JP4555233B2 - Device for removing particles contained in a fluid flow - Google Patents

Description

  The present invention relates to removal of fine particles contained in a gas. In particular, the present invention takes advantage of certain effects associated with turbulence in special and new ways, and uses purely mechanical means to diffuse dust, haze, which is diffused into a turbulent gas. Facilitates separation and recovery of particles such as smoke and harmful gases.

  It is well known to those skilled in fluid mechanics and related areas that particulates diffusing in a turbulent fluid tend to follow turbulent vortices.

  Separation of very fine particles having dimensions from 0.01 to 100 microns and contained in industrial gases or ambient air requires complex and expensive operations.

  Commonly used devices for this include electrostatic precipitators, various filters and wet precipitators. A gas scrubber is also used to remove harmful gases contained in industrial gas. Cyclone dust collectors have been used in conventional ways to remove particles having dimensions greater than about 5 microns, and in recent years efforts have been made to extend their effectiveness to particles having a size of about 1 micron. It is done all at once.

Patent Document 1 discloses a method capable of removing fine particles diffusing in a fluid flow by using a turbulent mixing effect to separate and collect fine particles by a new special method, In this method, a fluid flow in a turbulent state is passed through a flow path having a free space inside, and a zone freely communicating with the flow path is arranged along this space. The flow is interrupted by a large number of objects placed in close proximity to each other in the middle of this fluid, so that the turbulent flow turns into a viscous flow. Turbulent vortices with particles enter continuously into a zone forming a viscous expanded lower layer and deposit the particles on the surface of the object present in this zone. Particle adhesion to the surface of objects is improved if these objects are static. An apparatus that operates on the above principle of collecting particles contained in a fluid flow will be referred to hereinafter as a “turbulent dust collector”.
WO93 / 15,822

  The present invention discloses a method for separating particles which is not described in Patent Document 1.

  In all of the various embodiments, the dust collection mechanism is the same and relies on turbulent deposition due to vortex penetration. This patent application applies to all embodiments described herein based on the above principles, and to any modifications that may be made in the future. Although several methods for collecting or removing collected dust are described in this document, none are the only methods for removing collected dust. Some are based on purely physical means (utilizing gravity), others are based on mechanical means (screens, screw conveyors, belt conveyors, vibration mechanisms, fast return vibration devices, etc.) Yes. Certain embodiments are utilized for small scale (500acfm = feet / minute) applications, some for medium scale (5000acfm) applications, and others for large industrial units. All of the same basic principle, ie turbulent deposition as described in this specification and patent application WO 93 / 15,822 and British Patent GB 9407441.6. Based on the principle. The majority of the described embodiments, in addition to particle removal, impregnate the turbulent gas stream by impregnating the collection surface with an appropriate catalyst or absorbent such as activated carbon, or upstream of the collection device. It can be used to remove harmful gases by finely spraying water or an appropriate aqueous solution. In the first case, the vortex carries this gas to the collecting surface where the harmful gas reacts or is absorbed. In the second case, fine atomized atomization after absorbing harmful gases is deposited by turbulent deposition. In this case, the turbulent dust collector acts as a wet dust collector. Dry sieving constitutes another application area for turbulent dust collectors. That is, it can be used to recover the dry particles formed during the process.

  Some additional means for enabling particle recovery will now be described with reference to the following attached drawings.

1. First additional means (FIG. 1)
In the first additional means shown in FIG. 1, it is installed at the bottom of the housing as described in document WO 93 / 15,822 or between the bottom 20 of the housing 10 and the lower edge of the plate 18. A relatively large number of plates 18 are placed one after the other so as to cross the plate 18 in the housing, with a gap in between. The gas flows through the flow path 16 in a turbulent state. Some or all of the plates have a large number of slots arranged one after the other to form a space that can be called a “canyon”, and this slot extends through these plates. . The width of each slot or canyon can vary, but is preferably between approximately 3 mm and 10 mm. The spacing between these slots or canyons made in the plate is also variable, but is preferably between about 1 cm and about 30 cm. For test dust ASP200 having a housing width of 61 cm, a gas flow path 16 height of 5 cm, a gas flow rate of 12 m / sec to 18 m / sec, a dust collector length of 3.4 m, and particles having an average diameter of 1.8 μm. During the test conducted, the recovery rate for the plate without “canyon” was 48%, while the recovery rate for plate 18 with 13 “canyons” having a width of 3 mm was 62%.

2. Second additional means (FIG. 2)
In a second additional means for carrying out the separation of the particles shown in FIG. 2, instead of a single transverse plate arranged closely as described in document WO 93 / 15,822, Although a relatively large number of mesh screens 6 can be used, each of these screens is supported by the frame 4, placed one after the other, and placed on a slider 26 attached to the bottom of the duct. The distance between the bottom of the dust collection tray 28 and the lower edge of the screen is approximately 0.5 cm to 2 cm. The pin 2 that will penetrate the screen is attached to the side of the tray 28. In a preferred variant, a metal belt 18 having a width of about 1 cm to 4 cm can be placed in place of the screen on the upper edge of each screen instead of a plate. Each screen can be placed at any spacing from about 0.5 cm to about 5 cm. The screen can be made of fibers, filaments or metal wires, preferably having a diameter from about 0.1 mm to about 1 mm. The screen mesh size can vary greatly, but it will preferably be between about 1 mm and about 10 mm. This arrangement is similar to that described in document WO 93 / 15,822. A gas containing dust enters the housing 10 from the inlet 12 and flows through the flow path 16, and the purified gas is discharged from the outlet 14. There are edges 24 at the entrance and exit. Particles are entrained by vortices generated in the gas flowing through free passages on the screen towards the zone occupied by the screen, where the vortices are attenuated and dust is on the screen mesh (and the upper edge of the screen) The deposited particles fall to the bottom of the apparatus after a sufficient thickness of deposit has been formed. The dust collection tray 28 is attached to a heavy steel plate 52, which is approximately 1 cm, using a bellows 34 that serves as a sealing means for the drive shaft 36 or any other means suitable for this purpose. Is vibrated by a cam 38 with a quick return mechanism via a shaft 36 at an amplitude of about 3 cm and a frequency of about 2 Hz, and this cam 38 is driven by a motor 40. The reciprocating speed ratio reaches about 2 or 3, and the dust collected in the tray is sent to the hopper 46, while the dust continues to be collected without rest. The hopper is emptied by the rotary valve 44. As shown in FIG. 2, the progression is from right to left. Instead of installing the hopper 46 on the inlet 12 side, it is also possible to place the tip on the opposite side of the housing 10, i.e. where the purified gas exits the facility from the outlet. However, in this case, the progression goes from left to right. The use of a screen instead of a plate increases the accessible surface area of the collected particulates, resulting in increased particle recovery. The removal of the dust collected at the bottom of the facility, which is made by vibration using a quick return mechanism, can be applied to a plate without a “canyon” as described in document WO 93 / 15,822. A plate with slots such as those used in one new means can be used in the same way when the plate is used.

3. Third additional means (FIGS. 3, 4, 5, 6, 7, 8, and 9)
In a third additional means for the separation of the particles, instead of a large number of adjacent transverse plates or a large number of screens, a mat consisting of a textile fabric or pad arranged along the turbulent flow of gas in the apparatus. A pad is used. This textile fabric can be based on polyester, glass, metal or ceramic fibers and exhibits a porosity (porosity) in the range of about 0.90 to 0.999 and two adjacent strands. These fibers have a diameter of about 0.001 mm to about 0.1 mm so that the average spacing between the fibers is about 0.5 mm to about 0.1 mm. The pad fibers can be charged with static electricity and / or the pad can be pleated. The thickness of the pad can be from about 1 cm to about 30 cm. This new embodiment of the present invention is somewhat similar to the second additional means described in this document, but it can utilize much thinner collection fibers and as a result than is possible with a screen. It can have a large collection surface, as well as certain advantages in terms of structure and manufacturing. The gas contained in the high-porosity pad forms a viscous, expanded boundary layer into which vortices arising from turbulent gas flows and carrying suspended particles penetrate. The particles are captured by the fibers using any known collection mechanism. In the conventional filter, gas is introduced from one side of the filter medium and is discharged from the other side. As a result, the pressure loss is large and the filter medium is gradually clogged. Mostly flows in open channels along a porous pad, so that the pressure loss is always low, the gas flow rate is fast, stable flow rate and high particle recovery Is also secured.

  3a) In an embodiment of the third additional means shown in FIG. 3, the turbulent dust collector comprises a housing 10, an inlet 12 for a gas containing particulates, a generally horizontally arranged and rim 24 and an outlet 14 for the purified gas. Inside the housing 10, gas flows through the flow path 16 and is a collection that is spaced or continuously vibrated using the fast-return mechanism described in the embodiment shown in FIG. A sheet of fiber pads 30 held by metal wires 32 attached to the dust tray 28 is below the flow path, and the quick return mechanism includes a drive shaft 36 and a bellows 34 or appropriate. These other sealing means, a cam 38 with a quick return mechanism, and a motor 40 are included. Tests performed using glass fiber mats made of fibers of about 30 μm diameter and 10 cm thick and with a porosity of 99.5% are described for the first additional measure. The recovery was able to reach 70% when carried out under the same conditions. This embodiment has the advantage that the dust already collected from the device can be removed continuously and the cost and weight of the mattress can be very small compared to the plate.

  3b) The embodiment shown in FIG. 4 is very similar to the embodiment shown in FIG. This embodiment includes the housing 10, as well as the inlet 12, the outlet 14 for gas and the rim 24, but is centered about an axis inclined about 70 ° from the horizontal. The gas flows through the channel 16 and a sheet of textile fabric 30 held by a cage of metal wires 32 welded to a heavy steel plate 52 is below this channel, and for the embodiment of FIG. The steel plate is vibrated by a drive shaft 36 that is operated with a vibration mechanism 50 that operates at a similar amplitude and frequency as described and is attached to the support 54 but is not necessarily a fast return type. Be made. Bellows 34 or any other suitable means serves as a sealing means for drive shaft 36. A cage made of metal wire slides on the slider 26. Dust away from the fibers due to vibration falls into the dust discharge passage 48 and, due to gravity, falls to the sliding hopper 46 through the bottom 20 of the housing 10 and is discharged from there through the rotary valve 44.

  3c) A third embodiment of the third additional means of the present invention is shown in FIGS. 5a and 5b. Housing 10, inlet 12 and outlet 14, edge 24, gas flow path 16, dust collection tray 28 to which heavy steel plate 16 is attached, slider 26, bottom 20, quick return mechanism 38 including quick return cam, drive shaft 36 Bellows and any other suitable means 34 and motor 40, hopper 46 and rotary valve 44 are all equivalent to the corresponding components of the embodiment described with reference to FIG. 2 of this document. In this embodiment, the textile fabric is used in the form of a belt that is moved at a low speed by a shaft 56 with a pinion (not labeled). Dust is collected by the belt in the upper flow path and is discharged therefrom to the lower flow path by a dust removal shaft 76 which is also equipped with a pinion 104. The shaft is controlled by a motor (not shown).

Dimensions Exemplary dimensions suitable for all embodiments are described below. The width of the housing 10 is 10 cm to 1 m, and preferably about 50 cm, the height of the flow path 16 is 1 cm to 20 cm, and preferably reaches about 5 cm, and the thickness of the fiber mattress 30 is 1 cm to 30 cm. It is preferred to reach and reach about 10 cm. The length of the housing 10 depends on the work to be accomplished and the required recovery rate. The flow rate of the gas in the flow path 16 is 1 m / sec to 30 m / sec, and preferably about 15 m / sec. The rewind cam 38 has a reciprocating speed ratio of about 2 to 3, the stroke is about 2 cm, and the frequency reaches about 2 Hz.

  3d) A fourth embodiment of the third additional means of the present invention utilizing a textile fabric or pad having the above properties is shown in FIGS. 6a and 6b. In this case, the housing 10 consists of a tube 10 with an inlet 12 for a gas containing dust and an outlet 14 with a valve 78 for purified air. Inside the tube 10, the textile fabric 30 is inserted between two concentric tubes made of a medium metal wire grid or thin metal rods. The tube comprising the inner tubular grid 98 constitutes the flow path 16 and is attached to the outer tubular grid 32 by means of a reinforcing head plate 52. The cage is guided by two rods 100 and can move up and down in the middle of the housing 10, which rods 100 are securely attached to the lattice 32, as shown in FIG. Then, it slides in the guide groove 102 provided inside the housing 10. A funnel-shaped conical plate 96 connects the lower end of the outer tubular grid 32 to the lower end of the inner tubular grid 98. The cage composed of the tubular grids 32 and 98, the reinforcing head plate 52, and the conical plate 96 is intermittently reciprocated by a mechanism 50, which can be either a fast return mechanism or a single eccentric ring mechanism. Vibrated. The drive shaft 36 is attached to the reinforcing head plate 52 by a bellows 34 or some other sealing means suitable for that purpose. The dust falls into the hopper 46 and can be discharged from here through the rotary valve 44. The inner tubular lattice 98 has a diameter of 2 cm to 40 cm, preferably between about 10 cm and 20 cm, and the thickness of the textile fabric packing 30 is 2 cm to 15 cm, preferably between about 5 cm and 10 cm; The flow rate of the gas is from 2 m / sec to 30 m / sec. The length of the tubular mattress is 3 to 30 m depending on the work to be accomplished. As is common in the industry, when the gas flow rate is high, a large number of inner tubular grids are attached to the same reinforcing head plate 52, and a series of tubes are fitted in the outer tubular grid of large dimensions, The upper peripheral edge of the grid is attached to the head plate. The gap between the inner tubular lattice and the reinforcing head plate and the outer tubular lattice is filled with fiber fabric. Below each inner tube, at the bottom of the fiber packing, there is a funnel-shaped conical plate, whose upper tip is attached to the grooved bottom of the cage. The entire cage slides inside the housing and is intermittently vibrated by reciprocating motion by a vibrator located at the upper tip of the housing. The dust is sent to the hopper 46 and is discharged from there by a rotary valve. The inside diameter of the gas tubular channel is 20 cm, the length of the tube is 3 m, the flow rate of the gas is 12 m / sec to 18 m / sec, and the glass fiber mattress is composed of fibers with a diameter of about 30 μm and a porosity of 99.5%. In a test carried out on a 10 cm thick layer, the standard test dust ASP200 recovery was 78%.

  3e) A fifth embodiment of the third additional means of the present invention comprising a textile fabric or pad exhibiting the properties described above is illustrated in Figures 7a to 7e. This includes a rectangular housing 10 in which is disposed a rectangular cage 32 which can be freely adjusted and is separated into four equal sections by a sealing partition 90. Dust-containing gas enters from the inlet 12 into a tube made up of a grid made of medium metal wire, but first into compartment 82, then into compartment 84, then into compartment 86, and purification. The done gas finally enters compartment 88 and leaves compartment 88 from outlet 14. The flexible tube 108 shown in the cross-sectional view of FIG. 7c connects the inlet 12 and outlet 14 at both ends of the tube where the septum is made of a grid. The appearance of the housing is shown in FIG. 7b, which also shows the position of the cross section. The upper part of the cage is composed of a reinforcing head plate 52 connected via a drive shaft 56 to a vibration exciter that allows the cage to move up and down. 7d and 7e are two horizontal cross-sectional views of the device, the position of which is shown in FIG. 7b. Dust that has fallen from the fibers due to vibrations enters the hopper 46, where it is discharged by various suitable means such as a screw conveyor. The number of compartments or flow paths is not limited to four as in this embodiment, and may be increased if deemed necessary or appropriate. The dimensions selected in this embodiment are the same as those employed in the above embodiment shown in FIG. This embodiment offers the possibility of utilizing a device whose effective length for the flow path is the same as that selected for the above embodiment, but whose height is very small.

  3f) A sixth embodiment of the fourth additional means of the present invention comprising a textile fabric or pad whose properties are described above is shown in FIGS. 8a and 8b. It consists of several modules formed from two embedded fiber pads 30 approximately 1 cm to 2 cm thick, which are horizontally or vertically spaced 1 to 3 cm apart and have a height The flow paths 16 having a length of about 50 cm and a length of about 50 cm are formed, and the air / gas flow circulates in a turbulent flow through the flow paths 16. According to a preferred example of this embodiment shown in the top view of FIG. 8b, this mattress 30 has folds, which are similar in direction to the screen whose direction is shown in FIG. It is attached in a direction perpendicular to the circulation direction of the turbulent flow of gas / air. Also shown in FIG. 8b is a support edge 24 located at each end of each channel. Another feature of this embodiment is that dust is collected on both sides of the flow path through which the gas / air turbulence passes. This is why this embodiment is called a double-sided dust collector, and the arrangement of the dust collecting pads 30 is similar to the arrangement of the dust collecting electrodes in a plate-type electric dust collector. In this embodiment, several modules (five in FIG. 8) arranged in parallel, such as the modules described above, have a gas / air flow each time air moves from one module to another. They are connected in series by a U-shaped joint so that the direction changes by 180 °. A dusty air / gas stream enters from the inlet 12 and a purified air / gas stream exits from the outlet 14. The fitting fiber pad 30 is inserted into a structure composed of two front plates and four partition walls and housed in the housing 10. The gas / air flow is introduced by a fan 68 attached to the support plate 70. In this embodiment, the fiber pad does not need to be cleaned frequently, which is particularly advantageous for applications such as residential and office air cleaning that contain less particles in the air. For units that require very high recovery rates, a dust collecting pad 30 that is electrostatically charged can be used, whether it is wrinkled or flat, and / or for deodorization In addition, a pad containing an appropriate adsorbent such as activated carbon can be used in place of a certain existing pad. The enlarged variant of the double-sided dust collector of this embodiment can be utilized for industrial gas purification. In this case, however, the dust collection pad must be periodically cleaned by vibration or any other suitable means. In a test unit comprising a channel 16 having a width of 1.3 cm, an effective length of 2.5 m and a wrinkled fiber pad 30 having a thickness of 2.5 cm, and an air flow rate of 6.5 m / sec, the standard test dust ASP200 A recovery rate of 92% could be measured. In the same test unit, which was carried out using a fiber pad 30 having a thickness of 2.5 cm and having static electricity, the dust composed of particles having a diameter of 5 μm and contained in the surrounding air was removed. % Was recovered.

  3g) A seventh embodiment of the third new addition means of the present invention using a textile fabric or pad is shown in FIG. This consists of a helically structured pad 30 which is placed on an impermeable sheet 106. This sheet with a pad on it is wound spirally so as to leave a gap 16 between two successive turns, thus forming two parallel gas flow paths 16. Yes. The helical turbulent dust collector is housed in a cylindrical housing 10 with an inlet 12 for dusty gas at the center of the device and an outlet 14 for purified gas at the cylindrical housing. 10 are arranged in the tangential direction of the outer periphery. The cover of this unit connected to the inlet is not shown in FIG. As can be seen from this figure, this embodiment is also very suitable for air cleaning in residences and offices where the air does not contain much dust. This unit, including those by vibration or suction, only needs to be performed regularly after a considerable amount of time. The width of the air flow path is about 1 cm to 3 cm. The pad thickness is between about 2 cm and 5 cm, and the height of the unit varies from about 10 cm to 50 cm. One advantage of this helical structure is that it is suitable for the emergence of turbulent conditions that exhibit lower Reynolds numbers than those encountered in straight ducts (ie, having a gas with a slower flow rate in a given system). It is that you are. The enlarged deformation of the spiral turbulent dust collector can be used for industrial gas purification. In this case, the dust collecting pad needs to be periodically cleaned by vibration or some other appropriate means. In a test unit including a 1.3 cm wide channel 16 and a 2.5 cm thick fiber pad 30, having a 3 m channel 16 effective length, and an air circulation rate of 2.5 m / sec, a standard test dust ASP200 The recovery rate was 92%.

  In summary, the present invention provides several new structures and methods of implementation that can effectively remove particles of generally very small dimensions suspended in industrial gases or air. . Modifications can be made without departing from the scope of the invention.

It is a front view of the plate arrange | positioned in a housing and used for a 1st additional means. It is a side view with a fracture | rupture part which shows the turbulent dust collector by a 2nd addition means. It is a front view of a quick return mechanism. It is a figure which shows the sieving plate and dust collection tray which are arrange | positioned in the housing. It is a side view of the turbulent dust collector based on embodiment of the 3rd addition means. It is a front view with a several fracture | rupture part of the turbulent dust collector by 2nd Embodiment of a 3rd addition means. It is a side view of the dust collector by 3rd Embodiment. It is a cross-sectional view of a turbulent dust collector according to a third embodiment of the third additional means. It is a perspective view which has several fracture | rupture parts in the turbulent dust collector by 4th Embodiment of 3rd addition means. It is a cross-sectional view perpendicular to the main axis of the turbulent dust collector. It is a perspective view which has a several fracture | rupture part of the turbulent dust collector by 5th Embodiment of a 3rd additional means. It is a figure which shows the position of several cross sections. It is a cross-sectional view along the main axis. It is a cross-sectional view perpendicular to the main axis. It is a cross-sectional view perpendicular to the main axis. It is a perspective view including a fracture | rupture part in the turbulent dust collector by 6th Embodiment of a 3rd addition means. It is a cross-sectional view. It is a perspective view including the fracture | rupture part of the turbulent dust collector by 7th Embodiment of a 3rd addition means.

Claims (8)

A flow path for a fluid flow in a turbulent state and a direction crossing the direction of the flow, having a plurality of edges in contact with the fluid flow, and particles contained in the fluid flow are recovered. In a device for removing particles contained in a fluid flow, including a housing (10) having a plurality of objects forming a stay space between the plurality of edges,
The plurality of objects are elements having ridges whose side faces are in contact with the fluid flow, or any of a fiber pad, a fiber mat, and a fiber fabric in which the plurality of objects are arranged along a gas flow. So that either the edges on either side of the wrinkled element or the fiber pad, fiber mat, or fiber fabric have additional edges for collecting particles. Forming a fluid flow path, wherein the fiber pad, fiber mat, or fiber fabric forms a flow path for the fluid flow, wherein the flow path is tubular, curvilinear, or helical A device that removes particles.   The apparatus according to claim 1, wherein the plurality of objects are sequentially arranged adjacent to each other in a direction different from the direction of the flow.   The apparatus of claim 1, wherein the plurality of objects are charged with static electricity.   The plurality of objects are adjacent mesh screens, each of which is attached to a frame and generally positioned across the direction of flow. Item 1. The apparatus according to Item 1.   The apparatus of claim 1, wherein the plurality of objects are fiber mat fabric, carpet, or cloth.   The apparatus of claim 1, wherein the open channel is inclined to facilitate removal of particles collected in the space by gravity.   The apparatus of claim 1, comprising means for vibrating and / or moving the surface on which the particles are collected to facilitate removal of the particles. The channel is said mat, carpet or fabric, extends between the respective layers, apparatus according to claim 1.

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