Humidifying charge type horizontal dust remover applied to particulate matter trapping and dust removing method

Abstract

The invention relates to a humidifying charge type horizontal dust remover applied to particulate matter trapping and a dust removal method, in particular to the technical field of particulate matter efficient trapping. The first humidifying area, the charged dust removal area, the second humidifying area and the filter bag area are sequentially arranged in the shell; the filter bag area is provided with a cleaning unit; a dry ash collecting area is arranged below the first humidifying area and the charged dust removing area; and a wet ash collecting area is arranged below the second humidifying area and the filter bag area. According to the humidifying and charging type horizontal dust remover provided by the invention, through humidifying, charging coagulation, electric dust removal and filtering dust removal, fine particulate matter coagulation is enhanced, the trapping efficiency of total particulate matters in flue gas is improved, ultralow emission of the particulate matters in the flue gas is realized, and the particle removal rate is greater than or equal to 99.96%.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-efficiency particulate collection, and particularly relates to a humidification and charging type horizontal dust collector and a dust collection method applied to particulate collection. BACKGROUND

[0002] At present, the electric dust collector is a kind of industrial dust removal device widely used, but with the frequent occurrence of haze pollution, the particulate emission standards of various industries are increasingly strict, and the particulate concentration discharged by the existing electric dust collector is 10-20 mg / m 3 , which is difficult to meet the requirements of ultra-low dust emission (such as <5 mg / m 3 for coal-fired power plants and <10 mg / m 3 for other industries). Therefore, the electric dust collection technology needs to be combined with other dust removal technologies, such as bag dust removal and ceramic membrane dust removal, to meet the ultra-low emission standard.

[0003] For example, CN108325747A discloses a heat pipe and an electrostatic dust collection system based on partition humidification and dry-wet coupling of desulfurization wastewater treatment, the front end is dry electrostatic precipitation, and the rear end is wet electrostatic precipitation. The dry electrostatic precipitation removes most of the dust, and the fine particulate matter is improved in dust removal efficiency through humidification, charging and coagulation. However, the outlet dust concentration still does not meet the ultra-low emission standard.

[0004] CN103785267A discloses a pre-charging bag dust collector, which combines charging and filtration. The dust is charged in the electric field area and then enters the bag filter area. The composite dust collector strengthens the capture effect of fine particles in flue gas. This shows that the combination of electric dust removal and filtration dust removal can effectively improve the dust removal efficiency. However, the dust collector belongs to the category of dry dust removal.

[0005] CN112774360A discloses a metal filter bag dust collector. The metal filter screen is connected by folding layers to form a cylindrical filter screen unit. After the dust-containing flue gas passes through the filter screen unit, the dust is filtered and captured. The metal filter screen can replace traditional flexible filter material.

[0006] Although the combination of traditional electric dust collector and humidification and filtration dust removal can change the composition of flue gas, strengthen the coagulation of fine particulate matter and the efficiency of electric dust removal, and the remaining small amount of dust can be captured by subsequent filtration for secondary capture to avoid secondary dust raising, the current dust removal equipment still has the defect that humidification and filtration are difficult to be compatible, resulting in poor dust removal effect. SUMMARY

[0007] In view of the problems in the prior art, the present application aims to provide a humidification and charging type horizontal dust collector and a dust collection method applied to particulate collection, to solve the defect that the current dust removal equipment is difficult to be compatible with humidification and filtration, resulting in low particulate capture effect and poor dust removal effect.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a humidified charged horizontal dust collector for particulate matter collection, the humidified charged horizontal dust collector for particulate matter collection comprising: a shell;

[0010] The first humidification zone, the charged dust removal zone, the second humidification zone, and the filter bag zone are sequentially arranged within the housing.

[0011] The filter bag area is equipped with a cleaning unit;

[0012] A dry ash collection area is provided below the first humidification zone and the charged dust removal zone;

[0013] A wet ash collection area is provided below the second humidification zone and the filter bag zone.

[0014] The humidified charged horizontal dust collector provided by the present invention enhances the coagulation of fine particulate matter and improves the total particulate matter collection efficiency of flue gas through humidification-charged coagulation-electrostatic precipitation-filtration dust removal, thereby achieving ultra-low emissions of flue gas particulate matter with a particle removal rate of ≥99.96%.

[0015] As a preferred embodiment of the present invention, the charged dust removal zone includes: an anode plate and a cathode wire.

[0016] As a preferred embodiment of the present invention, the filter bag area includes at least one filter bag.

[0017] As a preferred embodiment of the present invention, the cleaning unit includes a nozzle disposed above the filter bag in the filter bag area.

[0018] Secondly, the present invention provides a dust removal method for particulate matter capture, the dust removal method comprising:

[0019] The flue gas is subjected to a first humidification, a charged dust removal process, a second humidification, and filtration in sequence to obtain purified flue gas.

[0020] As a preferred embodiment of the present invention, the spray volume of the second humidification is greater than that of the first humidification.

[0021] Preferably, the amount of the second humidifying spray is 1.2-2 times the amount of the first humidifying spray.

[0022] As a preferred embodiment of the present invention, the humidity of the flue gas obtained by the first humidification is ≤ saturated humidity.

[0023] As a preferred embodiment of the present invention, the residence time of flue gas in the charged dust collector is 2-4 seconds.

[0024] As a preferred embodiment of the present invention, the humidity of the flue gas obtained by the second humidification is greater than the saturation humidity.

[0025] As a preferred technical solution of the present invention, if the system resistance in the filter is >1200Pa, then cleaning is performed until the system resistance is <800Pa, and then cleaning is stopped.

[0026] Compared with existing technical solutions, the present invention has the following beneficial effects:

[0027] (1) The humidified charged dust collector provided by the present invention increases the humidity of flue gas through primary humidification, enhances the discharge electric field between the anode plate and the cathode wire, and increases the charge of particulate matter in the flue gas in the electric field. At the same time, the increase in humidity will increase the liquid bridging force between particles, accelerate the agglomeration of particles, increase the particle size, and significantly increase the driving speed of particles towards the anode plate. In addition, the increased humidity also improves the stability of the dust layer on the surface of the anode plate and reduces secondary dust.

[0028] (2) The humidified charged dust collector provided by the present invention still carries a small amount of particulate matter after the flue gas passes through the electrostatic precipitator. The flue gas is made supersaturated by secondary humidification, and droplets appear in the flue gas. After the droplets collide and agglomerate with the remaining particulate matter, they are captured by rigid metal filter bags or ceramic filter bags, which can achieve ultra-low emission of particulate matter in flue gas with a particle removal rate of ≥99.96%. After the ceramic filter bag has been running for a period of time, the resistance increases. It can be cleaned by spraying process water, and the filtration resistance is reduced after cleaning. Attached Figure Description

[0029] Figure 1 This is a side view of a humidified charged horizontal dust collector for particulate matter collection provided in an embodiment of the present invention;

[0030] Figure 2 This is a top view of a humidified charged horizontal dust collector for particulate matter collection provided in an embodiment of the present invention.

[0031] In the diagram: 100 - First humidification zone, 200 - Charged dust removal zone, 210 - Anode plate, 220 - Cathode wire, 300 - Second humidification zone, 400 - Filter bag zone, 410 - Filter bag, 420 - Cleaning unit, 500 - Dry ash collection zone, 600 - Wet ash collection zone.

[0032] The present invention will now be described in further detail. However, the examples described below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims. Detailed Implementation

[0033] To better illustrate the present invention and facilitate understanding of its technical solutions, typical but non-limiting embodiments of the present invention are as follows:

[0034] Currently, combining traditional electrostatic precipitators with humidification and filtration can alter flue gas composition, enhance fine particulate matter aggregation and electrostatic precipitator efficiency, and allow for secondary dust collection through subsequent filtration to prevent secondary dust re-entrainment. However, current dust collection equipment still suffers from poor dust removal efficiency. Therefore, this invention optimizes dust collection equipment, enhances fine particulate matter aggregation, and improves the total particulate matter collection efficiency of flue gas, achieving ultra-low emissions of flue gas particulate matter, as detailed below:

[0035] I. This embodiment provides a humidified charged horizontal dust collector for particulate matter collection, the humidified charged horizontal dust collector for particulate matter collection includes: a shell;

[0036] The first humidification zone 100, the charged dust removal zone 200, the second humidification zone 300, and the filter bag zone 400 are sequentially arranged within the housing, as follows: Figure 1 and Figure 2 As shown;

[0037] The filter bag area 400 is equipped with a cleaning unit 420;

[0038] A dry ash collection area 500 is provided below the first humidification zone 100 and the charged dust removal zone 200;

[0039] A wet ash collection area 600 is provided below the second humidification zone 300 and the filter bag zone 400.

[0040] In this invention, both the first humidification zone 100 and the second humidification zone 300 include a spray nozzle and a flue gas channel, with the spray nozzle facing the direction of flue gas flow or forming a certain angle with the direction of flue gas flow.

[0041] The charged dust removal zone 200 includes an anode plate 210 and a cathode wire 220.

[0042] The filter bag area 400 includes at least one filter bag 410.

[0043] In this invention, rigid filter bags are preferred for filter bag 410 to ensure that the cleaning unit 420 can clean dust efficiently.

[0044] The cleaning unit 420 includes a nozzle disposed above the filter bag 410 in the filter bag area 400.

[0045] In this invention, the dust removal device can be further configured with a control unit, and a particulate matter detection device can be configured at the flue gas outlet. Based on the particulate matter detection results, the control unit can adjust the operating conditions of humidification, charged dust removal, filter bags, etc. in the dust removal device, thereby realizing dynamic control of the dust removal device to ensure the dust removal effect.

[0046] In this invention, the exemplary operation process of the humidified charged horizontal dust collector is as follows: The first humidification zone 100 humidifies and cools the flue gas to enhance the discharge and dust removal between the anode plate and cathode wire in the charged dust removal zone 200. The flue gas after electrostatic precipitation is humidified again by the second humidification zone 300. The flue gas after secondary humidification passes through the filter bag zone 400 to filter out the remaining particulate matter. After the filter bag 410 has been running for a period of time, it is cleaned by the cleaning unit 420. The particles collected in the first humidification zone 100 and the charged dust removal zone 200 are collected in the dry ash collection zone 500, and the particles in the second humidification zone 300 and the filter bag zone 400 are collected in the wet ash collection zone 600.

[0047] II. This embodiment provides a dust removal method for particulate matter capture, the dust removal method comprising:

[0048] The flue gas is subjected to a first humidification, a charged dust removal process, a second humidification, and filtration in sequence to obtain purified flue gas.

[0049] Wherein, the spray volume of the second humidification is greater than the spray volume of the first humidification. The spray volume of the second humidification is preferably controlled to be 1.2-2 times the spray volume of the first humidification, for example, it can be 1.2 times, 1.28 times, 1.36 times, 1.44 times, 1.52 times, 1.6 times, 1.68 times, 1.76 times, 1.84 times, 1.92 times or 2 times, etc., but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0050] In this process, the humidity of the flue gas obtained from the first humidification is less than or equal to the saturated humidity. At this point, the water in the flue gas is still in a gaseous state, but the increased humidity significantly improves the conductivity of the flue gas, enhances corona discharge, and increases the number of charges in the electric field, potentially doubling the charge of the particles. Simultaneously, the number of water molecules adsorbed on the particle surface also increases, and the microscopic liquid bridge force between adjacent particles increases by up to one order of magnitude, significantly promoting particle aggregation and increasing the average particle size. The combination of these two factors significantly increases the driving speed of particles towards the anode plate. Since there is no liquid water present, the dust layer on the anode plate surface can still be cleaned by rapping, and the increased average particle size of the particles is subject to greater gravity, suppressing secondary dust re-entrainment. The combination of these three factors significantly improves the dust removal efficiency of the electrostatic precipitator area.

[0051] The residence time of flue gas in the charged dust collector is 2-4s, for example, it can be 2s, 2.2s, 2.4s, 2.6s, 2.8s, 3s, 3.2s, 3.4s, 3.6s, 3.8s or 4s, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0052] In this invention, the discharge voltage in the charged dust collector is 40-60kV, and the electric field strength between the cathode wire and the anode plate is 1.6×10⁻⁶.5 -3×10 5 V / m, the residence time is selected based on the dust concentration in the flue gas during the device design. For dust concentrations below 10 g / m³... 3 Residence time in the charged dust removal zone is 2-3 seconds; dust concentration is higher than 10g / m³. 3 The residence time in the charged dust removal zone is 3-4 seconds.

[0053] In this process, the humidity of the flue gas obtained by the second humidification is greater than the saturation humidity. At this time, the water vapor in the flue gas is supersaturated, and droplets appear in the flue gas. The droplets collide and condense with the remaining particulate matter.

[0054] If the system resistance in the filter is greater than 1200 Pa, cleaning is performed until the system resistance is less than 800 Pa, at which point cleaning stops.

[0055] In this invention, saturated humidity refers to the maximum amount of water vapor that can be contained in a unit volume of gas phase in flue gas under the current operating temperature and pressure.

[0056] III. To illustrate the dust removal effect achievable by the humidified charged horizontal dust collector and dust removal method for particulate matter capture provided by the present invention, the following example is used for explanation:

[0057] Example 1

[0058] This embodiment provides a humidified charged horizontal dust collector for particulate matter collection, the humidified charged horizontal dust collector for particulate matter collection includes: a shell;

[0059] A first humidification zone 100, a charged dust removal zone 200, a second humidification zone 300, and a filter bag zone 400 are sequentially arranged within the housing;

[0060] The filter bag area 400 is equipped with a cleaning unit 420;

[0061] A dry ash collection area 500 is provided below the first humidification zone 100 and the charged dust removal zone 200;

[0062] A wet ash collection area 600 is provided below the second humidification zone 300 and the filter bag zone 400;

[0063] The charged dust removal zone 200 includes an anode plate 210 and a cathode wire 220; the filter bag zone 400 includes nine filter bags 410; and the cleaning unit 420 includes nozzles disposed above the filter bags 410 in the filter bag zone 400.

[0064] Application Example 1

[0065] This embodiment provides a dust removal method for particulate matter capture, using the dust collector of Embodiment 1 for dust removal, as detailed below:

[0066] The inlet dust concentration of the humidified charged dust collector is 20 g / m³. 3 The first humidification zone sprays water mist to humidify the flue gas to saturation humidity. Afterward, the flue gas enters the charged dust removal zone, where dust particles remain in the electric field for 2 seconds for charged dust removal (discharge voltage 50kV, electric field strength 2.5×10⁻⁶). 5 (V / m), then control the spray volume of the second humidification zone to be 1.2 times that of the first humidification zone to perform a second humidification of the flue gas to make the flue gas supersaturated. Metal filter material is used as a rigid filter bag, and the outlet dust concentration is 8mg / m. 3 The total particulate matter removal efficiency exceeds 99.96%.

[0067] Application Example 2

[0068] This application example provides a dust removal method for particulate matter capture, using the dust collector of Example 1 for dust removal, as detailed below:

[0069] The inlet dust concentration of the humidified charged filter bag dust collector is 20 g / m³. 3 The first humidification zone sprays water mist to humidify the flue gas to saturation humidity. Afterward, the flue gas enters the charged dust removal zone, where dust particles remain in the electric field for 3 seconds for charged dust removal (discharge voltage 40kV, electric field strength 1.6×10⁻⁶). 5 (V / m), then control the spray volume of the second humidification zone to be 1.5 times that of the first humidification zone to perform a second humidification of the flue gas to make the flue gas supersaturated. Ceramic filter material is used as a rigid filter bag, and the outlet dust concentration is 6mg / m³. 3 The total particulate matter removal efficiency exceeds 99.97%.

[0070] Application Example 3

[0071] This application example provides a dust removal method for particulate matter capture, using the dust collector of Example 1 for dust removal, as detailed below:

[0072] The inlet dust concentration of the humidified charged filter bag dust collector is 20 g / m³. 3 The first humidification zone sprays water mist to humidify the flue gas until it reaches saturation humidity. Afterward, the flue gas enters the charged dust removal zone, where dust particles remain in the electric field for 4 seconds for charged dust removal (discharge voltage 60kV, electric field strength 3×10⁻⁶). 5 (V / m), then control the spray volume of the second humidification zone to be twice that of the first humidification zone to perform a second humidification of the flue gas, making the flue gas supersaturated. Metal filter material is used as a rigid filter bag, and the outlet dust concentration is 4mg / m³. 3 The total particulate matter removal efficiency exceeds 99.98%.

[0073] Application Example 4

[0074] The only difference from Application Example 1 is that the first humidification supersaturates the flue gas, at which point the total particulate matter removal efficiency is 70.98%.

[0075] Application Example 5

[0076] The only difference from Application Example 1 is that the second humidification only saturates the flue gas, at which point the total particulate matter removal efficiency is 85.91%.

[0077] In summary, the humidified charged horizontal dust collector provided by the present invention enhances the coagulation of fine particulate matter and improves the total particulate matter collection efficiency of flue gas through humidification-charged coagulation-electrostatic precipitation-filtration dust removal, thereby achieving ultra-low emissions of flue gas particulate matter with a particle removal rate of ≥99.96%.

[0078] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0079] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0080] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A humidified charged horizontal dust collector for particulate matter collection, characterized in that, The humidified charged horizontal dust collector used for particulate matter capture includes: a shell; The first humidification zone, the charged dust removal zone, the second humidification zone, and the filter bag zone are sequentially arranged within the housing. The filter bag area is equipped with a cleaning unit; A dry ash collection area is provided below the first humidification zone and the charged dust removal zone; A wet ash collection area is provided below the second humidification zone and the filter bag zone.

2. The humidified charged horizontal dust collector for particulate matter collection as described in claim 1, characterized in that, The charged dust removal zone includes an anode plate and a cathode wire.

3. The humidified charged horizontal dust collector for particulate matter collection as described in claim 1, characterized in that, The filter bag area includes at least one filter bag.

4. The humidified charged horizontal dust collector for particulate matter collection as described in claim 3, characterized in that, The cleaning unit includes a nozzle disposed above the filter bag in the filter bag area.

5. A dust removal method for particulate matter collection, characterized in that, The dust removal method includes: The flue gas is subjected to a first humidification, a charged dust removal process, a second humidification, and filtration in sequence to obtain purified flue gas.

6. The dust removal method as described in claim 5, characterized in that, The spray volume of the second humidification is greater than the spray volume of the first humidification; Preferably, the amount of the second humidifying spray is 1.2-2 times the amount of the first humidifying spray.

7. The dust removal method as described in claim 5, characterized in that, The humidity of the flue gas obtained by the first humidification is less than or equal to the saturated humidity.

8. The dust removal method as described in claim 5, characterized in that, The residence time of flue gas in the charged dust collector is 2-4 seconds.

9. The dust removal method as described in claim 5, characterized in that, The humidity of the flue gas obtained by the second humidification is greater than the saturation humidity.

10. The dust removal method as described in claim 5, characterized in that, If the system resistance in the filter is greater than 1200 Pa, cleaning is performed until the system resistance is less than 800 Pa, at which point cleaning stops.

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