Abstract: A method and apparatus for determining the coordinates of a point of contact of an object on a semianalog sensitive surface. The coordinates are of a zone of contact of a conductive object such as a finger on a sensitive surface. The surface consists of an insulating support having a grid formed by two terminals between which a certain number of emitting resistant strips are connected in parallel and detecting conductive strips, placed between the resistant strips. The conductive strips are connected separately to a selection switch making it possible successively to sample the voltage of each detecting strip. The operation is performed in two phases by polarizing the two terminals of the grid, first in phase, then in opposite phase, and in each phase of the process the averages are taken of a certain number of synchronous samples which make it possible to determine the two coordinates.

Abstract: Method and apparatus for removing ash formed within, and accumulated at the lower portion of, a fluidized bed coal gasification reactor vessel. A supplemental fluidizing gas, at a temperature substantially less than the average fluidized bed combustion operating temperature, is injected into the vessel and upwardly through the ash so as to form a discrete thermal interface region between the fluidized bed and the ash. The elevation of the interface region, which rises with ash accumulation, is monitored by a thermocouple and interrelated with a motor controlled outlet valve. When the interface rises above the temperature indicator, the valve opens to allow removal of some of the ash, and the valve is closed, or positioned at a minimum setting, when the interface drops to an elevation below that of the thermocouple.

Abstract: A coaxial feed system for fluidized bed coal gasification processes including an inner tube for injecting particulate combustibles into a transport gas, an inner annulus about the inner tube for injecting an oxidizing gas, and an outer annulus about the inner annulus for transporting a fluidizing and cooling gas. The combustibles and oxidizing gas are discharged vertically upward directly into the combustion jet, and the fluidizing and cooling gas is discharged in a downward radial direction into the bed below the combustion jet.