JP5912393B2 - Spray nozzle and method of mixing gas and liquid - Google Patents

Description

  The present invention relates to a spray nozzle for mixing and spraying a gas and a liquid and a method for mixing a gas and a liquid.

When liquefied natural gas (hereinafter referred to as “LNG”) is vaporized and supplied as city gas, the amount of heat is adjusted. In recent years, the import of LNG rich in methane components has increased, and in many cases the heat is increased for city gas. The calorific value is adjusted by mixing natural gas with a calorific value adjusting agent such as liquefied petroleum gas (hereinafter referred to as “LPG”).
As such a calorific value adjusting method, for example, Japanese Patent Laid-Open No. 63-265994 (Patent Document 1) supplies vaporized natural gas to a venturi-type liquid / gas mixer, and generates a high-speed flow and low pressure generated in a venturi pipe. A technique for atomizing, evaporating, and mixing a calorific value adjusting agent supplied in a liquid state to a venturi tube is disclosed.

Japanese Patent Laid-Open No. 53-131328 (Patent Document 2) relating to a fuel vaporizer for an internal combustion engine, although not a city gas heat increasing device, discloses a technique for providing a throttle member that can move in the flow path direction in a venturi pipe. Is disclosed.
Further, JP-A-8-75621 (Patent Document 3) relates to a constant flow rate sampling device, in which a spindle-shaped core is fixed in a tube serving as a gas flow path, and a throat portion disposed outside the core is pulsed. A technique for changing a cross-sectional area of a flow path by moving it in the flow path direction by a motor is disclosed.
Japanese Utility Model Laid-Open No. 56-41210 (Patent Document 4) and Japanese Patent Application Laid-Open No. 4-248414 (Patent Document 5) relate to a flow rate measurement control device, and a circular cross-sectional area is provided in the flow direction in the throat portion of the venturi tube. A technique is disclosed in which a movable body having a surface that changes along the line is disposed, and the movable body is driven by a motor disposed in a flow path.
Furthermore, JP 2011-56400 A (Patent Document 6) relates to a fluid mixing method, and a branch channel having a small diameter portion whose channel cross section is smaller than that of the main channel is provided by branching from the main channel. The flow rate of the first fluid that flows through the small-diameter portion of the branch flow path by arranging the outlet side in the main flow path, providing the second fluid supply section at or near the small-diameter section of the branch flow path, and adjusting the flow rate of the main flow path Is a technique for maintaining the flow rate required for mixing the first fluid and the second fluid.

JP 63-265994 A JP-A-53-131328 JP-A-8-75621 Japanese Utility Model Publication No. 56-41210 JP-A-4-248414 JP 2011-56400 A

The flow rate of natural gas varies according to the city gas demand. A value obtained by dividing the operation flow rate by the rated flow rate is referred to as a turndown ratio. However, when the turndown ratio of natural gas is low, it may be operated at about 1/20.
On the other hand, when the flow rate of the Venturi tube decreases, the flow velocity and the low pressure generation effect decrease. Like the one disclosed in Patent Document 1, there is a problem that it is impossible to cope with a large change in the amount of city gas demand if the sectional area of the venturi tube throat is constant.
Venturi pipes, etc. are designed based on the rated flow rate, but when the natural gas turndown ratio is low, the flow rate of the venturi section decreases, so the LPG added as a calorie regulator is sufficiently vaporized with natural gas A liquid dripping phenomenon occurs in which the liquid is accumulated at the bottom of the tube without being mixed. If this phenomenon occurs, it will interfere with the production of city gas.
The turndown ratio of natural gas that can be vaporized and mixed by the venturi tube is about 1/1 to 1/5. For this reason, when the technique of Patent Document 1 is used as an application destination with a large flow rate fluctuation range, it is necessary to prepare venturi pipes having different sizes according to the flow rate range, which causes problems such as complication of the apparatus.

In this regard, in the technique described in Patent Document 2, even if the flow rate of the air passing through the venturi pipe varies, the axial position of the throttle member is changed so as to cope with it.
However, Patent Document 2 does not disclose a driving method for moving the aperture member in the axial direction. Further, if the drive source is outside the flow path, the drive shaft penetrates outside the flow path, and the frequently moving surface is sealed. Therefore, there is a possibility that the fluid may leak from this surface, and there is a concern about safety when the fluid is flammable or dangerous.
Also in Patent Document 3, since the throat portion disposed outside the spindle core is moved in the direction of the flow path, it is possible to cope with fluctuations in the gas flow rate, but the drive section is outside the flow path. As in the case of Patent Document 2, the drive mechanism penetrates the inside and outside of the flow path, and there is a problem of sealing performance on the movable surface (sliding surface).

Similarly, in Patent Documents 4 and 5, although it is possible to cope with fluctuations in the gas flow rate, a motor as a drive source is disposed in the gas flow path, so that the structure becomes complicated. Considering the inflow of fluid into the motor unit that requires driving energy, there is a problem that it is difficult to apply to fluids that are flammable or corrosive.
Furthermore, in the one disclosed in Patent Document 5, the “flow rate” is controlled based on the pressure and temperature. However, what is important from the viewpoint of mixing the fluid is the throat of the venturi tube in accordance with the fluctuation of the flow rate. This is to control the flow velocity of the part, and such control is not possible with the one of Patent Document 5.

The one disclosed in Patent Document 6 is intended to solve these problems, and can reliably obtain a high mixing effect over a wide flow rate range, and does not require a movable part such as a movable body. Therefore, the driving unit for driving the movable unit is not required, the structure can be simplified, and the present invention can be applied to a flammable or corrosive fluid.
However, when mixing a gas and a liquid, when conditions such as a flow rate are severe, the liquid does not necessarily atomize, and there is a concern that a dripping phenomenon may occur.

  The present invention has been made in order to solve such problems, and has a simple structure, is applicable to fluids having flammability and corrosivity, and has a high effect of preventing dripping phenomenon and It aims at providing the mixing method of gas and a liquid.

(1) A spray nozzle according to the present invention is a nozzle that mixes and sprays gas and liquid, and is supplied to an outer tube that receives supply of gas, an inner tube that receives supply of liquid, and the outer tube. A two-phase flow pipe in which all or a part of the gas and all or a part of the liquid supplied to the inner pipe flow in a state of an annular flow or an annular spray flow,
The distal end portion of the inner tube is disposed in the outer tube in the same direction as the outer tube,
The two-phase flow tube is disposed in the outer tube in the same direction as the outer tube, and the tip of the two-phase flow tube is disposed at the same position as the tip of the outer tube or upstream of the tip of the outer tube. , the interior of the two-phase flow tube has a wall member provided in parallel with the flow of fluid, it forms a plurality of two-phase flow channel inside the two-phase flow tube by the wall member In addition, a tapered portion having a diameter decreasing toward the downstream side is provided on the inner surface proximal end side of the two-phase flow tube, and the downstream side of the tapered portion is a parallel portion .

( 2 ) Further, in the above (1), a guide part for guiding gas to the two-phase flow tube side is provided in the vicinity of the outer base end of the two-phase flow tube. It is.

( 3 ) The method of mixing gas and liquid according to the present invention is a method of mixing gas and liquid using the spray nozzle described in (1) or (2) above.
The flow rate of the gas flowing through the outer tube is adjusted so that the superficial velocity of the gas in the two-phase flow tube is 10 m or more per second.

( 4 ) Further, in the above ( 3 ), the spray nozzle is provided in a gas pipe through which a gas flows,
The gas pipe has a venturi near the downstream side of the installation position of the spray nozzle.

( 5 ) Further, in the above ( 4 ), the gas flowing through the gas pipe and the gas flowing through the outer tube have the same composition.

( 6 ) Further, in any of the above ( 3 ) to ( 5 ), the gas is natural gas and the liquid is liquefied petroleum gas.

According to the present invention, a high mixing effect can be reliably obtained over a wide flow rate range, and the effect of preventing the dripping phenomenon is high.
In addition, since a movable part such as a movable body is unnecessary and a drive part for driving the movable part is also unnecessary, the structure can be simplified.
Furthermore, since it is basically composed of only a pipe member, the degree of freedom in selecting a material is high, and it can be applied to a fluid having combustibility and corrosivity by selecting an appropriate material.

It is explanatory drawing of the spray nozzle which concerns on Embodiment 1 of this invention. It is explanatory drawing which illustrates typically the flow pattern by the difference in the flow velocity of the liquid phase which flows in a horizontal pipe, and a gaseous phase. It is explanatory drawing of the other aspect of the spray nozzle which concerns on Embodiment 1 of this invention. It is explanatory drawing of the other aspect of the spray nozzle which concerns on Embodiment 1 of this invention. It is explanatory drawing of the spray nozzle which concerns on Embodiment 2 of this invention. It is explanatory drawing of the other aspect of the spray nozzle which concerns on Embodiment 2 of this invention. It is explanatory drawing of the other aspect of the spray nozzle which concerns on Embodiment 2 of this invention. It is explanatory drawing of the other aspect of the spray nozzle which concerns on Embodiment 2 of this invention. It is explanatory drawing of the gas-liquid mixing apparatus which concerns on Embodiment 3 of this invention. It is explanatory drawing of the gas-liquid mixing apparatus which concerns on Embodiment 4 of this invention.

[Embodiment 1]
The spray nozzle 1 according to the present embodiment is a spray nozzle that mixes and sprays a gas and a liquid.
The properties and applications of the gas and liquid mixed by the spray nozzle 1 are not particularly limited, but as an example, when city gas is produced by adding and mixing LPG (liquid) to natural gas (gas) vaporized LNG Is mentioned.
Hereinafter, the spray nozzle of the first embodiment will be described mainly with reference to FIG. In FIG. 1, white arrows indicate the direction of gas flow, and hatched arrows indicate the direction of liquid flow.
Further, in the present specification, as a term for specifying a part of a member disposed in a gas and / or liquid flow path, the tip refers to the gas in the member, the downstream end in the liquid flow direction, and the base end refers to the gas in the member. The upstream end of the liquid flow direction. The distal end portion refers to the vicinity of the distal end of the member, and the proximal end portion refers to the vicinity of the proximal end of the member.

As shown in FIG. 1, the basic configuration of the spray nozzle 1 according to the present embodiment includes an outer tube 2 that receives gas supply, an inner tube 3 that receives liquid supply, and a gas supplied to the outer tube 2. A two-phase flow tube 4 in which all or a part and all or a part of the liquid supplied to the inner tube 3 flows in a two-phase state is provided.
Hereinafter, each configuration will be described in detail.

<Inner pipe>
The distal end portion of the inner tube 3 is disposed inside the outer tube 2 in the same direction as the outer tube 2. The inner pipe 3 receives supply of liquid from a liquid supply pipe (not shown) to the proximal end side and ejects liquid on the distal end side. The ejection is not only when the liquid is ejected vigorously by the force from the inner side of the inner tube 3, but also when the liquid supplied to the tip of the inner tube 3 is caught in and discharged from the air flow outside the inner tube 3. including. In addition, if the front-end | tip part of the inner tube 3 is coaxial with the outer tube 2, you may arrange | position in contact with the inner wall of the outer tube 2, and may arrange | position through space.
The cross-sectional shape of the inner tube 3 is not particularly limited, and may be a circle or a polygon. Further, as shown in FIG. 1, the inner tube 3 may be one having only an opening at the tip, or may be provided with a function of promoting atomization by installing a porous body or a mesh ring at the tip. Good. Furthermore, you may make it provide the structure which gives a swirl flow to the liquid which passes the inside of the inner tube 3, for example, a swirl | wing blade.
In addition, you may make the member attached to the front-end | tip and the inside of the inner tube | pipe 3 removable.
The inner tube 3 is fixed to the outer tube 2, but the fixing method is not particularly limited, and may be fixed by, for example, a stay (not shown).

<Outer tube>
The outer tube 2 is supplied with gas from the base end side. As an aspect in which the outer tube 2 is supplied with gas, for example, when the outer tube 2 is arranged in a pipe through which gas flows, or a gas supply tube (not shown) that supplies gas to the proximal end side of the outer tube 2 May be connected to.

<Two-phase flow pipe>
The two-phase flow pipe 4 is arranged coaxially with the outer pipe 2, and at least a part of the liquid ejected from the inner pipe 3 and at least a part of the gas supplied to the outer pipe 2 are in a two-phase state. Flowing. The two-phase flow tube 4 is fixed so as to be coaxial with the outer tube 2 by a stay or the like (not shown).

Two-phase flow refers to a phenomenon in which two phases, for example, a liquid phase and a gas phase, are mixed and flow. Mist has very small water droplets in the air. This is a two-phase flow called a spray flow (mist flow), and the liquid phase is dispersed in the gas phase.
On the other hand, beer poured into a glass, for example, contains a lot of small carbon dioxide bubbles in the beer, but this form is a two-phase flow called bubble flow, The gas phase is dispersed in the phase. The droplets in the spray flow and the bubbles in the bubble flow are called dispersed phases, while the gas phase in the spray flow and the liquid phase in the bubble flow are called continuous phases.
In an open space such as the earth's atmosphere, the dispersed phase is normally dispersed almost uniformly in the continuous phase, and there is a homogeneous flow such as a spray flow or bubble flow. However, a two-phase flow that flows in a closed space such as in a pipe generates not only a homogeneous flow but also a non-uniform flow.

The flow form of the two-phase flow depends on the flow velocity of the gas phase and the liquid phase, and a phase diagram showing how the flow form is obtained by these is experimentally obtained.
FIG. 2 is a diagram schematically showing a flow pattern according to a difference in flow velocity between the liquid phase and the gas phase flowing in the horizontal pipe. The figure shown here is the one described in the book “Gas-liquid two-phase flow” (author: Yasuhiro Ueda, publisher: Yokendo). The liquid phase and the gas phase flowing in the horizontal pipe show the following flow modes depending on the difference in flow velocity. The liquid-phase and gas-phase flow rates are apparent flow rates obtained by dividing the gas-phase and liquid-phase flow rates by the cross-sectional area of the flow path, and are also referred to as superficial velocity. Hereinafter, the flow velocity in this specification refers to the superficial velocity.
The transition of the flow pattern due to the difference in the flow velocity of the gas phase is as follows.
(1) When the gas phase flow rate is slow When the liquid phase flow rate is slow, the liquid phase flows along the bottom surface of the pipe (stratified flow). On the other hand, when the flow velocity of the liquid phase is increased, a spiral flow or a bubble flow is generated.
(2) When the gas phase flow rate is slightly high When the gas phase flow rate becomes high, the gas-liquid interface undulates and becomes a wavy flow or slag flow.
(3) When the gas phase flow rate is high, when the gas phase flow rate is further increased, part of the liquid is scattered, the liquid phase is pushed toward the wall surface and flows as an annular liquid film along the tube wall, and the gas phase Becomes an annular flow or an annular spray flow that continuously flows in the center of the tube at a considerable flow rate.
Note that the flow mode may be affected by the piping posture, and the flow mode is partially different for vertical pipes and the like whose gravity direction is different from that of the horizontal pipe. However, when the gas-phase flow velocity is high, the flow velocity (inertial force) becomes more dominant than gravity, so the influence of the piping posture on the flow mode becomes small. That is, when the gas phase flow velocity is high, the flow becomes an annular flow or an annular spray flow regardless of the piping posture.

In the spray nozzle 1 of the present embodiment, when an annular spray flow is generated in the two-phase flow tube 4, the atomization of the liquid is promoted, and the mixing of the liquid and the gas is increased.
In order to generate the annular spray flow, although depending on the flow rate ratio between the liquid and the gas, the superficial velocity of the gas may be 10 m or more per second, more desirably 20 m or more per second. In addition, although the atomization effect of a liquid is acquired also in the state of an annular flow, the effect can be heightened more by setting it as an annular spray flow. On the contrary, when the gas flow velocity in the two-phase flow pipe 4 is reduced, the annular flow or the annular spray flow state cannot be maintained, and a transition is made to a flow state such as a wavy flow, a slag flow, or a bubble flow. In that case, the dispersibility and uniformity of the liquid phase in the two-phase flow tube 4 is deteriorated, and the gas-liquid contact area is reduced, so that the atomization performance is lowered.

An experiment was conducted to investigate the relationship between the gas superficial velocity and the presence or absence of liquid sag. This will be described below.
The experimental conditions are as follows.
・ Gas: Natural gas ・ Liquid: LPG
・ Gas mass flow rate: Liquid mass flow rate = 1: About 0.1 to 0.2 (Table 1)
・ Gas mass flow rate: Liquid mass flow rate = 1: About 0.5 to 1.0 (Table 2)
-Method for confirming the presence or absence of dripping: It was confirmed by the difference in the surface temperature between the upper and lower surfaces of the LPG-added downstream pipe (horizontal pipe part) and the visualization part (sight glass) observation.
The experimental results are shown in Tables 1 and 2.

According to the results shown in Table 1, since the dripping phenomenon occurs when the superficial velocity of the gas is low, it is understood that the superficial velocity of the gas should be 10 m / sec or more.
Further, according to the result shown in Table 2 in which the flow rate of the liquid with respect to the flow rate of the gas is larger than that in Table 1, it is understood that the superficial velocity of the gas should be 20 m / second or more.

The position where the two-phase flow tube 4 is disposed may be either outside or inside the outer tube 3.
As described above, the flow form of the two-phase flow depends on the flow rates of the gas phase and the liquid phase. It is desirable to determine the flow path cross-sectional area of the two-phase flow tube 4 based on the flow rate of the liquid to be sprayed so that a flow velocity at which an annular spray flow is generated in the two-phase flow tube 4 is obtained.
The length of the two-phase flow pipe 4 in the flow path direction is desirably 5 times or more the flow path diameter of the two-phase flow pipe 4. By setting the flow path length of the two-phase flow pipe 4 as described above, an annular spray flow is easily formed inside the two-phase flow pipe 4 when the gas flow path has a sufficient speed.

The operation of the spray nozzle 1 according to the present embodiment configured as described above will be described.
The gas is supplied from the base end side of the spray nozzle 1, and the liquid is supplied to the inner tube 3 via a liquid supply tube (not shown).
A part of the gas supplied from the base end side flows into the two-phase flow pipe 4.

The liquid supplied to the inner pipe 3 through the liquid supply pipe merges with the gas flowing through the outer pipe 2 at the tip of the inner pipe 3 and flows through the two-phase flow pipe 4 in a two-phase state. As described above, by providing the two-phase flow pipe 4, the liquid supplied to the inner pipe 3 is once introduced into the two-phase flow pipe 4 to form a two-phase state, so that dripping can be prevented. .
As described above, the two-phase flow pipe 4 takes various flow forms depending on the flow velocity of the gas phase. A state where the mixed flow state flowing through the two-phase flow tube 4 is an annular flow or an annular spray flow is preferable because the atomization of the liquid is most favorable, that is, the particle droplet diameter is reduced.

  When the flow velocity of the gas phase is a flow velocity capable of forming an annular spray flow, the liquid supplied through the inner tube 3 becomes an annular spray flow and forms a liquid film on the inner wall surface of the two-phase flow tube 4. While flowing. At the outlet of the two-phase flow tube 4, the liquid film formed on the inner wall surface of the two-phase flow tube 4 is ejected while maintaining the liquid film state in the tube axis direction of the two-phase flow tube 4. Inside the liquid film is a gas flow that has flowed through the two-phase flow tube 4, the liquid film is in contact with the gas phase on the inner surface side, and the liquid film is sheared by the difference in flow rate between the liquid film and the gas phase. Is torn and atomized.

  Note that the gas phase flow rate is preferably maintained within a range in which the flow mode in the two-phase flow pipe 4 can maintain the annular flow or the annular spray flow, and conversely within this range, the gas phase flow rate can be reduced (gas phase side). Pressure may be small). In general, the gas phase flow rate may be maintained at 10 m or more per second, preferably 20 m or more per second.

Since the liquid film in the two-phase flow tube 4 is formed by a gas phase flow, there is no need to reduce the cross-sectional area of the liquid-phase flow path for liquid film formation, the liquid-phase flow path can be simple and the cross-sectional area can be increased, The pressure loss on the liquid phase side can be kept small.
Further, the gas-phase-side channel in the spray nozzle 1 has a substantially straight tube shape, and there is no obstacle, so the pressure loss is small.

  As described above, the spray nozzle 1 of the present embodiment has a simple structure, can be applied to a flammable or corrosive fluid, and has a high effect of preventing a dripping phenomenon.

In the above embodiment, the distal end side of the outer tube 2 and the proximal end side of the two-phase flow tube 4 are not connected, but the present invention is not limited to this, The distal end of the tube 2 and the proximal end of the two-phase flow tube 4 may be connected so that all the gas flowing through the outer tube 2 flows to the two-phase flow tube 4.
FIG. 3 is a diagram showing such an embodiment. In FIG. 3, the same parts as those in FIG. 1 are denoted by the same reference numerals. The spray nozzle 5 shown in FIG. 3 has the proximal end of the two-phase flow tube 4 disposed downstream of the distal end of the outer tube 3, and the flow path cross section of the proximal end portion of the two-phase flow tube 4 is the distal end of the outer tube 3. These are connected by a reduced diameter portion 7 that is smaller than the channel cross section of the portion and reduces the diameter toward the downstream side. Thus, by connecting the distal end of the outer tube 2 and the proximal end of the two-phase flow tube 4 at the reduced diameter portion 7, more gas can flow into the two-phase flow tube 4. The gas flow rate at 4 can be increased. This makes it easier to change the flow mode in the two-phase flow pipe 4 to an annular spray flow.

  The reduced diameter portion 7 serves to guide the gas flowing through the outer tube 2 to the two-phase flow tube 4, and in that sense, has a function as a guide portion in the present invention. As another mode of the guide portion for allowing more gas to flow into the two-phase flow tube 4, in addition to providing the reduced diameter portion 7, a plate inclined from the inner wall side of the outer tube 2 toward the two-phase flow tube 4 side. It is also possible to provide an inclined member having a shape.

In the above embodiment, the flow path of the two-phase flow pipe 4 is a single flow path, but the flow path of the two-phase flow pipe 4 in the spray nozzle according to the present invention is composed of a plurality of flow paths. There may be.
FIG. 4 is an explanatory view for explaining an example in which the flow path of the two-phase flow pipe 4 is constituted by a plurality of flow paths, and FIG. 4A is a cross-sectional view along the axial direction (fluid flow direction) of the spray nozzle 9. FIG. 4B is an axial cross-sectional view of the two-phase flow tube 4. In FIG. 4, the same parts as those in FIG. 1 are denoted by the same reference numerals.

The spray nozzle 9 shown in FIG. 4 is provided with a wall member 11 that divides a flow path in the flow direction in the two-phase flow tube 4 to form a plurality of flow paths.
The reason why the wall member 11 is provided is as follows.
When the flow rate of the gas phase flowing through the two-phase flow pipe 4 is large, the cross-sectional area of the two-phase flow pipe 4 needs to be increased. However, in a state where the flow mode in the two-phase flow tube 4 is an annular flow or an annular spray flow, the liquid phase flows in a liquid film form on the inner wall surface of the two-phase flow tube 4. As the cross-sectional area of 4 increases, the interface area between the liquid phase and the gas phase (the contact area between the gas phase and the liquid phase) with respect to the flow path volume of the two-phase flow tube 4 becomes relatively small. Atomization uses the action of tearing the liquid phase into the gas phase due to the shearing force caused by the difference in flow rate between the gas phase and the liquid phase, so the contact area between the gas phase and the liquid phase is relatively small. It will lead to performance degradation.
Therefore, by providing the wall member 11 that divides the two-phase flow pipe 4 in the flow direction, a liquid film that is a thin liquid phase flow is formed on a plurality of wall member surfaces, and the liquid film surface area, that is, the gas-liquid contact area is reduced. It increases and the atomization performance is improved.

  As shown in FIG. 4, the wall member 11 may have a flat plate shape, or a tubular shape that extends coaxially with the two-phase flow tube 4 (see FIG. 8), or a honeycomb-shaped member ( (Not shown).

[Embodiment 2]
The spray nozzle 15 according to the present embodiment will be described with reference to FIG. In FIG. 5, the same reference numerals are given to the same or corresponding parts as in FIG.
As in the first embodiment, the spray nozzle 15 according to the present embodiment is a nozzle that mixes and sprays a gas and a liquid. As shown in FIG. 5, the basic configuration includes an outer tube 2 that receives gas supply, an inner tube 3 that receives liquid supply, and all or part of the gas supplied to the outer tube 2 and the inner tube 3. A two-phase flow pipe 4 in which all or part of the supplied liquid flows in a two-phase state is provided. Further, the two-phase flow tube 4 is arranged in the outer tube 2 via the inner wall and the space of the outer tube 2, and the tip of the two-phase flow tube 4 is at the same position as the tip of the outer tube 2 or the tip of the outer tube 2. An air flow channel 17 in which gas mainly flows is formed in a space disposed on the upstream side and sandwiched between the inner surface of the outer tube 2 and the outer surface of the two-phase flow tube 4.
The spray nozzle 15 according to the present embodiment is different from the spray nozzle 1 according to the first embodiment in the presence or absence of the air flow channel 17. The other configuration is the same as that of the spray nozzle 1 of the first embodiment, and the function is not changed. Therefore, the air flow channel 17 will be described below.

<Air flow channel>
The gas flowing through the outer tube 2 mainly flows through the air flow channel 17. The flow in the annular flow or annular spray flow state formed in the two-phase flow tube 4 is a liquid film formed on the inner wall surface of the two-phase flow tube 4 at the outlet portion of the two-phase flow tube 4. The two-phase flow tube 4 is ejected while maintaining the liquid film state in the tube axis direction. The gas flow that has flowed through the two-phase flow pipe 4 exists inside the liquid film, and the gas flow that has flowed through the air flow channel 17 exists outside the liquid film. That is, the liquid film is in contact with the gas phase on both the inner and outer surfaces, and the liquid film is torn and atomized by the shearing force resulting from the difference in flow rate between the liquid film and the gas phase.
As described above, in the spray nozzle 15 of the present embodiment, the airflow channel 17 is formed on the outer periphery of the two-phase flow tube 4, so that the liquid film-like liquid is flown as described above. By sandwiching, the atomization of the liquid can be further promoted.
Further, even when the liquid flow rate increases and the cross-sectional area of the liquid flow path occupying the two-phase flow pipe 4 increases, the gas phase is autonomously divided so as to flow more into the air flow flow path 17 and excessive pressure loss occurs. Can be prevented.
In order to perform the function of the air flow channel 17 better, it is desirable to maintain an annular flow, more preferably an annular spray flow state, in the two-phase flow tube 4 to continuously generate a liquid film.

  The air flow channel 17 only needs to have a function of tearing the liquid film that has flowed through the two-phase flow tube 4. Therefore, if the gas flow channel is mainly a gas flow channel, a small amount of liquid can be obtained when the liquid flow rate is large. It may be something that flows in.

In order to allow a larger amount of gas flowing through the outer tube 2 to flow into the two-phase flow tube 4, a tapered portion that is reduced in diameter toward the downstream side toward the proximal end side of the two-phase flow tube 4 as in the spray nozzle 19 shown in FIG. 21 may be provided to guide the gas flowing through the outer pipe 2 to the two-phase flow pipe 4. By doing so, the flow velocity of the gas flowing through the two-phase flow tube 4 can be increased, and the formation of the annular spray flow in the two-phase flow tube 4 can be promoted. The taper portion 21 also has an effect of causing more liquid flowing through the inner tube 3 to flow into the two-phase flow tube 4.
In the example shown in FIG. 6, the distal end portion of the outer tube 2 is reduced in diameter so that the gas flow velocity passing through the air flow channel 17 is increased at the distal end portion. By increasing the gas flow velocity passing through the air flow channel 17, the shearing force that tears the liquid film formed on the inner wall surface of the two-phase flow tube 4 is increased, and atomization is further promoted.

  The tapered portion 21 serves to guide the gas flowing through the outer tube 2 to the two-phase flow tube 4. As another mode for allowing a larger amount of gas to flow into the two-phase flow tube 4, the outer tube 2 is moved from the inner wall side of the outer tube 2 toward the two-phase flow tube 4 side as in the spray nozzle 23 shown in FIG. A guide portion 25 that is reduced in diameter may be provided. The taper portion 21 and the guide portion 25 may have other modes as long as they have a function of guiding the gas flowing through the outer tube 2 to the two-phase flow tube 4 side.

Also in the second embodiment, as described in the first embodiment, the two-phase flow pipe 4 is provided with a wall member that divides the flow path in the flow direction to form a plurality of flow paths. May be.
FIG. 8 is an explanatory diagram of the spray nozzle 27 having such a configuration, FIG. 8A is a cross-sectional view along the axial direction (fluid flow direction) of the spray nozzle 27, and FIG. 8B is a two-phase diagram. 3 is an axial cross-sectional view of the flow tube 4. FIG. In FIG. 8, the same or corresponding parts as those in FIG.
The spray nozzle 27 shown in FIG. 8 arranges the tubular member 29 in the two-phase flow tube 4 as a wall member that divides the two-phase flow tube 4 in the flow direction. The tubular member 29 may be fixed to the two-phase flow tube 4 with, for example, a stay (not shown). 8A and 8B show an example in which one tubular member 29 is arranged substantially coaxially with the two-phase flow tube 4, but a plurality of coaxial members may be provided. Further, as shown in FIG. 8C, they may be arranged in parallel to each other in the flow path direction.
The function of the tubular member 29 as a wall member is the same as that of the wall member 11 demonstrated based on FIG.

  A liquid supply pipe 30 that supplies liquid to the inner pipe 3 is connected to the inner pipe 3 in the spray nozzle 27.

[Embodiment 3]
A gas-liquid mixing device 31 according to the present embodiment will be described with reference to FIG. In FIG. 9, the spray nozzle 5 shown in FIG. 3 is installed in a container-like gas-liquid mixing unit 33 that mixes gas and liquid.
In the gas-liquid mixing unit 33, the spray nozzle 5 is installed so that the tip side of the spray nozzle 5 extends into the gas-liquid mixing unit 33. A gas inlet 35 through which gas flows is provided on the upper side of the gas-liquid mixing unit 33, and a mixed gas outlet 37 through which the mixed gas flows out is provided below the side. In addition, the positional relationship of the spray nozzle 5, the gas inlet 35, and the mixed gas outlet 37 may be another mode capable of mixing gas and liquid.

  In the gas-liquid mixing device 31 configured as described above, a gas is supplied to the outer tube 2 of the spray nozzle 5, and a liquid mixed with the gas is supplied to the inner tube 3. The liquid supplied to the inner tube 3 merges with the gas flowing through the outer tube 2 at the tip of the inner tube 3 and flows through the two-phase flow tube 4 in a two-phase state. If the superficial velocity of the gas in the two-phase flow tube 4 is a predetermined value (at least 10 m / s or more), the mixed flow state flowing through the two-phase flow tube 4 becomes an annular spray flow, and the inner wall surface of the two-phase flow tube 4 It flows while forming a liquid film on top. At the outlet portion of the two-phase flow tube 4, the liquid film formed on the inner wall surface of the two-phase flow tube 4 is atomized so as to be torn off by the gas flowing in the two-phase flow tube 4, and the gas-liquid mixing unit 33. Is injected into the inside. The superficial velocity of the gas can be adjusted using known technical means such as providing a flow rate detector (not shown) and a flow rate adjusting valve (not shown) upstream of the outer tube. Further, in the spray nozzle in which the two-phase flow tube is arranged in the outer tube, the value calculated by dividing the gas flow rate by the cross-sectional area of the outer tube (at the position where the two-phase flow tube is arranged), It can be regarded as the superficial velocity of the gas in the two-phase flow tube.

  A gas having the same composition as the gas supplied to the spray nozzle 5 is supplied from the gas inlet 35, and diluted with the mixed gas injected from the spray nozzle 5. The diluted and mixed gas is discharged from the mixed gas outlet 37 and supplied to a necessary location.

[Embodiment 4]
A gas-liquid mixing apparatus 41 according to the present embodiment will be described with reference to FIG. The gas-liquid mixing device 41 is a device in which the spray nozzle 5 shown in FIG. 3 is arranged in a gas pipe 43 through which gas flows, and a venturi section 45 that narrows the flow path of the gas pipe 43 downstream of the spray nozzle 5. Is provided.
A liquid supply pipe 47 that supplies liquid is connected to the inner pipe 3 of the spray nozzle 5, and a gas supply pipe 49 that supplies gas is connected to the outer pipe 2. The gas supply pipe 49 may be branched from the gas pipe 43 or may be connected from another system.
The gas-liquid mixing device 41 according to this embodiment is suitable for use in producing city gas by increasing the temperature by adding LPG (liquid) to natural gas (gas) obtained by vaporizing LNG.

By providing the venturi portion 45 in the gas pipe 43, the gas flow velocity is increased in the venturi portion 45, the atomization of the liquid is promoted, and the effect of gas-liquid mixing with the gas is further enhanced.
When the flow rate of the gas flowing through the gas pipe 43 is small, the gas and the liquid are mixed mainly by the action of the spray nozzle 5. That is, in the spray nozzle 5, the gas and the liquid become an annular spray flow, and the liquid is atomized.
On the other hand, when the flow rate of the gas flowing through the gas pipe 43 is large, the flow rate of the LPG added as the calorie adjusting agent, that is, the flow rate of the liquid flowing through the spray nozzle 5 also increases, so that an annular spray flow hardly occurs in the two-phase flow tube 4. Thus, the liquid may not be sufficiently atomized by the action of the spray nozzle 5 alone. In this case, since the flow rate of the gas is increased, the flow velocity in the venturi section 45 is increased, and the liquid that has not yet been sufficiently atomized ejected from the spray nozzle 5 is atomized by the action of the venturi section 45 to form the gas. Mixing with liquid is promoted.

  In the present embodiment, since the spray nozzle 5 is arranged on the upstream side of the venturi part 45 in the gas pipe 43 having the venturi part 45, appropriate atomization of liquid according to the flow rate of the gas flowing through the gas pipe and Mixing can be realized.

  In addition, in the gas-liquid mixing apparatus 31 of Embodiment 3 and the gas-liquid mixing apparatus 41 of Embodiment 4, the example using the spray nozzle 5 shown in FIG. 3 was shown, but in addition to this, FIG. The spray nozzle 1 shown, the spray nozzle 9 shown in FIG. 4, the spray nozzle 15 shown in FIG. 5, the spray nozzle 19 shown in FIG. 6, the spray nozzle 23 shown in FIG. 7, and the spray nozzle 27 shown in FIG. Can be used for the gas-liquid mixing device 31 and the gas-liquid mixing device 41.

DESCRIPTION OF SYMBOLS 1 Spray nozzle 2 Outer tube 3 Inner tube 4 Two-phase flow tube 5 Spray nozzle 7 Reduced diameter part 9 Spray nozzle 11 Wall member 15 Spray nozzle 17 Air flow path 19 Spray nozzle 21 Taper part 23 Spray nozzle 25 Guide part 27 Spray nozzle 29 Tubular member 30 Liquid supply pipe 31 Gas-liquid mixing apparatus 33 Gas-liquid mixing part 35 Gas inlet 37 Mixed gas outlet 41 Gas-liquid mixing apparatus 43 Gas pipe 45 Venturi part 47 Liquid supply pipe 49 Gas supply pipe

Claims (6)

A nozzle for mixing and spraying a gas and a liquid, the outer tube receiving a gas supply, the inner tube receiving a liquid supply, all or part of the gas supplied to the outer tube, and the inner tube A two-phase flow pipe in which all or a part of the liquid supplied to the pipe flows in a state of an annular flow or an annular spray flow,
The distal end portion of the inner tube is disposed in the outer tube in the same direction as the outer tube,
The two-phase flow tube is disposed in the outer tube in the same direction as the outer tube, and the tip of the two-phase flow tube is disposed at the same position as the tip of the outer tube or upstream of the tip of the outer tube. , the interior of the two-phase flow tube has a wall member provided in parallel with the flow of fluid, it forms a plurality of two-phase flow channel inside the two-phase flow tube by the wall member A spray nozzle characterized in that a taper portion having a diameter decreasing toward the downstream side is provided on the inner surface proximal end side of the two-phase flow tube, and the downstream side of the taper portion is a parallel portion . 2. The spray nozzle according to claim 1, wherein a guide portion for guiding a gas toward the two-phase flow tube is provided in the vicinity of an outer base end of the two-phase flow tube. A method of mixing a gas and a liquid using the spray nozzle according to claim 1 or 2 ,
A method of mixing a gas and a liquid, wherein the flow rate of the gas flowing in the outer tube is adjusted so that the superficial velocity of the gas in the two-phase flow tube is 10 m / second or more. The spray nozzle is provided in a gas pipe through which gas flows,
The said gas piping has a venturi part in the downstream vicinity of the installation position of the said spray nozzle, The mixing method of the gas and liquid of Claim 3 characterized by the above-mentioned. The gas and liquid mixing method according to claim 4 , wherein the gas flowing through the gas pipe and the gas flowing through the outer pipe have the same composition. Gas is natural gas, the method of mixing gas and liquid according to any one of claims 3 to 5, characterized in that the liquid is liquefied petroleum gas.

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