DD212305A1 - SPIRAL BURNER TO NO DEEP X-ARM COMBUSTION - Google Patents

Abstract

Vortex burner for NO deep x-low combustion with a suction effect and a first and second swirl flow field for intensive combustion in short horizontal combustion chambers, zuendschwieriger combustible dust, preferably brown coal burning dust, is used. Erfindungsbemaess the Ansaugeeinrichtung is a Coande-Duese and in the flow direction is concentrically arranged around a diffuser channel a secondary and Tertiaerluftkanal with solid spin internals. Between the ends of the secondary and Tertiaerluftkanaele a conical burner pre-space is present, the upper air in the Tertiaerluftkanal for NO deep x-poor combustion is used. The whirling can be used in the energy industry.

Description

Title of the invention;

Whirling burner for ΪΓΟ-poor combustion

Field of application of the invention

The field of application of the invention comprises the combustion of fuels whose combustion leads to NO formation in combustion chambers of different applications, especially in combustion chambers of steam generators with lying flue gas.

Characteristic of the known technical solutions

Known are methods and apparatus for the combustion of treated raw coal, which differ in methods and apparatus for intensive combustion with short flames, which are bound to ignitable, high calorific fuels and methods and apparatus that are suitable for low calorie fuels and are characterized by unsafe ignition properties, which forces the use of supporting torches. For low calorific fuels after a grinding drying plant with process-related uncertainty

17th DE1932 * 055806

In the case of ignition properties, a bridge separator realizes the division into a flammable fuel stream and a vapor and residual gas stream. The supply of both partial streams through a burner into a combustion chamber takes place in a form permitting intensive combustion.

Known is a device according to DB-OS 2908448 for influencing the combustion by dividing the combustion air flow into different secondary air streams and the introduction of the same at different locations of the burner, the combustion such influencing that in a primary zone, a stable ignition with partial combustion and in a post-combustion zone Restausbrand takes place. Thereafter, air nozzles are provided around the burner calyx in a concentric arrangement, which are connected to the main air duct and allow control of the secondary air flows via flaps. In the Eernluftrohr is a lance for Zündfeuerung or alternative power firing. The disadvantage of this staged combustion is the injection of the entire fuel-vapor residual gas stream into the primary zone, where ignition firing is necessary to stabilize the partial combustion process.

Furthermore, a dust burner according to DD-WP 240361 is known which enables reliable ignition and stable combustion in the partial load range and largely eliminates the disadvantages of known burners. In the full load range, this prior art burner would have been equipped with an additional fan for the air in the inner swirl.

wreath, since the amount of air supplied in the inner swirl ring (core air) at full load is too low compared to the supplied in the outer swirl ring (secondary air).

Aim of the invention;

The aim of the invention is to develop a burner in which for solid fuels with a high gas content in the delivery line and existing Uiedrigstfließdruck a reduction of NO formation during intensive combustion in combustion chambers of different applications is possible.

presentation; the essence of the invention

The object of the invention is to develop a fluidized-bed burner which ensures intensive combustion in a subsequent combustion chamber with reduced formation of 110 and supplies the fuel to the combustion even when the lowest pressure flow pressure is present.

The object is achieved in that the fuel dust with a carrier gas passes through a gas inlet channel to a nozzle inlet, which follows a nozzle body and where due to a primary air inlet through a nozzle gap suction is ensured from the gas inlet channel, which is realized by the known Coanda effect and wherein a forwarding of

required Brennstaub carrier gas stream through a diffuser channel to. a Brennerovorraum takes place, it is concentric on the diffuser channel, a secondary air duct is present, which has the secondary Primärrad installations, which the secondary air vorrallt supplies the Brennervorraum, the formation of a first swirl flow field in the conical Brennervorraum, further includes the burner concentrically around the secondary air duct a Tertiärluftkanal, which directs the upper air to reduce the UO formation during combustion in the burner chamber and thereby impresses by means of Sekundärdralleinrichtungen at the end of the conical Brennervorraumes a coupled to the first swirl flow field second swirl flow field of the flame / the suction by means of a known device for obtaining a Coanda Effect allows for existing low-flow pressure of the Brennstaub-Trägergasströmes in the gas supply passage, a supply of the fuel dust in a burner chamber to achieve intensive combustion. The twisting in the primary and secondary twisting device can be the same or different, wherein the flame formation in the first swirl flow field is realized by reacting with a hankin ice, whereby according to the invention also difficult and solid solid fuels can be used and, above all, by means of the upper air in short combustion chambers, the combustion of the particles leading to ITO formation is ensured.

The design of the conical burner pre-chamber is significantly influenced by the fuel used, with a half-opening angle of 15 ° to 35 °, the failure

tion of the Rankine vortex favors. The length of the conical burner pre-space influences NO_ formation. The cone according to the invention has a Durchser-sser-Längenveriiältnis bis to 2. According to the invention lead into the cone of the burner pre-space three auxiliary channels, which allow the inclusion of auxiliary equipment, in particular ignition and flame monitoring. The cooling of the conical Brennervorraumes by the tertiary air leads to a warm-up, making them more effective as an upper air to reduce NO formation.

The primary air acts as a driving medium and must ensure the Coanda effect when flowing through the nozzle gap with a separation-free deflection. The pressure of the primary air is about 0.07 MPa. Depending on the design of the nozzle gap and the negative pressure to be generated, this required primary air pressure may also be less. With the pressure of 0.07 MPa, an intake pressure of 700 Pa can be achieved for burner outputs of up to 10 MW. The advantage of the burner according to the invention lies in the absorbency by the Coanda effect, which supports the supply of fuel for combustion, especially in long gas ducts, further in a closed impingement flame, which prevents a concern of the flame on the combustion chamber wall and realizes a short axial burn-out. Sin further advantage lies in the compactness and the forced cooling of all assemblies, which corresponds to the technological functioning, the maintenance requirement and the adjustment demand at combustion chambers of most different application cases.

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Ausführunssbeispiel

The invention will be explained in more detail below using an exemplary embodiment. The accompanying drawing shows a longitudinal section through a burner.

The burner 1 is supplied by the gas inlet channel 4 with solid fuel, in particular fuel dust, which is present as a fuel vapor carrier gas stream. By means of burner flange 2, the burner 1 is attached to the end wall 3 of a combustion chamber. The fuel dust carrier gas flow passes through the gas inlet channel 4 to a suction device, which is formed by the nozzle inlet 5), the nozzle body 6 and the Diisenspalt 7. By a primary air inlet 8 of the nozzle gap 7 is flown, whereby the Coanda effect is realized. The Coanda effect is based on a separation-free deflection and creates a suction effect. This suction effect causes a suction effect on the fuel dust carrier gas mixture in the gas inlet channel 4. In the further flow direction of the fuel dust carrier gas flow through the diffuser channel 15 is an introduction of the fuel dust carrier gas stream in the burner pre-chamber 16. At the Snde of the diffuser 15 are located around him concentrically arranged primary spin 11th These primary sound installations 11 are acted on by the combustion air through the secondary air inlet connection 9 via the secondary air duct 10 and form a first swirl flow field in the burner pre-chamber 16. To support the effectiveness of the Rankine vortex in the blast flame as well as to

tiäriuftaufwarmung the burner cavity 16 is conical, formed. Half the opening angle is 35 °. The diameter aspect ratio is 1. The primary impellers 11 are rigid and create a swirl flow field with the swirl number 2.7. The secondary air duct 10 is surrounded concentrically with the tertiary air duct 13. The. Upper air to reduce the formation of MO passes through the tertiary air inlet nozzle 12 to the Sekundärdralleinbauten 14. The Sekundärdralleinbauten 14 are arranged rigidly at the end of the conical Brennervorraumes 16. In the burner chamber 17, a coupled second swirl flow field is generated. The heating of the upper air when flowing through the • Tertiärluftkanals 13 is about 80 K. Lifting the heating of the upper air takes place thereby a cooling of the conical Brennervorraumes 16. The muffle 18 has a half-opening angle of 55 ° x 3? For a 12.5 t / h steam generator with lying combustion chamber 17, the burner 1 is supplied with brown coal burning dust. For this purpose, briquette waste is comminuted by a crushing mill and fed to the burner 1 by a pneumatic conveying system. The suction through the burner 1 supports the delivery process and ensures a sufficient plunger pressure of the fuel vapor carrier gas stream, whereby an intensive combustion is ensured even in short combustion chambers. The propellant gas with a pressure of 0.07 MPa is the primary air inlet 8 abandoned.

Claims (2)

-JT- Brfindungsans-pruch 1. vortex burner for NO-poor combustion, consisting of a fuel dust carrier gas leading gas inlet channel, a subsequent diffuser channel and concentrically arranged around the diffuser channel secondary and Tertiärluftkanäle having rigidly mounted at their end spin build-ins, characterized in that in front of the diffuser channel Ansaugeeinrichtung consisting of nozzle inlet and nozzle body, which form a controllable gap in the gap, is arranged, the Ansaugeeinrichtung by task of a propellant, which passes through the Frimärlufteintritt in the nozzle body, realized the Coanda effect and the Ansauwerirkung generated thereby on the In addition, a conical burner pre-space is arranged between the swirl internals, wherein the upper air in the tertiary air duct cools the conical burner premia on the air side, thereby warming up by 80 K and forming a swirl flow formed by the secondary air mung generated field coupled second swirl flow field for NO-poor combustion. 2, vortex burner according to item 1, characterized in that gaseous substances, in particular air, are used as propellant, wherein the pressure of the propellant by 0.03 MPa to 0.07 MPa greater than the pressure of the suctioned fuel dust carrier gas. For this 1 page drawing.