Objective
A Chinese OEM approached Solaft with concerns around the tightening regulations around particulate emissions, to find a cost-effective way to reduce PM10 emissions from the baghouse to meet regulatory targets.

Issue
China has a strict policy around these emission levels, with a high level of scrutiny and breaches attracting large fines and/or forced shutdowns. An existing coal-fired plant needed to move from PM30 to PM10 compliance without a baghouse refit, and without adversely affecting differential pressure or filter bag life.

Solution
Solaft Filtration Solutions technical team worked with the OEM to develop a specific Low Emission filter media that specifically addressed the need to lower PM10 emissions. Fine fibres were introduced into the fabric to optimise the pore size of the surface filtration media, this allowed particulate capture in the micro-pores of the surface filtration media and increased the rate of dynamic filtration resistance.
Several media were developed, and rigorously tested under dust load in Solaft’s VDI machine located in our Chinese laboratory. The resultant media was then successfully trialled on-site, before full installation of the Low Emission Filter Bags.

Outcome
The low emission filter bags were successfully trialled, and the benefits to the Coal-Fired Power Generation plant were:
• 97% removal of PM10 particles under extreme hazardous air-quality conditions.
• Particulate emissions were maintained below 5mg/Nm3.
• Successfully maintained operating DP.

Objective
An American Coal-Fired Power plant approached Solaft to solve an issue of premature filter bag failure, generally occurring within 2-3 weeks of installation.

Issue
The plant found that they were making excessive filter bag changes due to premature failure. This resulted in higher operating costs, significant diversion of scarce labour resources from other valuable tasks and lost production.  The method of failure was holing between the middle and the bottom of the bag, particularly for those bags in line with the inlet of the dust collector.

Solution
Solaft proposed introducing a shorter StarBags™, which represented a significant reduction in filter bag length from the existing 8.5m bags. The increased surface area of the StarBags™ relative to a standard bag of the same length enabled the reduced length without compromising particulate capture and production rates.
The reduction in filter bag length enabled the filter bags to have removed them from the line of the direct inflow thereby eradicating the premature failure.

Outcome
The trial was a success, and the benefits to the Coal-Fired Power Generation plant were:
• Operating DP was reduced 30% whilst maintaining gas flow.
• Pulse pressure was reduced 50%.
• Significantly improved uptime and reduced maintenance cost.
• Air-to-Cloth ratio remained unchanged.