RU2516638C1 - Cavitator - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: in a cavitator a swirling element is made in the form of peripheral narrowing spiral helicoid channels with an exit into a nozzle. Each spiral channel in the cross section has a shape of a helicoid with the ratio of the small and large axes 0.47…0.75 and with the inner smooth narrowing along the length of the spiral channels. Channels are simultaneously swirled with a number of turns from 1.5 to 2.5 around the conical surface in the form of spirals meeting at the top of the cone with a swirling pitch that increases as the spiral channels narrow. Spiral channels have the main inner ledge and additional inner smooth ledges. The main ledge in shape is made in the form of a geometric surface of the second order from the narrow end of the helicoid. Additional ledges are arranged at the blunt end of the helicoid. Helicoids together with the main and additional internal ledges are swirled around their longitudinal axes of spiral channels with a pitch of 0.9…1.3 from the largest axis of the helicoid in the direction opposite to the direction of swirling of spiral helicoid channels around the conical surface.

EFFECT: increased cavitation effect due to increased speed of liquid movement.

2 cl, 3 dwg

Description

The invention relates to a device for generating cavitation phenomena and can be used in the power industry, petrochemical industry, namely in hydrodynamic heat generators, systems for preparing hydrocarbon fuels for combustion, water treatment plants, in cavitation technologies associated with the processing of viscous oils, petroleum products, coal tar .

A device for preparing for burning waterlogged fuel oil is known, in which cavitation bodies are made of plates with a curved surface in the form of a direct helicoid (utility model patent RU No. 112984, IPC F23K 5/12, January 27, 2012).

The closest technical solution to the claimed invention is a cavitator containing a confuser, diffuser, nozzle, swirl element, fairing, inlet and outlet pipes (http://www.tstu.ru/r.php?r=structure.kafedra&sort=&id=3&f = eito. Static hydrodynamic cavitators). The disadvantages of the known device:

1. Inhibition of fluid flow by a swirl plate element causes a decrease in the flow rate and reduces the cavitation effect.

2. The inability to achieve a high cavitation effect due to the limitation of the fluid flow rates that can be achieved in the constricting element in the form of a nozzle.

These disadvantages are eliminated in the claimed invention, which is aimed at solving the problem of increasing the cavitation effect.

The technical result is achieved in that in a cavitator containing a confuser, a diffuser, a nozzle, a swirling element made in the form of a helicoid, a cowl, an inlet and an outlet pipe, according to the claimed invention, the swirling element is made in the form of peripherally arranged narrowing spiral-shaped helical channels with an exit to the nozzle, each spiral channel in the cross section has the shape of a helicoid with a ratio of the minor and major axes of 0.47 ... 0.75 and with an internal smooth narrowing along the length of the spiral channels, which are simultaneously are twisted with a number of turns from 1.5 to 2.5 around a conical surface in the form of spirals converging to the apex of the cone with a twist step that increases as the spiral channels narrow, the spiral channels have a main internal protrusion, which is shaped as a geometric surface of the second order from the narrow end of the helicoid, and additional internal smooth protrusions located from the blunt end of the helicoid, the helicoids together with the main and additional internal protrusions are twisted around their longitudinal axes piralevidnyh channels in increments of 0.9 ... 1.3 of the largest axis of the helix in a direction opposite the direction of twist of spiral channels helicoid around the conical surface.

The conical surface around which helical helicoid channels are twisted has the form of a straight cone surface or the appearance of a hyperbolic surface.

Thus, the technical result is achieved through the use of spiral helicoidal tapering channels of double twisting, the movement of fluid along which is accompanied by a sharp increase in speed and increase in the cavitation effect.

The essence of the invention is illustrated by drawings, where figure 1 shows the proposed cavitator, figure 2 - view a in figure 1, and figure 3 shows a view in figure 2.

The numbers in the drawings indicate the following elements: 1 - confuser, 2 - diffuser, 3 - nozzle, 4 - fairing, 5 - helical helicoid channels, 6 - main internal protrusion of helicoid channels, 7 - additional protrusions of helicoid channels, 8 - direction of rotation of the main vortex, 9 - direction of rotation of the additional vortex, 10 - direction of the helical twist of the helical helicoid channels, 11 - inlet pipe, 12 - output pipe.

The cavitator contains a confuser 1, a diffuser 2, a nozzle 3, a swirl element made in the form of a helicoid, a cowl 4, input 11 and output 12 of the pipe.

The difference of the proposed cavitator is that the swirl element is made in the form of peripherally located tapering spiral helicoid channels 5 with an exit to the nozzle 3.

Each spiral channel 5 in cross section has the shape of a helicoid with a ratio of small and large axes of 0.47 ... 0.75 and with an internal smooth narrowing along the length of the spiral channels 5.

Spiral helicoid channels 5 are simultaneously twisted with a number of turns from 1.5 to 2.5 around the conical surface in the form of spirals converging to the top of the cone with a twist step that increases as the channels 5 narrow.

Spiral helicoid channels 5 have a main inner protrusion 6, which is shaped as a second-order geometric surface from the narrow end of the helicoid.

Spiral helicoid channels 5 have additional internal smooth protrusions 7 located at the blunt end of the helicoid.

The helicoids, together with the main internal 6 and additional internal smooth 7 protrusions, are twisted around their longitudinal axes of the spiral channels 5 with a pitch of 0.9 ... 1.3 from the largest axis of the helicoid in the direction opposite to the direction of twisting of the spiral helicoid channels around the conical surface.

The conical surface around which the spiral-shaped helicoid channels 5 are twisted has the form of a straight cone surface or the appearance of a hyperbolic surface.

The purpose and interaction of the elements is as follows.

The confuser 1 (see figure 1) serves to gradually narrow the area of the total flow area of the fluid flow supplied to the nozzle 3 from the inlet pipe 11.

The nozzle 3 serves to form a coaxial direction of fluid flow relative to the cross section of the diffuser 2.

The diffuser 2 is a direct element in which cavitation occurs in the fluid flow exiting at high speed from the nozzle 3.

Cavitation is the formation in a fluid of cavities (cavitation bubbles or caverns) filled with steam. Cavitation occurs as a result of a local decrease in pressure in the liquid in the diffuser 2, which occurs due to an increase in its velocity. Moving with the flow to the area of the outlet pipe 12 with a higher pressure, the cavitation cavity slams, emitting a shock wave with the release of heat.

In the proposed cavitator, the fairing 4 serves for a preliminary increase in the fluid velocity and for the peripheral supply of fluid from the inlet pipe 11 to the entrance to the helical helicoid channels 5, which are designed to separate the fluid flow into separate jets and to subsequently increase the speed of movement of these jets by double helical twisting.

Fairing 4 (see figure 1) depending on the purpose of the cavitator can be made in the form of a round straight cone, a truncated straight cone, hyperboloid, paraboloid. In figure 1, the cowl 4 is shown in the form of a round straight cone.

Spiral helicoid channels 5 are made tapering in the direction of movement of the liquid and at the same time are located helically on a conical surface (in Fig. 1, the straight conical surface is not indicated by a position) with a screw-shaped direction 10 (see Fig. 2). A helical twist with a direction of 10 is made converging to the apex of the conical surface (in Fig. 1, the axis of the conical surface is not indicated by the position). At the same time, the area of its passage section decreases. Therefore, a centripetal force arises in the liquid stream, which increases the velocity of the liquid in the stream.

The number of spiral helicoid channels 5 can be from two to ten units, depending on the type of fluid, the flow rate and pressure with which the fluid is pumped.

The shape of the helicoid of the spiral channel 5 has a ratio of small and large axes of 0.47 ... 0.75, and the main inner protrusion 6 (figure 3) in shape is made in the form of a geometric surface of the second order from the sharp end of the helicoid.

Instead of a conical surface on which helical helicoid channels 5 are helically arranged, depending on the purpose of the cavitator, a hyperbolic surface can be used.

The spin pitch of the spiral helicoid channels 5 along the conical surface is variable and increases as the channel length increases. Before entering the nozzle 3, the twist of the helical helicoid channels 5 is minimal. The number of turns of helical helicoid channels 5 around the conical surface is from 1.5 to 2.5, depending on the purpose of the cavitator.

The main inner protrusion 6 (see FIG. 3) serves to twist the jets in direction 8, which is opposite to the direction of twist of the spiral helicoid channels 5 around the axis of the conical surface. Rotating vortex 8 is designed to create a region of lowering the pressure of the liquid along its progress along the channel 5, which allows to increase the speed of the fluid flow in the stream.

Additional internal smooth protrusions 7 (see figure 3) are used to excite additional vortices 9, which are a kind of "fluid bearings" to reduce friction, which moves the main fluid stream with a direction of rotation 8.

The protrusions 6 and 7, together with the sharp end of the helicoid (in Fig. 3, the sharp end is not indicated by the reference) are twisted helically along the length of the helicoid.

The length of the helicoid along the largest axis is 0.45 ... 0.65 from the pitch of the helical winding of the protrusions.

The sharp end of the helicoid (not indicated by figure 3 in the figure) is located at the place of the blunt end of the helicoid after 0.45 ... 0.65 from the winding pitch, that is, the helicoid rotates 180 °. Thus, the spin pitch of the helicoid and the internal protrusions 6, 7 around the axis of the helicoid channel is 0.9 ... 1.3 from the largest axis of the helicoid.

The twist of the protrusions 6, 7 (not indicated by the position in FIG. 3) is opposite to the direction 10 of the twist of the helicoid channels 5 and coincides with the direction of rotation of the main vortex 8. Moreover, as indicated above, the directly helicoid channel 5 is twisted in the direction 10 along the conical surface (on figure 1 the conical surface by the position is not indicated) with the number of turns from 1.5 to 2.5. Double swirling leads to the fact that in the area of the last turn in the helicoid channels 5, the liquid jets reach the maximum speed “by stretching the liquid” without an additional increase in the pressure of the liquid in the inlet pipe 11. The integrity of its flow is already violated at the exit from the helicoid channels 5 and vaporous cavities are formed already at the inlet section of the nozzle 3. The cavitation effect increases only due to the double swirling of the jets of liquid in the spiral helicoid channels 5 without an additional increase in pressure developed by asosome.

The proposed cavitator works as follows. When using a cavitator as a unit of a hydraulic heat generator, water or its mixture with chemicals dissolved in it under a pressure of 10 ... 18 kg / cm ² and at a flow rate of 1 ... 2 m ³ / h is pumped through a pipe 11 (see Figs. 1-3 ) to the entrance of the spiral helicoid channels 5. Due to the fairing 4, the flow is accelerated before entering the spiral helicoid channels 5. Moving along the helicoid channels 5, the fluid is twisted twice: spirally due to the main internal protrusions 6 and screw-like due to winding of the helicoid channels at 5 along a conical surface.

Due to the centripetal forces and the narrowing of the cross-sectional area of the helicoid channels 5, there is an increase in the velocity of the fluid flow in the channels 5. An additional increase in the velocity of the fluid flow occurs due to a decrease in the friction forces due to the “slipping” of the rotating jet with direction 8 along the additional vortex-like turbulent layer with the direction 9.

Double twisting of the jets in the helicoid channels 5 is carried out due to the spiral twisting of the channels in the direction of 10 and the twisting of the protrusions 6, 7 in the channels. At the exit from the helicoid channels 5, the liquid experiences maximum tension and primary cavitation bubbles form.

With the passage of fluid through the narrowing of the nozzle 3, and then with expansion in the diffuser 2, vortexes, separated flows, and cavitation occur in the fluid stream.

In this case, the liquid at the outlet of the nozzle 3 and the diffuser 2 is subjected to a pressure below the "tensile stress", the integrity of its flow is violated and vaporous cavities are formed. The liquid pressure drops below the value corresponding to the saturation pressure at a given ambient temperature, and the liquid goes into another state, forming phase voids, which are called cavitation bubbles.

For water, the maximum tensile strength of purified water at 10 ° C is 280 kg / cm ² . The rupture occurs at pressures only slightly lower than the saturated vapor pressure.

After the transition of the fluid in the diffuser 2 to the high pressure zone and the kinetic energy of the expanding fluid is exhausted, the bubble growth stops and it begins to contract.

The contraction of the cavitation bubble occurs at high speed and is accompanied by a sound pulse, which in its essence is a hydraulic shock. As a result of the collapse of cavitation gas bubbles, anomalous thermal energy of the liquid is released in small volumes with the formation of shock waves.

Due to this, places of increased temperature of the liquid up to 800 ° C are formed, that is, heat is released.

The higher the pressure of the liquid at the inlet of the cavitator and the higher the speed of the liquid at the entrance to the nozzle 3, the more powerful the cavitation and the more heat is generated, the more efficient the cavitator.

The conversion of the kinetic energy of a liquid into thermal energy also occurs through the triboelectric effect, which in essence is the heating of the liquid by the heat released during flow braking.

Heated liquid is used in heat generators for heating and hot water supply, as well as in industrial processes.

After the transfer of heat in the heating devices, the liquid is pumped back into the cavitator and the process is repeated.

Thus, the use of the claimed invention will increase the cavitation effect.

The proposed cavitator is a thermal transformer in which the energy of the hydrodynamic pressure of a moving jet of liquid obtained in the pump is converted by heat into cavitation energy. The electric power of the pump drive to obtain cavitation heating of the liquid according to this scheme should be commensurate with the generated thermal power.

Claims (2)

1. A cavitator containing a confuser, a diffuser, a nozzle, a swirl element, a cowl, an inlet and an outlet nozzle, characterized in that the swirl element is made in the form of peripherally arranged narrowing spiral channels with an exit to the nozzle, each channel in the cross section has the shape of a helicoid with the ratio minor and major axes 0.47 ... 0.75 and with an internal smooth narrowing along the length of the channels, which are simultaneously twisted with the number of turns from 1.5 to 2.5 around the conical surface in the form of spirals converging to the top of the cone with a twist ki, increasing as the channels narrow, the channels have a main internal protrusion, which is shaped like a second-order geometric surface from the narrow end of the helicoid, and additional internal smooth protrusions located from the blunt end of the helicoid, the helicoids together with the main and additional internal protrusions are twisted around their longitudinal axis of the channels in increments of 0.9 ... 1.3 from the largest axis of the helicoid in the direction opposite to the direction of twist of the helicoid channels around the conical surface. 2. The cavitator of claim 1, characterized in that the conical surface around which the helicoid channels are twisted has the form of a surface of a straight cone or the form of a hyperbolic surface.

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