US2167399A - Apparatus for increasing efficiency of gas cutting operations - Google Patents

Description

July 25,1939, 1 I V ''R. L. WACQQNER' 2,167,399

APPARATUS FOR INCREASING EFFICIENCY OF GAS CUTTING OPERATIONS Filed Dec. 18, 1936 2 Slwets-Sheet- 1 l Curr/HQ INVE NTOR ROBERT L.WAGNER BY, Qg F'IG.6

ATTORNEY July 25, 1939. R. WAGNER 7,

APPARATUS FOR INCREASING EFFICIENCY OF GAS CUTTING OPERATIONS Filed l Jec. 18, 1936 2 Sheets-Sheet 2 INVENTOR ROBERT L.WAGNER ATTORNEY Patented July 25, 1939. r

APPARATUS FOR INCREASING EFFICIENCY OF GAS CUTTING OPERATIONS Robert L. Wagner, Niagara Falls, N. Y., assignor to Oxweld Acetylene Company, a corporation of West Virginia Application December 18, 1936, Serial No. 116,575

21 Claims. (01. 158-274) This invention relates to blowpipes for use in cutting metals by means of apreheating flame and a stream of oxidizing gas, and particularly to apparatus for controlling the flow of the preheating gases in a blowpipe when the flow. of cutting gas is initiated.

In cutting metals with a stream of oxidizing gas, the metal to becut is first heated to the kindling temperature, which'is the temperature at oxidizing gas so that it may be easily removed and swept away as the oxide of the metal. When the temperature of the metal has been raised to this point, the valve for the cutting gas, usually oxygen, is opened and the cutting'phase of the process is started. If iron or steel is being out, much less auxiliary heat is required during the cutting phase, since the oxidation of these metals is an exothermic process. A certain amountpf auxiliary heat is desirable, however, inasmuch as the heat losses due toradiation, conduction and the like, will tend to reduce the temperature of the metal immediately in front of the cutting stream. Thus, for economical cutting, it is preferable to reducethe amount of auxiliary heat during the cutting phase, but still retain a small heating flame to produce efficient operation. Since the cutting of metals in this manner is an oxidizing process, the efficiency of the operation will be increased still further if, in addition to reducing the amount of auxiliary heat during the cutting phase, the proportion of oxygen in the auxiliary flame is increased.

It is 'an important object of this invention to provide an improved mechanism for reducing the quantity of heating gases flowing when the valve for the cutting gas is opened. Another and more specific object is to provide such apparatus in which the proportion of combustion supporting gas in the auxiliary flame mixture will be increased simultaneously with the reduction in quantity of the gases forsuch mixture.

The above and other objects and novel features of the invention will become apparent from the following description, having reference to the accompanying drawings,in which:

i Fig. 1 is a vertical sectional view of apparatus constructed in. accordance with this invention and forming one embodiment thereof;

Fig. 2 is a longitudinal view. with portions broken away, of a blowpipe adapted for machine cut- .ting, and having incorporated in it the apparatus Fig. 3 is an elevational view of the apparatus of Fig. 1 having additional parts by means of which the metal will combine with the stream of which certain portions of the apparatus of Fig. 1 may be rendered inoperative;

Fig. 4 is a vertical sectional view, taken along line 4-4 of Fig. 3 and illustrating certain parts of the apparatus of Fig. 3 more clearly;

Fig. 5 is a longitudinal view, partly in section, of apparatus constructed in accordance with this invention and forming a second embodiment thereof;

Fig. 6 is a. fragmentary elevational view of a modified blowpipe, with portions broken away and in section, and showing a cam arrangement for actuating the gas saving valves; and

Fig. 'l is a horizontal sectional view taken along the line |'l of Fig. 6.

In accordance with this invention one way of .reducing the amount of preheat mixture and simultaneously increasing the relative proportion of combustion supporting gas, when the flow of cutting gas is started in a cutting blowpipe, comprises passing the combustible gas and combustion supporting gas through gas controlling devices. Such devices may preferably include a primary passage and auxiliary valve for each gas, and secondary passages in by-pass relation to the primary passages and having orifices of prede-, termined size therein; During preheating the ases flow mainly through the primary passages and are regulated by the blowpipe control valves to provide a suitable preheating flame. When, however, the valve, for the cutting gas is opened the auxiliary valves in the primary passages are closed and the two gases are caused to flow only through the secondary passages. these secondary passages are of suitable dimensions so as to reduce the amount of the preheat mixture and simultaneously increase the proportion of one of the gases, the oxygen for example, of such mixture. A particular advantage of this procedure lies in the fact that the ordinary blowpipe control'valves are in no way disturbed.

Referring now to Fig. 1,-' it will be seen that one form of apparatus for practicing this invention comprises a heating oxygen block I l which is provided witha gas inlet conduit 10 and outlet conduit I2, and an acetylene block l4 having an inlet conduit l3 and an outlet conduit I5. Be-

tween these two blocks is a cutting oxygen chamber C which is provided with an inlet line in-- cluding a conduit l6, a control valve I1 and an inlet conduit I8 connecting the valve with the chamber C. An outlet conduit l9 may connect the chamber C with the blowpipe cutting nozzle which will be described briefly hereinafter.

The oxygen block II and acetylene block ll The orifices in are substantially identical in construction in that each is provided with an inlet passage 2! communicating with the respective inlet conduits and a primary duct or passage 22 opening to a valve chamber 33. The fluid flow through the passage 22 preferably is controlled by a needle valve having a stem 32. Each block is also provided with a secondary passage or duct 23, in by-pass relation to the primary passage 22, and an outlet passage 21. The oxygen by-pass passage 23, however, is provided with a disc 26 having a carefully measured orifice 25, while inserted in the corresponding acetylene passage is a disc 26 which has a carefully measured orifice 65' that is smaller than the orifice 25. Plugs 23a permit access to the secondary passages for the purpose of cleaning the orifices or changing the discs.

Disposed on opposite sides of the cutting oxygen chamber C and held between members 38 and 39 of the chamber casing are two diaphragms 35. A disc 3 3, attached to the head of the needle valve stem 32, is afflxed to the center of each diaphragm. Bearing against each disc and disposed about the valve stems are springs 36 which may be adjusted by means of caps 31 for varying the amount of pressure required to close the needle valves.

The diaphragms form a gas-tight connection at the sides of the chamber C. Each of the needle valves and the cutting oxygen valve may be made gas-tight by means of a packing 30 held between bevelled washers 29 by pressure exerted by a gland 3|. In addition, the various inlet and outlet connections of the chamber and blocks may be made gas-tight, as by means of weldsZD.

The blowpipe of Fig. 2, to which the apparatus of Fig. 1 is applied, may be of any suitable construction and, as shown, consists of a casing B having, at the inlet end thereof, oxygen and acetylene connections leading to an acetylene control valve 55, a heating oxygen control valve 54 and the cutting oxygen control valve I'I. At the discharge end of the blowpipe is a nozzle N having heating gas discharge passages 51 connecting with a mixer 56, and also having a cutting oxygen discharge passage 58. The nozzle is provided with suitable passages 59 and 59a adapted to lead heating oxygen and acetylene to the mixer 55. Installed within the casing of the blowpipe are the blocks II and I4 and the chamber C constructed as shown in Fig. 1. The inlet III of the heating oxygen block II is connected to valve 54 and the outlet I2 to the passage 59 leading to the mixer. The inlet l3 of the acetylene block I4 is connected to the valve 55, and the outlet I5 to the passage 59a leading to the mixer. The cutting oxygen supply conduit IS, the valve l1, and the connection I8 lead to the chamber C, as in Fig. 1. The out- 4 let conduit IQ of the chamber C communicates with the cutting oxygen discharge passage 58 of the nozzle.

During the preheating phase of the process, when no cutting oxygen is passing through the chamber C, the springs 36 will hold the needle valves open and a relatively large amount of gas may pass through the main ducts 22. The heating oxygen and acetylene forming the preheat mixture may be regulated in volume and proportion by the valves 54 and 55. Although during the preheat phase a small portion of the gases may pass through the orifices 25 and 45. control of the gases by the valves 54 and 55 will in no way be afiected.

When the metal under treatment has been heated to an elevated temperature, the cutting oxygen valve i! is opened to start the cutting phase of the process. When the valve I1 is opened, the cutting gas will pass through chamber C and thence to the discharge passage 58 in the nozzle. It will be seen that the pressure of the cutting oxygen in chamber C will cause the diaphragms to move further apart, overcoming the force of the springs 36, and automatically closing the primary passages 22 by means of the needle valves 33. Upon closure of these passages, the heating oxygen and acetylene will be forced to flow only through the by-pass or secondary passages 23, so that the orifices 25 and 45 therein will reduce the flow of each gas in proportion to the size of each respective orifice. It is highly desirable that the size of these orifices be carefully determined so that during the cutting phase a relatively greater proportion of heating oxygen will be present in the heating mixture than during the preheating phase. Accordingly, as shown in Fig. 1, the oxygen orifice 25 is larger than the acetylene orifice 45.

At certain times it may be found desirable to continue the full preheating volume of gas during portions of, or during the entire cutting phase. This may be accomplished in any suitable manner, such as by the additional construction shown in Figs. 3 and 4, with which the automatic operation of the needle valves maybe rendered inoperative. In Fig. 3 the acetylene and heating oxygen blocks II and I 4, the cutting oxygen chamber C, and the valve and conduits leading to them are the same as those shown in Fig. 1. To provide a means for rendering the action of the diaphragms inopera tive, the valve stems 32 are each provided with a bevelled collar or cam 60 adjustably mounted on the stem by means of a screw BI and operated by a fork 62 which is adapted to slide in a bearing bracket I attached to the casing members 38. Each of the forks 62 is provided with a pin 66 which engages in a cam slot 65 provided in a plunger rod 64, so that said forks may be raised or lowered by the pins 66 when the plunger is moved. The plunger rod slides in a bracket 61 attached to casing member 39, and may be provided with a push button head or knob 88 if desired. When the parts are in the position shown by full lines in Fig. 3, the needle valves are held in the open position even though the cutting oxygen may be turned on and pressure is produced in the chamber C against the diaphragms. When in this position with the knob 58 pulled out, as shown, the apparatus of Fig. 1 will be inoperative. To render such apparatus once more operative, the knob 68 may be pushed into a position 68a shown in dotted lines in Fig. 3. The plunger rod 54 will then move to a position a and, by means of the cam slots moving to the position 66a, pull the yokes 62 upwardly to a position 52a. When the yokes are in this upper position they no longer interfere with the normal operation of the diaphragms and valves, as explained with reference to Figs. 1 and 2.

A second embodiment of this invention is shown in-Fig. where it will be seen that the needle valves in valve chambers I33 are actuated by a single diaphragm I35 in ,a chamber C. This diaphragm is held between casing members I38 and I39 and actuates the valves through a rod "I connected to a bar I00 which in turn is connected to both valve stems I32. In this embodiment a single block III may be used in lieu of the blocks II and I4 of Fig. 1, and the oxygen and acetylene inlet conduits I0 and I3 may be connected thereto in communication with inlet passages I2I. As in Fig. 1, primary passages I22 and secondary, passages I23 in bypass relation therewith lead from the inlet passages I2I to outlet passages I21. Discs I24 and I25, similar to discs 24 and 26, respectively, having carefully measured orifices I25 and I45 are also inserted in the secondary'by-pass passages I23 for the oxygen and acetylene, respectively. It will be observed further that a single adjustable spring I 36 bears against a diaphragm plate I34 which acts through the rod IOI, bar I09 and stems I32 to hold the valves resiliently in their open position. The diaphragm I35 provides a gas-tight seal for the chamber C, and all inlets and outlets may be made gas-tight in any suitable manner.

It will be apparent that the operation of this second embodiment of the invention will be similar to the operation of the construction shown in Fig. 1. That is, when the valve for the cutting oxygen is opened, the pressure in the chamber C will create a force on the single diaphragm I35 causing it to move the members I00 and IIII to the right as shown in Fig. 5. Such movement will effect a closing of the primary passages I22 by means of the valves in chambers I33, so as to force the oxygen to flow through the orifice I25 and the acetylene through the orifice I45. Thus, when the flow of cutting gas is initiated the amount of preheating gases flowing to the blowpipe nozzle will be reduced and simultaneously the proportion of oxygen may be increased, provided the orifice I25 is larger. than the orifice I45.

In Figs. 6 and 7 there is shown a portion of a blowpipe B in which the valves in the primary passages are controlled directly and mechanically by the opening of the cutting oxygen valve, so that the fluid pressure of the cutting oxygen does not have to be relied upon. Accordingly, the blowpipe B is provided with a cutting oxygen passage 89 controlled by a valve 8|, and preheating oxygen and fuel gas passages 82 and 93 controlled by valves 84 and 85, respectively. As in the other forms of the invention described above, each of the primary preheating gas passages is provided with a secondary passage 86 in by-pass relation therewith, and having a carefully metered orifice 81 therein.

It will be noted that the cutting oxygen valve is in an upper portion of the blowpipe body and,

is provided with a stem 88 which extends down.- wardly as shown in Fig. 6) into a chamber'SII, said valve being resiliently held in an open position by a spring 9|. The preheating oxygen valve 84 and fuel gas valve 85 are each in a portion of the blowpipe below this chamber and have stems 92 and 93 extending upwardly into said chamber. Springs 94 and 95 resiliently hold these two valves in open position. All of the valve stems are preferably arranged on a diameter of the blowpipe, so that they may be actuated by an eccentric cam 96 mounted on a shaft 91 which is journalled in bearings 98 provided in the chamber 99. As shown in Fig. 6, the cam is so constructed that all of the spring pressed valve stems bear against it, and when the cutting oxygen valve BI is open, the preheating gas valves 84 and 85 are closed. A handle 99 is provided on one end of the shaft 91 outside the blowpipe casing, and when rotated 180 from the position shown in dotted lines in Fig. 6, will cause the cam 96 to close the cutting oxygen valve 8| and open the preheating gas valves 84 and 85.

It will thus be apparent that when the cutting oxygen valve is closed, preheating gas will flow through both the primary passages and the secondary passages in bypass relation therewith. However, when the handle is turned to the position shown in Fig. 6, so as to open the cutting oxygen valve 8|, the preheating gasvalves 84 and 85 will be simultaneously closed so that the preheating gases will not pass through the primary passages, but will only flow through the carefully metered orifices in the secondary passages. As in the other forms ofv the invention described above, this will reduce the quantity of the preheat mixture and will increase the proportion of preheating oxygen in said mixture.

It will be understood that other pressure responsive means, such as a bellows or piston, may

be used in lieu of the diaphragms; and that other types of valves, than needle valves, may be used to stop the flow of gases through the primary passages. Moreover, it will be understood that the valve 8| could be opened by the depression of a lever which, by means of suitable linkage, would simultaneouly close the valves 84 and 85, such a construction being used, if desired, in place of the cam 96.

Various other changes may be made in the construction, and certain features may be employed without others, without departing from the invention or sacrificing any of its advantages.

What is claimed is:

1. In a cutting torch, the combination comprising a combustible gas supply line, a combustion supporting gas supply line, and a cutting gas supply line, a valve and an orifice of predetermined size in by-pass relation thereto in each of said combustion supporting andcombustible gas supply lines for controlling the flow of gas therethrough, and means responsive to the pressure in said cutting gas supply line for. closing said valves so asto permit flow of such combustible gas and combustion supporting gas only through said by-pass orifices.

2. In a cutting torch, the combination comprising a heating oxygen supply line, a cutting oxygen supply line, and an acetylene supply line, a valve and an orifice of predetermined size in by-pass relation thereto in each of said heating oxygen and acetylene supply lines for controlling the flow therethrough, and means responsive to the pressure in said cutting oxygen supply line for closing said valves so as to permit flow of such heating oxygen and such acetylene only through said by-pass orifices.

'3. Apparatus comprising the combination of a chamber, a fluid conduit leading to said chamber,

and a fluid conduit leading from said chamber, at least one separate fluid conduit having a valve and an orifice of predetermined size in by-pass relationthereto for controlling the fluid flow therethrough, and means responsive to the pressure of the fluid in said chamberfor closing said valve so as to permit the flow of fluid in said separate conduit only through said by-pass orifice. I

4. In a cutting blowpipe, the combination of a cutting oxygen chamber having inlet and outlet conduits, a valve adapted to control the passage of cutting oxygen to said chamber through said inlet conduit, a separate preheating oxygen conduit, an acetylene conduit, a valve and an orifice of predetermined size in by-pass relation thereto in each of said acetylene and preheating oxygen conduits for controlling the flow therethrough, and means within said cutting oxygen chamber responsive to the pressure of cutting oxygen therein for closing said valves so as to cause fiow of such acetylene and such heating oxygen only through said by-pass orifices.

5. In a cutting blowpipe, the combination comprising a cutting oxygen conduit, a heating oxygen conduit, and an acetylene conduit, a valve for controlling the flow of cutting oxygen through said cutting oxygen conduit, a valve and an orifice of predetermined size in by-pass relation thereto for controlling the flow of acetylene through said acetylene conduit, a valve and bypass orifice of predetermined size greater than the size of said acetylene conduit by-pass orifice for controlling the fiow of heating oxygen through said heating oxygen conduit, and means responsive to the pressure in said cutting oxygen conduit adapted to close said acetylene and heating oxygen conduit valves so as to permit the fiow of acetylene and heating oxygen only through said bypass orifices.

6. In a cutting blowpipe, the combination of a nozzle; a cutting oxygen chamber having an inlet conduit and an outlet conduit, said outlet conduit leading to said nozzle; a heating oxygen conduit and an acetylene conduit leading to said nozzle; acetylene controlling means including a valve and an orifice of predetermined size in bypass relation thereto for controlling the fiow of acetylene through said acetylene conduit; oxygen controlling means including a second valve and an orifice of predetermined size in by-pass relation thereto for controlling the fiow of heating oxygen through said heating oxygen conduit; a pair of diaphragms disposed in said chamber and responsive to the pressure of the cutting oxygen therein; and means cooperating with said diaphragms for closing said valves in said acetylene and heating oxygen conduits so as to permit the flow of such acetylene and heating oxygen only through said by-pass orifices.

7. In a cutting blowpipe, the combination of a nozzle; -a cutting oxygen chamber having an inlet conduit and an outlet conduit, said outlet conduit leading to said nozzle; a heating oxygen conduit and an acetylene conduit also leading to said nozzle; controlling means including a valve and an orifice of predetermined size in by-pass relation thereto for controlling the fiow of acetylene through said acetylene conduit; asecond controlling means including a valve and an orifice of predetermined size in by-pass relation thereto for controlling the flow of fluid through said heating oxygen conduit; a single diaphragm disposed in said chamber and responsive to the pressure of cutting oxygen therein; and means cooperating with said diaphragm for closing said valves in said acetylene and heating oxygen conduits so as to cause flow of such acetylene and heating oxygen only throgh said by-pass orifices.

8. In a cutting blowpipe, the combination with a nozzle, of means for supplying cutting gas; primary passages for supplying fuel gas and combustion supporting gas in predetermined quantities for preheating; secondary passages for supplying fuel gas and combustion supporting gas in predetermined reduced quantities but with an increased ratio of combustion supporting gas for use during cutting, and means for closing each of said primary passages when cutting gas is supplied to said nozzle.

9. In a cutting blowpipe, the combination comprising a cutting oxygen conduit, a. heating oxymeans for closing said valves in said heating oxygen and acetylene conduits, and means for rendering each of said last mentioned means concurrently inoperative.

10, In a cutting blowpipe, the combination comprising a cutting oxygen chamber, a diaphragm disposed within said chamber, a needle valve having a stern cooperating with said diaphragm, a cam mounted on said stern, and means adapted to actuate said cam so as to-hold said valve open.

11. In a cutting blowpipe, the combination comprising a cutting oxygen chamber, a diaphragm disposed within said chamber and responsive to the pressure therein, a valve having a stem connected to said diaphragm, said diaphragm being adapted to close said valve in response to cutting oxygen pressure in said chamber, a cam affixed to said stem, and means for actuating said cam so as to hold said valve open.

12. In a cutting blowpipe, the combination comprising a heating oxygen conduit; an acetylene conduit; controlling means in each of said conduits and including a valve and an orifice of predetermined size in by-pass relation thereto for controlling the flow of said heating oxygen and acetylene through said conduits; a cutting oxygen chamber; a pair of diaphragms disposed in said chamber and connected to said valves; and a spring acting against each of said diaphragms and normally adapted to hold said valves in an open position, said diaphragms being adapted to overcome the force of said springs and close said valves in response to a predetermined pressure in said cutting oxygen chamber.

13. In a cutting blowpipe having a passage for cutting gas and passages for preheating gases, the combination of a valve in the cutting gas passage; valves in said preheating gas passages; and means, including a cam, for concurrently closing the valves in the respective preheating gas passages and opening the valve in the cutting gas passage.

14. In a cutting blowpipe having passages for cutting gas and preheating gas, the combination of a valve in said cutting gas passage; a valve and an orifice in by-pass relation therewith in said preheating gas passage, said valves normally being-resiliently held in open position; and a cam for holding said cutting gas valve closed while the preheating gas valve is open, said cam when actuated beingadapted to close said preheating gas valve and allow the cutting gas valve to open.

15. Apparatus comprising, means including a normally open valve and an orifice of predetermined size in by-pass relation thereto for delivering a preheating mixture of fuel gas and combustion-supporting gas to provide a high temperature flame adapted to progressively heat metal to a kindling temperature; separate means for progressively applying a stream of oxidizing gas against such heated metal; and means for closing said valve and reducing the amount of delivered preheating mixture when the flow of oxidizing gas is initiated and for simultaneously increasing the proportion of one of the gases in the preheating mixture.

16. Apparatus comprising, in combination,

in combination, I

means including a valve and an orifice of predetermined size in by-pass relation thereto for delivering a preheating mixture of fuel gas and combustion-supporting gas to provide a high temperature flame adapted to progressively heat metal to a kindling temperature; separate means for progressively applying a stream of oxidizing gas against such heated metal; and means for operating said valve and reducing the amount of the delivered preheating mixture when the flow of oxidizing gas is initiated and for simultaneously increasing the proportion 01 the combustion-supporting gas in the preheating mixture.

17. Apparatus for cutting metal by oxidation which comprises, in combination, means including valves and orifices in by-pass relation thereto for delivering a preheating mixture 'of acetylene and oxygen to provide a high temperature flame adapted to progressively heat the metal to a kindling temperature; separate means for progressively applying a stream of oxygen against the so-heated metal to cut the same; and means for operating said valves and reducing the amount of delivered preheating mixture when the cutting oxygen stream is applied and for. simultaneously increasing the proportion of oxygen in the preheating mixture in accordance with the size of said by-pass orifices.

18. Apparatus comprising, in combination, means acting to deliver a mixture of fuel gas and combustion-supporting gas to a nozzle; means for altering the quantity and changing the ratio of said fuel gasand combustion-supporting gas in said mixture and comprising a normally open valve and an orifice of predetermined size in bypass relation thereto; means for delivering a separate jet of cutting gas to the nozzle; means controlling the flow of cutting gas to said cutti jet; and pressure-responsive means actuated by said cutting gas for operating said quantity-altering andratio-changing means by closing said valve when said cutting gas is flowing to the nozzle.

19. In a blowpipe having a cutting nomle, the

combination of a body having two passages for oxygen gas and a passage for fuel gas therethrough; means for directing cutting oxygen through one of said oxygen passages to said cutting nozzle; a valve in the last-named oxygen passage for controlling fluid flow therethrough; and automatic means on the discharge side of said valve operable when said valve is open to limit independently of each other the respective amounts of oxygen gas and fuel gas respectively flowing to the cutting nozzle through the other of said oxygen passages and said fuel gas passage, said automatic means comprising normally open valves and orifices of predetermined size in by-pass relation thereto in said last-named passages for controlling the flow of gases therethrough, and means acting to close 'said last valves when said first-named valve is opened.

a 20. Ina blowpipe, the combination with a nozzle, of means continuously operable ior 'delivering a heating gas to said nozzle; independent means for delivering a combustion-supporting gas to said nozzle; separate means for conducting a cutting gas to said nozzle; and automatic means responsive to fluid pressure in said cutting gas conducting means and efiective for indendently varying the flow of gas ,tothe nozzle hrough each of the two first-named means, said automatic means comprising a normally open valve and an orifice of predetermined size in bypass'relation thereto in each of said first-named means, and means acting to close each valve when cutting gas is delivered to said nozzle.

21. In a blowpipe, the combination comprising a heating gas supply line, a separate oxidizing gas supply line, a valve and an orifice of predetermined size in by-pass relation thereto in said heating gas supply line for controlling theflow of heating gas therethrough, and means operative for closing said valve and causing flow oi the heating gas only through said by-pass orifice when oxidizing gas is supplied to said blowpipe.

' ROBERT L. WAGNER.

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