Permeability and dust filtration behaviour of porous SiC ceramic candle filter Dulal Das, Nijhuma Kayal ⇑ CSIR-Central Glass and Ceramic Research Institute, 196, Raja S. C. Mullick Road, Kolkata 700 032, India article info Article history: Received 6 February 2020 Received in revised form 1 April 2020 Accepted 6 April 2020 Available online xxxx Keywords: Candle filter Ramming Air permeability Mechanical strength Dust particle filtration abstract Porous SiC candle filter (660 mm L and 75 mm OD) were fabricated by ramming process using commercially available SiC powder (d 50 = 212 lm), with and without alumina and small amount (3 wt %) of clay as the major binder phase additives, following heat treatment at 1400 °C in air. Depending on the composition, porosity of the candle filters varied from 36 to 39 vol% and C-ring strength varied from 15 to 23 MPa. The air permeability and dust filtration efficiency of the candle filter were evaluated using laboratory made test set up. At room temperature, Darcian (k 1 ) and non-Darcian (k 2 ) permeability parameters varied from 1.9 to 2.2  10 12 m 2 and 5.4–9.72  10 8 m, respectively. Airborne fly ash particle filtration tests showed good performance of SiC candle filter with filtration efficiency of >97%. Ó 2020 Elsevier Ltd. All rights reserved. Selection and Peer-review under responsibility of the scientific committee of the 2nd International Conference on Recent Trends in Metallurgy, Materials Science and Manufacturing. 1. Introduction Porous SiC ceramic filters are mostly recommended for hot gas cleaning processes [1–4] as they possesses several advantageous properties such as low thermal expansion coefficient, excellent thermal shock resistance, high abrasion and erosion resistance, extreme inertness and mechanical strength even at high tempera- tures. Oxide bonding technique has been shown to be a very sim- ple, low-temperature and cost-effective processing method for fabrication of porous SiC ceramics. Permeability is also important to filter design, as it ultimately determines the type and power of blowers or compressors used to force the fluid through the filtering medium. In advanced coal-fueled processes for power production (IGCC and PFBC processes) and in biomass gasification/combustion, flues coming out from gasifiers or combustion boilers at high tem- peratures must be cleaned from entrained particles by ceramic fil- ters and fed to downstream turbines [5–8]. Typical candle filters are cylindrical tubular types, one side is closed and the other side is open. Hundreds of candle filters are set in a large hot gas filter unit and cleaning operations are periodically done to spate and remove dusts from the surface of filter element. The commercial filter candle lengths range from 1000 to 3000 mm with outer diameters between 60 and 150 mm and wall thicknesses between 10 and 20 mm. The useful filtering area (based on the outer candle surface) varies from 0.19 to 1.42 m 2 per element [3,7]. High-pressure drop during filtration means loss of energy and decrease in turbine efficiencies. Low-pressure drop values are always useful, as they can decrease the pumping power required in filtration processes. Permeability is an important property of porous ceramics because it directly correlates with the initial pressure drop of clean filters [9–10]. Fluid dynamical characterization of porous ceramics for filters thus becomes necessary to understand their permeation behavior. Most of the previous high temperature dust removal studies were carried out with commercial SiC ceramic candle filters in advanced power generation process [2–4,7,8]. Filtration performance in terms of collection efficiency and pressure drop of laboratory made samples are also evaluated using the laboratory test set up to filter nano aerosol particles [8–12]. Very few studies were reported in literature on evaluation of filtration performance of the ceramic candle filter using laboratory made test set up to filter coal fly ash particles in actual power generation conditions [13,14]. In this paper, we have fabricated SiC candle filter using a small amount of clay and alumina as the binder phase additives. The formation of the oxide binder phase in final ceramics was examined, the microstructural features of the candle filter were explained and the mechanical strength was determined. The air permeation https://doi.org/10.1016/j.matpr.2020.04.090 2214-7853/Ó 2020 Elsevier Ltd. All rights reserved. Selection and Peer-review under responsibility of the scientific committee of the 2nd International Conference on Recent Trends in Metallurgy, Materials Science and Manufacturing. ⇑ Corresponding author. E-mail address: nijhuma@cgcri.res.in (N. Kayal). Materials Today: Proceedings xxx (xxxx) xxx Contents lists available at ScienceDirect Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr Please cite this article as: D. Das and N. Kayal, Permeability and dust filtration behaviour of porous SiC ceramic candle filter, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2020.04.090