US1836025A - Blast furnace - Google Patents

Description

A. B. HASWELL BLAST FURNACE Dec. 15, 1931'.

Filed May 25, 1930 2 Shets-Sheet 1 'I////lIIIMI/IIIIIIIIIIIIIIIIIMII o I M w u Die. 15. 1931.

A. B. HASWELL BLAST FURNACE Filed May 25, 1950 2 Sheets-Sheet 2 4 Patented Dec. 15, 1931' UNITED STATES ARTHUR B. HASWELL, OF BIRMINGHAM, ALABAMA.

' Bmsa' summon Application filed May 23, 1930. Serial 1W0. 455,023.

This invention relates to improvements in blast furnace top construction and aims to provide means for reducing the amount of flue dust carried out of the top of the furnace by the escaping gases.

In the usual blast furnace, all of the gases which escape from the furnace pass through and commingle with the burden materials as they are charged from the top of the furnace. In the usual blast furnace heretofore in general use prior to my invention, the area through which the escaping gases pass is equal to the area at the stock line of the furnace. This results in the escaping gases leaving the furnace at a relatively high veloclty.

The improved furnace of my invention provides means whereby increased area is provided for the escaping gases. This materially reduces the velocity of the outgoing gases and cuts down the volume of flue dust carried away.

The improved arrangement also provides an area for the escape of gases which is substantially isolated from the zone through which the incoming burden materials travel. In this way, a large percentage of the escaping gases have no opportunity to commingle with the incoming burden materials.

These and other features of the invention will be apparent from the following specification when read in connection with the accompanying drawings. In the drawings:

Fig. 1 is a vertical section of one form of blast furnace top construction embodying the invention;

Fig. 2 is a horizontal section on line 22 of Fig. 1 at a reduced scale;

Fig. 3 is a detail section on line 33 of Fig. 2 illustrating means for holding a stock line ring in spaced relationship to the upper part of the furnace lining;

Fig. 4 is a vertical section illustrating the application of my invention to'an existing type of blast furnace; V

Fig. 5 is a horizontal section on line 55 of Fig. at a reduced scale;

Fig. 6 is a detail section on line 66 of Fig. 5.

Referring to Figs. 1 to 3 inclusive of the drawings, 10 represents the shell of a blast furnace which is lined on the interior with suitable brick work 12. The furnace top is enlarged in diameter as indicated at 14. The

roof of the furnace tapers inwardly as indicated at 16 and carries a charging hopper 18 and a charging bell 20 of standard design and of usual dimensions. Hung from the roof structure by means of a number of links 19, I provide a stock retaining shell 22. This shell as shown is of cylindrical form. And its diameter and area indicated by the dimension line A is substantially or approximately equal to the diameter and area of a blast furnace of the usual design. The relative sizes of the main bell 20 and the diameter at the stock line of the furnace is retained so as to keep the distribution of stock within proper control in accordance with present day practice. The placement of stock within the furnace with reference particularly to the distribution of fine materials and coarse materials is of utmost importance. Heretofore relative placement of materials has been governed largely by the relative diameters of the furnace at the stock line and the diameter gf the main bell. In the usual design of furnace with a stock line diameter and main bell properlydimensioned to give best distribution of stock, the gas escapes from the stock in the furnace only through the voids between the stock over an area equal to the area of the furnace at the stock'line. The area of a furnace above the stock line governs the velocity of the escaping gases in the top part of the furnace.

In the furnace of my invention, the enlarged top portion 14 of the furnace provides an annular space 24 which increases the area through which the outgoing gases flow to 0K- take pipes 26.

The shell 22 is held in proper spaced relationship with respect to the lining of the furnace by' means of links 27 which are pivoted to brackets 28 secured in the furnace lining. 1

These links engage lugs 30 secured to the shell 22 as clearly shown in Fig. 3. Lugs 30 are carried by channel bars 32, which in turn are secured to the shell 22.

When the bell 20 is lowered, the burden materials M, whichhave been previously fed to the hopper 18, descend into the furnace and accumulate within the ring 22 along the stock line as indicated at S. It is thus clear that the descending materials do not commingle with the escaping gases within the annular space 24. This zone 24 of increased diameter provides an additional area over that existing in blast furnaces heretofore used. Hence the velocity of the outgoing gases is materially reduced. This minimizes the dust carrying power of the escaping gases. In a blast furnace of known type. and modified to embody my invention, the area A is approximately 283 square feet and the larger diameter of the zone 24 is such that the area of the annular zone B is approximately 268 square feet. Thus the area for escaping gases in the furnace of my invention has been increased approximately 95% and the velocity of the gases as compared with prior practice has been reduced approximately 50%.

Sihce the force or dust carrying power of a gas is proportionate to the square of its velocity, it follows that in the blast furnace of known construction to which I have just referred the gases will carry only about /t as much dust as would be carried away by furnaces as heretofore constructed.

The furnace illustrated in Figs. 1 to 3 is specially constructed with a top of enlarged diameter so as to provide for the zone of increased area for the outgoing gases. It is to be understood.however, that the invention can be applied by making certain alterationsin existing furnaces of conventional tvpes. Such an application of the invention is illustrated in Figs. 4, 5 and 6.

Referring to these figures, 10 represents the usual'outer blast furnace shell. 12 the lining thereof. Near the top of the furnace, the lining is removed and an annular wear plate of substantially frustoconical form is incorporated 'in the furnace structure as indicated at 34. A stock retaining ring 22* is supported by links 19 from the furnace roof structure. The furnace shell 10 is continued upwardly as indicated at 36, thus leaving an annular space 24 for the free escape of gases from the furnace charge. The stock retaining ring 22 is held in proper spaced'relationship from the outer shell of the furnace by spacing members 27 as shown in Fig. 6. As thus arranged, it is clear that my invention may be incorporated in existing blast furnaces so as to reduce the velocity of escaping gases and thereby materially cut down the amount of flue dust blown from the furnace. It is also clear that only the gases passing through the stock line area A will commingle with the material released by the charging bell 20. l

The stock line of the furnace as indicated at S in Fig. 1 and at S in Fig. 4 is within the stock retaining ring 22 and is above the lower-edge 23 of said ring. As thus arranged, part of the gases escapin from the furnace are by-passed into channe s which begin at a point below the level of the stock line. That is part of the gases escaping from the furnace make their exit at a zone below the lower edge 23 of the ring 22. I

While I have described in considerable detail certain specific embodiments of the invention illustrated, it is not to be construed that I am limited thereto since various modifications and substitutions ofthe mechanical equivalents may be made without departing from the invention as defined in the appended claims.

What I claim is:

1. A blast furnace having a top structure including a ring adapted to retain a part of the stock in the upper part of the furnace, an outer wall surrounding the ring and having an inside diameter greater than that of the ring and adapted to provide a zone for the unobstructed escape of gases, means for suspending the ring from the top of the furnace, and members between the ring and said outer wall for holding the ring in spaced relationship with respect to said outer wall, said members making a breakable connectionbetween the ring and the wall of the furnace.

2. A blast furnace having a top structure including a ring adapted to confine the upper portion of the furnace burden therein, an outer wall surrounding the ring and having an inside diameter greater than that. of the ring to provide a zone for the unobstructed escape of gases, means for suspending the ring from the top of the furnace, and pivotally mounted members for maintaining the ring in spaced relationship with respect to said outer wall.

3. A blast furnace having a top structure including a ring adapted to confine the upper portion of the furnace burden therein, an outer wall surrounding the ring and having an inside diameter greater than that of the ring to provide a zone for the unobstructed escape of gases, and acing members pivoted to said outer wall an coacting with said ring so as to hold it in proper spaced relationship with respect to said outer wall.

4.-. A blast furnace having a top structure including a ring adapted to confine the upper portion of the furnace burden therein, an outer wall surrounding the ring and having an inside diameter greater than that of the ring to provide a zone for the unobstructed escape of gases, spacers secured to said outer wall, and. lugs secured to said ring which coact with said spacers.

In witness whereof, I have hereunto signed

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