Abstract: A tangential fired boiler includes a circumferential wall defining a combustion zone, the circumferential wall being generally rectangular when viewed along a generally horizontal cross-section. A fireball is disposed within the combustion zone, the fireball rotating about an imaginary axis when viewed along a generally horizontal cross-section. A corner member is disposed proximate to at least one corner of the combustion zone, with a plurality of fuel inlets disposed along the corner member. The plurality of fuel inlets inject fuel into the combustion zone, and at least some of the plurality of fuel inlets inject fuel in a direction which is angled with respect to a normal of the corner member and upstream relative to a direction of rotation of the fireball.

Abstract: A tangentially-fired furnace is disclosed in enough detail to illustrate the location of injection ports for excess air above the fireball of the combustion chamber to eliminate the swirl of the flue gases as the flue gases flow into the convection section, in order to produce a uniform mass flow and temperature pattern of the flue gases over the cross section of the furnace exit.

Abstract: The invention comprises a burner (10), a first fuel pipe (18) for conveying a mixture of air and pulverized coal to the burner (10), a second fuel pipe (32) for conveying the mixture to the first pipe (18), an elbow (26) joining the first pipe (18) to the second pipe (32), said elbow (26) having an inner radius and an outer radius (27), the improvement comprising a restriction (30) in the second pipe (32), being located such that it forces the coal particles towards the outer radius (27) of the elbow (26), thereby reducing impact wear on the outer radius wall (27) of the elbow (26).