AU2011364496A1

AU2011364496A1 - Heavy cutting nozzle for cutting steel workpieces in particular

Info

Publication number: AU2011364496A1
Application number: AU2011364496A
Authority: AU
Inventors: Wigbert Buhr; Alexander Deica
Original assignee: Gega Lotz GmbH
Current assignee: Alpine Metal Tech Gega GmbH
Priority date: 2011-03-29
Filing date: 2011-03-29
Publication date: 2013-05-23
Also published as: CN103403449A; WO2012130290A1; CA2823240A1; JP5782559B2; ZA201303354B; JP2014514527A; ES2593963T3; BR112013019315A2; BR112013019315B1; KR20130077891A; RU2013147723A; EP2625463A1; EP2625463B1

Abstract

A heavy cutting nozzle (1) for cutting workpieces of steel and workpieces (200) of iron alloys, particularly slabs, ingots and billets, has a nozzle body (2) with a thread (4) for fastening to a cutting torch (100). The heavy cutting nozzle (1) also comprises a centrally arranged cutting oxygen channel (5), a multiplicity of heating gas channels (10) arranged concentrically thereto on a specific inner pitch circle (10.1) and a multiplicity of heating oxygen channels (11) arranged concentrically thereto on a further middle pitch circle (11.1), wherein the outflow openings of the media channels (5, 10, 11) open out in a clearance (7) enclosed by the nozzle body (2). The clearance (7) enclosed by the nozzle body (2) is formed by the outflow openings of the media channels (5, 10, 11) for cutting oxygen, heating oxygen and heating gas in an angular, conical or approximately semicircular manner in relation to the outlet end thereof and in this way has the effect that the media flowing out are diverted at the inclined or curved outlet surfaces (F) towards the centre of the nozzle, and swirl with the surrounding air at a further distance (B) away from the heavy cutting nozzle (1) outside the nozzle body (2).

Description

1 Heavy cutting nozzle for cutting workpieces made of steel in particular Description 5 The invention refers to a heavy cutting nozzle for cutting workpieces made of steel and workpieces made of iron alloys, particularly slabs, ingots and billets, comprising a nozzle body with a thread for fastening to a cutting torch, a centrally arranged cutting oxygen channel, a multiplicity of heating gas channels arranged concentrically thereto on a specific inner pitch circle, and a multiplicity of heating 10 oxygen channels arranged concentrically thereto on a further middle pitch circle, wherein the outflow openings of the media channels open out into a clearance enclosed by the nozzle body. Oxygen gas cutting torches are designed for cutting workpieces made of steel and 15 workpieces made of iron alloys. These devices are used to efficiently cut slabs, ingots, and billets, for example. In this, the flame of the cutting gas torch ignited from a stream of oxygen and cutting gas is directed to the surface of the metal to be cut. Thereby, the metal is heated to its ignition temperature, whereby a stream of cutting oxygen oxidises the heated metal in order to provide for the cutting 20 operation. In this, the workpiece starts burning and forms a joint extending to become a cut as the stream proceeds. Since heat is generated during the process described above, this flame cutting process is referred to as autogenous, i.e. the next steel layers of the spot to be cut are further pre-heated from the temperature gained from the burning steel. 25 As a matter of principle, a differentiation between premixed or postmixed nozzles and/or torches must be made. In premixed nozzles, heating oxygen and heating gas are mixed within the torch head before streaming out for ignition. In a postmixed cutting torch, the heating oxygen and the heating gas escape from the 30 torch in an unmixed stream. Due to turbulences, the streams are mixed before ignition.

2 So-called postmixed cutting nozzles for a cutting torch device are known from US 6,277,323 B1 and the CA 2,109,772 C, within the framework of which the media heating oxygen, heating gas, and cutting oxygen are only mixed in the outflow area of the flame. The nozzle is held by a retaining nut surrounding the nozzle and 5 connected to the cutting torch. The nozzle is characterised by an axial drilling for the outflow of the cutting oxygen of a cutting torch. Furthermore, it contains a multiplicity of heating gas drillings arranged in an inner concentric circle around the axial cutting oxygen drilling. Moreover, the nozzle comprises a multiplicity of heating oxygen drillings arranged in an outer concentric circle around the axial 10 cutting oxygen drilling. Each of the drillings, i.e. the axial cutting oxygen drilling, the heating gas drillings, and the heating oxygen drillings open out to outflow openings at an outlet end migrate in a cylindrical clearance within the retaining nut where the cutting flame is generated. 15 Therefore, this nozzle is an externally mixing - also called "postmixing" - nozzle, i.e. there is no mixture of the media inside, but outside of the nozzle. Furthermore, the nozzle is designed in several parts due to the additional retaining nut so that the nozzle design is expensive and complex. Moreover, a relatively large cutting joint is generated. Additionally, contaminations such as cinder, dust, and dirt 20 particles may accumulate on the outflow area of the flame in the cylindrical clearance within the retaining nut, where these can also penetrate the nozzle shortening the service life of the cutting nozzle. The task of the invention is to create a heavy cutting nozzle of the type mentioned 25 above, during the operation of which the formation of steel / cinder particles is lower, that creates a smaller and smoother cutting joint at lower noise levels, and that allows for an extended service life of the nozzle. In accordance with the invention, the problem is solved by the clearance enclosed 30 by the nozzle body being designed from the outflow openings of the media channels for cutting oxygen, heating oxygen, and heating gas towards its outflow end in an angular, conical or approximately semicircular shape and, in this way, having the effect that the media flowing out are diverted at the inclined or curved 3 outlet surfaces towards the centre of the nozzle, and swirl with the surrounding air at a distance farther away from the heavy cutting nozzle outside the nozzle body. When compared to the traditional cutting nozzles, the workpiece to be cut can be 5 preheated and cut in a larger distance between heavy cutting nozzle and workpiece surface due to the arrangement of the media channels in the nozzle body of the heavy cutting nozzle, the special geometric design of the media channels for the supply of gas and oxygen, as well as the heating and flame cutting temperature required for autogenous flame cutting. Furthermore, cutting 10 with this heavy cutting nozzle produces less steel/cinder particles on the workpiece surface and at the heavy cutting nozzle. The cutting joint is smaller and smoother and the generated noise is lower. Moreover, the service life of the heavy cutting nozzle can be extended significantly. 15 With this nozzle design, the process of mixing heating gas and heating oxygen and the related highest achievable combustion temperature, as well as the protection of the escaping stream through the outer protective jacket consisting of the air/oxygen mixture is performed at a higher distance between heavy cutting nozzle and workpiece surface. 20 The sub-claims result in further embodiment features and advantages. According to that, the outflow surfaces of the media channels are located inside the nozzle body and can be combined with each other, if required. The angular, 25 conical, or semicircular or possibly even cylindrical clearance for the outflow of the media, namely cutting oxygen, heating oxygen, and heating gas, resulting thereof guides the escaping media. In the supersonic flow range, the escaping gases are directed towards the middle 30 in the area of the inclined and/or curved outflow surfaces and have the effect that the media swirl significantly farther away from the heavy cutting nozzle.

4 In accordance with a further development of the heavy cutting nozzle according to the invention, a multiplicity of oxygen channels runs through the nozzle body and opens out into a ring-shaped groove at the outflow end of the nozzle body so that additionally escaping oxygen forms a pipe-shaped protective oxygen wall and/or a 5 protective jacket. This jacket protects the outflow surface against contamination by dirt particles created during flame cutting. These particles are blown off the protective jacket of the escaped oxygen by the outflow surface of the nozzle. This way, the protective jacket prevents the dirt particles from gluing to the nozzle outlet end due to the cooling effect of the oxygen. Moreover, the air/oxygen mixture 10 additionally escaping from the ring-shaped groove forms the protective oxygen jacket around the cutting oxygen, the heating gas, and the heating oxygen preventing premature swirling in the margin areas and minimising the generated noise levels. 15 Furthermore, it is designed that the ring-shaped groove is characterised by a variable cross-section, preferably semicircular or rectangular. Moreover, the oxygen channels can be equipped with at least one further, rear mounted channel for sucking ambient air, whereby the channel runs from the 20 outside of the nozzle body to the respective oxygen channel. Furthermore, the clearance enclosed by the nozzle body has a cylindrical shape from the outflow openings of the media channels towards its outflow end and the media channels open out into the outflow surface of the clearance enclosed by the 25 nozzle body in a rectangular shape. The underlying idea of the invention is described in more detail within the framework of the following description on the basis of an exemplary embodiment shown in the drawings. The figures show the following: 30 Fig. 1 shows a heavy cutting nozzle according to the invention in accordance with view "Z" pursuant to Fig. 2 on the outflow openings of the media channels, 5 Fig. 2 shows a longitudinal section view of a heavy cutting nozzle along line A A according to Fig. 1, 5 Fig. 3 shows a sectional view of the heavy cutting nozzle along line B - B according to Fig. 1, Fig. 4 shows a view "Y" of the heavy cutting nozzle according to Fig. 5, 10 Fig. 5 shows a sectional view of the heavy cutting nozzle along line C - C according to Fig. 4, Fig. 6 shows a sectional view of the heavy cutting nozzle along line D - D according to Fig. 4, 15 Fig. 7 shows detail "X" according to Fig. 6 in a second embodiment, and Fig. 8 shows detail "X" according to Fig. 6 in a third embodiment. 20 The heavy cutting nozzle 1 according to Fig. 1 to Fig. 8 for cutting a workpiece 200 is equipped with a nozzle body 2 designed as one piece. The nozzle body 2 is equipped with a hexagonal bolt 3 along the circumference. Another section of the outer circumference of nozzle body 2 is characterised by an outer thread 4 in order to screw this to a cutting torch 100 represented schematically in Fig. 3 using a 25 suitable tool. Fig. 1 shows the distribution of the outflow channels for the media required for the cutting procedure. In the centre of the nozzle body 2 there is an axial cutting oxygen channel 5 covering an area from the inlet side 6 up to clearance 7 on the 30 outflow area 8 of the nozzle body, as can be seen in Fig. 2. Regarding this embodiment of the heavy cutting nozzle 1, clearance 7 has a pan-shaped cylindrical design.

6 In its end area directed towards the clearance 7, the axial drilling 5 comprises a conical extension, by means of which the cutting oxygen flowing through the cutting oxygen channel 5 is accelerated regarding its speed and, thus, its energy. At this end of the axial drilling 5 the cutting flame is formed. 5 Parallel to the cutting oxygen channel 5, a multiplicity of heating gas channels 10 is designed in an inner pitch circle 10.1 that are arranged concentrically within the nozzle body 2. 10 Furthermore, within a middle pitch circle 11.1, the nozzle body 2 comprises a multiplicity of heating oxygen channels 11 running parallel to the cutting oxygen channel 5 from the inlet end 6 of the heavy cutting nozzle 1 to the clearance 7 of the nozzle body 2. 15 Moreover, at its outflow end, the nozzle body 2 comprises a ring-shaped groove 12 surrounding the clearance 9 for further oxygen channels 13 running from the middle pitch circle 11.1 from the inlet side 6 inclined towards the groove 12. The longitudinal section A - A through the nozzle body 2 shown in Fig 2 in 20 accordance with Fig. 1 shows the course of the cutting oxygen channel 5, the heating gas channels 10, and the heating oxygen channels 11. The media channels 5, 10, and 11 open out into clearance 7. Fig. 3 shows a longitudinal section B - B through the nozzle body 2 in accordance 25 with Fig. 1 containing a cutting oxygen channel 5, a heating oxygen channel 11, and an additional oxygen channel 13 towards the ring-shaped groove 12. Furthermore, another channel 14 for sucking the ambient air 15 is designed in each case, opening out in the assigned oxygen channel 13 and running from the outer side of the nozzle body 2 to this channel in an inclined manner. The media 30 channels 5 and 11 escape in clearance 7 at the outflow surface 8. The additional oxygen from the further oxygen channels 13 escapes together with the ambient air 15, caught by the suction effect, of the channels 14 in the ring-shaped groove 12 and forms a pipe-shaped protective oxygen wall 16 around the cutting flame in 7 order to improve the flame's efficiency. The process of mixing heating gas and heating oxygen and the related highest achievable combustion temperature "T", as well as the protection of the escaping stream through the protective jacket consisting of an air/oxygen mixture is performed at a higher distance "A" between 5 the heavy cutting nozzle 1 and the surface of the workpiece 200. Fig. 4 again shows the view in accordance with Fig. 1 in order to illustrate the sections C - C and D - D in Fig. 5 and Fig. 6. 10 Fig. 5 shows a longitudinal section C - C through the nozzle body 2 with the cutting oxygen channel 5, the heating gas channels 10, and the heating oxygen channels opening out into the clearance 7. With the embodiment 11, the clearance 7 enclosed by the nozzle body 2 is designed conically so that the heating gas and heating oxygen media pass through the clearance 7 in an inclined manner and 15 mix, causing the media to swirl at a distance "B" farther away from the heavy cutting nozzle 1. Fig. 6 shows a longitudinal section D - D through the nozzle body 2 in accordance with Fig. 4 running through the heating oxygen channels 11, the cutting oxygen 20 channel 5, and the additional oxygen channel together with channel 14 for sucking ambient air 15 towards the ring-shaped groove 12. The media channels 5 and 11 open out into the conical clearance 7. The additional oxygen of the channels 13 and 14 escapes into the ring-shaped groove 12. 25 Fig 7 shows an embodiment modified on the basis of Fig. 6, within the framework of which the clearance 7 is characterised by a predominantly tapered and/or conical shape, whereby the tapered and/or conical surface is characterised by angular surfaces. 30 Fig. 8 shows a detail X in accordance with Fig. 7, whereby the media outflow for cutting oxygen and heating oxygen opens into an approximately semicircular clearance 7.

8 Of course, the features mentioned above can not only be used in the combination specified in each case, but also in other combinations or alone, without leaving the framework of the present invention.

9 List of reference numbers 1 Heavy cutting nozzle 2 Nozzle body 3 Hexagonal bolt 4 Outside thread 5 Cutting oxygen channel 6 Inlet side 7 Clearance 8 Outflow area 9 Conical extension 10 Heating gas channel 10.1 Inner pitch circle 11 Heating oxygen channels 11.1 Middle pitch circle 12 Groove 13 Oxygen channels 14 Channel 15 Ambient air 16 Protective oxygen wall 100 Cutting torch 200 Workpiece A Distance B Distance T Combustion temperature

Claims

1. Heavy cutting nozzle (1) for cutting workpieces made of steel and workpieces (200) made of iron alloys, particularly slabs, ingots and billets, comprising a nozzle body (2) with a thread (4) for fastening to a cutting torch (100), a centrally arranged cutting oxygen channel (5), a multiplicity of heating gas channels (10) arranged concentrically thereto on a specific inner pitch circle (10.1) and a multiplicity of heating oxygen channels (11) arranged concentrically thereto on a further middle pitch circle (11.1), wherein the outflow openings of the media channels (5, 10, 11) open out into a clearance (7) enclosed by the nozzle body (2), characterised in that the clearance (7) enclosed by the nozzle body (2) is formed in an angular, conical or approximately semicircular manner from the outflow openings of the media channels (5, 10, 11) for cutting oxygen, heating oxygen and heating gas and, in this way, has the effect that the media flowing out are diverted at the inclined or curved outlet surfaces (F) towards the centre of the nozzle, and swirl with the surrounding air at a distance (B) farther away from the heavy cutting nozzle (1) outside the nozzle body (2).

2. Heavy cutting nozzle in accordance with claim 1, characterised in that the outflow surfaces (F) of the media channels (5, 10, 11) are located inside the nozzle body (2) and can be combined with each other, if required.

3. Heavy cutting nozzle in accordance with claim 1, characterised in that a multiplicity of oxygen channels (13) additionally runs through the nozzle body (2) and opens out into a ring-shaped groove (12) at the outflow end of the nozzle body (2) so that additionally escaping oxygen forms a pipe-shaped protective oxygen wall (16).

4. Heavy cutting nozzle in accordance with claim 3, characterised in that the ring shaped groove (12) is characterised by a variable cross-section, preferably semicircular or rectangular. 11

5. Heavy cutting nozzle in accordance with claim 3, characterised in that the oxygen channels (13) are equipped with at least one further, rear-mounted channel (14) for sucking ambient air (12), whereby the channel (14) runs from the outside of the nozzle body (2) to the respective oxygen channel (13).

6. Heavy cutting nozzle in accordance with claim 1, characterised in that the clearance (7) enclosed by the nozzle body (2) has a cylindrical shape from the outflow openings of the media channels (5, 10, 11) towards its outflow end and the media channels (5, 10, 11) open out at the outflow surface (F) of the clearance (7) enclosed by the nozzle body (2) in a rectangular manner.