CS220322B2 - Method of and apparatus for thermochemically descaling metal workpieces - Google Patents

Abstract

The present invention relates to the thermochemical scarfing of metal workpieces. The present invention seeks to provide a method for scarfing the surface of a metal workpiece that provides acceptably short preheat times for scarfing relative cold workpieces without being subject to flashback and without requiring adjuvant material. In accordance with the present invention post-mixed scarfing pre- heating flame is produced by discharging fuel and oxygen from separate ports to impinge forming acute included angle. The flame is stabilized with a low-intensity stream of oxygen, directed in same general direction as the flame, close to but not passing through the point of impingement. <IMAGE>

Description

The present invention relates to a method for thermochemical descaling of a metal workpiece, in which the point on the surface of the workpiece where the descaling reaction is to start is preheated to the ignition temperature of the workpiece site and oxygen.

A complete descaling cycle typically consists of three steps: 1. Placing the workpiece in line with the descaling units; 2. Preheating the workpiece to form a molten pool; descaling units. In particular, the invention relates to a preheating step.

The prior art knows several methods for carrying out the preheating step. U.S. Pat. No. 2,267,405 discloses preheating with a flame formed by combining oxygen and fuel gas inside the burner and igniting the gas mixture when it exits the burner. The problem of combining oxygen and fuel gas inside the burner, hereinafter referred to as "pre-blending", is that the explosive mixture tends to backfire, ie ignite inside the burner, which can damage the burner and become a source of danger .

The refinement of premixed flame 2 is not described in U.S. Pat. No. 2,356,197, in which oxygen and fuel gas are combined just prior to discharge from the nozzle. Although this was an improvement over the prior art, the apparatus still tended to fall back. If the outer nozzle is clogged, for example with splashed metal, while the oxygen and fuel gas openings within the unit remain open, the two gases mixed inside the unit to form an explosive mixture exposed to back-ups.

U.S. Pat. No. 3,231,431 discloses a pre-heating apparatus with additional mixing in which oxygen and fuel gas are combined outside the unit, thereby completely eliminating the possibility of a back-up. However, the intensity of the flame produced by this additional mixing apparatus is limited. Although this process can be used to preheat hot workpieces, its low intensity flame requires an unacceptably long time to preheat cold workpieces.

U.S. Pat. No. 3,752,460 discloses a pre-heating apparatus with additional mixing that uses a stream of "retained" oxygen to reduce the preheating time. Although the present invention is an improvement over the prior art, it is not able to preheat relatively cold workpieces quickly enough for industrial operations.

U.S. Pat. Pat. No. 3,966,503 describes a method of ^{PU p} ro ^yl Vore Mze ^to OV ^eh odoltujiíovacího the start, that reduces the time required for preheating the workpiece, to practically zero. The method of this patent provides ^h c r ^y Lay ^width not ^{from PU} method ccording ^{p y} n and ^l in the cut; Avşa ^to this known method requires a rod feed mechanism and a jet of oxygen is a high intensity, which is not necessary according to the invention. Therefore, the advantages of the ^invention-if not in ^{the YZ} and ^d Ovan wage scarfing start, but is applied fast enough to start on cold steel.

The purpose of the ^y n and ^l is therefore cut vytvortt method as well as apparatus for scarfing the surface of the workpiece to allow an acceptably short preheat times for scarfing relatively cold workpieces, without danger of flashback, and without requiring the auxiliary material.

A given úteha after ^dL ev ^y n and ^l cut in ^YR solved by means of a thermochemical scarfing a metal workpiece, in which the location on the surface of the workpiece where to start scarfing reaction, preheated to ignition temperature points of a workpiece in oxygen by this preheated instead directs additionally mixed preheat flame which is formed by discharging at least one stream of preheat fuel gas and at least the ^d amino ^h o ^p Roudou ^p redefinitions ^HRI VACI ^h oo ^alkyl sličovacího gas and the stream of scarfing oxidizing gas is directed at an acute ^angles at ^P ovrc ^h olbrob ^to in this ^EXAMPLE edehřátém place and simultaneously causing relative movement between odolkujňovacím oxidizing gas and a workpiece, thereby forming a scarfing cut, while the principle of the invention spočrv ^s in the current ^instance e ^d e ^HRI vac ^¹H the oxidizing gas and the stream of preheating fuel gas is directed towards each other upon d through the workpiece surface, the axes of these streams forming an acute angle, and that the preheating flame is stabilized by discharging a low intensity stabilizing oxidizing gas stream in the same general direction as the flame direction or at an angle of 10-90 ° to the forward flame axis and the stabilizing oxidant gas stream passes or near the point of impact of the preheating oxidizing gas and preheating fuel gas streams.

Come above ^h o ^d N O ^{P eh} rovedern from ^para uso ^b u ^p ccording to the invention is an acute angle between the axes of the preheat oxygen and preheat fuel gas stream in the range between 5 ° and 50 °.

The oxidizing stabilizing gas preferably consists of oxygen.

According to another embodiment of the VYN ^AL Cutting Růt ^p ^ o r ^{y c} on chtest rou ^{p d} u ^{d p} re ehřívacího fuel gas and preheat oxidizing gas stream in the range of 1 to 3.5 m3 / h, measured .When 0 ^c C and under pressure

101,325 psi and flow rate of the transfer currents ^IIc with ^alkyl EDGINGPROFILE ^¹H about ptynu ^K Y ^{P d d} is drilled in the range of 1-6 m ^{3 /} hm ^of Reno at 0 ° C and. pressure 101,325 kPa.

^{Úč HeATING} Ruto ^{p c} on r ^y ^ chtost stabihsa him oxidizing gas per centimeter of width of the scarfing nozzle orifice in the range of ^{3, and 5 10111} ¾ eno m ^measured at ⁰ ° C and ^p ri UBATT 101,325 kPa.

Apparatus ^kp ROV ^ADE her way ^of method ^{for the} compliance in the ^y finding comprises a peeling unit which is provided with at least one nozzle onto the scarfing oxygen and whose central axis is directed at the surface odolkujňovaného workpiece and NEJM Step ^E is ^D EN hole ^P ro ^ edelhrivam oxidizing gas and at least one opening for the preheat fuel gas and according to the invention essentially designed so that the axis of the preheat fuel gas is directed toward the surface of the workpiece, the hole axis preheat oxygen crosses in place until ^ d ^ ^p ri o ^{p p} and ^DE average ^of the ^No. I ^{to the} bore axis at the preheat fuel gas sharply angled outwardly and said apertures above the workpiece surface and the hole for stabilizing oxygen is deposited on the peeler .jednotce and its axis is directed in the same ^e m m ⁱⁿ general direction ^of interference I ^to the lining of the bore axis ^P ro ^{d Pla HRI} vac e ^s o ^ slmovam ^ply opening preheat fuel gas or angles at 10 ° to 90 ° to the forward facing 'resultant uvedenýc ^H axis and ^{d p} r ena ^of the ^Čík these axes not em ^b o ^h o is MmtosU.

According to a preferred embodiment of the device after at le ^{d y} n and ^l is cut sharp clamped Bricks tooimný intersection of the hole axis preheat fuel ^{ply ordinate} opening ^P ro ^ nv edelmvarn otystíífovarf ^ply between 5 ° and 50 °.

Hole stabilizing oxygen is ^Prior e ^l n ^of identical orifice t r ^{y y} sk for a ^d of ^the uj ^least ovations ^also on ^alkyl with ^LIC EDGINGPROFILE ^í n ^ply.

According to a further embodiment of an apparatus according to the opening vynátozu ^yp ro podehrivací to ^p p ^l Nu yn in the ^{p th} t ^{loan IM.} Not ^of drives located ^ ^y in ^R and ^DE in substantial equal to ^{It runs} continuously ^{E d} is more than opening it preheat oxygen, arranged in a row.

According to another embodiment of the apparatus according to the invention, the number of the preheat fuel gas and preheat series of holes oitysltoovam ^ply umíston n ^y in the upper ^straight edehřívacím block of the scarfing unit.

According to yet another embodiment of the invention, the number of the preheat fuel gas and preheat series of holes acidified ^No EDGINGPROFILE ^{ply s} n m ^{d y} ston dolrnm ^{Pla d} e ^HRI block adapters, the preheating unit.

Until the development of the invention it was not possible prelude surface portion of the relatively cold metal workpiece to scarfing ^even the ^p Lot u for ^p sing ^pl Amen ^without no ^b ez ^p e ^{whose PE} tn ^eh the above ^ er ^ or without using ^{rods d} muchave ^to s with ^{y Ké} rntenzKě or JL · Joint auxiliary accessories.

While not meant to be bound by theory, it is possible to provide the following explanation of how the invention achieves shorter preheating times. It was observed ^{and no,} that additional nestabihzovaný-mixed flame generated by the impact of preheat fuel gas and preheat oxidizing gas tends to have a relatively large zone of low intensity and a relatively small high intensity zone. In some cases, no high intensity band could be observed. In addition, the unstabilized post-mixed flame tends to flutter. If you will make an attempt to increase rntenzitu nestabihzované ^h o ^{p w} tions Lamen increase current preheat oxygen and preheat fuel gas becomes significant flutter. Finally, the nestabilisovaný flame blows from the preheat orifices increased flow of gas and ^{h s} and up. ^{He was} observed ^and no. ^Z e ^é reflective plate helps to keep the flame at the point ^E, and allow one ^to u ^{p d} ridicule Member ^No. velocity of the preheating flame until the flame is extinguished.

When the addition-mixed flame stabilizes the flow of oxidizing gas of which ^Ké rntenzitě e ^p o ^dl VYN ez ^ ^y ^ v · vrne stabilL Sovano flame very rapidly pronounced long range, high intensity and fluttering stops. The flame remains stable even when the currents preheat fuel gas and for ^D ehnvac ^¹H mesh sHku ^y increases to r ^y c ^{y hl} Ost SSI than the speeds that nestabilisovaný extinguished flame.

^You n and ^l EZ te ^dy significant improvement preheating methods of the prior art because it gives preheating time is less than half the required according Pat. No. 3,752,460 for workpieces above 200 ° C. For workpieces below 200 ^° C, the invention needs considerably less than half the pre-heating time according to the procedure just mentioned. Note that the graph indicates that the oxygen retention procedure cannot achieve preheating times below 20 seconds for workpieces below 250 ° C, while the invention requires less than 20 seconds to preheat the workpiece at 0 ° C.

Term "oxidizing or oxidizing gas" for ^further uses, ^and e ^p ro Denote the gas containing the oxidizing agent. The preferred oxidizing gas is commercially pure kysU ^ Avşa ^to VYN ^AL EZ can rovád ^{p E} t рй use other oxidizing gases than pure oxygen. For example, oxidizing gas for scarfing and of stabilizing can be oxygen having a purity of only 99 percent or even lower and ^to AV ^S bui ^{l b} e u ^{d thanks to} ou ^h or ^width with the use of impure oxygen, especially with oxygen of less than 99 percent purity. The preheating oxidant gas may contain only 21 percent oxygen, i.e. it may be air, but the preheating times will increase as the percent oxygen decreases in the preheating oxidizing gas stream.

^In ýrazem ^"p ředehřívání" the MMI ^d Uve measurement surface portion of the workpiece to ignition temperature of the ^Ca in the STI oxtéačním gas; TFM is meant the temperature at which the workpiece will ignite ^kd yz is in and mos ^{t f} era went on ^{alkyl No} EDGINGPROFILE ^¹H op nu ^ly.

The invention will now be explained by means of several embodiments with reference to the drawings.

Giant. 1 is a side view of a descaling unit and shows a preferred embodiment of the invention.

^Ob r. ^P 2 růřez of ^b r. ^{P 1 at} pH ozorov ^and that ^p ccording line 2 to 2

Giant. 3 is an enlarged side view of FIG. 1 showing the main elements of the invention.

^Ob r. ⁴ znázoniuje ^YH in odné umfctétí molten puddle Vuc ^IP Roudou of ^d o ^ uj ^least EDGINGPROFILE ^¹H oo ^alkyl snčovacího p nu ^{ly p} ro ^d scalings ^least cheers starts on the flat surface portion of the workpiece.

Giant. 5 shows the start at the end of the workpiece surface.

^Ob r. 6 ^graphite ck ^y ^ edehnvarn compares ^and time obtained according to the invention with prior art methods for preheating the workpiece surface.

^Ob r. ⁷ zor ^least Zn ^and U is ^t o ^p Roveda in ^{Y is N,} climbing, in which ^ edelhHvací rou ^{p y Dy} used ^š women from the lower preheat block of the scarfing apparatus.

Giant. 8 is a side view of apparatus having separate stabilizing holes oxygenated ^ply odokujnovarn ^alkyl BIP.

Giant. 9 is a front view of the apparatus of FIG. 8 ^p s ^{p p} o Omeda ^dl ar e ^{No 9} to 9

^Ob r. ^P is about ^{19 hl} e ^d a ^d u ^Pla machine according to the ^{CMD b} r. ^{8, the} ONS ^t ruovaný jrným manner.

Giant. 11 is sideways^potee^d on^toIt has separate openings for stabilizing oxygenated^{- p}l^yn^- and a descaler^sayem^ofstabihsarnh and ^ edehnvate^proud^ydopada in a common place.

Giant. 12 is a side view of apparatus similar to FIG. 3, but current s.tatelisačnteo ^BC e ^d e ^HRI vac ^¹H about okyslmovacího ^ply nu ^d of ^d and ^{p <s} ^ j to s ^p o ^{l s} mfeto ECN.

Giant. 13 is a side view of the apparatus in which the stabilizing stream is directed proximate to the impact of the preheat streams, and ^AK nikohv in the same general direction as the flame ^of interference.

Giant. 14 is a side view of apparatus similar to ^P Admin istra ^] swarm ^ip on ^dL e in FIG. 3 but ^- Prou ^d stabihsačnteo by ^alkyl with ^LIC EDGINGPROFILE ^¹H about ptynu P ^ro c ^h AZI locations spaced ^Star it impact Prou ^{Importan Pla} dehnvachio ok ^ Uěovateho gas.

Giant. 1 2 a³ display^and you^hodn^E version in^yn^álezu.^TypiC^toá o^d° kujⁿpoisoning poison not^toand consists of^horteho predelinvacteo No^to1, lower preheating block 2, head 3 and socket 4. Blocks 2 and 3 are called preheating blocks.^blO^ky lamb from técteo blo^toů s^Ev obvyteém^exdevice^and in^yplet go^and pre-rotating flames. However, in the apparatus shown in FIGS. 1 and 2 a³ se^pOnly look at the flames discharged from the top^pdiluted^Řívac^íhO^blo^toSlotted stripping nozzle with orifices 16 from which a flat stripping stream is discharged^toysli

The lower preheating block 2 is provided with a plurality of pre-heating fuel gas openings 19 which are in communication with conventional suitable passages (not shown) of the upper preheating block 1 and the upper surface 21 of the lower preheating block 2. for gas. Oxidizer gas and preheat fuel gas are supplied to head 3 not represented nozzles and the respective lung ^h of the ^reason for the m n ^p p ^ly OM ⁱⁿ CKAM ^and Zn ^and my in the art. During descaling, the base 4 travels over the workpiece surface W so that the descaling nozzle is positioned at a constant distance Z (FIG. 3) from the workpiece surface. The scarfing reaction is carried out in that a molten puddle ^P impact ^and TACH rou ^{p d} scarfing oxygen discharged from the scarfing nozzle openings 16 at an acute angle to the surface of the workpiece · while causing relative movement between the workpiece and the scarfing unit.

According to the invention, the upper preheat block is provided with a series of holes 17 for the preheat fuel gas and a series of holes 18 for the preheat oxygen, each of the openings is in Tocht with ^p he concept with gentle ^and represented, * feed passages for the fuel or the oxygen. Although the drawing shows that the preheating oxidant gas openings 18 are located above the preheating fuel gas openings 17, the inverted arrangement, although not as advantageous, is also capable of working. ^G eneral ^R e ^v eno is preferred ab ^y orifices ^p ro ^p R E ^D EH ^{of manufacture} VACI that ^p Nu ^ply N ^were umístony between the preheat oxidizing gas ", and the below described hole for staHhsacm OK ^y ND-or ^gases but ^other configurations are capable of action.

The device works as follows: 9 currents preheat the gas from the openings 18 and streams 10 of preheat fuel gas ports 17 impinge on each other and in ^Y The officials ^even at ^p Alnö mixture. . Instead of ^p adu FIG. 3 is indicated as the intersection of axis 10 of bore 30 17 of preheat fuel gas and the axis 9 of the bore 18 preheat oxygen. After ignition the combustible mixture creates a flame ^{14 which} has a zone 13 of low ^Star mtenzitě zone 12 and a high intensity. It was found that the band 12 of high intensity can be extended so that its tip 27 is just above the surface of the workpiece W, thereby creating more intense flame and that the preheat flame stabilizes creating a stream of the stabilizing oxidizing ^ply nu Citations ^s míenz ^ ^the esters Proch ^b ^ in Hz ^{to the} ostium ^b mod ODU ^and gently it ^{é d} litter, popřl · intersection 30 and fall in the same general direction as the flame 14. This provides that the jet 15 from the opening of whom was mtenzíto is conducted "in BHZ ^{to the} ostium "bo ^d-dopa in the mrnj that ^p rou ^d should pass close to the intersection point 30 or impact, but 'not this point. Although b ^y lo of the term "point ^d of ^p, and ^d u", it is apparent that b ^{y BC} esněj ^{he was} about užitf term "mfeto ^d of ^p, and ^d u" jehkož it ^gives no many intersecting streams, and therefore many impact points; Furthermore, since the currents have prčitou their Houšť ^ r ^{p s p} s is ^číky Reich ^{ky p} Tash than mere points. Therefore, it is for brevity. to ^forward e ^p ou ^{from an} IV ^and NO ^"D o ^p AD ^'kt erým refers instead impact surfaces preheat fuel gas and preheat oxygenated mho ^p l ^y nu. Preferred swarm of ^{d p d} drilled at about ¹⁵ stabihsačntoo ^alkyl sličovac ^{¹H ply} of Nu is scarfing nozzle orifice 16. The valve not shown are provided devices for generating a stream of the stabilizing mesh ^ply ltoovarnho ^ nu mzké intensity (rnžší intensity than the stream of scarfing oxygen) through the opening 16.

The stabilizing oxidant gas stream with the axis 15 should be directed in the same general direction as the flame. That is, if this stream is resolved into two vector components, one parallel to the direction ^P Lamen ¹⁴ and ^{hole H} ou perpendicular ^has vectors ^and component ^YC and parallelepiped ^Ez n ^{and p} Lamen ^b YT Nammen the same ^e m direction I ^k o ^pl amen 14.

In the practice of the example shown in Fig. 3, with preferred values according to Tables I and II, the flame 14 will be close to the resultant of the axes 9, 10 of the preheating oxidant gas opening 18 and the preheating fuel gas apertures 17 or more closely near the bisecting angle. formed by the two axes 9 and 10. preferably, ^p RUM ^E t ^y axis rou ^{p d} US axis I ⁵ and I ^{4 p p} Lamen rotínají for the ^Y consists ^of a ^h em sharp sevřetaho angle as shown in FIG. 1 and 3. it is also preferable that the axis of the stabilizing oxidant stream 15 is parallel to the axis ^P from the ^PR Rou ^d e e ^{d d HRI} vac him it ^p n ^{s p} l ^y n ^ j and ^k are also shown in FIGS. 1 and 3 .

^P rou ^d y for ^D E ^HR IVAC ^¹H on the ^p Joint ^p l ^y Nu okyshčovactoo ^ply nu need to ^p ADAT ^p from sharp belching, J. ^C o ^{d angles} em sentences ^with MI than 0 ° but less than 90 ° . The preferred range is ⁵⁰ to ⁵⁰ °, and it nejvýho ^{d br} s ⁱⁿ HEL to ^p and ^d at 15 °.

^{P D 15} staMUsataíta rou ^s went OK ^No ovacího nu ^ly p of the opening ¹⁶ has to ^remain MH which ^to ou i.e. rnžč FAST axis ^L in ^t tr ^{y SCE} rychtost not ^of the preheat oxygen and fuel gas from the holes 18a. 17. Preferably, the ttysková rychtest hundred ^{b No} Ilisa the mesh ^{y H} u sl ^Cart hžn at ^{b e} l ^y r ^0% Chlost edehnvacmh ^ ^p roud.

If the preheat flame has been stabilized as described above, the length of the high band rntenzity ^(dd on the ^P and ^D at the ^{apex 3} 0 CE 2 ⁷⁾ so fráftá. that ^{Pla d} ehřívací step should not be ^p rovetan in ^p řijatelně times ^to ACTIVE tahách ^aunt e ^would decrease vztatenost ^from the ^d stu ^p u. Sntéern distance Z of ^d to ^P and ^RC and nestabilisovataho ^p Lamen sv ^y with ^the ou rntenzitou ^thee uvetana tightly ^{kb EXPERIMENT W} would mean in ^y otalkujtavací jetaot stop by ^to many sentences in his ^P & IP ^to marry sprayed from ^the ovu and slag than ^ us ^that the s ^{and p} normálnfch vztalenostech distance.

The flames formed by the preheating fuel gas from the lower orifices 19, mixed with the stabilizing ^gas from the orifice 16, serve to maintain the descaling reaction. These flames are not necessary during ^the předeMEten ^ Avşa that ^p Nu ^ply nm ^and a ^p roudit of the openings 1 17 in the preheating, in order to prevent clogging.

K ^d YZ in locations В vyteon melting ^and pool, sets the valve control oxygen flow from the opening 16 to increase the intensity of the oxygen flow from low intensity to scarfing intensity, and start the relative motion between the workpiece and the scarfing unit, thereby forming the scarfing In the descaling, the pre-heating flames generated by the currents with the axes 9 and 10 are lowered at a lower intensity than during preheating to promote maintenance of the descaling reaction. A reflecting plate 28 located above the preheating holes 17 and 18 is used to prevent blowing of a low intensity flame during descaling.

In the production of ^p pnstroje ^dL e vynatezu need roztodnout about někohka konstrukčrnch ROM, ^{e p h} nnýc of rncto ° h ^E mn are not ^vz Ai than ^á vis ^treatment. For Berný odokujúiovací PRL machine statutes ^í obvyWe tosledupri transformation:

1. G is the angle between the scarfing oxygen and the workpiece surface;

2. X is the height of the opening 16,

3. Z is the distance to the head,

4. U is the width of the descaler unit (see Figure 2),

The fifth ^{type p d} Ostu Joint ptynu heating,

6. type of available oxidant gas.

For each set of values of the above ^HEA tode exist ^of the effective range and a preferred value for the variables used in the construction of a preheating apparatus of the invention.

The following two tables give examples of values found to be satisfactory for the practice of the invention. Table I is a list of typical parameter values for conventional descaling equipment which is known to give good descaling.

TABLE I

G, the angle of the quenching oxygen 35 ° X, hole height 16 ^5,6 mm Z, head distance 25 mm U, stripping unit width 270 mm fuel preheating gas natural gas oxidizing gas oxygen.

Table II gives the effective range and preferred values of the variables whose usefulness has been found to practice the invention when the fixed parameters are those given in Table I.

TABLE II variable bargain value approximate working range

^The diameter of the holes ¹⁷ for the heater fuel gas: 1.0 mm 0.7 to 1.7 mm pre - heating flow rate 1.7 m3 / h at 0 ° C 1-3, ⁵ m ³ / h at 0 ° C fuel gas per opening and pressure 101 ^{, 32} 5 to ^p a UBATT and ^101, 3 to ²⁵ and ^p The holes vzdátenost ^'s for the fuel gas ptedehHvatí [Y dimension, in ^b r. 2} 6.0 mm 3 to 16 mm Rumer opening 18 ^p ro ^{p BC} Ede ^h řívací lsyshk 1.6 mm 1 to 2.3 mm pre-heating oxygen flow rate 3.7 m3 / h at 0 ° C ^{1, 5,} and ^from about 6 m ³ / ^h PN 0 ° C per hole and a pressure of 101.325 kPa and the hook ^101, 3 ²⁵ kPa hole spacing for preheating the gaseous ^y SMK [¥ dimension ^of r ⁱⁿ Fig. 2) 6.0 mm 3 to 16 mm ⁱⁿ HEL incidence between the axis ^of hole ^P ro preheating fuel and apertures apos edehnvarn ^ky ^ sl ^{cart (with} HE ^{L D} in Fig. ³⁾ 15 ° 5 ° to 50 ° the distance 26 between the surface 20 and the holes 16 for preheating fuel gas 10 mm ^{3 to 15} mm angle between the axis of the oxygen pre-bore hole and the workpiece (angle H, Fig. 3) 50 ° 40 ° to 75 ° the distance 31 and 32 from the impact 30 to the preheating holes 15 mm 3 to 22 mm the distance 29 (see FIG. 2) between the center lines of the opening 17 and the opening 18 4 mm ^{1.5 to 6} mm the flow rate of the stabilizing oxygen from the slot 16 during preheating 6 m ³ / ^h pH 0 ° C 3 to ¹⁰ m ^{3 / h at} 0 ° C per 1 cm of slot width and a pressure of 101.325 kPa and Uaku ¹ 0 ^{1, 2} 32 ⁵ to ^p a

The variables compiled in Table II are interdependent. Therefore, in the event that some of them deviate significantly from the preferred value, the preferred value and the working range of the other variables may vary. Of course, if any of the determined parameters of Table I are changed, the preferred and working ranges of some of the variables in Table II may change. The expert knows well sna ^{d Z} e témrn 'unlimited number of combinations of values for Tables I and -II - uspokojivé- gives results.

The preferred shape of ports 17 and 18 is circular, and ^the Avşa JME shapes ^either ou úmnnto Napnktad holes - might - be square or ^rectangle b ^s. B ^y lo ^could be ^which just u ^ IT is ^di n ^e poidlouto ^treatment Fryske for p ^ ehnvam ^alkyl sl ⁱ K in the ^P nn ection with a single elongate nozzle preheat fuel gas, although such arrangement ^{and the} NEN ^still above ^H o ^d n ^é . The ^y n and ^l ez: Records ^p e works, however, if at ^p Ravi in ^Et, with ^{the co p} očeí: openings - for oxygen and fuel gas, which is adjusted in the ^R & ^D Ac ^H navz ^JEM elongated j and ^k shown in Figs . 2 and 10. If ^it used phrases ^p o u ^th e ^d e ^BC bags ^HRI holes is effective to make the spacing of holes, a dimension Y in Fig. 2 were rovonoměrné. Each oxygen opening 18 should lie directly opposite the fuel gas opening 17. This preferred arrangement gives the nestejnom NQM and assorted ^ ^y ^ edehMh chlej ^width but i • ^{- ters of} uneven odctalení holes. or offsetting the fuel gas orifices into oxygen or both can work well.

Angle F P ^{L VMenu,} i.e. angle in the ^y axis Eny formed ^of the flame 14 with respect to the surface of the workpiece W to be ^- between ⁴⁰ to 55 ° for ^{d p} ro ^{p Z} hundred of ^{25 -} mm. Jes ^^ e ⁱⁿ HEL ^{F BC} ge t ^ ^at 55 ^- 14 has a flame Slope excavate workpiece. Jesniže angle F - is - less than 40 ^'3, the tip 27 of the band 12 - a high intensity will be far Prill ^ S - - by - surface - T - workpiece W than to - achieve VITANA short preheat times. Angle F '. flame 14 is determined by the parameter values in Tables I in II. The above-enumerated preferred values of the variables can be arranged satisfactorily-angle of the flame 14, but artisan will readily recognize that many others are possible penê above o'dné komtanace ^h.

The invention works best if the preheat fuel gas in an oxygen together as tightly as possible without streams converge inside the unit, thus establishing ly ^from Nost for ^D normal ^e it nhsern mod ^Walking tn ^s him ^VY lying position.

Giant. 4 shows the preferred location of the starting pool B relative to the projection of the center line of the axis 15 of the finishing hole 16 when starting is performed on the upper surface T of the workpiece W. As shown in FIG. puddle B with respect to the direction of the scarfing cut indicated by arrow J. This location of the starting puddle B allows U is ^Zn, and ^N in ^the molten materi ^l off any of the puddle was blown forward, so that no material remains ^P ro vytaorern Mebenů or burrs on the back side of the notch.

In order to perform start at one end of revival ^W j and ^k is Zn ^and Zorn ^of NO to the OTA. 5 ^, pa, ^the results will be satisfactory if the descaling oxygen stream from the slot 16 impinges on any part of the starting pool B, since there is no surface T of the workpiece w on the back of the pool to burr, if burrs are formed on the end surface E.

Giant. Ί through 14 illustrate various embodiments of the invention which, although not preferred and ^p reste capable of producing alkylated stabi.l ^ ^d to ^{some initial} smféený ^ etehHvad ptamen.

^Ob r. 7 bocrn ^p ohtad otokujtovarí per unit, which is similar to the unit shown in FIGS. 1, 2, 3, except that the openings 18 in 17 of preheat oxygen, respectively. preheating fuel gas are ^U M ^I ST ^of n ^y in the ^p odrnm pfedeWfratím btatai

2. The apparatus acts similarly to the apparatus of FIGS. 1, 2 in 3.

Giant. 8, 9 show a configuration in which ^E is m TTAB tation ^{when d} o ^ shcovací ^p l ^y n pnváděn from the aperture 16 'in different separate from the opening 16 scarfing oxygen. Here Prou ^d for ^d e ^HRI vac ^¹H the mesh ^ply hčovamho ^ nu from the orifice 18 with the axis 9 impinges on the stream předehnvamho ^{P eh} n o ^{p y} l nu opening 17 from the axis 10, to provide additional flame smyšeného 14th flame 14 stabilized stream 15 'oxygen of low intensity from the aperture 16', directed proximate - intersection 30 vv ^o ce s ^s m smoer ptamene I ^4th The diverters in the stabilization holes 17, 18 in 16 'are located in the upper preheating block 1 as shown. They could also be placed in the lower preheating block 2. After the preheating is completed, the descaling oxygen stream is started from the slot 16 to peel the workpiece W As described above, the fuel gas discharged from the aperture 19 helps maintain the descaling reaction.

Giant. 10 is the same - - as in Fig. - 9 by - ^ subtract portions ^that stabilization of sličovám ^ ^p l ^y n coming from the elongated slot nozzles 16 '. 'In front ^HRI defects ^- for ^alkyl sl ^IR ovations ^{also ply} nv ^p ahvo b ^y l ^{h y} MO also be supplied from elongated nozzles štěrbinovitýc ^h, ačkohv arranged such that ^ can not so convenient.

Giant. 11 is a side view of the apparatus having stabilizing oxidant gas openings 16 'separated from the descaling oxygen opening 16, similar to FIG. 8. However, the stabilizing oxidant gas stream 15' passes through the intersection 30 of the preheating oxidant gas axis 9 at the preheater axis 10 ^. n ^{e p} lynu him. ^Was detected by ^W t ^{E No,} the reflective plate 28 at 28 ', although not necessary, vol ^^ T range in Taer ^will have been altered stream rychtosti ^ edeiifívatích the stabilizing currents in still produce a stabilized flame. Jeslzliže opening the fuel gas' is not between the preheat in stabihzačto tysKh is particularly užhečná ^F n ^{and cracking, and D} in ESKA bhztostí hole that ^p Nu pl ^y n.

Giant. 12 is a side view of an apparatus in which both stabilizing and descaling oxygen are discharged from the same nozzle, i.e. nozzle or opening 16, as in FIG.

However, according to FIG. 12, the stabilizing oxygen passes through the point of impact, i.e. the intersection of the preheating streams. This arrangement, although not as advantageous as the arrangement of FIG. 3, is also capable of producing a stabilized preheating flame, provided that the impact or intersection 30 is located above the workpiece (not shown).

It is expedient for the stabilizing oxygen stream to be directed in the same general direction as the flame 14. As mentioned above, when the stabilizing oxygen stream is broken down into two vector components, one parallel to the flame direction and the other perpendicular to it, the vector the component parallel to the flame is directed in the same direction as the flame. However, it has been found that a stabilized flame capable of producing short preheating times can be formed if the stabilizing oxygen stream is directed perpendicular to the flame or even opposite to the overall directions of the flame.

Giant. 13 is a side view of an apparatus in which the stabilizing oxygen stream 15 'is not directed in the same general direction as the flame. Here, the preheating oxygen stream with the axis 9 and the preheating fuel gas stream with the axis 10 impinge on the impact or intersection 30 as described above and additionally form a mixed flame 14 having a forward axis 22 defined as a straight line segment of the central flame axis lying before point 23. in which the stabilizing flame intersects the central axis of the flame. The term "before" is intended to mean the same direction that a V-shaped formation formed by the impact of preheating currents is directed. Thus, if the stabilizing oxygen stream forms an angle větší greater than 90 ° with the forward flame axis 22, the stabilizing stream is directed in the same general direction as the flame. However, it was found that even if angle A is between 10 and 90 ° ^е creates nevertheless stabilized flame. It should be noted that the positioning of the flame relative to the forward resultant of the preheating aperture axes (i.e., the line bisecting the angle therebetween) is influenced by the direction, velocity and velocity of the stabilizing oxygen flow. Satisfactory results can also be obtained if the stabilizing current is directed beyond the intersection.

Giant. 14 is a side view of the apparatus similar to that of FIG. 13 except that the stabilizing oxygen stream 15 ' crosses or intersects the preheating streams. This arrangement is also capable of achieving satisfactory results.

It is believed that the beneficial effect of the stabilizing current, especially when directed as shown in Figure 3, is achieved for the following reasons:

1. Since the stabilizing oxidizing gas is added with a low intensity stream, it does not interfere with the external mixing of the preheating oxidizing gas and the preheating fuel gas or their stream. However, it adds oxygen, which helps maintain combustion and creates an oxygen atmosphere surrounding the high flame intensity band. This oxygen atmosphere creates an excellent environment for the flame to propagate back towards the preheating exhaust orifices and ignite unburned fuel gas closer to these orifices.

2. The stabilizing oxidant gas stream also forms a shield to protect the flame from air, which does not create as good a flame propagation environment as oxygen, and causes the flame to become unstable and blow away from the preheating outlet.

Examples based on Tables I and II

The descaling starts on the upper surface of the workpiece W, as shown in Fig. 4, were performed in the laboratory using an apparatus having the values compiled in Table I and the preferred values according to Table II. The test results are graphically represented by the X curve in Figure 6, in which the initial temperature (T ° C) of the workpiece is deposited on one axis, while the required pre-heating time t in seconds is deposited on the other axis. For comparison, the Y curve shows the results obtained under comparable conditions using a descaling apparatus of US Pat. No. 3,752,460, while curve Z shows the results obtained with a conventional pre-mixed pre-heating flame generated by the discharge of oxygen from the descaling nozzle and fuel nozzles of U.S. Pat. No. 3 231 431.

Examples based on Fig. 11

The post-mixed stabilized flame was formed by the impact of the two preheating streams and the stabilizing stream on a common location as shown in FIG. 3 gives the working range and preferred values of variables useful in practicing the invention. As in Table II, the variables are dependent on each other. The deviation of one variable from the preferred value can change the working range and the preferred values of the other variables.

TABLE III variable angle C (FIG. 11), the distance from the incidence openings 30 to preheat and stabilizing oxygen orifice 15 'stabilizing oxygen average ^of r flow bore above the ^H N ^{and H d} of ^d nota approximate operating range

25 ° mm mm

1.3 m ³ / h ^{at 0} ° C and ^tl a ^k u 1 ^01.325 kPa to 90 ° to 22 mm to 6 mm to ⁴ m ^{3 / h at 0} ° C and Daku ¹⁰ l, ³²⁵ k ^p a

Preferred values of the variables not compiled in Table III are the same as those listed in Table II.

Example based on Fig. 13

The lump-IV indicates the operating range and dispose ^{n e} value ^of variable nných ^account elnýc ^{h p} for the vynátezu Rovai ^{ga p} e ^dl of FIG. ^13.

TABLE IV variable distance from the holes 30 impact the preheat and stabilizing oxygen hole 15 'the diameter of the stabilizing oxygen flow to an opening angle and you ^h o ^d to ^{h t} and stolons pnbhžný working range

¹⁵ mm 3 to 27 mm 2 mm 1.3 ^m3 / h at 0 ° C and a pressure of 101.325 kPa 60 ° 1 to 6 mm 1 to ⁴ m ^{3 / hp} ř. ^{0 DEG} C. and 10 to 90 DEG

As in the previous tables, the values depend on each other. Changing one value can change the range of the other values. You ^h o ^{n e h} o ^d music prom ^ ^ ^kt NYC ns are shown in Table IV, are the same values of j and ^k in the above ^e tebiúce П.

Claims (11)

^1. scope of tarmochemicktařio ^d ujňování of ^the metal workpiece, in which the location on the surface of the workpiece ^to begin de scarfing reaction is preheated to combustion temperature in oxygen sites of the workpiece that is to place the preheated directs additionally mixed preheating a flame formed by discharging at least one preheater fuel gas stream and at least one preheater oxidant gas stream, and wherein the descaling oxidant gas stream is directed at an acute angle on the workpiece surface at the preheated spot while simultaneously causing relative movement between the descaling oxidant gas; workpiece, thereby forming a scarfing cut, characterized in that the preheat streams and rou ^{p s d} předehnvacího TopN it Týn ^p sm ^of estrous into mutual collision surface is machined over přicíemž axis tacteo ^p Roudou svíraj ^d acute angle, and f e the preheat flame is stable discharge current of the stabilizing mesh ^{Y LIC} ovacího ^ply nu RNE ^Ké rntenzhě in the same general direction as the flame or at an angle of 10-90 ° to the axis of the flame, which is directed forward, and the stream of stabilizing oxidizing gas is transmitted through the mutual collision a preheating current with ^{alkyl LIC} ovacího ^ply Nu ^ edelmvacího top- N INVENTION ^eh of a wall or ^ply of ^{the closer} of the space ^h oto. 2. The method of claim 1, wherein:^ofe sharp^athe^l clamped limit^and osami př^dehn vací^ho ok^ywith^faceovací^habout ptyn and current p^Řthe pre-heating fuel gas is within the range of the limit^{i 5}° a⁵⁰°. ^3. operates ^dL e kteréhotohv of ^b ODU 1 and ^2, wherein the ^ ^that otysltóovací staMhzaraí p n ^ly consisting of ^alkyl went ^to u. ⁴ . ^From P ^u e ^dL method after any of ^{b of} from 1 to ^3, characterized in that ^p tm růtočná r ^y s ^l ost stream preheat fuel gas and preheat oxidizing gas stream is in the range of ^{d is from 1 to 3.5} m ^{3 /} hm ^measured eno at ⁰ DEG C. and, Thank ^101,325 km, and ^{p and} velocity růtočn preheat streams for each stream is in the range ^{is from 1 to 6} m ^{3 /} hm ^measured at eno ΟΎ / and at a pressure of 101.325 kPa. ⁵ . ^Zp Úsobí after ^dL e to any of item ^{1 to} 4, characterized in that the flow rapidly and ^l os ^t stabihza ^No her ^h oo ^ shěvamlio ptynu is' ^D en centimeter ^{IR alkyl} opening scarfing ^t feature ^alkyl in the range of ^{d 3} and ^{? 10} m ³ / m ^ ^of Reno at 0 ° C and at a pressure of 101.325 kPa. 6. The apparatus for performing the method of any one of ^b on ^{d 1-5,} oteahujírí taupací unit which has at least one nozzle onto the scarfing oxygen and whose axis before it is directed to the surface odokujňovaného workpiece, and at least one opening for the preheat oxygen and at least one preheating fuel gas orifice, characterized in that the axis (10) of the preheating fuel gas orifice (17) is directed towards the surface of the workpiece, the axis (9) of the preheating oxidant gas orifice (18) intersects at at the point of impact, or the intersection (30), the axis (10) of the preheating fuel gas orifice (17) at an acute closed angle outside said holes [17, 18] and above the workpiece surface and a hole (16, 16 ', 16 ") the gas is deposited on the peeler unit and its axis (15, 15 ') is directed in the same general direction as the resultant axes (9, 10) of the preheating oxygenator hole (18) and at an angle (A) of 10 ° to 90 ° to the forward facing resultant (22) of said axes (9, 10) and guided by the intersection (30) of these axes (9, 10) or near it. 7. The apparatus according to claim 6, characterized in that the acute angle formed by the intersection of the axis (10) of the opening (17) for preheating the fuel gas and the axis (9) of the opening (18) for preheat oxygen is between 5 and 50 ° ^е . Apparatus according to claim 6 or 7, characterized in that the opening (16) for the stabilizing oxidizing gas is identical to the opening of the descaling oxidizing gas nozzle. Apparatus according to any one of Claims 6, 7 or 8, characterized in that the preheating fuel gas apertures (17) in a number greater than one are disposed in a row substantially parallel to the more than one preheating oxidizer aperture (18). gas arranged in a row. Apparatus according to claim 9, characterized in that a series of holes (17) for preheating fuel gas and a series of holes (18) for preheating oxygenation gas are located in the upper preheating block (1) of the peeling unit. Apparatus according to claim 9, characterized in that a plurality of holes (17) for preheating fuel gas and a plurality of holes (18) for preheating oxidizing gas are located in the lower preheating block (2) of the preheating unit.