JP3352148B2 - Dish-type rolling granulation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dish rolling granulation method for producing a granulated product having a small particle size.

[0002]

2. Description of the Related Art Rolling granulation in a dish type involves rotating a tub-shaped container (hereinafter referred to as a pan) inclined at 40 to 60 degrees.
This is a general rolling granulation method in which a powder and a binder liquid are added to this container continuously or alternately little by little, and the powder is rolled to grow in a snowball manner and granulate into a spherical shape. It is used to granulate powder of feed, metal, ceramics, etc. into a spherical shape. The granulated product obtained in this way usually has to have a dense inside and good sphericity. For example, a ceramic granulated product is an intermediate for firing into a spherical ceramic product such as a crushing ball, but the molded product has an internal defect in order to make the product high strength. It is also required that the product be close to a true sphere in order to make the product highly wear-resistant.

[0003] By the way, if the droplet of the binder liquid is large,
The granules adhere to each other to form a gourd, or several granules adhere to each other to form a dumpling, which is far from a true sphere. In addition, if the growth is performed while the core particles and the granules during the growth process are attached, the granulated product not only has a bad shape but also has internal defects.

[0004] In order to avoid such a problem, a method of uniformly dispersing the binder liquid into droplets as small as possible using a sprayer or the like has conventionally been adopted.

[0005]

However, when a sprayer is used, the binder liquid is spread over a wide area, so that not only the rolling layer but also the inner wall of the bread scatters, where the droplets aggregate to form a larger liquid. The raw material powder adheres and deposits on the surface, and the surface state of the bread becomes uneven, and the rolling state of the granules deteriorates, or the granulated materials adhere to each other due to the aggregated liquid, and the shape is poor. In addition, a molded article having a defect therein can be obtained.

Further, the size of the droplets sprayed from the sprayer is not always uniform, and sometimes a large droplet drips from the tip of the nozzle of the sprayer. As described above, these large droplets are obstacles to obtaining a granulated product having good sphericity and a dense inside.

When the size of the target granulated product is as small as 2 mm or less, the influence of the size of the droplet is particularly large, and the particles that have adhered to each other due to their small weight cause rolling. It is hard to separate even if you receive it.

In the case of a dish-type granulator having a pan diameter of 1 m or less, the sprayer and the spray amount per unit time must be small, but it is difficult to obtain and manufacture such a sprayer. .

An object of the present invention is to solve such a problem,
That is, when granulating with a dish granulator, without adhering the binder liquid to unnecessary places, and
The supply flow rate of the binder liquid can be extremely reduced, and even when a core particle having a small particle size of 2 mm or less is used, the core particle and the granulated product are not adhered to each other without causing any adhesion. It is an object of the present invention to provide a method capable of producing a sphere having good sphericity and having no defect inside.

[0010]

SUMMARY OF THE INVENTION The present invention relates to a method for producing a granulated product by a dish-type tumbling granulation method using core particles and adding a binder solution and powder .
Diameter of lower particle size or less of the nuclear particles, and, characterized in that said tip is supplied binder liquid from the tip of the capillary is inserted into the rolling layer, dish rolling granulation method. When using a thing having a particle diameter of 2 mm or less as core particles, and obtaining a granulated product by a dish-type tumbling granulation method by adding a binder liquid and powder, the inner diameter of the tip is not larger than the particle diameter of the core particles, In addition, the gist of the present invention is a dish-type tumbling granulation method by supplying a binder liquid from the tip of a thin tube having a tip inserted into a rolling layer.

Hereinafter, the details will be described.

There are various methods for producing core particles.
There is no particular problem in any method as long as there is no defect inside the nucleus. For example, if the particle size of the desired core particles is 0.5
When the diameter is not more than mm, core particles may be produced by a stirring granulation method, and dense core particles can be obtained by the method. Further, the particle size of the desired core particles is 0.3 to 2.
In the case of 0 mm, the present invention is applied in two or more stages as in the stirring granulation method → the present invention method → the present invention method, and the same as the above-described core particles of the desired size in the stage before the final stage. What is necessary is just to obtain a granulated product having a size and use it as a core particle in the final stage to produce a desired granulated product. The core particles having a particle diameter of 0.3 mm were subjected to a dish-type tumbling granulation method of the present invention to have a particle diameter of 10 mm.
However, in the dish-type tumbling granulation method, it takes a relatively long time to grow small core particles to a large size. It is preferable to use core particles having a particle size as close as possible to the particle size. Therefore, the method of applying the present invention in a plurality of stages is effective. Further, for example, when the purpose is to produce a molded granulated product having a particularly small particle size, a product very close to the particle size is produced by a stirring granulation method or the like, and the sphericity obtained in this manner is obtained. The present invention can be applied to the inferior granules as core particles to increase the sphericity with little growth.

The insertion position of the tip of the capillary for supplying the binder liquid may be anywhere as long as it is within the rolling layer while the granulator is operating. The inside diameter of the tip of the capillary must be smaller than the particle size of the core particles. If the inner diameter is too large, the core particles and the granules in the granulation process adhere to each other. However, the smaller the inner diameter is, the higher the supply pressure of the binder liquid must be.
m or less, the inner diameter of the tip may be 0.3 mm or less within a range not exceeding the particle diameter of the core particles, and 0.5 mm if the diameter of the granulated material is larger than 0.5 mm. do it.

The rate of injecting the binder solution varies depending on the amount of the powder, its properties, the size and rotation speed of the bread, etc., but usually it is preferably about 1 to 3 ml / min per thin tube. If the injection speed is too high with only one of the thin tubes, the amount of the binder solution is locally too large, so that it is difficult to avoid the adhesion of the granules and the like.

A bread diameter of 1 m or less and an amount of granulated material of 2 kg
In the case of less than about, one thin tube is sufficient, but when the bread diameter is large and there are many granulated materials, the number of thin tubes is increased according to the amount of granulated material to shorten the injection time. Is preferred.

As the thin tube, a commercially available injection needle or the like can be suitably used. Injection of the binder liquid can be carried out by using a trace amount metering pump or a medical dropper when the scale is small.

The granulated material is injected by the above-described method, and the granulated material is humidified with the binder liquid. The addition of the binder liquid is stopped immediately before the adhesion of the granulated materials starts, and then the powder is added little by little to humidify. The powder is evenly attached to the surface of the granulated material. As described above, the spheres can be grown and the spheres having the desired size can be produced by repeating the operation of adding the liquid and adding the powder.

[0018]

According to the present invention, the adhesion and accumulation of the raw material powder on the inner wall of the bread and the prevention of the adhesion of the granulated materials can be achieved because the supply of the binder liquid is carried out by a thin tube, so that the supply flow rate can be reduced. In addition, since the tip of the thin tube is buried in the rolling layer, it is considered that the binder liquid is prevented from being continuously adhered and removed by the granulated material to form a large droplet.

[0019]

According to the present invention, the binder liquid is not attached to unnecessary places, the supply flow rate of the binder liquid can be extremely reduced, and the core particles can be as small as 2 mm or less. Even when a sphere is used, spheres having good sphericity and having no defect inside can be produced by a dish granulator without causing adhesion of core particles and granules.

[0020]

Examples are shown below.

Example 1 A stirring granulator for a vertical cylindrical container (stirring blade length 147)
TD-3YS-T2 manufactured by Tosoh Corporation, using four paddle-type blades having a height of 25 mm and a height of 25 mm, and a container made of polyethylene and having an inner diameter of 165 mm and a height of 170 mm.
000 g was put into a container, and water was added little by little as a binder while rotating the stirring blade at 750 rpm, to make the whole powder into small granules. The obtained small granules were once taken out and classified with a 0.3 mm sieve to obtain 0.3 g.
Coarse grains exceeding mm were removed to obtain 1300 g of granules having a size of 0.3 mm or less.

1300 g of the granules having a size of 0.3 mm or less
Is charged into the above-mentioned stirring granulation container, and the stirring blade is set at 750 rpm.
While rotating at m, small amounts of zirconia powder and water were alternately added to grow granules to obtain 2498 g of small spheres.

This small sphere is classified into 0.3 to 0.5 mm
1120 g of a sphere was obtained.

Next, this 0.3-0.5 mm sphere 10
As a core particle, 00 g was charged into a pan-type granulator (pan diameter 60 cm, pan inclination angle 50 degrees) manufactured by Kushida Ironworks Co., Ltd., and the pan was rotated at 36 rpm. In order to add water as a binder, the injection needle (inner diameter 0.3 mm) of a medical dropper is inserted into the rolling granulation layer, and water is discharged from the dropper at a rate of 1.5 ml / min. At a speed of 2 minutes. Stop the injection, and then add 30 g of the above zirconia powder to 0.5 m
Then, the powder was sprinkled little by little on the granulated material through a sieve of m to attach the powder to the granulated material, and then liquid injection was started in the same manner as described above. In this way, the injection and the addition of the powder were alternately repeated to grow the nucleus, and a sphere having a diameter of about 2 mm was obtained.

During the granulation operation, there was no unnecessary adhesion of the powder to the inner wall of the bread, and no adhesion between the core particles and the granules occurred.

Each of the obtained granulated spheres had a ratio of the maximum diameter to the minimum diameter of the same sphere of about 1.03, and had good sphericity.

Comparative Example 1 Granulation was performed in the same manner as in Example 1 except that the dish-type tumbling granulation liquid was injected using a sprayer for home ironing.

The sprayed water adheres to the inner wall of the bread,
Powder and spheres adhered where water adhered, and the normal rolling state of the granulated product could not be obtained.

At the start of the granulation, a large amount of core particles adhered to each other, and some of the obtained granulated spheres were adhered to each other.

Claims (2)

(57) [Claims] When a granulated product is manufactured by a dish-type tumbling granulation method using a core particle and adding a binder solution and powder, the inner diameter of the tip is smaller than the particle size of the core particle.
Is lower, and, characterized in that said tip is supplied binder liquid from the tip of the capillary is inserted into the rolling layer, dish rolling granulation method. 2. Use of core particles having a particle size of 2 mm or less.
The method of claim 1, wherein the method comprises the steps of :