JPS6295125A - Method for controlling granulation of hygroscopic powder - Google Patents

Abstract

PURPOSE:To eliminate the defective fluidization of a material to be granulated by controlling the velocity of a binder supply pump or the opening degree of a flow control valve on the basis of the water content of the material to be granulated detected by a water content detecting means provided in a fluidization chamber. CONSTITUTION:Hot air at a temp. regulated by a temp. controller is forced under pressure from a hot air chamber 12 into the fluidization chamber 1a in the main granulator body 1 through many through holes 13a provided to a gas diffusion plate 13, and the material to be granulated on the inside is fluidized. Meanwhile, purging air supplied from the main purge pipe 4a furnished to a detection cylinder 4 is passed through the detection cylinder 4 and blown on the fluidized material to be granulated in the vicinity of the opening part of the main ganulator body 1. Consequently, the powdery particles are not allowed to intrude into the detection cylinder 4 and practically moved the opening part.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention is a method of manufacturing granules or granules of a desired particle size by adding a binder liquid to a highly hygroscopic powder while fluidizing it. The present invention relates to a method of controlling a granulation device to achieve this.

[Conventional technology]

In the case of fluidized granulation equipment, which fluidizes the raw material powder in a hot air stream and adds a binder liquid to it, the powder particles adhere and aggregate to form granules. The moisture content of the granules has a certain range depending on their properties, and when the moisture content exceeds this upper limit, the flow rapidly slows down and agglomerates are generated.

Furthermore, when the moisture content increases, the flow stops and the powder solidifies into lumps, making it impossible to operate the granulator. Some I/1s use methods such as detecting exhaust humidity and controlling the hot air temperature or binder addition rate, and in the case of batch type, the binder addition is done while controlling the hot air temperature and air volume at a constant level. A common method was to set the time using a timer. On the other hand, in the granulation operation of hygroscopic powder, the range of moisture content that can maintain proper fluidity is very narrow; for example, in the case of amino acid-containing seasonings, this upper limit is about 3% D, B, and powdered soy sauce. If the case is 5, 13. If the water content exceeds this level, the flow condition will rapidly deteriorate and the flow will stop within a very short time.

[Problems to be solved by the invention] With the conventional control method of the granulation device as described above, such a minute change in moisture content cannot be detected as a change in exhaust temperature or humidity, and batch operation is not possible. In this case, the supplied heat landscape is not constant due to clogging of the pack filter built into the main unit, etc., so drying f'r = t such as repeating addition of binder liquid and intermediate drying, etc. In order to avoid the possibility that the powder particles would stop flowing and solidify, it was necessary to keep the water content quite low.

As shown in this Q], conventional methods cannot detect the increase in water content that causes poor flow;
Therefore, the growth rate of particles is slow because it has to be monitored and the moisture content has to be monitored and operated at a low level.
Therefore, a long granulation time is required, and the desired particle size (
However, there was a problem in that it was difficult to improve the yield of the product.

This invention has been developed to solve these problems, and it is possible to obtain products with a stable particle size during continuous operation without causing poor flow of the granulated material, and to reduce the granulation time. The purpose of the present invention is to provide a method for controlling granulation of hygroscopic powder that can shorten the time and improve product yield.

[Means for solving problems]

In the granulation control method according to the present invention, the moisture content of a flowing granulated material is detected with high precision by a moisture content detection means, and based on this detected value, the moisture content is detected through a moisture regulator. The water content of the article 7 (women's article) is controlled to be uniform by adjusting the rotational speed of the binder supply pump to increase or decrease the rate of addition of the binder.

[(action)]

In this process, the flowing granulated material is continuously maintained at an appropriate moisture content, so that lumps are generated in the granulated material during operation. In addition, it is possible to control the growth time of the lint to obtain a uniform particle size, that is, the rate of increase in the moisture content of the odor product during the granulation operation, and to obtain the desired Accurately control the water content at the end of the granulation operation to obtain an average particle size.

〔Example〕

FIG. 1 is a schematic diagram showing the overall configuration of a granulating apparatus for hygroscopic powder according to an embodiment of the present invention, in which (1) is a main body of the granulating apparatus for storing and processing a material to be granulated; ) is the binder liquid spray nozzle, (3) is the infrared absorption moisture meter, and the detection tube (4) is the
The moisture content of the powder during the granulation process, which is flowing into the inside of the apparatus main body (1) through the granulation process, is detected continuously and in a non-contact manner. (5) 1′! Infrared absorption moisture meter (
(3) is a moisture controller that moves f/F according to the detected output signal; (6) is a speed setting device that is set by the adjustment output f of this moisture controller; (the force is set by this speed setting device ( A binder supply pump that operates according to the settings in step 6), which increases or decreases the amount of binder liquid supplied to the binder liquid spray nozzle (2). A blowing fan blows air to (9), (1, 1 detects the outlet temperature of the heat exchanger (9) and sets it to the deviation t.) The control valve (11) is actuated by an output signal corresponding to the temperature at the outlet of the heat exchanger (9). A temperature regulator controls the amount of steam supplied to the granulator (9); one is the opening provided at the bottom of the granulator body (1) through which hot air from the heat exchanger (9) is sent. Hot air chamber, (13)
αa is a gas dispersion plate with a large number of holes penetrating the hot air chamber α and the flowing granulated material, and αa is a gas dispersion plate that collects fine powder scattered from inside the granulator main body (1) and recycles it. A bank filter is used to blow the air into the fluidized bed, and an exhaust fan is used to discharge the purified air to the outside.

FIG. 2 is a cross-sectional view showing the details of the infrared absorption moisture meter (3), the detection cylinder (4), and the attachment part of the granulator main body (1) to which they are attached in FIG. Figure, Nishi 1
(4a) is the main purge pipe, (4b) is the sub purge pipe,
Purge air is supplied from an air source (not shown).
I'm in peace.

In the granulation control device according to the present invention configured as described above, as shown in FIG. 2, the granulation device body ( 1) Hot air at a predetermined temperature controlled by the flow chamber (1a)z temperature controller α0 inside the flow chamber (1a) is forced into the flow chamber (1a) of the granulator main body (1), and the material to be granulated inside is brought into a fluid state. On the other hand, purge air supplied from the main purge pipe (4a) provided with the detection cylinder (4) passes through the detection cylinder (4) and is maintained near the opening of the granulator main body (1). In order to spray the fluidized material to be granulated, the powder moves along the detection tube (4b) without entering the detection tube (4b). ) Purge air is used to eliminate powder particles that tend to adhere to the bottom of the detection tube (4).

Therefore, the powder and granular material appears to remain in a constant state relative to the infrared absorption moisture meter (3), so when infrared rays are irradiated, the light energy is absorbed by the measured object according to the amount of water contained in the measured object. This satisfies the requirements for a measurement surface that measures the amount of attenuation of light that is reflected and returns.

Under the above stable measurement conditions, the moisture content of the granulated material detected by the infrared absorption moisture meter (3) is converted into a predetermined signal and input to the moisture controller (5). The speed setting device (6) is actuated according to the amount of deviation between the detected moisture content and the desired setting value depending on the type of grain, and the binder supply pump ( 7) rotation speed, that is, the flow rate, the binder liquid and jetting air are mixed and exposed, and the binder liquid jetting nozzle (
2) The material to be granulated is granulated while being fluidized within a predetermined temperature and moisture content range by injecting the material.

That's it! ! As a result of conducting experiments on fluidized bed granulation of hygroscopic powders such as powdered soy sauce and amino acid-containing seasonings using the granulation control method based on the present invention, it was found that: Regardless of the amount of solids in the binder liquid, it is determined only by the moisture content of the powder. (2) The amount of solids in the binder liquid added affects the strength of the particles, and if the amount added is small 1/1, the proportion of powdering during finishing drying increases. ■
Therefore, for example, if the particles after finishing drying are sieved using a 100-mesh sieve 1 and the yield of particles on the sieve 1 is compared, it is found that if the solid content of the binder is the same, the powder The yield of the product will be better if the granulation operation is performed with a higher moisture content. We were able to understand the correlation between the above granulation conditions and the results.

In other words, by appropriately setting the powder moisture content at the end of binder addition or the rate of increase in moisture content at the time of binder addition, the product particle size can be arbitrarily controlled, and the desired particle size can be achieved. It was found that the yield of the product could be improved.

FIGS. 3 and 4 are diagrams showing experimental results based on the above embodiment in a batch type granulator.

Figure 6 shows an example of the operation of powdered soy sauce, and is a diagram comparing the yield of the granulated material on a 100-mesh sieve when the amount of binder liquid added is the same and only the operating moisture content is changed.
There was a clear correlation between the moisture content and the yield on a 100 mesh sieve, and by increasing the moisture content at the end of the operation by 21 D, B, it was possible to increase the yield by 35%.

Figure 4 shows an example of the operation of an amino acid seasoning, and the horizontal axis represents the operation time for the conventional method and the method according to the present invention, and the moisture content and the yield on 100 mesh sieves of the granulated material. By setting the water content at the end of the operation to 28% D, B, just before flow failure occurs, the operation time and amount of binder liquid added can be reduced by approximately 1/2 compared to the conventional method. However, on the contrary, the yield on the 1 Dog sieve was able to be improved by more than 18.

The operating conditions for the above experiment were as follows.

Equipment used: Batch-type fluidized bed granulation equipment (with built-in stirring device) Fluidized bed area: 0.2 yl Hot air temperature ° 80°C Flow, air speed: o, s2 m, skin binder 2.0 ml Potato starch binding liquid speed : (Conventional method) 1. 0 to 48 minutes, 7 minutes, 5 minutes of spray, 1 minute in between (cycle spray) 2. 48 to 60 minutes - 1109 fi (continuous spray) (according to this invention) Method) 1. Maximum binder addition rate: 110g 2. Moisture controller setting: 2.8% D, B.

In the above embodiment, hot air is blown from the gas dispersion plate (1) provided at the bottom of the granulator body (1) to fluidize and stir the granulated material. (1)
Even when the material to be granulated is fluidized using a mechanical stirring device or the like, the same effect as in the above embodiment can be obtained.

[Effects of the Invention] As explained above, the present invention detects the moisture content of a flowing granulated material with high accuracy, and determines the appropriate moisture content for the granulated material during granulation based on this detected value. In addition to maintaining the moisture content at the same rate, the increase rate of the water content can be controlled freely, so products with the desired particle size can be stably obtained through continuous automatic operation, and the granulation time can be shortened. In addition, it has the effect of improving product yield.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram schematically showing an apparatus according to a granulation control method E according to an embodiment of the present invention, and FIG. 2 is a detailed view of a main part of a moisture content detection section in FIG. 1. 3 and 4 are diagrams showing the experimental results according to the present invention. part, (2) is a binder liquid jet 7 nozzle, (3) is an infrared absorption moisture meter, (5) is a moisture controller,
(6) is a speed setting device, (7) is a binder supply pump, (8
) is a blower fan, 0■ is a temperature controller. Note that the same reference numerals in the figures indicate the same parts. Agent Patent Attorney Tadashi Sato Figure 1 5X molecule 1ill'5R+0: A11e1 Section Fh 2nd
Figure 3 Figure 4 Kichi de Te*ll t Karo! = 4i Heite Shibu 11 (Hyakuta Shibu)) / Ondi 4kF Roga Sugi 6 [%Co Figure 4 Between No. T3 (minutes)

Claims (2)

[Claims] (1) The material to be granulated stored in the fluidization chamber is fluidized using forced air or a stirring device, and a binder is added to the fluidized material to aggregate and granulate the powder particles. In the apparatus, the moisture content of the fluidized granulation material is directly and continuously detected by a moisture content detection means installed at an appropriate position in the fluidization chamber, and the moisture content of the fluidized granulated material is directly and continuously detected. By adjusting the speed of the binder supply pump or the opening of the metering valve, the rate of addition of the binder liquid from the binder liquid spray nozzle can be increased or decreased, and the flow hot air can be By adjusting the temperature or air flow rate, the drying rate of the solvent in the binder liquid is increased or decreased, and the moisture content of the granulated material or the rate of increase in the moisture content is controlled to a predetermined value, and the rate of increase in the moisture content is controlled to be closely related to the moisture content. Moisture absorption characterized by obtaining granules or granules of a desired particle size while maintaining the values of the above specifications so that granulation proceeds in a short time with the highest yield in the growth rate of particles that have a relationship between A method for controlling granulation of powder. (2) Moisture absorption according to claim 1, characterized in that an infrared absorption moisture meter is used as the moisture detection means to detect moisture without contacting the granulated material as the object to be measured. A method for controlling granulation of powder.