JPH0248028Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a fluidized bed granulation drying device, and in particular, the filter chamber is divided into two or more chambers, each chamber is equipped with an independent baggage filter, and each baggage filter is shaken independently of each other. The present invention relates to a fluidized bed granulation/drying device characterized by:

A fluidized bed granulation/drying device is capable of spraying a solution of a binder or coating agent onto powder and granules to obtain granules and drying them while maintaining the powder in a fluidized state. This method is significantly superior to conventional devices in that there is little variation in the particle diameter of the particles produced, and that the solute is uniformly coated on the surface of the particles.

When performing granulation using this device, the solutes of the solution sprayed onto the powder that cannot adhere to the powder immediately dry, turn into fine powder, and fly up, eventually reaching the bag filter. It will be collected. For this reason, as the processing progresses, the filtering resistance of the bag filter increases and the filtering efficiency decreases.
The bag filter is shaken for about seconds to shake off the fine powder adhering to the bag filter.

However, in the conventional fluidized bed granulation drying equipment, only one filter chamber is provided to accommodate the bag filter, and of course there is only one bag filter.
Only one set is provided. Therefore, during the shaking operation of the bag filter, it is necessary to completely stop the flow of the powder in the flow chamber, resulting in the following problems.

(1) Since the granulation operation is stopped during the time the fluidization is stopped and until the normal fluidized bed state is achieved after the fluidization is restarted, the working time becomes longer.

(2) When the flow is stopped, the powder and granules pass through the perforated plate at the bottom of the flow chamber and fall, so to prevent this, the perforated plate must have fine mesh. There is a limit to the amount and speed of air that can be blown up from the plate, reducing work efficiency and drying performance.

(3) When the flow is stopped, if some of the powder or granules are semi-dry, they may stick to the perforated plate, or the powder or granules may stick to each other and form clumps, making it impossible to continue normal work. Therefore, there are restrictions on the properties of the solution and the amount of spraying, and it is necessary to spray a solution that tends to dry easily in small amounts.

An example of this type of fluidized bed granulation/drying apparatus is the one described in Japanese Patent Application Laid-Open No. 53-21084. This conventional technology equips the filter with a shaking mechanism,
It is equipped with a discontinuous granulation automatic control device that repeatedly performs a liquid spray cycle that repeats liquid spray and filter shaking, and a drying cycle that repeats drying and filter shaking.

However, in this conventional technology, there is only one set of filter chamber and bag filter.
During filter shaking, it is necessary to completely stop the flow of the powder in the flow chamber, so the problems in (1) to (3) above have not been solved at all.

The purpose of the present invention is to solve the problems of the conventional technology described above, and to enable continuous and efficient granulation drying without stopping the flow of powder and granules in the fluidization chamber. The goal is to provide equipment.

In order to achieve this purpose, the fluidized bed granulation drying apparatus of the present invention divides the filter chamber into a plurality of divided chambers each communicating with the fluidized chamber, and mechanically completely connects the bag filters to each divided chamber. The bag filters in each divided chamber are connected to respective shaking devices different from the bag filters in other divided chambers, and each shaking device is mechanically completely independent from other shaking devices. The baggage filters in each divided chamber are controlled completely independently from each other, and the baggage filters in each divided chamber can be controlled independently of the baggage filters in other divided chambers without stopping the flow of powder or granules in the flow chamber. Due to the configuration in which the shaking is performed independently, even when the baggage filter in one of the divided chambers is shaken, the other baggage filters are not shaken, so that the flow of the powder and granules in the flow chamber is prevented. It is possible to carry out granulation and drying work continuously without any interruptions.

Hereinafter, the present invention will be specifically explained based on the illustrated embodiments.

FIG. 1 is a partially cutaway vertical cross-sectional view of a fluidized bed granulation drying apparatus which is an embodiment of the present invention, and FIG. 2 is a plan view thereof.

In the fluidized bed granulation and drying apparatus of this embodiment, reference numeral 1 indicates a fluidization chamber, 2 a spray chamber, and 3 a filter chamber. These are the same as ordinary fluidized bed granulation and drying equipment of this type, and the fluidization chamber 1 is for making the powder or granules, which is the material to be processed, into a fluidized state, and has an inverted truncated conical shape. The bottom surface is composed of a perforated plate 4 having holes through which a gas such as hot air or cold air can flow, and a hot air supply duct 5 is connected to the lower side of the perforated plate 4 so that the hot air can flow through the perforated plate 4. The liquid is blown up into the flow chamber 1 through the holes in the dish plate 4.

The spray chamber 2 is for spraying a binder or coating agent solution onto the powder particles forming a fluidized bed in the fluidized chamber 1. For this spraying, one or several particles are sprayed toward the fluidized bed. spray nozzles 6 are arranged.

The filter chamber 3 is divided into two or more chambers. Each of the divided chambers in this filter chamber 3 is independent, and one set of baggage filters 7 is installed in each divided chamber independently of the baggage filters 7 in other divided chambers. Exhaust ducts 8 are individually connected to. As is clear from FIG. 2, the exhaust ducts 8 are combined into one common duct outside the apparatus and connected to the same exhaust source (not shown), such as an exhaust fan.

Each set of bag filters 7 is suspended from a hanging rod 9, and each hanging rod 9 is connected to a shaking cylinder 10 installed outside. Shaking is automatically performed at regular intervals independently of the bag filter 7 in the divided chamber. On the other hand, each exhaust duct 8 is provided with a damper flap 11, and the damper flap 11 is connected to a damper flap cylinder 12 provided outside the exhaust duct 8. By operating the flap 11, the exhaust duct 8 is automatically opened or closed.

Of course, in this case, a shaking cylinder 10 installed for shaking each bag filter 7 for each divided chamber of the filter chamber 3, and a damper flat installed in the exhaust duct 8 communicating with each divided chamber are also used. push cylinder 12
and are linked to each divided room. Therefore, when shaking the bag filter 7 in one divided chamber, the damper flap 11 corresponding to that divided chamber is closed to stop the exhaust gas. At that time, the bag filter 7 in the other divided chamber is not shaken and remains in a state where normal fine powder collection is possible, and the flow of the powder and granules in the flow chamber 1 is always continuously carried out. .

Next, a procedure for performing a granulation operation using the fluidized bed granulation and drying apparatus of this embodiment configured as described above will be explained.

First, a predetermined amount of granular material is put into the flow chamber 1 according to a conventional method, and an exhaust fan (not shown) is started. Then, the air in the tank is exhausted through the exhaust duct 8, so hot air enters the tank from the supply duct 5 through the perforated plate 4 and into the flow chamber 1, and this hot air further rises inside the tank. Eventually, the fine powder is collected through the bag filter 7 and then discharged to the outside of the system. The powder particles are blown up in the fluidization chamber 1 by this rising air flow to form a fluidized bed. Therefore, a required solution such as a binding liquid is sprayed onto the fluidized bed from the spray nozzle 6.

The granulation work is performed in this manner, but as the work time elapses, the bag filter 7 becomes clogged with the collected fine particles and the filtration resistance increases.

Therefore, first, the damper flap cylinder 1 provided for one of the divided chambers of the filter chamber 3 is
2 to close one exhaust duct 8, and then operate the shaking cylinder 10 provided for the same divided chamber to shake the bag filter 7 provided in the divided chamber to remove the fine powder attached thereto. brush off.

At this time, the exhaust duct 8 provided for the other divided chamber remains open, and the other shaking cylinder 10 is also not operated.
The bag filter 7 in the other divided chamber is not shaken, and the hot air in the tank is discharged from the other divided chamber through the other exhaust duct 8 by the suction force from an exhaust fan (not shown), so that the air inside the flow chamber 1 is not shaken. The powder remains in a fluid state continuously.
Therefore, even at this time, the granulation operation is not stopped and is always carried out continuously.

Next, the baggage filter 7 in the other divided chamber
is also shaken in the same manner, but at this time, the bag filter 7 in the one divided chamber that has already finished shaking as described above is not shaken, and the filtering and discharge of hot air from the one divided chamber continues. Therefore, even at this time, the flow of the powder and granules in the flow chamber 1 does not stop, and the granulation operation continues without any interruption.

In this manner, the bag filter 7 is alternately shaken in each of the divided chambers of the filter chamber 3, and the granulation and drying operation is carried out continuously without interruption.

It should be noted that the present invention is not limited to the above embodiments, and various other modifications are possible.

For example, the inside of the filter chamber 3 may be divided into three or more divided chambers, and a bag filter 7 and a shaking device may be provided for each divided chamber.

As detailed above, in the fluidized bed granulation drying apparatus of the present invention, the filter chamber is divided into two or more chambers, and the baggage filter in each divided chamber is separated from the baggage filter in the other divided chambers. In other words, the bag filter is divided into two or more sets corresponding to each divided chamber of the filter chamber, and shaking is performed for each divided unit, so that one divided filter is formed. While the bag filter in the room is being shaken, the bag filters in other divided chambers are not shaken, and the other bag filters can perform ventilation, filtration, and exhaust as usual, so the granulation work can be continued at all times. Shaking of the bag filters can be performed alternately and sequentially in each divided chamber.

Therefore, the fluidized bed granulation and drying apparatus of the present invention has the following advantages.

(1) When shaking the bag filter, the granulation and drying work is not interrupted, so the work time is shortened and work efficiency is improved.

(2) While one set of baggage filters is being shaken, the filtration efficiency decreases accordingly, but by sequentially shaking multiple baggage filters, individual baggage filters can be cleaned before the degree of clogging increases. As a result, the bag filter as a whole can maintain a high filtration capacity at all times, improving and stabilizing work efficiency.

(3) Since the granulation and drying work is not interrupted, hot air is constantly blown up from the perforated plate during the work, and there is no risk of the powder falling from the perforated plate.
Since a perforated plate plate with large openings can be used, a large amount of hot air can be blown up, and the drying efficiency is significantly improved.

(4) For the same reason as (3) above, it is now possible to use a rotating punching plate or a rotating slit plate (for example, Japanese Patent Publication No. 61-5591) instead of a screen for the perforated plate, and The number of body types increases.

(5) Since the powder does not rest on the perforated plate during work, it is possible to spray a large amount of solution onto the powder, and it is also possible to spray a solution that dries slowly. .

(6) Even if it becomes necessary to replace or repair the baggage filter, etc., it is only necessary to replace or repair one set or one baggage filter.
This is more cost-effective than replacing the entire bag filter.

(7) Furthermore, in the present invention, not only the filter chamber is divided into a plurality of divided chambers, but also
Each of the shaking devices to which the baggage filters in each divided chamber are connected is made completely mechanically independent from other shaking devices, and individually controls the baggage filters in each divided chamber completely independently of each other. With this structure, the shaking of the bag filters in each divided chamber can be controlled independently and more easily and more reliably than, for example, a method of switching the pulse jet using a switching valve. .

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway vertical cross-sectional view showing a fluidized bed granulation and drying apparatus which is an embodiment of the present invention, and FIG. 2 is a plan view thereof. 1... Flow chamber, 2... Spraying chamber, 3... Filter chamber, 4... Perforated plate, 5... Hot air supply duct, 6
...Spray nozzle, 7...Bag filter, 8...
... Exhaust duct, 9 ... Hanging rod, 10 ... Shaking cylinder, 11 ... Damper flap, 12
...damper flap cylinder.

Claims (1)

[Scope of utility model registration request] The filter chamber is divided into a plurality of divided chambers each communicating with a flow chamber, and each divided chamber is provided with a bag filter that is mechanically completely independent of each other, and the bag filter in each divided chamber is connected to the bag filter in another divided chamber. and each shaking device is connected to each shaking device separate from the other shaking devices, and each shaking device is configured to be mechanically completely independent from the other shaking devices so that the bag filters of each divided chamber are individually controlled completely independently of each other. The fluidized bed granulation is characterized in that the bag filter in each divided chamber is shaken independently from the bag filters in other divided chambers without stopping the flow of the powder or granules in the fluidizing chamber. drying equipment.