Abstract: The method of the invention for combustion of residues from refining petroleum in a boiler comprising a hearth and injectors is characterized in that cooled gas containing oxygen is injected into the hearth in the hottest region of said hearth. Injection into the very hot region of the hearth cracks tar or aromatic polycyclic hydrocarbons and converts them into basic compounds that are easily combustible and therefore less pollutant.

Abstract: A superheater bundle for a horizontal steam separator-superheater, the bundle comprising an array of parallel tubes disposed in a triangular pitch inside a frame (3, 4) which is polygonal in shape and symmetrical about its plane of symmetry, with the bottom of the frame delimiting an inlet orifice for steam to be superheatd and with the top of the frame delimiting an outlet orifice for superheated steam. At least two of the sloping sides (11, 13, 15, 15, 17; 12, 14, 16, 18) of th polygon-shaped frame (3, 4) are parallel to the sloping segments formed by the pitch of the tubes.

Abstract: A device for fixing a perforated sheet (8) against the perforated tube plate (1) of a heat exchanger having a bundle of tubes (4, 5), the perforated sheet (8) controlling the rate of fluid flow along the tubes, and the device comprising hollow pins (10) inserted in the ends of some of the tubes (4) and expanded therein, the hollow pins terminating outside the tubes with threaded ends (12) onto which respective nuts (15) are screwed for clamping the perforated sheet against the perforated tube plate, the nuts having heads including respective axial fluid-flow controlling bores (17).