Traveling grate method for the recovery of oil from shale

Abstract

Abstract A METHOD IS DISCLOSED FOR RECOVERING OIL FROM OIL BEARING SHALE ROCK IN WHICH THE ROCK IS SCREENED TO PROVIDE THREE SIZE FRACTIONS, LARGE SIZE, INTERMEDIATE SIZE AND SMALL SIZE. THE LARGE SIZE NEED HAVE NO UPPER SIZE LIMIT BUT MAY, FOR EXAMPLE, BE SCREENED TO PLUS 1 INCH MINUS 1 1/2 INCH. THE INTERMEDIATE SIZE MAY BE PLUS 5/8 INCH MINUS 1 INCH; AND THE SMALL PLUS 1/4 INCH MINUS 5/8 INCH. SUCH SIZE FRACTIONS ARE DEPOSITED ON A TRAVELING GRATE IN A SEGREGATED BED WITH THE LARGE SIZE ON TOP, THE INTERMEDIATE SIZE ON THE BOTTOM AND THE SMALL SIZE THEREBETWEEN. THE TRAVELING GRATE CARRIES THIS BED THROUGH A PREHEATING ZONE WHERE MODERATELY HEATED GASES (FROM A RETORTING ZONE SUCH AS WILL BE DESCRIBED) PASS UPWARDLY THROUGH THE BED AND THEN THE BED PASSES THROUGH A RETORTING ZONE WHERE OIL IS EDUCTED FROM THE SHALE BY HIGHLY HEATED GASES PASSING DOWNWARD THROUGH THE BED. IN THE RETORTING ZONE THE BOTTOM LAYER OF INTERMEDIATE SIZE PARTICLES PREVENTS THE SMALLEST PARTICLES FALLING THROUGH OR PLUGGING HAS PASSAGES IN THE GRATE WHILE THE LARGEST AND MOST DIFFICULT TO PROCESS PARTICLES MAKE FIRST CONTACT WITH GASES THAT ARE THE HOTTEST AND CONTAIN THE LEAST AMOUNT OF EDUCTED OIL, FOR MAXIMUM TEMPERATURE AND MASS (I.E., OIL) TRANSFER THEREBETWEEN, AND THESE LARGEST PARTICLES SHEILD THE SMALLEST PARTICLES FROM THE HIGHEST TEMPERATURE OF THE GASES IN THE RETORTING ZONE TO PREVENT THE SMALLEST PARTICLES ADHERING TOGETHER IN A MANNER THAT WOULD DESTROY THE GAS PERMEABILITY OF THE BED ON THE GRATE. IN THE PREHEATING AND CONDENSING ZONE THE TOP LAYER OF THE LARGEST PARTICLES PROVIDES A BARRIER AGAINST FINE PARTICLES ESCAPING WITH THE GAS STREAM CONTAINING OIL MIST.

Inventors

• 👤 Chester A Rowland
• 👤 Robert D Frans

Bibliographic Details