ASTM D246 Method for Distillation of Creosote and Creosote-Coal Tar Solutions
6. Preparation of Sample
6.1 Thoroughly stir or otherwise mix the sample immediately before removing the portion for testing, to ensure that such portion will be representative of the sample. If warming is necessary, take care to avoid loss of volatile material.
7. Dehydration of Sample
7.1 If not more than 3.0 % of water is present, the sample may be tested without previous dehydration. If the water content exceeds 3.0 %, dehydrate a representative portion of the sample before distillation, in accordance with Test Method D370. In case of dispute the determination shall be carried out on a dehydrated sample.
8. Apparatus Assembly
8.1 Assemble the apparatus as described in 8.1.1-8.1.3 and as shown in Fig. 2 and Fig. 3.
8.1.1 Suspend the burner chimney by its flange from the support ring, place the specified two sheets of wire gauze on the burner chimney, and place the flask shield on the upper sheet of gauze. In case the electric furnace is used, attach the electric heater to a vertical support so that at the end of the distillation, it can be lowered for a distance of at least 6 in. (15 cm). Place the upper refractory on the heater with its larger opening facing upwards. Set the flask shield on the upper refractory.
8.1.2 Insert the thermometer through a regular-length No. 13 cork, rolled before use, in the neck of the flask so that the bottom of the cork is from 23 to 28 mm above the lowest point of the juncture between the tubulature and the neck of the flask, and the bottom of the bulb is 12 to 13 mm from the surface of the liquid in the flask. The exact location of the thermometer bulb may be determined by calculating the number of divisions on the thermometer which are equal to 12 to 13 mm, lowering the thermometer through the cork until the tip of its bulb touches the surface of the 100-g sample in the flask, and then raising the thermometer the calculated number of degrees to give the correct distance from the surface of the liquid. Align the stem on the axis of the bulb through the neck of the flask.
8.1.3 In the case of the flame distillation apparatus, place the flask in the flask shield with its bulb resting on the gauze. In the case of the electric-heater distillation apparatus, place the flask in the flask shield and support the flask so that its bottom is between 4 and 7 mm above the heating coils. Connect the condenser tube to the tubulature of the flask with a tight cork joint, having the tubulature project 30 to 50 mm through the cork. The distance from the neck of the flask to the outlet end of the condenser tube shall be not more than 600 nor less than 500 mm. Support the condenser tube in a position so that it is in alignment with the tubulature of the flask, and the thermometer is vertical. Place the shield cover on the flask shield around the neck of the flask.
