JP2572809B2 - Manufacturing method of granular fertilizer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a granular fertilizer. More specifically, the present invention relates to a method for stably producing a granular fertilizer with high yield.

(Prior art)

Conventionally, in the production of granular fertilizer, the operator samples the granulated fertilizer coming out of the granulator, visually or by hand sieving to grasp the granulation state, and the amount of water supplied to the granulator. Was decided.

[Problems to be solved by the invention]

According to this method, it takes much time and labor, and the difference between individuals cannot be neglected due to the intuition and experience of the operator, and improvement has been desired in terms of stable operation and improvement of yield.

[Means for solving the problem]

The present inventors have conducted intensive studies on the method of manufacturing granular fertilizer, and as a result, captured the granulated fertilizer output from the granulator as a still image, processed this specific computer, and operated based on the obtained information. When determining the amount, it was confirmed that labor could be reduced and time could be reduced, and that stable operation could be performed for a long period without any problem of individual differences between operators, and the present invention was completed.

That is, an object of the present invention is to produce a granular fertilizer in an industrially advantageous manner. The purpose of the present invention is to supply a fertilizer raw material, water and / or steam to a granulator, granulate the resultant, and screen it. In the method of manufacturing a granular fertilizer to obtain a product granular fertilizer by: a) photographing the flow of the granulated fertilizer as a still image at an arbitrary point from the granulator outlet to the sieve inlet; Calculate the weight and particle size distribution of the granulated granulated fertilizer and calculate the particle size range of the desired product granular fertilizer (hereinafter referred to as product size), the particle size range smaller than the desired product granular fertilizer (hereinafter referred to as fine powder), and Determine the weight percentage of the range of particle size larger than the product granular fertilizer (hereinafter referred to as coarse grain), and c compare the weight percentage of each of the above ranges with the weight percentage of those ranges when ideally granulated. By granulation of granular fertilizer Recognizing the condition, d When it is necessary to increase the particle size of the granulated fertilizer as a whole, increase the water content in the granulator and reduce the particle size of the granulated fertilizer as a whole. When necessary, this is achieved by reducing the amount of water in the granulator.

The granular fertilizer to be used in the present invention is a fertilizer based on the Fertilizer Control Law, and is a granular or lump having a particle size of 1 to 4 mm. In terms of fertilizer components, nitrogenous fertilizer, phosphate fertilizer, potassium fertilizer, first-class composite fertilizer, calcareous fertilizer, silicate fertilizer, magnesia fertilizer, manganese fertilizer, boric fertilizer, trace element composite fertilizer, etc. However, natural products such as phosphate rock, which is a raw material of fertilizer, can also be used.

Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing an example of an embodiment of the present invention. In the figure, 1 is a granulator, 2 is a fertilizer raw material inlet, 3 is a water and / or steam inlet, 4 is a circulating fine powder inlet, 5 is a flow of granulated fertilizer, 6 is a television camera, 7 is a control system. , 8 is a control signal, 9 is a dryer, 10 is a flow of dry granular fertilizer, 11 is a fine powder hopper, 12 is a product size hopper, 13 is a coarse particle hopper, 14 is a product granular fertilizer outlet, 15 is a crusher, Reference numeral 16 denotes a circulating fine powder line and 17 denotes a circulating fine powder hopper.

The fertilizer raw material, water and / or steam and circulating fine powder are supplied to the granulator 1, and the granulation is performed to perform granulation. Although various types of granulators can be used, a drum type granulator is suitable for continuous operation.

From the fertilizer raw material inlet 2, the fertilizer raw materials are introduced individually or mixed. From the water and / or steam inlet 3
Water and / or steam are introduced according to a formula determined according to the type of granular fertilizer to be produced. Circulating fine powder inlet 4
Then, the circulating fine powder from the circulating fine powder hopper 17 is introduced.

The granular fertilizer granulated by the granulator 1 is dried by the dryer 9, and the dried granular fertilizer 10 is sieved into fine powder, product size and coarse particles by a sieve, and the fine powder hopper 11 and the product size hopper respectively. 12 and coarse hopper 13.

In order to capture the flow of the granular fertilizer as a still image, the granulated fertilizer from the granulator 1 to the dryer 9 can be arbitrarily selected from the outlet of the granulator 1 to the entrance of the sieve. Flow 5
Or flow 10 of dry granular fertilizer from dryer 9 to the entrance of the sieve
It is preferable to take an image of the flow 5 of the granulated fertilizer as it is not affected by crushing during drying.

In order to form a still image of the flow of the granular fertilizer, it is preferable to employ a combination of the television camera 6 and a strobe light or a shutter. For example, a television camera as described in Japanese Patent Application Laid-Open No. 60-15541. Then, a still image can be easily obtained by irradiating the object with the stroboscopic slit light from the direction perpendicular to the optical axis of the television camera using the film-like strobe light through the slit.

Although various types of the dryer 9 can be used, a drum type dryer is suitable for continuous operation.

The granular fertilizer that has been sieved and introduced into the product size hopper 12 is extracted from the outlet 14 as product fertilizer. Coarse grain hopper
The coarse particles introduced into 13 are pulverized by a pulverizer 15 and stored in a circulating fine powder hopper 17 through a circulating fine powder line 16 together with the fine powder of the fine powder hopper 11.

In the present invention, in the method for producing a fertilizer as described above, the weight particle size distribution of the granular fertilizer is calculated from the still image, and the weight ratio of the certain particle size range is ideally granulated. By recognizing the granulation state of the granular fertilizer in comparison with the weight ratio, based on the recognition, by adjusting the amount of water in the granulator,
It produces granular fertilizer stably with good yield,
The details will be described below.

In the present invention, the granulation state of the granular fertilizer granulated by the granulator 1 is grasped from a still image photographed by the television camera 6. Specifically, the still image is subjected to computer processing to calculate the particle size distribution, and the weight ratio of the product size, the weight ratio of the fine powder, and the weight ratio of the coarse particles are calculated from the particle size distribution. On the other hand, when the operator collects the granular fertilizer granulated by the granulator 1 from the flow 5 of the granular fertilizer and hand-sieves the product, the product size and the fineness when the granulation is ideally performed. The weight ratio of the powder and the coarse particles is determined as each set value. Specifically, for example, the weight ratio of the product size is 50 to
60%, fine powder weight ratio 25-30%, coarse particle weight ratio 15
It is a value of ~ 20%. By comparing the weight ratio of the product size, the weight ratio of the fine powder, and the weight ratio of the coarse particles, by comparing the value calculated from the still image with the value (set value) when granulation is ideally performed. Recognize the granulation state of granular fertilizer.

That is, if the weight ratio of the fine powder of the granular fertilizer granulated by the granulator 1 is larger than the weight ratio (set value) of the fine powder in the ideal granulated state, the granulated state of the granular fertilizer is If the weight ratio of the coarse particles of the granular fertilizer granulated by the granulator 1 is larger than the weight ratio (set value) of the coarse particles in the ideal granulation state, it can be recognized as being small. The grain state can be recognized as being large. Further, if the weight ratio of the product size of the granular fertilizer granulated by the granulator 1 is equal to or more than the weight ratio (set value) of the product size in the ideal granulated state, the granulated state of the granular fertilizer is good. Can be recognized. In addition, in the comparison of the ideal product size, the weight ratio (set value) of the fine powder and the coarse particles in the ideal granulated state, and those of the granular fertilizer granulated by the granulator 1, other than the above examples There are also complex combinations, for example, the purpose can be achieved by comparing two of the three divisions of fine powder, product size and coarse grain, or fine powder, product size and coarse grain. The grains may be divided into three or more for comparison. Although it is necessary to take into account the degree of expressing the size and the degree of smallness, it is dealt with by performing fuzzy inference using a recognition rule created based on the empirical knowledge of the operator on a computer.

What has the greatest effect on the granulation state or the particle size distribution of the granular fertilizer is the water content of the granulated material. Particles grow larger. Therefore, when it is necessary to increase the particle size of the granular fertilizer in the granulator 1 as a whole,
That is, when the granulation state is recognized to be small by recognition of the granulation state by computer processing or the like, the object can be achieved by increasing the water content of the granular fertilizer in the granulator 1. Conversely, when it is necessary to suppress the growth of the granular fertilizer in the granulator 1, that is, when it is recognized that the granulation state is large, the purpose is to reduce the water content of the granular fertilizer in the granulator 1. Can be achieved.
In other words, the particle size distribution of the granular fertilizer granulated by the granulator 1 is adjusted to an ideal particle size by appropriately adjusting the amount of water supplied to the granulator 1 based on the recognition of the granulation state. The distribution can be approximated.

The following three types of operation variables are used when the granulation state is adjusted in the production of the granular fertilizer, that is, when the water content of the granular fertilizer in the granulator 1 is adjusted.

(I) Water (ii) Water vapor (iii) Circulating fine powder Each of the above three types of manipulated variables has characteristics relating to the granulation of fertilizer, and therefore it is necessary to use differently according to the characteristics. That is, the granulation state of the granular fertilizer is very sensitive to water, and depending on the type of the granular fertilizer, the water content of the granular fertilizer in the granulator 1 becomes too large by adding even a little water, and Some are muddy instead.
Therefore, water is not used for the type where the fertilizer becomes muddy when water is used, and water is not used for other types of fertilizer mainly for the purpose of coarse adjustment of the particle size, that is, when the particle size is required to be largely changed. Good to use. For example, a granulator 1
When the granulation state is small even when 3 to 4% of steam of the weight of the granulated material is supplied, 0.5 to 0.7 of the weight of the granulated material in the granulator 1
5% of water is supplied, and thereafter, if the granulation state remains small, water of 1.0 to 1.5% of the weight of the granulated material in the granulator 1 is supplied to the granulator 1. If the granular fertilizer becomes too large, it is preferable to adjust the granulation state using water as a rough adjustment and steam as a fine adjustment according to the degree.

On the other hand, water is mainly used for coarse adjustment of the granulation state, whereas water vapor is mainly used for fine adjustment of the granulation state. For example, when it is recognized that the granulation state is a little small, the steam supplied to the granulator 1 is increased by about 0.1% of the weight of the granulated material in the granulator 1, and when it is recognized that the granulation state is a little large, the steam is reduced. It is preferable to reduce the weight of the granulated material in the granulator 1 by about 0.1%. If the amount of steam supplied to the granulator 1 is smaller than 3 to 4% of the weight of the granulated material in the granulator 1, coarse adjustment of the granulation state is also performed with steam, and for example, it is recognized that the granulation state is considerably small. It is preferable to increase the steam by about 0.2% of the weight of the granulated material in the granulator 1, and conversely, when it is recognized that the steam is considerably large, reduce the steam by about 0.2% of the weight of the granulated material in the granulator 1. For the granular fertilizer of the type that becomes muddy due to water, even if the amount of steam supplied to the granulator 1 exceeds 3 to 4% of the weight of the granulated material in the granulator 1, It is better to adjust.

Further, since the circulating fine powder stored in the circulating fine powder hopper 17 has been dried by the drier 9, the moisture content of the granulated material in the granulator 1 can be reduced by manipulating this fine powder circulation amount. Can be adjusted. That is, by increasing the amount of circulation of the dried circulating fine powder, the amount of water relative to the weight of the granulated material in the granulator 1 is reduced, and conversely, by decreasing the amount of circulation, the weight of the granulated material in the granulator 1 is reduced. The amount of water to the water increases.
Therefore, the granulation state can be adjusted by increasing or decreasing the fine powder circulation amount. It is also possible to adjust the amount of the circulating fine powder stored in the circulating fine powder hopper 17 by operating the fine powder circulation amount. That is, if the amount of circulating fine powder in the circulating fine powder hopper 17 decreases, the amount of circulating fine powder may be reduced, and if the amount of circulating fine powder stored in the circulating fine powder hopper 17 is large, the amount of circulating fine powder may be increased. Therefore, regarding the operation of the fine powder circulation amount, the operation amount is determined from the relationship between the recognition result of the granulation state and the amount of the circulating fine powder in the circulating fine powder hopper 17.

The operation amounts of the above three types of operation variables are determined by performing fuzzy inference using a control rule created based on the empirical knowledge of the operator by a computer.

The frequency of this treatment may be about once an hour when stable, but usually once every 5 to 40 minutes, preferably 8 to 12 minutes.
Once a minute.

〔The invention's effect〕

According to the method of the present invention, it is possible to greatly reduce labor and time, and there is no problem of individual differences among operators, so that a granular fertilizer can be stably produced with a high yield.

[Brief description of the drawings]

 FIG. 1 is a schematic diagram showing an example of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Granulator 2 ... Fertilizer raw material inlet 3 ... Water and / or steam inlet 4 ... Circulating fine powder inlet 5 ... Flow of granulated granular fertilizer 6 ... TV camera 7 ... Control system 8 Control signal 9 Dryer 10 Dry granular fertilizer flow 11 Fine powder hopper 12 Product hopper 13 Coarse hopper 14 Product granular fertilizer outlet 15 Crusher 16 … Circulating fine powder line 17 …… circulating fine powder hopper

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuhisa Isayama 2447 Fujita, Yawatanishi-ku, Kitakyushu-shi, Fukuoka 1 Kurosaki Plant, Mitsubishi Kasei Kogyo Co., Ltd. (56) References JP-A-62-279835 (JP, A )

Claims (1)

(57) [Claims] 1. A method for producing a granular fertilizer, comprising supplying a fertilizer raw material and water and / or steam to a granulator, granulating and sieving to obtain a product granular fertilizer, comprising: a. At any point up to the entrance, the flow of the granulated fertilizer is photographed as a still image, and b. Calculate the weight range of the diameter range, the range of the particle size finer than the desired product granular fertilizer, and the range of the particle size larger than the desired product granular fertilizer. C The weight ratio of each of the above ranges and each range when ideally granulated. D by recognizing the state of granulation of the granular fertilizer, and when it is necessary to increase the overall particle size of the granulated fertilizer, the water content in the granulator To increase the overall particle size of the granulated fertilizer. When you need to process for the preparation of granular fertilizer, characterized in that to reduce the water content of the granulator.