US2316336A - End dump cinder pot - Google Patents

Description

. A ril 13, 1943. w. JOHNSTON; JR

END DUMP CIND-ER POT Filed Aug. 27, 1941 3 Sheets-Sheet l .FIG'.I. HM m H I INVENTOR v April 13, 1943. w. JOH NSTON, JR 2,316,336

END DUMP CINDER POT Filed Aug. 27, 1941 3 SheetsSheet 2 INVENTOR Mann 1' jnmigg.

April 13, 1943- w. JOHNSTON, JR 2,316,336

END DUMP YCINDER POT Filed Aug. 27f1941 3 Sheets-Sheet 3 FIGIV.

w y tay. Quad, Z2 @Mw fi 115 4y?! Patented Apr. 13, 1943 UNITED STATES PATENT OFFICE END DUMP CINDER POT William Johnston, Jr., Wilkinsburg, Pa. Application August 27, 1941, Serial No. 408,471 4 Claims. (01. 266-39) This invention relates to a cinder pot of the end-dump type.

As I use the term cinder pot and asthat term is commonly used in the iron and steel making arts, it refers generically to vessels of various forms and structural details which receive slag and cinder from blast furnaces, openhearth furnaces, and the like iron and steel making instrumentalities, and which serve to convey the slag and cinder to a point of disposal. In usual practice such cinder pots are one-piece castings of iron and steel, but preferably are onepiece steel castings. The general type of cinder pot preferred in the iron and steel making arts is a vessel formed as a downwardly tapered onepiece steel casting of general circular, or ovate, shape in horizontal section. Such cinder pots, when used to convey slag, such as open-hearth slag, to slag-disposal yards, are so mounted on cars that they may be dumped over the side of the cars, their tilting movement being in a direction perpendicular to the tracks upon which the cars run. Such cinder pots are preferred where the slag-disposal yards, or dumps, are relatively wide, so that the slag may be dumped to the sides of the cars carrying the cinder pots, to lie in the slag-disposal yard until broken up and removed.

Cinder pots of another type are known as end-dump cinder pots. These pots are mounted on cars of relatively short wheel base, and are dumped over the end of the car. Their use is indicated when the area available for a slag dump is so narrow or such other conditions exist, such as low head-room adjacent blast-furnaces, openhearth furnaces, and other sources of slag and cinder, that the use of side-dump cinder pots is precluded. End-dump cinder pots possess other particular utility, because of the fact that they are dumped over the end, rather than over the side, of the car which carries them. For example, they may be used to fill in areas of slag yards between, or around, areas which have been filled from side-dump cinder pots and which the track arrangement for the side-dump cars does not permit them to reach. It is, therefore, not unusual to employ a few end-dump cinder pots in conjunction with a number of side-dump cinder pots. The cinder pots themselves are relatively shallow and are primarily f rectangular contour at their upper edges or rims, declining forwardly and rearwardly from the upper edges of the front and rear walls to a bottom which is rounded transversely of the cinder pot.

- Whereas the side-dump cinder pots are trunnion-mounted on pedestals extended transversely of the cars which carry them, and some enddump cinder pots are similarly mounted, the preferred types of end-dump cinder pots rest directly on surfaces forming part of or carried by the car structure. This mounting permits the cinder pots to be rotated longitudinally of the car in rocking movement to and from their dumping position. This rocking movement of the cinder pots on cars, gives linear movement along the cars on which the cinder pots are mounted, as well as tilting movement, so that the cinder pots may be discharged well beyond the edge of the slag bank on which the tracks for the cars carrying the cinder pots are laid. This lessens, or dispenses with temporary track-supporting trestles built to support a track beyond the edge of the slag bank.

In both types of cinder pots under consideration heat dissipation from the pots and temperature conditions in the pot walls are matters of primary importance in determining the useful life of the cinder pots. In cinder pots of both these types, rapid heat dissipation from all regions of the cinder pots is, of course, to be desired, but the zones of highest temperature to which the walls of the cinder pots are raised difier strikingly in cinder pots of the two diverse types. In side-dump cinder pots made primarily in the form of an inverted cone, the zone of highest temperature occurs at about two-thirds the height of the pot, measuring upwardly from the pot bottom. This is for the reason that the slag, usually being retained in such cinder pots for a relatively extended length of time, tends to chill at the open upper end of the pot, and in the lower region of the pot in which its volume is relatively restricted and air circulation against the wall of the pot is relatively effective. This causes the formation of a skull which seals-in the molten slag, limiting heat dissipation from it to heat-transfer directly through an area of the cinder pot wall which is relatively small with respect to the volume of slag which it encloses. It s desirable, therefore, so to support cinder pots of this type that the hottest region of the cinder pot lying above the horizontal center of the pot is relieved of stresses and of the weight of the cinder pot and its contents.

In cinder pots of the end-dump type on the contrary, the cinder pots are relatively shallow and are of relatively great area at their open upper ends, so that heat dissipation directly to the air, as well as through the walls of the cinder pot, can take place throughout a substantial portion of the cinder pot depth. The heating effect in these cinder pots is concentrated in the lower region of the pots and the difference in the heating conditions encountered between cinder pots of this type and cinder pots of the side-dump type is intensified by the fact that in end-dump cinder pots, which are used chiefly for blastfurnace slag, slag is seldom retained for any extended length of time. Their problem is one of relatively rapid heating to a high temperature in the bottom region of the cinder pot, rather than one of regional high temperature in a higher region of the cinder pot walls caused by heattransfer from the slag during prolonged retention of slag in the cinder pot.

As end-dump cinder pots of the preferred types are dumped, they are rocked on their bottoms in the direction of dumping as by pushing with a yard locomotive, and are pulled back into vertical position. The cinder pots thus are rocked on that region of their walls which is at the highest temperature, and the stresses of dumping are taken by that region of the cinder pot wall which, because of its high temperature, is least capable of withstanding them. During transfer of slag from a furnace, such as a blastfurnace, to a point of dumping, the hottest region (i. e. the bottom region) of the cinder pot endures the weight of the slag which is carried. It thus results that end-dump cinder pots have very short useful life, even though they may be called upon to retain slag for relatively short periods of time. It has been usual to make the bottoms of end-dump cinder pots much thicker than the upper regions of the walls, but it has been found that such expenditure of metal is not attended by a greatly extended life of the cinder pots. This is particularly a fact because it introduces non-uniformity in the section of the cinder pot walls, which under the temperatures of use sets up unequal thermal stresses in the cinder pot walls, causing cracks. It has been found inexpedient to provide cinder pots of the end-dump type with trunnions upon which they may be rotated in dumping. Trunnioning these cinder pots, makes them short-pour rather than long-pour vessels, so that the cars on which they are mounted must be lengthened and equipped with racks and the like in order to dump even at the end of the car. With end-dump cinder pots shaped and mounted to rock on their bottoms, cars of short wheel base are used, and as noted slag may be dumped well beyond the end of the car.

These problems I have solved by providing simple and effective means organized in association with end-dump cinder pots for so mounting the cinder pots that the bottom region of the cinder pot is relieved of contact with and movement against the structure of cars by which the cinder parts are carried, while retaining the advantages of a bottom contour which provides rocking movement for the cinder pot. Desirably the cinder pot is supported in the cradle by a supporting contact of the cradle with the cinder pot in the region of the cinder pot upwardly of its hottest bottom region.

Herein I use such terms as longitudinal" and transverse" and front and rear walls with reference to normal mounted position of the cinder pots and not with reference to proportional dimensions in the cinder pot structure.

In the accompanying drawings showing a preferred embodiment of my invention Fig. I is a plan view of an end-dump cinder pot organized above its bottom region to rest on suitable supporting structure.

Fig. I0. is a plan view of a rocking cradle organized to receive and to support a cinder pot such as the cinder pot shown in Fig. I.

Fig. II is a cross-sectional view through the cinder pot taken in the plane of the section line II--II of Fig. III.

Fig. 11a is a view of the cinder pot cradle, showing the cradle partly in end elevation and partly in vertical section.

Fig. III is a side elevation of the cinder pot.

Fig. IIIa is a side elevation of the cinder pot cradle with the cinder pot shown, in chain lines, mounted therein.

Fig. IV is a central longitudinal sectional view of the assembly of cinder pot cradle and cinder pot mounted therein, showing the cinder pot in its level or carrying position.

Fig. V is a view similar to Fig. IV, but showing the cinder pot and cradle tilted to full dumping position.

In accordance with my invention I associate with an end-dump cinder pot which is typically a cinder pot having a rounded bottom upon which it may be rocked, a cradle structure shaped in substantial conformity with the cinder pot, and which carries the cinder pot and relieves the cinder pot bottom of contact with a surface on which the assembly rests. The cradle structure has a rounded bottom which may rock longitudinally of a car carrying the assembly upon a supporting surface carried by, or incorporated in, the structure of the car. Desirably, as shown, the cradle and the cinder pot are so organized that the cradle supports the cinder pot substantially above the bottom region of the cinder pot and somewhat below the upper edge of its walls. In order that the cinder pot may not be discharged from the cradle, nor have substantial movement in the cradle in rocking movement of the assembly, the cinder pot is secured to the cradle in its position of rest therein. Further to limit shifting movement of the cinder pot in the cradle, and slightly to space the surface of the cinder pot walls from the embracing surface of the cradle, the cinder pot is desirably provided with a plurality of positioning and spacing lugs, or teats, projecting from the outer surface of the cinder pot walls. Advantageously, but not necessarily, the bottom of the cinder pot is corrugated longitudinally of the pot to provide flexibility in the pot bottom for accommodation to temperature changes therein, and to provide an increased area of heat dissipating surface at the bottom of the cinder pot.

Turning to the specific embodiment of my invention illustrated by the accompanying drawings, and considering first thosefigures of the drawings which show the end-dump cinder pot by itself, reference numeral l designates the side walls of the cinder pot and reference numerals 2 and 3 designate respectively the front wall and rear wall of the cinder pot, which front and rear walls slope convergently downward to a bottom 4. Above the bottom region of the cinder pot, a plurality of feet 5, reenforced by webs 6, project outwardly from the cinder pot walls. The bottom 4 of the cinder pot has longitudinally extended corrugations I, and positioning teats, or bosses 8, project from the surface of the cinder pot at its bottom and at separated points around the cinder pot adjacent its bottom. The cinder pot is composed of iron or steel, and preferably is made as a one-piece casting.

The rocking cradle is a relatively massive iron or steel structure which also is preferably a onepiece casting. It has side walls 9 and front and rear walls iii and H, which slope convergently downward to a bottom l2, formed on lines of longitudinal curvature to give it a surface suitable for rocking movement on the surface of a car or other structure on which it rests. .On the working surface of the cradle there are curved positioning flanges l3, which will lie in grooves or slots in the surface, or surfaces, of a car or other structure on which the cinder pot and cradle assembly are mounted. Desirably, as shown, the body of the cradle has a number of relatively large windows I 4, provided to economize the weight of metal of which the cradle is composed, and providing air circulation to a cinder pot mounted in the cradle. The open upper end of the cradle walls has an upper edge I 5, which carries a plurality of positioning lugs IS. A pair of spool-form lugs l7, each such lu being in line with the space between two of the positioning lugs I6, projects outwardly in the upper region of each of the cradle side walls 9. A plurality of perforate lugs I 8 are carried by the front and rear walls of the cradle to provide connecting lugs and clevises for the attachment of instrumentalities to limit rocking movement of the cradle.

In the assembly shown as exemplary of my invention, the cinder pot rests in the cradle with its feet in contact with the upper edge I 5 of the cradle and each between two of the positioning lugs l5 thereon. The cinder pot and the cradle are, as shown, so dimensioned that there is substantial clearance between the walls of the cinder pot and the embracing walls of the cradle. As above-noted, the cinder pot is tied firmly in its mounted position in the cradle. Each of the two feet 5 of the cinder pot which overlie the spoolform lugs I! of the cradle at both sides of the assembly are perforate for the passage of the shanks I9 of a U-bolt, the bight of which embraces the adjacent spool-form lug of the cradle. Nuts 20, threaded on the shanks of the U-bolts and bearing against the upper surfaces of the feet 5, tend to pull the feet down firmly on the upper edge of the cradle.

In the assembly thus made, the feet 5 of the cinder pot being each received in the interval between two of the positioning lugs I6, the lugs inhibit shifting of the cinder pot in the cradle, while the engagement of the feet 5 with the spool-form lugs l1 holds the cinder pot in the cradle when the cradle is rocked in dumping. The teats or bosses 8, act as positive spacers between the walls of the cinder pot and the embracing walls of the cradle, insuring that a space will be defined between the bottom of the cinder pot and the wall of the cradle even though the bottom of the cinder pot sags after long continued use. Through the space between the outer surface of the cinder pot and the inner surface of the cradle air may circulate to and from the windows Id of the cradle in heat-transfer from the walls of the cinder pot.

The uniform wall thickness of the cinder pot need be no greater than the minimum wall thickness, at the top of cinder pots of the rocking bottom type as previously made. The combined weight of my cinder pot and cradle assembly may thus be no greater than the sole weight of cinder pots of the rocking bottom type as previously made. While I prefer a suspended mount ing of the cinder pot in the cradle, and particularly a mounting which suspends the cinder pot by transmitting the load of the cinder pot and its contents from a region well above its bottom to the cradle, modified mounting of the cinder pot in its rocking cradle may be practiced without subjecting the bottom of the cinder pot to movement on a supporting surface. r

The practice of my invention herein described results in great economy, because it extends the life of the cinder pot of the general sort to which it applies many times that previously experienced, without increased wall thickness of the cinder pot. I have found that in use of the assembly, the tendency for the cradle to become heated is so moderate that the life of the cradle is indefinitely long, and is to be considered as terminated only by accident.

I have described a preferred form and arrangement of elements constituting an embodiment of my invention. Departure from the elements i1- lustrated and described as embodying my invention may, however, be made, while remaining within the spirit of my invention and the definition of the claims appended hereto.

I claim as my invention:

1. In an end-clump cinder pot assembly organized to rock to dumping position on the surface of supporting structure, a cinder pot and an upwardly open cinder-pot-receiving and supporting cradle having a curved rocking bottom surrounding the lower region of the cinder pot, the cinder pot having structure peripherally projecting part way the height of the cinder pot walls, and overlying and resting upon the top edge of the cradle for supporting the cinder pot in the cradle.

2. In an end-dump cinder pot assembly organized to rock to dumping position on the surface of supporting structure, a cinder pot and an upwardly open cinder-pot-receiving and supporting cradle having a curved rocking bottom surrounding the lower region of the cinder pot, the cinder pot having structure peripherally projecting part way the height of the cinder pot walls, and overlying and resting upon the top edge of the cradle for supporting the cinder pot in the cradle, the bottom region of the cinder pot being contoured approximately to match the bottom region of the cradle, and spaced therefrom in supported assembly of the cinder pot with the cradle.

3. In an end-dump cinder pot assembly organized to rock to dumping position on the surface of supporting structure and including a cinder pot, a cradle for holding the said cinder pot above the supporting surface of a carriage, the said cradle comprising pot-suspending structure supportingly underlying structure of the cinder pot above the cinder pot bottom, a curved bottom portion arranged below the level of the bottom of the cinder pot, and having a curved bearing surface for rocking contact with the supporting surface of a carriage, and means engaging the cinder pot on the cradle.

4. In an end-dump cinder pot assembly organized to rock to dumping position on the surface of supporting structure and including a cinder pot, a cradle for holding the cinder pot above the supporting surface of a carriage, the said cradle comprising pot-suspending structure, supportingly underlying structure of the cinder not above the cinder pot bottom, and a curved bottom portion arranged below the level of the bottom of the cinder pot, and having a curved bearing surface for rocking contact with the supporting surface of a carriage.

WILLIAM JOHNSTON, JR.

Images