US1986666A - Slag-tapping furnace having a floor with inclined edges - Google Patents

Description

' 1935- R. M. HARDGROVE 1,986,666

SLAG TAPPING FURNACE HAVING A FLOOR WITH INCLINED EDGES Original Filed Aug. 15, i950 2 Sheets-Sheet 1.

Jan. 1, 1935. I R. M. HARDGROVE 1,986,666

SLAG TAPPIN G FURNACE HAVING A FLOOR WITH INCLINED EDGES Original Filed Aug. 13, 1930 2 Sheets-Sheet 2 ENTOR ATTORNEY;

Patented 1, 1935 UNITED STATES sue-ammo FURNACE HAVING A FLoo wrrn mcnmsn spurs Ralph Hardgrove, Westfleld, N. 1., ass ignor to Fuller Lehigh Company, Fullerton, Pa, a corporatlon of Delaware Application August 13, 1930, Serial No. 475,011-

.. Renewed November 19, 1934.

8 Claims. (Cl. Rib-235) and is drawn off at intervals.

In furnaces of this character that have been used heretofore, troubles have arisen when the slag is permitted to freeze and subsequently expand when again heated, with a result that the furnace walls are pushed outwardly. This danger is sometimes caused because when the slag cools and freezes, cracks form in it which subsequently receive more molten slag that hardens therein, thus causing the slag slab to grow and expand .by successive heating and cooling.

By the present invention, the danger of the walls of the furnace being forced outwardly is obviated by forming the floor in such a manner that the slag that collects upon the floor has thin edges that would be crushed without pushing the furnace walls out. The major portion of the furnace floor is made substantially level but the edges thereof slope upwardly or edges of the furnace floor merge into the lower portions of walls of the furnace along inclined surfaces. In this way, inclined water cooled surfaces are provided upon which the edges of the slab of slag that may form in the furnace can slide.

The invention will be understood from the description in connection with the accompanying drawings, in which Fig. 1 is a vertical section through an illustrative embodiment of the invention; Fig. 2 is a section along the line 2-2 of Fig. 3, and Fig. 3 is asection along the line 3-'-3 of Fig. 1.

In the drawings, reference character 1 indicates a furnace that is provided with one or more fuel burners 2 through one wall thereof.

- The front and rear walls of the furnace are provided with upwardly extending water tubes 3 and the side walls of the furnace are provided with upwardly extending water tubes 4. The lower ends of the tubes 3 and 4extendinto horizontally disposed lower headers 6 and the upper ends of these tubes extend outwardly and into horizontally disposed headers 7. Recirculating tubes 8 are provided on the outside of the furnace between the headers 6 and 7. Tubes 9 extend from the upper headers 'l to the steam space of the water tube boiler that is located above the furnace 1, only the lowest row of tubes 10 of this boiler being indicated on Fig. .1 of the drawings.

' The lower headers 6 may be connected to the water space of the boiler by pipe connections in the usual manner.

A slag tap opening 11 is provided througha. wall of the furnace at a slightelevation above the floor of the furnace. The major portion of the floor of the furnace is made up of refractory material 12 supported on cross supports 13.

The lower ends of the front and rear wall tubes" 3 and the lower ends of the water tubes 4 in thewall opposite the slag tap opening 11 are bent inwardly at their lower ends, as indicated at 14, to provide sloping surfaces adjacent three of the edges of the floor of the furnace. The fourth wall is substantially vertical where it contacts with the floor. (See Fig. 2.) i

It will thus be seen that the lower ends: of the water tubes 14 with the refractory covering thereon, provide inclined surfaces along the" edges of the floor. As will be seen by referring to Figure 1, rigid supports are provided at the ends of the water tube sections 14, and resilient supports, here shown as spring supports, are provided intermediate the ends of these tube sections.

Short auxiliary headers 6' are provided at two of the corners of the furnace. A few of the tubes at these corners are bent first inwardly and then outwardly as shown in Fig. 3 at 4' and are connected to these headers in such a manner as to prevent tubes in adjacent walls from overlapping or interferring with each other, as indicated in Figsl 2 and 3 of the drawings. Tubes near these comers are bent successively to greater extents to provide satisfactory cooling means over the entire area of the sloping corner portions of the furnace. The headers 6' are connected to the water circulation system of the boiler in a manner similar to the connection of the headers 6.

During the operation of the furnace, the molten slag from the products of combustion falls to the bottom of the furnace and forms a layer, as indicated at 15. Molten slag can be tapped out through the opening 11 when desired. Since the inclined surfaces are water cooled, slag may harden on these surfaces with thin edges, so that heating'and cooling of the slag which causes expansion thereof will not force the furnace walls outwardly as the slag can slide up the inclined surfaces along the edges and the thin edges of the slag will be crushed without displacing the furnace walls.

I claim:

1. In a furnace for burning a slag-forming fuel, a furnace bottom constructed to sustain a pool of molten slag, said furnace bottom comprising a central horizontally extending portion comprehending a major portion of said bottom and edge tion and sloping upwardly from said central portion, said edge portions being subjected to a greater degree of cooling than said central por-.

tion.

2. In a furnace for burning a slag-forming fuel, a furnace bottom' constructed to sustain a pool of molten slag, said furnace bottom comprising a central horizontally extending portion comprehending a major portion of said bottom and edge portions on at least three sides of the central portion and sloping upwardly from said central portion, and cooling tubes in said edge portions, said edge portions being subjected to a greater degree jected to a greater degree of cooling than said.

central portion. a

4. In a furnace for burning a slag-forming fuel, vertically extending j side walls having cooling tubes, a furnace bottom comprising a central,

horizontally extending portion comprehending a major portion of said bottom and inclined mar gin portions on at least three sides of the central portion, said horizontal portion extending into contact with a vertical portion of one of said portions on at least three sides of the central per,

side walls and a slag tap opening in said side wall. 5. In a furnace for burning a slag-forming fuel,

upwardly extending side walls having cooling tubes, a furnace bottom comprising a central horizontally extending portion comprehending a major portion of said bottom, and inclined margin portions on at least three sides of the central portion, the lower ends of said side wall tubes being bent and extended in heat transfer relationship to said margin portion.

6. In a furnace for burning a slag forming fuel, upwardly extending side walls comprising spaced water tubes and closure elements for the spaces, and a furnace bottom comprising a central horizontally extending portion constructed to sustain a pool of molten slag and margin portions on at least three sides of the central portion and inclined to said central portion.

7. In a furnace for burning a slag forming fuel, upwardly extending side walls comprising spaced water tubes and closure elements for the spaces, and a furnace bottom comprising a central horizontally extending portion constructed to sustain a pool of molten slag and margin portions on at least three sides of the central portion and inclined to said central portion and extending above the levelsof said pool.

8. In a furnace for burning a'slag forming fuel, upwardly extending side walls comprising spaced water tubes and closure elements for the spaces,

and a furnace bottom comprising a central horizontally extending portion constructed to sustain a pool of molten slag and margin portions on at least two adjacent sides of the central portion and inclined to said central portion.

.RALPH M. HARDGROVE.

Images