JP2004204132A - Method for reducing sulfur compound contained in gas in coke dry quenching equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for reducing the amount of sulfur compounds contained in the gas produced by burning of coke by air existed in a pre-chamber of coke dry quenching equipment. <P>SOLUTION: This method for reducing the amount of sulfur compounds contained in the gas in the coke dry quenching equipment is to throw 30-650g lime, which contains at least 10 wt% lime whose grain diameter is not more than 10mm, per one ton coke into the pre-chamber 105, which is a space of the coke dry quenching equipment 101 for receiving red-heat coke, and/or into a bucket car 102. The sulfur compounds formed by burning can be removed and recovered by fixing them by the casted lime. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a technique for reducing sulfur compounds in a gas by charging lime in a coke dry fire extinguishing facility (hereinafter, also simply referred to as CDQ).
[0002]
[Prior art]
The coke oven is an external heating type heating furnace, and has become a very advanced facility as an energy recovery technology due to the fact that it is inevitably upsized to improve thermal efficiency and the development of energy saving technologies in the past. The main method of energy recovery technology is to use coke dry fire extinguishing equipment, which cools coke with a large amount of circulating gas (mostly nitrogen), generates steam using the heat obtained from the circulating gas, and operates a steam turbine. And collect it as electricity.
[0003]
In such a coke dry-fire extinguishing system, red hot coke discharged from a coke oven is charged into a pre-chamber, and while passing through a lower cooling chamber, circulating gas is supplied to the cooling chamber as a cooling gas, thereby producing red hot coke. Extinguishes and cools, and as described above, heat exchanges the sensible heat obtained from the high-temperature circulating gas discharged from the cooling chamber by a heat exchanger such as a boiler to generate steam and operate a steam turbine to generate electric power. As a result, the two objectives of efficient collection are achieved. Cooling coke discharged from the cooling chamber is charged into a blast furnace. That is, it is charged into a blast furnace and used as a fuel for raising and reducing the temperature of the sintered ore.
[0004]
In such a coke dry fire extinguishing system, a technique of introducing air into a pre-chamber has been proposed for the purpose of stabilizing gas components or increasing the amount of sensible heat recovery by burning coke (for example, Patent Document 1). -3).
[0005]
In the conventional method of producing lime by causing a thermal decomposition reaction of lime (mainly calcium carbonate and slaked lime), a fuel such as a heavy oil burner is used to decompose lime and generate carbon dioxide, It was an inefficient, large-scale carbon dioxide generation process that also generated carbon dioxide from the source (for example, see Non-Patent Document 1).
[0006]
[Patent Document 1]
JP-A-6-336588
[Patent Document 2]
JP-A-7-145377
[Patent Document 3]
JP-A-7-242879
[Non-patent document 1]
Industrial Furnace Handbook (edited by the Japan Industrial Furnace Association), p352, 2nd edition, published April 20, 1982
[0007]
[Problems to be solved by the invention]
The proposals in Patent Documents 1 to 3 above relate to a technique for stabilizing gas components by introducing air and a technique for increasing sensible heat recovery by circulating gas by burning coke by introducing air. At present, little attention has been paid to trace amounts of sulfur compounds produced by combustion of coke by air present in the pre-chamber.
[0008]
However, sulfur compounds generated during the combustion of coke are transported as circulating gas components to the circulator of the coke dry fire extinguishing system, where they are cooled in the low-temperature section (outlet) of the boiler (heat exchanger), and part of the sulfuric acid is released. (H _Two SO _Four ) Or sulfurous acid (H _Two SO _Three Condensation in the form of For this reason, metal corrosion due to the condensed acid on the metal surface in the device proceeds. For this reason, during maintenance that is performed by periodically stopping the equipment, repair work of metal corrosion parts found in the relevant parts (mainly repair work by polishing the corroded metal surface, etc. If it becomes severe, it is necessary to replace the device parts). Therefore, if the number of maintenances caused by the corrosion can be reduced, it can be expected that it can greatly contribute to the reduction of precious time, labor, and cost for the maintenance. Nevertheless, no effective measures to prevent metal corrosion (corrosion prevention technology) at the circulating system of such coke dry fire extinguishing equipment, especially at the low temperature section (exit) of a boiler (heat exchanger), have been proposed. It is the current situation.
[0009]
Accordingly, an object of the present invention is to provide a method for reducing a sulfur compound in a gas in a coke dry fire extinguishing system, which is generated by burning coke by air existing in a pre-chamber.
[0010]
[Means for Solving the Problems]
Therefore, the present inventors have found that even when lime is charged into the pre-chamber, compared to the use of fuel such as a conventional heavy oil burner, CDQ has sufficient temperature and residence time for decomposition, and uses only coke sensible heat. Heat source does not contribute to the increase in carbon dioxide, and it has advantages such as high recovery efficiency.By using the sensible heat of red-hot coke, lime is decomposed and de-flowed. , Sulfur compounds generated by combustion (SO _X ) Can be removed and recovered from the gas, and it has been found that sulfur compounds can be greatly reduced, and the present invention has been completed.
[0011]
That is, the present invention can be achieved by the following (1) to (10) methods for reducing sulfur compounds in gas in a coke dry fire extinguishing facility.
[0012]
(1) A method for reducing sulfur compounds in gas in a coke dry fire extinguishing facility, which comprises introducing lime into a coke dry fire extinguishing facility.
[0013]
(2) The method for reducing sulfur compounds in gas in a coke dry fire extinguishing facility according to the above (1), wherein the lime is introduced into a prechamber, which is a charging space of red hot coke in the coke dry extinguishing facility.
[0014]
(3) The coke dry fire extinguishing equipment according to the above (1) or (2), wherein the lime is put into a bucket and / or a bucket truck, which is a facility for moving and putting red hot coke in the coke dry fire extinguishing equipment. Method for reducing sulfur compounds in gas inside.
[0015]
(4) The coke dry fire extinguishing equipment according to any one of the above (1) to (3), wherein a part or the whole of the space inside the pre-chamber has an ambient temperature of 1000 to 1100 ° C. Method for reducing sulfur compounds in gas inside.
[0016]
(5) The lime in a gas in a coke dry fire extinguishing facility according to any one of the above (1) to (4), wherein the lime contains lime having a particle diameter of 10 mm or less in an amount of 10% by mass or more. Method for reducing sulfur compounds.
[0017]
(6) The sulfur in the gas in the coke dry fire extinguishing facility according to any one of the above (1) to (5), wherein the lime is charged in a range of 30 to 650 g per ton of coke. Compound reduction method.
[0018]
(7) The lime is introduced into the pre-chamber during and / or simultaneously with the introduction of red-hot coke into the coke dry fire extinguishing system, which is performed intermittently. The method for reducing a sulfur compound in a gas in a coke dry fire extinguishing facility according to any one of 1) to (6).
[0019]
(8) The method according to any of (1) to (7), wherein the lime is introduced from a coke inlet above a coke dry fire extinguishing facility and / or one or more inlets installed in a pre-chamber. The method for reducing sulfur compounds in gas in a coke dry fire extinguishing facility according to any one of the first to third aspects.
[0020]
(9) In the coke dry fire extinguishing facility according to any one of the above (1) to (8), wherein the lime is introduced by air current conveyance using nitrogen and / or circulating gas as a carrier gas. For reducing sulfur compounds in gases.
[0021]
(10) The method according to (1) to (1), wherein the lime is charged before, during, and / or after loading of the red hot coke on a bucket and / or a bucket truck intermittently made from a coke oven. 9) The method for reducing a sulfur compound in a gas in a coke dry fire extinguishing facility according to any one of 9).
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
The method for reducing sulfur compounds in a gas in a coke dry fire extinguishing facility of the present invention is characterized in that lime is introduced into a coke dry fire extinguishing facility to reduce sulfur compounds in the gas.
[0023]
According to the present invention, the sulfur present in the coke is converted to sulfur compounds (SO _X ) And migrates into the gas. In addition, the lime charged into the pre-chamber (directly or indirectly via a bucket truck or the like) undergoes a pyrolysis reaction (CaCO _Three → CaO + CO _Two Reaction temperature; 700 to 900 ° C.). Further, sulfur compounds (SO 2) are contained in the gas (circulating gas and space gas in the pre-chamber). _Two Or H _Two S), (1) CaO + SO between CaO generated by thermal decomposition of lime _Two + 1 / 2O _Two → CaSO _Four , (2) CaO + H _Two S → CaS + H _Two O, CaS + 2O _Two → CaSO _Four (The time required for the charged lime (CaO) to pass (reside) in the temperature range of 800 to 1000 ° C. in the CDQ is approximately 1 hour, and the reaction proceeds sufficiently). SO in (gas phase) _Two Or H _Two S is the stone (CaSO _Four ) Is attached (fixed) to the coke surface (solid phase). As a result, the sulfur compound in the gas is significantly reduced (in the embodiment, the SO _X The concentration can be reduced by 92%), and acid corrosion in the system can be significantly suppressed (approaching a maintenance-free state). Further, in the present invention, the sulfur compound in the gas is immobilized by lime injection, _Three , CaO can be used as a lime substitute material in the sintering process, and can exhibit a desulfurization effect in either the CDQ or sintering process.
[0024]
Here, the lime used in the present invention is calcium carbonate (CaCO 2). _Three ), Slaked lime (calcium hydroxide; Ca (OH) _Two ) Or a mixture of one or more of these and quicklime (calcium oxide; CaO). Natural limestone mainly composed of calcium carbonate is also included in the category of lime in the present invention.
[0025]
The particle size of the lime used in the present invention is not particularly limited, but preferably contains 10% by mass or more of lime having a particle size of 10 mm or less. More specifically, lime having a particle size of 10 mm or less is in a range of 10 to 100% by mass, preferably 50 to 100% by mass, and lime having a particle size of more than 10 mm and 200 mm or less is 0 to 90% by mass, preferably 0 to 90% by mass. It is desirable that the content be in the range of 50 to 50% by mass. This is because if large-sized particles are added to the lime to be added, some of the lime will be subjected to a thermal decomposition reaction and a desulfurization reaction inside the CDQ, and the effect of fixing the sulfur compound may be reduced. This is because it is necessary to increase the amount of lime to be input. Normally, the pyrolysis reaction and desulfurization reaction sufficiently proceed during about one hour when the lime put into the pre-chamber passes through (exits) the temperature range of 700 ° C. or higher required for the pyrolysis reaction and desulfurization reaction. It can be said that the suitable particle size (particle size distribution) that can be obtained is within the range specified above. That is, the particle size of the lime to be introduced is too large, and a thermal decomposition reaction (part of the lime is CO _Two As a result, the thermally decomposed part becomes brittle and becomes finer. If the particles pass through the high-temperature region in a state in which some of the particles contain unreacted parts before proceeding, the progress of the thermal decomposition reaction by utilizing the coke sensible heat becomes difficult, This is because the reaction with the sulfur compound in the gas does not sufficiently proceed even by the contact, and it becomes difficult to obtain the effect of reducing the sulfur compound by immobilization.
[0026]
However, in the present invention, lime having a particle size exceeding 200 mm may be included. Such large lime is refined to an appropriate size by friction and an increase in weight applied during the passage through the CDQ, and comes to fall within the particle size distribution range specified above. This is because even the particles are sufficiently refined before passing through the above-mentioned high temperature range and are subjected to the thermal decomposition and desulfurization reactions, which can contribute to the achievement of the object of the present invention. In addition, even if the amount of lime is increased by assuming that part of the lime is not thermally decomposed, the coke after passing through the CDQ has an average particle size of about 45 to 55 mm and is sized. Is desirably crushed by a coke cutter, and finely divided to a size that can be sent to a sintering process together with coke breeze in a classification process (at a joint of about 25 to 30 mm). There is no problem because it can be effectively used as a substitute material.
[0027]
The reason that lime having a particle size of 10 mm or less is included in an amount of 10% by mass or more, preferably 50 to 100% by mass (total amount) is because usually the particle size of lime or the like in sintering is 10 mm or less. This is because it is convenient to handle when the size is equal to or smaller than. From the above, in the present invention, for example, the particle size of lime or the like in sintering is not 10 mm or less, for example, it is possible to use a thing of 15 mm or less. In a broad sense, the particle size of lime used in sintering is not more than 10 mm (for example, if lime used in sintering is 10 mm or less, it is 10 mm or less, and lime used in sintering is 15 mm or less. The lime having a particle size of 15 mm or less is in the range of 10 to 100% by mass, preferably 50 to 100% by mass, and the particle size of 200 mm or less exceeding the particle size of lime used in sintering. Of lime in the range of 0 to 90% by mass, preferably 0 to 50% by mass.
[0028]
The particle size of lime referred to here can be defined as follows.
[0029]
The size of the sieve mesh (the size of the "mesh" of a screen or other sieve) when lime that has been reduced in particle size by a crusher, 2 (B) to 2 (E) for the form, but the present invention is not limited to these forms, and other forms may be used as in FIG. The area indicated by the arrow in the middle) may be defined as the mesh size.) Is defined as the particle size of lime in the present invention.
[0030]
The above crusher, crusher and the like are usually reduced in size by impact, friction, cutting or the like. Hammer mills and ball mills are representative of impact systems, grind mills are representative of friction systems, and cutter types are representative of cutting systems. In the case of lime, as in the case of pulverization of coal or food, many of the shapes are close to spheres or cubes, and the concept of particle size = particle size is relatively clear. Therefore, although concepts such as a representative diameter and an average diameter are easy to use, in the present invention, evaluation and definition are performed by using a sieving apparatus used in most practical crushing processes, particularly through an opening such as a screen. The screen used for evaluation and definition in the present invention is not a screen attached to the crusher shown in FIG. 2, but a screen obtained by separately sieving the crushed material that has passed through the screen of the crusher. By minimizing vibration in the vertical direction with respect to the screen (vibration in the horizontal direction when the inclination is 0), the size in the long axis direction is set as the passage diameter (here, the above crushed material is separately separated). The form of the “opening” of the screen when sieved is the same as the form of the “opening” of the screen attached to the crusher shown in FIGS. 2 (B) to 2 (E). , See this.).
[0031]
In order to obtain lime having a reduced particle size by a crusher, a crusher, or the like, for example, as shown in FIG. 2A, a lime raw material (eg, limestone) 301 is crushed by a crusher (in the figure, An example of a hammer-type crusher is shown.) It is charged from the input port of 302 as shown by the thick arrow in the figure. When the lime is rotated in the rotation direction 305 of the thin line arrow by the rotating body 303 in the crusher, when the lime collides with one or a plurality of hammers (part) 304 installed in the crusher or when the hammers and the rotating body 303 When passing through the gap, lime is crushed and reduced in particle size. The lime having a reduced particle diameter comes out due to centrifugal force during rotation. Therefore, the size of the appropriate aperture 308 (see FIGS. 2B to 2E) on the outer surface side of the rotation path of the crusher (the arrow in the enlarged view of FIGS. 2B to 2E). By installing a screen 307 having a range (length) corresponding to the size of the aperture) and a shape, lime (lime) reduced in size to a size (grain size) passing through the aperture is provided. Only the crushed material 306) passes through the screen 307 and is taken out.
[0032]
Hereinafter, a specific example of the sieving will be described in detail.
[0033]
Hammer type crusher: 100 kg / h crushing amount, 200 rpm, hammer width 10 mm, hammer number 12, lime crushed material with exit screen size □ 50 mm (opening, square), vibrating sieve: □ 10 mm screen (opening, square) ), 5 ° tilt, horizontal and perpendicular to the tilt direction, vibration amplitude of 10 mm, number of vibrations of 30 times / min. As a result of sieving, when the sieving amount is 10, 9, 10 mass% (3 trials), It is assumed that lime having a particle diameter of 10 mm or less is contained at 10% by mass (rounded off on average). Similarly, if the screen size of the crusher exit side is □ 30 mm and the size of the vibrating screen is □ 10 mm and the underscreen is 20, 20, 20% by mass, lime having a particle size of 10 mm or less shall be included at 20% by mass, If the screen size at the crusher side is □ 10 mm and the size of the vibrating sieve screen is □ 10 mm, the sieving amount is 80, 79, 79% by mass, and lime having a particle size of 10 mm or less is included in 80% by mass.
[0034]
The above values are those of the crusher A, and in this method, the data of the crusher B (50 kg / h crush, 200 rpm, hammer width 10 mm, hammer number 12, slightly smaller than the crusher A) can be used together. , The reliability of the data may be increased.
[0035]
As described above, the ratio (content) of “lime having a particle size of 10 mm or less” in the present invention is the mass% under the sieve based on the screen size of the sieve, and in order to change the mass% under the sieve, The size of the crusher screen eyes has changed. As a method of changing the particle size, in addition to the eye size of the crusher screen of the specific example shown above, the shape of the hammer, the width, the number of revolutions, the screen position, and the like, by changing the crushing method such as a grind mill, a cutter mill, etc. In any case, the numerical value can be defined by sieving with a sieving screen. Also, the sieve can be changed by the vibration type and vibration method (impact by a cam, circle / ellipse in the sieve direction, number of vibrations, etc.), screen mesh shape (rectangle, circle, ellipse, etc.), etc. By sieving with the vibration method in the specific example described above, it is possible to define a common numerical value.
[0036]
Next, the input amount of the coal is not particularly limited, and the amount of sulfur compounds in the gas can be reduced in proportion to the input amount of lime. It is desirable to add lime in the range of 50 to 500 g per ton of coke in correspondence with the above. If the amount of the lime is less than 50 g per ton of coke, the removal of sulfur compounds may be insufficient. On the other hand, when the input amount of the lime exceeds 500 g per ton of coke, the sulfur compounds have been sufficiently removed and recovered, and further removal and recovery effects cannot be expected. However, there is no particular problem as long as the amount of unreacted lime remaining after being charged above the upper limit is within a range usable as a lime material used in the sintering step as described above.
[0037]
This is based on the amount of coke burned by the amount of air per ton of coke (the amount of air that enters through openings and the like when entering coke (the amount of air naturally introduced) and the amount of air introduced for other purposes). This is because the amounts (concentrations) of sulfur compounds generated by combustion are different.
[0038]
For example, 5 to 20 Nm per ton of coke ^Three When air enters the pre-chamber, 1.13 to 4.5 kg of coke burns. By the combustion of the coke, 4.5 to 18 g of sulfur in the coke moves into the gas (gas phase), and 3.2 to 13 liters of SO _X (This is based on the results of a demonstration experiment using an actual _X This corresponds to a concentration of 13 to 52 ppm. ).
[0039]
Here, assuming that (1) the fluidized state of lime and its pyrolysis product (CaO) in coke by the circulating gas is in a fluidized bed state, Ca / S = 2 or more (that is, circulating). Efficient desulfurization is possible because the amount of Ca in the input lime is at least twice the amount of sulfur (S) in the gas (see FIG. 3). Therefore, the lime per ton of coke is CaCO _Three An appropriate amount is 30 to 130 g (fluidized bed) in conversion.
[0040]
{Circle over (2)} Assuming that the fluidized state of lime and its pyrolysis product (CaO) in coke by the circulating gas is in a packed bed state, it is possible that shortage of contact may occur, so Ca / S = 10 or more (see FIG. 3). Therefore, the lime per ton of coke is CaCO _Three An appropriate amount is 160 to 650 g (filled layer) in conversion.
[0041]
Since the coke in the CDQ of the present system is a moving bed, it can be in an intermediate contact state between both the above (1) and (2). Therefore, it can be said that lime should be introduced in the range of 30 to 650 g per ton of coke. However, it is desirable to determine the optimum amount of lime under the moving bed with respect to a change in the amount of air, preferably by performing a preliminary experiment with an actual machine.
[0042]
Further, in addition to coke, for example, the present applicant has already proposed a technique of charging biomass into a prechamber and performing alternative combustion.When using another alternative fuel such as biomass, in addition to changing the air amount, biomass It can be said that it is sufficient to determine the amount of sulfur compound generated in the gas and determine the amount of lime input, taking into account changes in the amount of input, etc. It is desirable to determine the optimum amount of lime to be supplied for a change in the amount of air or a change in the amount of input such as biomass.
[0043]
It is not always necessary to put the lime into the pre-chamber. In the present invention, lime, in particular, limestone, calcium carbonate, slaked lime, etc. is thermally decomposed (reaction proceeds at 700 ° C. or higher) to convert it to calcium oxide (CaO), and the sulfur compound in the CDQ gas is converted into calcium oxide (CaO). It is intended to react and fix the sulfur content. Of these, in order to promote the lime pyrolysis reaction, the sensible heat of red hot coke (about 1000 ° C.) charged into the pre-chamber can be utilized, and the lime is extruded from a coke oven into a bucket / bucket truck. This is because the sensible heat of red hot coke can also be used. That is, the sensible heat of the red-hot coke is not used before being charged into the pre-chamber, and the sensible heat of the red-hot coke is radiated to the atmosphere during the conventional loading on a bucket / bucket truck and moving to the CDQ (about 5 minutes). However, by mixing lime input, the sensible heat of red-hot coke that has been released to the atmosphere can be effectively used for lime preheating (pyrolysis).
[0044]
The above requirements of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram schematically showing a typical CDQ that can be used in the present invention.
[0045]
First, a normal operation example of CDQ is shown based on FIG. The red-hot coke 151 of about 1000 ° C. produced in the coke oven 201 is extruded by an extruder (not shown) into a bucket / bucket truck (hereinafter simply referred to as a bucket truck 102 or the like), and is conveyed to the CDQ101. The upper lid 103 is opened, and the pre-chamber (space portion) 105 is loaded. The portion blocked by the upper lid 103 is the upper coke inlet 104. After the injection of the red hot coke 151, the upper lid 103 is closed, and the amount of air that naturally flows in is restricted. The emptied bucket truck 102 is sent to the coke oven 201 to load the next lot of red hot coke.
[0046]
The hot red hot coke 151 entering the pre-chamber 105 is cooled to about 200 ° C. while being gradually cooled by the circulating gas 107 while passing through the lower cooling chamber 106, and is taken out from the lower outlet 108 of the cooling chamber 106. Taken out of In the figure, red hot coke to be charged into the CDQ is represented by a thick arrow with reference numeral 151. The coke in the CDQ is denoted by reference numeral 153, and its moving direction is indicated by a thick arrow (no reference numeral). Further, the coke extracted from the CDQ (including lime and lime which is decomposed by the decomposition of lime and immobilized by reaction with sulfur in the present invention) is indicated by a thick arrow with reference numeral 155.
[0047]
On the other hand, heat is recovered in a heat exchanger (boiler) 109 by a circulating gas 107 containing nitrogen or the like as a main component, and steam 111 generated by the heat is used to operate a steam turbine 113 to generate power. At this time, residual volatile matter and coke breeze (further, in the present invention, lime powder and part of lime powder decomposed by the decomposition of lime and immobilized by reaction with sulfur) reach the heat exchanger 109 and coke. In order not to cause troubles such as heat transfer inhibition and the like, air (outside air) 117 is added near the ring duct 115 which is a discharge port of the gas after exiting the pre-chamber 105 to complete combustion. Further, a dust catcher 123 is provided on the circulation path 121 from the ring duct 115 to the heat exchanger 109, and the dust coke (in the present invention, lime powder and lime are decomposed and fixed by reaction with sulfur). Limestone powder) is removed and recovered, but it is desirable to use it effectively in the next sintering process. The circulating gas 107 recovered by the heat exchanger (boiler) 109 is adjusted to an appropriate pressure by a circulating gas blower 125 provided on a circulating path 121 and then introduced into a cooling chamber 106 through a circulating gas inlet 127. do it. In addition, for example, in order to keep the supply flow rate of the circulating gas into the CDQ 101 constant, for example, a radiating device for radiating a part of the circulating gas 107 from the circulating path 121 between the circulating gas blower 125 and the circulating gas inlet 127. A gas extraction path 129 may be provided, and the gas may be diffused through the path 129. Therefore, it is needless to say that a flow regulating valve, a flow meter, an exhaust gas purifying device (all not shown and omitted) and the like may be provided on the path 129 as necessary. In the figure, the movement of coke is indicated by a thick line, and the movement of gas is indicated by a thin line.
[0048]
The method for reducing the sulfur compound in the gas in the CDQ according to the present invention will be further described with reference to FIG.
[0049]
In the present invention, as shown in FIG. 1, (A) the lime 181a may be (directly) introduced into the pre-chamber 105, which is a space for the red hot coke 151 in the coke dry fire extinguishing system (CDQ) 101. , (B) The lime 181b may be injected into a bucket and / or a bucket truck 103, which is a facility for moving and charging the red hot coke 151 in the coke dry fire extinguishing system (CDQ) 101, or (A) and (B). B).
[0050]
Hereinafter, the charging mode (A) and the charging mode (B) will be described separately.
[0051]
<In the case of the charging mode of (A) above>
Next, a case where lime is charged according to the charging mode (A) of the present invention will be described with reference to FIG.
[0052]
(A-1) Since the charging of the red hot coke 151 is a batch charging performed at intervals of several minutes to several tens of minutes, the charging mode of the lime of the present invention is, It can be said that lime 181a may be charged into the pre-chamber 105 via a suitable charging device 183 between the charging of the coke 151, but preferably, the lime 181a is charged into the pre-chamber 105 immediately after the charging of the red hot coke 151. Things. As described above, as long as the lime 181a charged can be used to make the pyrolysis reaction and the desulfurization reaction proceed using the sensible heat of the red hot coke, the inside of the CDQ101 is usually a space part by the sensible heat of the red hot coke. Is in a temperature atmosphere of 1000 to 1100 ° C., and therefore does not need to be in a state of being uniformly mixed with coke. Furthermore, since the residence time in the temperature range of 800 to 1000 ° C. while passing through the inside of the CDQ 101 is about 1 hour, a sufficient reaction proceeds while passing through this range. It can be said that it is not limited. However, if lime is injected into the pre-chamber 105 immediately after the injection of the red hot coke 151, if the amount of sulfur compounds in the gas that can be fixed before being sucked into the circulation path can be increased, Sulfur dew condensation at the boiler outlet or the like can be further reduced, and the degree of acid corrosion in the system can be suppressed to a smaller level.
[0053]
Here, the period between the charging of the red hot coke 151 is defined as the time when the coke in the bucket car 102 disappears when the red hot coke of a certain lot is charged into the pre-chamber 105 and the preheating of the red hot coke 151 of the next lot. This refers to a time immediately before the opening of the lower portion of the bucket car 102 or the like starts to be started when the battery is put into the chamber 105.
[0054]
In the case where lime is injected between the injections of the red hot coke, the input coke layer and the input lime layer alternately descend in the CDQ while maintaining a sandwich shape, and from the lower outlet 108. Before being discharged, the lime layer undergoes a thermal decomposition reaction and a desulfurization reaction, is fixed as limestone, and is discharged in a form adhering to the surface of the sized coke in the vicinity.
[0055]
(A-2) As another charging mode of the biomass of the present invention, lime 181a may be charged into the pre-chamber 105 via the charging device 183 (or the charging device 163) simultaneously with the charging of the red hot coke 151. . Since this is a form in which lime is mixed and dispersed in the red hot coke layer by simultaneous charging, it can be said that this is one of the preferable embodiments in that the sensible heat of the red hot coke surrounding the lime is easily received and thermal decomposition is promoted. The pyrolyzed lime has good contact efficiency with sulfur compounds in the circulating gas passing through the gap between coke, and can fix sulfur content efficiently.
[0056]
Here, “to be charged at the same time” means that charging of the lime 181a starts and ends between the time when the red hot coke 151 of a certain lot starts falling from the bucket car 102 or the like and the time when the falling ends. In the same time slot, the diffusion of coke is used to make it evenly mixed with coke by utilizing the diffusion of coke to promote the contact opportunity between lime and coke (promotion of thermal decomposition reaction by improving heat transfer efficiency of coke sensible heat) In addition, it is possible to promote the opportunity of contact with the circulating gas (promote the fixation of sulfur by improving the reaction efficiency between the sulfur compound in the gas and CaO).
[0057]
When the red hot coke is charged simultaneously with the charging, the mixed layer of the red hot coke 151 and the lime 181a simultaneously charged is stacked for each lot and descends in the CDQ until the lime is discharged from the lower outlet 108. Is subjected to a thermal decomposition reaction and a desulfurization reaction, is fixed as stone, and is discharged in a form adhering to the surface of the sized coke in the vicinity.
[0058]
(A-3) As another charging mode of the lime of the present invention, the charging modes of (A-1) and (A-2) described above may be combined. That is, the lime may be charged into the pre-chamber between the charging of the red hot coke and the charging of the red hot coke. This is useful in that a required amount of lime can be charged into the coke layer or into the coke surface layer according to the purpose of use.
[0059]
In the above methods (A-1) to (A-3), the lime 181a corresponding to the amount of red hot coke for each input lot is placed between the input of the red hot coke 151 and / or simultaneously with the input of the red hot coke 151. Is not particularly limited, for example, the entire amount may be added at a time, the input may be performed continuously over a certain period, or the input may be performed intermittently. When charging continuously or intermittently within a fixed period, the charging may be performed with the charging amount kept constant, or the charging amount may be changed so as to vary with time.
[0060]
Further, in the above (A), the lime 181a is particularly limited such that the lime 181a may be introduced from the coke inlet 104 on the upper part of the CDQ 101 and / or one or more lime inlets 185 provided in the pre-chamber 105. Not something.
[0061]
That is, the charging position of the lime 181a into the pre-chamber 105 depends on whether the lime 181a is from the coke input port 104 or from one or more lime input ports 185 and the biomass input port 165 newly installed in the pre-chamber 105. In some cases, these may be used in combination.
[0062]
Here, the number of the lime charging ports 185 installed in the pre-chamber 105 is not particularly limited, but is uniformly dispersed in the pre-chamber 105 and deposited as uniformly as possible in the pre-chamber 105. Since it is desirable to increase the contact efficiency with the sulfur compound in the circulating gas in the inside (and, consequently, the reaction efficiency), two or more, preferably three or more, more preferably 4 to It is desirable to provide about 16 places. However, although there is no problem with more than 17, it is sufficient from the viewpoint of simplification that the number of devices is 17 or less because the device configuration and control become complicated. When a plurality of lime inlets 185 are provided, they are installed on the same circumference of the inner peripheral surface (that is, at the same height). It is easy to control or determine the charging flow rate, charging angle, and the like.
[0063]
In the case where a plurality of inlets 185 are provided, the lime 181a may be injected by synchronizing the input amount, the input timing, the input flow rate, and the like from each input port (in the same manner). Alternatively, the lime input amount, input timing, input flow rate, and the like may be changed for each input port. In any case, there is no particular limitation as long as the object can be efficiently achieved by effectively utilizing the sensible heat of coke to fix and reduce sulfur compounds in the gas phase by a thermal decomposition reaction and a desulfurization reaction of lime. Not something. For example, the amount of lime, the timing of injection, and the flow velocity of each injection port are varied so that the lime distribution is not localized between the central part and the side part of the prechamber. Then, it is desirable to adjust the lime to be uniformly supplied to the whole so that the reaction efficiency with the sulfur compound in the circulating gas does not decrease. Furthermore, if necessary, it is needless to say that the type of lime and the method of blending may be changed depending on the charging time.
[0064]
Also, as shown in FIG. 1, the installation height of the lime inlet 185 is desirably provided at a portion where the pre-chamber 105 above the ring duct 115 expands in diameter toward the lower part. It may be provided on the upper lid 103.
[0065]
In the method (A), the total amount of lime, the input timing, and the input position (upper or inner periphery) regarding the input amount, input flow rate (flow rate), input angle, and the like of lime from each input port. It should be appropriately determined according to the number of inputs, etc., and if optimum conditions are determined in advance by performing preliminary experiments or simulations with a computer or the like in advance so that the lime input purpose can be achieved. Good. More preferably, it is desirable to carry out a verification test using an actual machine and finally adjust the value. In particular, with respect to the amount of lime, the flow rate (flow rate), and the angle of lime from each of the inlets, the lime is adjusted so as to be uniformly distributed in the pre-chamber by, for example, changing the amount of carrier gas described later. It is desirable.
[0066]
In the method (A), when the lime 181a is charged from the coke charging port 104 or the coke top cover 103, depending on the charging timing, if the lime 181a is performed between charging of the red hot coke 151, The coke inlet 104 does not have to be fully opened, and may be slightly opened so that lime can be introduced. Alternatively, a separate charging port (not shown) may be provided in a part of the upper lid 103 for charging lime, and the lime may be charged (dropped) through the charging port. Therefore, it is possible to provide a plurality of lime inlets even when lime is injected from the coke inlet. However, since the apparatus configuration may be complicated, it is convenient to open the upper lid 103 even when lime is charged.
[0067]
In the method (A), when the lime 181a is introduced from the upper coke inlet 104 or the lime inlet 185 provided on the inner peripheral surface of the pre-chamber 105, the lime 181a is uniformly diffused (distributed) into the pre-chamber 105. In order to be able to make these inlets larger, or by providing a movable mechanism or nozzle at the tip of the inlet, it may be easier to diffuse, but by using a carrier gas described later. It is more desirable to diffuse. This is because the ambient temperature at the inlet becomes high, so even if existing driving devices and mechanisms can be used, high heat-resistant members are required for the members to be used, so it is difficult to commercialize in terms of cost. is there.
[0068]
In the case where the lime 181a is charged at the same time as the charging of the red hot coke 151 in the above (A-2), even if the lime 181a is charged from the lime charging port 185 provided on the inner peripheral surface of the pre-chamber 105 toward the center, the lime does not fall. Since it is difficult to uniformly distribute the lime because of the red hot coke 151, it is more suitable to drop the lime 181a together with the red hot coke 151 from the coke inlet 104 in this case.
[0069]
As a method of charging (conveying) lime in the above method (A), a method of dropping by its own weight at an appropriate charging device 183, for example, a cutting device such as a screw feeder or a table feeder at each charging position, There is a method of injecting (blowing) by airflow conveyance using (or a part of) the circulating gas as a carrier gas.
[0070]
In the latter method, in which nitrogen and / or a part of the circulating gas is used as a carrier gas and injected (blown) by airflow conveyance, when a circulating gas is used, as shown in FIG. At the time of the drop, for example, the gas after the circulation gas blower 125 for circulation is partially branched, pulled by a pipe 186 to a cutout device such as an input device 183, for example, a table feeder, and is fed from the cutout device to the lime input port 185. It is used in combination with a cutting-out facility so that the circulating gas can be supplied as a carrier gas into the lime transfer pipe 187. In the case of nitrogen gas, nitrogen is pulled from the outside to a feeding device 186 by a pipe 188, for example, to a cutting facility such as a table feeder, and similarly, the nitrogen gas is introduced into a lime conveying pipe 187 from the cutting facility to a lime input port 185. Used in combination with a cut-out facility so that it can be supplied as a carrier gas. Further, when both the nitrogen gas and the circulating gas are used as the carrier gas, both of the above-mentioned piping paths may be provided. In this way, if necessary, the nitrogen gas and the circulating gas can be used simultaneously, or the piping paths can be switched between open and closed so that they can be used alternately. Supply becomes possible.
[0071]
In the present invention, the gas that can be used as the carrier gas is not limited to the above-described nitrogen gas and circulating gas, and may be any of inert gas (such as argon gas) and air (particularly other than natural inflow). A part of the air which is positively input for other purposes may be used), various gases produced in steelmaking equipment, for example, coke oven gas, blast furnace gas, alternative oxygen source for air which is positively input such as converter gas What can be used as such can be suitably used.
[0072]
The superiority of the airflow conveyance is that the dispersion range can be expanded with a smaller number of inlets, so that the uniformity of the layer thickness is increased as compared with the case of dropping by its own weight (in the case of coke injection, the dispersibility is improved). Further, by using the circulation gas 107 as the carrier gas, it is possible to minimize the cost disadvantage of using nitrogen gas.
[0073]
In addition, the method of dropping under its own weight does not require a carrier gas, and can reduce running costs. In particular, when lime is charged from the coke input port 104, the gas in the pre-chamber 105 is appropriately dispersed even when it falls under its own weight because the gas in the pre-chamber 105 is thermally convected.
[0074]
<About the method (B)>
First, the bucket and the bucket car are distinguished as follows. The bucket refers to a container for transferring red hot coke, and the bucket truck has a truck (with wheels and the like) suitable for easy transport as shown in FIG. In the present invention, it is needless to say that the present invention is not limited to these, and other moving and charging equipment can be used.
[0075]
If the method (B) is described without misunderstanding, the bucket and / or the bucket truck 102 which is a lime moving and charging facility can use the sensible heat of the red hot coke as described above. The red hot coke 151 needs to be loaded before, simultaneously with, and / or after charging the lime 181b. Accordingly, the red-hot coke 151 and the lime 181b are loaded onto the bucket and / or the bucket truck 102 to be transported to the pre-chamber 105 of the CDQ 101 (specifically, above the coke input port 104) and input. Therefore, only the lime 181b may be thrown into the dedicated bucket and / or bucket car 102, transported to the pre-chamber 105, and thrown in. In that case, however, the method is substantially in the category of the method (A). It can be said that it is included. The method of “charging lime into coke dry fire extinguishing equipment” includes the charging modes (A) and / or (B). This is because the bucket and / or bucket car 102 can also be regarded as ancillary equipment of the CDQ 101. Note that even if the bucket and / or the bucket car is not included in the CDQ 101, the charging mode of (B) of “putting lime into the bucket and / or the bucket car” will be described later. It is essential to put the red hot coke 151 and the lime 181b into the pre-chamber 105 of the CDQ 101. As a result, "the lime 181b is put into the CDQ 101 (using the bucket and / or the bucket wheel 102)". Therefore, the charging mode of (B) is also included as one of the methods of “charging lime into coke dry fire extinguishing equipment”.
[0076]
Further, as described above, the timing of charging the lime to the bucket and / or bucket wheel (also simply referred to as a bucket wheel or the like) is not particularly limited, and the red hot coke 151 from the coke oven 201 to the bucket wheel or the like 102 is not limited. May be performed before, simultaneously with, and / or after loading. This is because in any case, the lime can be preheated by effectively utilizing the sensible heat of coke.
[0077]
(1) Before loading the red hot coke 151, the lime 181b is put into the bucket truck 102 in advance. For example, from the relationship between the arrangement of the lime charging device to the bucket truck 102 and the easiness of charging, the lime charging device is set while the empty bucket truck 102, etc. after the red hot coke 151 is loaded into the CDQ 101 returns to the coke oven. (Similarly to the charging mode described in the above (A), a suitable charging device 183, for example, a cutting device such as a screw feeder or a table feeder, or a rotary feeder may be used. ) Is provided therein, and lime 181b is put into an empty bucket truck 102 or the like by a method of dropping from the lime charging device by its own weight, or a method of injecting (blowing) by airflow using air or the like as a carrier gas. Then, the red hot coke 151 may be pushed out and loaded.
[0078]
{Circle around (2)} The lime 181b is put into a bucket truck 102 or the like on which the red hot coke 151 is loaded. For example, after extruding the red hot coke 151 from the coke oven 201 with an extruder and loading the coke oven 201 on a bucket truck 102, the bucket truck 102 is moved to a position directly below a lime inlet (not shown) of a lime charging device to perform lime charging. Apparatus (Similar to the charging mode of (A) described above, a suitable charging apparatus 183, for example, a cutting apparatus such as a screw feeder or a table feeder, or a rotary feeder may be used. ) Is provided, and the lime 181b is injected (dropped) onto the loaded red hot coke by a method of dropping by its own weight or a method of injecting (blowing) by airflow using air or the like as a carrier gas. You may do so. Each of them is advantageous in that the operation is simple and the lime charging device does not interfere with other coke extruders or CDQ equipment.
[0079]
In the above (1), after loading the red hot coke 151 on the bucket truck 102 or the like, the bucket can be transported to the CDQ 101 without taking extra time. In the above (2), the surface of the red hot coke 151 loaded on the bucket truck 102 can be covered with lime 181b. ) And the red hot coke 151 can be cut off, and the red hot coke 151 can be effectively prevented from burning during transportation.
[0080]
Further, in the present invention, the above-mentioned charging modes (A) and (B) can be combined. That is, in the charging mode of (B), only the lime charging amount sufficient to promote the thermal decomposition of the lime 181b while suppressing the emission of the red hot coke 151 sensible heat to the atmosphere by (2) above is added. It can be said that it is desirable to input the remaining amount of lime depending on the input form so as to be evenly mixed and dispersed in the red hot coke as much as possible.
[0081]
Further, when the lime is finally charged into the pre-chamber 105 by one of the charging modes (A) and / or (B), a part or all of the internal space of the pre-chamber 105 becomes 1000 It is desirable that the ambient temperature is 1100 ° C. In this method, coke sensible heat is used for the reaction. By increasing the reaction temperature (= atmospheric temperature of the internal space of the pre-chamber), the pyrolysis reaction of lime, pyrolysis products (CaO) and gas The sulfur is fixed in the form of stone by the reaction with the sulfur compounds in it, and is removed and recovered from the gas (adhering to the surface of coke, which is a solid layer). This is advantageous in that the effect is enhanced. It should be noted that CaSO immobilized and adhered to the coke surface _Four The powder is unreacted CaCO _Three , CaO, etc., are taken out together with the cooled coke 155 from the outlet 108 below the CDQ, and then the large lump is pulverized by a coke cutter, classified, and coke powdered coke under the sieve to the next sintering step. Sent. The sized coke on the sieve is supplied to the blast furnace. Here, usually, lime is added to iron ore together with coke breeze to perform sintering, and sinter (particularly, limestone powder is generally added to the sinter in advance so as not to add a solvent to the blast furnace. (Self-soluble sinter or lime sinter) which has been baked. In the present invention, CaCO contained in coke breeze is used. _Three In addition, CaO powder can be effectively used as a lime substitute material as it is, and there is an effect of reducing lime in the sintering process, so that extremely efficient use is achieved. CaSO in either CDQ or sintering process _Four However, it is effectively used as a desulfurizing agent in the iron making process.
[0082]
When the atmosphere temperature in the space inside the pre-chamber is lower than 1000 ° C., CaCO _Three → CaO + CO _Two The reaction hardly occurs (decomposes at 900 ° C. or more), and the degassing reaction efficiency cannot be increased. Therefore, the sulfur compound removal rate (desulfurization rate) may not be increased. On the other hand, when the temperature exceeds 1100 ° C., the cooling efficiency of the CDQ decreases due to an increase in heat loss such as heat dissipated, so that the overall thermal efficiency decreases.
[0083]
Here, the reason why a part or all of the space inside the pre-chamber is set is that there is no particular problem even if the entire inside of the pre-chamber is not a uniform temperature distribution and the temperature is locally out of the above temperature range.
[0084]
【Example】
Hereinafter, the present invention will be described with reference to examples, but it is needless to say that the present invention should not be limited to these examples.
[0085]
Comparative Example 1 (Example without lime)
First, about 5Nm per ton of red hot coke ^Three Normal operation was performed using the CDQ shown in FIG. 1 assuming that air enters the pre-chamber. The amount of air that flows in naturally when the upper lid 103 is opened when red hot coke is charged is 5 Nm. ^Three (This point was assumed by estimating an almost accurate natural inflow from the actual operation results of the CDQ of the actual machine). Further, the sulfur content in the coke used in this comparative example was 0.4% by mass (dry), and the volatile substance (VM) was 3%. The space inside the pre-chamber was at an ambient temperature of 1000 to 1100 ° C. during operation. This ambient temperature was measured by installing a temperature sensor 191 inside the pre-chamber 105 at the position shown in FIG. In addition, the particle size of the coal charged into the coke oven 201 was 10 mm or less.
[0086]
5Nm of introduced air ^Three Oxygen gas (O _Two ) The amount is 1.05 Nm ^Three And combusts with red hot coke (1.13 kg), transferring 4.5 g of sulfur (S) to gas. Thereby, 3.2Nl of SO _X Occurs. This is combined with the SO in the released gas that is released through the released gas extraction path 129 in FIG. _X It was measured as a concentration. As a result, the SO in the released gas without lime _X The amount is 13 ppm (SO in gas released during CDQ operation) _X (Average value of concentration).
[0087]
Example 1 (Example of lime input)
On the other hand, as in Comparative Example 1, about 5 Nm per ton of red hot coke ^Three Was assumed to enter the pre-chamber. Further, from four lime charging ports 185 installed at equal intervals around the same circumference of the pre-chamber 105 in FIG. 1, an appropriate charging device 183 is provided at each charging position, and in this embodiment, a cutting device for a table feeder is provided. Using a method of blowing air by air flow using air as a carrier gas (specifically, by adjusting (fluctuation) the flow rate of lime and carrier gas from the cutting equipment, the same amount of Was blown to adjust a uniform lime layer on the coke surface.) During the intermittent charging of the red hot coke 151 to the CDQ 101, 300 g / ton of red hot coke was added. A normal operation was performed using the CDQ shown in FIG. 1 in the same manner as in Comparative Example 1 except that lime was charged. In addition, the sulfur content in the coke used in this example was 0.4% by mass (dry), and the volatile substance (VM) was 3%. In addition, the lime used in the present example was entirely calcium carbonate (CaCO 3). _Three ) Was used. Furthermore, also in this embodiment, since the coal charged to the coke oven 201 used had a particle size of 10 mm or less, the lime used in this example had a particle size of 10 mm or less. Containing 10% by mass. Specifically, as shown in FIG. 2, a hammer-type crusher: 100 kg / h crushing amount, 200 rpm, hammer width 10 mm, hammer number 12, crushed material with an outlet screen size □ 50 mm (opening, square), are subjected to a vibration sieve. : □ 10 mm screen (mesh, square; the screen of FIG. 2 (B) was used), 5 ° tilt, 10 mm horizontal and horizontal vibration amplitude, and 30 times / minute of vibration frequency. Since the amount under the sieve was 10, 9, and 10% by mass (three trials), these were used in this example assuming that lime having a particle size of 10 mm or less was 10% by mass.
[0088]
In the present embodiment, 300 g of lime (CaCO 2) _Three ) Is input to operate the CDQ, the SO2 in the released gas released through the released gas extraction path 129 in FIG. _X The concentration was measured. As a result, SO _X 1 ppm (SO in gas released during CDQ operation) _X (Average concentration). From this, SO _X It was confirmed that the removal / recovery rate (desulfurization rate) by immobilization of the compound reached 92%.
[0089]
As a result, the sulfur compound becomes H on the outer surface of the heat exchange pipe (water / steam circulation pipe) inside the boiler 109 or on the outlet of the boiler. _Two SO _Four Or H _Two SO _Three The problem caused by the acid corrosion of the metal surface due to the condensation in the form of (1) was significantly reduced, and from the condition of the condensation, Example 1 with respect to Comparative Example 1 was much better.
[0090]
Example 2
300 g of lime 181b (the same lime used in Example 1 was used as lime) in a bucket truck 103 loaded with red hot coke 151 per ton of red hot coke. In this case, the thermal decomposition reaction (CaCO _Three → CaO + CO _Two ) Occurs, and the amount of steam considered to correspond to the heat of decomposition increases (0.5 t / h). 7.5% of the calorific value was decomposed before CDQ101 (increase in vapor = (0.64-0.635) / (0.702-0.635) × 100), which was conventionally released into the atmosphere. The sensible heat of red hot coke could be recovered as heat of decomposition of lime.
[0091]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the sulfur compound in the gas in CDQ can be reduced. Specifically, 5 Nm per ton of coke ^Three In the case where the air (air which naturally flows in at the time of charging coke or the like) enters the pre-chamber, the sulfur compound SO _X The amount is reduced by about 92% from 13 ppm to 1 ppm. For this reason, the number of maintenances associated with acid corrosion was conventionally once / three years, but since it can be reduced to at least once / five years, precious time, labor, and costs required for repairing or repairing corroded parts are reduced. It can be greatly reduced. Also, in the past, due to polishing by renovation, the metal corroded portion was less than the design allowable thickness earlier than expected, so it was necessary to replace parts including that portion, but by adopting the present invention In addition, the life of the apparatus can be greatly extended. Also, the SO _X Since the amount can be significantly reduced, the running cost and the like of the device for purifying the emitted gas installed in the emission path can also be significantly reduced.
[0092]
Also, the coke cooled by the CDQ is sieved, and the sized coke on the sieve is sent to a blast furnace, while the fine coke under the sieve is sent to a sintering process and used to form a sintered ore. That is, in the sintering step, coke breeze and lime are added to iron ore and sintered to form a sintered ore having a particle size of 10 to 20 mm. In the present invention, the lime added to the CDQ reduces the sulfur content to limestone (CaSO _Four And immobilized as CD), removed from the CDQ, and sieved and recovered together with coke breeze under the sieve. Therefore, the stone stone (CaSO _Four ) Is also used in the sintering step, so that the lime used in the sintering step can be significantly reduced or the lime need not be used. The sulfur content was originally contained in the coke, and only part of it was transferred to the sinter side, and there was no significant difference in the amount of sulfur brought into the blast furnace. The sulfur content removed and recovered is also excellent in that there is no need to perform any extra treatment or operation, such as separately removing it in a later step.
[Brief description of the drawings]
FIG. 1 is a schematic diagram schematically showing a representative CDQ that can be used in the present invention.
FIG. 2 (A) is a schematic view of a crusher used for crushing biomass, and FIGS. 2 (B) to (E) show only lime which has been reduced in particle size by the crusher. It is a drawing schematically showing the form and size of the openings of the sieve provided at the outlet of the crusher used to make the lime having a small particle size further passed through the sieve of the crusher. In order to regulate the proportion of lime having a particle size of 10 mm or less as defined in the present invention, particles larger than 10 mm are sorted on a sieve and particles of 10 mm or less are sorted under a sieve using a separately provided sieving facility. At this time, it may be a drawing schematically showing the form and size of the openings of the sieve.
FIG. 3 is a drawing excerpted from Chemical Engineering Handbook, 5th edition, page 279, wherein (1) to (5) in FIG. 3 (A) represent a fluidized state diagram of a gas-based fluidized bed; FIG. 3B is a graph showing the relationship between the gas superficial velocity and the particle diameter in the above (1) to (5).
[Explanation of symbols]
101 ... CDQ, 102 ... bucket truck, etc.
103: Upper lid of CDQ, 104: Upper coke inlet,
105… Prechamber (space part of), 106… Cooling chamber,
107: circulating gas, 108: outlet under the CDQ,
109 ... heat exchanger (boiler), 111 ... steam,
113… Steam turbine, 115… Ring duct,
117 ... air (outside air), 121 ... circulation path,
123… Dust catcher, 125… Circulating gas blower,
127… Circulation gas input port, 129… Dissipated gas extraction path,
151 ... red hot coke, 153 ... coke in CDQ,
155… Coke extracted from CDQ, 181… lime,
183… lime input device, 185… lime input port,
191… Temperature sensor, 201… Coke oven,
301 ... lime raw material, 302 ... hammer type crusher,
303 ... rotating body, 304 ... hammer (part),
305: hammer rotation direction, 306: lime crushed material,
307… Screen, 308… Aperture.

Claims (10)

A method for reducing sulfur compounds in gas in a coke dry fire extinguishing facility, which comprises introducing lime into a coke dry fire extinguishing facility. The method for reducing sulfur compounds in gas in a coke dry fire extinguishing facility according to claim 1, wherein the lime is introduced into a pre-chamber, which is a charging space of red hot coke in the coke dry extinguishing facility. The sulfur in a gas in a coke dry fire extinguishing facility according to claim 1 or 2, wherein the lime is put into a bucket and / or a bucket car, which is a facility for moving and putting red hot coke in the coke dry extinguishing facility. Compound reduction method. The sulfur in the gas in the coke dry fire extinguishing equipment according to any one of claims 1 to 3, wherein a part or all of the space inside the pre-chamber has an ambient temperature of 1000 to 1100 ° C. Compound reduction method. The method according to any one of claims 1 to 4, wherein the lime contains 10% by mass or more of lime having a particle size of 10 mm or less. The method according to any one of claims 1 to 5, wherein the lime is charged in a range of 30 to 650 g per ton of coke. 7. The method according to claim 1, wherein the lime is introduced into the pre-chamber during and / or simultaneously with the injection of red hot coke into the coke dry fire extinguishing system. The method for reducing sulfur compounds in gas in a coke dry fire extinguishing facility according to any one of the above. The said lime is thrown in from the coke throwing-in port of the coke dry-fire extinguishing equipment upper part, and / or one or two or more throwing-in ports installed in the pre-chamber. Method for reducing sulfur compounds in gas in coke dry fire extinguishing equipment. The sulfur compound in a gas in a coke dry fire extinguishing facility according to any one of claims 1 to 8, wherein the lime is introduced by air current conveyance using nitrogen and / or a circulating gas as a carrier gas. Reduction method. The lime is charged before, during and / or after loading of red hot coke onto a bucket and / or a bucket truck intermittently made from a coke oven. The method for reducing a sulfur compound in a gas in a coke dry fire extinguishing facility according to the above item.

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