US2859023A

US2859023A - Continuous furnaces

Info

Publication number: US2859023A
Application number: US645799A
Authority: US
Inventors: Bucci Robert
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-03-13
Filing date: 1957-03-13
Publication date: 1958-11-04
Anticipated expiration: 1975-11-04

Description

Nov. 4, 1958` R. Bucci 2,859,023

J CONTINUOUS FuRNACEs f Filed March 15, 1957 v 4vsheets-s11eet 1 m N INVENToR.

BY 7%@ W R. Bucci CONTINUOUS FURNACES 4 Sheets-Sheet 2 Filed March 15, 1957 Nov. 4, 1 958 R'. uccl CONTINUOUS FURNACES 4 Sheets-Sheet 5 Filed March 1:5,l 195'! IN VEN TOR. @Yau/f am' m NQV. 4, 1958 R, Buccl 2,859,023

- CONTINUOUS FURNAcEs l V Filed March 1:5. 1957 4 sheets-sheet 4 INV ENTOR.

fwd@ BY m7,

States APatent O ,CONTINUOUS FURNACES Robert Bucci, Amhridge,Pa. i Application March 13, 1957, Serial No. 645,799

6 claims. (C1. 263-6) This invention relates to new and useful improvements in continuous furnaces for reheating wrought iron or steel and it is among the objects thereof to provide a reheating furnace in which the furnace hearth for supporting the metal is especially designed for reheating 4wrought iron.

It is a further object of the invention to provide a continuous heating furnace with conveying means normally disposed below the surface of the furnace hearth away from the high temperature prevailing within the furnace chamber, the conveyor being operative for raising the metal being heated above the hearth and advance the same in the direction of the discharge end of the furnace.

It is a further object of the invention to provide such conveying means mounted on a vertically movable support or elevator whereby the entire conveyor may be simultaneously raised or lowered in relation to the furnace hearth.

It is a further object of the invention to provide conveying means for continuous heating furnaces in which the carriers that engage and support the billets or slabs while being conveyed above the furnace hearth are water cooled. i

It is a further object of the invention to provide a continuous furnace for reheating wrought iron billets or slabs in which the furnace hearth or bottom is provided with slag drains for sloping areas, the slag being received in water troughs below the hearth drains by means of which the slag is washed away.

It is still another object of the invention to provide a single continuous heating furnace for wrought iron billets or slabs which shall eliminate the need of a series of individual heating furnaces with their attendant high labor cost.

The invention will become more apparent from a consideration of the accompanying drawing constituting a part hereof in which like reference characters designate like parts and in which:

- Figure 1 is a side elevational view, partially broken away, of a continuous heating furnace and conveying means embodying the principles of this invention;

Figure 2 is a vertical section taken transversely of the view shown in Figure 1 Figure 3 is a side elevational view of a conveyor and support;

-Figure 4, an isometric view of a carrier used on the conveyor;

Figure 5, an end elevational view of a portion of the water cooling system for the carriers;

Figure 6, a side elevational view of the furnace hearth and conveyor support; and,

Figure 7, atop plan view thereof.

With reference to Figure 1 of the drawing, the furnace proper consists of buckstays 1 supporting a lire brick wall 2 and roof structure 3, the buckstays being mounted on a superstructure of structural steel generally designated by the numeral 4 and `reinforced concreteV ICC walls 5. The furnace hearth designated by the numeral 6 is made of re brick 7, as shown in Figure 2 of the drawings, there being slag drains 8 spaced at intervals throughout the furnace hearth, the slag drains draining sloping areas as indicated by arrows in Figure 2 of the drawing.

The numeral 9 designates the charging end of the furnace and the numeral 10 the skid by which the billets or slabs are discharged from the furnace to a receiving table 11, as shown by arrows.

The numeral 12 designates an inspection door of which there may be several on both sides of the furnace through which the billets or slabs could be manipulated or turned, if so desired.

With reference to Figure 2 of the drawing, the hearth is provided with a pair of

slots

13 and 14 extending the length of the furnace through which carriers 15 of a conveyor can be raised above the furnace hearth for lifting the slabs or billets from the hearth and advancing them in the direction of the discharge end of the furnace. The carriers 15 are mounted on an endless `chain 16, Figure 3, that passes over a drive wheel 17 `nels and I-beams generally designated by the numeral 27 that constitute an elevator that extends the full length of the conveyor.

`As shown in the several ligures of the drawing, particularly Figure 2, the elevator 27 is provided with

jack screws

28 and 29 having worm gear wheels 30 and 31, respectively, that are engaged by the Worm 32 of a drive shaft 33 that is driven by

gear wheels

34, 35 and 36, the latter being the pinion gear of a drive motor, not shown. Thejacks and worm wheels and worm drives are suitably journaled in pillow block bearings 37. There may be three or more sets of jack screws spaced longitudinally of the furnace beneath the elevator 27 driven by a common shaft 33 and when the drive motor is energized, the jack screws will function simultaneously to raise or lower the elevator 27 that supports the entire conveyor mechanism. In this manner the carriers 15 will be raised or lowered with reference to the furnace hearth, line 6, Figure l.

Y With reference to Figure 2 of the drawing, gutters 38, 39 and 40 are disposed below the slag drains 8. Burners 41 are provided beneath the slag drains 8 to keep them hot and water sprays 42 are provided in the slag troughs to sinter the hot slag as it falls into the trough or gutters which are inclined to wash the sintered slag away from beneath the slag drains.

With reference to Figure 4, it is to be noted that the carriers 15 are hollow and are provided with ilanges 43 with holes 44 for attachment to the chain links 16. Each carrier is provided with threaded openings 45 and 46 for connection with fluid conduits to deliver a coolant such as water to the interior of the carrier wherein it is circulated to cool the same and drained through the other opening. These individual inlets and outlets are connected by ileXible, preferably helically shaped conduits 47 or flexible hose connected to a common reservoir 48 that is mounted on the ends of the shaft 25, as shown in Figure 2. As shown in Figure 5, conduits 47 will stretch from the reservoirs 48 which are on the shaft 25 at the center of the conveying mechanism and follow the carriers 15 on around the endless conveyor without crossing or becoming tangled.

4skid 10 onto the receiving platform or table 11.

In the operation of the above-described continuous heating furnace, a suitable combustion system, not shown, is utilized. Such a system is usually operated with a recuperator to obtain economic operation by heat exchange to absorb the heat from the waste products of combustion and through the heat exchanger to preheat the air delivered to the fuel burners. Since the combustion system is no part of the present invention, it is not shown.

The products of combustion are drawn from the rear or center of the furnace chamber to the front end and exhausted through the

passages

50 and 51 leading to a stack or the inlet side of a recuperator structure (not shown). The connecting passages may be formed by metal or refractory construction.

Also, if during the operation of the furnace the pressure within the furnace chamber is lowered due to opening of the side doors or for any other reason and air passes up through the

conveyor slots

13 and 14, the latter may be sealed in any suitable manner or the space below the furnace may be closed in with appropriate doors for access to the operating equipment.

The operation of the above-described furnace and conveying system is briefly as follows:

With reference to Figure l, the billets or slabs are placed on the charging end of the furnace designated by the numeral 9 in the drawing. The conveying system is then brought into action by raising the elevator 27 through operation of the shaft 33 that raises the jack screws 28. As the conveyor is raised, the carriers will extend through the

slots

13 and 14, Figure 2, and engage the billets or slabs resting on the charging end 9, Figure 1, and convey it forward towards the discharge end. Each time the billet or slab has been advanced a desired distance, as for example the width of the slab, the elevators are lowered until another slab has been placed on the charging end 9 of the furnace hearth. When the elevator 27 is again raised, it will engage all of the slabs previously charged from the furnace hearth and advance them forward to the discharge end where the end slab will slide down the Each time the charge in the furnace has been advanced a desired amount, the elevator 27 is lowered to move the carriers below the hearth surface to the position shown in Figure 2 of the drawing.

Wrought iron, when heated to the rolling point, gives olf slag which must be removed from the furnace bottom. As shown in Figure 2, slag drains 8 are provided in sloping areas as indicated by the arrows, so that the slag will drain off through the furnace bottom. The top portion of the slag drains 8 are kept hot by the heat of the furnace and the bottom portion will be kept hot by the burner jets 41, Figure 2, and the slag will not harden or freeze in the drain holes.

The arched openings 12 serve for inspection of the billets or slabs and for refinishing the furnace bearth surface as by the application of sand. The furnace walls and roof structures are preferably lined with highly refractory fire brick such as silica brick, the brick being suspended from channel shaped steel structures in the usual manner. The slag drains may be lined with high temperature tire clay and packed to form a hard surface, or special preformed lining sleeves of suitable clays may be inserted in the drain openings. Because of the high temperature conditions prevailing in the furnace for reheating wrought iron for rolling, provisions must be made to cool the doors and other portions of the furnace, which is no part of the present invention. Suitable control levers for operating the elevator jacks and the endless conveyor to move the carriers in the

openings

13 and 14 of the hearth and indicating means for temperature and other operating characteristics may be provided in the usual manner so that substantially the entire furnace operation may be controlled by a single operator.

Although one embodiment of the invention has been herein illustrated and described, it will be evident vto those skilled in the art that various modifications may be made in the details of construction without departing from the principles herein set forth.

I claim:

1. In a continuous heating furnace for reheating wrought iron a hearth structure having a plurality of slag drains extending vertically through the hearth spaced longitudinally and transversely of the furnace, the furnace hearth having sloping areas converging in said slag drains and means for heating said drains throughout to prevent freezing of the slag therein, said slag drains being disposed in rows and outside gutters disposed beneath said rows of slag drains having water sprays for cooling and'sintering the slag and for washing the same down said gutters.

2. In a continuous heating furnace a hearth having parallel slots extending longitudinally thereof, conveying means the load supporting surface of which is disposed below said hearth and being adapted to be raised through said slots to extend above the hearth surface, means for raising and lowering said conveying means operative to raise the billets or slabs from the furnace lhearth for advancing the same towards the discharge end of the furnace, and means for lowering said conveying means to deposit the billets or slabs on the furnace hearth, said conveying means being in the form of an endless conveyor having water cooled carriers for engaging and supporting the billets and slabs being heated, said carriers being disposed below the hearth surface when not transportingbillets or slabs through the furnace chamber.

3. In a continuous heating furnace for reheating wrought iron, parallel slots extending through the vertical dimension of the furnace hearth, endless conveyors beneath said slots having carriers mounted on an endless chain disposed in said slots, said conveyors being mounted on an elevator having means for raising and lowering the same to project the carriers through the slots into the furnace chamber for advancing billets or slabs through said chamber, the said slots in said hearth being of inverted V-shape and the carriers being of complementary shape but of lesser dimension to be adapted to extend at least in part through the slots into the furnace chamber.

4. In a continuous heating furnace for reheating wrought iron, parallel slots extending through the vertical dimension of the furnace hearth, endless conveyors beneath said slots having carriers mounted on an endless chain disposed in said slots, said conveyorsibeing mounted on an elevator having means for raising and lowering the same to project the carriers through the slots into the furnace chamber for advancing billets or slabs through said chamber, the said slots in said hearth being of inverted V-shape and the carriers being of complementary shape but of lesser dimension to be adapted to extend through the slots into the furnace chamber, the endless conveying chain being disposed over gear wheels having sprocket teeth for engaging the `links of the chain and said conveyor having rests for supporting said carriers on the return strand of the conveying means, said rests having rollers at the sides and bottom to provide anti-friction contact with the carrier ends and walls.

5. In a continuous heating furnace for reheating wrought iron, parallel slots extending through the vertical dimension of the furnace hearth, endless conveyors beneath said slots having carriers mounted on an endless chain disposed in said slots, said conveyors being mounted on an elevator having means for raising and lowering the same to project the carriers through the slots into the furnace chamber for advancing billets or slabs through said chamber, the said slots in said hearth being of inverted V-shape and the carriers being of complementary shape but of lesser dimension tobe adapted to extend in part through the slots into the furnace chamber and cooling means for circulating water through said carriers.

6. In a continuous'heating vfurnace a hearth structure.

a furnace chamber constituted by the hearth structure, side walls and a rough structure, the side walls having arched openings therein With door closures therefor, the furnace hearth having parallel slots extending from the charge to the discharge end of said furnace, the latter being provided with skids for directing the materials from the furnace hearth to a receiving table, an endless conveyor beneath the furnace hearth having carriers mounted on4 endless chains, said carriers being disposed in the hearth slots, sprocket Wheels for said conveyor chains mounted on an elevator and carrier rests mounted on said elevator having rollers for making anti-friction contact with the conveyor carriers, said elevator constituting structural steel members supported on a plurality of screw jacks, worm wheels for rotating said screw jacks and a worm shaft engaging said worm wheels, said worm shaft being connected to all of the Worm Wheels to actuate the jack simultaneously to raise or lower the elevator, water reservoirs mounted for rotation on a central conveyor sprocket Wheel shaft to be rotatable therewith having flow conduits connecting said reservoir to said carriers to circulate water therein, said furnace hearth being sloped and being provided with slag drains, the high points of the sloping hearth being at the slots for the conveyor carriers.

References Cited in the file of this patent UNITED STATES PATENTS 671,893 Laughlin Apr. 9, 1901 694,569 Nau Mar. 4, 1902 1,209,021 Phillips Dec. 19, 1916 1,452,045 Hawley Apr. 17, 1923 1,878,896 Sessions Sept. 20, 1932 2,028,941 McIntyre Ian. 28, 1936