Low NOx liquid fuel oil atomizer spray plate and fabrication method thereof

An atomizer spray plate for discharging fuel oil, comprising:

• a rear portion;
• a front portion;
• a whirl chamber extending from said rear portion to said front portion;
• said whirl chamber having a central longitudinal axis extending therethrough;
• said rear portion including a plurality of whirl slots extending radially inward from an outboard region of said rear portion to said whirl chamber;
• said whirl slots adapted to receive fuel oil at said outboard region and supply the fuel oil to said whirl chamber;
• and
• a discharge slot provided in said front portion for receiving the fuel oil from said whirl chamber;
• wherein said discharge slot comprises:
• (a) a cylindrical through-hole with a diameter d having a central longitudinal axis that is co-linear with said central longitudinal axis of said whirl chamber;
• and
• (b) at least three lobes equally spaced about the through-hole and oriented in a radial direction, each lobe having a semi-circular cross-section with radius r, said lobes extending approximately perpendicular to said central longitudinal axis of said cylindrical through-hole.