JP5768433B2 - Cement burning burner - Google Patents

Description

  The present invention relates to a burner for firing cement.

  Conventionally, what is employ | adopted as the cement rotary kiln which bakes a cement clinker as a burner for cement baking is known (for example, refer patent document 1). The cement burning burner described in Patent Literature 1 includes a main burner that is inserted into a rotary kiln and supplies pulverized coal, and a supply nozzle that supplies combustible waste of waste plastic material. The supply nozzle has a straight pipe portion with a length of 5 m or more from the tip. The combustible waste supplied from the straight pipe part burns in a state where it falls onto the material to be fired in the rotary kiln (landing combustion).

Japanese Patent No. 3586575

  By the way, in the cement rotary kiln described in Patent Document 1, the waste plastic material may adversely affect cement firing depending on the area where the waste plastic material lands and burns. In order to solve such a problem, it is conceivable to combust in the air before the combustible waste lands.

  Then, this invention is made | formed in order to solve such a technical subject, Comprising: It aims at providing the burner for cement baking which can burn a combustible waste efficiently.

That cement firing burner according to the present invention includes a main burner for supplying primary fuel, provided vertically above the main burner, a cement burning burner and a waste burner supplying combustible waste A fuel burner that is provided vertically above the waste burner and supplies another fuel having better combustibility than the combustible waste, and is disposed horizontally in the radial section of the tip of the waste burner. X> y, where x is the horizontal distance between the two points L1 and L2 farthest in the direction and y is the vertical distance between the two points H1 and H2 furthest in the vertical direction. The

According to the burner for cement firing according to the present invention, in the radial section of the tip of the waste burner, the horizontal distance between the two points that are the farthest apart in the horizontal direction is the vertical direction between the two points that are the farthest apart in the vertical direction. Since the distance is larger than the distance, combustible waste is supplied in a horizontal direction as compared with the case where the radial cross-sectional shape is circular. Thus, combustible waste can be efficiently burned by expanding the contact area between the flame of the main burner and the combustible waste. Furthermore, it is possible to suppress the variation in combustion of the combustible waste by sandwiching the combustible waste between the flame of the main burner and the flame of the other fuel burner. Therefore, it becomes possible to burn combustible waste efficiently.

  Here, the waste burner is formed from the tip portion and a circular tube portion connected to the tip portion, and the combustible waste passes through the waste burner in the order of the circular tube portion and the tip portion. You may comprise. By comprising in this way, the waste burner which reduced the stress concentration at the time of welding or thermal expansion is easily realizable.

  Moreover, it is preferable that the shape of the radial direction cross section in the said front-end | tip part is a rectangle. By configuring in this way, it is possible to easily realize a cross-sectional shape in which the horizontal distance between two points farthest in the horizontal direction is larger than the vertical distance between two points farthest in the vertical direction.

  In addition, it is preferable that the radial cross section of the waste burner is widened at the tip of the waste burner. By comprising in this way, it becomes possible to supply a flammable waste further expanding in the horizontal direction, and the contact area between the flame of the main burner and the flammable waste can be further expanded.

  In addition, it is preferable that a central axis of the waste burner is inclined toward a vertically lower side at a front end portion of the waste burner. By comprising in this way, since a combustible waste is efficiently supplied toward the flame side of a main burner, a combustible waste can be burned efficiently.

  According to the present invention, combustible waste can be efficiently burned.

It is a schematic diagram which shows the structure of the apparatus using the burner for cement baking which concerns on a reference form. It is a partially expanded sectional view and front view of the burner for cement baking of FIG. It is a perspective view of the waste burner in FIG. It is the side view of the waste burner in FIG. 1, and the front view of a front-end | tip part. It is a front view which shows the other example of the front-end | tip opening part in the waste burner in FIG. It is the side view and front view which show the other example of the waste burner in FIG. It is a schematic diagram explaining the effect of the burner for cement baking of FIG. Is a partially enlarged cross-sectional view and a front view of a cement burning burner according to implementation embodiments. It is a schematic diagram explaining the effect of the burner for cement baking of FIG. It is the partially expanded sectional view and front view in the modification of the burner for cement baking. It is the side view and front view of a waste burner in FIG. It is the partially expanded sectional view and front view in the modification of the burner for cement baking.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference embodiments and embodiments of the present invention will be described below with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, the dimensional ratios in the drawings do not necessarily match those described.

( Reference form)
FIG. 1 is a schematic diagram showing a configuration of an apparatus using a cement burning burner according to a reference embodiment of the present invention. The apparatus shown in FIG. 1 is a part of a cement manufacturing apparatus and is used in a clinker firing process.

  As shown in FIG. 1, the apparatus employ | adopted for a clinker baking process is equipped with the rotary kiln 3 which is a substantially columnar rotary kiln. The rotary kiln 3 generates a clinker by firing a cement raw material. The rotary kiln 3 is inclined so that the cement raw material moves from the kiln bottom (inlet) to the front of the kiln (exit). Connected to the kiln bottom of the rotary kiln 3 are a preheating unit 4 having a cyclone for preheating the cement raw material and a calcining furnace 5 for calcining the cement raw material, and the preheated and calcined cement raw material is connected to the rotary kiln. 3 is supplied inside. The cement raw material supplied to the inside of the kiln moves to the front side of the kiln according to the rotation of the rotary kiln 3 while being calcined, and is discharged as a fired clinker. The discharged clinker is cooled by a cooling unit 6 provided on the front side of the kiln of the rotary kiln 3.

  Here, on the front side of the rotary kiln 3, the cement burning burner 1 is inserted from the outside of the furnace into the rotary kiln 3 (inside the furnace). 2A is a partially enlarged cross-sectional view of the cement firing burner 1, and FIG. 2B is a front view of the cement firing burner 1. FIG. As shown in FIG. 2, the cement burning burner 1 is inserted into the furnace through the furnace wall 20. The cement burning burner 1 includes a main burner 10 for supplying main fuel and a waste burner 11 for supplying combustible waste.

  The waste burner 11 is disposed vertically above the main burner 10. 3 is a perspective view of the waste burner 11, FIG. 4A is a side view of the waste burner 11, and FIG. 4B is a front view of the front end portion 11 a of the waste burner 11. As shown in FIGS. 3 and 4, the waste burner 11 is formed of a tip portion 11a and a circular tube portion 11b connected to the tip portion 11a. The tip opening 11d at the tip 11a of the waste burner 11 has a rectangular shape. As shown in FIG. 4B, the horizontal distance between the two points L1 and L2 farthest apart in the horizontal direction is represented by x. When the vertical distance between the two points H1 and H2 that are farthest in the vertical direction is y, the shape satisfies the relationship x> y. FIG. 5 shows another example of a shape that satisfies the above relationship. As shown in FIGS. 5A to 5E, the shape of the tip opening 11d is not limited to a rectangle, and any shape that satisfies the relationship x> y may be used.

  In FIG. 4B, the position of one end portion in the vertical direction of the tip opening portion 11d is arranged to coincide with the position of one end portion in the vertical direction of the circular tube portion 11b. It is not a thing. 6A is a side view of the waste burner 11, and FIG. 6B is a front view of the front end portion 11 a of the waste burner 11. As shown in FIG. 6, the center of gravity of the cross-section of the tip opening 11d may be arranged so as to coincide with the cross-sectional center of the circular tube portion 11b. 4 and 6, the longitudinal direction of the tip opening 11d is completely parallel to the horizontal direction, and the horizontal distance x and the vertical distance y are the same distance at each position on each side. However, you may rotate the front-end | tip opening part 11d in the range with which the said relationship is satisfy | filled.

  The combustible waste passes through the waste burner in the order of the circular tube portion 11b and the tip portion 11a. As the flammable waste, for example, waste plastics are used.

  The main burner 10 and the waste burner 11 have their surfaces covered with a refractory 12 and are formed integrally with the refractory 12. For example, the main burner 10 and the waste burner 11 and the refractory 12 are fixed to each other by stud welding. Further, the main burner 10 and the waste burner 11 are supported by a vertical load by a support portion (not shown) arranged outside the furnace.

Next, the effect of the cement baking burner 1 which concerns on a reference form is demonstrated. FIG. 7 shows an example of a waste burner having a different radial cross-sectional shape. 7A shows a waste burner 100 having a circular tip opening 100d, and FIG. 7B shows a rectangular waste burner 11 having a tip opening 11d having a long side in the horizontal direction. . As shown in FIG. 7A, in the case of the waste burner 100 having a circular sectional shape of the tip opening 100d, the inner wall of the waste burner 100 is compared with the rectangular sectional shape having the same sectional area. Since the waste plastic P is moved downward in the vertical direction along the shape, the emission area of the waste plastic P is narrowed, so that it is difficult to sufficiently diffuse in the horizontal direction. For this reason, in the case of the waste burner 100 having a circular cross-sectional shape of the tip opening 100d, the contact area between the waste plastic P and the flame of the main burner 10 is larger than that of a rectangular cross-sectional shape having the same cross-sectional area. Get smaller. Therefore, in the waste burner 100, it does not burn completely in the space of the rotary kiln 3, but it lands on the lower side of the rotary kiln 3 and continues to burn (landing combustion), which may adversely affect cement firing. Further, when a flame retardant material such as carbon fiber is mixed in the waste plastic, such a landing combustion may further occur. For this reason, in the case of the waste burner 100 having a circular sectional shape of the tip opening 100d, it is necessary to limit the type and amount of waste plastic to be supplied.

On the other hand, as shown in FIG. 7B, in the cement burning burner 1 according to the reference embodiment, the horizontal distance x of the tip opening 11d of the waste burner 11 is the vertical direction of the tip opening 11d. Since the waste plastic P is formed to be larger than the distance y, the waste plastic P spreads in the horizontal direction inside the waste burner 11 and is supplied after being diffused. As the waste plastic P diffuses in the horizontal direction, the contact area between the waste plastic P and the flame of the main burner 10 increases. For this reason, the burning rate of the waste plastic P improves. Therefore, the waste plastic P can be burned efficiently. Further, since the burning speed of the waste plastic P is improved, a large amount of the waste plastic P can be employed as combustible waste.

Further, in the upper region of the flame of the main burner 10, there is a large amount of residual oxygen and excess oxygen, and the temperature due to the flame is the highest and turbulence is formed. Further, when the exhaust heat recovery flow path is provided, since it is connected to the front side of the kiln of the rotary kiln 3, a large amount of air is introduced into the upper region of the flame of the main burner 10. This region is close to the flame of the main burner 10 and is a high temperature region. For this reason, the upper region of the flame of the main burner 10 is an optimal region as a combustion space for other fuels. According to the cement burning burner 1 according to the reference embodiment, the waste burner 11 is disposed above the main burner 10 and the waste plastic P is horizontally disposed on the upper area of the flame of the main burner 10 which is the most suitable area for combustion. It becomes possible to supply by diffusing in the direction, and combustion of the waste plastic P can be promoted.

  Furthermore, since the relationship between the distances x and y between the horizontal and vertical directions in the tip opening 11d is x> y, the sectional shape of the tip 11a is not a circular pipe. As for the burner, the circular tube is more resistant to thermal deformation and is easy to manufacture. On the other hand, when the burner is not a circular pipe, processing is complicated, and in the case of a cross-sectional shape having a vertex such as a rectangle or a triangle, stress concentration occurs at the vertex due to thermal expansion, which may cause damage. In particular, when a flat plate is bent to have a rectangular or triangular cross-sectional shape, the ends of the bent flat plate are connected by welding to form a rectangular or triangular tube, but the thermal expansion may adversely affect the welded portion. large. Therefore, a rectangular tip or the like 11a is formed with an integral object such as a casting or a machined part, and the circular tube portion 11b is connected to the tip 11a formed of a casting or the like to bend the flat plate and to cross-section the waste burner. It is possible to avoid the problem of stress concentration at the welded portion that occurs when the whole is rectangular, triangular, or the like. In addition, although the circular pipe part 11b and the front-end | tip part 11a of an integrated object are connected by welding, since it welds over the circumference of the circular pipe part 11b and the front-end | tip part 11a, the thermal deformation concerning a welding location acts on the whole circumference, Stress concentration can be avoided.

[Effect of reference form]
(1) A cement burning burner having a main burner for supplying main fuel and a waste burner provided vertically above the main burner for supplying combustible waste, the diameter of the tip of the waste burner In the direction cross section, the horizontal distance between two points that are the most spaced apart in the horizontal direction is greater than the vertical distance between the two points that are the most spaced apart in the vertical direction. By making the tip of the waste burner the above shape, the waste is distributed and supplied compared to the case of a circular shape (with the same cross-sectional area), and the contact area between the flame of the main burner and the waste plastic is expanded. Waste plastic can be burned efficiently.
(2) The shape of the radial cross section of the tip of the waste burner is rectangular. Thereby, the shape of (1) can be obtained with a simple configuration.

(Implementation form)
It will be described implementation form of the present invention. FIG. 8 is a partially enlarged sectional view and a front view of a cement burning burner. The cement burning burner 2 shown in FIG. 8 is configured in substantially the same manner as the cement burning burner 1 according to the reference embodiment, and is different in that it includes a burner for supplying other fuel. In the following, in consideration of the ease of understanding the description, the description overlapping with the cement burning burner 1 is omitted, and the difference will be mainly described.

As shown in FIG. 8, the cement burning burner 2 includes an other fuel burner 40 that is disposed vertically above the waste burner 11 and supplies another fuel different from the main fuel. The other fuel burner 40 is inserted into a through hole 12 a formed in the refractory 12 and is placed on the refractory 12 covering the surface of the main burner 10. For this reason, the vertical load of the other fuel burner 40 is received by the other fuel burner support part (not shown), the main burner 10 and the waste burner 11 arranged outside the furnace. Further, the inner diameter of the through hole 12 a of the refractory 12 is formed larger than the outer diameter of the other fuel burner 40. For example, the inner diameter of the through hole 12 a of the refractory 12 is formed to be 5 to 10 mm larger than the outer diameter of the other fuel burner 40. For this reason, the other fuel burner 40 is arrange | positioned in the refractory 12 in the state which is not mutually fixed with the refractory 12. Therefore, the other fuel burner 40 is movable relative to the axial direction without being fixed to the main burner 10. In addition, as other fuel supplied by the other fuel burner 40, fuel with combustibility better than the combustible waste supplied from the waste burner 11, such as meat-and-bone meal, is used. Other configurations are the same as those of the cement firing burner 1 according to the reference embodiment.

Above, the cement burning burner 2 according to the implementation form, the upper and lower waste burner 11 has a configuration sandwiched by the main burner 10 and the other fuel burner 40 using a fast burn rate fuel than combustible waste . FIG. 9 is a schematic diagram for explaining the function and effect of the cement burning burner 2. In the figure, only the arrangement of each burner is shown for simplification. Waste plastic is supplied from the waste burner 11, pulverized coal having a combustion speed faster than that of the waste plastic from the main burner 10, and meat and bone powder having a combustion speed higher than that of the waste plastic is supplied from the other fuel burner 40. It shall be.

  As shown in FIG. 9, the combustion timing of the pulverized coal supplied from the main burner 10 located at the bottom of the three burners and the meat-and-bone meal supplied from the other fuel burner 40 located at the top is the middle part. It is relatively earlier than the combustion timing of the waste plastic supplied from the waste burner 11 located at 1. For this reason, since the waste plastic is simultaneously heated at a high temperature from above and below by the flames of the main burner 10 and the other fuel burner 40, it is quicker than the case where the cement burning burner is composed of only the main burner 10 and the waste burner 11. It is possible to burn waste plastic.

  By the way, when the cement burning burner is constituted only by the main burner 10 and the waste burner 11, the waste plastic is heated from the lower side, and therefore, the combustion of the upper waste plastic may be delayed. Moreover, although the crushed thing is employ | adopted for a waste plastic, since there is dispersion | variation in a magnitude | size, there exists a possibility that dispersion | variation may arise in combustion. Further, when a flame retardant material such as carbon fiber is mixed in the waste plastic, there is a possibility that variation in combustion may further occur. As described above, when there is a variation in the combustibility of the waste plastic, the supplied waste plastic does not burn completely in the space of the rotary kiln 3 but lands on the lower side of the rotary kiln 3 and continues to burn (landing). Combustion) and cement firing may be adversely affected. For this reason, when the cement burning burner is constituted only by the main burner 10 and the waste burner 11, it is necessary to limit the type and amount of waste plastic to be supplied.

In contrast, according to the cement burning burner 2 according to the implementation embodiments, waste plastics, because it is heated at high temperatures simultaneously from above and below by the flame of the main burner 10 and the other fuel burner 40, the upper waste plastics burn Delay can be improved. Further, by heating up and down, the combustibility of the waste plastic is improved, and it is possible to reduce the landing combustion on the lower side of the rotary kiln 3, and a large amount of waste plastic can be adopted as combustible waste. it can.

Also, the cement burning burner 2 according to the implementation embodiments, other fuel burner 40 is provided to be relatively moved with respect to the main burner 10 and the waste burner 11 in the axial direction while being supported by an independent support portion . For this reason, even if there is a difference in the amount of thermal expansion between the main burner 10 and the waste burner 11 and the other fuel burner 40 during actual operation, the other fuel burner 40 is inserted into the through hole of the refractory 12. The inside of 12a can be slid by functioning like a sheath. For this reason, breakage of the refractory 12 can be suppressed, or displacement and deformation of the other fuel burner 40 can be suppressed. Therefore, it becomes possible to reduce the influence of the thermal stress generated between the burners. Further, the durability of the other fuel burner 40 can be improved, and the other fuel burner 40 can be supported with a simple configuration, so that it is possible to make the configuration excellent in economy.

[Effect of the implementation form]
(3) Another fuel burner that is provided vertically above the waste burner and supplies other fuel is provided. As a result, the waste plastic can be heated at the same time from above and below at a high temperature, the combustion delay of the upper waste plastic can be improved and combustion with excellent uniformity can be realized. Further, since the combustibility of the waste plastic is improved, it is possible to reduce the landing combustion on the lower side of the rotary kiln 3, and it is possible to employ a large amount of waste plastic as combustible waste.

In addition, embodiment mentioned above shows an example of the burner for cement baking which concerns on this invention. Cement firing burner according to the present invention is not limited to the cement burning burner according to implementation embodiments, modification of the cement burning burner according to implementation form, or be those applied to others Also good. Although using MBM as other fuels in implementation form, may be of other if fast burn rate fuel than waste plastics.

(Modification 1)
For example, in the reference embodiment described above, the relationship between the cross section of the tip portion 11a and the cross section of the circular tube portion 11b connected to the tip portion 11a in the waste burner 11 is not particularly limited, but the cross section of the tip portion 11a is the tip portion. The case where it is the same or larger than the cross section of the circular pipe part 11b connected to 11a may be sufficient. FIG. 10 shows a modification of the cement firing burner 1. FIG. 11A is a side view of the waste burner 11 in FIG. 10, and FIG. 11B is a front view of the waste burner 11 in FIG. In addition, in the modified example mentioned later, the description which overlaps with the cement-burning burner 1 which concerns on a reference form is abbreviate | omitted in consideration of the ease of explanation understanding, and it demonstrates centering on difference.

  As shown in FIGS. 10 and 11, the waste burner 11 disposed vertically above the main burner 10 includes a circular pipe portion 11 b having a circular radial cross-sectional shape and a tip portion 11 a having a rectangular radial cross-sectional shape. It is formed by joining at the joint portion 11c. The radial cross section on the distal end portion 11a side is provided to be equal to or larger than the radial cross sectional area of the circular pipe portion 11b. That is, the waste burner 11 is widened in the vertical direction and the horizontal direction on the tip end portion 11a side. For this reason, the waste plastic P can be further diffused and supplied in the horizontal direction, and the waste plastic can be burned more rapidly. In addition, when the rectangular shape of radial cross-sectional shape is long, you may make it put the partition plate inside and make waste plastic P of a uniform quantity flow through a cross section. Moreover, although the front-end | tip part 11a of FIG. 10, FIG. 11 decided to expand both the vertical direction and a horizontal direction, you may expand only a horizontal direction.

[Effect of Modification 1]
(4) The radial cross section of the waste burner was widened at the tip. By expanding the radial cross section in the horizontal direction, the contact area between the main burner and the waste plastic can be further increased. Moreover, the waste plastic supply speed can be reduced by configuring the waste burner 11 so that the cross section of the waste burner 11 increases toward the tip end portion 11a. Conversely, the waste plastic supply speed can be increased by configuring the waste burner 11 so that the cross section of the waste burner 11 becomes smaller toward the tip end portion 11a. In this way, the waste plastic supply speed can be changed according to the way of processing the distal end portion 11a.

(Modification 2)
Moreover, although the center axis | shaft of the waste burner 11 demonstrated the example extended straight toward the front-end | tip part 11a side from the rear-end part side in the reference form mentioned above, it is not restricted to this. FIG. 12 shows a modification in which the cement burning burner 1 includes a refracted waste burner 11. In addition, in the modified example mentioned later, the description which overlaps with the cement-burning burner 1 which concerns on a reference form is abbreviate | omitted in consideration of the ease of explanation understanding, and it demonstrates centering on difference.

  As shown in FIG. 12, the waste burner 11 arranged vertically above the main burner 10 has a rectangular cross-sectional shape in the radial direction, and a bent portion 11g is provided between the front end portion 11a and the rear end portion 11e. I have. The central axis of the waste burner 11 is substantially horizontal from the rear end portion 11e to the bent portion 11g, and is inclined vertically downward from the bent portion 11g to the front end portion 11a. That is, the tip end portion 11a of the waste burner 11 is inclined vertically downward. For this reason, the waste plastic P supplied from the tip opening 11 d of the waste burner 11 is supplied toward the upper region of the flame of the main burner 10. As a result, the waste plastic P can be supplied to a location optimal as a combustion space while diffusing the waste plastic P in the horizontal direction, and the waste plastic can be burned more rapidly.

[Effect of Modification 2]
(5) The central axis of the waste burner is inclined toward the vertically lower side at the tip. Thereby, waste can be efficiently supplied to the flame of the main burner, and combustion of waste can be promoted.

Furthermore, it may be applied to a cement burning burner 1 according waste burner 11 according to the modified example described above in the implementation form.

  DESCRIPTION OF SYMBOLS 1, 2 ... Burner for cement baking, 10 ... Main burner, 11 ... Waste burner, 11a ... Tip part, 12 ... Refractory, 40 ... Other fuel burner.

Claims (5)

A main burner for supplying primary fuel, provided vertically above the main burner, a cement burning burner and a waste burner for supplying a combustible waste,
Another fuel burner provided vertically above the waste burner and supplying other fuel having better combustibility than the combustible waste;
In the radial cross section of the tip of the waste burner, x is the horizontal distance between the two points L1 and L2 farthest apart in the horizontal direction, and y is the vertical distance between the two points H1 and H2 furthest apart in the vertical direction. Then, the burner for cement firing, wherein x> y. The waste burner is formed from a circular pipe part connected to the tip part and the tip part,
The burnable cement burner according to claim 1, wherein the combustible waste passes through the waste burner in the order of the circular pipe portion and the tip portion.   The burner for firing a cement according to claim 1 or 2, wherein a shape of a radial cross section at the tip is rectangular.   The burner for firing a cement according to any one of claims 1 to 3, wherein a cross section in the radial direction of the waste burner is widened at a front end portion of the waste burner.   The cement burning burner according to any one of claims 1 to 4, wherein a central axis of the waste burner is inclined toward a vertically lower side at a tip portion of the waste burner.

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