US1169336A - Sintering device. - Google Patents

Description

M. McMURRAY & B. J. MULLEN.

SINTERING DEVICE.

APPLICATION FILED mac. 20, 1913.

Patented Jan. 25, 1916.

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MAX MCMURRAY, OF CLEVELAND, AND'BENJ'AMIN J. MULLEN, OF LEETONIA, OHIO; SAID MULLEN ASSIGNOR TO UNITED IRON AND STEEL COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF PENNSYLVANIA.

SINTERING DEVICE.

Original application filed October 14, 1913, Serial No. 795,143.

Specification of Letters Patent.

20, 1913. Serial No. 307,932.

To all whom it may concern:

Be it known that we, MAX MC-MURRAY and BENJAMIN J. MULLEN, citizens of the United States, residents, respectively, of Cleveland, county of Cuyahoga, and State of Ohio, and Lcetonia, county of Columbiana, and State of Ohio, have invented a new and useful Improvement in Sintering Devices, of which the following is a specification, the principle of the invention being herein explained and the best mode in which we have contemplated applying that principle, so as to distinguish it from other inventions.

Our invention relates to sintering pans used for the purpose of sintcring or agglomerating pulverulent material or ores, such as for instance, flue dust from blast furnaces.

The subject-matter of this application constitutes a division of our application I 795,1-i3, filed October 1a, 1913 for grate-bars.

One well-known method of sintering involves the use of a receptacle comprising a main or body portion forming the sides and ends, together with a bottom structure composed of grate-bars perforated uniformly throughout *ith slots parallel with each other and running at right-anglesto the axis of the bar. Upon this there is laid a layer of material forming a porous hearth of a character such as will prevent the pulverulent material from passing through said perforations. The charge of pulverulent material is then laid upon the porous hearth, air passed through it from the top downward and thechargeignited. After ignition the passage of air is continued and the sintering process thus carried out and completed, all as is well-known to those skilled in the art. We have found, however, that the use of a sintering pan of usual and above-described construction in said process, produces a resultant material which is not uniform in character. That is, we have found that the sintering process is not carried out uniformly throughout the mass and that that portion of the charge adjacent to and extending a substantial distance inwardly from the sides and ends is subjected to a less active sintering operation, than is the remainder of the charge.

Heretofore it has been customary to utilize a multiplicity of grate-bars of the above described character, each of which was pro vid'ed with the same number and size of perforations or slots similarly located, so that all of the bars were equally permeable and the degree of permeability was the same throughout all of the operative portions of each bar. Such construction of bars, we have found, permitted the air to short-circuit along the side and end walls of the pan and prevented the air from passing through that portion of the charge contiguous to said sides and ends for a substantial distance inwardly, in the'amount necessary to produce uniform sintering throughout the entire charge. In other words the air did not pass through all of the charge at the same rate, thus obviously producing a product non-uniform in character.

The object of our invention, therefore, is to provide a sintering apparatus by means of which the sintering process may be carried out uniformly throughout the entire charge and a consequent uniformity of the resultant product thus obtained. The desirability of obtaining such uniformity is readily apparent and understood by those skilled in the art.

lVith the said object in view, our invention consists of means hereinafter fully described and particularly setforth in the claims.

The annexed drawlng and the following description set forth in detail certain means embodying our invention, the disclosed means, however, constituting but one of various mechanical forms in which the principle of the invention may be employed.

In said annexed drawing: Figure l is a plan of a sinteringp-an embodying our invention. Fig. 2 is a longitudinal central section of same. Fig. 3 is a fragmentary side elevation showing the grate-bars forming a part of the said pan. Fig. at is a fragmentary plan of such bar. Fig. 5 is a vertical transverse section of a bar. Fig. 6 is a fragmentary plan of a modified form of bar and Fig. 7 is a similar view of a second modification.

In the illustrated embodiment of our in vention, A is the main or body portion of a well-known type of sintering pan, forming the ends and sides of the latter. Se-

cured in any suitable manner and forming a bottom structure is a series of grate-bars B of suitable width, all of which, excepting the end bars B B, are provided with a multiplicity of equidistant circular perforations which occupy the major portion of each bar, a substantial portion of each end, however, being left blank, as shown in Figs. 1 and 4. Below these bars is the exhaust chamber C, having the outlets 0 c, which may be connected with suitable exhausting apparatus. As in the previously-known apparatus, a layer of suitable material D, such as limestone screenings, is placed upon the bars and forms the porous hearth for the charge E. The two end bars B B are left completely blank. In a pan having inside dimensions of twelve by seven feet, these bars are about 12% inches in width at the ends and the distance from such ends to the center-lines of the nearest row of perforations is also made about 12% inches. Viewed from below, then, the perforated portion of the bottom structure will be seen to be surrounded by an imperforate rectangular annulus about 12 inches in width. The effect of this imperforate portion is to modify the course of the air in so far as relates to the outside portion of the charge, so as to cause such air to pass through this part of the charge at substantially the same rate as that at which it passes through every otherpart of the charge. While we prefer to use circular perforations, slots may be employed, as shown, in Fig. 7, in which event the length of the blank portion may be made substantially the same as in the case of the circular perforations, provided the area of each slot is substantially equal to the area of one transverse row of circular perforations.

The above-described construction of the bars may be modified in the circular-perforation construction, by decreasing the length of the blank portions and introducing a lesserv number of circular perforations between such blank portions and the normally perforated portion, as shown in Fig. 6. When slots are used, a similar modification may be resorted to, smaller slots be ing used as shown in Fig. 7.

In any of the above-described vconstructions of our improved bar, a bar is provided which has a varying degree of permeability throughout its operative portions, that is, that portion exposed in the exhaust chamber, a substantial part of each end being imperforate. In the first-described bar the permeability varies from zero throughout one portion thereof, to a maximum throughout the remainder. In the modified construction, it varies from zero at the end to the normal, with an intermediate part having an intermediate degree of permeability. This being the case, the entire bottom structure is arranged to have a varying permeability. l/Vhile slots instead of circular perforations may be employed, as above noted, we have found the circular perforations to be preferable.

Having fully described our invention, What we claim and desire to secure by Letters Patent is 1- 1. A sintering pan comprising the combination with the main or body portion forming the ends and sides; of a bottom structure composed of perforated gratebars; a substantial portion of said bottom structure contiguous to said ends and sides being imperforate, and extending a distance from the sides or ends of said pan substantially greater than the imperforate distance between the individual grate bars.

2. In a sintering pan, the combination with a main or body portion forming the ends and sides; of a bottom structure composed of perforated grate bars; a substantial portion of such bottom structure contiguous to said ends and sides and exposed to the space beneath said bottom structure, being imperforate, and extending a distance from the sides or ends of said pan substantially greater than the imperforate distance be tween the individual grate bars.

Signed by me, this 6th day of December,

4 MAX MGMURRAY. Attested by D. K. Row, K. L. SISUNG. Signed by me, this 3 day of December,

1913. BENJAMIN J. MULLEN. Attested by N. E. WARREN, C. J. SULLIVAN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G.

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