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CN-121988098-A - Filter material for dust removal of flue gas of sintering machine head and preparation method thereof

CN121988098ACN 121988098 ACN121988098 ACN 121988098ACN-121988098-A

Abstract

The invention belongs to the technical field of air pollution control technology and industrial dedusting materials, and discloses a filter material for flue gas dedusting of a sintering machine head and a preparation method thereof. The filter material for flue gas dust removal is obtained by adopting a plurality of fibers with specific compositions, matching a multi-layer structure and combining a specific preparation method, and the conductivity of the filter material is improved, the influence of static electricity on the blowback effect is reduced, the strength of the filter material is enhanced, and the fire resistance of the filter material is improved.

Inventors

  • HUANG YUNTAO
  • LU JIUMIN

Assignees

  • 一重集团大连工程建设有限公司

Dates

Publication Date
20260508
Application Date
20251224

Claims (8)

  1. 1. A filter material for dust removal of flue gas of a sintering machine head is characterized by comprising a film coating layer, a composite fiber layer, a stainless steel fiber net layer and a base cloth layer which are sequentially arranged from a dust facing surface to a gas purifying surface in sequence, wherein the filter material is formed by sequentially paving the filter material from top to bottom, the overall thickness of the filter material is 1.5-6 mm, and the gram weight of the filter material is 500-1000 g/m 2 .
  2. 2. The filter material for dust removal of flue gas of a sintering machine head according to claim 1, wherein the raw material of the film coating layer is polytetrafluoroethylene microporous film with the aperture of 0.3-2 μm and the thickness of 200-300 μm.
  3. 3. The filter material for dust removal of flue gas of a sintering machine head according to claim 1, wherein the composite fiber layer comprises 2-15wt% of stainless steel fibers, 18-35wt% of basalt fibers, 25-35wt% of poly m-phenylene isophthalamide fibers and 25-35wt% of polytetrafluoroethylene fibers.
  4. 4. The filter material for flue gas dust removal of a sintering machine head according to claim 1, wherein the stainless steel fiber mesh layer is made of stainless steel wires, the stainless steel wires are woven, and the wire diameter of the stainless steel wires is 0.035-0.05 mm.
  5. 5. The filter material for dust removal of flue gas from a sintering machine head according to claim 1, wherein the raw material of the base cloth layer is polytetrafluoroethylene base cloth or basalt fiber base cloth.
  6. 6. The filter material for flue gas dust removal of a sintering machine head according to claim 4, wherein the radial distance a between adjacent stainless steel wires in the stainless steel fiber net layer is 10-30 mm, and the latitudinal distance b is 50-100 mm.
  7. 7. A method for preparing a filter material for flue gas dust removal of a sintering machine head according to any one of claims 1 to 6, wherein the film-coating layer, the composite fiber layer, the stainless steel fiber net layer and the base cloth layer are sequentially arranged in sequence and are manufactured by a post-needling film-coating process.
  8. 8. The preparation method according to claim 7, comprising the following steps: s1, preparing a primary composite layer of a base cloth layer and a stainless steel fiber net layer; Preparing a base cloth layer, namely, if polytetrafluoroethylene base cloth is selected, carrying out plasma surface etching treatment, and improving the surface roughness to Ra 0.8-1.2 mu m; The net layer positioning and compounding, namely spreading a stainless steel fiber net of a stainless steel fiber net layer on a pretreated base cloth layer, and pre-fixing by dispensing to form a primary composite layer after the base cloth layer and the stainless steel fiber net layer are compounded; S2, preparing quaternary fiber composite fiber layer Weighing the fibers, namely weighing the four fibers respectively according to a proportion; The fiber pretreatment comprises the steps of cleaning stainless steel fibers by ultrasonic wave for degreasing, shaping basalt fibers at high temperature, respectively carrying out antistatic treatment on poly (m-phenylene isophthalamide) fibers and polytetrafluoroethylene fibers; The method comprises the steps of grading cotton opening and mixing, wherein a comb-needle type cotton opener is adopted for stainless steel fibers, a saw-tooth type cotton opener is adopted for the rest fibers, the diameter of a fiber bundle after cotton opening is less than or equal to 0.5mm, the fibers after cotton opening are mixed in three stages, firstly, polytetrafluoroethylene fibers after cotton opening and poly (m-phenylene isophthalamide) fibers after cotton opening are premixed for 3-5 min, then basalt fibers after cotton opening are added and mixed for 5-8 min, finally, the stainless steel fibers after cotton opening are added and mixed for 8-10 min, and the mixing uniformity is more than or equal to 96%, so that uniformly mixed quaternary fibers are obtained; Carding and lapping, namely layering uniformly mixed quaternary fibers in multiple layers at 15-30 g/m 2 of each layer by a carding machine and a cross lapping machine, wherein the lapping thickness is controlled to be 1-5 mm, so as to form a quaternary fiber composite fiber layer; s3, preparing the composite needled felt Pre-needling, namely covering the quaternary fiber composite fiber layer on the primary composite layer, and adopting an inverted needling needle to perform needling with the density of 200-300 p/cm 2 so as to fix the quaternary fiber composite fiber layer and the primary composite layer in a intertwining manner; The main needling process comprises the steps of adopting a gradient needling process, using a fine needle on the side of a quaternary fiber composite fiber layer, and using a coarse needle on the side of a base cloth layer, wherein the needling density is 700-900 p/cm 2 , and the needling density is 400-600 p/cm 2 ; Needling post-treatment, namely pre-drying by hot air to remove air among fibers, so as to obtain a composite needled felt; s4, surface optimization and film coating After singeing, shaping and film coating, the composite needled felt is subjected to singeing, shaping and film coating to obtain a finished filter material; Singeing, namely, adopting a natural gas singeing machine, wherein the flame temperature is 800-1000 ℃, the speed of the fabric is 8-12 m/min, and the residual quantity of fluff on the surface after singeing is less than or equal to 0.5g/m 2 ; Shaping in a hot air shaping machine, wherein the temperature is 200-230 ℃ or 250-280 ℃, the tension is 5-8N/cm, the shaping time is 3-5 min, and the width shrinkage is controlled to be 1-2%; The method comprises the steps of laminating a layer of laminated film on the composite needled felt after shaping treatment, adopting an electromagnetic induction heating roller laminating machine, carrying out hot pressing at 240-270 ℃, carrying out 2.5-3.5 MPa, carrying out compounding at 4-6 m/min, carrying out hot pressing for 10-15 s, and shaping by a cooling roller after laminating to obtain the finished filter material.

Description

Filter material for dust removal of flue gas of sintering machine head and preparation method thereof Technical Field The invention belongs to the technical field of air pollution treatment technology and industrial dedusting materials, and relates to a filter material for dust removal of flue gas of a sintering machine head and a preparation method thereof. Background In recent years, with the promotion of ultralow emission in the steel industry, more and more manufacturers reform the flue gas dust removal of the head of the sintering machine, and the original electrostatic dust removal is changed into bag dust removal so as to meet the requirement of ultralow emission of particulate matters. In order to meet the ultra-low emission requirement that the particle is less than 10mg/m 3, the filter materials used in the cloth bags of the bag type dust collector are all coated with a high-temperature resistant composite filter material by needling, the base cloth is PTFE or glass fiber base cloth, and the composite layer is formed by compounding one or more polymer fibers such as PTFE, polyphenylene sulfide (PPS), polyimide (P84), aramid fibers and the like. However, in the practical use process, the existing filter materials have some problems to be solved. Firstly, no matter the polymer fiber or the glass fiber is conductive, static electricity is easy to generate in the using process, so that the effect of back blowing ash removal is influenced due to static electricity adsorption, secondly, because a small amount of spark particles are often carried in the machine head smoke, the small spark particles cannot be completely stopped from entering a cloth bag area despite a spark removing device, high-temperature damage and even perforation of a cloth bag filter material are caused, so that the dust removal efficiency of the cloth bag is influenced, even serious safety accidents such as cloth bag ignition are caused, and in addition, because the machine head smoke volume of a sintering machine is large, the used cloth bags are long bags with the size of not less than 6m, so that the requirement on the larger back blowing air pressure is higher, and the filter material is required to have higher strength, so that the service life of the cloth bag is ensured. Disclosure of Invention In order to overcome the defects of the prior art, the invention provides the filter material for flue gas dust removal of the head of the sintering machine and the preparation method thereof, which are characterized in that a plurality of fibers with specific compositions are adopted to be matched with a multi-layer structure, and the specific preparation method is combined to obtain the filter material for flue gas dust removal, and the synergistic effect of the compositions, the structures and the preparation methods is utilized to improve the conductivity of the filter material, reduce the influence of static electricity on the back blowing effect, enhance the strength of the filter material and improve the fire resistance of the filter material. The above object of the present invention is achieved by the following technical solutions: a filter material for dust removal of flue gas of a sintering machine head comprises a film coating layer, a composite fiber layer, a stainless steel fiber net layer and a base cloth layer which are sequentially arranged from a dust facing surface to a gas purifying surface, wherein the filter material is formed by sequentially paving the filter material from top to bottom, the overall thickness of the filter material is 1.5-6 mm, and the gram weight of the filter material is 500-1000 g/m 2. The raw material of the coating layer adopts Polytetrafluoroethylene (PTFE) microporous membrane with the aperture of 0.3-2 mu m, and the thickness of the membrane layer is 200-300 mu m. The composite fiber layer raw material comprises 2-15wt% of stainless steel fiber, 18-35wt% of basalt fiber, 25-35wt% of poly m-phenylene isophthalamide (PMIA) fiber and 25-35wt% of Polytetrafluoroethylene (PTFE) fiber. The stainless steel fiber net layer is made of stainless steel wires and is woven by the stainless steel wires. The stainless steel wire comprises 304, 304L, 316 or 316L, and the wire diameter of the stainless steel wire is 0.035-0.05 mm. Preferably, the stainless steel wire is 316L, and the wire diameter of the stainless steel wire is 0.035mm. The radial distance a between adjacent stainless steel wires in the stainless steel fiber net layer is 10-30 mm, and the latitudinal distance b is 50-100 mm. Preferably, the radial spacing a=20 mm and the latitudinal spacing 60mm of adjacent stainless steel wires in the stainless steel fiber mesh layer. The raw material of the base cloth layer is Polytetrafluoroethylene (PTFE) base cloth or basalt fiber base cloth. The invention also claims a preparation method of the filter material for dust removal of the flue gas of the head of the sintering machine, and the filter mat