Cleaning processes used in Gas-Solid filtration systems

Gas-solid filtration applications follow the process designs- continuous process filters and trap filters. These designs are perfect for sintered porous metal elements and they function in an equivalent manner- gas travels through the metal mesh where particles are hold and captured on it. The basic difference between them is the frequency and particle elimination methods and element reproduction.  The decision for the type of filter used is based on the individual process factors and basically the solids loading.

The trap filters are used on clean streams for protection of downstream process and system. This type of filters does not need in-situ cleaning and solid elimination needs disassembly. The filter components are usually cleaned through chemical methods. The cleaning frequency varies with solid load and feed gas.

A regular process tungsten wire mesh filter is perfect for heavily particulate streams or in processes involving the use of dangerous materials. The cleaning interval is based on solid loading. Usually the cleaning durations vary from 1-2 minutes to a few hours. The blowback cycle can be initiated manually or automatically.

The applications involving gas stream processing need on-line blowback cleaning, the sintered mesh filters are perfect for automated process control and in-situ cleaning.

The particulate loading on the filter cartridges is similar for both filter designs. During the process, gas-solid combination moves towards outside the sintered metal filter components that have captured the solids. The processed gas travels along the filter wall and is released from the unit.

After reaching the specific differential pressure or cycle time, the supply is stopped at this time the backflow cycle starts. The system is separated and gas enters. Reverse flowing through the chamber and elements release the cake from the filter.

The sintered mesh featured system offers high throughput with nominal backpulse gas needs. Sintered metal filters are backpulsed sequentially even when the system remains active. When the specific differential pressure or cycle time limit reaches, the mesh elements are backpulsed to eliminate the cake. During the service, a massive high pressure gas enters the nozzle along the valves. The blowback gas releases from the nozzles and enters into the venturis entraining the gas from the chamber. The resulting gas flow develops a strong backpulse on the filter components that uplifts the filter cake. The cake drops on the discharge hopper then discarded. The reverse pulse of blowback gas usually remains for a few seconds. A part of the filter elements are pulse cleaned at one moment while the rest remains active to continue the filtration process hence ensuring the regular flow of the process gas stream.

The choice of suitable media and the equipment service conditions for liquid-gas filtration units is often confirmed through prolong testing to receive performance efficiency and required operation rates. The recovery pressure drop after blowback can be confirmed to offer long service. Suitable service media are essential for prolong operation life. Suitable particle loading and pulse blowback cleaning are essential choosing the ideal functional conditions. The mesh filters use diverse filtration technologies such as wide level cross flow filtration, in-situ back pulse and in-line gas filtration.