Abstract: A method for controlling pitch still operations is disclosed comprising measuring the temperature of a sample of pitch from the still at a preselected viscosity value, comparing the measured temperature with a predetermined temperature value, and adjusting the parameters of the still operation in response to the comparison. An apparatus for carrying out the method is also disclosed comprising a means for withdrawing and returning a sample of pitch from the reactor, a chamber for holding the sample of pitch, the chamber having a means for heating and cooling the sample, a temperature sensing device and a viscosity measuring device located in the chamber, and a means for recording the temperature value when the viscosity has reached a predetermined value.

Abstract: Isotropic carbon fibers are disclosed and a method is disclosed for making them from liquid hydrocarbon distillates comprising reacting the distillate with elemental oxygen to produce a pitch-like product which will yield isotropic carbon upon subsequent carbonization, forming the pitch-like product into a filament and carbonizing the filament in an inert atmosphere at temperatures in excess of 800.degree. C wherein the distillate is reacted with the oxygen until at least 0.5 standard cubic feet of elemental oxygen is reacted per pound of distillate.

Abstract: A method for controlling the production of pitch and the like is disclosed comprising simultaneously measuring the viscosity and temperature of the pitch material from the production unit, comparing the measured value with a predetermined correlation of the viscosity and temperature for the pitch, and adjusting the parameters of the production operation in response to the comparison. An apparatus for carrying out the method is also disclosed comprising a means for withdrawing and returning a sample of the pitch material from the still, a chamber for holding the sample of the pitch material, the chamber having a means for heating and cooling the sample, a temperature sensing device and a viscosity measuring device located in the chamber, and a means for recording the temperature and viscosity values.

Abstract: A method for controlling the production of pitch and the like is disclosed comprising simultaneously measuring the viscosity and temperature of the pitch material from the production unit, comparing the measured value with a predetermined correlation of the viscosity and temperature for the pitch, and adjusting the parameters of the production operation in response to the comparison. An apparatus for carrying out the method is also disclosed comprising a means for withdrawing and returning a sample of the pitch material from the still, a chamber for holding the sample of the pitch material, the chamber having a means for heating and cooling the sample, a temperature sensing device and a viscosity measuring device located in the chamber, and a means for recording the temperature and viscosity values.