JPH0626699B2 - Method of preventing powder particles from adhering to spray equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a method of spraying a liquid to a powder or granular material to form a solid agent. The present invention relates to a method for preventing adhesion of powder or granular material to a gun and its peripheral portion.

[Prior Art] Conventionally, a spray device in a coating device or a granulating device, particularly, to prevent adhesion of powdery or granular material to the tip portion of a spray gun that produces a mist-like liquid by jetting a liquid and a pressurized gas and its vicinity As a method, only the tip portion of the spray gun itself, that is, the shape of the ejection nozzle has been studied.

[Problems to be Solved by the Invention] As described above, the shape of the spray nozzle at the tip of the spray gun has been conventionally examined, but the sufficient effect has not been obtained, and the adhesion around the spray gun has been taken into consideration. Therefore, in the continuous operation for a long time, adverse effects such as non-uniform spraying by the grown powder and granular mass or mixing of the powder and granular mass into the product occurred. In order to prevent this, continuous work for a long time must be interrupted without interruption, and cleaning must be performed manually, which is a problem in terms of work efficiency and product quality.

[Means for Solving the Problems] As a result of various studies conducted by the present inventors to solve the above-mentioned problems, as a result, a partition wall is provided so as to avoid contact of the spray gun itself with the powder or granules except for the tip thereof. And the partition wall is made of a flexible and elastic material to expand or contract or vibrate to easily cause distortion on the surface, thereby preventing adhesion or shaking off adhered powder or granules. , Found that the goal was easily reached.

That is, the structure of the present invention that solves the problems of the prior art is a partition wall that is movable and elastic at the liquid ejection port of the spray gun when a liquid is sprayed and adhered to a powder or granular material flowing by the spray gun to form a formulation. Is provided to block the spray gun main body from the flow zone of the powder and granules, and also to give an intermittent strain to the partition wall.

[Operation] The third position for attaching the spray gun to the formulation device is
As shown in the figure, the entire spray gun enters into the fluidized bed structure formulation device and is fixedly or movably attached by a pillar (not shown), and only the spray nozzle at the tip of the spray gun as shown in FIG. Some of them are attached to the side of the formulation device, and some of which are not shown in the figure, but are also attached to the bottom with their tips exposed. The spray gun used is not limited to a commonly used spray gun.

In the case of the former, the preferred method of applying the method of the present invention is to cover the entire spray gun or a portion with significant adhesion with a bag-shaped material made of polyethylene, polypropylene, a rubber thin film, or the like, and to make the tip of the spray gun open. Make a small hole in the product and make a close contact with the spray gun at this part. In the other part of the bag-shaped object, a small hole may be opened and connected to the conduit as needed so that gas such as air and nitrogen can be introduced and extracted. In order to prevent gas from leaking from other contact points between the bag-like object and the spray gun or the support, it is preferable to adhere the bag-like object with a string, a rubber string, a tape or the like. As an example of actually operating the device as described above, gas is introduced from a conduit to inflate the bag-shaped product to a medium degree before the start of the work of the formulation process, and the powder and granules are converted into the bag-shaped product during the work. When it adheres to a certain extent, the gas of the bag-like material is introduced under pressure to be fully deformed. Next, a part of the gas is removed, and the introduction and extraction of this gas are repeated until the deposits fall. It did not matter if the work was continued during this period. Alternatively, instead of introducing and discharging the gas, a swelled bag-like object may be vibrated by a vibrator.
Further, when the above operation was carried out from the beginning of the work, it was possible to prevent the adhesion of the powder or granular material.

Next, in the latter case where it is installed so that only the tip of the spray gun is exposed to the side or bottom of the formulation device, the tip of the spray gun or a portion close to the tip can be deformed to some extent with an appropriate size. Attach a thin film-shaped or thin plate-shaped partition wall. The shape may be circular, elliptical or rectangular. The peripheral portion of this membrane-shaped or thin-plate-shaped partition wall was fixed in close contact with the formulation device. At this time, most of the spray gun except the tip portion is exposed to the outside of the preparation apparatus, and therefore, the spray gun may be supported by a column for stability and for movement as described later, if necessary. It is sufficient for the partition wall to have a size in the range where the particles adhere during the work so as to have a bad influence. The material of the partition wall is preferably Teflon or a synthetic polymer having heat resistance and chemical resistance similar thereto or stainless steel. When powder particles adhere to the partition wall during the process of the formulation process, the partition wall is deformed by applying a pressing force and an attractive force to the outside of the partition wall, or a vibrator is applied to distort the partition wall surface. Peel off. The pushing / pulling force, the vibration, etc. may be applied through the column of the spray gun. Further, if the above operation is carried out from the start of the work, it is possible to prevent the adhesion of the powder or granular material.

EXAMPLES Next, the present invention will be described in more detail by the description of the drawings.
However, the method of the present invention is not limited thereby.

FIG. 1 shows a commonly used spray gun 1, which is a liquid ejection port 2 and a pressurized gas ejection port 3 which constitute ejection nozzles.
In addition, a liquid supply part 4 and a gas introduction part 5 from the outside are provided. The partition wall 6, which is a feature of the present invention, is installed at the tip of the spray gun so as to be flush with the gas ejection surface as shown in FIGS. 2a and 2b. a ′ and b ′ are front views thereof, respectively.

In the case where the spray gun is installed inside the fluidized bed structure formulation device 7 as shown in FIG. 3, the powder and granules are fluidized by the gas flow introduced in the direction of the dotted arrow 8, and the spray gun is sprayed. 1 is processed by the liquid stream atomized by the spray gun 1. In this case, as shown in FIG. 5, the entire spray gun is provided with a gas introduction port 9 having a hole at the tip of the spray port. It is covered with a partition wall 6. A column (not shown) for fixing the spray gun 1 to the formulation device 7 is also provided with a hole so as to be in close contact therewith. At the start of the spraying operation, the bag-shaped partition wall 6 is in a semi-expanded state as shown in FIG. 5a, the gas is fed from the gas inlet 9 of the bag-shaped partition wall 6, and is inflated as shown in FIG. 5b. Then, intermittent expansion / contraction strain is generated on the surface of the partition wall 6. By repeating the removal and delivery of the above-mentioned gas, it is possible to prevent the adherence or to sufficiently remove the adherent.

No. 4 installed on the side of the formulation device 7 with the spray gun 1 part
In the case as shown, the particles are dispersed by the gas flow introduced in the direction indicated by 8 and treated by the liquid flow atomized by the spray gun 1. In this case, the partition wall 6 is fixed to the tip portion of the spray gun 1 and the side wall 10 of the formulation device 7. 6 to 8 show an example thereof. In the case of FIGS. 6a and 6b, the spray gun 1 itself, which is normally installed as shown in a, is pushed out in the direction of the dotted arrow 11 as shown in FIG. Distortion. In the case shown in FIGS. 7A and 7B, an extruding device 12 is provided on the back side of the partition wall 6, the position of the spray gun 1 is fixed, and the extruding device 12 is indicated by a dotted arrow 13 as shown in FIG. 7B. Direction is extruded, and intermittent distortion is given to the surface of the partition wall 6 to separate the deposit. In the case shown in FIGS. 8 a and b, holes 14 are formed in the side wall 10 of the formulation device 7.
8b, a pressurized gas is injected from this portion in the direction of the arrow 15 to expand the space between the partition wall 6 and the side wall 10 to give an intermittent strain to the surface of the partition wall 6 as shown in FIG. 8b. Is. In any case, by repeating the operation of giving the strain to the partition wall 6, it is possible to prevent the adhesion of the powder or granular material or to sufficiently remove the adhered material.

Further, in FIG. 6A, a vibrator (not shown) is provided on the partition wall 6 or the side wall 10 instead of pushing out the spray gun itself.
May be brought into contact with each other, and the partition wall 6 may be vibrated by its operation. This is the same even when the extruding device 12 in FIG. 7 is replaced with a vibrator.

[Advantages of the Invention] Conventionally, when a powder or granular material absorbed by liquid spray adheres to a spray gun and growth of a mass of adhered powder or granular material occurs, the manufacturing operation must be interrupted and cleaned. As in the method of the present invention, a partition is provided at the tip of the spray gun,
By stretching or vibrating it to distort the partition wall surface intermittently, it is possible to prevent the adhesion of powder particles to the spray device without interrupting the manufacturing operation, and to reasonably remove the deposits from the partition wall. You can

[Brief description of drawings]

FIG. 1 is a side view of an example of a spray gun, and FIG. 2a,
Reference numerals a ', b, b'represent the tip of a spray gun having a partition wall of the present invention, and a and b are sectional views, and a' and b '.
Is a front view thereof, FIG. 3 and FIG. 4 are schematic views of a formulation apparatus having a spray gun installed, and FIGS. 5a, b to 8a, b are strains of partition walls according to the method of the present invention. FIG. 1 ... Spray gun, 2 ... Liquid jet, 3 ... Pressurized gas jet, 6 ... Septa, 7 ... Formulation device.

Claims (5)

[Claims] 1. When a liquid is sprayed and adhered to a powder or granular material flowing by a spray gun to prepare a formulation, a movable and elastic partition wall is provided at a liquid ejection port of the spray gun to provide a main body of the spray gun and the granular material. The method for preventing adhesion of powdery particles to a spray device, characterized in that the partition wall is blocked and the partition wall is subjected to intermittent strain. 2. The method for preventing powder particles from adhering to a spray device according to claim 1, wherein the partition wall has a bag shape surrounding a spray gun. 3. The method for preventing powder particles from adhering to a spray device according to claim 1, wherein the partition wall is provided on a side wall of the formulation device. 4. The method for preventing powder particles from adhering to the spray device according to claim 1 or 2, wherein the partition wall is made of a material selected from synthetic polymers, rubber and synthetic rubber. 5. The partition wall is made of synthetic polymer, rubber, synthetic rubber,
The method for preventing powder particles from adhering to a spray device according to claim 1 or 3, which is made of a material selected from stainless steel.