Furnace and combustion system for furnace

Abstract

A furnace and a combustion system for a furnace. The combustion system comprises a plurality of burners (2) arranged spaced apart from each other along two opposite sides (31) of the furnace (4). The burners (2) face each other and face the material to be heated. The first part burner (2) is configured to provide a flame (6) having a first type of flame characteristic and the second part burner is configured to provide a flame (6) having a second type of flame characteristic. Each side (31) is provided with at least one burner (2) belonging to a first part burner and at least one burner (2) belonging to a second part burner.

Description

Technical Field

[0001] The present disclosure relates to industrial heating equipment and, more particularly, to systems and methods for controlling a firing system. Background Art

[0002] In the combustion zone of various industrial heating plants and process engineering systems, there is an inhomogeneous temperature distribution. For example, in known solutions, all burners usually have flow patterns that are similar to one another, or at least usually aim to have flow patterns that are as similar as possible, taking into account the local environment. Adjacent burners are operated at similar or even identical powers. Thus, for example, in Figure 2 and Figure 3 As shown on the left side of the figure, similar heat flow patterns appear at all burners, where Figure 2 A furnace with a slow burner is shown, Figure 3 A furnace with a fast burner is shown. Figure 2 and Figure 3 As shown on the right side of the figure, as the pallet cars carrying pellets continuously move through the furnace, streaking occurs, with some pellets being loaded with mainly high temperature inclusions and others being loaded with mainly low temperature inclusions. This results in a variable product quality. Utility Model Content

[0003] An object of the present disclosure is to provide a new combustion system and a new method of controlling a combustion system.

[0004] The object of the present disclosure is achieved through a method and a device described in some embodiments of the present disclosure.

[0005] The present disclosure is based on the idea of ​​providing burners with different types of flame characteristics in a combustion system.

[0006] One advantage of the present disclosure is that better control of the heating of the material to be heated by the combustion system over the width of the furnace can be achieved. Thus, for example, a desired temperature distribution of the material to be heated, such as a uniform temperature distribution over the width of the furnace, can be achieved by the combustion system and method.

[0007] The present disclosure provides a combustion system for a furnace, the combustion system comprising: a plurality of burners, which are arranged spaced apart from each other along two opposite sides of the furnace, wherein the burners are directed toward each other and toward a material to be heated, and in the combustion system: a first part of the burners are configured to provide a flame having a first type of flame characteristic, and a second part of the burners are configured to provide a flame having a second type of flame characteristic; and each side is provided with at least one burner belonging to the first part of the burners and at least one burner belonging to the second part of the burners, and at least two of the burners include adjustable burners, wherein the adjustable burners are capable of producing different flame characteristics at the same combustion rate.

[0008] Furthermore, at least 30% of the burners in the combustion system are modulating burners.

[0009] Furthermore, at least 60% of the burners in the combustion system are modulating burners.

[0010] Furthermore, the combustion system also includes a non-adjustable burner.

[0011] Further, at least two burners are formed in pairs in such a manner that the two burners are disposed directly opposite to each other on opposite sides of the furnace.

[0012] Further, at least two burners are formed in pairs in such a manner that the two burners are disposed on opposite sides of the furnace offset from each other.

[0013] Further, the combustion system comprises a plurality of such burner pairs, each burner pair being formed by a pair of burners disposed on opposite sides of the furnace.

[0014] Further, at least one burner pair comprises two modulatable burners.

[0015] Further, in the direction of one side of the furnace, after a maximum of two adjacent burner pairs with non-adjustable burners, at least one burner pair with adjustable burners is arranged adjacent to one of the burner pairs with non-adjustable burners.

[0016] Further, the two burners of at least one burner pair are configured to have flame characteristics different from each other.

[0017] Further, the two burners of at least one burner pair are configured to have flame characteristics that are similar to each other and different from at least one adjacent burner on either side.

[0018] Further, the flame characteristic includes at least one of a combustion rate of the burner and a flow pattern of the burner.

[0019] Further, the flame having the first type of flame characteristics has an average exit velocity of at least 150 m / s.

[0020] Further, the flame having the first type of flame characteristics has an average exit velocity of at least 200 m / s.

[0021] Further, the flame having the second type of flame characteristics has an average exit velocity below 150 m / s.

[0022] Further, the flame having the second type of flame characteristics has an average exit velocity lower than 80 m / s.

[0023] Furthermore, the combustion system further comprises at least one valve device for controlling at least one of a primary air flow and a fuel flow to the burner.

[0024] Furthermore, the combustion system also includes a detector for detecting the temperature of the material to be heated.

[0025] Further, the detector is configured to detect the surface temperature of the material to be heated.

[0026] Further, the detector comprises an optical measuring device.

[0027] Furthermore, the combustion system comprises a plurality of detectors, and the detectors are used to detect the temperature of the material to be heated.

[0028] Further, the detector is configured to detect the temperature across the entire width of the furnace.

[0029] Further, at least one detector is configured to detect temperature from a sub-region of the width of the furnace.

[0030] Furthermore, the combustion system further comprises at least one control unit, and the control unit is used to control at least one of a primary air flow and a fuel flow to the burner.

[0031] Further, the control unit is configured to control the flow of at least one of fuel and main air to the burner by controlling the valve device.

[0032] Further, the control unit is configured to control at least one burner based on a temperature detected by at least one detector, the detector being configured to detect a temperature.

[0033] Furthermore, the combustion system includes at least 8 burners.

[0034] The present disclosure also provides a furnace, which includes the combustion system according to the present disclosure.

[0035] Further, the furnace comprises a moving device for moving the material to be heated between the burners in a direction parallel to the side.

[0036] Further, the moving device includes at least one of the following: a conveyor belt and a chain pallet truck.

[0037] Further, the combustion system is a combustion system of a pellet plant, and the moving device includes a chain pallet truck for pellets. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Hereinafter, the present disclosure will be described in more detail by way of preferred embodiments with reference to the accompanying drawings, in which:

[0039] Figure 1 Schematically illustrates an industrial heating plant according to an embodiment, showing a cross section as viewed from one end of a furnace;

[0040] Figure 2 and Figure 3 shows the heat flow pattern on the left and the final temperature range of the moving material on the right, when viewed from above in a heated furnace, in each case heated with a prior art combustion system;

[0041] Figure 4 shows the heat flow pattern on the left and the final temperature range of the moving material on the right, as viewed from above, in a furnace heated by a combustion system according to a first embodiment of the present disclosure;

[0042] Figure 5 shows the heat flow pattern on the left and the final temperature range of the moving material on the right, as viewed from above, in a furnace heated by a combustion system according to a second embodiment of the present disclosure;

[0043] Figure 6 shows the heat flow pattern on the left and the final temperature range of the moving material on the right, as viewed from above, in a furnace heated by a combustion system according to a third embodiment of the present disclosure;

[0044] Figure 7 schematically illustrates a burner lance for an adjustable burner according to an embodiment, showing a cross section viewed from the side of the burner lance; and

[0045] Figure 8 A method of controlling a combustion system is shown.

[0046] The accompanying drawings are only for illustrating some features of the present disclosure and are not shown to scale. In different drawings and embodiments, the same reference numerals are used for similar features. For the sake of clarity, not all similar features must be provided with reference numerals. DETAILED DESCRIPTION

[0047] Figure 1 An industrial heating plant according to one embodiment is schematically illustrated, showing a cross section as viewed from one end of a furnace.

[0048] In the industrial heating device 1, the burner 2 can be used for heating. The industrial heating device 1 can further include a combustion chamber 3, and one or more burners 2 can be arranged on the combustion chamber 3. On the other hand, the combustion chamber 3 can be installed in an oven or a furnace 4.

[0049] The burner 2 may include a burner lance 10 . Figure 7 A burner lance 10 is shown according to one embodiment. Figure 1 and Figure 7 In an embodiment, the fuel and primary air (in other words, the primary air flow 25 and the fuel flow 26) can be configured to flow through the burner lance 10 and enter the combustion chamber 3 through the burner lance. The process air 5 can be configured to enter the combustion chamber through its own channel. After the fuel / air mixture is ignited, a flame 6 is generated. The flame is at least partially provided in the combustion chamber 3, but in some embodiments, the flame can also extend into the furnace 4. The flame 6 is configured to generate a heat flow 27 (in other words, a hot gas flow). According to an embodiment, the furnace 4 may include a moving device 7, such as a conveyor belt and a chain pallet car, for moving the material to be heated in the furnace 4. According to an embodiment, the heated material can also be subsequently discharged from the furnace 4 by the moving device 7.

[0050] According to an embodiment, at least one end of the furnace 4, such as the second end 34, may have an opening, and the heat flow 27 may leave the furnace 4 through the opening. According to an embodiment, the heat flow and the heated material (in other words, the product) may leave the furnace 4 through the same end including the opening. According to another embodiment, such as an embodiment related to a granulation device, the moving device 7 may include a porous material or a porous structure, and the heat flow 27 may leave the furnace 4 through the moving device.

[0051] Figure 4 shows the heat flow pattern on the left and the final temperature range of the moving material on the right, as viewed from above, in a furnace heated by a combustion system according to a first embodiment of the present disclosure; Figure 5shows the heat flow pattern on the left and the final temperature range of the moving material on the right, as viewed from above, in a furnace heated by a combustion system according to a second embodiment of the present disclosure; Figure 6 1 shows the heat flow pattern on the left and the final temperature range of the moving material on the right, when viewed from above, in a furnace heated by a combustion system according to a third embodiment of the present disclosure. Figures 2 to 6 The region 32 shown on the right side of the center is a hot region (in other words, the region where the material to be heated includes the highest temperature), and the temperature between the regions 32 and / or on both sides of the regions 32 is not as hot.

[0052] The industrial heating device 1 may include a combustion system 20. The combustion system 20 may also be referred to as a combustion system or a burner device. The combustion system 20 (such as a Figure 4 , Figure 5 or Figure 6 The combustion system of the furnace 4 comprises a plurality of burners 2 arranged spaced apart from each other along two opposite sides 31 of the furnace 4. The burners 2 are oriented towards each other and towards the material to be heated. According to an embodiment, the sides 31 are configured to be arranged at opposite sides of the material to be heated. According to an embodiment, the sides 31 and therefore the burners 2 are arranged at opposite sides, but horizontally upwards (in other words, at a higher level in the vertical direction) relative to the material to be heated.

[0053] In the combustion system 20 (such as Figure 4 , Figure 5 or Figure 6 In the combustion system 20), the first part of the burners is configured to provide a flame having a first type of flame characteristics, and the second part of the burners is configured to provide a flame having a second type of flame characteristics. In the combustion system 20, each side portion 31 is provided with at least one burner 2 belonging to the first part of the burners and at least one burner belonging to the second part of the burners.

[0054] exist Figure 4 , Figure 5 and Figure 6 In FIG. 1 , these flames with different types of flame characteristics are shown by the specific shapes of the heat flow 27 areas. In other words, for example, Figure 4 In the figure, as viewed in the direction of the arrow (in other words, in the moving direction 35 of the material to be heated or as viewed from the bottom to the top in the figure), the first burner 2 has the first type of flame characteristics, the second burner 2 has the second type of flame characteristics, the third burner 2 has the first type of flame characteristics, and the fourth burner 2 has the second type of flame characteristics. Figure 5In the figure, as seen in the direction of the arrow, the first and third burners 2 on the right and the second and fourth burners 2 on the left have the first type of flame characteristics, while the first and third burners 2 on the left and the second and fourth burners 2 on the right have the second type of flame characteristics. It is clear to those skilled in the art that Figure 4 , Figure 5 and Figure 6 The embodiments are illustrative and arbitrary examples, the purpose of which is only to explain the concepts of the present disclosure. It should also be understood that Figure 4 , Figure 5 and Figure 6 The first type of flame characteristics and Figure 4 , Figure 5 and Figure 6 The second type flame characteristics may be different from each other, and in the combustion system 20 of the present disclosure, in addition to the first and second types, burners 2 having other types of flame characteristics may also be included.

[0055] According to an embodiment, in the combustion system 20, at least two of the burners 2 may include adjustable burners 2. According to an embodiment, the adjustable burners 2 are capable of producing different flame characteristics at the same combustion rate. According to an embodiment, at least one of the adjustable burners 2 (preferably at least two of the adjustable burners 2) may include an adjustable burner according to an embodiment or a combination of embodiments disclosed in the present specification and / or the attached claims and / or the drawings. According to an embodiment, all adjustable burners 2 may include adjustable burners according to an embodiment or a combination of embodiments disclosed in the present specification and / or the attached claims and / or the drawings.

[0056] According to an embodiment, at least 30% of the burners in the combustion system are adjustable burners 2. According to another embodiment, at least 60% of the burners in the combustion system are adjustable burners 2. According to an embodiment, all burners 2 of the combustion system 20 may include adjustable burners 2. Such an embodiment is particularly beneficial in applications where a high adjustability is required for the heating and therefore the heat flow 27 and the flame characteristics.

[0057] According to one embodiment, the combustion system further comprises a non-adjustable burner 2. In other words, according to one embodiment, the combustion system 20 comprises adjustable and non-adjustable burners. Such an embodiment may be beneficial in applications where a simpler structure is important and sufficient control and adjustability can be achieved with fewer adjustable burners 2.

[0058] According to an embodiment, at least two burners 2 may be formed in pairs, also referred to as burner pairs or a pair of burners. More specifically, at least two burners 2 may be formed in pairs in such a way that the two burners 2 are arranged directly opposite each other on opposite sides 31 of the furnace 4, such as in Figure 4 and Figure 5 The side 31 of the furnace 4 refers to the side 31 extending on each side of the area in which the material to be heated is arranged. More specifically, the side 31 extends from a first end 33 of the furnace 4 to a second end 34 of the furnace 4, and the material to be heated is configured to be provided to the furnace 4 at the first end, and the material to be heated is configured to leave the furnace 4 at the second end. Figures 2 to 6 In FIG. 4 , arrows are used to show the direction along which the material to be heated can be arranged to pass through the furnace 4, ie, the moving direction 35. According to an embodiment, the burner 2 is arranged at the furnace 4 in a vertical direction above the material to be heated.

[0059] According to one embodiment, such as Figure 6 In an embodiment, at least two burners 2 are formed in pairs in such a way that the two burners are arranged offset from each other on opposite sides of the furnace. In other words, the two burners 2 formed in pairs are also spaced apart from each other in the moving direction 35, such as Figure 6 According to one embodiment, the combustion system 20 comprises a plurality of such burner pairs, each burner pair being formed by a pair of burners 2 arranged on opposite sides of the furnace. According to one embodiment, at least one burner pair comprises two adjustable burners 2.

[0060] According to one embodiment, in the direction of a side 31 of the furnace 4, after a maximum of two adjacent burner pairs with non-adjustable burners 2, at least one burner pair with adjustable burners 2 is arranged adjacent to a burner pair with non-adjustable burners 2.

[0061] According to one embodiment, the two burners 2 in at least one burner pair may be configured to have flame characteristics that are different from each other. In other words, the two burners 2 in one burner pair may include a first type of flame characteristic, a second type of flame characteristic, or another type of flame characteristic. According to one embodiment, the two burners 2 in at least one burner pair may be configured to have flame characteristics that are similar to each other and different from at least one adjacent burner on either side.

[0062] According to an embodiment, the flame characteristics may include at least one of a burning rate of the burner, a flow pattern of the burner, and an average exit velocity of the burner. The flow pattern of the burner 2 refers to a heat flow pattern configured to be generated by the burner 2 .

[0063] According to an embodiment, the flame having the first type of flame characteristic may have an average outlet velocity of at least 150 m / s. According to an embodiment, the flame having the first type of flame characteristic may have an average outlet velocity of at least 200 m / s. According to an embodiment, the flame having the first type of flame characteristic and the flame having the second type of flame characteristic may both have an average outlet velocity of at least 150 m / s. The fast burner may include a burner configured to provide a high average outlet velocity (such as an average outlet velocity of at least 150 m / s) so that the heat flow reaches a farther position in the furnace 4. Similarly, a burner configured to provide an average outlet velocity of at least 150 m / s may be referred to as a fast burner, while a burner configured to provide an average outlet velocity of at least 200 m / s may be referred to as a fast burner or a faster burner.

[0064] According to an embodiment, the flame having the second type of flame characteristic has an average exit velocity lower than 150m / s (in other words, less than 150m / s). According to an embodiment, the flame having the second type of flame characteristic has an average exit velocity lower than 80m / s. According to an embodiment, the flame having the first type of flame characteristic and the flame having the second type of flame characteristic may both have an average exit velocity lower than 150m / s. The slow burner may include a burner configured to provide a low average exit velocity (such as an average exit velocity lower than 150m / s), so that the distance reached by the heat flow in the furnace is shorter than the distance reached by the heat flow of the fast burner. The burner configured to provide an average exit velocity lower than 80m / s may be referred to as a slow burner or a slower burner.

[0065] According to one embodiment, for example, a flame having a first type of flame characteristic may have an average exit velocity of at least 200 m / s, and a flame having a second type of flame characteristic may have an average exit velocity of at least 150 m / s. According to one embodiment, for example, a flame having a first type of flame characteristic may have an average exit velocity of less than 150 m / s, and a flame having a second type of flame characteristic may have an average exit velocity of less than 80 m / s.

[0066] According to an embodiment, the flame having the second type of flame characteristics may have an average exit velocity which differs from an average exit velocity of the flame having the first type of flame characteristics by at least 20%, preferably by at least 30%.

[0067] In the present disclosure, the average exit velocity refers to the average exit velocity of the fuel flow and / or primary air at the outlet end 13 of the burner 2 (and thus the burner lance 10). In other words, the average exit velocity refers to the average exit velocity of the fuel flow and / or primary air at the outlet member 12, 15, 17 (such as a nozzle).

[0068] According to an embodiment, the combustion system 20 may further include at least one valve device 22 for controlling at least one of a primary air flow 25 and a fuel flow 26 to the burner. According to an embodiment in which the combustion system 20 includes an adjustable burner 2, the valve device 22 may be configured to selectively allow and prevent primary air from the air supply and fuel from the fuel supply from flowing to the air channel 14 and at least one of the fuel channels 11, 16, respectively. According to an embodiment with two fuel channels 11, 16, in the use state of the combustion system 20, the ratio of the fuel supply may be 100% of the fuel flow is supplied to one of the fuel channels, and 0% of the fuel flow is supplied to the other fuel channel, or the ratio may be 70% and 30%, and so on. Therefore, allowing fuel or primary air to flow to a channel may include providing a percentage of the total fuel or air flow greater than 0 and up to 100% to the channel. According to an embodiment, the valve device 22 may be configured to control different proportions of fuel supply at different use stages of the combustion system 20. According to one embodiment, a first proportion of fuel supply may be provided to a burner 2 of a combustion system 20 to ignite a flame, and a second proportion of fuel supply may be provided to the same burner 2 after ignition. According to one embodiment, a third proportion of fuel supply may be provided to the burner 2 after the second proportion of fuel supply (e.g., after the second proportion of fuel supply is used for a predetermined time or after a predetermined temperature is reached (e.g., a predetermined temperature of the furnace and / or a predetermined temperature of the material to be heated is reached)). According to another embodiment, a third proportion of fuel supply may be provided to one burner 2 of the combustion system 20 while at least partially providing another burner 2 of the combustion system 20 with a second proportion of fuel supply.

[0069] According to an embodiment, the combustion system 20 further comprises a detector (not shown) for detecting the temperature of the material to be heated. According to an embodiment, the detector may be configured to measure the surface temperature of the material to be heated. According to an embodiment, the detector may comprise an optical measuring device. According to an embodiment, the combustion system 20 may comprise a plurality of detectors for detecting the temperature of the material to be heated. According to an embodiment, the detector may be configured to measure the temperature over the entire width of the furnace. According to an embodiment, at least one detector may be configured to measure the temperature from a sub-region of the width of the furnace. According to an embodiment, the combustion system 20 may comprise at least one detector for detecting the temperature of the material to be heated after a maximum of 6 burner pairs in each case. The detector for detecting the temperature may be configured to measure the temperature (such as the surface temperature), or to detect the temperature or a characteristic indicating the temperature, such as detecting the radiation emitted by the material to be heated, the hardness of the material, or the color of the material by an optical detector. The detector is known in the art and is therefore not explained in detail here.

[0070] According to one embodiment, the combustion system 20 may further include at least one control unit (not shown) for controlling at least one of the primary air flow 25 and the fuel flow 26 flowing to the burner 2. According to one embodiment, the control unit may be configured to control the flow of at least one of the fuel and the primary air to the burner. More specifically, the control unit may be configured to control the flow of at least one of the fuel and the primary air to the burner, such as the fuel supply ratio or the air supply ratio, by controlling the valve device 22.

[0071] According to an embodiment, the control unit may be configured to control the at least one burner 2 based on a temperature detected by at least one of the detectors, which is configured to detect a temperature. According to an embodiment, a feedback loop from the detected temperature, preferably the temperature of the material to be heated, may be used for the control, such as for controlling the flame characteristics provided by the burner.

[0072] According to one embodiment, the plurality of burners 2 of the combustion system 20 may be configured to be controlled to produce such a heat flux pattern, that is, so as to achieve the desired temperature of the material to be heated, such as the temperature distribution of the material to be heated over the width of the furnace. According to one embodiment, the plurality of burners 2 may include adjustable burners and / or non-adjustable burners, at least some of which may be configured to be controlled to provide heat flux patterns that are different from each other. According to one embodiment, at least some adjacent burners 2 or pairs of burners of the combustion system 20 are controlled to produce heat flux patterns that are different from each other, thereby providing the desired temperature of the material to be heated. These burners 2 or pairs of burners may include a combination of fast, relatively fast, slow and / or relatively slow burners 2.

[0073] According to one embodiment, the combustion system 20 may include at least eight burners 2 .

[0074] According to an embodiment, the furnace 4 may include a combustion system 20 according to an embodiment or a combination of embodiments disclosed in the present specification and / or the attached claims and / or the drawings. According to an embodiment, the furnace 4 may include a moving device 7 for moving the material to be heated between the burners 2 in a direction parallel to the side 31 (in other words in a moving direction 35). According to an embodiment, the moving device 7 may include at least one of the following: a conveyor belt and a chain pallet truck.

[0075] According to an embodiment, the combustion system 20 may be a combustion system of a pellet plant, and the moving device includes a chain pallet truck for the pellets.

[0076] According to an embodiment, the industrial heating plant 1 may comprise a combustion system 20 according to an embodiment or a combination of embodiments disclosed in the present description and / or the appended claims and / or the drawings.

[0077] Figure 7 A burner lance 10 for an adjustable burner 2 according to one embodiment is schematically shown, showing a cross section from the side of the burner lance. Figure 1 According to one embodiment, at least one of the burners 2 (preferably at least two burners 2, said burners 2 including adjustable burners) comprises a burner lance 10 as described in this specification, for example, as described below with reference to Figure 7 It should be understood that Figure 7 The embodiments are only used to schematically explain such a burner lance 10 and related features, and the actual construction of the burner lance 10 and, for example, the number, order and structure of fuel passages and primary air passages may vary within the embodiments described in the specification, the appended claims and / or the drawings.

[0078] The burner lance 10 , the burner 2 , the combustion system 20 and the method for controlling a combustion system may be used in industrial heating plants and / or process engineering systems.

[0079] According to one embodiment, the burner lance 10 and / or the burner 2 can be used to optimize the temperature in the furnace. According to one embodiment, the burner lance 10, the burner 2 and / or the combustion system 20 can be used in a straight grate pelletizing plant, and more specifically, to optimize pellet quality.

[0080] According to one embodiment, a burner lance 10 for an industrial heating device, more specifically a burner lance 10 for an adjustable burner 2 of a combustion system 20 of the present disclosure (e.g. Figure 7 The burner lance 10 of the embodiment of the present invention may include a first fuel passage 11 for fuel. The first fuel passage 11 may be provided with a first fuel outlet member 12 at an outlet end 13 of the burner lance 10. The burner lance 10 may also include a first air passage 14 for air (more specifically, for primary air). The first air passage 14 may be provided with a first air outlet member 15 at the outlet end 13. The burner lance 10 may also include a second fuel passage 16 for fuel, which may be provided with a second fuel outlet member 17 at the outlet end 13.

[0081] The first air passage 14 may be disposed radially outward from at least two of the fuel passages 11 , 16 at the outlet end 13 .

[0082] According to an embodiment, at least the second fuel outlet member 17 may be provided with a widening member configured to widen the angle 9 of the fuel flow leaving the burner lance 10 outwardly from the longitudinal axis 8 of the burner lance 10. According to an embodiment, the widening member (such as the widening member of the second fuel outlet member 17) may include at least one of the following: a swirl member, a porous plate with radially inclined holes, or a porous plate with tangentially inclined holes.

[0083] According to an embodiment, the first fuel outlet member 12 is not provided with a widening member. In other words, according to an embodiment, the first fuel outlet member 12 does not include a widening member, while the second fuel outlet member 17 includes a widening member. According to an embodiment, the burner lance 10 may include additional fuel channels and fuel outlet members, which may or may not include a widening member at the outlet end 13. According to an embodiment, the first fuel outlet member 12 may include an outlet member in the form of a nozzle, an annular opening or a perforated plate.

[0084] According to an embodiment, the widening member, such as the widening member of the second fuel outlet member 17, is configured to produce an injection angle of at least 15 degrees relative to the direction of the longitudinal axis 8 of the burner lance 10 at the outlet end 13. According to another embodiment, the widening member, such as the widening member of the second fuel outlet member 17, is configured to produce an injection angle of at least 17.5 degrees relative to the direction of the longitudinal axis 8 of the burner lance 10 at the outlet end 13. According to another embodiment, the widening member, such as the widening member of the second fuel outlet member 17, is configured to produce an injection angle of at least 20 degrees relative to the direction of the longitudinal axis 8 of the burner lance 10 at the outlet end 13.

[0085] According to an embodiment, the first fuel outlet member 12, the second fuel outlet member 17 and the first air outlet member 15 are arranged concentrically relative to each other. In other words, the first fuel channel 11, the second fuel channel 16 and the first air channel 14 may be arranged concentrically relative to each other at least at the outlet end 13 of the burner lance 10. According to an embodiment, the first fuel outlet member 12, the second fuel outlet member 17 and the first air outlet member 15 are arranged concentrically relative to each other and relative to the longitudinal axis 8 of the burner lance 10.

[0086] According to an embodiment, the first fuel passage 11 may include an innermost passage at the outlet end 13, and the second fuel passage 16 may be disposed radially outward from the first fuel passage 11 at the outlet end 13. In other words, the second fuel outlet member 17 may be disposed radially outward from the first fuel outlet member 12.

[0087] According to an embodiment, the first air passage 14 may be disposed radially outward from the second fuel passage 16 at the outlet end 13. In other words, the first air outlet member 15 may be disposed radially outward from the second fuel outlet member 17.

[0088] Figure 8 A method of controlling a combustion system is shown.

[0089] A method for controlling a combustion system (such as Figure 8 The method of the invention may include step 81 of providing a plurality of burners 2 spaced apart from each other along two opposite sides 31 of the furnace 4. The burners 2 may be oriented toward each other and toward the material to be heated. The method further includes step 83 of configuring the first part of the burners 2 to provide a flame having a first type of flame characteristics and the second part of the burners 2 to provide a flame having a second type of flame characteristics; and step 85 of providing each side 31 with at least one burner belonging to the first part of the burners and at least one burner belonging to the second part of the burners.

[0090] According to an embodiment, the method for controlling the combustion system 20 may be implemented by an embodiment or a combination of embodiments of the combustion system 20 disclosed in the present specification, the appended claims and / or the drawings.

[0091] According to an embodiment, the method further comprises configuring the flame having the first type of flame characteristic and the flame having the second type of flame characteristic to have a desired burning rate. According to an embodiment, the desired burning rates of the flame having the first type of flame characteristic and the flame having the second type of flame characteristic comprise burning rates according to an embodiment disclosed in conjunction with the combustion system embodiment or a combination thereof.

[0092] According to an embodiment, the method may further comprise controlling the operation of the burner 2 by means of at least one valve device 22 .

[0093] According to an embodiment, the method further comprises moving the material to be heated between the burners 2 in a direction parallel to the side 31 by means of the moving device 7. More specifically, the material to be heated can be moved between the burners 2, but at a lower level relative to the burners 2 in the vertical direction. The direction in which the material to be heated moves in the furnace 4 (in other words, the moving direction) is determined by Figures 2 to 6 The arrow in indicates.

[0094] According to an embodiment, the method may further include detecting the temperature of the material to be heated by at least one detector. The detector, detection and / or measurement may be consistent with the embodiments or combinations of embodiments disclosed in conjunction with the combustion system 20 embodiment.

[0095] According to an embodiment, the method may further comprise controlling at least one of the burners, a group of burners or all burners by at least one control unit. According to an embodiment, controlling the burners by the control unit may comprise controlling the flow of at least one of fuel and primary air to the burners. According to an embodiment, controlling the burners by the control unit may comprise controlling the flow of at least one of fuel and primary air to the burners by controlling a valve arrangement. According to an embodiment, controlling the burners 2 by the control unit may comprise controlling at least one of the burners 2 based on a temperature detected by at least one of the detectors.

[0096] According to an embodiment, the moving device 7 may include at least one of the following: a conveyor belt and a chain pallet truck.

[0097] According to an embodiment, the combustion system 20 may be a combustion system 20 of a pellet plant, and the moving device 7 may include a chain pallet truck for the pellets.

[0098] According to an embodiment, the method may further include heating the material to be heated disposed in the furnace by a burner.

Claims

1. A combustion system for a furnace, the combustion system comprising: a plurality of burners disposed spaced apart from one another along two opposite sides of the furnace, The burners are directed toward each other and toward the material to be heated, wherein in the combustion system: The first portion of the burners is configured to provide a flame having a first type of flame characteristics, and the second portion of the burners is configured to provide a flame having a second type of flame characteristics; and Each side is provided with at least one burner belonging to the first part of burners and at least one burner belonging to the second part of burners, and At least two of the burners include adjustable burners, wherein the adjustable burners are capable of producing different flame characteristics at the same firing rate.

2. The combustion system according to claim 1, characterized in that: At least 30% of the burners in the combustion system are modulating burners.

3. The combustion system according to claim 2, characterized in that: At least 60% of the burners in the combustion system are modulating burners.

4. The combustion system according to any one of claims 1 to 3, characterized in that: The combustion system also includes a non-regulatory burner.

5. The combustion system according to any one of claims 1 to 3, characterized in that: At least two burners are formed in pairs in such a manner that the two burners are arranged directly opposite to each other on opposite sides of the furnace.

6. The combustion system according to any one of claims 1 to 3, characterized in that: At least two burners are formed in pairs in such a manner that the two burners are disposed offset from each other on opposite sides of the furnace.

7. The combustion system according to claim 5, characterized in that: The combustion system comprises a plurality of such burner pairs, each burner pair being formed by a pair of burners arranged on opposite sides of the furnace.

8. The combustion system according to claim 5, characterized in that: At least one burner pair comprises two controllable burners.

9. The combustion system according to claim 5, characterized in that: In the direction of one side of the furnace, after a maximum of two adjacent burner pairs with non-adjustable burners, at least one burner pair with adjustable burners is arranged adjacent to one of the burner pairs with non-adjustable burners.

10. The combustion system according to claim 5, characterized in that: The two burners of at least one burner pair are configured to have flame characteristics that are different from each other.

11. The combustion system according to claim 5, characterized in that: The two burners of at least one burner pair are configured to have flame characteristics that are similar to each other and different from at least one adjacent burner on either side.

12. The combustion system according to any one of claims 1 to 3, characterized in that: The flame characteristic includes at least one of a firing rate of the burner and a flow pattern of the burner.

13. The combustion system according to any one of claims 1 to 3, characterized in that: The flame having the first type of flame characteristics has an average exit velocity of at least 150 m / s.

14. The combustion system according to any one of claims 1 to 3, characterized in that: The flame having the first type of flame characteristics has an average exit velocity of at least 200 m / s.

15. The combustion system according to any one of claims 1 to 3, characterized in that: Flames having the second type of flame characteristics have an average exit velocity below 150 m / s.

16. The combustion system according to any one of claims 1 to 3, characterized in that: A flame having the second type of flame characteristics has an average exit velocity below 80 m / s.

17. The combustion system according to any one of claims 1 to 3, characterized in that: The combustion system further comprises at least one valve device for controlling at least one of a primary air flow and a fuel flow to the burner.

18. The combustion system according to any one of claims 1 to 3, characterized in that: The combustion system further comprises a detector for detecting the temperature of the material to be heated.

19. The combustion system according to claim 18, characterized in that The detector is configured to detect a surface temperature of the material to be heated.

20. The combustion system according to claim 18, characterized in that The detector comprises an optical measuring device.

21. The combustion system according to claim 18, characterized in that The combustion system includes a plurality of detectors for detecting the temperature of the material to be heated.

22. The combustion system according to claim 18, characterized in that The detector is configured to detect the temperature across the width of the furnace.

23. The combustion system according to claim 18, characterized in that At least one detector is configured to detect temperature from a sub-region of the width of the furnace.

24. The combustion system according to any one of claims 1 to 3, characterized in that: The combustion system further comprises at least one control unit for controlling at least one of a primary air flow and a fuel flow to the burner.

25. The combustion system according to claim 24, characterized in that The control unit is configured to control the flow of at least one of fuel and primary air to the burner by controlling the valve arrangement.

26. The combustion system according to claim 24, characterized in that The control unit is configured to control at least one burner based on a temperature detected by at least one detector configured to detect a temperature.

27. The combustion system according to any one of claims 1 to 3, characterized in that: The combustion system includes at least 8 burners.

28. A furnace, characterized in that: The furnace comprises a combustion system according to any one of claims 1 to 27.

29. The furnace according to claim 28, characterized in that The furnace comprises movement means for moving the material to be heated between the burners in a direction parallel to the sides.

30. The furnace according to claim 29, characterized in that The moving device includes at least one of the following: a conveyor belt and a chain pallet truck.

31. A furnace according to claim 29 or 30, characterised in that The combustion system is a combustion system of a pellet plant, and the moving device comprises a chain pallet truck for pellets.

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