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EP-4737800-A1 - A FUEL ATOMIZING NOZZLE

EP4737800A1EP 4737800 A1EP4737800 A1EP 4737800A1EP-4737800-A1

Abstract

The present invention provides a fuel atomizing nozzle (1) for handling at least two fuels and an atomizing fluid, the fuel atomizing nozzle (1) comprising a solid body (10) having a mainly cylindrical shape around a longitudinal axis (X) defining a first end (11), a second end (12) and a contour surface (16) extending there between connecting the two ends (11, 12), wherein the first end (11) comprises at least one outlet (17), wherein the fuel atomizing nozzle (1) further comprises a fluid compartment (14) being arranged centrally around the longitudinal axis (X) in the solid body (10), at least a first and a second fuel compartment (15a, 15b) being arranged in a radial plane between the fluid compartment (14) and the contour surface (16), the fuel compartments (15a, 15b) having an annular shape, the at least first and second fuel compartments (15a, 15b) being connected to a pre-filling chamber (35) by at least a first and a second fuel channel (25a, 25b), respectively, at least one mixing chamber (40) being arranged between the fluid compartment (14) and the at least one outlet (17), and a fluid channel (24) connecting the at least one mixing chamber (40) and the fluid compartment (14), wherein the pre-filling chamber (35) has an annular shape, and the pre-filling chamber (35) is connected via a pre-filling channel (45) to the at least one mixing chamber (40).

Inventors

  • GRAM BILDE, KASPER
  • HEDE EBBESEN, Lennart

Assignees

  • Alfa Laval Corporate AB

Dates

Publication Date
20260506
Application Date
20241031

Claims (15)

  1. A fuel atomizing nozzle (1) for handling at least two fuels and an atomizing fluid, the fuel atomizing nozzle (1) comprising a solid body (10) having a mainly cylindrical shape around a longitudinal axis (X) defining a first end (11), a second end (12) and a contour surface (16) extending there between connecting the two ends (11, 12), wherein the first end (11) comprises at least one outlet (17), wherein the fuel atomizing nozzle (1) further comprises a fluid compartment (14) being arranged centrally around the longitudinal axis (X) in the solid body (10), at least a first and a second fuel compartment (15a, 15b) being arranged in a radial plane between the fluid compartment (14) and the contour surface (16), the fuel compartments (15a, 15b) having an annular shape, the at least first and second fuel compartments (15a, 15b)being connected to a pre-filling chamber (35) by at least a first and a second fuel channel (25a, 25b), respectively, at least one mixing chamber (40) being arranged between the fluid compartment (14) and the at least one outlet (17), and a fluid channel (24) connecting the at least one mixing chamber (40) and the fluid compartment (14), wherein the pre-filling chamber (35) has an annular shape, and the pre-filling chamber (35) is connected via a pre-filling channel (45) to the at least one mixing chamber (40).
  2. A fuel atomizing nozzle (1) according to claim 1, wherein the body (10) is one single solid part.
  3. A fuel atomizing nozzle (1) according to claim 1 or 2, wherein one outlet (17) is connected to one mixing chamber (40), respectively.
  4. A fuel atomizing nozzle (1) according to any previous claim, wherein the first end (11) comprises at least one chamfered surface (13) comprising the at least one outlet (17).
  5. A fuel atomizing nozzle (1) according to any previous claim, wherein the mixing chamber (40) has a mainly cylindrical shape.
  6. A fuel atomizing nozzle (1) according to any previous claim, wherein the pre-filling chamber (35) is arranged in a radial plane between the fluid compartment (14) and the contour surface (16) and being arranged in an axial plane between the fuel compartments (15a, 15b) and the first end (11).
  7. A fuel atomizing nozzle (1) according to any previous claim, comprising at least three mixing chambers (40) and three outlets (17).
  8. A fuel atomizing nozzle (1) according to any previous claim, wherein the fluid compartment (14) has a mainly cylindrical shape and a longitudinal extension being closer to the first end (11) than the fuel compartments (15a, 15b).
  9. A fuel atomizing nozzle (1) according to any previous claim, wherein the number of first and second fuel channels (25a, 25b) is at least three for each first and a second fuel channel (25a, 25b), respectively.
  10. A fuel atomizing nozzle (1) according to any previous claim, wherein the cross sectional shape of the fuel channels (25a, 25b) is rectangular.
  11. A fuel atomizing nozzle (1) according to any previous claim, wherein the size of the cross sectional shape of the fluid channel (24) varies along its length.
  12. A fuel atomizing nozzle (1) according to any previous claim, wherein the pre-filling channel (45) connects to the mixing chamber (40) at its side, and the fluid channel (24) and the pre-filling channel (45) are perpendicular to each other.
  13. Method (100) of atomizing at least one fuel by the use of a fuel atomizing nozzle (1) according to claims 1 to 12, wherein the method comprises the steps of - leading (101a) a first fuel from a first fuel compartment (15a) by a first fuel channel (25a) to a pre-filling chamber (35), - leading (102a) the fuel from the pre-filling chamber (35) by a pre-filling channel (45) further to a mixing chamber (40), - leading (103) a fluid from a fluid compartment (14) by a fluid channel (24) to the mixing chamber (40), - mixing (104a) the fuel and the fluid in the mixing chamber (40), and - letting (105) the mixture of the fuel and the fluid out through at least one outlet (17) being connected to the mixing chamber (40).
  14. Method (100) of atomizing at least two fuels according to claim 13, wherein the method comprises the steps of - leading (101a) a first fuel from a first fuel compartment (15a) by a first fuel channel (25a) to a pre-filling chamber (35), - leading (101b) a second fuel from a second fuel compartment (15b) by a second fuel channel (25b) to the pre-filling chamber (35), - leading (102b) the first fuel and the second fuel from the pre-filling chamber (35) by a pre-filling channel (45) further to a mixing chamber (40), - leading (103) a fluid from a fluid compartment (14) by a fluid channel (24) to the mixing chamber (40), - mixing (104b) the at least two fuels and the fluid in the mixing chamber (40), and - letting (105) the mixture of the at least two fuels and the fluid out through at least one outlet (17) being connected to the mixing chamber (40).
  15. A system comprising a fuel atomizing nozzle (1) according to claims 1 to 12, wherein the system comprises at least a first and a second fuel compartment (15a, 15b) for handling at least two fuels, which compartments are separated so that the first fuel is kept separate from the second fuel, and wherein the first and the second fuels are in liquid form.

Description

Field of the Invention The present invention relates to the field of nozzles for fuel atomizers, and more specifically to nozzles for fuel atomizers used for boilers. The present invention also relates to a method of atomizing fuel by the use of a fuel atomizing nozzle and a system of a fuel atomizing nozzle. Background of the Invention Boilers are used in a wide range of applications such as in power plants, on-board ships and, for processing of food and vegetable oils, etc. One type of boiler is the steam boiler that produces pressurized steam by heating water to its boiling point using a combustion process. For a boiler the combustion is done in a burner that mixes fuel and air in order to push heat into the steam boiler system. The mixture of fuel and air is combusted and for having an efficient combustion the fuel is atomized before being combusted. During operation of a boiler a fuel atomizing nozzle is used in the burner for atomizing the fuel in order to achieve a fine spray of the fuel, so it is efficiently combusted. An atomizing nozzle might be referred to as an atomizer, which disperses a liquid by transforming it into a spray. A nozzle can have one or several outlets. In a burner for a boiler the nozzle normally comprises several outlets. A well-known type of nozzle is the so called Y jet nozzle. In this type of nozzle, a number of ports are arranged at an angle to the burner axis to produce a hollow conical spray nozzle. Each port or outlet has a co-axial fluid port for injecting a compressed fluid and a fuel port entering at an angle. The fluid and the fuel are mixed in the exit port, this mixture then expands out of the port and forms a spray. Often the jet of fuel from the fuel port impinges on the one side of the exit port and forms a thick film. This thick film is then transmitted through the exit port and lead to formation of larger fuel droplets than desired. This may result in smaller sized droplets are produced at the outer radius of an exit port and larger droplets are produced at the inner radius of an exit port. If droplets are too large the combustion is non-effective. There are thus challenges of known nozzles to achieve an efficient full combustion. Problems with irregular spray having varying droplet size and exiting intermittently. This leads to a non-effective combustion that is environmentally nonsustainable. There is thus a need in the art for improved fuel atomizing nozzles. Summary of the Invention A main object of the present invention is to provide a fuel atomizing nozzle for handling at least two fuels and an atomizing fluid having an improved function to create droplets having regular size resulting in an even spray, leading to more efficient combustion. As a first aspect of the invention, there is provided a fuel atomizing nozzle for handling at least two fuels and an atomizing fluid, the fuel atomizing nozzle comprising a solid body having a mainly cylindrical shape around a longitudinal axis (X) defining a first end, a second end and a contour surface extending there between connecting the two ends, wherein the first end comprises at least one outlet. The fuel atomizing nozzle further comprises a fluid compartment being arranged centrally around the longitudinal axis in the solid body, at least a first and a second fuel compartment being arranged in a radial plane between the fluid compartment and the contour surface, the fuel compartments having an annular shape, the at least first and second fuel compartments being connected to a pre-filling chamber by at least a first and a second fuel channel, respectively, at least one mixing chamber being arranged between the fluid compartment and the at least one outlet, and a fluid channel connecting the at least one mixing chamber and the fluid compartment. The pre-filling chamber has an annular shape, and the pre-filling chamber is connected via a pre-filling channel to the at least one mixing chamber. As used herein, the term "axially" denotes a direction which is parallel to a longitudinal axis (X). Accordingly, relative terms such as "above", "upper", "top", "below", "lower", and "bottom" refer to relative positions along the longitudinal axis (X). Correspondingly, the term "radially" denotes a direction extending radially from the longitudinal axis (X). A "radially inner position" thus refers to a position closer to the longitudinal axis (X) compared to "a radially outer position". A radial plane is a plane having its normal parallel to the longitudinal axis (X). An axial plane is a plane having its normal perpendicular to the longitudinal axis (X). The first end corresponds to the upper end of the nozzle and the second end corresponds to the lower end of the nozzle. The fuel compartments having annular shape mean that these compartments are concentric with each other around the longitudinal axis (X). The first fuel compartment has a radially inner position in relation to the second fuel compartment. The radial extens