On-line pulse-jet cleaning of pleated fabric cartridge filters for collecting pesticides

RSC Advances ◽  
2015 ◽  
Vol 5 (59) ◽  
pp. 48086-48093 ◽  
Author(s):  
Cuiping Yan ◽  
Mingxing Zhang ◽  
Longyuan Lin

Cleaning performance of pleated fabric cartridge filters for collecting pesticide particles and the effect of cleaning on system operational process.

Author(s):  
Xin Luan ◽  
Zhongli Ji ◽  
Longfei Liu ◽  
Ruifeng Wang

Rigid filters made of ceramic or metal are widely used to remove solid particles from hot gases at temperature above 260 °C in the petrochemical and coal industries. Pulse-jet cleaning of fine dust from rigid filter candles plays a critical role in the long-term operation of these filters. In this study, an experimental apparatus was fabricated to investigate the behavior of a 2050 mm filter candle, which included monitoring the variation of pressure dynamic characteristics over time and observing the release of dust layers that allowed an analysis of the cleaning performance of ISO 12103-1 test dusts with different particle size distributions. These results showed the release behavior of these dusts could be divided into five stages: radial expansion, axial crack, flaky release, irregular disruption and secondary deposition. The cleaning performance of smaller sized dust particles was less efficient as compared with larger sized dust particles under the same operating conditions primarily because large, flaky-shaped dust aggregates formed during the first three stages were easily broken into smaller, dispersed fragments during irregular disruption that forced more particles back to the filter surface during secondary deposition. Also, a “low-pressure and long-pulse width” cleaning method improved the cleaning efficiency of the A1 ultrafine test dust from 81.4% to 95.9%.


2013 ◽  
Vol 800 ◽  
pp. 149-152
Author(s):  
Yun Lei Li ◽  
Ling Bo Jiang

High temperature ceramic filter is designed and implemented for purification of hot coal gas, and then an experimental system is build in order to test its filtration performance. The reverse-pulse-jet-cleaning is introduced in detail. Finally, field experiment has been carried out and the results show that the ceramic filter keeps a high dust control efficiency and long on-line stability.


Author(s):  
Shaowen Chen ◽  
Yun Gong

Patchy cleaning is one of the principal factors resulting in the reduction of the efficiency and quality of reverse pulse-jet cleaning as well as the service lifetime of filtration units. To resolve the above issues, a new pleated cartridge shape was introduced in this study to improve the cleaning efficiency and quality of pleated filter cartridges. To calculate the transient flow and pressure fields for a simple filtration system with one filter cartridge in the reverse pulse-jet cleaning process, an unsteady computational fluid dynamics model was developed via the commercial computational fluid dynamics software of ANSYS CFX. The transient static pressure fields for filter cartridges under four different pleated cartridge shapes were studied. The conventional cylindrical cartridge was selected as the base-model of filter cartridge and contrasted with other three cartridge shapes. It was found that the convergent–divergent cartridge was able to effectively improve the cleaning performance without the increase of tank pressure. Different pleated cartridge shapes are expected to be able to redistribute the pressure drop across the porous media along the filter height and to improve the flow behavior after pulsing gas releasing from the nozzle. For convergent–divergent cartridge shape, the peak pressure on the inner surface of porous media has an obvious increase and the peak pressure arriving time is earlier than other cases. It shows that the reverse flow has much more competence to remove the dust powder or cake from the porous media. At the same time, the area-averaged pressure drop at the bottom section of the filter has an increase of 50% under the cartridge with a convergent–divergent shape compared to that with a cylindrical shape. It is considered to enhance the cleaning mechanical stress at the bottom section of the filter cartridge. The better cleaning performance was observed in the medium, with 150% increase compared to that with a cylindrical shape. Furthermore, the cleaning performance gets improved because the value enhances on the top section. The redistribution of pressure drop observed is mainly because the special geometric construction of pleated cartridges compresses the flow on the medium and produce higher pressure drop there. Further studies indicate that the improved cleaning performance was observable under the consideration of the tank pressure reduction and variation of media permeability during each cleaning phase, and the change of pleated cartridge shapes can also improve the cleaning performance when combined with other improvement methods.


Author(s):  
Longfei Liu ◽  
Zhongli Ji ◽  
Xin Luan

Sudden fractures in rigid ceramic filter tubes hinder the stable long-term operation of advanced power-generation processes. In this study, Time difference of arrival (TDOA) of dynamic pressure in the inner wall of filter during pulse jet cleaning process and outlet concentration with diameter of leakage during filtration and pulse jet cleaning process are investigated using high frequency sensors and optical particle spectrometry. The outlet concentrations measured under different leakage agreed with the theoretical values, with the peak outlet concentration being 2.5 times greater than stable outlet concentration. There is a linear relationship between leakage aperture and theoretical outlet concentration in leaking ceramic filter tubes. A positioning model that can precisely locate the leaking ceramic filter tube using the time difference in the dynamic pressure as measured at different positions is established. This research can quickly and accurately determine whether a ceramic filter tube is broken and location of breakage.


Author(s):  
Jeff Ladwig ◽  
Robin Linton

Like many coal-fired power plants today, the waste-to-energy (WTE) industry is faced with a number of challenges including the need to maximize plant output, lower outlet emissions and increase plant efficiencies. Within WTE, there’s also been a move from reverse-air baghouses to pulse-jet collectors due to lower initial capital costs and the ability to operate pulse-jet collectors at higher air-to-cloth ratios (3–4:1), allowing for a smaller housing footprint. However, the majority of today’s pulse-jet collectors utilize an off-line cleaning mode where modules are taken out of service and pulsed to lower the differential pressure. There are inherent advantages in switching from an off-line cleaning mode to an on-line cleaning mode. This paper discusses the idea of using the fabric filter as a damper and stabilizing draft through the baghouse and boiler. It also outlines the use of pleated filter element (PFE) technology to address increased production concerns, and the need for lower outlet emissions.


2015 ◽  
Vol 277 ◽  
pp. 82-88 ◽  
Author(s):  
Yunlou Qian ◽  
Yuanxia Bi ◽  
Mingxing Zhang ◽  
Haiyan Chen ◽  
Guanjie Xu

2019 ◽  
Vol 9 (18) ◽  
pp. 3687
Author(s):  
Xingcheng Liu ◽  
Henggen Shen

In order to study the effect of venturi structures on the cleaning performance of a pulse jet baghouse, several cleaning tests are carried out applying the pulse jet test bench. Experiments are performed using different filter bags with venturi tubes of varying throat diameters and lengths. Peak pressure and peak pressure arrival time are selected to evaluate the cleaning efficiency under different conditions. On this basis, a series of comparative experiments are conducted between a typical venturi-type and a new venturi tube design on a semi-industrial pulse jet baghouse. The effects of the new venturi-type on baghouse cleaning performance and dust emission are studied. The results show that pulsing air pressure has a significant effect on bag-cleaning performance; the larger the throat diameter and the shorter the venturi length, the higher the peak pressure and the shorter the peak pressure arrival time. This improves the cleaning efficiency of the filter bags. The new venturi design changes the distribution of the cleaning pressure in the vicinity of the bag mouth, effectively extending the cleaning cycle and reducing the energy consumption as well as reducing the dust emission concentration of the baghouse.


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