Abstract: In a combustion installation for burning a fuel, which installation includes a hearth operating as a circulating fluidized bed, and in which installation at least a fraction of the flow of solid particles resulting from the combustion of the fuel in the hearth is returned to the hearth via a heat exchanger operating as a fluidized bed, the method of decreasing nitrogen oxide emissions consisting in the heat exchanger being fed with a fluidization gas which is considerably poorer in oxygen than air.

Abstract: Smoke inlet trunking for a cyclone separator has two lateral faces referred to as an extrados face and an intrados face, the latter terminating at a nose of the cyclone, a ceiling face and a floor face. The intrados face, which connects a point at the start of the trunking to a point at the nose of the cyclone, has a profile such that it includes at least two separate tangents such that one tangent intersects the extrados face at a point upstream of the foot of a perpendicular to the extrados face dropped from the nose of the cyclone. The intrados face begins at the point at the start of the trunking with a first part having a rectilinear profile followed by a second part having a curvilinear profile with a point of inflexion or a second rectilinear part connected to the nose of the cyclone and the point at the start of the trunking is located at an outlet from the furnace.

Abstract: In a combustion installation for burning a fuel, which installation includes a hearth operating as a circulating fluidized bed, and in which installation at least a fraction of the flow of solid particles resulting from the combustion of the fuel in the hearth is returned to the hearth via a heat exchanger operating as a fluidized bed, the method of decreasing nitrogen oxide emissions consisting in the heat exchanger being fed with a fluidization gas which is considerably poorer in oxygen than air.

Abstract: The present invention relates to a device for regulating the flow of a fluid, the device comprising an inlet receptacle and an outlet receptacle that releases the fluid at a regulated flow rate via an outlet opening, the two receptacles being separated by a common wall. The common wall extends from the bottom walls of the receptacles, and a "bell" contrivance is disposed over the common wall to form on either side of the common wall first and second intermediate receptacles in which a gas pressure is kept constant.