US1943957A - Furnace - Google Patents

Description

Jan. 16, 1934-. s GQDARD 1,943,957

FURNACE Filed Sept. 15, 1932 2 Sheets-Sheet 1 E Ed U2 2/ I J R. S. GODARD Jan. 16, ll 4,

FURNACE Filed Sept. 15, 1932 2 Sheets-Sheet 2 1| IIIIIIIIIIIIIIIIII H, H. 1 -LT- lNVENTOR W W d a n 0 r G m S M M Patented Jan. 16,1934

UNITED STATES PATENT OFFICE 1,943,957 FURNACE Ray S. Godard, Pittsburgh, Pa.

Application September 15, 1932 Serial No. 633,277

8 Claims. (Cl. 263-15) same.

Generally stated, an object of this invention is the provision of furnace ports so constructed and arranged that a continuous unobstructed sheet of flame may be directed overthe combustion, melting or heating chamber of the furnace, and thereby avoid the so-called dead spots that occur in prior art furnaces, of the cross and end fired types, having a. plurality of individual ports separated by sections of the furnace walls.

Another object of the invention is the provision of furnace ports that shall be continuous over a width at least five times greater than the height thereof, and means for maintaining uniform flow of media through said ports whether such media are being delivered to or discharging from the furnace.

A further object of the invention is the provision of means whereby the rate of flow of media, such as an element essential to combustion, through a continuous port may be made uniform from one side of the port to the other, or selectively varied from one side to the other depending upon particular. furnace operating conditions that must be satisfied in a given case.

The invention resides also in novel details of construction and in the arrangement-and combination of parts as will be apparent from the following description and as indicated in the appended claims.

Throughout the specification and claims the term preheater type furnace is intended to embrace and include all types of fuel fired furnaces, whether regenerative or recuperative, or whether cross or end fired. By the term continuous port I contemplate particularly ports having a width at least five times or more greater than the height.

Other objects and advantages 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 vertical transverse section, of a furnace embodying the invention;

Figure 2 is fragmentary sectional view of the furnace taken on line II--II of Figure 1, showing the construction of one of the ports of the furnace, the other potr being similar in construction;

Figure 3 is longitudinal view of the furnace partly in side elevation and partly in section, the

section being taken on lines HI-HI and IIIa- IIIa respectively of Figures 1 and 2; and

Figure 4 is a fragmentary top plan view of one side of the furnace showing the roof over the port and a connecting passage therefor and the 00 manner in which the roof is supported on partitions disposed in the passage.

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

The invention disclosed herein may be applied 55 to fuel firedfurnaces generally and in order to illustrate a practical application thereof, the invention is shown as being embodied in a crossfired regenerative, reversing type glass melting furnace having a melting or heating chamber 1,

ber where it is melted, 'themolten glass flowing 7 to the refining tank. As the glass is drawn off to be manufactured in o various articles, fresh batch is fed to the melting chamber through a so-called doghouse, indicated at 3.

The furnace proper is built on and carried by supporting frame work including cross beams 4, carried by girders 5 which in turn are supported on columns 6, the columns being carried by suitable footings as indicated at 7. The supporting frame is usually located below the factory floor line indicated by line 8. In the construction of the furnace, buckstays 9 and other structural members that enter into the make up of any furnace, are employed, and form no part of the invention.

Since the furnace which has'been chosen for purposes of illustration is of the cross-flred-regenerative type, it is provided with preheaters 10, disposed on opposite sides thereof and extending preferably for a distance more than the full length of the side walls 11 of the melting tank or chamber.

The melting chamber is provided with similar continuous ports12, of width W and height H, located on opposite sides thereof through either of which media, such as an element essential to combustion may be delivered to the chamber, or

through either of which media, such as prodlivered through separate ports so arranged that the fuel and air will mix properly for efficient combustion.

The furnace, as herein illustrated, is provided with independent porls 13 (that is the ports are separate from ports 12) located above continuous ports 12, through which fuel, such as natural gas or oil may be delivered to the point of combustion, the air required to support combustion being delivered through one of ports 12, and the products of combustion being discharged through the other port 12.

Since the furnace herein shown is of the reversing regenerative type, the furnace is fired alternately from one side and then the other. When fired from one side, the air for combustion is passed through one of the preheaters and preheated before being delivered to one of ports 12, and the products of combustion are discharged through the other port 12 into and through the other preheater, wherein heat is absorbed to be given up to the combustion air when the firing is reversed.

In order that the preheaters may be utilized in this manner, each port 12 is connected by means of a conduit 14 having a passageway 15 therein, to the top of is adjacent preheater 10. The width of each passageway 15 is preferably equal to the width of the continuous port to which it is connected.

The walls of each conduit 14 may be built up of slabs or tile 16 of refractory material, and, in effect, form a continuation of the inner and outer side walls and .end walls of preheaters 10.

Each preheater is provided with checkerwork made up of blocks 17 of refractory material so laid up that numerous passages are formed through which either media, essential to combustion, such as air, or products of combustion, may flow.

Since preheaters or checkers, as they are often called, are well known, in the art, further detailed description is believed to be unnecessary.

It will be understood that in practise, chamber 18, in the bottom of each preheater is adapted to be connected alternately to an air duct and to a stack with each reversal of firing. Since the means for accomplishing these connections are old and well known in the art, such have been omitted from the drawings.

In the construction of ports 12 I propose to utilize a suspended roof or cap 19 over the melting chamber. A suspended roof may also be provided for the refining tank; but for my purpose, it is immaterial whether the roof over the refining tank is of the suspended or conventional sprung arch typo.

As may be seen in Figure 1, the roof or cap is suspended above the side walls 11 of the melting chamber at such a distance therefrom that the ports 12 of height H may be formed therebetween.

The roof or cap comprises a plurality of courses of individually suspended refractory blocks 21 the courses extending crosswise of the furnace. The method of suspending the blocks forms no part of this invention and it is to be understood that any standard or known type of suspended roof may be employed. As shown in the drawings, the blocks are suspended in groups of three (each block being in a different course) by hangers 22, each hanger in turn being suspended by means of hanger rods 23 from rods 24 extending transversely of the furnace and forming P t of the overhead frame work which carries the load of the cap.

The overhead frame work includes girders 25 disposed on opposite sides of the cap and running lengthwise of the melting chamber. These girders of course are carried by suitable props or columns (not shown). Girders 25 carry cross beams 26 which are suitably spaced. Beams 26 in turn support relatively short beams 27 that extend in a direction lengthwise of the furnace. Beams 27, as shown, are secured to the webs of beams 26 by means of clips 28 or other suitable means, and carry the rods 24.

Each port 12 comprises a fioor 29 and a roof 30. The port floors may be formed of slabs or tile 31 of refractory material supported by the inner walls of the preheaters and the side walls of the melting chamber (see Fig. 1).

Port roofs 30 may be constructed of slabs or tile 32 and nose blocks 33 in which the fuel ports 13 are formed. Ports l3 slope downwardly so that the fuel delivered herethrough will be directed at an angle into the combustion air being delivered to the furnace through the port 12 located directly below the same. While each nose block 33 is shown as having only one fuel port, it is to be understood that each nose block may have two or more fuel ports therein.

In order that fuel may be delivered to the furnace through ports 13, a fuel supply line 34 is provided on each side of the furnace to which laterals 35 (one for each fuel port) are connected. These laterals extend into the various fuel ports, and may be provided with valves 36 so that the rate of fuel delivered to ports 13 may be individually and selectively regulated or adjusted.

To insure uniform distribution of media flowing through continuous ports 12, (which in the furnace under consideration is air and products of combustion) and to prevent drifting of such media from one side of these ports to the other, the passageways 15 in conduits 14, are subdivided into a plurality of passages 37 by means of partition walls 38. These partition walls are supported on sprung arches 39 that extend across the tops of the pre-heater sidewalls. As shown in Fig. 1, these arches are anchored in the sidewalls of the preheaters. Angle bars 40 may be employed to take the thrust of these arches and the load thereon.

The partition walls extend upwardly to the roofs 30 of ports 12, and support slabs 32 and the nose blocks 33 thereof. The inner top edges of the partition walls 38 may be curved upwardly as at 38 to conform to the contour of the nose blocks and thereby provide a positive means of holding the nose blocks in place under the edges of cap 19.

The partition walls cause the air flowing to the ports 12 and products of combustion discharging therefrom, to flow in well defined channels. Thus, in the case where the furnace is being fired from one side, air will be delivered uniformly to all parts of port 12 on the firing side, insuring efficient furnace operation and effective heating. Since the products of combustion must pass through port 12, on the exhaust side of the furnace, and into the channels defined by the partition walls, the products of combustion will be uniformly distributed to all parts of the preheaters. Thus a maximum amount of checker work is exposed to the hot gases, and a maximum of the heat therein is absorbed thereby.

Since the gases of combustion are uniformly distributed to the preheaters, the checker work therein will be heated to uniform temperature throughout, without overheating portions thereof, as is often the case in preheaters of furnaces having narrow ports.

It is therefore apparent that, when the furnace is reversed, the combustion air will be effectively and efficiently preheated to the desired temperature.

By providing a furnace with wide continuous ports, a continuous uninterrupted sheet of flame may be established in the combustion chamber. Therefore, practically all of the working surface in the melting or heating chamber will be subjected to flame and be heated uniformly, instead of being heated in zones separated by cold spots as is the case with prior art furnaces having multiple ports separated by sections of the furnace wall. For this reason greater production or output per square foot of heating, surface can be obtainable with furnaces having continuous ports instead of multiple ports of the type referred to above.

In case it is desirable to regulate the flow of media through different portions of ports 12, either for the purpose of obtaining a uniform rate of combustion from one side of these ports to the other or for the purpose of graduating the rate of combustion from one side to the other, dampers 41 maybe disposed in the passageways defined by the flow-equalizing partitions .38.

-These dampers may be flat and rectangular in form and designed to endure high temperatures and the effect of high velocity gases. The dampers extend through slots formed in the outer side walls of conduits 14, and may be manually and individually adjusted.

In the construction of furnaces, the location of the ports with respect to the working surface in the combustion chamber is important. The working surface referred to in the furnace illustrated may be considered as the area bounded by the side and end walls of the combustion or heating chamber. In order that efficient heating of the; work may be obtained the flame should come in contact with as much of the workin surface as possible. Therefore, it is proposed to locate ports 12 and 13 away from the side walls 11 and at such a distance therefrom that the flame will strike the working surface as close to the side walls at the firing side as possible.

'To accomplish this result, the cap 19 is constructed so that the edges thereof over-hang the side walls by an amount indicated by dimensions 0, and the mouth of each port 12 will be located a distance D outside of the side walls. By so locating the ports, the flame comes in contact with the work at the very edge, or nearly so, of the melting or heating surface. Thus, instead of the flame shooting through the opposite port 12, it will give up its useful working heat to the materialbeing heated before it passes through the exhaust port into the checkers.

If the combustion or heating chamber is narrow, the fuel and air ports should be set back farther from the side walls of the chamber than in the case where the chamber is wide. Where the chambers are relatively wide, there is not so much tendency for-high temperature gases to discharge through the exhaust ports, so that the ports may be built closer to the furnace sidewalls the invention solely to this type of furnace. The invention may be embodied in any fuel fired furnace where wide continuous ports may be utilized to advantage. The invention may be embodied in end fired as well as,cross fired furnaces and in recuperative as well as regenerative furnaces.

It will be appreciated e se by those skilled in this art, that various modifications and changes may be made in the invention without departing from either the spirit or the scope thereof. It is desired therefore that only such limitations shall be placed on the invention as are imposed by the prior art and the appended claims.

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

1. In a furnace having a combustion chamber provided with a port, that is horizontally continuous throughout substantially a horizontal dimension of said chamber, for the admission of an element essential to combustion, a conduit connected'to said port having a passage-way substantially as wide as the port, and partial partitions in the passage-way terminating at said port in edges extending from the base to the roof of said port for causing said element to flow in well defined channels to said port.

2. In a furnace having a combustion chamber provided with a port, that is continuous through out substantially a horizontal dimension of said chamber for the admission of an element essential to combustion, a conduit connected to said port having a passage-way substantially as wide as the port, partial partitions in the passage-way terminating in vertical edges at said port for causing said element to flow in well defined channels to said port, and a damper in one or more of said passage-ways.

3. In, a furnace having a combustion chamber provided with a port, which is continuous in substantially a horizontal dimension thereof for a distance at least five times the height thereof, for the admission of air, a preheater having a connecting passage to said port, said passage being substantially as wide as the port, partial partitions in said passage located in spaced relation to each other from side to side of the port and terminating in substantially vertical edges at said port adapted to cause parallel streams of air to be delivered to the port, and means for introducing fuel into the air streams discharging from the port into said combustion chamber.

4. A furnace having a combustion chamber provided with ports that are horizontally continuous throughout substantially a horizontal dimension of said chamber for the admission and discharge, respectively, of media, such as an element essential to combustion and products of combustion, respectively, andmeans extending from the base to the roof of said ports for maintaining the media flowing to or from said ports in well defined channels.

5. A furnacehaving a roof disposed in spaced relation above the side walls thereof, a port formed between the roof and one of said walls and that is continuous throughout substantially a horizontal dimension of said chamber, a checker chamber having a connecting passage between said chamher and port, partial partitions disposed in said passage in spaced relation between the sides of the port and terminating in substantially vertical edges at said port to maintain media flowing to or from said port in well defined streams, and a discharge port for said furnace.

6. A regenerative furnace having a roof disposed in. spaced relation above the side walls thereof, ports formed between said roof and side walls, for the admission and discharge, respectively, of media, such as an element essential to combustion of fuel and products of combustion, said ports being continuous throughout substantially a horizontal dimension of said walls, means associated with each port for introducing fuel into the furnace, a checkerchamber for each port having a connecting passage vtherebetween, and partial partitions in said passageways disposed in spaced relation between the sides of said ports, said partitions terminating in substantially vertical edges at said ports to maintain the media flowing between the ports and checker chambers in well defined channels.

'7. A furnace having a roof disposed in spaced relation above and overhanging the side walls thereof, a port, that is continuous throughout substantially a horizontal dimension of said furnace, formed under one edge of the roof, the mouth of said port being disposed outside of the adjacent side wall, and means, including spaced partitions terminating in edges extending from the base to the roof of the port, connected to said port through which media, such as an element essential to combustion, or products of combustion, may flow to or from the furnace.

8. A furnace having a roof disposed in spaced relation above and overhanging opposite walls thereof, ports formed under the overhanging edges of the roof, said ports being continuous throughout substantially a horizontal dimension of the furnace and the mouths of said ports being located outside of said walls, flues connected to said ports through which media such as elements essential to combustion or products of combustion may flow to or, from the furnace, partition walls in said flues terminating in edges at the mouths of said ports that extend from the base to the roof of said ports, and dampers between the partition walls. I

RAY S. GODARD.

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