A Burner for a Kiln

Patent metadata

Field	Value
Publication number	US-2018363896-A1
Application number	US-201615781202-A
Country	US
Kind code	A1
Filing date	Dec 12, 2016
Priority date	Dec 23, 2015
Publication date	Dec 20, 2018
Grant date	—

Abstract

A burner for a rotary kiln comprising
an elongated tubular body ( 6 ) having a longitudinal axis (L) and a discharge end ( 7 ) adjacent a combustion zone comprising a flame, at least one fuel supply pipe for transporting and ejecting fuel through a fuel pipe outlet ( 10 ) at the discharge end ( 7 ), the fuel being alternative fuel or a mixture of alternative fuel and fossil fuel, and at the discharge end ( 7 ), a number of high speed primary air jet outlets for ejecting primary air and being arranged, when seen towards the discharge end, along a closed line, such as a circle, outwardly of the fuel outlet ( 10 ) and surrounding the fuel outlet,

wherein at least one of the primary air outlets and preferably a number of the primary air outlets comprise a single orifice outlet or a multiple orifice outlet forming a flat jet air outlet ( 11 ) having a major axis and a minor axis and being configured to eject a flat jet air stream ( 13 ) having a flat fan pattern with a predetermined fan angle v.

First claim

1 . A burner for a kiln comprising
an elongated tubular body having a longitudinal axis and a discharge end adjacent a combustion/one comprising a flame, at least one fuel supply pipe for transporting and ejecting fuel through a first fuel pipe outlet at the discharge end, and a number of high speed first primary air jet outlets for ejecting primary air, the first primary air jet outlets being located at the discharge end and being arranged, when viewed towards the discharge end, along a closed line, such as a circle, outwardly of the first fuel outlet and surrounding the fuel outlet,
wherein at least one of the first primary air jet outlets comprises a single orifice outlet or a multiple orifice outlet forming a flat jet air outlet having a major axis and a minor axis, the flat jet air outlet being configured to eject a flat jet air stream having a flat fan pattern with a predetermined fan angle.

2 . The burner of claim 1 , wherein a majority of the first primary air jet outlets are the flat air jet outlets.

3 . The burner of claim 1 , wherein the ratio between the length of major axis and the minor axis of the flat jet air outlet is at least 1.5:1 and less than 20:1.

4 . The burner of claim 1 , wherein the spacing between the first primary air jet outlets having flat air jet outlets and any intermediate first primary air jet outlets allows air streams ejected from neighbouring first air jet outlets to essentially overlap when the major axes of the air jet outlets are arranged.

5 . The burner of claim 1 , wherein the first primary air jet outlets are all flat jet air outlets that are mutually spaced to allow fans ejected by neighbouring outlets to overlap when the orifices of the first primary air jet outlets are arranged essentially tangent to the closed line on which the first primary air jet outlets are arranged.

6 . The burner of claim 1 comprising an additional primary air channel comprising a swirl air-generating device with a number of additional primary air outlets, the additional primary air outlets being arranged, when viewed towards the discharge end, inwardly of the first primary air jet outlets and being arranged on a second closed line, such as an circle, the swirl air-generating nozzle device being configured to eject multi-point air streams of additional primary air from the additional primary air outlets.

7 . The burner of claim 6 , wherein the first fuel pipe outlet is an annular fuel outlet being arranged, when viewed towards the discharge end, between the first primary air jet outlets and the additional primary air outlets and surrounded by the first primary air jet outlets and surrounding the additional primary air outlets.

8 . The burner of claim 6 , wherein the first fuel pipe outlet is an essentially central fuel pipe outlet being arranged, when viewed towards the discharge end, inwardly of the additional primary air outlets and surrounded by the additional primary air outlets.

9 . The burner of claim 8 comprising an additional annular fuel outlet being arranged, when viewed towards the discharge end, between the primary air jet outlets and the additional primary air outlets and surrounded by the first primary air jet outlets and surrounding the additional primary air outlets.

10 . The burner of claim 8 , wherein the essentially central fuel supply pipe and the additional primary air channel are retractable from a forward position in which the primary air jet outlet, the additional primary air outlet and the first fuel pipe outlet are essentially arranged in a common plane at the discharge end and a second position in which the first fuel pipe outlet and the additional primary air outlet are retracted and spaced from the plane of the primary air jet outlets.

11 . The burner of claim 10 , wherein the essentially central fuel supply pipe and the additional primary air channel are axially retractable over a length being between 0.2-2.0 times the diameter of the circle on which the additional primary air outlets are arranged.

12 . The burner of claim 1 , wherein the primary air outlets are provided in respective nozzles comprising a nozzle body having an outer cylindrical portion, wherein the nozzles are angularly adjustable and wherein the nozzles are arranged in a front plate of the burner or at an outer end of respective air tubes of the burner.

13 . The burner of claim 12 , wherein the nozzles are angularly adjustable during operation of the burner.

14 . The burner of claim 12 , wherein the nozzles comprise an inner air duct comprising an inlet portion having a circular cross section and an outlet portion gradually changing from the circular cross section of the inlet portion to the cross section of the flat air jet outlet with the major and minor axis, the inner air duct being angled, along a line parallel to the major axis, the flat fan being thereby ejected from the nozzle in a plane that is not parallel to the longitudinal axis of the burner, the angle between the inlet portion and the outlet portion of the nozzle being between 0°-30°.

15 . A rotary kiln comprising the burner of claim 1 .

Assignees

• Smidth As F L

Inventors

• Nielsen Mads
• Drivsholm Morten
• Norskov Linda Kaare

Classifications

• F27B7/34

  Arrangements of heating devices · CPC title

• F23D1/04 Primary

  Burners producing cylindrical flames without centrifugal action · CPC title

• F27D99/0033

  using burners · CPC title

• F23D17/005

  gaseous or pulverulent fuel · CPC title

• F23D1/00 Primary

  Burners for combustion of pulverulent fuel · CPC title