JP7283714B2 - manifold spray gun - Google Patents

Description

TECHNICAL FIELD The present invention relates to a spray gun for spraying a liquid such as a coating liquid onto a granular material such as a tablet. The present invention relates to a manifold-type spray gun that supplies a coating liquid and spray air to a plurality of spray guns.

2. Description of the Related Art Conventionally, coating treatment using a spray gun has been widely performed on tablets of medicines, foods, and the like. The coating process is often carried out by a pan coating apparatus (pan coater) using a rotating drum with a polygonal cross section or circular cross section (hereinafter abbreviated as drum as appropriate). A spray gun is provided for spraying a binder liquid or a coating liquid (hereinafter abbreviated as coating liquid or the like) onto the tablets rolling along with the rotation. The spray gun uses compressed air to spray a coating liquid or the like onto the rolling tablets. In the drum, along with the spraying of the coating liquid, etc., hot air or cold air is appropriately supplied and exhausted, thereby forming a coating layer on the surface of the tablet.

In such a pan coating apparatus, the spray guns are installed in two types: a one-gun, one-pump type that supplies liquid and air to each spray gun individually; There are two types of manifolds that supply fluid and air to the gun. In the former case, a plurality of spray guns are attached to an arm provided inside the drum, and pipes from a pump are individually attached to each spray gun to supply liquid and air. On the other hand, in the latter case, a flow path is provided inside the arm, and a plurality of flow paths are further branched from this flow path to supply liquid and air to a plurality of spray guns.

Japanese Patent Publication No. 2006-521206 Utility Model Registration No. 3142265

However, each of the above-described installation forms of the spray gun also has advantages and disadvantages. In other words, the one-gun, one-pump type spray gun has the advantage of being able to accurately control the flow rate because each spray gun is connected to a pump, but the number of pipes is large and the handling is complicated, and the pipes get dirty. have drawbacks. On the other hand, in the manifold type, since the manifold inside the arm serves as the flow path, the piping is minimized, and there are no problems with handling or contamination. However, when supplying liquid or air from a manifold to multiple spray guns, there is a difference in the pressure applied to the fluid between the part near the fluid supply source and the part far from the fluid supply source, and the discharge amount of the spray gun in the far part is small. There was a problem that there was a tendency to

SUMMARY OF THE INVENTION It is an object of the present invention to provide a manifold-type spray gun that does not cause a difference in the amount of discharge due to a difference in distance from a fluid supply source.

A manifold spray gun of the present invention includes a spray gun that sprays a liquid using compressed air, a liquid supply passage to which the spray gun is attached and for supplying the liquid to the spray gun, and and a manifold provided with an air flow path for supplying the compressed air, wherein the manifold supplies a branched liquid branched from the liquid supply flow path and connected to the spray gun. The liquid supply channel has an inner diameter D1 that is two to four times the inner diameter D2 of the branched liquid channel (2×D2≦D1≦4×D2). do.

In the present invention, in the manifold type spray gun, the inner diameter D1 of the liquid supply channel is set to be larger than the inner diameter D2 of the branched liquid channels (2 x D2 ≤ D1 ≤ 4 x D2). The feed channel itself acts as a chamber to relieve pressure differentials across each spray gun. As a result, the pressure difference between the portion close to the liquid supply source and the portion far from the liquid supply source can be suppressed, and the discharge amount of each spray gun can be made uniform.

In the manifold spray gun, the cross-sectional area S1 of the liquid supply channel is set to be larger than 1/4 and smaller than 1/2 of the cross-sectional area S2 of the manifold ((S2)/4<S1<(S2)/2). Also good. As a result, the pressure difference between the nozzles can be reduced without impairing the compactness of the manifold spray gun and the layout of the flow paths, and the same amount of liquid can be discharged in each spray gun.

Further, the manifold is composed of a liquid supply unit provided with the liquid supply channel and an air supply unit provided with the air channel, and the liquid supply unit is detachable from the air supply unit. It may be provided if possible. It is also possible to change the specifications so that the liquid supply unit is removed and the manifold spray gun is individually supplied with the liquid from the liquid supply source to the spray gun attached to the air supply unit. As a result, hybrid use is possible, and one-gun, one-pump specifications can be selected depending on the physical properties of the coating liquid, making it possible to carry out a variety of coating processes.

According to the manifold spray gun of the present invention, in the manifold type spray gun, the inner diameter D1 of the liquid supply channel is set larger than the inner diameter D2 of the branch liquid channel (2×D2≦D1≦4×D2). As a result, the liquid supply channel itself acts as a chamber, and the pressure difference applied to each spray gun is alleviated. As a result, the pressure difference between the portion close to the liquid supply source and the portion far from the liquid supply source can be suppressed, and the discharge amount of each spray gun can be made uniform. Stable coating of tablets is possible without reducing the discharge amount of the spray gun in the far part.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows the state which attached the manifold spray gun which is one embodiment of this invention to the pan-coating apparatus (granular material processing apparatus). BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows the structure of the manifold spray gun unit which is one embodiment of this invention. FIG. 3 is an explanatory view showing a cross-sectional configuration of the manifold spray gun unit of FIG. 2; FIG. 4 is an explanatory diagram showing the configuration of a single manifold block; It is explanatory drawing which shows the assembly procedure of a manifold spray gun unit. FIG. 3 is an explanatory diagram showing a configuration when the manifold spray gun unit of FIG. 2 is used as a one-gun, one-pump type spray gun;

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. FIG. 1 is an explanatory diagram showing a state in which a manifold-type spray gun, which is one embodiment of the present invention, is attached to a pan coating apparatus. As shown in FIG. 1, a manifold spray gun unit 1 (hereinafter abbreviated as gun unit 1) according to one embodiment of the present invention is used in a pan coating apparatus 3 having a rotating drum 2. It is attached to a support holder 4 provided inside. The rotating drum 2 is arranged in the central part of the housing 5 of the pan coating apparatus 1 and rotates around a substantially horizontal rotational axis O. As shown in FIG. Inside the rotating drum 2, tablets as objects to be treated are placed and stored, and a binder liquid, a coating liquid, etc. are sprayed by the gun unit 1 arranged in the drum.

2 is an explanatory diagram showing the configuration of the gun unit 1, and FIG. 3 is an explanatory diagram showing the cross-sectional configuration of the gun unit 1. As shown in FIG. As shown in FIG. 2, the gun unit 1 has a manifold 6 and a plurality of spray guns 7 attached to the manifold 6 . The manifold 6 is composed of a liquid supply unit 11 and an air supply unit 21, and has an inlet block 31 attached to one end and an end block 32 attached to the other end. The liquid supply unit 11 and the air supply unit 21 are made of synthetic resin such as polyacetal. The inlet block 31 and the end block 32 are made of stainless steel.

In the gun unit 1, the liquid supply unit 11 and the air supply unit 21 are divided into a plurality of (here, three) blocks in the longitudinal direction for each spray gun 7 (manifold liquid blocks 11a to 11c, manifold air blocks 21a to 21c, hereinafter abbreviated as manifold blocks 11a to 11c and 21a to 21c). FIG. 4 is an explanatory diagram showing the configuration of a single manifold block. The gun unit 1 is provided with holder mounting holes 33a and 33b formed through the longitudinal direction for mounting the support holder 4. Holder mounting holes 33a and 33b are provided at the same positions.

The gun unit 1 is attached to the support holder 4 by sequentially inserting the blocks 11a to 11c and 21a to 21c in the longitudinal direction. FIG. 5 is an explanatory diagram showing the procedure for assembling the manifold spray gun unit. First, the inlet block 31 is inserted into the support holder 4, as shown in FIG. 5(a). The inlet block 31 is also provided with holder mounting holes 33a, 33b, and the inlet block 31 is mounted by inserting the support holders 4 (4a, 4b) therein. After the inlet block 31 is placed deep inside the support holder 4 (at the right end in the figure), a holder block 36 made of synthetic resin is inserted into the support holder 4 (FIG. 5(b)). One to three holder blocks 36 are arranged for spray gun position adjustment.

After attaching the holder block 36, each of the blocks 11a to 11c and 21a to 21c is inserted into the support holder 4 (FIG. 5(c)). In this case, one end side of each of the blocks 11a to 11c and 21a to 21c is provided corresponding to each hole such as the liquid supply channel 12 and the cylinder air channel 22 for supplying the coating liquid, cylinder air, etc. to the spray gun 7. A mouthpiece (fitting projection) 34 protrudes and fits into a fitting recess 35 formed on the opposing surface of the adjacent block. An O-ring (not shown) is fitted to each fitting protrusion 34, and each block is connected in a state in which the flow paths such as the liquid supply flow path 12 are sealed. A holder block 36 arranged between the inlet block 31 and the manifold blocks 11a, 21a has the same structure.

After the blocks 11a to 11c and 21a to 21c are attached to the support holder 4, the end blocks 32 are attached to the ends of the support holder 4 (FIG. 5(d)). A fitting hole 39 is provided in the end block 32 , and the end of the support holder 4 is fitted into this fitting hole 39 . As a result, the manifold blocks 11a to 11c and 21a to 21c are integrally attached to the support holders 4a and 4b, and the gun unit 1 forms the liquid supply unit 11 and the air supply unit 21, and is attached to the support holders 4a and 4b. It is mounted and fixed (FIG. 5(e)).

The gun unit 1 has a structure in which the liquid supply unit 11 and the air supply unit 21 of the manifold 6 are detachable. The spray gun 7 is fixed to the liquid supply unit 11 by a mounting bolt 37 for fixing the nozzle, and to the air supply unit 21 by a mounting bolt 38, respectively. By fixing to the air supply unit 21 , the liquid supply unit 11 and the air supply unit 21 are integrated to form the gun unit 1 .

In this case, the gun unit 1 according to the present invention can also be used as a one-gun, one-pump type spray gun by removing the liquid supply unit 11 and separately attaching a liquid piping part 41, as shown in FIG. The liquid pipe part 41 is attached to the lower part of the spray gun 7 in place of the liquid supply unit 11 and is connected to a liquid supply source (not shown) via a liquid supply pipe 42 and a return pipe 43 . As a result, the spray gun 7 is individually supplied with the coating liquid or the like through the liquid supply pipe 42 , and the surplus liquid is individually returned through the return pipe 43 . As described above, the gun unit 1 has not only a manifold type configuration as shown in FIG. The unit configuration can be changed as appropriate, and various coating processes can be performed.

The spray gun 7 atomizes the coating liquid or the like using compressed air to form a spray mist, which is sprayed onto the tablets in the rotating drum 2 in a desired spray pattern. A coating liquid or the like is supplied from a liquid supply unit 11 to each spray gun 7 . Cylinder air (needle air), atomized air, and pattern air are supplied from the air supply unit 21 to each spray gun 7, and an air passage through which each air (compressed air) such as cylinder air flows is formed in the spray gun 7. is provided.

The liquid supply unit 11 is provided with a liquid supply channel 12 for supplying the coating liquid or the like to the spray gun 7 and a liquid return channel 13 for returning surplus liquid from the spray gun 7 . . The air supply unit 21 is provided with a cylinder air channel 22, an atomizing air channel 23, and a pattern air channel 24 for supplying cylinder air, atomizing air, and pattern air to the spray gun 7. there is The liquid supply channel 12 and the liquid return channel 13 are formed by press-fitting and fixing a pipe-shaped member 29 made of stainless steel into a through hole 28 formed in the liquid supply unit 11 along the longitudinal direction. One end of the pipe-shaped member 29 protrudes from the end face of each of the blocks 11a to 11c to form a base portion 34. As shown in FIG.

On the other hand, each of the cylinder air flow path 22, the atomizing air flow path 23, and the pattern air flow path 24 is formed as a through-hole along the longitudinal direction of the air supply unit 21 made of resin. A cylindrical member made of stainless steel is attached as a mouthpiece 34 to one end of each air flow path. Although it is possible to use the through-hole 28 itself as the liquid supply channel 12 and the liquid return channel 13, since the coating liquid or the like circulates inside the through-hole 28, considering the washability and corrosiveness, etc., it is difficult to use stainless steel. It is preferred to use members. It is also possible to use a stainless steel pipe member for the air flow path.

The spray gun 7 is provided with a spray liquid passage (not shown) to which the coating liquid and the like are supplied from the liquid supply unit 11 and a liquid return passage to which the unsprayed coating liquid and the like is returned. The spray liquid passage is connected to the branched liquid passage 14 branched from the liquid supply passage 12 corresponding to each spray gun 7, and the liquid return passage is connected to the branched return passage 15 communicating with the liquid return passage 13. be done. The spray passage is opened and closed by a needle valve with a cylinder, and the spray gun 7 is provided with a cylinder air passage (not shown) to operate the needle valve. The cylinder air passage is connected to the cylinder air passage 22 via a branch air passage 25 to supply compressed air to a cylinder formed within the spray gun 7 . As a result, the piston connected to the needle valve is operated to control the opening and closing of the spray passage.

The spray gun 7 also has an atomizing air passage (not shown) for supplying atomizing air for atomizing the coating liquid and the like, and a pattern air passage for adjusting the atomized spray mist into a desired spray pattern. are provided with pattern air passages (not shown) for supplying the The atomized air passage is connected to the atomized air passage 23 via the branched air passage 26, and the pattern air passage is connected to the pattern air passage 24 via the branched air passage 27, respectively.

Here, in the gun unit 1 according to the present invention, the inner diameter of the liquid supply channel 12 in the liquid supply unit 11 is set larger than the inner diameter of the branch liquid channel 14 . In a conventional manifold spray gun, both inner diameters are generally the same, but in the gun unit 1, the inner diameter D1 of the liquid supply channel 12 is twice or more (4 times or less) (2×D2≦D1≦4×D2). As described above, when the diameter D1 of the liquid supply channel 12 on the manifold 6 side is made larger than the diameter D1 of the branched liquid channel 14 for each spray gun 7, the liquid supply channel 12, which is a concentrated channel, can supply the coating liquid. , etc., and the difference in liquid pressure in the longitudinal direction in the liquid supply channel 12 is reduced. Therefore, the pressure applied to each spray gun 7 is equalized, the pressure difference between the nozzles is reduced, and the variation in the amount of liquid ejected from each spray gun 7 is suppressed.

In addition, in the gun unit 1, the cross-sectional area S1 of the liquid supply channel 12 is smaller than 1/2 of the cross-sectional area S2 of the gun unit 1 (the combined cross-sectional area of the liquid supply unit 11 and the air supply unit 21). /4 ((S2)/4<S1<(S2)/2). In this case, it is preferable for the inner diameter D1 of the liquid supply channel 12 to be larger than the inner diameter D2 of the branched liquid channel 14 in order to equalize the liquid pressure. , the weight is also increased, which is not preferable.

Regarding this point, according to experiments by the inventors, it is preferable for D1 to be two times or more D2 for hydraulic pressure equalization, but even if it exceeds four times, there is not much difference. Also, if S1 is more than half of S2, the overall size of the device becomes large and lacks compactness. However, if S1 is 1/4 or less of S2, the space for arranging each flow path becomes difficult in terms of design. Therefore, in the gun unit 1, by setting D1, D2, S1, and S2 within the ranges described above, the pressure difference between the nozzles can be reduced without impairing the compactness of the device and the layout of the flow path. The spray gun 7 secures an equivalent liquid discharge amount.

Thus, in the gun unit 1 of the present invention, in the manifold type configuration, the inner diameter D1 of the liquid supply channel 12 in the liquid supply unit 11 is set larger than the inner diameter D2 of the branch liquid channel 14 (2×D2≦ D1≦4×D2), the liquid supply channel 12 itself can be used as a chamber, and the pressure difference applied to each spray gun 7 can be alleviated. Thereby, the pressure difference between the portion close to the fluid supply source and the portion far from the fluid supply source can be suppressed, and the discharge amount of each spray gun 7 can be made uniform. Therefore, the discharge amount of the spray gun 7 in the far portion is not reduced, and stable coating of tablets is possible.

It goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.
For example, in the above-described embodiment, the gun unit 1 having three blocks arranged in the longitudinal direction was described, but the number of blocks (the number of spray nozzles) can be changed as appropriate, and the number of spray nozzles can be changed as appropriate according to specifications. is also one of the features of the manifold spray gun of the present invention. Alternatively, the liquid supply unit 11 and the air supply unit 21 may not be divided into blocks for each spray gun, but each may be made into an elongated integral member, and a plurality of spray guns may be attached thereto. Also, a configuration may be adopted in which a plurality of spray guns are attached to one block and a plurality of blocks are joined together.

INDUSTRIAL APPLICABILITY The present invention is widely applicable not only to pharmaceutical tablets, but also to the manufacture of tablet-like foods such as health foods and sweets.

1 manifold spray gun unit 2 rotating drum 3 pan coating device 4 support holder 4a, 4b support holder 5 housing 6 manifold 7 spray gun 11 liquid supply units 11a to 11c manifold liquid block 12 liquid supply channel 13 liquid return channel 14 branches Liquid flow path 15 Branched return flow path 21 Air supply units 21a to 21c Manifold air block 22 Cylinder air flow path 23 Atomizing air flow path 24 Pattern air flow path 25 Branched air flow path 26 Branched air flow path 27 Branched air flow path 28 Through Hole 29 Pipe-shaped member 31 Inlet block 32 End blocks 33a, 33b Holder mounting hole 34 Fitting projection 35 Fitting recess 36 Holder block 37 Mounting bolt 38 Mounting bolt 39 Fitting hole 41 Liquid pipe part 42 Liquid supply pipe 43 Return pipe D1 Liquid supply channel inner diameter D2 Branch liquid channel inner diameter O Rotational axis S1 Liquid supply channel cross-sectional area S2 Manifold spray gun unit cross-sectional area

Claims (3)

a spray gun that sprays a liquid using compressed air;
The manifold is provided with a liquid supply channel for supplying the liquid to the spray gun, and an air channel for supplying the compressed air to the spray gun. A manifold spray gun,
The manifold has a branch liquid flow path branched from the liquid supply flow path and connected to the spray gun,
A manifold spray gun, wherein the inner diameter D1 of the liquid supply channel is two to four times the inner diameter D2 of the branched liquid channel (2×D2≦D1≦4×D2). The manifold spray gun of claim 1, wherein
A manifold spray gun characterized in that the cross-sectional area S1 of the liquid supply channel is larger than 1/4 and smaller than 1/2 of the cross-sectional area S2 of the manifold ((S2)/4<S1<(S2)/2). . The manifold spray gun according to claim 1 or 2,
The manifold includes a liquid supply unit provided with the liquid supply channel and an air supply unit provided with the air channel,
The manifold spray gun, wherein the liquid supply unit is provided detachably with respect to the air supply unit.

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