US1487333A - Method of and apparatus for producing the reversal of regenerative furnaces - Google Patents

Description

March 18 1924 G. H. lSLEY METHOD OF AND APPARATUS FOR PRODUCING THE REVERSAL 0F REGENERATIVE FURNACES Filed March 31. 1920 Patented 192d,

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GEORGE H. ISLEY, 0F WORCESTER, MASSACHUSETTS, ASSIGNOR T0 MOBCTAN CON- STRUGTION COMPANY, MASSACHUSETTS.

METHOD OF AND APFARATUS FOR PRODUCING THE REVER'SAL OF REGENEBATIVE OF WORCESTER, MASSACHUSETTS, A CORPORATION OF FURNACES.

Application filed March 31, 1920. Serial No. 370,186.

To all whom it may concern:

Be it known that I, Gnonen H. IsLEY, a citizen of the United States, residing at -ll orcester, in the county of Worcester and Commonwealth of Massachusetts, have invented a new and useful Improvement in a Method of and Apparatus for Procuring the Reversal of Regenerative Furnaces, of which the following, together with the accompanying drawings, is a specification.

The. present invention relates to certain improvements connected with the act of reversing a regenerative furnace, in order to change, when desired, the direction of flow of the air and gas through the passages of said furnace.

The improvements reside in a novel method of procuring the reversal, as well as in the construction and arrangement of the reversing instrumentalities. The objects of the invention are to obtain greater simplicity in the construction of devices of this class, and to provide for the effective combustion of all gases that are trapped or otherwise confined, when the reversal of the furnace is inaugurated; a further object is to provide improved means for controlling the flow of air to the furnace with the use of a specially constructed damper or valve disposed between the furnace and the stack.

The several features of the invention will be fully pointed out in detail hereinafter, reference being had to the accompanying drawings, wherein Figure 1 is a diagrammatic view illustrating the application of the invention to a regenerative furnace of well known construction.

Figure 2 is a longitudinal sectional view on the line 2 2, Fig. l, of the reversing device that is provided at each end of the arrangement shown in Fig. 1.

Figure 8 is a sectional view, on an enlarged scale, taken on the line 33, of Fig. 1, and showing the detailed construction of one form of air controlling device. 7

Figure 4: is a sectional view showing a modified form of air controlling device.

Figure 5 is a diagrammatic view, illustrating a somewhat different arrangement of reversing apparatus from the arrangement shown in Fig. 1.

Like reference characters refer to like parts in the different figures.

In the form of the invention illustrated in Fig. 1, the regenerative furnace 1, of any ordinary type, is provided with the usual gas regenerator passages 2, 2, and the usual air regenerator passages 3, 3, At each end of the furnace are provided reversing devices 4:, 1, respectively, each of which is of the form shown in Fig. 2, consisting of a single shiftable hood 5, that cooperates with the terminals of three adjacent alined flues 6, 7 and 8. These terminals are completely surrounded by a body of water contained in a water seal pan or casing 9. 'Each' hood 5 is of suflicient length to cover and water seal, by means of its depending apron 10, two of the three adjacent terminals of lines 6, 7 and 8, and each hood 5 is so pivoted to its pan 9, by means of links 11, 11, as to be capable of being shiftedbodily, by a parallel motion, into its other position, where it covers and seals theremaining flue terminal, at the same time exposingthe one at the opposite end which it had previously sealed.

At each end of the furnace, the fine 6 is in communication with a source of gas supply 12, usually connected with a gas producer, not shown. Each flue 7 communicates directly with the adjacent gas regenen ator passage 2 or 2 of the furnace. Each fine 8 communicates with a conduit or passage 13 that at one end connects with the adjacent airregenerator passage 3 or 3, and at the other end joins with a common stack passage 14.

The two reversing devices 4, a, do not differ in construction essentially from the gas reversing devices shown and described in my United States Letters Patent No. 1,408,946, dated March 7, 1922. Associated with each of said reversing devices 1-, 1 are swinging gravity closing covers 15, 15, one for the terminal of gas supply flue G, and the other for the terminal of flue 8 that has a connectionto passage 13. As described in my aforesaid copending application, each cover 15 is pivoted on a rod 16 that extends 'transversely of the water pan 9, and each cover adjacent its pivotal axis has an out wardly projecting ear or lip 17 adapted to be engaged by the depending skirt or apron,

10 of the hood 5. In this way, each cover 15 is tipped up into open position, immediately following the descent of the hood 5 into position for sealing the flue terminal with which said cover is associated; and when the hood 5 is moved to its other position, uncovering said flue terminal, the associated cover 15 descends by gravity and seals the terminal before the seal made by the apron 10 is broken.

In each passage Or conduit 13, between the stack connect-ion 1a and the terminal 8 is disposed a sliding damper 18, Fig. 3, which when lowered, in the position shown, is adapted to close off coinmunca'tron with said stack connection. Said damper 18 is made hollow to provide an interior passage 19 therethrough, which opens at its lower end at 20, on the side leading to the furmice. The operation of the damper 18 may be effected in any suitable manner, as by means of a rod 21, which passes through a suitable housing 22 erected on the conduit or passage 13, said rod serving to raise or lower the damper, as desired. The housing 22 provides an opening to the atmosphere, said opening being controlled by a swinging gate 24 that has a suitable connection 25 with the rod 21. When the damper 18 is in the position illustrated in Fig. 3, it completely shuts off communication with the stack connection ll, and at the same time, the gate 2fbeing open, air enters the housing 22 therethrough and is drawn through the passage 19 of the damper to the furnace, by way of passage or conduit 13. In this way the air supply to the furnace is made available to keep the damper 0001, thus preventing the frequent burning out of same which would otherwise occur, due to its proximity to the stack connection 1 1. hen the damper 18 is raised, the communication of passage 13 with the stack connection let is restored and at the same time the gate 2 f is closed, due to its connection with the rod 21.

Referring to Fig. 1, when the two hoods 5, 5, are disposed in the positions indicated, that is, at their extreme left hand positions, burning gaseous fuel will pass through the furnace in the direction indicated by the arrows. That is to say, the gas from the producer or other source enters the, furnace from the left hand side, by way of supply lines 12 and 6, hood 5 of reversing device 1, flue 7, and gas regenerator passage 2; the exposed terminal of adjacent flue 8 under these conditions being sealed by its cover 15. The air enters the left hand passage or conduit 13 through the hollow damper 18 which under these conditions is in its closed position, as shown in Fig. 3, and completely shuts off the left hand passage 13 from the stack connection 1 1. This air passes into the furnace by way of regenerator passage 3, and is prevented from escaping past the exposed terminal of flue 8 because, as before stated, the cover 15 seals said terminal,

Leaving the furnace at the right hand side thereof, the products of combustion on their way to the right hand passage or conduit 13 and stack connection 14 pass in part directly into passage 13 from air regenerator passage 3, and in part through gas regenerator assage 2, flue 7, hood 5 of reversing device 4, and flue 8, the terminal of the latter being open because its cover 15 is held in raised position by the hood 5. Under these conditions the right hand damper 18 is maintained in raised or open po-sition,thus communicating the right hand passage 13 with the stack connection 1%. Also, as will be clear, the exposed gas supply fine 6 at the right hand side of the furnace, is com pletely sealed at this time by its associated cover 15.

When it is desired to reverse the flow of gases through the passages of thefurnace the following preferred method of operation may be adopted :The hood 5 of the left hand reversing device 4 is first moved into its other position, thereby causing the cover 15 of fine 6 to shut off the supply of gas, said hood at the same time opening the other cover 15, and connecting the flues 7 and 8. lVith no other change in the relative position of the parts, the furnace is allowed to operate for a short time under these conditions, and it will be clear that during this period of operation the direction of gaseous flow through the furnace remains unchanged, since the stack draft is exerted through the right hand regenerator passages 2 and 3. With the aid of this draft, supplemented by the high temperatures prevailing in the regenerator passages, all the fresh gas between reversing device 4.- and the furnace is drawn inwardly, said gas being displaced by an inwardly drawn volume of cold air, namely a part of the air that enters through left hand hollow damper 18 and passes to the furnace through conduit 13. The entrance of this air by way of flue 8, hood 5, and flue 7, in the wake of fresh gas, absolutely insures that all gas remaining in the left hand passages shall be burned. After allowing a suitable time for the combustion of all such trapped fresh gases, the hood 5 of righthand reversing device 41- is shifted, and simultaneously therewith the dampers 18, 18, have their positions reversed, the left hand damper being raised and the right hand damper lowered. When this is done, the reversal of the furnace is completed, the gas and air entering at the right hand side. and the burned gases leaving at the left hand side, and passing to stack connection 14 by way of left hand passage 13. Because of the combustion of the trapped gas, carried into the furnace by the air that enters passage 2, all danger of the explosions that frequently occur when reversing a furnace, is eliminated. In lieu of the mode of operation above pointed out, it is obvious that the furnace can be reversed in the usual Way, if desired, by operating the hoods 5, 5, and dampers 18, 18. simultaneously.

The parallel motion of which the hoods 5, 5, partake may be imparted thereto in any suitable manner; the force required to impart the initial upward componentof the motion is supplied in part by the gravitational tendency ofthe open cover 15, and may be augmented by the use of counterweights, not shown. To control the volume of gas entering the furnace, the degree of opening of the covers 15 of gas flue 6 may be regulated by an adjustable stop 26, to limit the descent of skirt 10. Such of the covers 15 as are subject to hot exhaust gases from the furnace may be provided with pipes 27 for circulating cooling Water, and all of said covers 15, as pointed out in my aforesaid copending application are readily removable for replacement or repair.

A modification of the air controlling mechanism is illustrated in Fig. 4, where, instead of separate dampers 18, 18, for the two passages 13, a singleswinging valve or damper 28 is provided. Said single damper 28 is made hollow for the passage of air, the

same as the two dampers 18, and the air en- 2 ters through a suitable hollow extension or stem 29. The damper structure is pivoted at 30, andin one position, as shown in Fig.

4, cuts off communication between stack connection 14 and the left hand passage 13, at the same time opening said left hand passage 13 to the atmosphere. In the other po sition the damper 28 performs the same functions with respect to the right hand passage 13, but permits communication of left hand passage 13 with the stack connection 14. v

A modification-inthe construction and arrangement of the apparatus employed for securing the improved method of reversing the furnace, as described above, is shown in Fig. 5. In this figure the same arrangement of reversing device 4 and 4 is shown,

' but the'opposite passages or conduits 13 here areprovided with open terminals 31, 31, disposed in. alinement and having interposed between them the open terminal of a stack flue 32. A reversing device 33, similar in all respects to the shiftable hoods 5 is made operative over the terminals of the flues 31, 31, and 32; at its ends the hood of device 33 carries pivoted adjustable extensions 34, 34, for cooperation, when needed, with the exposed terminals 31, to control the amount of air entering the same. In the position of parts shown in Fig. 5, the flow of gaseous products through the furnace is from left to right, in the direction of the arrows, the two reversby the gas being filled with cool air drawn in through passage 13 and hood 5. Thereupon the devices 4 and 33 are shifted, the former to the right and the latter to the left, with a consequent immediate reversal in the flow ofgases through the furnace. Obviously, as

in the first described form of the invention,

the reversal may, if desired, be accomplished by moving all the reversing devices simul taneously, but when this is done, there is invariably some wastage of the fresh gas that is'trapped in the regenerator passages 2, 2? of the furnace.

I claim,

1. The herein described method of reversing a regenerative furnace, which consists in discontinuing the gas supply to one gas regenerator passage while simultaneously con necting said gas regenerator passage to the associated air regenerator passage on the same side of the furnace, and afterwards connecting both of said regenerator passages to the stack, simultaneously with the. connection ofthe opposite gas and air regenerator passages to the gas and air supply.

2. The herein described method of reversing a regenerative furnace, which consists in cutting oil the gas supply to one side of the furnace in advance of actual reversal, and causing a part of the air normally supplied to said side to be diverted into the adjacent gas regenerator passage.

' The herein described method of resists in disconnecting the gas regenerator passage on one side of the furnace from the;

source of gas supply, connecting said passage with the air regenerator passage on the same side of the furnace, and afterwards opening said side of the furnace to the stack, simultaneously with the connection of the other side of the furnace to gas and air supply. I 4. The herein described method of reversing a regenerative furnace, which consists in allowing an interval to elapse between the act of shutting off the supply of gas to one gas regenerator passage and the act of disconnecting the opposite air and gas regenerator passages from the stack, and in said interval providing a connection betweensaid first mentioned gas regenerator passage and its associated air regenerator passage on the same side of the furnace.

5. The combination with the air and gas In advance of the actual reversal of Under these s condi fines atone end of a regenerative furnace, of reversing means for said furnace, adapted in one position to procure connection of both of said fines, to a single source of air supply.

'6. The combination with the air and gas flues at one end of a regenerative furnace, of a single air supply conduit at said end, and reversing means for said furnace adapted in one position to connect both of said flues with said air supply conduit.

7. The combination with the air and gas fines at each end of a regenerative furnace, of a stack flue connectedwith each air flue, means for admitting air to one of said stack flues when the other is connected to the stack, and reversing means for the furnace adapted in one position to connect the said fine to which air is admitted to the gas fine at the same end of the furnace.

8. The combination with a discharge conduit or passage, of a shut-off device therefor, adapted, when closed, to admit air to said conduit or passage, for flow in the opposite direction to said discharge.

9 The combination with a, stack flue of a furnace, of a damper adapted in one position to shut off the furnace from the stack, and in said position to provide a. passage there-through for the entrance of air to the furnace.

10. In apparatus of the class described, a passage connecting a furnace with a stack, and a damper for closing said passage, adapted, when closed, to connect said furnace through said passage with the atmosphere.

11. In apparatus of the class described, a passage connecting a furnace with a stack, and a damper for closing said passage, and providing, when closed, a conduit for the flow of air to said furnace.

12. In apparatus of the class described, a passage for the flow of burned gases from a furnace to a stack, and a damper for closing said passage, said damper being cooled by a current of air therethrough flowing to said furnace.

13. In apparatus of the class described, a pair of passages leading from a furnace to a stack, and means operable to shutoff one of said passages from the stack, and to cause a flow of air therethrough to the furnace.

14. In apparatus of the class described, a damper for shutting off communication, between afurnace and a stack, said damper having a passage therethrough for connecting said furnace with the atmosphere.

15. In apparatus of the 'class described, the combination with the stack flue of a furnace, of a damper operable in said fine and providing, when closed, a passage for the entrance of air to said furnace, and means operable by the movement of said damper into open posit-ion for preventing the flow of air through said passage.

16. The combination with a regenerative furnace having adjacent air and gas flue terminals at each end, a movable reversing device at each end, operable to connect the gas flue terminal either with the source of gas supply or with the air flue terminal, a.

stack passage at each end connnunicating with the air flue terminal, and means for supplying air to the furnace through one or the other of said stack passages.

17. The combination, with each set of air and gas passages of a regenerative furnace, of a reversing device adapted in one position to discontinue the'gas supply, said reversing device, in said position, providing a connection between the gas passage and the air supply. 1

18. The combination, with each set of air and gas passages of a regenerative furnace, of a reversing device adapted, by actuation in advance of actual reversal of the furnace, to connect adjacent gas and air passages.

19. The combination, with a regenerative furnace, of duplicate reversing devices therefor, adapted to procure a reversal in the flow of gaseous products through the furnace, one of said devices, when actuate-d in advance of the other, procuring disconnection of the gas supply, and sinniltaneously, the passage through itself of air, in the wake of the trapped gas;

20. The combination with a' regenerative furnace, of air and gas passages at each end thereof having adjacent terminals, a gas supply passage at each end of the furnace with its terminal adjacent that of the gas passage, gravity actuated closures for the terminals of said gas supply and air passages, and a shiftable reversing hood'in operative relation to said terminals and adapted to mmal.

' GEORGE I-I. ISLEY.

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