RU2803224C2 - Device and method for fluid medium cleaning - Google Patents

Abstract

FIELD: fluid purification.

SUBSTANCE: invention relates to a device for removing solid or liquid impurities from a fluid stream by means of centrifugal forces and to a method for removing solid or liquid impurities from a fluid stream. Device (1) comprises inlet pipe (2) having inlet (3) for receiving an incoming fluid flow, vortex section (4) whose diameter decreases in the flow direction; moreover, the vortex section contains at least one internal helical wall (6), forming at least one helical channel; annular outlet section (8) having at least one peripheral outlet (9) and outlet pipe (10) located coaxially with inlet pipe (2). Annular section (8) of the outlet connects inlet pipe (2) to outlet pipe (10). Inlet pipe (2) additionally contains separating section (7) having a constant diameter and length at least five times greater than the width of the helical channel of vortex section (4) and located between vortex section (4) and annular section (8) of the outlet. The width of the helical channel is defined as the distance between inner helical walls (6) forming said at least one helical channel. The vortex section contains body (5) of the core, passing along the central axis. Core body (5) has the first end (27) expanding in the flow direction, an intermediate section having a constant diameter, and the second end (28) tapering in the flow direction and passing into separating section (7).

EFFECT: removal of solid or liquid impurities from the fluid flow by means of centrifugal forces.

13 cl, 7 dwg

Description

FIELD OF TECHNOLOGY TO WHICH THE INVENTION RELATES

[1] The invention relates to the field of fluid purification. More specifically, the invention relates to a device for removing solid or liquid impurities from a fluid stream by means of centrifugal forces and to a method for removing solid or liquid impurities from a fluid stream.

BACKGROUND OF THE ART

[2] Removing pollutants from the air is a long-standing problem, the importance of which is greatly increased by the pollution problems of today. The main technical solution for separating solid particles from a fluid stream is a cyclone.

[3] Complex air purification applications require development of the cyclone concept. Various screw separators have been developed containing screw channels within the gas pipeline and outlets for solids-reduced and solids-rich streams, respectively.

[4] EP 0 344 749 A2 discloses a separation device suitable for use in treating a gas stream containing particles, for separating particles from a gas, or for purifying a gas from particles. The device comprises an outer pipe having an inlet end, a vortex generation area and a separation area; and an internal exhaust pipe to remove purified air from the device. The vortex generating region has a central core and helical blades located around the core, and has a constant diameter or divergent diameter. The outer pipe and the exhaust pipe are concentric, and between the pipes there is an exhaust hole running along part of the circumference. Particles in the feed stream arriving at the inlet end are set into rotational motion and are transferred to the periphery of the outer pipe. The particle-enriched stream exits the outlet, while the particle-depleted stream exits through the exhaust pipe.

DISCLOSURE OF THE INVENTION

[5] An object of the present invention is to provide a device for separating solid particles or liquid droplets from a fluid, hereinafter referred to as a “separator”. The separator includes an inlet pipe having an inlet for receiving a flow of fluid, and a vortex section, the diameter of which decreases by direction of flow. The vortex section contains at least one internal wall defining at least one helical channel. Preferably, the vortex section is conical, tapering in the direction of flow.

[6] Preferably, a helical channel surrounds a core body extending along the central axis of the inlet tube. The core body has ends of different diameters, widening in the direction of flow at the upstream end and tapering in the direction of flow at the downstream end. The intermediate portion of the core body may have a constant diameter. In one embodiment, the intermediate portion of the core body may be divergent, preferably tapering in the direction of flow. The end sections of the core body of different diameters preferably have a conical shape.

[7] The first end of the core body, which expands in the direction of flow, controls the incoming fluid containing particles and droplets in the screw channel in a laminar manner, with the particles and droplets of the flow moving in even parallel layers upstream without mixing with each other. The other end (terminal end) of the core body, tapering in the direction of flow, stabilizes the flow exiting the screw channel towards the outlet section. Laminar flow and stabilization of the flow at the outlet of the screw channel are of particular importance in order to ensure that the clean flow enters the outlet pipe, and the solids-rich flow is in turn directed to the outlet(s) around the outlet pipe.

[8] Preferably, the fluid guide vanes are connected to a screw channel at the upstream end of the core body. Such fluid guide vanes facilitate the rotation of the flow from vertical to rotational, thereby helping the flow settle and reduce pressure loss.

[9] The separator further comprises an annular outlet section having at least one peripheral outlet, preferably a plurality of outlets separated by wall portions, and an outlet pipe extending along a central axis. Thus, the outlet pipe is located next to the outlet(s) or between them, i.e. in the case of multiple outlets, they are located around the outlet pipe. The expression ''ring'' in this context includes both bodies that have rotational symmetry and bodies that do not have rotational symmetry.

[10] The outlet section connects the inlet pipe to an outlet pipe located coaxially with the inlet pipe. Preferably, the separator includes a separating section located between the swirl section and the outlet section, which is preferably substantially free of internal structures. The separating section may have a constant diameter.

[11] According to another embodiment, the spacer section has either a constant diameter or a divergent diameter. Preferably, the spacer section has a tapering diameter.

[12] The separator and its function in directing the flow of fluid through the device are described below. During operation, the fluid enters the inlet end of the inlet pipe, which may contain an initial section of constant diameter. The fluid is introduced into a helical channel or channels, which are preferably arranged in a helical line along the entire length of the tapered vortex section around the central body of the core. Solid particles suspended in the fluid flow are carried by centrifugal forces to the periphery of the screw channels as the fluid flow passes through the vortex section. One or more outlet channels communicating with the screw channel may be provided on the outer wall of the vortex section. The outlet pipeline exits the screw channel tangentially to the main pipe, carrying a flow of fluid enriched with suspended particles.

[13] When the fluid flow leaves the vortex section, at least a portion of the suspended particles can be removed through additional tangential outlet channels. Then, if a separating section is provided, the fluid flow enters the separating section, which preferably has a constant diameter substantially corresponding to the diameter of the outlet end of the swirl section. Particles accumulate significantly on the outer wall of the pipe as they exit the vortex section and pass through the separation section.

[14] The fluid flow then enters the outlet section, which includes a flange portion connecting the main pipe to the central outlet pipe. The outlet section may comprise one outlet, but preferably multiple outlets separated by wall portions evenly spaced around the periphery of the flange portion. The particle-enriched portion of the fluid stream leaving the vortex section or separation section exits through the peripheral outlet(s).

[15] In that portion of the fluid flow that does not exit through the peripheral outlets, the particle content is reduced and the flow exits the separator through a coaxially positioned outlet pipe.

[16] According to a further embodiment of the present invention, the separator is equipped with a pre-separation unit designed as a cyclone, preferably with a tangential inlet. When reference is made below to the top and bottom of the cyclone, it is assumed that the cyclone is positioned in a position where its central axis is vertical, the inlet is at the top and the outlet for separated particles or droplets is at the bottom end. The pre-separation unit preferably has a basic design in accordance with a conventional cyclone design, comprising a cylindrical body with a main inlet at its top, tapering downwards, preferably a conical bottom and central vertical main outlets for solids down and fluid up.

[17] According to a further embodiment, the cyclone contains, in addition to its primary inlet for fluid containing solid particles or droplets, at least one secondary inlet channel in its upper part. The secondary inlet channel may supply clean fluid. In this embodiment, at least one secondary inlet channel is connected to the dividing section of the separator.

[18] According to a further embodiment, the cyclone includes, in addition to its primary outlet through which fluid exits the cyclone upward along a central axis, at least one secondary outlet at its bottom. In this embodiment, the flow from this outlet exits the device and may be filtered or directed to a dust collector before being released. In another embodiment, the flow from this outlet channel is introduced into the inlet pipe of the separator. This channel can additionally serve to regulate the pressure in the cyclone.

[19] According to a further embodiment of the invention, the vortex section of the inlet pipe comprises on its outer wall at least one outlet opening allowing a part of the flow enriched in particles to leave the vortex section in a direction substantially tangential to the outer wall of the inlet pipe.

[20] The preferred material for the device according to the invention is steel; if operating conditions require it, stainless steel of various grades can be used. Polymeric materials, possibly fiber reinforced, can also be used. Other possible materials are ceramics, powder metal products and coated steels.

[21] A second aspect of the invention is a method for separating solid particles or liquid droplets from a fluid using a device according to the invention, comprising the following steps: introducing a stream of fluid containing solid particles or droplets into an inlet pipe containing a vortex section, the diameter of which is reduced by flow direction, and at least one inner wall defining at least one helical channel around the core body; thus, the fluid flow is driven into a vortex motion; removing a particle- or droplet-rich fluid stream through at least one peripherally located outlet located in the outlet section downstream of the vortex section, and removing a particle- or droplet-reduced fluid stream through an outlet pipe, located coaxially with the inlet pipe.

[22] In a preferred embodiment, the vortex section includes a core body extending along a central axis, a core body having a first end flared in a flow direction; intermediate section; and a second end tapering in the direction of flow.

BRIEF DESCRIPTION OF THE DRAWINGS

[23] FIG. 1 is a schematic side sectional view of a separator in accordance with the invention,

[24] FIG. 2 - perspective view of the flange part of the outlet section,

[25] FIG. 3 is a schematic side view of a separator according to the invention in combination with a cyclonic pre-separator,

[26] FIG. 4 is another schematic side view of a separator according to the invention in combination with a cyclonic pre-separator, rotated 90 degrees about a vertical axis with respect to FIG. 3,

[27] FIG. 5 is a top view according to section AA, as shown in FIG. 3,

[28] FIG. 6 is a detailed side view of the internal structure of the cyclone pre-separator,

[29] FIG. 7 is a cross-sectional side view of a cyclone pre-separator.

IMPLEMENTATION OF THE INVENTION

[30] The invention will now be described in more detail with reference to the accompanying drawings. The same structures are associated with the same reference designations throughout.

[31] As used herein, the term “fluid” refers to any substance that is capable of flowing or deforming under the influence of an applied shear stress or external force. Fluids include liquids, gases and plasma. In particular, the present invention is applicable to removing particulate matter such as dust from gases (air) and particulate matter from liquids.

[32] With reference to FIG. 1 separator works as follows. A fluid stream containing particles or droplets, for example a gas stream containing solid particles, enters the inlet pipe 2 of the separator 1 through the inlet 3. The separator shown has an initial section 11 with a constant diameter. The vortex section 4 contains a core body 5 extending into the initial section 11 and surrounded by a structure containing helical walls 6 forming helical channels that fill the space between the core body 5 and the inner surface of the wall of the inlet pipe 2. The core body has an expanding front end 27 and a tapering rear end end 28. Vortex section 4 tapers in the direction of flow through the separator, which causes the fluid velocity to increase as the fluid passes through the separator. The vortex section has at least one and preferably four helical walls. The walls are preferably angled in the range of 60 to 90 degrees relative to the central axis of the inlet pipe. The distance between the walls, i.e. The width of the screw channels is preferably in the range from 50 to 70 mm.

[33] According to one embodiment, the distance between the walls, i.e. the width of the screw channels has a constant diameter along the entire length of the vortex section. According to another preferred embodiment, the width of the screw channels decreases in the direction of flow.

[34] The swirl section may be provided with one or more outlet channels (not shown) extending from the screw channel in a substantially tangential direction. These outlet channels remove partial flows in which the particle concentration has increased due to centrifugal forces caused by the helical flow path.

[35] The flow direction length of the flared front end 27 of the core body 5 is preferably at least three times the distance between the helical walls 6. The flow direction length of the tapered rear end 28 of the core body 5 is preferably at least four times the distance between the helical walls walls 6.

[36] The preferred core body shape described causes the front end to expand in the direction of flow to direct incoming flow, including particles or droplets, into the screw channel(s) in a laminar manner. The rear end, which tapers in the direction of flow, stabilizes the flow exiting the screw channel(s) to the periphery of the pipe.

[37] In the illustrated embodiment, the fluid flow exits the vortex section into the separation section 7, which includes the rear, tapered portion of the core body 5. As a consequence of passing along the helical trajectory of the vortex section, the flow is in energetic vortex motion, and the particles are highly concentrated at the periphery, i.e. adjacent to the pipe wall. Preferably, the length of the separating section 7 is at least five times greater than the distance between the helical walls of the vortex section.

[38] The particle-enriched portion then collides with the outlet section 8, which in the illustrated embodiment comprises a first flange portion 12 and a second flange portion 13 that are bolted between respective end flanges (not specified) of the inlet pipe 2 and the outlet pipe 10. Construction flange part 13 is shown in FIG. 2. In this embodiment, the flange portions have four symmetrically arranged outlet passages 15, which are angled to receive the vortex flow adjacent to the inner wall of the separating section.

[39] Thus, the particle-enriched portions of the flow leave the separator through the outlets 9 in the outlet section 8, while the remainder of the fluid, in which the particle content is reduced, enters the outlet pipe 10 and leaves the separator through the outlet 14 The outlet pipe may have a constant diameter or expand in the direction of flow. Preferably, the outlet pipe has a conical shape, expanding in the direction of flow.

[40] In FIG. 3 and 4 are side cross-sectional views of a separator 1 according to the present invention connected to a cyclone pre-separator 15. FIG. 4 is rotated 90° around the vertical axis relative to FIG. 3.

[41] In FIG. 3 and 4, a particle-containing fluid, herein referred to as “dusty air,” enters 16 and is introduced into the cyclone pre-separator 15 tangentially at the top of the cyclone, as is known in the art. Thus, the fluid flow is driven in a downward helical motion, as schematically shown by the helical line in FIG. 4. Particles accumulate on the wall of the cyclone and sink to the bottom at 17.

[42] The resulting stream of pre-cleaned fluid exits the cyclone in an upward motion through the vertical central outlet pipe 18 and is transported to the inlet 3 of the separator 1 by the primary fan 19. After passing through the separator 1, as shown in FIG. 1, the purified stream is forced into 20 using a secondary fan 21.

[43] In the illustrated embodiment, the particle-rich portions exiting the separator outlet section are recirculated to the top of the cyclone pre-separator through conduits 22. Preferably, the recirculation conduits 22 are arranged symmetrically in the cyclone riser 25, as shown in FIG. 5, which is a top view of section AA shown in FIG. 3 (only one pipeline 22 is provided with the reference symbol in FIG. 5).

[44] Conduits 22 may supply additional clean fluid to the cyclonic pre-separator instead of recycled particle-enriched fluid from the separator.

[45] Preferably, the conduits 22 terminate in nozzles 26 directing flow to the inner surface of the cyclone wall, as shown in more detail in connection with FIG. 6.

[46] FIG. 3 and 4 further show a secondary outlet 24 at the bottom of the cyclonic pre-separator 15. From this outlet, a conduit 23 directs a secondary flow directly to the inlet of the separator inlet pipe 2. This arrangement reduces the pressure in the cyclone during operation and makes it possible to separate very fine particles. The preferred secondary stream is 10 to 20% of the fluid stream entering the cyclone. This arrangement significantly improves the performance of the cyclone.

[47] In FIG. 6 shows the arrangement of one recirculation line 22 with a nozzle 26 installed in the riser 25 within the cyclonic pre-separator. Fig. 7 is a cross-sectional side view of a cyclone pre-separator with four recirculation lines 22 and nozzles 26 mounted symmetrically around the cyclone riser tube 25. The nozzles 26 are directed to direct the particle-enriched recirculated flow from the separator outlet section into a downward helical flow at the cyclone wall.

[48] Although not shown in the figures, the instruments may be installed as implemented by one skilled in the art. For example, control valves, pressure sensors, and digital control equipment may be provided to control, for example, secondary flow into conduit 23.

[49] It should be understood that the disclosed embodiments of the invention are not limited to the specific structures, process steps or materials disclosed herein, but are extended to equivalents thereof as would be recognized by those ordinarily skilled in the relevant fields of technology. It should also be understood that the terminology used herein is used only to describe specific embodiments and is not intended to be limiting.

[50] Reference throughout this specification to “one embodiment” or “embodiment” means that the particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the expressions “in one embodiment” or “in an embodiment” throughout this specification does not necessarily refer to the same embodiment.

[51] As used herein, a plurality of elements, structural elements, compositional elements and/or materials may be presented in a general list for convenience. However, these lists should be interpreted as if each member of the list is individually identified as a separate and unique member. Thus, no individual member of such a list should be considered to be the actual equivalent of any other member of the same list solely on the basis of their representation in the overall group, without indication to the contrary. In addition, various embodiments and examples of the present invention may be mentioned herein, along with alternatives for various components thereof. It is understood that such embodiments, examples and alternatives should not be construed as factually equivalent to each other, but should be considered as separate and distinct representations of the present invention.

[52] Additionally, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, many specific details are set forth, such as examples of length, width, shape, etc., in order to provide a thorough understanding of the embodiments of the invention. One of ordinary skill in the art will recognize, however, that the invention may be practiced without one or more specific details or using other methods, components, materials, etc. In other cases, well-known structures, materials, or operations are not shown or described in detail to avoid complicating aspects of the invention.

[53] Although the given examples illustrate the principles of the present invention in one or more specific applications, it will be apparent to those of ordinary skill in the art that numerous changes in form, use, and implementation details can be made without the exercise of inventive skill and without deviations from the principles and concepts of the invention. Accordingly, it is not intended that the invention be limited except as provided by the claims set forth below.

[54] The verbs “contain” and “include” are used in this document as open-ended restrictions that do not exclude or require the presence of unspecified features. The features specified in the dependent claims of the invention can be freely combined with each other, unless explicitly stated otherwise. In addition, it should be understood that the use of the singular grammatical form throughout this document does not preclude plurality.

Claims (25)

1. Device (1) for separating solid particles from a fluid medium, containing an inlet pipe (2) having: - inlet (3) for receiving the incoming fluid flow, - vortex section (4), the diameter of which decreases in the direction of flow; wherein the vortex section contains at least one internal helical wall (6) forming at least one helical channel; an annular outlet section (8) having at least one peripheral outlet (9), and an outlet pipe (10) located coaxially with the inlet pipe (2), while the annular section (8) of the outlet connects the inlet pipe (2) with the outlet pipe (10), wherein the inlet pipe (2) additionally contains a separating section (7) having a constant diameter and a length at least five times greater than the width of the screw channel of the vortex section (4) and located between the vortex section (4) and the annular section (8) of the outlet holes, wherein the width of the screw channel is specified as the distance between the internal screw walls (6) forming said at least one screw channel, wherein the vortex section contains a core body (5) extending along the central axis; wherein the core body (5) has a first end (27) that expands in the flow direction, an intermediate section having a constant diameter, and a second end (28) that tapers in the flow direction and extends into the separating section (7). 2. The device according to claim 1, in which the helical walls (6), forming the helical channels in the vortex section (4), are installed at an angle in the range from 60 to 90 degrees relative to the central axis of the inlet pipe. 3. A device according to any of the previous paragraphs, in which the distance between the helical walls (6), that is, the width of the helical channels, decreases in the direction of flow. 4. An apparatus as claimed in any one of the preceding claims, wherein the fluid guide vanes are connected to a screw channel at the upstream end of the core body. 5. Device according to any one of paragraphs. 1-4, in which the length of the first end (27) of the core body expanding in the flow direction is at least three times the distance between the helical walls (6). 6. Device according to any one of paragraphs. 1-5, in which the length of the second end (28) of the core body, tapering in the direction of flow, is at least four times the distance between the helical walls (6). 7. The device according to any of the previous paragraphs, comprising a plurality of outlet openings in the annular section (8) of the outlet opening. 8. The device according to any of the previous paragraphs, further comprising a cyclone (15) connected upstream of the inlet pipe (2). 9. The device according to claim 8, containing at least one secondary inlet pipeline (22) in the upper part of the cyclone (15). 10. The device according to claim 8 or 9, comprising at least one secondary outlet pipe (23) at the bottom of the cyclone (15). 11. A method for separating solid particles or liquid droplets from a fluid, including the following steps: - introducing a fluid stream containing solid particles or droplets into an inlet pipe containing a vortex section (4), the diameter of which decreases in the direction of the flow, and at least one internal helical wall (6), forming at least one helical channel, thus bringing the fluid flow into a vortex motion; - removing a flow of fluid enriched with particles or droplets through at least one peripherally located outlet (9) located in the annular section (8) of the outlet downstream of the vortex section (4), - removal of a fluid stream in which the content of particles or droplets is reduced through an outlet pipe (10) located coaxially with the inlet pipe (2), wherein the inlet pipe (2) additionally contains a separating section (7) having a constant diameter and a length at least five times greater than the width of the screw channel of the vortex section and located between the vortex section (4) and the annular section (8) of the outlet, wherein the width of the screw channel is specified as the distance between the internal screw walls (6) forming said at least one screw channel, wherein the vortex section contains a core body (5) extending along the central axis; wherein the core body (5) has a first end (27) that expands in the flow direction, an intermediate section having a constant diameter, and a second end (28) that tapers in the flow direction and extends into the separating section (7). 12. The method according to claim 11, further comprising the step of passing the fluid stream through a cyclone (15) before introducing it into the inlet pipe (2). 13. The method of claim 12, further comprising the step of removing the secondary fluid stream from the bottom of the cyclone (15).