Low-temperature carbonization of coal

Claim 1

IN THE METHOD OF DISTILLING HIGHLY COKING COAL BY CONTACTING SAID COAL DIRECTLY WITH HOT DISTILLATION RESIDUE FROM PREVIOUSLY DISTILLED CARBONACEOUS SOLIDS IN A CLOSED UNOBSTRUCTED SUBSTANTIALLY CYLINDRICAL HORIZONTAL RETORT WHICH IS MOUNTED FOR ROTATION ABOUT ITS LONGITUDINAL CENTRAL AXIS, THE STEPS COMPRISING MAINTAINING A GRANULAR BED CONSISTING OF SAID DISTILLATION RESIDUE IN SAID RETORT IN DIRECT CONTACT WITH THE WALLS OF SAID RETORT TO SERVE AS A BARRIER BETWEEN FRESH FEED AND SAID RETORT WALLS, ROTATING THE RETORT, WHEREBY A ROTARY MOVEMENT IS IMPARTED TO SAID BED, CONTINUOUSLY AND SEPARATELY FEEDING A STREAM OF SAID COAL IN FINELY DIVIDED FORM AND A STREAM OF HOT FINELY DIVIDED DISTILLATION RESIDUE INTO ONE END OF SAID RETORT ONTO THE TOP OF SAID BED, THE MIXING OF SAID FRESH COAL AND SAID HOT RESIDUE BEING EFFECTED SOLELY BY THE AFORESAID ROTARY MOVEMENT OF SAID BED, SAID HOT DISTILLATION RESIDUE BEING AT SUCH A TEMPERATURE AND IN SUCH QUANTITY THAT THE AVERAGE TEMPERATURE OF THE TOTAL SOLIDS IN THE RETORT IS AT A DISTILLATION TEMPERATURE OF SAID COAL, THE RATIO BY WEIGHT OF COAL AND DISTILLATION RESIDUE FED TO SAID RETORT BEING LESS THAN 1 TO 3, DISTILLING THE COAL SOLELY BY THE