Pressurization type steam-aging device

[0065] The inventors have conducted intensive research on suppressing the frequency of equipment maintenance and improving the aging efficiency in the pressurized steam aging device. As a result, the following findings were obtained.

[0066] Such as Figure 10A , Figure 10B As in the illustrated prior art, when the hole 205a for ejecting steam is formed in the pipe 205 arranged in the longitudinal direction, the steelmaking slag in the vicinity of the hole 205a exists with a high degree of filling. In this case, steam is prevented from being ejected from the hole 205a. In addition, there is a risk of clogging of the hole 205a. Therefore, if the steam hole is formed on the side surface of the branch pipe portion that rises in the vertical direction, the steelmaking slag dropped from above and charged collides with the upper part of the pipe, and the filling degree of the steelmaking slag near the hole can be reduced. As a result, steam can be effectively ejected from the holes, and clogging can be prevented.

[0067] In addition, in Figure 10A , Figure 10B In the shown prior art, there is also a risk of clogging due to the inflow of slag surface water (lime water) into the spray hole. However, by forming the steam hole on the side surface of the branch pipe portion standing in the vertical direction, it becomes possible to alleviate the inflow of water on the slag surface.

[0068] Furthermore, in Figure 10A , Figure 10B In the illustrated prior art, since the pipe 205 is arranged higher than the center in the height direction, the steelmaking slag dropped from above and charged into the pipe collides with the pipe many times, and there is a risk of physical damage to the pipe. However, if the branch pipe portion is installed to stand up from the main pipe portion installed in the horizontal direction toward the vertical direction, the main pipe portion can be arranged at a lower position in the slag storage container, and the ejection hole can be arranged at The height direction area of ​​0.3×H to 0.6×H of the storage area of ​​the slag storage container. Thereby, the frequency of equipment maintenance can be suppressed, and steam aging can be effectively performed.

[0069] Hereinafter, the pressurized steam ageing device 1 for steelmaking slag (hereinafter simply referred to as "steam ageing device 1") according to one embodiment of the present invention completed based on the above findings will be described with reference to the drawings.

[0070] Such as figure 1 , figure 2 As shown, the steam ageing device 1 according to the present embodiment is a substantially cylindrical device, and includes a slag storage container 11, a pressure container 12, a first pipe 13 and a second pipe 14.

[0071] In the following description, the longitudinal direction X refers to a direction along the longitudinal direction of the steam ageing device 1, the height direction Y refers to a vertical direction, and the width direction Z refers to a direction perpendicular to the longitudinal direction X and the height direction Y.

[0072] The slag storage container 11 is a container for storing steam-aged steelmaking slag, such as figure 2 As shown, it is composed of a pair of storage members 111 and two support members 112.

[0073] Each storage member 111 is composed of a bottom surface 111a extending along the longitudinal direction X, a first inclined surface 111b, a side surface 111c, a second inclined surface 111d, and an end surface 111e connected to both ends of the second inclined surface 111d in the longitudinal direction.

[0074] The support member 112 has a column portion 112a that is provided to stand upward from the bottom of the pressure vessel 12, and a shaft 112b that extends along the longitudinal direction X from the upper end of the column portion 112a. The shaft 112b is provided so as to form a shaft mount with the column portion 112a in a state where the pair of end surfaces 111e are overlapped with each other, and each of the pair of storage members 111 is rotatably supported around the shaft 112b.

[0075] An opening is formed above the slag storage container 11, and steel-making slag is charged into the slag storage container 11 from the opening. Furthermore, in figure 2 In the illustrated example, when the steelmaking slag is charged into the slag storage container 11 and when steam aging is performed, the top ends of the pair of bottom surfaces 111a are in a state where they are in contact with each other and face each other. However, it may be in a state where a part of the top ends of the pair of bottom surfaces 111a overlap each other.

[0076] Moreover, after steam aging, such as figure 2 As shown by the two-dot chain line, with the shaft 112b as the center, the pair of storage members 111 are opened, and the steelmaking slag is discharged.

[0077] In addition, regarding the operation of the storage member 111, a hydraulic cylinder or the like (not shown) may be used. In addition, when the storage member 111 is rotated in order to discharge the steelmaking slag, in order to perform the work smoothly, the bottom of the storage member 111 may be formed in an arc shape, and a roller, etc. (not shown) may be arranged below it. .

[0078] In addition, when the steelmaking slag is charged into the slag storage container 11, usually, as Figure 9A As shown, the slag storage container 11 is transported out of the pressure vessel 12. Therefore, the steam ageing device 1 according to the present embodiment preferably has the following structure: when the slag storage container 11 is transported out of the pressure vessel 12, and when the steelmaking slag is loaded and then transported and installed in the pressure vessel 12, The main pipe part 14a and the branch pipe part 14b mentioned later can be carried in and carried out in a state where they are installed in appropriate positions inside the slag storage container 11.

[0079] Here, refer to image 3 The storage area α of the slag storage container 11 will be described.

[0080] The storage area α is an internal space of the slag storage container 11 in which steelmaking slag is stored. image 3 To show an example of the storage area α, the shapes of the slag storage container and the storage area α are not limited. The steelmaking slag may be charged at a position higher than the opening provided in the upper portion of the slag storage container 11, but even in this case, the area higher than the opening is not included in the storage area α. That is, the storage area α does not depend on the amount of steelmaking slag charged, but on the internal dimensions of the slag storage container 11.

[0081] Such as image 3 As shown, in the present application, for the storage area α, the end-to-end length along each axis is taken as the dimension, the dimension in the height direction Y is defined as H (mm), and the dimension in the length direction X is defined as L (mm), the dimension in the width direction Z is defined as W (mm).

[0082] The pressure vessel 12 is a sealable container that houses the slag storage container 11. The pressure vessel 12 is provided with an opening and closing cover 12a that can carry in and discharge the slag storage container 11. The pressure vessel 12 is provided with a sensor (not shown in the figure) that measures the pressure and temperature inside. In addition, in the pressure vessel 12, a first pipe 13 is arranged on the upper part of the pressure vessel 12 (above the opening of the slag storage container 11) so that pressurized steam can be supplied to the inside. On the other hand, the second pipe 14 is led to the inside of the slag storage container 11 so that pressurized steam can be directly supplied to the steelmaking slag charged in the slag storage container 11 carried inside.

[0083] The first pipe 13 is provided outside the pressure vessel 12 and is connected to the upper part of the pressure vessel 12 to supply the pressurized steam supplied from the pressurized steam supply device 50 to the inside of the pressure vessel 12. The pressurized steam supplied through the first pipe 13 directly contacts the steelmaking slag exposed in the vicinity of the opening of the slag storage container 11, thereby promoting the progress of steam aging.

[0084] The second pipe 14 is provided inside the pressure vessel 12 and connected to the side of the pressure vessel 12 to supply the pressurized steam supplied from the pressurized steam supply device 50 to the inside of the slag storage container 11.

[0085] The second pipe 14 includes a main pipe portion 14a and a branch pipe portion 14b, and pressurized steam is ejected from a spray hole 14ba formed in the branch pipe portion 14b. Thereby, by bringing the pressurized steam into contact with the inside of the steelmaking slag charged in the slag storage container 11, the progress of steam aging can be promoted.

[0086] In addition, in the steam ageing device 1 according to the present embodiment, the pressurized steam supply device 50 is connected to the first pipe 13 and the second pipe 14 via a pipe 52 having a valve 51.

[0087] Department in charge 14a, such as figure 1 As shown, the connecting pipe portions 14d are connected to both ends in the longitudinal direction X, and are provided along the longitudinal direction X inside the slag storage container 11. The connecting pipe portion 14d is provided in an inverted U shape so as to straddle the end surface 111e of the storage member 111 of the slag storage container 11. Furthermore, the connecting pipe portion 14 d is connected to a pressurized steam supply device 50 provided outside the pressure vessel 12 via a valve 51 and a pipe 52.

[0088] It is preferable that the main pipe part 14a is provided in the height direction area of ​​0.1×H to 0.3×H in the storage area α of the slag storage container 11.

[0089] When the main pipe portion 14a is installed in a height direction area smaller than 0.1×H, the gap between the main pipe portion 14a and the slag storage container 11 becomes smaller, and the fine powder slag in the drain water existing under the slag storage container 11 increases. In the case of, it is possible that the gap will be buried. In this case, it may cause malfunction when opening the pair of storage members 111, and therefore, it is preferable that the main pipe portion 14a is provided in a height direction region of 0.1×H or more.

[0090] On the other hand, when the main pipe portion 14a is arranged in a height direction area of ​​0.3×H or less, even if a long branch pipe portion 14b is used, the ejection hole 14ba can be arranged in an appropriate height direction area. In this case, it is possible to prevent clogging of the ejection hole 14ba caused by the steelmaking slag present at a high filling degree by being deposited on the upper part of the main pipe, which is preferable in this point. Furthermore, when the main pipe part 14a is arranged in a height direction area of ​​0.3×H or less, the number of collisions with the steelmaking slag dropped from the opening is reduced, so that physical damage to the main pipe part 14a can be prevented. Preferred.

[0091] Such as Figure 4A , Figure 4B As shown, the branch pipe portion 14b is provided on the main pipe portion 14a by standing upward from a plurality of locations spaced at predetermined intervals along the longitudinal direction X. Multiple branch pipe parts 14b may be provided, as long as there is at least one. A pressurized steam ejection hole 14ba is provided on the side surface of each branch pipe portion 14b. A plurality of ejection holes 14ba may be provided on the side surface of the branch pipe portion 14b, or a plurality of ejection holes 14ba may be provided in the circumferential direction of the branch pipe portion 14b. In addition, on the side surface near the tip of each branch pipe portion 14b, a plurality of pressurized steam ejection holes 14ba are provided at equal angular positions in the circumferential direction.

[0092] The pressurized steam supplied from the pressurized steam supply device 50 is ejected from the ejection hole 14ba through the main pipe portion 14a and the branch pipe portion 14b, and is supplied to the steelmaking slag charged in the slag storage container 11.

[0093] The pressurized steam ejected from the ejection hole 14ba is ejected at a predetermined expansion angle, so as Figure 5A As shown, when the filling degree of the steelmaking slag around the ejection hole 14ba is high, the area where the pressurized steam collides with the steelmaking slag becomes smaller. On the other hand, as Figure 5B As shown, when the filling degree of the steelmaking slag around the ejection hole 14ba is low, the area where the pressurized steam collides with the steelmaking slag increases.

[0094] In the steam ageing device according to the present embodiment, the branch pipe portion 14b is erected upward. Therefore, when the steelmaking slag is poured into the slag storage container 11 and charged, the steelmaking slag collides against the tip of the branch pipe portion 14b. Therefore, the filling degree of the steelmaking slag in the vicinity of the pressurized steam ejection hole 14ba formed on the side surface of the branch pipe portion 14b decreases, and therefore the pressurized steam can be efficiently supplied to the center of the charged steelmaking slag. In addition, it is possible to prevent clogging of the ejection hole.

[0095] The ejection hole 14ba is arranged in a height direction area of ​​0.3×H to 0.6×H in the storage area α. Compared with the opening of the slag storage container 11 and the vicinity of the pair of storage members 111 where the pressurized steam supplied from the first pipe 13 directly contacts, the steam aging (hydration reaction) of the steelmaking slag is in the center of the slag storage container 11 The department proceeded slowly.

[0096] Therefore, by arranging the ejection hole 14ba in the height direction area of ​​0.3×H to 0.6×H in the storage area α, it is possible to supply pressurized steam to the steelmaking slag from the center of the height direction of the charged steelmaking slag. Efficient steam aging. It is preferably set at 0.35×H to 0.6×H, more preferably set at 0.4×H to 0.6×H, and still more preferably set at 0.45×H to 0.6×H.

[0097] The height direction position of the ejection hole 14ba can be adjusted by the formation position of the ejection hole 14ba on the branch pipe portion 14b, the height of the branch pipe portion 14b, or the height direction position of the main pipe portion 14a.

[0098] According to the steam ageing device 1 according to this embodiment, the branch pipe portion 14b is erected upward from the main pipe portion 14a. Therefore, even if the ejection hole 14ba is arranged at a height of 0.3×H to 0.6×H in the storage area α In the direction area, the main pipe section 14a can also be arranged at a low position in the storage area α (for example, a height direction area of ​​0.1×H to 0.3×H). Therefore, it is possible to suppress the number of times that the steelmaking slag collides with the main pipe part 14a when the steelmaking slag is charged into the slag storage container 11 to prevent physical damage to the main pipe part 14a, and to efficiently focus the steelmaking slag into the center of the charged steelmaking slag. Supply pressurized steam.

[0099] In order to perform steam aging more efficiently, it is preferable to supply pressurized steam to the longitudinal center portion of the steelmaking slag. Therefore, it is preferable that the ejection hole 14ba be provided in the longitudinal direction region of 0.2×L to 0.8×L in the storage area α of the slag storage container 11. More preferably, it is set to 0.25×L to 0.75×L.

[0100] Similarly, in order to perform steam aging more efficiently, it is preferable to supply pressurized steam to the center part in the width direction of the steelmaking slag. Therefore, it is preferable that the ejection hole 14ba is provided in the width direction region of 0.2×W to 0.8×W in the storage area α of the slag storage container 11. It is more preferably set at 0.3×W to 0.7×W, and still more preferably set at 0.4×W to 0.6×W.

[0101] In the steam aging device 1 involved in this embodiment, as Figure 4C As shown, a circular plate-shaped enlarged diameter portion 14c is formed at the top end of the branch pipe portion 14b, and the outer diameter D of the enlarged diameter portion 14c is larger than the outer diameter d of the branch pipe portion 14b. Such as Figure 4C As shown, the outer diameter D of the enlarged diameter portion 14c is larger than the outer diameter d of the branch pipe portion 14b. In addition, when the plan view shape of the enlarged diameter portion 14c is not circular, the equivalent circle diameter (equivalent circle diameter) of the plan view shape of the enlarged diameter portion 14c is treated as the outer diameter.

[0102] When the expanded diameter portion 14c is formed, when the steelmaking slag is charged into the slag storage container 11, the steelmaking slag collides with the expanded diameter portion 14c at the tip of the branch pipe portion 14b. Therefore, as compared with the case where the enlarged diameter portion 14c is not formed, the area where the steelmaking slag collides is increased. Therefore, the filling degree of the steelmaking slag in the vicinity of the pressurized steam ejection hole 14ba formed on the side surface of the branch pipe portion 14b is further reduced, and therefore the pressurized steam can be efficiently supplied to the center of the charged steelmaking slag. In addition, it is possible to further prevent clogging of the ejection hole 14ba.

[0103] Furthermore, when the enlarged diameter portion 14c is formed, the effect of preventing slag surface water (lime water) from flowing into the ejection hole 14ba can be further improved, and therefore the clogging of the ejection hole 14ba can be prevented more reliably.

[0104] In addition, the physical damage caused by the steelmaking slag dropped from above and hitting the main pipe part 14a can be reduced.

[0105] The size (outer diameter, thickness, etc.) of the enlarged diameter portion 14c is determined to be the optimum size based on the outer diameter d of the branch pipe portion 14b, the position and size of the spray hole 14ba in the erecting direction, so as to produce the aforementioned effects . Conversely, the size and the position of the ejection hole 14ba may be appropriately determined according to the size of the enlarged diameter portion 14c.

[0106] In order to reduce the filling degree of the steelmaking slag in the vicinity of the ejection hole 14ba, prevent clogging of the ejection hole 14ba, and achieve further efficiency of steam aging, it is preferable to satisfy one or more of the following conditions.

[0107] (Condition 1) D≥2×d

[0108] (Condition 2) θ≤45°

[0109] (Condition 3) L1≤d

[0110] Here, such as Figure 4C As shown, D is the outer diameter (mm) of the enlarged diameter portion 14c, d is the outer diameter (mm) of the branch pipe portion 14b, and L1 is the separation distance from the center point of the ejection hole 14ba to the lower end of the enlarged diameter portion 14c ( mm), θ is the inclination angle from the horizontal of the line connecting the center point of the ejection hole 14ba and the end edge of the lower surface of the enlarged diameter portion 14c that is closest to the center point of the ejection hole 14ba (° ).

[0111] The outer diameter and thickness of the main pipe portion 14a and the branch pipe portion 14b, the upward direction and length of the branch pipe portion 14b, the number of installations (installation intervals), the number and size of the ejection holes 14ba provided on the side of the branch pipe portion 14b, as long as The range in which the effect of the present invention can be obtained is not particularly limited. That is, the outer diameter and thickness of the main pipe portion 14a and the branch pipe portion 14b depend on the amount of pressurized steam that should be supplied to the steelmaking slag, and the ability to withstand the impact of the charged steelmaking slag during loading and the steelmaking after loading. The size of the weight of steel slag. In addition, the upward standing direction and length of the branch pipe portion 14b should be determined according to the installation position of the slag storage container 11 of the main pipe portion 14a so that the ejection hole 14ba provided in the branch pipe portion 14b is arranged in the storage of the slag storage container 11. The appropriate position of the area α is sufficient.

[0112] According to the steam aging device 1 according to the above-mentioned embodiment, even when the steelmaking slag with a large proportion of powdery matter is charged into the slag storage container 11, the steelmaking in the vicinity of the ejection hole 14ba can be reduced. The filling degree of the slag and the clogging of the ejection hole 14ba are prevented. Therefore, it is possible to efficiently supply pressurized steam to the center of the steelmaking slag charged in the slag storage container 11, in addition to the pressurized steam supplied from the first pipe 13 to the inside of the pressure vessel 12, and it can be achieved in a short time. Steam aging of steelmaking slag. As a result, it is possible to suppress the frequency of equipment maintenance and perform aging efficiently.

[0113] The present invention is not limited to the above-mentioned examples, and it goes without saying that the embodiment can be changed as appropriate if it is within the scope of the technical idea described in the claims.

[0114] For example, the installation number (installation interval) of the branch pipe portion 14b and the position, number, and size of the ejection holes 14ba provided in the branch pipe portion 14b in the circumferential direction and the standing direction are not limited to the examples shown in the above-mentioned embodiment What is necessary is just to determine so that pressurized steam can be efficiently supplied to the steelmaking slag located in the center part of the slag storage container 11.

[0115] The branch part 14b can also be like Figure 6A , Figure 6B As shown in the first modification example, it stands obliquely in the longitudinal direction X, or it may be Figure 7A , Figure 7B As shown in the second modification example, it stands obliquely in the width direction Z, or it may be Figure 8A , Figure 8B As shown in the third modified example, it stands obliquely in the longitudinal direction X and the width direction Z.

[0116] In addition, the ejection hole 14ba can also be as Figure 6A~Figure 8B As in the illustrated first modification to the third modification, multiple locations are provided in the height direction Y of the branch pipe portion 14b. When multiple ejection holes 14ba are provided, it is preferable that all the ejection holes 14ba are arranged in a height direction area of ​​0.3×H to 0.6×H in the storage area α.

[0117] In the steam ageing device 1 according to the above embodiment, the second pipe 14 has the enlarged diameter portion 14c, but it does not have to have the enlarged diameter portion 14c.

[0118] In the steam ageing device 1 according to the above-mentioned embodiment, the main pipe part 14a is provided inside the slag storage container 11 along the longitudinal direction X, but it may be provided in a meandering manner in the width direction Z. That is, the main pipe part 14a may be provided along the horizontal direction.

[0119] In the steam aging device 1 according to the above-described embodiment, the ejection holes 14ba of all the branch pipe portions 14b have the same size, but the sizes may be different.

[0120] In the steam aging device 1 according to the above embodiment, the ejection hole 14ba provided in the branch pipe portion 14b is circular, but the shape of the ejection hole 14ba is not limited to a circle, and may be an ellipse or a polygon. In addition, a slit may be provided in the branch pipe portion 14b.

[0121] In the steam ageing device 1 according to the above-described embodiment, a disk-shaped enlarged diameter portion 14c is provided at the tip of the branch pipe portion 14b. However, the shape in plan view of the enlarged diameter portion 14c may be an ellipse or a polygon. In addition, it does not have to be a plate shape, but may be a conical shape. In addition, the position where the enlarged diameter portion 14c is provided may not be the tip of the branch pipe portion 14b, as long as it is above the ejection hole 14ba.

[0122] The steam aging device 1 according to the above-mentioned embodiment has only one main pipe part 14a. However, the capacity of the slag storage container 11 increases, and only the pressurized steam ejected from the branch pipe portion 14b provided in one main pipe portion 14a cannot reach the center of the steelmaking slag charged in the slag storage container 11. In the case of efficiently supplying pressurized steam, a plurality of main pipe portions 14a including branch pipe portions 14b may be provided.

[0123] (Example)

[0124] In Experimental Example 1, use figure 1 In addition, in the illustrated steam aging device 1, in Experimental Examples 2 to 9, a steam aging device in which the steam aging device 1 was changed in various ways was used to perform the steam aging treatment.

[0125] The main common conditions in each experimental example are as follows.

[0126] ·Average particle size of steelmaking slag: as the particle size of steelmaking slag, it is 0~40mm of steel slag for road use

[0127] ·The pressure inside the pressure vessel: 0.5MPa

[0128] ·The height of the storage area H: 1790mm

[0129] ·The width of the storage area W: 2800mm

[0130] ·Length of storage area L: 6400mm

[0131] ·The width direction position of the main department: 0.5×W

[0132] ·The diameter of the main department: 4.5mm

[0133] ·Steam aging time: 2 hours/cycle

[0134] ·Steelmaking slag volume: 45 tons/cycle

[0135] In Experimental Examples 1 to 8, the branch pipe sections were erected at four longitudinal positions of 0.25×L, 0.42×L, 0.58×L, and 0.75×L of the main pipe section. In addition, in each branch pipe portion, 8 ejection holes are provided at equal intervals in the circumferential direction. As a result, the steam is ejected from 32 ejection holes.

[0136] On the other hand, in Experimental Example 9, as Figure 10A and Figure 10B In that way, the branch pipe is not provided, and the main pipes are installed at the height of 710 mm and 1530 mm of the storage area, and 10 ejection holes are provided at equal intervals on each side of each main pipe in a row along the longitudinal direction. As a result, the steam is ejected from a total of 40 ejection holes in the two main pipe sections.

[0137] In the experiment, in order to perform one-time aging, a step of heating the steelmaking slag into the steam aging device 1 and then heating it to a predetermined temperature and a step of bringing it to a predetermined temperature after the steam aging is completed. These steps require a total of 1 hour. That is, in the experiment, the steelmaking slag was charged into the steam aging device 1 and the steam aging treatment was performed. The time required until the steelmaking slag was discharged from the steam aging device 1 was 3 hours/cycle.

[0138] In one day, 8 cycles of the above experiment were carried out, and 360 tons/day of steelmaking slag was processed. The above-mentioned experiment was carried out for 8 cycles, and the steelmaking slag treatment of 360 tons/day was carried out for 1 month, 3 months, and 6 months without stopping the operation.

[0139] Each condition in each experimental example is shown in Table 1.

[0140] table@

[0141]

[0142] The steelmaking slag subjected to the above-mentioned steam aging treatment was subjected to the water immersion expansion test specified in Annex B of JIS A 5015 (2013), and the water immersion expansion ratio was measured. The results are shown in Table 2.

[0143] Table 2

[0144]

[0145] a: Water immersion expansion test result of steelmaking slag before steam aging: water immersion expansion ratio (%)

[0146] b: Water immersion expansion test result of steelmaking slag after steam aging: water immersion expansion ratio (%)

[0147] Decrease rate: Decrease rate=(b/a)×100(%)

[0148] Initial stage of implementation: Result of water immersion expansion test on slag that was aged on the first day