JPH0250793B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a liquid atomizing method and apparatus, which are characterized by atomizing a liquid and atomizing it so as to obtain a uniform dispersion amount distribution. including gas-liquid reactions, drying, painting, humidity control,
It is used for equipment such as cleaning or liquid spraying.

Conventionally, when atomizing a liquid, the liquid to be sprayed is introduced into a cylindrical swirl chamber diagonally or in the connection direction through a flow path, swirled in the chamber, and then atomized liquid is placed at the center of the bottom of the swirl chamber. Swirl-type spray nozzles are often used, which have a structure that atomizes liquid by jetting it into the atmosphere from a nozzle.

Problems to be Solved by the Invention Although the rotating spray nozzle has a simple structure, it has excellent features such as being able to obtain fine droplets under relatively low injection pressure. Due to its structure, the swirling flow in the swirl chamber is ejected from the nozzle to atomize the liquid, so the spray spreads in a hollow cone shape, which has the disadvantage that the dispersion distribution near the central axis is extremely reduced. This is particularly inconvenient when used in a vacuum.

Means for Solving the Problem The present invention eliminates the above-mentioned drawbacks, and instead of providing a complicated structure within the spray nozzle body, the liquid to be sprayed is The present invention provides a new liquid spraying method and apparatus for spraying such that a uniform dispersion amount distribution is obtained.

As shown in FIG. 1, the liquid spraying method having a uniform dispersion amount distribution according to the first invention is characterized in that the liquid to be sprayed flowing into the main body 1 from the inlet 10 is turned into a swirling flow by the flow path element 2, and its central part is The jet flow is separated into the jet flow flowing into the nozzle 7, and the swirl flow and the jet flow are brought into contact with each other in the outflow chamber 6, thereby exchanging the energy of the circumferential velocity and the axial velocity.
into the atmosphere.

Further, the liquid spraying device having a uniform dispersion amount distribution according to the second invention is an apparatus for carrying out the first invention, in which a flow path element 2 is provided in the main body 1, and the flow path element 2 is connected to the main body by the flow path element 2. 1 into an inflow chamber 3 and an outflow chamber 6.
The flow path element 2 is provided with a swirling flow forming channel 4 on its outer circumferential side for forming a swirling flow in the outflow chamber 6 by passing a part of the liquid to be sprayed, and a swirling flow forming channel 4 is provided in the center thereof. , providing an orifice 5 for forming a jet flow in contact with the center of the swirling flow by passing another part of the liquid to be sprayed;
An outflow chamber 6 is located at a position facing the orifice 5 of the main body 1.
By providing a nozzle 7 that communicates with the sprayed liquid, the liquid to be sprayed is discharged into the atmosphere as a spray having a uniform dispersion amount distribution.

Effects The effects of the liquid spraying method and device having a uniform dispersion amount distribution of the present invention will be explained according to the examples shown in FIGS. 1 to 4.

As shown in FIG. 1, a part of the liquid that has flowed into the inflow chamber 3 in the main body 1 through the inlet is passed through the swirling flow forming channel 4 provided on the outer peripheral side of the channel element 2 to the outflow chamber. The liquid flows into the outflow chamber 6 and reaches the center while rotating inside the outflow chamber 6. At this time, the circumferential velocity distribution of the swirling flow in the radial direction on the A-A cross section in the outflow chamber 6 is as shown in FIG. The circumferential speed increases as the At the same time, another part of the liquid that has flowed into the inflow chamber 3 passes through an orifice 5 provided at the center of the flow path element 2, and then passes through the outflow chamber 6.
The swirling flow flows into the center of the swirling flow as a jet flow. At this time, the jet flow has no circumferential velocity and passes through the boundary surface in contact with the swirling flow.
The rotational energy due to the increased circumferential velocity of the swirling flow is applied to the jet flow, and the circumferential velocity energy is exchanged. On the other hand, as shown in FIG. 4, the axial velocity distribution on the A-A cross section in the outflow chamber 6 shows that there is a difference in axial velocity between the jet flow near the center O and the swirling flow swirling around it. While the jet stream and the swirl stream move toward the nozzle 7, an exchange of axial velocity energy occurs. Therefore, due to the exchange of circumferential velocity energy and axial velocity energy that takes place in the outflow chamber 6, the liquid flowing out from the nozzle 7 has a circumferential velocity and an axial velocity that correspond to the radial position on the nozzle cross section. , attempts to continue its motion at a speed that is a combination of the circumferential velocity and the axial velocity. At this time, if the energy of the synthesized velocity is greater than the cohesive force of the liquid, the liquid will not be able to maintain a continuous state.
Breaks up into droplets to form a spray. Therefore, the method and device for spraying a liquid with uniform distribution of the amount of dispersion of the present invention effectively utilizes the kinetic energy of the liquid itself to continuously and efficiently generate a stable spray. When atomizing liquids with relatively low viscosity, it has unparalleled excellent properties.

Embodiments Hereinafter, embodiments of the method and apparatus for jetting a liquid having a uniform dispersion amount distribution according to the present invention will be described with reference to FIGS. 1 and 2 as examples. FIG. 1 shows an example of the spray device of the present invention, and shows a sectional view of the spray device, and FIG. 2 shows a perspective view of the flow path element 2. As shown in FIG.

The head 1 of the spray device consists of two parts 1A and 1B, and the flow path element 2 is provided with a swirling flow forming flow path 4 on its outer circumferential side and an orifice 5 in the center. An inflow chamber 3 and an outflow chamber 6 are formed in the main body 1 by connecting the main bodies 1A and 1B with a threaded portion 8 fitted into the shoulder portion 9 of the main body 1B.
A nozzle 7 communicating with the outflow chamber 6 is provided at a position facing the orifice 5 of the main body 1B.

The dimensions of each part of the liquid spraying device having a uniform dispersion amount distribution according to the present invention can be determined, for example, theoretically as follows. That is, when a part of the liquid that has flowed into the inflow chamber 3 in the main body 1 through the inflow port 10 is caused to flow into the outflow chamber 6 as a swirling flow through the swirling flow forming channel 4 provided on the outer periphery of the channel element 2, The swirling flow moves toward the center while swirling inside the outflow chamber, changes the flow to the axial direction near the center (O) of the outflow chamber, and flows out into the atmosphere through the nozzle 7. A cavity is created in the center of the swirling flow. At the same time, another part of the liquid that has flowed into the inflow chamber 3 in the main body is caused to flow into the outflow chamber as a jet flow through the orifice 5 provided at the center of the flow path element 2, and the swirl flow and the A mixed flow of the swirl flow and the jet flow is formed by the exchange of the swirl flow and the kinetic energy of the jet flow through the contacting boundary surfaces of the jet flow,
The mixed flow flows out into the atmosphere from a nozzle 7 communicating with the outflow chamber 6 to form a spray. Therefore, in order to generate a spray with a uniform dispersion amount distribution using the present spraying method and spraying device, the diameter of the cavity created by the swirling flow flowing into the outflow chamber 6 as described above must be made sufficiently large. In consideration, it is necessary to set the diameter of the orifice 5 of the flow path element approximately equal to the diameter of the cavity, and at the same time to make the momentum of the jet flow and the momentum of the swirling flow approximately equal.

The diameter of the cavity is related to the cross-sectional area of the swirling flow forming channel provided in the flow channel element, the cross-sectional area of the nozzle, the nozzle radius, and the inlet radius of the swirling flow flowing into the outflow chamber 6, and is expressed by the following equation. That is, However, Km=(1/cosθ)(As/A)( _re / _rn ) ξ=√1−( _{ca )} ² Km: Shape factor of outflow chamber θ: Inclination angle of swirl flow forming channel (° ) A _s : Cross-sectional area of swirling flow forming channel (m ² ) A: Nozzle cross-sectional area = πr ² _e m ² r _e : Nozzle radius (m) r _n : Swirling flow inlet radius (m) k _a : Swirling flow inlet radius (m) Inflection point radius ratio k _c : Cavity coefficient = r _c / r _e r _c : Cavity radius (m) The value of the inflection point radius ratio k _a in the above equation (1) is experimentally expressed by the following equation. , k _a ≈1.25k The relationship between the above k and the shape factor Km of the outflow chamber is theoretically expressed by the following equation.

Km=1/k√1− ² −kln1/k(1+√1− ²
) Therefore, the diameter of the cavity can be determined from the shape of the outflow chamber using the above equation (1), and the diameter of the orifice provided at the center of the flow path element can be determined.

Further, the relationship between the momentum of the jet flow and the momentum of the swirling flow in the spraying method and spraying device of the present invention is expressed by the following equation. That is, Mj/M _s = (Cj/C _s ) ² (D/d) ² Km (2) where, Mj: Momentum of jet flow (Kg・m/s) M _s : Momentum of swirling flow (Kg・m/s) s) Cj: Flow coefficient of jet flow C _s : Flow coefficient of swirl flow D: Diameter of nozzle (m) d: Diameter of orifice provided in flow path element (m) Km: Shape coefficient of outflow chamber (2) above The flow rate coefficient Cj of the jet flow in the formula is experimentally expressed by the following formula, Cj≒(0.62~0.60)(D/d) ^2where , D: Nozzle diameter (m) d: Nozzle diameter (m) The diameter of the orifice (m) and the flow coefficient _Cs of the swirling flow are theoretically expressed by the following equation. That is, C _s = (k _a /√1 + ² _{) Km, where ka: inflection point radius ratio ξ = √1 − (ca )} ² k _c : cavity coefficient When designing a spray device using the spray method of the present invention, is the diameter d of the orifice provided in the flow path element.
is determined to be approximately equal to the cavity diameter k _c D obtained using the cavity coefficient k _c calculated from equation (1), and the momentum ratio of the jet flow and swirling flow calculated from equation (2) Mj/M Set _s to be approximately equal to 1.

For the spray device designed as above, the flow rate is expressed by the following formula, Q = (C _s + Cj) π/4D ² √2・△ where, Q: flow rate (m ³ /s) C _s : Flow coefficient of swirl flow Cj: Flow coefficient of jet flow D: Diameter of nozzle (m) △H: Differential pressure head between injection pressure and atmospheric pressure (m) g: Gravitational acceleration (m/s ² ) Said spray device The spray angle is given by the following equation. That is, α=2tan ^-1 {k _c /√1− _c ² } where α: spray angle (°) k _c : cavity coefficient Figure 5 shows the actual results obtained using the spray device of the present invention shown in Figure 1. Water is atomized and placed 1m directly below the spray device.
This is a comparison of the spray dispersion amount distribution measured on a horizontal plane with the measurement results for a conventional spray device. This shows that the dispersion amount distribution is well uniformed.

Furthermore, Fig. 6 shows the results of measuring the average particle size of the sprayed droplets at the positions where the distribution of the dispersion amount was measured. This shows that when used, not only the dispersion amount distribution becomes uniform, but also the average particle size of the droplets is averaged, resulting in a good spray.

Effects of the Invention Unlike conventional spraying methods and devices, the liquid spraying method and its device having a uniform dispersion amount distribution of the present invention are based on the principle of fluid dynamics, and the liquid to be sprayed that has flowed into the main body is transferred to, for example, a flow path element. A part of the flow is made into a swirl flow and the other part is made to flow into an outflow chamber as a jet flow, and the swirl flow and the jet flow are mixed by utilizing the exchange effect of kinetic energy of the swirl flow and the jet flow. It has a structure that ejects into the atmosphere from the rear nozzle, and by determining the dimensions of each part of the spray device as described above, it is possible to generate a spray with a uniform dispersion amount distribution and particle size distribution of the atomized liquid. can. Therefore, it is possible not only to eliminate the non-uniformity of the dispersion amount distribution when using a fixed spraying device, but also to eliminate the non-uniformity of the particle size distribution at the same time.

[Brief explanation of the drawing]

FIG. 1 is an elevational view of a spraying device according to the spraying method of the present invention. FIG. 2 is a perspective view of the channel element. FIG. 3 is an explanatory diagram of the circumferential velocity distribution of the flow on the section AA in FIG. 1 of the outflow chamber. FIG. 4 is an explanatory diagram of the shaft velocity distribution on the AA cross section. FIG. 5 is a diagram showing an example of the results of measuring the distribution of spray dispersion using the present spray device. FIG. 6 is a diagram showing an example of the results of measuring the average particle size of sprayed droplets. 1: Main body, 2: Flow path element, 3: Inflow chamber, 4: Swirl flow forming flow path, 5: Orifice, 6: Outflow chamber,
7: Nozzle.

Claims (1)

[Claims] 1. The liquid to be sprayed is divided into a swirling flow and a jet flow flowing into the center thereof, and the swirling flow and the jet flow are brought into contact with each other to create an energy exchange effect of the circumferential velocity and the axial velocity. A liquid spraying method characterized in that the atomized liquid is sprayed so as to obtain a uniform dispersion amount distribution by ejecting the liquid from a nozzle after the spraying is performed. 2. A flow path element 2 is provided in the main body 1, and the inside of the main body 1 is divided into two into an inflow chamber 3 and an outflow chamber 6 by the flow path element 2,
The flow path element 2 is provided with a swirling flow forming channel 4 on its outer circumferential side that forms a swirling flow in the outflow chamber 6 by passing a part of the liquid to be sprayed, and
An orifice 5 is provided in the center of the body 1 to form a jet flow in contact with the center of the swirling flow by passing another part of the liquid to be sprayed.
By providing a nozzle 7 that communicates with an outflow chamber 6 at a position facing an orifice 5, a spray having a uniform distribution of atomized liquid can be obtained.