5 Steps to Specify a Filter BagJump to - Step 1, Step 2, Step 3, Step 4, Step 5
Step. 1 MATERIAL SELECTION(choose the right filter media for your application)You should choose the media from which your filter bags will be constructed based on the type of application they will be used for. Take the following things into consideration prior to selecting your media:
Choosing the correct filter media is an important and sometimes difficult process. To assist you in the identification of the right media for your bags, keep the following in mind: Filter bag performance is directly related to how well it can tolerate the environment in which it is being used, how efficiently it can remove the dust particles and it’s ability to clean and renew. You must first learn to identify the type of filter media currently used in your application. Below you will find a list of typical construction methods:
For additional information on media types please examine our Sample Chart A simple test to determine if a material is a thermoplastic is to take a small swatch and put a flame to it. A thermoplastic material will begin to melt when exposed to direct heat. The selection criterion eliminates materials based on temperature and chemical characteristics. The first cut is usually made based on temperature. Then the chemical characteristics of the gas stream are considered to further refine the search. Next, the efficiency of the material further dictates the construction of the material i.e. – the weight – oz/sq. ft., fiber and surface treatments/membranes. Last but not least, if there are still two or more candidates it comes down to a price versus performance trade off.
Step. 2 MEASUREMENTS (get accurate measurements for optimal performance) Most dust collectors have been upgraded over the years due to the need for new permits which called for reconfiguration of the bag house in which case OEM configurations will have changed. Because of this you will need to obtain accurate measurements for your filters before ordering replacement filter bags. If you currently have filter bags installed that are functioning properly, you can pull out one of those bags to get the proper measurements for your replacement order. (spare bags not yet used can also be measured if available) If you are removing a used bag to measure, please be sure to use all necessary precautionary measures set in place prior to removal (i.e. – gloves, protective garments, & respiratory equipment if needed) It is best not to pull the numbers off the unit because of possible changes to the configurations.
Step. 3 and 4 TOP & BOTTOM CONSTRUCTION
(of the filter bag play can determine
it’s efficiency)
MECHANICAL CLEANING (SHAKER) BAG HOUSES - usually found in critical applications
REVERSE AIR BAGHOUSES - usually found in large air handling environments such as power plants and cement plants although they do have uses in a variety of industries.
Pulsejet (Reverse jet) Baghouses - found in almost every industrial environment. They are by far the most popular design and are seen in nearly all industry segments.
Step. 5 ADDITIONAL OPTIONS (can improve filter bag performance)
GROUND WIRE – Use to comply with Factory Mutual requirements for static dissipation. Groundwire can be found in stainless steel and copper and actually only works in a localized area of the filter. For optimal static dissipation look at conductive fiber filter made with Epitropic or Stainless Steel fibers. WEAR CUFFS – Used to combat abrasion at the bottom of the bag either from “sandblasting” of the bags or bag-to-bag abrasion due to turbulence in the bag house. Usually 2 to 4 inches in length and made of a material similar to that of the body of the filter bag. SPECIAL FINISHES – There are many finish options that can be added to the filter media at the time it is manufactured. Please refer to the materials selection area for further details. Jump to - Step 1, Step 2, Step 3, Step 4, Step 5
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