초록 ▼

As hot oil depleted shale from an indirect retorting process passes downward through a vertical shaft furnace, the residual carbon in the shale is burned out in the upper portion by air fed into the top of the furnace. The temperature of combustion is moderated by an inert gas also fed into the top

As hot oil depleted shale from an indirect retorting process passes downward through a vertical shaft furnace, the residual carbon in the shale is burned out in the upper portion by air fed into the top of the furnace. The temperature of combustion is moderated by an inert gas also fed into the top of the furnace. Additional inert gas fed into the bottom of the furnace flows upward in countercurrent contact with the descending hot shale to cool the shale and heat the inert gas. The downwardly flowing gases from the upper, combustion portion of the furnace and the upwardly flowing gas from the lower, cooling portion are withdrawn from the furnace intermediate the upper and lower portions. The inert gas can be recycle gas which is heated by direct contact with the hot shale, a separate inert gas which is circulated through the heat exchanger to heat the recycle gas or a combination of the two.

대표청구항 ▼

A process for the combustion of the residual carbon in hot oil depleted shale from which the oil has been recovered through indirect retorting with hot recycle gas, and for recovering the heat generated thereby, said process comprising the steps of: charging the hot oil depleted shale into the top o

A process for the combustion of the residual carbon in hot oil depleted shale from which the oil has been recovered through indirect retorting with hot recycle gas, and for recovering the heat generated thereby, said process comprising the steps of: charging the hot oil depleted shale into the top of a vertical shaft furnace for descending passage therethrough; feeding an oxygen containing gas into the upper portion of the vertical shaft furnace for downward flow concurrent with the hot oil depleted shale to effect combustion of the residual carbon therein resulting in the generation of combustion gases and hot spent shale; introducing a cool, inert gas into the upper portion of said vertical shaft furnace for downward flow with the oxygen containing gas and the hot oil depleted shale to control the temperature of combustion of the residual carbon in the hot oil depleted shale and wherein said cool, inert gas is introduced into the upper portion of said vertical shaft furnace at a point below the level at which the oxygen containing gas is fed into the furnace such that ignition of the residual carbon in the hot oil depleted shale is not inhibited; introducing additional cool, inert gas into the bottom portion of the vertical shaft furnace for upward flow countercurrent to the downward flow of the hot spent shale to cool and transfer the heat therein to said inert gas; and withdrawing the downward flowing inert gas and combustion gases and the upward flowing additional inert gas intermediate the upper and lower portions of said vertical shaft furnace.