US2090056A - Charging device for metallurgical furnaces - Google Patents

Description

Aug. 17, 1937. s. LONGENECKER CHARGING DEVICE FOR METALLURGICAL FURNACES Filed July 16, 1956 2 Sheets-Sheet 1 Llllllllll m A #84 ATTORNEYS.

1937- L. s. LONGENECKER I 2,090,056

CHARGING DEVICE FOR METALLURGICAL FURNACES Filed July 16, l956 2 Sheets$heet 2 v INVEN TOR. I

BY $272M I @ATTORNEYS. 1

Patented. Aug. 17, 1937 CHARGING DEVICE FOR METALLURGICAL FURNACES Levi S. Longenecker, Pittsburgh, Pa.

Application July 16, 1936, Serial No. 90,926

5 Claims.

This invention relates to material handling devices and more particularly to machines for charging open hearth and other metallurgical furnaces.

The practice followed in charging open hearth furnaces involves the use of relatively small charging boxes carried by the peel arm of a charging machine. A box is filled with a charge, steel scrap for example, pushed through the door of a furnace and the peel arm rotated until the box is upside down, thereby discharging the contents on the furnace hearth. Furnaces as now designed are provided with a plurality of doors located between the buck-stays in the furnace front wall. These doors are, because of the space between buckstays, relatively small and this necessitates the use of small charging boxes. The use of small charging boxes entails a long charging time, a reduction in the rates of active period of the furnace to charging time, and uneven distribution of the charge over the furnace hearth.

This invention is designed to be used with open front furnaces, such as shown by my United States Letters Patent No. 2,024,649 and Naismith Patent No. 1,778,505, and accordingly may be made almost as wide as the door opening and of a capacity that will, in its largest size, carry and deliver a full furnace charge in one operation. Of course, the machine may be made smaller if desired so that a complete charge may be delivered in two or more operations.

An object of this invention is to provide a charging machine of such construction that the charge may be deposited in the furnace without turning the charge carrier upside down.

Another object of the invention is to provide a machine whereby the material may be deposited uniformly over the furnace hearth without pushing the material out of the charge carrier.

A further object of the invention is to provide a machine which, when operated to discharge material, will cause the material to fall by gravity uniformly on the furnace hearth, and to this end a charging box is provided having a bottom which in effect is gradually pulled out from under the charge whereby the charge is not subject to forces tending to roll it up into balls'or to move the same violently into contact with the furnace arch or back wall.

And a still further object of the invention is to provide a charging machine having a bottom so constructed that the charge will be deposited on the furnace hearth in a progressive manner from the back Wall to the front of the furnace. 7 Other objects of the invention will, in part,

be apparent and will, in part, be obvious from the following description taken in conjunction with the accompanying drawings in which:-

Figure 1 is a view in longitudinal section of a charging device or box disposed in charge re- 5 ceiving position and embodying one form of the invention;

Fig. 2 is a fragmentary view showing the box in its unloaded position;

Fig. 3 is a view in section taken on line III-III of Fig. 1;

box.

Throughout the drawings and the specification, like reference characters indicate like parts.

The charging machine which I have chosen to illustrate in Figures 1 to 4, inclusive, of the drawings, as embodying one form of the invention, comprises a main frame or supporting structure I having sides 2 and 3 braced at suitable points with angle bars 3 and a charge supporting and dumping structure comprising a bottom or floor 4 and back 5 both disposed between sides 2 and 3 and forming therewith a box or carrier for scrap or other material to be charged into a funace.

The charge supporting structure is supported by the main frame I, the one being movable relative to the other.

When the frame and charge supporting structure occupy the relative positions shown in Figure 1, the machine is ready to receive and transport material, say scrap steel, and charge the same into an open hearth furnace, or billets may be transported and charged into a heating furnace.

The bottom or floor 4 is constructed to be extended as in Fig. 1 when a charge is to be transported, and contracted to the position shown in Fig. 2 when the charge is to be unloaded in a furnace.

The manner of accomplishing this actending beams 6 are disposed.

These beams, as

shown, may be of inverted T-shape with the flanges 1 thereof in the plane of the lower edges of sides 2 and 3.

The upper edges 8 of these beams slope downwardly from a point 9 behind back 5 to the front ends l thereof to conform to the sloping or stepped contour of floor 4. To strengthen and rigidify the edges 8, angle bars H are secured on each side of the webs of each beam 6. Angle bars H are also secured to sides 2 and 3 to strengthen and rigidify them at the points adjacent the side edges of floor 4. The rear ends of beams 6 are tied together by means of a heavy beam [2 preferably of channel shape.

Beams 6 are further tied together by means of I-beams l3. in depth and are short, being only long enough to span the space between a pair of beams 6 or the space between sides 2 and 3 and the adjacent beams 6. As may be seen in Fig. 1, I have shown three beams I 3 disposed between and spaced lengthwise of a pair of beams 6, and the ends of these beams rest on flanges 1 when they are 10- cated between a pair of beams 6, while the ends of the beams between the sides 2 and 3 and an adjacent beam 6, are carried by flanges I of a beam 6 and angles I4 secured to the sides 2 and 3 adjacent their lower edges. Of course, the

beams above described that form the main frame structure are appropriately secured together to insure a rigid strong structure and to obtain this end any means and methods known to the art of steel fabrication would be employed.

Sides 2 and 3 and beams 6 have secured thereto channels I5 that serve as supports and tracks for floor 4, and extend, as shown in Figure 1, throughout substantially the full length of beams 6.

The floor of the charge supporting frame comprises a series of plates a to i, inclusive, disposed transversely of and above beams 6 in spaced relation to angle bars II, and in stepped relation to each other, i. e., the forward edge of one plate overlies the rear edge of an adjacent plate. Plate a is secured at its ends to sides 2 and 3 and to an end plate "5 which in turn extends across and is secured to the front ends of beams 6. The remaining plates 1) to i inelusive are supported at their rear edges on support legs I! disposed in pairs between beams 6 and the sides 2 and 3 and adjacent beams 6. Each pair of support legs I! has a shaft l8 journaled therein carrying wheels I9 that run in track channels l5. The forward edges of these plates are supported by the rear edges of adjacent plates. In order to limit the travel of axles l8 in a spreading direction, stop links 20 are employed to connect one axle to the other.

5' Rear wall 5 is secured to the forward edge of plate i and rigidly braced by struts 2| and 22 which are anchored to structural steel frame members 23 supported on posts 24 having wheels 25 at their lower ends running in the track channels l5.

From the drawings and the above description it will be apparent that the main support frame and the charge carrying frame are movable relative to each other and that if either is held sta- 6 tionary the other may be moved with respect to it.

If the charging machine is in charge receiving adjustment as shown in Fig. 1, is fully charged with scrap or other material, and if the 70 charge is uniformly distributed over floor 4, and if it be assumed that the machine is suspended from a crane attached to the framework of the charge receiving frame adjacent wall 5, then by pulling main frame l rearwardly the floor plates 75 starting with plate a will slide one under the These beams are relatively shallow other until they occupy the relative position shown in Fig. 2. As each plate moves under another plate, the charge is unloaded progressively from front to back and falls by gravity in a uniform manner on the furnace hearth. The above described action of floor plates at to 2' takes place because the plates back of plate a are held by friction, caused by the weight of the material on them, against movement while plate It moves rearwardly with the main frame. As soon as the rear edge of plate a strikes supports I! at the rear edge of plate b plates "11, and b will move rearwardly together and when plates 12 and b are under plate "0 and the rear edge of plate 17 strikes the supports at the rear edge of plate c, plate d and plates a 1) start moving rearwardly, meanwhile the material which was carried by them will have dropped by gravity to the place intended. This action continues with movement of the main frame until the plates are in the position shown in Fig. 2.

When the charging machine has been actuated to the unloading position indicated in Fig. 2, the machine may be extended to its loading position by merely pushing the main frame forwardly, or by pulling the charge support frame rearwardly. If the first named movement is employed, it Will be seen that plate a will move forwardly a distance equal to the length of chain or link 20 at which time plate b is pulled forwardly by a chain 28, and when plate "b has moved forwardly the length of a chain, plate 0 will be pulled forwardly, and in like manner plates (1 to 2' will be pulled forwardly to position until floor 4 is in its fully extended position. If the second movement is employed, the reverse action takes place, i. e., plate 2' will move rearwardly a distance equal to a chain length and then plate h etc., until the floor is in extended position.

Relative movement between the main frame and charge carrying frame may be accomplished in a number of ways and by various means. In Figures 1, 2 and 4, I have indicated a motor driven chain and sprocket wheel drive comprising a plurality of chains 26 extending lengthwise of the main frame and between beams 6, idler sprockets 21 and 28 associated with each chain, a driving sprocket 29 for each chain disposed between a pair of idler sprockets 21 and 28, a driven sprocket 38 coupled to the respective shafts 3| on which sprockets 29 are mounted. All of the driven sprockets 36 are driven by chains 32 and sprockets 38 mounted on a shaft 34 which in turn is driven by a motor M. The idler sprocket shafts 35 and shafts 3! are carried by the framework of the charge carrying frame between beams 6, and chains 26 are anchored at their opposite ends in channel l2 and plate l6 respectively of the main frame. To provide a resilient drive between the machine frames, the rear ends of the chains may be connected by bolts 31 to compression springs 33, the bolts being anchored in thrust plates 39 disposed over the outer ends of the springs.

In Fig. 5, different means for handling the charging machine and obtaining relative movement between the main and charge supporting frames, are illustrated. The charging device in this instance is supported on rollers R carried on a car 46 running on tracks along the fronts of furnaces, one furnace being diagrammatically illustrated at 4| carried by car 46 while being loaded with scrap or other material and transported by the car to The charging device would be p the particular furnace to be charged. When the charging device is in position, a machine 42 running on tracks 43 and having independently operable sets of peel arms 44 and 45, (as many as required in each set), would be coupled to main and charge supporting frames of the charging device or box.

The peel arms 44 of one set are connected by couplings 46 to the rear end of the main frame i. e., to channel beam 12 and the peel arms 45 of the other set are connected by couplings 4'! to rear end of the framework associated with the charging carrying frame. In the case of peel arms 44, there would be one arm coupled to the main frame at each end of beam [2, with as many intermediate arms coupled to this beam as may be required to carry the stresses involved. Likewise, in the case of peel arms 45, there would be one arm coupled to the rear end of the charge carrying frame adjacent the sides thereof and as many additional intermediate arms as may be required to hold the charge carrying frame rigidly in place while the main frame is being retracted in the unloading operation.

When the charging box is in position in front of a furnace, the peel arms are moved by mechanism not shown towards the furnace until the charge carrying floor 4 is entirely within the furnace. When in the furnace, peel arms 45 are held stationary and peel arms 44 are moved rearwardly whereby floor plates 0. to i are caused to move progressively rearwardly in the manner already described in connection with Figs. 1 to 4.

When operating the charging device into or out of a furnace either by a crane as mentioned in connection with Figs. 1 to 4, or by the means described in connection with Fig. 5, it will be understood by those skilled in this art that the charging device will require more or less counterweighting to compensate for the overhanging weight of the charge and the weight of the portion of the charging machine extending into the furnace.

While I have described the unloading operation of the machine as involving movement of the main frame while the charge carrying frame is held stationary, it will be appreciated that the unloading may be accomplished also by moving both frames in opposite directions or I may move the charge carrying frame and hold the main frame stationary. This latter movement, however, is subject to a possible disadvantage in that small pieces of scrap might become wedged between the floor plates at the places where they overlap, as the material is pushed off, whereas in the other movement, the material is not pushed off, but drops by gravity because the fioor is moved out from under the material.

As various changes may be made in the details of construction or" the machine herein disclosed without departing from the spirit or scope of the invention. I desire that only such limitations shall be imposed as are required by the prior art and the appended claims.

What I claim as new and desire to secure by Letters Patent is:-

1. A device designed to be moved into a furnace with a charge of material to be deposited therein, comprising a main support frame, an auxiliary support frame carried by the main frame and mounted for movement relative thereto, said auxiliary support framehaving a floor made up of a plurality of members, rollers for individually supporting said floor members for movement on said main frame, said floor members being disposed to move relatively one under the other when relative movement between the frames is effected, and cause material carried thereby to fall by gravity and be discharged on the floor or hearth of a furnace, and means for moving said frames relative to each other.

2. A device according to claim 1 in which the floor is made up of a plurality of substantially fiat plates, that the support rollers are positioned under and adjacent the rear edges of said floor plates, and that the front edges of successive plates are supported by the rear edge of an adjacent plate so that the plates may move one under the other successively and progressively from front to back as the plates are moved from charge supporting to charge unloading position.

3. A device according to claim 1 in which the main and auxiliary frames are provided with sides and a back, respectively, forming with the floor a charge carrying box and from which the charge falls by gravity as the floor members are moved out from under the material.

4. A device according to claim 1 characterized by the fact that side members are attached to the sides of the main frame, that .a back is attached tothe auxiliary frame adjacent the rear edge of the rear floor member, and that the front floor member is attached to the main frame.

5. A device according to claim 1 characterized by the fact that the rear edges of the floor members are supported on rollers, that the main frame is provided with tracks to guide and support the rollers, that the forward edges of said plates rest on the rear edge of an adjacent plate and that the front plate is connected to the main frame, whereby when the main frame is moved rearwardly relative to the floor, the front floor plate slides under the next plate until it strikes the supports of such next plate causing the second plate to move rearwardly until it strikes the supports of the third plate, such action continuing with movement of the main frame until all the plates have moved one under another and causing material carried by the floor to fall by gravity as the fioor plates are pulled from under the same.

LEVI S. LONGENECKEBk

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