JPH057357U - Spraying device - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent liquid leakage from the spray nozzle when the operation is stopped, without providing a stop valve or a screwed part near the spray nozzle. The liquid sprayer is controlled to be switched between a communication position where the base end side of the liquid supply path L2 whose tip side is connected to the liquid ejection port 4 and the liquid supply device 1 communicate with each other, and a shut-off position where the liquid supply device 1 is shut off. A switching valve V1 is provided, and further a means V2 for supplying gas is arranged at the base end side of the liquid supply passage L2. When the operation is stopped, the liquid switching valve V1 connected to the base end side of the liquid supply passage L2 is held at the shutoff position. Then, the liquid supply to the liquid supply path L2 is cut off. In this state, when gas is supplied to the liquid supply path L2 from the means V2 for supplying gas to the base end side of the liquid supply path L2, the liquid remaining in the liquid supply path L2 is the liquid together with the gas. The spray is discharged from the jet port 4.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

  The present invention relates to a spraying device that does not cause liquid leakage during spraying or after spraying has stopped. It is a thing.

[0002]

[Prior art]

  In granulation of powder or spray drying of liquid samples, in a granulator or spray drying equipment. In the storage, there is a widespread spraying device that atomizes liquid such as water or solution with gas such as air. Has been used. Many conventional spraying devices stop the liquid supply when spraying is stopped. In order to control the liquid stop valve installed near the tip of the spray nozzle, It has a structure that can be activated by air or electricity. With this conventional atomizer As a stop valve is installed near the tip of the spray nozzle, the liquid supply Pipes, gas supply pipes, valve control air supply pipes (or valve control electric wires), etc. Or a plurality of members incorporating them and a stop valve are connected by, for example, screwing. It was customary to tie.

[0003]   However, with conventional equipment, the screwed part may become loose due to severe vibration during operation. Caused by liquid leakage, and liquid leakage due to malfunction of the stop valve at the time of spray stop. Problems such as granules or powder being manufactured are solidified into lumps, and operation is often Discontinue, disassemble, clean, reassemble spray nozzle and surrounding area, or It was necessary to discharge good products. Operation interruption, disassembly of complex parts, cleaning, reassembly Or the discharge of defective products not only reduces work efficiency and productivity, but also However, if it is a food or drug, there is a risk of microbial contamination. Loose threaded part A double nut may be used for prevention, but powder in the gap of the double nut uneven part Adhesion becomes a problem.

[0004]   Furthermore, the atomizer that installs the stop valve near the atomizer nozzle has a mechanism that causes It is unavoidable that a horizontal part (a part where substances are deposited) is formed near the Where the powder is scattered at a high concentration, such as inside the granulator, the powder is attached to the horizontal portion. There is also a problem of wearing and further solidifying. The conventional stop valve was installed in this way Since the sprayer has liquid leakage and other drawbacks, it may leak even under severe vibration. There has been a long-awaited need for a spray device that can be operated for a long time without a break.

[0005]

[Problems to be solved by the device]

  In consideration of the above-mentioned circumstances, the present invention has a stop valve and a screw-in portion at a position near the spray nozzle. To prevent liquid leakage from the spray nozzle when the operation is stopped. This is an issue.

[0006]

[Means for Solving the Problems]

  Next, the present invention devised to solve the above problems will be described. Elements of the present invention In order to facilitate correspondence with the elements of the examples described later, Those enclosed in brackets are added. It should be noted that the present invention corresponds to the reference numerals of the embodiments described later. The reason for this explanation is to facilitate the understanding of the present invention, and the scope of the present invention will be realized. It is not limited to the examples.   In order to solve the above problems, the spraying device of the first invention of the present application is   The liquid supply is connected to the base end of the liquid supply passage (L2) whose front end is connected to the liquid ejection port (4). Switching control is performed between a communication position in which the feeding device (1) communicates with and a cutoff position in which the supply device (1) is cut off. Liquid switching valve (V1)   The tip side is connected to the gas ejection port (8) arranged adjacent to the liquid ejection port (4). And a gas supply path (A2) whose base end is connected to the gas supply device (5). e,   The liquid jet port (4) and the gas jet port (8) form a spray nozzle (N). In the atomizing device,   A means (V2) for supplying gas is arranged at the base end side of the liquid supply path (L2). And are characterized.   The spray nozzle (N) may have a conventionally known structure. For example, by strongly ejecting gas toward the center from the peripheral part of the supplied liquid, It is possible to use a structure in which the liquid is atomized.   The gas ejected from the spray nozzle (N) is usually used for atomizing air, nitrogen gas, etc. The gas to be supplied, said gas being said gas supply device (5), for example a compressor. Sir, gas cylinder, etc. The gas supply path (A2) is normally a gas supply pipe (7) The material of the member that forms the gas supply passage (A2) and can be formed by The inner and outer diameters can be selected appropriately, but when handling foods and pharmaceuticals, the material Tensile steel, etc. shall be able to withstand cleaning and heating to maintain hygiene. Is desirable.

[0007]   The liquid ejected from the spray nozzle (N) is normally used when granulating powder. Water, which is a raw material solution before drying when spray drying. Liquid supply device (1) Is usually a combination of a liquid tank and a pump, but the drop from the liquid tank is used You can also do it. The liquid supply path (L2) is usually formed by a liquid supply pipe (3), etc. However, the material and inner / outer diameter of the member forming the liquid supply path (L2) are appropriately selected. However, when handling foods and pharmaceuticals, use hygienic materials such as stainless steel It is desirable to be able to withstand cleaning and heating for cleaning.

[0008]   The liquid switching valve (V1) is provided at least from the liquid supply device (1) to the liquid supply passage ( Any material having a function of allowing or closing the inflow of the liquid into L2) may be used. An example For example, a two-way valve that has the function of simply letting the liquid flow in or closing it, It has the function of flowing into the liquid supply path (L2) and the function of closing it, and at the same time it is a liquid For example, it is possible to use a three-way valve or the like having a function of returning the liquid to the liquid supply device (1). it can.

[0009]   The spraying device of the second invention of the present application is the same as the spraying device of the first invention,   A means (V2) for supplying gas to the base end side of the liquid supply path (L2) is used for supplying the liquid. A communication position where the base end side of the supply path (L2) and the gas supply device (5) communicate with each other and a shield. It is equipped with a gas switching valve (V2) that is controlled to switch between cut-off positions. And   The gas switching valve as means for supplying gas to the base end side of the liquid supply path (L2) When (V2) is used, the gas switching valve (V2) is integrated with the liquid switching valve (V1). The liquid is made to flow into the liquid supply path (L2) while the gas is liquid. A function of preventing the liquid from flowing into the supply path (L2), and the liquid supply path (L2) ), And at the same time, it has the function of flowing gas to the liquid supply path (L2). It can be a three-way valve. In addition, the liquid flows into the liquid supply path (L2). And a function to prevent gas from flowing into the liquid supply path (L2) and A liquid supply device (1) is provided by closing the inflow of liquid to the liquid supply path (L2). To the base end side of the liquid supply path (L2) at the same time. It is also possible to use a one-way valve.

[0010]   The liquid switching valve (V1) and the gas switching valve (V2) are switched manually. It is also possible to do so by using the switching valve control device (9), but at substantially the same time. It is possible to perform a switching operation. In that case, switch valves (V1) and (V2) are created. For the driving force and control system to operate, well-known valve operation control technology such as air, electricity, etc. Can be used.

[0011]   The spray device of the third invention of the present application is the spray device of the first invention or the second invention. In the   The liquid supply path (L2) and the gas supply path (A2) are the inner pipe (3) and the outside thereof. A flow path (L2) inside the inner pipe (3) of the double pipe having the outer pipe (7) arranged on the side, And a flow path (A2) between the inner pipe (3) and the outer pipe (7), A heat-insulating outer tube (11) for forming a closed air layer (D) on the outer side of the outer tube (7) Is provided, and the tip of the heat insulation jacket tube (11) is close to the spray nozzle (N). It is characterized in that it is closed at a different position.

[0012]

[Action]

  In the spraying device of the first invention of the present application having the above-mentioned configuration, the tip end side is the liquid ejection port (4 ) And the base end side of the liquid supply path (L2) connected to the liquid supply device (1) communicate with each other. The liquid switching valve (V1) that is controlled to switch between the communication position and the shut-off position A means (V2) provided for supplying gas to the base end side of the liquid supply path (L2). ) Is provided.   The liquid connected to the base end side of the liquid supply path (L2) during the operation of the spraying device. When the switching valve (V1) is held in the communication position, the liquid is supplied from the liquid supply device (1). Liquid flows through the liquid switching valve (V1) and the liquid supply path (L2), and the spray nozzle (N ) Is ejected from the liquid ejection port (4).

[0013]   When the operation of the spraying device is stopped, the sprayer is connected to the base end side of the liquid supply path (L2). The continued liquid switching valve (V1) is held at the shutoff position. Then the liquid supply The liquid supply to the line (L2) is cut off. In this state, the liquid supply path (L2) Gas is supplied to the liquid supply path (L2) from the means (V2) for supplying gas to the base end side. Then, the liquid remaining in the liquid supply path (L2) is jetted out by the gas. Discharged through the mouth (4).   In this way, the liquid remaining in the liquid supply path (L2) is discharged by the gas. Then, if the operation of the spraying device is stopped, the liquid supply path (L2) when the operation is stopped No inconvenience such as liquid leakage from the liquid ejection port (4) connected to the tip side occurs. Become

[0014]   Therefore, according to the first invention of the present application, the position near the liquid ejection port (4) That is, liquid leakage of the residual liquid in the liquid supply path (L2) to a position near the spray nozzle) To prevent the stop valve and the threaded part for attaching the stop valve. There is no need to kick.

[0015]   The spraying device of the second invention of the present application having the above-mentioned configuration is the spraying device of the first invention. In the above, the means (V2) for supplying gas to the base end side of the liquid supply path (L2) is The base end side of the liquid supply path (L2) and the gas supply device (that is, the gas of the spray nozzle). A device for supplying gas to the body ejection port) and a communication position where the device is cut off It is equipped with a gas switching valve (V2) that is controlled to switch between shutoff positions.   During operation of the spraying device, the gas switching valve (V2) is kept in the shut-off position to operate. At the time of stoppage, the communication position is maintained before the operation is stopped. Then the liquid The remaining liquid in the supply path (L2) is discharged by spraying.   Therefore, in the second device, the gas supply device ( That is, a gas supply device (5) for supplying a gas for atomization (5) is used to produce a liquid Since the liquid remaining in the supply path is discharged, the structure for preventing liquid leakage should be simplified. You can

[0016]   The spraying device of the third invention of the present application having the above-mentioned configuration is the first invention or the second invention. In the devised spraying device,   The liquid supply passage (L2) and the gas supply passage (A2) are connected to the inner pipe (3) and the outside thereof. A flow path (L2) inside the inner pipe (3) of the double pipe having an outer pipe (7) arranged, and And a flow path (A2) between the inner pipe (3) and the outer pipe (7), An outer jacket tube (11) for heat insulation having both ends closed is provided outside the outer tube (7), The tip of the heat insulation jacket tube (11) is closed at a position close to the spray nozzle (N). ing.   Therefore, the double layer forming the liquid supply path (L2) and the gas supply path (A2) Even when the temperature of the fluid supplied by the pipe is low, the air layer (D) as a heat insulating layer is Therefore, there is no condensation on the surface.

[0017]   When the third invention of the present application is installed in a granulating device or a spray drying device, The surface of the double pipe consisting of the body supply passage (L2) and the gas supply passage (A2) has the following (a), (b) In the case of, there is a risk of dew condensation. (a) Liquid and gas passing through the liquid supply path (L2) and the gas supply path (A2) If the body temperature is low, (b) When the humidity in the granulator or spray dryer is high,   When dew condensation occurs on the surface of the part inside the granulator or the spray dryer , Powder that has been rewound in the granulator or spray dryer, and has adhered to it If it becomes a certain thickness, it becomes flakes and peels off, causing defective products. Become. Liquid supply path (L2) and gas supply path (A2) are formed to prevent dew condensation All or at least the liquid jet port (4) or the gas jet port ( 8) a part of the side in contact with 8) is arranged especially in the granulator or in the spray dryer. The covered part is covered with a jacket tube (11) whose tip is closed to form a closed air layer (D). Therefore, it insulates.

[0018]   Thus, the double tube placed in the granulator or spray dryer is It is necessary to cover the surface with a mantle tube (11) whose tip is closed to form a triple tube in terms of work and sanitation. Most desirable on tally. As described above, the mantle tube (11) having the closed tip. Extremely simple structure by insulating with an air layer (D) that is covered and sealed with Surely prevents dew condensation, thus preventing powder adhesion and peeling off due to dew condensation. It is possible to achieve the effect.

[0019]   As can be seen from the above description, the first to third inventions of the present application are granulation of powder or Is particularly excellent when used in an apparatus that contains powder inside, such as spray-drying a solution sample. However, it does not prevent the liquid from dripping during spraying, such as spray painting. It is also effective when

[0020]

【Example】

  Next, an embodiment of the spraying device of the present invention will be described with reference to the drawings.   FIG. 1 is an explanatory view of a first embodiment of the spraying device of the present invention.   In FIG. 1, a liquid supply device 1 includes a liquid delivery pipe formed by a liquid delivery pipe 2. It is configured to supply liquid to the passage L1. Liquid delivery pipe 2 and liquid supply pipe The base end side (upstream end side) of 3 is a liquid gas that can be switched between a communication position and a blocking position. It is connected by the body switching valve V1. A liquid supply path L2 is formed by the liquid supply pipe 3. The liquid discharge port 4 is formed at the tip (downstream end) of the liquid supply path L2. There is.

[0021]   The gas supply device 5 supplies the gas ( Nitrogen). The tip of the gas delivery pipe 6 is a gas supply pipe. 7 is connected to the base end side (upstream end side). The gas supply pipe 7 is the liquid supply pipe 3 Is formed on the outer side of, and forms a double pipe together with the liquid supply pipe 3. And said The space between the outer surface of the liquid supply pipe 3 and the inner surface of the gas supply pipe 7 supplies the gas. A supply path A2 is formed. At the tip (downstream end) of this gas supply path A2, gas is exhausted. An outlet 8 is formed.   The gas discharge port 8 is formed in a ring shape around the liquid discharge port 4. Then, the spray nozzle N is formed from the gas discharge port 8 and the liquid discharge port 4 as described above. Is made. Then, the liquid supply pipe 3 and the gas supply pipe 7 forming the double pipe. And most of them and the spray nozzles N at their tips are arranged in the tank T. .

[0022]   The gas delivery path A1 to which gas is supplied from the gas supply device 5 and the liquid supply A gas switching valve V2 that can switch between a communication position and a blocking position is provided between the passage L2 and the passage L2. It has been burned.   The liquid switching valve V1 and the gas switching valve V2 are operated by the control air to control the switching valve. The control device 9 is configured to be switch-controlled. The switching valve control device 9 , A liquid switching valve V1 and a control air feeding device for operating the gas switching valve V2. It consists of a trolley.

[0023]   Next, the operation of the first embodiment will be described.   When the liquid is ejected from the spray nozzle N in a mist state, the liquid switching valve V1 The liquid is a liquid supply path in which the liquid is connected from the liquid supply device 1 to the liquid ejection port 4 on the tip side Operate so that it can pass to L2. At the same time, hold the gas switching valve V2 in the shutoff position, The gas is caused to flow from the gas supply device 5 to the gas ejection port 8. This causes the liquid to It spouts in a muzzle in the Nuzzle N.   When stopping the ejection of the liquid from the spray nozzle, the switching valve control device 9 is used. Therefore, the liquid switching valve V1 is turned off so that the liquid does not flow to at least the liquid jet port 4. Replace. At the same time, the gas switching valve V2 is switched from the shutoff state to the communication state to While flowing the body from the gas supply device 5 to the gas ejection port 8 via the gas supply path A2 , Flow from the base end side (upstream end side) of the liquid supply path L2 to the liquid jet port 8 at the downstream end . By this switching, the liquid jet port 8 is provided from the base end side (upstream end side) of the liquid supply path L2. Liquid is sprayed out by the gas, and therefore the liquid from the liquid jet port 8 is discharged. Body leakage completely disappears.   In the first embodiment, the liquid leakage of the residual liquid in the liquid supply passage is caused at a position near the spray nozzle. Stop valve to prevent this and screwed parts to attach the stop valve Since it is not provided, the structure in the vicinity of the liquid ejection port is simplified and there is no horizontal portion.   For this reason, from the screw-in part near the liquid ejection port during spraying that occurred with conventional equipment Liquid leakage and screwing in or near the liquid jet when the spray is stopped Liquid leakage from parts and the like is eliminated, and troubles that frequently occurred with conventional equipment are completely eliminated. It became possible to avoid it.   In the above embodiment, the structure of the spray nozzle is simple, so the manufacturing cost of the spray nozzle is low. Can be saved.

[0024]   Next, a second embodiment of the present invention will be described with reference to FIG.   In the description of the second embodiment, the components corresponding to those of the first embodiment will be described. The same reference numerals as in the first embodiment are used for the components of the second embodiment. like this By using the reference numerals, the description overlapping with the description of the first embodiment will be omitted.   In the spraying device of the second embodiment shown in FIG. 2, the liquid switching valve V1 is connected to the liquid supply device 1. A communication position for connecting the liquid delivery path L1 and the liquid supply path L2, and a blocking for blocking This is the same as the first embodiment in that it can be switched between the disconnection positions. Shi However, the liquid recirculation pipe 10 forming the liquid recirculation path L3 is provided in the liquid switching valve V1. When it is connected and the liquid switching valve V1 is in the shut-off position, the liquid delivery Point L1 is configured to be connected to the liquid return path L3, and The liquid flowing into the liquid reflux path L3 is configured to flow back to the liquid supply device 1. This is different from the first embodiment in that   In addition, in the second embodiment, the liquid supply pipe 3 and the gas supply pipe 7 outside the liquid supply pipe 3 are used. The portion of the double pipe formed from the inside of the tank T is the tip (spray nozzle). It is also a point that it is made into a triple tube by covering the outer tube 11 which is closed) This is different from the first embodiment. The inner surface of the outer tube 11 and the outer side of the substrate supply tube 7. An air layer D as a heat insulating layer is formed between the surface and the surface.   The structure of this second embodiment is the same as that of the first embodiment except the above.

[0025]   Next, the operation of the second embodiment of the present invention having the above construction will be described.   In the second embodiment, when the liquid switching valve V1 is in the shutoff position, the liquid The delivery passage L1 is connected to the liquid return passage L3, and the liquid flowing into the liquid return passage L3 is Reflux to the liquid supply device 1.   In addition, the liquid supply pipe 3 forming the liquid supply passage L2 and the gas supply passage A2, Even when the temperature of the fluid supplied by the double pipe of the liquid supply pipe 7 is low, the liquid Since there is an air layer D as a heat insulating layer between the supply pipe 7 and the jacket pipe 11, No condensation will occur on the. Therefore, liquid leakage due to dew condensation may occur in the tank T. There is no messing. Furthermore, the effect of heat insulation and heat retention of the double pipe portion covered with the outer pipe 11 is provided. You can raise the fruit.   The other operation of the second embodiment is the same as that of the first embodiment.   In the second embodiment, the liquid pipe flow path L3 is connected to the liquid supply device 1 It is also possible to connect to a waste liquid tank or the like (not shown) instead of connecting to.

[0026]   Next, a third embodiment of the present invention will be described with reference to FIG.   In the description of the third embodiment, the components of the first and second embodiments will be described. The same reference numerals as in the first and second embodiments are used for the components of the third embodiment. This By using the code like this, the explanation overlapping with the explanations of the first and second embodiments is omitted. To do.   In this third embodiment, a batch type fluidized bed type milk powder granulator is equipped with the spraying device of the present invention. FIG. 3 is a batch type fluidized bed milk powder equipped with the spraying device of the present invention. It is explanatory drawing of the granulator U. The part of the spraying device is the same as the structure shown in FIG.   In the lower part of the tank T of the batch type fluidized bed milk powder granulator U, a powder fluidized bed forming gas is formed. A body introduction path 12 is provided. In addition, in the upper part of the tank T, A gas discharge path 13 for discharging air to the outside and a cyclone 14 are connected. .

[0027]   Next, the operation of the third embodiment of the present invention having the above construction will be described.   Granulation of powdered milk using the batch type fluidized bed powdered milk granulator U is described in "Powdered milk preparation", " Granulation (fluidized bed formation and water spray) "," preliminary drying "," semi-finished products (preliminary dried products) " The four steps of "discharging" are defined as one cycle, and this cycle is repeated and continuously performed.   In the granulation step, the powdered milk charged in the batch type fluidized bed milk powder granulator U is in the powder flow state. The fluidized bed F is formed by the air introduced into the granulator from the fluidized bed forming gas introduction passage 12. To achieve. Use a sprayer to spray water into a powdered milk powder and atomize the powdered milk powder into granules. Granulate. Air for powder fluidized bed formation and air ejected from the atomizer during operation are air It is discharged to the outside of the granulator through the body discharge path 13 and the cyclone 14.   When water is sprayed from the spray nozzle N to granulate powder, the liquid switching valve V1 is set to The water is made to flow from the liquid supply device 1 to the liquid supply path L2. Also, gas switching valve V2 Is in a shutoff state, and the air from the gas supply device 5 does not flow into the liquid supply path L2, Flow only to supply path A2. As a result, the water becomes a mist at the spray nozzle N and is sprayed. Put out.

[0028]   To stop the jet of water from the spray nozzle N when moving to the next preliminary drying step The liquid switching valve V1 is switched from the communication state to the cutoff state to supply water with the liquid. It is in a state of flowing from the device 1 to the liquid return path L3. At the same time, shut off the gas switching valve V2. The state is switched to the communication state, and the air is caused to flow into the base end side of the liquid supply path L2. It The air that has flowed into the base end side of the liquid supply path L2 flows through the liquid supply path L2 It spouts from the spout 4. Before switching the liquid switching valve V1 and the gas switching valve V2 The switching valve control device 9 sends control air to the valves V1 and V2 for simultaneous switching. To do. By this switching, the liquid ejection path 4 is reached from the base end side of the liquid supply path L2. The water runs out during the heat. Even when spraying is stopped, the gas supply device 5 supplies gas to the gas supply path A2 and injects gas. The air is continuously supplied to the outlet 8, and the water flowing to the liquid return path L3 is liquid. Reflux to the feeder 1.   Using the batch type fluidized bed milk powder granulator U, granulation of milk powder in a continuous batch method for 4 days (96 hours) Although it was carried out continuously, there was no water leakage from the spray nozzle N and the product was manufactured smoothly. I was able to continue building. In addition, adhesion of rewound raw material milk powder to the outer tube 11 Was hardly seen.

[0029]

[Effect of device]

  The effects of the present invention are as follows. (1) No liquid leakage even under violent vibration during operation, and can withstand continuous operation for a long time It is a spraying device. (2) A spraying device that does not leak liquid while spraying is stopped. (3) No liquid leakage occurs even after repeated spraying and stopping spraying, and continuous spraying for a long time It is a spraying device that can continue operation. (4) The configuration is simple and the maintenance of the device is easy. (5) The structure is simple, and the spray nozzle and the vicinity thereof have good cleanability.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a spraying device of the present invention.

FIG. 2 is a block diagram showing a second embodiment of the spraying device of the present invention.

FIG. 3 is an explanatory view of a third embodiment of the spraying device of the present invention, showing an example of a batch type fluidized bed milk powder granulator equipped with the same spraying device as in the second embodiment. is there.

[Explanation of symbols]

A1 ... Gas delivery passage, A2 ... Gas supply passage, D ... Heat insulation layer (air layer), F ... Fluidized bed, L1 ... Liquid delivery passage, L2 ... Liquid supply passage, L3 ... Liquid return passage, N ... Spray nozzle, T …tank,
V1 ... Liquid switching valve, V2 ... Gas switching valve, 1 ... Liquid supply device, 2 ... Liquid delivery pipe, 3 ... Liquid supply passage, 4 ... Liquid jet port, 5 ... Gas supply device, 6 ... Gas delivery pipe, 7 ... Gas supply pipe, 8 ... Gas ejection port, 9 ... Switching valve control device, 10 ... Liquid recirculation pipe, 11 ... Mantle tube, 12 ... Powder fluidized bed forming gas introduction passage, 13 ... Gas discharge passage, 14 ... Cyclone,

Claims (3)

[Scope of utility model registration request] 1. A liquid switching valve that is switch-controlled between a communication position where a base end side of a liquid supply path whose front end side is connected to a liquid ejection port and a liquid supply device communicate with each other and a blocking position where the liquid supply device is blocked, A gas supply passage having a tip end side connected to a gas ejection port arranged adjacent to the liquid ejection port and a base end side connected to a gas supply device, wherein the liquid ejection port and the gas ejection port are spray nozzles. In the spraying device forming the above, the spraying device is provided with a means for supplying gas to the base end side of the liquid supply path. 2. The means for supplying gas to the base end side of the liquid supply passage is switched between a communication position where the base end side of the liquid supply passage communicates with the gas supply device and a shut-off position where the gas supply device is shut off. The atomizing device according to claim 1, further comprising a controlled gas switching valve. 3. The liquid supply path and the gas supply path are a flow path inside the inner pipe of a double pipe having an inner pipe and an outer pipe arranged outside thereof, and between the inner pipe and the outer pipe. And a heat insulating outer tube for forming a closed air layer is provided on the outer side of the outer tube, and the heat insulating outer tube has a tip closed at a position close to the spray nozzle. The spraying device according to claim 1 or 2.