Installation of filter bags and cages that required grounding
The following are instructions for the proper installation of filter bags and cages that required grounding. Ensuring that metal cages are not isolated from the ground with the tube-sheet (cell plate) in applications that have a potential for an explosion hazard is very important.
Proper installation of filter bags and filter bag cages is required to ensure that the metal cages are not isolated from ground with the tube-sheet (cell plate) in applications that have potential for an explosion hazard.
WARNING: The effectiveness of a grounding mechanism depends upon proper installation and connection of the grounding mechanism to an adequately grounded collector component. Failure to properly install and connect grounding mechanism or maintain grounding of the collector component may result in static electricity discharge and possible explosion of dust stream within the collector and serious property damage and/or bodily injury. Proper installation must be verified per section 2 of these instructions prior to operating collector.
Section 1: Bag Installation
Bottom load collectors
The two grounding straps at the top of the filter bag are intended to ground the cage and clamp to the metal bag cup/venture. Ensure that the bag cup/venture is cleaned to remove dust and corrosion buildup. Position the cage in the bag so that the split in the cage top is located at 90 degrees from the seam on the bag. This will ensure that both grounding straps will not be located in between the split. Tuck the bag top into the cage top and install bag, cage and clamp per equipment manufacturer’s guidelines. Warning: If bag cup/venture is plastic, bag must be designed with different ground wire that can be attached to grounding bolt or stud.
Top load collectors with snap-band filter bags
The two grounding straps at the top of the filter bag are intended to ground the filter bag cage to the tube-sheet. Ensure that the hole is cleaned to remove dust and corrosion buildup. Install filter bag in the hole and insert filter bag cage.
Top load collector with flange top or ring top filter bags
The two grounding straps at the top of the filter bag are intended to provide a grounding path between the filter bag cage and the tube-sheet in addition to any ground achieved using the hold-downs. Ensure that the top surface of the tube-sheet is cleaned to remove dust and corrosion buildup. Install filter bag/cage per equipment manufacturer’s guidelines.
Section 2: Verification of proper grounding
Proper installation must be confirmed by testing to verify 1x10^6(1 megohm) maximum resistance at 500 volts between cage and tube-sheet (cell plate)
About filter bag ground wire:
Description: stainless steel ground wire, available in knit or braided construction. Stainless steel braid made from type 430 stainless steel. Stainless steel knit made of type 304 stainless steel.
Application: To eliminate static electricity from the filter bags. The static can cause a spark discharge that may set off explosion if gas stream in collector is an explosive mixture or flammable.
Specifications:
|
Style |
Width |
|
|
Inches |
mm |
|
|
Knit |
3/16 |
4.8 |
|
Knit |
3/4 |
19 |
|
Knit |
1 |
25.4 |
|
Braid |
3/32 |
2.4 |
|
Braid |
5/32 |
11.8 |
Static removal varies with the type of metal, ground wire (knit or braided) and the type fiber and construction of fabric used in the filter bags.