RU2212282C2 - Probe - Google Patents

Abstract

FIELD: concentration of aerosol particles and deposition by spraying; samplers for check of gases; acceleration of gases. SUBSTANCE: proposed probe includes nozzles mounted coaxially and hermetically interconnected; their throats are no less than throat of first nozzle (in way of gas flow). At least one nozzle is free in axial motion for regulation of distance between nozzle throats during operation of probe. Due to change in distance between nozzle throats, ejection effect occurs at lesser pressure differential, thus giving rise to supersonic flow at lesser power requirements and ensuring steady obtaining of working mode. Better working mode is achieved due to regulation of distance between nozzle throats at minimum pressure differential, thus making it possible to place probe in supersonic mode of operation. EFFECT: enhanced stability of placing in working mode. 2 dwg

Description

 The invention relates to a technique for concentrating aerosol particles, as well as to a technique where it is necessary to accelerate gas to high speeds, it can also be used as an alternative energy source.

Prototype
The USSR author's certificate 1426642 is known additional to 1422248, in which a nozzle consisting of supersonic nozzles connected tightly together and provided with at least one additional nozzle, the critical section of which is chosen smaller than the critical section of the previous nozzle in the direction of gas movement, but not less than the critical section of the first supersonic nozzle. The prototype has the disadvantage that a supersonic pressure drop is required to create supersonic speed in the first nozzle.

Analog 1
The USSR author's certificate 1242248 is known in which nozzles containing coaxially mounted supersonic nozzles, the critical section of each of which is not less than the critical section of the nozzle previous in the direction of the aerosol movement, are supersonic nozzles connected to each other with the formation of an airtight joint.

 However, the aforementioned analogue requires a pressure drop for its operation, which ensures supersonic aerosol air outflow in the first supersonic nozzle, which is not always economically justified.

 An object of the invention is the stability of the output to the operating mode at the lowest initial pressure drops in the nozzle.

 The technical task is performed as follows.

 At least one nozzle has freedom of axial movement, regulating the distance between the critical sections of the nozzles during operation of the nozzle.

 The invention is shown in figures 1 and 2.

 In FIG. 1 shows a variant of the Shesterenko nozzle, in which it consists of a Laval nozzle 1, a Laval nozzle 2 and a Laval nozzle 3.

 Laval nozzles 1, 2, 3 have critical sections 4, 5, and 6, respectively.

 On the Laval nozzle 1, a Laval nozzle 2 is installed using guides 7 and 8, as well as a corrugated flexible element 9, which, using bolts 10 and 11, nuts 12 and 13 and gaskets 14 and 15, is mounted on the installation planes 16 and 17, respectively welded to Laval nozzles 1 and 2. The installation planes are equipped with a distance-controlling bolt 18 with a nut 19 and a spring 20 (there may be several bolts, nuts and springs). There is a gap between the Laval nozzles 1 and 2 (chamber 21).

 The Laval nozzle 2 is hermetically connected to the Laval nozzle 3 using bolts 22, nuts 23 and gaskets 24. Figure 1 also shows a cut-off 25 with a critical section 26 and a reflector 27, which are necessary if the Shesterenko nozzles are used for aerosol concentration.

 Figure 2 shows the option when the supersonic nozzle Laval 1 is replaced by a tapering nozzle 28 with a critical section 29.

 Laval nozzles 2 and 3 are replaced by tapering nozzles 28, 30 and 31, and tapering nozzles 32 and 33 are installed between the tapering nozzles 30 and 31 (the number of additional tapering nozzles is dictated by the physical parameters of the gas, as well as the purpose for which nozzles are used).

 The tapering nozzles 28, 30, 32, 33 and 31 are mounted on top of each other using guides 34, 35, 36, 37 and 38, which are equipped with planes 39, 40, 41, 42 and 43 welded to them, which are equipped with corrugated flexible elements 44 and distance-adjusting bolts 45 with nuts 46 and springs 47.

 The tapering nozzles 28, 30, 31, 32, 33 have critical sections 29, 48, 49, 50, and 51, respectively.

 Between the tapering nozzles 28, 30, 31, 32, and 33 there are gaps (chambers) 52, 53, 54 and 55.

 The proposed nozzles Shesterenko works as follows.

 First, the distance-adjusting bolts 18 and 43 compress the springs 20 and 45.

 We analyze the mode of operation of the nozzle shown in figure 1.

 The distance between the critical sections 4 and 5 at the time of launch is the smallest.

 Under the action of a pressure drop sufficient to create an ejection effect (at this moment the Laval nozzle 1 operates in the Venturi tube mode), a gradual rarefaction process will begin in the gap (chamber) 21, which in turn will cause a further increase in gas velocity and flow rate through critical section 4. This will continue until the critical flow regime is established in critical section 4, after which the increase in gas flow and the increase in velocity in critical section 4 will stop.

 A further increase in the effect of ejection and evacuation of the gap (chamber) 21 will lead to local over-expansion of the gas between critical sections 4 and 5.

Considering that the supersonic part of the Laval 1 nozzle is made short, behind the Laval 1 nozzle a flow overspill appears, which is decelerated on the surface of the Laval 2 nozzle before the critical section 5, and the profile of this surface is such that it provides the angle of oblique shock waves with respect to the incident supersonic flow not exceeding 60 ^o , which in turn eliminates the transition of supersonic speed to subsonic.

 Therefore, having passed critical cross section 5, the gas will begin to expand by inertia a second time, and on the walls of the Laval nozzle 3 to slow down to critical cross section 6 and everything will repeat again (behind critical cross section 6, the gas flow is again accelerated to supersonic speeds). In this case, the nozzle cavity between the critical sections 5 and 6 is almost instantly evacuated. In this cavity, the gas reaches its maximum expansion and accelerates to maximum speed, then it is inhibited and again expands beyond the critical section 6.

 In critical section 6, a supersonic (hypersonic) speed is established. As soon as a supersonic flow is established in the nozzle, with the help of springs 20 and control bolts 18, the distance between the critical sections 4 and 5 increases, allowing the gas to expand as much as possible and develop a maximum or predetermined speed. This contributes to an increase in gas velocity even between critical sections 4 and 5. Thus, the stability of operation at the optimum mode is improved, and output to it is possible with a minimum pressure drop. It should be noted that the critical section 4 is a sound barrier, and a vacuum is created inside the nozzle in the chamber 21. In the operating mode, air is sucked into the nozzle through the nozzle 1 and the critical section 4 by the internal vacuum and the source of the differential pressure does not play a role. At the outlet of the nozzle in the operating mode, the gas has a hypersonic speed, which blocks the last critical section 6 in the direction of travel, preventing elementary waves from penetrating the inside of the nozzle. The number of nozzles installed one after another with a tight connection between each other is determined by the tasks and physical parameters of the gas.

 Similar happens in the embodiment shown in figure 2. Only instead of the Laval nozzle 1, the narrowing nozzle 28 is installed. Its critical section 29 can be even closer to the critical section 48 during start-up, and this in turn allows you to create an ejection effect even with a lower pressure drop than in the previous version. In the nozzle shown in FIG. 2, all nozzles are tapering. When the distance between the critical sections 29, 48, 50, 51 and 49 is minimal, the nozzles in the best way, with the smallest pressure drop due to ejection, enter the supersonic mode. When the distance between the critical sections 29, 48, 50, 51, and 49 is greatest, the maximum effect of both ejection and evacuation of the cavities is achieved, while if the nozzles play the role of an aerosol concentrator, the best discharge of aerosol particles as a result of oblique shock jumps to the central part flow, while the particles behind the nozzle are discharged into the cutter 25 using a vacuum pump on a filter (not shown). The purified air is deflected 27 to the side. The proposed nozzles Shesterenko can serve as a device that accelerates the flow of gas in various industries. It can be used as an alternative energy source, for example, in areas where winds have significant speeds, and also be a nozzle apparatus for a turbine.

 The technical effect of the proposed nozzle is that by adjusting the distance between the critical sections, it is possible, with minimal pressure drops, to bring the nozzles to a supersonic mode of operation.

Claims (1)

 A nozzle containing nozzles coaxially mounted with a tight connection between each other, the critical section of each of which is not less than the critical section of the first nozzle in the direction of gas movement, characterized in that at least one nozzle has freedom of axial movement that regulates the distance between the critical sections of the nozzles during work nozzle.

Images