Airblast atomizer nozzle
AssigneeAsea Brown Boveri AG
InventorsFranz Joos, Marcel Stalder
Life of this patent
Estimating the term…
Abstract
In an airblast atomizer nozzle (2) for the operation of a burner (1) operated with liquid and gaseous fuels (4, 6) the intermediate wall (18) between the inner (14) and outer (13) air duct is held via inner and outer support elements (21) which have a sliding fit (28) and which can be designed as swirl vanes. The atomizer edges (19) of the airblast nozzle (2) are angled in the direction of the nozzle axis (11). The nozzle is distinguished by small dimensions, a low pressure loss and a negligible tendency to coking.
Claims14
A method for operating a burner with liquid and gaseous fuel, the burner having an airblast nozzle including a nozzle outer body mounted to the burner and defining an air feed conduit having a nozzle axis, an intermediate wall disposed in a downstream portion of the air feed conduit to define an inner air duct and an outer air duct, a downstream portion of the intermediate wall forming an atomizer edge, an outlet of the atomizer edge defining an atomization plane, the atomizer edge having a frustoconical shaped narrowing toward the outlet, wherein, the inner air duct and outer air duct are positioned concentrically about the nozzle axis, the air ducts open into a burner interior at the atomization plane, and wherein a cross section of the outer air duct narrows upstream of the atomization plane, a liquid fuel pipe disposed centrally on the nozzle axis and having means for applying liquid fuel to the atomizer edge, said means located at a downstream end of the liquid fuel pipe, inner and outer support elements fixedly supporting the intermediate wall between the inner and outer air duct, the inner support elements being arranged between the intermediate wall and the fuel pipe and the outer support elements being arranged between the intermediate wall and the nozzle outer body, and a pilot gas duct arranged radially outward of and concentrically to the liquid fuel duct, the burner being mounted firmly on a combustion chamber, and having air throttling means attached between the liquid fuel conduit and the burner at an inlet to the burner, the liquid fuel conduit being slidable relative to the burner,
- the method comprising the steps of:
- closing a fuel supply to the liquid fuel conduit for operation of the burner with gaseous fuel;
- and
- throttling an inflow of air into the air feed conduit by guiding air into the air feed conduit past the liquid fuel conduit to heat the liquid fuel conduit, wherein different thermal expansion of the liquid fuel conduit and the burner causes the liquid fuel conduit to expand to close the air throttling means.
An airblast atomizer nozzle for a burner having liquid and gaseous fuel feeds, the nozzle comprising:
- a nozzle outer body defining an air feed conduit having a nozzle axis;
- an intermediate wall disposed in a downstream portion of the air feed conduit to define an inner air duct and an outer air duct, the intermediate wall having an upstream edge disposed in the air feed conduit to define inlets to the inner air duct and outer air duct, and having a frustoconically shaped downstream outlet portion narrowing to form an atomizer edge, an outlet of the atomizer edge defining an atomization plane, and an outer profile of the atomizer edge tapering toward the outlet,
- wherein, the inner air duct and outer air duct are positioned concentrically about the nozzle axis, the inner and outer air ducts opening into a burner interior at the atomization plane, and wherein a cross section of the outer air duct narrows upstream of the atomization plane,
- a liquid fuel pipe disposed centrally on the nozzle axis and extending into the intermediate wall, the liquid fuel pipe having means for spraying liquid fuel to the atomizer edge, said means located at a downstream end of the liquid fuel pipe, and
- inner and outer support elements supporting the intermediate wall between the inner and outer air duct, the inner support elements being arranged in the inner air duct between the intermediate wall and the fuel pipe and the outer support elements being arranged in the outer air duct between the intermediate wall and the nozzle outer body.
Dependencies are inferred from the claim text.