JP2017185450A - Crystallization classifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crystallization classifier having a continuous reaction tank, capable of further at high accuracy, classifying a slurry including many small-sized grains classified by a draft tube.SOLUTION: An objective crystallization classifier comprises: a reaction tank 10 holding a raw material to be crystallized; agitation means 20 equipped with a pivot 21 extending in a vertical direction and the agitation blades 23 provided on the pivot; a first draft tube 32 provided to surround the periphery of the agitation blades; and a second draft tube 31 having a larger diameter than the first draft tube, surrounding a part of the first draft tube so that the upper end of the second draft tube becomes higher than that of the first draft tube and the lower end becomes lower than the upper end of the first draft tube, and provided apart from the first draft tube.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a crystallization classifier applied to obtain intermediate products and final products in medical, food and industrial fields.

  2. Description of the Related Art Conventionally, there is known a crystallization classifier that mixes a plurality of raw materials in a reaction tank and classifies the precipitated particles into small and large particle diameters (see, for example, Patent Document 1).

  The particle size generated by the apparatus described in Patent Document 1 is the reaction rate of raw materials (growth speed of particle size), the capacity of the reaction tank, and the time from the supply of the raw material to the reaction tank until the generated particles are discharged. Expected based on the determined residence time. In this case, although the average particle diameter can be predicted to some extent, the residence time in the tank varies, so that the distribution (variation) in the particle diameter also occurs, and as a result, there are also small particles that are smaller than the target particle diameter. About this small particle, it is necessary to grow to a particle larger than the target particle size, and after discharging from the reaction tank, the small particle smaller than the target particle diameter is recovered with a sieve device, etc., slurried, and supplied to the reaction tank again There was a need to do.

  On the other hand, solid particles that have reached the target particle size to be classified are preferably separated from the circulating flow in the reaction tank and deposited on the bottom of the reaction tank, and classified quickly and with high accuracy.

JP-A-10-265225

  However, in the crystallization classifier described in Patent Document 1, it is difficult to classify the solid particles that have reached the target particle size with high accuracy, and the recovered slurry has a particle size larger than the target particle size that can be a product. Large particles are also included. As described above, the large particles that have reached the target particle size are preferably separated from the small particles quickly and deposited and classified, but in the configuration described in Patent Document 1, the large particles are small particles. There existed a problem that it was easy to mix in a slurry and high-precision classification was difficult.

  Therefore, the present invention is to classify the solid particles having reached the target particle size with high accuracy from the slurry containing many small-sized particles classified by the draft tube in the crystallization classifier having a continuous reaction tank. An object of the present invention is to provide a crystallizing and classifying apparatus that can be used.

In order to achieve the above object, a crystallization classifying apparatus according to one embodiment of the present invention includes a reaction tank holding a crystallization raw material,
A stirring means comprising a rotary shaft extending in the vertical direction and a stirring blade provided on the rotary shaft;
A first draft tube provided so as to surround the periphery of the stirring blade;
The first draft tube has a larger diameter than the first draft tube, the upper end is higher than the upper end of the first draft tube, and the lower end is lower than the upper end of the first draft tube. And a second draft tube that surrounds and is spaced apart.

  According to the present invention, it is possible to recover a slurry containing only small-sized particles that does not include large-sized particles to be classified.

It is the figure which showed an example of the crystallization classification apparatus which concerns on embodiment of this invention. It is the figure which showed the example which provided two pairs of baffle plates in the reaction tank.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing an example of a crystallization classifying apparatus according to an embodiment of the present invention. The crystallization classifier according to the embodiment of the present invention includes a reaction vessel 10, a stirrer 20, a draft tube 30, draft tube fixing jigs 35 and 36, a baffle plate 40, a small diameter particle slurry outlet 50, A crystallization raw material supply device 60 and a classification outlet 70 are provided. The draft tube 30 has an upper draft tube 31 and a lower draft tube 32 and has a two-stage configuration. The upper draft tube 31 provided at the upper side has a larger diameter than the lower draft tube 32 provided at the lower side, and partial regions on the lower end side of the upper draft tube 31 and the upper end side of the lower draft tube 32 are mutually connected. They are arranged so as to overlap.

  Hereinafter, each component will be described.

  The reaction tank 10 is a means for holding the crystallization raw material 110 in the tank, and is a means for stirring and causing the crystallization raw material 110 held in the tank to generate and accelerate the crystallization reaction. The crystallization raw material 110 is in a liquid state or a slurry state composed of liquid and fine particles when the raw material is charged, but as the crystallization reaction proceeds, solid particles 111 are generated and the particle size of the solid particles 111 increases. Go. Therefore, the reaction tank 10 normally holds the crystallization raw material 110 in which the liquid and the solid particles 111 are mixed in the tank.

  The reaction vessel 10 is preferably configured in a cylindrical shape having a mirror bottom. By having the said shape, it becomes easy to form the circulation flow which circulates up and down. A specific description of the circulation flow will be described later.

  As the crystallization raw material 110, various raw materials may be selected according to the crystallization target and application, but for example, the crystallization raw material 110 for crystallizing the Ni solid particles 111 may be used.

  The stirrer 20 is a stirring means for stirring the crystallization raw material 110 in the reaction vessel 10. The stirrer 20 includes a rotating shaft 21, a stirring blade support part 22, a stirring blade 23, and a motor 24. The rotating shaft 21 may be provided at an arbitrary position in the reaction vessel 10, but is generally provided near the center of the reaction vessel 10, and the reaction is performed around the rotating shaft by rotating the stirring blade 23. It is installed so that a symmetrical flow can be generated in the tank 10. The rotating shaft 21 extends in the vertical direction and rotates the stirring blade 23 horizontally.

  The stirring blade support portion 22 is a support means for supporting the stirring blade 23. The stirring blade support 22 is fixed to the rotating shaft 21 and plays a role of transmitting the rotation of the rotating shaft 21 to the stirring blade 23.

  The stirring blade 23 may be configured to have various shapes depending on the application. For example, the stirring blade 23 has an inclination with respect to the horizontal direction or the vertical direction in order to form a vertical flow of the crystallization raw material 110. Propeller-type or inclined paddle-type stirring blades 23 are preferably used. By being provided with an inclination, it is possible to form a vertical flow that extrudes the crystallization raw material 110 up and down.

  The stirring blade 23 preferably has a shape extending in the horizontal direction (left-right direction) around the rotation shaft 21. Thereby, the rotation of the rotating shaft 21 can be efficiently transmitted to the crystallization raw material 110 without loss, and a flow symmetrical to the rotating shaft 21 can be formed.

  One or more stirring blades 23 are provided around the stirring blade support 22. When the number of stirring blades 23 extending left and right around the rotating shaft 21 is counted as one, at least one stirring blade 23 is provided, and circulation in the reaction tank 10 is further performed according to the application and the length of the reaction tank 10. A plurality may be provided to the extent that the flow can be maintained. In the present embodiment, an example in which one stirring blade 23 is provided at each of an upper portion and a lower portion in the lower draft tube 32 will be described.

  In the present embodiment, the stirring blade 23 is preferably provided only in the lower draft tube 32. The stirring blade 23 is generally configured to form an upward flow in the draft tube 30 among the upstream and downstream. Therefore, in order to effectively form the upward flow, it is preferable to provide the stirring blade 23 below the upper side in the draft tube 30. Further, the stirring blade 23 is preferably provided so as to form a uniform flow of the crystallization raw material 110 in cooperation with the draft tube 30. If the draft tube 30 has a single cylindrical shape having a constant diameter in the vertical direction, the stirring blades 23 are arranged one by one above and below the entire draft tube 30 to form a uniform upward flow. However, in this embodiment, the diameters of the lower draft tube 32 and the upper draft tube 31 are different. Therefore, when the stirring blades 23 are provided in the lower draft tube 32 and the upper draft tube 31 (for example, one each), it is difficult to form a uniform upward flow in the draft tube 30. Therefore, in the crystallization classifying apparatus according to this embodiment, two stirring blades 23 are provided above and below only in the lower draft tube 32 having a constant diameter and provided below the reaction vessel 10. Yes.

  As described above, the stirring blade support portion 22 and the stirring blade 23 may be provided in a plurality of stages in the vertical direction in the lower draft tube 32. In FIG. 1, the agitating blade support 22 and the agitating blade 23 are provided one unit at each of the upper and lower stages in the lower draft tube 32. When the length of the reaction vessel 10 is increased, it becomes difficult to produce a sufficient flow of the crystallization raw material 110 with only one stage. Therefore, when the reaction vessel 10 is vertically long, the stirring blade support 22 and the stirring In many cases, the wings 23 are provided one unit at each of the upper stage and the lower stage. That is, in the present embodiment, the lower draft tube 32 itself is about half the length of the reaction tank 10 and is short, but the entire draft tube 30 including the upper draft tube 31 is long, and the lower draft tube 32 is stirred. It is necessary to make a flow of the crystallization raw material 110 that circulates the draft tube 30 and the entire reaction tank 10 with the blades 23. Therefore, in the present embodiment, an example in which the agitating blade support portion 22 and the agitating blade 23 are provided in the lower draft tube 32 by one unit at the upper and lower stages will be described.

  The motor 24 is a driving means for rotating the stirring blade 23 via the stirring blade support portion 22, and various motors 24 may be used as long as the stirring blade 23 can be rotated at an appropriate speed and torque. .

  The draft tube 30 is provided to adjust the flow in the reaction vessel 10 and functions as a rectifying member. As described above, in the crystallization classifying apparatus according to this embodiment, the two-stage draft tube 30 including the upper draft tube 31 and the lower draft tube 32 is provided.

  The lower draft tube 32 has a cylindrical shape and is provided so as to surround the stirring blade 23. The lower draft tube 32 has a vertical flow of the crystallization raw material 110 formed by the stirring blades 23 along the inner peripheral surface thereof, and flows in one direction in the vertical direction into the draft tube 30, specifically ascending flow. Play a role in forming.

  The upper draft tube 31 has a larger diameter than the lower draft tube 32 and is provided to be separated from the lower draft tube 32. By making the upper draft tube 31 larger in diameter than the lower draft tube 32, it is possible to reduce the rising speed of the upward flow generated by the lower draft tube 32. That is, as shown in FIG. 1, when an upward flow having a velocity v1 is formed in the lower draft tube 32, if the upward flow moves to an upper region surrounded by the upper draft tube 31, the velocity decreases to a velocity v2. (V2 <v1). Thereby, it is possible to prevent the solid particles 111 having a predetermined particle diameter or more from further moving up.

  Since the inner peripheral surface of the upper draft tube 31 is spaced apart from the outer peripheral surface of the lower draft tube 32 in the horizontal direction and has a distance D, the solid raised from the lower draft tube 32 by the stirring blade 23 The particles 111 can be deposited again on the bottom surface of the reaction vessel 10 by lowering the distance D between the upper draft tube 31 and the lower draft tube 32. Thereby, solid particles having a predetermined particle diameter or more, that is, solid particles to be classified, are once wound up by the agitating blade 23 and the upper end of the upper draft tube 31 cannot be exceeded even when the flow velocity is lowered. It can pass through the distance D between the inner peripheral surface of the draft tube 32 and the outer peripheral surface of the lower draft tube 32 and can be deposited on the bottom surface of the reaction vessel 10, and many times in the flow of the crystallization raw material 110. It can prevent being wound up. Therefore, the distance D between the upper draft tube 31 and the lower draft tube 32 is configured to be wider than the diameter of the solid particles 111 to be classified.

  The upper draft tube 31 and the lower draft tube 32 constitute a large draft tube 30 that extends vertically in the reaction vessel 10 as a whole, so that the lower end portion of the upper draft tube 31 and the upper end portion of the lower draft tube 32 are formed. Are overlapped with each other in a partial region in the height direction, and the upper draft tube 31 surrounds or covers a part of the lower draft tube 32. That is, the lower end of the upper draft tube 31 is configured to be lower than the upper end of the lower draft tube 32. Further, the upper end of the upper draft tube 31 is naturally configured to be higher than the upper end of the lower draft tube 32. Thereby, the long draft tube 30 can be comprised as a whole, and the circulation flow of the crystallization raw material 110 can be formed in the reaction tank 10 inside and outside the draft tube 30. In addition, the overlapping region of the lower draft tube 32 and the upper draft tube 31 is not very long (wide) from the viewpoint of reducing the cost and reducing the flow, and is 1/3 or less of the height of the lower draft tube 31. In addition, the upper draft tube 31 may be configured to be 1/3 or less of the height. Further, from the viewpoint of forming a symmetric flow with respect to the central axis of the reaction vessel 10, the upper draft tube 31 is preferably provided coaxially with the lower draft tube 32.

  The draft tube 30 can be made of various materials as long as it does not affect the properties of the crystallized particles. For example, the draft tube 30 may be made of stainless steel.

  When performing classification using the draft tube 30 having such a configuration, small-diameter particles that are not subject to classification flow to the outside of the upper draft tube 31 beyond the upper end of the upper draft tube 31 and descend. It is discharged by opening the particle slurry outlet 50.

  The small diameter particle slurry outlet 50 is an outlet for discharging a small diameter particle slurry having a particle diameter smaller than a predetermined particle size to be classified, and is provided as necessary. The small diameter particle slurry outlet 50 can be provided at various locations as long as the small diameter particle slurry having a particle diameter less than a predetermined particle diameter can be discharged to the outside of the reaction tank 10. For example, the small diameter particle slurry outlet 50 may be provided on the side surface of the reaction tank 10. May be. The crystallization raw material 100 containing the small-diameter particle slurry exceeding the upper end of the upper draft tube 31 descends along the inner peripheral surface of the reaction tank 10 after exiting the upper draft tube 31 as shown in FIG. Since the flow is formed, the small particle slurry can be efficiently captured and discharged by providing the small particle slurry outlet 50 on the side surface of the reaction vessel 10.

  The small-diameter particle slurry outlet 50 may be provided at various positions on the side surface of the reaction vessel 10 depending on the application, but is preferably provided above the lower side in order to classify the solid particles 111 having a large particle diameter. . Specifically, it is provided at a position higher than the lower end of the upper draft tube 31, more preferably near the upper end of the upper draft tube 31, and further preferably higher than the upper end of the upper draft tube 31. The upper limit at which the small particle slurry outlet 50 is provided is the liquid level of the crystallization raw material 110 and is provided at a position lower than this.

  The upper draft tube fixing jig 35 is a jig for fixing the upper draft tube 31. FIG. 1 shows a configuration in which the upper draft tube fixing jig 35 is fixed to the baffle plate 40, and the draft tube fixing jig 35 further fixes the upper upper draft tube 31 inside. The jig 35 may have various configurations as long as the upper draft tube 31 can be fixed at an appropriate position.

  Similarly, the lower draft tube fixing jig 36 is a jig for fixing the lower draft tube 32 and, like the upper draft tube fixing jig 35, is fixed to the baffle plate 40, and the upper draft tube fixing jig 35 is fixed. The lower draft tube 32 is fixed at a position lower than the upper draft tube fixing jig 35 by extending further inward.

  FIG. 1 shows an example in which the draft tube fixing jigs 35 and 36 are fixed to the baffle plate 40, but the draft tube fixing jigs 35 and 36 may be fixed to the inner peripheral wall surface of the reaction vessel 10. Good. Further, the draft tube fixing jigs 35 and 36 may be configured to suspend and support the draft tubes 31 and 32 from above instead of horizontally extending horizontally. Thus, if the draft tubes 31 and 32 can be fixed, the draft tube fixing jigs 35 and 36 may have various configurations according to applications.

  The baffle plate 40 is a baffle plate for converting the flow of the crystallization raw material 110 in the horizontal direction and the oblique direction into the vertical direction or the axial flow direction, and extends in the vertical direction along the inner peripheral side surface of the reaction tank 1. At the same time, it is provided so as to protrude toward the center of the reaction vessel 10, that is, toward the rotating shaft 21. Specifically, the baffle plate 40 plays a role of forming a vertical flow of the crystallization raw material 110 between the outer peripheral side surface of the draft tube 30 and the inner peripheral side surface of the reaction vessel 10. As described above, when an upward flow is formed inside the draft tube 30, the crystallization raw material 110 exceeds the upper end of the upper draft tube 31 and then between the upper draft tube 31 and the reaction vessel 10. Form a downflow. Thereby, the crystallization raw material 110 can form a circulating flow that circulates up and down inside and outside of the draft tube 30 as a whole, promotes the crystallization reaction, and reduces the crystallized solid particles 111 to a particle size. Can be efficiently sorted up and down. That is, the solid particles 111 and the small particle slurry that have not reached the predetermined particle size can be raised by the upward flow, and the upper draft tube 31 and the lower draft tube are used for the solid particles 111 that have reached the predetermined particle size. By the fall from the distance D between the uppermost draft tube 31 and the reaction tank 10, it can be quickly deposited on the bottom of the reaction tank 10. The small-diameter particle slurry is extracted from a small-diameter particle slurry outlet 50 provided as necessary at the upper part of the side surface of the reaction vessel 10 where the solid particles 111 having such a predetermined particle size do not accumulate. Alternatively, when the small particle slurry outlet 50 is not present, the crystallization reaction is continued by circulating in the reaction vessel 10.

  The baffle plates 40 are provided so as to sandwich the draft tube 30 from both sides, that is, in pairs. For example, only one pair of baffle plates 40 may be provided so as to sandwich the draft tube 30 from the left and right, or two pairs may be provided so as to sandwich the draft tube 30 from four directions. Or more may be provided as needed. Thus, the number of baffle plates 40 may be appropriately determined according to the application. The baffle plate 40 may be referred to as a baffle 40.

  FIG. 2 is a view showing an example in which two pairs of baffle plates 40 are provided in the reaction vessel 10. In this manner, the baffle plate 40 may be provided so as to form a cross. FIG. 2 shows the configuration of the stirring blade 23 in the lower draft tube 32 in more detail. As shown in FIG. 2, the stirring blade 23 may use an inclined paddle that is inclined to the opposite side on the left and right of the rotating shaft 21. By using an inclined paddle for the stirring blade 23 and surrounding it with a cylindrical lower draft tube 32, an upward flow having a high flow velocity can be formed in the short lower draft tube 32.

  For convenience of explanation, the draft tube fixing jigs 35 and 36 are omitted in FIG.

  Returning to the description of FIG. Thus, the lower draft tube 32 is formed in a cylindrical shape to form an upward flow in the draft tube 30, but the upper draft tube 31 maintains the distance D from the outer peripheral surface of the lower draft tube 32, If it has substantially cylindrical shape, the structure which has a taper shape in the lower end part or upper end part vicinity may be sufficient. Further, it is not essential to narrow the region where the upper draft tube 31 and the lower draft tube 32 overlap, and the lower end of the upper draft tube 31 is further extended downward in a range above the lower end of the lower draft tube 32. It is good also as a structure which covers the side surface of the lower draft tube 32. FIG.

  The crystallization raw material charging device 60 is a means for charging the crystallization raw material 110 into the reaction tank 10, and includes a crystallization raw material tank 61 and a crystallization raw material charging port 62. The crystallization raw material tank 61 is a tank for accumulating the crystallization raw material 110, and stores, for example, a slurry-like crystallization raw material 110. The crystallization raw material charging port 62 is a raw material charging port or a raw material supply port for charging or supplying the crystallization raw material 110 accumulated in the crystallization raw material tank 61 into the reaction tank 10.

  The classification outlet 70 is a product outlet for discharging fixed particles having a predetermined particle size or more from the reaction tank 10, and is provided connected to the bottom of the reaction tank 10. Thereby, the classified solid particles 111 having a desired particle diameter can be obtained.

  In the crystallization classifier having such a configuration, a stirrer 20 having a necessary power corresponding to the specific gravity and slurry concentration of the slurry is provided, and the stirring blade 23 is rotated with a predetermined power, so that a small diameter equal to or smaller than the target particle diameter is obtained. The particles can flow upward in the draft tube 30.

  That is, as shown in FIG. 1, the slurry containing a large amount of small particles smaller than the target particle diameter that has flowed upward in the lower draft tube 32 at the speed v1 is the sedimentation speed of large particles larger than the target particle diameter. The particles are further classified by the upper draft tube 31 enlarged so as to have a smaller velocity v2, and the large-diameter particles settle down to the bottom of the reaction tank. In this way, by providing the upper draft tube 31 having a diameter larger than that of the lower draft tube 32, it is possible to quickly deposit large-diameter particles to be classified on the bottom of the reaction tank 10 and perform classification with high accuracy. It becomes.

  On the other hand, the small-diameter particle slurry continues to flow upward at the velocity v2 and can be extracted from the small-diameter slurry outlet 50.

  The small-diameter particle slurry extracted from the upper part of the reaction vessel 10 will contain large-diameter particles that can be a product without the upper draft tube 31 having an enlarged diameter, and must be classified in the next step. By using the upper draft tube 31 having an enlarged diameter, it is possible to classify with high accuracy, so that it is not necessary to perform classification in the next step.

  Thus, according to the crystallization classification apparatus according to the present embodiment, when the crystallization raw material 110 is flowing in the lower draft tube 32, the slurry containing many small-diameter particles smaller than the target particle diameter is contained. The upper draft tube 31 having an enlarged diameter has a large diameter that can be a target product by lowering the flow rate of the circulating flow of the crystallization raw material 110. The solid particles 111 can be deposited on the bottom of the reaction vessel 10 and can be classified quickly and with high accuracy.

  In addition, when the small-diameter particle slurry outlet 50 is provided, it is possible to collect a slurry containing only small-diameter particles that does not include large-diameter particles that have reached the target diameter.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

DESCRIPTION OF SYMBOLS 10 Reaction tank 20 Stirrer 21 Rotating shaft 22 Stirring blade support part 23 Stirring blade 24 Motor 30 Draft tube 31 Upper draft tube 32 Lower draft tube 35, 36 Draft tube fixing jig 40 Baffle plate 50 Small particle slurry outlet 60 Crystallizing raw material Feeder 61 Crystallization raw material tank 62 Crystallization raw material inlet 70 Classification outlet 110 Crystallization raw material 111 Solid particles

Claims (10)

A reaction vessel holding the crystallization raw material,
A stirring means comprising a rotary shaft extending in the vertical direction and a stirring blade provided on the rotary shaft;
A first draft tube provided so as to surround the periphery of the stirring blade;
The first draft tube has a larger diameter than the first draft tube, the upper end is higher than the upper end of the first draft tube, and the lower end is lower than the upper end of the first draft tube. And a second draft tube that surrounds and part of the crystallization classifier.   The crystallization classifier according to claim 1, wherein the second draft tube is provided coaxially with the first draft tube.   The region where the first draft tube and the second draft tube overlap in the height direction is the region where the first draft tube does not overlap the second draft tube and the second draft tube. The crystallization classifier according to claim 1 or 2, which is narrower than any of the regions that do not overlap with one draft tube.   The height of the region where the first draft tube and the second draft tube overlap in the height direction is 1/3 or less of the height of the first draft tube, and the second draft The crystallization classifier according to claim 3, which is 1/3 or less of the height of the tube.   The crystallization classification apparatus according to any one of claims 1 to 4, wherein a distance between the first draft tube and the second draft tube in a horizontal direction is larger than a particle size of solid particles to be classified.   The crystallization classification apparatus according to any one of claims 1 to 5, further comprising a small-diameter particle slurry outlet provided on a side surface of the reaction vessel.   The crystallization classifier according to claim 6, wherein the small-diameter particle slurry outlet is provided at a position higher than an upper end of the second draft tube.   The crystallization classifier according to any one of claims 1 to 7, wherein the second draft tube includes a shape portion that is not cylindrical.   And at least a pair of baffle plates extending in the vertical direction along the inner peripheral side surface of the reaction tank and projecting toward the rotating shaft so as to sandwich the first and second draft tubes from both sides. The crystallization classifier according to any one of claims 1 to 8. A crystallization raw material inlet for supplying the crystallization raw material to the reaction vessel;
The crystallization classification apparatus according to any one of claims 1 to 9, further comprising a classification outlet provided at the bottom of the reaction tank and for discharging solid particles having a predetermined particle diameter or more.

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