US2020264A - Smokeless boiler - Google Patents

Description

Nov. 5, 1935.

C OLSON ET AL SMOKELES S BOILER Filed April 5, 1953- 2 Sheets-Sheet 1 I Jrwenfarz? C/zarZes 44. Olson and Lbfin P Magyar" M MCMM p m Nov. 5, 1935. A LSON H A; 2,026,264

1 a ar/65 .25 065016, @051 Patented Nov. 5, 1935 UNITED STATES PATENT OFFICE SMOKELESS BOILER Application April 5, 1933, Serial No. 664,460

3 Claims. (Cl. 110-75) This invention relates to boilers suitable for steam or hot water and is particularly applicable to sectional boilers of the vertical section type shown in the Olson Patent No. 1,856,355, issued May 3, 1932, upon which this invention is in the nature of an improvement. a

It is the purpose of this invention to provide a smokeless boiler of this type capable of buming solid fuels. 7

It is well known that when boilers are fired with fuel having a high percentage of volatile matter, unless a proper amount of air is introduced over the fire bed, considerable smoking in the chimney and fire door results which obviously is very objectionable and is detrimental to obtaining higher boiler efficiency.

In accordance with our invention primary and secondary air is introduced towards the rear of the fire box and in order to obtain more efiicient combustion means are provided for heating the secondary air and also for controlling the flow of both the primary and secondary air. In the illustrated form the latter means constitutes a damper on the ash pit which controls the amount of air supplied to the fire bed, both below the grates for primary combustion and as secondary air in the path of the unburnt gases, as the demand on the boiler warrants. By this means a substantially complete and uniform combustion is obtained which for all practical purposes eliminates smoking.

Other advantages will be apparent to those skilled in the art from the following description of our invention given in connection with the drawings in which:

Fig. 1 is a perspective of a boiler having our improvements incorporated therein, a portion of the boiler sections being broken away to better illustrate the auxiliary air intake, and

Fig. 2 is a front elevation of a portion of a boiler section'illustrating the installation of an auxiliary air intake constructed in accordance with this invention.

For purposes of illustration the boiler has been shown as a vertical section boiler comprising end sections Iv and intermediate sections 2. Each of the sections is provided with a pair of side vertical water legs 4in communication with each other at their upper and lower ends through the usual intercommunicating passages. The water legs of each section communicate with each other through an upwardly arched water channel 8, and side passages or channels 9, leading to the upper water drum ID, the latter water chambers being in communication with each other through the usual connections. The arched water channel 8 is also in communication with the upper drum through a Y channel II. The legs 4 and upwardly arched channel 8 define a fire box I2 at the bottom of which are supported the usual grates l3 upon saddles I4 which permit rocking of the grates and below which is the ash pit l5. The foregoing structure is substantially that shownin the prior Olson patent and need not, therefore, be described in greater detail. 10

Air for combustion is supplied through an adjustable damper in the side of the boiler below the grates, through which air passes into the ash pit. The air drawn in through the damper constitutes the primary and secondary 1 or auxiliary air.

Towards the rear of the fire box there is inserted an oxidizer or secondary air supply. This oxidizer is in effect an auxiliary air supply which communicates at its lower ends with. the ash pit and at its upper end with the combustion chamber so that secondary air preheated-in the ash pit may reach the rearsection of the fire bed without passing through the grates.

For convenience in manufacture and installation the oxidizer is made in three sections, two hollow vertical risers l6 which communicate with the ash pit, and a substantially horizontal hollow cross duct I! which communicates with the combustion chamber and fire bed as will later be pointed out. The air taken into the ash pit receives some heat from the grates, the ashes and the surrounding gases before entering the risers l6 and the horizontal cross member ll, all of which are exposed to the fire and thus further heat the secondary air.

The lower ends of the risers are provided with supports l8 which fit in the saddles I4 formed on the lower ends of the water legs and assume the position normally occupied by the grate trunnions. The inner walls of the vertical risers are in turn provided with saddles [9 to receive the trunnions of a shortened grate bar 20. Each riser is provided with lugs 2| which engage the inner sides of the water legs and retain the risers in upright position. The horizontal duct I1 is also provided with lugs 22 similar to lugs 2! which engage the inner surfaces of the water channel 8. The oxidizer is thus positively supported in upright position yet it is capable of slight movements to compensate for expansion and contraction.

The upper member ll spans the combustion chamber with the ends fitting into the upper ends of riser I 6 and is provided with openings 23 in its lower wall directed toward the fire bed and openings 24 in its upper wall directed toward the upper region of the combustion chamber. These openings distribute the preheated secondary air taken in through the bottom of the oxidizer over the fire bed and into the combustion chamber.

It will be apparent from the foregoing that we have provided means for admitting a controlled amount of preheated air onto that portion of the fire bed and into that portion of the combustion chamber which ordinarily lacks a proper supply with the result that smoking is substantially eliminated and complete and uniform combustion is assured, thus permitting burning of smoky fuels.

Furthermore the secondary air is supplied at a location where the hot and partially burnt gases contact with the cross member which provides for a uniform and thorough distribution of the preheated secondary air to effect efficient and more complete combustion.

Another important advantage of this invention is that the device as described herein may be installed on new boilers or by the removal of a grate section may also be installed on boilers now in service. The advantage of this construction lies in its elimination of expensive and unwieldy special sections of boilers which have heretofore been required. It thus provides for ready and economical conversion of an ordinary boiler to one of the smokeless type without requiring special openings to be cut into the boiler casing or special shaking devices for the additional grate or grates. 7

It will be apparent to those skilled in the art that the embodiment of this invention shown in the drawings is illustrative only and that variations may be made in the details of construction and/or the type of boiler without departing-from the spirit and scope of this invention as defined in the appended claims.

We claim:

1. In a boiler having afire box, removable grates, trunnions on said grates and saddles at the sides of said fire box, a pair of vertically extending ducts positioned at opposite sides of the fire box, each duct having a trunnion'for seating in an associated saddle, air conducting means for spacing the upper ends of said ducts 5 and constructed for receiving air therefrom, and saddles provided on the inside surfaces of said ducts at the grate level for supporting thereupon a grate extending between the ducts, each of said ducts opening into the ash pit immediately below 10 the grates, said means having an opening positioned for discharging air into the fire box above the grate surface.

2. In combination with a boiler having a fire box and saddles at the sides thereof for rotatably 15 supporting grates, a member having trunnions seating in two opposed saddles and including vertically rising elements positioned within the fire box together with air conducting means extending over the fire box connecting said ele- 20 ments, one of said vertical elements being provided with an upwardly extending duct opening into the ash pit belowthe grates and into said air conducting means, said means having a discharge opening within the fire box above the g5 grates. v

3. In combination with a boiler having a fire box and saddles at opposite sides for rotatably supporting grate trunnions, a pair of upwardly extending members wholly within said fire box 3 provided with trunnions on their outside walls for seating in two directly opposed saddles, means extending across the upper portion of the fire box detachably connecting said members to support them against collapsing toward each other, 35 one of said members having an upwardly extending duct opening into the ash pit below the grates and having a discharge outlet within the fire box higher than the grate level, the inside walls of said members having saddles for supporting a 0 shortened grate between them.

CHARLES A. OLSON. JOHNP. MAGOS.

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