US2554384A - Furnace wall construction for gas or oil and solid fuel - Google Patents

Description

May 22, 1951 FURNACE WALL CONSTRUCTION FOR GAS OR OIL AND SOLID FUEL Fig.1

- G. A. REHM 2,554;384

Filed Oct. 23, 1947 gmc/wm 60.5741/ A /PEHM Patented May 22, 1951 FURNACE WALL CONSTRUCTION FOR GAS R OIL AND SOLID FUEL Gustav A. Rehm, Worcester, Mass., assignor to Riley Stoker Corporation, Worcester, Mass., a corporation of Massachusetts Application October 23, 1947, Serial No. 781,689

6 Claims. 1

This invention relates to furnaces, and more particularly to furnaces for burning a uent fuel such as gas or oil, and a solid fuel such as coal. Furnaces of this type have the advantage that either the fiuent fuel or the solid fuel may be burned, as may be most economical in view of the prevailing market conditions.

One prior furnace construction for burning solid fuel comprises a furnace combustion chamber having a grate therein, and a spreader stoker for throwing fuel onto the grate through an opening in the front wall of the combustion chamber. The wall above the opening is usually supported by a horizontal beam. In order to permit ring such a furnace with fluent fuel, it has been proposed to provide a burner opening for the fluent fuel through the front wall above the beam. However, this brings the burner opening a considerable distance above the grate, and unless the combustion chamber is very high the flame wi1l be too close to the roof of the chamber.

It is accordingly one object of the invention to overcome this diculty and to provide a furnace construction which will permit the burner opening to be placed in a considerably lower position than in prior arrangements.

It is a further object of the invention to provide, 'in combination with a spreader Stoker furnace, a new and advantageous construction for the front wall of the furnace, which will permit the introduction of fluent fuel through the wall at a relatively low elevation.

With these and other objects in View, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specifications and covered by the claims appended hereto.

Referring to the drawings illustrating one embodiment of the invention, and in which like reference numerals indicate like parts,

Fig. vl is a longitudinal vertical sectional view through the front portion of a furnace, taken on the line I-l of Fig. 4;

Fig. 2 is a section taken on the line 2-2 of Fig. l, with the refractory portion of the Wall removed;

Fig. 3 is a section taken on the line 3-3 of Fig. 2; and

Fig. 4 is a section taken on the line 4-4 of Fig. l, with the oil burner removed.

The embodiment illustrated comprises a furnace front wall It, two opposed side walls Il, and a roof l2. Upright water wall tubes I4 are provided adjacent to the side walls Il, the upper portions of these tubes being bent laterally to extend beneath the roof I2 and support the same. The water wall tubes may form part of a steam generator of the general type disclosed in the patent to Kuhner No. 2,221,382, granted Nov. 12, 1940. A grate l5 is provided in the lower portion of the furnace, with an ash pit I6 beneath the grate. Access may be had to the ash pit through an opening i8 in the lower portion of the front wail, this opening having the usual ash door It associated therewith. The door I9 is mounted on an upright metal front plate 2U.

Provision is made for supplying solid fuel to the grate l5, thereby forming a fuel bed in which combustion will take place. For this purpose an opening 22 is provided in the front wall l0 somewhat above the level of the grate, and a spreader Stroker 23 is mounted in front of this opening. This stoker comprises a hopper 24 for a suitable solid fuel, such as crushed coal, a horizontal rotor 23 to throw fuel rearwardly through the opening 22, and a reciprocable ram 2l to feed fuel to the rotor from the bottom of the hopper.

The lower portion of the front wall I0, beneath the opening 22 and at the sides thereof, may rest on the foundation therebeneath. The portion of the wall above the opening 22 must be supported independently of the lower portion to avoid excessive weight on the latter, as well as other difficulties. For this purpose there is provided a horizontal beam in the form of a plate girder 29 spaced above the opening 22. This girder comprises a vertical plate or web 30 of considerable height, a horizontal plate 3l adjacent the upper edge of the web, and a horizontal plate 32 adjacent the lower edge of the web. The upper plate 3l is connected to the web by a pair of horizontally extending reinforcing members 34 of channel-shaped cross section located on opposite sides of the web. Similarly, the lower plate 32 is connected to the web 'by a pair of horizontally extending reinforcing members 35 of channel-shaped cross section located on opposite sides of the web. The ends of the girder 29 are suitably attached to two upright columns 36 which provide a support for the girder.

The upper margin of the fuel admission opening 22 is formed by an arch 38 which preferably extends horizontally from one side wall Il to the other. This arch is formed by refractory blocks which are carried by metal brackets 40 of well known construction attached to the lower plate 32 of the girder 29.

Means is provided for introducing fluent fuel into the furnace through the front wall l0, to-

gether with the air necessary for combustion of such fuel. This requires an opening of considerable size, but by employing the girder 29 with its high web 39 it becomes feasible to provide this web with an opening 42 large enough for the required purpose. By this means the point of fuel introduction may be brought much lower than would otherwise be possible. y The construction of the girder is such that it retains ample strength to support the wall. In the particularembodiment illustrated, the opening l2 is square, and extends from the bottoms of the upper channel members 3d to the tops of the lower channel members 35. Within the opening 32;- there is mounted a square burner bcifri'v which extends rearwardly beyond the web 353 and is provided with a transverse vertical plate @d parallel with the web and having a large circular opening 46 therethrough. Withinvthe rear portion ofthe box 43, behind the plate 44, there is installed refractory material i? which defines a circular opening 43 in registration with the plate opening 55. The front portion of the box 3 is enlarged to provide an air chamber i! to which air may be supplied under pressure from any suitable source through a .duct 5i. An oil burner nozzle 52 is mounted within the box 43 coaxial with the opening 4S, and an air register 5 5 surrounds the nozzle to whirl the combustion air approaching the opening and direct it into proper contact with the oil spray in known manner.

Io permit inspection of combustion conditions, openi-ngs 59 (Fig. 4) are provided in the front wall I adjacent to the side walls il. These openings `register with openings 5i in the web Sil, the latter openings being provided with suitable doors '58.

In order to minimize the possibility of overheating the girder 29 and adjacent metal parts, provision is made for the natural upward circulation of cooling air between the girder and the refractory portion of `the wall directly behind the same. For this purpose vertical passages 66 (Fig. 4) are provided `on opposite sides of the burner box 43, the girdersiorrning the front wall of each passage. The rear edges of the girder plates 3i and 32 lare notched at 62 and G3 respectively :(Fig. 3) in registration with these passages to permit the desired air ow. The front plate 2l! is provided with openings 85 near its upper edge -fcr the admission of air into contact with the brackets 49 and thence into the passages 5,9. Boxes 66 are mounted on the top of the girder to register with the upper ends of the passages 6i) and permit the air `therefrom to flow forwardly -into the room.

It will now be apparent that the furnace may be fired either with solid fuel by means of the spreader stoker 23, or with oil by means of the burner 52. The girder 29 provides a strong and dependable support for the portion of the front wall I9 above the opening 22. Air entering the openings VE55 under the action of natural draft will provide adequate cooling for the :brackets :40 'and the girder. By introducing the oil and the combustion air therefor through the opening 42 in the girder web 30, it is possible to provide a flame comparatively close to the grate I5 and thus obtain better combustion conditions and less danger of flame impingement on the furnace roof l2'.

Having thus described my invention, what I claim as newA and desire to secure by Letters Patent is:

1. A furnace front wall construction comprising a lower upright wall portion of refractorl7 material having an opening therethrough for the admission of solid fuel, a horizontal metal girder located somewhat above the opening, two horizontally` spaced upright columns supporting the opposite ends ofthe girder, and an upper upright wall portion of refractory material locatedY above the said lower wall portion and supported by the girder, the girder having an opening extendine herizeetelly therethreueh ieiermediete enfle en@ the. upper, Well Dertien extending lee: hind the girder and having an opening in registration with the girder opening for the admission of fluent fuel in a rearward direction.

2, n furnace as set forth in claim 1, in which the girder comprises an upright web of yconsiderable height, and the girder opening is provided through the' web.

3,. A furnace as set forth in claim 2, in which the girder comprises horizontal plates attached to the upper and lower edges of the web.

4. A furnace as set forthn in claim 3, in which refractory blocks provide a horizontal arch forming the upper edge ofthe sol-id fuel admission opening, and in Vwhich metal brackets arerv attached to the bottom'of the girder to support the said blocks. l y 5 A furnace as set forth in .claim kLl, in which horizontally extending reinforcing members are provided on both sides of the `girder web adjacent to the upper and lower edges thereof."A

6. A furnace as s et forth in claim l, in which the wall is formed with passages behind Athe girder for the natural upward circulation of air in cooling contact with the girder.

GUS'IfAV A.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED sTA'rEs PATENTS

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