RU2393908C1 - Kochetov's acoustic dust separator - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to dust separation and can be used in chemical, food light industries etc. for purification of dusty gases. Proposed separator comprises cyclone making first dust separation stage, acoustic system and sleeve filter making second dust separation stage. Said cyclone comprises housing, bin communicated by bypass branch pipe with acoustic column case, exhaust pipe with louver-type dust separator fitted at its bottom. Exhaust pipe is communicated air pipe with acoustic column. Said sleeve filter is communicated with acoustic column outlet via air line and flange intended for feeding purified gas into sleeve filter filtration chamber. Filter incorporates temperature pickup arranged in filtration chamber case and emergency dust level pickup arranged in dust collection bin. Filtration chamber outlet box accommodates automatic thermal indicator pickup and manifold with nozzles to be connected to firefighting system. Filter regeneration system comprises valve units incorporating electromagnetic valves, pulse valves with pulse pipes and branch pipes, Venturi nozzles, differential pressure gauge and a set of valves and accessories for feeding compressed air to said valve unit.

EFFECT: higher efficiency of dust separation.

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Description

The invention relates to techniques for dust collection and can be used in chemical, textile, food, light and other industries for the purification of dusty gases.

The closest technical solution to the claimed object is a dust collection unit containing a cyclone containing a housing consisting of a cylindrical and conical parts, a peripheral gas inlet and an axial outlet of the purified gas located in its upper part, an acoustic column with an acoustic oscillator located in the upper part (RF patent No. 2302283) - prototype.

The disadvantage of the prototype is the relatively low efficiency of the first stage of dust collection.

The technical result is an increase in the efficiency of dust collection.

This is achieved by the fact that in the installation of an acoustic dust collecting unit containing a cyclone as a first stage of cleaning the air-gas mixture, an acoustic system and a bag filter, which is the second stage of the dust collecting system, the cyclone comprises a housing, a hopper that is connected bypass to the acoustic housing, while the cyclone contains an exhaust pipe with a louvered dust separator located in its lower part, which is connected by an air duct to the acoustic column with a sound generator located in its upper part 's oscillations and the bottom - a conical baffle washer, wherein the loudspeaker and baghouse interconnected duct, and a bag filter connected to the loudspeaker via the output duct entrance flange for gas to be cleaned into the filter bag filter chamber.

In Fig.1 shows a General view of an acoustic dust removal unit, Fig.2 is a General view of a bag filter, Fig.3 is a profile projection of Fig.2, Fig.4 is a diagram of a pulse filter regeneration system.

The acoustic dust removal installation includes the following main subsystems: a cyclone (Fig. 1) connected to an acoustic dust coagulation system, the output of which is connected to a bag filter (Figs. 2-3), a pulsed bag filter regeneration system (Fig. 4), a system ensure fire and explosion safety of the filter (not shown).

The cyclone contains a housing 1, a hopper 2, which is connected bypass bypass 6 with the housing 4 of the speaker. The cyclone contains an exhaust pipe with a louvered dust separator 3 located in its lower part. The cyclone exhaust pipe is connected by an air duct 34 to an acoustic column 4 with an acoustic oscillation generator located in its upper part, and a conical washer 5 in the lower part. The acoustic column 4 and a bag filter are connected between each other by air duct 33.

For the unit to operate in the optimum dust collection mode, the following size ratios must be fulfilled:

- the ratio of the inner diameter D of the cylindrical part of the cyclone body 1 to the diameter d of the outlet pipe lies in the optimal ratio of the values D / d = 1.5 ÷ 4.63;

- the ratio of the inner diameter D of the cylindrical part of the cyclone body 1 to the height of the cyclone H lies in the optimal ratio of the values D / H = 0.13 ÷ 0.135;

- the ratio of the height of the cyclone H to the height of the cylindrical part H _{1 of the} cyclone lies in the optimal ratio of values H / H ₁ = 2.67 ÷ 2.7;

- the ratio of the height of the cyclone H to the height of the conical part H _{2 of the} cyclone lies in the optimal ratio of values H / H ₂ = 1.9 ÷ 2.0;

- the ratio of the inner diameter D of the cylindrical part of the cyclone body 1 to the length l of the outlet pipe lies in the optimal ratio of values D / l = 0.78 ÷ 0.8;

- the ratio of the diameter d of the outlet of the cyclone to the length l of the outlet is in the optimal ratio of d / l = 0.49 ÷ 0.52;

- the ratio of the length l of the outlet pipe to its width B lies in the optimal ratio of l / B = 1.46 ÷ 1.5;

The optimal parameters for sound processing are: sound pressure level in the range 130 ÷ 145 dB, sound frequency in the range 900 ÷ 2000 Hz, sound time in the range of 1.5 = 2.5 s, dust concentration in the gas stream is not less than 2 g / m ³ .

A bag filter (Figs. 2-3) is connected to the output of the acoustic column 4 by an air duct 33 through a flange 15 and a pipe 14 for entering the gas to be cleaned into the filter chamber 7 of the bag filter, which is the second stage of the dust collection system and looks like a cabinet with a convenient recess through the side doors 12 vertically arranged filter elements 24 in the form of filter bags. The control panel 16 for the regeneration of the filter bags is placed outside the chamber 7. The flange 13 for the outlet of the purified gas is located in the chamber 22 of the purified gas located above the filter chamber 7 and has a cross-sectional size equal to the flange 15 for the entrance of the gas to be cleaned into the filter (Fig. 3 )

The chambers 7 and 22 of the filter form its housing together with a simple conical hopper 17 located below them with a double flasher dust collector (not shown) or a conical hopper with an auger 18 with a dust gate 19 with a manual drive with a dust puller and a rotary lock 21, as well as the local remote control 20 auger and rotary lock gate. A single dust level sensor (not shown) is installed on any type hopper.

The filter housing is equipped with a support rack, made in the form of at least three racks 8, rigidly interconnected by horizontal rods 9, and inclined stiffeners 10, one end of which is connected to the racks 8 and rods 9, and the other to the hopper 17 of the filter. On the overpass are rigidly installed and fixed between themselves and the filter housing of the stairs 23 and fences 11.

The ratio of the overall dimensions of the filter with the flyover: height H and length L lies in the optimal range of values H / L = 1.0 ÷ 2.0;

the ratio of the filter height H to the height B of the flyover lies in the optimal range of values H / B = 1.0 ÷ 2.0;

the ratio of the height M of the geometric center of the flange 13 for the outlet of the purified gas to the height N of the geometric center of the flange 15 for the entrance of the gas to be cleaned into the filter chamber 7 lies in the optimal range of values M / N = 1.5 ÷ 2.0.

Filter bags (not shown) are assembled into easily removable cartridges, 6 pcs. In each cartridge, vertically (4 pcs. For light dusts are possible: cartridges - 2 pcs. In a fine dust cartridge, etc.). The filter bags have a rectangular cross-section (total filtration area S _f = 1.4 m ² ). Bag filter elements - flat; they have a rectangular cross-section - 340 × 32 mm, heights of 2 and 3 m. The filters are collected in cassettes, mainly 6 or 4 pieces (cassettes weigh 18 and 14 kg respectively). Filter hoses and cartridges are replaced only with cassettes. A filter element of a similar shape has the following advantages: high compactness; increased degree of regeneration - this is due to the fact that the flat sleeve has less internal volume, which increases injection.

As a material for filter elements of a bag filter, the following can be applied: non-woven polyester reinforced with an internal frame mesh; non-woven aramid reinforced with an internal wire mesh: non-woven thin-fiber polyester reinforced with an internal wire mesh with a special coating; moisture resistant non-woven polyester, hardened with an internal frame mesh, with a special coating; non-woven, hardened with an internal frame mesh polyester, antistatic with oil and water repellent impregnation with a smooth surface; non-woven, thin-fiber polyester, reinforced with an internal wire mesh, with a special coating. Filter bags for filter elements are made of non-woven reinforced filter material (polyester or nomex) with special impregnation.

Cartridge filter elements have dimensions: diameter 327 mm, height 1 m.

The filter elements are made of a special filter cloth and have a larger filtration area compared to a cartridge equipped with six sleeves. The fine-fiber composition of the filter element allows you to get very low rates of residual dust - not more than 0.2 mg / m ³ _.

Cartridge filter elements are used in case of obtaining a high degree of purification and small dimensions of the filter. In the filters, 2 pieces are collected per cartridge (cartridge weight - 10.4 kg).

Filters can also be equipped with: a conical, flat or special hopper, horizontal cyclone, which allows to reduce the input dust load, and provide spark suppression with a gas-air gas cooler, which reduces the temperature of the gas entering the filter; atmospheric air suction valve, as well as shut-off and control valves for installation on gas flues: transport container - dust box; dust collecting devices; dust suction hose (not shown).

The scope of the proposed filter design is the filtration of dry dusty gas environments of low flow rates - from 1100 to 30,000 m ³ / h, when installed in cramped conditions.

Work with high initial dusting and low residual dust content (not exceeding 10 mg / m ³ as standard: when using cartridges with cartridge filter elements or non-woven fine-fiber polyester filter material - up to 0.2 mg / m ³ ; purified air can be dumped directly into shop).

Universality of filters: simple replacement of cartridges with filter elements with cartridges of a different type allows you to use a filter to filter other types of dust (for example, filter heavy and then light dust first).

Pulse filter hose regeneration system with Venturi nozzles and flat rectangular filter hoses allows you to work effectively with sticky, clumping dusts.

Bag filters can be protected from environmental influences. In this case, the filters can be equipped with: a light canopy over the regeneration system and the service platform, a thermally insulated coating of the bag filter housing, a thermally insulated coating of the hopper, shelter of the sub-bin from profiled sheet or heat-insulating sandwich panels (not shown).

The pulse filter bag regeneration system (Fig. 4) includes valve blocks 26 in which solenoid valves 25 are mounted, the input of which is connected to the output of the control controller 32, pulse valves 27 with pulse pipes and nozzles, Venturi nozzles 23, differential pressure gauge 31. connected through the pressure sensor 28 to the chamber 22 for the outlet of the purified gas and through the pressure sensor 29 connected by a communication line 30 to the control controller 32, to the filter chamber 7 for the entrance of the purified gas, as well as a set of fittings for supplying compressed about air to the valve blocks (not shown), and the differential pressure gauge 31 is connected to the control controller 32.

The fire and explosion safety system of the filter (not shown) contains a temperature sensor installed in the filter housing, an emergency dust level sensor installed in the dust collection bin. In the chamber 22 for the outlet of the purified gas a thermal automatic sensor-detector is installed, the inputs and outputs of the sensors being connected to the control controller 32, while in the chamber 22 for the outlet of the purified gas there is a collector with nozzles for connection to a fire extinguishing system, the control unit of which is also connected to control controller 32.

Installation of acoustic dust works as follows.

The dusty gas stream is fed to the inlet of the cyclone. Here it is twisted due to a tangential peripheral input and a screw-shaped cover (not shown), then it is directed along a downward spiral line along the walls of the cyclone body 1. As a result, the dust particles under the action of centrifugal force move from the center of the cyclone 1 to the periphery and, reaching its walls, are transported down to the hopper 2 to collect trapped dust. The purified air is discharged from the cyclone through an exhaust pipe with a louvered dust separator 3. In the acoustic column 4, the sound vibration parameters of which are adjusted from the control unit (not shown in the drawing), dust particles are separated from the air, since under the influence of the sound field and associated vibrational processes occurring in the air, dust particles coagulate, and large particles settle down the columns, from where the air flow enters the cyclone hopper 2 through the bypass outlet 6. At the same time light, finely dispersed fractions of dust particles not captured in the previous stages of purification are retained on a bag filter connected by an air duct 33 to an acoustic column 4.

A reflecting washer (not shown), mounted coaxially with the cyclone body in its middle part, prevents the entrainment of the finely dispersed fraction of dust particles, thereby increasing the efficiency of dust collection.

Then the dusty gas stream enters through the flange 15 (Fig.2-3) to enter the cleaned gas into the filter chamber 7 of the bag filter, which is the second stage of the dust collection system, inside the filter elements 24 in the form of filter bags, where dust is retained on the filter material, and the cleaned air enters the purified gas chamber 22. The flange 13 serves to exit the purified gas and is located in the purified gas chamber 22, which is located above the filter chamber 7.

The pulse regeneration system of the bag filter (figure 4) works in the following order. When filtering gases on the surface of the sleeves, a dust layer builds up, increasing the hydraulic resistance of the filter, i.e. differential pressure between the chamber 22 and the filter chamber 7 (this differential pressure is involved in the regeneration system as a control factor). The differential pressure gauge 31 constantly measures the differential pressure; when the set value is reached (at the set position on the dial), a signal is issued to the controller 32, the latter, in accordance with its program, starts the operation of the pulse valves 26. When the pulse valve 27 is activated, compressed air from this valve block is discharged through the pulse pipe with the nozzle into the Venturi 23 nozzle 23 and, further, inside the sleeves 24 (or cartridges). The presence of pulse nozzles and Venturi nozzles increases the effectiveness of the impact of a pulse of compressed air and provides improved cleaning of filter elements from dust.

All filters are equipped with a compressed air preparation system (not shown) at the entrance to the regeneration system. The preparation system allows the filter to operate from compressed air at virtually any ambient temperature. The regeneration system can be installed with minimal air conditioning: compressed air inlet filter and dehumidifier.

The regeneration system ensures timely cleaning of bags from dust and maintains the nominal gas permeability of filter elements.

With insufficient efficiency of the regeneration system, the hydraulic resistance of the filter increases and the flow rate of the purified gas decreases. At the same time, with an excessive increase in the degree of cleaning of the sleeves during filtering from settled dust, an increased breakthrough of dust through the filter sheet is observed, since the outer side of the sleeve is too “exposed” - the filter layer is removed from it.

Therefore, the regeneration system contains elements that provide tuning of its effectiveness in various operating conditions due to the control controller 32.

The system of fire and explosion safety works as follows.

A thermal detector detector and a collector with nozzles of the fire extinguishing system are installed in the filter chamber 22 because it is an output link in the proposed device, and in order to prevent the spread of flame in case of fire further through the ventilation ducts, these systems are installed here, which will increase reliability and safety the whole device.

The work of the collector with nozzles is carried out according to the principle of opening the emergency electromagnetic water supply valve: when a control signal is supplied to the valve from the control controller 32, the signal from the heat detector detector is processed, which in turn responds to an increase in temperature in the filter chamber 22, up to self-ignition of dust aerosols and filter media filter element.

Claims (1)

An acoustic dust collecting unit containing a cyclone as a first stage for cleaning the air-gas mixture, an acoustic system and a bag filter, which is the second stage of the dust collecting system, characterized in that the cyclone comprises a housing, a hopper that is connected bypass to the housing of the speaker, while the cyclone contains an exhaust a pipe with a louvered dust separator located in its lower part, which is connected by an air duct to an acoustic column with a sound generator located in its upper part oscillations, and in the bottom - a baffle cone, the acoustic column and the bag filter connected by an air duct, and the bag filter is connected to the output of the speaker by an air duct through a flange for the gas to be cleaned into the filter chamber of the bag filter, which has the form of a cabinet with a convenient recess through the side doors of vertically arranged filter elements in the form of filter bags, and the flange for the outlet of the purified gas is located in the chamber of the purified gas located above the filter chamber, and has a size cross-sections equal to the flange for the gas to be cleaned into the filter, which is additionally equipped with a temperature sensor installed in the filter section housing, and an emergency dust level sensor is installed in the dust bin, an automatic thermal detector is installed in the outlet box of the filter section, and in the outlet box of the filter section of the filter there is a collector with nozzles for connecting to a fire extinguishing system, the control unit of which is connected to the control controller, and the reg era tio filter includes manifolds in which the solenoid valves are mounted, which input is connected to the output of the master controller; impulse valves with impulse pipes and nozzles, venturi nozzles; a differential pressure gauge connected through the pressure sensor to the chamber for the outlet of the purified gas and through a pressure sensor to the filter chamber for the entrance of the gas to be purified, as well as a set of valves for supplying compressed air to the valve blocks, and the differential pressure gauge is connected to the control controller.

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