US3186471A - Fluid fuel injection apparatus for blast furnace - Google Patents

Description

E. A. COSTENBADER ETAL 3,186,471-

FLUID FUEL INJECTION APPARATUS FOR BLAST FURNACE Filed Aug. 7. 1962 June 1, 1965 INVENTORS Ead A. Cos/enbqder Pair/bk 6. Dur/rin United States Patent 3,186,471 FLUID FUEL INJECTION APPARATUS FOR BLAST FURNACE Earl A. Costenbader and Patrick G. Durkin, Baltimore, Mcl., assignors, by mesne assignments, to Bethlehem Steel Corporation, a corporation of Delaware Filed Aug. 7, 1962, Ser. No. 215,417 3 Claims. (Cl. 158-76) This invention is a device for the injection of fuel or other materials into a blowpipe of a blast furnace.

It is an object of this invention to provide a fuel injection device which functions satisfactorily in operation while enabling repairs or substitutions to be made quickly, safely, inexpensively and easily.

Another object is to provide an adjustable pressure seal.

Other objects, purposes and advantages of this invention will appear hereinafter in the specification and claims, and in the appended drawings.

In the drawings:

FIGURE 1 is a side elevation of our fuel injection device in operating position in a blast furnace blowpipe; and

FIG. 2 is a top sectional detail view of the invention.

In the conventional construction of a blast furnace for producing pig iron, the lower portion which serves a receptacle for the molten metal and slag is the hearth. This is built of firebrick and is externally reinforced by a circumferential metal jacket 2. The hot air of the blast is admitted to the furnace through a plurality of tuyeres 3 which are hollow copper castings inserted in tuyere coolers 4 positioned symmetrically around the circumference of the hearth.

The blowpipe 5 thereto is usually a horizontal cast iron pipe, through which the hot blast is delivered to the tuyere 3 from the depending L-shaped tuyere stock 6. The forward end of said tuyere stock 6 may be turned to fit closely into socket 7 in the blowpipe 5.

The blowpipe is held in place with its forward or smaller end fitting into socket 8 of the tuyere by pressure from the tuyere stock 6, which is suspended by conventional means attached to its upwardly extending portion and is provided on its lower portion with a depending lug 9 having a hole 10 through which an end-threaded connecting rod 11 provided with a heavy coiled spring 12 extends to another lug 13 on the hearth jacket 2' where it is anchored. A large nut 14 of stainless steel or brass on the outer end of the rod 11 will enable adjustment of the spring to create the desired pressure while allowing for motion due to contraction and expansion.

In the preferred embodiment of this invention, the shell 15 of the blowpipe 5 has mounted on its exterior side surface a sloping metal block or sleeve 16 having a rearwardly flared seat 17 and a forwardly inclined hole or passage 18 communicating with a correspondingly inclined hole or passage 19 in the forward portion of the shell, and a U-shaped lug 20, having a slot 21, in alignment with, the block on the rear portion of the shell.

Insertable into said blowpipe 5 through the flared seat 17 and passages 18 and 19 is the pipe nozzle 22. Said nozzle is a heavy stainless steel pipe of about 'Vs" inside diameter, the forward end of which slidably projects inwardly at an angle of about 20 between the central axes of said pipe nozzle 22 and of the blow pipe 5, and extends to the front end of the shell 15, for a suflicient distance to inject the fuel at the center axis of the inner end of the tuyere 3. The rear end of said nozzle 22 is externally threaded and screws into a conical collar or ferrule 23 which engages in the flaring seat 17. The surface of :seat 17 forms an angle of approximately with the central axis of nozzle 22.

3,186,471 Patented June 1, 1965 "ice Welded at an angle to the outer face 24 of said collar 23 is the oil supply pipe 25, which later has a side nipple 26 before the closure plug 27 and a slotted end 28. The assembly is held in place by the wedge key 29 which 1s driven against the slotted pipe end 28 into the slot 21 in the U-shaped lug 20. During the operation of the furnace, lengthening of the blowpipe shell 15 due to expansion, such as may result from an increase in the hot blast air temperature or the like, can break the seal between seat 17 and ferrule 23, because the fuel pipe 25 is normally at a lower temperature than said shell. The fluid seal may then be reformed by hammering wedge key 29 so as to force the ferrule and seat back into sealing contact.

To afford proper clearance from and access to other parts of the blast furnace, and also to diminish the discomfort to workmen from excessive heat, it will be found preferable in most installations for the apparatus to be mounted on the more accessible side of the blowpipe 5, as shown, but the device may obviously be mounted on the top or bottom of the blowpipe where this is convenient or desired.

As the nozzle does not extend for more than about a" third of the length of the blowpipe, it has a minimum of exposure to the hot blast, and is also a safe distance from the nose of the tuyere.

Fuel oil is supplied through a flexible hose (not shown), which may be attached to or removed from the pipe nipple 26 by any standard quick locking and disconnecting means. The oil feed must of course be entirely disconnected before the nozzle assembly can be safely installed or removed. Also, the blast air must be taken off the furnace so that no blow-by can escape through the sleeve 16 and thereby endanger the workmen. Accordingly, the preferable time for changing these assemblies is directly after a cast.-

The above-described injection device can obviously be adapted to the use of other fluid fuels than oil, including gaseous, liquid, semi-solid, or solid-in-liquid fuels such as natural or artificial gas, pitch, tar or powdered coal, singly or combined, or with steam or oxygen, depending on their relative delivered costs at the particular location.

We claim:

1. A fuel injection device comprising:

(a) a hollow blowpipe shell,

(b) means forming a first cylindrical passage extending forwardly at an angle through the wall of said blowpipe,

(c) a sleeve mounted on said blowpipe shell having a second cylindrical passage therethrough in alignment with and communicating with said first passage and having a conically flared seat portion therein at the outer end of said second passage,

(d) a slidably insert-able and removable pipe nozzle extending through both said passages,

(e) a conical collar concentrically attached to said pipe and seated in said conically flared end portion in fluid tight relation therewith, and A (f) adjustable wedge means pushing the conical collar into substantially gastight engagement with the flared end portion and releasably securing said collar within the flared portion.

2. A fuel injection device comprising:

(a) a hollow blowpipe shell,

(b) means forming a first cylindrical passage extending forwardly at an angle through the wall of said blowpipe shell,

(-c) a sleeve mounted on said blowpipe shell having a second cylindrical passage therethrough in alignment with and communicating with said first passage and having a conically flared seat portion therein at the outer end of said second passage,

(d) slotted lug means mounted on the blowpipe shell in aligned spaced relation behind said sleeve,

(e) a slidably insertable and removable pipe nozzle extending through both said passages and said sleeve and having a conical collar concentrically connected to said pipe nozzle and seated in said conically flared end portion in fluid tight relation therewith,

(f) a fuel supply pipe integrally secured to the outer end of the pipe nozzle, and

(g) adjust-able wedge means inserted in the slotted lug in engagement with the rear end of the fuel supply pipe and thereby holding the conical collar tightly in place in said conically flared end portion of the sleeve.

3. A fuel injection device comprising:

(a) a hollow blowpipe shell,

(b) means forming a first cylindrical passage extending forwardly at an angle through the Wall of said shell, p

(c) a sleeve mounted on said blowpipe shell having a second cylindrical passage therethr-ough in alignment With and communicating with said first passage and having a conically flared seat portion therein at the outer end of said second pass-age,

(d) lug means provided with longitudinally extending slots and mounted on the blowpipe shell in aligned spaced relation behind said sleeve,

(e) a slidably insertable and removable pipe nozzle extending through 'both said pass-ages and said sleeve and having a conical collar integrally concentrically attached to said pipe nozzle and seated in said coni cally flared seat portion in fluid tight relation therewith,

(f) a fluid fuel supply pipe integrally connected to the outer end of the pipe nozzle,

(g) said fluid fuel supply pipe extending rearwardly substantially parallel to the blowpipe shell,

(11) said fluid fuel supply pipe having a slotted rear end portion and an inner plug closure and a side JAMES W. WESTHAVER, Primary Examiner. MEYER PERLIN, Examiner.

Claims (1)

1. A FUEL INJECTION DEVICE COMPRISING: (A) A HOLLOW BLOWPIPE SHELL, (B) MEANS FORMING A FIRST CYLINDER PASSAGE EXTENDING FORWARDLY AT AN ANGLE THROUGH THE WALL OF SAID BLOWPIPE, (C) A SLEEVE MOUNTED ON SAID BLOWPIPE SHELL HAVING A SECOND CYLINDRICAL PASSAGE THERETHROUGH IN ALIGNMENT WITH AND COMMUNICATION WITH SAID FIRST PASSAGE AND HAVING A CONICALLY FLARED SEAT PORTION THEREIN AT THE OUTER END OF SAID SECOND PASSAGE, (D) A SLIDABLY INSERTABLE AND REMOVABLY PIPE NOZZLE EXTENDING THROUGH BOTH SAID PASSAGES, (E) A CONCIAL COLLAR CONCENTRICALLY ATTACHED TO SAID PIPE AND SEATED IN SAID CONICALLY FLARE END PORTION IN FLUID TIGHT RELATION THEREWITH, AND (F) ADJUSTABLE WEDGE MEANS PUSHING THE CONICAL COLLAR INTO SUBSTANTIALLY GASTIGHT ENGAGEMENT WITH THE FLARED END PORTION AND RELEASABLY SECURING SAID COLLAR WITHIN THE FLARED PORTION.

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