US1950454A

US1950454A - Boiler furnace

Info

Publication number: US1950454A
Application number: US544833A
Authority: US
Inventors: Charles E Lucke
Original assignee: Fuller Lehigh Co
Current assignee: Fuller Lehigh Co
Priority date: 1931-06-16
Filing date: 1931-06-16
Publication date: 1934-03-13
Anticipated expiration: 1951-03-13

Description

March 13, 1934.

c. E. LUCKE 1,950,454

BOILER FURNACE Filed June 16. 1931 Fig-1 2 Sheets-Sheet l INVENTOR @5244 & M w/wq ATTORNEYS March 13, 1934. Q LUCKE Q 1,950,454

BOILER FURNACE Filed June 16. 1931 2 Sheets-Sheet 2 INVENTOR Patented Mar. 13, 1934 BOILER FURNACE Charles E. Lucke, New York, N. Y., assignor to Fuller Lehigh Company, Fullerton, Pa., a corporation of Delaware Application June 16, 1931, Serial No. 544,833

1 Claim.

This invention relates to a furnace that is useful in connection with burning gaseous or powdered fuel or fuel in suspension. The invention is especially applicable to furnaces for steam boilers, but it is not restricted to this particular use.

By this invention fuel can be partially burned in the lower portion of the furnace and additional air admitted further along in the products of combustion to complete the burning of the fuel. The air is admitted at a very large number of points in the gaseous stream in proportion to the cross sectional area of the stream.

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. 1; and Fig. 3 is a section along the line 3-3 of Fig. 2.

In the drawings reference character 1 indicates a furnace that is provided with one or more burners at the lower portion thereof. Fuel, such as gas, oil or powdered fuel may be introduced through the pipe 2 and combustion air through the pipe 3 of the burners in the usual way with insufiicient air to complete the combustion of the fuel.

A boiler of the Babcock & Wilcox type may be located above the furnace 1 with the usual bank of inclined tubes 4 connected to uptake headers 5 and downtake headers 6 which are in turn connected to the steam and water drum 7 of the boiler by the tubes 8 and nipples 9, respectively, with bafiies 10 directing the products of combustion from the furnace across the tubes 4 in a plurality of passes to the outlet 11, all in the wellknown way.

Rows of inclined tubes 12 extend across the furnace 1 between the fuel burners and the bank of tubes 4, these tubes 12 being preferably arranged in pairs and the pairs being stepped in the general direction of the flow of products of combustion. The lower ends of the tubes 12 are connected to a V-shaped header 13 and the upper ends thereof are connected to a V-shaped header 14, the

headers

13 and 14 being located outside the furnace walls.

A downtake pipe 15 extends from the water space of the steam and water drum '7 to the lower portion or point of the header 13, and uptake pipes 16 extend from the upper ends of the header 14 to the steam space of the steam and water drum, thus providing circulation through the tubes 12. Water circulation through the tubes 12 may, however, be provided in other ways or from other sources. 7

Air pipes or conduits 17 extend across the furnace 1 between the burners and the bank of tubes 4. These air conduits 17 extend from an air box 18 to which a supply of air, which may be preheated, is introduced through the inlet 19, through a wall of the furnace and into the opposite wall of the furnace where the ends are closed, as indicated at 20. These conduits 17 may be made of refractory material and when they are not mechanically strong enough to avoid the danger of sagging down or breaking due to their own weight, they may rest upon the pairs of water tubes 12 to support them and also to aid in keeping them cool. A series of holes or perforations 21 is provided on each side of each of the conduits 1'7, the series of holes in the respective conduits being preferably staggered on opposite sides of the conduits, so that the air escaping from these conduits will be intimately mingled with the rising combustion products or fuel.

The conduits 17 are preferably inclined to the horizontal and are arranged in a stepped relation with respect to the flow of fuel so that greater w areas are provided through which the products of partial combustion from the lower part of the furnace pass as they are being mixed with the fresh air from the conduits 17. Two sets of approximately horizontally disposed jets of hot air are thus projected into divided streams of hot gases as they pass between the conduits 17. By this arrangement the flow resistance of the products of combustion is decreased or a larger number of air conduits are provided per unit of width of gas conduit without increasing the flow resistance of the products of combustion.

The operation is as follows: Fuel is introduced into the lower portion of the furnace with a deflciency of combustion air so that only partial combustion of the fuel takes place below the tubes 12 and conduits 17, thus preventing the lower portion of the furnace walls from becoming injured, and thereby enabling this portion of the furnace walls to be made cheaper than would be necessary if the temperatures; were excessive. The products of partial combustion pass upwardly between the conduits l7 and are thus divided into streams, and more combustion air from the holes 21 in the conduits 1'7 is added and mixed with the numerous streams of products of partial combustion. The numerous jets of air escaping from the conduits 17, which extend across the furnace, cause fresh combustion air to be quickly and. thoroughly mingled with the products of combustion so that rapid combustion takes place in the space between tubes 12 and the bank of tubes 4, this space being made sufficiently large for this purpose. The holes 21 are so placed that the jets of air from these holes strike the streams of products of partial combustion at angles so as to facilitate ready and intimate mixing of the air and fuel.

By employing this invention fuel in a gaseous form, or solid or liquid particles of fuel in suspension in a gas can be introduced with very little or no air below the conduit 17, so that very little or no combustion takes place below these conduits, and the air for combustion purposes can be introduced entirely or substantially entirely through the conduits 17, so that all or substantially all of the combustion takes place at or above the place where the jets of air are introduced. In a similar manner, all of the air for combustion purposes may be introduced below the conduits 17 with very little if any gas, and all or substantially all of the gas for combustion purposes may be introduced through the conduits 17 instead of air being introduced through these conduits, so that all or substantially all of the combustion will likewise be caused to take place above the conduits 17.

With certain relations of the conduits 17 to each other the jets escaping from a lower conduit may strike the next upper one thereby causing better mixing of the fuel and air to take place.

I claim:

In a water tube boiler, a furnace, a steam and water drum, two circulation systems connected to said drum and each having tubes extending across said furnace, one of said circulation systems comprising tubes arranged in stepped relation in a plane at an acute angle to the direction of travel of gases in said furnace both immediately before they reach said tubes and immediately after they leave them, and perforated air conduits resting upon said tubes.

CHARLES E. LUCKE.