US2178366A - Sintering - Google Patents

Description

0d. 31, 1939. BRUQERUN 2.178.366

SIN'I'ERING 'Filed Feb. 19. 1937 3 Sheets-Sheet l INVENTOR E. J. BRUDE'RLIN SINTERING Filed Feb. 19, 1937 s Sheets-Sheet 2 s 75 ATTORNEY Oct. 31, 1939. E. J. BRIJDERLIN SINTERING Filed Feb. 19, 1937 3 Sheets-Sheet 3 l N V E N To R [5" fig/.1 fiilldllllli/ Patented Oct, 31, 1939 UNITED STATES 2,178,368 SINTERING Emil J. Bruderlin, Amarillo, Tex, assignor to American smelting and Refining Company, New York, N. Y., a corporationofNew Jersey Application February 19, 1937, Serial No. 126,623

6Claims.

This invention relates to sintering and partlcularly concerns a novel conditioning and discharge device for sintering machines.

In accordance with the invention, a sinterin Y machine, preferably of the straight line or Dwight-Lloyd type, is provided at its discharge end with one or more rotating or revolving cylinders having helicoid or spiral flights mounted thereon in a manner calculated to cut and condition the sinter cake and deliver the resultin product from the machine. I

Although the novel featureswhich are believed to be characteristic of this invention will be particularly pointed out in the claims appended hereto, the invention itself, as to its objects and advantages, and the manner in which it may be carried out, may be better understood by referring to the following description taken in connection with the accompanying drawings forming a part thereof, in which Fig. 1 illustrates diagrammatically a sintering machine embodying the invention;-

Fig. 2 is an enlarged cross section taken on the line 2--2 of Fig. 1; I Fig. 3 is a cross section taken on the line 3-3 of Fig. 2;

Fig. 4 is a, longitudinal section through the-type of conditioning and discharge device illustrated in Fig. 2';

90 Fig. 5 is a cross section taken on-the line 5-5 ofv Fig. 4, and

Fig. .6 is a fragmentary longitudinal cross section of a sintering machine equipped with two devices of the type shown in Figs; 2, 4 and 5.

Like reference characters denote like parts in the several figures of the drawings.

Referring to Fig. 1, there is illustrated a sintering machine of the Dwight-Lloyd type having bull wheel ID for conveying pallets ll along the track I2 under charging device l3 and ignition device It and over windbox 9 to the discharge end of the machine enclosed in hood l5. Positioned at the discharge end of the machine and mounted transversely to the direction of movement of'the pallets II is the revolving cylinder it.

As is well illustrated in Figs. 2 and 4, spiral flights i1 and it are mounted externally and intemally,-respectively, on the walls of the cylinder it. The flights, which are of steel that may be specially treated to resist wear, are secured to the cylinder wall in any suitable manner as, for-esample, by appropriate lugs and bolts (not shown); a

The cylinder." 'is provided at its ends with websl9 which are keyed to shaft 2| carried by bearings 2| on pedestals 22, 23 supported by the frame 24 of the sintering machine. Means, for example, shims 25 between the bearing 2| and pedestals, are provided for adjusting the cutting edges of the external flights ll with respect to 6 thegrates 26 of the pallets ll.

A variable speed reducer drive 21 permits rotation of the cylinder It at any desired predetermined speed anda discharge spout 28 is positioned atthe discharge end of the cylinder I6. 10 The configuration of the external flights is such as to form two scoop-like members 29 with openings at the bases thereof into the interior of the cylinder l6.

While the invention is not limited in use to the sintering of any particular material, it will be specifically described with reference to the sintering of zinc ores or concentrates for purposes of illustration.

In a preferred mode of operation, zinc concentrates after pre-roasting are sintered in the manner disclosed in United States Letters Patent No. 2,064,479 granted December 5, 1936 to Stuart H. Levison and Emil J. Bruderlin. preferably with a small amount of additional fuel being supplied to the lower portion of the charge in accordance with the teachings of United States Letters Patent Nos. 1,926,043 and, 1,926,044 granted September 12, 1933 to Bruce W. Gonser.

As the sinter cake approaches the discharge end of the machine it meets the cutting edges of the flights I! mounted on the revolving cylinder it which cut up the cake and deliver the sized product from either side to the center of the bed where it encounters the scoop members 29 and is delivered to the interior of the cylinder.

As the crushed and sized product enters the interior of the drum l6 it is conveyed by the spiral internal flights l8 to one end of the drum where it passes through the web or spider l9 into the discharge spout 28. In the preferred practise Just described, the cylinder is so positioned that the cutting edges just barely clear the grate bars with the result that all of the sintered product isdelivered to the spout 2t therebypractically eliminating the dust nuisance which exists when the cake is dumped from the pallets in the usual manner.

Further, the invention delivers the sintered product from the discharge spout 28 in such size and condition that it may be directly mixed and charged to the reduction retorts. Thus, not only is the need for crushers, crushing rolls, screens, etc. eliminated but a superior sintered product is obtained-actual screen analyses show that the u 7 product produced by the device of the invention is not only more uniform in size but that the percentage or amount of dust and fines is markedly less. The desired predetermined size is readily procured by correlating the speed of the revolving cutter II with that of the pallets of the sintering machine proper. By eliminating all necessity for crushers, crushing rolls, screens, etc., material savings both in power and equipment are effected and at the same time another former constant source 'of dust and dirt is eliminated.

The novel apparatus of the invention may also be employed in a classifying capacity. For instance, it is well known in sintering zinc ores on a down draft sintering machine that the lower portion of the sinter cake will be materially higher in cadmium and lead than the centralor even upper portion thereof unless some provision is made to overcome it. Accordingly, when no such provision is made, it is highly advantageous to grade the sintered product.

Such grading or classifying may be readily accomplished by varying the position of the revolving cutter with respect to the grates of the pallets or by employing a plurality of cutters or both. Thus, instead of operating the cylinder l6 so that the external flights just clear the grate bars as previously described, the cylinder It may be raised a suitable distance from the grates by inserting sufllcient shims 25 between the bearings 2| and pedestals 22, 23. When operated in this manner, the upper portion of the cake is removed as previously described while the inferior portion nearest the pallet grates proceeds past the cutter and is dumped in the usual manner.

In Fig; 6 there is illustrated another possible variation in which the sintering machine is pro. vided with two of the revolving devices embodied by the invention. In construction, they are the same as the single device illustrated in the other drawings except for the provision of the gear 30 and gears II for driving one from the other although they can, of course, be so mounted as to be driven independently of each other and at diiierent speeds if desired.

In operating the specific apparatus shown in Fig. 6, the top of the cake 32 is removed by the first cutter while the remainder of the cake 33 is removed by the second cutter. ever, the two cutters can be adjusted to yield three classifications by removing a selected different portion of the bed by each of the cutters and permitting the remaining portion nearest the grates to pass both cutters and be dumped in the usual manner. The particular classification made in any given operation will, of course, be influenced by the other details of the sintering operation such as composition of the charge, its preparation, etc.

While various specific disclosures have been made for the purpose of illustrating the invention, it will be readily apparent that the invention is not strictly limited thereto but that, on the contrary, various changes both in the operation and in the detailed construction of the apparatus may be indulged in within its scope. Thus, the flights on the cylinder may be single or multiple varying conditions and uses.

If desired, howand so designed as to discharge the sintered product'to either or both ends of the cylinder. Accordingly, it is desired to include within the scope of the invention these and such other similar modifications as are useful in adapting it to What is claimed is:

1. Apparatus of the class described comprising a revolving cylinder mounted transversely to the direction of travel of the bed of a sintering machine, a plurality of helical blades encircling said cylinder and mounted thereon, and means for discharging treated material from said machine via the interior of said cylinder.

2. A device for conditioning a sintered product in situ on the bed of a sintering machine and removing the resulting conditioned product therefrom comprising a rotary drum having an opening in the wall thereof, a helicoid blade member encircling and afiixed to said drum and terminating in a baliie at said opening, and means for discharging the conditioned product from the interior of said drum.

3. In the combination of a sintering machine with a cylindrical discharge device having an opening in the cylinder wall for receiving material from the bed of the machine, transfer means for removing material from the bed and delivering it to the interior of the device via said opening, and an internal screw conveyor for discharging material from the interior of the cylinder, that improvement comprising an external screw on the periphery of the cylinder for engaging the cake and conveying it laterally of said bed to said transfer means.

4. A device for physically conditioning and discharging sintered material from the bed of a sintering machine comprising a rotatable drum for mounting across the bed of the machine, the central portion of said drum being provided with openings for the passage of material from the bed into the drum, a plurality of external screw filghtson the drum for engaging the sintered material and conveying it inwardly from the sides of the bed to said openings, and baflle members aflixed to the drum at said openings for receiving the sintered material and delivering it into the drum.

5. The improved method for treating sinter cake which consists in cutting and sizing same to desired predetermined condition in situ on the bed of the sintering machine, forming the resulting properly sized product into a continuous windrow in the center of the bed of the machine as a part of the cutting and sizing operation and discharging the windrowed product from the machine.

6. The method of operating a sintering machine which consists in performing the sizing of the final product upor .the bed of the sintering machine, continuously forming the sized, final product into a window by conveying the product inwardly from both sides of the bed toward the central portion thereof, and removing the windrow from the machine.

EMIL J. BRUDERIJN.

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