RU2258567C1 - Liquid sprayer - Google Patents

Abstract

FIELD: liquid spraying equipment, particularly used in fire-fighting, sanitary and watering facilities, for liquid fuel combustion, etc.

SUBSTANCE: sprayer has body with channels for liquid jets forming and liquid supply nipple. The channels are directed so that axes thereof cross beyond channel outlets in sprayed liquid flow generation space. Minimal distance between crossing axes does not exceed hydraulic channel radius R_h value. Distance between outlet channel sections and sprayed liquid flow generation space defined by plane with minimal distance between crossing channel axes preferably does not exceed 80R_h. Sprayer body may be provided with chamber shaped as solid of revolution and installed beyond outlet channel sections. Axial channel may be formed in the sprayer body. Channels may have equal cross-sections. Sprayer in accordance with the second embodiment has one channel with cross-sectional area, which is not more than 2 times greater than that of another one.

EFFECT: increased uniformity of droplet intensity and dispersion over flow section, reduced energy consumption.

1 cl, 7 dwg

Description

The invention relates to techniques for spraying liquid and can be used in fire extinguishing systems, plumbing equipment, devices for burning liquid fuel, watering units, etc.

A known atomizer comprising a housing with channels for forming liquid jets and a nozzle for supplying liquid, in which the axis of each pair of channels are arranged so that the sprayed fuel jets intersect and combine, forming a single torch of sprayed particles of a conical shape with a minimum deviation from the central axis of the sprayer ( see patent US 5044562, published 03.09.1991, IPC F 02 M 51/06). The disadvantage of this device is the significant loss of kinetic energy when spraying a liquid, which is caused by the formation of ring jets.

Also known is a sprayer comprising a housing with channels for forming jets of liquid and a fitting for supplying liquid. The outlets of the fluid supply channels are formed on an axisymmetric surface with a V-shaped profile. The spraying of liquid in the known device occurs as a result of the collision of the jets of liquid in a certain spatial region located opposite the outlet openings of the channels for supplying liquid (see patent JP 11-076871, published March 23, 1999, IPC 05 V 1/26). The atomizer of the described design allows you to create a stream of droplets of fine dispersion only due to the impact energy of the flows against each other, which limits the ability to minimize energy costs for generating a spray stream.

The closest analogue of the claimed invention is a spray containing a housing with curved channels for forming a jet of liquid and a fitting for supplying liquid (see patent US 5358179, published 10/25/1994, IPC 05 V 1/26). The axes of the channel outlet openings intersect at some point outside the atomizer body. A finely dispersed fluid stream is formed upon the collision of liquid jets previously formed in the channels. Due to the presence of curved channels in the sprayer housing, the fluid flow, before entering the cylindrical portions of the channels, the axial lines of which intersect in the spatial region beyond the surface of the sprayer housing, acquires an additional angular velocity.

An increase in the relative velocity of the jets due to preliminary swirling of the jets and, accordingly, an increase in the angular velocity of the jets makes it possible to increase the efficiency of spraying jets of liquid into a finely dispersed gas-droplet stream. However, despite these advantages of the known device, in the process of forming swirling jets of liquid, additional losses of kinetic energy appear due to an increase in the hydraulic resistance of the supply channels of the fluid supply.

The objective of the present invention is to provide a liquid atomizer that allows you to generate flows of liquid droplets of finely dispersed spray with a given spatial configuration, provided that the flow rate and pressure of the liquid in the supply lines are reduced. Achievable technical result is to reduce energy costs for the generation of finely dispersed gas-droplet flows.

Achievable technical result is achieved when using a liquid atomizer containing a housing with channels for forming liquid jets and a nozzle for supplying liquid. According to the present invention, the channels for forming liquid jets are directed in such a way that their axial lines intersect beyond the outlet sections of the channels in the spatial region of formation of the atomized liquid stream. Moreover, the minimum distance between the intersecting axial lines of the channels does not exceed the average value of the hydraulic radius of the cross section of the channels.

In the General case, the value of the hydraulic radius for channels of arbitrary section is determined from the relation:

where R _G is the average value of the hydraulic radius of the channels, mm;

ω is the living cross-section of the fluid flow, mm ² ;

χ - wetted channel perimeter, mm.

For cylindrical channels completely filled with liquid, the value of the hydraulic radius of the channels is determined by the formula:

R _G = 0.25 D, where D is the diameter of the cylindrical channels, mm

The average value of the hydraulic radius R _G channels is determined by the formula:

where R _Г1 , R _Г2 , ... R _ГN - hydraulic radii of channels 1 ... N, respectively, mm;

N is the number of channels.

In a preferred embodiment of the atomizer design, the distance between the outlet sections of the channels and the region of formation of the atomized liquid stream, at the boundary of which the distance between the intersecting axial lines of the channels has a minimum value, is selected no more than 80 R _G.

The spray channels can be made cylindrical. It is advisable that the length of the channels does not exceed 40 R _G. The intersection angle of the frontal projections of the axial lines of the channels is selected in the range from 1 ° to 179 °, and for the generation of long-range jets, the optimal values of this angle approach 1 °, and for the generation of gas-droplet flows with a wide spray jet, the optimal values of the angle are close to 180 °. In preferred embodiments of the design of the liquid atomizer, said angle is selected in the following ranges: from 50 to 70 ° and from 150 to 179 °.

The surface of the input and / or output section of the channels can be made flat. The planes or forming surfaces of the input and output sections of the channels made in the housing may be parallel and located at an angle of not more than 90 ° to the axis of symmetry of the housing. In preferred embodiments of the invention, this angle is selected in the range from 50 to 70 °. It is advisable that the axial lines of the channels are perpendicular to the planes of the output sections of the channels.

The surface of the input and / or output section of the channels of the atomizer may be in the form of a body of revolution. Forming surfaces of the input and output sections of the channels can be parallel. It is also advisable that the axial lines of the channels are perpendicular to the generatrix of the surface of the output sections of the channels.

The channels can have the same cross-section or the cross-sectional area of at least one of the channels can exceed the cross-sectional area of any other channel by no more than two times. The optimal number of channels is selected from two to six.

An axial channel may be provided in the atomizer body. To concentrate the generated flow in a certain direction, the atomizer body is equipped with a camera in the form of a body of revolution mounted behind the outlet sections of the channels. In various embodiments of the atomizer, the chamber may have a conical or cylindrical shape.

In order to reduce hydraulic losses, the channels can have tapering inlet sections that are conical or conoidal in shape.

The invention is further illustrated by examples of specific performance of the liquid atomizer with reference to the explanatory drawings, which depict the following:

figure 1 is a General view of the atomizer from the side of the area of formation of the atomized fluid flow on an enlarged scale;

figure 2 is a stepped section of a liquid atomizer along the planes aa;

figure 3 is a stepped section of a liquid atomizer along the planes aa in an embodiment with an additional cylindrical chamber;

figure 4 is a diagram of the formation of a sprayed fluid flow in the spatial region of the intersection of the jets (view from the side of the formation region of the sprayed fluid flow);

figure 5 is a schematic representation of the frontal projections of the axial lines of the channels with the velocity vectors of the intersecting jets of liquid (stepwise section along the planes aa);

Fig.6 is a General view of the sprayer from the area of formation of the sprayed fluid stream in the embodiment when the angle of intersection of the frontal projections of the axial lines of the channels is 179 °.

in Fig.7 is a stepwise section of the liquid atomizer shown in Fig.6, along the planes BB.

The liquid spray shown in figures 1 and 2 contains a housing 1 with two cylindrical channels 2 for forming jets of liquid and a fitting 3 for supplying liquid. Channels 2 for forming liquid jets are directed in such a way that their axial lines 4 are crossed beyond the outlet sections of the channels in the spatial region of the formation of the sprayed liquid stream (see Figs. 4 and 5), while the minimum distance between the crossed axial lines of the channels does not exceed the average value hydraulic radius R _{G of the} cross section of the channels K ₁ and K ₂ (see figure 4). The length of the cylindrical channels 2 is 8 R _G , which corresponds to the condition for choosing the optimal dimensions of the channels 2 (the length of the channels does not exceed 40 R _G ).

Generating 5 and 6 of the conical surfaces of the input and output sections of the channels 2 are located at an angle α to the axis of symmetry 7 of the housing. In this example implementation of the invention, the value of α is chosen equal to 50 °, i.e. within the range of 50 ° to 70 ° according to the claims. Generators 5 and 6 are parallel to each other and perpendicular to the axial lines of 4 channels 2.

The body of the liquid atomizer in this embodiment is made with an axial channel 8. The axial lines 4 of the channels 2 of the liquid atomizer shown in FIGS. 2 and 3 are located at an acute angle β with respect to each other. In another example of a fluid atomizer, the center lines of the channels may be at an obtuse angle (β = 179 °), as shown in FIG. 7.

An embodiment of the liquid atomizer shown in FIG. 3 includes a cylindrical chamber 9. The chamber 9 is installed behind the outlet sections of the channels 2 along the fluid flow. The length of the chamber L _K does not exceed twenty times its diameter D _K. The optimal ratio D _K / L _K in this embodiment is 1.5.

The axial lines of 4 channels 2 are made crossing with a minimum distance between them, not exceeding the average hydraulic radius R _{G of} channels 2. Channels 2 are made of cylindrical shape with the same cross section. For two identical channels 2 with a diameter of D = 2 mm, the hydraulic radius is: R _G = 0.25D = 0.5 mm.

The distance between the outlet sections of the channels and the region of formation of the sprayed fluid stream, at the boundary of which the distance between the intersecting axial lines of the channels has a minimum value, is 40 R _G (see Fig. 5), i.e. does not exceed 80 R _G according to the claims. The boundary 10 of the spatial region of the formation of the atomized flow shown in FIG. 5 is characterized by a minimum distance between the intersecting axial lines of the 4 channels 2. FIG. 5 shows the intersection point of the frontal projections of the axial lines 4 of the channels 2, which defines the minimum distance between the intersecting axial lines 4, located in parallel planes.

The angle β of the intersection of the frontal projections of the axial lines 4 of the channels 2, which is shown in FIG. 5, is 50 °, i.e. in the range of optimal values of β from 50 ° to 70 ° according to the claims (figure 5).

Figure 6 presents another embodiment of the design of the spray liquid. In this sprayer, the axial lines 11 of the channels 12 are located at an angle to the symmetry axis 13 of the housing, the magnitude of which is close to 90 °. The distance between the axial lines 11 of the channels 12 in the same way as in the first embodiment, does not exceed R _G.

The channels 12 are made in a cylindrical insert 14, coaxially mounted in the housing 15 of the liquid atomizer (Fig.7). The frontal projections of the axial lines of 11 channels 12 intersect at an angle whose magnitude is 179 ° (within the range of optimal values of 150-179 °).

In this embodiment, the liquid atomizer, the surface of the outlet sections of the channels 12 is in the shape of a cone, and the surface of the inlet sections of the channels 12 has the shape of a cylinder. Accordingly, the generatrix 16 of the conical surface of the output sections of the channels 12 is not parallel to the generatrix 17 of the cylindrical surface of the input sections of the channels 12.

The channels 12 for forming liquid jets are made with inlet conical sections 18 to reduce hydraulic losses. The spray gun housing 15 in the second embodiment, as in the first embodiment, has a fitting 19 for connecting to the fluid supply line.

The generation of atomized jets using a liquid atomizer made according to the present invention is as follows.

The working fluid comes from the fluid supply line, to which the liquid atomizer is connected using the nozzle 3, and enters the channels 2 and 8, intended for the formation of jets of liquid. Since the axial lines of the 4 channels 2 are crossed in the spatial region of the formation of the atomized liquid flow with a minimum distance between the lines not exceeding the average hydraulic radius of the channels 2, only the peripheral parts of the liquid jets intersect.

As shown in figure 4, when generating jets of liquid C ₁ and C ₂ from channels K ₁ and K ₂ in the area of formation of the sprayed liquid stream, the peripheral parts of jets C ₁ and C ₂ moving at speeds V ₁ and V ₂ collide and intersect . It should be noted that Fig. 4 shows the velocity vectors V ₁ and V _{2 of the} jets C ₁ and C _2, respectively, with normal components V _n1 and V _n2 perpendicular to the plane of the drawing, and tangential components V _τ1 and V _τ2 lying in the plane of the drawing.

In the region of intersection of the jets C ₁ and C ₂ under the influence of the tangential components of the velocities V _τ1 and V _τ2 , a vortex formation zone is formed (shown in Fig. 4 by circular arrows), in which the liquid jets are intensively destroyed and, as a result, a finely dispersed gas-droplet stream is generated. In the vortex formation zone, the fluid flow captured by intersecting jets rotates with an angular velocity ω and a linear velocity V _τ . The vortex formation zone expands as the liquid jets C ₁ and C ₂ approach and capture the liquid jets in the process of moving away from the outlet sections of the channels 2. The axial movement of the vortex formation zone is carried out at a speed V _n , which is the resulting velocity of the liquid droplets in the region of the intersection of the liquid jets (see figures 4 and 5).

We can estimate the angular velocity of rotation ω of the fluid flow in the region of vortex formation, which is located at the center of intersection of the fluid jets. The speed of the jets in the area of their intersection is from units to tens of meters per second. The displacement of the axial lines of the jets of liquid is of the order of one millimeter or less. It is assumed that the offset of the axial lines of the liquid jets C ₁ and C ₂ with respect to the axial lines of the channels K ₁ and K ₂ at distances not exceeding 80 R _G from the output sections of the channels is insignificant. Based on these parameters, the vortex rotation speed in the region of formation of the sprayed stream will be from tens to hundreds of thousands of revolutions per second.

The resulting high-speed vortex due to the action of centrifugal force destroys the intersecting jets of liquid. As a result, thin films of liquid are transformed into small droplets.

The distance between the outlet cross sections of the channels and the region of formation of the sprayed fluid stream, at the boundary of which the distance between the intersecting axial lines of the channels K ₁ and K ₂ has a minimum value, preferably does not exceed eighty values of the average hydraulic radius of the channels. This is due to the fact that, at large distances from the outlet sections of the channels, there is a substantial expansion of the C ₁ and C ₂ jets and their trajectories are displaced, accompanied by losses of kinetic energy.

The combination of the shock forces of the interaction of the jets with the centrifugal force of the generated vortex makes it possible to obtain a uniform stream of droplets of finely dispersed liquid in the region of formation of the atomized fluid stream. At the same time, the action of centrifugal forces makes it possible to obtain smaller droplets at lower pressure drops. Impact of the jets provides a spatially uniform stream of droplets. Thus, with the same initial kinetic energy of the liquid jets when using the invention, the energy efficiency of the process of spraying liquid jets is significantly increased and the spatial uniformity of the finely dispersed stream of liquid droplets increases.

The effect described above is fully manifested if the minimum distance between the axial lines of the 4 channels 2 (K ₁ and K ₂ ) and, accordingly, the axial lines of the jets C ₁ and C ₂ (see figure 4) does not exceed the average value of the hydraulic radius R _G channels 2. In this case, the following dependence should be taken into account: the greater the distance between the axial lines of the channels, the lower the angular velocity of rotation of the vortex ω and, therefore, the effect of spraying liquid jets due to the action of centrifugal forces is less pronounced.

It should also be borne in mind that with an increase in the number of channels 2, a more uniform spray of liquid is obtained due to the complete intersection of the jets in the region of action of the centrifugal forces of the vortex. However, there is a real restriction on the number of channels, in which the effect of liquid atomization under the action of centrifugal forces is most fully manifested: the number of channels in the preferred embodiment of the liquid atomizer should not exceed six.

The use of liquid sprayers with different angles β of intersection of the frontal projections of the axial lines of 4 channels 2 in the range from 1 ° to 179 ° (see FIGS. 5 and 7) allows one to obtain fluid spray nozzles with different taper angles and with different intensities of surface irrigation.

In the case of one of the channels 2 with a cross-sectional area exceeding the cross-sectional area of the other channel 2, a finely dispersed droplet stream with a displaced spray jet torch relative to the axis of symmetry 7 of the housing 1 can be obtained. Moreover, the cross-sectional area of one channel should not exceed the area the cross section of the other channel is more than doubled. This limitation is associated with a decrease in the efficiency of crushing jets with a significant difference in the cross-sectional areas of channels 2, since with large differences in the areas of the channels, the spraying efficiency under the action of centrifugal forces decreases.

Losses of the kinetic energy of the liquid jets due to friction limit the length of the channels 2 to twenty values of their diameters. An increase in the length of the channels entails a decrease in the pressure drop in the channel 2, which determines the magnitude of the kinetic energy and, as a consequence, a decrease in the rate of its outflow from the channel 2.

The distance between the output sections of the channels and the boundary 10 of the spatial region of formation of the atomized liquid flow (see Fig. 5) is selected from the condition of minimizing the loss of kinetic energy of the jets associated with the action of the resistance forces of the medium. Due to the fact that in order to achieve a more complete fragmentation, the jets must approach the place of their intersection with the maximum kinetic energy (speed), the indicated distance should not exceed 80 R _G.

The maximum uniformity of the droplet flow is achieved when the outlet openings of the channels 2 are equidistant from the axis of symmetry 7 of the housing 1. In this case, the jets intersect in the same focal plane perpendicular to the axis of symmetry 7 of the housing 1. When the outlet openings of the channels 2 with respect to the equidistant position, a finely divided droplet is possible flow with various spatial configurations.

In order to concentrate the sprayed stream in a certain spatial region and increase the efficiency of spraying jets of liquid, the sprayer is equipped with a chamber 9 installed behind the output section of the channels 2 (Fig. 3). In the exemplary embodiment of the atomizer shown in FIG. 3, the chamber 9 has a cylindrical shape. When fluid flows from channels 2, a vacuum is created at their outlet sections due to the ejection action of the jet.

In the process of expiration of the jets of liquid through the channels 2 as a result of suction of gas from the environment in the chamber 9, an oncoming gas stream is formed, which helps to spray the liquid. An increase in the length L _k more than 20D _K (where D _K is the diameter of the cylindrical chamber 9) leads to a decrease in this effect due to the influence of friction forces. The optimal size of the chamber 9 in this example spray gun corresponds to the ratio D _K / L _K = 1,5.

An additional reduction in hydraulic fluid losses is ensured by the fact that the generatrices 5 and 6 of the conical surfaces of the inlet and outlet sections of the channels 2 are parallel and perpendicular to the axial lines of the 4 channels 2. Moreover, the cone angle of the generated spray torch can be changed using sprayer housings with different angles of inclination forming 6 conical surface to the axis of symmetry 7 of the atomizer. The angle of the cone of the torch of the sprayed stream also changes when exposed to the area of formation of the sprayed liquid stream, in which the intersection of the liquid jets is carried out by an axial liquid jet, which is formed in the axial channel 8 of the housing 1 (see Figs. 1-3).

The generation of atomized fine droplet stream can also be carried out using a liquid atomizer, shown in Fig.6 and 7.

The working fluid is supplied to the cavity of the housing 15 of the liquid atomizer through the nozzle 19, through which the atomizer is connected to the fluid supply line.

Next, the fluid enters the channels 12 through the inlet sections 18 having a conical shape. The use of the conical sections 18 in the atomizer design in the considered example allows to reduce hydraulic losses at the inlet to the channels 12 and thereby increase the velocity of the fluid jets.

The frontal projections of the intersecting center lines 11 of the channels 12 intersect at an angle of 179 °. Since the axial lines 11 of the channels 12 in the considered sprayer embodiment are displaced by a distance not exceeding R _Г , only peripheral parts of the liquid jets intersect in the region of formation of the atomized liquid stream. As a result, in the region of intersection of the liquid jets (the region of formation of the atomized liquid stream), vortex formation is carried out in the same way as described for the embodiment of the atomizer shown in Figs. 1-3. The resulting vortex with an angular velocity of rotation ω due to the action of centrifugal forces destroys the liquid jets, transforming them into drops.

The execution of the surface of the outlet sections of the channels 12 of the conical shape in this embodiment of the atomizer provides the intersection of the jets of liquid in the immediate vicinity of the outlet sections of the channels 12. In this region, the kinetic energy (speed) of the jets is close to maximum, thereby achieving more complete fragmentation of the jets in the sprayed area flow. In addition, the conical surface of the outlet sections of the channels forms a cavity in the cylindrical insert 14, in which the jets of liquid intersect and the vortex region forms. Due to the interaction of the sprayed jets of liquid with the conical surface of the insert 14, it becomes possible to concentrate the flow of fine droplets in a certain spatial region and the formation of a torch of sprayed liquid of a given configuration is carried out.

When using a liquid atomizer, made according to the present invention, a torch of finely dispersed liquid is generated with uniform intensity and dispersion of droplets over the flow cross section, while a significant reduction in energy costs for generating a sprayed liquid stream is achieved. As a result of the experiments in the range of working fluid pressures of 0.2 ÷ 0.5 MPa, it was found that with the help of a liquid sprayer, a stream of fine droplets of various spatial configurations with a given irrigation intensity over large and small areas can be created.

The invention can be used in fire extinguishing systems and as part of technological equipment for various purposes. Along with fire extinguishing systems, a liquid atomizer can be used to burn fuel in the power system and transport, as well as to humidify the environment and spray disinfectants and insecticides.

Claims (20)

1. A liquid sprayer comprising a housing with channels for forming liquid jets and a nozzle for supplying liquid, characterized in that the channels for forming liquid jets are directed so that their axial lines intersect beyond the outlet sections of the channels in the spatial region of formation of the atomized liquid stream, this minimum distance between the intersecting axial lines of the channels does not exceed the average value of the hydraulic radius of the cross section of the channels. 2. The liquid sprayer according to claim 1, characterized in that the distance between the outlet sections of the channels and the region of formation of the sprayed liquid stream, at the boundary of which the distance between the intersecting axial lines of the channels has a minimum value, does not exceed 80 R _G , where R _G is the average value hydraulic radius of the cross section of the channels. 3. The sprayer according to claim 1, characterized in that the channels have a cylindrical shape. 4. The sprayer according to claim 1, characterized in that the angle of intersection of the frontal projections of the axial lines of the channels is 50 ÷ 70 ° or 150 ÷ 179 °. 5. The sprayer according to claim 1, characterized in that the length of the channels does not exceed 40 R _G. 6. The sprayer according to claim 1, characterized in that the housing of the sprayer is equipped with a camera mounted behind the output sections of the channels, while the camera has the shape of a body of revolution. 7. The atomizer according to claim 1, characterized in that the atomizer body is equipped with a cylindrical chamber mounted behind the outlet sections of the channels, while the length of the chamber does not exceed twenty times its diameter. 8. The atomizer according to claim 1, characterized in that the atomizer body is equipped with a conical chamber mounted behind the outlet sections of the channels. 9. The sprayer according to claim 1, characterized in that the channels are made with tapering inlet sections of a conical shape. 10. The sprayer according to claim 1, characterized in that the channels are made with tapering inlet sections of conoidal shape. 11. The sprayer according to claim 1, characterized in that the surface of the input and / or output section of the channels is made flat. 12. The sprayer according to claim 1, characterized in that the surface of the input and / or output section of the channels has the shape of a body of revolution. 13. The sprayer according to claim 1, characterized in that the plane of the output sections of the channels are located at an angle of 50 ÷ 70 ° to the axis of symmetry of the housing. 14. The sprayer according to claim 1, characterized in that the surfaces of the input and output sections of the channels are made flat, while the planes of the input and output sections of the channels are parallel. 15. The sprayer according to claim 1, characterized in that the forming surfaces of the output sections of the channels are located at an angle of 50 ÷ 70 ° to the axis of symmetry of the housing. 16. The sprayer according to claim 1, characterized in that the generatrices of the surfaces of the input and output sections of the channels are parallel. 17. The sprayer according to claim 1, characterized in that the axial lines of the channels are perpendicular to the forming surface of the output sections of the channels. 18. The atomizer according to claim 1, characterized in that an axial channel is made in the atomizer body. 19. The sprayer according to claim 1, characterized in that the channels have the same cross section. 20. The sprayer according to claim 1, characterized in that the cross-sectional area of at least one channel exceeds the cross-sectional area of any other channel by no more than two times.

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