Mixing nozzle for a laser processing system

Abstract

A nozzle for a laser processing head is provided. The nozzle includes a main passage disposed in a body of the nozzle. The primary passage is configured to direct the laser beam and the primary fluid from the proximal end of the body to the distal end of the body. The nozzle also includes a set of at least one auxiliary passage disposed in the body of the nozzle and radially offset from the longitudinal axis of the main passage. The distal portion of the auxiliary passage is diverted into two fluid flow passages including (i) a first fluid flow passage configured to direct a first portion of the auxiliary fluid axially forward toward the distal end of the nozzle body, and (ii) a second fluid flow passage configured to direct a second portion of the auxiliary fluid radially inward to mix with the main fluid in the main passage.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 276,792 filed on November 8, 2021 and U.S. Provisional Patent Application No. 63 / 401,224 filed on August 26, 2022, the entire contents of both of which are owned by the assignee of this application and are incorporated herein by reference in their entirety. Technical Field

[0002] The present invention generally relates to one or more nozzle designs for use in laser processing systems. Background Art

[0003] Material processing systems including laser processing systems, liquid jet processing systems and plasma arc torch systems are widely used to process (e.g., heat, cut, melt and mark) materials, such as metal sheets. Laser processing systems typically include a high-power laser, an airflow, an optical system and a computer controlled digital system (CNC). In operation, the laser processing system uses an airflow to blow the molten material away from the workpiece while controllably delivering a laser beam to the workpiece to process the workpiece. Laser processing systems are often used for precision cutting operations because the laser beam, airflow and laser nozzle geometry are easily controlled.

[0004] In a laser processing system, the flow profile of the gas flow is determined by the operating pressure and the physical characteristics of the nozzle geometry. Traditionally, the gas flow includes air, oxygen, nitrogen, argon, etc. or a mixture of two or more of these gases. Oxygen and compressed air are the cheapest to use in the gas flow, but they will cause the workpiece to oxidize as they cut, so post-cutting treatments such as chemical finishing or grinding are required. In cases where the cutting material is prone to oxidation, it may be beneficial to use nitrogen or argon in the gas flow because they are generally inert and will not react with the workpiece as they cut. However, nitrogen and argon gases typically operate at very high pressures and flow rates, making them more expensive to use than oxygen, thereby increasing the operating cost of the laser processing system.

[0005] One way to change the flow profile of the gas flow in a laser processing system is to increase the velocity and pressure profile of the peripheral area of ​​the laser cutting nozzle relative to the central area. However, this is difficult because the peripheral area and the central area are usually fed by the same static pressure chamber. In the case where the two areas are fed with different pressures or gases, even if the gap is small, the gap between the nozzle and the workpiece can produce an area of ​​uniform static pressure, thereby minimizing the impact of different feeding parameters. In addition, if the pressure in the peripheral area and the central area of ​​the nozzle is different, the gas may flow back into the low-pressure area within the nozzle, which may produce splashes that are harmful to the nozzle. This is particularly harmful when the splashes pass through the central area of ​​the nozzle because the optical lens may be damaged or the nozzle may be clogged, resulting in reduced cutting quality and a reduced overall life of the laser consumables.

[0006] Therefore, there is a need for nozzles for laser processing systems that can improve control of the pressure and velocity flow profiles of the gas streams in these systems to achieve the desired cuts. Summary of the invention

[0007] In some embodiments, the present invention provides a nozzle for laser cutting applications, which is configured to passively mix a primary fluid (e.g., gas) and a portion of a secondary fluid (e.g., gas) within the nozzle. The resulting nozzle design improves control of the pressure and velocity profiles of the gas flow in the area between the nozzle end face and the workpiece to achieve the desired cut in the workpiece. In some embodiments, the nozzle of the present invention is configured to produce multiple fluid flow pathways that remain distinct from each other, while one or more of these pathways are introduced to the surrounding environment through exhaust, which allows gas mixing, pressure changes, or both. These multiple pathways allow for better control of cutting variables, which results in more controlled cutting at lower operating costs and improved cutting quality.

[0008] In one aspect, a nozzle for a laser processing head is provided for processing a workpiece. The nozzle includes a main passage disposed in the body of the nozzle. The main passage is configured to guide a laser beam and a primary fluid from a proximal end of the body to a distal end of the body to process the workpiece. The nozzle also includes at least one auxiliary passage in a group, which is arranged in the body of the nozzle and radially offset from the longitudinal axis of the main passage. The distal portion of at least one auxiliary passage is turned into two fluid flow passages, including a first fluid flow passage and a second fluid flow passage, wherein the first fluid flow passage is configured to guide a first portion of the auxiliary fluid axially forward toward the distal end of the nozzle body to substantially shield the laser beam emitted from the main passage, and the second fluid flow passage is configured to guide a second portion of the auxiliary fluid radially inward to mix with the primary fluid in the main passage.

[0009] In another aspect, a method for mixing at least two fluids within a nozzle of a laser processing head of a laser processing system is provided. The method includes directing a primary fluid axially forward through a primary passage disposed in the body of the nozzle from a proximal end to a distal end of the body, and providing an auxiliary fluid to at least one auxiliary passage disposed in the body of the nozzle. A distal portion of the auxiliary passage is configured to turn into a first fluid flow passage and a second fluid flow passage. The method also includes directing a first portion of the auxiliary fluid axially forward toward the distal end of the nozzle body through a first fluid flow passage of the auxiliary passage, directing a second portion of the auxiliary fluid inward toward the primary fluid in the primary passage through a second fluid flow passage of the auxiliary passage, and mixing the second portion of the auxiliary fluid with the primary fluid in the primary passage to produce a mixed processing fluid.

[0010] In yet another aspect, a nozzle for a laser processing head is provided for processing a workpiece. The nozzle includes a main passage disposed in the body of the nozzle. The main passage is configured to guide a laser beam and a main fluid from a proximal end of the body to a distal end of the body to process the workpiece. The nozzle also includes a group of at least one auxiliary passage disposed in the body of the nozzle. The distal portion of the at least one auxiliary passage is configured to turn into two fluid flow passages, including (i) a first fluid flow passage configured to guide a first portion of the auxiliary fluid in an axial forward direction toward the distal end of the nozzle body to substantially shield the laser beam emitted from the main passage, and (ii) a first fluid flow passage configured to guide a first portion of the auxiliary fluid in an axial forward direction toward the distal end of the nozzle body to substantially shield the laser beam emitted from the main passage. The nozzle also includes a group of at least one exhaust passage extending outward from the main passage to fluidly connect the main passage to the atmosphere.

[0011] Any of the above aspects may include one or more of the following features. In some embodiments, the first fluid flow path directs a first portion of the auxiliary fluid forward toward the distal end of the body, and the second fluid flow path directs a second portion of the auxiliary fluid toward the proximal end of the body in a partial or substantially reverse direction (e.g., substantially axially opposite to the direction of the primary fluid in the primary path). In some embodiments, the second fluid flow path is at an angle of between about 15 degrees and about 75 degrees relative to the first fluid flow path. In some embodiments, the primary fluid and the auxiliary fluid are gases.

[0012] In some embodiments, the group of at least one auxiliary passage includes at least three different auxiliary passages arranged circumferentially around the main passage in the nozzle body. In some embodiments, at least one auxiliary passage has a rectangular cross-section. In some embodiments, the main passage has a cross-section of 0.78 mm. 2 Up to 19.6mm 2The cross-sectional area between the auxiliary passage and the auxiliary passage has a cross-sectional area of ​​5.5mm 2 Up to 40mm 2 In some embodiments, the ratio of the cross-sectional area of ​​the main passage to the cross-sectional area of ​​the auxiliary passage is less than about 8.

[0013] In some embodiments, a set of at least one exhaust passage is provided, the exhaust passage extending outwardly from the main passage to fluidly connect the main passage to the atmosphere. In some embodiments, the at least one exhaust passage is oriented substantially perpendicular to at least one of the first fluid flow passages of the main passage or the at least one auxiliary passage. In some embodiments, the at least one exhaust passage is located at a position axially distal to the second fluid flow passage. In some embodiments, the at least one exhaust passage is fluidly isolated from the first fluid flow passage.

[0014] In some embodiments, the nozzle is a two-piece nozzle including an inner body and an outer body, wherein (i) the inner body includes a second fluid flow passage, and (ii) the outer body cooperates with the inner body to define a first fluid flow passage. In some embodiments, the nozzle is a three-piece nozzle, which also includes an insert disposed within the inner body. In some embodiments, the insert is disposed in a main passage near the proximal end of the body of the nozzle. In some embodiments, the insert includes at least at least one foot, an inner orifice, and a group of spray holes disposed around the inner orifice. In some embodiments, a mixing chamber is disposed in the main passage between the inner orifice of the insert and the outlet orifice of the nozzle. The mixing chamber is in fluid communication with the first fluid flow passage of the auxiliary passage. In some embodiments, a discharge chamber is located between the mixing chamber and the outlet orifice, and the discharge chamber has a smaller volume than the mixing chamber.

[0015] In some embodiments, the laser beam is directed axially forward through the primary passage and the laser beam is ejected from the primary passage at a distal end of the nozzle together with the mixed treatment fluid. In some embodiments, a first portion of the secondary fluid is ejected from a first flow passage of the secondary passage at a distal end of the nozzle to substantially shield the laser beam when the laser beam is emitted from the primary passage.

[0016] In some embodiments, when the primary fluid enters the primary passage from the proximal end of the nozzle, its pressure is between about 60 pounds per square inch (psi) and about 300 psi. In some embodiments, when the secondary fluid enters the secondary passage from the proximal end of the nozzle, its pressure is between about 30 psi and about 300 psi.

[0017] In some embodiments, the primary fluid is constricted prior to mixing with the second portion of the secondary fluid. In some embodiments, the mixed treatment fluid is constricted prior to discharging the mixed treatment fluid from the primary passage.

[0018] In yet another aspect, a method for mixing at least two fluids within a nozzle of a laser processing head of a laser processing system is provided. The method includes directing a primary fluid axially forward through a primary passage disposed in the body of the nozzle from a proximal end to a distal end of the body, providing a secondary fluid into at least one secondary passage disposed in the body of the nozzle, directing at least a portion of the secondary fluid inwardly through the secondary passage toward the primary fluid in the primary passage, and mixing at least a portion of the secondary fluid with the primary fluid in the primary passage to produce a mixed processing fluid.

[0019] In yet another aspect, a nozzle for a laser processing head is provided for processing a workpiece. The nozzle includes a body, a main passage disposed in the body, and at least one auxiliary passage disposed in the body. The main passage is configured to guide a laser beam and a primary fluid from a proximal end of the body to a distal end of the body. At least one auxiliary passage is configured to guide at least a portion of the auxiliary fluid toward a path of the primary fluid to mix the portion of the auxiliary fluid with the primary fluid in the body of the nozzle.

[0020] In some embodiments, the distal portion of the auxiliary passage is configured to turn into a first fluid flow passage and a second fluid flow passage. In some embodiments, a second portion of the auxiliary fluid is directed axially forward toward the distal end of the nozzle body through the first fluid flow passage of the auxiliary passage. In some embodiments, at least a portion of the auxiliary fluid is directed inwardly toward the primary fluid through the second fluid flow passage of the auxiliary passage.

[0021] In some embodiments, directing at least a portion of the secondary fluid inwardly comprises directing the at least a portion in a direction substantially axially opposite to the direction of the primary fluid in the primary passage. In some embodiments, the second fluid flow passage is angled between about 15 degrees and about 75 degrees relative to the first fluid flow passage. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and further advantages of the present invention may be better understood by referring to the following description taken in conjunction with the accompanying drawings, which are not necessarily drawn to scale, emphasis instead generally being placed upon illustrating the principles of the invention.

[0023] Figure 1 A side cross-sectional view of an exemplary nozzle for a laser processing system according to some embodiments of the present invention is shown.

[0024] Figure 2 Some embodiments of the present invention are shown Figure 1 A cross-sectional view of the other side of the nozzle.

[0025] Figure 3a-3d Some embodiments of the present invention are shown Figure 1 and Figure 2A plan cross-sectional view of the nozzle, taken at various planes perpendicular to the longitudinal axis A of the nozzle.

[0026] Figure 4 It shows that according to some embodiments of the present invention Figure 1 and Figure 2 Example flow patterns of the primary fluid and secondary / auxiliary fluid of a nozzle.

[0027] Figure 5 Some embodiments of the present invention are shown. Figure 1 and 2 An exemplary method for mixing a primary fluid and a secondary fluid within a nozzle.

[0028] Figure 6a and Figure 6b Figures 1 and 2 respectively show the process of laser cutting during the laser cutting operation according to some embodiments of the present invention. Figure 1 and 2 An exemplary pressure profile 600 within the nozzle 100 and a refined version of the pressure profile 600 .

[0029] Figure 7 shows a laser cutting operation during the laser cutting operation according to some embodiments of the present invention Figure 1 and Figure 2 An exemplary computational flow dynamics (CFD) pressure profile of a nozzle.

[0030] Figure 8 A side cross-sectional view of another exemplary nozzle for a laser processing system according to some embodiments of the present invention is shown. DETAILED DESCRIPTION

[0031] Figure 1 A side cross-sectional view of an exemplary nozzle 100 for a laser processing system according to some embodiments of the present invention is shown. As shown, the nozzle 100 includes a body having a proximal end 102 and a distal end 104 along a central longitudinal axis A of the body, wherein the distal end 104 is defined as the end closest to the workpiece 126 during operation of the laser processing system, and the proximal end 102 is opposite the distal end 104 along the longitudinal axis A.

[0032] The main passage 106 is disposed in the body of the nozzle 100 and extends substantially along the central longitudinal axis A between a proximal opening 107 at the proximal end 102 of the nozzle body and a distal opening 109 at the distal end 104 of the nozzle body. The main passage 106 is configured to receive a primary fluid (e.g., a gas, a liquid, or a mixture of the two) via its proximal opening 107 and deliver a laser beam and a mixture of the primary fluid and at least one auxiliary fluid to a workpiece 126 (e.g., a metal) via its distal opening 109 to process the workpiece 126. In some embodiments, an internal mixing chamber 112 is located along the main passage 106 between the proximal opening 107 and the distal opening 109 of the main passage 106.

[0033] As shown, at least one auxiliary passage 108 is arranged in the body of the nozzle 100, wherein each auxiliary passage 108 has a proximal opening 110 radially offset from the longitudinal axis of the main passage 106. Each auxiliary passage 108 is configured to guide an auxiliary fluid (e.g., a gas, a liquid, or a mixture of both) through the nozzle 100 to process the workpiece 126. In some embodiments, each auxiliary passage 108 is fluidly connected to a circumferential auxiliary fluid chamber 150, which is arranged in the nozzle body substantially around the main passage 106. The circumferential auxiliary fluid chamber 150 is configured to receive the auxiliary fluid from the group of one or more auxiliary passages 108 and to divide the auxiliary fluid between the group of one or more forward auxiliary passages 108a and the group of one or more reverse auxiliary passages 108b. Therefore, the distal portion of each auxiliary passage 108 is turned to at least one of the group of forward fluid flow passages 108a and at least one of the group of reverse fluid flow passages 108b.

[0034] Each forward auxiliary passage 108a is configured to direct a portion of the auxiliary fluid (received from one or more auxiliary passages 108) axially forward toward the distal end 104 of the body of the nozzle 100. The one or more forward auxiliary passages 108a can eject the auxiliary fluid from the nozzle 100 via their respective distal openings 111 at the distal end 104 of the nozzle body to substantially shield the mixed fluid and laser beam emerging from the main passage 106 via the distal opening 109 of the main passage 106.

[0035] Each reverse auxiliary passage 108b has an inlet 120 in fluid communication with a circumferential auxiliary fluid chamber 150 (which fluidly connects the reverse auxiliary passage 108b with the group of main auxiliary passages 108 and with the group of forward auxiliary passages 108a) and an outlet 122 in fluid communication with the mixing chamber 112 of the main passage 106. Each reverse auxiliary passage 108b is configured to radially inwardly direct another portion of the auxiliary fluid (received from one or more auxiliary passages 108) to mix with the main fluid in the mixing chamber 112 of the main passage 106.

[0036] In some embodiments, the mixing chamber 112 of the main passage 106 is axially positioned proximal to the circumferential auxiliary fluid chamber 150, at which point the main auxiliary passage 108 is divided into a forward auxiliary passage 108a and a reverse auxiliary passage 108b. Thus, each reverse auxiliary passage 108b can be configured to direct the auxiliary fluid to the mixing chamber 112 in a direction substantially opposite / opposite to the fluid flow in the main passage 106, while directing the auxiliary fluid inwardly toward the main passage 106. In some embodiments, each reverse auxiliary passage 108b maintains an angle 113 (e.g., 114) with respect to the forward auxiliary passage 108a. Figure 1 ), the angle is between about 0 degrees and about 90 degrees, such as between about 15 degrees and about 75 degrees. This reverse flow geometry of the reverse auxiliary passage 108b is advantageous because it can enhance the mixing characteristics of the primary fluid and the auxiliary fluid in the mixing chamber 112 when there is limited space within the nozzle 100. In some embodiments, the reverse flow through each reverse auxiliary passage 108b is achieved by manipulating the relative fluid pressure at the proximal opening 107 of the main passage 106 and / or the proximal opening 110 at each auxiliary passage 108. In some embodiments, the combined area of ​​the proximal openings 110 at all auxiliary passages 108 in the nozzle 100 can be greater than the total area of ​​the inlet 120 of the reverse auxiliary passage 108b to allow the fluid flow of the main auxiliary passage 108 to fully supply the auxiliary fluid to the forward auxiliary passage 108a and the reverse auxiliary passage 108b.

[0037] In some embodiments, the mixing chamber 112 is configured to fully mix the primary fluid received from the proximal opening 107 of the primary passage 106 and the secondary fluid received from the set of reverse secondary passages 108b to produce a mixed fluid. The mixed fluid is then constricted as it flows distally through the primary passage 106 and ejected from the nozzle 100 (along with the laser beam) via the distal opening 109 of the primary passage 106 to contact and process the workpiece 126. In some embodiments, the mixing of the primary and secondary fluids in the mixing chamber 112 occurs inside the cutting head of the laser processing system, within 2 feet of the nozzle orifice 145 near the workpiece 126.

[0038] In some embodiments, two separate fluid supply lines 114, 116 are connected to a corresponding one of the proximal openings 107 of the main passage 106 and the proximal openings 110 of the group of one or more auxiliary passages 108, so that two separate fluids (e.g., gases) are delivered to each type of passage in the nozzle 100. More specifically, the fluid supply line 114 can provide the main fluid to the main passage 106 via the proximal opening 107. The fluid supply line 116 can provide the auxiliary fluid to the group of one or more auxiliary passages 108 via their corresponding proximal openings 110. In some embodiments, one or both of the main fluid and the auxiliary fluid are gases. Exemplary main fluids include nitrogen, oxygen, air, argon, methane, hydrogen, etc. The main fluid and the auxiliary fluid can be the same or different. In some embodiments, the fluid supply lines 114, 116 are independently controlled to provide fluid streams with independent flow parameters, such as pressure, velocity and / or flow rate. As an example, when entering the main passage 106 via the proximal opening 107, the supply line 114 can supply the main fluid at a pressure between about 60 pounds per square inch (psi) and about 300 psi. When entering the group of one or more auxiliary passages 108 via their corresponding proximal openings 110, the supply line 116 can supply the auxiliary fluid at a pressure between about 30 pounds per square inch (psi) and about 300 psi. As described above, the nozzle 100 can be configured to mix these fluids at appropriate concentrations (e.g., at the mixing chamber 112 of the main passage 106) to achieve the desired cutting operation by the laser processing system. In some embodiments, one or more of the auxiliary passages 108a, 108b and the main passage 106 are shaped to cause a pressure drop and / or adjust the characteristics of the fluid flowing through the nozzle 100 (e.g., pressure value, flow rate, etc.), such as between the proximal end 102 and the distal end 104 of the nozzle 100.

[0039] In some embodiments, one or more of the auxiliary passages 108a, 108b and the main passage 106 are in communication with the surrounding environment (e.g., in contact with air outside the nozzle assembly 100) via one or more exhaust passages 124 located upstream of the distal opening 109 of the main passage 106. In some embodiments, the group of one or more exhaust passages 124 is isolated from direct interaction with one or more forward auxiliary flow passages 108a. In addition, when the main passage 106 and the auxiliary passages 108a, 108b are supplied by the same or different fluids and at the same or different operating parameters (e.g., operating pressures), the exhaust passages 124 can control one or more characteristics of the main passage 106 and the auxiliary passages 108a, 108b, such as static pressure, flow rate, and / or mixture concentration.

[0040] Figure 1An exemplary configuration of the nozzle 100 is shown, which includes a group of at least one discharge passage 124 extending outwardly from the main passage 106 to connect the main passage 106 fluid to the environment (e.g., atmosphere) outside the nozzle 100. This allows the pressure of the fluid flow in the main passage 106 to remain positive, even if the pressure between the nozzle 100 and the workpiece 126 tends to zero, as explained in more detail below. As shown, each discharge passage 124 can be connected to and extend outwardly from a discharge chamber 128 of the main passage 106, wherein the discharge chamber 128 is located distally relative to the mixing chamber 112 (and the group of reverse auxiliary passages 108b), but proximal to the distal opening 109 of the main passage 106. Each discharge passage 124 can also be located axially distally (i.e., downstream) relative to the mixing chamber 112 and / or the reverse auxiliary passage 108b. In some embodiments, the discharge chamber 128 has a smaller volume than the mixing chamber 112. Each exhaust passage 124 may be oriented substantially perpendicular to at least one of the main passage 106 or the forward auxiliary passage 108a (both of which may extend substantially parallel to the longitudinal axis A). Figure 1 The exhaust passages 124 project perpendicularly relative to the longitudinal axis A, but these exhaust passages 124 may also be inclined / angled relative to the longitudinal axis A. In some embodiments, these exhaust passages 124 are axially proximal to one or the reverse auxiliary passages 108b, rather than axially distal as shown.

[0041] In some embodiments, each exhaust passage 124 may be fluidly isolated / separated from the forward auxiliary passage 108a, allowing only the main passage 106 and / or the reverse auxiliary passage 108b to communicate with the surrounding environment. Figure 2 Some embodiments of the present invention are shown Figure 1 Another side cross-sectional view of the nozzle 100. Figure 1 and Figure 2 When put together two perspective cross-sections of the same discharge nozzle 100 are shown, wherein Figure 2 Rotate about the longitudinal axis A to a position without the exhaust passage 124. Figure 1 to Figure 2 The rotation angle can be about 22.5 degrees. Figure 2 It is clearly shown that the forward auxiliary flow passage 108a is not in fluid communication with the exhaust passage 124. However, in alternative embodiments, in addition to or in lieu of the main passage 106, the exhaust passage 124 may extend / protrude from the forward auxiliary flow passage 108a.

[0042] In some embodiments, Figure 1 and Figure 2The nozzle 100 of the embodiment of the present invention is a three-piece nozzle that includes an insert 130, an inner body 132, and an outer body 134. The three layers can be concentrically nested, wherein the insert 130 is substantially disposed within the inner body 132, and the combination of the insert 130 and the inner body 132 is substantially disposed within the outer body 134. In some embodiments, the insert 130 includes at least one foot 136 oriented inwardly at an angle 137 and an inner orifice 138. In some embodiments, the insert 130 further includes a group of spray holes (not shown) disposed around the inner orifice 138. The insert 130 can be located within the main passage 106 near the proximal end 102 of the nozzle 100. The mixing chamber 112 is also disposed within the main passage 106 between the inner orifice 138 of the insert 130 and the distal opening 109 of the main passage 106. In some embodiments, the inner body 132 defines at least a portion of the main passage 106. In some embodiments, the reverse auxiliary passages 108b are located on the inner body 132 such that each reverse auxiliary passage 108b extends from the inner surface of the inner body 132 to the outer surface. In some embodiments, the inner body 132 and the outer body 134 together define the forward auxiliary passage 108a therebetween. In some embodiments, the nozzle 100 is constructed as a two-piece nozzle, wherein the insert 130 is removed, thereby only including the inner body 132 and the outer body 134. In some embodiments, advanced manufacturing methods such as 3D printing can be used to achieve similar geometries and features in a single-piece construction. In some embodiments, as Figure 2 As shown, the nozzle 100 includes an alignment feature 155 to indicate a mounting alignment datum on the body of the nozzle 100 to allow for optimized alignment with the nozzle orifice 145 .

[0043] In some embodiments, the vent passage 124 is compatible with a two-piece or three-piece design of the nozzle 100. The vent passage 124 allows substantially more design space for the size of the inner nozzle body 132 and the outer nozzle body 134, and more uniform pressure and flow as the distance between the nozzle 100 and the workpiece 126 varies. In some embodiments, the vent passage 124 allows the velocity of the fluid flowing within the nozzle 100 to be positive even as the distance from the nozzle to the workpiece approaches zero. In order to keep the pressure positive, the total amount of fluid supplied to the nozzle 100 (e.g., the combination of the primary and secondary fluids) needs to be greater, and the increase in fluid supply can be provided by the secondary fluid fed to the secondary passage 108 using a less expensive fluid. In addition, the vent passage 124 helps prevent negative axial pressure gradients in the flow path as the gap distance between the distal end 104 of the nozzle 100 and the workpiece 126 decreases. Negative axial pressure gradients are generally undesirable because they can cause fluid to flow back into one or more flow paths, which can allow material splashes to adhere to the nozzle 100 or plug flow paths, or worse, contaminate the laser optics, which can greatly reduce the life of the laser optics and process stability.

[0044] Figure 3a-3d Some embodiments of the present invention are shown Figure 1 and 2 A planar cross-sectional view of the nozzle 100 is taken at various planes perpendicular to the longitudinal axis A of the nozzle 100. Figure 3a As shown, Figure 3a is Figure 1 The nozzle 100 is shown as a cross-sectional view taken at the radial plane D-D', and the nozzle 100 may include 16 auxiliary passages 108 arranged circumferentially around the central main passage 106. In some embodiments, the main passage 106 has a diameter of about 0.78 mm. 2 To about 19.6mm 2 In some embodiments, each auxiliary passage 108 has a cross-sectional area of ​​about 0.55 mm 2 To about 40mm 2 In some embodiments, the ratio of the cross-sectional area of ​​the main passage 106 to the cross-sectional area of ​​a single auxiliary passage 108 is less than about 8. As an example, the diameter of each of the 16 auxiliary passages 108 may be about 1.5 mm, and the total area of ​​the 16 auxiliary passages is about 28.3 mm. 2 (16*π*0.85 mm*0.85 mm). In alternative embodiments, the nozzle 100 may include fewer or more auxiliary passages 108 , such as 3, 6, or 24 auxiliary passages 108 .

[0045] In some embodiments, Figure 3b As shown, Figure 3bis Figure 1 The nozzle 100 is shown in a cross-sectional view taken at the radial plane CC', and the nozzle 100 may include 8 reverse auxiliary passages 108b in fluid communication with the circumferential auxiliary chamber 150, and the 16 main auxiliary passages 108 are also connected to the circumferential auxiliary chamber 150. In some embodiments, each reverse auxiliary passage 108b has a diameter of about 1.2 mm, and the total area of ​​all 8 reverse auxiliary passages 108b is about 9 mm 2 (8*π*0.6mm*0.6mm). Therefore, Figure 3a-3d In the configuration of the nozzle 100 shown, the total area of ​​the main auxiliary passages 108 is much larger than the total area of ​​the reverse auxiliary passages 108b. In alternative embodiments, the nozzle 100 may include fewer or more reverse auxiliary passages 108b, such as 4 or 16 reverse auxiliary passages 108b.

[0046] In some embodiments, Figure 3c As shown, Figure 3c is Figure 1 1. The nozzle 100 is a cross-sectional view of the nozzle 100 taken at the radial plane BB' shown, and the nozzle 100 may include a group of 8 discharge passages 124 extending outward from the discharge chamber 128 of the main passage 106 to connect the main passage 106 fluid to the atmosphere. In general, there may be more or fewer discharge passages 124 of different shapes, sizes or spacings as needed to achieve the desired operating speed and pressure profile in the primary and secondary fluids. As shown, the discharge passages 124 are fluidly isolated from the forward auxiliary passage 108a.

[0047] In some embodiments, Figure 3d As shown, Figure 3d is Figure 1 In the cross-sectional view of the nozzle 100 taken at the radial plane AA' shown, the nozzle 100 may include a group of 8 forward auxiliary passages 108a dispersed around the main passage 106. In alternative embodiments, the nozzle 100 may include fewer or more forward auxiliary passages 108b, such as 4 or 16 forward auxiliary passages 108b. Figure 3a-3d The main passage 106, auxiliary passage 108, forward auxiliary passage 108a, reverse auxiliary passage 108b, and exhaust passage 124 are shown as having circular cross-sections, but in alternative embodiments, these passages may have different cross-sectional shapes, such as rectangular cross-sections.

[0048] Figure 4 It shows that according to some embodiments of the present invention Figure 1 and 2 1 and 2. Example flow patterns of the primary fluid and the secondary / auxiliary fluid of the nozzle 100. Figure 5 Some embodiments of the present invention are shown. Figure 1and 2 An exemplary method 100 for mixing a primary fluid and a secondary fluid within a nozzle 100 of a device. Figure 5 Method 500 can be found in Figure 4 1. The method 500 is described in the context of the fluid flow pattern shown. At step 502 of the method 500, the primary fluid is directed to the proximal opening 107 of the primary passage 106 of the nozzle 100 located at the proximal end 102 of the nozzle body. The primary fluid may be supplied by the input line 114. The primary fluid is adapted to flow axially forward (along the proximal end 102) through the primary passage 106. Figure 4 The auxiliary fluid is directed to the proximal opening 110 of each of the one or more auxiliary passages 108 in the nozzle body around the main passage 106. The auxiliary fluid may be supplied by an input line 116 that may be independently controlled and operated relative to the main input line 114. The auxiliary fluid is adapted to flow axially forward (along the circumferential auxiliary fluid chamber 150) through each of the one or more auxiliary passages 108. Figure 4 Upon reaching the circumferential auxiliary fluid chamber 150, the auxiliary fluid supplied by the group of one or more auxiliary passages 108 is adapted to be diverted / diverted into the group of forward fluid flow passages 108a and the group of one or more reverse fluid flow passages 108b.

[0049] At step 506, a portion of the auxiliary fluid provided by the set of auxiliary passages 108 is directed by each reverse fluid flow passage 108b to flow radially inward (along the Figure 4 The mixing chamber 112 is configured to receive a portion of the auxiliary fluid received from the one or more reverse fluid flow passages 108b and mix the portion of the auxiliary fluid received from the one or more reverse fluid flow passages 108b with the primary fluid in the primary passage 106 to produce a mixed treatment fluid ( Figure 4 In some embodiments, the primary fluid in the primary passage 106 is constricted prior to mixing with the secondary fluid. For example, the inner orifice 138 of the insert 130 may provide constriction to the primary fluid as it enters the primary passage 106. In some embodiments, the mixed treatment fluid is directed axially forward (along the axis of the laser treatment system) along with a laser beam (not shown) of the laser treatment system. Figure 4The path 412 of the main passage 106 is a path 412 through the main passage 106. The mixed treatment fluid and laser beam combination can be ejected from the main passage 106 via the distal opening 109 of the main passage 106 to the workpiece 126 for treating the workpiece 126. In some embodiments, the mixed treatment fluid is constricted before being discharged from the main passage 106. For example, narrowing the nozzle hole 145 in the main passage 106 adjacent to the distal opening 109 of the main passage 106 can provide such constriction.

[0050] At step 510, another portion of the auxiliary fluid provided by the group of auxiliary passages 108 is directed by each forward fluid flow passage 108a to flow axially forward (along the Figure 4 The auxiliary fluid may flow through the distal end 104 of the nozzle body along the path 406 of the main passage 106. This portion of the auxiliary fluid may be ejected from the forward fluid flow passage 108a via its respective distal opening 111 to substantially shield the laser beam and the mixed treatment fluid (e.g., as a shield or protective gas) as the laser beam and the mixed treatment fluid are emitted from the distal opening 109 of the main passage 106. Figure 4 As shown, the path 406 of the auxiliary fluid flow in the forward auxiliary passage 108a can be substantially parallel to the path 412 of the mixed fluid and laser beam flow in the main passage 106.

[0051] In some embodiments, a portion of the mixed treatment fluid in the main passage 106 is discharged through a group of one or more radial discharge passages 124 (along the distal end of the nozzle 100) before the mixed fluid is ejected from the nozzle 100 through the distal opening 109. Figure 4 108a) to the atmosphere. Each exhaust passage 124 can be connected to and extend outwardly from the exhaust chamber 128 of the main passage 106 located far from the mixing chamber 112. In some embodiments, a portion of the discharged mixed process fluid is fluidically isolated from the auxiliary fluid in one or more forward fluid flow passages 108a. Therefore, the paths 406 and 414 are fluidically isolated from each other.

[0052] In general, the flow direction of the fluid through the nozzle 100 (e.g., through the discharge passage 124, the forward passage 108a and the reverse passage 108b) depends on the relative pressure of the main fluid and the auxiliary fluid provided to their corresponding proximal openings 107, 111 and the related geometric characteristics (e.g., the passage opening size, number, position, angle, pressure drop caused, etc.). These operating parameters and geometric characteristics can be controlled and adjusted accordingly to achieve the desired cutting results. In some embodiments, although the nozzle 100 is described as involving two fluids (i.e., the main fluid and the auxiliary fluid), it is understood by those of ordinary skill in the art that the nozzle 100 can be easily designed to accommodate the flow and mixing of additional fluids, such as a third and / or fourth fluid and more fluids. In various embodiments, the fluid mixed by the nozzle 100 can be a liquid, a gas, or a combination of one or more gases and one or more liquids (e.g., a mist). In some embodiments, the nozzle 100 is constructed of the same material. Alternatively, the nozzle 100 can utilize multiple materials or multiple components to achieve the desired results.

[0053] In some embodiments, such mixing of the processing fluid in the nozzle 100 as described above can occur at different locations of the laser processing system, such as in or near the nozzle holder. For example, portions of the auxiliary fluid may be introduced and / or mixed into the main fluid stream within about 2 feet of the nozzle hole 145 (e.g., close to the workpiece, inside the cutting head, etc.). In these embodiments, portions of the auxiliary fluid may be introduced / injected into the main fluid stream via features in the cutting head, the nozzle holder, and / or the nozzle 100 itself. In some embodiments, a first portion of the auxiliary fluid stream is introduced into the main fluid stream in the cutting head, a second portion of the auxiliary fluid stream is introduced into the main fluid stream via features in the nozzle holder (e.g., passages / holes), and a third portion of the auxiliary stream is introduced into the main stream via features in the nozzle 100. This staged introduction promotes mixing of the fluids. In some other embodiments, the auxiliary fluid is introduced at only one of these stages. In some embodiments, an auxiliary fluid (e.g., a second (secondary) fluid, a third fluid, a fourth fluid, etc.) is introduced / mixed into the main fluid near the optical surface (e.g., a laser lens).

[0054] In general, the various embodiments of the nozzle 100 described herein have many benefits, including the creation of a mixing zone (e.g., mixing chamber 112) that mixes an auxiliary fluid with a primary fluid near a workpiece 126 (e.g., within 2 feet of the workpiece 126). The auxiliary fluid is provided by an external auxiliary passage 108 and is adapted to flow radially inward through the nozzle 100 to mix with the primary fluid in the mixing zone of the internal primary passage 106 before being discharged through the distal opening 109 of the primary passage 106. This passive mixing reduces and / or eliminates the need for expensive and large mixing system settings employed in existing laser processing systems. Another benefit includes better control of pressure within different passages of the nozzle 100. The discharge within the nozzle 100 creates flow characteristics that enable the mixing zone to mix the primary and secondary fluids. In general, a discharge nozzle consumes more total fluid than a non-discharge nozzle, but the above-described nozzle design using the auxiliary passage 108 and the auxiliary fluid can support and reduce the use of the primary fluid, which is typically more expensive than the auxiliary fluid. More specifically, the auxiliary passage can form a sheath of the auxiliary fluid that shields the typically more expensive primary fluid. This configuration improves the robustness of the process while using the minimum amount of primary fluid required for the desired process task.

[0055] However, another benefit involves the reduced costs associated with the mixing of fluids in the above-mentioned nozzle design. For laser processing, air may be the cheapest auxiliary gas because it generally requires only electricity to operate and compressors and filtering components to remove moisture, oil and particles. Nitrogen and oxygen are the second-lowest-cost options, but due to the high flow rates required for high-pressure laser processing, their associated operating costs are still the main driving factors for consumable costs. As an example, liquid nitrogen is commonly used to supply auxiliary gas for laser processing and may require a flow rate of about 50 to about 100 standard cubic feet per minute (SCFM). At the nominal price of $1 / liter for liquid nitrogen, this means an operating cost of $122-$244 per hour of consumption. In addition, when the total nitrogen concentration is at an appropriate level, the amount of burrs on the bottom of the cut edge of certain materials can be reduced or eliminated. However, in this case, most of the gas consumed is still nitrogen, which brings high operating costs and expensive equipment for mixing gases in the correct proportions. In addition, as laser power continues to increase, the requirements for optical devices and their cleanliness also increase, requiring a lot of maintenance on the air filter used in the mixed gas because it is in contact with the optical devices. By introducing the systems and methods of the present technology for gas mixing within the nozzle, such as using nitrogen as the primary fluid and air as the secondary fluid, the consumption rate of nitrogen and / or oxygen can be greatly reduced because the correct mixed concentration is only required in a small processing area (e.g., in the mixing chamber 112), and the remaining overall flow can be composed of lower cost air (e.g., secondary fluid). In addition, high purity nitrogen (e.g., primary fluid) can be introduced only in the area in contact with the optical device, and lower quality air (e.g., secondary fluid) can be utilized for delivery to the nozzle for mixing. As an example, the nitrogen flow rate required in the metered mixing nozzle can be in the range of 9-12 SCFM, which is 80% or more less than the conventional flow rate, equivalent to a consumption saving of up to $195 / hour. Therefore, mixing air and nitrogen at high nitrogen concentrations in a small processing area can achieve significant benefits compared to using nitrogen or air alone.

[0056] Figure 6a and 6b Figures 1 and 2 respectively show the process of laser cutting during the laser cutting operation according to some embodiments of the present invention. Figure 1 and Figure 2 6 and a refined version of the pressure profile 600 within the nozzle 100. A secondary fluid, such as oxygen or air, provided as a gas (indicated by blue) by supply line 116 can be mixed with a primary fluid, such as nitrogen, provided as a gas (indicated by red) by supply line 114 to support the flow of the primary gas and change the chemistry in the processing area 602. The added support allows for the design combination of flow profiles and gas compositions to optimize cutting parameters and minimize operating costs. Figure 6a As can be seen in FIG. 1 , the primary gas and the auxiliary gas are initially supplied from different sources via supply lines 114, 116 and are subsequently mixed in the mixing chamber 112 of the nozzle 100 before the mixture flows into the processing area 602 together with the laser beam. The mixing of the gases can assist the cutting process by, for example, oxygenating the primary supply gas before it reaches the workpiece 126 and / or creating a gas mixture of appropriate concentrations depending on the primary and auxiliary gases and / or fluids used. Figure 6b yes Figure 6a Detailed view of the pressure profile 600 of FIG. 600, wherein the concentration range is narrowed to show the design concentration 603 in the critical processing area is between about 80% and about 90%. In some applications, oxidation of the main supply gas may be beneficial because oxygen often reacts exothermically with the material being cut, which can result in increased cutting speeds while beneficially changing other thermophysical properties, such as melt viscosity and surface tension. As is generally understood, different gases have different cutting characteristics depending on the material being cut.

[0057] Figure 7 shows a laser cutting operation during the laser cutting operation according to some embodiments of the present invention Figure 1 and 2 100 . As shown, the use of the discharge passage 124 allows a higher pressure around the peripheral region of the nozzle 100 than in the central region. The control enables the user to modify the pressure of each peripheral region and the central region individually by appropriately determining the size of the individual passages in the nozzle 100 and / or adjusting the flow / pressure of the auxiliary and / or main fluid streams. Traditionally, it is difficult to provide a higher peripheral pressure in the nozzle without increasing the central pressure. The enhanced control provided by the above-mentioned ventilation nozzle design can optimize the flow and pressure profile of a given processing operation. However, one problem that may arise from different pressure regions in the nozzle is the possibility of backflow from the high pressure region to the low pressure region. This problem is particularly harmful when there is backflow in the central flow region (e.g., the main passage 106) due to the increased risk of contamination during optics. This problem is avoided in the discharge nozzle 100 by adding a discharge passage 124, which transfers excess pressure and still allows positive flow to pass through the inner orifice 138 from the central flow region.

[0058] Figure 8 A side cross-sectional view of another exemplary nozzle 500 for a laser processing system according to some embodiments of the present invention is shown. As shown, the nozzle 500 includes a body having a proximal end 502 and a distal end 504, wherein the distal end 504 is defined as the end closest to the workpiece 526 during operation of the laser processing system, and the proximal end 502 is opposite to the distal end 504 along the longitudinal axis A.

[0059] A primary passage 506 is disposed in the body of the nozzle 500. The primary passage 506 is configured to receive a primary fluid 510 (e.g., gas, liquid, or a mixture of both) via its proximal opening 507. The body of the nozzle is configured to deliver a laser beam together with a mixture 514 of the primary fluid and at least one auxiliary fluid to a workpiece 526 (e.g., metal) via its distal opening 509 for processing the workpiece 526.

[0060] As shown, at least one auxiliary passage 508 is disposed in the body of the nozzle 500. Each auxiliary passage 508 is configured to direct at least a portion of an auxiliary fluid 512 (e.g., a gas, a liquid, or a mixture of the two) toward the path of the primary fluid 510, mix a portion of the auxiliary fluid 512 with the primary fluid 510 in the body of the nozzle, and then deliver a mixture 514 of the primary fluid and a portion of the auxiliary fluid to the workpiece 526.

[0061] It should be understood that the various aspects and embodiments of the present invention can be combined in various ways. Based on the teachings of this specification, those of ordinary skill in the art can easily determine how to combine these different embodiments. Those skilled in the art can also think of modifications after reading the specification.

Claims

1. A nozzle of a laser processing head for processing a workpiece, the nozzle comprising: a primary passage disposed in a body of the nozzle, the primary passage configured to direct a laser beam and a primary fluid from a proximal end of the body to a distal end of the body to process the workpiece; as well as A grouping of at least one auxiliary passage, the at least one auxiliary passage being disposed in the body of the nozzle and radially offset from the longitudinal axis of the main passage, the distal portion of the at least one auxiliary passage being diverted into two fluid flow passages, comprising: a first fluid flow passage configured to direct a first portion of a secondary fluid axially forwardly toward a distal end of a body of the nozzle to substantially obscure the laser beam emitted from the primary passage; as well as A second fluid flow passage directs a second portion of the secondary fluid radially inwardly to mix with the primary fluid in the primary passage.

2. The nozzle according to claim 1, characterized in that (i) the first fluid flow path directs the first portion of the auxiliary fluid forwardly toward the distal end of the body, and (ii) the second fluid flow path directs the second portion of the auxiliary fluid in a substantially reverse direction toward the proximal end of the body.

3. The nozzle according to claim 1, characterized in that The second fluid flow path is angled between about 15 degrees and about 75 degrees relative to the first fluid flow path.

4. The nozzle according to claim 1, characterized in that The set of at least one secondary passage comprises at least three different secondary passages circumferentially arranged around the primary passage in the body of the nozzle.

5. The nozzle according to claim 1, characterized in that The at least one auxiliary passage has a rectangular cross-section.

6. The nozzle according to claim 1, characterized in that Also included is a set of at least one exhaust passage extending outwardly from the main passage to fluidly connect the main passage to the atmosphere.

7. The nozzle according to claim 6, characterized in that The at least one exhaust passage is oriented substantially perpendicular to at least one of the first fluid flow passages of the primary passage or the at least one auxiliary passage.

8. The nozzle according to claim 6, characterized in that The at least one exhaust passage is located at an axially distal position relative to the second fluid flow passage.

9. The nozzle according to claim 6, characterized in that The at least one exhaust passage is fluidly isolated from the first fluid flow passage.

10. The nozzle according to claim 1, characterized in that The nozzle is a two-piece nozzle including an inner body and an outer body, wherein (i) the inner body includes the second fluid flow path, and (ii) the outer body cooperates with the inner body to define the first fluid flow path.

11. The nozzle according to claim 10, characterized in that The nozzle is a three-piece nozzle that also includes an insert disposed within the inner body.

12. The nozzle according to claim 1, characterized in that The primary fluid and the secondary fluid are gases.

13. The nozzle according to claim 1, characterized in that The main passage has a width of 0.78 mm. 2 Up to 19.6mm 2 The cross-sectional area between the auxiliary passage and the auxiliary passage has a cross-sectional area of ​​5.5mm 2 Up to 40mm 2 The cross-sectional area between.

14. The nozzle according to claim 1, characterized in that A ratio of a cross-sectional area of ​​the primary passage to a cross-sectional area of ​​the secondary passage is less than about 8.

15. The nozzle according to claim 1, characterized in that Also included is an insert disposed in the main passage proximate the proximal end of the body of the nozzle.

16. The nozzle according to claim 15, characterized in that The insert includes at least one foot, an inner aperture, and a set of spray holes disposed around the inner aperture.

17. The nozzle according to claim 16, characterized in that Also included is a mixing chamber disposed in the primary passage between the inner orifice of the insert and the outlet orifice of the nozzle, wherein the mixing chamber is in fluid communication with the first fluid flow passage of the secondary passage.

18. The nozzle according to claim 18, characterized in that Also included is a discharge chamber located between the mixing chamber and the outlet orifice, the discharge chamber having a smaller volume than the mixing chamber.

19. A method of mixing at least two fluids in a nozzle of a laser processing head of a laser processing system, the method comprising: directing a primary fluid axially forwardly through a primary passage disposed in a body of the nozzle from a proximal end to a distal end of the body; providing an auxiliary fluid into at least one auxiliary passage disposed in the body of the nozzle, a distal portion of the auxiliary passage configured to turn into a first fluid flow passage and a second fluid flow passage; directing a first portion of the auxiliary fluid axially forwardly through the first fluid flow passage of the auxiliary passage toward the distal end of the body of the nozzle; directing a second portion of the auxiliary fluid inwardly through the second fluid flow path of the auxiliary passage toward the primary fluid in the primary passage; and The second portion of the secondary fluid is mixed with the primary fluid in the primary passage to produce a mixed treatment fluid.

20. The method according to claim 19, characterized in that Also includes: directing a laser beam axially forward through the main passage; and The laser beam and the mixed treatment fluid are ejected from the main passage at the distal end of the nozzle.

21. The method according to claim 20, characterized in that Also included is ejecting the first portion of the auxiliary fluid from the first flow passage of the auxiliary passage at the distal end of the nozzle to substantially shield the laser beam when the laser beam is emitted from the main passage.

22. The method according to claim 19, characterized in that Directing the second portion of the secondary fluid inwardly includes directing the second portion in a direction substantially axially opposite to a direction of the primary fluid in the primary passage.

23. The method according to claim 19, characterized in that The second fluid flow path is angled between about 15 degrees and about 75 degrees relative to the first fluid flow path.

24. The method according to claim 19, characterized in that When the primary fluid enters the primary passage from the proximal end of the nozzle, the primary fluid has a pressure between about 60 pounds per square inch (psi) and about 300 psi.

25. The method according to claim 19, characterized in that When the auxiliary fluid enters the auxiliary passage from the proximal end of the nozzle, the auxiliary fluid has a pressure between about 30 psi and about 300 psi.

26. The method according to claim 19, characterized in that Also included is exhausting a portion of the mixed treatment fluid to atmosphere via at least one radial exhaust passage disposed in the body of the nozzle.

27. The method according to claim 26, characterized in that The discharged portion of the mixed treatment fluid is fluidly isolated from the first portion of the auxiliary fluid in the first fluid flow path.

28. The method according to claim 19, characterized in that Also included is shrinking the primary fluid prior to mixing the primary fluid with the second portion of the secondary fluid.

29. The method according to claim 19, characterized in that Also included is constricting the mixed treatment fluid prior to discharging the mixed treatment fluid from the main passage.

30. The method according to claim 19, characterized in that The primary fluid and the secondary fluid are gases.

31. A nozzle of a laser processing head for processing a workpiece, the nozzle comprising: a primary passage disposed in a body of the nozzle, the primary passage configured to direct a laser beam and a primary fluid from a proximal end of the body to a distal end of the body to process the workpiece; A set of at least one auxiliary passage disposed in the body of the nozzle, a distal portion of the at least one auxiliary passage configured to turn into two fluid flow passages, comprising: a first fluid flow passage configured to direct a first portion of a secondary fluid in an axial forward direction toward the distal end of the body of the nozzle to substantially obscure the laser beam emitted from the primary passage; and a second fluid flow passage configured to direct a second portion of the secondary fluid toward the primary passage to mix with the primary fluid in the primary passage; and At least one exhaust passage is grouped and extends outwardly from the main passage to fluidly connect the main passage to atmosphere.

32. The nozzle according to claim 31, characterized in that The second fluid flow passage is configured to direct the second auxiliary fluid portion inwardly toward the primary passage and in a direction axially opposite to a forward direction of the first fluid flow passage.

33. The nozzle according to claim 31, characterized in that The second fluid flow path is angled between about 15 degrees and about 75 degrees relative to the first fluid flow path.

34. The nozzle according to claim 31, characterized in that The at least one exhaust passage is oriented substantially perpendicular to the main passage.

35. The nozzle of claim 31, wherein: The at least one exhaust passage is fluidly isolated from the first fluid flow passage.

36. A method of mixing at least two fluids in a nozzle of a laser processing head of a laser processing system, the method comprising: directing a primary fluid axially forwardly through a primary passage disposed in a body of the nozzle from a proximal end to a distal end of the body; providing an auxiliary fluid to at least one auxiliary passage disposed in the body of the nozzle; directing at least a portion of the auxiliary fluid inwardly through the auxiliary passage toward the primary fluid in the primary passage; as well as At least a portion of the secondary fluid is mixed with the primary fluid in the primary passage to produce a mixed treatment fluid.

37. The method according to claim 36, characterized in that The distal portion of the auxiliary passage is configured to turn into a first fluid flow passage and a second fluid flow passage.

38. The method according to claim 37, characterized in that Also included is directing a second portion of the auxiliary fluid axially forwardly through the first fluid flow passage of the auxiliary passage toward the distal end of the nozzle body.

39. The method according to claim 37, characterized in that At least a portion of the secondary fluid is directed inwardly toward the primary fluid through the second fluid flow passage of the secondary passage.

40. The method according to claim 36, characterized in that Directing the at least a portion of the secondary fluid inwardly includes directing the at least a portion in a direction substantially axially opposite to a direction of the primary fluid in the primary passage.

41. The method according to claim 39, characterized in that The second fluid flow path is angled between about 15 degrees and about 75 degrees relative to the first fluid flow path.

42. A nozzle of a laser processing head for processing a workpiece, the nozzle comprising: ontology; a primary passage disposed in the body, wherein the primary passage is configured to direct a laser beam and a primary fluid from a proximal end of the body to a distal end of the body; and At least one secondary passage is disposed in the body, wherein the at least one secondary passage is configured to direct at least a portion of a secondary fluid toward a path of the primary fluid to mix the portion of the secondary fluid with the primary fluid in the body of the nozzle.

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