Cement clinker manufacturing method

Abstract

To prevent CO from being generated due to incomplete combustion of a solid content when ammonia is supplied into a calcination furnace.SOLUTION: A method for producing a cement clinker includes: a first supplying step of supplying, into an interior (S) of a calcination furnace (30), a heat energy source containing a solid content by one or more first supply members (60); and a second supplying step of supplying, into the interior (S) of the calcination furnace (30), ammonia by one or more second supply members (70). A position at which the one or more second supply members (70) supply ammonia is arranged on an upstream side relative to a position at which the one or more first supply members (60) supply the heat energy source containing the solid content. A ratio of heat generation by the ammonia supplied into the preheater kiln (30) from the one or more second supply members (70) to a total heat generation by the heat energy sources supplied into the calcination furnace (30) from the one or more first supply members (60) and the one or more second supply members (70) is from 0.01 to 0.90.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a method for producing cement clinker and an apparatus for producing cement clinker. [Background technology]

[0002] Patent Document 1 discloses a method for producing cement clinker using an NSP kiln equipped with a calciner and a rotary kiln. This method includes an introduction step of introducing a thermal energy raw material containing ammonia gas through a first inlet provided in the calciner, and a combustion step of burning the ammonia gas in the calciner. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-28050 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a method for producing cement clinker and an apparatus for producing cement clinker that are useful for suppressing CO generation due to incomplete combustion of solids when ammonia is supplied into a calciner. [Means for solving the problem]

[0005] [1] A method for producing cement clinker, comprising: a first supplying step of supplying a thermal energy source containing solids by one or more first supplying members to the interior of a calciner into which exhaust gas from a rotary kiln that heats cement raw materials to produce cement clinker is introduced; and a second supplying step of supplying ammonia by one or more second supplying members to the interior of the calciner, wherein, based on a gas flow inside the calciner, a position from which the one or more second supplying members supply the ammonia is located upstream of a position from which the one or more first supplying members supply the thermal energy source containing solids, and a ratio of a calorific value of the ammonia supplied from the one or more second supplying members to a total calorific value of the thermal energy source supplied from the one or more first supplying members and the one or more second supplying members to the calciner is 0.01 to 0.90.

[0006] [2] The method for producing cement clinker according to the above [1], wherein in the second supplying step, the ammonia is supplied to the inside of the calciner together with air having an air ratio of 0.1 to 1.0.

[0007] [3] The method for producing cement clinker according to [1] or [2] above, wherein the solid content is pulverized coal, and the pulverized coal has proximate analysis values, on an air-dry basis, of a volatile matter of 25 to 35 mass%, a moisture content of 2 to 4 mass%, a fixed carbon content of 40 to 60 mass%, and an ash content of 10 to 25 mass%, and chemical analysis values, on an air-dry basis, of C (carbon) of 60 to 75 mass%, H (hydrogen) of 3 to 5 mass%, O (oxygen) of 6 to 9 mass%, N (nitrogen) of 1 to 3 mass%, and S (sulfur) of 0.1 to 1.0 mass%, and the calorific value of the pulverized coal is 4500 to 6500 kcal / kg.

[0008] [4] The method for producing cement clinker according to any one of [1] to [3] above, wherein the solid content is pulverized coal, and the particle size distribution of the pulverized coal is such that particles having a particle size of 8.00 μm or more and less than 16.00 μm account for 5 to 20 mass %, particles having a particle size of 16.00 μm or more and less than 32.00 μm account for 20 to 40 mass %, particles having a particle size of 32.00 μm or more and less than 64.00 μm account for 20 to 40 mass %, and particles having a particle size of 64.00 μm or more and less than 128.00 μm account for 10 to 30 mass %.

[0009] [5] The method for producing cement clinker according to any one of [1] to [4] above, further comprising a third supply step of supplying a hot gas containing oxygen to the inside of the calciner by one or more third supply members, wherein the temperature of the hot gas is 700°C to 1000°C, and the position to which the one or more third supply members supply the hot gas, based on the gas flow inside the calciner, corresponds to the position to which the one or more first supply members supply the thermal energy source containing the solid content, or is arranged upstream of the supply position, and is arranged downstream of the position to which the one or more second supply members supply the ammonia.

[0010] [6] The method for producing cement clinker according to [5] above, wherein in the third supply step, extracted gas from a clinker cooler that cools the cement clinker produced in the rotary kiln is supplied as the hot gas.

[0011] [7] The method for producing cement clinker according to any one of the above [1] to [6], wherein a ratio of a calorific value of the ammonia supplied from the one or more second supply members to the calciner to the total calorific value is 0.01 to 0.55, and a ratio of a calorific value of the thermal energy source including the solid content supplied from the one or more first supply members to the calciner to the total calorific value is 0.45 to 0.99.

[0012] [8] An apparatus for producing cement clinker, comprising: a rotary kiln that heats cement raw materials to produce cement clinker; a calciner into which exhaust gas from the rotary kiln is introduced and which heats the cement raw materials; one or more first supply members that supply a thermal energy source containing solids to the inside of the calciner; and one or more second supply members that supply ammonia to the inside of the calciner, wherein, based on the gas flow inside the calciner, a position at which the one or more second supply members supply the ammonia is located upstream of a position at which the one or more first supply members supply the thermal energy source containing solids, and a ratio of a calorific value of the ammonia supplied from the one or more second supply members to the calciner to a total calorific value of the thermal energy source supplied from the one or more first supply members and the one or more second supply members to the calciner is 0.01 to 0.90. [Effects of the Invention]

[0013] According to the present disclosure, there are provided a method for producing cement clinker and an apparatus for producing cement clinker that are useful for suppressing CO generation due to incomplete combustion of solids when ammonia is supplied into a calciner. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram showing an example of a cement clinker manufacturing apparatus. [Figure 2] FIG. 2 is a side view schematically showing an example of a calciner and its peripheral members. [Figure 3] FIG. 3 is a side view schematically illustrating an example of the supply member. [Figure 4] FIG. 4 is a diagram illustrating a simulation result according to a reference example. [Figure 5] FIG. 5 is a diagram illustrating a simulation result according to the embodiment. [Figure 6] FIG. 6 is a diagram illustrating a simulation result according to the embodiment. [Figure 7] FIG. 7 is a diagram illustrating a simulation result according to the embodiment. [Figure 8] FIG. 8 is a diagram illustrating a simulation result according to the embodiment. [Figure 9] FIG. 9 is a diagram illustrating a simulation result according to the comparative example. [Figure 10] FIG. 10 is a diagram illustrating a simulation result according to the comparative example. [Figure 11] FIG. 11 is a diagram illustrating a simulation result according to the comparative example. [Figure 12] FIG. 12 is a diagram illustrating a simulation result according to the comparative example. [Figure 13] FIG. 13 is a graph illustrating the simulation results. [Figure 14] FIG. 14 is a graph illustrating the simulation results. DETAILED DESCRIPTION OF THE INVENTION

[0015] An embodiment will be described below with reference to the drawings. In the description, identical elements or elements having the same functions are designated by the same reference numerals, and redundant description will be omitted. The following embodiment is an example for explaining the present disclosure, and is not intended to limit the present disclosure to the following content. Furthermore, the dimensional ratios of each element are not limited to those shown in the drawings.

[0016] [Cement clinker manufacturing equipment] FIG. 1 schematically shows a cement clinker manufacturing apparatus according to one embodiment. The manufacturing apparatus 100 (cement clinker manufacturing apparatus) shown in FIG. 1 is an apparatus that manufactures cement clinker, an intermediate cement product, by burning cement raw materials. The manufacturing apparatus 100 is equipped with a preheating device of the NSP (New Suspension Preheater) type. The manufacturing apparatus 100 is also referred to as an NSP kiln. The manufacturing apparatus 100 includes, for example, cyclones C1, C2, C3, and C4, a calciner 30, a rotary kiln 40, and a clinker cooler 48.

[0017] Cyclones C1, C2, C3, and C4 and the calciner 30 function as preheaters that preheat and calcinate the cement raw materials. The cement raw materials may include, for example, two or more selected from the group consisting of incineration ash, coal ash, limestone, an iron source, and slag. The cement raw materials are introduced from the connection between cyclones C1 and C2, heated while flowing through cyclones C1, C2, C3, the calciner 30, and C4, and introduced into the kiln end 42 of the rotary kiln 40. When introduced into the kiln end 42 of the rotary kiln 40, the cement raw materials are heated to, for example, 850°C to 1000°C, preferably 850°C to 900°C.

[0018] The calciner 30 and the kiln end 42 of the rotary kiln 40 are connected by a rising duct 34. Exhaust gas from the rotary kiln 40 is introduced into the calciner 30 via the rising duct 34. The exhaust gas generated in the rotary kiln 40 includes combustion exhaust gas. The exhaust gas from the rotary kiln 40 flows through the calciner 30, cyclone C4, cyclone C3, cyclone C2, and cyclone C1, and heat exchange occurs between the exhaust gas and the cement raw materials.

[0019] The calciner 30 calcines the cement raw materials using exhaust gas from the rotary kiln 40 and a thermal energy source supplied to the calciner 30. In other words, the calciner 30 is a heating furnace that heats the cement raw materials. At least a portion of the calciner 30 is cylindrical (see also FIG. 2). In at least a portion of the calciner 30, the sidewall of the calciner 30 may extend around the central axis of the calciner 30. The central axis of the calciner 30 is an imaginary line, for example, a line extending in the vertical direction.

[0020] A probe 36 is connected to the rising duct 34, which extracts the exhaust gas from the rising duct 34. A chlorine bypass system having a cooler, a bag filter, etc. is installed downstream of the probe 36, and dust contained in the extracted gas (exhaust gas) extracted by the probe 36 is recovered. By installing the chlorine bypass system, volatile matters such as chlorine compounds and alkalis can be reduced from within the manufacturing apparatus 100. The probe 36 may be connected to the kiln end 42 instead of the rising duct 34, or may be connected to the boundary between the rising duct 34 and the kiln end 42.

[0021] The rotary kiln 40 burns cement raw materials to produce cement clinker (hereinafter, sometimes simply referred to as "clinker"). In other words, the rotary kiln 40 is a heating furnace that heats the cement raw materials. The rotary kiln 40 is equipped with a burner 44 that burns fuel. The burner 44 is disposed at the downstream end of the rotary kiln 40 (the end close to the clinker cooler 48). The cement raw materials are heated in the rotary kiln 40 to, for example, 1300°C to 1450°C by combustion in the burner 44. In the rotary kiln 40, the cement raw materials that have been preheated and calcined are heated by combustion in the burner 44 to become clinker.

[0022] The clinker produced in the rotary kiln 40 is discharged to the clinker cooler 48. The clinker cooler 48 cools the clinker with cooling air such as outside air. The clinker cooled in the clinker cooler 48 is discharged from the manufacturing apparatus 100. A portion of the gas used to cool the clinker in the clinker cooler 48 may be introduced into the calciner 30 as bleed gas. The temperature of the bleed gas introduced from the clinker cooler 48 into the calciner 30 may be 700°C to 1000°C, or 800°C to 900°C. The introduction of a thermal energy source into the calciner 30 will be described below.

[0023] <Introduction of thermal energy source> FIG. 2 schematically shows a portion for introducing a thermal energy source into the calciner 30. The manufacturing apparatus 100 includes a thermal energy source supply unit 50. The thermal energy source supply unit 50 supplies two or more types of thermal energy sources. In order to reduce carbon dioxide emissions, ammonia (ammonia gas) is introduced into the calciner 30 as one type of thermal energy source. In addition to the calciner 30, ammonia (ammonia gas) may be introduced into the rotary kiln 40 as one type of thermal energy source. Ammonia gas is combusted in the calciner 30. In FIG. 2 and other figures, the "Z" axis direction represents the vertical direction, and "S" represents the internal space of the calciner 30.

[0024] The thermal energy source supply unit 50 has one or more supply members 60 (first supply members). In the example shown in FIG. 2, two supply members 60 are provided. The supply members 60 are members (burners) that supply a thermal energy source containing solid content to the inside of the calciner 30. The solid content means a solid thermal energy source. The supply members 60 may supply the solid content and combustion air to the inside of the calciner 30.

[0025] The solid content includes, for example, at least one of pulverized coal and waste material. The waste material supplied to the inside of the calciner 30 may include one or more types of waste material, such as waste plastic, RDF (Refuse Derived Fuel), or meat and bone meal. The supply member 60 may supply pulverized coal and combustion air, may supply waste material and combustion air, or may supply pulverized coal, waste material, and combustion air.

[0026] An inlet 62 is provided at an end of the supply member 60, through which solids (e.g., pulverized coal) and combustion air are discharged (blowed) into the interior of the calciner 30. The end of the supply member 60 including the inlet 62 functions as a nozzle. The end of the supply member 60 that functions as a nozzle may be installed horizontally. FIG. 3 schematically illustrates an enlarged view of the portion marked III in FIG. 2. As shown in FIG. 3, the end of the supply member 60 may be connected to a side wall of the calciner 30.

[0027] The supply member 60 may transport the solid content by conveying air up to its inlet 62. The supply member 60 may separately supply the solid content (solid content and conveying air) and the combustion air to the inside of the calciner 30. In this case, the inlet 62 at the end of the supply member 60 may include one or more openings for discharging the solid content and one or more openings for discharging the combustion air. When the solid content and the conveying air are supplied separately, the solid content and the combustion air do not merge during transport by the supply member 60.

[0028] In the example shown in Figures 2 and 3, one of the two supply members 60 is referred to as the "supply member 60a" and the other is referred to as the "supply member 60b." The supply members 60a and 60b have similar functions and configurations. In the direction of gas flow inside the calciner 30, at least a portion of the inlet 62 of the supply member 60a is disposed in the same position as at least a portion of the inlet 62 of the supply member 60b. The direction of gas flow inside the calciner 30 (hereinafter referred to as the "gas flow direction F") is defined as the direction from the inlet 30a, through which exhaust gas from the rotary kiln 40 of the calciner 30 is introduced, to the outlet 30b, through which combustion gas containing that exhaust gas is discharged.

[0029] In the examples shown in FIGS. 2 and 3, the gas flow direction F is a vertical direction from bottom to top. Inside the calciner 30, combustion gas, including exhaust gas from the rotary kiln 40, may circulate while swirling. The gas flow direction F is defined by the relative positions of the exhaust gas inlet 30a and the combustion gas outlet 30b. The height position of at least a portion of the inlet 62 of the supply member 60a may coincide with the height position of at least a portion of the inlet 62 of the supply member 60b. In a plan view (viewed vertically from above), the inlet 62 of the supply member 60a and the inlet 62 of the supply member 60b are positioned differently in the circumferential direction around the central axis of the calciner 30. In one example, the angle (the smaller angle of deviation) between the inlet 62 of the supply member 60a and the inlet 62 of the supply member 60b in the circumferential direction may be approximately 150° to 180°, approximately 160° to 180°, or approximately 170° to 180°. The position of the inlet 62 in the circumferential direction in a plan view is defined by the center of the inlet 62.

[0030] In a plan view, the direction in which the end portions of the supply members 60 (each of the supply members 60a and 60b) that function as nozzles extend may be perpendicular to the side wall of the calciner 30. The direction in which the end portions of the supply members 60 extend may coincide with a direction perpendicular to the inlet 62. Alternatively, in a plan view, the direction in which the end portions of the supply members 60 extend may be inclined with respect to a direction perpendicular to the side wall of the calciner 30 (a radial direction of a circumference around the central axis of the calciner 30) so as to follow the swirling flow formed in the calciner 30. In one example, the angle at which the end portions are inclined with respect to a direction perpendicular to the side wall of the calciner 30 in a plan view may be approximately 10°, 20°, 30°, or 40°.

[0031] In the case where the supplying member 60 supplies pulverized coal as solid content, an example of the components, calorific value, and particle size distribution of the pulverized coal supplied from one or more supplying members 60 will be described. The proximate analysis values ​​(mass %: air-dry basis) of the volatile matter, moisture, fixed carbon, and ash content of the pulverized coal may be in the following ranges. (a) The proximate analysis value of the volatile content may be 25% by mass or more, 26% by mass or more, 27% by mass or more, or 28% by mass or more. The proximate analysis value of the volatile content may be 35% by mass or less, 34% by mass or less, 33% by mass or less, or 32% by mass or less. In one example, the proximate analysis value of the volatile content is 25 to 35% by mass, or 28 to 32% by mass. (b) The proximate analysis value of the moisture content may be 2.0% by mass or more, 2.2% by mass or more, 2.4% by mass or more, or 2.6% by mass or more. The proximate analysis value of the moisture content may be 4.0% by mass or less, 3.8% by mass or less, 3.6% by mass or less, or 3.4% by mass or less. In one example, the proximate analysis value of the moisture content is 2.0 to 4.0% by mass, or 2.6% to 3.4% by mass. (c) The proximate analysis value of fixed carbon may be 40% by mass or more, 42% by mass or more, 44% by mass or more, or 46% by mass or more. The proximate analysis value of fixed carbon may be 60% by mass or less, 58% by mass or less, 56% by mass or less, or 54% by mass or less. In one example, the proximate analysis value of fixed carbon is 40 to 60% by mass, or 46 to 54% by mass. (d) The proximate analysis value of the ash content may be 10% by mass or more, 11% by mass or more, 12% by mass or more, or 13% by mass or more. The proximate analysis value of the ash content may be 25% by mass or less, 24% by mass or less, 23% by mass or less, or 22% by mass or less. In one example, the proximate analysis value of the ash content is 10 to 25% by mass, or 13 to 22% by mass.

[0032] In one example, the proximate analysis values ​​of the components of pulverized coal are 25 to 35 mass% for volatile matter, 2 to 4 mass% for moisture, 40 to 60 mass% for fixed carbon, and 10 to 25 mass% for ash. The proximate analysis values ​​of the components of pulverized coal are analytical values ​​measured by the test method described in JIS M8812 "Coals and cokes - Proximate analysis methods."

[0033] The chemical analysis values ​​(mass %: air-dry basis) of C (carbon), H (hydrogen), O (oxygen), N (nitrogen), and S (sulfur) of the pulverized coal may be in the following ranges. (a) The chemical analysis value of C may be 60% by mass or more, 61% by mass or more, 62% by mass or more, or 63% by mass or more. The chemical analysis value of C may be 75% by mass or less, 74% by mass or less, 73% by mass or less, or 72% by mass or less. In one example, the chemical analysis value of C is 60 to 75% by mass, or 63 to 72% by mass. (b) The chemical analysis value of H may be 3.0% by weight or more, 3.2% by weight or more, 3.4% by weight or more, or 3.6% by weight or more. The chemical analysis value of H may be 5.0% by weight or less, 4.8% by weight or less, 4.6% by weight or less, or 4.4% by weight or less. In one example, the chemical analysis value of H is 3-5% by weight, or 3.6-4.4% by weight. (c) The chemical analysis value of O may be 6.0% by weight or more, 6.2% by weight or more, 6.4% by weight or more, or 6.6% by weight or more. The chemical analysis value of O may be 9.0% by weight or less, 8.8% by weight or less, 8.6% by weight or less, or 8.4% by weight or less. In one example, the chemical analysis value of O is 6-9% by weight, or 6.6-8.4% by weight. (d) The chemical analysis value of N may be 1.0% by weight or more, 1.1% by weight or more, 1.2% by weight or more, or 1.3% by weight or more. The chemical analysis value of N may be 3.0% by weight or less, 2.8% by weight or less, 2.6% by weight or less, or 2.4% by weight or less. In one example, the chemical analysis value of N is 1-3% by weight, or 1.3-2.4% by weight. (e) The chemical analysis value of S may be 0.1% by weight or more, 0.2% by weight or more, 0.3% by weight or more, or 0.4% by weight or more. The chemical analysis value of S may be 1.0% by weight or less, 0.9% by weight or less, 0.8% by weight or less, or 0.7% by weight or less. In one example, the chemical analysis value of S is 0.1 to 1.0% by weight, or 0.4 to 0.7% by weight.

[0034] In one example, the chemical analysis values ​​(air-dry basis) of the components of the pulverized coal are 60 to 75 mass% C, 3 to 5 mass% H, 6 to 9 mass% O, 1 to 3 mass% N, and 0.1 to 1.0 mass% S. The chemical analysis values ​​(air-dry basis) of the components of the pulverized coal are analytical values ​​measured by the test methods described in JIS M8813 "Coals and cokes - Methods for elemental analysis" and JIS M8810 "Coals and cokes - General rules for sampling, analysis, and test methods."

[0035] The chemical analysis values ​​(mass %: dry and ash-free basis) of C, H, O, N, and S of the pulverized coal may be in the following ranges. (a) The chemical analysis value of C may be 75% by mass or more, 76% by mass or more, 77% by mass or more, or 78% by mass or more. The chemical analysis value of C may be 90% by mass or less, 89% by mass or less, 88% by mass or less, or 87% by mass or less. In one example, the chemical analysis value of C is 75 to 90% by mass, or 78 to 88% by mass. (b) The chemical analysis value of H may be 4.0% by weight or more, 4.2% by weight or more, 4.4% by weight or more, or 4.6% by weight or more. The chemical analysis value of H may be 6.0% by weight or less, 5.8% by weight or less, 5.6% by weight or less, or 5.4% by weight or less. In one example, the chemical analysis value of H is 4-6% by weight, or 4.6-5.4% by weight. (c) The chemical analysis value of O may be 8.0% by weight or more, 8.2% by weight or more, 8.4% by weight or more, or 8.6% by weight or more. The chemical analysis value of O may be 11.0% by weight or less, 10.8% by weight or less, 10.6% by weight or less, or 10.4% by weight or less. In one example, the chemical analysis value of O is 8 to 11% by weight, or 8.6 to 10.4% by weight. (d) The chemical analysis value of N may be 1.0% by weight or more, 1.1% by weight or more, 1.2% by weight or more, or 1.3% by weight or more. The chemical analysis value of N may be 3.0% by weight or less, 2.9% by weight or less, 2.8% by weight or less, or 2.7% by weight or less. In one example, the chemical analysis value of N is 1-3% by weight, or 1.3-2.7% by weight. (e) The chemical analysis value of S may be 0.1% by weight or more, 0.2% by weight or more, 0.3% by weight or more, or 0.4% by weight or more. The chemical analysis value of S may be 1.0% by weight or less, 0.9% by weight or less, 0.8% by weight or less, or 0.7% by weight or less. In one example, the chemical analysis value of S is 0.1 to 1.0% by weight, or 0.4 to 0.7% by weight.

[0036] In one example, the chemical analysis values ​​(on an anhydrous ash-free basis) of the components of pulverized coal are 75 to 90 mass% C, 4 to 6 mass% H, 8 to 11 mass% O, 1 to 3 mass% N, and 0.1 to 1.0 mass% S. The chemical analysis values ​​(on an air-dry basis) of the components of pulverized coal are analytical values ​​measured by the test methods described in JIS M8813 "Coals and cokes - Methods for elemental analysis" and JIS M8810 "Coals and cokes - General rules for sampling, analysis, and test methods."

[0037] The calorific value of the pulverized coal (more specifically, the lower heating value of the pulverized coal on arrival) may be 4500 kcal / kg or more, 4700 kcal / kg or more, 4900 kcal / kg or more, or 5100 kcal / kg or more. In the present disclosure, the calorific value of the pulverized coal refers to the lower heating value (on arrival). The calorific value of the pulverized coal may be 6500 kcal / kg or less, 6300 kcal / kg or less, 6100 kcal / kg or less, or 5900 kcal / kg or less. In one example, the calorific value of the pulverized coal is 4500 to 6500 kcal / kg or 5100 to 5900 kcal / kg. The calorific value of the pulverized coal, i.e., the lower heating value (on arrival) of the pulverized coal, is measured by the test method described in JIS M8814, "Coals and cokes - Method for measuring gross calorific value using a bomb calorimeter and method for calculating net calorific value."

[0038] The particle size distribution of the pulverized coal (mass proportion for each particle size division) may be in the following ranges: The mass proportion (mass %) for each particle size division means the proportion of the mass of particles in that particle size division to the total mass of the pulverized coal. (a) Particles having a particle size of less than 8.00 μm may be 15% by mass or less, 13% by mass or less, 11% by mass or less, or 9% by mass or less. It is also possible for particles having a particle size of less than 8.00 μm to be absent. (b) The content of particles having a particle size of 8.00 μm or more and less than 16.00 μm may be 5% by mass or more, 6% by mass or more, 7% by mass or more, or 8% by mass or more. The content of particles having a particle size of 8.00 μm or more and less than 16.00 μm may be 20% by mass or less, 19% by mass or less, 18% by mass or less, or 17% by mass or less. In one example, the content of particles having a particle size of 8.00 μm or more and less than 16.00 μm is 5 to 20% by mass, or 8 to 17% by mass. (c) The content of particles having a particle size of 16.00 μm or more and less than 32.00 μm may be 20% by mass or more, 22% by mass or more, 24% by mass or more, or 26% by mass or more. The content of particles having a particle size of 16.00 μm or more and less than 32.00 μm may be 40% by mass or less, 38% by mass or less, 36% by mass or less, or 34% by mass or less. In one example, the content of particles having a particle size of 16.00 μm or more and less than 32.00 μm is 20 to 40% by mass, or 26 to 34% by mass. (d) The content of particles having a particle size of 32.00 μm or more and less than 64.00 μm may be 20% by mass or more, 22% by mass or more, 24% by mass or more, or 26% by mass or more. The content of particles having a particle size of 32.00 μm or more and less than 64.00 μm may be 40% by mass or less, 38% by mass or less, 36% by mass or less, or 34% by mass or less. In one example, the content of particles having a particle size of 32.00 μm or more and less than 64.00 μm is 20 to 40% by mass, or 26 to 34% by mass. (e) The content of particles having a particle size of 64.00 μm or more and less than 128.00 μm may be 10% by mass or more, 12% by mass or more, 14% by mass or more, or 16% by mass or more. The content of particles having a particle size of 64.00 μm or more and less than 128.00 μm may be 30% by mass or less, 28% by mass or less, 26% by mass or less, or 24% by mass or less. In one example, the content of particles having a particle size of 64.00 μm or more and less than 128.00 μm is 10 to 30% by mass, or 16 to 24% by mass. (f) Particles having a particle size of 128.00 μm or more may be 10% by mass or less, 9% by mass or less, 8% by mass or less, or 7% by mass or less. It is not necessary for particles having a particle size of 128.00 μm or more to be contained.

[0039] In one example, the particle size distribution of the pulverized coal is such that particles having a particle size of 8.00 μm or more and less than 16.00 μm account for 5 to 20 mass %, particles having a particle size of 16.00 μm or more and less than 32.00 μm account for 20 to 40 mass %, particles having a particle size of 32.00 μm or more and less than 64.00 μm account for 20 to 40 mass %, and particles having a particle size of 64.00 μm or more and less than 128.00 μm account for 10 to 30 mass %. In this case, the pulverized coal may contain at least one of particles having a particle size less than 8.00 μm and particles having a particle size of 128.00 μm or more, or may not contain both of these particles. The particle size distribution (particle size) of the pulverized coal is measured by the test method described in JIS Z 8825 "Particle Size Analysis - Laser Diffraction and Scattering Method."

[0040] The thermal energy source supply unit 50 has one or more supply members 70 (second supply members). In the example shown in FIG. 2, two supply members 70 are provided. The supply members 70 are members (burners) that supply ammonia as a thermal energy source to the inside of the calciner 30. The supply members 70 are configured to supply an ammonia-containing gas containing ammonia. The ammonia-containing gas supplied by the supply member 70 may be ammonia gas alone, or may be a mixed gas of ammonia gas and other gases such as air or methane.

[0041] As shown in Fig. 3, the supplying member 70 may supply ammonia together with combustion air to the inside of the calciner 30. In the supplying member 70, the ammonia and the combustion air may be merged before being introduced into the inside of the calciner 30, or the ammonia and the combustion air may be supplied separately without being merged. The air ratio of the combustion air supplied together with ammonia is, for example, 0.1 to 1.0. The air ratio is defined as the ratio of the amount of air actually supplied to the minimum amount of air required for theoretically completely combusting the ammonia supplied from the supplying member 70.

[0042] The air ratio of the combustion air from the supply member 70 may be 0.15 or more, 0.2 or more, or 0.25 or more, from the viewpoint of promoting the combustion of ammonia. The air ratio of the combustion air from the supply member 70 may be 0.9 or less, 0.8 or less, or 0.7 or less, from the viewpoint of efficiently introducing air. In one example, exhaust gas from the chlorine bypass facility is introduced as combustion air from each of the supply member 70 and the supply member 60.

[0043] The supply member 70 may supply the ammonia-containing gas continuously while the calciner 30 is operating, or may supply the ammonia-containing gas for part of the period while the calciner 30 is operating.

[0044] A part of the ammonia-containing gas supplied from the supply member 70 may be used as a thermal energy source, and another part may be used for denitration. That is, the reaction may occur not only as shown in the following formula (1) but also as shown in formula (2). NH3 + 1 / 4O2 → 1 / 2N2 + 3 / 2H2O (1) NH3 + NO + 1 / 4O2 → N2 + 3 / 2H2O (2) The calciner 30 has a temperature range in which both the combustion reaction and the denitration reaction can proceed, and therefore can perform both the ammonia combustion reaction and the denitration reaction, thereby reducing the emissions of both carbon dioxide and nitrogen oxides.

[0045] The ammonia contained in the ammonia-containing gas supplied from the supply member 70 may undergo both combustion and denitration in the calciner 30, or all or most of the ammonia from the supply member 70 may be used for the combustion reaction, and the ammonia used for the denitration reaction may be supplied from an inlet 20 located at a position separate from the supply member 70. The ammonia-containing gas supplied from the inlet 20 may contain only ammonia, or may be a mixed gas of ammonia gas and other gases. The inlet 20 is provided, for example, in a connection part 38 that connects the outlet 30b of the calciner 30 to the cyclone C4 and through which the exhaust gas from the calciner 30 flows.

[0046] An end of the supply member 70 is provided with an inlet 72 for discharging (blowing) the ammonia-containing gas into the interior of the calciner 30. The end of the supply member 70 including the inlet functions as a nozzle. The inlet of the supply member 70 may be provided with one or more openings for introducing the ammonia-containing gas. The inlet 72 at the end of the supply member 70 may include one or more openings for discharging the combustion air in addition to one or more openings for discharging the ammonia-containing gas. A portion of the combustion air introduced together with the ammonia-containing gas may be discharged from the inlet 72 as a swirling flow, and another portion of the combustion air may be discharged from the inlet 72 without swirling (for example, in a straight line). The end of the supply member 70 functioning as a nozzle may be installed horizontally. As shown in FIG. 3, the end of the supply member 70 may be connected to a side wall of the calciner 30.

[0047] In the example shown in FIGS. 2 and 3 , one of the two supply members 70 is referred to as the “supply member 70a,” and the other is referred to as the “supply member 70b.” The supply members 70a and 70b have similar functions and configurations. In the gas flow direction F within the calciner 30, at least a portion of the inlet 72 of the supply member 70a is disposed at the same position as at least a portion of the inlet 72 of the supply member 70b. When the gas flow direction F is along the vertical direction, the height position of at least a portion of the inlet 72 of the supply member 70a may coincide with the height position of at least a portion of the inlet 72 of the supply member 70b. In a plan view, the inlet 72 of the supply member 70a and the inlet 72 of the supply member 70b are positioned at different circumferential positions around the central axis of the calciner 30. In one example, the angle (the smaller angle of deviation) between the inlet 72 of the supply member 70a and the inlet 72 of the supply member 70b in the circumferential direction may be approximately 150° to 180°, approximately 160° to 180°, or approximately 170° to 180°. The position of the inlet 72 in the circumferential direction in a plan view is defined by the center of the inlet 72.

[0048] In a plan view, the direction in which the end portions of the supply members 70 (each of the supply members 70a and 70b) that function as nozzles extend may be perpendicular to the side wall of the calciner 30. The direction in which the end portions of the supply members 70 extend may coincide with a direction perpendicular to the inlet 72. Alternatively, in a plan view, the direction in which the end portions of the supply members 70 extend may be inclined with respect to a direction perpendicular to the side wall of the calciner 30 (a radial direction of a circumference around the central axis of the calciner 30) so as to follow the swirling flow formed in the calciner 30. In one example, the angle at which the end portions are inclined with respect to a direction perpendicular to the side wall of the calciner 30 in a plan view may be approximately 10°, 20°, 30°, or 40°.

[0049] Next, a description will be given of the positional relationship between one or more supply members 70 and one or more supply members 60. Below, the positional relationship will be described focusing on one supply member 70 and one supply member 60, but the same positional relationship holds for all combinations of supply members 70 and supply members 60.

[0050] The supply member 70 is formed separately from the supply member 60. That is, the supply member 70 is physically separated from the supply member 60. The supply member 70 discharges ammonia gas from a position different from the position from which the supply member 60 supplies the thermal energy source. That is, the position from which the supply member 60 supplies solid content to the interior of the calciner 30 and the position from which the supply member 70 supplies an ammonia-containing gas to the interior of the calciner 30 are different from each other. In the present disclosure, supplying (discharging) a thermal energy source from different positions (locations) means that two supply members formed separately each supply (discharge) a thermal energy source.

[0051] With respect to the gas flow direction F in the calciner 30 as a reference, the position where the supply member 70 supplies ammonia is disposed upstream of the position where the supply member 60 supplies the thermal energy source containing solid content. The position where the supply member 70 supplies ammonia corresponds to the position of the inlet 72 of the supply member 70, which discharges ammonia (ammonia-containing gas), and this position will be referred to hereinafter as the "supply position of the supply member 70." The position where the supply member 60 supplies the thermal energy source containing solid content corresponds to the position of the inlet 62 of the supply member 60, which discharges the thermal energy source, and this position will be referred to hereinafter as the "supply position of the supply member 60." When the gas flow direction F is along the vertical direction, the uppermost position (the highest position) of the inlet 72 of the supply member 70 is located below the lowermost position (the lowest position) of the inlet 62 of the supply member 60.

[0052] As described above, (all of) the supply positions of one or more supply members 70 are disposed upstream of (all of) the supply positions of one or more supply members 60 in the gas flow direction F. When the gas flow direction F is along the vertical direction, (all of) the supply positions of one or more supply members 70 are disposed at a lower position than (all of) the supply positions of one or more supply members 60. In the example shown in FIG. 2, the supply position of supply member 70a is disposed at a lower position than both the supply position of supply member 60a and the supply position of supply member 60b. The supply position of supply member 70b is also disposed at a lower position than both the supply position of supply member 60a and the supply position of supply member 60b. In a plan view, the supply positions of supply member 60a and supply member 70a may be approximately aligned with each other, and the supply positions of supply member 60b and supply member 70b may be approximately aligned with each other. The supply position of the supply member 60a (supply member 60b) and the supply position of the supply member 70a (supply member 70b) may be different from each other in a plan view, as long as the combustion of the ammonia or solid content is not affected. In one example, the supply positions may be shifted by about 10°, 20°, or 30° in the circumferential direction around the central axis of the calciner 30 in a plan view.

[0053] There is a concern that the supply of ammonia into the calciner 30 will increase the concentration of carbon monoxide contained in the gas discharged from the calciner 30. The following two factors are thought to be factors that cause the increase in carbon monoxide concentration. (A) Inhibition of combustion of solid matter such as pulverized coal by combustion of ammonia (B) Reaction of ammonia with carbon dioxide

[0054] Regarding factor (A), this is thought to be due to the fact that oxygen around the solids is consumed first by the combustion of ammonia gas, a combustible gas, resulting in a temporary shortage of oxygen for the combustion reaction of the solids. Generally, the combustion of solids involves the thermal decomposition of the solids into gas and char, which then combust separately. Therefore, it is presumed that the combustion rate of the combustible gas (ammonia gas) is faster than that of the solids. Consider the case where solids, which have a relatively slow combustion rate, and ammonia gas, which has a relatively fast combustion rate, are supplied from the same position in the gas flow direction F within the calciner 30, or the case where solids are supplied upstream and ammonia gas is supplied downstream. In these cases, due to the difference in combustion rate, oxygen is consumed around the downstream supply position due to the combustion of ammonia gas, resulting in a temporary shortage of oxygen at the upstream supply position for burning the incompletely combusted solids. This results in accelerated carbon monoxide generation.

[0055] In contrast, in the manufacturing apparatus 100, ammonia gas is supplied upstream in the gas flow direction F by the supply member 70, and solid content is supplied downstream by the supply member 60. In this case, the possibility of oxygen shortage around the solid content supplied downstream due to combustion of ammonia gas can be reduced. It is also considered that the reaction between carbon dioxide generated by combustion of the solid content and ammonia can be suppressed. Therefore, by supplying ammonia gas upstream and supplying the solid content downstream, it is possible to suppress an increase in carbon monoxide concentration caused by ammonia gas.

[0056] The thermal energy source supply unit 50 supplies various thermal energy sources to the inside of the calciner 30 so that the calorific value ratio, defined below, is 0.01 to 0.90. Calorific value ratio: The ratio of the calorific value of ammonia supplied from one or more supply members 70 to the total calorific value of the thermal energy source supplied from one or more supply members 60 and one or more supply members 70. The total calorific value is the sum of the calorific values ​​of all the thermal energy sources supplied from one or more supply members 60 and all the calorific values ​​of all the thermal energy sources supplied from one or more supply members 70. The calorific value of ammonia supplied from one or more supply members 70 is the calorific value of all the ammonia supplied from one or more supply members 70. In this disclosure, the calorific value of ammonia refers to the lower heating value (anhydrous basis). The calorific value of ammonia may be 3000 kcal / kg or more, 3200 kcal / kg or more, 3400 kcal / kg or more, or 3600 kcal / kg or more. The calorific value of ammonia may be 6000 kcal / kg or less, 5800 kcal / kg or less, 5600 kcal / kg or less, or 5400 kcal / kg or less. In one example, the calorific value of ammonia is 3000 to 6000 kcal / kg or 3600 to 5400 kcal / kg.

[0057] From the viewpoint of promoting effective use of ammonia, the calorific value ratio may be 0.05 or more, 0.1 or more, 0.15 or more, or 0.20 or more. From the viewpoint of suppressing inhibition of combustion of solids due to ammonia, the calorific value ratio may be 0.7 or less, 0.55 or less, 0.50 or less, 0.45 or less, 0.4 or less, 0.35 or less, or 0.3 or less. The calorific value ratio may be 0.01 to 0.55. In this case, the ratio of the calorific value of the thermal energy source containing solids supplied from one or more supply members 60 to the total calorific value may be 0.45 to 0.99. The calorific value ratio may be 0.01 to 0.3. In this case, the ratio of the calorific value of the thermal energy source containing solids supplied from one or more supply members 60 to the total calorific value may be 0.7 to 0.99. These calorific value ratios can be calculated using the supply amounts of various thermal energy sources.

[0058] The manufacturing apparatus 100 may include one or more supply members 80 (third supply members). In the example shown in FIG. 2, one supply member 80 is provided, but two or more supply members 80 may be provided. The supply member 80 is a member that supplies hot gas containing oxygen and having a temperature of 700°C to 1000°C to the inside of the calciner 30. The temperature of the hot gas supplied from the supply member 80 may be 800°C to 900°C. The supply member 80 may supply the extracted gas from the clinker cooler 48 to the inside of the calciner 30 as the hot gas.

[0059] An inlet is provided at the end of the supply member 80 for discharging (blowing) hot gas into the interior of the calciner 30. The position to which hot gas is supplied by the supply member 80 corresponds to the position of the inlet provided at the end of the supply member 80, and hereinafter, this position will be referred to as the "supply position of the supply member 80." In the gas flow direction F within the calciner 30, the supply positions of one or more supply members 80 may correspond to the supply positions of one or more supply members 60, or may be located upstream of the supply positions and downstream of the supply positions of one or more supply members 70. In the gas flow direction F within the calciner 30, the supply position of the supply member 80 corresponding to the supply position of the supply member 60 means that at least a portion of the inlet of the supply member 80 and at least a portion of the inlet 62 of the supply member 60 are located at the same position. By blowing hot gas from the supply member 80 into the interior of the calciner 30, the combustibility of the solid content can be further improved.

[0060] In the example shown in FIG. 2, the supply position of supply member 80 is located lower than the supply positions of both supply member 60a and supply member 60b. That is, the uppermost position of the inlet of supply member 80 is located lower than the lowermost position of the inlet of both supply member 60a and supply member 60b. Furthermore, the supply position of supply member 80 is located higher than the supply positions of both supply member 70a and supply member 70b. That is, the lowermost position of the inlet of supply member 80 is located higher than the uppermost position of the inlet of both supply member 70a and supply member 70b. The supply position of supply member 80 may be located between the supply positions of supply member 60 and supply member 70 and closer to the supply position of supply member 60. Unlike the example shown in FIG. 2, the height position of the supply position of supply member 80 may coincide with the height position of the supply position of supply member 60a and the height position of the supply position of supply member 60b. The fact that the height positions of the supply positions are the same means that the height position of at least a part of the inlet of one supply member is the same as the height position of at least a part of the inlet of another supply member. When another supply member 80 is provided in addition to one supply member 80, the positional relationship of the other supply member 80 with respect to supply member 60 and supply member 70 is also the same.

[0061] When one supply member 60 and one supply member 80 are provided, in a plan view, the supply position of the supply member 80 may be approximately aligned with the position of the supply member 60 located downstream in the circumferential direction around the central axis of the calciner 30, or the angle of deviation between them may be approximately 30° or less. In this case, it is possible to more effectively increase the combustion temperature around the solid content. Even when two supply members 60 and two supply members 80 are provided, the degree of deviation between the supply position of one supply member 60 and the supply position of the corresponding supply member 80 in the circumferential direction may be approximately aligned or may be approximately 30° or less.

[0062] [Cement clinker manufacturing method] Next, as an example of a method for producing cement clinker, a clinker production process performed in the production apparatus 100 will be described. The clinker production process performed in the production apparatus 100 includes, for example, a preheating process, a calcining process, a firing process, and a cooling process. These processes are performed in at least partially overlapping periods. The preheating process is a process in which cement raw materials are preheated in cyclones C1 to C4 by high-temperature gases including exhaust gas from the rotary kiln 40.

[0063] The calcination process is a process in which the cement raw materials are calcined in the calciner 30 using exhaust gas from the rotary kiln 40 and various thermal energy sources supplied to the interior of the calciner 30. The firing process is a process in which the cement raw materials are calcined in the rotary kiln 40 using combustion gas from the burner 44. The cooling process is a process in which the clinker produced in the rotary kiln 40 is cooled in the clinker cooler 48.

[0064] An example of the calcination process will be described in detail. The calcination process includes, for example, a first supplying process, a second supplying process, a third supplying process, and a heating process. The first supplying process, the second supplying process, the third supplying process, and the heating process are each performed during at least partially overlapping periods. The first supplying process is a process of supplying a thermal energy source containing solid content to the inside of the calciner 30 by one or more supplying members 60. In the first supplying process, for example, a thermal energy source containing solid content is supplied from each of supplying members 60a and 60b (two supplying members 60). The solid content supplied from each supplying member 60 in the first supplying process may be pulverized coal, may be waste, or may be both pulverized coal and waste.

[0065] The second supply step is a step of supplying ammonia to the interior of the calciner 30 by one or more supply members 70. In the second supply step, for example, an ammonia-containing gas is supplied from each of two supply members 70, namely supply member 70a and supply member 70b (two supply members 70). In the second supply step, ammonia may be supplied to the interior of the calciner 30 together with air having an air ratio of 0.1 to 1.0. The position from which each supply member 70 supplies ammonia in the second supply step is located upstream, based on the gas flow direction F, of the position from which each supply member 60 supplies a thermal energy source containing solid content in the first supply step.

[0066] The ratio of the calorific value of the ammonia supplied to the calciner 30 in the second supply step to the total calorific value of the thermal energy sources supplied to the calciner 30 in the first supply step and the second supply step is 0.01 to 0.90. The ratio related to the calorific value of the ammonia may be 0.01 to 0.55. In this case, the ratio of the calorific value of the thermal energy source including the solid content supplied to the calciner 30 in the first supply step to the total calorific value of the thermal energy sources supplied to the calciner 30 in the first supply step and the second supply step may be 0.45 to 0.99.

[0067] The third supply step is a step of supplying a hot gas containing oxygen to the inside of the calciner 30 using one or more supply members 80 (for example, one or two supply members 80). The temperature of the hot gas supplied from the supply member 80 may be 900°C to 1200°C. The extracted gas after being used to cool the clinker in the clinker cooler 48 may be used as the hot gas supplied from the supply member 80. The position at which the supply member 80 supplies the hot gas in the third supply step may coincide with the position at which each supply member 60 supplies a thermal energy source containing solids in the first supply step, based on the gas flow direction F, or may be located upstream of that position. The position at which the supply member 80 supplies the hot gas in the third supply step may be located downstream of the position at which each supply member 70 supplies ammonia in the second supply step, based on the gas flow direction F.

[0068] The heating step is a step of heating the cement raw materials while burning ammonia gas in the calciner 30. The calcination step may include a denitration step. For example, in the denitration step, an ammonia-containing gas is supplied into the connection part 38 from an inlet 20 provided in the connection part 38 that connects the upper part (outlet 30b) of the calciner 30 and the cyclone C4. This allows the exhaust gas after being used for calcination in the calciner 30 to be denitrified.

[0069] [Verification results by simulation] Next, we will explain the results of a simulation performed to verify the effect of supplying ammonia to the interior of the calciner 30. The simulation was performed using R-FLOW, a thermal fluid and powder analysis software manufactured by R-FLOW Corporation. In the simulated calciner 30, two burners were placed on the lower level and two burners were placed on the upper level. Hereinafter, the two burners placed on the lower level will be referred to as "lower burner 1" and "lower burner 2," and the two burners placed on the upper level will be referred to as "upper burner 1" and "upper burner 2." Lower burner 1 and lower burner 2 correspond to supply member 70a and supply member 70b, respectively, and upper burner 1 and upper burner 2 correspond to supply member 60a and supply member 60b, respectively. Only pulverized coal was supplied as a solid content, without including any waste. Assuming that 100% pure ammonia is supplied, the lower heating value of ammonia (anhydrous basis, 100% purity) is 4,427 kcal / kg, or 1.86 x 10 7 J / kg.

[0070] The proximate analysis values ​​(mass %: air-dry basis), chemical analysis values ​​(mass %: air-dry basis), and chemical analysis values ​​(mass %: dry ash-free basis) of the components of the pulverized coal assumed in the simulation are shown in Table 1 below. In addition, the lower heating value of the pulverized coal (arrival basis) is set to 5,749 kcal / kg, or 2.415 x 10 7 J / kg. [Table 1]

[0071] The particle size distribution of the pulverized coal assumed in the simulation is shown in Table 2 below. [Table 2]

[0072] In Table 2 above, the cumulative mass ratio (11.00 mass%) at a particle size of 8.00 μm means the ratio of the mass of particles less than 8.00 μm to the total mass of pulverized coal. The mass ratio (6.00 mass%) at a particle size of 8.00 μm means the ratio of the mass of particles having a particle size of 4.00 μm or more and less than 8.00 μm to the total mass of pulverized coal. The same applies to the columns for particle sizes other than 8.00 μm.

[0073] (Reference example) A simulation was carried out in which pulverized coal was supplied from all four burners. The simulation conditions are outlined below. Upper burners 1 and 2: The calorific value ratio of pulverized coal supplied from each burner was 25%, and the supply rate was 1.3 t / h. Lower burners 1 and 2: The calorific value ratio of pulverized coal supplied from each burner was 25%, and the supply rate was 1.3 t / h. In each burner, pulverized coal is transported by conveying air, and the flow rate of the conveying air is set to 500 Nm 3 / h and the oxygen concentration was set to 21%. In other words, the amount of oxygen resulting from the transport air from each burner was 500 × 0.21 = 105 Nm 3 / h. - For each burner, combustion air is supplied separately from (pulverized coal + transport air), and the flow rate of the combustion air is set to 1,200 Nm 3 / h and the oxygen concentration was 18%. In other words, the amount of oxygen resulting from the combustion air from each burner was 1200 × 0.18 = 216 Nm 3 / h. The flow rate of the upward flow introduced from the inlet 30a of the calciner 30 is set to 40,000 Nm 3 / h, and the oxygen concentration of the ascending flow was set to 4%. In other words, when focusing on one of the lower burners 1 and 2, the oxygen near that burner (for example, lower burner 1) contains 40000 / 2 × 0.04 = 800 Nm3 from half (one side) of the ascending flow in the calciner 30, in addition to the oxygen in the transport air and combustion air. 3 / h of oxygen is added. The theoretical combustion oxygen amount for pulverized coal at 1.3 t / h, which corresponds to a calorific value of 25%, is 1830 Nm 3 / h. On the other hand, the amount of oxygen near the lower burner 1 is 105 + 216 + 800 = 1121 Nm 3 / h. In other words, near the lower burner 1, the amount of oxygen available for combustion of pulverized coal is less than the theoretical amount, and the air ratio is 1121 / 1830 = 0.61.

[0074] The heat rate ratio for each burner means the ratio of the heat rate of the thermal energy supplied from that burner to the total heat rate of the thermal energy sources supplied from the upper burners 1 and 2 and the lower burners 1 and 2. The oxygen concentration means the concentration on a volume basis (volume %).

[0075] FIG. 4 shows the concentration source distribution of carbon dioxide (CO2) generated inside the calciner 30, obtained by a simulation according to a reference example. The contour diagram shown in FIG. 4 is the simulation result of the CO2 concentration source distribution inside the calciner 30. The color intensity in the contour diagram represents the amount of CO2 generated and lost per unit time and unit volume. The lower end of the contour diagram corresponds to the inlet 30a of the calciner 30, and the upper end of the contour diagram corresponds to the outlet 30b (outlet) of the calciner 30. The results shown in FIG. 4 show that the combustion rate of pulverized coal is slow, and CO2 generation continues up to near the outlet of the calciner 30.

[0076] Example 1 Similar to the introduction of the thermal energy source described with reference to Fig. 2 etc., a simulation was performed in which pulverized coal was supplied from the upper burners 1 and 2 and ammonia was supplied from the lower burners 1 and 2. The conditions for the simulation are outlined below. The conditions for the upward flow in the calciner 30 were the same as those in the reference example. Upper burners 1 and 2: The supply rate of pulverized coal from each burner was set to 2 t / h. In each of the upper burners 1 and 2, pulverized coal is transported by the transport air, and the flow rate of the transport air is set to 500 Nm 3 / h and the oxygen concentration was 21%. In each of the upper burners 1 and 2, combustion air is supplied separately from the pulverized coal and transport air, and the flow rate of the combustion air is set to 1,200 Nm 3 / h and the oxygen concentration was 18%. Lower burners 1 and 2: Ammonia supply volume from each burner is 1,100 Nm 3 / h. In each of the lower burners 1 and 2, combustion air is supplied separately from ammonia, and the flow rate of the combustion air is set to 1,200 Nm 3 / h and the oxygen concentration was 18%. In each of the lower burners 1 and 2, combustion air other than the above (ammonia + combustion air) is supplied, and the flow rate of that combustion air is set to 500 Nm 3 / h and the oxygen concentration was 21%.

[0077] Under the above conditions for Example 1, the calorific value ratio of the pulverized coal from each of the upper stage burners 1 and 2 is 38%, and the calorific value ratio of the ammonia from each of the lower stage burners 1 and 2 is 12%. In other words, the ratio of the calorific value of the ammonia supplied from the lower stage burners 1 and 2 to the total calorific value of the thermal energy sources supplied from all four burners (corresponding to the above-mentioned calorific value ratio) is 0.24.

[0078] Fig. 5 shows the concentration source distribution of carbon dioxide (CO2) generated inside the calciner 30, obtained by the simulation according to Example 1. The simulation results shown in Fig. 5 correspond to the simulation results shown in Fig. 4. In the simulation according to Example 1 as well, it can be seen that the combustion rate of pulverized coal is slow, and CO2 generation continues up to near the outlet of the calciner 30.

[0079] FIG. 6 shows the concentration source distribution of ammonia (NH3) generated inside the calciner 30, obtained by the simulation of Example 1. The contour diagram shown in FIG. 6 is the simulation result of the concentration source distribution of NH3 inside the calciner 30. The color intensity in the contour diagram represents the amount of NH3 generated and lost per unit time and unit volume. The lower end of the contour diagram corresponds to the inlet 30a of the calciner 30, and the upper end of the contour diagram corresponds to the outlet 30b of the calciner 30. The results shown in FIG. 6 show that the combustion rate of ammonia is fast and that ammonia disappears immediately after being supplied from the lower burner.

[0080] Under the above conditions for Example 1, ammonia 1100 Nm 3 The theoretical combustion oxygen per hour is calculated from the above formula (1): 1100 × 3 / 4 = 825 Nm 3 The amount of oxygen near the lower burner 1 is calculated from the amount of combustion air supplied and the oxygen concentration as follows: 1200 × 0.18 + 500 × 0.21 = 321 Nm 3 The air ratio of the combustion air from the lower burner 1 is 321 / 825 (approximately 0.39). The oxygen near the lower burner 1 is supplied with 40000 / 2 x 0.04 = 800 Nm3 from half (one side) of the upward flow in the calciner 30, in addition to the oxygen in the combustion air. 3 / h of oxygen is added, for a total of 1121 Nm 3 / h, which exceeds the theoretical combustion oxygen. Due to the oxygen exceeding the theoretical combustion oxygen, the ammonia from the lower burner 1 is theoretically completely combusted. There is no ammonia near the upper burner 1 that preferentially consumes oxygen.

[0081] Example 2 As in Example 1, a simulation was performed in which pulverized coal was supplied from the upper burners 1 and 2 and ammonia was supplied from the lower burners 1 and 2. The conditions for the simulation are outlined below. The conditions for the upward flow in the calciner 30 were the same as those in the reference example. Upper burners 1 and 2: The supply rate of pulverized coal from each burner was set to 1.3 t / h. In each of the upper burners 1 and 2, pulverized coal is transported by the transport air, and the flow rate of the transport air is set to 500 Nm 3 / h and the oxygen concentration was 21%. In each of the upper burners 1 and 2, combustion air is supplied separately from the pulverized coal and transport air, and the flow rate of the combustion air is set to 1,200 Nm 3 / h and the oxygen concentration was 18%. Lower burners 1 and 2: Ammonia supply volume from each burner is 2,300 Nm 3 / h. In each of the lower burners 1 and 2, combustion air is supplied separately from ammonia, and the flow rate of the combustion air is set to 1,200 Nm 3 / h and the oxygen concentration was 18%. In each of the lower burners 1 and 2, combustion air other than the above (ammonia + combustion air) is supplied, and the flow rate of that combustion air is set to 500 Nm 3 / h and the oxygen concentration was 21%.

[0082] Under the above conditions for Example 2, the calorific value ratio of the pulverized coal from each of the upper stage burners 1 and 2 is 25%, and the calorific value ratio of the ammonia from each of the lower stage burners 1 and 2 is 25%. In other words, the ratio of the calorific value of the ammonia supplied from the lower stage burners 1 and 2 to the total calorific value of the thermal energy sources supplied from all four burners (corresponding to the above-mentioned calorific value ratio) is 0.50.

[0083] Fig. 7 shows the concentration source distribution of carbon dioxide (CO2) generated inside the calciner 30, obtained by the simulation according to Example 2. The simulation results shown in Fig. 7 correspond to the simulation results shown in Fig. 4. In the simulation according to Example 2 as well, it can be seen that the combustion rate of pulverized coal is slow, and CO2 generation continues up to near the outlet of the calciner 30.

[0084] Fig. 8 shows the concentration source distribution of ammonia (NH3) generated inside the calciner 30, obtained by the simulation according to Example 2. The simulation results shown in Fig. 8 correspond to the simulation results shown in Fig. 6. From the results shown in Fig. 8, it can be seen that the combustion rate of ammonia is fast and most of the ammonia disappears immediately after being supplied from the lower burner.

[0085] Under the above conditions for Example 2, ammonia 2,300 Nm 3 The theoretical combustion oxygen per hour is calculated from the above formula (1): 2300 × 3 / 4 = 1725 Nm 3 The amount of oxygen near the lower burner 1 is calculated from the amount of combustion air supplied and the oxygen concentration as follows: 1200 × 0.18 + 500 × 0.21 = 321 Nm 3 / h. In addition to the oxygen in the combustion air, the oxygen in the lower burner 1 is 40000 / 2×0.04=800 Nm3 from half (one side) of the upward flow in the calciner 30. 3 / h of oxygen is added, for a total of 1121 Nm 3 / h, resulting in an air ratio of 1121 / 1725 = 0.65. The unburned ammonia that is generated diffuses upward and is completely burned by the cooler bleed gas (with an oxygen concentration of 20% or more, for example) introduced from downstream of the gas flow. There is no ammonia, which preferentially consumes oxygen, near the upper burner 1 to which pulverized coal is supplied.

[0086] (Comparative Example 1) A simulation was performed in which pulverized coal and ammonia were supplied from the upper burner 1 and the lower burner 1, and pulverized coal was supplied from the upper burner 2 and the lower burner 2. The conditions for the simulation are outlined below. The conditions for the upward flow in the calciner 30 were the same as those in the reference example. Upper burner 1 and lower burner 1: The supply rate of pulverized coal from each burner is 1 t / h, and the supply rate of ammonia is 1,100 Nm 3 / h. Upper burner 2 and lower burner 2: The supply rate of pulverized coal from each burner was set to 1 t / h. Pulverized coal is transported by conveying air in each of the four burners, and the flow rate of the conveying air is set to 500 Nm 3 / h and the oxygen concentration was 21%. In each of the upper burner 1 and lower burner 1, combustion air is supplied in addition to (pulverized coal + conveying air) and ammonia, and the flow rate of the combustion air is set to 1,200 Nm 3 / h and the oxygen concentration was 18%. In each of the upper burner 2 and lower burner 2, combustion air is supplied separately from (pulverized coal + conveying air), and the flow rate of the combustion air is set to 1,200 Nm 3 / h and the oxygen concentration was 18%.

[0087] Under the above conditions for Comparative Example 1, the calorific value ratio of pulverized coal from each of the four burners was 19%, and the calorific value ratio of ammonia from each of the upper burner 1 and lower burner 1 was 12%. FIG. 9 shows the concentration source distribution of carbon dioxide (CO2) generated inside the calciner 30 obtained by simulation for Comparative Example 1. The simulation results shown in FIG. 9 correspond to the simulation results shown in FIG. 4. FIG. 10 shows the concentration source distribution of ammonia (NH3) generated inside the calciner 30 obtained by simulation for Comparative Example 1. The simulation results shown in FIG. 10 correspond to the simulation results shown in FIG. 6. The results shown in FIGS. 9 and 10 also show that the combustion rate of pulverized coal is slow, CO2 generation continues up to near the outlet of the calciner 30, and that the combustion rate of ammonia is fast.

[0088] Under the above conditions for Comparative Example 1, the theoretical combustion oxygen amount for pulverized coal from the lower burner 1 was calculated as follows: From the elemental composition of pulverized coal, C 66.5 wt% (air-dry basis), H 4.0 wt% (air-dry basis), and O 7.3 wt% (air-dry basis), and taking into consideration the reaction equations of C + O2 = CO2 and H + (1 / 4)O2 = (1 / 2)H2O, the theoretical combustion oxygen amount per kg of pulverized coal was calculated as {66.5 / 100 / 12 + (4 - 7.3 / 8) / 100 / 1 × (1 / 4)} × 22.414 = 1.41 Nm 3 / kg. When converted to 1 ton, the theoretical combustion oxygen amount is 1410 Nm 3 / t. 1100Nm 3 The theoretical combustion oxygen amount for 1 t / h of ammonia and 1 t / h of pulverized coal is 825 + 1410 = 2235 Nm 3 On the other hand, the amount of oxygen near the lower burner 1 is 500 × 0.21 + 1200 × 0.18 = 321 Nm3 / h, based on the supply amount of carrier air and combustion air and the oxygen concentration. 3 / h. In addition, the oxygen (800 Nm 3 / h), the total amount of oxygen is 321 + 800 = 1121 Nm 3 / h. Near the lower burner 1, the amount of oxygen required for the theoretical combustion of ammonia and pulverized coal is less than the theoretical amount, and ammonia, which has a faster combustion rate, consumes oxygen preferentially and burns completely, but there is a shortage of oxygen for the pulverized coal, resulting in unburned fuel. Similarly, near the upper burner 1, ammonia burns completely, but unburned fuel is generated.

[0089] (Comparative Example 2) A simulation was performed in which pulverized coal was supplied from the upper burners 1 and 2, and pulverized coal and ammonia were supplied from the lower burners 1 and 2. The conditions for the simulation are outlined below. The conditions for the upward flow in the calciner 30 were the same as those in the reference example. Upper burner 1 and upper burner 2: The supply rate of pulverized coal from each burner was set to 1 t / h. Lower burner 1 and lower burner 2: The supply rate of pulverized coal from each burner is 1 t / h, and the supply rate of ammonia is 1,100 Nm 3 / h. Pulverized coal is transported by conveying air in each of the four burners, and the flow rate of the conveying air is set to 500 Nm 3 / h and the oxygen concentration was 21%. In each of the upper burners 1 and 2, combustion air is supplied separately from the pulverized coal and carrier air, and the flow rate of the combustion air is set to 1,200 Nm 3 / h and the oxygen concentration was 18%. In each of the lower burners 1 and 2, combustion air is supplied in addition to (pulverized coal + carrier air) and ammonia, and the flow rate of the combustion air is set to 1,200 Nm 3 / h and the oxygen concentration was 18%.

[0090] Under the above conditions for Comparative Example 2, the calorific value ratio of pulverized coal from each of the four burners was 19%, and the calorific value ratio of ammonia from each of lower stage burner 1 and lower stage burner 2 was 12%. FIG. 11 shows the concentration source distribution of carbon dioxide (CO2) generated inside the calciner 30 obtained by a simulation for Comparative Example 2. The simulation results shown in FIG. 11 correspond to the simulation results shown in FIG. 4. FIG. 12 shows the concentration source distribution of ammonia (NH3) generated inside the calciner 30 obtained by a simulation for Comparative Example 2. The simulation results shown in FIG. 12 correspond to the simulation results shown in FIG. 6. The results shown in FIGS. 11 and 12 also show that the combustion rate of pulverized coal is slow, CO2 generation continues up to near the outlet of the calciner 30, and that the combustion rate of ammonia is fast.

[0091] From the above conditions for Comparative Example 2, similar to the calculation for Comparative Example 1, 1100 Nm 3 The theoretical combustion oxygen amount for 1 t / h of ammonia and 1 t / h of pulverized coal is 2235 Nm 3 / h. On the other hand, the amount of oxygen near the lower burner 1 is 321 + 800 = 1121 Nm 3 / h. Near the lower burner 1, the amount of oxygen required for the theoretical combustion of ammonia and pulverized coal is less than the theoretical amount of oxygen required for the combustion of ammonia and pulverized coal, and ammonia, which has a faster combustion rate, consumes oxygen preferentially and burns completely, but the pulverized coal is short of oxygen and unburned fuel is generated. Near the upper burner 1, as in Examples 1 and 2, there is no ammonia that consumes oxygen preferentially.

[0092] (Summary of main conditions) The main conditions for the above Reference Example, Comparative Example 1, Comparative Example 2, and Examples 1 and 2 are shown in Table 3 below. In Table 3, the values ​​in parentheses indicate the ratio of the heat amount of each thermal energy source to the total heat amount of the thermal energy sources from the four burners. [Table 3]

[0093] (Comparative verification based on the theoretical amount of oxygen for combustion) Examples 1 and 2 are compared with Comparative Examples 1 and 2 with respect to phenomena occurring near the upper burner 1 and the lower burner 1. In Example 1, ammonia is completely combusted near the lower burner 1, and pulverized coal is not supplied, so the CO concentration can be lowered compared to Comparative Examples 1 and 2. Furthermore, near the upper burner 1, pulverized coal, which has a slow combustion rate, remains unburned due to a lack of oxygen. However, since there is no ammonia, which preferentially consumes oxygen, the pulverized coal is more easily combusted than in Comparative Example 1. In Example 2, the CO concentration can also be lowered compared to Comparative Examples 1 and 2 near the lower burner 1, and since there is no ammonia, which preferentially consumes oxygen, the pulverized coal is more easily combusted than in Comparative Example 1 near the upper burner 1. In Comparative Example 1, the amount of unburned pulverized coal is greater than in Examples 1 and 2 due to the introduction of ammonia near the upper burner 1 and the lower burner 1, and in Comparative Example 2, the amount of unburned pulverized coal is greater than in Examples 1 and 2 near the lower burner 1.

[0094] As described above, the amount of unburned pulverized coal generated in Examples 1 and 2 is the smallest compared to Comparative Examples 1 and 2. Note that by introducing cooler bleed gas (e.g., with an oxygen concentration of 20% or more) as hot gas into the calciner 30, the amount of unburned pulverized coal at the outlet of the calciner 30 can be reduced.

[0095] (Comparative verification of average CO concentrations across a cross section) For each of the above-described Reference Example, Example 1, Example 2, Comparative Example 1, and Comparative Example 2, a simulation was performed to calculate the average CO concentration in a cross section at each height (by changing the height). The results calculated by the simulation are shown in Fig. 13. In the graph of Fig. 13, the horizontal axis represents the value obtained by dividing the height [m] from the bottom (furnace bottom) of the calciner 30 by the total length [m] in the vertical direction of the calciner 30, and the vertical axis represents the calculated value of the average CO concentration in a cross section perpendicular to the vertical direction.

[0096] From the graph shown in FIG. 13, the calculated values ​​at a height near the lower burners 1 and 2 (the value on the horizontal axis is around 0.23) and the calculated values ​​at a height near the outlet of the calciner 30 (the value on the horizontal axis is around 1.0) were read, and the results are shown in Table 4 below. [Table 4]

[0097] The results shown in Table 4 show that the average CO concentrations in Examples 1 and 2 are lower than those in Comparative Examples 1 and 2 at both the height near the lower burners and the height near the outlet of the calciner 30. That is, it is understood that in Examples 1 and 2, ammonia is combusted after the occurrence of incomplete combustion of pulverized coal is suppressed compared to Comparative Examples 1 and 2. The reason why the average CO concentration in Comparative Example 2 is higher than that in Comparative Example 1 at the height near the lower burners is that ammonia, which inhibits the combustion of pulverized coal, is supplied from the lower burners in greater amounts in Comparative Example 2 than in Comparative Example 1.

[0098] (Comparative verification of average NH3 concentration across the cross section) For each of the above-described Reference Example, Example 1, Example 2, Comparative Example 1, and Comparative Example 2, the average NH3 concentration in a cross section at each height (while changing the height) was calculated by simulation. The results calculated by simulation are shown in Fig. 14. In the graph of Fig. 14, the horizontal axis represents the value obtained by dividing the height [m] from the bottom (furnace bottom) of the calciner 30 by the total length [m] in the vertical direction of the calciner 30, and the vertical axis represents the calculated value of the average NH3 concentration in a cross section perpendicular to the vertical direction.

[0099] From the graph shown in FIG. 14, the calculated values ​​at a height near the lower burners 1 and 2 (the value on the horizontal axis is around 0.23) and the calculated values ​​at a height near the middle of the calciner 30 (the value on the horizontal axis is around 0.32) are shown in Table 5 below.

[0100] [Table 5]

[0101] The results shown in Table 5 reveal that the average NH3 concentration in Example 1 is lower than in Comparative Examples 1 and 2 at both the height near the lower burner (Z = 0.23) and the height near the middle of the calciner 30 (Z = 0.32). This indicates that ammonia is more efficiently combusted in Example 1 than in Comparative Examples 1 and 2. The average NH3 concentration near the lower burner and the middle of the calciner in Example 2 is higher than in Comparative Examples 1 and 2. This is because 2.1 times the amount of ammonia added compared to Comparative Examples 1 and 2. However, as shown in FIG. 14 , ammonia is zero at the outlet of the calciner 30, indicating complete combustion and no problems. Furthermore, despite adding 2.1 times the amount of ammonia added compared to Comparative Examples 1 and 2, the CO concentration in Table 4 is lower than in Comparative Examples 1 and 2. This also demonstrates the effectiveness of supplying ammonia gas upstream of the pulverized coal, based on the gas flow inside the calciner 30.

[0102] Summary of this disclosure The method for producing cement clinker described above includes a first supplying step of supplying a thermal energy source containing solids by one or more first supplying members (60) to the interior (S) of a calciner (30) to which exhaust gas is introduced from a rotary kiln (40) that heats cement raw materials to produce cement clinker, and a second supplying step of supplying ammonia by one or more second supplying members (70) to the interior (S) of the calciner (30). With reference to the gas flow in the interior (S) of the calciner (30), the positions at which the one or more second supplying members (70) supply ammonia are located upstream of the positions at which the one or more first supplying members (60) supply the thermal energy source containing solids. The ratio of the calorific value of the ammonia supplied to the calciner (30) from the one or more second supplying members (70) to the total calorific value of the thermal energy sources supplied to the calciner (30) from the one or more first supplying members (60) and the one or more second supplying members (70) is 0.01 to 0.90.

[0103] As described above, the occurrence of combustion inhibition of the solid content can lead to incomplete combustion of the solid content, which can increase the generation of carbon monoxide (CO). In contrast, in the above-described production method, the solid content is supplied from the downstream side and ammonia is supplied from the upstream side based on the gas flow inside the calciner (30). This reduces the degree to which combustion inhibition occurs due to a lack of oxygen for burning the solid content caused by the introduction of ammonia due to differences in combustion speed. Therefore, the above-described production method is useful for suppressing the generation of CO due to incomplete combustion of the solid content when ammonia is supplied into the calciner.

[0104] In the method for producing cement clinker described above, the solid content may be pulverized coal. The pulverized coal may have proximate analysis values ​​(air-dry basis) of 25-35% by mass of volatile matter, 2-4% by mass of moisture, 40-60% by mass of fixed carbon, and 10-25% by mass of ash. The pulverized coal may have chemical analysis values ​​(air-dry basis) of 60-75% by mass of C (carbon), 3-5% by mass of H (hydrogen), 6-9% by mass of O (oxygen), 1-3% by mass of N (nitrogen), and 0.1-1.0% by mass of S (sulfur). The pulverized coal may have a calorific value of 4500-6500 kcal / kg.

[0105] The above-described simulation verification confirmed that, at least when pulverized coal having such components and calorific value is supplied as a solid content from the first supply member (60), CO generation is suppressed.

[0106] In the method for producing cement clinker described above, the solid content may be pulverized coal, whose particle size distribution may be such that particles having a particle size of 8.00 μm or more and less than 16.00 μm account for 5 to 20 mass %, particles having a particle size of 16.00 μm or more and less than 32.00 μm account for 20 to 40 mass %, particles having a particle size of 32.00 μm or more and less than 64.00 μm account for 20 to 40 mass %, and particles having a particle size of 64.00 μm or more and less than 128.00 μm account for 10 to 30 mass %.

[0107] The above-described simulation verification confirmed that, at least when pulverized coal having such particle size distribution is supplied as a solid content from the first supply member (60), CO generation is suppressed.

[0108] In the above-described method for producing cement clinker, in the second supply step, ammonia may be supplied to the interior (S) of the calciner (30) together with air having an air ratio of 0.1 to 1.0. Because ammonia has a high combustion rate, its disappearance on the upstream side has little effect on the combustion of solids supplied downstream. In the above method, supplying ammonia together with air having an air ratio of 0.1 to 1.0 makes it possible to more reliably eliminate ammonia immediately after supply. This is therefore useful for suppressing CO generation due to incomplete combustion of solids caused by the introduction of ammonia.

[0109] The method for producing cement clinker described above may further include a third supply step of supplying oxygen-containing hot gas to the interior (S) of the calciner (30) using one or more third supply members (80). The temperature of the hot gas may be 700°C to 1000°C. Based on the gas flow in the interior (S) of the calciner (30), the one or more third supply members (80) may supply the hot gas at a position corresponding to the position where the one or more first supply members (60) supply the thermal energy source containing the solid content, or may be located upstream of the supply position and downstream of the position where the one or more second supply members (70) supply the ammonia. Even if the solid content is supplied downstream, the supply of ammonia reduces oxygen, resulting in a slight shortage of oxygen for burning the solid content downstream. In the above method, supplying oxygen-containing hot gas from a position corresponding to the position where the solid content is supplied or between the position where the solid content is supplied and the ammonia supply position promotes combustion of the solid content and reduces the amount of unburned solid content. Therefore, even when ammonia is introduced, it is useful for suppressing the generation of CO due to incomplete combustion of solids.

[0110] In the above-described method for producing cement clinker, in the third supplying step, the extracted gas from the clinker cooler (48) that cools the cement clinker produced in the rotary kiln (40) may be supplied as the hot gas. In this case, the gas used for cooling the clinker can be effectively used as the hot gas for promoting the combustion of the solid content.

[0111] In the above-described method for producing cement clinker, the ratio of the calorific value of ammonia supplied from one or more second supply members (70) to the calciner (30) to the total calorific value may be 0.01 to 0.55. The ratio of the calorific value of the thermal energy source including solids supplied from one or more first supply members (60) to the calciner (30) to the total calorific value may be 0.45 to 0.99. In this case, by setting the ratio of the calorific value of ammonia to the total calorific value to 0.55 or less, it is possible to reduce the occurrence of inhibition of combustion of the solids due to the introduction of ammonia.

[0112] The cement clinker manufacturing apparatus (100) includes a rotary kiln (40) that heats cement raw materials to produce cement clinker, a calciner (30) that receives exhaust gas from the rotary kiln (40) and heats the cement raw materials, one or more first supply members (60) that supply a thermal energy source containing solids to the interior (S) of the calciner (30), and one or more second supply members (70) that supply ammonia to the interior (S) of the calciner (30). With respect to the gas flow in the interior (S) of the calciner (30), the positions at which the one or more second supply members (70) supply ammonia are arranged upstream of the positions at which the one or more first supply members (60) supply the thermal energy source containing solids. The ratio of the calorific value of the ammonia supplied to the calciner (30) from one or more second supply members (70) to the total calorific value of the thermal energy sources supplied to the calciner (30) from one or more first supply members (60) and one or more second supply members (70) is 0.01 to 0.90. This production apparatus (100) is useful for suppressing CO generation due to incomplete combustion of solids when ammonia is supplied to the calciner, as in the above-described production method. [Explanation of symbols]

[0113] 100... manufacturing apparatus (cement clinker manufacturing apparatus), 30... calciner, 40... rotary kiln, 48... clinker cooler, 50... thermal energy source supply unit, 60, 60a, 60b... supply member (first supply member), 70, 70a, 70b... supply member (second supply member), 80... supply member (third supply member), F... gas flow direction.

Claims

1. a first supplying step of supplying a thermal energy source containing solids by one or more first supply members to an interior of a calciner into which exhaust gas from a rotary kiln that heats cement raw materials to produce cement clinker is introduced; a second supply step of supplying ammonia to the inside of the calciner using one or more second supply members, a position at which the one or more second supply members supply the ammonia based on a gas flow inside the calciner is disposed upstream of a position at which the one or more first supply members supply the thermal energy source containing the solid content, a ratio of a calorific value of the ammonia supplied from the one or more second supply members to the calciner to a total calorific value of the thermal energy source supplied from the one or more first supply members and the one or more second supply members to the calciner is 0.01 to 0.90; A method for producing cement clinker.

2. the solid content is pulverized coal, The pulverized coal has proximate analysis values ​​on an air-dry basis of a volatile matter of 25 to 35 mass%, a moisture content of 2 to 4 mass%, a fixed carbon content of 40 to 60 mass%, and an ash content of 10 to 25 mass%, Chemical analysis values ​​of the pulverized coal on an air-dry basis are: C (carbon) 60 to 75% by mass; H (hydrogen) 3 to 5% by mass; O (oxygen) 6 to 9% by mass; N (nitrogen) 1 to 3% by mass; and S (sulfur) 0.1 to 1.0% by mass; The calorific value of the pulverized coal is 4500 to 6500 kcal / kg. The method for producing cement clinker according to claim 1.

3. the solid content is pulverized coal, The particle size distribution of the pulverized coal is 5 to 20% by mass of particles having a particle size of 8.00 μm or more and less than 16.00 μm, 20 to 40% by mass of particles having a particle size of 16.00 μm or more and less than 32.00 μm; particles having a particle size of 32.00 μm or more and less than 64.00 μm are 20 to 40% by mass, Particles having a particle size of 64.00 μm or more and less than 128.00 μm are 10 to 30% by mass, The method for producing cement clinker according to claim 1.

4. The method further includes a third supply step of supplying a hot gas containing oxygen to the inside of the calciner using one or more third supply members, The temperature of the hot gas is 700°C to 1000°C, With respect to the gas flow inside the calciner, the position to which the one or more third supply members supply the hot gas is The one or more first supply members are disposed at a position corresponding to a position where a thermal energy source containing the solid content is supplied, or upstream of the supply position; and the one or more second supply members are arranged downstream of the position where the ammonia is supplied; The method for producing cement clinker according to any one of claims 1 to 3.

5. In the third supply step, extracted gas from a clinker cooler that cools cement clinker produced in the rotary kiln is supplied as the hot gas. The method for producing cement clinker according to claim 4.

6. a ratio of a calorific value of the ammonia supplied from the one or more second supply members to the calciner to the total calorific value is 0.01 to 0.55; a ratio of the calorific value of the thermal energy source containing the solid content supplied from the one or more first supply members to the calciner to the total calorific value is 0.45 to 0.99; The method for producing cement clinker according to any one of claims 1 to 3.

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