Precoating for improving the cleaning of filter media clogged with metallic nanoparticles

Abstract

Filtration of dust nanoparticles emitted from metallurgical processes is currently problematic, due to a rapid increase of the pressure drop and an inefficient filter cleaning, inducing high maintenance costs. This paper investigates the use of precoating technique to overcome the cleaning difficulties caused by the metallic nanoparticles. It consists of protecting the filter surface with a dust layer composed of micron-sized particles that is easily discharged upon cleaning. In this study, the pulse-jet cleaning of flat filters with and without precoating is evaluated. The aim is to determine the effect of operating conditions on the cleaning efficiency and provide guidelines on the application of precoating. Different precoating materials are tested, to determine whether the material choice is of influence. Experimental results highlighted the increase of the collection efficiency and dust holding capacity using precoating. The cleaning efficiency was significantly improved from 10% without precoating to 90% with precoating. Clogging/unclogging cycles showed that the use of precoating allowed stabilizing the filtration process.

Airborne dust pollution emitted by El Hadjar Metallurgical Complex: quantification, characterization, and occupational health hazards

“…Filtration of dust nanoparticles emitted from metallurgical processes is currently problematic, due to rapidly increasing pressure drop and inefficient filter cleaning, leading to high maintenance costs. Authors of [11] have suggested a precoating technique to overcome cleaning difficulties caused by metallic nanoparticles. It consists of protecting the surface of the filter with a layer of dust made up of particles of micron size, which is easily evacuated during cleaning.…”

Influence of precoating on the regeneration efficiency of filtration inorganic membranes

“…8 This involves the formation of a filter-cake layer consisting of solid-waste microparticles that protect the filter surface, restrict the blockage of filter media by fine dust particles, and enhance the regeneration efficiency of the filter, thereby extending its operational lifespan. 9,10 Khirouni et al 11 improved the cleaning performance of pleated filters clogged with metal nanoparticles by precoating. They studied the influence of the precoating deposition mass on the regeneration efficiency and found that precoating could enhance the regeneration efficiency of the filter from 15% to 90% with an optimal precoating deposition mass of 20-40 g/m 2 .…”

“…Specific properties, such as chemical inertness, nontoxicity, and low cost, are required for precoating materials. 11 Wollastonite, a chain-like structured mineral composed of 48.3% CaO and 51.7% SiO 2 , exhibits needle-like characteristics, stable chemical properties, low thermal expansion, and low cost. 14 Compared to other particle shapes, needleshaped particles can provide higher porosity in filter cakes, reducing the interactions between particles and membrane surfaces and between the particles.…”

Customization of hierarchical air filter media by tailoring the structural parameters of needle punched nonwoven

“…There are two attributes that a filter media should possess. Usually, for filtration application, an optimization or balance is necessary of these two attributes [1–4]. Wang et al.…”

“…There are two attributes that a filter media should possess. Usually, for filtration application, an optimization or balance is necessary of these two attributes [1][2][3][4]. Wang et al [5] proposed a porous gradient geopolymer-based tube membrane and achieved a high PM2.5 and PM10 removal efficiency for air pollution.…”