US1937940A - Bottom for boiler furnaces - Google Patents

Description

2 Sheets-Sheet 1 A. J. BOYNTON Filed May 3, 1950 BOTTOM FOR BOILER FURNACES Dec. 5, 1933.

lI l 1933- A. J. BOYNTON BOTTOM FOR BOILER FURNACES Filed May 3, 1930 2 Sheets-Sheet 2 [1| .11L iLi|.L

Patented Dec. 5, 1933 1,937,940 BOTTQM FOR BOILER FURNACES Arthur J. Boynton, Winnetka, Il1., assignor to H. A. Brassert & Companmchicago, 111., a corporation of Illinois Application May 3, 1930. Serial No. 449,386

9 Claims. (Cl. 110-1) This invention relates to improvements in hottoms for boiler furnaces particularly adapted though not necessarily limited for use, in connection with powdered coal, and one of the oh- 5 jects of the invention is to provide an improved form or construction of bottom and to provide an improved combination and arrangement of certain materialswhereby the desired and new and improved results will be obtained.

Heretofcre, the use of powdered coal has resulted in temperatures suiiiciently high to flux the ash and form a slag therefrom, and various forms of furnace bottoms have been devised, some of which contemplate freezing the liquid slag in a hopper bottom either with or without use of a water screen.

The present invention, however, contemplates the use of an improved substantially flat bottom which is used to collect and retain liquid slag and from which it is drained at intervals through a suitable tapping hole.

In such a construction the boiler wall is usually composed of water cooled brick terminating at the lower end in a pipe of largediameter, the piping forming a part of the boiler circue lation. v

l-leretofore it has been customary to construct or build the boiler bottom tight against the walls of the furnace which in some instances have been suspended from above and in others have been carried from supports below, with the resuit that expansion of the boiler bottom. has caused considerable trouble, as upon the first firing of the boiler an initial expansion takes place which results in a pressure being exerted against the walls.

Upon cooling, the boiler does not contract back to its original position and re-expandedto the same extent or dimensions as those formerly taken after heating, but shows an inclination to progressive growth. This inclinationis due to the failure of the bottom material to go completely back into place or normal position. On the contrary hair line cracks are formed which resultin a sufficient dislocation of adja- [cent parts to. prevent the bottom from obtaining its former cold or normal size.

When the bottom is again heated the effect is toproduce a growth greater than the original growth, with the result that a successive enlargement of the bottom occurs which deforms the boiler walls and tends to force them apart at; the corners. r

In additionto this trouble, difiiculty has been experienced with the materials usually employed for the bottom, and such constructions have formerly included everything from an'acid micaschist to basic dolomite. The ash coal when liquid, will flux such materials and destroy the bottom. Various means have been attempted of which has been the use of coke braize which does not only inert to fiuxing action, but has 7 so little structural strength that the outer strains on the boiler construction are minimized. Such material, however, is not suitable for good or permanent construction and it requires to be backed up by a solid base of masonry which has a tendency to expand against the boiler wall.

to overcome this difiiculty, the most successful It is one of the objects of the presentinvention to overcome these difficulties and objections and to provide in a furnace of this character a bottom which is entirely separate from the walls thereof and of such dimensions that it may he raised or lowered if desired independently with respect to and without interfering with the construction of the boiler proper.

A further object is to provide in a construction of this character a layer of suitable material immediately inside of the bottom jacket which is capable of expanding and contracting under pressure, and to arrange immediately inside of such material a sectional water cooled casting extending preferably from the topto thebottom of the bottom proper and supported upon a bottom plate.

A further object is to provide in a structure of this character an inclined wall immediately below the vertical boiler wall and to arrange beneath said inclined wall an inclined water cooled the bottom and the walls to prevent theescape of gas and improved means for supplying a cooling liquid to the cooling areas and from them into the water seal from which the liquid will subsequently escape and flow away.

To the attainment of these ends and the accomplishment of other new and useful objects as will appear, the invention consists in the features of novelty in substantially the construction, combination and arrangement of the several parts hereinafter more fully described and claimed and shown in the accompanying drawings 111110- trating this invention, and in which Figure 1 is an enlarged detail sectional view of a portion of the bottom and the adjacent furnace wall, constructed in accordance with the principles of this invention.

Figure 2 is a detail sectional view taken on line 22, Figure 3.

Figure 3 is a detail sectional view taken on line 3-3, Figure 2.

Referring more particularly to the drawings,

the numeral 10 designates generally the shell of a boiler which is lined with a standard lining or blocks 11, and arranged at the bottom of the walls 10 is a header 12 to which is connected pipes 13 forming a part of the circulating system.

The bottom of the boiler consists of a bottom or supporting plate 13 which is supported by suitable supports 14.

Around the outside of the bottom proper a casting or shell 15 which is supported by and secured to the bottom plate 13 by means of suitable fastening devices 16.

Arranged within the casting 15 is a sectional water cooled wall 17 of a height substantially equal to the height of the casting 15 and is spaced from the casing so that a cushioning element 18 constructed of any suitable resiliently yielding material, such as rubber or the like, may be arranged therebetween'and will be protected by the water cooled wall 17.

The water cooled wall encompasses the hearth proper and the hearth itself is preferably composed of a layer of insulating material 19 such as brick or the like and is arranged within the Water cooled wall 17 and rests upon the bottom 13 superposed upon the insulating material 19 is a layer of refractory material 20, preferably first-class fire clay. brick and the insulating ma terial 19 and the layer 20 may be of any desired thicknesses.

superposed upon the refractory material 20 is a layer 21 preferably carbon blocks and the height of the hearth formed by these superposed layers is equal to the height of the water cooled wall 17 so that the top of the hearth is flush with the top of the wall 17.

Supported by the casting 15 and encompassing the bottom, preferably resting upon the top of the wall 17 is an inclined water cooled wall 22, preferably formed of a casting which is secured in position in any suitable manner preferably by being bolted to the casting 15 by means of suitable bolts or fastening devices 23 This wall or surface 22 is of any desired height and is spaced below the furnace wall. The interior of the inclined wall 22 has communication with the interior of the water cooled wall 17 in any suitable manner preferably by means of a pipe or passage 23 which is connected by means of another pipe 24 with a passage 25 having communication with the interior 26 of the wall 22, and the wall 22 is provided'with an outlet passage 2'7 which discharges into a receptacle 28 supported in any suitable manner, and from which'receptacle 28 leads an overflow pipe 29.

Cooling liquid is supplied through a pipe 30 from any suitable source and is delivered into the interior 31 of the water cooled wall 1'? and flows therefrom through the pipes 23-24 into the passage 25, and into the space 26 in the wall 22 to be discharged therefrom and through the pipe 27 to be discharged into the receptacle 28.

This receptacle 28 forms a portion of the liquid seal to prevent escape of gas between the bottom and the wall of the furnace.

To that end there is provided a plate or depending member 32 which is secured preferably to the furnace wall in any suitable manner such as by means of a bracket 33.

It will therefore be manifest that the cooling liquid flows successively through the wall 17, wall 22 and into the liquid seal 28.

Supported above the inclined wall 22 is another inclined wall 34 which is arranged below the wall 11 of the furnace and terminates short of and is spaced above the wall 22. The wall 34 is formed in any suitable manner preferably from refractory material and this wall 34 is cooled in any suitable manner such as through the medium of cooling pipes 35.

The inclined walls are preferably employed when carbon is used as a bottom on account of the fact that any wall construction of carbon raises the latter above the slag line and would result in probable burning and destruction of the same.

The slag from the furnace is discharged through the usual outlet 36.

A lower header 37 may also be employed in the I boiler construction.

With this improved construction it will be manifest that the bottom will be free and detached from the walls of the furnace and at the same time the space between the bottom and H the walls will be sealed against the escape of gases.

Furthermore, by this arrangement the bottom of the furnace may be raised or lowered according to the construction of the furnace and as desired.

While the preferred form of the invention has been herein shown and described, it is to be understood that various changes may be made in the details of construction and in the combination and arrangement of the several parts, within the scope of the claims, without departing from the spirit of this invention.

What is claimed as new is:-

1. In a furnace of the character described, a bottom independent of and disconnected from the furnace walls, whereby said bottom will be free to expand and contract independently of the furnace walls and the latter will be relieved of any strain caused by such contraction and expansion of the bottom, means forming a seal between the bottom and the furnace walls, said bottom comprising a shell, a hearth, means forming a cooling liquid circulation space about the hearth, means forming a cushion between said cooling space forming means and said shell, l35 and means for circulating cooling liquid through said space.

2. In a furnace of the character described a bottom separate and detached from the furnace wall, said bottom including a supporting plate, a hearth supported thereby, said hearth comprising a layer of insulating material resting upon the said plate, a layer of refractory material superposed upon said insulating material, a layer of carbon blocks supported upon said refractory material, and a continuous upright liquid cooled wall extending about said hearth.

3. In a furnace of the character described a bottom separate and detached from the furnace walls, a liquid seal between said bottom and the said Walls, said bottom comprising a hearth proper and a continuous upright liquidcooled wall extending about the hearth said hearth comprising a bottom, a layer of insulating material thereupon, a layer of carbon blocks at the top of the hearth and a layer of refractory material intermediate said insulating material and said carbon blocks.

4. In a furnace of the character described, a bottom disposed within, disconnected from, and spaced with respect to the walls of the furnace whereby the bottom will be adapted for free expansion and contraction with respect to the Y furnace walls, said bottom comprising a hearth,

means forming a cooling liquid circulation space about the hearth, an encompassing shell, means for circulating a cooling liquid through said space, a cushion between said shell and said coolingspace forming means, and means forming a liquid seal for the space between the said bottom and the furnace walls.

5. In a furnace of the character described, a bottom disposed Within, disconnected from, and spaced with respect to the walls of the furnace whereby the bottom will be adapted for free expansion and contraction with respect to the furnace walls, said bottom comprising a hearth,

means forming a cooling liquid circulation space about the hearth and an encompassing shell, all separate from the furnace walls, means for one eulating a cooling liquid through said space, said shell being spaced from said cooling liquid space forming means, a cushion between said shell and said cooling space forming means, means forming a liquid seal for the space between the said bottom and the furnace walls, an inclined Wall disposed above and about the periphery of said bottom, the said inclined wall resting upon the said shell and cooling liquid space forming means and extending over and forming a protection for said cushion, and means for circulating a cooling fluid through the body of said inclined wall. I

6. In a furnace of the character described, a bottom disposed within, disconnected from, and spaced with respect to the walls of the furnace whereby the bottom will be adapted for free expansion and contraction with respect to the furnace walls, said bottom comprising a hearth, means forming a cooling liquid circulation space about the hearth and an encompassing shell, means for circulating a cooling liquid through said space, said shell being spaced from said cooling liquid space forming means, a cushion between said shell and said cooling space forming means, means forming a liquid seal for the space between the said bottom and the furnace walls, an inclined wall disposed above and supported by said shell, and an additional inclined wall supported by the furnace wall, said additional wall being disposed above and projecting over the upper edge of the first recited inclined wall.

7. In a furnace of the character described, a

bottom disposed within, disconnected from, and

whereby the bottom will be adapted for free expansion and contraction with respect to the furnace walls, said bottom comprising a hearth means forming a cooling liquid circulation space about the hearth, and an encompassing shell, all separate from the furnace walls, means for circulating a cooling liquid through said space, said shell being spaced from said cooling liquid space forming means, a cushion between said shell and said cooling space forming means, means forming a liquid seal for the space between the said bottom and the furnace walls, an inclined wall disposed above and supported by said shell, an additional inclined wall supported by the furnace walls, said additional wall being disposed above and projecting over the upper edge of the first recited inclined wall, and means furnace walls, said bottom comprising a hearth,

means forming a cooling liquid circulation space about the hearth, and a shell encompassing the bottom, all separate from the furnace walls, means for circulating a cooling liquid through said space, said shell being spaced from said cooling liquid space, forming means, a cushion between said shell and said cooling space forming means, means forming a liquid seal for the space between the said bottom and the furnace walls, an inclined wall disposed above and about the periphery of said bottom, the said inclined wall resting upon the said shell and cooling liquid space forming means and extending over and forming a protection for said cushion, and

means for circulating a cooling fluid through the ing successively through said cooling space, inclined wall, and into the water seal.

9. In a furnace of the character described, a bottom disposed within, disconnected from and spaced with respect to the walls of the furnace whereby the bottom will be adapted for free expansion and contraction with respect to the furnace walls, said bottom comprising a hearth, means forming a cooling liquid circulation space about the hearth and separate from the furnace walls, an encompassing shell separate from the furnace walls and spaced from said cooling liquid space formingmeans, a cushion between said shell and said cooling liquid space forming means, means for circulating .a cooling liquid through said cooling space, means forming a liquid seal for the space between the said bottom and the furnace walls, and an inclined wall disposed above and about the periphery of said bottom, the said inclined wall resting upon the said shell and cooling liquid space forming means and extending over and forming a protectionfor said cushion.

ARTHUR J. BOYNTON.

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