Guidelines for Fabric Filter Trial Bag Test

Before switching to a new type of filter media, or a new bag design, we recommend performing a field test under typical operating conditions. Regardless of reasons for considering a bag change”extending bag life, improving efficiency, lowering cost, reducing pressure drop, supplier change, or better compatibility with process/gas chemistry”a trial provides valuable information to help you successfully achieve your goals.

• Choose Location: Choose a compartment/module or location in the baghouse that’s representative of conditions the bags may experience. For example, if you have issues with bag wear from abrasion, or where temperature extremes (hot/cold) negatively impact media, place the trial bags in the same location where the problem typically occurs.
• Record Details: Use a tube sheet bag layout chart to record location of each trial bag, along with specifications for the installation: quantity of bags, manufacturer, date the trial begins. Without this information, it may be difficult later to identify the test bags, since after being in service for a while identification markings tend to fade away.
• Direct Comparison: For an accurate comparison, place some brand new bags of the type you use now adjacent to the trial bags. This way, you can see how both types of bags wear under the same conditions.
• Supervise Installation: We recommend direct supervision of trial bag installation, using manufacturer recommendations. Bag media varies in how it must be handled to avoid damage during installation; play it safe and avoid taking for granted that procedures for existing bag installation will be appropriate for the trial bags.
• Periodical Bag Testing: If time and process allows, perform periodical visual checks of the bags, along with permeability and strength testing. This may prevent emergency shutdown if the bags don’t perform as expected. The tests should be performed on the trial bags, and also on existing bags installed when the trial began. How often you perform these checks depends on offline availability of the collector, and on your objectives. If on-site testing is not available, contact the manufacturer for support or have an outside independent laboratory conduct the evaluation.