JPH0252765B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a burner that can use particulate fixed fuel, gas fuel, and/or liquid fuel, in which the fuel is sent to the combustion chamber where the main combustion takes place. On the upstream side of the flow, an ignition chamber connected to the combustion chamber, a fuel supply pipe extending along the central axis of the ignition chamber and opening into the ignition chamber, and an opening of the pipe to the ignition chamber. an annular first combustion air inlet that surrounds and is formed substantially coaxially with the pipe and receives combustion air, that is, first combustion air, into the ignition chamber substantially coaxially with the fuel jet jetted from the pipe; The combustion chamber has a flow path that passes through the outside of the combustion chamber without passing through the ignition chamber and supplies the remainder of the air necessary for combustion of all the fuel to the combustion chamber, and the ignition chamber is located on the downstream side with the central axis as the center of rotation. The first inlet is provided with a peripheral wall made of a rotating surface whose diameter increases as the diameter increases, and an exhaust pipe provided adjacent to the downstream side of the peripheral wall and communicating with the combustion chamber. It has a swirling flow generating device that gives a swirling motion to the combustion air flow, and by generating a circulation of combustion air in the ignition chamber, the high temperature combustion gas of the fuel is sufficiently mixed in the ignition chamber and ignited. Relating to a burner configured to heat up to a temperature.

[Conventional technology]

With the prices of liquid and gaseous fuels, which have shown a strong upward trend in recent years, there is an increasing tendency to make available solid fuels, which are often available at well-valued prices. There is. In the case of solid fuels, the grate combustion method, which is mainly used for steam generation and hot water production, is
It cannot be used as a heat source for processes in a wide range of fields. The reason for this is that special conditions are generally imposed on the location where the condensate is combusted. Therefore, in such fields, it is necessary to use burners that produce a flame similar to that produced by liquid or gaseous fuels, and for this purpose the solid fuels are burned in a finely divided and powdered form. must be done.

For example, the use of fuels such as pulverized coal, i.e., pulverized fuel, has been limited to large combustion devices that burn continuously under substantially uniform conditions, particularly in thermal power plants and rotary furnaces in the cement industry. However, there is now a growing trend to use pulverized fuel even for medium-sized combustion equipment. Examples are, for example, heating furnaces and melting furnaces in the metal industry, combustion furnaces used in the nitrogen industry, melting furnaces for hollow glass and plate glass, combustion chambers of steam boilers, combustion chambers of drying equipment, etc. These new fields require burners that have an extremely wide range of applications. The reason for this is that medium-sized fuel systems such as those mentioned above are able to perform almost the same ignition and combustion operations (including a constant flame shape) even under highly variable load conditions. This is because a function such as this is necessary, and a function that allows use of fine powder fuels having various ignitability and calorific values is also required. This is because not only pulverized coal, which is inexpensive in terms of price, but also pulverized brown coal, sawdust, or sludge obtained from wastewater treatment may be used. From the above considerations, only a small portion of the many technologies obtained in pulverized powder combustion devices used in conventional large-sized combustion devices can be applied to medium-sized combustion devices.
Therefore, it can be seen that new burner technology, which was not previously known, is required for the above-mentioned medium-sized combustion apparatus. On the other hand, the combustion of fine powders has different ignition and combustion characteristics than the flames of liquid or gaseous fuels, and therefore medium-sized combustion is possible on the basis of already mature burner technology for gaseous or liquid fuels. It is not possible to proceed with the development of the device.

The pulverulent fuel is normally fed into the pulverulent combustion burner in a relatively dense jet in a mixture with a small amount of conveying air. This jet must first be made ready for ignition, for which it must be heated and mixed well with the combustion air. In such a pretreatment step, the volatile components contained in the volatile substances contained in the pulverized combustion material are first gasified, and when the fuel reaches a sufficiently high temperature, this gasification is performed. The volatile components ignite and burn, followed by combustion of the combustible solid components. Such ignition and combustion behavior is influenced by the particle size of the pulverized fuel and the properties of the pulverized fuel material. For example, if the above-mentioned particle size is small, the fuel heats up rapidly, and the differences in the substances contained in the fuel material itself, that is, the content ratios of volatile components, moisture, and ash, vary greatly depending on the type of fuel material. The differences greatly affect the ignition of the fuel material and the operation of the combustion chamber.

Larger equipment is usually operated with pulverized fuel that remains fairly constant, so large variations in the quality and type of pulverized fuel need not be taken into account. Generally, in burners designated for large scale production, the jet of fuel is delivered directly into the combustion chamber. The pretreatment and ignition of this fuel jet takes place as follows, either solely by the thermal conditions in the combustion chamber or with the aid of oil or gas as auxiliary fuel. That is, the hot gases present in the combustion chamber are directed toward the burner opening and are mixed into the fuel jet. In this case, there is a method of promoting even more high-temperature gas to enter the fuel jet to further stabilize the ignition operation. For example, by blowing air into the fuel jet or by introducing air in a swirling or swirling flow, the fuel jet can be expanded more or less strongly into a conical shape. A similar effect can be obtained by feeding the combustion air around the burner opening, by constricting or conically expanding the air supply pipe opening as appropriate, and by forming a circulating flow of combustion air to This can also be obtained when a negative pressure region is formed near the base of the jet stream. By enlarging the flow path of the fuel jet, the combustion flame becomes short and swollen, and in addition, more and more fine powder particles and ash particles generated by combustion are ejected from the flame extension path and spread outward in the radial direction. emitted in the direction.

Burners which pre-treat and ignite the fuel jet in the combustion chamber are thus unsuitable for varying requirements. This is because, in the above case, the ignition operation can no longer be kept stable. Furthermore, as a heat source for many processes used in various industrial sectors, it is not appropriate to blow relatively strong air into the fuel jet in order to stabilize ignition. This is because various particles are emitted in the radial direction, which causes contamination of the external environment and also causes various problems to the combustion chamber. i.e. approx.
In the combustion chamber at a high temperature of 1100℃ or higher, the discharged ash particles soften or even become liquid, causing seizure and corrosion phenomena, and in the combustion space at a temperature lower than the above temperature, the discharged ash particles soften. Although it is maintained in a sufficiently hard state, the ejected fine powder will no longer ignite or will be extinguished before it is completely combusted. This obviously results in a loss of fuel. Therefore, it can be seen that a flame that is elongated and has fewer particles escaping outward is preferable, rather than a flame that is thick and short as described above.

A method in which the jet of fuel is not ignited for the first time in the combustion chamber, but is ignited in a special ignition chamber placed in front of the burner opening was proposed by F. Schoppe at the publisher AW Gentmer KG in Stuttgart. Catalog “Calculation of burners, combustion chambers and similar flow devices” published by
It is described on page 37 and below. in this case,
The ignition chamber has a conically expanding peripheral wall and transitions into an exhaust pipe leading into the combustion chamber. In the central part of the peripheral wall of this chamber there is provided a pipe opening for supplying the fuel jet, which opening is surrounded by an air flow inlet (for example an annular slit), through which the air flow can be supplied. Combustion air in the form of a swirling stream is introduced into the ignition chamber and forms a negative pressure region near the root of the fuel jet.

During operation, the swirling flow flows along the peripheral wall of the ignition chamber toward the end of the chamber, where it is divided into two streams. Of the two branches, the one closer to the wall reaches into the combustion chamber through the discharge pipe, and the other branch forms a circulating flow based on the negative pressure region,
It flows in the opposite direction to the fuel jet and is sent back to the root of the jet. Due to the generation of the above-mentioned flow, the high-temperature gases generated by the combustion action taking place in the ignition chamber are sent to the root of the fuel jet, and as a result, the fuel jet The pretreatment and ignition operation of the outer peripheral area of the engine are started. In this case, since a vortex is generated between the fuel jet and the circulation flow flowing in the opposite direction to the jet, the ignition propagates relatively rapidly toward the inside of the fuel jet.

Although the above-mentioned burner was newly developed for use in relatively small capacity applications (one example being boilers for central heating), it still has some essential drawbacks. Therefore, it is unsuitable as a medium power heat source used as an industrial process heat source. In the conventional burner as explained above, all of the air for combustion is sent into the ignition chamber as a swirling flow, so in this ignition chamber, not only ignition but also combustion occurs in a considerable portion of the fine fuel powder. Only a short flame from the almost burnt out pulverized fuel emerges from the burner opening. In the above case, the fuel jet is almost completely decomposed in the ignition chamber, so that a considerable amount of ash particles are delivered to the walls of the chamber. In this case, if the combustion amount of the burner is not small enough,
Temperatures that are high enough to occur in the ignition chamber cause these ash particles to become liquid or viscous, causing them to stick to the walls. Moreover, a portion of the constantly swirling flow reaches into the combustion chamber, where it causes further radial ejection of ash and pulverized fuel particles.

[Purpose of the invention]

The object of the present invention is to achieve stable ignition even under moderate combustion scales and variously changing requirements, and to create an elongated flame inside the combustion chamber that releases fewer particles in the radial direction. It is possible to provide a burner that can be generated.

[Means to solve the problem]

In order to achieve the above object, the burner of the present invention includes an annular second combustion air flow that introduces a second flow of combustion air into an intermediate region between the peripheral wall of the ignition chamber and the exhaust pipe.
An inlet is provided along the outer periphery of the peripheral wall, and as a result, the axial length of the circulation in the ignition chamber is limited by the flow of second combustion air flowing in from the inlet, and the second combustion air is supplied to the combustion chamber. The fuel jet is formed so as to flow out from the exhaust pipe substantially in the direction of the central axis while the swirling movement is stopped in the exhaust pipe,
The total amount of combustion air supplied to the ignition chamber via the first inlet and the second inlet does not exceed 50% of the total stoichiometrically required amount of air depending on the supplied fuel. It is formed like this.

[Operation and effect of the invention]

This invention meets many of the requirements of medium combustion capacity burners used in normal industrial processes, provided that the drawbacks previously associated with burners of this type are overcome. We started from the idea that it should be possible to use it sufficiently. As a result of various studies, the above-mentioned drawbacks were solved by adopting the technology described in the claims of the present invention.

During operation of the burner of the present invention, the combustion air supplied into the ignition chamber from the first inlet as a swirling flow forms a negative pressure region at a position surrounding the fuel jet, and this negative pressure region is It blows up and expands the fuel jet a little, and it also works to flow the high-temperature circulating flow back toward the root of the fuel jet. Also, a part of the combustion air sent from the second inlet flows as a swirling flow that surrounds the fuel jet in an annular manner, helping to form the above-mentioned negative pressure region and helping to realize stable ignition of the fuel jet. do. The other part of the combustion air supplied from the second inlet also has other functions. That is, the swirling flow of air easily transitions to the reflux flow,
The part of the reflux near the peripheral wall has a weaker flow through the discharge pipe.
Further, the circulating flow is such that the above-mentioned transition occurs at a certain point in the ignition chamber.
In addition, it is possible to produce the effect that the operation is carried out within a predetermined cross-sectional area, in other words, the axial length of the circulation area can be changed. Further, an effect obtained in addition to the above-mentioned effect is that the swirling flow that exists in the swirling flow of combustion air and the fuel jet in the exhaust pipe (this swirling flow may be formed by a special device, and the swirling flow of the swirling air (It may be formed by the influence of swirling flow.)
However, the flow of pulverized fuel particles in a predominantly axial direction through the burner opening is substantially completely or substantially inhibited, at least to the extent possible. For this purpose, it may be advantageous if the other combustion air is configured to swirl in the opposite direction. It should be noted that the combustion air supplied through this second inlet serves to cool the discharge pipe and prevent residues, in particular molten ash particles, from settling therein.

It is equally important in this invention to maintain a sub-stoichiometric combustion rate in the ignition chamber. The first effect of this is that the fuel jet is only slightly broken down in the ignition chamber, and fewer particles are emitted in the radial direction within the ignition chamber. Also, the ignition chamber is sufficient to ignite and start combustion;
Only a small amount of air is needed due to intense combustion.
Since it only acts on the fuel jet, the effect can also be obtained that complete combustion of the fuel jet takes place within the combustion chamber and that the ignition chamber is kept at a relatively low temperature.

According to the invention, it is therefore possible to obtain a burner which is extremely versatile and flexible.
Further, according to the present invention, even in a burner that handles a medium-sized combustion amount, it is possible to operate without causing ash content that causes various problems, and there is no swirling flow and the ignition is completely and well. approximately based on the fuel used and required operating conditions.
Generates a strong central axial fuel jet reaching temperatures of 700-1200℃. As a result, in all combustion chambers, when the temperature is high, an elongated flame shape and a stable fuel jet result in almost complete combustion, regardless of when the temperature is not so high. Ru.

Ignition and combustion within the ignition chamber are carried out using fuel and combustion air in a proportion less than the stoichiometric amount, and this proportion is determined by considering the following points. That is, it depends on the nature of the fuel used and a number of conditions related to it, and on the amount of total combustion air introduced into the ignition chamber that is required to mix with the fuel jet and cause ignition and initiation of combustion. It will be done. When the burner operates as described above, the combustion air introduced into the ignition chamber is the carrier air (corresponding to about 2 to 7% of the total amount of air) necessary to supply the pulverized fuel. ), one that is supplied from the first inlet to form swirling flow air (corresponding to about 2 to 15% of the total air amount), and combustion air other than the above that is sent from the second inlet. be done. Of these, the conveying air is completely mixed, and the swirling air is almost completely mixed with the fuel jet, while the remaining combustion air is used for various purposes. The conveying air and the combustion air supplied from the first and second inlets may be thoroughly mixed. However, in that case, the amount of combustion air must not exceed 50% of the total amount of combustion air based on stoichiometry. However, if particularly required, the amount of combustion air may be greater than the stoichiometric amount. In this case, only a portion corresponding to the highest permissible amount is mixed with the combustion jet, for example by means of suitable flow regulation means, and the remaining portion is passed into the combustion chamber through the outside surrounding the fuel jet. It may be injected. By selecting the amount of combustion air as described above, the correspondence between the amount of combustion air at the burner opening and the temperature changes.

One of the advantages of the present invention is that the burner is not limited to using, for example, solid, pulverized fuel, but can also be operated using liquid fuel or gaseous fuel. When using pulverized fuel as the main fuel and gas or oil as the auxiliary fuel, for example, if a bottleneck occurs in supplying the pulverized fuel, the main fuel supply can be cut off and the auxiliary fuel can be used if necessary. The supply can be increased to an amount corresponding to full load and the burner can continue to operate. When gas and/or oil are used, ignited heavy oil can also be used as the main fuel. Next, embodiments of the burner of the invention will be described. In this case, identical or functionally similar parts are provided with the same reference numerals.

〔Example〕

The embodiments shown in Figs. 1 and 2 use fine particulate fuel (hereinafter simply referred to as fine powder fuel) consisting of solid, liquid, or gas as the main fuel, and gas as an auxiliary fuel to be mixed with this. The principle of the burner of the present invention used is shown. Inside the pipe 16 for combustion air there are three pipes 1, 2 and 3 arranged coaxially with the pipe 16, which together open into the ignition chamber 20. 3 pipes 1,
The centrally located pipe 1 of 2 and 3 is used to supply the fuel jet. The intermediate pipe 2 is used for supplying auxiliary fuel gas, and a swirl generator 21 is provided at the opening thereof. The outer pipe 3 is used to supply swirling flowing air into the ignition chamber 20.
In the illustrated embodiment, the swirl generating device 21
is provided at the end of the pipe 3, and includes:
A space in which air flows while swirling, that is, an annular space 4 for swirling flow is formed. The annular space 4 is connected to the internal space of the pipe 3 through a plurality of tangentially bored holes 5, and an inlet 50
are respectively connected to the ignition chamber 20 via.
In this case, it is preferable that the inlet 50 is provided with an annular protrusion 22 that acts as a throttle. This protrusion 22 serves to prevent the main fuel, auxiliary fuel, and air from flowing back from the ignition chamber 20 into the annular space 4 .

The ignition chamber 20 is surrounded by a curved peripheral wall 8.
This peripheral wall extends from the swirling air inlet 50 in the opposite direction to the pipes 1, 2, and 3 (to the right in the figure), and the cross section perpendicular to this direction becomes larger toward the right. The arrows shown in the figure indicate the direction in which the main fuel, auxiliary fuel and air flow. A discharge pipe 17 is attached downstream from here. Discharge pipe 17
may be formed into a cylindrical shape with a uniform cross-sectional diameter, or may be formed so that the cross-sectional diameter increases or decreases toward the downstream side. In the example shown in FIG. 1, the discharge pipe 17 has a diameter that gradually decreases until it reaches the cylindrical opening 11. 17' in the figure shows a cylindrical discharge pipe with a broken line. The ignition chamber 20 is located between the peripheral wall 8 and the discharge pipe 17,
It has an annular inlet 60. The inflow port 60 is formed by the discharge pipe 17 having a diameter slightly larger than the diameter of the right end of the peripheral wall 8 at this portion. It is preferable that the cross-sectional area of the opening of the inlet 60 is adjustable. For this purpose, for example, the discharge pipe 17 may be disposed so as to be movable in the axial direction of the air pipe 16, that is, to the left and right in the figure, or may be disposed outside the peripheral wall 8 of the ignition chamber in the axial direction of the air pipe 16. A movable and adjustable aperture (not shown) may also be provided.

When operating the burner of FIGS. 1 and 2, auxiliary fuel gas is first fed into the ignition chamber 20 together with swirling flowing air and combusted. Next, a jet of pulverized fuel, or a fuel jet, consisting of a mixture of pulverized fuel and air carrying the pulverized fuel is supplied to the ignition chamber 20 via the pipe 1 . At this time, it is also possible to provide another swirl generating device 24 in the pipe 1 so that the fuel jet in the ignition chamber 20 is expanded into a conical shape as indicated by arrow A in the figure and then sent out.

The swirling flowing air discharged from the inlet 50 flows outward along the peripheral wall 8 inside the ignition chamber 20,
Then, a part of the flow is diverted to the ignition chamber 2 as indicated by arrow B.
Moving on to the reflux circulating within 0. The high temperature gas generated by the ongoing combustion in the ignition chamber 20 is thereby directed to the root of the fuel jet. The fuel jet exiting from the pipe 1 therefore begins to ignite immediately and reliably and is fully ignited at all burner openings 49 facing the combustion chamber (not shown).

In the embodiment of FIGS. 1 and 2, the main amount of the total required combustion air is supplied from the left side of FIG. The other part enters the ignition chamber 20 through the inlet 60, where it flows directly into the combustion chamber (not shown) as shown by the arrow D through the outside of the , flows along the discharge pipe 17 towards the burner opening 49. The divided flow C in the air that has flowed into the ignition chamber 20 is approximately 5 to 50% of the total air amount.
It can be made to account for 45%. This branch flow C acts in cooperation with the swirling flow air from the pipe 3 and the conveying air from the pipe 1 inside the ignition chamber 20 . It works to help ignite pulverized fuel and start combustion. The combustion air available for complete combustion of the fuel jet in the combustion chamber is therefore limited to the ignition chamber 2.
0 and possibly a branch C
is given by the unburned remainder of

The simplest method to be adopted when it is necessary to apply a swirling flow in the opposite direction to the divided flow C to prevent swirling flow is to install a swirling device (see Fig. (not shown).

Note that the swirling flowing air from pipe 2 is transferred to pipe 1.
It would be convenient to generate sufficient swirling energy from a small amount of air by injecting it at a higher pressure than the main air from the air. A typical range for the overpressure applied to the combustion air in pipe 16 above air pressure is about 0.01 to 0.06 bar, and the overpressure applied to the swirling flow air in pipe 2 is 0.08 to 0.4 bar.

FIG. 3 shows a burner constructed in such a way that the introduction of the branched stream C into the ignition chamber 20 takes place by means of a pipe 10. This pipe 10 is provided coaxially with respect to the centrally located pipe 1, and is connected to the ignition chamber 2 through a predetermined number of inclined perforations 29.
Connected to 0. In this embodiment, the ignition chamber 2
The circumferential wall 8 of 0 is made flat, and the discharge pipe 61 connected to the perforation 29 has a cylindrical shape. However, this does not change the basic operation of the burner. As in the case of FIG. 1, the effect of suppressing the swirling flow of the branch flow C can be achieved by providing means for generating a flow that swirls in the opposite direction in the pipe 10, or by appropriately inclining the perforation 29 in the tangential direction. This can be achieved by arranging them in the following manner. The branch flow D can be supplied into the combustion chamber 20 using the air pipe 16 as in FIG. However, it is preferable to provide a suitable number of separate air inlets for the operation to be carried out, each of which may be preceded by an air preheater (not shown).

In the embodiment shown in FIG. 3, the length of the circulating flow B of the swirling air in the central axis direction can be changed by adjusting the amount of the branched flow C and, if necessary, its flow velocity. By the above adjustment, the circulation B is extended until it reaches the opening 49 (see arrow B').
It can also be moved back to the position of the perforation 29 (see arrow B). Using the above adjustment,
Only after the swirling flow air has fulfilled its predetermined function can it stop its swirling motion. This means that
This is important, for example, when using pulverized fuel with variable properties. Furthermore, if necessary, it is also possible to adjust the divided flow C so that it is equal to the total amount of combustion air required, that is, so that there is no need to introduce combustion air insufficient to the total amount into the combustion chamber. .

The embodiment shown in FIG. 4 is very similar to the embodiment of FIG. 3, except that in FIG. In this case, the peripheral wall of the ignition chamber 20 is divided into an inner peripheral wall 8 and an outer peripheral wall 9. One of the swirling air flows through the pipe 27 and the perforation 5, as in the case of FIG. 1, and is fed into the annular space 4 where swirling air is generated. The swirling air flow therefore flows into the ignition chamber 20 through the inlet 50 . For the other swirling air flow, an annular inlet is further provided between the two peripheral walls 8 and 9, which inlet is opened tangentially to the pipe 28 concentrically surrounding the pipe 27. Air is supplied from an annular space 7 which generates swirling air by the action of the perforations 6. The branched stream C is also delivered via the pipe 10 and introduced into the ignition chamber 20 via the inlet 60;
The discharge pipe 62 has a slightly conical shape and widens. In this embodiment, an additional inlet 5
1 is arranged at a relatively large distance from the axis of the ignition chamber, so that the advantage of a strong swirling air flow can be obtained.

In the embodiment shown in FIGS. 5 and 6, the peripheral wall of the ignition chamber 20 is formed of an inner wall portion 8 and an outer wall portion 9, as in the case of FIG. All of the flowing air is fed through the pipe 3 and introduced through the perforations 5 and 6 into the inner swirling flow annular space 4 and the outer swirling flow annular space 7 . The swirling flow air flows out from the spaces 4 and 7 via annular inlets 51 and 52 onto the respective circumferential walls 8 and 9, which are configured in the form of a cone. The discharge pipes 17 of this ignition chamber are designed as external pipes, through which the partial flow of combustion air delivered is led into the ignition chamber 20 by the side of the inner circumferential wall 8 . FIG. 5 shows the provision of means 18 in the pipe 10 for the formation of swirling air flow.

In the embodiment of FIGS. 1 to 6, the swirling flow air delivered from the inlets 50 and 51 is provided by perforations 5 and 6 tangentially provided in the swirling flow annular spaces 4 and 7. It is formed. However, instead of this, it is also possible to use a grid-like guide vane for generating a swirling flow, as shown at 18 in FIG. Figures 7 and 8 show such a structure. The circular inlets 50 and 51 are provided with their own pipes 14 and 15, in which grid-shaped guide vanes 12 or 13 are arranged for creating a swirling flow of air. In this embodiment, a guide plate 23 is additionally provided in the opening 11 of the discharge pipe to restrict the swirling flow of air, and a flow restriction radially directed outside the opening 11. Ignition chamber 2 by plate 19
It flows outside of 0. A desired degree of turbulence can also be generated in the combustion air flow path.

FIG. 9 shows an alternative embodiment to the embodiments described above. In this embodiment, the auxiliary fuel is connected to the fuel pipe 2.
This is different from the previously described embodiments in that the ignition chamber 20 is introduced into the ignition chamber 20 through an inner pipe 25 provided in the ignition chamber 6. Therefore, the supply of fuel takes place through the annular space formed between the tube 25 and the pipe 26.

The embodiment of FIG. 10 shows an alternative structure of the inlet for forming the branch C. The peripheral wall 9 of the ignition chamber is connected to the discharge pipe 17 at its maximum diameter,
In this case, the inlet through which the branched flow C flows is formed by a perforation 29 or a slit 58.

The embodiment of FIGS. 11 and 12 differs from the previous embodiments in that oil is used as the auxiliary fuel. The supply of oil as auxiliary fuel is carried out through a pipe 30 coaxially surrounding the fuel pipe 1 disposed along the central axis of the ignition chamber. The pipe 30 is closed at its downstream end and is connected by a radial perforation 31 to a further coaxially arranged pipe 33 into which air for the atomizer is fed. The auxiliary fuel oil flows into the ignition chamber 20 through the opening 32 of the flow path 54 together with the next atomizer air. The perforations 32 can be arranged to extend obliquely as required, and can also impart swirling flow to the auxiliary fuel. It is also possible to use oil (especially heavy oil) as the main fuel.
A number of embodiments suitable for this are shown in Figures 13-15. These embodiments have in common that only the fuel supply is suitable for the use of oil. Also, the point that an ignition chamber and the above-mentioned swirling flowing air or other combustion air (merging C) are used is the same.

The embodiment shown in FIG. 13 is provided with an atomizing device that adds swirling oil to the main fuel oil. The main fuel oil is introduced into the ignition chamber 20 via a swirl generator 40 through a centrally arranged pipe 35, to which an outlet nozzle 41 is connected. This pipe 35
Oil is likewise supplied through a surrounding pipe 36, which is fed tangentially through a perforation 37 into a swirling flow chamber 38 and from there into a fuel nozzle 39 provided beyond the opening of an outlet nozzle 41. , and is further sent into the ignition chamber 20 together with the main fuel oil. In this case, the outlet nozzle 41 is preferably mounted so as to be axially movable with respect to the fuel nozzle 39. Furthermore, to facilitate the supply of swirling fluid oil, the pipe 36 is surrounded by a pipe 42, which forms an annular jacket closed at its downstream end and whose downstream end is closed. A heating medium for fuel preheating is introduced therein.

Although only the internal structure of the burner shown in FIG. 14 is shown, atomizing of the main fuel oil is performed by oil that undergoes swirling flow, similar to the burner described above. In this case, the main fuel oil is introduced via a central pipe 45, which is provided with an outlet nozzle 53 at its downstream end. A fuel nozzle 39 is provided at the tip of the opening 46 of the outlet nozzle 53. Together with the main fuel oil exiting the opening 46, the swirling fluid oil reaches the fuel nozzle. The above swirling fluid oil is transferred to the pipe 3 as in the case of Fig. 13.
6, receives swirling flow from the perforation 37, passes through the swirling flow chamber 38, and enters the nozzle 39.
flows into. In this embodiment, the relative positions of the pipe 45 and the fuel nozzle 39 cannot be changed. Instead, a central nozzle needle 55 is inserted into the pipe 35 so as to be axially movable, and the amount of oil discharged can be adjusted by means of the conical section of the tip 59 of the needle 55. Note that the main fuel oil can also be introduced into the fuel nozzle 39 with a swirling flow, in which case means 48 for imparting a swirling flow is provided in the intermediate space between the nozzle needle 55 and the pipe 45.

The burner shown in FIG. 15 differs only in that, instead of the central nozzle needle 55, a pipe 43 is arranged in a central position and is supported for axial movement within the pipe 45. 1st
It is different from the burner in Figure 4. The front end 47 of the pipe 43 is formed conically and is provided with a passage 44 therein for regulating the delivery of fuel through the outlet nozzle 53, through which air enters the fuel nozzle 39. The blown air acts to aid atomization of the main fuel oil by the swirling fluid oil. Here too, a heating jacket can be provided (not shown) as in the embodiment of FIG.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view of a burner that uses pulverized fuel as the main fuel and gas as auxiliary fuel, Figure 2 is a sectional view of this burner taken along the - section in Figure 1 above, and Figure 3 is the ignition chamber. Figure 4 is a longitudinal cross-sectional view of a burner that has an inlet of a different structure for introducing combustion air into the ignition chamber, and Figure 4 is a longitudinal cross-sectional view of a burner that has an inlet that is different from the existing one for introducing swirling flow air into the ignition chamber. 5 is a longitudinal sectional view of a burner equipped with a burner different from that in FIG. 4, FIG. 6 is a sectional view of the burner in FIG. 5, and FIG. A longitudinal section of a burner that is different from previously described burners that use gas as auxiliary fuel, Figure 8 is a cross section of the burner in Figure 7,
FIG. 9 is a longitudinal section of a new pulverized fuel burner for auxiliary fuel supply; FIG. 10 is a longitudinal section of the ignition chamber for the remaining combustion air with a configuration different from that shown in FIG. 1; 11 is a longitudinal cross-sectional view of a burner that uses pulverized fuel as the main fuel and oil as an auxiliary fuel, FIG. 12 is a cross-sectional view taken along line XII-XII of FIG. 11, and FIG. 13 is a swirling flow atomizer. FIG. 14 is a longitudinal sectional view of a burner for liquid fuel having a modified example shown in FIG. 13, and FIG. It is a sectional view. 1, 2, 3...pipe, 4...annular space, 5,
6... Perforation, 7... Annular space, 8, 9... Peripheral wall,
10...pipe, 11...opening, 12,13...
...Guide vane, 14, 16...Pipe, 17,
17'...Exhaust pipe, 18...Air flow swirling fluid air forming means, 20...Ignition chamber, 21...Swirl generator, 26, 27, 28...Pipe, 29...Perforation, 35, 45... Pipe, 50, 51... Inlet, 58... Slit, 60... Inlet, 61,
62...Distribution pipe.

Claims (1)

[Scope of Claims] 1. A burner that can use particulate fixed fuel, gas fuel, and/or liquid fuel, in which the combustion chamber an ignition chamber 20 connected to the ignition chamber, and a fuel supply pipe 1 extending along the central axis of the ignition chamber and opening into the ignition chamber;
45, and is formed substantially coaxially with the pipe surrounding the opening of the pipe 1; 26; 35; An annular first combustion air inlet 5 that receives combustion air into the ignition chamber 20
0 and a flow path that passes through the outside of the combustion chamber without passing through the ignition chamber and supplies the remainder of the air necessary for combustion of all the fuel to the combustion chamber, and the ignition chamber 20 rotates about the central axis. Peripheral walls 8, 9 consisting of a rotating surface whose diameter increases toward the downstream side from the center, and exhaust pipes 17, 11; 17', which are provided adjacent to the downstream side of the peripheral wall and communicate with the combustion chamber.
61 and 62, the first inlet 50 has a swirling flow generating device that gives swirling motion to the first combustion air flow, and generates a combustion air reflux B in the ignition chamber. In a burner formed to sufficiently mix fuel and high-temperature combustion gas in the ignition chamber and heat it to the ignition temperature, the peripheral walls 8, 9 of the ignition chamber 20 and the discharge pipes 17, 1
1; 17'; 61, 62, an annular second inlet 60 for introducing the second combustion air flow C is provided along the outer periphery of the peripheral walls 8, 9;
As a result, the axial length of the reflux B in the ignition chamber is limited by the flow of the second combustion air flowing in from the inlet, and the fuel jet A supplied to the combustion chamber is limited to the exhaust pipes 17, 11; 17', 61, 62 while the rotational movement is stopped, it flows out from the discharge pipe approximately in the direction of the central axis, and through the first inlet 50 and the second inlet 60. The total amount of combustion air supplied to the ignition chamber 20 is 50% of the total stoichiometrically required amount of air depending on the supplied fuel.
A burner characterized by: being formed so as not to exceed %. 2 The second inlets 60, 29, 58 are arranged inside the pipe 16 supplying combustion air in the following way, that is, the second part of the combustion air enters the combustion chamber 20,
Burner according to claim 1, characterized in that the remainder D flows into the ignition chamber through the outside. 3. Second inlet 6 for the second part of combustion air
2. Burner according to claim 1, characterized in that air supply pipes 0, 29, 58 are connected to separate air supply pipes (10). 4. Any one of claims 2 and 3, characterized in that the second inlet 60 is formed between the peripheral walls 8, 9 of the ignition chamber and the discharge pipes 17, 11; 17, 61, 62. Burner as described in. 5. Any one of claims 2 and 3, characterized in that the second inlet 60 consists of a number of holes 29 or openings 58, which are provided at a transition point from the wall of the ignition chamber to the discharge pipe. 1. The burner described in 1. 6. A swirl generating device 18 for forming a swirl in the opposite direction to the reflux B is provided at the second inlet 60, 29, 58, according to any one of claims 1 to 5. burner. 7. Burner according to any one of claims 1 to 6, characterized in that the second inlet 60, 29, 58 is configured to be adjustable. 8 The wall 8 of the ignition chamber has a conical or dome shape and a first inlet 50 for the first combustion air flow.
The inlet is located close to the swirl generating device 2.
8. Burner according to claim 1, characterized in that it is connected via separate air supply pipes 3, 27, 14 having 1, 13 in the region of the outlet. 9 The peripheral wall of the ignition chamber 20 is divided into an inner wall part 8 and an outer wall part 9, the inner wall part is arranged close to the first inlet 50, and an annular swirling air space is provided between the two peripheral walls. 9. According to claim 8, an inlet 51 is provided, in which a partial air flow separated from the total combustion air flow formed is introduced into the ignition chamber via the respective air inlet. burner. 10. The two inlets 50, 51 are each connected to a separate air pipe 27, 28, each air supply pipe being provided with a swirl generating device 4, 5 in its respective discharge area. Burner according to claim 9. 11. Burner according to claim 9, characterized in that the inlets 50, 51 are provided with a common air supply pipe 3 with two swirl generators 4, 5, 6, 7. 12 The air imparted with swirling motion has at least 1
12. The combustion air flow is introduced into the two air supply pipes 3, 27, 28, 14 at a higher pressure than the second combustion air flow.
Burner as described in. 13 One or both of the air inlets 50 and 51 are
12. Burner according to claim 8, characterized in that it is formed as an annular gap. 14 Inside the first inlet 50 for first combustion air, a pipe 1 coaxially arranged at the center with the inlet 50 and a pipe 2 coaxially surrounding it are provided, one pipe 1 Claim 1 characterized in that the pipe is used to supply main fuel, and the other pipe 2 is formed to supply swirled carrier gas or non-swirled carrier gas, and granular fuel is used as the main fuel. 14. The burner according to any one of 13 to 13. 15 Inside the first inlet 50 for the first combustion air, the outlet of the pipe 1 arranged in a central position for supplying the main fuel, and the outlet 1 coaxially surrounding the pipe 1
A common opening 32 of the pair of pipes 30 and 33 is provided to ensure that air for atomization is injected into the carrier oil that has been given a swirling motion or the carrier oil that has been supplied without being given a swirling motion. Burner according to any one of claims 1 to 13. 16 Inside the first inlet 50 for the first combustion air, the outlet of the centrally located pipes 34, 45 with an outlet nozzle 41 for outflowing the oil used as the main fuel; . main fuel flow through the nozzle;
14. The burner according to claim 1, wherein swirling fuel flows merge. 17. Burner according to claim 16, characterized in that the outlet nozzle 41 and the fuel nozzle 39 are movably mounted. 18. Burner according to claim 16, characterized in that an axially adjustable nozzle needle is provided in the centrally located pipe 45. 19. Burner according to claim 18, characterized in that the nozzle needle is adjustable in the axial direction, through which air flows for pulverizing the fuel introduced into the fuel nozzle (39). 20 Pipe 36 for supplying swirling fluid fuel
20. A burner according to any one of claims 16 to 19, characterized in that the burner is surrounded by a heating jacket (42).