JP2012250197A - Joined drum mixer apparatus for sintering raw material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent fall in throughput of a first mixer even when two drum mixers are joined.SOLUTION: In a rotary cylinder type joined drum mixer apparatus, two drum mixers 1, 2 for mixing and pelletizing a sintering raw material 3 are directly joined by fitting and a raw material 3 is charged therein from a raw material charging end 1a of a first mixer 1 on an upstream side and the sintering raw material 3 subjected to mixing and pelletizing treatment is discharged from a pelletized material discharge end 2a of a second mixer 2 on a downstream side. An inner diameter in a range where main mixing in the first mixer 1 on the upstream side is carried out is made larger than an inner diameter of a fitting joining part 4 on a discharge side of the first mixer 1. For the first mixer, a state where a weir appears at an exit is caused, a raw material occupation rate is raised and residence time is prolonged, and thereby effect of main mixing is improved.

Description

  The present invention relates to a drum mixer apparatus for mixing and granulating a sintering raw material.

The sintering raw material is composed of several types of iron ore, limestone as a CaO source, serpentine powder as a SiO ₂ and MgO source, powder coke as a fuel, and return ore. These raw materials are cut out from the respective raw material tanks in a fixed amount and sequentially placed on a conveyor belt for conveyance, and all the raw materials are merged at a position on the outlet side of the most downstream raw material tank. At this time, the state of each raw material is a non-uniform state laminated on the belt conveyor, so it cannot be directly supplied to the sintering machine, and a mixing operation for homogenization is required in advance. Become.

  Furthermore, since the raw material is usually a powder having a particle size of 5 mm or less and coarse particles and fine powders having a large particle size difference are mixed, the gaps between the raw material particles are small. It is difficult to form an air flow path for burning coke. In order to eliminate this state, a granulation operation is required in which pseudo-particles are created by sucking and adhering other fine powder raw materials on the surface by using a relatively coarse raw material as a core and water capillary adsorption force on the surface. . By forming the pseudo particles, the difference in the particle diameters of the raw materials is reduced, and a void necessary for ventilation can be secured.

  Currently, in the raw material processing line of a sintering machine, it is common to perform the above mixing operation and granulation operation simultaneously with a rotating cylindrical drum mixer (hereinafter simply referred to as a drum mixer).

  The raw materials of a plurality of brands after joining on the belt conveyor are mixed uniformly in the drum mixer and added with moisture, and granulation proceeds. The wet raw material after mixing and granulation is charged into a sintering machine, ignited on the surface, and then coke is burned by the sucked air. Due to the heat generated by the combustion, a so-called sintering reaction in which iron ore, limestone, serpentine powder, and the like are welded to each other proceeds from the upper layer to the lower layer. As the sintering reaction zone progresses, the wet raw material zone in the lower layer gradually disappears.On the other hand, a sintering completion zone called a sinter cake is newly formed in the upper layer of the sintering reaction zone, and the thickness gradually increases. Will increase.

  As the sintering proceeds further, the wet raw material zone and the sintering reaction zone disappear completely, leaving only the sinter cake. At this point, the sintering is completed. The sinter cake discharged from the sintering machine is crushed and sized to a size suitable for blast furnace charging, separated into products and fine-grained ore, and the returned ore is used again as a raw material for sintering.

  As described above, three types of zones appear in the progress of sintering. Among these, the wet raw material zone and the sinter cake disappear or are formed as a result of the progress of the sintering reaction zone. Therefore, the productivity of the sintering machine is uniquely determined by the progress speed of the sintering reaction zone.

  In the sintering reaction zone, coke combustion reaction and ore welding using this combustion heat occur. The reaction in the sintering reaction zone is preceded by the combustion reaction of coke, which determines the rate of progress of the sintering reaction zone.

  In the raw material processing line, coke for depositing ore in the raw material is blended in advance, so the combustion rate in the sintering machine is limited by the supply rate of air, not the supply amount of coke. Furthermore, since air is supplied by the suction exhaust fan, the air supply speed is determined by the ventilation resistance obtained by adding the resistance of each of the three zones of the sintered completion zone, the sintering reaction zone, and the wet raw material zone. Among these three zones, the wet raw material zone has the largest ventilation resistance, and it is advantageous to improve the air permeability of the wet raw material zone in order to promote the combustion of coke. Therefore, as described above, in order to improve the air permeability of the wet raw material band, it is indispensable to promote the formation of pseudo particles by the granulation operation.

  The formation of pseudo-particles makes the air supply uniform, increases the coke combustion efficiency, and strengthens ore-to-ore welding, thus contributing to the improvement of product yield, resulting in a sintering machine. Has the effect of improving the productivity.

  Conventionally, it is known that the adequacy of the amount of water added as a binder has a strong influence on the formation of pseudo particles of raw materials in granulation operations. Therefore, in order to promote the growth, it is necessary to add an appropriate amount of water without excess or deficiency.

  On the other hand, in an actual sintering machine, the moisture absorption rate varies depending on the type of raw material used, and the moisture contributing to granulation varies. In addition, even in the same raw material, segregation occurs in the storage yard and the raw material storage tank of the subsequent sintering machine, and dispersion occurs in the particle size distribution and moisture content when blended. Furthermore, the temperature of the return ore added to the raw material before granulation is not constant, and the amount of water evaporation due to this also changes, causing fluctuations in the water content of the raw material to be blended.

  Under such circumstances where the raw material properties change from moment to moment, the moisture content of the blended raw material also varies in the same manner, and accordingly, a moisture addition control technique and drum for maximizing the formation of pseudo particles accordingly. It is necessary to adjust the rolling state such as changing the inclination angle and rotation speed of the mixer.

  As described above, the mixing and granulation process is an important process in the sintering process in which powdered iron ore that cannot be charged directly into the blast furnace is sintered as a pretreatment to be a massive ore. At that time, since a large amount of processing is required, a cylindrical rotating type mixing and granulating device called a drum mixer is most suitable, not a small processing method such as a dish type rotary granulator with excellent fine granulation performance. Used in most sintering processes. In addition, because the mass processing is necessary, the size of the device is increased, and the performance, which is determined by the size, number of rotations, and angle of the device that was constructed first, has been changed in recent years. Since there is a technology that can be adjusted, it is possible to perform mixed granulation operations that match the raw materials.

  In the mixing / granulating function, the diameter, length, and inclination angle of the drum mixer determine the residence time of the raw material or the rolling distance, so that determination must be made carefully. In the case of a single drum mixer, the larger the diameter, the better the rolling occurs. However, when two drum mixers are connected, the material must be transferred from the upstream drum mixer to the downstream drum mixer. In the fitting connection portion, the diameter of the drum mixer on the upstream side is always small. At that time, if the mixer inner diameter in the range of the main rolling mixing section of the upstream drum mixer is matched with the fitting connection section, a drum mixer with a small diameter is obtained, and a diameter corresponding to the processing amount cannot be obtained.

  Further, when only entering / exiting the drum mixer device is seen, mixing and granulation seem to be performed at the same time. However, sufficient mixing occurs first, and granulation proceeds as mixing proceeds. Therefore, two drum mixers for mixing and granulation are generally provided, and the upstream side is mainly expressed as a primary mixer mainly for mixing, and the downstream side is mainly expressed as a secondary mixer mainly for granulation. Has been called.

  Conventionally, the primary mixer and the secondary mixer have been separately arranged and connected by a belt conveyor, so a site for each mixer is required. In addition, since one of the drum mixers is stopped due to a failure, it takes time to install a belt conveyor that bypasses the failed drum mixer, and a long-term stop cannot be avoided. In the case of distant arrangement, a belt conveyor connecting the primary mixer and the secondary mixer is required, and a supply device for each drum mixer is required, which increases the equipment cost and generates dust at the time of input. It was necessary for each mixer to take countermeasures and measures for powder falling, or for powder conveyors to be connected and for maintenance.

  In order to promote the granulation of the pseudo-particles, raw materials that are easy to adhere and solidify such as quick lime are blended, so that the raw materials are easily attached to the inner surface of the drum mixer. Inside the drum mixer, the raw material is lifted by the rotation of the mixer main body, and when it becomes higher than the deposition slope, it is carried to the discharge side by the tilt angle of the drum mixer while being circulated and started to be discharged. However, when the raw material adheres and grows on the inner surface of the drum mixer, it does not easily peel off, and when it reaches a certain thickness, it may peel off at once and fall into a large lump, making it impossible to continue operation.

  In one example, the raw material adheres to the inner surface of the drum mixer by a thickness of about 300mm and the granulation performance deteriorates, and the internal material space factor exceeds the limit of the equipment, causing problems such as spilling from the raw material input end. It was. At the same time, a part of the cylindrical deposit may be broken and the cylindrical deposit may be peeled off over the entire circumference, resulting in a situation where the operation cannot be continued. The raw material space factor means the raw material volume ratio (raw material volume / drum mixer volume) relative to the volume of the drum mixer.

  When the raw material adheres to the inner surface of the drum mixer, the mixing granulation state is smaller than the inner diameter of the original drum mixer, so the rolling distance is shorter than the predetermined distance and the residence time is shortened. And granulation will not be possible.

  In order to prevent this, a method of preventing adhesion of raw materials by attaching a rubber liner or the like to the inner surface of the drum mixer, or a scraper device is attached. Of these, when a rubber liner is pasted, if the protrusions that prevent the raw material from slipping are misplaced, the adhesion will grow, or there will be two extreme results: the adhesion will soon occur and no adhesion will occur. There is a fear. However, the arrangement interval of the protrusions varies depending on the raw material properties, moisture, and the diameter of the mixer body, and cannot be defined.

  In addition, if the rubber liner is worn out and worn out, the replacement cost is high, so the cell steel may be welded to the inner surface of the steel strip, but in this case the deposits will grow reliably. The scraper must always be scraped off so that the inner diameter is constant.

  However, if the length of the drum mixer becomes longer, the support point becomes longer and the vibration during scraping greatly shakes the scraper garter that holds the scraper, so that it becomes impossible to simply install the scraper device.

  That is, in order to install the scraper device, there is a restriction that the length of the drum mixer must be shortened. The same applies to the case where a water injection device for adding moisture is arranged in the drum mixer.

  Patent Document 1 proposes an apparatus for washing the material adhering to the inside of the drum mixer with a high-pressure washing nozzle. However, when the adhering matter is washed with high-pressure water during operation, the moisture content of the material depends on the amount of the washing water. Becomes too much, and it becomes a sintering raw material with a large amount of moisture, which impairs the sintering productivity. This can be done while the machine is stopped, but the internal diameter of the drum mixer during operation cannot always be kept constant.

JP-A-6-106038

  The problem to be solved by the present invention is that when two drum mixers are connected in order to solve the problem when the primary mixer and the secondary mixer are arranged on different sites, the primary mixer is connected to the fitting connection portion having a small diameter. If the inner diameters of these are combined, the amount of processing by the primary mixer is reduced.

The connected drum mixer device for sintered raw materials of the present invention is
In order not to reduce the processing amount of the primary mixer even when two drum mixers are connected,
Two drum mixers that mix and granulate the raw materials for sintering are directly fitted and connected, the raw materials are charged from the raw material input end of the primary mixer on the upstream side, and the granule discharge end of the secondary mixer on the downstream side A rotating cylindrical connected drum mixer device for discharging the sintering raw material mixed and granulated from the part,
The main feature is that the inner diameter of the primary mixer in the main mixing range is made larger than the inner diameter of the fitting connection portion on the discharge side of the primary mixer.

  In the present invention, even when two drum mixers are connected so as to enable an arrangement that saves the site, the primary mixer has a weir at the outlet and the material space factor increases and the residence time increases. By increasing the length, the main mixing effect is improved.

It is the figure seen from the side of the connection drum mixer apparatus for sintering raw materials of this invention. It is the figure which looked at FIG. 1 from the plane. It is a figure explaining the rotation detector which detects rotation of a support roller, (a) is the figure seen from the side surface, (b) is the figure which looked at (a) from the discharge side of a raw material. It is the figure which looked at the inside of the connection drum mixer apparatus for sintering raw materials of this invention from the discharge side. It is the figure which showed the protrusion of the liner provided in the inner surface of the connection drum mixer apparatus for sintering raw materials of this invention, and the ideal adhesion state of the raw material for sintering. (A) is the longitudinal cross-sectional view of the drum mixer which showed the arrangement | positioning state of the liner provided in the inner surface of the connection drum mixer apparatus for sintering raw materials of this invention, (b) is an expanded view. (A) is the longitudinal cross-sectional view of the fitting connection part of the connection drum mixer apparatus for sintering raw materials of this invention, (b) is an enlarged view of the clearance shielding member installation part in (a) figure, both are the thickness of a raw material layer Indicates the thickness at a position inclined 45 ° upward from the vertical bottom. It is a cross-sectional view of the fitting connection part of the connection drum mixer apparatus for sintering raw materials of this invention. It is a figure explaining the discharge port part provided in the fitting connection part of the connection drum mixer apparatus for sintering raw materials of this invention, and the thickness of a raw material layer shows the thickness of the position inclined 45 degrees upwards from the perpendicular bottom part Yes. It is the figure which showed the rolling state in the drum mixer of the connection drum mixer apparatus for sintering raw materials of this invention, (a) is the figure which showed the relationship between a raw material space factor and a fluid number, (b) is a residence time. It is the figure which showed the relationship between a fluid number.

  In the present invention, even in the case where two drum mixers are connected, the purpose of avoiding reducing the throughput of the primary mixer is to set the inner diameter of the primary mixer in the main mixing range to the discharge side of the primary mixer. This was realized by making it larger than the inner diameter of the fitting connection part.

Hereinafter, examples for carrying out the present invention will be described with reference to FIGS.
When a new sintering process is added at an existing steelworks, the site area restriction is a major obstacle, and it may be difficult to arrange the equipment in the normal process. The present invention is effective when the drum mixer for processing the mixing and granulation process of the raw material for sintering is arranged on a narrow site, when the conventional primary mixer and the secondary mixer cannot be arranged on different sites, The configuration described in is adopted.

  As an effective means when the site area is small, a rotary cylindrical primary mixer 1 mainly used for mixing and a rotary cylindrical secondary mixer 2 mainly used for granulation, which were conventionally arranged on different sites, are fitted. The raw material 3 is supplied from the raw material input end 1a of the primary mixer 1 and the mixed granulated raw material 3 can be discharged from the flow output end 2a of the secondary mixer 2. The present invention has been completed.

  At that time, the outer diameter of the discharge-side end portion 1b of the primary mixer 1 constituting the fitting connection portion 4 of the primary mixer 1 with the secondary mixer 2 is determined when the raw material 3 is transferred from the primary mixer 1 to the secondary mixer 2. In order to prevent spillage, it is necessary to make it smaller than the inner diameter of the charging-side end 2b of the secondary mixer 2, and the inner diameter of that portion is further reduced by the thickness of the drum body. When the processing amount of the raw material for sintering is determined based on the primary mixer 1 with the smaller inner diameter, the inner diameter of the secondary mixer 2 becomes larger than necessary.

  Therefore, in the present invention, the inner diameter of the body portion 1c for main mixing and granulation, upstream of the discharge-side end portion 1b of the primary mixer 1, is used as the fitting connection portion 4 between the primary mixer 1 and the secondary mixer 2. By making it larger than the inner diameter of the discharge-side end 1b of the primary mixer 1, the inner diameter of the secondary mixer 2 was prevented from becoming larger than necessary. If the inner diameter of the secondary mixer 2 is increased more than necessary, there is a problem that the equipment cost becomes high and a large site area is required for installation, but the space factor is also low from the viewpoint of raw material granulation. As a result, the raw material does not roll and is discharged while sliding, and the granulation effect deteriorates.

  In order to make the inner diameter of the body portion 1c upstream of the discharge-side end portion 1b of the primary mixer 1 larger than the inner diameter of the discharge-side end portion 1b of the primary mixer 1 constituting the fitting connection portion 4, the fitting connection portion 4, the diameter of the cylindrical portion 1c on the upstream side is made larger than the diameter of the discharge side end portion 1b of the primary mixer 1 in FIG.

  In the case of the above configuration, since the raw material 3 is blocked at the boundary between the discharge-side end 1b of the primary mixer 1 and the cylindrical portion 1c, the raw material space factor in the primary mixer 1 increases and the primary mixer 1 The time for staying inside becomes longer, which is convenient for mixing and granulation.

  In the present invention, the installation inclination angle of the rotating cylindrical body is set to the same angle as that of a conventional drum mixer, and the mixing / granulating function is not changed. However, a gap 4a is provided in the fitting connection portion 4 of the two drum mixers 1 and 2, so that the rotation speeds of the two drum mixers 1 and 2 can be changed independently, so that various raw material changes can be handled. ing.

  Further, in the present invention, the raw materials 3 such as iron ore are prevented from sticking to the inner surfaces of the drum mixers 1 and 2, and the inner diameters of the drum mixers 1 and 2 are always kept constant so that mixing and granulation can be performed stably. In order to obtain the effect, the scraper 5 is disposed over the entire length of the two drum mixers 1 and 2 as necessary.

  At that time, the scraper garter 6 to which the scraper 5 is attached is supported by the raw material input end 1a of the primary mixer 1, the end support members 7a and 7c installed at the granulated product discharge end 2a of the secondary mixer 2, and the intermediate This is carried out at three places by the intermediate support member 7b installed in the fitting connection portion 4 of FIG. With such three-point support, the scraper 5 can be firmly supported even when different vibrations occur due to the primary mixer 1 and the secondary mixer 2 rotating at independent rotation speeds.

  The support by the intermediate support member 7 b is a partial annular holding portion 7 bb inserted into the gap 4 a of the fitting connection portion 4 from a support frame 7 ba (see FIG. 8) arranged outside the fitting connection portion 4, and the scraper garter 6. This is performed by holding the support member 7bc that supports the slab (see FIG. 7A). The end support members 7a and 7c can be supported by projecting the scraper garter 6 beyond the raw material input end 1a of the primary mixer 1 and the granulated product discharge end 2a of the secondary mixer 2.

  The raw material 3 in the drum mixers 1 and 2 is lifted in the rotation direction and forms an inclined surface at a repose angle depending on the properties of the raw material 3. Then, while forming a roughly crescent-shaped accumulation shape, the surrounding area is lifted at the rotational speed of the drum mixers 1 and 2, and when it reaches the apex of the shape formed by the angle of repose, it falls by gravity and rolls the inclined surface. It moves and repeats to reach the lowest vertex.

  For this reason, the raw material 3 deposited on the fitting connection portion 4 of the two drum mixers 1 and 2 spills out from the gap 4 a of the fitting connection portion 4. In order to prevent this, an object that closes the gap 4a is required at least in a range where the raw material 3 is rolling and accumulated (see FIG. 8).

  In this case, the gap 4a of the fitting connection portion 4 does not necessarily need to block the entire circumference, and a partial annular gap shielding member 8 that plugs only the range is inserted into the gap 4a in a non-rotating state and fitted. What is necessary is just to hold | maintain with the holding member 9 from the outer side of the connection part 4 (refer FIG. 8).

  Although not shown in the drawings, when the entire circumference of the gap 4a is blocked, the gap shielding member such as a plate is fixedly secured from the scraper support frame outside the fitting connection portion 4 in a range other than the gap shielding member 8 attached to the range where the raw material contacts. It is possible by attaching the material.

  The gap shielding member 8 may be a plate-like member in a freely supported state that can be shielded while contacting an iron plate or a gap. As a result, the raw material 3 that spills out can be minimized by minimizing the gap through which the raw material 3 spills out from the fitting connection portion 4 of the connected primary mixer 1 and secondary mixer 2, and is rotating. The drum mixer can be mechanically contacted to prevent problems such as rotation failure.

  By the way, in order to prevent the raw material 3 from spilling into the gap 4a of the fitting connection portion 4 between the primary mixer 1 and the secondary mixer 2, for example, a partial annular gap shielding member 8 is provided as described above. Insertion is arranged. For this reason, the raw material 3 that has entered the gap 4a causes contact rolling friction with the outer surface of the upstream primary mixer 1 and the inner surface of the downstream secondary mixer 2, and the cylindrical surfaces of the two drum mixers 1 and 2 Wear is significantly faster.

  Therefore, in the present invention, it is desirable to take a measure for preventing wear of a cell flying method using a steel strip or the like. FIG. 7A shows the cell flying 21 provided in the fitting connection portion 4.

  In addition, even if a partial annular gap shielding member 8 is inserted and arranged in the gap 4a of the fitting connection portion 4, the raw material 3 that spills out is operated continuously for 24 hours. Gradually it becomes a big deposit.

  Therefore, it is desirable to install an apparatus for returning the spilled raw material 3 to the belt conveyor 10 that is discharged from the secondary mixer 2 and conveyed to the sintering machine.

  In order to simplify the apparatus for returning to the belt conveyor 10, the center of the belt conveyor 10 in the conveying direction is arranged close to the length direction of the two drum mixers 1 and 2, and the raw material charging end 1a of the primary mixer 1 is arranged. The raw material 3 spilled from the gap 4a of the fitting connection portion 4 between the primary mixer 1 and the secondary mixer 2 is disposed at a position where it can be introduced into the belt conveyor by a chute or the like. Then, a discharge chute 11 or a belt conveyor for guiding the raw material 3 spilled from the gap 4a to the belt conveyor 10 is disposed. Thereby, the stable operation can be obtained.

  In addition, the raw material 3 is charged into the mixing primary mixer 1 on the upstream side by inserting the end portions of the belt conveyor 18 and the vibration feeder into the inside from the raw material charging portion 1 a of the primary mixer 1. In such charging, the charged raw material 3 may spill out of the raw material charging end portion 1 a due to rolling caused by the rotation of the primary mixer 1. The spilled raw material 3 can be prevented from accumulating powder dust by being guided to the belt conveyor 10 with a chute or the like, similarly to the raw material 3 spilling from the gap 4a of the fitting connection portion 4.

  By these, it becomes possible to prevent the environmental deterioration by falling ore and environmental load decreases.

  Conventionally, the primary mixer 1 and the secondary mixer 2 are arranged at different locations, so if one drum mixer fails and stops, the long-distance belt conveyor and the accompanying basic and electrical facilities become enormous. , Could not escape long-term suspension.

  However, in the present invention, if, for example, a substantially rectangular discharge port 2c is provided on the cylindrical surface of the charging side end 2b of the secondary mixer 2 and the lid 12 is provided, the secondary mixer 2 on the downstream side breaks down. Even in the event of a long-term stoppage, the raw material 3 can be discharged to the belt conveyor 10 via the discharge chute (not shown) simply by removing the lid 12, and the sintering machine can be prevented from stopping for a long time. Can be stabilized.

  On the other hand, when the upstream primary mixer 1 breaks down, the sintering machine is temporarily stopped, a temporary belt conveyor is inserted into the upstream primary mixer 1, and the raw material 3 to be fed is transferred to the belt conveyor. By connecting to the secondary mixer 2 on the downstream side, the upstream primary mixer 1 can be bypassed in a short time. When the conventional primary mixer and the secondary mixer are arranged separately, it is necessary to install a foundation for placing the belt conveyor on the ground, a base, and a connecting chute. However, if these are arranged in the primary mixer, these are unnecessary. It can be installed in a short period of time.

  Further, the primary mixer 1 and the secondary mixer 2 are supported by support rollers 13a to 13d arranged at four locations, and are rotated at different rotational speeds and different peripheral speeds by the electric motors 14a and 14b, respectively. It circulates in a single layer.

  When the mechanical failure such as rotation failure occurs in the support rollers 13a to 13d, if the primary mixer 1 and the secondary mixer 2 continue to rotate, the primary mixer 1 and the secondary mixer 2 that are in contact with the support rollers 13a to 13d. The surface of the annular tires 1d and 2d may be damaged, resulting in a major failure that takes a long time to recover. In addition, when the failure occurs in the secondary mixer 2 on the downstream side, a large amount of the raw material 3 may accumulate in the secondary mixer 2 and may be difficult to discharge.

  Accordingly, rotation detectors 15a to 15d for detecting the rotation are installed on the respective support rollers 13a to 13d (see FIG. 3), and the rotation speeds of the respective support rollers 13a to 13d are set by these rotation detectors 15a to 15d. The detected number of rotations is input to the judgment control device 16.

  The determination control device 16 determines the bearing breakage or rotation failure of the support rollers 13a to 13d from the input rotation speed. If it is determined that the bearing is broken or rotation failure, the support rollers 13a to 13d support. The electric motors 14a and 14b that rotate the drum mixers 1 and 2 are stopped. In this way, the drum mixers 1 and 2 can be stopped quickly, and safe operation can be maintained.

  In the case of a flat surface where the raw material 3 does not adhere at all, since the raw material 3 slides on the inner wall surface when the raw material 3 is lifted by the cylindrical inner surface of the rotating drum mixers 1 and 2, the inner surface of the drum mixers 1 and 2 is worn. Become intense. Moreover, since the raw material 3 cannot be lifted up to the point where the angle of repose is formed, the mixing performance is lowered. Furthermore, since the amount of rolling decreases, granulation performance is also insufficient.

  Therefore, there is a technique for sticking a rubber liner having a protrusion that serves as a resistance to lift the raw material 3, but when the interval between the protrusions is narrow, the attached raw material 3 is not peeled off and becomes the same state as the cell flying state by the strip steel. It is not preferable. On the other hand, if the distance between the protrusions is too wide, a smooth sliding surface is formed, so that the effect of mixing / granulation is reduced and wear is increased.

  In view of this, the inventors have repeatedly considered the protrusions attached as means for preventing the raw material 3 from adhering to the inner surfaces of the drum mixers 1 and 2 in the present invention. That is, the present inventors have sought to repeat the state in which the raw material 3 adheres to and peels from the inner surfaces of the drum mixers 1 and 2 by providing the protrusions. Hereinafter, such a state is referred to as “appropriate cell flying state”.

  As a result, as shown in FIGS. 5 and 6, the protrusions 17a to 17c having a height of about 100 mm may be attached to the inner surfaces of the drum mixers 1 and 2 so as to be formed at intervals of 300 mm to 550 mm in the circumferential direction. I understood that.

  The protrusions 17a to 17c are attached so that the time for which the raw material 3 rolls inside the drum mixers 1 and 2 is extended as much as possible. For example, at the raw material charging end 1a and the charging side end 2b of the primary and secondary mixers 1 and 2, the raw material 3 is sent to the inside by the rotation of the primary and secondary mixers 1 and 2, as shown in FIG. The protrusion 17a is inclined. Further, the intermediate body portions 1c and 2e are attached with protrusions 17c parallel to the length direction of the drum mixer, while the discharge side end 1b and the granulated product discharge end 2a have primary and secondary mixers 1 and 2 attached. A protrusion 17b that is inclined in a direction to push the raw material 3 back to the upstream side in the mixer by rotation is attached.

  At that time, it was also found that a resin-molded liner 17 using inexpensive waste plastic or the like can be used as a liner for forming the protrusions 17a to 17c.

  When such a resin-molded liner 17 is attached to the inner surfaces of the drum mixers 1 and 2, the lifting of the raw material 3 at the time of mixing and the sliding phenomenon of the raw material 3 at the time of granulation are reduced, and the mixing performance and granulation performance are improved. While improving both, the wear of the resin-molded liner 17 itself can be reduced by appropriate self-flying, and the drum mixer 1 is pushed back to the upstream side in the drum mixers 1 and 2 by the projection 17b on the discharge end side. , 2, the residence time of the raw material 3 becomes longer, and the mixing / granulation treatment time by rolling becomes longer, so that the effect of mixing / granulation is further improved.

  Needless to say, a resin-molded liner using a material such as waste plastic may be used as long as the “appropriate self-flying state” can be made with a conventional rubber-molded liner or steel material. Further, when the properties of the raw material 3 have such adhesiveness that the scraper 5 is unnecessary, a protrusion 17aa having a height of about 200 to 300 mm is formed on a part of the protrusions 17a to 17c of about 100 mm. It is also possible to attach the raw material back to the upstream side in 2 in a direction that does not push it back (see FIG. 6). 6B shows a development view of the resin-molded liner 17, and the raw material 3 on the inner surface of the drum mixers 1 and 2 is moved from the right to the left in the drawing by the inclination of the protrusions 17a, 17b, 17c, and 17aa. The direction of rotation of the drum mixers 1 and 2 is indicated by white arrows.

The results carried out to confirm the effects of the present invention will be described below.
The specifications of the connected drum mixer apparatus used for the implementation are as follows.

(Processing volume of connected drum mixer)
Raw material: 800ton / hr

(Upstream primary mixer)
Diameter: 4.3m
Fitting connection diameter: 4.1m
Length: 11.9m
Tilt angle: 1.8 degrees Rotation speed: 6-9rpm
Electric motor output: 560kW

(Secondary mixer on the downstream side)
Diameter: 5.1m
Length: 26.0m
Inclination angle: 1.8 degrees Rotation speed: 4.5 to 6.2 rpm
Electric motor output: 1120kW

FIG. 9 shows the result of calculating the rolling state of the raw material in the drum mixer. The horizontal axis in FIG. 9 is the Froude number proportional to the square of the diameter and rotation speed of the drum mixer, the vertical axis is (a) the figure is the raw material space factor determined by the equipment and the raw material throughput, and (b) is the stay It's time. The Froude number is a dimensionless number proportional to the square of the diameter D and the rotation speed N when the acceleration of gravity is g, and is a numerical value represented by Fr number (−) = D × N ² / g. It can express the state that the raw material slips, rolls and jumps in relation to the space factor.

  As an example, the raw material of 800 ton / hr was supplied to the drum mixer of the above specifications, and the rotation speed was changed to 6 rpm, 7.5 rpm, 9.5 rpm for the primary mixer, 4 rpm, 5 rpm, 6.2 rpm for the secondary mixer. The calculation result of the change of the rolling state in this case and the residence time in the drum mixer is shown.

  In FIG. 9A, the normal rolling region indicates the region where the raw material rolls cleanly, the slip region indicates the region where the raw material does not roll, and the jumping region indicates the region where the raw material jumps. Since each of these areas does not have a clear boundary, FIG. 9 (a) is a rough judgmental figure, and from FIG. The motion state can be estimated.

  As is clear from FIGS. 9 (a) and 9 (b), when both the primary mixer and the secondary mixer are rotated at a low speed (small Froude number), the raw material space factor increases and the residence time tends to increase. However, since the primary mixer is rather for mixing purposes, it is desirable that the primary mixer be as close as possible to the jump region rather than close to the slip region. On the other hand, since the primary purpose of the secondary mixer is granulation, it is desirable that the raw material space factor be as low as possible as close to the slip region as possible from the jump region. Therefore, what is necessary is just to change the rotation speed of a primary mixer and a secondary mixer according to the raw material state at that time.

  The present invention is not limited to the above example, and it goes without saying that the embodiments may be changed as appropriate within the scope of the technical idea described in each claim.

  For example, the scraper garter 6 may be provided with a water injection nozzle 19 or a high-pressure washing nozzle 20 as shown in FIG.

DESCRIPTION OF SYMBOLS 1 Primary mixer 1c Body part 2 Secondary mixer 2c Discharge port 3 Raw material 4 Fitting connection part 4a Gap 5 Scraper 6 Scraper garter 7b Intermediate support member 8 Gap shield member 10 Belt conveyor 11 Discharge chute 13a-13d Support roller 15a-15d Rotation Detector 16 Judgment control part 17 Resin molding liner 17a-17c, 17aa Protrusion

Claims (8)

Two drum mixers that mix and granulate the raw materials for sintering are directly fitted and connected, the raw materials are charged from the raw material input end of the primary mixer on the upstream side, and the granule discharge end of the secondary mixer on the downstream side A rotating cylindrical connected drum mixer device for discharging the sintering raw material mixed and granulated from the part,
A connecting drum mixer device for a sintering raw material, characterized in that the inner diameter of the upstream primary mixer is larger than the inner diameter of the fitting connection on the discharge side of the primary mixer. A scraper and a scraper garter are disposed through the two connected drum mixers,
2. The connected drum mixer apparatus for sintering raw materials according to claim 1, wherein an intermediate portion of the scraper garter is supported by an intermediate support member that is inserted and disposed through a gap between fitting connection portions of the two drum mixers.   The connecting drum for sintering raw materials according to claim 1 or 2, wherein a non-rotating annular or partial annular gap shielding member is inserted and arranged from the gap between the fitting connection portions of the two drum mixers. Mixer device.   The two drum mixers are arranged such that the center of the conveying direction of the belt conveyor discharged from the downstream secondary mixer and conveyed to the sintering machine is parallel to or near the longitudinal center of the two drum mixers. The connected drum mixer device for sintered raw materials according to any one of claims 1 to 3, wherein the connected drum mixer device is disposed below.   A chute or a belt conveyor is provided for guiding the raw material spilled from the fitting connection part of the two drum mixers and the raw material spilled from the raw material supply part to the upstream primary mixer to the belt conveyor, respectively. Item 5. A connected drum mixer device for a sintered material according to any one of Items 1 to 4.   The sintering raw material according to any one of claims 1 to 5, wherein a discharge port that can be discharged midway is provided at a charging side end of a downstream secondary mixer of the two drum mixers. Connected drum mixer device. Rotation detecting means for each supporting roller for rotating the two drum mixers;
When the rotation speed of the support roller detected by these rotation detection means is input, and based on the input rotation speed, it is determined whether the bearing of the support roller is damaged or defective, and if it is determined that the bearing is damaged or defective, The connected drum mixer device for sintered raw materials according to any one of claims 1 to 6, further comprising a determination control device for stopping the rotation of the drum mixer supported by the support roller.   A resin-molded or rubber-molded liner provided with protrusions at intervals to form a self-flying state in the circumferential direction is disposed on the raw material contact surface of the drum mixer. The connected drum mixer apparatus for sintering raw materials according to any one of 7.

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