Electrostatic & bag composed precipitator
key word：Heat exchange element
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Product description
Electrostatic & bag composed precipitator
1. Introduction
1.1. Purpose
The electrostatic bag composite dust collector is a kind of high efficiency dust removal equipment used to collect dust, fog beads and other particles. It is widely used in coal-fired power station, metallurgy, chemical industry, cement, paper-making and other industries.
1.2. Model meaning
DC-1-3-280
DC -- electric bag type dust collector equipped with other high voltage power supply
1 -------- number of electric fields in electrostatic precipitator area
3 -------- number of electric fields in bag filter area
280-------Effective sectional area of electric field
1.3. Structural features
The electrostatic bag composite dust collector is of box structure and outdoor type. Its structure is equipped with inlet smoke box, dust removal shell, air purification chamber, bypass flue along the flue gas direction, and ash storage system is set below. The electric field area and filter bag area are set in the dust removal shell, and there are two types of arrangement: series type and series alternating type. The former stage of Shenlian type is the electrostatic precipitator area, and the latter stage is the filter bag dust removal area. The area division is clear, the technology is mature, and the application is extensive; the structure of the series interphase type is more complex and less used. Smoke inlet box is set in smoke box. The dust collector is equipped with high voltage power supply, electrical control device and dust cleaning device.
1.4. Working principle
The electrostatic bag composite precipitator is a kind of dust remover, which reasonably installs the electric field area and the filter bag area in a box, organically combines the two mechanisms of electrostatic precipitation and filtering dust removal. Usually, electrostatic precipitator area is set at the front and filter bag area is set at the back, and the two are arranged in series. The electrostatic precipitation area can collect most of the dust in the flue gas by cathode discharge and anode dust collection, and the dust collection efficiency is more than 85%. At the same time, the micro dust not collected is ionized and charged. Filter bag dust removal area is set in the back stage to collect the charged flue gas with low dust concentration through the filter bag, so as to meet the environmental protection requirements of emission concentration less than 50mg / m3 under standard state.
1.5. Product series
According to the layout form, the electrostatic fast composite precipitator can be divided into two categories: the series of electric field area and filter bag area and the series of alternating arrangement of electric field area and filter bag area. Each unit can be divided into two electric fields, i.e., 300 MW and more than 300 MW, which can be divided into two electric fields according to the size of each unit.
2. Main technical parameters
See table 14-1 for the main technical parameters of the Electrostatic & bag composed precipitator
Table 14-1 main technical parameters of electric bag composite precipitator
| No. | Item | Remarks |
| 1 | SCA of the electric field[m2/(m3/s)] | Ratio of effective dust collection area of electric field plate to flue gas treatment |
| 2 | Effective circulation area of electric field（m2） | capacity of dust collector under working conditions |
| 3 | Effective dust collection area of electric field plate（m2） | The effective dust collection area of the electric field plate is twice of the product of the effective length of the electric field, the effective height of the electric field, and the number of electric fields and the number of channels |
| 4 | Wind speed of electric field（m/s) | Ratio of flue gas volume treated by dust collector to effective circulation area of electric field under working conditions |
| 5 | Total filtering area of filter bag area（m2） | The total filtering area of filter bag is the product of filter bag diameter (or equivalent diameter), effective length of filter bag, total number of filter bag and PI |
| 6 | Air cloth ratio (filtering wind speed)（m/min） | Ratio of flue gas volume treated by dust collector to total area of filter bag under working conditions |
| 7 | Pressure drop（Pa) | Difference of average total pressure between inlet section and outlet section of dust collector |
| 8 | Air leakage rate（%） | Under the standard state, the difference between the flue gas volume at the outlet of the precipitator and the inlet flue gas volume and the percentage of the inlet flue gas volume |
| 9 | DC voltage（KV） | — |
| 10 | Rated output DC current of high voltage power supply device（A） | — |
| 11 | Injection pulse width of dust cleaning system in filter bag area （ms) | — |
| 12 | Pulse interval time of ash cleaning system in filter bag area（s) | — |
| 13 | Injection cycle of ash cleaning system in filter bag area（S） | — |
3. Equipment appearance and structural dimensions
See Fig.14-1 and Fig. 14-2
4. Selection method
4.1. It is recommended to use the electrostatic bag filter for the coal which is difficult to collect dust by the electrostatic precipitator; the electrostatic precipitator with more than four electric fields should be used because of the high requirements for the dust emission quality concentration.
4.2. For the retrofitted unit, since the resistance of the electrostatic precipitator is between 800 and 1200 PA, if the original unit adopts the electrostatic precipitator, the induced draft fan needs to be replaced or transformed.
4.3. In the project of electrostatic precipitator transforming into Electrostatic & bag composed precipitator, one or two electric fields can be reserved, and the internal structure of the original precipitator in the remaining electric fields can be removed, and the shell and heat preservation shall be retained to reduce the transformation cost.
4.4. When it is used to deal with the dust containing gas with high relative humidity, insulation measures should be taken to avoid condensation causing "paste bag". When dealing with corrosive flue gas, appropriate anti-corrosion filter materials should be selected; when dealing with high-temperature flue gas, cooling measures should be taken to reduce the temperature of flue gas to below the temperature that the filter bag can bear for long-term operation, and high-temperature filter materials should be used as far as possible.
4.5. The selection of key components of electrostatic bag filter is the decisive factor for long-term use without damage.
4.5.1. Filter bag. The selection of filter bag material of bag filter should generally consider the temperature of flue gas, composition of flue gas, characteristics of dust, dust concentration of flue gas and price of filter bag material.
4.5.2. Bag cage. The cage is made of 12x ∮ 4mm carbon steel longitudinal reinforcement wire, and all reinforcement lines are connected by spot welding. The bag cage is made of carbon steel with oil immersion and anti-corrosion treatment, and it is designed in two sections with plug-in structure. The top of the bag cage is connected with a 6 mm thick carbon steel ring, the lower part of the bag cage is connected with a 1.2 mm thick low carbon steel cap, and the upper part is provided with a venturi tube. After the frame is welded and assembled, pickling and derusting are carried out, and the surface is galvanized with thin layer. Finally, the frame is treated with multi silicification and oil.
4.5.3. Pulse valve. According to the different air pressure, high-efficiency pulse cleaning can be divided into high-pressure pulse (0.5-0.7mpa) and low-pressure pulse (0.2-0.3mpa). High pressure pulse ash cleaning is usually used in the dust with high viscosity, fine particles, high concentration and humidity; low pressure pulse dust cleaning technology is developed on the basis of high voltage pulse. Generally, the low-voltage pulse can fully meet the needs of dust cleaning in thermal power plants.
4.5.4. Pattern board. High temperature carbon steel plate with thickness of 6 mm is used for fixing filter bag, and the bottom of flower plate is provided with reinforcing rib.
5. Scope of supply and ordering instructions
The scope of supply and loan includes equipment body, dust remover accessories, dust remover protection system, precipitator electric control equipment, spare parts, special tools and imported parts list.
5.1. Equipment body. It includes shell, air purification chamber, cathode and anode frame, anode plate, cathode wire, inlet and outlet smoke box and distribution plate, rapping device (including motor), platform, escalator, top lifting device, ash hopper, casing insulation and accessories, flower board assembly, ash cleaning system, air bag, spray pipe, pressure reducing device, air pressure system, pneumatic lift valve, thermal insulation components and external protection
Plate, steel pillar, anchor bolt, bridge, cable and pipeline for the body, body lighting, roof rainproof shed and ash hopper inspection and leveling
Taiwan, etc.
5.2. Dust collector accessories. It includes filter bag, bag cage, pulse valve, ash hopper plate electric heating, gasification plate, insulating parts, insulator electric heater, pressure transmitter and inlet and outlet differential pressure transmitter.
5.3. Dust collector protection system. It includes bypass flue system, sealed bypass valve and pre spraying system.
5.4. Electric control equipment of dust collector. It includes silicon rectifier transformer, high-voltage microcomputer control cabinet, high-voltage wall bushing, damping resistance, high-voltage isolation switch cabinet, low-voltage control cabinet (including power circuit), electromagnetic rapping control cabinet, rapping operation terminal box, electric heating terminal box, maintenance box, body lighting box, temperature measuring element, safety interlock box, top busbar, adapter, turbidity meter, pulse valve operation box, etc Bypass valve operation box, lifting valve operation box, program control system, temperature sensor, upper computer, color display, printer, UPS, computer console, ash hopper level meter and body lighting.
5.5. Spare parts. It includes body part, C-type electrode plate, wear-resistant sleeve, anode hammer head, wear-resistant tile sleeve, coupling, RS type corona wire, cathode hammer head, wear-resistant tile sleeve, coupling, porcelain shaft, porcelain sleeve, electric control part, thyristor trigger unit, relay board, fuse, rectifier transformer, silicon stack, moisture absorber, axial fan, damping resistance, varistor, bag dust removal area, bag cage, electricity Magnetic pulse valve, primary and secondary ammeter and primary and secondary voltmeter.
5.6. Special tools. Including insulation test meter, clamp type ammeter, digital multimeter, special electrical tools.
5.7. List of imported parts (at least, but not limited to). It includes turbidity meter, industrial computer, filter material, electromagnetic pulse valve and PLC.
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