JPH0425474B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a floor plate in a continuous fluidized bed granulation dryer, and in particular, this invention is formed by a floor plate in which a large number of slit-like blowholes are formed in the same direction of rotation, and It is characterized by being freely rotatable. (Prior art) A continuous fluidized bed granulation dryer is a device that granulates powder by making the powder into a fluidized state on a fluidized bed, then spraying a binder solution onto it to agglomerate the powder and drying. be. In this equipment, the powder and granules are granulated in a floating state in the hot airflow blown up from below without receiving almost any external force during the granulation process, so the granules have relatively large variations in particle size and are irregularly shaped. It becomes porous. Therefore, when trying to obtain heavy, uniformly sized spherical particles of pharmaceuticals, foods, industrial chemicals, etc., it is necessary to rotate the floor plate or provide a rotor disk on the floor plate and rotate it. This creates a swirling flow in the tank, which applies centrifugal force to the powder and granules, increasing the rubbing action and rolling action between the powder and granules and between the powder and the tank wall. An attempt was made to do so. However, in the former method of rotating the floorboard (for example, Japanese Patent Publication No. 59-21651), the particles blown upward by the wind are suspended, so contact with the floorboard is not very good, and the rotation speed of the particles is determined by the rotational speed of the floorboard. much slower than . Therefore, the granular material is
Although rolling action and rubbing action occur between the tank wall surface and between the powder and granules, making them heavier and spheroidized, there is almost no such action between them and the floorboard, so the effect is low. . Another problem with the conventional method is that powder and granules leak from the gap between the rotor and the tube wall due to turbulent air flow when stationary or during operation, which is a major problem in terms of product yield and sanitary performance. In addition, in the latter method of rotating the rotor disk (for example, Japanese Patent Application Laid-open No. 54-62978), the rotor disk is placed on a perforated floor plate, and although the rotor is also perforated, air is blown up from the floor plate. Most of the hot air passes through the gap between the floor plate and the rotor and blows up at the outer periphery of the rotor, greatly impairing the function of the floor plate, which is the essence of a continuous fluidized bed granulation dryer. You can't get things. (Means for Solving the Problems) The present invention solves the above-mentioned conventional drawbacks, and has a floor plate with a large number of slits oriented in the same turning direction, and the center of the disc is The shaft is freely rotatable, and by adjusting its rotational speed, a rolling action is exerted between the floor plate and the granular material, thereby enhancing the granulation effect. Hereinafter, the present invention will be specifically explained based on illustrated embodiments. In the figure, reference numeral 1 is a fluidized chamber which is the main body of the dryer, and 2 is a fluidized bed. A blower 3 is connected below the fluidized bed 2, and hot air sent from the blower 3 is sent to the fluidized bed.
The fluid is injected into the fluid chamber 1 through the fluid.
A duct 4 is attached to the upper end of the flow chamber 1, and an exhaust fan 5 is connected to the exhaust duct 4. Exhaust gas enters the exhaust fan 5 through the exhaust duct 4 and is discharged into the atmosphere. Reference numeral 6 denotes an input conveyor for inputting powder or granular material, which is a material to be dried, into the machine, and numeral 7 denotes an outlet for taking out the dried material outside the machine. As shown in Fig. 3, the fluidized bed 2 is formed of a floor plate with a large number of slit-shaped nozzles 9 opening in the same swirling direction in a donut-shaped area around the central part, except for the central part. , the floorboard is also connected to a drive motor 10 for rotation at a suitable speed. Further, below the fluidized bed 2, a donut-shaped perforated plate 8 is attached to the tube wall. This perforated plate 8 is used to prevent powder particles from falling from a slight gap between the outer peripheral edge of the fluidized bed 2 and the tube wall, and to prevent this from occurring. Although the diameter of the fluidized bed 2 depends on the angle of repose of the powder, it is formed smaller than the diameter of the fluidized bed 2, so that the two are slightly overlapped. To further explain the fumarole 9, for example, as shown in FIG.
1 and a fan-shaped valley-fold fin 12 are opened at equal radial intervals and in the same turning direction, and the downward slope on one side of the mountain-fold fin 11 and the valley-fold fin 12 and the other upwardly inclined surface are overlapped with each other with an appropriate interval, and this becomes the blowhole 9. To explain another example of a fumarole, as shown in Fig. 4, the hot air blown up is given directionality by press working, and by making the direction of each hole tangential, the hot air blown up is swirled. A method of giving it gender may also be taken. (Function) When granulating powder using the continuous fluidized bed granulation dryer constructed in this way, hot air is blown out from the blowhole 9 while the floor plate is rotated. now,
If the jetting speed of hot air is b and the rotational speed of the floor plate in the opposite direction is v, then the granular material in the tank is subjected to a rolling action whose relative speed to the rotation of the bed is approximately b+v. By blowing out the necessary amount of hot air according to the physical properties of the powder and the amount of input, and adjusting the rotation speed of the floor plate appropriately, it is possible to prevent the particles from forming between each other and between the powder and the floor or the wall of the flow chamber. An extremely large rubbing action and rolling action can be obtained between the particles, thereby making it possible to obtain particles with high uniformity and high density. The present invention is based on a continuous flow granulation device (patent application No. 58-
69805), but it goes without saying that similar effects can be obtained using a batch type fluidized granulation device. (Effects) The results of a comparative experiment between rotating the rotating slit fluidized bed plate shown in FIG. 4 described in the detailed explanation above and ordinary fluidized bed granulation are shown below. 1 Particle size adjustment effect Experimental conditions Materials Lactose: Cornstarch 7: 35Kg/batch Spray liquid 8% HPC-L aqueous solution 2.2Kg/batch Product uniformity (an indicator of how uniform the product particle size is) and materials at the end of granulation Figure 6 shows the moisture content at the end of the test. If the swirl slit fluidized bed plate is rotated, the uniformity of the product will be reduced regardless of the moisture content during granulation. In other words, it can be seen that the product particle size is uniform and the particle size regulating effect is large. Furthermore, the uniformity referred to here means that in the cumulative particle size distribution, the bottom of the sieve is exactly
It is the value obtained by dividing the particle size corresponding to 60% by the particle size corresponding to exactly 10% under the sieve, and this value approaches 1 as the particle size distribution becomes more uniform. 2 Heaviness effect material Lactose: Cornstarch = 7:3
5Kg/batch Spray liquid HPC-L 8% solution 2.6Kg/batch A comparison of the apparent densities of the granulated products is shown in the following table.

[Table] The effect of increasing the weight by rotating the swirling slit fluidized bed is clearly recognized.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view showing an embodiment of the present invention, Fig. 2 is a longitudinal sectional view showing the main parts of the same, Fig. 3 is a partially exploded perspective view showing an example of a fluidized bed, and Fig. 4 is a fluidized bed. FIG. 5 is a plan view showing another example, FIG. 5 is a vertical cross-sectional view showing the essential parts of the same, and FIG. 6 is a correlation diagram between particle uniformity and water content. 1...Fluidized chamber, 2...Fluidized bed, 3...Blower,
4...Duct, 5...Exhaust fan, 6...Input conveyor, 7...Outlet, 8...Perforated plate, 9...Full port, 10...Drive motor, 11...Fin, 12
...Fin.

Claims (1)

[Scope of Claims] 1. A large number of slit-shaped nozzles are opened in a donut-shaped area around the floor plate constituting the fluidized bed, excluding the central part, and are open in the same swirling direction and are rotatable. A continuous fluidized bed granulation dryer characterized by being connected to a motor and rotating at an appropriate speed. 2. The continuous fluidized bed granulation dryer according to claim 1, wherein a donut-shaped perforated plate having an inner diameter at least smaller than the outer diameter of the floor plate is attached to the tube wall below the floor plate.