US2432996A - Apparatus for punching tuyeres of copper converters and the like - Google Patents

Description

1.. LARSON ETAL Dec. 23, 1947.

APPARATUS FOR PUNGHING TUYERE OF COPPER CONVERTERS AND THE LIKE Filed Oct. 1, 1945 6 Sheets-Sheet 1 LEONA/90 LARSON -BYRON 7f BEPGE INVENIORS.

ATTORNEY. I

Dec. 23, 19 47} LARSON EI'AL- 2,432,995

APPARATUS FOR PUNCHING TUYERES OF COPPER CONVERTERS AND THE LI KE Filed Oct. 1, 19 45 6 sheets-sheet 2 LEONARD LARSON BYRON T. BERGE INVENIORS.

ATTORNEY.

Dec. 23, 1947. LARSON ETAL 2,432,996

APPARATUS FOR PUNCHING TUYERES OF COPPER CONVERTERS AND THE LIKE Filed 001:. 1, 1945 6 Sheets-Sheet s INVENTORS LEONARD LARSON BYRON 7. BERGE Dec. 23,1947.

L. LARSON EI'AL APPARATUS FOR PUNCHING TUYERES 0E COPPER CONVERTERS AND THE LIKE 6 Sheets-Shqet 4 Filed Oct. l, 1945 o I n "2 n v 4 C 0 E i N w 3 g; [52 R v N 0 O "fi v Q 3 INVENTORS LEONAQD LARSON BYRON 7. SERGE,

Dec. v LARSON ETAL APPARATUS FOR PUNCHING TUYERES COPPER CONVERTERS AND THE LIKE Filed Oct. 1, 1945 6 Sheets-Sheet 5 BYRON 7'. BERGE INVENTORS.

ATTORNEY.

Penna Dec. 23, 1941 umreo srn'rss PATENT orrica APPARATUS FOR PUNCHING TUYEBE S OF COPPER CONVERTERS AND THE Leonard Larson and Byron 'r. Berge, mom, Nev, assign'ors to Kennecott Copper Corporation, New York, N. Y:, a corporation of New York Application October 1, 1945, Serial No. 619,588

This application relates to power-driven means for punching the tuyre openings provided in conventional copper-converters, and the like, and

pertains particularly to a detachable mechanical puncher device adapted to be secured to the shell of such a converter. One of the particular objects of the invention is to provide a device for punching converter tuyeres, which is capable of performing the punching operation with a high degree of reliability over long periods of use, and at a low cost for service and maintenance;-

In the production of blister copper, in a smelt ing plant it is necessary to treat the cjopper'matte i which is produced in the reverberatory furnace to remove the impurities, consisting mainly of iron and sulphur. This final step in the production of blister copper is carried out in what is known as a converter, the material under treatment being maintained in molten condition, and the air is introduced to the molten mass through 1s Claims. ((1266-42) In addition to the danger of being burned by the slag which is blown against him, dimculties are introduced by the not infrequent occasions when a punch rod sticks in -a tuyere opening,

both on the inward stroke and on the outward stroke, causing delays in the punching operation while the stuck punch rod is being freed. The man who is punching stands in front of the tuyere assembly and as he proceeds with he p n hs most experienced and adept of punchers is una plurality of openings which are submerged below the level of the molten mass in the converter.

During the introduction of this air at these sub-" merged openings, which are termed tuyres, it is necessary to "punch" the tuyere openings at rather frequent intervals in order to prevent obstruction by the accumulation or growth of slag and the like at the discharge end of the tuyres. Numerous forms of apparatus have heretofore been proposed for the mechanical punching of these tuyeres during the converter cycle, but the effectiveness of the hitherto proposed forms ofmechanical punching devices has been rather unsatisfactory, and so far as is known, the principal proportion of blister copper is now pro-+1 duced solely by utilizing hand to keep the tuyeres open.

The hand punching operation is commonly considered to be very laborious and disagreeable. Each converter is equipped with a. large number of closely spaced tuyeres, as an example, there may be about forty-five tuyeres horizontally. alined and spaced about six inches apart along the length of the converter at one side, Under ordinary operating conditions it is'necessary to punch through each tuyere every few minutes or more as required in order to clear the tuyere pipe outlet. During this hand punching, blowing air is wasted through the aperture through which the hand punch rod is inserted in the tuyere and quite frequently when the punch rod is withdrawn after a punching operation this outward blast of air around the punch rod sweeps away adhering particles of hot slag and forces the same against the man who is doing the punching.

{as punching methods able to regulate with any consistency the distance the rod penetrates into the molten bath and it is difllcult for him to withdraw the rod quickly enough to avoid overheating and deformation of the rod.

Any device for mechanically punching the tuyres of a converter of the type used in copper smelting must maintain the desirable features obtainable by hand punching, and'must in addi tion, we have determined, meet the following specific requirements:

(1) Provision must be made for individual mountings of separate mechanical punching devices at the position of eachtuyere in a converter, j

rather than-a multiple punching construction as has heretofore been suggested in the art, in view of theefactfthat it is necessary, periodically, to renew the refractory liningof the converting vessel because it is fluxed away during the blowing period in the converting operation, and whenever a new lining is installed and the tuyere pipes are disposed along a predetermined angle so as to dispose the inner ends of the tuyere tubes as nearly as possible along a given level, difiiculty is encountered in alining the plurality of tuyere openings at the periphery of the converting vessel because of the uneven expansion and movement which has occurred in the shell structure during the operation period, resulting in warping and distortion. Misalinement of tuyre mountings takes place both vertically and horizontally, and this results in an uneven location of the various tuyere openings at the periphery or shell portion of the converter. Furthermore, the uneven heating and consequent distortion which resuits during the converter operation necessitates wise inadequate such device may quickly be removed from the ponverter and hand punching resorted to. Furthermore, the air supply housing which remains attached to the converter at the position of a tuyere should be of such character as to permit normal hand punching of that particular tuyere immediately upon withdrawal or disattachment of the mechanical punching device.

(3) Means must be provided for the complete support of the mechanical puncher upon the converter when in use thereon, independent of any outside structure so that, in effect, the mechanical puncher when mounted upon the converter will actually become a part of the converter and v will move integrally therewith.

(4) A mechanical puncher must be arranged for attachment to the converter, in cooperation with the air supply housing which forms a part of the converter, in such manner as to prevent loss of blowing air, while at the same time carrying the mechanism (punch rod, sleeve and for-\ ward end of piston rod) which does the actual punching within the tuyere in a freely supported condition independent of the air supply housing, for free reciprocating motion within the tuyere tube.

(5) Suitable means must be provided for aline. ment of the punching mechanism and the accompanying punch rod which is disposed within the tuyere tube upon the blowing air supply housing. in such manner that the punch rod is substantially alined with the tuyere openings, for free operation at various angular positions of the converter.

(6) The mounting for the punch rod should be such that a pronounced "whipping action is secured at the inner end of the punch rod during th punching operation, so that the free end of the rod will have a tendency to shake ofl adhering slag or metallic material, and thus, inhibit accumulation upon the rod, and also have a tendency to punch an opening through the tuyere accretion which is somewhat larger than the punch rod itself.

(7) The combination must provide for a supply of blowing air through the tuyre tube and the punched opening at the inner end of the tuyere tube when the tip of the punch rod has been passed through the obstruction zone at such inner end, in a punching operation, so that blowing air is substantially continuously introduced to the interior of the converter around the tip portion of the punching rod as it is returned through the obstruction zone in the completion of a punching stroke. I

(8) The mechanical driving member for the punch rod should be such as to drive the punch rod forwardly under a high force until the tip of the punch rod has passed through the obstruction zone, and to thereafter quickly stop the forward motion of the punch rod and quickly reverse itsdirection of movement to withdraw the rod from the molten bath rearwardly past the obstruction zone, .while positively limiting the extent of penetration of the tip portion of the punch rod past such obstruction zone into the molten bath.

It is a particular object of this invention to proaesaeee 4 vide a device which will meet all of the above enumerated requirements.

A further object is to provide a device of the character described. carrying a punch rod normally disposed within the tuyre when the device is attached to the converter shel1,.but in a withdrawn position with respect to the inner end ofthe tu'yre, in position to be continuously cooled by the blowing air which is supplied to such tuyere.

\ A further object of the invention is to provide a device of the character set forth immediately above and including fluid-operated reciprocating motor means adapted to establish a forward and rearward reciprocator motion of an associated punch rod which is disposed within the tuyere, such a. reciprocating motor means being provided with means normally causing the punch rod to occupy a rearward or withdrawn position with respect to the inner end of the tuyere.

A further and specific object of the invention is to provide a detachable tuyere punching device, together with an air supply housing member permanently secured to the converter and adapted to receive and support the punching device, such housing member being provided with a valve member adapted to prevent egress of blowing air from the housing member upon detachment of the punching device, together with support means provided on the punching device adapted to engage such valve member and maintain the same out of contact with the reciprocable punch rod associated with such punching device when such punching device is attached to the housing member in use.

The above and other objects of this invention will be brought out in more particularity in the accompanying description of a certain preferred embodiment thereof, or will be apparent from such description. This preferred embodiment is illustrated in the accompanying drawings, in

which:

Fig. 1 is a partly broken away side elevation of a copper converter, provided with mechanical punching devices according to this invention;

Fig. 2 is a partly broken-away end elevation thereof, as taken on line 2-2 in Fig. 1;

Fig. 3 is a sectional detail through the converter shell and through one of the punching devices, as taken on line 3-3 in Fig. 1;

Fig. 4 is a view generally corresponding to Fig. 3, but showing the punching device in elevation, on a reduced scale as compared with Fig. 3;

Fig. 5 is a longitudinal section through the mechanical punching device per se, as it would appear when removed from the converter;

Fig. 6 is a transverse sectional view thereof as taken on line 6-6 in Fig. 3;

Fig. 7 is a plan view of the device of Fig. 5;

Fig. 8 is a front view of the air supply housing portion of the construction, as taken on line 8-8 in Fig. 3, but with the puncher device removed from the air supply housing;

Fig. 9 is a transverse sectional view of the structure of Fig. 8, as taken on line 9--9 therein;

Fig. 10 is a view corresponding to Fig. 5, showing a modified form of mechanical punching device adapted to effect positive return of the punching rod upon completion of the forward stroke, independent of the skill of the operator;

Fig. 11 is a front elevation as taken on line I I- II in Fig. 10;

Fig; 12 is a fragmentary vertical section as taken on line l2l2 in Fig. 10; and

Figs. 13 through 15 are fragmentary longi- 5 tudinal sections. all as taken on line ll-ll in Fig. 12. showing certain relatively movable parts in alternative operative positions.

Referring to the drawings. a copper converter is indicated at I, provided with supporting rings (or riding rings. as they are termed) as at 2, which ride on rollers' 3 carried by base members I. A fume hood is provided as at to for exhaust of the sulphuroas fumes which are formed during the converter operation. and a shield member is provided as at 4b to protect the men engaged in the punching operation from the spash of slag or the like from the discharge opening. A cooperating shield member lo is preferably provided, mounted upon the converter 1 in position to engage the shield 4b in the normal operating position of the converter. The converter l cofrig prises a shell 5 of metal. and a refractory lining 6. An opening 1 is provided in the wall of the converter, through which the converter is charged with matte, fluxes and thelike, and through which the molten slag and'the end product (blister copper) may be discharged upon rotation of the converter clockwise from the position of Fig. 2.

Along one side of the converter a. bustle pipe 3 is provided for suoplv of blowing air to the tuyeres. individual flexible connectors 9 being provided from the bustle pipe 8 to the air-supply housings l which communicate with the tuyere openings. A radially extending connector II is usually provided between the bustle pipe 8 and an axially arranged blowing air inlet pipe l2, so that air may be supplied to the tuyeres at all rotative positions of the converter.

For the purposes of this invention, a. high pressure air supply line is provided as at i3, preferably running alongside the bustle pipe 8, together with flexible connectors i4 and couplings a which connect the high pressure air supply to the tuyere punchers i provided for each of the tuyere openings. The housings ill are attached to the shell 5 of the converter through flanges l5 and bolts l1, and the shell 5 is provided with an opening at the position of each housing Ill, as at it, to receive a tuyere pipe or tube l9 extending through an opening 20 in the refractory lining it and leading to the interior of the converter. A passage ii is defined by the housing I0 topro-'-. vide blowing air communication from the bustlepipe connectors 9 to the tuyere pipe I9. I

. The respective housings iii are arranged not only to supply low pressure blowing air to the tuyeres; but are adapted also to receive the mechanical punching device [5, and means are animate.

dash lines in Fig. 9, as more'particularly described hereinafter.

The mechanical puncher assembly may comprise a cylinder 30 provided with a forward head member 3! adapted to engage the outer wall of the housing III as defined by the rearward face Ilaof the nut 26. a rearward head member I2, and a reciprocating piston rod 34, the forward end'of the piston rod extending through the forprovided for preventing egress of low pressure blowing air from the space 2| when the puncher i5 is attached to or detached from the housing in. The housings iii are each provided with a puncher-receiving opening 22, as defined by a valve seatmember 23. A positioning pin 24 is arranged to engage a recess or slot 25 in the rim of-the valve seat member 23, to prevent rotationof the seat member w th respect to the housing, and a. retaining nut 26 is provided to lock the member 23 in place. said nut forming part of the outer wall of housing 10 and further adapted to serve as alinement means for the punching device, as hereinafter described. A valve assembly is carried by the valve seat member 23, and this assembly may comprise a valve ball 21 adapted to mate with a valve seat 28 in the inwardly directed face of the member 23, and a suitable guide cage 29 is provided to guide the valve ball 21 between the positions indicated in full and dotward head member 3| and terminating in a coupling lly' iz'dapted to receive a punch rod 33 to normally dispose said punch ro'd within the tuyere pipe 18. Projecting forwardly from the forward head member 3| we provide a ball support sleeve 21 adapted to engage the valve ball 21 when the puncher assembly is attached to the housing l0, and to hold said ball out of engagement with the reciprocating piston rod. The forward'end of the head member M is preferably recessed as at 38 to receive the support sleeve 51, and the member .31 may conveniently be utilized as a gland nut for .a packing around the piston rod 34. The head member-3|" may be retained on the cylinder '30 through the agency of a retainin nut 40.

The piston member 33 is preferably provided with forward and rearward piston skirts a and lib having packing means such as oppositely directedcup seals 33:; and adapted to define oppositely directedcompression spaces 42a and 42b at the respective sides of the piston. Coactingly shaped projections are provided as at 43 and 44 on the respective rearward and forward ends of the head members 3! and 32, to enter the respective compression spaces 42a and 4217, said compression spaces being adapted to prevent the piston from hammering against the head member at the respective forward and rearward ends of the reciprocating stroke of the piston member while providing both 'a rapid deceleration of the reciprocating assembly and a rapid acceleration in the opposite direction.

The puncher assembly is retained in place upon a housing l0 through the agency of an adjustable bail type clamp, the rearward end of the rearward head member 32 being recessed as at 45 to slidably receive a jack screw nut 48 which is longitudinally grooved as at 41 to receive a dog point set screw 48 threadedly locatedln the head member 32 and protected by the retaining nut 49 which holds the head member 32 in place upon the rearward end of the cylinder 30. A jack screw 46a is threadedly disposed within the jackscrew nut 46 and is provided with a hexagonal socket |6b to receive the wrench used to tighten the nut 46 against .a relative y rigid cross-strap 50 of a bail 5| is pivotally mounted on the housing ID as at 52. The cross-strap 50 is provided with an opening 50a through which the above-mentioned wrench may be extended into engagement with the socket 45b.

The puncher cylinder 30 is provided with a valve chest 53 carrying a double D valve 54 having separate "D valves 54a and 54b. Inlet ports 55 and exhaust ports 56 are provided, together with a common intake and exhaust port 51 at each end of the cylinder 30 which are alternatively connected to the inlet and exhaust ports governed by the movement of the double "D valve under the influence of an operating yoke 58 connected to a valve actuating rod 59 pivotally connected to an operating or control handle 50 pivotally mounted on the valve chest head 61. A packing 62 is preferably provided for the rod 59, together with a gland nut 63.. A high pressure inlet 54 is nector Ila.

When a puncher 5 is to be attached to a housing l0. the ball valve 21 will be in the full line position of Fig. 9, and as the puncher is attached to the housingthe forward end or enlarged tip 38a of the punch rod is passed into the vopening 22 in the valve seat member 23 into contact with the ball 21. The puncher is then pressed forwardly. lifting the ball 21 from its seat 23 against the blowing-air pressure, and the punc rod is then passed into the tuyere pipel3. When the support sleeve 31 surrounding the piston rod 34 is passed through the hole 22 into contact with the ball 21 this ball will be supported in the dot-dash position of Fig. 9, out of contact with the rod 34. The forward face of the head member 3| is then brought against the rearward face of the retaining nut 26 to aline the puncher relative to the housing i and the associated tuyre openingas defined by the tuyere pipe l9, and to seat thereupon and prevent egress of air from the space 2| to the atmosphere. The usual pressure in the blowing air line will not ordinarily exceed about 12 to 15 p. s. i., wherefore an adequate seal may readily be had between the mating flat faces of the nut 26 and the head member 3|. The rearwardface of the nut 26 may be provided with a conical guiding seat 66 and the rearward end of the support sleeve may be enlarged to form a male seat member 61 coactingly shaped with respect to the seat 66 to assist in positioning the puncher 5 centrally of the hole 22, so that the punch rod 36 will be substantially centered within the tuyere pipe l9 as well as axially alined therewith. When the puncher I5 is in place upon the housing III, the bail clamp 5|l5| may be swung upwardly to cause the cross-strap 50 to be positioned behind the jack screw 46a, and the jack screw tightened through the above-mentioned wrench, which will force the nut 46 outwardly against the cross-strap and force the puncher firmly against the housing. A shoulder 50b may be provided along the lower edge of the cross-strap 50 to engage the lower edge of the retaining nut 49 and facilitate the rapid placement of the bail clamp with respect to the puncher, if desired.

During operation of a converter in the production of blister copper, the puncher assembly |5 will be attached to a housing i0 after the manner shown in Fig. 3, with the punch rod 36 extending through the tuyere pipe l9 towards the discharge end |9a of the pipe iii. In the normal position of the valve-actuating handle 60 the air pressure from the air chest 53 is applied to the forward side of the piston 33, the double D valve assembly 54 being in the position of Fig. 3 and the inlet port 55 at the forward end of the cylinder 30 being uncovered. The continued supply of high pressure air in this manner would cause the piston 33 to be moved to the positon of Fig. 5. With the piston in the position of Fig. 5, the forward end of the punch rod 36a will be located at a withdrawn or rearward position such as shown in dot-dash lines at 36a. When the handle 60 is moved forwardly,

the double D valve assembly 54 is moved forwardly and the valve portion 54a connects the cylinder inlet port 55 at the forward end of cylinder 30 to the adjacent exhaust passage 56, and the valve portion 54b uncovers the inlet-port 55 at the rearward end of the cylinder 30 and allows the air from the chest 53 to enter the cylinder 30 at the rearward end. This air is admitted rearwardly of the piston packing or cup seal 33a, and

sufficient clearance is allowed between the skirt 4|b and the cylinder 30 to allow the air to pass rearwardly of the skirt to force the piston forwardly. Relatively high ressure air is employed to operate the puncher l5, compared with the low-pressure air supplied for blowing purposes, and we have found that air at a gauge pressure in the neighborhood of 70 p. s. i. or more is satisfactory.

As the piston 33, the piston rod 34 and the punch rod 36 are driven forwardly, toward the position indicated in dot-dash lines at 36a" in Fig. 3, the skirt 4| a will cover the cylinder port 55 at the forward end of the cylinder 30, defining a compression zone between thearea 421: within the skirt Ma and the inwardly projecting portion 43 of the cylinder head member 3|. The pressure build-up within this space will cause a rapid deceleration of the piston 33 and the elements connected thereto, preventing forcible impact against the cylinder head member 3|, and will cause the projecting end 36a of the punch rod 36 to quicky reverse its direction of movement. The chest pressure acting upon the valve operating rod 59 will normally aid said rod to assume the position of Fig.5, so it is merely necessary for the operator to press the handle 60 forwardly momentarily, and then immediately reverse his pressure, so that the valve assembly is returned by the chest air pressure and the pull of the operator's hand, to the position of Fig. 5. The release of pressure at the rearward side of the piston 33 upon movement of the double D'valve to the position of Fig. 5, taken with the admission of pressure to the forward side of the piston, produces a rapid acceleration of the piston and the parts carried thereby and the punch rod tip is therefore rapidly withdrawn from the molten charge. It has been found that the operator soon judges the length of time to maintain pressure upon the handle 60 to effect an almost instantaneous reversal of the stroke of the piston 33. As the result of motion studies on the puncher action, it has been found that satisfactory reversal of the piston assembly is obtained as long as the pressure on the valve handle 60 is reversed somewhere near the end of the .ward end of the stroke.

piston stroke, the precise timin not being critical, but the more rapid the reversal the better.

The timing of the release of the valve handle 60 does have an effect upon the length of time the projecting tip 36a of the punch rod remains within the molten charge, which normally varies from a maximum of about A second to as little as /7 of a second.

The punching device is adapted to provide a rapid'acceleraticn of the punch rod tip along the tuyere tube until the position of an accretion or obstruction is reached, and preferably to a position slightly forward of the inner end of the tuyere opening, wherefore a maximum velocity is obtained for the purpose of shearing through or breaking away such accretion or obstruction. This maximum velocity is preferably then quickly reduced by a rapid deceleration of the punch rod assembly so as to permit a quick reversal of the motion of such punch rod without deleterious impact upon the cylinder head member at the for- A rapid acceleration in the rearward stroke of'the punch rod assembly is also desired, so that the enlarged tip portion of the punch rod may be pulled back through the restriction II a without danger of sticking. The air cushion provided between the piston 33 and the cylinder head member 3| assists materially in stimulating this rapid development of high nuance velocity in the return stroke. It will be observed that the piston cup seals 884 are so located with respect to the ports 88 in the cylinder 88 that these cup seals are not required to pass over the ports. and are consequently protected against undue wear. The projecting skirt portions a and lib serve to cut off theports 55 at the forward and rearward stroke positions of the piston, and the acceleration of the piston from either the forward or rearward full stroke positions, as well as the deceleration of the piston at the ends of the strokes, will-be a function of the amount of clearance provided between the piston skirts Ila-lib and the side wall of the cylinder 88. The less this clearance is, the greater the deceleration from the air cushion at each end of the stroke; the more this clearance is, the greater the acceleration away from such end positions, both the deceleration and the acceleration being controlled by the air flow between the respective compression spaces 42a and 42b and the ports 55, past the piston skirt portions, under any given inertia value for the reciprocable punch rod assembly.

In order to secure optimum punching results, independent of the skill of the operator in judg:

ing the most effective instant for returning the handle 68 to effect the outward punch rod stroke, we may provide automatic means for effecting a reversal of the operation of the mechanical punching device. trated in Figs. 10-15, and referring thereto: a puncher cylinder is indicated at 18, correspond- Such an embodiment is illusoperative engagement is re-established manually.

ing to the cylinder 88, above, provided with forward and rearward head members 1| and I2, and a reciprocable rod assembly including a piston member 18 and a piston rod 14 adapted to carry a punch rod at its forwardly projecting end, after the manner of the piston rod 34, above. A ballsupport sleeve 151s preferably provided, mounted on the head 12, together with packing means 18 for the rod II. I

A valve chest or air chamber 11, provided with a pressure air inlet Ila is mounted upon the cyl, inder 18, within which a slide valve 18 carrying 10 t rearward head member I! and provided with ports 88:: adapted to be uncovered by the piston 18. The control tube 88 extends through a bore 88 in the piston 88 thence through a bore 88 in the piston rod 18. some clearance is preferably provided at the bore 88 so that pressure from the bore portion 88a may be dissipated into the cylinder l8 and thence outwardly through ports 8I, 82 and passage 88even though the ports 88a are covered by the piston 18. A venting opening is provided as at 88 to connect the cylinder bore 88a rearwardly of the piston portion 8la to the atmosphere, to facilitate free movement of the differential piston 8! as hereinafter described.

The form of mechanical punching device shown in Figs. 10 through 15 is adapted to cause forward movement of the piston 18, piston rod 14 and the thereto-connected punch rod upon movement of the handle 8! from the dot-dash position I82 towards the full-line position of Fig. 10, with the return action of I the piston assembly being eifected independent of the position of the handle 81.. For this purpose,'we provide means whereby the handle 81 may be caused to engage and operate the valve 18 to the forward stroke openating position, and then disengage the valve stem so as to become independent thereof until such Such means may be attained by providing opposed flats 81 on the re'arwardly projecting end of the stem 84, against which the forked side arms 8'lacap means IN.

--shown at I83. The valve stem 84 would be in an forward and rearward D valve members Tfii-nd 88 cooperating with inlet ports 8| in the cylinder wall 38 and outlet ports 82 communicating with ports 8i and adapted to be placed in communication with the port 8| at the respective ends oi the cylinder in the valve position shown for the member I8. A valve actuating stem 88 is provided, extending through packing 85 in the head member 88 at the rearward end of valve chestl'l, and adapted to be engaged by a valve-actuating handle or lever 81 provided with forked side arms 81a pivotally mounted as at 88 on a guide bracket 88 and adapted for movement between the full line position of Fig. 10 to the dot-dash position Interiorly of the chamber I1 we p ferential cylinder 88 having an enla I 7 tion 88a and a reduced bore' port'ion 88 within which a differential piston member 8 I is disposed, said piston having an enlarged portion 8Ia' disposed within the bore portion 88a and a reduced extreme left hand position, with the extreme left end I88 of the valve stem in engagement with the inner edge vJIM of the guide bracket 88. The pins 88 are thus in engagement with the notches 88. The diflerentlal piston member 8| would be in an extreme righthand position, with the piston rod 8| in engagement with an abutment I88 on the forward wall I86 of the chamber 11,

as a result of the valve chamber air pressure against the small piston Bib. Upon forward pressure being applied to the handle 81, the pins 88 will cause the valve stem to be moved forwardly to the position shown in Fig. 10. This opens the passage 8i at the left hand end of the cylinder 18 by movement of the double D valve 18 to the position of Fig. 10, allowing the chest pressure to be imposed upon the piston 18, moving it forwardly, or to the right. When the limit of the forward travel of the valve stem 88 has been reached, by engagement of the end 841: with the piston rod 8i, continued forward pressure on the handle 81 will cause the pins 88 to slip out of the notches 88, and the arms 8111 will ride forward until they hit the rearward face of the head :1. This position is shown in Fig. 14.

When the piston 13 reaches a forward position such as to uncover the ports 83a, the cylinder pressure will be communicated to the cylinder portion 88a of the diiierentialcylinder 88, and when the pressure at 88 builds up sumciently to overcome the chest pressure on the piston -portion .8"), the differential piston member ill will be moved to the left, pushing the valve stem 88 11 with it, and moving the outer end of thevalve stem to the relation shown in Fig. 15. This movement moves the double D valve 18 to the left, opening the passage 8| at the right end of cylinder 18 to the chest 11 and connecting the scribed above in connection with the first form of theinvention. Some clearance between the skirt 18a andthe cylinder wall will be provided, as described above, and the pressure applied at 8| will be communicated to the forward face of the piston 13 and the return action instituted. The pressure drop in the rearward end of the cylinder will cause a pressure drop in the cylinder portion 90a, allowing the chest pressure to return the differential piston member to its right hand position. This completes a cycle of the punching operation, and a new cycle may be started after returning the handle 81 to the position represented in Fig. 13.

The operation of a converter in the production of blister copper requires that the converter be rotated to various angular positions for the different phases of the converter cycle. In Fig. 2 the converter is shown in what may be termed a "normal" blowing position, in which the tuyere pipes or openings are submerged to a desired operating depth. As the blowing is continued, and slag is skimmed off from the molten charge, the size of the charge will lessen, requiring the converter to be rotated counterclockwise, for example, to a position such that the puncher mechanism occupies a position as shown in dot-dash lines at 15A. When it is desired to charge matte, flux or the like to the interior of the converter, it is customary to rotate the converter clockwise to such position, for example, as that shown at I5B for the puncher assembly, or an even further clockwise position may be required when pouring slag or the like from the opening I; a dumping position for the converter is shown by the dotdash position I5C for the puncher assembly, constituting an even further clockwise rotation of the converter.

Inasmuch as no time must be lost between the blowing periods, and by reason of the fact that blowing air must be supplied whenever the inner ends of the tuyere openings are submerged within the molten charge, it will be appreciated that the puncher assemblies should be maintained in fully operative condition at all positions of the converter, so that the punch rods may be operated when required at all times during which blowing air is supplied to the tuyeres. The puncher assemblies are for this reason caused to be carried by the side wall or shell of the converter, and are of such over-all dimensions in a radial direction as not to materially exceed the radial dimensions of the converter, as defined by the riding rings 2; Such a requirement enforces the utilization of a punch rod operating mechanism providing a rather short operating stroke as compared to hitherto-proposed forms of mechanically operating puncher devices. This short operating stroke is adequate for the punching operation as long as the proper positioning of the inner end of the punch rod is secured. This proper positioning is preferably such as to limit the extent of penetration of the rod tip 36a into the molten charge; we have determined that a penetration of from about 3" to 4 is satisfactory. This proper positioning is obtained according to our invention by providing punch rods 36 of a proper length, so when attached to the piston rod 34 as at 35 the proper over-all length is secured. Inasmuch as the refractory lining 8 issubject to fiuxin'g away during the blowing periods of the converter operation, for example, at the beginning of a converting campaign, with a new refractory lining in place around the tuyere pipes, the refractory lining isv usually about 22 inches in thickness. This lining gradually erodes or fluxes away as the campaign proceeds. At the end of a campaign, usually several months later, this lining may be only 6 inches in thickness. The proper positioning of the punch rod tip as a result of this variation in lining thickness is adjusted by attaching shorter and shorter punch rods 36 to the piston rod 34.

The provision of a high-velocity inward and outward movement of the punch rod tip past the obstruction zone at the end 19a of the tuyre pipe l9 serves to cleanly remove the obstruction, and this motion, taken with the rapid withdrawal of the tip from the molten charge, results in proper maintenance of the desired flow of blowing air through the tuyeres with a minimum deterioration of the punch rods. We have found that a punch rod velocity of approximately 20 ft. per second at the time the punch rod tip cuts through the accretion or obstruction is required in order to secure the desired shearing action upon the incrustation. Velocities lower than about 20'/sec. seem to result in a mere pushing of the accretion away from the tuyere opening, often breaking away relatively large areas of the lining material from adjacent the tuyere opening and seriously damaging the lining. With the high speed punching operation, the accretion is sheared through cleanly, and without damage to the interior lining.

The rapid Withdrawal of the punch rod tip from the molten charge, both from the standpoint of the short duration of submergence of the tip in the charge and the high velocity attained by the tip as it reaches the obstruction zone on the return stroke, attains the desired punching operation without unduly heating the punch rod and without coating the rod tip with molten material. The tip end of the punch rod does not become deformed or become blunted, as is the case with hand-operated punch rods, but retains its relatively sharp shearing edge for an indefinite period. Actual operations have been carried out in which the punch rod was in use for hundreds of punching strokes without deterioration or accumulation of molten material on the rod. In contrast to this, a hand-operated punch rod will require cleaning after punching each "round of tuyeres (i. e., with three men to a converter, and each man attending to 15 tuyeres, the rod requires cleaning after punching about 15 tuyeres) not infrequently, however, a hand punch rod will stick in a tuyre opening the first time it is used, requiring its removal with "dogs and sledges, and that punch rod will then require cleaning and usually will require re-working at its tip portion, before it may again be used.

In addition to providing the above-mentioned rapid forward and rearward punching strokes, the mechanical punching device is also preferably so arranged as to cause the projecting end of the punch rod to exhibit a pronounced whipping action in the punching stroke.

This whipping action may be obtained in cylinder 3ll and the valve chest 53 is asymmetrically disposed with respect to the axis of movement of the rod 36, and this results in a whipping oi the rod tip portion 36a in a generally vertical plane. Amplitude observations made on the structure of Fig. 4, provided with an operating stroke of approximately 12 /2 inches, showed an amplitude averaging about 1.1" in a vertical plane and about 0.2" in a horizontal plane, measured at the inward position of the punch rod tip. The strap attachment 5| also provides some flexibility in the mounting of the puncher IS on the adapter l0, contributing in part to-the amplitude oi the whipping action. It has been found, for example, that a more rigid mounting of the puncher l5 on the adapter Ill causes a reduction in the amplitude of the whipping action, In the specific arrangement shown, the whipping movement is mainly vertical; an equally useful horizontal whipping action is obtainable by mounting the member IS with the valve chamber 53 disposed laterally to one side of the cylinder 30 instead of vertically above such cylinder.

This whipping action is further effective dur-' ing the outward or withdrawal stroke, in that the rapidly vibrating end portion of the punch rod has to be withdrawn through the accretion zone at the tuyre discharge, which results in a battering action of the rod upon the accretion and a consequent enlargement of thetuyere opening. The material forming the accretion will ordinarily be somewhat malleable at the temperatures which exist, so that the battering delivered by the vibrating punch rod tip is productive of an appreciable enlargement. By actual observation, the openings are found to be larger than the punch rod tip diameter, and the openings in tuyeres punched with our mechanical punching device are found always to be larger than the openings formed by hand-punching, using the same diameter punch rod tip in both cases.

In order to provide ample space for the whipping action of the rod tip portion, the tuyere tube I9 is preferably made of somewhat larger diameter than the diameter of the rod tip, and inasmuch as the major portion of the whipping'action takes place when the rod tip is located inwardly, as at position 36a" in Fig. 3, thereduced diameter of the rod 36 forwardly of the tip portion 36a permits a wide amplitude of vibratory movement to take place. The object of the whipping action is to effect an enlargement of the tuyre discharge opening at Ila to a maximum amount, limited only by 'the diameter of the tuyere tube l9, so that the maximum amount of air can be introduced to the molten charge through the tuyere discharge, it being appreciated that the production capacity of a copper converteris directly related to the volume of oxidizing air which can be introduced.

Numerous modifications of the punching apparatus of this invention will occur to those skilled in the art. For example, the substitution of electromagnetic motive force for the fluid-operated punch rod reciprocating means will immediately occur to one contemplating a departure from our specific showing. For this and other obvious reasons, we do not consider our invention to be l4 limited to the precise details of construction herein delineated and described, but rather to the scope of the subjoined claims.

We claim:

1. In an apparatus for punching a tuyere of a rotatable converter, the combination which comprises: a housing member adapted to be secured to the shell or such a converter adjacent a tuyere opening therein, and provided with an air supply inlet, an aperture alined with said tuyere opening and spaced therefrom, valve seat means for said aperture, and a movable valve member located within said housing member and movable into and out of position to engage said valve seat means in the space between said aperture and said tuyere opening, to prevent egress of air through said aperture; and power means detachably secured to and supported by said housing member at the position of said aperture and provided with a. reciprocable rod member extending axially through said aperture into said tuyere opening, said power means being adapted to engage said valve member to hold the same away from said valve seat means and out of contact with said reciprocable rod member when said power means is attached to said-housing.

2. In an apparatus for punching a tuyre of a rotatable converter having a shell; a tuyere, and an air supply housing attached to said shell and connected to said tuyre, the combination which comprises: an integral punching unit adapted for attachment to and for support substantially wholly by said housing and carrying a punch rod adapted to be disposed within said tuyere, said punching unit being provided with means supporting said punch rod independent of said housing for free reciprocatory movement therewithin.

3. In an apparatus for punching a tuyere of a rotatable converter having a shell, a refractory lining, a tuyre extending through said shell'and refractory lining into the interior of said converter and terminating at an obstruction zone at theinner end of said tu yere, the combination which comprises: a punching tool mounted on said converter at the position of said tuyere and including -a punch rod extending within said tuyere, said punch rod being normally disposed in such position that the inner end thereof is located outwardly of said obstruction zone, said punching tool including means for reciprocating said punch rod from said normal position to a second position inwardly of said obstruction zone and back to said normal position under conditions such that the velocity of movement of said punch rod is quickly accelerated to pass through said obstruction zone at a high velocity on its inward stroke and to then quickly decelerate said punch rod as it is moved to said second position, and to quickly reverse the direction of movement of said punch rod and accelerate the return velocity thereof to pass through said obstruction zone at a high velocity in returning to said normal position.

4. In an apparatus for punching atuyere of a rotatable converter having a shell, a tubular air inlet member defining a. tuyere, and man supply housing attached to said shell and connected 'to said tuyere, the combination which comprises:

an integral punching unit adaptedlior attachment to said housing and carrying a punch rod adapted to. be disposed within said tuyere for reciprocatory movement therewithin, said punching unit being provided with means supporting said punch rod independent of said housing and said tuyere and out of contact therewith at ll reciprocative positions thereof, and with means for causing a rapid forward movement of said punch rod towards the interior of said converter and for rapidly decelerating such inward movement toward an inward position and effect a rapid rearward movement, the mounting of said punch rod being such as to cause the end of said punch rod disposed within said tuyre to exhibit a whipping action when moved to said inward position, in response to such rapid deceleration.

5. In' an apparatus for punching a tuyre of a rotatable converter having a, shell, a tuyere, and an air supply housing attached to said shell and connected to said tuyre and provided with an outer wall provided with an opening alined with said tuyere, the combination which comprises: an integral punching unit adapted for attachment to said housing at said outer wall and carrying a punch rod adapted to be disposed within said tuyere for reciprocatory movement therewithin, said punching unit being provided with means engaging said outer wall of said housing about said opening in sealing relation to said outer wall to prevent egress of air from said housing when said unit is attached upon said housing, said engagement of said punching unit with the outer wall of said housing being adapted to aline said punch rod substantially axially of said tuyre, and said punching unit being provided with means supporting said punch rod independent of said housing.

6. In an apparatus for punching a tuyere of a rotatable converter having a shell, a tuyre, and an air supply housing attached to said shell and connected to said tuyere and having an outer wall provided with an opening alined with said tuyre and valve means normally positioned to close said opening, an integral punching unit adapted for attachment to said housing at the position of said opening and including a punch rod adapted to extend through said opening past said valve means into said tuyre, and further including means separate from said punch rod adapted to be positioned in engagement with said valve means to hold the same out of said normal position and out of engagement with said punch rod, and means for reciprocating said punch rod within said tuyere.

7. In an apparatus for punching a tuyere of a rotatable converter having a shell, a tuyre, and an air supply housing attached to said shell and connected to said tuyre, said air supply housing 16 having an outer wall provided with an opening alined with said tuyere, the combination which comprises: a punching tool provided with a rod projecting therefrom and adapted to extend through said opening and into said tuyere, said punching tool being provided with operating means for reciprocating said rod within said tuyere, said means including a cylinder member having a forward cylinder head, a piston rod extending through said cylinder head and connected to said rod, the forward end of said cylinder head being adapted to engage the outer wall of said housing in sealing engagement therewith when said rod is extended through said opening and into said tuyre; and means for detachably securing said tool to said housing and supporting said tool with said forward end of said cylinderhead in engagement with said outer wall of said housing.

8. In an apparatus for punching a, tuyere of a rotatable converter having a shell, a tubular air inlet passage member defining a tuyre, and an air supply housing attach'edto said shell and connected to said tuyere, the combination which comprises: an integral punching unit adapted for attachment to said housing and carrying a punch rod adapted to be disposed within said tuyere, saidvpunching unit being provided with means supporting said punch rod independent of said housing and said tuyere for free inward and outward reciprocatory movement within said tuyere, and the mounting of such unit on said housing being such as to cause the end of said punch rod removed from said unit to undergo a whipping movement having a marked amplitude transverse to the direction of reciprocatory movement in the reversal of reciprocatory movement from inward .to outward motion.

LEONARD LARSON. BYRON T. BERGE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,007,149 Smith Oct. 31, 1911 1,135,489 Baggaley Apr. 13, 1915 1,276,251 Mullen Aug. 20, 1918 1,997,640 Royse Apr. 30,1935

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