringe barrel, and cannot be blown off by pressure. 4.4 Metal coking furnace, constructed of solid metal
7、, having coking bulb wells 25,45 mm + 0,l mm in internal diameter and 76 mm deep to the centre of the well bottom, with suitable arrangements for heating to a uniform temperature of 550 “C. The bot- tom of the well shall be hemispherical to accommo- date the bottom of the glass coking bulb (4.1). DO
8、 not cast or otherwise form the furnace with un- necessary voids which will impede heat transfer. If a molten metal furnace is used, provide it with a suitable number of bulb wells, the internal dimensions of which correspond to the internal dimensions of holes in the solid metal furnace. The bulb w
9、ells shall be immersed in the molten metal to leave not more than 3 mm of the bulb weil exposed above the molten metal at operating temperatures. NOTE 7 been fou n A description of one type of furnace wh d to be satisfacto ry is given in annex B. ich has 4.5 Temperature-measuring devices. A removabl
10、e iron-constantan thermocouple with a sensitive pyrometer, or other suitable temperature-indicating device shall be used, located centrally near the bot- tom Portion of the furnace and arranged to measure the temperature of the furnace, thus enabling the performante tests specified in clause 5 to be
11、 carried out. NOTES 8 When a molten bath is used, it is desirable to protect the temperature-indicating device with a quartz or thin metal sheath. 9 lt is good practice to calibrate the thermocouple or other temperature-measuring device against a Standard thermocouple or a reference Standard approxi
12、mately once a week when the furnace is in constant use, the actual fre- quency depending on experience. ISO 4262:1993(E) Ceramic insulator with two holes length 64 for thermocouple 0,s mm wires Double glass-lapped and silicone- impregnated 1 500 mm lang with M two holes for thermocouple wires R 0,8
13、7 Dimensions in miliimetres Tolerante on dimensions f 0,4 unless othervvise stated 25,02 ext. 6,4 ! Iron-constantan thermocouple, 0,s mm wires Stainless steel 1 Austenitic stainless Wall thickness 0,9 mm steeL Onforming t” stainless steel ISO 683-13 Threaded Hemispherical outside radius 12,4 mm to 1
14、2,7 mm NOTE - Total mass of control bulb less thermocouple: 24 g k 1 g Figure 2 - Control bulb 5 Verification of apparatus Performance 5.1 General Periodically check the Performance of the furnace (4.4) and temperature-measuring devices (4.5) as de- scribed in 5.2 to 5.4 to ensure that as used they
15、con- form to the requirements of the method. Consider the furnace as having Standard Performance when the operating requirements described are met by each coking bulb well while the bath is fully loaded as well as singly Ioaded. Once these criteria have been met, use the furnace with any degree of l
16、oading. Use only a furnace that has successfully undergone the per- formante or control tests given in this clause. 5.2 Thermocouple Calibrate the thermocouple in the control bulb against a Standard thermocouple at least once every 50 h of use of the control bulb (4.2). NOTE 10 During use at the hig
17、h temperature of the test, iron-constantan thermocouples oxidize and their calibration curves Change. 5.3 Fully-loaded furnace When the furnace temperature is within a previously Chosen 2 “C temperature range within the general range 550 “C + 5 “C (which is to be used thereafter with that part%ular
18、furnace for both standardization and routine Operation), insert the control bulb (4.2) in one weil. Within 15 s, insert in each of the other wells a glass coking bulb (4.1) containing 4 g $- 0,l g of a viscous neutral Petroleum lubricating oil with a vis- cosity within the range 60 mm*/s to 100 mm*/
19、s at 40 “C. With a suitable accurate Potentiometer or millivoltmeter (sensitive to 1 “C or less), observe the temperature rise in the control bulb at 1 min intervals for 20 min. If the temperature in the control bulb reaches 547 “C in not less than 4 min and not more than 6 min from the instant of i
20、ts insertion in the fur- nace, and remains within the range 550 “C + 3 “C for the remaining Portion of the 20 min test, cokider that particular coking bulb well to be suitable for use as a “Standard Performance weil” when the furnace is used fully loaded. Check each weil in a similar fashion, with t
21、he furnace fully loaded each time. 5.4 Singly-loaded furnace When the furnace temperature is within a previously Chosen 2 “C temperature range within the general range 550 “C + 5 “C (which is to be used thereafter with that pa&ular furnace for both standardization and routine Operation), insert the
22、control bulb (4.2) in one weil, with the remaining wells unoccupied. With a suitable accurate Potentiometer or millivoltmeter (accurate to 1 “C or less), observe the temperature rise in the control bulb at 1 min intervals for 20 min. If the temperature in the control bulb reaches 547 “C in not less
23、than 4 min and not more than 6 min from the instant of its insertion in the furnace, and remains within the range 550 “C + 3 “C for the remaining Portion of the 20 min test, consider that particular coking bulb weil to be suitable for use as a “Standard Performance well” when the furnace is used wit
24、h only a Single bulb. Check each well in a similar fash- ion, with the furnace singly loaded each time. lt is possible that not all of the wells in old furnaces will meet the requirements when fully loaded and singly loaded, and. if this is the case, check each well for any degree of furnace loading
25、 which may be used. For example, if not more than three wells of a six-well furnace are used at any one time, choose the three wells to be used from the performante data obtained with fully-loaded and singly-loaded furnaces. Check each of the three wells for triple loading, two of the wells for doub
26、le loading, and one for Single loading. Use the checked wells and no others in applying the test procedure. 6 Samples and sampling 6.1 Obtain samples in accordance with ISO 3170, ISO 3171 or an equivalent national Standard. 6.2 Products examined by this International Stan- dard are not always comple
27、tely homogeneous, and therefore appropriate precautions shall be taken dur- ing the procurement of both bulk and laboratory test samples (see 7.2). 7 Test procedure 7.1 Place a new glass coking bulb (4.1) (see note 11) in the coking furnace (4.4) at 550 “C for ap- proximately 20 min to decompose any
28、 foreign organic matter and to remove water. DO not re-use a glass coking bulb, as unpredictable results tan be obtained in such cases. Place the bulb in a closed desiccator over Calcium chloride or silica gel for 20 min to 30 min and then weigh to the nearest 0,l mg. NOTE 11 For routine testing, ne
29、w bulbs may be used without pre-ignition provided that they are visibly free from particles or other contamination. 7.2 Shake thoroughly the oil Sample to be tested, first warming if necessary to reduce its viscosity. Strain the Sample through a 150 Pm wire sieve. By means of the hypodermic Syringe
30、(4.3) or the device shown in figure3, introduce into the coking bulb an amount of Sample as indicated in table 1. Ensure that no oil remains on the exterior surface or on the inside of the neck of the bulb. Reweigh the bulb and con- tents to the nearest 0,l mg. Table 1 - Test Portion mass s Ramsbott
31、om carbon residue Test Portion mass % (dm) g 6,00 410 * 03 6,00 to 14,0 LO zt 03 14,l to 30,o 0,5 * 0,1 NOTES 12 If difficulty is encountered in loading very viscous or asphaltic test portions, of whatever size, into the glass coking bulb, the apparatus shown in annex B may be used. 13 When obtainin
32、g the test Portion of oils containing Sediment (for example, used oils), it is important to make the transfer of test portions in the shortest possible time to avoid Segregation of the Sediment. Samples containing Sediment which settles quickly after stirring tan be placed in the coking bulbs more expeditiously by using an ar- rangement such as that shown in figure3. This device con- sists of a three-way 2 mm stopcock to which have been fused two lengths of capillary tubing (1,5 mm to 2,0 mm 4
