AUTHOR : admin FROM : 未知ADD TIME : 2019-10-16 10:01 HITS : BELONG : INDUSTRY NEWS
  • Air cooled coal-fired unit, equipped with two subcritical, four corner tangential firing, single furnace Π shaped layout, one intermediate reheat, balanced ventilation,
    all steel frame suspension structure, tight sealing, solid-state slag removal, natural circulation drum coal-fired boilers,

    The boiler uses local coal as fuel, light diesel oil as ignition and combustion support, and the pulverizing system adopts the positive pressure direct blowing
    medium speed pulverizer system. The discharge requirement of the precipitator is that the maximum dust concentration at the outlet is less than or equal to 50mg / Nm3

    Bag filter equipment for dust control in thermal power plant, this product is a special environmental protection equipment for dust removal. The high efficiency of bag filter results in low concentration emission of dust.

    At present, the direct economic benefits brought by the environmental economic policies of emission charges and excessive fines are incomparable.

    The economic benefit brought by the high efficiency of bag filter is considerable, and this kind of economic benefit is a long-term, stable and benign economic benefit.
    What's more important is the social and environmental benefits brought by low concentration emissions.

    Working process of the bag filter: filtering condition - the dust laden air flow enters the upper space of the filter chamber from the tangential direction, and the inlet is volute type.
    Under the action of centrifugal force, the large particles and agglomerated particles whirl down the ash hopper along the cylinder wall.

    The small particles are dispersed in the space between the bags of the filter chamber and thus blocked by the filter bag. Adhered to the outer layer of the filter bag,
    purified air is collected in the cleaning room through the filter wall and the filter bag guide on the flower plate, and then is sucked out by the ventilator and discharged into the atmosphere.

    The bag filter in the power plant adopts the chamber positioning back blowing mechanism and automatic tension device, which is simple in structure and reliable in operation.
    When the filter bag is cleaned, it relies on the back blowing air flow, that is, changing the dynamic cleaning principle, realizing the static cleaning, so as to improve the service life of the filter bag.

    Due to the small power consumption of the chamber positioning system, the equipment shut down the counter blower and only relied on the pressure difference between
    the outlet of the induced draft fan and the clean air chamber of the dust remover to carry out the counter blowing and soot cleaning of the purified flue gas, which was successful.

    The dust remover of power plant is composed of filter bag component, diversion device, pulse injection system, ash discharge system, control system, off-line protection system, box, etc.

    The dust gas enters each unit room through the guide pipe. Under the function of the guide device, the large particle dust will directly fall into the ash hopper after separation,
    and the rest dust will evenly enter the filtering area of each bin room along with the air flow. The filtered clean gas will be discharged through the filter bag through the upper box body,
    lifting pipe and exhaust pipe.

    With the progress of the filtration condition, when the dust on the surface area of the filter bag reaches a certain thickness, the dust removal control device
    (differential pressure or timing, manual control) closes the lifting valve according to the set procedure, controls the current unit offline, opens the electromagnetic pulse valve for blowing,
    and shakes off the dust on the filter bag.

    After the dust falling into the ash hopper is discharged through the ash unloading valve, it is sent out by the ash conveying system.

    The composition of the flue gas in the power plant is complex, which requires the bag filter to be selected with various factors such as acid resistance,
    heat resistance, oxidation resistance, waterproof solution, etc. Therefore, it should be comprehensively considered in the common PPS fiber, P84, PTFE filter materials.

    Finally, a kind of filter bag suitable for the coal-fired flue gas of the power plant is determined. These aspects are also applicable to other industries when choosing bag filter.

    I. impact of chemical corrosion on filter bags

    II. Influence of temperature change on filter bag

    III. Influence of oxidation factors on filter bag

    IV. influence of hydrolysis factors on filter bags

    V. effect of heat shrinkage of filter material on filter bag

    Because most of the filter materials are made of chemical fiber, and the filter materials will shrink under certain temperature conditions,
    the heat setting treatment must be carried out in the production of filter materials, and the heat setting process is very important.

    Excessive heat setting requires a small heat shrinkage rate and may shorten the service life of the filter bag.


    When the new filter bag is installed, if the filter bag just enters the bag cage, due to the problem of heat setting, the bag shrinks and tightly wraps on the bag cage
    during the hot operation. In addition, the vertical bars of the bag cage are less arranged, and the filter bag expands rapidly during the daily dust removal of the dust remover.

    Pulse air flow quickly sucked back to the bag cage after passing, which inevitably led to mechanical friction and damage of the filter bag for a long time.

    Therefore, in the production of filter material, the heat shrinkage index of filter material is a non negligible index.

    The above are the main factors that should be considered when selecting the filter bag of the bag filter. We hope that our customers will comply with the
    requirements of the dust remover manufacturer and standardize the operation of the dust remover.

    In case of any significant change in production conditions, the manufacturer of the precipitator shall be contacted in time to explain the situation,
    so as to avoid serious damage to the precipitator