WO2008138168A1

WO2008138168A1 - Dust collecting process and equipment combining electrostatic and bag

Info

Publication number: WO2008138168A1
Application number: PCT/CN2007/001555
Authority: WO
Inventors: Xiaoqiang Wang
Original assignee: Jiangsu Yuda Valve And The Auxiliary Machine Of The Powerplant Co., Ltd
Priority date: 2007-05-14
Filing date: 2007-05-14
Publication date: 2008-11-20

Abstract

A dust collecting process combining electrostatic with bag comprises: smoke containing dust entering the electrostatic dust collecting section which is located into the inner chamber of a horizontal house (16) from an inlet (1); then entering the bag dust collecting section which is also located into the inner chamber of the horizontal house (16); finally, smoke after cleaning discharging from an outlet (15) of the horizontal house (16). A dust collector combining electrostatic with bag comprises: a horizontal house (16) and an inner chamber defined thereby, an ash bucket (17) below the house, an inlet (1) and an outlet (15) in the horizontal house (16), an electrostatic dust collecting section in the inner chamber which is near the inlet (1), a bag dust collecting section in the inner chamber which is near the outlet (15). A plurality of monitors resistant to high temperature and smoke operating condition-adjusting devices are provide into the inner chamber of the horizontal house (16).

Description

Electrostatic and filter bag combination dust removal process and equipment thereof

The invention relates to a dust removing process and a device thereof, in particular to an electric bag combined dust removing process and a device thereof in the field of an electrostatic precipitator and a filter bag dust collector. Background technique

Dust removal technology is a technology for capturing and separating solid particles such as dust in dusty gas streams. In industrial dust removal technology, it is often used for gas-solid separation of gas streams carrying solid particles. Currently, it can be industrially achieved. Electrostatic precipitators and bag filters are required for environmentally-friendly emission requirements and for large-scale practical applications. The electrostatic precipitator comprises a casing, the air inlet and the air outlet are connected to the outer casing, the air outlet is connected with the fan, a high voltage direct current electrode is installed in the inner cavity of the outer casing, and an electric field is formed by using a potential difference on the high voltage direct current electrode to inject a charge into the dusty gas. The flow of electricity electrons charges the dust. The charged dust is collected by the electric field force to the dust collecting plate, thereby achieving the purpose of separating the dust from the dust-containing gas. Its dust removal efficiency is greatly affected by dust performance and smoke gas components, and it varies exponentially with the area of the dust removal plate. In a three-field electrostatic precipitator, the dust removal efficiency of the first electric field is usually about 80 to 90%, and the second and third electric fields collect only about 10 to 20% of the dust in the dust-containing gas. In order to achieve an emission concentration of 50 mg/Nm ³ or less, it is necessary to add fourth and fifth electric fields, and it is necessary to increase a large equipment investment in order to collect a small amount of dust. The bag type dust collector comprises a casing, the air inlet and the air outlet are connected to the outer casing, a bag room is installed in the inner cavity of the outer casing, a filter bag is placed in the bag room, and a dust removing device is installed on the outer side of the outer casing, and the outer casing is provided with a cleaning device The air outlet is connected to the air outlet of the bag room, and a dust removing device is arranged in front of the air outlet on the outer casing. The characteristics of the bag filter are: high dust removal efficiency, especially for fine dust, generally up to 99.5%; adaptability, can capture dust of different nature; air volume can be hundreds of hours per hour From cubic meters to millions of cubic meters per hour; stable operation, easy to recycle dry materials, and easy to maintain. However, the bag filter is limited by the temperature resistance and corrosion resistance of the filter material, especially in the high temperature. Currently, the commonly used filter materials (such as polyester needle felt) are suitable for 120~130 °C, and the glass fiber filter can be used. Resistant to about 250 °C; when the flue gas temperature is higher, special filter materials with higher cost should be used, or cooling measures should be taken, which will lead to the complication of the system structure and the system cost will increase; more importantly, The life of the filter bag is very short, and the operation and maintenance cost and the cost of replacing the filter bag are very high. In addition, as the processing air volume increases, the floor space also increases. China utility model patent "Electric filter bag dust collector", patent number is 02224478. 6, the electrostatic precipitator and bag filter are installed in the same vertical housing, the lower end of the vertical housing is the air inlet, vertical The lower part of the casing is an electric dust removal chamber, the electric dust removal chamber contains a cylindrical anode plate, and the cylindrical anode plate has a large cross cathode line. The upper part of the vertical casing is a bag dust removal chamber, and the bag is dusted. There are a plurality of zipper bags in the chamber, and the electric dust removal chamber and the bag dust removal chamber communicate with each other. However, since the vertical housing is placed vertically, the electrostatic precipitator chamber is in the lower half of the vertical housing, and the bag dedusting chamber is in the upper half of the vertical housing. The design of this structure is destined to the height of the whole machine. Due to certain restrictions, this is a very important miniaturization feature of the patent. Therefore, the number of electric fields and bags cannot be large, the length of the bag cannot be too long, and the cross section of the vertical casing cannot be made. Too large, so the flow rate of the flue gas in the vertical housing is high. Whether it is the electric dust removal part or the dust removal part of the bag, the flue gas has been discharged without the filter of the flue gas. These two technologies The indicator has a great influence on the dust removal effect of the whole machine. Summary of the invention

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrostatic and filter bag combination dust removing process and apparatus thereof which have high dust removal efficiency and low use cost.

The destaticizing process of the electrostatic and filter bag combination dust removing process of the invention is: the dusty flue gas enters the electric dust removing part in the inner cavity of the horizontal casing from the dusty flue gas inlet port on the horizontal casing, and performs electrostatic dust removal treatment, and then enters The dust removal part of the filter bag in the inner cavity of the horizontal casing is filtered, and finally the purified flue gas is discharged from the purified flue gas outlet on the horizontal casing.

The dynamic fluid field monitoring and adjustment of the flue gas flow in the cross section of the precipitator is performed by a computer before the dusty flue gas is subjected to filter bag dust removal treatment.

Before the dusty flue gas is subjected to the bag dust removal treatment, a plurality of high temperature resistant and high sensitivity monitors disposed on the cross section between the front dedusting chamber of the precipitator and the rear bag dust removing chamber are detected to detect the flue gas flow. The change data of the working condition, the data is provided to the computer, and the computer compares with the preset theoretical values, comprehensively analyzes the processing, and then outputs the command according to the computer result; after a certain time interval, the height is uniformly distributed on the section of the precipitator The sensitivity monitor again detects the change value of the airflow condition and provides it to the computer, compares it with the preset value, comprehensively analyzes the processing, and outputs the command according to the computer result. The cyclically reciprocating dynamic adjustment is performed so that the root mean square value of the smoke flow portion between the front electric dust removing chamber and the rear bag dust removing chamber reaches 0.25 and below, thereby maintaining the front electric dust removing chamber smoke. Uniformity of airflow distribution.

The de-blocking scheme of the electric cloth combined with the dust removing device of the invention comprises: an outer casing, and a lower part of the outer casing is a ash hopper, The outer casing is a horizontal outer casing, and the inner cavity of the horizontal outer casing is penetrated. The horizontal outer casing has a dusty flue gas inlet port and a purifying flue gas outlet port, and the portion of the horizontal casing inner cavity that is connected to the dusty flue gas inlet port is In the electric dust removal part, the part of the inner cavity of the horizontal casing which is purified by the flue gas outlet is the dust removal part of the filter bag.

The electric dust removing portion in the inner cavity of the horizontal casing contains at least one electric field, and the dust removing portion of the bag contains at least one set of cloth bags.

The bag dust removal part in the inner cavity of the horizontal casing contains a plurality of closed filter bags vertically suspended from the suspension hole plate, the upper opening of the filter bag and the hole on the suspension hole plate penetrate, the hole on the suspension hole plate and the purification The flue gas chambers are connected, and the purifying flue gas chamber is connected with the purifying flue gas outlet.

A purge blower or a simple mechanical rapping device for removing dust that has been filtered and accumulated on the outer wall of the bag is installed in the purge flue gas chamber.

The smoke flow field automatic monitoring and adjusting device is installed before the dust removal part of the dusty flue gas is filtered by the dust removal part.

The invention organically combines the electrostatic precipitator and the bag filter technology, and the electric dust removing part and the bag dust removing part are horizontally arranged, and after the dusty flue gas enters the device, the first part adopts one to three electric field electrostatic precipitators, It can collect 80%~99% of the finer dust in the flue gas, and the remaining fine dust particles flowing along the flue gas flow enter the dust removal part of the back part. Due to the small amount of remaining ash, the bag load is low, and the cleaning cycle is low. Greatly lengthened, the service life of the bag has doubled. The bag dust removal part contains multiple sets of cloth bags, and since the dusty flue gas directly enters the bag dust removal chamber, the smoke resistance is small, the filtration efficiency is higher, and more than 99.5% of the dust particles can be collected, so that the total dust removal efficiency is up to 99. More than 9%, the dust emission concentration of the flue gas can reach 30mg/Nm ³ or less. DRAWINGS

FIG. 1 is a schematic diagram of the operation of an embodiment of the present invention.

In the figure: 1--dusty flue gas inlet; 2—inlet airflow uniform device; 3—cathode; 4--anode; 5—suspension beam; 6—lifting device; 7—fluid gas flow field distribution Automatic adjustment device; 8--guide vane group; 9-guide vane; 10-bag; 11-suspension plate; 12--hole; 13--anti-blowing cleaning device; 14--purification of flue gas chamber; 15- - Purify the flue gas outlet; 16 horizontal shell; 17 - ash bucket.

Figure 2 is a schematic diagram of a computer-controlled flue gas flow condition monitoring automatic adjustment system. detailed description

The embodiments of the present invention are described in detail below with reference to the accompanying drawings:

Electric cloth combined with dust removal process: dusty flue gas enters from dusty flue gas inlet 1 on horizontal casing 16 The inner cavity of the horizontal casing 16 is uniformly distributed by the inlet airflow distributing device arranged in front of the electric dust removing portion, and then the flow velocity of the flue gas flowing into the electric dust removing portion is evenly distributed, and then enters the electric dust removing portion for electric dust removing treatment. With the unbalanced ash accumulation on the bag in the bag dedusting chamber at the rear of the precipitator, the distribution of the flue gas flow rate in the cross section of the precipitator changes accordingly. The block is placed in the front of the precipitator and in the ESP chamber. A plurality of high-temperature-resistant and high-sensitivity monitors across the cross-section of the bag-removing chamber detect the change data of the flue gas flow conditions, and the data is provided to the computer, and the computer compares with the preset theoretical values and comprehensively analyzes the data. Processing, and then outputting instructions according to computer results; after a certain time interval, the high-sensitivity monitor uniformly distributed on the section of the pre-duster detects the change value of the airflow condition again and provides it to the computer for comparison with a preset value. , comprehensive analysis and processing, and then output instructions according to computer results. The cyclically reciprocating dynamic adjustment is performed so that the root mean square value of the smoke flow distribution between the front electric dust removing chamber and the rear bag dust removing chamber reaches 0.25 and below, thereby maintaining the front electric dust removing chamber flue gas. The uniformity of the flow distribution. The evenly flue gas enters the dust removal portion of the filter bag for filtering and dust removal treatment; finally, the purified flue gas is discharged from the purified flue gas outlet port 15 on the horizontal casing 16.

The electric cloth is combined with the dust removing device: the outer casing is provided, the outer casing is a horizontal outer casing 16, and the lower portion of the horizontal outer casing 16 is a ash hopper 17. The inner cavity of the horizontal casing 16 is penetrated, and the horizontal casing 16 has a dust-containing flue gas inlet port 1 and a purifying flue gas outlet port 15, and the portion of the inner casing 16 of the horizontal casing 16 that is connected to the dust-containing flue gas inlet port 1 is In the electric dust removing part, a mouth airflow uniformizing device 2 is installed between the dusty flue gas inlet port 1 and the electric dust removing portion, and the speed of the dusty airflow entering the high speed is lowered due to the diffusion effect, and the inlet airflow uniformizing device is passed. The cross-sectional flow velocity of the inner cavity of the horizontal casing 16 is evenly hooked. The electric dust removal part contains one to three electric fields, and the cathode 3 and the anode 4 are arranged alternately in the electric field to form a charging region. After the dust is charged, the pole is moved, and the charged dust adheres to the anode 4, and is mechanically oscillated. The dust falls into the ash hopper 17 in a block form. After repeating one to three times, the dust concentration in the flue gas flowing out from the electric field is already small, and then enters the bag dust removing portion to perform the second stage dust collecting. The dust removal part of the bag contains a plurality of sets of cloth bags 10, and the cloth bags 10 are arranged in a staggered manner. The hanging manner of the cloth bag 10 is fastened, and a plurality of closed air bag 10 are vertically suspended on the hanging hole plate 11, and the upper mouth and the hanging hole of the filter bag 10 The hole 12 in the plate 11 is penetrated, and the hole 12 in the suspension hole plate 11 communicates with the purge flue gas chamber 14, and the purge flue gas chamber 14 is connected to the purge flue gas outlet port 15. The cleaned air stream enters the bag 10, exits the hole 12 in the suspension orifice 11, and flows into the purge chamber 14 and is vented to the atmosphere. The suspension beam 5 above the electrostatic precipitator portion and the suspension orifice plate 11 above the dust removal portion of the filter bag are connected by the guide vane group 8. The dust removal part of the filter bag adopts the external filter type dust removal. Since the guide vane group 8 is obliquely disposed in the region between the electric dust removing portion and the dust removing portion of the filter bag, and the lower portion is connected to the guide vane 9, the guide vane 9 is installed and adjusted. On the shaft, the adjustment shaft is driven by an electric (gas) actuator, and the computer is based on the monitor's smoke flow. The actual measured value is compared with the theoretical value for analysis and processing, and an instruction is given to the electric (gas) actuator to drive the adjustment shaft to rotate, and then the guide vane 9 is rotated to keep the flow rate of the smoke flow uniform, so that the front part is dedusted. The electric field will not cause a large area of smoke flow dead zone and improve dust removal efficiency. A reverse blow cleaning device 13 for removing dust that has been filtered and accumulated on the outer wall of the bag is installed in the purge chamber 14 in the inner chamber of the horizontal casing 16. The bag 10 is made of a composite high-temperature resistant material, and the cleaning operation is performed at regular intervals, so that the dust collected on the outer wall of the bag falls into the ash hopper 17. An equipment inspection lifting device 6 is mounted on the upper portion of the horizontal casing 16.

Claims

Claim

1. Electrostatic and filter bag combination dust removal process, characterized in that dusty flue gas enters the dust removal part of the horizontal casing inner cavity from the dusty flue gas inlet port on the horizontal casing, and then enters the horizontal casing. The dust removal part of the filter bag in the inner cavity is subjected to dust removal treatment, and finally the purified flue gas is discharged from the purified flue gas outlet port on the horizontal casing.

2. The electrostatic and filter bag combination dust removing process according to claim 1, characterized in that the flow field distribution of the smoke flow cross section of the dust remover is adjusted by a computer before the dusty flue gas is subjected to the filter bag dust removal process.

3. The electrostatic and filter bag combination dust removing process according to claim 2, characterized in that a plurality of high temperature and high sensitivity monitoring devices are disposed on the cross section of the dust remover before the dusty flue gas is subjected to the filter bag dust removal process. The instrument detects the change data of the flue gas working condition, and the data is provided to the computer, which is compared with the preset theoretical value by the computer, comprehensively analyzed and processed, and then the command is output according to the calculation result.

4. The combination of electrostatic and filter bag dust removal equipment, including the outer casing, the lower part of the outer casing is a ash hopper, which is characterized in that the outer casing is a horizontal outer casing, the inner cavity of the horizontal outer casing is penetrated, and the horizontal outer casing has a dusty gas inlet and purification. The flue gas outlet, the part of the inner cavity of the horizontal casing that is connected to the dusty flue gas inlet is an electric dust removing part, and the part of the inner cavity of the horizontal casing that purifies the flue gas outlet is the dust removing part of the filter bag.

The electrostatic and filter bag combination dust removing device according to claim 4, wherein the electric dust removing portion in the inner cavity of the horizontal casing contains at least one electric field, and the dust removing portion of the filter bag contains at least one set of cloth bags.

6. The electrostatic and filter bag combination dust removing device according to claim 5, wherein the dust removing portion of the filter bag in the inner cavity of the horizontal casing comprises a plurality of airtight bags that are vertically suspended from the hanging hole plate, and the bag is The upper port and the hole on the suspension hole plate penetrate, the hole on the suspension hole plate communicates with the purification flue gas chamber, and the purified flue gas chamber is connected with the purified flue gas outlet port.

7. The electrostatic and filter bag combination dust removing apparatus according to claim 6, wherein the cleaning flue gas chamber is provided with a reverse blow cleaning device or a simple machine for removing dust which is filtered and accumulated on the outer wall of the bag. Rapping the cleaning device.

8. The electrostatic and filter bag combination dust removing apparatus according to claim 7, wherein a portion of the guide vane group between the electric dust removing portion and the bag dust removing is dynamically adjustable in the inner cavity of the horizontal casing.

9. The electrostatic and filter bag combination dedusting apparatus according to claim 8, wherein the guide vane component block is disposed and controlled by a computer.