JPS5844406B2 - Granular fertilizer manufacturing equipment - Google Patents

Description

[Detailed description of the invention] The present invention relates to an apparatus for producing granular fertilizer.

Fertilizers are usually commercially available in granular form for their effectiveness or application.

For example, water, a binder such as an aqueous urea solution is added to a powdered compound fertilizer, and the mixture is rolled and granulated on a rotating plate or in a rotating drum, or a fertilizer mixture containing urea that has been turned into a molten slurry is poured into an air stream or oil. Granular products are manufactured by spraying, cooling and solidifying.

On the other hand, the powdered compound fertilizer is passed through a roll press machine in which many tablet shapes are densely carved, and pressure is continuously applied, and the resulting tablet particles are connected and solidified, and the solidified plate is lightly crushed. Methods for producing granular products are also known.

However, in this method, the tablets produced when the plate-like material is crushed have a large diameter, for example, 41n11L.
For tablets larger than φ, the tablets can be separated and recovered with a relatively good yield by simply applying a transport device such as a screw feeder or a light impact; however, tablets with a small diameter,
For example, when manufacturing tablets smaller than 411TItφ, there is a problem that the tablets are difficult to separate even by applying a light impact because there is not much difference between the thickness of the board that connects the tablets and the diameter of the tablets.

Therefore, in order to separate the tablet from the disk-shaped object, a proposal was made to use a set of 1,000 rolls whose surfaces were processed with rubber or plastic (Japanese Patent Application Laid-open No. 48-48257), but this method still did not allow the tablet to be separated from the tablet. Separation was insufficient and a satisfactory yield could not be obtained.

The present inventors have arrived at the present invention as a result of various studies on devices that can improve the separation of tablets and obtain high yields.

That is, in producing granular fertilizer, the present invention charges a powdery raw material between a pair of press rolls having a large number of four parts on the surface, and presses them under high pressure with the rotation of the rolls. The present invention provides a method for producing granular fertilizer, which is crushed by a pair of meshing rolls made of an elastic material and having corrugated grooves that mesh with each other.

Next, an example of a granular fertilizer manufacturing apparatus according to the present invention will be explained with reference to the drawings.

FIG. 1 shows the overall configuration of the manufacturing apparatus 1. As shown in FIG.

The manufacturing device 1 includes a raw material feeder 3 that supplies powdered fertilizer raw materials 2.
, a press roll 4°4' for pressing the raw material 2, a crushing roll 6.6' for separating the plate-like material 5 formed by the press rolls 4, 4', and a crushing roll 6°6'. A transporter 8 transports the crushed pieces 7, a dryer 9 dries the transported crushed pieces 7, a sieve 10 classifies the dried crushed pieces 1 according to size, and a sieve 10 further crushes large pieces 11. It is equipped with a crusher 12.

Powdered fertilizer raw material 2 is fine particles 1 separated by a sieve 10.
After being mixed with raw material feeder 3, the moisture content is adjusted and the raw material feeder 3
Powered by.

If there is too much moisture at this time, it will be difficult to dust the press rolls 4, 4' and cause a lot of powdering. The strength of the plate-like material formed by 1 becomes too large and cannot be easily loosened, resulting in an increase in large lumps, resulting in poor yield and poor shape.

As described above, the yield, physical properties, and workability are affected by moisture, and the appropriate moisture content is preferably about 5 to 7%.

The press rolls 4, 4' are equipped with a raw material hopper for guiding the raw material 2 between the rolls, and are further provided with a pushing device 11 consisting of a pushing arm 15 and an air cylinder 16 so as to supply the raw material 2 smoothly and without interruption. ing.

As shown in detail in FIG.
A large number of, for example, hemispherical concave portions 18 corresponding to the desired grain size are formed on the surface of the roll 4, and the concave portions 18 of both rolls 4 and 4' are completely overlapped at the place where both rolls 4 and 4' are in contact. It is configured.

The raw material 2 is processed by this pair of press rolls 4, 4' to 500
A pressure of more than kg/cfIi is applied to form a plate-like object 5 having a large number of tablet-like protrusions 19 on both sides.

The disks 5 thus formed are fed through a guide 20 to a pair of crushing rolls 6, 6' which are arranged in contact directly below the contact area of the press rolls 4, 4'.

At this time, it is also a sufficiently effective method to provide a guide plate (not shown) so that the plate-like material 5 is smoothly inserted into the crushing roll 6.6'.

The crushing rolls 6, 6' have a metal core whose surface is coated with an elastic body such as rubber or plastic, and a large number of grooves 22 are formed on the surface of the elastic body.

As shown in detail in FIG. 3, the respective grooves 22 of both rolls 6, 6' are formed to fit into each other so that the convex portions and all four portions engage with each other.

In addition, the diameter of the recess 18 on the press rolls 4, 4',
In other words, the tablet protrusions 19 have an radius approximately equal to the diameter of the tablet protrusions 19, and are formed in a waveform manner at a pitch close to the interval between the protrusions 19 of the plate-like object 5 (distance between the ends of adjacent protrusions). It is preferable to have

In this way, it is preferable to select the degree of curvature R of the groove 22 close to the diameter of the tablet protrusion 19 because if R is too large, the crushing effect will be reduced, and if R is too small, the crushing effect will be reduced. This is because more powder is formed instead of rising.

The reason why the pitch of the grooves 22 is set to be almost the same as the interval between the tablet protrusions 19 is because if the pitch is much larger than that, the crushing effect will be reduced and it will be easier to form pieces that remain connected. This is because increasing the pitch increases the crushing effect at the cost of increasing powdering, and this is the same as in the case of the degree of curvature R.

Here, the distance approximately the same as the interval between the tablet protrusions 190 specifically refers to the distance between the ends of adjacent protrusions, preferably in the range of L±r, where r is the diameter of one protrusion.

In addition, the distance between the two crushing rolls 6 and 6' is set such that the distance between the protruding portions of the plate-like material 5 is set so that the distance between the adjacent portions of the roll surface is set so that the crushing effect is exhibited.
It is preferable to adjust the thickness so that it is less than the thickness of the connecting part between 90mm and 90mm.

The disks 5 fed by such crushing rolls 6 , 6 ′ are effectively folded into crushed pieces 7 containing tablet fertilizers 23 and fragments 24 .

The crushed pieces 7 are transported by a transporter 8 to a dryer 9, dried there, and then sent to a sieve 10.
The fertilizer is separated into tablet fertilizer 23, fine particles 13 and large lumps 14.

Then, the fine particles 13 are mixed into the raw material 2, and the large lumps 14 are returned to the sieve 10 via the crusher 12.

According to the apparatus according to the present invention described above, the crushing efficiency was improved compared to the conventional apparatus using a flat roll as the crushing roll, and granular tablet fertilizer could be efficiently produced.

Examples manufactured using the apparatus according to the present invention will be shown below.

Example 1 Powdered raw material consisting of 70 parts of ammonium chloride and 30 parts of potassium chloride with a moisture content of 6% was transferred from a feeder to a press roll at 50°C.
A plate-like material was formed at a pressure of 700 kg/crri.

The press roll consists of a set of two rolls each having a large number of semicircular depressions with a diameter of 3.5 mm, and the peripheral speed of the rolls is 0.6.
I drove at m/see.

The plate-shaped object having a large number of spherical tablet protrusions formed by the press roll is then guided by a guide and passed through the crushing roll (
It was introduced at a circumferential speed of 3.4 m/sec).

The crushing roll is a metal roll whose surface is coated with wear-resistant rubber, and the rubber surface is perforated with many grooves with a radius of curvature of three angles perpendicular to the axial direction of the roll at a pitch of 8 m.
- The surfaces of the set of rolls are installed with a gap of 1.21t11L so that the convex portion and the concave portion engage with each other so that they fit tightly into each other.

The obtained fertilizer has a particle size of 3.5 to 4 degrees and a hardness (according to a bookstore hardness tester) of 3.5 kg/crA, and the yield of the crushing roll is 9.
It was 0%.

When a flat roll coated with the same wear-resistant rubber was used as the crushing roll, the yield of the crushing roll was 65%.

Example 2 Moisture was added to a powdery raw material consisting of 45 parts of ammonium chloride, 26 parts of ammonium phosphoric acid, and 29 parts of potassium chloride, and the adhering moisture was adjusted to 6.5%. It is introduced into a set of two press rolls each having a large number of depressions, and the pressure is 9.
00 kg/Ci at a peripheral speed of 0.7 m/'see to form a tablet sheet.

This disk-shaped object is made of a metal roll whose surface is coated with ultra-wear-resistant natural rubber, and on which a large number of grooves with a radius of curvature of 3 mm and 7 mm are bored across the entire width at right angles to the roll axis direction. Disintegrated.

The crushing rolls were adjusted so that they fit together, and the gap between the two rolls was set to 1.

The circumferential speed was 3.8 m/sec.

The size of the obtained fertilizer grains was 3 to 3.2 degrees, the hardness was 3.2 to 9/c4, and the yield with the crushing roll was 88%.

When a flat roll was used instead of a corrugated crushing roll, the yield with the crushing roll was 60%.

[Brief explanation of the drawing]

FIG. 1 is a schematic view showing an embodiment of the apparatus according to the present invention, FIG. 2 is a perspective view showing the main part of the apparatus shown in FIG. 1, and FIG. 3 is a sectional view showing the engagement of crushing rolls. Explanation of symbols, 2...Powdered fertilizer raw material, 4,4'...
...Press roll, 5...Plate-shaped object, 6,
6'...Crushing roll, 19...Protrusion, 22...Groove.

Claims (1)

[Claims] 1. A means for introducing powdered raw material, a pair of press rolls having a number of recesses on the surface for pressing the raw material to form a connected plate-like object, and a roll for crushing the plate-like object. A granular fertilizer manufacturing apparatus comprising a pair of crushing rolls whose surfaces are made of an elastic material and whose surfaces are formed with grooves so as to engage with each other.