JP2012030200A - Fluid atomization nozzle and fluid atomizing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid atomization nozzle which achieves low pressure loss on the gas phase and increases a flow rate range in the liquid phase, and a fluid atomizing device using the fluid atomization nozzle.SOLUTION: The fluid atomization nozzle comprises: a sleeve 3 which receives a gas to be supplied from the base end side and discharges the gas toward a distal end; a hollow bushing 5 which is arranged concentrically with the sleeve 3, in the sleeve 3, and spaced from the inner wall of the sleeve 3; and a liquid supply pipe 7 which supplies liquid to the inner wall of the bushing 5. In addition, the base end side of the bushing 5 is arranged downstream of the base end of the sleeve 3, and the distal end of the bushing 5 is arranged in the same position as the distal end of the sleeve 3 or upstream of the distal end of the sleeve 3. Further, the liquid supply pipe 7 penetrates the side wall of the sleeve 3, and is connected with the side wall of the bushing 5. The liquid supplied by the liquid supply pipe 7 is atomized by the gas supplied to the sleeve 3 and the bushing 5 and then, is mixed into the gas.

Description

  The present invention relates to a fluid atomization nozzle for atomizing a liquid and a fluid atomization apparatus using the fluid atomization nozzle.

As an example of a fluid atomization nozzle for atomizing a liquid, there is a prefilmer type air blast atomization nozzle described in Patent Document 1.
The pre-filmer type air blast atomization nozzle described in Patent Document 1 is “a liquid supply cylinder in which a plurality of atomized air swirl blades are arranged in the circumferential direction outside a cylindrical central body having a liquid manifold, A liquid film forming section formed of a cylindrical liquid film forming body in which one or more cross-sections are arranged coaxially on the outside of the liquid supply cylinder and an inner peripheral surface forms a liquid film forming surface; A liquid distribution flow path extending from the liquid manifold and disposed inside the atomized airflow swirl vane, and a blade of the atomized airflow swirl vane. An opening is formed at the end, and the liquid branched from the liquid manifold to the liquid distribution channel flows out from the opening of the liquid distribution channel onto the liquid film forming surface of the liquid film forming body to form a liquid film, The liquid film is mainly the atomized airflow Is made of being atomized "by the action of turning is given stream by the blade (see claim 1 of Patent Document 1).

JP 2005-106411 A

  In the pre-filmer type air blast atomization nozzle described in Patent Document 1 (hereinafter simply referred to as “conventional example”), a cylindrical central body is disposed in the center of a flow path, and a plurality of outer bodies are disposed outside the central body. Atomizing airflow swirl vanes are arranged in the circumferential direction. Then, the air flow is swirled by the atomized air flow swirl blade, and the liquid film formed on the liquid film forming surface of the liquid film forming body is atomized by the swirl flow.

In the conventional example, the central body is arranged at the center of the gas flow path, and the swirl vane is further installed in the flow path, so that the gas flowing at high speed comes into contact with the surface of the central body and the swirl blade. , Resistance to the flow, that is, pressure loss (hereinafter referred to as pressure loss) increases. In order to make the atomizing nozzle with a large pressure loss function, it is necessary to increase the pressure of the gas supplied to the nozzle and increase the differential pressure between the nozzle inlet side and the outlet side. In order to increase the pressure of the gas, a booster (compressor) for that purpose is required, and the required power is also large. Therefore, application of the conventional atomizing nozzle may be difficult due to cost, space, and power constraints.
For example, there is a heat increasing device that increases the temperature with liquefied petroleum gas when liquefied natural gas is vaporized and supplied as city gas. As this heat increasing device, a method of supplying liquid liquefied petroleum gas to vaporized liquefied natural gas is often used. In this case, it is desirable to atomize the liquefied petroleum gas supplied as a liquid as finely as possible. On the other hand, if the pressure loss required for atomization is large, the pressure at the outlet of the heat increasing device is reduced and sent out as city gas. Insufficient pressure may interfere with gas delivery.

  Further, in the conventional example, a liquid flow path is formed in the central body disposed in the gas flow path, and the liquid is supplied from the flow path to the liquid film forming body through a branch flow path having a small flow section. It is the structure which forms. Since the cross section of the flow path is made small, there is a possibility that the flow path is blocked by foreign matter. Moreover, the flow range of the liquid which can form a liquid film appropriately is narrow. That is, when the flow rate of the liquid is increased, the pressure loss on the liquid phase side becomes very large. On the contrary, when the liquid phase flow rate becomes small, the formation of the liquid film becomes insufficient.

The present invention has been made in order to solve the problems of the conventional example, and uses a fluid atomizing nozzle that has a small pressure loss on the gas phase side and can take a large liquid phase flow rate range, and the fluid atomizing nozzle. An object of the present invention is to provide a fluid atomizer.

(1) The fluid atomization nozzle of the present invention includes an outer cylinder that receives gas supply from the base end side and ejects gas toward the distal end side, and an outer cylinder inner wall that is coaxial with the outer cylinder in the outer cylinder. An inner cylinder having a hollow interior and a liquid supply pipe for supplying a liquid to the inner wall of the inner cylinder, the proximal end side of the inner cylinder being downstream of the proximal end of the outer cylinder The tip of the inner cylinder is arranged at the same position as the tip of the outer cylinder or upstream of the tip of the outer cylinder, and the liquid supply pipe is connected to the side wall of the inner cylinder. The liquid supplied by the liquid supply pipe is atomized by the gas supplied to the outer cylinder and the inner cylinder and mixed with the gas.

(2) Further, in the above-described (1), the front end side of the flow path formed by the inner peripheral surface of the outer cylinder and the outer peripheral surface of the inner cylinder is directed to the center side of the flow path. Is.
(3) Further, in the above-described (1) or (2), the upstream end of the inner cylinder has a tapered contracted flow shape.
(4) Further, in any of the above (1) to (3), the gas supply pipe is disposed coaxially facing the upstream end of the inner cylinder, and its relative position is variable. It is characterized by being.

(5) A fluid atomization apparatus according to the present invention is a fluid atomization apparatus using the fluid atomization nozzle according to any one of (1) to (4), and is supplied to the fluid atomization nozzle. The flow rate detection device for detecting the flow rate of the gas and the flow rate of the gas flowing in the fluid atomization nozzle based on the detection value of the flow rate detection device are necessary for the gas to entrain the liquid into an annular spray flow. A flow rate adjusting valve for adjusting the flow rate is provided.

  The fluid atomization nozzle of the present invention includes an outer cylinder that receives gas supply from the base end side and ejects gas to the distal end side, and is coaxial with the outer cylinder in the outer cylinder and through the inner cylinder inner wall and the space. And a liquid supply pipe for supplying a liquid to the inner wall of the inner cylinder, the proximal end side of the inner cylinder being disposed downstream of the proximal end of the outer cylinder The tip of the inner cylinder is disposed at the same position as the tip of the outer cylinder or upstream of the tip of the outer cylinder, and the liquid supply pipe penetrates the side wall of the outer cylinder and Since the liquid supplied by the liquid supply pipe is atomized by the gas supplied to the outer cylinder and the inner cylinder and mixed with the gas, it is low in a wide liquid phase flow rate range. It is possible to obtain good atomization / mixing performance while suppressing an increase in pressure loss in both liquid phase and gas phase at the gas phase pressure. Can.

It is explanatory drawing of the fluid atomization nozzle which concerns on one embodiment of this invention. It is explanatory drawing explaining the relationship between the flow rate of the liquid phase and gas phase which flow in a pipe | tube, and a flow mode. It is a graph explaining the relationship between the nozzle pressure loss and the atomization diameter in the fluid atomization nozzle shown in FIG. It is explanatory drawing of Embodiment 2 of this invention. It is an enlarged view which expands and shows a part of FIG. It is explanatory drawing of Embodiment 3 of this invention.

[Embodiment 1]
The fluid atomization nozzle 1 according to the present embodiment includes an outer cylinder 3 that receives supply of gas from the base end side and ejects gas toward the distal end side, and an outer cylinder that is coaxial with the outer cylinder 3 in the outer cylinder 3. 3 An inner cylinder 5 which is disposed through an inner wall and a space and has a hollow inside, and a liquid supply pipe 7 which supplies a liquid to the inner wall of the inner cylinder 5 are provided, and the liquid supplied by the liquid supply pipe 7 is It is characterized by being atomized by the gas supplied from the base end side of the outer cylinder 3 and mixed with the gas.
Hereinafter, each configuration will be described in detail.

<Outer cylinder>
The outer cylinder 3 is supplied with gas from the proximal end side and ejects gas at the distal end side. The distal end side of the outer cylinder 3 is gradually reduced in diameter toward the center of the outer cylinder, and has a shape similar to a truncated cone.

<Inner cylinder>
The inner cylinder 5 is disposed in the outer cylinder 3 in the same direction as the outer cylinder 3 and through the inner wall of the outer cylinder 3 and a space. A space formed between the inner wall of the outer cylinder 3 and the outer wall of the inner cylinder 5 forms a ring-shaped flow path 9.
The inner cylinder 5 is hollow and forms a central flow path 11. Nothing that blocks the flow path is arranged in the hollow flow path.
On the proximal end side of the inner cylinder 5, an inclined surface 13 that is inclined from the outer peripheral surface side toward the downstream side of the inner peripheral surface is formed, whereby the area of the opening portion on the proximal end side of the inner cylinder 5 is the inner cylinder 5. It is wider than the central channel cross-sectional area. The flow rate of the gas introduced into the inner cylinder 5 and the gas introduced into the outer flow path is defined by the ratio between the area of the opening on the proximal end side of the inner cylinder 5 and the cross-sectional area of the ring-shaped flow path. Therefore, it is preferable to set this ratio in advance suitable for atomization.
However, the gas supply pipe 14 and the inner cylinder 5 are configured such that the position of the gas supply pipe 14 that is supplied coaxially with the outer cylinder 3 and supplies the gas from the base end side of the outer cylinder 3 with respect to the inner cylinder 5 base end side is variable. The gas supply ratio to the central flow path 11 and the ring-shaped flow path 9 may be set by adjusting the distance between the proximal ends.

  The outer peripheral surface on the distal end side of the inner cylinder 5 is gradually reduced in diameter toward the center in the same manner as the inner peripheral surface on the distal end side of the outer cylinder 3, and has a shape like a substantially truncated cone. Thus, the tip side of the inner cylinder 5 and the outer cylinder 3 is shaped like a truncated cone, so that the cross-section of the ring-shaped channel is reduced and the flow velocity of the gas passing through the ring-shaped channel 9 is increased. This further promotes atomization of the liquid.

  The inner cylinder 5 is fixed in the outer cylinder 3, but the fixing method is not particularly limited, and may be fixed by, for example, a stay (not shown).

<Liquid supply pipe>
The liquid supply pipe 7 supplies liquid to the inner wall of the inner cylinder 5. As shown in FIG. 1, the liquid supply pipe 7 has a tip inserted into the wall portion of the inner cylinder 5. A liquid channel 15 communicating with the liquid supply pipe 7 is provided in the wall portion of the inner cylinder 5 so as to communicate with the inner peripheral surface of the inner cylinder 5.
In the conventional example, since the liquid flow path 15 is formed in the central body disposed at the center of the gas flow path, the central body becomes a resistance and the pressure loss is increased, but in this embodiment, the liquid supply pipe 7 Are arranged as described above, the liquid supply pipe 7 does not block the central flow path 11, and the pressure loss due to the liquid supply pipe 7 does not occur.
In the present embodiment, as shown in FIG. 1, the liquid supply pipe 7 is arranged to be inclined toward the outlet side, and in this way, the liquid supplied from the liquid supply pipe 7 flows into the central flow. The flow velocity increases in the direction of the gas flow through the passage 11, and a stable flow state is easily obtained even when the liquid flow rate is increased.
The distance from the opening at the front end of the liquid flow path 15 to the downstream end of the central flow path 11 is preferably set to 5 times or more the diameter of the central flow path 11. By setting in this way, an annular spray flow is reliably formed in the central flow path 11 and atomization is promoted.

The operation of the fluid atomization 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 fluid atomization nozzle 1, and the liquid is supplied from the liquid supply pipe 7.
The gas supplied from the base end side flows through the central flow path 11 and the ring-shaped flow path 9 having a double pipe structure formed by the inner cylinder 5 and the outer cylinder 3 at a predetermined distribution ratio. As described above, this distribution ratio is defined by the opening area on the proximal end side of the inner cylinder 5 and the ratio of the cross-sectional area between the outer peripheral surface of the inner cylinder 5 and the inner peripheral surface of the outer cylinder 3.

The liquid supplied from the liquid supply pipe 7 contacts the gas flow on the inner surface of the inner cylinder 5 and takes various flow forms depending on the flow velocity of the gas flow. When the mixed flow state flowing through the central flow path 11 of the inner cylinder 5 is an annular flow or an annular spray flow, atomization is most favorable, that is, the particle droplet diameter is reduced.
Here, the annular spray flow generated in the inner pipe 12 will be described.

FIG. 2 is a diagram (FIG. 2 (a)) showing the relationship between the liquid phase flowing in the pipe and the flow rate of air feeding and the flow mode, and the flow mode shown in the diagram is schematically shown. The figure shown (FIG.2 (b)) is shown. The figure shown here is the one described in the book “Gas-liquid two-phase flow” (author: Yasuhiro Ueda, publisher: Yokendo).
As shown in FIG. 2 (a), the liquid phase and the gas phase flowing in the pipe have different flow modes depending on the respective flow rates. And an annular spray flow (see the lower right figure in FIG. 2 (b)) in which the liquid in the annular liquid phase is entrained with the liquid in the ring and the gas phase in the form of a spray flows. .
In the present embodiment, liquid is supplied to the inner wall of the inner cylinder 5 by the liquid supply pipe 7 and high-speed gas flows through the central flow path 11 of the inner cylinder 5, so that the flow pattern in the inner cylinder 5 is an annular spray. The liquid is atomized and effectively mixed with the gas. In addition, although the atomization effect of a liquid is acquired also in the state of a tubular flow, the effect can be heightened more by setting it as a tubular spray flow.

The liquid supplied from the liquid supply pipe 7 to the inner wall of the inner cylinder 5 becomes a tubular spray flow and flows while forming a liquid film on the inner wall surface of the inner cylinder 5. A ring-shaped channel 9 is also formed on the outer peripheral side of the inner cylinder 5, and gas flows through the ring-shaped channel 9. At the outlet portion of the inner cylinder 5, the liquid film formed on the inner wall surface of the inner cylinder 5 is ejected while maintaining the liquid film state in the tube axis direction of the inner cylinder 5. The gas flow that has flowed through the inner cylinder 5 exists inside the liquid film, and the gas flow that has flowed through the ring-shaped channel 9 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.
By adopting such a double tube structure, as described above, liquid atomization can be further promoted by sandwiching the liquid film-like liquid with a gas flow.
When the gas flow velocity in the inner cylinder 5 is reduced, the tubular flow or the tubular spray flow state cannot be maintained, and the state transitions to a flow state such as a wavy flow, a slag flow, or a bubble flow. In this case, not only the atomization characteristics in the inner cylinder 5 are deteriorated, but also the state in which the liquid film is sandwiched by the gas flow at the outlet of the inner cylinder 5 cannot be formed, and the atomization performance is drastically lowered.

  Note that the gas phase velocity can be reduced (the gas phase pressure may be small) as long as it is within the range of an annular flow or an annular spray flow. In general, the gas phase apparent flow rate may be maintained at 20 m / s or more. For example, when the apparent gas phase flow velocity is 30 m / s, the theoretical gas phase differential pressure is about 0.5% of the original pressure. For example, when the original pressure is atmospheric pressure (100 kPa (abs)), The required differential pressure is as small as 0.5kPa.

  Since the liquid film is formed by a gas-phase flow, it is not necessary to reduce the cross-sectional area of the liquid-phase flow path for liquid film formation as in the conventional example, so 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.

The central flow path 11 serving as the gas phase side flow path has a substantially straight tube shape, and there is no obstacle, so the pressure loss is small.
FIG. 3 shows this point in comparison with the conventional example, showing the relationship between nozzle pressure loss and atomization performance (atomization diameter), the horizontal axis is nozzle pressure loss, and the vertical axis is fine particles. The diameter is shown. Both the vertical and horizontal axes are dimensionless.
In order to generate droplets having the same diameter 100, the pressure loss of the prior art is more than 100, whereas the nozzle of the present embodiment requires less than 10 pressure loss.
Thus, since the pressure loss is extremely small, even when it is difficult to apply the conventional atomization nozzle because the gas-phase supply pressure is low, this nozzle can be applied.For example, to vaporized liquefied natural gas When liquefied petroleum gas is supplied in a liquid state to increase heat and applied to a system that sends it out as city gas, atomization can be performed while suppressing pressure loss, so reliable heat increase without impairing the gas supply pressure An effect can be obtained.

  Further, even when the liquid phase flow rate increases and the liquid cross-sectional area occupying the central flow path 11 increases, the gas phase is diverted autonomously so as to flow more into the ring-shaped flow path 9, and the pressure loss is excessively increased. Can be prevented.

  As described above, according to the present embodiment, it is possible to obtain a good atomization / mixing performance while suppressing an increase in pressure loss in both the liquid phase and the gas phase at a low gas phase pressure in a wide liquid phase flow rate range. Can do.

[Embodiment 2]
This embodiment shows an example of a atomization apparatus using the fluid atomization nozzle of the present invention. When producing city gas by increasing the heat by adding LPG to natural gas obtained by vaporizing LNG. It is used. In the second embodiment, a venturi pipe is installed in a mainstream pipe through which natural gas flows, and is configured as a venturi type atomization apparatus.

  As shown in FIG. 4, the basic configuration of the venturi-type atomization apparatus 21 according to the present embodiment includes a venturi pipe 25 provided in a main flow pipe 23 through which natural gas flows, and an outlet channel than the main flow pipe 23. A branch pipe 27 having a small cross section is provided by branching from the main flow pipe 23, the outlet side of the branch pipe 27 is connected to the throat portion 29 of the venturi pipe or the upstream side thereof, and the outlet pipe of the branch pipe 27 (corresponding to an outer cylinder) An inner pipe 32 (corresponding to an inner cylinder) is installed so that the outlet part has a double-pipe structure, and an LPG supply pipe 31 (corresponding to a liquid supply pipe) for supplying LPG to the inner pipe 32 31a is attached. The outlet pipe of the branch pipe 27, the inner pipe 32, and the LPG supply pipe 31 constitute a fluid atomization nozzle of the present invention.

In the venturi-type atomization apparatus 21 of the present embodiment, the branch pipe 27 is provided with a flow rate detector 33 for detecting the flow rate of natural gas flowing through the branch pipe 27, and the venturi pipe 25 and the branch pipe in the main flow pipe 23 are branched. A flow rate adjustment valve 35 is provided between the branching portions, and the opening degree of the flow rate adjustment valve 35 is adjusted based on the detection signal of the flow rate detector 33.
Hereinafter, each configuration will be described in detail.

<LPG supply pipe>
The LPG supply pipe 31 is for supplying LPG into the venturi pipe 25, and the supply part 31a serving as the LPG supply place is disposed on the pipe wall of the inner pipe 32 as shown in FIGS. Yes. By arranging the supply portion 31a on the tube wall of the inner tube 32, the LPG supplied to the inner tube 32 is entrained by the natural gas having an increased flow velocity in the inner tube 32 to form an annular spray flow. Chemical mixing is performed effectively.

<Branch pipe>
The branch pipe 27 branches from the upstream side of the venturi pipe 25 in the main pipe 23, and the outlet side thereof is connected to the upstream side of the venturi pipe throat portion 29 or the venturi pipe throat portion 29.
The flow passage cross-sectional area of the branch pipe 27 has a portion having a smaller diameter than the main flow pipe 23, and the flow rate of the natural gas flowing through the small diameter portion of the branch pipe 27 is faster than the flow rate of the natural gas flowing through the main flow pipe 23. It is set to be. The small diameter portion is generally disposed at the outlet of the branch pipe 27.
By increasing the flow rate of natural gas in the small diameter portion arranged at the outlet of the branch pipe 27, an annular spray flow involving LPG supplied into the inner pipe 32 arranged here is generated, and the fine particles of LPG are produced. Is promoted.

  Arrangement | positioning by the side of the exit of the branch pipe 27 may be arbitrary. As shown in FIG. 4, the most desirable one is arranged in the same direction as the venturi tube 25, but is not particularly limited.

The flow velocity at the portion of the branch pipe 27 where the inner pipe 32 is provided has a great influence on the atomization / mixing performance of LPG. The flow rate is increased by flowing the natural gas through the branch pipe 27 having a smaller flow path cross-sectional area than the main flow pipe 23, and an annular spray flow is generated by the natural gas having the increased flow speed, and LPG is atomized and mixed. It is.
The pipe diameter of the portion of the branch pipe 27 where the inner pipe 32 is provided is such that the flow rate of the natural gas flowing through the inner pipe 32 maintains the flow rate necessary for generating the annular spray flow even when the city gas is operated at the lowest flow rate. The diameter should be such that it can be used.
For example, assuming that the fluctuation range of the city gas flow is 300,000 Nm ³ / h to 6,000 Nm ³ / h, when the city gas flow rate is 6,000 Nm ³ / h, which is the lowest flow rate, natural gas is branched. 27, and the natural gas flow rate of the portion where the inner pipe 32 is provided in the branch pipe 27 at this time (small diameter portion in the branch pipe 27) is set to a pipe diameter that maintains the flow speed necessary for generating the annular spray flow. (At this time, the flow rate of natural gas flowing through the branch pipe 27 is the lowest flow rate assumed as the flow rate of natural gas.)
In addition, if the assumed minimum flow rate is always allowed to flow through the branch pipe 27, LPG atomization and mixing that is easy and stable can be realized. In the following description, the minimum flow rate that provides a flow rate necessary for atomization / mixing of LPG in the branch pipe may be referred to as a predetermined value A.

  The flow rate required for generating the annular spray flow varies depending on the implementation case, but is generally 20 m / s or more as shown in FIG. Therefore, the branch pipe 27 may be set so that the flow rate can be ensured in the inner pipe 32 of the branch pipe and the pressure loss does not become excessively high at the assumed city gas flow rate. .

For example, the pipe diameter of the branch pipe 27 may be the same from the inlet side to the outlet side, but the flow path cross section of the portion where the inner pipe 32 is provided is set to a smaller diameter portion smaller than the flow path cross section of the main flow pipe 23. This part may have a larger tube diameter than the small diameter part. By making the pipe diameters other than the small diameter part larger than this, it is possible to avoid the pressure loss in the branch pipe 27 from becoming too large.
The diameter of the venturi throat portion 29 is designed so that the pressure loss at the maximum design flow rate does not become excessive for the application system.

<Flow detector>
The flow rate detector 33 is provided in the branch pipe 27 and detects the flow rate of natural gas flowing through the branch pipe 27.
It should be noted that a differential pressure detector is provided in place of the flow rate detector 33 and pressure loss in the branch pipe 27 is detected, so that the relationship between the flow rate and pressure loss in the branch pipe 27 that has been grasped in advance is determined in the branch pipe 27. You may make it detect the flow volume of the natural gas which flows through.

<Flow control valve>
The flow rate adjustment valve 35 is provided between the venturi pipe 25 and the branch part of the branch pipe 27 in the main flow pipe 23, and adjusts the flow rate of natural gas flowing through the main flow pipe 23 based on the detection signal of the flow rate detector 33. As a result, the flow rate of natural gas flowing through the branch pipe 27 is set to a predetermined flow rate.
As shown in FIG. 2 (a), the gas phase flow rate for making the tubular spray flow is affected by the liquid phase flow rate. For this reason, it is also possible to provide a second flow rate detector that detects the amount of LPG flowing through the LPG supply pipe 31, and to calculate and set the predetermined amount of natural gas flowing through the branch pipe 27 in consideration of the supply LPG amount. . However, since the second flow rate detector is required and the control is complicated, practically a constant natural gas flow rate (for example, a flow rate of 20 m / s in the inner pipe 32) is set regardless of the LPG supply amount. It is convenient to use a fixed amount.

<Description of operation>
Next, the operation of the venturi type fluid atomization apparatus 21 according to the present embodiment configured as described above will be described.
Natural gas supplied from the upstream side also flows into the branch pipe 27 when passing through the branch portion, and generates an annular spray flow including LPG supplied into the inner pipe 32 on the outlet side of the branch pipe 27, LPG is atomized and mixed, and flows into the venturi tube throat 29. On the other hand, natural gas flowing through the main flow pipe 23 also flows into the venturi throat 29. Therefore, the natural gas to which LPG is added via the branch pipe 27 and the natural gas from the mainstream pipe 23 flow into the venturi pipe throat portion 29 and pass through the venturi pipe throat portion 29, and further the LPG Mixing is promoted.

The flow rate of city gas increases or decreases depending on the demand. For example, when the demand for city gas decreases and the flow rate of the fluid flowing through the flow path decreases, the total flow rate of natural gas flowing through the branch pipe 27 and the main flow pipe 23 decreases. When the flow rate of natural gas flowing through the branch pipe 27 decreases below the predetermined value A, the flow velocity in the inner pipe 32 decreases, and a tubular spray flow is not formed, and there is a concern that the atomization / mixing of LPG becomes insufficient. The
Therefore, when the flow rate detected by the flow rate detector 33 is less than the predetermined value A, the flow rate of the natural gas flowing through the branch pipe 27 is maintained at the predetermined value A by reducing the opening degree of the flow rate adjustment valve 35. .
By maintaining the flow rate of the natural gas flowing through the branch pipe 27 at a predetermined value A or higher, the flow rate in the branch pipe 27 is maintained, and the effect of atomization / mixing of LPG can be ensured.

Conversely, when the demand for city gas increases and the flow rate of the fluid flowing through the flow path increases, the flow rate of natural gas flowing through the branch pipe 27 and the main flow pipe 23 increases. When the flow rate of natural gas flowing through the branch pipe 27 increases beyond a predetermined amount, the pressure loss increases.
Therefore, when the flow rate detected by the flow rate detector 33 increases above the predetermined value B, the opening degree of the flow rate adjustment valve 35 is increased to increase the amount flowing through the main flow pipe 23, and the flow rate of natural gas flowing through the branch pipe 27 is predetermined. The value B is set. Here, there is a relationship of the predetermined value B ≧ the predetermined value A.
By setting the flow rate of natural gas flowing through the branch pipe 27 to a predetermined value A or more and B or less, the flow velocity in the branch pipe 27 is maintained within a predetermined range, and the atomization / mixing of LPG can be sufficiently performed and the pressure loss is excessive. An increase can be prevented.

For example, the simplest control method is a case where the predetermined value A = predetermined value B = [natural gas flow rate at the lowest city gas flow rate (natural gas minimum flow rate)].
As in the previous example, assuming that the fluctuation range of the city gas flow rate is 300,000 Nm ³ / h to 6,000 Nm ³ / h, when the city gas flow rate is 6,000 Nm ³ / h, which is the lowest flow rate, A total amount of gas is flowed from the branch pipe 27, that is, a flow rate of a predetermined value A (= predetermined value B).
When the city gas flow rate is greater than 6,000 Nm ³ / h, the opening degree of the flow rate adjustment valve 35 is set so that the flow rate measured by the flow rate detector 33 installed in the branch pipe 27 maintains a predetermined value A. Increasing the natural gas flow rate causes the increase in the natural gas flow rate to flow from the main flow pipe 23. That is, even if the city gas flow rate fluctuates, the natural gas flow rate of the predetermined value A always flows through the branch pipe 27. By doing so, a flow rate necessary for atomization / mixing is always supplied to the branch pipe 27. Further, the velocity component from the main flow tube 23 contributes to the direction of further increasing the flow velocity in the venturi tube throat 29.
In the above description, the predetermined value A is [natural gas flow rate at the minimum city gas flow rate (natural gas minimum flow rate)], but may be simply [minimum city gas flow rate].

  As described above, according to the present embodiment, the natural gas flow rate of the branch pipe 27 at the position where the inner pipe 32 serving as the LPG supply unit is disposed is predetermined even if the flow rate flowing through the flow path changes greatly. It is possible to maintain the flow rate of LPG, and it is possible to obtain the effect of atomization / mixing of LPG and to prevent the pressure loss from becoming excessively large.

Here, in order to distribute the natural gas flow rate of the predetermined value A to the branch pipe side, it is necessary to narrow down the flow rate control valve 35 so that the pressure loss is equal to or higher than the pressure loss on the branch pipe side including the nozzle. Therefore, if the pressure loss of the atomization nozzle disposed at the tip of the branch pipe is large, the pressure loss of the atomization apparatus as a whole increases, and the gas pressure for sending out as city gas cannot be maintained.
Since the atomization apparatus of the present invention can perform atomization while suppressing pressure loss by using the fluid atomization nozzle of the present invention, it is possible to obtain a reliable heat increase effect without impairing the gas supply pressure. It becomes.

[Embodiment 3]
In the second embodiment, as an example of the fluid atomization apparatus using the fluid atomization nozzle of the present invention, an example in which a venturi pipe is installed in the mainstream pipe and the fluid atomization nozzle is arranged in the venturi pipe is shown. .
However, the fluid atomization apparatus of the present invention is not limited to the one in which the fluid atomization nozzle is disposed in the venturi pipe, and may be configured by directly installing the fluid atomization nozzle in the gas supply pipe.

  FIG. 6 is an explanatory diagram of the fluid atomizer 41 of the present embodiment, and the same reference numerals are given to the same parts as those in FIG. The fluid atomization device 41 of the present embodiment includes a fluid atomization nozzle 1 installed at an end of the gas supply pipe 14, a flow rate detection device 43 that detects the flow rate of gas supplied to the fluid atomization nozzle 1, and A flow rate adjusting valve 45 for adjusting the flow rate of the gas flowing in the fluid atomization nozzle based on the detection value of the flow rate detection device 43 so that the gas becomes a flow rate necessary for entraining the liquid into an annular spray flow. It is prepared.

DESCRIPTION OF SYMBOLS 1 Fluid atomization nozzle 3 Outer cylinder 5 Inner cylinder 7 Liquid supply pipe 9 Ring-shaped flow path 11 Central flow path 13 Inclined surface 14 Gas supply pipe 15 Liquid flow path 21 Venturi type atomization apparatus 23 Main flow pipe 25 Venturi pipe 27 Branch pipe 29 Venturi pipe throat part 31 LPG supply pipe 31a Supply part 32 Inner pipe 33 Flow rate detector 35 Flow rate adjustment valve 41 Fluid atomization device 43 Flow rate detection device 45 Flow rate adjustment valve

Claims (5)

  An outer cylinder that receives gas supply from the base end side and ejects gas to the distal end side, and is disposed in the outer cylinder in a direction coaxial with the outer cylinder and through the inner wall of the outer cylinder and a space inside. An inner cylinder and a liquid supply pipe for supplying a liquid to the inner wall of the inner cylinder, the proximal end side of the inner cylinder being disposed downstream of the proximal end of the outer cylinder, and the distal end of the inner cylinder is The liquid supply pipe is connected to the side wall of the inner cylinder at the same position as the front end of the outer cylinder or upstream of the front end of the outer cylinder, and the liquid supplied by the liquid supply pipe is A fluid atomization nozzle characterized by being atomized by a gas supplied to a cylinder and the inner cylinder and mixed with the gas.   2. The fluid atomizing nozzle according to claim 1, wherein a front end side of a flow path formed by the inner peripheral surface of the outer cylinder and the outer peripheral surface of the inner cylinder is directed toward the center side of the flow path.   The fluid atomization nozzle according to claim 1 or 2, wherein an upstream end of the inner cylinder has a tapered contracted flow shape.   The fluid atomization nozzle according to any one of claims 1 to 3, wherein the gas supply pipe is coaxially disposed facing the upstream end of the inner cylinder, and the relative position thereof is variable. .   A fluid atomization device using the fluid atomization nozzle according to any one of claims 1 to 4, wherein the flow rate detection device detects a flow rate of a gas supplied to the fluid atomization nozzle, and the flow rate detection device. And a flow rate adjusting valve that adjusts the flow rate of the gas flowing in the fluid atomization nozzle based on the detected value so that the flow rate of the gas is necessary to entrain the liquid into an annular spray flow. A fluid atomizer characterized by the above.