Method and apparatus for the operation of a boiler installation with stoker firing

Claim 3

The method as defined in claim 1 wherein said constricted flow of said gas current is accomplished by reducing the cross-section of said flow to about 1/3 to 1/4 of the cross-sectional area of the stoker chamber and wherein said flow is subsequently expanded again to at least approximately the cross-section area of the stoker chamber.

Claim 4

A combustion apparatus comprising a stoker chamber with a burner grating for supporting combustion material and primary air ducts associated with the grating for the supply of fresh air, air supply nozzles distributed over the periphery of said stoker chamber for the supply of secondary air; said primary air ducts and secondary air supply nozzles being controlled to provide less than sufficient air for complete combustion in the stoker chamber whereby during operation both combusted and uncombusted gases ascend in said stoker chamber; a tubular boiler placed coaxially adjacent to the stoker chamber having an inner chamber with upper ceiling means, and annular gas extraction means; means connecting the stoker chamber to the inner chamber of the boiler forming a nozzle-like constriction for receiving said ascending gases; said tubular boiler flaring outwardly from said constriction; and a generally annular system to provide a tangential supply of pressurized tertiary air, sufficient for complete combustion, into said apparatus at the narrowest point of said nozzle-like constriction and being capable of placing ascending gases from said stoker chamber into rotation at said constriction and facilitate mixing with said tertiary air whereby after-burning of uncombusted gases initiates at said nozzle-like constriction and continues upwardly therefrom into said boiler inner chamber, and whereby said rotating gases flare outwardly and move upwardly from said constriction toward the ceiling means; said annular system and boiler inner chamber being cooperative to facilitate flowing said rotating gases upwardly toward said ceiling means wherein a part of said upward flow is redirected at said ceiling means in a central downward core-type flow back toward said constriction to meet ascending gases from said stoker chamber and wherein part of said upwardly flowing gases is extracted at said extraction means; pipe means associated with said boiler inner chamber capable of being heated by combusted gases; and, wherein complete burning of combustion gases is obtained in the boiler and part of the combustion occurs in the stoker chamber whereby said stoker chamber receives a reduced thermal charge permitting temperatures to be maintained below critical values.

Claim 5

A combustion apparatus comprising a stoker chamber with a burner grating for supporting combustion material and primary air ducts associated with the grating for the supply of fresh air, air supply nozzles distributed over the periphery of said stoker chamber for the supply of secondary air; said primary air ducts and secondary air supply nozzles being controlled to provide less than sufficient air for complete combustion in the stoker chamber whereby during operation both combusted and uncombusted gases ascend in said stoker chamber; a tubular boiler placed coaxially adjacent to the stoker chamber having an inner chamber with upper ceiling means, and annular gas extraction means; means connecting the stoker chamber to the inner chamber of the boiler forming a nozzle-like constriction for receiving said ascending gases; said tubular boiler flaring outwardly from said constriction; and a generally annular system to provide a tangential supply of pressurized tertiary air, sufficient for complete combustion, into said apparatus at the narrowest point of said nozzle-like constriction and being capable of placing ascending gases from said stoker chamber into rotation at said constriction and facilitate mixing with said tertiary air whereby after-burning of uncombusted gases initiates at said nozzle-like constriction and continues upwardly therefrom into said boiler inner chamber, and whereby said rotating gases flare outwardly and move upwardly from said constriction toward the ceiling means; said annular system and boiler inner chamber being cooperative to facilitate flowing said rotating gases upwardly toward said ceiling means wherein a part of said upward flow is redirected at said ceiling means in a central downward core-type flow back toward said constriction to meet ascending gases from said stoker chamber and wherein part of said upwardly flowing gases is extracted at said extraction means; pipe means associated with said boiler inner chamber capable of being heated by combusted gases; and, wherein complete burning of combustion gases is obtained in the boiler and part of the combustion occurs in the stoker chamber whereby said stoker chamber receives a reduced thermal charge permitting temperatures to be maintained below critical values.

Claim 6

The apparatus in accordance with claim 3 wherein the cross-sectional area at the narrowest point of the constriction is approximately 1/3 to about 1/4 of the cross-sectional area of the stoker chamber.

Claim 7

The apparatus in accordance with claim 4 wherein the cross-sectional area of the inner chamber of said boiler is approximately equal to the cross-sectional area of said stoker chamber.

Claim 8

The apparatus in accordance with claim 3 wherein the cross-sectional area of the inner chamber of said boiler is approximately equal to the cross-sectional area of said stoker chamber.

Claim 9

The apparatus in accordance with claim 3 wherein said air supply nozzles in said stoker chamber are arranged in a circumferential ring around a wall of the stoker chamber and provide a supply of secondary air to said stoker chamber and further wherein the radius of said nozzles slope with respect to the central axis of said stoker chamber by an angle in the range of between about 10° and 40°.

Claim 10

The apparatus in accordance with claim 7 wherein alternative nozzles in a circumferential direction vary in slope.

Claim 11

The apparatus in accordance with claim 3 wherein the tangential supply of tertiary air is provided by an annular gap having guiding means comprising a plurality of guide panels arranged in a spiral and partially overlapping configuration which form apertures in the annular gap pointing in a substantially circumferential direction.

Claim 12

The apparatus in accordance with claim 3 wherein the cross-sectional area of the inner chamber of said boiler is approximately equal to the cross-sectional area of said stoker chamber, and further wherein said air supply nozzles in said stoker chamber are arranged in a circumferential ring around a wall of the stoker chamber and provide a supply of secondary air to said stoker chamber and wherein the radius of said nozzles shape with respect to the central axis of said stoker chamber by an angle in the range of between about 10° and 40°.

Claim 13

The apparatus in accordance with claim 7 or 10 wherein said nozzles slope at an angle in the range of between 15° and 35°.