Dust removal device and dust removal system for dust-containing gas with saturated or nearly saturated steam

Abstract

The utility model provides a dust removal device and a dust removal system for dust-containing gas with saturated or nearly saturated steam, which relate to the technical field of dust removal and comprise a vertical centrifugal mixer and a bag-type dust remover, the vertical centrifugal mixer comprises a barrel-shaped shell which is vertically arranged, a mixed gas outlet which is positioned at the top end of the barrel-shaped shell, and a dusty gas pipeline and a hot flue gas pipeline which are positioned on the side wall of the barrel-shaped shell; the dusty gas pipeline and the hot flue gas pipeline are positioned at one end, close to the mixed gas outlet, of the side wall of the barrel-shaped shell; double-end spiral blades are arranged in the barrel-shaped shell, and the dust-containing gas pipeline and the hot flue gas pipeline correspond to lower openings in starting positions of two spiral blades in the double-end spiral blades respectively; a gas inlet of the bag-type dust collector is communicated with the mixed gas outlet; a second conical pipe is arranged at the bottom of the barrel-shaped shell. The problems that in the prior art, dust-containing gas of saturated or nearly-saturated steam dews in a conventional bag-type dust collector, and dust sticks a bag are solved. The water treatment pressure caused by dust removal modes such as spraying is further eliminated.

Description

Technical Field

[0001] This utility model relates to the field of dust removal technology, and in particular to a dust removal device and dust removal system for dust-laden gas that is saturated or nearly saturated with steam. Background Technology

[0002] In the field of pulverized coal pyrolysis, whether it is the drying of coal or the extraction of some water vapor in the low-temperature section of the pyrolysis kiln for pulverized coal containing water, the water vapor contains a large amount of coal dust. The treatment of this dust often employs bag filters, spray towers, impact wet scrubbers, wet electrostatic precipitators, water film cyclone dust collectors, Venturi scrubbers, or air scrubbers.

[0003] When using only a bag filter, if dust-laden gas with saturated or near-saturated steam enters the bag filter where the ambient temperature is low, a large amount of condensate will be generated when the steam temperature is close to the dew point temperature. This causes dust to adhere to the surface of the filter element, resulting in poor dust removal, filter element blockage, and filter failure.

[0004] Similar to spray towers and water film cyclone dust collectors, coal powder with a fineness of less than 100 micrometers, especially when the particles are less than 20 micrometers, is difficult to dissolve in water, the dust is easily scattered, the environment is harsh, and the difficulty and cost of water treatment make it difficult for enterprises to survive.

[0005] Wet electrostatic precipitators are typically used as "fine" dust collectors in conjunction with other wet dust collectors. They have strict requirements on the concentration of dust at the equipment inlet. In addition, they have high energy consumption, complex equipment, high maintenance costs, and are not suitable for hydrophobic dust. In particular, the dust is conductive and can cause production and safety accidents due to the electric sparks generated inside.

[0006] In view of the above, this utility model is hereby proposed. Utility Model Content

[0007] One of the objectives of this invention is to provide a dust removal device for dust-laden gas with saturated or near-saturated steam, in order to solve the technical problems of condensation and dust clogging in conventional bag filters when dust-laden gas with saturated or near-saturated steam is present.

[0008] The second objective of this invention is to provide a dust removal system for dust-laden gas that is saturated or nearly saturated with steam.

[0009] In order to achieve the above-mentioned objectives of this utility model, the following technical solution is adopted:

[0010] In the first aspect, this utility model provides a dust removal device for dust-laden gas that is saturated or nearly saturated with steam, including a vertical centrifugal mixer and a bag filter.

[0011] The vertical centrifugal mixer includes a vertically arranged barrel-shaped outer shell, a mixed gas outlet located at the top of the barrel-shaped outer shell, a dust-laden gas pipe and a hot flue gas pipe located on the side wall of the barrel-shaped outer shell, with the dust-laden gas pipe and the hot flue gas pipe located on the side wall of the barrel-shaped outer shell near the mixed gas outlet.

[0012] The barrel-shaped outer shell is equipped with double-headed helical blades, and the dust-laden gas pipe and the hot flue gas pipe are respectively corresponding to the lower openings of the two helical blades in the double-headed helical blades;

[0013] The air inlet of the bag filter is connected to the outlet of the mixed gas;

[0014] The bottom of the barrel-shaped outer shell is provided with a tapered tube.

[0015] Furthermore, the axis of the dust-laden gas pipe and the axis of the hot flue gas pipe are respectively tangent to the rotation direction of the spiral blades;

[0016] Preferably, the included angle between the axis of the dust-laden gas pipe and the axis of the hot flue gas pipe is 45° to 180°.

[0017] Furthermore, the starting point of the double-headed helical blade is 5 to 20 degrees downward.

[0018] Furthermore, the bag filter is provided with a tube sheet, which divides the bag filter into an upper chamber and a middle chamber. A filter unit is provided on the tube sheet and located in the middle chamber. The air inlet is located on the middle chamber.

[0019] Preferably, the middle box is provided with an upward air guide channel, which is connected to the air inlet;

[0020] Preferably, a second ash hopper for collecting dust is provided below the middle box;

[0021] Preferably, the upper housing is provided with a gas outlet;

[0022] Preferably, the top of the filter unit is provided with a backflushing unit;

[0023] Preferably, the filter material of the filter unit is any one of PTFE, PPS or acrylic.

[0024] Furthermore, the air guiding channel includes a flat plate and a vertical plate, and the vertical plate, the flat plate and the middle box cooperate with each other to form an air guiding channel;

[0025] Preferably, the vertical distance between the top plane of the upright plate and the lower end face of the flower plate is 0.3 to 1 m;

[0026] Preferably, the gas guiding channel is provided with a plurality of flow dividers, which cooperate with the gas guiding channel to disperse the gas in different directions;

[0027] Preferably, the bottom of the manifold is connected to the flat plate, and the top surface height of the vertical manifold is consistent with the top surface height of the air inlet;

[0028] Preferably, the plurality of the diverter plates are distributed in a fan shape along the surface of the flat plate.

[0029] Furthermore, the air guiding channel is a pipe structure;

[0030] Preferably, the vertical distance between the plane of the air outlet end of the pipe structure and the lower end face of the tube sheet is 1 / 3 to 1 / 3 of the diameter of the pipe structure;

[0031] Preferably, the pipe structure includes a vertical straight pipe and an elbow, with one end of the elbow connected to the air inlet and the other end of the elbow connected to the bottom of the vertical straight pipe.

[0032] Furthermore, the top of the barrel-shaped outer shell is provided with a conical tube, and the outlet of the mixed gas is located at the top of the conical tube.

[0033] Preferably, the outlet of the mixed gas is connected to the inlet via a pipe.

[0034] Secondly, this utility model provides a dust removal system for dust-laden gas that is saturated or nearly saturated with steam, including the aforementioned dust removal device, induced draft fan, and dust collection equipment. The induced draft fan is connected to the outlet of the bag filter, and the dust collection equipment is located below the dust removal device.

[0035] Furthermore, the dust collection and recovery equipment includes a finished product silo, which is connected to the conical pipe II and the ash hopper II respectively;

[0036] Preferably, the dust collection and recovery equipment further includes a closed belt conveyor connected to the finished product silo;

[0037] Preferably, the finished product silo is connected to the conical pipe via a screw unloader or a disc-type airlock unloading valve;

[0038] Preferably, the finished product silo is connected to the ash hopper via a screw conveyor or a disc-type airlock discharge valve.

[0039] Furthermore, the induced draft fan is connected to the gas outlet via pipe two.

[0040] This invention provides a dust removal device for dust-laden gas containing saturated or near-saturated steam. The hot flue gas duct and the dust-laden gas duct correspond to the spiral channels formed by two spiral blades in a double-headed spiral blade system. This allows the hot flue gas and dust-laden gas to be mixed in a vertical centrifugal mixer, especially during gas reversal, achieving thorough mixing of the dust-laden saturated or near-saturated steam and the hot flue gas, transforming it into dry dust-laden gas. This allows it to filter dust normally, similar to a dry dust collector, and essentially eliminates the water treatment pressure associated with this gas. This invention offers significant advantages over any other dust removal solution. It solves the problems of condensation and dust clogging in conventional baghouse dust collectors when using dust-laden gas containing saturated or near-saturated steam. Furthermore, it eliminates the water treatment pressure associated with spray dust removal methods, offering significant advantages over any other dust removal solution. Attached Figure Description

[0041] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0042] Figure 1 A schematic diagram of the structure of a dust removal device and dust removal system for dust-laden gas containing saturated or near-saturated steam, provided by this utility model. Figure 1 ;

[0043] Figure 2 A perspective structural diagram of the vertical centrifugal mixer provided by this utility model;

[0044] Figure 3 A schematic diagram of the air guiding channel in the bag filter provided by this utility model;

[0045] Figure 4 A schematic diagram of the air guiding channels in a bag filter with multiple parallel arrangements provided by this utility model;

[0046] Figure 5 A schematic diagram of the structure of a dust removal device and dust removal system for dust-laden gas containing saturated or near-saturated steam, provided by this utility model. Figure 2 .

[0047] Icons: 1-Dust-laden gas duct; 2-Hot flue gas duct; 3-Vertical centrifugal mixer; 31-Barrel-shaped outer shell; 32-Double-headed spiral blades; 33-Conical tube one; 34-Conical tube two; 4-Pipe one; 5-Bag filter; 51-Upper housing; 52-Tube plate; 53-Middle housing; 54-Air inlet; 55-Dust hopper two; 56-Air guide channel; 561-Flat plate; 562-Vertical plate; 563-Diverter plate; 57-Filter unit; 58-Gas outlet; 59-Backflushing unit; 6-Pipe two; 7-Exhaust fan; 81-Screw unloader; 82-Disc-type airlock unloading valve; 9-Enclosed belt conveyor; 10-Finished product silo. Detailed Implementation

[0048] Unless otherwise defined herein, the scientific and technical terms used in connection with this utility model shall have the meanings commonly understood by one of ordinary skill in the art. The meaning and scope of terms shall be clear; however, in any case of potential ambiguity, the definitions provided herein shall prevail over any dictionary or foreign definitions. In this application, unless otherwise stated, the use of "or" means "and / or". Furthermore, the use of the term "comprising" and other forms is non-limiting.

[0049] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0050] This utility model provides a dust removal device for dust-laden gas that is saturated or nearly saturated with steam, including a vertical centrifugal mixer 3 and a bag filter 5.

[0051] The vertical centrifugal mixer 3 includes a vertically arranged barrel-shaped outer shell 31, a mixed gas outlet located at the top of the barrel-shaped outer shell 31, a dust-laden gas pipe 1 and a hot flue gas pipe 2 located on the side wall of the barrel-shaped outer shell 31, with the dust-laden gas pipe 1 and the hot flue gas pipe 2 located on the side wall of the barrel-shaped outer shell 31 near the mixed gas outlet.

[0052] The barrel-shaped outer shell 31 is provided with double-headed spiral blades 32, and the dust-laden gas pipe 1 and the hot flue gas pipe 2 are respectively corresponding to the lower openings of the two spiral blades in the double-headed spiral blades 32.

[0053] The air inlet 54 of the bag filter 5 is connected to the mixed gas outlet;

[0054] The bottom of the barrel-shaped outer shell 31 is provided with a tapered tube 34.

[0055] The hot flue gas duct 2 and the dust-laden gas duct 1 correspond to the spiral channels formed by the two spiral blades in the double-headed spiral blade 32, allowing the hot flue gas and dust-laden gas to be mixed in the vertical centrifugal mixer 3 through vortex mixing, especially during gas reversal. This achieves thorough mixing of the dust-laden saturated or near-saturated steam with the hot flue gas, transforming it into dry dust-laden gas. This allows it to filter dust normally, just like a dry dust collector, and essentially eliminates the water treatment pressure caused by this gas. This offers significant advantages over any other dust removal solution. It solves the problems of condensation and dust clogging in conventional baghouse dust collectors caused by saturated or near-saturated steam dust-laden gas. Furthermore, it eliminates the water treatment pressure caused by dust removal methods such as spraying, offering significant advantages over any other dust removal solution.

[0056] In some specific embodiments, the axis of the dust-laden gas duct 1 and the axis of the hot flue gas duct 2 are respectively tangent to the rotation direction of the spiral blades.

[0057] In some specific embodiments, the included angle between the axis of the dust-laden gas duct 1 and the axis of the hot flue gas duct 2 is 45 to 180°.

[0058] In some specific embodiments, the starting point of the double-headed helical blade 32 is 5 to 20 degrees downward.

[0059] In some specific embodiments, the bag filter 5 is provided with a tube sheet 52, which divides the bag filter 5 into an upper chamber 51 and a middle chamber 53. A filter unit 57 is provided on the tube sheet 52 and is located inside the middle chamber 53. The air inlet 54 is located on the middle chamber 53.

[0060] In some specific embodiments, the middle housing 53 is provided with an upward air guide channel 56, which is connected to the air inlet 54.

[0061] The mixed gas is guided to the upper part of the middle chamber 53 through the upward air guide channel 56, and then turns back downward, which is consistent with the direction of dust falling in the filter chamber, thus improving the dust removal efficiency; otherwise, if the gas moves from bottom to top and the airflow direction is opposite to the direction of dust falling, the dust will repeatedly fall and rise under the influence of the airflow, and be filtered repeatedly, thus affecting the filtration efficiency.

[0062] In some specific embodiments, a second ash hopper 55 for collecting dust is provided below the middle box 53.

[0063] In some specific embodiments, the upper housing 51 is provided with a gas outlet 58. The gas outlet 58 may be located on the top or side of the upper housing 51.

[0064] In some specific embodiments, the top of the filter unit 57 is provided with a backflush unit 59.

[0065] In some specific embodiments, the filter material of the filter unit 57 is any one of PTFE, PPS, or acrylic. Optionally, the filter material includes a filter element or a filter bag, preferably a filter bag.

[0066] In some specific embodiments, the air guiding channel 56 includes a flat plate 561 and a vertical plate 562, which cooperate with each other to form the air guiding channel 56. In some specific embodiments, the vertical distance between the top plane of the vertical plate 562 and the lower end face of the perforated plate 52 is 0.3 to 1 m.

[0067] The vertical distance between the top plane of the vertical plate 562 and the bottom surface of the flower plate 52 can be, but is not limited to, 0.3m, 0.4m, 0.5m, 0.6m, 0.7m, 0.8m, 0.9m or 1m, or any value between 0.3m and 1m.

[0068] In some specific embodiments, the air guiding channel 56 is provided with a plurality of flow dividers 563, which cooperate with the air guiding channel 56 to disperse the gas in different directions, so that the airflow is evenly distributed inside. In some specific embodiments, the bottom of the flow divider 563 is connected to the plate 561, and the top height of the flow divider 563 is consistent with the top height of the air inlet 54. In some specific embodiments, the plurality of flow dividers 563 are distributed in a fan shape along the surface of the plate 561.

[0069] In some specific embodiments, the air guide channel 56 is a pipe structure; in some specific embodiments, the vertical distance between the plane where the air outlet of the pipe structure is located and the lower end face of the perforated plate 52 is 1 / 3 to 1 of the pipe structure diameter. In some specific embodiments, the pipe structure includes a vertical straight pipe and an elbow, one end of the elbow being connected to the air inlet 54, and the other end of the elbow being connected to the bottom of the vertical straight pipe.

[0070] In some specific embodiments, the top of the barrel-shaped outer shell 31 is provided with a conical tube 33, and the mixed gas outlet is located at the top of the conical tube 33.

[0071] In some specific embodiments, the mixed gas outlet is connected to the air inlet 54 via pipe 4.

[0072] To facilitate gas flow rate adjustment, a shut-off valve and a flow regulating valve are installed on the hot flue gas duct 2. This allows for duct opening and closing, and adjustment of flue gas flow rate, changing the mixing ratio of flue gas with dust-laden gas in saturated or near-saturated steam. This ensures the mixed gas has a suitable temperature, maintaining a dry state while ensuring the dust has appropriate humidity.

[0073] According to another aspect of the present invention, a dust removal system for dust-laden gas that is saturated or nearly saturated with steam is also provided, comprising the aforementioned dust removal device, induced draft fan 7, and dust collection equipment, wherein the induced draft fan 7 is connected to the outlet of the bag filter 5, and the dust collection equipment is located below the dust removal device.

[0074] The filtered gas is drawn out by the induced draft fan 7, and the dust collected by the dust removal equipment is recovered by the dust collection device. The system is reliable, requires little investment, is environmentally friendly, and has low operating costs.

[0075] To reduce the difficulty of dust collection, in some specific embodiments, the dust collection and recovery equipment includes a finished product silo 10, which is connected to a conical pipe 34 and an ash hopper 55. The dust collected by the dust collector falls into the finished product silo 10 and mixes with the finished product, allowing the dust (fine coal powder) collected by the dust collector to be directly mixed with the upgraded coal after pyrolysis, becoming the finished product material, which greatly reduces the difficulty of dust collection.

[0076] In some specific embodiments, the dust collection and recovery equipment also includes a closed belt conveyor 9 connected to the finished product silo 10.

[0077] In some specific embodiments, the finished product silo 10 is connected to the conical pipe 34 via a screw unloader 81 or a disc-type airlock unloading valve 82; in some specific embodiments, the finished product silo 10 is connected to the ash hopper 55 via a screw unloader 81 or a disc-type airlock unloading valve 82.

[0078] In some specific embodiments, the induced draft fan 7 is connected to the gas outlet 58 via pipe 6.

[0079] The present invention will be further illustrated by the following embodiments. Unless otherwise specified, the materials in the embodiments are prepared according to existing methods or purchased directly from the market.

[0080] Example 1

[0081] Combination Figure 1 and Figure 2 The dust removal device for dust-laden gas containing saturated or near-saturated steam includes a vertical centrifugal mixer 3 and a bag filter 5.

[0082] The vertical centrifugal mixer 3 includes a vertically arranged cylindrical shell 31. Inside the cylindrical shell 31, there are double-headed spiral blades 32 pointing downwards at 10°. The upper end of the cylindrical shell 31 is provided with an inwardly tapered tube 33. The tapered tube 33 is connected to the air inlet 54 of the bag filter by a pipe 4. Dust-laden gas pipe 1 and hot flue gas pipe 2 are respectively arranged on the cylindrical shell 31 near the tapered tube 33, and are tangentially connected to the cylindrical shell 31 so that the axis is tangent to the rotation direction of the spiral blades and runs through the vertical centrifugal mixer 3. The angle between the center line of the dust-laden gas pipe 1 and the center line of the hot flue gas pipe 2 is 90°. The lower end of the cylindrical shell 31 is provided with an inwardly tapered tube 34, which is equivalent to a dust hopper. A screw unloader 81 is arranged below the tapered tube 34.

[0083] The positions of the dust-laden gas duct 1 and the hot flue gas duct 2 correspond to the lower ends of the two spiral blades in the double-headed spiral blade 32, respectively. The starting positions of the two spiral blades are 90° apart, so the angle between the centerline of the dust-laden gas duct 1 and the centerline of the hot flue gas duct 2 is 90°. Although the two airflows are initially in their respective downward rotating spiral paths, the width of the double-headed spiral blade 32 is smaller than the width of the inlet of the dust-laden gas duct 1 and the hot flue gas duct 2. Therefore, the two streams mix near the center during the flow process. The gas flow process is not completely laminar, and more and more are mixed. Especially when the gas reaches the conical tube 34, the conical tube 34 constricts downward in a cone shape, causing the airflow to turn back upward from the center of the vertical centrifugal mixer 3. The two airflows mix more thoroughly, and some dust falls to the bottom of the conical tube 34 due to the centrifugal force and the downward cyclone force, which plays a pre-dust removal role and reduces the load on the bag filter 5.

[0084] A shut-off valve and a flow regulating valve are installed at the front end of the hot flue gas duct 2 entering the vertical centrifugal mixer 3 to facilitate the opening and closing of the duct and the adjustment of the flue gas flow rate. The flue gas flow rate is adjusted to control the ratio of flue gas flow rate to dust-laden gas, so that the temperature of the mixed gas in the bag filter is between 110 and 180°C and the moisture content of the dust is between 5 and 16%.

[0085] The bag filter 5 consists of an upper housing 51, a middle housing 53, and a second ash hopper 55 arranged from top to bottom. The upper housing 51 has a gas outlet 58 on its top or side that connects to the induced draft fan 7. The upper housing 51 serves as a gas collection chamber and is constructed with an integrated welded structure. A maintenance manhole with a sealed structure is provided on its side. A tube sheet 52 is installed between the upper housing 51 and the middle housing 53. A filter unit 57 is installed corresponding to the tube sheet 52. The filter material of the filter unit 57 is a filter bag. A back-blowing unit 59 is installed on the top of the filter unit 57. Due to the characteristics of the dust-laden vapor, although the dust-laden gas has been heated and diluted in the vertical centrifugal mixer, the filter bag is made of PTFE material with high temperature resistance, acid and alkali resistance, and good hydrophobicity in order to improve dust removal efficiency and the service life of the filter bag. An air inlet 54 is installed on the side of the middle housing 53 and connects to the conical tube 33 of the vertical centrifugal mixer. A guide channel 56 is installed at the corresponding position of the air inlet 54 and connects to the air inlet 54. The top of the guide channel 56 is 0.5 meters away from the lower surface of the tube sheet 52.

[0086] Combination Figure 3 To illustrate, in this example, the air guide channel 56 comprises a vertical plate 562 and a flat plate 561. The flat plate 561 is positioned below the lower edge of the air inlet 54. One end of the flat plate 561 is fixedly connected to the side wall of the middle housing 53 on the air inlet side, and the other end is fixedly connected to the vertical plate 562. The cavity formed by the vertical plate 562, the flat plate 561, and the middle housing 53 constitutes the air guide channel 56. Depending on the structure of the bag filter, multiple fan-shaped vertical diversion plates 563 can be installed within the air guide channel 56.

[0087] Example 2

[0088] Combination Figure 4 To illustrate, unlike Example 1, this embodiment includes three baghouse dust collectors 5 arranged in parallel.

[0089] Example 3

[0090] Combination Figure 5 To illustrate, unlike Embodiment 1, the air guide channel 56 is a pipe, which includes an upper vertical straight section and a lower elbow. One end of the elbow is connected to the straight section and the other end is connected to the air inlet 54. The distance between the top of the air guide channel and the lower surface of the tube sheet is 0.6 times the diameter of the air guide channel. No vertical diverter plate is installed in the air guide channel 56.

[0091] Example 4

[0092] Combination Figure 1The dust removal system for saturated or near-saturated steam containing dust includes the dust removal device provided in Example 1, an induced draft fan 7, and a dust collection device. The inlet of the induced draft fan 7 is connected to the gas outlet 58 of the bag filter 5 via pipe 6. The dust collection device includes a finished product silo 10 and a closed belt conveyor 9.

[0093] The dust removal device is installed above the enclosed belt conveyor 9, which cools and humidifies the solid materials after coal pyrolysis, and the finished product silo 10. A disc-type airlock discharge valve 82 is installed below the ash hopper 55 of the bag filter 5, allowing dust to fall directly into the finished product silo 10 through the valve. A screw conveyor 81 is installed below the conical pipe 34 to transport the dust into the finished product silo 10.

[0094] Example 5

[0095] Combination Figure 5 To illustrate, unlike Example 4, the dust removal device provided in Example 3 is used instead of the dust removal device provided in Example 1.

[0096] Working principle

[0097] Combination Figure 1 and Figure 2 The procedure includes the following steps: First, open the hot flue gas duct 2 to preheat the vertical centrifugal mixer 3 and the bag filter 5 to 130-160°C. Then, introduce dust-laden gas with saturated or near-saturated steam. Adjust the hot flue gas flow rate according to the flow rate of the dust-laden gas with saturated or near-saturated steam, the temperature of the mixed gas, and the humidity of the dust. Control the inlet temperature of the bag filter to 110-180°C to obtain a dust moisture content of 5-16%, thus avoiding the dust from becoming too dry and easily causing dust to be generated.

[0098] Preheating prevents condensation from occurring in the dust-laden gas after it enters due to temperature drop. The dust-laden gas is heated by hot flue gas to obtain dry dust-laden gas, ensuring continuous and stable operation of the filter. This avoids the problem of dust ash not falling smoothly due to excessive moisture content, and in particular, it can prevent dust ash from sticking to the bag and causing filter failure.

[0099] The temperature of the hot flue gas is 150–300℃, preferably 180–260℃. The hot flue gas is industrial flue gas. By using this temperature range of waste flue gas as a mixture to heat saturated or near-saturated steam containing dust, the steam is kept in a dry state, thus realizing the utilization of industrial flue gas resources while saving costs.

[0100] Application examples

[0101] The dust concentration in the steam obtained during the pyrolysis of low-rank coal using low-temperature rotating bed technology is 10–15 g / m³. 3The temperature is between 80 and 110°C, the humidity is between 50 and 100%, and the steam contains some oil and gas; the flue gas temperature for coal pyrolysis is between 150 and 300°C.

[0102] Using the dust removal system provided in Example 3, before production, the dust removal system is preheated to 130-160°C using waste heat flue gas at 180-260°C, and then dust-laden gas is introduced. The flow rate of the hot flue gas is adjusted according to the temperature of the mixed gas and the humidity of the dust, and the inlet temperature of the bag filter is controlled to be ≥110°C. The dust collector discharges continuous dry ash, and the moisture content of the discharged ash is about 10%. This not only meets the economic requirements of mixed air but also meets the gas transportation requirements of the dust. After long-term operation, the surface of the filter bags was inspected after disassembling the dust collector, and no bag clogging was found. The gas collection chamber was clean and dust-free, meeting the emission standards.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A dust removal device for dust-laden gas that is saturated or nearly saturated with steam, characterized in that, Includes a vertical centrifugal mixer (3) and a bag filter (5); The vertical centrifugal mixer (3) includes a vertically arranged barrel-shaped shell (31), a mixed gas outlet located at the top of the barrel-shaped shell (31), a dust-laden gas pipe (1) and a hot flue gas pipe (2) located on the side wall of the barrel-shaped shell (31), with the dust-laden gas pipe (1) and the hot flue gas pipe (2) located on the side wall of the barrel-shaped shell (31) near the end of the mixed gas outlet; The barrel-shaped outer shell (31) is provided with double-headed spiral blades (32), and the dust-laden gas pipe (1) and the hot flue gas pipe (2) correspond to the lower openings of the two spiral blades in the double-headed spiral blades (32), respectively. The air inlet (54) of the bag filter (5) is connected to the mixed gas outlet; The bottom of the barrel-shaped outer shell (31) is provided with a tapered tube (34).

2. The dust removal device according to claim 1, characterized in that, The axis of the dust-laden gas pipe (1) and the axis of the hot flue gas pipe (2) are tangent to the rotation direction of the spiral blades, respectively. The included angle between the axis of the dust-laden gas pipe (1) and the axis of the hot flue gas pipe (2) is 45~180°.

3. The dust removal device according to claim 1, characterized in that, The starting point of the double-headed helical blade (32) is 5~20° downward.

4. The dust removal device according to claim 1, characterized in that, The bag filter (5) is provided with a tube sheet (52), which divides the bag filter (5) into an upper box (51) and a middle box (53). A filter unit (57) is provided on the tube sheet (52) and is located in the middle box (53). The air inlet (54) is located on the middle box (53). The middle box (53) is provided with an upward air guide channel (56), which is connected to the air inlet (54); Below the middle box (53) is a ash hopper (55) for collecting dust. The upper housing (51) is provided with a gas outlet (58); The top of the filter unit (57) is provided with a backflush unit (59). The filter material of the filter unit (57) is any one of PTFE, PPS or acrylic.

5. The dust removal device according to claim 4, characterized in that, The air guide channel (56) includes a flat plate (561) and a vertical plate (562), and the vertical plate (562), the flat plate (561) and the middle box (53) cooperate with each other to form the air guide channel (56). The vertical distance between the top plane of the vertical plate (562) and the bottom surface of the flower plate (52) is 0.3~1m; The gas guiding channel (56) is provided with a plurality of flow dividers (563), which cooperate with the gas guiding channel (56) to disperse the gas to different directions; The bottom of the splitter plate (563) is connected to the flat plate (561), and the top surface height of the splitter plate (563) is consistent with the top surface height of the air inlet (54). Several of the aforementioned diverter plates (563) are distributed in a fan shape along the surface of the flat plate (561).

6. The dust removal device according to claim 4, characterized in that, The air guide channel (56) is a pipe structure; The vertical distance between the plane where the air outlet of the pipe structure is located and the lower end face of the tube sheet (52) is 1 / 3 to 1 / 3 of the diameter of the pipe structure. The pipeline structure includes a vertical straight pipe and an elbow. One end of the elbow is connected to the air inlet (54), and the other end of the elbow is connected to the bottom of the vertical straight pipe.

7. The dust removal device according to claim 1, characterized in that, The top of the barrel-shaped outer shell (31) is provided with a conical tube (33), and the outlet of the mixed gas is located at the top of the conical tube (33); The outlet of the mixed gas is connected to the inlet (54) through pipe 1 (4).

8. A dust removal system for dust-laden gas that is saturated or nearly saturated with steam, characterized in that, The device includes the dust removal device, the induced draft fan (7) and the dust collection equipment as described in any one of claims 1 to 7, wherein the induced draft fan (7) is connected to the outlet of the bag filter (5) and the dust collection equipment is located below the dust removal device.

9. The dust removal system according to claim 8, characterized in that, The dust collection and recovery equipment includes a finished product silo (10), which is connected to the conical pipe (34) and the ash hopper (55) respectively. The dust collection and recycling equipment also includes a closed belt conveyor (9) connected to the finished product silo (10); The finished product silo (10) is connected to the conical pipe (34) via a screw unloader (81) or a disc-type airlock unloading valve (82); The finished product silo (10) is connected to the second ash hopper (55) via a screw unloader (81) or a disc-type airlock unloading valve (82).

10. The dust removal system according to claim 8, characterized in that, The induced draft fan (7) is connected to the gas outlet (58) through pipe two (6).

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