Abstract:
A reforming furnace having a radiant section containing cracking tubes, a convection section and a stack is controlled so as to maintain a desired synthesis gas temperature unless such maintenance would result in the violation of a process constraint. The desired excess oxygen concentration in the combustion gases withdrawn from the radiant section is also maintained while maintaining the desired synthesis gas temperature. As for the convection section, the temperature of a fluid stream passing through the convection section is maintained while still maintaining a desired excess oxygen concentration in the stack gas.
Abstract:
Disclosed is a partial oxidation process for producing synthesis gas, fuel gas or reducing gas from slurries of solid carbonaceous fuel and/or liquid or gaseous hydrocarbon fuel. The burner has a high turndown feature and comprises a central conduit; a central bunch of parallel tubes that extend longitudinally through said central conduit; an outer conduit coaxial with said central conduit and forming an annular passage therewith; and an annular bunch of parallel tubes that extend longitudinally through said annular passage; and wherein the downstream ends of said central and annular bunches of parallel tubes are respectively retracted upstream from the burner face a distance of about 0 to 12 i.e. 3 to 10 times the minimum diameter of the central exit orifice and the minimum width of the annular exit orifice. Three ranges of flow through the burner may be obtained by using one or both bunches of tubes and their surrounding conduits. Throughput levels may be rapidly changed - up and down - without sacrificing stable operation. Additional mixing of the reactant streams is obtained in one embodiment by providing one or more coaxial cylindrical shaped pre-mix chambers in series in the central conduit and/or one or more annular shaped pre-mix chambers in series in the annular passage.
Abstract:
A pneumatic or electrical signal indicating the flow mass of a fine-grained fuel suspended in a carrier gas is produced by computer means. The input for the computer is constituted by the quantity determined for the volume of the carrier gas and the quantity determined for the density of the carrier gas together with the quantity determined as the specific weight of the fuel and the quantity determined by a radiometric measurement of the total density of the fuel and carrier gas flow. The computer is programmed to produce the above signal on the basis of a mathematical relationship defined in the above text. A valve controlling the feed of fuel into a gasifier is operated by the signal produced by the computer.