JP5388962B2 - Dry classification method for workpieces - Google Patents

Description

  The present invention relates to a method for drying and classifying an object to be processed.

  In the production of coke, production using coal with low caking properties is frequently performed due to a shortage of high-quality caking coal (strong caking coal and weak caking coal) and price increase. Coal with low caking property is used after being dried. However, when the water content becomes 6.5% or less, coal fine particles of about 100 μm or less generate dust, which causes problems such as deterioration of the working environment. Further, when coal fine particles of about 300 μm or less are supplied to the coke oven, there is a problem that carbon adheres to the coke oven. In order to solve these problems, fine particles are classified and removed from coal by a classifier before or after drying.

  On the other hand, horizontal rotary dryers and fluidized bed dryers have conventionally been used to dry coal, but horizontal rotary dryers consume less power and have a lower equipment cost than fluidized bed dryers. This is advantageous.

  As a typical example of a conventional horizontal rotary dryer, a so-called steam tube dryer (STD) is known. In drying using a steam tube dryer, carrier gas is generally blown in order to improve drying efficiency (see, for example, Patent Document 1). As shown in FIG. 7, the steam tube dryer includes a rotating cylinder 110 that can rotate about its axis, and the rotating cylinder 110 is rotated and supplied (charged) from one end side of the rotating cylinder 110. The dried product is conveyed to the other end and discharged. In the course of this conveyance, the material to be dried is dried by heating steam as external heat for drying.

  More specifically, the rotating cylinder 110 has a length of, for example, 10 to 30 m, and is heated by supplying steam heated as a heat medium between both end plates inside the rotating cylinder 110. Many heating tubes 111 extend along the axial direction. When the material to be dried, such as wet powder or granular powder, is supplied to the inside of the rotating cylinder 110, it is heated and dried by contacting the heating tube 111, and moves toward the discharge port 112 as the rotating cylinder 110 rotates. It is moved sequentially.

  Also, a carrier gas blowing port 113 is provided at one end side of the rotating cylinder 110, and is provided in communication with the discharge port 112 on the other end side along with the evaporating gas generated inside the rotating cylinder 110. The carrier gas is discharged from the gas exhaust port 122.

  However, since this conventional horizontal rotary dryer does not have a classification function, when drying coal and further classifying and removing fine particles, it is necessary to install a classification device separately with the dryer, Equipment costs increase. Moreover, since these devices are designed only considering drying or classification, respectively, when drying and classification are performed using these devices, the drying and classification are simply performed in order. Sex is reduced.

JP 2004-44876 A

  The main problem to be solved by the present invention is to provide a method capable of efficiently drying and classifying a workpiece.

The present invention that has solved this problem is as follows.
[Invention of Claim 1]
A method for drying and classifying an object to be processed, wherein the object to be processed supplied from one end of a rotating cylinder rotatable around an axis is heated and dried in the process of discharging from the other end, and the dried object is classified. ,
The carrier gas blown from one end side of the rotating cylinder is discharged together with the object to be processed from the other end side,
In the classification space after the discharge, the fine particles in the object to be processed are guided upward together with the carrier gas, and the object to be processed excluding the fine particles is guided to the lower fixed discharge port, respectively.
The dispersed gas is blown up in the classification space,
The flow rate of the dispersion gas is less than the flow rate of the carrier gas blown from one end of the rotating cylinder,
The dispersion gas is blown up in the middle of the flow path of the object to be processed , which is below the rotating cylinder and descends toward the fixed discharge port.
A method for drying and classifying an object to be treated.

(Main effects)
When the carrier gas is discharged together with the object to be processed from the other end of the rotating cylinder, the particles with a relatively large diameter among the objects to be processed accompanying the carrier gas in the classification space after the discharge have an early rise in energy due to gravity. Therefore, it starts descending at that time, and is guided to the lower fixed discharge port in the classification space together with the object not to be accompanied by the carrier gas. On the other hand, particles having a relatively small diameter among the objects to be treated accompanying the carrier gas are guided upward in the classification space while being accompanied by the carrier gas. Accordingly, particles having a relatively small diameter (fine particles) can be classified and removed from the object to be treated after drying.

  When the dispersion gas is blown up in the classification space, the dispersion gas blows up the fine particles that have fallen with the object not to be accompanied by the carrier gas or the fine particles that have fallen due to insufficient ascending energy. Since it is guided upward, the classification accuracy is improved.

  If the flow rate of the dispersion gas is less than the flow rate of the carrier gas blown from one end of the rotating cylinder, the flow of the carrier gas in the rotating cylinder is not affected, and as a result, the drying of the object to be processed is not affected.

  When the dispersed gas is blown below the rotating cylinder, the blowing effect is reliably exerted on the fine particles that are discharged from the rotating cylinder and fall freely in a state of being wrapped in the object not to be accompanied by the carrier gas. .

  According to the present invention, it becomes a method which can dry and classify a processed material efficiently.

It is a front view of the horizontal type rotary dryer of this form. It is the enlarged view of the other end side of a rotation cylinder, and is the figure which abbreviate | omitted the classification hood. It is the XX sectional view taken on the line of FIG. It is an enlarged view of classification food. It is an enlarged view of the means for blowing up the dispersed gas. It is explanatory drawing of the blowing-up means of dispersion gas. It is a perspective view of the conventional steam tube dryer. It is a flowchart of the dry classification process of a 1st form. It is a flowchart of the drying classification process of a 2nd form.

Next, an embodiment of the present invention will be described.
FIG. 1 shows a horizontal rotary dryer used for the drying classification of this embodiment. This horizontal rotary dryer has a cylindrical rotary cylinder 10 and is installed such that the axis of the rotary cylinder 10 is slightly inclined with respect to a horizontal plane, and one end of the rotary cylinder 10 is located more than the other end. Located high. Below the rotating cylinder 10, two support units 20 and a motor unit 30 are installed so as to support the rotating cylinder 10, and the rotating cylinder 10 is rotated around its own axis by the motor unit 30. It is supposed to be free. As shown in FIG. 3, the rotary cylinder 10 rotates in one direction, in the illustrated example, in the counterclockwise direction (arrow R direction), and the rotation speed is, for example, less than 1 m / s in circumferential speed. It has become.

  A number of steam tubes 11, which are metal pipes inside the rotating cylinder 10 and are capable of circulating steam or the like as a heating medium, extend along the axial direction of the rotating cylinder 10. It is attached. For example, a plurality of the steam tubes 11 are arranged in the circumferential direction and the radial direction so as to form a concentric circle with respect to the axis of the rotating cylinder 10.

  As shown in FIG. 2, a plurality of discharge ports 50 are formed through the peripheral wall on the other end side of the rotating cylinder 10. The plurality of discharge ports 50 form two rows along the circumferential direction of the rotary cylinder 10 and are formed apart from each other. Moreover, although the several discharge port 50 is all made the same shape, it can also be made into a different shape.

  As shown in FIG. 3, a plurality of scraping plates 61 extending from the inner wall of the rotating cylinder 10 toward the axis of the rotating cylinder 10 are provided inside the rotating cylinder 10. As shown in FIG. 1, the plurality of scraping plates 61 are arranged so as to be separated from each other in the axial direction so as to form a plurality of rows, that is, three rows in the illustrated example. As shown in FIG. 3, each of the scraping plate rows 60 includes a plurality of, in the illustrated example, four scraping plates 61 that are spaced apart from each other at equal intervals.

  Each scraping plate 61 is formed of a thick metal, and has a hook shape in which a tip end portion is bent toward the front side in the rotation direction R of the rotary cylinder 10. The extension length of the scraping plate 61 is, for example, 1/10 to 3/10 of the inner diameter D of the rotary cylinder 10.

  Each scraping plate 61 extends from the vicinity of a straight line passing through the front end of the discharge port 50 located on the rear side in the rotation direction R of the rotating cylinder 10 and parallel to the axial direction of the rotating cylinder 10. It is arranged to put out. Therefore, the discharge port 50 does not exist in the immediate vicinity of the scraping plate 61, and the inner wall of the rotating cylinder 10 exists.

  As shown in FIG. 1, the scraping plate row 60 is disposed between the discharge port 50 and a supply port 41 described later in the rotary cylinder 10, and is the other end in the rotary cylinder 10 than the discharge port 50. Does not exist on the side. Further, the scraping plate row 60 is disposed in a portion near the discharge port 50 between the discharge port 50 and the supply port 41.

  As shown in FIG. 1, the agitation means for agitating the workpiece W supplied (charged) into the rotary cylinder 10 on one end side of the rotary cylinder 10 relative to the scraping plate row 60 inside the rotary cylinder 10. 65 is installed. The stirring means 65 is also separated from the scraping plate row 60 arranged on the most end side inside the rotary cylinder 10. As this stirring means 65, a well-known stud type, a reverse blade, etc. can be used, for example. Among these, it is preferable to select the reverse blade because of the effect of fine particle separation (dispersion) and the STD structure limitation.

  As shown in FIGS. 1 and 4, the rotary cylinder 10 is provided with a classification hood 55 capable of discharging the workpiece W and the carrier gas A so as to cover the other end side having the plurality of discharge ports 50. . The classification hood 55 is formed of a thick metal, and as shown in FIG. 3, a dried and classified workpiece W, that is, a fixed discharge port 57 for the processed product E is provided on the bottom surface of the lower portion 55d. The fixed exhaust port 56 for the carrier gas A is provided on the top surface of the upper portion 55u. Further, the classification hood 55 is narrower as the upper portion 55u is directed to the fixed exhaust port 56 in the width direction orthogonal to the axial direction, and similarly, the lower portion 55d is also narrower as it is directed to the fixed discharge port 57 in the width direction. It has become. The fixed exhaust port 56 and the fixed exhaust port 57 are located substantially at the center of the classification hood 55 in plan view.

  The inside of the classification hood 55 is a classification space filled with air, and in particular, the inside of the classification hood 55 above the rotary cylinder 10 (range indicated by the symbol L) is a settling area 90. That is, the classification hood 55 is provided so that the sedimentation zone 90 is formed above the rotary cylinder 10. Further, the classification hood 55 is fixed to the ground by means not shown, and is not rotated with the rotation of the rotary cylinder 10.

  The fixed exhaust port 56 is opened in the vertical direction, and is connected to the dust collecting means 201 as shown in FIGS. From the fixed exhaust port 56, when the carrier gas A is exhausted along with the evaporating gas, the fine particles C are discharged. The fixed discharge port 57 is also opened in the vertical direction, and is connected to a conveying means 204 such as a belt conveyor. From the fixed discharge port 57, the fine particles C are classified and removed, and the processed product E is discharged.

  The distance L between the upper edge of the rotating cylinder 10 and the fixed exhaust port 56 is preferably L> 0.3D with respect to the inner diameter D of the rotating cylinder 10, and 0.8D <L <4.0D. It is more preferable that 1.0D <L <2.5D. When the separation distance L is 0.3D or less, the classification function cannot be sufficiently exhibited, and the relatively large diameter particles F are also discharged through the fixed exhaust port 56 together with the carrier gas A, and the classification accuracy is reduced. There is a risk of increasing the load on the dust means 201. On the other hand, if the separation distance L is 4.0 D or more, a space greater than the separation distance necessary for classification is provided, which is not economical.

  Moreover, in the sedimentation zone 90, as shown in FIG. 4, the classification hood 55 has spread in the axial direction. When the classification hood 55 spreads in the axial direction in the sedimentation zone 90, the probability that the fine particles C collide with other particles F or the like or the classification hood 55 (particularly the wall materials 55A and 55B at both ends in the axial direction of the classification hood 55) decreases. Therefore, the classification accuracy is improved. Note that spreading in the axial direction means spreading compared to the connection portion with the rotating cylinder 10.

  The subsidence zone 90 does not need to extend in the axial direction over the entire length in the vertical direction. In the vicinity of the rotating cylinder 10, the particulates C and the like are immediately after being discharged from the rotating cylinder 10 through the discharge port 50, and since they do not spread in a plane, they can not be expanded in the axial direction as in the illustrated example. Further, the upper portion 55u of the classification hood 55 is preferably narrower toward the fixed exhaust port 56 in the axial direction as shown in the illustrated example.

  The extent of spreading of the classification hood 55 is preferably 1.5Z1 <Z2 <6Z1, where Z1 is the axial length of the connecting portion with the rotary cylinder 10 and Z2 is the axial length of the spreading portion, and 2Z1 < More preferably, Z2 <4Z1.

  In the settling zone 90, as shown in FIGS. 3 and 4, a plurality of support members (62, 63) are provided between one wall member 55A in the axial direction of the classification hood 55 and the other wall member 55B in the axial direction. Is provided. If the classification hood 55 spreads in the axial direction, the strength may decrease, but a plurality of support members (62, 63) are provided between one axial wall material 55A and the other axial wall material 55B. By providing, the strength of the classification hood 55 is maintained. The support members (62, 63) can also be provided between the one wall member 55A and the other wall member 55B of the portion that does not spread in the axial direction of the classification hood 55 as in the illustrated example.

  The support material for maintaining the strength of the classification hood 55 can be composed of only a straight bar, a pipe, or the like, but in this embodiment, the support is arranged on the pipe 62 and the pipe 62. It is comprised with the umbrella material 63. FIG. The umbrella material 63 has an umbrella shape with the center in the width direction protruding upward, and is arranged so as to extend along the extending direction of the pipe material 62. The presence of the umbrella material 63 prevents the workpiece W from being deposited on the pipe material 62. The umbrella material 63 itself may or may not have a function for maintaining the strength of the classification hood 55.

  As described above, the upper portion 55u of the classification hood 55 is narrower toward the fixed exhaust port 56 in the width direction. In this case, below the fixed exhaust port 56, as shown in FIG. It is preferable that the support material (62, 63) is not located. If the upper portion 55u of the classification hood 55 becomes narrower toward the fixed exhaust port 56 with respect to the width direction, as shown in FIG. 3, a flow S1 along the narrow wall material is generated, and this flow S1 Fine particles C will be on board. Therefore, the rising fine particles C do not collide with the top surface of the classification hood 55 and descend, and the classification accuracy is improved. In the classification hood 55, a flow S1 along the wall material is generated, and a flow S2 that rises vertically in the center is mainly generated, and the fine particles C are also carried on the flow S2. Therefore, if a plurality of support members (62, 63) are not positioned below the fixed exhaust port 56, the fine particles C riding on the flow S2 rising vertically in the center collide with the support members (62, 63) and descend. The classification accuracy is further improved.

  As shown in FIG. 3, inside the classification hood 55, on the flow path of the workpiece W from the discharge port 50 of the rotary cylinder 10 to the fixed discharge port 57 by free fall or the like, that is, below the rotary cylinder 10. Dispersing gas N blowing means 58 is provided. Thus, when the dispersion gas N is blown up inside the classification hood 55 (classification space), the fine particles C that have fallen with the workpiece W not accompanied by the carrier gas A and the rising energy are insufficient. Since the descending fine particles C are blown up by the dispersion gas N, the classification accuracy is improved. Further, when the dispersion gas N is blown up on the flow path of the workpiece W reaching the fixed discharge port 57, the dispersion gas N is discharged from the rotary cylinder 10 in a state of being wrapped in the workpiece W not accompanying the carrier gas A. Therefore, the workpiece W that reliably blows up the free-falling fine particles C and that does not blow up is discharged as it is from the fixed discharge port 57 on the bottom surface of the classification hood 55 to the outside as the processed product E. For this reason, it is not necessary to consider the workpiece W that does not blow up to the fixed discharge port 57.

  As described above, in the present embodiment, not only the classification region 90 but also the entire classification space (inside the classification hood 55), the fine particles C in the workpiece W together with the carrier gas A are disposed upward. The workpieces W to be removed are respectively guided downward.

  The specific form of the blowing means 58 for the dispersed gas N is not particularly limited. For example, the dispersing gas N can be constituted by a dispersing plate made of a mesh material and the like, and a means for blowing the dispersed gas N through the mesh material. If the blowing means 58 is not provided on the flow path of the workpiece W reaching the fixed discharge port 57, it is conceivable that the dispersion plate is inclined toward the fixed discharge port 57 as the above consideration. Even if it is tilted, the workpiece W that does not blow up accumulates on the dispersion plate, and it is necessary to consider in order to guide the workpiece W to the fixed discharge port 57 separately.

  On the other hand, in the present embodiment, as the blowing means 58 for the dispersed gas N, as shown in FIGS. 5 and 6, a hole 58Ac is formed in the peripheral wall across the flow path of the workpiece W reaching the fixed outlet 57. The pipe material 58A is provided, and the dispersion gas N is blown up from the hole 58Ac formed in the pipe material 58A. In this way, when the dispersion gas N blowing means 58 is composed of the pipe material 58 </ b> A crossing the flow path of the workpiece W reaching the fixed discharge port 57, the fixed discharge port 57 allows the workpiece W not to blow up. Consideration to lead to Further, when the dispersion gas N is blown up from the hole 58Ac formed in the peripheral wall of the pipe member 58A, the blowing effect is reliably exerted on the fine particles C.

  In this embodiment, the holes 58Ac formed in the peripheral wall of the pipe material 58A are formed in a circular shape, and a plurality of holes are formed at appropriate intervals in the extending direction of the pipe material 58A. Further, as shown in FIG. 6A, the hole 58Ac is formed so that the dispersed gas N blows up obliquely upward.

  It is preferable that a plurality of pipe members 58A are arranged in parallel in the axial direction in the vicinity of the fixed discharge port 57 as shown in the illustrated example. In this embodiment, the dispersion gas N is blown to the workpiece W to be lowered between the pipe materials 58A adjacent to each other, and the fine particles C are blown up by the dispersion gas N, while the workpiece W not blown up is The space between the pipe members 58A is lowered as it is, and discharged from the fixed discharge port 57 to the outside as the processed material E. The fine particles C blown up to the dispersion gas N soar in the classification hood 55, and then soar to the carrier gas A and are discharged to the outside from the fixed exhaust port 56.

  The pipe material group composed of the plurality of pipe materials 58A can be provided in a plurality of stages separated in the vertical direction. Further, the amount of the dispersion gas N blown up from each hole 58Ac can be changed according to the amount of the workpiece W that descends. Further, as in the present embodiment, the umbrella material 58B can be disposed on each pipe material 58A. The umbrella material 58B has an umbrella shape with the center in the width direction protruding upward, and extends along the extending direction of the pipe material 58A. The presence of the umbrella material 58B more reliably prevents the workpiece W from being deposited on the pipe material 58A.

  As the dispersion gas N, for example, in addition to air, an inert gas such as nitrogen gas or argon gas can be used, and may be selected depending on the characteristics of the workpiece W. However, it is preferable to use an inert gas when the workpiece W is ignitable, such as coal, or when a dust explosion occurs.

  In this embodiment, as shown in FIG. 8, an inert gas N2 such as nitrogen is mixed in the air N1, and this mixed gas is heated and dispersed in the heat exchanger 205 using a heat medium S such as steam. Gas N.

  The mixing ratio of the inert gas N2 to the air N1 is not particularly limited, but when the workpiece W is ignitable such as coal, or when it causes a dust explosion, It is preferable to mix the gas exhausted from the fixed exhaust port 56 so that the oxygen concentration of the gas is 13% or less, preferably 12% or less. The reason for keeping the oxygen concentration low in this way is to avoid the explosion of fine particles C such as coal. The carrier gas A contains water vapor evaporated as the workpiece W is dried, so that the oxygen concentration is low and the possibility that the fine particles C will explode is low. That is, this explosion is a problem that becomes noticeable when the dispersion gas N is blown.

  However, when the mixing ratio of the inert gas N2 is increased, the cost increases. On the other hand, the dispersion gas N is exhausted from the fixed exhaust port 56 together with the carrier gas A and the like, and then the conveying means 202 such as a belt conveyor is connected. Fine particles C are removed by the dust collecting means 201 and are only exhausted from the chimney 203.

  Therefore, as shown in FIG. 9, the gas exhausted from the fixed exhaust port 56 is preferably reused as the dispersed gas N after the fine particles C are removed by the dust collecting means 201. Since the carrier gas A (including the dispersion gas N) discharged from the inside (classification space) of the classification hood 55 has a low oxygen concentration and is heated, the carrier gas A after removing the fine particles C is It can be suitably used as the dispersion gas N. Of course, the carrier gas A can be appropriately heated using the heat exchanger 205.

  Although all of the carrier gas A exhausted from the fixed exhaust port 56 can be used as the dispersed gas N, only a part is used as shown in the figure, and the remainder is exhausted from the chimney 203 to the atmosphere. You can also. However, the flow rate of the dispersion gas N is preferably smaller than the flow rate of the carrier gas A blown from one end of the rotating cylinder 10, and more preferably 1/5 to 1/2 of the flow rate of the carrier gas A. As described above, when the flow rate of the dispersion gas N is smaller than the flow rate of the carrier gas A blown from one end of the rotating cylinder 10, the flow of the carrier gas A in the rotating cylinder 10 is not affected. It does not affect the drying of the product.

  Here, when the workpiece W is ignitable, such as coal, or when dust explosion occurs, the oxygen concentration of the gas exhausted from the fixed exhaust port 56 is 13% or less ( It is desirable that it is preferably 12% or less. Therefore, although not shown in the figure, the oxygen concentration of the gas exhausted from the fixed exhaust port 56 is measured (monitored) with an oximeter, and when this measured value exceeds a specified value, the measured value is not more than a predetermined value. It is preferable to mix the inert gas into the dispersion gas N so as to be.

  On the other hand, as shown in FIG. 1, a supply pipe 70 and a drain pipe 71 that supply steam into the steam tube 11 are provided on the other end side of the rotary cylinder 10. In addition, a screw feeder 42 having a screw inside and having a cylindrical shape is installed on one end side of the rotary cylinder 10 so as to be fitted into the rotary cylinder 10. One end of the screw feeder 42 is provided with a driving means 43 such as a motor for rotating a screw provided inside the screw feeder 42. Further, a supply port 41 is opened above the screw feeder 42, and the supply port 41 communicates with the inside of the screw feeder 42.

  The workpiece W to be dried by the horizontal rotary dryer according to the present embodiment is supplied into the screw feeder 42 from the supply port 41, and the screw installed in the screw feeder 42 is rotated by the driving means 43. By this, it is supplied to the inside of the rotary cylinder 10. Further, in the vicinity of the screw feeder 42, there is provided a gas blowing means (not shown) for blowing air, inert gas or the like as the carrier gas A into the rotary cylinder 10 from the supply port 41 which is also a gas blowing port. The carrier gas A blown by this gas blowing means flows through the inside of the rotating cylinder 10 toward the other end side of the rotating cylinder 10.

Next, the operation of the horizontal rotary dryer will be described.
In drying the workpiece W with the horizontal rotary dryer, the workpiece W is supplied to the supply port 41 as shown in FIG. The workpiece W supplied from the supply port 41 is supplied to the inside of the rotary cylinder 10 by the screw feeder 42 and moves to the other end side of the rotary cylinder 10 while being dried by contact with the steam tube 11 heated by the steam. (Drying process).

  When the workpiece W reaches the position where the stirring means 65 exists, the workpiece W is stirred by the stirring means 65, and then, as shown in FIG. It is scraped up. When the scraped plate 61 is positioned on the upper side of the rotating cylinder 10, the workpiece W thus picked up naturally falls, and at that time, the fine particles C contained in the workpiece W are dispersed in the rotating cylinder 10 ( So-called flight action).

  On the other hand, the carrier gas A blown from the supply port 41 by the blowing means provided on one end side of the rotating cylinder 10 passes through the rotating cylinder 10 and is a discharge port 50 that is also a discharge port for the workpiece W. To the outside of the rotary cylinder 10. At this time, the carrier gas A is exhausted from the discharge port 50 along with the fine particles C dispersed in the rotary cylinder 10 by the scraping plate 61. The carrier gas A exhausted from the exhaust port 50 is exhausted from the inside of the classification hood 55 (classification space) through the fixed exhaust port 56 together with the fine particles C. Further, the dispersion gas N is supplied so as to be blown up above the classification hood 55 by the dispersion gas N blowing means 58. The flow rate of the dispersion gas N is usually smaller than the flow rate of the carrier gas A. The carrier gas A has a flow velocity of, for example, 5 to 10 m / s when exhausted from the discharge port 50. This flow rate is appropriately adjusted according to the area of the discharge port 50 and the amount of carrier gas A blown.

  Of the workpiece W, particles having a large particle diameter and a heavy weight fall in the rotary cylinder 10 and fall naturally from the discharge port 50 located on the lower side without accompanying the carrier gas A. The particles that have fallen naturally (the object to be processed W) are not blown up by the dispersed gas N, pass through between the pipe members 58A, and are discharged to the outside as the processed object E from the fixed discharge port 57. Of the workpiece W, the relatively large particles F are discharged from the discharge port 50 along with the carrier gas A, but are heavy and reach the fixed exhaust port 56 along with the carrier gas A. Instead, it falls downward and is discharged as the processed object E from the fixed discharge port 57 together with the processed object W having a large particle diameter.

Next, the function and effect of the horizontal rotary dryer will be described.
When the scraper plate 61 is provided inside the rotary cylinder 10 as in the horizontal rotary dryer of this embodiment, the fine particles C contained in the workpiece W are dispersed in the space inside the rotary cylinder 10, The fine particles C can be put on the carrier gas A and discharged together with the carrier gas A from the fixed exhaust port 56. As a result, the fine particles C contained in the workpiece W can be classified and removed.

  Further, each scraping plate 61 passes through the front end portion of the discharge port 50 located on the rear side with respect to the rotation direction R of the rotary cylinder 10 and is a straight line that is parallel to the axial direction of the rotary cylinder 10. If it arrange | positions so that it may extend from the vicinity, the to-be-processed object W mounted on the raising board 61 will be located in the back side of the discharge port 50. FIG. Therefore, the workpiece W on the scraping plate 61 is prevented from directly entering the discharge port 50, and the probability that the workpiece W in a state where the fine particles C are mixed is discharged from the discharge port 50 is reduced. .

  When the plurality of scraping plate rows 60 are intermittently positioned in the axial direction of the rotating cylinder 10, the workpiece W moving inside the rotating cylinder 10 does not exist with the portion where the scraping plate 61 exists. Pass through the parts alternately. Therefore, the workpiece W is scraped up in a plurality of times, and the scraping efficiency is improved.

  Further, if the scraping plate 61 is intermittently positioned so as to be spaced apart from each other at equal intervals in the circumferential direction of the rotary cylinder 10, the workpiece W can be efficiently scraped up. Specifically, a scraping plate row 60 that is a row of scraping plates 61 that extends from the inner wall of the rotating barrel 10 toward the axial center and scrapes the workpiece W along with the rotation of the rotating barrel 10 is arranged in the circumferential direction. When a plurality are provided at intervals, the carrier gas A passes through the workpiece W falling from the scraping plate 61, so that many fine particles C can be accompanied by the carrier gas A, and the classification accuracy is improved. In addition, the scraping plate row 60 increases the contact efficiency between the workpiece W and the steam tube 11, and has a secondary advantage of increasing the drying efficiency.

  In this embodiment, the scraping plate 61 of the scraping plate row 60 on at least the other end side (downstream side) of the scraping plate row 60 has a front side edge of the discharge port 50 with reference to the rotation direction R of the rotary cylinder 10. The proximal end of the scraping plate 61 is in a position close to, and is in a positional relationship extending from the inner wall of the rotating cylinder 10 toward the axis. Therefore, a large number of workpieces W can be held and scraped up with the next discharge port 50 on the front side in the rotation direction of the rotary cylinder 10. As a result, compared to the kiln action, the workpiece W is more finely agitated and the classification effect of the workpiece W can be enhanced.

  Furthermore, in the present embodiment, the scraping plate 61 extends from the base end toward the axis of the rotating cylinder 10 and the extending distal end portion is bent forward with respect to the rotation direction R of the rotating cylinder 10. Has been. Therefore, more workpieces W can be held and scraped up with the next discharge port 50 ahead of the rotating cylinder 10 in the rotational direction. As a result, the classification effect of the workpiece W can be further enhanced.

  When the stirring means 65 for stirring the workpiece W supplied into the rotary cylinder 10 is installed on the one end side of the rotary cylinder 10 with respect to the scraping plate row 60, the workpiece W is moved by the scraper board 61. Since the workpiece W is agitated prior to scraping up, the fine particles C contained in the workpiece W are washed out. As a result, the dispersion efficiency of the fine particles C by the scraping plate 61 is improved. In addition, although the above stirring means 65 and the raking board 61 can be omitted, if they are provided, the classification efficiency and the like are improved, and the apparatus is more preferable.

  A discharge port 50 that moves in the circumferential direction along with the rotation of the rotary tube 10 provided on the peripheral wall of the rotary tube 10, and a fixed portion that is provided below the classification hood 55 that is installed so as to cover the discharge port 50. When the fixed exhaust port 57 that does not move and the fixed exhaust port 56 provided on the upper portion of the classification hood 55 are combined, the carrier gas A and dispersion are distributed in the entire classification space including the classification area 90. Classification with gas N is performed. That is, the fine particles C are guided upward along with the carrier gas A and then discharged from the fixed exhaust port 56, and the other particles are guided downward and discharged from the fixed exhaust port 57 to be classified. Realized.

  When the inside of the classification hood 55 above the rotary cylinder 10 is a sedimentation zone 90 that is a space filled with air, the relatively large diameter particles F accompanying the carrier gas A are caused by inertia in the sedimentation zone 90. It falls and is discharged from the fixed discharge port 57.

  When the spraying means 58 for the dispersion gas N is provided on the flow path of the workpiece W below the fixed discharge port 57, the fine particles C falling along with other workpieces W are fixed to the fixed discharge port 57. It can be raised toward the exhaust port 56, and as a result, the classification and removal efficiency of the fine particles C is improved.

  In this embodiment, the number of the scraping plates 61 per each scraping plate row 60 is not particularly limited as long as it is four, but may be 4 to 6 in order to secure the scraping capacity. preferable. Further, the number of the discharge ports 50 per line is not particularly limited, but is preferably 10 to 17 in consideration of reduction of pressure loss, dispersion of fine particles C, mechanical strength of the rotating cylinder 10 and the like.

  The present invention is applicable as a method for drying and classifying an object to be treated such as coal.

  DESCRIPTION OF SYMBOLS 10 ... Rotating cylinder, 11 ... Steam tube (heating means), 41 ... Supply port, 50 ... Discharge port, 55 ... Classification hood, 56 ... Fixed exhaust port, 57 ... Fixed discharge port, 58 ... Blow-up means, 61 ... Scratch Upper plate, 65 ... stirring means, A ... carrier gas, E ... processed material, N ... dispersed gas, N1 ... air, N2 ... inert gas, W ... processed material.

Claims (1)

A method for drying and classifying an object to be processed, wherein the object to be processed supplied from one end of a rotating cylinder rotatable around an axis is heated and dried in the process of discharging from the other end, and the dried object is classified. ,
The carrier gas blown from one end side of the rotating cylinder is discharged together with the object to be processed from the other end side,
In the classification space after the discharge, the fine particles in the object to be processed are guided upward together with the carrier gas, and the object to be processed excluding the fine particles is guided to the lower fixed discharge port, respectively.
The dispersed gas is blown up in the classification space,
The flow rate of the dispersion gas is less than the flow rate of the carrier gas blown from one end of the rotating cylinder,
The dispersion gas is blown up in the middle of the flow path of the object to be processed , which is below the rotating cylinder and descends toward the fixed discharge port.
A method for drying and classifying an object to be treated.

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