FI73894B - FOERRENINGSANORDNING FOER GASER. - Google Patents

Description

1 73894

This invention relates to an apparatus for wet scrubbing mechanical impurities. The cleaning device comprises a cyclone having an inlet pipe and an outlet pipe; and an apparatus for bringing the gas into contact with the liquid, connected to the cyclone and including a liquid collector communicating via spray passages to a gas flow passage with different cross-sectional points .

The wet scrubbing process of the gases depends on the kinematic coagulation of solid particles suspended in the gases with small droplets of liquid when the gas stream comes into contact with the atomized liquid. This process consists in solid particles, when they collide with liquid droplets, overcome the surface tension of the latter and, as a result, adhere to them. Once inside the liquid droplet, the particle is more effortless to remove from the gas than when it is floating freely in it, because the liquid droplets are both larger in size and about 1,000 times the density of the gases. 25 There are many different devices for wet treatment of gases. Wet cyclones, in particular, have been widely used in which the gas to be treated is rotated by feeding it into a cylindrical dust separator with a tube tangentially fitted thereto or with a vortex blade mounted therein, consisting mainly of air guide flanges and purifying water. The fine liquid droplets sprayed from the nozzles, together with the dust particles adhering to them, are forced by centrifugal force against the wall of 35 cyclones, from which the liquid flows into the settling tanks.

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Due to its simple structure, the cyclone described above has gained widespread use in various fields of industry. However, this device does not guarantee sufficient cleaning power (their cleaning power does not exceed 90-92% when the dust is in the fine-5 supports), which must be attributed mainly to the relatively low speed achieved by the gas in the cyclone. Increasing this rate to achieve more efficient kinematic coagulation would result in quite high energy consumption and increase operating costs.

Another disadvantage of the above-mentioned device, which also results in its low cleaning efficiency, is the spray system included in the device, as it is not possible to distribute the liquid droplets evenly over the entire flow of gas due to the relatively large space inside the cyclone. In addition, the nozzles are located relatively close to the outflow point of the cyclone, so that the sprayed liquid does not have enough time to catch solid particles floating in the gas.

The above drawbacks have been partially eliminated in the gas pre-cleaning device described in U.S. Patent No. 3,696,590, which comprises a cyclone and gas-liquid mixing devices for applying gas to liquid droplets, which means that there is a separate device connected to said cyclone via an angle connector. . The gas-liquid mixing device has a liquid collector connected to the gas duct, the channel having a somewhat uniform cross-section (although its inlet part is made in the shape of a nozzle with its largest cross-section 30 partially covered by a cylindrical wall of the liquid collector). The purification water is led to a gas duct inlet with a much smaller cross section than the cyclone dome. As a result, the liquid droplets are more evenly distributed across the cross-section of the gas flow, and the combined "collision time" of the gas and liquid is longer due to the smaller gas flow distance, including the gas channel, angle connector and cyclone.

The device described above is characterized by a relatively low hydraulic resistance (about 200 mm of water column) which improves its efficiency. I

The cleaning power of this device is somewhat higher than that of the above-mentioned wet cyclone cleaner. However, the relatively low gas flow rate in the gas-liquid mixing channel does not allow this device 10 to achieve cleaning power values that meet current health standards (generally higher than 98%).

The dilemma of achieving higher cleaning efficiency has been more successfully addressed in a solution called 15 Venturi gas pre-cleaner.

Among these is a gas pre-cleaning device, comprising a cyclone with an inlet and outlet pipe and a gas-liquid mixing channel for injecting contaminated gas into the cleaning liquid, connected to the cyclone and made in the form of a venturi. The gas-liquid mixer is provided with a liquid collector from which the liquid is led along spray lines to a gas duct located in said venturi. The gas duct of the gas-liquid mixer is connected at the outlet end to the cyclone inlet pipe, can be compared to e.g. Polish Patent No. 63,414, Cl. 12 2 (01, 1973).

This device is characterized by a high cleaning efficiency (98% or more) which is possible in the form of a sensible gas-flow channel with a constriction (throat) located at a point which narrows from the inlet pipe to the throat (this part is called the nozzle) and from the throat to the outlet. between the expanding point (called the decomposer).

Such a shape of the gas channel causes the gas flow to be treated through the throat to accelerate 10 times higher than the acceleration of the cleaning liquid droplets sprayed therein. Thus, due to the different velocities present in the venturi, the gas flow to be treated has to pass through, as it were, a filter chamber consisting of fine droplets of cleaning liquid injected into it. As the cleaning liquid passes through the nozzle, its degree of misting increases considerably, as a result of which the surface area of the cleaning liquid encountered by the contaminated gas also increases considerably. In the throat of the gas channel, the pressure drops, causing a velocity difference between the liquid droplets and the gas to be treated. The high velocity (on the order of 40 to 150 m / s) at which the gas is treated causes it and the cleaning fluid to interact in the venturi, increasing the kinematic coagulation efficiency of the solid particles in the gas. In addition, such a gas flow rate in the throat 15 is subject to intense turbulence, as a result of which the solid particles not only stick to the liquid droplets, but also to each other, forming larger particles which can already be more easily separated and removed from the gas. This same turbulence motion also causes the droplets charged by the particles 20 to coalesce.

The particles continue to collide with and adhere to the liquid droplets in the diffuser, which is the most important step and provides a steady flow of gas along the travel portion through which the gas flow rate corresponds to that required to feed it into the cyclone.

It should be noted that the droplets charged with the particles and the free-flowing (not yet adhered) as they are directed into the cyclone are distributed over the entire cross-sectional area of the gas mass flowing in, which in a certain sense makes them difficult to capture and separate.

The gas flow channel, which is designed to meet the requirements of efficient trapping of particles and liquid droplets, causes both high hydraulic resistance (400-500 mm water column) as a result of the vortex phenomenon, which occurs in part at points 5 73894 between the nozzle and the throat, into the throat and diffuser that high energy costs when driving gases through this type of device.

It is also not worth anything that the Venturi pre-5 cleaner guarantees high cleaning efficiency provided that the gas supply rate is constant, this when it is difficult to ensure. As a result, the device described above, as well as other devices of this type, is equipped with automatic gas feed rate control, which complicates the 10 devices to make them large, given that the device described above includes a separate cyclone and gas-liquid mixer.

Furthermore, although in the device described above, the liquid droplets are more evenly distributed on the cross-sectional surface of the gas stream, for example in the above-mentioned cyclone precleaner, part of the cross-section of the gas duct is not wetted by the washing liquid. In cases where the cross-section of the gas channel is large, the above-mentioned drawback considerably reduces the kinematic coagulation of the solid particles suspended in the gas. This explains precisely the fact that a venturi diameter greater than 500 mm is not recommended (cf. "Spravochnik po pyle i zoloulavlivaniyu" pod redaktsiey Rusanova, M., 25 "Energiya", 1975, p. 118).

As can be seen from the above description of previous devices, improving the cleaning efficiency of these devices results in higher energy costs, a more complex structure, and a larger size.

It is an object of the present invention to provide a gas pre-cleaning device in which by changing the shape and location of the gas channel a higher cleaning power, lower energy consumption, a smaller size of the device and a simpler structure are achieved. This object is achieved by a gas pre-cleaning device according to the invention, characterized in that the inner side wall of the gas flow channel, which is curved with respect to the central axis of the cyclone, together with the outlet pipe forms a liquid supply chamber for pre-cleaning.

5 Such a gas flow channel allows simultaneous processes to take place in the preceding devices. The kinematic coagulation process caused by the high velocity of the gas flow channel in the throat and the separation process caused by the centrifugal force, which occurs as the gas flow travels along the curved path and forces the high density particles to the outer edge of the gas flow channel. As a result, the particles, once entering the cyclone, are already close to its wall, which contributes to the conditions for their separation and removal. At the same time, this allows solid particles suspended in the gas to be separated from the gas at lower speeds than in Venturi purifiers. The lower the velocity with kaa flow, the lower the energy requirement to achieve it (after all, it is known that the energy requirement increases per square square of velocity).

The curved design of the gas flow channel and the arrangement to rotate the central axis of the cyclone make the latter a solid unit compressed into a small space.

25 Another advantage of the device shown is that its operation is not affected by fluctuations in the flow of the gas being treated. It has been found experimentally that the deviations of _ + 50% from the estimated gas supply do not practically change the cleaning result. This can be accounted for by the fact that the gas flow is compressed by centrifugal force so that the effective cross-sectional area of the gas flow channel does not mean that the cross-sectional area through which the gas flows is virtually unchanged and does not depend on the internal cross-section of the gas flow hub. Therefore, the present invention does not require methods for controlling the gas supply, which in turn simplifies its structure.

Thus, in pursuit of the same cleaning efficiency as in previous devices, the device presented here consumes less energy, is smaller in size and simpler in structure.

In a preferred embodiment, the upper and lower walls of the gas flow channel extend from the inner side wall 10 toward the central axis of the cyclone and are secured to an outlet pipe running along the central axis of the cyclone so that its inlet is lower than the outlet and chamber. from the upper and lower 15 walls and the inner side wall of the gas flow channel, is provided with at least one inlet connection and acts as a liquid collector.

It is obvious that such a collector structure simplifies the structure of the whole device, since a specially made collector and its associated connectors are not necessary. In this case, the openings in the inner side wall of the duct serve as shower ducts.

This wall is a divider that may have the shape of a geometric pattern known as a longitudinal section. Such a 25-wall structure provides a flexible transition from the mixer to the throat and from the throat to the diffuser, which eliminates the subjects of the vortex phenomenon at this point. In its simplest form, the inner side wall of the gas flow channel is made in the shape of a circular cylinder eccentrically with respect to the central axis of the cyclo 30 ion, in which case the gas flow channel has one throat (in the plane passing through the central axes of the cylinder and cyclone).

According to an alternative embodiment of the present invention, the inner side wall of the gas flow passage 35 is shaped to have an elliptical section of length S 73894. In this case, the gas flow channel has two cucumbers (in a plane running along the major axis of the ellipse) and can be comprised of two venturi connected in series, providing a two-stage 5-stage gas cleaning that may be required when particularly high cleaning power is required.

Most preferably, the inner sidewall of the gas flow passage is shaped in longitudinal section in the form of a geometric pattern substantially formed by two intersecting Archimedean helices arranged so that the line passing through the intersections is substantially at right angles to the inlet mounted tangentially to the cyclone. It has been shown that, with certain geo-15 metric parameters, such a shape of the inner outer wall of the gas flow channel provides an optimal ratio of gas flow rates between the narrow and wide points of the two-phase gas flow channel bounded by said wall. The above parameters are the direction of the coils and the placement of the na-20 pins.

It is expedient for the spray passages to be guided tangentially to the gas flow channel relative to the inner side wall surface towards the gas flow and directed towards the outlet end of the gas flow channel. Directed tangentially to the gas flow passage 25, the liquid jet provides additional energy to the gas particles which have slowed down their passage through the inner side wall of the gas flow passage, for which a so-called boundary layer blowing, preventing boundary layer flow-30 at high gas flow rates, leading to an increase in hydraulic resistance. The tangential fit of the jet duct does not prevent the liquid droplets from being evenly distributed over the entire cross-sectional area of the gas stream, since under centrifugal force the droplets reach the opposite wall, thus passing through the entire flow of the gas stream.

Il 9 73894

It is useful if the outermost side wall of the gas flow channel has at least one tangentially directed channel for the immediate removal of trapped particles from the gas flow.

In this case, the heaviest particles floating in the gas, which are forced against the outer side wall by centrifugal force, drift out with the same force through said outlet, i.e. at the beginning of the curved gas flow paths, preventing the particles from returning to the gas stream and improving the cleaning efficiency of the device.

The invention will now be described with reference to various embodiments thereof, shown in the accompanying drawings, in which: Figure 1 is a general view, partly in section, illustrating one embodiment of an apparatus according to the invention in which a cyclone wall acts as an outer outer wall of a gas flow channel.

Fig. 2 is a sectional view of the section IV-IV of Fig. 1.

Fig. 3 is a general view, partly in cross-section, illustrating one alternative variant of the device according to the invention with a side supply of cleaning liquid and in which the gas flow channel has a rectangular cross-section.

Fig. 4 is an enlarged longitudinal view of the gas flow passage of the device of Fig. 3 with the inner side wall made in the shape of a cylinder.

Fig. 5 is an enlarged longitudinal sectional view of the gas flow channel associated with the device in Fig. 3 in the case where the inner side wall is made in the shape of an ellipse.

Fig. 6 is an enlarged longitudinal sectional view of the gas flow passage of the device shown in Fig. 3 in the case where the inner side wall of the gas flow passage is made to follow the geometric shape of two intersecting Archimedean helices.

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Fig. 7 is a longitudinal section of the gas flow channel of the device according to the invention with a tangential side supply of cleaning liquid.

Fig. 8 is a longitudinal section of a gas-flow channel according to the invention with a tangential side supply of cleaning liquid and in which the inner side wall of the gas flow channel is made of separate plates.

Fig. 9 is a longitudinal section of the gas flow channel of the device, in which an opening is placed for the pre-removal of the trapped particles 10.

Fig. 10 is a partial longitudinal section of a device according to the invention provided with an outlet connection pipe and a recirculation channel.

Fig. 11 is a section from XIII to XIII in Fig. 15.

The gas pre-cleaning device includes a cyclone 1 for separating the solid particles suspended in the gas and a gas-liquid-mixing device 2 connected to the cyclone 1 and in which the solid particles are trapped by means of liquid droplets. The cyclone 1 has a jacket body 3 covered by a cover 4.

The jacket body 3 includes a compartment 5 made in the shape of a vertical cylinder and adapted to impart a vortex motion to the gas. Attached to the bottom of the cylindrical part 5 of the jacket body 3 is a conical funnel 6 for removing sludge 25. The cyclone 1 has an inlet pipe 7 (described later) and an outlet pipe 8 located at the top of the body cylinder and intended as an outlet duct for purified gases. The outlet pipe can be positioned in several ways, as will be shown later.

The gas-liquid mixing device 2 has a gas flow channel 9 with varying cross-sections, including a throat 10 and a compartment 11, referred to herein as a nozzle, which tapers towards this throat and a compartment 12 which expands from the throat 10 towards the outlet channel and is referred to herein as a diffuser.

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The gas flow channel 9 curves the central axis of the cyclone 1. At its outlet, the duct 9 is connected via a port 13 to the sink of the cyclone and the inlet end of this gas flow duct is connected to an inlet pipe 7 mounted tangentially to the curved outer wall of the gas flow duct 9 together with this wall to form a substantially integral structure. Such an arrangement of the inlet pipe 7 is preferable, since the latter directs the gas flow to the vortex movement, whereby the inlet connected tangentially to the gas flow channel 9 does not create additional hydraulic resistance in the flow path of the gas to be treated.

The cross-sectional area of the gas flow channel 9 can be shaped in many ways and the channel can be constructed as a separate curved tube either inside or outside the cyclone.

The gas-liquid mixing device 2 also includes a liquid-liquid collector 14 which communicates with the gas flow channel 9 via the spray passages 15. As shown in Figures 1 and 20 2, the manifold 14 is made in the form of a jet and mounted on the control inlet pipe 7. As will be seen, the manifold 14 can be constructed and positioned in another way.

In various embodiments of the device according to the invention, seen in Figures 1-6, the gas flow channel is arranged to follow a helical line (which is expedient from a hydrodynamic point of view, as such a structure provides a more flexible outlet for the gas flow from the cyclone 1 where a continuous helical surface 1 at the top. The cylindrical part 5 of the jacket body 3 as the wall of the cyclone 1 acts as the outer wall of this channel part, which makes the device simpler and pressed into a single piece.

In one embodiment of the device according to the invention in Figures 1 and 2, the inner side wall has a curved profile at the cross-sectional point of the gas flow channel 9. In this embodiment, the outlet pipe 8 is arranged along the center line of the cyclone 1, the inlet 17 of this pipe being below the outlet 13 of the gas flow channel 9, which prevents the gas from escaping before cleaning.

The lid 4 of the cyclone 1 is made in the form of a screw plate and attaches the jacket body 3 of the cyclone 1 to the outlet pipe 8.

According to a variant of the present invention, Figures 3 and 4, the cross-sectional area of the gas flow channel is rectangular (Figure 3), which is desirable in the interest of simplicity in the manufacture of the device. The upper wall of the channel 9 is built together with the cyclone cover 4, as in the previous embodiment, in the form of a screw plate. This inner side wall 6 in the longitudinal section of the gas flow channel 9, congruent with the cross-section of the device, is in the shape of a circular cylinder arranged eccentrically with respect to the wall of the cyclone 1. It is natural that a side wall 16 of this shape is more effortless during the manufacturing step.

The smallest cross-section (throat) of the duct 9 and the largest cross-section of the same duct 9 formed in the plane A to A passing through the wall 16 of the wall 16 of the cyclone 1 and the wall 16 of the gas flow duct 9, which should preferably coincide with the cross-section of the inlet pipe 7, A is perpendicular to the baseline of the inner surface of this inlet tube.

The lower wall 18 of the gas flow channel 9 (Fig. 3), made like a jacket 5, extends in the shape of a screw damper from the inner side wall 16 towards the central axis 30 of the cyclone 1 and is connected, like the cover 4, to the outlet pipe 8. Shaped to the jacket 5 extension and wall 18 on one side and between the wall of the gas flow channel 9 and the wall of the outlet pipe 8 on the other, there is a chamber acting as a liquid collector 14. The collector 14 is provided with an inlet-35 connector 19 mounted on the cover 4 for supplying cleaning fluid to the collector 14. The holes made in the wall 16 in the zone of the throat 10 act as spray paths 15.

Fig. 5 shows a longitudinal section of the gas-5 flow channel 9, in which, according to a modification of the invention, the inner side wall 16 in the gas flow channel 9 is formed as an ellipse, resulting in two cucumbers 10 in the gas flow channel 9. Half of the gas flow channel 9 is connected , one side of the same channel to the nozzle 11.

In general, the longitudinal section of the gas flow channel in the above case can be thought of as similar to the longitudinal section of the venturi in series. Comparing which structure 15 proves to be more advantageous, it can be seen that the latter is smaller in size and easier to build. It can be stated with certainty that the best hydrodynamic properties, with such a wall 16 structure, are characteristic of a device modification in which the angle of the ellipse between the base line of the tangentially arranged inlet tube 7 and the main axis B to B is 60 °, in which case the nozzle length to diffuser the length in each stage of the gas flow channel (if the first stage of the channel is part of an arc with a length of 180 °, measured from the intersection of the inlet pipe C to C and the second stage is the next part of the channel with an arc length equal to the first) is 1: 4 and coincides with the optimal ratio of the lengths of the known straight venturi nozzle and diffuser.

The gas flow channel 9, the longitudinal section of which can be seen in Figure 1, offers even better hydrodynamic properties. The wall 16 in this longitudinal section of the gas flow channel has a geometric shape formed by two intersecting Archimedean helices so-35 overcome so that the line E - E passing through the intersection of the helices at right angles or at least near the right angle tangentially to the cyclone 1 relative to the baseline of the inner surface.

The gas flow channel 9, thus formed 5 between the wall 16 and the wall of the cyclone 1, also has two stage sections in which the cucumbers 10 pass somewhat laterally from the plane F to F through the central axis of the cyclone 1 and the hubs P of the coils.

In this case, ideal conditions have been created for the kinematic coagulation in the gas flow channel 9 by arranging the coils such that their radial vector R increases as it gets closer to the outlet tube of the gas flow channel, and the poles P are spaced 0.4 D, where D = cyclone in the cylindrical part 5) and is located in a straight line passing through the central axis of the cyclone 1 (in the plane F to F) and forms an angle α = 60 ° with respect to the base line of the inner surface of the inlet pipe 7, in which case the nozzle 11 and diffuser 12 are in all stages of the gas flow channel 9 in a ratio of 1: 4, where the ratio of the smallest cross-sectional area (throat 10) of the gas flow channel 9 to the largest cross-sectional area in the channel is 1: 5, which corresponds to the optimal ratio in similar rectilinear venturis.

With a flue width of the gas flow channel 9 equal to 25 0.2 D, which corresponds to the optimal size of the annular space between the wall of the cylindrical part 5 belonging to the jacket body 3 of the cyclone 1 and the outlet pipe 8 (diameter d is recommended to be selected d = 0.6 D, cf. "Spravochnik po pyle i zoloulavlivaniya "pod redaktsiey Rusanova," Energiya "M, 30 1975, p. 62) the throat width in this case is 0.2 D: 5 = 0.04 D. With such a size and structure of the wall 16 of the gas flow channel 9, the liquid collector 14 consists of two separate from a chamber, each of which is therefore provided with its own inlet connector (not visible) for supplying cleaning fluid.

li 15 73894

According to the modification shown in Figures 7 and 8, the spray passages 15 are arranged in the gas flow channel 9 tangentially with respect to the surface of the inner outer wall 16, pointing inside the channel and directed towards it to the outlet opening 5. This is the preferred orientation of the spray passages 15, as such passages, as shown below, are capable of reducing the hydraulic resistance in the gas flow channel 9.

As can be seen in Figure 7, each of the spray passages 10 15 is a gap between the surfaces of the wall 16 and the plate 20 and has a curved shape and is tangentially mounted on this wall at the discharge opening made therein.

Figure 8 shows an alternative structure of tangentially directed spray ducts 15. According to this variant, the inner outer wall 16 of the gas flow channel 9 is made of separate plates 21 connected to its upper and lower walls so that the beginning of each successive plate is covered by the end of the previous plate the gap between the plate 21 20 acts as a spray channel 15.

Figure 9 shows a further modified structure of the proposed device, in which the outer outer wall of the gas flow channel 9 is connected to the wall of the cyclone 1 in the cylindrical part 5 of the jacket body 3 and also has tangentially directed channels 22 for immediate removal of trapped particles from the gas flow channel. The number and location of these channels may vary, but preferably their number and location are selected based on the cucumbers of the gas flow channel 9. It is justified 30 to fit each channel 22 immediately after the throat 10 in the direction of the gas flow, since the particles at this point have a maximum velocity and have enough energy to exit the channel 22 through the channel 22. Each channel 22 is a gap between the cyclone 1 and the jacket plate 23 and has a curved shape and is mounted tangentially to this wall at an opening in the wall. The channel 22 can also be constructed in another way f, for example in the form of a nozzle, fixed tangentially to the wall of the cyclone 1.

Figures 10 and 11 show a modification of the proposed device 5 in which a return circuit 24 is placed to return still free particles to the gas stream. The duct 24 is formed by a sleeve connecting the outlet pipe 8 and the inner side wall 16 of the gas flow duct 9. In order to reach and separate solid particles from the gas and remove them from the cyclone 1, the device is provided with a gas lock made in an annular shaft 25 inside the outlet pipe 8. This shaft is separated from the central zone of the outlet pipe 8 by an outlet connecting pipe 26, which is partly inside the outlet pipe 15 and fixed to this position by a cover 4 attached to the outlet connecting pipe. The inlet of the connecting pipe 26 is under the return circuit 24. The return pipe 24 is guided in the throat 10 of the gas flow channel 9 so that when the gas flows at a high speed, a thinning zone is created in the return pipe 20, pulling solid particles from the area around the outlet pipe 8. It is obvious that when there are two or more cucumbers in the gas flow channel 9, each of these cucumbers can be connected to the outlet pipe 8 via the return circuit 24.

25 The proposed gas cleaning device operates as follows.

The gas to be cleaned is passed through the inlet pipe 7 to the gas flow channel 9, which is a part of the device, and at the same time cleaning water is sprayed from the supply pipe 7 through the collector 14 and the spray nozzle. Kinematic coagulation occurs in the gas flow hub 9 in a manner similar to that of straight venturi tubes. At the same time, within the gas flow channel 9 and due to its arc shape, the separation of particles (both liquid and solid) floating in the gas occurs, a process similar to that which takes place in a cyclone. Due to the fact that both processes take place simultaneously, the particles move to the circumferential zone by centrifugal force as soon as they have passed through the nozzle 11 in the gas flow channel 9. At throat 10, both the gas and liquid velocities increase, causing centrifugal forces. incrementally, as the centrifugal force increases, adapting to the neural dependence of growth. When these forces act, those of the solid particles which weigh more than the gas are forced to the outer edge of the outer wall of the gas flow channel 9. Inside the body jacket 3 of the cyclone 1, the purified gas discharged from the diffuser 12 of the gas flow channel 9 is driven through a port 13, which, unlike the connecting pipes of the previous devices, does not cause additional hydraulic resistance in the gas flow. At the entrance to the interior of the cyclone 1, solid particles can be found in its circumferential zone. The droplets of liquid charged with the particles flow down along the walls of the cylindrical part 5 and the funnel-shaped body 6 of the body 3 of the cyclone 1 into a pellet drum or 20 into any suitable container (not shown). The gas thus purified flows upwards and leaves the device through the outlet duct 8. Two important processes taking place simultaneously in the gas flow channel 9 make it possible to separate particles 25 of comparable fineness at a much lower gas flow rate than in a straight venturi. As a result, all other factors being similar, the same cleaning power with the proposed device is obtained with lower hydraulic losses and therefore also with lower energy costs than with the previous devices. It has been experimentally proven that there is no practical effect on the cleaning efficiency with reasonable variations (_ + 50%) in the dispersed gas feed rate for cleaning, which is also an advantage of the proposed device, as it can be used without supply control devices that 73894 throw extra hydraulic resistance.

The gas flow passage 9 performs the functions of at least three units as part of previous gas pre-cleaning devices, namely a gas-liquid mixing chamber, a trap for trapping droplets, the operation of which in previous devices is performed by a cyclone and a vortex chamber for circulating gas flow . It is natural that such an arrangement simplifies the gas pre-cleaning device 10 as a whole.

The operation of the device shown in Figures 3 and 4 is characterized in that the cleaning liquid is sprayed into the gas flow channel 9 through the spray passages 15 as radially directed openings to the outer side wall 16 in the gas flow channel 9 at its throat 10. The liquid droplets, which are heavier than gas under the action of the centrifugal force generated by the gas stream advancing in the vortex, run towards the outer side wall in the gas flow channel 9, pass through the throat 10 size. Therefore, the proposed device 25 of this construction may include gas flow channels with 2 large cross-sections (larger than 250 cm). Thanks to the centrifugal forces acting on the liquid jets, the pressure applied to the inlet 14 of the collector can be reduced and, as a result, energy costs can be reduced.

30 In a device with a gas flow channel 9, shown in Figures 5 and 6, the gas stream passes twice the cleaning stages it enters in the channel 9 according to Figure 4: From the first stage diffuser 12 the gas stream passes to the second stage nozzle 11 and accelerates to its maximum speed II 19 73894 10, in which the cleaning liquid is sprayed into the mixture to mix with the particles which have not become trapped in the first stage of the channel 9 and they drive to the outer outer wall, after which the gas flow passes through the port 13 into the inner part of the cyclone 1. It is clear that such a two-step purification method is more efficient than a one-step one. The same effect has been achieved in the existing gas pre-purifier, which consists of two consecutive venturi tubes (cf. e.g. LR Bogdanov, Ll Kropp 10 " VDNH, May, 1978, pp. 10-11).

The modification of the device shown in Figure 6 provides optimum conditions for the gas flow in terms of the intensity of the kinetic coagulation: the gas flow rate in the throats 10 and in the large parts of the gas flow channel 9 are in a ratio of 1: 5.

In the device with the cross-sectional surface according to Figures 20 or 7, the spraying of the purification water takes place tangentially via the spray passages 15 (in the direction of gas flow).

The cleaning fluid sprayed tangentially to the gas flow passage 9 at a high velocity, separate from the scrubbing of the contaminated gas, which is its main function, provides additional energy on the inner sidewall 16 to the decelerated particles, which eliminates the overflow of the boundary layer. 30 known afterflow-related phenomenon in aerodynamics). Boundary layer displacement causes a large hydraulic energy loss, so boundary layer blowing is of great value in terms of process efficiency. In the described device variant, since the ducts 15 are located along the entire length of the gas-35 flow channel 9, the boundary layer blow by means of these ducts affects the entire flow path of the gas flow. It should be noted that the tangential orientation of the cleaning liquid jets does not prevent the jet from reaching the opposite wall of the gas flow channel 9 under the action of the central force. Therefore, entrapment of liquid droplets and solid particles occurs over the entire depth of the gas stream.

In the device shown in Fig. 9, the heaviest particles are forced to press on the outer edge of the kaa-10 stream by centrifugal force, i.e. the outer wall of the gas flow channel 9, their velocity in the first stage throat 10 accelerated and removed through the outlet channel 22 for immediate removal of trapped particles. The agglomerated and thus heaviest particles removed through the direct discharge channel 15 22 form a significant part of the resulting sludge. As a result, the gas to be treated contains less dust when it reaches the second stage nozzle 11 in the gas flow channel 9. The amount of solid particles in the gas 20 is further reduced in the second stage when a new batch of separated particles is removed through the next outlet 22. Immediate removal of the separated particles reduces the possibility of the particles returning to the gas stream (well possible in a gas with a high particle concentration), thus ensuring a higher efficiency of the purification process. In addition, the presence of an immediate discharge channel 22 is likely to increase the service life of the device, as its operating surfaces thus avoid being subjected to abrasion by the abrasives. Immediate removal of particulates (if equipped) in previous devices has been accomplished by a separate auxiliary device that sucks out the separated particles and is placed between the venturi tubes in the case of a multi-stage gas pre-cleaning device (cf. Bulletin of Chemico-Chemical Construction li 21 73894 / GB / Limited, Ragel House / Twickenham, Middlesex, England, p. 8). However, this method makes the device large and causes additional hydraulic resistance.

Immediate removal of trapped solid particles from the proposed device can be provided at any stage of purification without the need to suck them, as the arrangements described above and the orientation of the direct discharge passages 22 force the particles out by mass tension directed tangentially to the gas flow.

The proposed equipment modification, as in Figures 10 and 11, is characterized by the final stage of the purification process, when the gas, after purifying most of the impurities, passes into the outlet pipe 8. As it flows up to 15 in the outlet pipe 8, the gas stream continues to rotate around the cyclone's central axis. , by centrifugal force, forced on the outer edge of this tube and in the annular cavity 25 formed by the wall of the outlet tube 8 20 and the wall of the outlet connecting tube 26, both of which are concentric with each other and the space closed at the upper end. From this cavity through the return pipe 24, these particles are driven back to the gas transport channel 9 with the intention of having to go through all the successive cleaning operations 25 again. The suction effect is provided by a pressure difference between the annular cavity 25, where the pressure is relatively low, and the throat 10, with which the return circuit communicates, and where, due to the high gas flow rate, a gas thinning zone is formed. To compare the device with previous equivalents, it should be noted that the recirculation system used in previous devices is usually based on a separate device sucking particles aside and directing them back to the gas flow channel (compare e.g. Chemico Bulletin, pages 8, 9, 12, 13 ).

22 73894

Meaningless, although each of the device modifications with tangentially directed spray passages, direct exhaust passages, and return circuit is described and illustrated separately (Figures 7-11) showing the possibility of their separate use, all of these modifications can be combined into one and the same device ( not shown).

Once certain modifications of the invention have been shown and described, many modifications will obviously occur to those skilled in the art and are therefore not intended to limit the invention to the described modifications or parts thereof, but may be used as a starting point for applications within the spirit and scope of the invention. defined.

The pre-cleaning device according to the invention has a high cleaning efficiency, is adapted to a small space, has a simple structure and is economical in operation. The cleaning efficiency in the device is 99.4 - 99.9% and the hydraulic losses do not exceed 200 mm of water column. 20 The disclosed gas pre-purification device may have extensive use in the chemical, power and metallurgical industries for purifying gas from mechanical contaminants. The proposed device is also suitable for other uses where intense variation of heat and mass is required.

Il

Claims (7)

An apparatus for gas purification, comprising a cyclone (1) having an inlet pipe (7) and an outlet pipe (8); and a device (2) for contacting the gas with a liquid, said device being connected to the cyclone and comprising a liquid collector (14) communicating through a radiator channel (15) with a gas flow channel (9) having cross-sectional sites which have different shapes, and are curved in relation to the central axis of the cyclone, and on the inlet side with the inlet tube, and in which the wall of the purification apparatus forms the outer side wall (5) of the curved gas flow channel, characterized in that gas flow 9) the inner side wall (16), which is curved in relation to the central axis of the cyclone (1), together with the outlet tube (8) forms a feeding chamber for the liquid to be purified. 2. Apparatus according to claim 1, characterized in that the upper and lower wall of the gas flow channel (9) extends from the inner side wall towards the central axis of the cyclone (1) and is attached to an outlet tube (26) extending along the central axis of the cyclone (1). means that its inlet opening is located lower than the outlet opening of the gas flow passage (9), and a chamber bounded by the wall of the outlet tube (8), portions of said upper and lower wall, and the inner side wall of the gas flow opening (9) is provided with at least one (19) and acts as the liquid collector (14). 3. Apparatus according to claim 1, characterized in that the inner side wall (16) of the gas flow channel (9) is in the form of a round cylinder and is arranged eccentrically in relation to the center axis of the cyclone (1). 4. Apparatus according to claim 1, characterized in that the longitudinal section of the inner side wall (16) of the gas flow channel (9) is elliptical.