JP2006061761A - Spray-drying apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spray-drying apparatus giving granules with less variation of particle sizes and being capable of preventing contamination of impurities effectively. <P>SOLUTION: The apparatus has a slurry-discharging section 5a for discharge of slurry, holding sections 6 and 7a holding the discharging section 5a and a rotating disk 3 spraying slurry discharged from the discharging section 5a radially. The disk 3 has an upper plate 33. In the holding sections 6 and 7a, a taper 8 is formed at least in a part of the overlapped portion of the plate 33 and the holding sections 6 and 7a so that the clearance between the plate 33 and the holding sections 6 and 7a becomes wider toward the outer periphery when seeing from the rotation axis 4 of the disk 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a spray drying apparatus for spraying and drying a slurry, and more particularly to a spray drying apparatus capable of effectively preventing impurities from being mixed with a small variation in the particle size of the granules obtained.

  The spray drying apparatus is an apparatus for spraying a slurry composed of raw material powder, a solvent, a binder, and the like by a spraying unit such as a nozzle or a rotating disk and drying it instantaneously with hot air. Such a spray drying apparatus is conventionally used for obtaining granules in pharmaceuticals, fine ceramics and the like.

  As the spray unit of the spray drying apparatus, a pressure nozzle, a rotating disk or the like is mainly used. When a rotating disk is used as the spraying part, finer granules can be obtained as compared with the case where a pressure nozzle is used. Therefore, a rotating disk is preferably used as the spraying part.

  The rotating disk generally has a disk shape, and includes a lower plate supported by a rotating shaft, a dispersion pin for spraying droplets, and an upper plate formed on the dispersion pin. Further, a slurry discharge part for discharging slurry onto the rotary disk and a holding part for holding the slurry discharge part are formed above the rotary disk (for example, Patent Document 1).

  However, in the spray drying apparatus having a rotating disk as described in Patent Document 1, when spray drying is continuously performed, the upper plate of the rotating disk and the slurry discharge unit are affected by the splash of the slurry and the effect of hot hot air. Adhesion (scaling) of the raw material occurs in the gap between the holding portion and the holding portion. When the raw material adheres to the gap between the upper plate and the holding portion, and this deposit accumulates, the deposit that has become a certain size due to deposition falls off and mixes into the product. A product with a uniform particle size cannot be obtained.

  Furthermore, due to the accumulation of deposits, friction due to the deposits occurs between the upper plate of the rotating disk that rotates at a high speed and the holding unit, and the friction causes wear of the upper plate or the holding unit. There is also a problem that the product is mixed as an impurity in the product and adversely affects the product.

Japanese Patent Laid-Open No. 10-118536

  The present invention has been made in view of such circumstances, and prevents the raw material from adhering to the gap between the upper plate of the rotating disk and the holding portion that holds the slurry discharge portion, and reduces the variation in the particle size of the obtained granules. In addition, the present invention relates to a spray drying apparatus that can effectively prevent contamination of impurities.

In order to achieve the above object, a spray drying apparatus according to the present invention comprises:
A spray drying apparatus having a slurry discharge unit for discharging slurry, a holding unit for holding the slurry discharge unit, and a rotating disk for spraying the slurry discharged from the discharge unit radially,
An upper plate is formed on the rotating disk,
The holding portion has a taper such that a gap between the upper plate and the upper plate becomes wider toward an outer periphery in at least a part of a portion where the upper plate and the holding portion overlap when viewed from the rotation axis direction of the rotating disk. Is formed.

  In the present invention, a taper is formed in at least a part of a portion of the holding portion where the upper plate and the holding portion overlap so that a gap with the upper plate becomes wider toward the outer periphery. Thereby, since the clearance gap between the upper plate of the said rotation disc and the said holding | maintenance part can be expanded, adhesion of the raw material to the said clearance gap can be prevented effectively. Therefore, according to the present invention, it is possible to prevent the raw material from adhering to the gap between the upper plate and the holding portion, which causes variations in the particle size of the product that causes the deposit to fall off, and wear due to the deposit. It is possible to effectively prevent the contamination of impurities.

  Preferably, the taper of the holding portion is formed over the entire portion where the upper plate and the holding portion overlap each other when viewed from the rotation axis direction of the rotating disk.

  By forming the taper of the holding part over the entire part where the upper plate and the holding part overlap, in particular, the part where the adhesion of the raw material is remarkably generated, the adhesion of the raw material can be prevented more effectively. And the effects of the present invention can be enhanced.

Alternatively, the spray drying apparatus according to the present invention is
A spray drying apparatus having a slurry discharge unit for discharging slurry, a holding unit for holding the slurry discharge unit, and a rotating disk for spraying the slurry discharged from the discharge unit radially,
An upper plate is formed on the rotating disk,
A taper is formed on the upper surface of the inner peripheral side end portion of the upper plate so that the gap becomes wider toward the inner periphery.

  Preferably, the taper of the upper surface of the inner peripheral side end portion of the upper plate is formed in at least a part of a portion where the upper plate and the holding portion overlap each other when viewed from the rotation axis direction of the rotating disk.

  Preferably, the taper of the upper surface of the inner peripheral end portion of the upper plate is formed over the entire portion where the upper plate and the holding portion overlap each other when viewed from the rotation axis direction of the rotating disk.

  In the present invention, the gap between the upper plate of the rotating disk and the holding portion can be widened by forming a taper on the upper surface of the inner peripheral side end portion of the upper plate so that the gap becomes wider toward the inner periphery. Since it can do, adhesion of the raw material to the said clearance gap can be prevented effectively. In addition, the taper of the upper plate is preferably formed on at least a part of the overlapping portion of the upper plate and the holding portion, so that the adhesion of the raw material can be more effectively prevented. The effect of the invention can be enhanced. In particular, it is preferable to form the taper of the upper plate over the entire portion where the upper plate and the holding portion overlap.

In the present invention,
The holding portion has a taper such that a gap between the upper plate and the upper plate becomes wider toward an outer periphery in at least a part of a portion where the upper plate and the holding portion overlap when viewed from the rotation axis direction of the rotating disk. Forming, and
A taper that widens the gap toward the inner periphery may be formed on the upper surface of the inner peripheral side end portion of the upper plate.

  By providing both the holding portion and the upper plate with a taper, the gap between the upper plate and the holding portion can be made wider, and the operational effects of the present invention can be further enhanced. In addition, also when providing a taper in both the said holding | maintenance part and the said upper board, these taper can be set as the structure similar to the taper mentioned above.

  Preferably, the upper plate is formed with a slit or a through hole in at least a part of a portion where the upper plate and the holding portion overlap each other when viewed from the rotation axis direction of the rotary disk.

  By forming a plurality of slits or through holes in at least a portion of the portion where the upper plate and the holding portion overlap, in the portion where the slits or through holes are formed, the upper plate and the holding portion The gap between them can be eliminated. And since the clearance gap between the said upper plate and the said holding | maintenance part is lose | eliminated in the part in which the said slit or the through-hole was formed, adhesion of a raw material can be prevented effectively.

  It is preferable that the slits are formed radially from the inner side (inner diameter side) to the outer side (outer diameter side) of the upper plate of the rotary disk. The effect can be enhanced. The through holes are preferably arranged concentrically on the upper plate. By arranging the through holes concentrically in this way, the rotation of the rotating disk can be stabilized.

  In the present invention, it is preferable that the holding portion is provided with a gas discharge mechanism for discharging gas. By providing a gas discharge mechanism in the holding part and discharging gas, it becomes possible to prevent the adhesion of the raw material to the gap between the upper plate of the rotating disk and the holding part and to remove the adhering matter.

  The method for drying a powder according to the present invention is characterized in that the slurry containing the raw material powder is spray-dried and granulated using any one of the above-described spray-drying apparatuses. According to the drying method of the present invention, since the spray drying apparatus of the present invention is used, a powder having a good particle size distribution and containing very little impurities can be obtained.

  According to the present invention, since the taper is formed on the holding plate or the upper plate of the rotating disk, it is possible to effectively prevent the raw material from adhering to the gap between the upper plate of the rotating disk and the holding portion. It is possible to effectively prevent the variation in the particle size of the product caused by the contamination and the mixing of impurities caused by the abrasion due to the deposits.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
FIG. 1 is an overall configuration diagram of a spray drying apparatus according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of an essential part of a spraying part of a spray drying apparatus according to an embodiment of the present invention,
FIG. 3 is an enlarged cross-sectional view of a spray portion of a spray drying apparatus according to an embodiment of the present invention,
4 to 10 are cross-sectional views of main parts of a spray unit of a spray drying apparatus according to another embodiment of the present invention,
FIG. 11 is a cross-sectional view of an essential part of a spraying part of a conventional spray drying apparatus.

First Embodiment As shown in FIG. 1, a spray-drying system according to an embodiment of the present invention includes a spray-drying device 1 that is a drying means, and a slurry that supplies slurry to the spray-drying device 1 via a slurry pump 11. It has a supply means, a hot air supply means for supplying hot air for drying via the blower 12, and an exhaust means (a cyclone 14, a bag filter 15, and a blower 16 for a recovery machine).

  In the spray drying system of the present embodiment, a slurry composed of raw material powder, a solvent, a binder, and the like is supplied from the slurry supply unit to the spray drying device 1 via the slurry pump 11, and hot air supply unit via the blower 12. The raw material is dried in the spray-drying apparatus 1 by the hot air for drying sent from to obtain granular raw material grains.

  The spray drying apparatus 1 includes a cylindrical drying cylinder 10 and a spray unit 2 located at the upper center of the drying cylinder 10. Slurry is supplied to the spray unit 2 from the slurry supply unit via the slurry pump 11, and the supplied slurry is radially directed toward the inner wall of the drying cylinder 10 by the spray unit 2. Sprayed. Then, the slurry sprayed by the spraying unit 2 is dried by hot air for drying sent from the hot air supply means via the blower 12, becomes granules, and is taken out from the dry material discharge port 13.

  As shown in FIG. 2, the spray unit 2 includes a rotating disk 3, a slurry hose (part of slurry supply means) 5, a rotating shaft 4, and a slurry hose 5 that are rotatably arranged via a rotating shaft 4. And a distributor 6 for holding. Further, the distributor 6 is fixed from the outer peripheral side by a lower end portion 7-1 of the casing 7. The distributor 6 and the lower end portion 7-1 of the casing 7 constitute the “holding portion” of the present invention.

  The slurry hose 5 has a discharge part 5a for discharging the slurry supplied from the slurry supply means. The slurry supplied from the slurry supply means is dropped to the vicinity of the rotary shaft 4 on the rotary disk 3 through the discharge unit 5a. In the present embodiment, as shown in FIG. 2, two slurry hoses 5 are arranged at 180 ° symmetrical positions around the rotation shaft 4, but the number and arrangement positions of the slurry hoses 5 are not particularly limited. When two or more slurry hoses 5 are arranged, it is preferable to arrange them at equal intervals in the circumferential direction of the rotating disk 3 so that the slurry dripping is constant. Moreover, the material which comprises the slurry hose 5 is not specifically limited, For example, nylon etc. can be used.

  The rotating disk 3 has a disk shape and has a lower plate 31 supported by the rotating shaft 4. A plurality of dispersion pins 32 are arranged on the outer peripheral side upper surface of the lower plate 31 in the circumferential direction of the rotating disk 3. is there. Further, an upper plate 33 is fixed on the dispersion pin 32. The rotating disk 3 is rotatable by a rotating shaft 4, preferably at a rotation speed of 3000 to 8000 rpm, and slurry discharged from the discharge unit 5a can be sprayed radially by centrifugal force due to rotation.

  The concrete spraying method of the slurry by the spraying part 2 in this embodiment is shown next. First, the slurry is dropped in the form of droplets from the discharge unit 5a onto the surface of the lower plate 31 of the rotating disk 3. Next, the slurry droplets move to the outer peripheral side on the lower plate 31 by the centrifugal force generated by the rotation of the rotating disk 3, and adhere to the lower peripheral surface of the dispersion pin 32. Then, the slurry droplets adhering to the dispersion pin 32 rise on the surface of the dispersion pin 32 by centrifugal force, and are sprayed away from the dispersion pin 32 in the vicinity of the upper end of the dispersion pin 32.

  In the present embodiment, the upper plate 33 formed above the dispersion pins 32 has a function of stabilizing the spraying of slurry droplets. By forming the upper plate 33, the particle size of granules obtained The distribution can be sharpened. In the present embodiment, since the particle size distribution can be sharpened by forming the upper plate 33, the yield rate based on the particle size distribution can be increased by about 10%.

  In this embodiment, as shown in FIGS. 2 and 3, a taper 8 is formed on the lower surface of the distributor 6 over the entire circumference so that the gap with the upper plate 33 becomes wider toward the outer circumference. In the present embodiment, since the taper 8 is formed on the lower surface of the distributor 6, the gap between the upper plate 33 and the distributor 6 can be widened, and adhesion of the raw material to this gap can be effectively prevented. Further, by preventing the adhesion of the raw material, it is possible to effectively prevent the variation in the particle size of the product caused by the falling off of the attached matter and the mixing of impurities caused by the abrasion caused by the attached matter.

  As shown in FIG. 3, the taper 8 is formed from the taper start point 8-1 on the inner peripheral side to the taper end point 8-2 on the outer peripheral side. In this embodiment, the taper 8 is the inner periphery of the distributor 6. It is formed from the side to the lower end portion 7-1 of the casing 7. Note that the concept of a taper start point and a taper end point is convenient, and from a different perspective, the start point becomes the end point, and conversely, the end point becomes the start point.

  In the present embodiment, the taper start point 8-1 on the inner peripheral side of the taper 8 is on the inner peripheral side (or the same position as the inner end portion 33-1) from the inner end portion 33-1 of the upper plate 33. A taper 8 is formed. Therefore, the taper 8 is formed on the entire portion where the upper plate 33 and the distributor 6 and the lower end portion 7-1 of the casing 7 overlap (that is, above the upper plate 33) when viewed from the direction of the rotation axis 4. It becomes. As a result, in the present embodiment, the entire gap where the upper plate 33 and the distributor 6 overlap can be widened, and the adhesion of the raw material to this gap can be effectively prevented. As shown in a second embodiment to be described later, the taper 8 does not necessarily have to be formed on the entire overlapping portion, and may be formed on at least a part of the overlapping portion. The effect of is demonstrated.

  In the present embodiment, the formation angle θ1 of the taper 8 is not particularly limited, but is preferably 3 to 30 degrees, and more preferably 5 to 15 degrees. If the formation angle θ1 of the taper 8 is too small, the effect of forming the taper 8 tends not to be obtained. If θ1 is too large, the thickness of the distributor 6 becomes too thin, which is not preferable.

  Normally, in the spray unit 2, it is necessary to install the rotating disk 3 at a position as close as possible to the distributor 6, which is a holding unit, in order to prevent rotational shaking of the rotating disk 3. For this reason, the gap between the upper plate 33 of the rotating disk 3 and the distributor 6 needs to be relatively narrow.

  Therefore, in the spray part 2g of the conventional spray drying apparatus, as shown in FIG. 11, the gap between the upper plate 33 formed on the rotary disk 3 and the distributor 6g is very narrow, about 1 to 2 mm. It was. Therefore, in the spray unit 2g of the conventional spray drying apparatus, when spray drying is continuously performed, adhesion (scaling) of the raw material occurs in the gap between the upper plate 33 and the distributor 6g due to the splash of the slurry and the influence of hot hot air. Was. Then, the raw material adheres to the gap between the upper plate 33 and the distributor 6g, and this adhering matter accumulates. The adhering matter having a certain size due to the accumulation falls off and is mixed into the product, and the particle size of the product is reduced. There was a problem that the variation became large.

  Furthermore, due to the accumulation of the deposits, friction due to the deposits occurs between the upper plate 33 of the rotating disk 3 rotating at a high speed and the distributor 6g. Further, due to this friction, a part of the upper plate 33 or the distributor 6g is abraded, and there is a problem that the worn product is mixed as an impurity in the product and adversely affects the product.

  On the other hand, in this embodiment, since the taper 8 is formed in the lower surface of the distributor 6, the clearance gap between the upper board 33 and the distributor 6 can be enlarged, and in the spray part 2g of the conventional spray drying apparatus. The problem of deposits can be solved.

  Then, the slurry droplets sprayed from the spray unit 2 are dried by hot air for drying (preferably 180 to 230 ° C.) sent from the hot air supply means via the blower 12 shown in FIG. Then, it is taken out from the dry material discharge port 13. According to this embodiment, it is possible to obtain a granule having a good particle size distribution and containing very little impurities.

  The hot air for drying sent from the hot air supply means is recovered by the cyclone 14, the bag filter 15 and the recovery machine blower 16 as exhaust means together with the solvent and dust vaporized by spray drying.

Second Embodiment The spray unit 2a of the present embodiment shown in FIG. 4 has the same configuration and operation as those of the spray unit 2 of the first embodiment except for the following, and redundant description thereof is omitted.

  Unlike the first embodiment, the distributor 6a of the present embodiment is formed with a taper 8a so that the taper starting point 8a-1 on the inner peripheral side is on the outer peripheral side with respect to the inner end portion 33-1 of the upper plate 33. It is. That is, the taper 8a is formed in a part of a portion where the upper plate 33 overlaps with the distributor 6 and the lower end portion 7a-1 of the casing 7a (that is, above the upper plate 33) when viewed from the direction of the rotation axis 4. Will be.

  Unlike the first embodiment, as in the present embodiment, the taper 8a has a gap between the upper plate 33 and the distributor 6 even when the taper 8a is formed in a part of the overlapping portion instead of the entire overlapping portion. The raw material can be prevented from adhering to the surface. Therefore, the taper 8a may be formed not on the entire overlapping portion but on a part thereof in accordance with the structural reason of the spraying part 2a or the properties of the raw material to be spray-dried.

Third Embodiment The spray unit 2b of the present embodiment shown in FIGS. 5 and 6 has the same configuration and operation as those of the spray unit 2 of the first embodiment except for the following, and redundant description thereof is omitted. .

  Unlike the first embodiment, the upper plate 33b of the rotary disk 3b of the present embodiment is formed with a taper 34b on the upper surface of the inner peripheral side end portion, with a gap widening toward the inner periphery over the entire periphery. Furthermore, in the present embodiment, the distributor 6b is not tapered.

  Even when the taper 34b is formed on the upper plate 33b instead of the distributor 6b, the gap between the upper plate 33b and the distributor 6b can be widened as in the first embodiment. It can be effectively prevented. Further, by preventing the adhesion of the raw material, it is possible to effectively prevent the variation in the particle size of the product caused by the falling off of the attached matter and the mixing of impurities caused by the abrasion caused by the attached matter.

  As shown in FIG. 6, the taper 34b is formed from the taper start point 34b-1 on the outer peripheral side to the taper end point 34b-2 on the inner peripheral side.

  In this embodiment, the taper 34b is formed so that the taper start point 34b-1 on the outer peripheral side is on the outer peripheral side with respect to the outer peripheral surface of the lower end portion 7b-1 of the casing 7b. That is, the taper 34b is formed on the entire portion where the upper plate 33b overlaps the distributor 6b and the lower end portion 7b-1 of the casing 7b (that is, above the upper plate 33b) when viewed from the direction of the rotation axis 4. It becomes.

  In the present embodiment, the formation angle θ2 of the taper 34b may be the same as the formation angle θ1 of the taper 8 formed in the distributor 6 in the first embodiment. However, since the upper plate 33b is thinner than the distributor 6 of the first embodiment, the upper limit of θ2 is usually smaller than the upper limit of θ1.

Fourth Embodiment The spray unit 2c of the present embodiment shown in FIG. 7 has the same configuration and operation as those of the spray unit 2b of the third embodiment except for the following, and redundant description thereof is omitted.

  Unlike the third embodiment, the upper plate 33c of the present embodiment has a taper 34c such that the taper starting point 34c-1 on the outer peripheral side is on the inner peripheral side with respect to the outer peripheral surface of the lower end portion 7c-1 of the casing 7c. Is formed. That is, the taper 34c is formed in a part of a portion where the upper plate 33c overlaps with the lower end portion 7b-1 of the distributor 6c and the casing 7c (that is, above the upper plate 33c) when viewed from the direction of the rotation axis 4. Will be.

  Unlike the third embodiment, as in the present embodiment, the taper 34c is not the entirety of the overlapping portion but the gap between the upper plate 33c and the distributor 6c even when formed in a part of the overlapping portion. The raw material can be prevented from adhering to the surface. Therefore, the taper 34c may be formed not on the entire overlapping portion but on a part thereof in accordance with the structural reason of the spraying part 2c or the properties of the raw material to be spray-dried.

Fifth Embodiment The spray drying apparatus according to the fifth embodiment has the same configuration as the spray drying apparatus 1 of the first embodiment, except that the upper plate 33d shown in FIG. 8 is formed on the rotating disk of the spray section. The description which overlaps is abbreviate | omitted. 8 corresponds to a cross-sectional view taken along line VIII-VIII in FIG.

  In the present embodiment, as shown in FIG. 8, the upper plate 33 d has a plurality of short portions in a portion where the upper plate 33 d overlaps with the lower end portion 7-1 of the distributor 6 and the casing 7 when viewed from the direction of the rotation axis 4. It has a shape slit 35d. In the present embodiment, by forming a plurality of slits 35d on the upper plate 33d, the gap between the upper plate 33d and the distributor 6 can be eliminated in the portion where the slits 35d are formed. Therefore, it is possible to prevent the raw material from adhering to the gap between the upper plate 33d and the distributor 6.

  In addition, in the present embodiment, since the upper plate 33d is formed with the slit 35d, even if the slurry adheres, the adhering slurry accumulates and becomes a large deposit. The deposit can be dropped from the slit 35d. Therefore, it is possible to effectively prevent deposition due to slurry adhesion.

  The number of the slits 35d is not particularly limited, and it is preferable to form as many as possible within a range in which the strength of the upper plate 33d is sufficiently secured. However, the slit 35d is formed so as to avoid the dispersion pin 32d (not shown) located below the upper plate 33d. The width w of the slit 35d is about 1/20 to 1/10 of the inner diameter r1 of the upper plate 33d. Alternatively, the width w of the slit 35d is about 5 to 10 mm. The size of the inner diameter r1 of the upper plate 33d is usually about 50 to 100 mm. In the present embodiment, as shown in FIG. 8, the plurality of slits 35d are arranged at equal intervals in the circumferential direction of the rotating disk 33d, so that the rotation of the rotating disk 33d can be stabilized.

Sixth Embodiment The spray drying apparatus according to the sixth embodiment has the same configuration as the spray drying apparatus 1 of the fifth embodiment, except that the upper plate 33e shown in FIG. 9 is formed on the rotating disk of the spray section. The description which overlaps is abbreviate | omitted. 9 corresponds to a cross-sectional view taken along the line IX-IX in FIG.

  Unlike the fifth embodiment, the upper plate 33e of the present embodiment has a plurality of through holes in a portion where the upper plate 33e overlaps the lower end portion 7-1 of the distributor 6 and the casing 7 when viewed from the direction of the rotation axis 4. 35e is formed. In the present embodiment, by forming a plurality of through holes 35e in the upper plate 33e, a gap between the upper plate 33e and the distributor 6 is formed in the portion where the through holes 35e are formed, as in the fifth embodiment. Can be eliminated. Therefore, it is possible to prevent the raw material from adhering to the gap between the upper plate 33e and the distributor 6.

  Moreover, in the present embodiment, as shown in FIG. 9, the plurality of through holes 35e are arranged concentrically with the rotating disk 33e and at equal intervals in the circumferential direction of the rotating disk 33e. Therefore, the rotation of the rotating disk 33e can be stabilized.

  The number of the through holes 35e is not particularly limited, and it is preferable to form as many as possible within a range in which the strength of the upper plate 33e is sufficiently secured. The size of the inner diameter r2 of the through hole 35e is about 1/10 to 1/5 of the inner diameter r1 of the upper plate 33e, or about 5 to 10 mm.

Seventh Embodiment The spray unit 2f of the present embodiment shown in FIG. 10 has the same configuration and operation as those of the spray unit 2 of the first embodiment, except for the following, and redundant description thereof is omitted.

  Unlike the first embodiment, the spray section 2f of the present embodiment is provided with a gas discharge hose 9 in the distributor 6f so that gas can be discharged from the gas discharge section 9a provided on the lower surface of the distributor 6f. It has become.

  In the present embodiment, a taper 8f is formed on the distributor 6f, and further, a gas discharge portion 9a for discharging gas via the gas discharge hose 9 is formed on the lower surface of the distributor 6f. Therefore, by discharging the gas from the gas discharge portion 9a through the gas discharge hose 9, it is possible to prevent the adhesion of the raw material in the gap between the upper plate 33 and the distributor 6f, and if the raw material has adhered Even in the case, the deposits can be effectively removed. The gas discharge portions 9a are preferably formed on at least a part of the lower surface of the distributor 6f, and a plurality of gas discharge portions 9a can be formed as necessary.

  In addition, in this embodiment, although the gas discharge part 9a was formed in the lower surface of the distributor 6f, you may form in the surface of the outer peripheral side of the casing 7. FIG. Further, the gas discharge part 9a may be formed on both the lower surface of the distributor 6f and the outer peripheral surface of the casing 7.

The gas discharged from the gas discharge unit 9a is not particularly limited, and may be appropriately selected according to the raw material to be spray-dried. For example, air or N ₂ gas can be used, and moisture is contained as necessary. May be. Moreover, it is preferable that the temperature of the gas discharged from the gas discharge part 9a is about normal temperature-about 400 degreeC, More preferably, the same thing as the hot air for drying supplied from a hot air supply means via the air blower 12 is used.

Other Embodiments The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention.

  For example, in the above-described embodiment, the taper 8 (first embodiment) of the distributor 6 and the taper 34b (third embodiment) of the upper plate 33b are formed separately, but can also be formed simultaneously. is there. Moreover, in each embodiment mentioned above, although the slit 35d, the through-hole 35e, and the gas discharge part 9a were formed separately, respectively, as long as the effect of this invention is not impaired, these can also be formed combining. It is.

  Hereinafter, although this invention is demonstrated based on a more detailed Example, this invention is not limited to these Examples.

  First, a ceramic raw material was prepared as a starting raw material, the ceramic raw material, a binder, and pure water were stirred and mixed, and then mixed and pulverized using a compounding pulverizer to produce a ceramic slurry.

  Next, the obtained ceramic slurry was spray dried using the spray drying apparatus (Example) of the present invention having the spray section 2 shown in FIGS. The spray drying conditions were such that the rotational speed of the rotary disk 3 was 3500 rpm and the temperature of the hot air for drying was 190 ° C. In the present embodiment, the forming angle θ1 of the taper 8 is 5 degrees.

  Further, separately from the above, the obtained ceramic slurry was spray-dried using the conventional spray-drying apparatus (comparative example) having the spray part 2g shown in FIG.

  Next, with respect to the ceramic granules obtained using the spray drying apparatus (Example) of the present invention and the ceramic granules obtained using the conventional spray drying apparatus (Comparative Example), appearance inspection and non-defective rate of the granules Was measured.

  The appearance inspection was performed by evaluating whether or not black foreign substances exist and whether or not there is a lump of granules. The appearance inspection was performed for the number of inspection lots shown in Table 1. A lot where black foreign matter or a lump of granules existed was determined as a defective lot, and the ratio of the number of defective lots to the number of inspection lots was determined as a defective rate. It is preferable that the defect rate is low. The results are shown in Table 1.

  The measurement of the non-defective product ratio of the granule is performed by measuring the particle size distribution of the obtained ceramic granule. The particle having a particle size in the range of 300 μm or less is determined to be non-defective, and the weight of the non-defective product with respect to the total weight of the particle is obtained. The non-defective product rate. The results are shown in Table 2. It is preferable that the yield rate is high.

Evaluation 1
From Table 1, the ceramic granule obtained using the spray-drying apparatus (Example) of the present invention did not have any black foreign matter and no mass of granules, and gave good results. On the other hand, in the ceramic granule obtained using the conventional spray drying apparatus (comparative example), black foreign substances and agglomeration of the granule were confirmed, and the defect rate was 1.38%. Note that the black foreign matter confirmed in the comparative example is a worn object mixed by wear of a part of the upper plate of the distributor and / or the rotating disk, and the mass of granules is between the distributor and the rotating disk. It was a deposit deposited between the upper plate.

  From this result, it can be confirmed that by using the spray drying apparatus (Example) of the present invention, it is possible to effectively prevent the adhesion of the raw material to the gap between the upper plate of the rotating disk and the distributor (holding portion). It was.

Evaluation 2
From Table 2, the ceramic granule obtained using the spray drying apparatus (Example) of the present invention had a good product rate of 94%, which was a good result. On the other hand, the ceramic granule obtained using the conventional spray drying apparatus (comparative example) had a non-defective product ratio of 87.6%, less than 90%, and a poor product ratio.

  From this result, it was confirmed that the dispersion of the particle size distribution can be eliminated by using the spray drying apparatus (Example) of the present invention, and as a result, the yield rate can be improved.

FIG. 1 is an overall configuration diagram of a spray drying apparatus according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the main part of the spray unit of the spray drying apparatus according to one embodiment of the present invention. FIG. 3 is an enlarged cross-sectional view of the spray section of the spray drying apparatus according to one embodiment of the present invention. FIG. 4 is a cross-sectional view of a main part of a spraying part of a spray drying apparatus according to another embodiment of the present invention. FIG. 5 is a cross-sectional view of an essential part of a spraying part of a spray drying apparatus according to another embodiment of the present invention. FIG. 6 is a cross-sectional view of an essential part of a spraying part of a spray drying apparatus according to another embodiment of the present invention. FIG. 7 is a cross-sectional view of an essential part of a spraying part of a spray drying apparatus according to another embodiment of the present invention. FIG. 8 is a cross-sectional view of a main part of a spraying part of a spray drying apparatus according to another embodiment of the present invention. FIG. 9 is a cross-sectional view of an essential part of a spraying part of a spray drying apparatus according to another embodiment of the present invention. FIG. 10 is a cross-sectional view of an essential part of a spraying part of a spray drying apparatus according to another embodiment of the present invention. FIG. 11 is a cross-sectional view of an essential part of a spraying part of a conventional spray drying apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Spray drying apparatus 10 ... Drying cylinder 11 ... Slurry pump 12 ... Blower 13 ... Drying material discharge port 14 ... Cyclone 15 ... Bag filter 16 ... Blower 2 for collection machines ... Spraying part 3 ... Rotary disk 31 ... Lower plate 32 ... Dispersion pin 33 ... Upper plate 4 ... Rotating shaft 5 ... Slurry hose 5a ... Discharge part 6 ... Distributor 7 ... Casing 7-1 ... Lower end part 8 ... Taper 8-1 ... Taper start point 8-2 ... Taper end point

Claims (8)

A spray drying apparatus having a slurry discharge unit for discharging slurry, a holding unit for holding the slurry discharge unit, and a rotating disk for spraying the slurry discharged from the discharge unit radially,
An upper plate is formed on the rotating disk,
The holding portion has a taper such that a gap between the upper plate and the upper plate becomes wider toward an outer periphery in at least a part of a portion where the upper plate and the holding portion overlap when viewed from the rotation axis direction of the rotating disk. A spray-drying device characterized in that is formed.   2. The spray drying apparatus according to claim 1, wherein the taper of the holding portion is formed over the entire portion where the upper plate and the holding portion overlap when viewed from the rotation axis direction of the rotating disk. A spray drying apparatus having a slurry discharge unit for discharging slurry, a holding unit for holding the slurry discharge unit, and a rotating disk for spraying the slurry discharged from the discharge unit radially,
An upper plate is formed on the rotating disk,
The spray drying apparatus characterized in that a taper is formed on the upper surface of the inner peripheral side end portion of the upper plate so that the gap becomes wider toward the inner periphery.   The taper of the upper surface of the inner peripheral side end portion of the upper plate is formed in at least a part of a portion where the upper plate and the holding portion overlap when viewed from the rotation axis direction of the rotating disk. The spray-drying apparatus as described.   5. The spray according to claim 4, wherein the taper of the upper surface of the inner peripheral side end portion of the upper plate is formed over the entire portion where the upper plate and the holding portion overlap when viewed from the rotation axis direction of the rotating disk. Drying equipment. A spray drying apparatus having a slurry discharge unit for discharging slurry, a holding unit for holding the slurry discharge unit, and a rotating disk for spraying the slurry discharged from the discharge unit radially,
An upper plate is formed on the rotating disk,
The holding portion has a taper such that a gap between the upper plate and the upper plate becomes wider toward an outer periphery in at least a part of a portion where the upper plate and the holding portion overlap when viewed from the rotation axis direction of the rotating disk. Is formed, and
The spray drying apparatus characterized in that a taper is formed on the upper surface of the inner peripheral side end portion of the upper plate so that the gap becomes wider toward the inner periphery.   The upper plate is formed with a slit or a through hole in at least a part of a portion where the upper plate and the holding portion overlap when viewed from the rotation axis direction of the rotary disk. A spray drying apparatus according to any one of the above. The spray drying apparatus according to any one of claims 1 to 7, wherein the holding unit includes a gas discharge mechanism for discharging gas.

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