Boiler

Claim 2

A water tube boiler comprising, in combination, a furnace area having opposed ends, an upper tank and a lower tank, at least two adjacent rows of riser tubes extending along said furnace area and arranged such that there is an inner row of tubes and an outer row of tubes relative to said furnace area, a burner assembly at one end of and operatively opening into said furnace area, said one end being otherwise closed to said furnace area and the opposite end of said furnace area being closed, and means defining an opening in said inner tube row in the area of said one end of said furnace area and means closing the area between adjacent tubes in the remainder of said inner tube row to flow through the area between adjacent tubes, means closing the area between adjacent tubes in said outer tube row to flow through the area between adjacent tubes so that said inner and outer tube rows define a passageway therebetween open to said furnace area only in the area of said one furnace area end, and means defining an exhaust communicating with said passageway, whereby products of combustion penetrate said furnace area from said burner assembly and turn back on themselves to exit the furnace area and enter said passageway through the openings between said tubes in said inner tube row.

Claim 3

The water tube boiler of claim 1 including a second arrangement of at least two adjacent rows of riser tubes extending along said furnace area opposite to said first mentioned rows of riser tubes and also arranged in an inner row of tubes and an outer tow of tubes relative to said furnace area, and in said second arrangement means defining an opening in said inner tube row means in the area of said one end of said furnace area and means closing the area between adjacent tubes in the remainder of said inner tube row to flow through the area between adjacent tubes, means closing the area between adjacent tubes in said outer tube row to flow through the area between adjacent tubes so that said inner and outer tube rows define a passageway therebetween open to said furnace area only in the area of said one furnace area end, and means defining an exhaust communicating with said passageway.

Claim 4

The water tube boiler of claim 2 wherein said burner assembly has an extension into said furnace beyond the tubes in said inner tube rows having the opening into said furnace area and being open to said furnace area at the end thereof and closed to said furnace area along the extension thereof.

Claim 5

The water tube boiler of claim 3 wherein said extension of said burner assembly comprises a refractory tunnel.

Claim 6

The water tube boiler of claim 4 wherein the interior of said refractory tunnel is generally conical in axial cross section.

Claim 7

The water tube boiler of claim 2 including two rows of inner riser tubes extending along but spaced from said inner row of riser tubes and terminating in spaced relation from said opposite end of said furnace area and means closing the areas between the tubes in the rows of inner riser tubes.

Claim 8

The water tube boiler of claim 6 including riser tubes in the areas between said inner and outer tube rows.

Claim 9

The water tube boiler of claim 1 wherein said burner assembly has an extension into said furnace beyond the tubes in said inner tube row having the opening into said furnace area and being open to said furnace area at the ends thereof and closed to said furnace area along the extension thereof.

Claim 10

The water tube boiler of claim 7 wherein said extension of said burner assembly comprises a refractory tunnel the interior of which is generally conical in axial cross section.

Claim 11

The water tube boiler of claim 1 including riser tubes in the areas between said riser and outer tube rows.

Claim 12

The water tube boiler of claim 2 wherein the tubes of said inner and outer rows are staggered As between rows to thereby attribute a generally tortuous configuration to said passageways.

Claim 13

The water tube boiler of claim 1 wherein the tubes of said inner and outer rows are staggered as between rows to thereby attribute a generally tortuous configuration to said passageways.

Claim 14

The water tube boiler of claim 2 wherein said exhaust opens into said passageways in the area of the opposite end of said furnace area.

Claim 15

The water tube boiler of claim 1 wherein said exhaust opens into said passageway in the area of the opposite end of said furnace area.

Claim 16

The water tube boiler of claim 2 wherein said upper and lower tanks and said rows of riser tubes are arranged symmetrically about a central vertical plane through said boiler.

Claim 17

The water tube boiler of claim 1 including at least one downcomer tube extending between said upper and lower tanks outside of said one end of said furnace area.

Claim 18

The water tube boiler of claim 2 wherein said means closing the areas between adjacent tubes comprises metal webs extending between and connected to adjacent tubes.

Claim 19

The water tube boiler of claim 1 wherein said means closing the areas between adjacent tubes comprises metal webs extending between and connected to adjacent tubes.

Claim 20

A water tube boiler comprising, in combination, a furnace area having opposite ends and sides, an upper tank and a lower tank, at least two adjacent rows of riser tubes extending along each side of said furnace area and, at each side and with respect to said furnace area, arranged in an inner row of tubes and an outer row of tubes, a burner assembly at one end of said furnace area extending into said furnace area and being closed to the furnace area along the extension thereof, a plurality of adjacent tubes in said inner tube rows and in the area of said one furnace area and being relatively spaced and having an opening therebetween and means closing the area between adjacent tubes in the remainder of said inner tube rows to flow through the area between adjacent tubes, means closing the area between adjacent tubes in said outer tube rows to flow through the area between adjacent tubes so that said inner and outer tube rows define passageways therebetween open to said furnace area only in the area of said one furnace area and, the extension of said burner assembly into said furnace area being beyond said inner row tubes having the openings therebetween, and means defining an exhaust communicating with said passageways, whereby products of combustion penetrate said furnace area from said burner assembly and turn back on themselves to exit the furnace area and enter said passageways through the openings between said tubes in said inner tube rows.

Claim 21

A water tube boiler comprising, in combination, a furnace area having opposite ends and sides, an upper tank and a lower tank, at least two adjacent rows of riser tubes extending along each side of said furnace area and, at each side and with respect to said furnace area, arranged in an inner row of tubes and an outer row of tubes, a burner assembly at one end of said furnace area extending into said furnace area and being closed to the furnace area along the extension thereof, a plurality of adjacent tubes in said inner tube rows and in the area of said one furnace area and being relatively spaced and having an opening therebetween and means closing the area between adjacent tubes in the remainder of said inner tube rows to flow through the area between adjacent tubes, means closing the area between adjacent tubes in said outer tube rows to flow through the area between adjacent tubes so that said inner and outer tube rows define passageways therebetween open to said furnace area only in the area of said one furnace area and, the extension of said burner assembly into said furnace area being beyond said inner row tubes having the openings therebetween, and means defining an exhaust communicating with said passageways, whereby products of combustion penetrate said furnace area from said burner assembly and turn back on themselves to exit the furnace area and enter said passageways through the openings between said tubes in said inner tube rows.

Claim 22

The water tube boiler of claim 19 wherein said extension of said burner assembly comprises a refractory tunnel the interior of which is generally conical in axial cross section.

Claim 23

The water tube boiler of claim 20 wherein the tubes of said inner and outer rows are staggered as between rows to thereby attribute a generally tortuous configuration to said passageways.

Claim 24

The water tube boiler of claim 19 including at least one downcomer tube extending between said upper and lower tanks outside of said one end of said furnace area.

Claim 25

The water tube boiler of claim 19 wherein said means closing the areas between adjacent tubes comprises metal webs extending between and connected to adjacent tubes.