Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D1/00—Burners for combustion of pulverulent fuel
  • F23D1/02—Vortex burners, e.g. for cyclone-type combustion apparatus
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
  • F23C7/00—Combustion apparatus characterised by arrangements for air supply
  • F23C7/002—Combustion apparatus characterised by arrangements for air supply the air being submitted to a rotary or spinning motion
  • F23C7/004—Combustion apparatus characterised by arrangements for air supply the air being submitted to a rotary or spinning motion using vanes
  • F23C7/006—Combustion apparatus characterised by arrangements for air supply the air being submitted to a rotary or spinning motion using vanes adjustable

Definitions

• the invention relates to a burner for a rotary kiln, with an annularly arranged channel for the pneumatic transport of fine-grained solid fuel through a nozzle mouth and with a concentrically arranged combustion air channel, at the mouth of which a swirl generator is arranged, which has guide vanes distributed around the circumference.
• calcined raw cement meal is burned into cement clinker in the sintering zone of a rotary kiln.
• a long burner lance is inserted into the end of the furnace outlet through the stationary furnace outlet housing, at the mouth of which the fuels introduced into the lance burn to form a burner flame.
• solid fuels in particular coal dust, but also pneumatically transportable waste fuels are increasingly being used as secondary fuels.
• the correct temperature and length of the burner flame are important for the formation of clinker minerals in the rotary kiln.
• the development is towards building the rotary kiln itself as short as possible due to the high-grade calcination of the raw cement flour outside the rotary kiln, so that in response to this, the burner flame should generally be as short and hot as possible. This applies to all fuels that can be used in rotary kilns.
• Known rotary kiln burners are usually designed as so-called three-channel burners (publication "KHD Symposium '90" volume 2 page 98 with the essay “Operating experience with the KHD PYRO-JET burner”), with at least three channels concentric with each other, that is, through the middle burner channel as the fuel, the pneumatically transported coal dust, which exits through an annular gap nozzle, the outflowing coal dust being surrounded by radially inner as well as radially outer primary air as combustion air.
• the radially external air also called jet air
• jet air is divided into many individual high-speed primary air jets by means of a large number of individual nozzles arranged in the ring-shaped jet air channel, which create a negative pressure area in their environment, that is to say the many high-speed primary air jets serve as propulsion jets according to the injector principle , through which the large mass of the rotating furnace burner, practically still hot secondary air of z. B. about 1000 ° C is sucked in towards the core of the burner flame, where an intensive mixing of the hot secondary air with the coal dust escaping through the annular gap nozzle takes place, which is to burn quickly and completely with the formation of a short hot flame. It is also important, however, that the combustion air flow emerging radially within the coal dust nozzle from the burner mouth.
• the primary air duct of the known rotary kiln burner located radially inside the coal dust duct has a swirl generator at its mouth, so that the primary air escaping there receives a rotational component and is also called swirl air, swirl air or radial air.
• the swirl generator has spirally arranged air outflow channels, or at the mouth of the swirl air channel of the rotary kiln burner, wing-like guide vanes distributed around the circumference are arranged, such as these.
• B. from EP-B 0 421 903 are known. All these known swirl generators cannot be adjusted, especially not during operation of the rotary kiln, so that different fuels used and changing flame shapes cannot be reacted to by changing the intensity and / or in particular the outflow angle of the swirl air.
• a rotary kiln burner is known from the special print from ZKG INTERNATIONAL 1993, issue 12, pages 779 to 783, in whose swirl air duct flexible metallic air hoses with air nozzles distributed around the circumference are arranged, the air outflow direction of which can be adjusted from axial to radial by the flexible air hoses with their air outlet nozzles can also be set at an angle to the burner axis to increase the swirl component of the radial air.
• This known swirl setting device of a rotary kiln burner is comparatively complex.
• the invention has for its object to provide a rotary kiln burner, in particular for fine-grained solid fuel, with a swirl air duct with a swirl generator which, for the purpose of changing the outflow angle of the swirl air and changing the shape of the flame, can be controlled simply and yet effectively even in response to different types of fuel even during rotary kiln operation.
• the guide vanes of the swirl generator are set at an angle to the swirl air duct axis
• Guide vanes can each be rotated on a radial guide vane limitation side in a ring section of the swirl air duct or pivoted. On their respective opposite radial guide vane limitation side, the guide vanes each have a projecting guide pin z. B. ball studs, the guide studs engaging in a respective guide groove of an annular control body arranged in the swirl air duct. By axially displacing and / or rotating the control body with its guide grooves distributed over the circumference, the guide vanes can be given away and the outflow angle of the swirl air influenced by the swirl generator and the flame shape of the rotary kiln burner according to the invention can be varied during burner operation.
• the guide vanes distributed around the circumference of the swirl generator are designed as one-armed levers, in that the guide pins of the guide vanes are each arranged at a distance from the axis of rotation or pivoting of the guide vanes.
• Either the rotating or swiveling axes of the guide vanes are located on their radially outer side and they are pivotably mounted in the radially outer boundary tube of the swirl air duct, and the guide pins and the grooved control body are on the radially inner boundary tube side of the swirl air duct, or vice versa.
• the guide grooves distributed around the circumference of the control body can have an approximately helical shape. Then the control body is axially displaced, and in this way the guide vanes are pivoted. Or the guide grooves distributed around the circumference of the control body are deformed approximately axially in a straight line. Then the control body is rotated, and in this way the guide vanes of the swirl generator are pivoted. It is also possible to shape the guide grooves distributed around the circumference of the control body differently in terms of position and geometry, z. B. in the helical position with mutually different angles to the longitudinal axis of the burner.
• a different or asymmetrical angle adjustment of the guide vanes can also be effected, for example a different outflow angle of the swirl air can be set on the top of the burner mouth than on the burner underside, in order in this way for special mixing effects of the Solid fuel escaping via a conical annular gap nozzle, such as. B. to provide coal dust.
• FIG. 3 enlarged, drawn out from FIG. 2, the perspective view of one of the guide vanes pivotably arranged at the burner mouth in the swirl air duct,
• FIG. 4 the axially displaceable control body drawn enlarged from FIG. 2 in a perspective view
• FIG. 5 as a variant of FIG. 4, a perspective view of a control body rotatable about its axis for adjusting and adjusting the guide vanes in the swirl air duct.
• the rotary kiln burner according to the invention is a three-channel burner with an annularly arranged channel 10 for the pneumatic transport of fine-grained solid fuel such as. B. coal dust that flows out through an annular gap nozzle mouth with a small outward diverging angle.
• the coal dust duct 10 is concentrically surrounded both by a radially outer combustion air duct and by a radially inner combustion air duct, these combustion air flows forming the primary air for the burner.
• the radially outer primary air also called jet air, emerges at high speed in the form of jet streams from individual nozzles distributed around the circumference of the burner mouth Burner nozzles 11 out.
• the jet air jets are able to remove as much as possible of the hot secondary air surrounding the rotary kiln burner in the rotary kiln, e.g. B. 1000 ° C into the core of the burner flame for the purpose of quick and complete combustion of coal dust.
• the further primary air duct which is arranged concentrically within the coal dust duct 10, is equipped with a swirl generator with guide vanes 12, 13, etc., which are distributed around the circumference and can be directed obliquely to the air flow, so that this radially inner primary air duct is also called swirl air duct 14.
• At least one pilot burner can also be arranged in the center of the burner mouth.
• the guide vanes 12, 13 etc. in the swirl air duct 14 can even be adjusted during operation of the rotary kiln, in that the guide vanes in the exemplary embodiment in FIGS. 2 and 3 each have a projecting cylindrical articulated pin 15 on their radially outer sides as a pivot axis, the articulated pins are stored in circumferentially distributed bores of a retaining ring 16 which is fastened by means of fastening elements such.
• bolts 17 from the burner mouth to the end face of the swirl air duct 14 outside limiting tube is mountable.
• the guide vanes 12, 13, etc. each have a projecting guide pin 18 on their side opposite the pivot pin 15, for. B.
• the flame shape of the rotary kiln burner is set during burner operation via the outflow angle of the swirl air influenced by the swirl generator.
• B. reacts to changing compositions of the solid fuel.
• the axial displacement of the control body 21 can, as shown in FIG. 1, be carried out by axial displacement of the central tube 22 carrying the control body 21, which can be sensitively adjusted axially with the aid of a displacement linkage 23 by means of a spindle lifting element 24.
• the swirl air duct 14 is sealed by means of a compensator 25 between the axially displaceable central pipe 22 and the fixed pipe connection.
• the swivel angle set on the guide vanes 12, 13 can be recognized by scales on the adjustment drive or by electrical signal feedback.
• the invention can also be used to convert existing rotary kiln burners. For this purpose, in addition to installing the adjustment mechanism at the cold end of the burner lance, only the swirl system and, if necessary, the coal dust ring nozzle must be replaced.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Muffle Furnaces And Rotary Kilns (AREA)
• Pre-Mixing And Non-Premixing Gas Burner (AREA)
• Drying Of Solid Materials (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=34877236

Family Applications (1)

Country Status (6)

Cited By (4)

Families Citing this family (5)

Family Cites Families (9)

• 2004
  • 2004-03-02 DE DE102004010063A patent/DE102004010063A1/de not_active Withdrawn
• 2005
  • 2005-02-28 DK DK05707659.8T patent/DK1725811T3/da active
  • 2005-02-28 AT AT05707659T patent/ATE519073T1/de active
  • 2005-02-28 BR BRPI0508293-5A patent/BRPI0508293A/pt not_active IP Right Cessation
  • 2005-02-28 WO PCT/EP2005/002099 patent/WO2005085707A1/fr active Application Filing
  • 2005-02-28 EP EP05707659A patent/EP1725811B1/fr not_active Not-in-force

Non-Patent Citations (1)

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