Cartridge filter and transformation

Category: Applications Date: 2012-7-5 Source:

    1, an overview

    The first filter is rarely used cartridge as the dust removal device in Japan and some countries in Europe and America until the 1970s, cartridge filter, it has many advantages of small size, high efficiency, small investment, easy maintenance, However, due to technical reasons at that time its equipment capacity is small, difficult to form the amount of wind equipment, filtration velocity is low, narrow range of applications, only applications in industries such as food, welding, so many years not a lot of promotion. The new century, with the constant development of new technologies, new materials, Japan's ambition Corporation, Donaldson Company, on behalf of precipitator dust cartridge filter, making filter tube precipitator is widely used in the field of cement, steel, electricity, food, metallurgy, chemical industry, the overall capacity increase to several times the filter area> 2,000 square meters of large-scale precipitator is to solve the traditional filter ultra-fine dust collection difficult. high filtration velocity, poor cleaning effect, the bag is easy to wear and tear leaking, the best solution with high operating costs, and available on the market all kinds of bag, electrostatic precipitators compared with the effective filtration area, low differential pressure, low emission, small size, long service life, a new direction for the development of the industrial cartridge dust collector.

    2, cartridge filter structure

    The structure of the cartridge filter is composed by the inlet pipe, exhaust pipe, box, ash bucket, cleaning devices, guiding device, airflow diversion distribution board, cartridge and electric control device, similar to the air box pulse bag dust structures.

    Cartridge dust collector in the layout is very important, both vertically arranged in the box flower panel can be tilted arrangement in the flower board, from the cleaning effect of the vertical arrangement is more reasonable. Tubesheet the lower part of the filter chamber, the upper air box pulse chamber. Equipped with a dust collector at the entrance to the air distribution plate.

    3, the cylindrical filter works

    Dusty gas enters the precipitator ash hopper, the sudden expansion of air distribution board role, part of the coarse particles in the air flow deposition in ash hopper under the action and the force of inertia; fine grain size, density of the dust particles into the airflow section Dust Room by the combined effects of Brownian diffusion and sieving, so that dust deposited on the filter surface, the purified gas is discharged by the fan into the net chamber exhaust pipe.

Increases the resistance of the cartridge filter with the filter surface dust layer thickness increases. Resistance to achieve a specified value when cleaning. PLC program control pulse valves open and close, the first sub-chamber poppet valve closed, the filter airflow truncated, and electromagnetic pulse valve opens, compressed air and a short period of time in the rapid expansion on the cabinets, into the cartridge, so that the cartridge expansion and deformation vibration, and the role of the reverse flow erosion, attached to the bag outer surface of the dust is stripped fall into the hopper. After cleaning, the electromagnetic pulse valve is closed, the poppet valve to open, the room to restore the filter state. Cleaning of each room in turn, from the first chamber cleaning between the start of next cleaning for a cleaning cycle. Off the dust to fall into the ash bucket unloaded gray valve discharge.

    4, the technical improvements and selection of technology

    4.1 The cleaning device

    Traditional cartridge filter cleaning method, a high pressure air backflush pulse gas injection, the practice shows that the former has the advantage uniform airflow, the drawback is that the consumption of wool large amount; the latter advantage is consumption is small, the disadvantage is that air flow weak. To do this for two improvements: on the one hand, increase in pulse-jet tube guiding device to enhance the airflow induced by the other hand, the cartridge the upper diversion duct removed so that the pulse air flow and induced flow at the same time full access to the cartridge. Improved air consumption less uniform airflow, better cleaning, cleaning air flow calculations, technical improvements are 3-5 times the pulse volume.

    4.2 The gas distribution plate

    Cartridge dust collector airflow distribution is very important to consider how to avoid the import of equipment at wind speed higher cause high wear areas on the filter. Air distribution plate for the cartridge filter has a unique air distribution must be very stable and uniform. Be conducive to the decline of the rising air currents and dust, the air distribution plate opening rate of 35%. According to calculations, the drag coefficient of < 2, can be seen in the case of flow velocity < 0.8m / s, porous air flow distribution requirements of the board to meet the cartridge filter.

    4.3 cartridge and filter

    The cartridge is folded into a pleated calculate the length of the filter, both adhesive into the tube, inside the cylinder with a metal grid support, under the cover and base fixed the length of the filter is determined by the nature of the dust and the dust concentration .

    Filter cartridge filter core part of the cartridge filter and the key to the success of> 99.9% filtration efficiency, the dust of the fiber filter media used in the past generally have paper pages of this filter> 0.5um , but its drawback is that large dust capacity, cleaning difficulties should not be used in high concentrations, Japan's ambition Corporation in 2000 to produce a continuous long-fiber filter has its own intellectual property rights, to resolve these difficulties, available on the market acupuncture it filter bag for the deep bed filtration media, and your new order made the bag at an early stage the need to establish a primary dust cake on the surface. Very easy to penetrate this dust filter, increasing emissions, or clogged air channels, so the bag to premature failure. Particularly in the collection with moisture dust and easier to paste bag. Japan ambition filter has the following characteristics:

    1) the usual media deep bed filtration, it relies on the surface of the dust in the filter layer to achieve an effective filter, the establishment of effective filtration time is about 10% of the entire filtration process. Membrane Filter is the filter surface, the dust does not penetrate into the filter, the filter of no early, beginning close to 100 percent effective filtration.

    2) traditional media after the high concentration of dust into the air permeability decreased, the resistance rise. Membrane Filter uniform fine pore size and its not sticky, and put into use immediately to provide excellent filtration performance, the dust transmittance approximate the zero, the resistance was stable, tested in the filtration rate 1-2m/min conditions its resistance is about 300-500Pa.

    3) needle felt filter, generally high-energy pulse jetting cleaning in order to maintain the filter of the conventional resistance, reduce the injection strength of 30% -50% of the conventional resistance to maintain the filter membrane filter media.

    4) long life, the same kinds of conditions, usually five times the life of the traditional needle felt filter.

    5, and industrial applications

    5.1 Application grinding system

    Using this technology, in June 2004 to transform the cement plant raw mill bag filter. Maintain the original filter shell case, the replacement of the flower board, to improve the pulse-jet system, an increase of air distribution devices, specially designed cartridge and cartridge waterproofed.

    The transformation of 5.2 pairs of electrostatic precipitator

    III cement mill electrostatic precipitator handling capacity of annual output of 3 million tons of cement plant, the emission volume. The original model: AAF / ELEX electrostatic precipitator, electric field and electrical room are two to fight the system, cleaning system for the machinery around the arm hammer vibration, dust collection plate area of ​​792M2.

    Pulse jet dust collector dust cartridge to transform the first to remove the electrostatic precipitator internal plate, plate wire and mechanical rapping and other parts, the construction of a pedestrian passage in the original shell. Second, through the louvers and sealed steel plate, correctly guide the airflow direction in the new flower board to install cartridge without the cage frame and venturi tube. Finally fitted with jet dust control system put into use. 3 weeks to complete the whole process.

    6, Conclusion

    Cartridge filter can be widely used in the cement industry grinding system, grinding system, vertical kiln, rotary kiln, the kiln, kiln inlet dust point of collecting, to transform all kinds of traditional dust collector can also be made very good results, the key is to select the advanced and reasonable structure, to adapt the characteristics of various dust.