US1766175A - Furnace construction - Google Patents

Description

' June 24, 1930. I

L. H. HOSBEIN ET AL. FURNACE CONSTRUCTION 3 Sheets-Sheet v1 Filed Sept. 17. 1928 June 24, 1930. L. H. HOIASBEIN Er AL FURNACE CONSTRUCTION Filed sept. 17. 1928 3, Sheets-Sheet [7206 7 6 lamflfioabezrz,

Welcom June 24, 1930. 1.. H. HOSBEIN Er AL 1,766,175

I FURNACE CONSTRUCTION Filed se t.1'1. 192s SiSheets-Sheet s ZZZ/670%: lowfl/Eoabam 027D Wdeoma Patented June 24, 1930 I UNITED STA TES PATENT OFFICE.

LOUIS H. HOSBEIN, 0F ,WINNETKA, AND 'OTTO VVELGOIVIIE, OF CHICAGO, ILLINOIS,

I ASSIGNORS TO M. H. DETRICK COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS summon conszrnuc'rxon I Application filed September 17, 1928. Serial No. 306,571.

This invention relates to improvements in furnace construction and pertains particularly to the construction of furnace walls in association with fuel-feeding apparatus, such 'as oil burners and pulverized fuel burners whereby the fuel is injected into the combustion chamber through one or more of its walls.

Experience has shown that in the use of such fuel-feeding apparatus, particularly in large furnaces which are operated at high temperatures, wall portions adjacent the burners are subject to wear at a rate disproportionate to the rate of wear occurring won the wall generally. We have ascertained that this has been due, in part, to inadequate provision for control of the temperature of wall refractories adjacent the burner, and to some extent to eroslve action of the injected fuel, and other influences.

Experience has also demonstrated that the b in the combustion chamber, particularly in installations in which the furnace is fired by a plurality of burners, wherein the firingfrom one burner may injure another burner, particularly a burner which is not operating at the same time. This condition arises, for example, when some of the burners are shut down when power requirements are low, or in furnaces equipped with both oil and pulverized fuel burners which are operated interchangeably, that is, the oil burners being out of operation while the pulverized fuel burners are operating, and vice versa.

It has also been ascertained that wall portions about the pulverized fuel burners, as heretofore formed, are likely to accumulateencrustations or accretions of coke and ash which are likely tointerfere, to some extent.

with the proper operation of burners, and to I contribute to disintegration of the wall refractories.

The present invention has for its object adequate protection and avoid interference with their proper operation, and which will urners are liable to injury, from the heat 7 certain details of which willafi'ord the burners 1 exposed to the furnace heat and forwall re- ..fractories around the burner openings.

Another object is the provision of such a construction which may be installed and repaired with facility and in which the various elements may be interchangeable and of standardized form.

Other objects include the provision of i'm-' proved features and elements of the construction as hereinafter pointed out and claimed.

Further objects will be pointed out or indicated hereinafter, or will be apparent to one skilled in the art upon an understanding of the invention or its employment in practice. 3 In thedrawings forming a part of this specification we show one form of construction embodying the invention, but it is to be understood that this is presented for purpose of illustration only and is not to be given any interpretation calculated to limit'the claims short of the true and most comprehensive scope of the invention in the art.

In said drawings Fig. 1 is a sectional elevational view of a portion of a furnace wall provided with burner openings and constructed in accord ance with the invention, same corresponding to a sectionon line 1.-1 of Fig. 2;

Fig. 2 is a part elevation of the interior of such a wall and showing also parts of'the exterior sheathing;

Fig. 3 is another sectional along line 33 of Fig. 2;

Fig. 4 is a detail in the nature of a section on line H of Fig. 5;

Fig. 5 is a part horizontal line 5-5 of Fig. 2, and

' Fig. 6 is a perspective view illustrating the wall construction adjacent the burner o enin A wall construction with which the present invention may be employed to particuar advantage is that described and claimed in the U. S. Patents Nos. 1,747,822 and 1,7 t7,823 to Raymond J). Foltz, and a wall elevation as section as along of that general type is presented herein' by ranged to discharge 1nto the furnace chamber, being supplied with fuel from a duct or ducts .14 and with air from an air duct or ducts 15. The frame carries horizontal members 16, extending from one upright to another and affording support for the wall hangers 17 which may have the same general form and arrangement as described in the applications referred to above. These hangers carry the straight'wall sections made up of flat refractories 18 and joint refractories 19, said hangers also acting as spacing members to maintain the wall sections spaced inwardly away from the frame members. Above the burners are disposed series of curved hangers 20 having hooked arms 20 at their upper ends for engagement retained with certainof the members 16 and horizontal arms 20 at their lower ends for abutment with horizontal members 21 which are carried on the frame. Between these arms 20 and 20, the upri ht body portion of these hangers is curved outwardly at its upper part and inwardly at its lower part and provided with lateral flanges 20 and 20 conforming to the curves of these respective portions. Inclined shelves 20 extend inwardly from the hanger body portions at about the point where the curvature reverses, and bottom flanges 20 are provided along the lower margins of the arms 20 and terminate at depending stop members 20 On the flanges 2O are suspended slotted tile 22 which depend vertically into contact with the casing of the burner 12, said tile being susceptible of a limited-extent of vertical play on said flanges and being retained against shifting outwardly by the stop members 20 which are spaced inwardly from the frame members 10. On the inner ends of the flanges 20 and on the flanges 20 are shiftably supported supplemental tile suspension members 24 and wedge-shaped tile 25, both being in the general form and arrangement as illustrated and described in U. S. Letters. Patent No. 1,544,580, said wedge-shaped tile being associated to form. a convex wall portion curving inwardly and upwardly in the furnace chamber above the burner. By virtue of the connection by which the tile 25 are anchored to the hangers 20, they are susceptible of vertical movement, but securely against falling out of the wall.

' cured by Flat brick 26 are inserted above the uppermost tile 24 and below the shelves 20 and with the hanger flanges 20. Thus, they are supported independently of the refractories below the shelves and are susceptible of upward movement while at the same time remaining anchored to the hangers in such fashion that they are held against displacement out of the plane of the wall. Joint refractories 19 are placed on top of the re fractories 27 and arranged in overlapping relationship with the lowermost refractories of the superj acent wall sections, compressible refractory material being arranged on top of said joint refractories to accommodate upward expansion of the refractories 27 and 19' and maintain a closed joint between the sections. By virtue of this construction, therefore, the furnace wall immediately above the burner opening projects into the furnace chamber beyond the general vertical plane of the-wall, and takes a regular convex form'which gives the wall opening for the burner an inward flare.

At the end of the series of hangers 20 are disposed the hangers 28 which are likewise supported on members 16 and 21 and have the upper parts of their body portions curved outwardly in conformity with the corresponding parts of the hangers 20. Their lower portions, however, are provided with vertically extending lateral flanges 28 which terminate at horizontal shelves 28". Flat re fractories 29 with slotted outer ends are engaged with the flanges 28 and above them wedge-shaped refractories 25 and refractories 27 are supported on and anchored to the hangers 28. Below the refractories 29, the wall is continued downward in substantially vertical direction by refractories 30, 32

and 34 at the side of the burner openings.

The manner in which these last-mentioned refractories are maintained in place at the sides of the burner openings is illustrated generally-in Figs. 3 and 4. On a suitable supporting sill 35 wedge-shaped refractories 34 are laid in such relationship as to form a sort of pilaster extending inwardly from the general vertical plane of the wall. These are disposed in superimposed courses and are anchored at their outer ends, as in the manner described in the patent above referred to, to the arcuate flanges 36 of horizontal anchor castings 36. These anchor castings are sebolts 37 to the outer frame members or .to the sheating plates 38 secured. thereto,

' T-shaped slots receiving marginal portions A-continuous sheathing 5 at. 47 in and extending beyond the 'ly while possessing a desirable freedom for shifting laterally. Depending on circumstances such as the spacing of the burner openings and their distance from the side walls, the width of these pilasters may be increased where desired by the interposition of parallel-sided refractories 32 between the wedge-shapedrefractories 34, said parallelsided refractories being set on edge and their of the anchor castings 36. By this pilaster arrangement, the sides of the burner openings are given a curved contour, so that the burner opening flares toward the furnace chamber and the wall extends for a considerable distance beyond the discharge ends of the burners. 4

Likewise, an inwardly flaring wall portion is provided at the bottom of the burner openings by the wedge-shaped refractories 39. The lowermost course of these refractories is laid on an expansion cushion 40 of compressible refractory material, which cushion rests on the supporting sill structure 35, and superimposed courses of similar wedge-shaped refractories are laid on them in such fashion as to form. an arch-like structure curving downwardly toward the furnace chamber burners. The refractories of this structure are maintained in place by their own weight and are connected in pairs by retaining members 41, the uppermost courseabutting a ledge 43 which is built up of ordinary fire-brick and formed with air passages 43 at intervals in its lower part. Where burner openings are relatively close'together one above another, as in the example illustrated, the intervening wall portion may be formed of refractories 44 having bevelled inner corner portions and slotted outer end. portions. These are arranged in a horizontally running course supported on the lower burner casing and projecting for a substantial distance inwardly beyond the ends of the burner. They are maintained in position by anchorage on an anchor bar 45, the flanged margin of which is engagedin their slots, said bars being retained by bolts 46 against shifting inwardly. The tops of the pilasters, Where they jut inwardly from the superjacent wall portions,

may be capped off With plastically appliec refractory material in suitable contour as indicated at c in g Wallis provided by the plates 38 and the frame members 11, so that an air chamber is formed between the refractory This air chamber may be subdivided into horizontal lanes by partition bricks 42 supported on the hangers 17. The air chamberprovided at suitable locations with air inis lets through the sheathing wall, as indicated .units retained thereby,

wall and such sheathing wall. b

Fig. 2, which inlets prefer a'bly are with pneumatic fuel feeding.

damper controlled. In the construction illustrated, air inlets are also afforded by thepassages 43 at the bottom of'the wall, which passages are supplied with air by way of passages 48* of the hollow wall of the ash hopper 48. An outlet duct 49 also has communication with the air chamber or air lanes of the Wall at points spaced from the various air inlets. through the duct 49, external air will be caused to enter through the inlets 47 and the passages 43 and to flow through the air chamber in contact with-the outer faces of the wall refractories and the exposed portions of the hangers and anchoring members,

Suitable suction being maintained and also in contact with the surfaces of the burner casings exposed in the air chamber. Thus an effective cooling of the wall refractories and their supporting andanchoring embers is maintained, and dead air is not permitted to remain in the bulging portions of the wall about the burner openings. As a consequence, therefractories in the bulging portions of the wall, whichbecause of their position in the furnace chamber might be subjected to heating to an extent disproportionate with the heating of refractories in other portions of the wall, may be kept at a temperature sufficiently low to. avoid their rapid destruction by slagging and other disintegrating influences, so that their term of serviceability will be commensurate with that of the other wall refractories generally. The bulging wall portions about the burners, consequently, exercise three important functions, viz: they permit the burners being inset into the horizontal area .of the wall and afford them the necessary shading and protection from the heat of the furnace champarticularly from the flame of other without necessitating wall they keep'slag and ber and discharging burners, any thickening of the encrustations away from the burners; and,

being themselves subjected to cooling influence, they are effective to limit the heating of the burner portions with which they are associated.

The construction vantages in combining flexibility of various portions of the wall with stability of the strltcture as a whole. For example, the various supporting and anchoring members of the wall, such as'the hangers 20 and 28 and the members 36, 46, etc. have a desirable freedom for movement, so that the assembled as well as the individual refractories, may adjust themselves in the structure to accommodate expansion, ut at the same time all are definitely anchored in such fashion that they cannot be displaced out of the desired relationship with associated portions, either by their own weight or by thermal expansion or by pulsations or vibrations such as frequently occur The sectional possesses particular adthe fuel jets and minimizes erosive action on the refractories.

The construction makes possible the desired shading of the burners without increase in t 1e thickness of the refractory wall at those 10 ations. This is important from the standpo'nt of controlling transmission of heat through the refractory wall and also from the standpoint of cost, the latter from the fact that the various shapes of refractories may be of uniformsize throughout the structure, and by suitable cooling control the normal wear of the refractories may be equalized over the wall.

What we claim is:

1. In a furnace, an upright furnace cham ber wall formed of refractories arranged in superposed horizontally running courses, said wall being provided with a burner opening therethrough, refractories above and adjacent the burner opening being offset 1nwardly with respect to the general inner surface plane of the wall to form an inwardly protruding wall portion about the burner opening.

2. In a furnace, a furnace chamber Wall formed of refractories and of approximately uniform thickness, said 'wall having a portion bowed inwardly so as to protrude into the furnace chamber beyond the general plane of the inner wall surface, and the wall afi'ording a burner opening bounded by said protruding portion.

3. In a furnace, an upright furnace cham ber wall formed of refractories and of substantially uniform thickness, said wall affording a-burner opening and having portions adjacent said opening bowed inwardly beyond the general plane of the inner wall surface and forming inwardly flaring walls for the burner opening.

4. In a furnace, an upright furnace chamber wall formed of refractories and afl'ording a burner opening and having pilasters at the sides of the burner opening and a protruding portion above the burner opening, said pilasters and protruding portion projecting inwardly in the furnace chamber beyond the genfiral inner surface plane of the wall and eac posed refractories. a I 5. In a furnace,.in combination, an upright furnace chamber wall, a fuel-discharging-device extending. through the wall, sald wall having portions adjacent the, fuel-discharging device bowed inwardly of the furnace chamber beyond the'fuel-discharging being formed of a plurality of superdeviceand the general inner surface plane of v the wall.

6. In a furnace, in combination, a hollow.

upright furnace chamber wall affording a burner opening therethrough and including a refractory lining, said refractory lining approximately uniform thickness and being bowed inwardly adjacent the burner opening, and the air chamber provided with iulet and outlet arranged to direct air circulation in the air chamber across the outer surfaces of said bowedrefractory wall portion.

8. In a furnace, in combination, refractories arranged to form an upright furnace chamber wall having portions projecting into the furnace chamber beyond the general surface plane of the wall to form walls of a burner opening, a frame arranged externally of said wall, and anchoring members connecting refractories in said inwardly projecting portions to said frame to holdsaid refractories' against displacement inwardly from the wall.

9. In a furnace, a furnace chamber wall built up of refractories and of substantially uniform thickness, said wall afiording a burner opening and having portions formed of refractories anchored in superposed relationship and protruding inwardly of the furnace chamber adjacent said opening, and means for directing cooling air across outer surfacesof the refractories in said protrud mg portions.

10. A furnace structure comprising a refractor wallportion having its inner sur-v face su stantially in a common plane, a fueldischarging device extending transversely of said wall portion to dischargefuel into the furnace chamber, hangers supported'adjacent said fuel-discharging device, and refractories supported on said hangers in superposed horizontally running courses to form a wall part conjoining said wall portion and rotruding inwardly of the furnace chamber eyond the general inner surface plane of the wall portion and adjacent the fuel-discharging device.

11. A furnace structure as specified in claim 10 and wherein said wall part is of approximately the same thickness as said wall portion. r

12. A furnace structure as specified in claim 10 and wherein said hangers and refractories are movable relative to the wall portion and fuel-discharging device to accommodate thermal expansion. 13. A furnace structure as specified in claim 10 and wherein the inner surface of said wall part flares from the fuel-discharging device toward the furnace chamber.

'14. A furnace structure as specified in claim 10 and wherein said inwardly protruding wall device.

15. Furnace structure comprising, in combination, a wall supporting frame, refractory Wall sections supported on the frame with their inner faces approximately in a common general wall plane of the furnace chamber, supports carried on the frame, and refractories supported by and anchored to said supports and off-set inwardly in the furnace chamber from said general plane to form an inwardly protruding wall portion, said inwardly protruding wall portion conjoining the wall sections to maintain continuity of the wall.

16. In a furnace, a refractory furnace chamber wall affording a burner opening, portions of the wall adjacent the burner opening being bowed inwardly into the furnace chamber, said inwardly bowed portions being of approximately uniform thickness, and a burner set into the.wall within the burner opening in position to discharge into the furnace chamber.

172' In a furnace, an upright refractory wall affording a burner opening therethrough, said wall having portionsbowed inwardly into the furnace chamber adjacent the burner opening, said inwardly bowed portions being made up of a plurality of refractories each having but a single face exposed within the furnace chamber, and means engaging outer portions of said refractories to anchor them in the structure.

In testimony whereof we have hereunto subscribed our names.

LOUIS H. HOSBEIN. OTTO WELCOME.

part is in overhanging relationship to the discharge path of the fuel-discharging

Images