RU2588427C2 - Improved device for formation of fog and foam - Google Patents

Abstract

FIELD: agriculture.

SUBSTANCE: device for mist and/or foam formation contains multiple first channels (60b) for supply of fluid medium, each of which has inlet communicated with first fluid source, and corresponding hole for discharge of fluid medium; second channel (66) for supply of fluid that has inlet communicated with second fluid source, and second hole to discharge fluid; and nozzle (72), communicated with first and second holes for discharge of fluid media. Nozzle (72) has an input part (74) of nozzle, outlet (78) of nozzle and neck (76) of nozzle. Neck (76) of nozzle has cross section area, which is less than cross section area both input part (74) of nozzle and outlet (78) of nozzle. Second hole for discharge of fluid medium includes porous element (100), through which second fluid should pass.

EFFECT: technical result consists in increasing of turbulence generated by first fluid medium.

14 cl, 8 dwg

Description

The present invention relates to a device for the formation of mists and / or foams from two fluids.

Devices that generate fog due to the interaction of two fluids in a device are often referred to as “twin fluid atomisers”. In many cases, these nozzles use passage openings and channels of very small diameters to allow fluids to pass through them. These passage openings and channels require extremely high levels of accuracy when machining parts and / or assembling a number of parts together. Therefore, it is likely that inaccurate machining or assembly will adversely affect the efficiency and performance of the spray gun.

In addition, when achieving the goal of small droplet formation in fogging applications, many existing atomizers for two fluids create high degrees of shear and turbulence in the interaction between the two fluids to achieve a given degree of atomization. Although this is desirable in applications for fogging, these high degrees of shear and turbulence are undesirable in applications for foaming, as they can prevent the formation of bubbles in the foam. Therefore, the existing device for fogging should be replaced by a foaming nozzle when it is necessary to move from the formation of fog to the formation of foam, for example, in the case of fire extinguishing.

An object of the present invention is to eliminate or mitigate one or more of the aforementioned disadvantages.

In accordance with the present invention, a device for the formation of fog and / or foam, the device contains:

at least one first fluid supply passage having an inlet in fluid communication with the source of the first fluid, and a first fluid outlet;

at least one second fluid supply passage having an inlet in fluid communication with the source of the second fluid, and a second fluid outlet; and

the nozzle in fluid communication with the first and second openings for the release of fluid, the nozzle having an inlet nozzle, an nozzle outlet and a nozzle neck between the nozzle inlet and the nozzle exit, wherein the nozzle neck has a cross-sectional area that is smaller the cross-sectional area of both the inlet part of the nozzle and the outlet part of the nozzle;

wherein the second fluid outlet includes a porous element through which the second fluid must pass.

A “porous element” is an element that enables the movement of fluids through it through pores.

The nozzle may be located behind the first and second openings for the release of fluid along the stream, while the first and second openings for the release of fluid are in fluid communication with the inlet part of the nozzle.

The device may further comprise a mixing chamber between the first and second openings for the release of fluid and the inlet of the nozzle.

The porous element may be hollow and may surround a second fluid outlet to form an inner chamber at least partially located in the mixing chamber. The porous element may be configured to allow movement of the second fluid through it only in the radial direction. In other words, the movement of the second fluid through the porous element in the axial direction can be prevented.

The device may comprise a plurality of first fluid supply paths having corresponding first fluid outlet ports, wherein the first fluid outlet ports are arranged and distributed in a single circle around the second fluid outlet.

Alternatively, the first fluid outlet may be in fluid communication with the nozzle inlet at a time when the second fluid outlet may be opened into the nozzle neck.

The device may further comprise at least one nozzle nozzle having a nozzle channel with a first end adapted to be connected to the nozzle inlet and a second end remote from the nozzle exit, the first end of the nozzle channel having a substantially cross-sectional area the same as the cross-sectional area of the outlet part of the nozzle, and the cross-sectional area of the nozzle channel increases between the first and second ends of the channel. The increase in the cross-sectional area of the nozzle channel may be linear.

In accordance with a second aspect of the invention, a method for generating fog and / or foam is provided, the method comprising the following steps:

supplying the first and second fluids under pressure to the respective first and second fluid channels of the fog / foam generating apparatus, wherein the second fluid channel has a second fluid outlet in which there is a porous element;

the direction of the first fluid from the first fluid channel to the nozzle having an inlet nozzle, an nozzle outlet and a nozzle neck, the cross-sectional area of which is less than the cross-sectional area of both the nozzle inlet and the nozzle exit;

directing the second fluid from the second fluid passage through the porous member and into the nozzle for mixing with the first fluid;

acceleration of the first and second fluids through the nozzle neck;

and spraying the first and second fluids from the outlet of the nozzle.

The first fluid may be a gas. The gas may be selected from the group consisting of compressed air, carbon dioxide, and nitrogen. The second fluid may be a liquid. The fluid may be selected from the group consisting of water, a liquid disinfectant, and a liquid extinguishing agent.

The nozzle may be located behind the outlet openings of both the first and second fluid channels in the upstream direction, with the directional steps directing the first and second fluids to the inlet of the nozzle.

Alternatively, the second fluid channel may open into the nozzle neck, whereby the first fluid may be directed from the first fluid channel to the inlet of the nozzle while the second fluid is directed into the nozzle neck.

The first and second fluids can be accelerated to at least a speed equal to the speed of sound through the nozzle neck.

Alternatively, the first fluid may be a liquid foam solution, and the second fluid may be compressed air or carbon dioxide. The foam solution may be a fire fighting foam and, in the most preferred embodiment, may be an aqueous film-forming foam solution.

The method may further include the step of passing the first and second fluids from the nozzle exit portion through the nozzle nozzle channel connected to the nozzle inlet portion, wherein the nozzle nozzle channel has a cross-sectional area that increases from the first end connected to the nozzle exit portion to the second end remote from the outlet of the nozzle.

Alternatively, the method may further include the step of passing the first and second fluids from the nozzle exit portion through the nozzle nozzle channel connected to the nozzle inlet portion, wherein the nozzle nozzle channel has a nozzle neck whose cross-sectional area is less than the cross-sectional area of both the first and and the second ends of the nozzle channel.

Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings. The drawings show the following:

figure 1 is a longitudinal section of a first embodiment of a device for the formation of fog and / or foam;

figure 2 is a longitudinal section of a modified variant of the embodiment according to figure 1;

figure 3 is a longitudinal section of a second embodiment of a device for the formation of fog and / or foam;

4 is a longitudinal section of a third embodiment of a device for generating fog and / or foam; and

5-8 are longitudinal sections of alternative embodiments of a nozzle nozzle, which may form part of the present invention.

A first embodiment of a device for generating fog and / or foam, indicated generally at 10, is shown in FIG. The device 10 is formed of four main components: a substantially cylindrical body or body 20, a first fluid distribution insert 50, a nozzle insert 70, and a retaining ring 90.

The housing 20 has first and second ends 22, 24. The tapered portion 26 protrudes axially from the first end 22 of the housing 20. At the second end 24 of the housing there is a chamber 28 that is open at the second end 24 of the housing 20 and is configured to receive an insert 50 for fluid distribution and nozzle insert 70, as will be described below. The first fluid supply passage 30 extends longitudinally through the housing 20. The first fluid supply passage 30 has an inlet 32 in the tapered portion 26 and an outlet 34 that is open to the chamber 28. The first fluid supply passage 30 has an expanding a profile, while the cross-sectional area of the channel 30 increases as it passes through the housing 20 from the inlet 32 towards the outlet 34. The second channel 36 for supplying fluid is also made in the housing 20 and passes into the direction through the side wall of the housing 20. The second fluid supply passage 36 has an inlet 38 on the outer surface of the housing 20 and an outlet 40 that is open to the chamber 28. The first and second fluid supply passages 30, 36 are substantially perpendicular to each other to a friend. The tapered portion 26 and / or inlet 32 is configured to connect to a first fluid source (not shown), while the second fluid inlet 38 is configured to connect to a second fluid source (not shown). The second end 24 of the housing 20 has an axially projecting flange portion 42 with an outer diameter reduced compared to the rest of the housing 20. At least a portion of the outer surface of the flange portion 42 is threaded (not shown).

The first insert 50 is a substantially cylindrical insert that is substantially I-shaped when viewed in longitudinal section, as seen in FIG. In other words, the first insert 50 has the largest thickness at its outer periphery, while the central part of the insert 50 has a thickness reduced compared to the thickness at its outer periphery. The insert 50 has a first end surface 52 and a second end surface 54, each of which has an annular groove 56, 57 extending circumferentially in the area of the outer periphery of the insert 50. An o-ring 58, 59 is located in each of the annular grooves 56, 57.

Since the insert 50 is I-shaped when viewed in longitudinal section, the first and second end surfaces 52, 54 of the insert 50 have corresponding first and second concave cavities 53, 55 formed therein. Many of the first fluid channels 60b extend longitudinally through the insert 50 and are fluidly coupled to the first and second cavities 53, 55. The first channels 60b are arranged and distributed circumferentially around the longitudinal axis L and are substantially parallel to the longitudinal axis L common to insert 50 and device 10 assembly. If desired, the first fluid channels 60b may be external first fluid channels, and the insert 50 may also have an internal first channel 60a located at the center of the insert 50 so that it is coaxial with respect to the longitudinal axis L.

The insert 50 also has an outer circumferential peripheral surface 62 in which a groove 64 is formed. The groove 64 extends around the entire circumferential periphery of the insert 50. A plurality of second fluid supply channels 66 extend radially inwardly through the insert 50 from the groove 64. The second channels 66 along substantially perpendicular to the first channels 60 and the longitudinal axis L. The feed channels 66 extend radially inwardly through the insert 50 in zones in the circumferential direction formed between the first channels 60b. The feed channels 66 allow fluid communication between the groove 64 and the third cavity 51 located in the center of the insert 50.

The third cavity 51 is coaxial with respect to the longitudinal axis L. The third cavity 51 is formed so that it is in fluid communication with each element from the supply channels 66, the second cavity 55 and a possible internal first fluid channel 60a, if one is provided. The third cavity 51 has an internal thread, as well as an inner diameter that is larger than the inner diameter of the inner first channel 60a, but smaller than the inner diameter of the second cavity 55.

A substantially cylindrical element 100 is provided for insertion into the third cavity 51 from the second cavity 55. The element 100 is porous, as a result of which it allows the movement of fluids through it through the pores. Element 100 may be formed of porous metal or ceramic material. Most preferably, the element 100 is formed of sintered bronze. Element 100 has a first end 101 and a second end 102. The first end 101 is open, while the second end 102 is closed. The second end 102 is also preferably hermetically sealed so that the fluid cannot pass through the pores at the second end 102. The element 100 has an inner diameter that is substantially constant and an outer diameter that decreases from the first end 101 towards the second end 102. As a result, the outer surface 103 of the element 100 has the shape of a surface of a truncated cone. The first end 101 of the element 100 also has a protruding part 104, which extends axially from the first end 101. The outer surface of the protruding part 104 is threaded to allow engagement with the third threaded cavity 51. Thus, the first end 101 of the element 100 is attached to the first insert 50.

When the porous member 100 is secured in the third cavity 51, the inner space of the member 100 defines the boundaries of the inner chamber 105. The inner chamber 105 will receive a second fluid from the second fluid channels 66 or, if there is an inner first fluid channel 60a, the first and second fluids, respectively, from the inner first fluid passage 60a and second fluid passages 66. The porosity of the element 100 allows the passage of fluid (s) received (s) into the inner chamber 105, in the radial direction from the inner space of the element 100 into the space external to it, and into the outer mixing chamber 45, partially formed by the second cavity 55.

The outer first fluid channels 60b are radially removed and circumferentially distributed so as to surround a possible inner first fluid channel 60a, as well as a third cavity 51 and a porous member 100. In the case where the inner first fluid channel not required, insert 50 may be formed without an internal first fluid channel, or a plug (not shown) may be inserted into and secured to the internal first fluid channel 60a to prevent entry of any fluid medium into the inner chamber 105 or the exit of any fluid from the inner chamber 105 through the inner first channel 60a for the fluid.

As with the fluid distribution insert 50, the nozzle insert 70 is substantially cylindrical and coaxial with respect to the other components of the device 10. The second insert 70 has a nozzle 72 formed therein, the nozzle 72 having an nozzle inlet 74, a neck 76 and nozzle exit 78. The nozzle 72 is coaxial with respect to the L axis, and the neck 76 between the nozzle inlet 74 and the nozzle exit 78 has a cross-sectional area that is smaller than the cross-sectional area of both the nozzle inlet 74 and the nozzle exit 78. You can also see that the decrease and subsequent increase in cross-sectional area in the nozzle 72 is gradual. In other words, there are no stepwise changes in the cross-sectional area that would cause the formation of ledges or niches in the nozzle wall that would affect the flow of fluid passing through it. Therefore, the nozzle 72 is a "tapering-expanding nozzle", as understood in the art.

The nozzle insert 70 has first and second ends, respectively having a first end surface 71 and a second end surface 73. The groove 80 is located on the outer circumferential peripheral surface of the insert 70 near the first end. The groove 80 extends around the entire circumferential periphery of the insert 70, and the o-ring 82 is located in the groove 80. The nozzle insert 70 has a reduced diameter portion 75 near the second end. The difference between the outer diameter of the main part of the insert 70 and the outer diameter of the part 75 with a reduced diameter provides the formation of a supporting surface 77, which faces towards the second end 73 of the insert 70.

The last component of the main device 10 is a holding ring 90, which has a first side surface 92 and a second side surface 94. The holding ring 90 has a hole passing through it, which is divided into the first and second parts 96, 98. The first part 96 of the hole is open on the first the side surface 92, while the second part 98 of the hole is open on the second side surface 94. The first part 96 of the hole has a larger diameter compared to the second part 98 of the hole. The difference in diameter between the first and second parts 96, 98 of the hole provides the formation of the supporting surface 97, which faces in the direction of the first side surface 92 of the retaining ring 90. At least a portion of the inner surface of the first part 96 of the hole is made with a thread (not shown). The second end 94 of the retaining ring 90 is made with one or more threaded holes 99, which include mechanical fasteners designed to attach additional components to the main device 10, as will be further discussed below.

When assembling the device 10, the porous element 100 is screwed into the third cavity 51 of the insert 50 for distributing fluids, as described above. Then, the insert 50 is pushed into the chamber 28 through the second end 24 of the housing 20. The inner diameter of the chamber 28 and the outer diameter of the insert 50 are such that a stationary sealing fit is created between the insert 50 and the housing 20. When the insert 50 is positioned properly in the chamber 28, the first end surface 52 is adjacent to the outlet 34 of the first channel 30 in the housing 20 for supplying fluid. As a result, the outlet 34 of the first fluid passage 30 is in fluid communication with the first cavity 53 of the insert 50, and the second fluid passage 36 is in fluid communication with the groove 64 of the insert 50. The seal ring 58 provides a seal between the first insert 50 and housing 20.

As soon as the first insert 50 is installed in a predetermined position, it will be possible to insert the nozzle insert 70 into the chamber 28 through the second end 24 of the housing 20. As with the first insert 50, the inner diameter of the chamber 28 and the outer diameter of the second insert 70 are such that the stationary seal a fit is made between the insert 70 and the housing 20. When the second insert 70 is appropriately placed in the chamber 28, the first end surface 71 of the second insert 70 abuts against the second end surface 54 of the first insert 50. As a result, the outer mixing chambers 45 with a common longitudinal axis L is formed by the inlet portion of the nozzle 74 in the second insert 70 and the second cavity 55 of the first insert 50. The porous member 100 and inner chamber 105 formed therein, disposed at least partially within the outer 45 of the mixing chamber.

After the housing 20 is assembled, the first insert 50 and the second insert 70 will now all communicate in fluid with each other through the previously described cavities, fluid channels and channels formed in these components, as will be described below with further details. The second of the sealing rings 59, located on the second end surface 54 of the first insert 50, provides a seal between the first and second inserts 50, 70.

Finally, when the first and second inserts 50, 70 are placed in their proper positions in the chamber 28 of the housing 20, it will be possible to place the retaining ring 90 over the second end of the second insert 70. Threaded portions of the flange 42 of the housing 20 and the first side surface 92 of the retaining ring 90 interact with each other so that the retaining ring 90 can be screwed onto the housing 20 until the respective supporting surfaces 77, 97 of the second insert 70 and the retaining ring 90 come into contact with each other. As soon as this happens, the first and second inserts 50, 70 will be firmly held in position, being located between the housing 20 and the retaining ring 90.

Next, also with reference to figure 1 will be described how the device 10 operates in the formation of fog. In this preferred embodiment, the inner first fluid passage 60a is plugged so that no first fluid can flow into the passage. It should be understood that the inner channel 60a should be open if some degree of pre-mixing of the first and second fluids is desired, but the fogging method described herein does not require such pre-mixing, and therefore, the inner channel 60a is closed in the operation method described below.

First, a first fluid is introduced from a suitable source (eg, a compressed gas cylinder) into a first fluid inlet 32. There are many different fluids that will be suitable for use as a first fluid, but in this preferred example, the first fluid is compressed air. The supply pressure of the first fluid may be in the range of 2 to 40 bar, or more preferably in the range of 5 to 20 bar. The first fluid passes through the first fluid supply path 30 in the direction of arrow T to the first cavity 53 formed in the first insert 50. As soon as the first fluid enters the first cavity 53, the first fluid is divided into a number of flows when it enters into the outer first fluid passages 60b formed in the first insert 50. The first fluid passing through the outer first fluid passages 60b enters the outer mixing chamber 45 formed between the second cavity 55 of the first insert 50 and nozzle inlet 74 in the second insert 70. The first fluid streams exiting the external fluid channels 60b increase in volume and come into contact with each other in the outer mixing chamber 45, thereby creating a turbulent zone in the outer mixing chamber 45. The first fluid enters the outer mixing chamber 45 at high pressure, but at a relatively low speed.

Simultaneously with the first fluid being introduced into the first fluid supply passage 30, the second fluid is introduced from a suitable source at a preferred supply pressure in the range of 2 to 40 bar, most preferably in the range of 5 to 20 bar. The second fluid is introduced into the second fluid passage 36 formed in the housing 20. As with the first fluid, the second fluid may be some fluid, but in this preferred example is water. When the second fluid passes through the second fluid supply passage 36, it enters a groove 64 formed on the outer surface of the first insert 50. After that, the second fluid can extend around the entire circumferential periphery of the first insert 50 through a groove 64 that is located between the housing 20 and the first insert 50. When the second fluid passes through the groove 64, it enters the plurality of radial feed channels 66 in the first insert 50 and extends inward to the longitudinal axis L of the device. At the inner ends of the supply channels 66, the second fluid enters the inner chamber 105 formed within the porous element 100.

The first and second fluids can be supplied at a mass flow rate, the values of which are in a wide range. The mass flow ratio of the first and second fluids may vary in a preferred range from 20: 1 to 1:10.

When the second fluid enters the inner chamber 105, it begins to seep through the porous element 100 into the outer mixing chamber 45. The degree of porosity and / or pore size in the material from which the element 100 is formed, as well as operating conditions, such as pressure drop on the porous element 100 between the inner chamber 105 and the mixing chamber 45, determine the speed at which the second fluid enters the mixing chamber 45. In addition, extrusion of the second fluid through the pores of the element 100 provides extremely small drops of the second fluid, so that the second fluid will be sprayed at least partially upon entering the mixing chamber 45. When the drops of the second fluid come into contact with the streams of the first fluid in the mixing chamber 45, the friction forces between the two fluids and turbulent mixing of the two fluids leads to further crushing of the droplets of the second fluid. The turbulence created by the first fluid entering the mixing chamber 45 further ensures that droplets created by this spraying of the second fluid will be distributed throughout the mixing chamber 45. This represents the first stage of the implementation of the fogging mechanism used in the present invention .

The remaining stages of the implementation of the spraying mechanism are implemented in the nozzle 72 of the device 10. Drops of the second fluid in the mixing chamber are transferred by the turbulent first fluid to the inlet part 74 of the nozzle. A gradual decrease in the cross-sectional area between the nozzle inlet 74 and the nozzle neck 76 accelerates the first fluid to a very high speed, preferably equal to the speed of sound, at the location in the neck 76 with the smallest cross-sectional area. This acceleration of the first fluid means that there is a velocity gradient at the droplets of the second fluid in the tapering zone of the nozzle (i.e., in the zone between the inlet part of the nozzle and the nozzle neck), since the part of each drop closest to the nozzle neck will move faster than the part closest to the inlet of the nozzle. This ensures that the droplets of the second fluid are exposed to shear forces and stretch or elongate in the direction of flow. When the shear forces exceed the surface tension forces, further spraying occurs because the droplets deform and burst to form even smaller droplets. This shift represents the second stage in the implementation of the spraying mechanism.

Drops of the second fluid having a reduced size emerge from the nozzle neck 76 at a very high speed, preferably equal to the speed of sound. As described above, the nozzle exit portion 78 has a larger cross-sectional area than the nozzle neck 76. Therefore, the first fluid having a high speed undergoes an increase in volume as it extends from the nozzle neck 76 toward the outlet portion 78. This causes the droplets of the second fluid contained in the first fluid to stretch and cause them to separate further smaller droplets of the second fluid. This droplet gap represents the third step in the implementation of the atomization mechanism used in the present invention.

Finally, droplets are sprayed from the nozzle exit 78 in the form of a mist containing a dispersed phase formed from droplets of a second fluid in a continuous phase formed from a first fluid. Depending on the operating conditions, the flow passing through the nozzle 72 may be subsonic in the area between the neck 76 and the outlet portion 78 of the nozzle. Alternatively, the operating conditions may mean that the flow in this zone may be supersonic along some or all of its length, while the supersonic zone ends in the form of a shock wave or between the neck 76 and the nozzle exit 78, in the nozzle exit 78 or outside the device 10. Under such operating conditions under which a shock wave occurs, it can provide the fourth stage of the mechanism of droplet rupture due to a sudden increase in pressure in the shock wave. Additional droplet rupture can occur behind the nozzle exit along the flow due to the high degree of turbulence created in the stream, as well as due to interaction with the environment outside the nozzle exit.

The main device described above is intended primarily for fogging. A modified variation of this first embodiment of the device 10 is shown in FIG. 2, and this variation is primarily intended for foaming. The main device 10 is the same device as described above with reference to figure 1, and therefore, each of the elements described in connection with figure 1, has the same reference position in figure 2. These common elements will not be fully described again with reference to FIG. 2.

The modified device 10 differs from the device of FIG. 1 in that it includes a nozzle nozzle 110. The nozzle 110 is a substantially cylindrical element with a first end 111, a second end 112 and a nozzle channel 113 extending longitudinally through the nozzle 110 from the first end 111 to the second end 112. The first end 111 is made with a flange 114 protruding in the radial direction, in which there are a number of through holes 115 extending in the axial direction. The holes 115 are aligned with the corresponding holes 99 in the retaining ring 90, and mechanical fasteners 116 are inserted into the holes 115, 99 for attaching the nozzle 110 to the retaining ring 90 and the rest of the housing 10.

When the nozzle 110 is attached to the rest of the device 10, the first end 117 of the nozzle channel 113 will be connected to the nozzle exit portion 78. The cross-sectional area of the first end 117 of the nozzle channel 113 is preferably identical to the cross-sectional area of the nozzle exit portion 78. The second end 118 of the nozzle channel 113 has a cross-sectional area that is larger than the cross-sectional area of the first end 117 of the channel 113. Thus, there is a gradual expansion of the nozzle channel 113 from the first end 117 to the second end 118, but the expansion ratio is relatively small. In a preferred embodiment, the degree of expansion may correspond to an increase in the diameter of the nozzle channel by 0.5 mm for every 30 mm of the channel length from the first end 117 to the second end 118.

The method of operation of the device 10 for the formation of foam will be discussed below with reference to figure 2. In this case, the inner first fluid passage 60a is also blocked. If the device previously operated in the fogging mode before adding the nozzle nozzle 110, the sources of the first and second fluids are disconnected from their respective first and second channels 30, 36 for the passage of fluids. Then, the source of the first fluid is reconnected to the device 10 via a second fluid supply passage 36. As a result, compressed air or other suitable fluid will now enter the device through second channels 66 for supplying fluid. After that, the source of the second fluid is connected to the first channel 30 for supplying fluid. In this foaming mode, a suitable second fluid for this task is a foam solution, such as, for example, an aqueous film-forming foam (AFFF) intended for use in fire fighting.

The supply pressure of the second foaming fluid may be in the range of 5 to 20 bar. The second fluid passes through the first fluid supply passage 30 in the direction of arrow T to the first cavity 53 formed in the first insert 50. As soon as the second fluid enters the first cavity 53, the second fluid is divided into a number of flows when it enters into the outer first fluid channels 60b formed in the first insert 50. The second fluid passing through the outer first fluid channels 60b enters the outer mixing chamber 45 formed between the second cavity 55 of the first minutes insert 50 and the entry portion 74 of the nozzle 70 in the second insert.

Simultaneously with the introduction of the second fluid into the first fluid supply passage 30, the first fluid is introduced from a suitable source at a preferred supply pressure in the range of 2 to 40 bar, most preferably in the range of 5 to 20 bar. The first fluid is introduced into the second fluid supply passage 36 formed in the housing 20. When the first fluid passes through the second fluid supply passage 36, it enters a groove 64 formed on the outer surface of the first insert 50. In this case, the first fluid the medium may extend around the entire circumferential periphery of the first insert 50 through a groove 64 that is between the body 20 and the first insert 50. When the first fluid passes through the groove 64, it enters into a plurality of radial feed channels 66 in the first insert e 50 and extends inwardly toward the longitudinal axis L of the device. At the inner ends of the supply channels 66, the first fluid enters the inner chamber 105 formed within the porous element 100.

In this embodiment, designed for foaming, the flow rate of the first fluid passing into the device may be in the range of 3 to 16 liters per minute, while the mass flow rate of the second fluid may be in the range of 0.5 to 2 kg / min In the most preferred embodiment, the flow rate of the first fluid passing into the device may be in the range of 3 to 13 liters per minute, while the mass flow rate of the second fluid in the most preferred embodiment is in the range of 0.5 to 1.5 kg / min

When the gaseous first fluid enters the inner chamber 105, it will begin to seep through the porous element 100 into the outer mixing chamber 45. The degree of porosity and / or pore size in the material from which the element 100 is formed, as well as operating conditions, such as differential pressure on the porous element 100 between the inner chamber 105 and the mixing chamber 45, determine the speed with which the first fluid enters the mixing chamber 45. In addition, extrusion of the first fluid through the pores of the element 100 providing This results in the formation of small bubbles of the first fluid that enter the mixing chamber 45 and into the second fluid located therein.

Bubbles of the first fluid are transferred by the second fluid from the mixing chamber 45 to the inlet 74 of the nozzle. A gradual decrease in the cross-sectional area between the nozzle inlet 74 and the nozzle neck 76 accelerates the second fluid. This acceleration of the second fluid and its passage through the nozzle neck 76 result in a change in pressure acting on the bubbles of the first fluid in the second fluid. Therefore, when the mixture of the first and second fluids passes through the neck 76, the bubbles of the first fluid will begin to increase in volume as the fluid flow passes to the nozzle exit 78. The nozzle nozzle 110 and the gradually expanding channel 113 therein ensure that the bubbles of the first fluid will gradually increase in volume along the length of the channel 113, resulting in the formation of larger bubbles and large amounts of foam when the fluids exit the device 10.

A second embodiment of a device for generating fog and / or foam, indicated generally at 10 ′, is shown in FIG. The second embodiment has a number of common components and elements with both the base and modified versions of the first embodiment shown in Figs. 1 and 2. Therefore, elements that are the same in each embodiment have the same reference position in this the second embodiment and again will not be described in detail in this case.

In the second embodiment of the device 10 ', the third insert 120 is inserted into the chamber 28 after the first insert 50 is inserted, but before the second insert 70 is inserted. The third insert 120 is tubular and has an outer diameter that is selected so as to provide a stationary sealing fit between the outer surface of the third insert 120 and the inner surface of the chamber 28. In order to facilitate the creation of a sealing connection, the end 122 of the third insert 120 adjacent to the second insert 70 is made with an annular groove 124, in which a sealing ring 126. is put in place. Thus, when the third insert 120 is positioned in the chamber 28 appropriately, one end 121 of the insert 120 abuts against the second end 54 of the first insert 50, while the other end 122 of the insert 120 abuts the first end 71 of the second insert 70.

Some changes to the housing 20 for embedding the third insert 120 can be made. For example, the length of the housing 20 and the chamber 28 in the axial direction can be increased so that all three inserts 50, 70, 120 can be accommodated in them. Alternatively, as shown 3, the length of the retaining ring 90 'in the axial direction can be increased to accommodate most of the nozzle insert 70 protruding from the chamber 28. Alternatively, an additional outer section (not shown) can be added between the housing 20 and erzhivayuschim ring 90 and suitably attached so as to surround the third insert 120. The nozzle 110 has a nozzle in a second embodiment, as it is shown in the foam mode, but the second embodiment can be used without a nozzle misting regime if necessary.

With the exception of the insertion of the third insert 120, the second embodiment of the device 10 'is assembled and functions essentially the same as the first embodiment. However, the presence of a tubular third insert 120 between the first and second inserts 50, 70 provides an increase in the length of the mixing chamber 45 'in the axial direction behind the first insert 50 along the flow. Changing the length of the mixing chamber 45 'in the axial direction contributes to the formation of foam bubbles in the foaming mode, and in the mode of fogging provides a change in the degree of turbulence and the degree of swirling and mixing in the mixing chamber 45' and changes in the first stage of the spraying mechanism used during the formation of fog.

FIG. 4 shows a third embodiment of a device for generating fog and / or foam, generally designated 200. This third embodiment of a device 200 includes a first fluid supply passage 202 having an inlet 204 in fluid communication with a source of the first fluid (not shown), and a first fluid outlet 206. The device 200 also has an annular second fluid supply passage 210 having an inlet 212 in fluid communication with a second fluid source (not shown) and a second fluid outlet 214. The nozzle 220 is in fluid communication with the first and second openings 206, 214 for discharging fluids, and has an inlet part 222, an outlet part 226 and a nozzle neck 224 between the inlet part 222 of the nozzle and the outlet part 226 of the nozzle. The nozzle neck 224 has a cross-sectional area that is smaller than the cross-sectional area of both the nozzle inlet portion 222 and the nozzle exit portion 226. The porous annular element 230 is located in the second fluid outlet 214 so that any fluid passing through the second fluid passage 210 must flow through the porous element 230. The first fluid outlet 206 communicates with the nozzle inlet 222 while the second fluid outlet 214 is open into the nozzle neck 224.

If desired, the nozzle 220 may have at least one additional channel 240 having an additional inlet 242 located upstream of the nozzle 224 of the nozzle and an auxiliary outlet 244 opening into the second fluid channel 210. The additional channel 240 may be a single annular channel surrounding the nozzle 220, or, as shown in FIG. 4, a plurality of additional channels 240 may be provided distributed in a circle around and parallel to the nozzle 220. The porous element 230 may be located in the second fluid passageway 210 or to that point upstream where the auxiliary outlet (auxiliary outlet) 244 is open (s) into the second channel 210, or behind that location.

As can be seen in FIG. 4, the cross-sectional area of the nozzle 220 gradually increases from the nozzle neck 224 in the direction of the nozzle exit portion 226. The device 200 may be supplemented with a nozzle nozzle of the type described above to extend the expanding channel of the device.

As with the previous embodiments, a third embodiment of the device 200 can be used to form fog and / or foam. In a fogging mode, a first fluid, such as compressed air, carbon dioxide, steam, or nitrogen, is supplied to the first fluid passage 202. From there, the first fluid under pressure enters the nozzle 220 and is accelerated by the nozzle neck 224 to a high speed, preferably equal to the speed of sound, at a place in the neck having the smallest cross-sectional area. At the same time, a second fluid medium, such as water, a liquid disinfectant or an extinguishing agent, is supplied to the second fluid passage 210. The porous element 230 in the second fluid passage 210 provides control of the flow of the second fluid passing into the nozzle neck 224, so that small droplets of the second fluid will exit the porous element 230 and enter the nozzle 220. In the case of auxiliary (s) channel (s) 240 auxiliary (auxiliary) channel (s) 240 provides (is) a deflection of a portion of the first fluid in the second fluid channel 210, which creates the effect of partially spraying the second fluid before it is introduced into the nozzle 220.

When droplets of the second fluid enter the accelerated flow of the first fluid in the nozzle throat 224, they are exposed to large shear forces and turbulence created by the first fluid, which leads to additional atomization of the droplets of the second fluid into smaller droplets. The dispersed phase formed by the droplets of the second fluid in the continuous phase formed by the first fluid then passes towards the nozzle exit portion 226. In this case, the droplets increase in volume and again burst with the formation of droplets of an even smaller size before spraying from the device in the form of fog.

In order for the device according to the third embodiment to function in a foaming mode, the source of the first fluid is disconnected and reconnected to the second fluid channel 210, as in the case of the other embodiments. Then, the second fluid, which is a foam solution, is supplied to the first fluid passage 202. Then, the first fluid bubbles exit the porous element 230 in the second fluid passage 210 and enter the second fluid in the nozzle neck 224. Bubbles increase in volume as the first and second fluids move toward the nozzle exit portion 226 and the nozzle nozzle (not shown) attached thereto in the same manner as described above in connection with earlier embodiments. After this, the first and second fluids exit the device in the form of foam.

Through the use of a porous element, the device of the present invention can provide the introduction of one fluid into another fluid with low flow rates and / or with a given size of droplets or bubbles, which otherwise would require accurate and highly skilled, machining of the channels is very small diameter. Thus, the present invention eliminates the possibility of inaccurate machining or manufacturing, affecting the operational characteristics of the device.

In accordance with the present invention, one device has also been developed that can provide fog formation from droplets in one mode and foam formation in a second mode. Two devices are usually required, since fogging involves droplets that are as small as possible, but when foam is formed, it is desirable to form bubbles that are as large as possible. The degrees of shear and turbulence created by droplet crushing in the fogging mode do not contribute to the formation of large bubbles, if the same device is also used for the formation of foam. However, simply switching the source of the gaseous fluid from the first supply channel to the second supply channel makes it possible for the device of the present invention to also form foam and mists by converting the gaseous first fluid bubbles through the porous element into a foam solution. The increase in the volume of bubbles in the foam solution slows down due to the addition of a nozzle nozzle, so that the bubbles will be as large as possible when they exit the device.

In addition to a separate supply of foam solution, the nozzle nozzle is the only additional detail necessary to put the device into foaming mode. A number of alternative embodiments of the nozzle nozzle shown in Fig.5-8. 5 shows a first alternative nozzle 310 having a nozzle channel 313 with a neck 315, the cross-sectional area of which is smaller than the cross-sectional area of both the first and second ends 311, 312 of the nozzle channel 313. 6 shows a second alternative nozzle 410 in which the nozzle channel 413 has walls that taper or expand smoothly in the direction of flow, so that the cross-sectional area of channel 413 gradually increases in the direction of flow along channel 413. FIG. 7 shows the third alternative nozzle 510, in which the channel 513 has walls that have a relatively sharp cone-shaped change or expansion to quickly increase the cross-sectional area of the portion of the channel 513 located further downstream. In a third alternative embodiment, the rate of expansion or increase of the cross-sectional area gradually decreases in the direction of flow, until the channel 513 reaches its largest cross-sectional area. Finally, a fourth alternative nozzle 610 is shown in FIG. This embodiment is similar to the third alternative embodiment in that the rate of increase of the cross-sectional area in the channel 613 is initially relatively high, but then gradually decreases before the channel reaches its largest cross-sectional area. The fourth embodiment is characterized in that the cross-sectional area of the channel 613 near the first end 611 sharply increases and decreases to form a chamber 615 with a larger cross-sectional area compared to the first end 611 of the channel 613. An expanding part of the channel 613 is located downstream of the chamber 615 similar to that shown in the third alternative embodiment.

The device may also comprise a set of nozzle nozzles, which may have different lengths and / or internal geometry of the type described in the nozzle embodiments described herein. Alternatively, nozzle nozzles of various shapes can be attached to each other in series to further lengthen the gradually expanding channel.

The nozzle channel may have a ratio of D: L, where D is the diameter of the first end of the nozzle channel and L is the channel length, measured in a straight line, which is selected from the group including the following relations: 1: 3, 1: 4, 1:16, 1: 20, 1:30 and 1:40.

Although the nozzle nozzle is preferably attached by mechanical fasteners as described above, other fixing methods are possible. For example, the nozzle may be screwed onto the end of the nozzle by means of interacting threaded parts. In addition, the protruding flange 114 may not be permanently attached, but may be configured to quickly attach and remove by using a quick-release mechanism.

Although the ability of the device to switch between fogging and foaming is preferred, the device of the present invention does not have to be used for both functions. In other words, the device and its porous element can be used only as a device for forming fog or only as a device for forming foam.

A number of porous elements, each of which has a porosity different from the porosity of other porous elements, can be provided with the device, so that the flow rate and / or the size of the droplets or bubbles of the fluid coming from the inner chamber to the mixing chamber can be changed in a desirable way. As indicated, the porous element (s) may be formed from a porous metal (e.g., sintered bronze or brass) or from a porous ceramic element.

In the fogging mode, the first fluid may be compressed air, carbon dioxide, or nitrogen, and the second fluid may be water, a liquid disinfectant, or an extinguishing agent. In the foaming mode, the first fluid may be a foam solution, and the second fluid may be compressed air or carbon dioxide. The foam solution may be a fire fighting foam, such as, for example, an aqueous film-forming foam solution. In an alternative embodiment, the foam may be a coating for disinfection or a surface coating for cleaning.

These and other modifications and enhancements may be included without departing from the scope of the present invention.

Claims (14)

1. Device for the formation of fog and / or foam, while the device contains:
a plurality of first fluid supply channels (60b), each of which has an inlet in fluid communication with a first fluid source and a corresponding first fluid outlet;
at least one second fluid supply passage (66) having an inlet opening in fluid communication with the source of the second fluid, and a second fluid outlet; and
a nozzle (72) in fluid communication with the first and second openings for releasing fluids, the nozzle (72) having an inlet part (74) of the nozzle, an outlet part (78) of the nozzle and a neck (76) of the nozzle between the inlet part (74) the nozzle and the nozzle exit part (78), and the nozzle neck (76) has a cross-sectional area that is less than the cross-sectional area of both the nozzle inlet part (74) and the nozzle exit part (78),
wherein the second fluid outlet includes a porous element (100) through which the second fluid must pass, and
the first fluid discharge openings of the plurality of first fluid supply channels (60b) are circumferentially distributed around the second fluid discharge opening. 2. The device according to claim 1, in which the nozzle (72) is located behind the first and second holes for the release of fluid along the stream, while the first and second holes for the release of fluid are in fluid communication with the inlet part (74) of the nozzle. 3. The device according to claim 2, further comprising a mixing chamber (45) between the first and second holes for the release of fluid and the inlet part (74) of the nozzle, while the porous element (100) is hollow and surrounds the second hole for the release of fluid for the formation of the inner chamber (105), at least partially located in the mixing chamber (45). 4. The device according to claim 1, additionally containing at least one nozzle nozzle (110) having a nozzle channel (113) with a first end configured to connect to the nozzle exit and a second end remote from the nozzle exit, the first end of the nozzle channel (113) has a cross-sectional area substantially the same as the cross-sectional area of the nozzle exit portion (78), and the cross-sectional area of the nozzle channel (113) increases between the first and second ends of the channel. 5. The device according to claim 4, in which the increase in the cross-sectional area of the channel (113) of the nozzle is linear. 6. A method of forming fog and / or foam, the method comprising the following steps:
supplying the first fluid under pressure to the plurality of first fluid channels (60b) of the fog / foam generating device (10), wherein each first fluid channel (60b) has a corresponding first fluid outlet;
supplying a second fluid under pressure to a second fluid channel (66) of the device (10), wherein the second fluid channel (66) has a second fluid outlet, in which there is a porous element (100), and the first fluid outlet is distributed circumferentially around the second fluid outlet;
the direction of the first fluid from the first fluid channel (60b) to the nozzle (72) having an inlet part (74) of the nozzle, an outlet part (78) of the nozzle and a nozzle neck (76) whose cross-sectional area is smaller than the cross-sectional area as the input part (74) of the nozzle and the output part (78) of the nozzle;
directing the second fluid from the second fluid channel (66) through the porous element (100) and into the nozzle (72) for mixing with the first fluid;
acceleration of the first and second fluids through the nozzle neck (76); and
spraying the first and second fluids from the nozzle exit portion (78). 7. The method according to claim 6, in which the nozzle (72) is located behind the outlet openings of both the first and second channels (60b, 66) for the fluid along the flow, and in which the stages of the direction provide the direction of the first and second fluids in the inlet part (74) of the nozzle. 8. The method according to claim 6, in which the first and second fluids are accelerated to at least a speed equal to the speed of sound by means of the nozzle neck (76). 9. The method of claim 6, wherein the first fluid is a gas selected from the group consisting of compressed air, carbon dioxide, and nitrogen. 10. The method of claim 6, wherein the second fluid is a liquid selected from the group consisting of water, a liquid disinfectant, and a liquid extinguishing agent. 11. The method of claim 6, wherein the first fluid is a liquid foam solution and the second fluid is compressed air or carbon dioxide. 12. The method according to p. 11, in which the foam solution is an aqueous film-forming foam solution. 13. The method according to p. 11 or 12, further comprising the step of passing the first and second fluids from the outlet part (78) of the nozzle through the channel (113) of the nozzle nozzle connected to the outlet part (78) of the nozzle, and the channel (113) of the nozzle the nozzle has a cross-sectional area that increases from the first end connected to the nozzle output part (78) to the second end remote from the nozzle output part (78). 14. The method according to p. 11 or 12, further comprising the step of passing the first and second fluids from the nozzle exit (78) through a nozzle nozzle channel (313) connected to the nozzle exit (78), the nozzle channel (313) the nozzle has a neck (315) of the nozzle, the cross-sectional area of which is less than the transverse area of both the first and second ends of the channel (313) of the nozzle.

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