US1760118A - Boiler furnace - Google Patents

Description

J; B. CRANE BOILER FURNACE May 27, 1930.

2 Sheets-Sheet 1 Filed Feb. 17-, 1926 y 1930- I J. B. CRANE I 1,760,118

BOILER FURNACE Filed Feb. 17, 1926 2 Sheets-Sheet 2 IN VEN TOR Maw / 6( I +1: 4 L Warming Patented May 27, 1930 UNITED STATES PATENT OFFICE J'OSELPfi B. CRANE, OF IITTSBUEGH, PENNSYLVANIA, ASSIGNOR TO LADD WATER TUBE BOILER COMPANY, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE BOILER FURNACE Application filed February 17, 1326. Serial No. 88,762.

This invention relates to boiler furnaces and is especially useful where the fuel to be burned is in finely divided form, such as pulverized coal.

One of the primary objects of the invention is to greatly increase the capacity of a boiler of the type having substantially horizontal banks of tubes without materially increasing the size of the installation.

By my invention I propose by a novel arrangement of a boiler of the above character and a combustion chamber therefor to convert an ordinary installation of this type into a high capacity boiler installation, or to construct a new installation from parts heretofore used in constructing the standard form of boilers of this class.

The invention is particularly useful, although not necessarily restricted to, the conversion of Babcock and Wilcox boilers in connection with which it will be described.

Another object of my invention is the provision of a novel arrangement of water tubes for use as a water wall of a combustion chamber.

Still another object of my invention is to provide a novel arrangement whereby the degree of superheat may be readily controlled.

A more specific object is to provide a novel arrangement of the water tubes forming the sides of the combustion chamber whereby burner openings are afforded without very materially reducing the tube surfaces exposed to radiant heat. A

Other objects and advantages of my invention will be set forth hereinafter as they will be more readily understood in connection with the description of the invention.

How the foregoing, together with such other objects as may be incident to my invention, are realized is illustrated in preferred form in the accompanying drawings wherein Fig. 1 is a vertical section thru a boilerfurnace embodying the preferred form of my invention;

Fig. 2' is a plan section taken on the line 2-2 of Fig. 1;

Fig. 3 is a similar plan section to that of Fig. 2 showing a modified burner arrangement;

Figs. 4 and 5 are enlarged fragmentary views showing modified arrangements of the side wall tubes;

v Figs. 6 and 7 are plan sections taken on the line 66 and 7-7 of Figs. 4 and 5 respectively;

Fig. 8 is an enlarged fragmentary view showing a modified arrangement of end wall tubes; and

Fig. 9 is a plan section taken on the line 9-9 of Fig. 8.

Referringto the drawings and particularly to Fig. 1 in which I have shown how my invention would be carried out in connection with a boiler of the cross drum type having two banks of substantialv horizontal boiler tubes A and B, it will be seen that I preferably drop the bank of tubes B and their headers a sufiicient distance to provide adequate space for a combustion chamber 0 therebetween.

The side and end walls of the combustion chamber are defined by walls formed of evaporating elements connected for circulation as will further appear. As shown in Figs. 1,2 and 3 the side walls 10 and 11 'comprise a plurality of finned tubes 12 preferably vertically arranged and connected to the upper and lower headers 13 and 14 respectively. The end walls 15 and 16 each comrise a plurality of finned tubes 17, the tubes 7 of one wall being connected to the headers 18 of the upper bank of tubes A and to the headers 19 of the lower bank of tubes B, and the tubes 17 of the other wall being connected to the headers 20 of the upper bank of tubes A and to the headers 21 of the lower bank of tubes B; and a plurality of other finned tubes 22 connected to cross headers 23 and 24. The tubes 22 are shown as being shorter than the tubes 17 and are bent outwardly at their ends for connection to the headers 23 and 24 outside the combustion chamber. Furthermore, it will be seen that these tubes 22 are so positioned with respect to the tubes 17 that aplurality of openings 25 are provided, between certain of the tubes 17 and in the lower portion of the walls of the other end wall are similarly connected to the drum 27. The tubes 17 of these walls, as before mentioned, connect the upper and lower headers of the vertical rows of tubes of the banks of tubes A and B, which headers may be either straight or sinuous, the upper means of the finned downcomer tubes 30 and I the upper headers 20 being connected to the drum 27 by means of the u comer tubes 31. Thus it will be seen that the ow is downward through the tubes 17 of the wall 16 and upward through the tubes 22 thereof. The flow through the tubes of the end wall 15 is upward.

The lower headers 14 of the- side walls 10 and 11 are connected to the drum 27 by means of downcomer pipes 32 and the upper headers 13 thereof are connected to said drum by means of upcomer pipes 33, thus the How is upward through these side tubular walls.

Fuel, such as pulverized coal, and air are introduced to the boiler furnace through the burners 26 which are shown in Fig. 2 as being oppositely disposed. and in this instance 1ying in an inclined plane, by virtue of which the fuel streams will impinge, causing turbulent combustion. As a further aid in causing turbulent combustion, the burners may be disposed in staggeredrelation as indicated in Fig. 3. Preheated combustion air may be admitted with the fuel, which air may be heated by a suitable heater in the stack, whereby the coal and highly preheated air produce an intensely hot flame practically filling the combustion chamber Withthe exception of in the region of the burners. Hence the furnace temperature head is increased, and since the combustion chamber is defined by evaporating elements exposed to radiant heat, there is a very rapid transfer of heat.

The products of combustion are drawn through the banks of tubes A and B under the influence of the stack draft, there bemg a damper controlled ofitake D above the bank of tubes A and a damper controlled ofl'take E below the bank of tubes B. In the particular arrangement shown in the drawings I have indicated a superheater F located between the upper bank of tubes A and the offtake D. the degree of superheat of which may becontrolled by manipulation of the dampers. More specifically stated, the upper damper would be preferably kept full open and the lower one .regulatedto control headers 18 being connected to the drum 27 by stood that the superheater may be located below the lower bank of tubes, in which case the lower damper would be preferably kept full open and the upper one regulated to control the amount of gas passing through the upper bank of tubes.

Referring now to the modification shown in Figs. 4 and 6, I have shown a wall con-' struction comprising a pair of superimposed upper headers 34 and 35, a pair of superimposed lower headers 36 and 37 and a plurahty of closely adjacent tubes 38, alternate ones of which are connected to the headers 35' and 36. By this, employment of double upper and lower headers, I am enabled to have the tubes substantially abut and have sufficiently strong ligaments in the headers. In Figs. 5 and 7 I have shown another modified form of tubular wall structure in which that portion of the tubes exposed to radiant heat is arranged in two different planes which. in effect, provides a double water wall as indicated at 39, whereby a-maximum of heat absorbing surface is exposed to the.

chamber.

In Figs. 8 and 9 I have shown how the arrangement of Figs. 4 and 6 could be applied to the end walls of the boiler-furnace described, the tubes between the headers of the banks of tubes being indicated by the reference numeral 17 and the shorter tubes by the numeral 22*.

It is understood that any suitable form of sheathing for the boiler-furnace such as that shown may be employed. 7

The boiler is capable of developing a very high capacity and very high ratings in comparison to present practice, and it will also be seen that the boiler-furnace is one that is well adapted to be operated at a positive pres-- sure whereby combustion is speeded, and it is possible to make the combustion space of relatively small size.

I claim:

1. .The combination with a boiler of the type including vertically spaced banks of substantially horizontal water tubes and their headers, of a combustion chamber intermediate the levels of said banks of tubes, said combustion chamber being defined by said banks of tubes and by vertical water tubes,

.mcans for introducing fuel to be burned in suspension therein, and an ofitake for the products of combustion beyondv each of said banks of tubes, a superheater located between 2. The combination with a. boiler of the type including vertically spaced banks of substantially horizontal water tubes and their headers, of a combustion chamber inte mediate the levels of said banks of tubes, said combustion chamber being defined by said banks of tubes and "by vertical water tubes, means for introducing fuel to be'burned in suspension therein, a damper controlled ofl'take for the products of combustion beyond each of said banks of tubes, and a superheater located between one of said banks of tubes and the ofl'take therebeyond.

3. The combination with a boiler of the type including vertically spaced banks of substantially horizontal water tubes and their headers, of a combustion chamber intermediate the levels of said banks of tubes, said combustion chamber being defined by said banks of tubes and by vertical water tubes, means for introducing fuel to be burned in suspension therein, an ofl'take for the products of combustion beyond each of said banks of tubes, a superheater located between one of said banks of tubes and the offtake therebeyond and means for controlling of tubes into which the ends of the tubes are connected, upright tubes connecting the front headers of the banks of tubes, upright tubes connecting the rear headers of the anks of tubes, an upper steam and. water drum,

said upright tubes, and the sides by tubular water walls having upcomer and downcomer connection with the steam and water drum, and means for introducing fuel to be burned in suspension in said combustion space.

In testimony whereof I- have hereunto signed my name. I JOSEPH B.CRANE.

tubes, relative to the amount passing over the other bank of tubes.

4. The combination with a boiler of the type including vertically spaced banks of substantially horizontal water tubes and their headers, of a combustion chamber interme-,

diate the levels of said banks of tubes, said combustion chamber being defined by said type including vertically spaced banks of substantially horizontal water tubes and their headers, said banks of tubes however being substantially separated to provide a combus- I tion space therebetween; of upright water tubes marginal of the sides of said combustion space; upper and lower headers for said water tubes; upright water tubes marginal of the ends of said combustion space, said last mentioned water tubes being connected into the headers of the aforesaid banks of tubes; other upright water tubes marginal of the ends of said combustion chamber; other upper and lower headers for said last mentioned water tubes; upcomer and downcomer means connecting the last mentioned tubes into the circulation of the boiler; upcomer and downcomer means connectin the side tubes into the circulation of the boi er; means 'for admitting fuel and air into said combustion space; and an ofi'take for the products of combustion.

' 6. In combination, a boiler of the horizontal type having vertically spaced banks of tubes, front and rear headers for each bank

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