US1298761A - Blast-furnace. - Google Patents

Description

F. 0. MILLER.

BLAST FURNACE.

APPLICATION FILED AUG-8. I918.

1,298,761. Patented Apr. 1,1919.

2 SHEETS-SHEET 1. 24

14 44 Q I if I 1 j M O F. 0. MILLER.

BLAST FURNACE.

, Y APPLICATION FILED Aus.a. 191a Patented'Apr. 1', 1919a.

' 2 SHEETS-SHEET 2.

' of the hangin BLAST-FURNACE.

Specification of Letters Patent.

Patented Apr. 1, 1919.

Application flled August 8, 1918. Serial No. 248,861.

To all whom it may concern:

Be it known that I, FRANK OSKAR MILLER, a citizen of the United States, resldmg at Portsmouth, in the county of Scroto and State of Ohio, have invented a certain new and useful Improvement in Blast-Furnaces, of which the following is a full, clear, concise, and exact description, reference be ng had to the accompanying drawlngs, forming a part of this specification.

This invention relates to improvements in blast furnaces.

Heretofore, in the operation of blast furnaces for the manufacture of steel and other products, great difficulty has been encountered in maintaining the full capaclty for the reduction of the ore in the blast furnace. After the blast furnace is first charged and started, it has been found that the material gradually clings to the side walls of the furnace ust above the usual restncted throat at the bottom. This clinging of the material to the side walls is generally termed hanging and it is obvious that as a result of this hanging, the effective opening through which the material can feed to the discharge outlet of the furnace, is gradually restricted. -In actual operation, it has been found that furnaces which can treat 600 or 700 tons per day will gradually be restricted to an output of about 400 or 500 tons per day, the amounts varying in accordance with different conditions. Of course, as is well known, manufacturers can ill afford to shut down the furnace except when absolutely necessary and as a result, the furnace is permitted to operate with'the gradually increasing amount of hanging until such time as the clingin mass breaks off and passes on to the disc arge outlet.

Another difiiculty arising from the result above mentioned, is the rolling whic is produced at the bottom of the furnace because of the restricted opening through which the gases or hot blasts can pass upward through the molten metal. Furthermore, the hanging of the material and the sudden breaking away thereof from the walls in combination with the rolling efi'ect increases to a sents decreased efficiency of the furnace.

The main object of my invention is to provide an arrangement for blast furnaces, which may be embodied either in new furnaces or introduced in blast furnaces now in great extent, the production of flue dust, whlch in turn represervice, that will overcome the hangin now encountered in the operation of ordinary blast furnaces and thereby increase effectively the output and efficiency of the blast furnace and decrease the rolling which now occurs and also decrease the amount of flue dust;

Another object of my invention is to provide an improved arrangement for more uniformly mixing the charges of material as the same are dellvered into the blast furnace and in this way also increasing the efficiency of the furnace.

The invention furthermore consists in the improvements in the parts and devices and in the novel combinations of the parts and devices herein shown, described and made the subject matter of the claims.

In the drawing forming a part of this specification, Figure l is a vertical, sectional. view of a well known type of blast furnace showing my improvements in connection therewlth, the section being taken centrally of the furnace, as apparent from the drawing. Fig. 2 is a horizontal, sectional view, taken substantially 0n the line 22 of Fig. 1. Fig. 3 is an enlarged, detailed, sectional view illustrating one of my improved foreblowers and the manner of arranging the 85 same with regard to the walls of the furnace. Fig. 4 is an inner end elevational view of the fore-blower shown in Fig. 3. And Fig. 5 is a bottom plan view of the fore-blower shown in Fig. 3 and taken on the line 55 thereof.

In said drawing, and referring first to Fig. 1, A designates a blast furnace of a well known type such as used for the reduction of iron for steel and the like, said blast furnace being broken away in the drawing in two places so as to maintain a sufficiently large scale for the novel parts and. without crowding of the drawing. The furnace A, as shown, is formed with an outer shell of sheet metal plates 10, in the usual manner, and is lined on the interior with any suitable fire brick or other lining indicated at 11. From the top to a section near the bottom, the blast furnace is flared outwardly until it reaches a point as indicated at 12, where the diameter of the furnace is gradually restricted until the diameter of the discharge opening is approached as indicated at 13. The furnace is suitably 110 supported on base structures, as indicated at 1414. At the bottom or discharge section of the furnace, the latter is provided with the usual water-cooled twyers as indicated at 15, there being approximately 14 or 16 of these to each furnace and through which the hot air blasts are introduced.

At the top of the furnace, is provided the usual shield 16, hopper 17 and bell 18. The bell is provided with an upwardly extending arm 19 ivoted as indicated at 20 to the inner end 0 a lever 21. The lever 21 is pivoted on a suitable bracket or standard as indicated at 22 and is held so as to hold the bell in normal position. by any suitable means such as the latch indicated at 23.

The material is dumped from the cars or otherwise into a chute as indicated at 24, the lower end of said chute having a cylindrical section as indicated at 25 disposed normally within the shield 16. I

In order to insure a more uniform mixture of the charges as the same pass from the chute 24 into the hopper 17 and onto the bell 18, I have provided a distributing cone as indicated at 26, the apex of said .cone ex- 25 tending into the cylindrical section 25 of the chute 24. The cone 26 is held rigidly by any suitable means such as an arm 27 extending from the standard 28. Discharge from the chute 24 will be prevented when the chute is 30 in normal position, as will be apparent from an inspection of Fig. 1. The chute 24v is however, vertically adjustable by any suitable means, as for instance, by the framework 29 carried by the vertically movable stems 30. The chute is also respect to the shield 16 by suitable uide rods 31. As will be evident, the materlal as dumped into the chute 24 will be held by the cone 26 and after the chute is lifted, the material will discharge all around the cone 26 and the small and large particles thereby the more evenly intermixed.

To still further insure uniformity of mixture before the material is actually delivered into the furnace, I have Provided an additional chute 32 located at the lower end of the hopper 17 The chute 32 is of conical form in its upper portion and'has a lower cylindrlcal section, as indicated at 33.

When the bell 18 is lowered, it is evident that the material will be again dischar ed all around the edge of the bell and will I e concentrated again by the chute 32 so that as the material passes through the section 33, it will have been thoroughly and uniformly mixed. Furthermore, the chute 32 serves to deliver the charge to the furnace at the center of the latter which, considered in connection with my improvements for eliminating the hanging lower down in the furnace, results in a more eflicient operation of the furnace.

As a means of preventing the hanging and rolling heretofore encountered in the opera- 3 66 tion of blast furnaces, I employ what I ided with may term fore-blowers. For this purpose, I may utilize the common twyers as indicated at 150 and in conjunction therewith I introduce a water-cooled, sheet metal, blast nozzle,as indicated at 34, the two together 70 constituting a fore-blower. These foreblowers I referably locate at approximately 14 or 16 filet above the supporting base for the blast furnace, that is, so as to bring the fore-blowers approximately 8 to 12 feet above the section of the blast furnace where the diameter begins to contract and in reality forms an annular shoulder on the interior of the furnace. The number of foreblowers may be varied as desired, but in actual practice, I prefer to use about 6 or is spaced equally distant around the furnace, as indicated in Figs. 1 and 2. By referring to Fig. 3, it will be seen that the nozzle 34 of the fore-blower is of generally tapered construction on the exterior 01 its main portion so as to fit the usual twyers 150. Each nozzle 34 is provided with a water-cooled outer end which is extended downwardly as indicated at 35 and is provided with a. passageway 36 directed downwardly as shown in Figs. 3 and 4. The downward extension 35 of the nozzle is so designed that it will not prevent the insertion of the nozzle through the tapered twyer 150, the nozzle being put in at an angle until the extension 35 has passed by the inner edge of the twyer 150, after which the nozzle 34 is centered and forced outwardly to its final position.

The discharge opening of the nozzle 34 is of extreme importance and to this end I construct the same so that it flares downwardly, as clearly indicated by the dotted lines 136 inFig. 4. In addition, the discharge opening is curved, as viewed horizontally, so as to conform substantially to the curvature of the wall of the furnace, as indicated at 236 in Fig. 5. In this manner, the blast discharge from each foreblower is made to spread out in the form of a fan and at the same time is inclined and directed toward the center of the furnace. The object of this is, of course, to keep the material thoroughly heated around the surfaces of the furnace as the material gradually feeds down to and throu h the restricted section to the usual ,twyers. In this manner, I effectively prevent the material from hanging or sticking to the furnace walls and insure a constant, uniform passage of the material through the furnac with consequent minimization of rolling and production of flue dust. By having the discharge openings of each fore-blower flared as shown at 136 in Fig. 4, it is evident that the blasts from one fore-blower will overlap with those of the adjacent fore-blowers on either side so that a complete hot blast is obtained for the inner circumference of the furnace.

In order to prolong the life of the nozzle 34 and prevent possible disintegration thereof where the blast is deflected from the horizontal to the vertical direction, I provide a pocket in u the nozzle, as indicated .at 13f within which I place suitable amount of fire brick 38 to receive and deflect the hot blast as it is forced through the nozzle. Each nozzle is supplied with circulating water by any suitable means such as the pipes 39 and 40 and similarly'in a well known manner, the twyers are provided with circulating water, as indicated by the pipes 41 and 42.

With my improvements, as above described, the charges are more uniformly mixed than heretofore and by means of the fore-blowers, the material keeps movin through the furnace with uniformity an without danger of hanging and the other disadvantages hereinbefore mentioned, with the result that the output of the furnace is kept at a maximum, shut-downs for repairs and cleaning out are minimized and the general efficiency increased. As will be understood by those skilled in the art, various changes and modifications may be made in the twyers and construction and arrangement of the parts without departing from the spirit of the invention, and I contemplate all changes and modifications that come within the scope of the claims appended hereto.

I claim:

1. As an article of manufacture, a twyer for blast furnaces and the like, said twyer having a main section through which the blast enters and a discharge opening at an angle to said main portion, said twyer being provided on the interior thereof with an insert of refractory material at the place where the direction of the blast is deflected into. the discharge opening.

2. In a blast furnace, fore-blowers disposed around the furnaces and located above the bottom thereof, said fore-blowers being provided with downwardly directed nozzles, the openings of the nozzles being. downwardly and outwardly flared to thereby spread the blast passing therethrough into the furnace.

3. In a blast furnace, having an inner lining, water-cooled fore-blowers located above the bottom of the furnace and dis posed there-around at intervals, each of said usual twyers in the bottom of the furnace,

of supplemental hot blast inlets located above the restricted section of the furnace, said supplemental hot blast inlets being disposed at intervals around the furnace and each of said inlets having a downwardly directed discharge opening, the openings being flared downwardly so that the blasts therefrom will overlap lengthwise of the inner surface of the furnace.

5. In a blast furnace havin a restricted bottom section, the combination with the usual twyers near the bottom of the furnace, of a series of fore-blowers extending through the walls of the furnace above the restricted section and disposed at intervals around the furnace, each of said fore-blowers including a nozzle with a downwardly directed opening and'arranged to direct the blasts lengthwise of the wall of the furnace.

6. As an article of manufacture,.a foreblower for blast furnaces and the like, said fore-blowers including a hollow sheet metal nozzle adapted for circulation of a cooling medium therein, said nozzle having a discharge opening flared toward the discharge end and curved in a direction to conform to the circumference of the furnace with which employed.

7. As an article of manufacture, a watercooled fore-blower for blast furnaces and the like, said fore-blower being of-tapered formation throughout its main portion and provided with a discharge opening at its smaller end arranged at an angle to the axis of the main portion, said fore-blower 'being provided on its interior with an insert of refractory material at the place where the direction of the blast is deflected into the discharge opening In witness that I claim the foregoing I I

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