RU2103047C1 - Method of aerodynamic suppression of nonorganized dust contaminated effluents and device for its realization - Google Patents

Abstract

FIELD: cleaning of gas flows from dust. SUBSTANCE: aerodynamic suppression and collection of nonorganized effluents of dispersed impurities in zones of operation of screens, elevators, drying and crushing devices, discharging chutes, pouring of dust-forming substances, their transportation by conveyors are realized by provision of cover of nonorganized effluents of dust by thin-walled shields, and direction of flow taken from such zones by air intakes through gas ducts at elevated temperature in the order of 500 C to aerodynamic dust collecting apparatuses. Intake of zone dust effluents is carried out without formation of mutually competitive exhaust flows, and installed at ends of discharging chutes are flexible dust-suppressing gates. In this case, low pressure in dust conduits is built up with respect to ambient pressure and flexible dust-suppressing valves are installed to prevent formation of hydraulic hammers and dust formation. EFFECT: higher efficiency. 6 cl, 10 dwg

Description

 The invention relates to dust removal of gas streams and can be used, in particular, in the metallurgical, cement, mining, metal, chemical and other industries.

 A device of the louvre type for separating dust particles from gas streams is known [1].

 The device reflects a typical version of an inertial dust collector in the form of a conically converging system of plates with slots between them. Such a technical solution, on the one hand, requires the formation of organized flows in the ducts of the flues, and on the other hand, it is not very efficient in capturing dispersed particles due to the existence of turbulent eddies in the canal of the louvre filter, contributing to the removal of contaminants from it into the common duct.

 The aim of the invention is to increase the efficiency of dust cleaning of contaminated gas streams and to reduce the scale of technical structures that implement such cleaning.

 The goal is achieved by the fact that aerodynamic suppression and capture of dusty polluted emissions is carried out by covering their sources and taking air intakes together with part of the surrounding air, after which such emissions are sent to gas ducts and then passed through aerodynamic dust collecting devices based on aerodynamic dust collecting modules as organized flows. moreover, the selection of dusty gases is carried out by the minimum number of air intakes that do not allow the occurrence of fronts of competing elongated flows, while at the ends of the pouring troughs create elastic gates by putting elastic stockings on the open parts of the outlets of such troughs touching the surface of the material carried by the conveyor, thereby regulating the flow rate of the material being poured and forming a column of dust-forming mass above the cut-out of the gutters, which prevents dust emissions, and partially leaving part of them, are captured by air intakes together with a finely dispersed fraction of poured substances that carry dust purification, and sent to the gas duct, after which aerodynamic dust-collecting apparatuses are installed, the finely dispersed fraction of dusted substances with a part of the dust formations is separated and returned to the general material flow to the conveyor, and then the air flow further organized is further refined, while in the channels for processing and movement of dust-forming substances together with the dust mass they create a reduced pressure relative to the external environment by the fact that part of the dusty air is sucked out from the internal objects of the emission sources and they are subjected to dust cleaning in aerodynamic dust collecting apparatuses, while the formation of hydraulic shocks that occur when inhomogeneous masses of materials fall along vertical and inclined troughs by installing elastic dust-absorbing valves in them, thereby reducing focal dust emissions.

 In the device for implementing this method, a dustproof elastic shutter is connected to the end of the gutter in the form of an elastic stocking touching the surface of the material on the conveyor, while an air intake is installed over it, passing into the gas duct connected to the inlet of the aerodynamic apparatus, and the bulk part of the hopper is mounted above the conveyor.

 In FIG. 1 shows a variant of a device for aerodynamic suppression and capture of fugitive emissions of particulate pollutants in the area of dusting and transportation of dust-forming substances; in FIG. 2 - a device for aerodynamic suppression and capture of dust emissions associated with the simultaneous operation of the screen, gutters, conveyors, crushing unit and elevator for delivering material to the screen; in FIG. 3 is a diagram of an aerodynamic dust collecting apparatus connected to an air flow drawing channel, and made in the form of an aerodynamic wave dust collector; in FIG. 4 is a diagram of an aerodynamic dust collecting apparatus based on aerodynamic dust collecting modules; in FIG. 5 is a diagram of asymmetric profiles; in FIG. 6 - symmetric profiles; in FIG. 7 - ruled updated profiles; in FIG. 8 - embodiment of the apparatus with two columns; in FIG. 9 is an embodiment of an aerodynamic dust collecting apparatus; in FIG. 10 is an embodiment of an apparatus with a dust collecting bin formed by a cavity extending beyond the flue circuit.

 The device for aerodynamic suppression and capture of fugitive emissions contains an extended bulking channel 1, dust-forming substance 2, a mobile conveyor 3, an air intake 4, a gas duct 5, an aerodynamic concentrator of dispersed particles, an aerodynamic dust-collecting module 6, a dust removal nozzle 7, a deposition hopper 9, an inclined hopper 8, an inclined hopper 8, aerodynamic dust collection module 10, dust removal nozzles 11, dust collecting hopper 12, inclined dusting tray 13, fan inlet manifold 14, fan 15, aerodynamic dust collection module 16, dust removal nozzles 17, precipitation hopper 18, inclined pouring tray 19, suction manifold 20, ejector 21, high-pressure nozzle 22 adjustable slot gap 23, elastic dust-proof shutter 24.

 The operation of the device is as follows.

 The gutter 1 is not only the carrier of the poured fine material, but also a dust component formed on the basis of this material. A larger and less volatile part of the material is poured onto the conveyor 3, in particular of the tape type.

 To eliminate the possibility of dust flow outside the conveyor, all types of competing air intakes are excluded except for one operating in the zone of direct exit of bulk material from the groove 1. To this end, the air intake 4 is installed so that the jet flows of entrained air and dust inclusions pass from the cavity of the groove 1 and the surrounding space into the cavity of the air intake 4, which then passes into the gas duct 5. A similar formation of flows in a given direction is provided by the limitation of the area di air intake and increase the speed of the taken dust and gas flow.

 Under these conditions, the volatile mixture of dust particles formed in the previous sections of the technological chain, as well as in the trough itself, is pulled out and organized in an aerodynamic dust-collecting module 6, which in this case acts as a conveyor for returning the captured dispersed mass of material to the chain its production. At the same time, a concentrated and compacted stream of particles of the working substance and dust, having passed the dust removal pipe 7, is deposited in the dust precipitation hopper 8, and then rolls down the inclined tray 9 without dust formation into the general product transportation stream to the conveyor 3.

 Thus, the first part of the device provides a barrier to the release of dust into the environment from the zone of powder filling. Such an obstacle is achieved by localizing the intake of dust and gas formations with a significant pressure gradient formed at the exit of the gutter 1. At the same time, part of the working substance is captured along with the dust, which is then returned to the conveyor.

 After suspending the spatial atomization of particles and transferring them to an organized stream, they are then captured by subsequent stages of the dust collecting devices.

 Their basis, similarly to the first stage of dust suppression, are aerodynamic dust collection modules 10 and 16.

 So after the dust collection module 10, concentrated dust through the pipe 11 is sent to the dust collecting bin 12, and then through the inclined tray after opening the shutter again returns to the conveyor 3. The outgoing gas stream through the manifold 14 is directed to the air intake part of the fan 15.

 The last stage of post-treatment of air from dust inclusions is realized using the third aerodynamic dust collection module 16 connected from the outlet side of the fan with an increased pressure of the outlet stream. Then, through the nozzle 17, the hopper 18 and the inclined tray, the remaining dust is returned to the conveyor.

 To form a draft of the dust and gas mixture from the hopper 18, an air discharge is created in it relative to the cut of the nozzle 17 by connecting its cavity through the manifold 20 to the inlet of the fan 15.

 Similarly, the problem is solved for the hopper 12. In the first case, the dust particles carried out from the hopper 18, after the implementation of the dust collection cycle again fall on the input of the dust collection module.

 The vacuum in the most dust-loaded bunker 8 can be created by connecting to the inlet duct 5 through the ejector 21 connected to the source of high air pressure through the pipe 22.

 The efficiency of the capture of dust is regulated by a gap gap 23 in the duct 5.

 FIG. 2 illustrates the operation of the device for aerodynamic suppression and capture of dust emissions associated with the simultaneous operation of a screen, gutters, dusting substances, conveyors, a crushing unit and an elevator for delivering material to a screen.

 In particular, it includes a screen 25, an elevator 26, an elevator shaft 27, a crushing unit 28, a conveyor 29, a sprinkling chute 30, a material return chute 31, an elastic dust blanking shutter 32, an elastic stocking 33, an air intake 34, an aerodynamic dust collecting module 35, a dust collecting hopper 36, connecting gas duct 37, aerodynamic dust collecting module 38, dust collecting hopper 39, air intake duct 40, plate dust-collecting valves 41, air intake 42, aerodynamic dust collecting apparatus 43, gas duct 44, gas weaving unit 45, as well as the outlet pipe 46.

 The process of dust suppression and dust collection is as follows.

 Finished products, sifted out of the screen 25 from the material fed through the elevator 26 from the crushing unit 28, are poured onto the conveyor (conveyor) 29 through the chute 30. The non-sifted part of the material from the screen 25 is returned to the process through another chute 31.

 Dust suppression in the material discharge zone is ensured by the inclusion of an elastic dusting shutter based on an elastic stocking worn on the end of the chute 30 and touching the surface of the products being transported with the conveyor. This solution leads to the formation of a column 33 of dust-forming mass above the output cut of the trough 30, limited by the area of output. This pillar locks out dust formations accompanied by hydrodynamic disturbances.

 The dust part, which is nevertheless formed in the material discharge zone, is captured by the air intake 34 and sent to the aerodynamic dust collection module 35. After separation in it, the dust stream settles in the dust collecting bin 36 installed directly above the conveyor 29, and then automatically returns to the conveyor through its shutter .

 To exclude the removal of dust from the screen 25, a reduced pressure is created inside it. The latter is achieved by drawing dusty air not only through the groove 30, but also through the channel 40 of the groove 31.

 The elongated stream is sent to the second dust collecting module 38 with a hopper 39, which through the connecting duct 37 is sequentially transferred to the first module 35.

 To reduce the effects of hydraulic shocks that occur when the masses of the substance fall, lamellar dust extinguishing valves 41 are introduced into the channel of the gutter 31.

 To suppress dust emissions from the elevator 26 and its shaft 27, a vacuum is also created inside them by drawing air flows into closed channels through an air intake 42, which is connected to an aerodynamic dust collecting device 43.

 The general pulling of the gas flows through the modules 35 and 38 is provided by the fan 45 with their subsequent direction to the outlet pipe 46.

 The technical construction of the aerodynamic dust collecting apparatus connected to the channel for drawing air flows through the elevator is illustrated in FIG. 3 and 4.

 It is presented in two parts: in the form of an aerodynamic wave dust collector 47 and a block of binary aerodynamic modules 48 with a dust collection hopper 49 (Fig. 3).

 The design of the aerodynamic wave dust collection module consists of a part of the gas duct 50, at an angle to which taps 51, 52 and 53 are connected, connected to a common bulking shutter 54.

 In the areas of the joints of the outlets with the gas duct 50, fairings 55 are installed, adjustable in angular position. The action of such fairings leads to the formation within the flue 50 of a wave-like trajectory of jet flows, stationary attached to the channel of movement of dusty gas environments.

 Under conditions of rarefaction formed in the bends, the separated mass of dust particles separated at the fronts of the wave formations is deposited and accumulated over the bulking gate, as in dust-collecting bins. When the shutter opens, the accumulated dust is poured into the place of its disposal.

 A particular technical solution for an aerodynamic dust collecting apparatus based on aerodynamic dust collecting modules is shown in FIG. 4.

 In it, a package of dust collecting modules 56 is represented by binary options. Such binary aerodynamic dust collection modules are designed as inserted into a single axisymmetric casing 57 coaxially with two aerodynamic concentrators 58 and 59 with a conically or wedge-shaped converging system of shaped rings or plates forming their aerodynamically matched pairs. Such pairs form lateral gas outlets with preliminary separation of dispersed particles from it in the zone above the gap between the elements of such pairs as shown in FIG. 5, 6 and 7.

 A distinctive feature of smoothly changing profiles of individual elements of pairs with a stepped cut at the outlet is the sufficiency of the length of the sections in front of the stepped cut parallel to the axis of symmetry, providing axial acceleration of particles to the velocities of the gas phase flow.

 The design with the axial alignment of the concentrators 58 and 59 makes it possible to convert the uniform dust distribution over the input section of the block 58 into a narrowly directed one at the input of the block 59, as a result of which the degree of purification is increased compared with the effect obtained from the action of two sequentially installed modules with one concentrator each.

 The package of modules 56 can be installed horizontally or obliquely between the inlet dust collector 60 and the outlet 61 through connecting taps 62 and 63. Both columns are formed by two adjacent cavities 64, 65, 66 and 67 (Fig. 8).

 In the area of their connection with the inlet of the gas duct 68 and the outlet 69, fairings 70 and 71 are mounted. Similar fairings 72 and 73 are also inserted at the joints of the nozzles 62 and 63.

 Both columns have hermetically acting gates 74 and 75. With dusty air in the zones of wave-shaped flow path formation, dust particles will separate and accumulate in the capacities of the column bases. Their accumulated mass can be discharged through grooves 76 and 77.

 Concentrated dust is removed from the battery of modules 56 through a hollow pillar 78 passing into the base of the dust collecting bin 79.

 In FIG. 9 and 10 show embodiments of aerodynamic dust collecting apparatuses combined with wave aerodynamic dust collectors. Their basis is the continuation of the flues 80, along which a system of aerodynamic dust concentrators 11 is installed. The cleaned dust stream is removed through the extensions of the flues 82 or 83.

 The dust mass from the concentrators 84 through the dust extraction pipes 84 and 85 is collected in the dust collecting hoppers 86 or 87. In the first case (Fig. 9), its base is an isolated cavity 86 located coaxially with the gas duct 80 and ending through the inclined ramp 88 with the 89 outlet.

 In the second embodiment (FIG. 10), the dust collecting bin is formed by a cavity extending beyond the flue 83.

 In this case, the dust pipe 85 has a direct entrance to the hopper 87 instead of the side as shown in FIG. 9. The collected dust from the hoppers is discharged through the gates 90 or 91 and the chutes 92 or 93.

 The scheme of wave aerodynamic dust collectors is implemented by introducing 81 fairings into the flow inlet zones of the aerodynamic dust concentrators, and in particular in the form of truncated cones 94 and 95 as shown in FIG. 9, 10.

 Columns 96 and 97 are installed behind this zone, as a continuation of the inlet part of the gas duct 80. These columns form cavities with a bottom in the form of bevels 98 and 99, ending with dust extraction 100 or 101 with shutters 102 or 103.

 With this solution, the reversal of the flow of the dust and gas mixture in the installation area of the fairings 94 or 95 under conditions of reduced pressure in the columns 96 and 97 leads to dust deposition in them.

 The remainder of dusting by aerodynamic concentrators 11 in the dust collecting bins.

Claims (6)

 1. The method of aerodynamic suppression and capture of fugitive dust polluted emissions, including the filling of dust-forming substances with pouring gutters and their transportation by conveyors, the source of emissions being covered and taken together with part of the surrounding air by air intakes, after which the emissions are sent to gas ducts and then passed as organized flows through aerodynamic dust collecting devices based on aerodynamic dust collecting modules, characterized in that the selection of emissions they have a minimum number of air intakes that prevent the occurrence of fronts of mutually competing elongated flows, while elastic gates are created at the ends of the pouring gutters by putting elastic stockings on the open parts of the gutter outlets touching the surface of the material carried away by conveyors, thereby regulating the flow rate of the material being poured, and forming higher a cut of the exit of the gutters, a column of dust-forming substances, which prevents dust emissions, and partly their partially exiting part, captures the air intake together with the finely dispersed fraction of the showered substances entraining dust formations and sent to the flue, after which the aerodynamic dust collecting apparatuses are installed, the finely dispersed fraction of the granulated substances with a part of the dust formations is separated and returned to the general stream of materials to the conveyor, and then they are cleaned further organized air flow, while in the channels of movement and processing of dust-forming substances together with the dust mass create a reduced pressure relative to the external environment the fact that part of the dusty air is sucked out from the emission sources and subjected to dust cleaning in aerodynamic dust collecting devices, while the formation of hydraulic shocks that occur when inhomogeneous materials fall along vertical and inclined trenches by installing elastic dusting valves in them is reduced, thereby reducing focal dust emissions .  2. The method according to claim 1, characterized in that when collecting dust using an aerodynamic dust collecting apparatus made in the form of two parts, the first of which form a wave aerodynamic dust collector, for which along the linear part of the common gas duct with respect to its axis gas is installed at an angle outlets, the cavities of which at the ends are combined and limited by gates providing air sealing and periodic filling of the accumulated dust mass, while in the area of the joint of the common gas duct and gas outlets they set angularly-controlled fairings, due to which they change the directions of the jet flows of the gas stream and form it in the form of a spatially stationary wave, within the boundaries of which dust particles are separated and then deposited in gas outlets, simultaneously using them as storage bins, and the second part for the formation of an aerodynamic dust collecting apparatus along a single axis of symmetry in a single axisymmetric casing one after the other after the conical air intake was installed They create two aerodynamic dust concentrators in the form of a periodic conically or wedge-converging system of rings or plates with a smoothly changing internal profile ending in a stepwise cut at the outlet, while the uniform distribution of dust particles in the stream at the inlet section of the first concentrator is transformed into uneven with a narrow axial orientation after which the flows of dust particles and the cleaned air are separated, and then the dust stream through the dust removal unit is sent to the dust precipitation hopper, in which The torus provides reduced pressure, damping of secondary dust formation and precipitation of dispersed particles, and then, after an additional porous filter, part of the air captured with trapped dust is diverted to the source of reduced pressure.  3. A device for aerodynamic suppression and capture of fugitive dust polluted emissions containing a sprinkling chute, conveyor, aerodynamic dust collecting apparatus with a gas drawing unit and a dust precipitation hopper, characterized in that a dustproof elastic shutter is connected to the end of the chute in the form of an elastic material covering the conveyor touching the surface of the conveyor and touching it while an air intake is installed above it, passing into a gas duct connected to the inlet of the aerodynamic dust collecting apparatus, moreover, the bulking part of the hopper is mounted above the conveyor.  4. The device according to claim 3, characterized in that in the presence of emissions in the action areas of screens, elevators, drying and crushing devices, two aerodynamic dust collecting devices are installed in series along the gas duct, while the outlet of the air intake is connected to the input of the second device between connecting it to the first and the inlet of the first is connected to the internal channel of the gutter, sprinkling material from the screen, while lamellar elastic dust extinguishing valves are mounted in it, and the closed part of the screen together with the upper part of the ele a vator, connected at the base with a crusher, is connected to a third dust collector, the first part of which consists of a wave dust collector in the form of a part of the flue, to which hollow side outlets are mounted at an angle from each other, united at the ends into a single outlet with a hermetically acting with a bolt shutter, while in the area of joints with the gas duct, angularly-adjustable fairings are inserted, and the second part of the device is made in the form of a block of aerodynamic dust-collecting modules on Snov aerodynamic dust concentrator, a conically converging or wedge-shaped system of rings or plates inserted axially into the shielding housings.  5. The device according to claim 3, characterized in that it is equipped with an aerodynamic concentrator, a wave aerodynamic dust collector and is made in the form of input and output vertical pairs of columns ending with hermetically acting gates and connected to the input and output manifolds of the duct, while horizontally or inclined between columns establish aerodynamic concentrators connected to the dust precipitation hopper through a hollow pillar, part in the form of a wave dust collector is represented by fairings, a wave manually wrapping dust and gas streams installed in the zones of connections of the inlet and outlet gas ducts with vertical columns, as well as in the zones of inlets and outlets of aerodynamic dust concentrators.  6. The device according to claim 3, characterized in that it is made in the form of a duct section, on the outside of which aerodynamic dust concentrators are placed in a longitudinal vertical or inclined position so that their inlet ends are connected to the duct cavity, while in the end zone of the concentrators dust precipitation bins are installed, including those made in the form of a part aligned coaxially with the gas duct, and the dust collector is formed by fairings, for example, in the form of a thin-walled truncated cone, in the area where the concentrate dust entrails with a cavity formed by the continuation of the part of the flue, bounded below by a hermetically acting shutter.

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