DE7904137U1 - BURNER FOR POWDER-SHAPED OR FINE-GRAINED SOLID FUELS AND COMBINATIONS OF SOLID, LIQUID AND / OR GASEOUS FUELS FOR THE MOST POSSIBLE ADJUSTMENT OF THE FLAME SHAPE, DURING OPERATION - Google Patents

Description

Burner for powder? or fine-grain solid fuels and combinations of solid, liquid and / or gaseous fuels for the greatest possible adjustment of the flame shape; even during operation. %

The invention relates to burners for combustion powder- §

shaped or fine-grained solid fuel alone or %

in combination with liquid and / or gaseous fuel |

materials for stoves and heating equipment, preferred |

way for rotary kilns, suspended gas heat exchangers, grates and ·;

Combustion chambers for the greatest possible adjustment of the $

Tame shape is also required during operation. |

Such burners should make it possible. Fuels and j

Combinations using the available air volume that |

partly as full combustion air, · partly only as a primer

Marble air may be passed through the burner, so to |

burn that the procedural process is optimal |

expires. I.

It is therefore required that the outflow form for fuel and air and, in the case of solid fuels that do not wear out much, also for the carrier gas-coal dust mixture also during the The operation can be adjusted continuously in the widest range so that the required combustion process is achieved.

In addition, it is required that, in particular with abrasive solid fuels, long service lives of the burner and the fired system can be achieved.

The burner construction must therefore be chosen so that the flowing carrier air-fuel mixture is deflected as little as possible and internals happen at the lowest speed.

To protect the fired system from wear and tear, it must also be possible to set the most suitable flame shape.

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The economic efficiency of the operation is also favorably influenced by optimally adapting the combustion process, because as a result, the lowest possible fuel consumption is required is.

In addition, it should be possible to use moderate fuels thermal properties, e.g. B. with little volatile Ingredients or very high ash content.

State of the art:

It is known that to partially meet these requirements, burners are used, oie from a single duct exist, through which the zvor mixed into the desired or available amount of carrier air and / or gas Amount of fuel flows out of a nozzle.

The influence on the shape of the plam is only extremely limited here possible by changing the amount of carrier air and thus the. Outflow velocity is influenced.

In addition, from the fuel side, by changing the grinding or choosing other fuels, a certain limit can be achieved Influence can be exercised. '

A significant improvement was achieved as a two-channel burner were used, in which the carrier air-fuel mixture flows out through the outer channel in the axial direction and the divergence and rotation through a clean air component is influenced, which is adjustable and is supplied within the fuel air flow.

A liquid or gaseous component for start-up operation and ignition can also be supplied in a central jacket tube will.

Since the axial component of the air supplied is already fueled loaded, it can only be used to a very limited extent.

be ried, so that the influence on the shape of the flame is greatly reduced. In addition, the solid fuel must be passed through the channel at the speed that the required outflow speed due to the used volume flow results. This increases the wear and tear accordingly and also in the inflow part the built-in components subject to wear and tear are subjected to greater volume flow rates.

The possibility of influencing the outflow from this channel are severely limited because of stronger deflections Divergence fixtures or even rotation are eliminated for reasons of wear. There is also no possibility of installation two-part outflow body, which increases the outflow speed through axial displacement at a given volume flow allow adjustment.

In the case of particularly heavy wear, the outer jacket tube is broken and a secondary flame is formed, causing it to more severe damage can occur.

It is also known that powdered for combustion solid fuels, burners consisting of three concentric tubes were also installed in which the individual clean air and carrier gas-pulverized coal components have been introduced tangentially to produce some rotation. Because The lack of outflow bodies for the generation of divergence and rotation only occurred, especially in the partial load area to very limited effect.

In particular, certain types of flow, such as a strong axial flow with little divergence, were possible due to the given rotation cannot be realized.

The outflow velocity from the clean air channels could also be used cannot be varied for a given volume flow.

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The burner should therefore offer the possibility of the flame ■ shape and thus the combustion process in the largest possible range can also be adjusted during operation.

The fuel should be released immediately after it leaves the burner be ignited.

In the burner and in the subsequent system should be the lowest Wear with abrasive fuels.

A :: The highest possible control range for the amount of fuel is required

will.

It is said to be with all possible fuel combinations like several solid fuels of various "quality or solid" Fuels can be worked with liquid and / or gaseous.

The shape of the flame should be constant, especially when the ratio between the different types of fuel must be adjusted during operation »

For fuels with unfavorable thermal properties a good ignition should still be achieved and the burn-up should take place in the desired time.

Bsi burners in which only a very small part of the combustion air is often used can be conducted in the form of primary air to influence the shape of the flame via the outflow system, because the remaining combustion air flows uncontrolled from the coolers downstream of the process into the combustion chamber, it depends on the outflow velocity of the individual clean air components that are used for a given volume flow Formation of the flame shape are combined, during the loading

set the drive to the most suitable value. Solution:

This object is achieved in that the Air and fuel are supplied through four concentric tubes, the innermost of which is used to accommodate the supply system for liquid and / or gaseous fuel components with a corresponding outflow system for atomization and / or gas outflow is provided, the next concentric channel (2) for a clean air component with an adjustable outflow system for divergence and / or rotation (5) is equipped, the next more concentric Channel (3) for the supply of the carrier air or gas / coal dust mixture with an outflow system for purely axial or divergent Outflow and its next concentric outermost channel (4) for clean air with an outflow system is equipped for axial or divergent outflow (6).

The influence of the Flammenfonü is expanded by that the outflow velocities at the point of the clean air ducts by axial displacement and / or rotation of two-part bodies by adjusting devices (5 + 6, 7 + 8) bai given Volume flow can be adjusted over a wide range.

Since in most cases a divergent outflow is required, there can be a channel for the carrier gas / coal dust mixture (3) in the case of a less severe wearing effect, a divergent preferred direction and / or rotation due to corresponding Installation in the outflow system of this channel can be given.

In many applications, for example when used in rotary kilns, there is a requirement that the proportion of primary air, which is passed over the burner to influence the shape of the flame, to be kept as small as possible in order to make one: large Share of waste heat from downstream coolers to be used.

For this purpose, throttle device ^ (9 + 10) attached, with which the volume flows in the individual channels can be regulated and the distribution of the primary air to the various outflow forms can be carried out during operation can.

To protect the burner from wear and tear, the coal dust feed duct Built-in components (12) that are subject to wear and tear are built into all deflections and can easily be replaced.

Coal dust that has precipitated out of the carrier air stream is back in front of the exit cross-section through an installation (11) in the Coal dust feed channel mixed into the carrier air.

Up until now it has generally been the practice to use the inflow section of the burner to be installed in a burner support. This required that the burners be withdrawn from the furnace when repairs are required.

By fastening the outer jacket tube (4) in the burner support, it is possible to carry out repairs to the internal fittings in Operating positions · to be carried out and thus to be accelerated considerably.

In addition, when switching to other operating situations, which make it necessary to replace parts of the burner, the conversion can be carried out quickly.

Advantages;

Since the shape of the flame is only or mainly influenced by streams of clean air that flow on both sides of the carrier gas / Coal dust feed channel are arranged, the adjustment options are not due to wear Coal dust limited. "

All types of flow can be realized with it, which are suitable for the special thermotechnical apparatus and lead to the optimization of operations.

Optionally, you can even work with backflow. Furthermore, unsymmetrical flame shapes can also be achieved by using appropriate Outflow systems are generated in the clean air ducts.

In spite of this, the wear in this burner is significantly less than even when using very abrasive fuels in earlier constructions, which were already characterized by limited possibilities for adjusting the shape of the flame; because the carrier gas / coal dust mixture can in any case with the lowest possible speed, which is just barely does not result in backfire in the duct. This also creates the conditions for immediate Ignition of the fuel improved.

Also in the inflow section, low speeds, minimal UiTilenkungen and particularly low carrier gas use A long service life is achieved by designing the small-sized built-in components that are subject to wear and tear.

The arrangement of the carrier gas / coal dust duct between two clean air ducts has the advantage that neither the outer jacket tube nor the centrally installed fuel supply system for

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liquid and / or gaseous fuel component damaged and thus serious accidents can be prevented.

The re-mixing of precipitated coal dust has the advantage that a homogeneous fuel jet emerges, which does not lead to one-sided heat presentation.

Optionally, it can be used in the duct for carrier gas / coal dust several different types of coal dust, which are supplied with separate pneumatic systems, take place.

The transition to significantly different solid fuels is made easier because the flame shape can be adjusted only or mainly outside of the carrier air coal dust channel lie.

It is of particular importance that there is a transition to significantly different fuels, for example from solid to liquid and / or gaseous, which often have very different burning properties, which see below with the same burner setting lead to a significant shift in heat output can be compensated for by adjusting the shape of the flame with the help of the clean air components.

In systems in which only a part of the combustion air in the form of primary air may be passed over the burner, while the main part from a downstream cooler flows unaffected into the combustion chamber, the advantage of this new design is that with very low primary air can be worked and thus the waste heat recovery from the downstream cooler is improved.

Example: See attached drawing. |

This drawing shows the example of a rotary kiln,

burner for solid, powdery or fine-grain fuel |

substances in combination with liquid and / or gaseous?

Fuels shown. |

The burner consists of the inflow section, the duct guide £

with four concentric tubes with a stabilizer in the J,

Fuel duct and the exhaust system for each $

Fuel and air components.

The outer jacket pipe is covered with a refractory coating |

provided and also serves to attach the burner f

in the burner support. This means that all fixtures are in operational |

The burner position can be easily adjusted using the slide-in system

changeable. In the inlet part of the clean air ducts are the |

t Throttle devices for setting the selected volume

i menstromus installed. . f.

To protect against wear from abrasive fuels, |

in the inflow area of the carrier air-fuel mixture f

Wear fixtures are provided that are easily replaceable j

so that the exchange has minimal interruptions |

of a few minutes. |

Structure of the canal routing: I.

In the central "casing" (1), the supply line for liquid or gaseous fuel for the start-up '<is operating and particularly inferior in burning solid fuels as a support flame.

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In the next concentric channel (2), pure air flows out to generate a divergence and rotation component via an adjustable swirl body (5) which is actuated by the adjustment device (7). '-

In the next concentric channel (3), the coal dust / carrier air or carrier gas mixture is fed in at the lowest possible speed. It flows out axially at the outlet without any installation or, in the case of less-wearing fuels, via a divergence body.

In the outer duct (4), pure air flows, which exits via axial bodies or, if necessary, is guided into the furnace with an adjustable, divergent preferential direction (6) which is actuated by the adjustment device (8).

The structural design of the central coal dust channel prevents dead corners and thus smoldering fires.

The volume flows of the primary air in the clean air ducts are regulated in the inner clean air duct for divergence and rotation via adjustment device (7), in the outer clean air duct for axial flow with weak divergence via adjustment device (8).

The exit speeds from the clean air ducts are set for divergence and rotation (inner clean air duct) via the adjustment device (9) and for axial flow and weak divergence (outer clean air duct) via adjustment device (10).

The variable exit cross-sections are therefore only located in clean air ducts.

In the inflow section, low speeds and minimal deflection long service life of the wear fixtures (12) achieved because of the low use of carrier air Can be made small and can be replaced in an extremely short time thanks to a sensible design.

. . Since the duct for the carrier air / coal dust is located between two cleaning air ducts, the pneumatic conveying can be used as an option also a gaseous auxiliary fuel can be used, for example, the ignition of a fuel with

S particularly low volatile content and

high ash content. Also, through this

Arrangement the risk of damage to the outer jacket tube or the central liquid or gaseous ignition component eliminated by particularly abrasive fuel.

For these reasons, the. Repair costs low.

J Since the mixture of the solid fuel with the carrier gas in the

When the burner is stabilized by special internals, there is already complete mixing of the two components, so that the ignition is significantly favored.

Start-up operation:

As with all PILLARD burners, this three-channel system for solid fuels and combinations with liquid and gaseous fuels can be started up continuously and without modification.

The start-up fuel component used for this, which is located in the center of the burner, is supplied under the most favorable conditions, so that damage to the refractory lining can be avoided with certainty if there are no deposits.

Fuel combinations: The burner also offers the option of using several types of coal dust either or at the same time in any variable amount.

The transition to other solid fuels is made easier because the adjustment options for the flame shape in this firing system are significantly expanded .

By combining the central jacket tube with the duct for coal dust and carrier air, the flame shape can also be varied within wide limits in the event of a temporary transition to pure gas operation.

The burner can also be used for the simultaneous operation of solid, liquid and gaseous fuel components.

In mixed operation, a change in the shape of the flame in the event of failure of a fuel component is avoided.

Claims (7)

r ι η 14 G 79 Q4 137.5 Pillard Feuerungen GmbH protection claims 1. Burners for burning powdery or fine-grained ones solid fuels and their combination with liquid and / or gaseous fuels for the Adjustment of the outflow shape and speed the fuel and air components, thereby characterized in that four concentric tubes (1-4) for the air and fuel feeds are provided, the innermost (1) for receiving the supply system for liquid and / or gaseous Fuel components with an outflow system for atomization and / or gas outflow is provided, the next concentric first channel (2) for a clean air component with a preferably adjustable one Outflow system (5) is equipped for divergence and / or rotation, the next second concentric channel (3) for the supply of the carrier air or gas / coal dust mixture with an outflow system for * pure-axial or divergent outflow and its third concentric outermost channel (4) for pure Air is equipped with an outflow system for axial or divergent flow (6). 2. Burner according to claim 1, characterized in that axially displaceable and / or rotatable two-part Outflow bodies (5, 6) are provided in the clean air ducts (2, 4). 3. Burner according to claim 1 or 2, characterized in that at the outlet end of the second channel (3) for the supply of the carrier air or gas-coal dust mixture a two-part vent body is installed. 4. Burner according to one of the claims. 1 to 3, characterized in that that in the connecting piece of the inlet s flow part throttle devices (9, 10) arranged are. 5 5. Burner according to one of claims 1 to 4, characterized in that that at the ümlenkstteile in the inflow part wear fixtures (12) are provided for the solid fuel. 6. Burner according to one of claims 1 to 5, characterized in that that a stabilizer (11) is installed at the beginning of the second channel (3). 7. Burner according to one of claims 1 to 6, characterized in that that the outer jacket tube is attached to the burner support.