JPS6012555B2 - Fluidized bed equipment - Google Patents

Description

[Detailed description of the invention] The present invention relates to a fluidized bed apparatus.

Fluidized beds have long been used for operations such as granulation, drying, and coating.

Conventionally, as a means for taking out treated powder and granules from the fluidized bed, in the case of continuous supply and discharge of powder and granules, the overflow method and the lower part of the fluidized bed extraction method were used, and in the case of intermittent supply and discharge, the powder at the bottom of the fluidized bed was used. Generally, a method was adopted in which the granule storage section was separated from the tower body. In the above-mentioned continuous supply and discharge method, since the powder and granules can be supplied and discharged while flowing, there is no need to pay attention to complete discharge, and it is easy to create a completely closed system. If an intermittent supply/discharge method is unavoidable due to the surface, complete discharge becomes a major issue.

However, in the intermittent supply and discharge type fluidized bed, there is no suitable means for discharging the entire amount of powder and granules, and it is necessary to adopt the above-mentioned separation type extraction means.

This not only causes problems in terms of safety and quality, such as dust scattering and bacterial contamination that occur when the powder storage section is removed, but also requires time and effort to transport the removed powder and granules, making it unmanned. There are also major problems in terms of productivity and productivity. Especially when the processes before and after a fluidized bed device are continuous processes with large capacity, the fluidized bed operation becomes rate-limiting, so when adopting a system in which multiple fluidized bed devices are operated in parallel and alternately, the above-mentioned disadvantages of the discharge system becomes a big problem. Various improvements and devises have been made to solve the problems of the intermittent supply and discharge method described above, but no satisfactory solution has yet been proposed.

For example, in a system that suctions and discharges powder and granules while blowing a swirling flow into a fluidized bed, not only does a large amount of air need to be supplied for swirling, but also there is a groove in which the powder remains near the center of the straightening network. In particular, this tendency increases as the cavity of the fluidized bed increases.In addition, in the case of a system in which a discharge port is provided in the rectifying network at the bottom of the fluidized bed and the powder is sucked or discharged by dropping, there is a tendency to leave a large amount of fluid at the bottom of the fluidized bed. However, this method has the disadvantage that so-called dead spaces, where large particles or particles accumulate, are likely to occur, which deteriorates the function of the fluidized bed of this pot. The present invention has been made with the aim of eliminating all of the above-mentioned conventional problems. Specifically, the present invention has a rectifying network installed at a lower part of the fluidized bed in the column at an angle of inclination of 30 to 60.
The flow control system is characterized in that the flow straightening network is provided at an angle so that Concerning layer equipment.

In the present invention, the rectifying net refers to one or an aggregate of a cloth and a wire net for preventing the perforated rectifying plate from falling. The device of the present invention uses the air slide effect of the rectifier network provided with a gentle slope at an angle of 3o to 60, while yielding and guiding the powder and granules in the fluidized bed toward the lower end of the rectifier network. The powder can be discharged from the discharge port provided on the same wall at the lower end, and the powder or granules can be discharged without any adverse effect on the flow state, and in a completely closed system, for example, by using suction by reduced pressure. It has the feature that it can be done in a labor-saving Z manner.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to drawings showing one example of carrying out the present invention.

In the apparatus of the present invention, the tower body 1 contains a furnace cloth 2, a rectifying net 3, and a spray device 4, and the air Z is passed through an inlet 6 and a hot air generator 7 by the exhaust action of an exhaust fan 8. The air is sucked into the tower body 1 from the lower end thereof, passes through the rectifier network 3, the flow chamber 8, and the furnace cloth 2 in this order, and is exhausted by the exhaust fan 5. The raw material powder is supplied by an air volume adjustment damper in the raw material powder pipe 9.
10 and the airflow damper 12 of the wind pipe 11 are opened,
This is done by closing the air volume adjusting damper 14 in the air supply pipe 13 and allowing air to flow from the raw material supply pipe 9 toward the exhaust pipe 11.

After supplying the raw material powder, when the damper 10 of the raw material supply pipe 9 is closed and the damper 14 of the one-way air supply pipe 13 is opened, air flows from the lower end of the tower body 1 to the top of the tower via the rectifying network 3. , a fluidized bed of raw material powder and granules is formed in the fluidization chamber 8, drying,
Predetermined treatments such as granulation and coating are performed.

A vibration source 15 may be provided to prevent clogging of the furnace cloth 2 during this process. When the vibration source 15 is driven, the dampers 12 and 14 are closed. In the present invention, the rectifying network 3 is provided with a gentle slope with an inclination angle of 30 to 60, and at this time, a discharge damper 17 is provided on the tower wall at the lower end of the oblique rectifying network 3. A discharge port 16 is provided, and the discharge port 16 is connected via a discharge chamber 18 to a transport pipe 19 having an intake function.

The discharge damper 17 is closed during processing of powder in the fluidized bed. When taking out the processed powder from the fluidization chamber 8, open the daso bar 17 of the discharge port 16 while continuing the ocean breeze action by the storm extractor 5, and open the discharge chamber 18 through the transport pipe 19. Air is taken in to maintain a negative pressure greater than that in the flow chamber 8.

As a result, the flow rate of the rising air in the column decreases, the fluidized bed in the fluidized chamber 8 collapses, and a part of the powder in the layer is entrained in the airflow flowing from the outlet 16 toward the discharge chamber 18. The liquid flows directly into the discharge chamber 18, and the remainder falls onto the rectifying net 3.
The powder and granules that have fallen onto the straightening net 3 are floated on the straightening net 3 by the airflow passing through the straightening net 3 and rising, and are gradually moved toward the lower end due to the air slide effect based on the slope of the straightening net 3. The remaining particulate material is also completely discharged from the discharge port 16 into the discharge chamber 18 . The powder discharged into the discharge chamber 18 is suctioned and conveyed to the next process via a transport pipe 19. When guiding the powder on the straightening net 3 toward the lower end by the air slide effect, it is desirable to adjust the flow velocity of the upward flow by adjusting the degree of damper 12, 14. Further, it is desirable that the vacuum in the discharge chamber 18 is set to a size such that an airflow in a direction perpendicular to the opening surface of the discharge port 16 is generated at a flow velocity higher than the floating velocity of the largest particle of the powder or granular material. As described above, the present invention can achieve intermittent supply and discharge of powder and granules without any adverse effect on the fluidization state of the fluidized bed while maintaining a completely closed system, and is particularly useful in pharmaceutical manufacturing. It is extremely useful when applied to the treatment of powder and granular materials.

In the present invention, the rectifying net 3 is provided so that the oblique angle is 30 to 60.

If the inclination angle of the straightening net 3 is too large, the fluidization state of the powder in the fluidized bed will become non-uniform, and if it is too small, a sufficient air sliding effect will not be obtained. In addition, it is most desirable to form the discharge port 16 for the powder and granular material in a closed state in which the lower side coincides with the upper surface of the circumference of the rectifying net 3. A distance may be provided between the upper surface of the greenery and the lower side of the outlet 16.

Although a piston-type discharge damper 17 provided at the powder discharge port 16 is shown in the figure, a gate valve or pinch valve type may also be adopted.

As an embodiment of the present invention, a suction-type fluidized bed device in which the inside of the fluidization chamber is made negative pressure has been shown, but the same effects can be obtained in the case of a blown-in fluidized bed device in which the fluidization chamber is made positive.

Experimental examples of the apparatus of the present invention are listed below to further clarify the effects of the present invention.

Experimental Example 1 60.5 kg of mixed powder for granulation consisting of the following composition was charged into a WSG-160 type fluidized granulator (equipment shown in the drawing: rectifier plate short diameter 72, manufactured by Freund Sangyo) and rectified. While changing the slant plate angle of the plate and operating the main layer under the following conditions, spray granulation was performed using the following granulation binder for 4 minutes, followed by drying for 10 minutes.

The dried powder was then subjected to the following discharge conditions for 10 minutes, and the weight and particle size distribution of the discharged dry powder were measured. The results are shown in Tables 1 and 2. o Mixed powdered lactose for granulation (average particle size 70 French, 25 cm heshpass 85%) 45k9
Corn starch (average particle size lor, 32 rules eshpas
s90%) 15.5k9o
Binder cornstarch for granulation
2.5kg water
Heat and mix 28 x 9 at 8 pi 0 and gelatinize o Operating conditions of this device Air flow rate 44/min Air blowing temperature 90q0 Spray speed 760'/mino
Emission conditions for this device Air flow rate
22〆/min rectifying plate passing line far 0.
9w/Sec. Table 1: Amount remaining in the equipment (phosphorus Table 2: Particle size distribution of discharged powder (grandchild)

[Brief explanation of drawings]

The drawing is a central vertical sectional view showing one example of carrying out the present invention. In the figure, 1 is the tower body, 2 is the furnace cloth, 3 is the rectifier network, 4 is the spray device, 5 is the exhaust fan, 6 is the air inlet, 7 is the hot air generator, 8 is the flow chamber, and 9 is the raw material. Supply pipe, 1 River Maso damper, 11 is an exhaust pipe, 12 is its damper, 13 is the air supply pipe, 14 is the damper, 15 is the vibration source, 16 is the outlet for powder and granular material, 17 is the discharge damper, 18 is the discharge chamber,
19 is a transport pipe.

Claims (1)

[Claims] 1. A rectifying network is installed at the bottom of the fluidized bed in the tower at an angle of inclination of 3° to 6°.
A fluidized bed is provided at an angle so that Device.