US1693400A - Furnace wall and brick therefor - Google Patents

Description

Patented Nov. 27, 1928.

UNITEDl STATES.

OSCAR NYGAARD, 0F SAUGUS, MASSACIHUSETTS, ASSIGNOR`TO BERNITZ FI'J'B'NACE 1,693,400 PATENT oFFlcls.`

APPLIANCE COMPANY, 0F BOSTON, MASSACHUSETTS, A CORPORATION 0F MAS-SA- CHUSETTS.

FUBNACE WALL AND BRICK THEBEFOR.

Application led J'uly 16, 1925. Serial no. 44,030.

the furnace wall is chipped off with it. As

this action is repeated during the running of the furnace the wall is rapidly worn away until it reaches the point where it must be renewed. It has been found that this action can be obviated and the life of the furnace wall very materially increased by admitting air to the .fuel bed throughthe part of the furnace wall'which is liable to fuse. Such a construction is shown in Patent No. 1,393,(3O6,v

granted October 11, 1921. U

The present invention is especially, although not exclusively, concerned with the general type of furnace wall shown in the patent just mentioned, and it aims to improve vthis construction with a view to further increasing its effectiveness. It is also an object of the invention to devise a brick which can be advantageously used in furnace constructions wherever it is desired to cool the walls or any area of a furnace by air, as'for instance, in pulverized fuel furnaces where it is found desirable to admit air through the furnace walls or portions thereof.

In the drawings,

Figure 1 is a vertical cross-sectional v1ew through a portion of a furnace having walls constructed in accordance with this invention;

Fig. 2 is a horizontal, cross-sectional view on the line 2-2, Fig. 1; j A

Fig. 3 shows a portion ofthe structure illustrated in Fig. 2 but on a larger scale; and

Figs. 4 and 5 are perspective views of bricks embodying features of the present invention.

The furnace shown in Fig. 1 includes front,

I bridge and side walls and'is equipped with an underfeed Stoker including a hopper 2, ram 3, and grates 4, the Stoker parts being` constructed and arranged in the usual manner.

Referring to Fig. 2 it will be seen that the side wall of the furnace includes a rear section 5 and a front section or facing 6, an air space 7 being provided between these sections. Usually the rear section 5 is made of ordinary brick, while the front section or facing is made of flre brick, or other refrac-V tory material and in the construction shown the front facing is vertically corrugated.

- The portion of the side wall shown in Fi 1 andv 2 is made up chiefly of bricks of t e character shown on a larger scale at B in Figs. 3 and 4. Referring to the latter figures it will be seen that the central portion of the brick B is bulged forwardly, as shown at 8,

or, in other words, it has a vertical rib which forms the central portion of the brick. The back of the brick is recessed or gro'oved opposite therib or bulged portion, as shown at 9, so that in horizontal cross""section the brick is of approximately V-shape with extended wings. Air holes 1 0 and 12 extend through the bulged or ribv portion 8 of the brick from the recess 9 to the front face thereof, these holes preferably bein o po# site'ly directed, and they open on to te ont face substantially at the base' of the bulge or rib 8.

, Air under pressure is forced into the space 7 between the front and rear sections of the wall and flows through the holeslO and '12 into the fuel `bed or into the interior of the furnace immediately adjacent to the fuel bed. The holes 10 and 12 are directed laterally so that they discharge air along the front surface of the facin 6, this air flowin across the surface of ad]acent",bricks and bem diffused by its contact with the corrugate surface of the facing. Each brick, therefore, is cooled partly b the Jair which Hows through it and partly ythe air which is directed across its face from the holes in neighboring bricks. This arrangement thus tends to maintain a relatively cool air curtain immediately in front of the facing 6 and thus keeps th1s facing suiciently cool to prevent slag and clinker from stickin to it. p It will be seen from an inspection o Figs. 1 and 4 that the air holes in eachbrick are staggered or oset vertically with reference to' each other so that 'a more uniform distribution of the air is produced.

The air which is discharged into the fire box through the wall is utilized in maintaining combustion, but only a relatively small part of the air required for combustion is discharged into the furnace in this manner, the greater part of the air for combustion -above described are laid in courses, as shown inFig. 1, with the'V-shaped sect-ions of superposed bricks in Vertical alinement so that they y form a vertically corrugated face.A The upper corners vof each brick are notched, as4 shown at 16, Fig. 4, to receive the brlc'ks C Which bond the facing 6 to the rear section 5 of the Wall.

It usually is preferable to build only that n portion of the Wall'which is subjected to highest temperature of the bricks shown in Fig. 4.

' Adjacent portions `of the facing which are not subjected to excessive temperature may advantageously bebuilt of brick of the same General construction as that shown in Fig. 4 but Without the air holes.- This is true, for example, in the upper portion of the bridge Wall Where the bricks 18 are like those shown in Fig. 4 except that they are imperforate. Here the corrugated construction of the brick is of advantage in producing a Wall which is stronger mechanically and is particularly efl'ectivein resisting the stresses set up in the .wall by construction and expansion. The

bridge wall, like that above described, has a' space betweenv the front and rear sections through which air is circulated to keep the* temperature of the facing within reasonable limits. At the bottom of this wall I prefer to use bricks 0f the construction shown in Fig. 4 and to blow air through them, as above stated, in connection with the description of the side wall. v

It is usually necessary to ventilate or air cool only a small part of the front wall, as shown in Fig. 1. Where the Wall rests on a girder, as does a part of the front wall, or Where it is desired to change the surface ofthe facing from a corrugated to a plain contour, a brick of the type shown at 20 in Fig. 5 may conveniently be used. The upper part of thisA brick is like the brick B in' horizontal cross section, but the lower part is of approximately rectangular form in horizontal outline with an inclined face` 21 leading 'downwardly from the notched corners 16-16. T e rear groove or recess 9 preferably lextends the entire height of the brick, although, if desired, this recess can'be stopped at any desired point.4 Such a brick has a fiat bottom face to rest on a girder, brick wall, or the like,l and an upper face'which iits the corrugated bricks of the type shown in Fig. 4.

Bricks of this character are shown at 20 in Figs. l and 2, and they may or may not be provided with air holes 10 and 12, as desired.

The bricks provided by this invention may be made of carborundum, lire clay, or any suitable refractory material. A furnace Wall in which these bricks are used has the advantage of being unusually strong mechanically while at the same time permitting the airlcooling which is so desirable for the reasons above described. Furthermore, the air is -so directed that the maximum effectiveness of' a given volume of air is realized in reducingthe' temperature of the Wall facing.

Whilev I havehereinshown and described the best embodiment of my invention that I have so far devised, it iscontemplated that the invention may be embodied in other forms Without departing from the spirit orl scope thereof. Bricks embodying this invention may also be used in other parts of the furnace, as for eXample,' in the construction of a cooling zone in the lower lpart of the furnace. Also, While I have chosen to illustrate my new form of brick as it may be used inv an underfeedstoker furnace to prevent clinkering in the side walls at the fuel bed area, it should be understood that the brick is not limited to use in furnaces of this character or for the particular purpose of avoiding elinkering. The brick construction 'provided by this invention is designed for use in any furnace or heater Where it is desired to cool the walls, or area of any sort, by air.

Having thus described my invention, What I desire to claim as new is:

1. A furnace Wall comprising a rear section and a vertically corrugated front section with an airspace between said sections, and laterall directed holes leadino' from said air space through said front section to the front surface of the Wall. e

2. A furnace Wall including a rear section, and a front section of bricks laid in courses,

the bricks in superposed courses having a proximately V-shaped sections vertical y alined with each other to form a corrugated face on said front section, said bricks having notched corners, and tie bricks located in said corners and connecting said front and rear sections together.

3. y A furnace wall includin a rear section and-a front section of bricks aid in courses, the bricks in superposed' courses havinv a proximately V- haped sections vertlcal y alined with each other to form a corrugated face on said front section, said bricks having notched corners, tie bricks located in said corners and connecting said front and rear sectionstogether, and laterally directed air holes leading through said front section and y projecting forwardly from the` said body being recessed o posite said rib, and oppositely directed air olesleadin from said recess throu h the wall of the brick and -opening on to t e .face thereof at opposite 1li- 7. A furnace wall comprising a rear section and a front section of bricks laid in courses,

said bricks in adjacent courses having approximately V-shaped sections alined with each other and projecting forward to form a corrugated face' on said front section, said V-sliaped sections having air holes therethrough.

8.*A brick for furnace wall construction comprising a body portion of refractory material havingan outwardly bulged front and a rear face recessed opposite said bulged front, and a straight laterallydirected air hole extending through s aid brick from said recess to the .base of said bulged portion.

9. A brick for furnace wall construction from the front face thereof, eac

comprising a body of non-metallic refractory material having'a recess in the rearward part thereof and a rejecting frontv face portion, and an air ho e leading from said recess to a laterally facin portion of the front face of the brick, said ole being directed laterally of the brick, whereby it will discharge air across the face of another brick located immediately beside it.

10. A brick for furnacey wall construction comprising a body of non-metallic refractory material having a ridge projecting from the front'fac'e thereof and a recess in the rearward part thereof, and an air hole leading from said recess at an angle to it and opening to the front face of the brick approximately at the base of said. ridge said hole being d1- rected laterally with reference tothe brick.

11.' A furnace wall comprising a rear section and a front section with an air space vbetween `said sections, said front section including bricks each having a ridge rojctin o sal bricks also having an air hole extending through it and-opening to the front face thereof at one side of sa1d ridge, said air hole extending at an inclinationservin to direct air against the inclined surface o the ridge portion-of a next adjacent brick.n

OSCAR NRYGAARD.

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