JPH0731914A - Coating device - Google Patents

Abstract

PURPOSE:To provide a novel coating device capable of efficiently coating uniformly on the surface of a particulate. CONSTITUTION:This coating device applies a coating agent on the surface of the particulates while the particulates are fallen in a rotary drum. The device is provided with a rotatable drum 2 arranged by placing the shaft line nearly in parallel in a housing body 1, a lift 3 being projectingly provided to the inner peripheral surface of the drum and scrubbing the particulates upwards in accordance with rotation of the drum, an injection nozzle 7 for a coating liquid arranged toward the falling path of the scrubbed particulates and a means supplying drying gas from the lower side of the falling path of the particulates to the upper side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating device, for example, a device used for coating a polymer such as a granular fertilizer surface with a uniform coating treatment on the surface of a granular material. The present invention relates to a coating device that can be efficiently applied.

[0002]

2. Description of the Related Art For example, in the case of granular fertilizers, a coated fertilizer whose surface is coated with a polymer has been proposed for the purpose of controlling the elution rate of fertilizing components. On the other hand, as a coating treatment method for granular materials such as coated fertilizer, a method of accommodating the granular materials in a rotating drum and stirring them and spraying a coating liquid such as an organic solvent solution of a thermoplastic resin in the drum has been studied. There is. In such a treatment method, it is intended to form a film on the surface of the granular material by utilizing the fact that the solution adhering to the granular material spreads on the surface and then the solvent evaporates.

[0003]

However, in the above coating method, since the coating liquid is sprayed during stirring in the drum, each granular material sticks to each other to become a nodule before the solution is dried. As a result, the formed film is apt to be biased, and when the granules are fertilizers, the elution rate of the components cannot be controlled. In addition, depending on the amount of the drum accommodated and the amount of spray, the above-mentioned nodule state increases and it is more difficult to form a uniform film, and further, industrially applicable treatment efficiency cannot be obtained. . The present invention has been made in view of such circumstances, and an object thereof is to provide a novel coating apparatus capable of efficiently performing a uniform coating treatment on the surface of a granular material.

[0004]

In order to solve the above-mentioned problems, the present invention is a coating apparatus for dropping a granular material in a rotary drum and coating the surface thereof with a coating agent. A rotatable drum disposed substantially horizontally, a lift provided on the inner peripheral surface of the drum to project upwardly with the rotation of the drum, and a lifted granular material. It is characterized in that it is provided with a coating liquid jetting nozzle arranged toward the dropping path and means for supplying a drying gas from the lower side to the upper side to the dropping path of the granular material.

[0005]

In the coating apparatus of the present invention, the granular material contained in the drum is scraped upward by the lift as the drum rotates and drops. Then, during dropping, the coating liquid is sprayed by the spray nozzle and dried.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the coating apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a side sectional view showing a configuration example of a coating apparatus of the present invention, and FIG.
II cutaway view, FIG. 3 is a perspective view showing a configuration example of a lift provided on the inner peripheral surface of the drum, FIG. 4, FIG. 5 and FIG. 6 are explanatory views showing an operating method of the coating apparatus of the present invention, and FIG. FIG. 8 is a side sectional view showing another configuration example of the transfer tube, and FIG. 8 is a partial sectional view showing the pneumatic transfer mechanism of the transfer tube in FIG.

The coating apparatus of the present invention is a coating apparatus for coating the surface of a granular material in a rotating drum while coating the coating agent with the drying gas introducing port (1A) and the vicinity of the bottom and the top. Outlet (1
B) each provided with a casing (1), and a rotatable drum (2) which is disposed in the casing with its axis being substantially horizontal and whose peripheral surface is formed of a breathable member. A lift (3) protrudingly provided on the inner peripheral surface of the drum to scrape up the particulate matter with the rotation of the drum, and a coating liquid disposed toward the dropping path of the scraped particulate matter. An injection nozzle (7).

The casing (1) is an airtight casing for accommodating the cylindrical drum (2),
If the drum (2) is long-axis, then such housing (1)
For example, it is formed in a substantially rectangular parallelepiped and is arranged horizontally in the longitudinal direction. The inlet (1A) and the outlet (1B) are arranged so that the supplied drying gas can pass through the drum (2) from the lower side to the upper side in a substantially straight line. It is provided below and above the side surface. Then, in order to reliably introduce the supplied gas into the drum (2) and allow it to pass through the inner wall of the casing (1) near the inlet (1A) and the outlet (1B), the partition walls (1d), (1e). ), (1c),
(1f) is projected to a position close to the outer peripheral surface of the drum (2) to form an introduction path (A) and a discharge path (B).

An inert gas such as air or nitrogen is used as the drying gas, and such gas is supplied by a separately provided air supply mechanism (not shown). And, in order to improve the drying effect, preferably, for example, 20 to 100
It is heated to ℃ and supplied to the above-mentioned inlet (1A). Moreover, the supply amount of the drying gas is, for example, 150 to 500 N.
It is about m ³ / min, and such an amount is adjusted to an appropriate amount according to the throughput of the particulate matter.

The drum (2) is usually 0.5 to 3.0 m.
The diameter is about 0.5m and the axial length is about 0.5-3.0m.
Such a volume can be set appropriately according to the throughput. Both end surfaces of the drum (2) are, as shown in FIG.
Each has a small diameter donut plate (22a) arranged on the axial center side.
And a large diameter donut plate (22b) arranged on the peripheral surface side. These donut plates (22a),
(22b) is connected via a bearing (24),
Moreover, the small diameter donut plate (22a) is fixed to the housing (1) side. That is, in the housing (1),
The drum (2) is supported by the housing (1) by the donut plate (22a), and the peripheral wall (21) is configured to be rotatable together with the donut plate (22b) on the outer peripheral portion. The portion corresponding to the donut plate (22a) may be integrally formed with the housing (1), and the portion corresponding to the bearing (24) may have improved airtightness.
You may use the bush formed with the resin material etc.

A roller (25) is in contact with the peripheral wall (21) forming the peripheral surface of the drum (2). Such rollers (25) are fitted with sprockets (2
7), the chain (29) and the sprocket (28) drive the geared motor (26) to rotate the drum (2) at a peripheral speed of about 0.1 to 0.7 m / min. There is. Further, the peripheral wall (21) is made of a gas permeable member such as a metal mesh that allows the drying gas to sufficiently pass through without leaking the particulate matter contained therein.

[0012] The lift (3) scrapes the particulate matter upward in the drum (2) as the drum (2) rotates,
It is formed in the shape of a strip plate and is arranged in parallel with the axis of the drum (2) over substantially the entire axial length of the drum (2), and is provided in a state in which its board surface is substantially orthogonal to the peripheral wall (21). The lift (3) is fixed to the donut plate (22b) and the peripheral wall (21), and the drum (2).
6 to 36 sheets, usually about 8 to 24 sheets are evenly arranged in the circumferential direction.

As the spray nozzle (7), various conventionally known spray nozzles are used, and are appropriately selected depending on the viscosity of the coating liquid and the treatment amount. Injection nozzle (7)
The coating liquid is supplied to the coating liquid by a coating liquid supply mechanism (not shown) provided separately. The supply amount of the coating liquid is appropriately set based on the type of granular material, the film thickness, etc., but is usually 150 to 250% by weight with respect to the processing amount of the granular material.

In a preferred embodiment of the present invention, the injection nozzle (7) is provided on the inner wall of the draft (6) which is erected in the dropping path of the particulate matter, as shown in FIG. The draft (6) is provided to prevent unnecessary scattering when the granular material scraped up by the lift (3) falls and to efficiently perform the covering process. The draft (6) is
The cross section is formed in a rectangular tube shape, and is opened along the axial length of the drum (2). Then, it is attached to the outer peripheral surface of the transfer pipe (9) and is configured to rotate together with the transfer pipe (9). Also, the injection nozzle (7)
Are provided on the inner wall of the draft (6) along the axial direction of the drum (2) at appropriate intervals, and are usually arranged in multiple stages on both inner walls facing each other parallel to the axis. It

On the other hand, in the inside of the drum (2), as a preferred embodiment of the present invention, as shown in FIG. 1, a substantially half circumference of the drum (2) on the rotational direction side from a substantially lowermost point to a substantially highest point. A guide plate (20) is arranged along the inside of the portion.
That is, the guide plate (20) is curved along the peripheral wall (21). The guide plate (20) is provided to more efficiently scrape the granular material stored in the drum (2) using the lift (3), and is fixed to the inner wall of the housing (1). It is attached to a donut plate (22a) forming the end surface of the drum (2) and is always in a predetermined position. The position of the guide plate (20) is somewhat on the inner peripheral side of the drum (2) with respect to the peripheral wall (21) rather than the edge of the lift (3).

In a preferred embodiment of the present invention, the lift (3) is provided with a peripheral wall (2) as shown in FIG.
1) A flat plate (3) which is fixed to the side and holds substantially the particulate matter.
1) and a scraper (33) that appropriately abuts the outer peripheral surface of the guide plate (20) and prevents the retained granular material from overflowing when scraping it up. The scraper (33) is swingably attached to the edge of the fixed plate (31) on the axis side of the drum (2) by a hinge (32), and is attached to the guide plate (20). It comes into contact with the outer peripheral surface.

Specifically, the drum (2) of the flat plate (31)
A stopper (34) is provided adjacent to the hinge (32) on the board surface on the rotation direction side of the scraper (3).
It is configured to restrict the bending range of 3) in the rotation direction to a predetermined angle. That is, the scraper (33)
By controlling the swing range of the scraper (3
3) the fixed plate (3
1) It is designed to prevent the superposition. The bending range of the scraper (33) is up to about 90 °, preferably up to about 60 ° with respect to the surface of the fixed plate (31) on the rotational direction side.

In a preferred embodiment of the present invention,
As shown in FIG. 2, a transfer pipe (9) for particulate matter is inserted through the axis of the drum (2), and the transfer pipe (9) is a donut plate ( A bearing (23) is interposed in a portion to be inserted into 22a) so as to be rotatable. Airtightness is maintained by the shielding member (11) at the portion inserted into the housing (1). As shown in FIG. 2, the transfer tube (9) has a motor (96) capable of rotating in the normal and reverse directions via a sprocket (98), a chain (98) and a sprocket (97) fitted to the transfer tube. )
Is configured to rotate by.

Further, as shown in FIG. 1, the transfer pipe (9) is provided with a slit (9c) along its longitudinal direction, and a hopper (for introducing a granular material) is provided above the slit. 9H) is projected. The opening of the hopper (9H) is formed along with the slit (9c) over substantially the axial length of the drum (2), and is scraped up by the lift (3) and dropped from the upper end of the guide plate (20). Configured to collect the treated particulate matter.

As a preferred embodiment of the transfer pipe (9), the transfer pipe (9) is provided with a screw conveyor (82) as shown in FIG. 2, and is used as a supply pipe and a discharge pipe of the particulate matter. . At one end of the transfer pipe (9), a supply pipe (8) for supplying the granular material is inserted, and the supply pipe (8) supplies the granular material into the pipe. A mouth (8A) is provided. The other end of the supply pipe (8) serves as an outlet (9B).
It is inserted in a storage tank (87) for storing the treated granular material.

The screw conveyor (82) is continuously inserted through the transfer pipe (9) and the supply pipe (8), and the motor (86) via the sprocket (88), the chain (89) and the sprocket (87). ) Is rotated by. The transfer pipe (9) and the supply pipe (8) are kept airtight by the shielding member (91), and the upstream end of the supply pipe (8) and the drive shaft of the screw conveyor (82) are shielded from each other. Airtightness is maintained by (81).

Next, a method of treating particulate matter by the coating apparatus of the present invention will be described. The coating device of the present invention is, for example, a granular fertilizer having a particle size of about 1 to 10 mm,
It can be applied to various kinds of granular materials such as granular agricultural chemicals, and can be applied to not only spherical shapes but also various shapes of granular materials. As the coating agent, if the granular material is a fertilizer, an agricultural chemical, or the like, for example, various conventionally known film-forming polymers such as polyethylene or a copolymer thereof can be used. The coating liquid is a solution of the above-mentioned polymer, and includes, for example, a halogenated hydrocarbon such as perchloroethylene, dichlorobenzene and trichloroethylene, a low boiling point organic solvent such as an aromatic hydrocarbon such as toluene and xylene. The solvent concentration is 1 to 7% by weight, preferably 3 to 5% by weight. In addition to the above-mentioned solvents, various additives such as a surfactant and an inorganic fine particle substance can be added.

[Loading of Raw Material Granular Materials] In the coating apparatus of the present invention, batch-type processing is performed, and a single processing amount is supplied to the drum (2). First, the transfer pipe (9) is rotated to move the slit (9) in the drum (2).
c) Turn the (hopper (9H)) downward. Next, the screw conveyor (82) is activated, and the granular material that is a raw material is charged into the supply port (8A) of the supply pipe (8). The charged granular material is sequentially transferred in the supply pipe (8) and the transfer pipe (9) by the screw conveyor (82), and
As shown by reference numeral (W) in FIG. 4, slits (9
It falls into the drum (2) through c).

[Coating Treatment] The granular material (W) is placed on the drum (2).
Then, the transfer pipe (9) is rotated again so that the opening of the draft (6) is positioned below the upper end of the guide plate (20) (state of FIG. 1). Then, drive motor (2
6) is activated to rotate the drum (2). On the other hand, after supplying the granular material (W), the inlet (1A) of the housing (1)
And a coating liquid is supplied to the spray nozzle (7) and sprayed into the draft (6).
The drum (2) may be activated when the granular material (W) is supplied.

With the rotation of the drum (2), the peripheral wall (21)
As shown in FIG. 5, the lift (3) protruding from the
The granular material (W) staying below the drum (2) is appropriately scraped up and sequentially conveyed upward. When scraping up the granular material (W), the swingable scraper (33) of the lift (3) is restricted in the bending range of the drum (2) in the rotation direction, and is located at the bottom of the drum (2). As it moves upward from the point position, it leans toward the axis of the drum (2) by its own weight,
Guide plate (20) located approximately half around the drum (2)
Abut on the outer peripheral side. Therefore, even when the flat plate (31) holding the granular material (W) moves further upward from the position where it is approximately horizontal, the scraper (33) and the guide (20)
By the above, it is possible to prevent the granular material (W) from overflowing from the lift (3) and efficiently scrape it.

As shown in FIG. 5, the granular material (W) scraped up along the guide (20) is transferred to the guide plate (2).
It falls from the upper end of 0) to the draft (6) provided in the fall path. The injection nozzle (7) provided in the draft (6) sprays the coating liquid onto the granular material (W) passing through the inside of the cylinder of the draft (6). At that time, the draft (6) prevents the falling granular material (W) from scattering, and thus enables efficient and uniform spraying treatment to each granular material (W).

On the other hand, the drying gas supplied from the introduction port (1A) of the housing (1) is introduced from the introduction path (A) to the drum (2).
Through the peripheral wall (21) of the draft, through the inside of the cylinder of the draft (6) to reach the discharge path (B). Then, the drying gas passing through the draft (6) flows in the direction opposite to the falling direction of the granular material (W), so that the contact efficiency with the granular material (W) is enhanced. As a result, the particulate matter (W) to which the coating liquid adheres
Is quickly dried while falling. Furthermore, when the drying gas is heated, the coating liquid applied to the particulate matter (W) can be dried more quickly. Although not shown, the exhaust gas containing the solvent discharged from the discharge port (1B) is detoxified by a standard method.

The peripheral wall (21) is sprayed with the coating liquid.
The granular material (W) that has dropped upward is scraped up again in the drum (2) by the rotating drum (2) and dropped into the draft (6). And the drum (2)
While repeating rolling and falling inside, uniform coating treatment is applied to each granular material (W). Moreover, the lift (3)
The granular material (W) scraped up by the drum is the drum (2).
Even when rolling on the peripheral wall (21) of the, since the coating liquid on the surface is previously dried by contact with the drying gas during dropping, it does not stick to the nodule shape,
Therefore, the uniform coating treatment can be efficiently applied to the surface of the granular material (W). Such an iterative process is performed on the granular material (W).
Is performed for a predetermined time based on the processing amount and the film thickness to be formed.

[Discharge of Particulate Product] After the coating treatment, the injection of the coating liquid and the supply of the drying gas are stopped, and the transfer pipe (9) is rotated again as shown in FIG. Move the hopper (9H) (slit (9c))
Is positioned below the upper end of the guide plate (20). The rotating drum (2) and the lift (3) scrape and drop the granular material (W) on the hopper (9H) in a substantially vertical state. When the granular material (W) is supplied from the hopper (9H) to the screw conveyor (82), the screw conveyor (82) conveys the inside of the transfer pipe (9) and discharges the product from the discharge port (9B) to the storage tank (87). Discharge as.

Next, in the coating apparatus of the present invention, another mode for supplying and discharging the particulate matter will be described. As shown in FIG. 7, another aspect of the coating apparatus of the present invention is, in the above-mentioned configuration, the transfer pipe (9) having a pneumatic transfer mechanism, which is used as a discharge pipe for particulate matter. In this case, the transfer pipe (9) is vertically partitioned by the perforated plate (83), and the discharge port (9) is
The end (9A) on the opposite side to B) is connected to an air supply mechanism (not shown) that supplies an inert gas such as pressurized air or nitrogen.

As shown in FIG. 8, the perforated plate (83) has a large number of holes (83c) having a diameter smaller than the particle size of the granular material and not allowing the granular material to pass therethrough.
These holes (83c) are usually inclined toward the discharge port (9B) side of the transfer pipe (8). On the other hand, as a mechanism for supplying the granular material to the drum (2), for example, one end on the upstream side is connected to the supply hopper (85) and the other end on the downstream side is one donut plate (22a) on the end surface of the drum (2). And a supply pipe (86) inserted through the housing (1).

Raw material granules are loaded from the feed hopper (85) through the feed pipe (86) into the drum (2), and the treated product granules are fed through the hopper (9H) (slit (9c)). Perforated plate (83) of transfer pipe (9)
It is dropped on the upper surface of. In the transfer pipe (9), the perforated plate (8) is formed by the pressurized gas sent from the end (9A).
3) Discharge port (9B) while appropriately floating the particulate matter above
Transfer to. According to such a pneumatic transfer mechanism, since the contact with the member in the transfer pipe (9) is small and the contact between the particles is buffered by the gas, the damage of the coating formed on the product granules is prevented. Can be done.

Incidentally, in the coating apparatus of the present invention, the drum (2) has a diameter of 600 mm and an axial length of 500 mm,
When the number of lifts (3) installed was 12, and the granular fertilizer was subjected to a coating treatment with a film thickness of 50 to 100 μm under the following conditions, good coated fertilizer could be obtained.

[0034]

[Table 1] Average particle size of fertilizer 3.0 mm Number of treatments per cycle 10 kg Number of circulations per treatment 100 to 400 times Coating liquid (polyethylene) concentration 5% by weight (solvent: perchloroethylene) Coating liquid injection amount 20 kg Drying Gas flow rate (flow velocity in draft (6)) 4.5 m / sec Drying gas temperature 80 ° C

In the above embodiment, as a means for supplying the drying gas from the lower side to the upper side in the dropping path of the granular material, the drying gas inlet (near the bottom and top of the casing (1) ( 1A) and a discharge port (1B) are respectively provided, and the peripheral surface of the drum (2) is formed of a breathable member, but the granular material (W) coated with the coating liquid dries while falling. Other configurations may be employed as long as they can make countercurrent contact with the working gas.

[0036]

As described above, according to the coating apparatus of the present invention, since the granular material coated with the coating liquid makes alternating contact with the drying gas while falling, the granular material is fixed in a nodular shape. Can be prevented, and the surface of the granular material can be efficiently coated uniformly.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a configuration example of a coating apparatus of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a perspective view showing a configuration example of a lift provided on an inner peripheral surface of a drum.

FIG. 4 is an explanatory diagram showing a method of operating the coating apparatus of the present invention.

FIG. 5 is an explanatory diagram showing a method of operating the coating apparatus of the present invention.

FIG. 6 is an explanatory diagram showing an operating method of the coating apparatus of the present invention.

FIG. 7 is a side cross-sectional view showing another configuration example of the transfer pipe.

8 is a partial cross-sectional view showing the pneumatic transfer mechanism of the transfer pipe in FIG.

[Explanation of symbols]

 1: Housing 1A: Inlet port 1B: Outlet port 2: Drum 20: Guide plate 3: Lift 31: Fixed plate 33: Scraper 6: Draft 7: Injection nozzle 82: Screw conveyor 9: Transfer pipe 9c: Slit 9H: Hopper W: Granular material

Claims (7)

[Claims] 1. A coating device for coating a coating agent on a surface of a rotating drum while dropping granular material, the rotatable drum being disposed in a housing with its axis being substantially horizontal. A lift provided on the inner peripheral surface of the drum to scrape up the particulate matter upward with the rotation of the drum, and a coating liquid jet nozzle arranged toward a dropping path of the scraped particulate matter, And a means for supplying a drying gas from below to above in the dropping path of the granular material. 2. An inlet and an outlet for a drying gas are provided near the bottom and the top of the casing, respectively, and
The coating device according to claim 1, wherein a peripheral surface of the drum is formed of a breathable member. 3. The coating apparatus according to claim 1, wherein a cylindrical draft is provided upright in the dropping path of the granular material, and the injection nozzle is provided on the inner wall of the draft. 4. A guide plate is disposed along the inside of a substantially half-circumferential portion on the rotational direction side from the substantially lowest point of the drum to the approximately highest point, and the lift is substantially parallel to the axis of the drum. The coating according to any one of claims 1 to 3, comprising a flat plate projecting from the flat plate, and a scraper swingably provided at an edge portion of the flat plate on the axis side and abutting on an outer peripheral surface of the guide plate. apparatus. 5. A granular material transfer pipe is rotatably inserted through an axial portion of the drum, and a slit is opened in the longitudinal direction of the transfer tube, and the granular material is introduced into the slit. The coating apparatus according to claim 1, further comprising a hopper. 6. The coating apparatus according to claim 5, wherein the transfer pipes are a granular material supply pipe and a discharge pipe provided with a screw conveyor. 7. The coating apparatus according to claim 5, wherein the transfer pipe is a discharge pipe for particulate matter having a pneumatic transfer mechanism.