Perhaps one of the most overlooked aspect of bag filter housings are the accessories available for increasing filtration efficiency, enhancing worker safety and reduction of product loss. The following bag filter accessories can be used in both #1 and #2 size bag filter vessels.

 

Displacement Balloons

These are hollow stainless steel tubes designed to sit within the center of your filter bag to displace the volume of liquid within the filter bag. Your liquid flows into the bag and around the displacement balloon and because it is centered within the bag and not touching the filter bag surface displacement balloons do not restrict flow or increase differential pressure. The purpose of filter bag displacement balloons is to reduce the amount of product loss when changing filter bags. Clogged filter bags often retain the liquid within and may require hours to completely drain through the filter bag. A #2 size filter bag has a volume of approximately 5 gallons, so with each filter bag change you could be losing about 5 gallons of process liquid. In some cases, such as waste water it may not matter, in other cases where the liquid is a coating, chemical or otherwise has value such losses are a significant expense.

 

Using displacement balloons also reduces the weight of the filter bag for personnel, making them easier to lift and reducing the chance for injury. Likewise once the displacement balloon is removed the residual level of fluid within the filter bag is very little, reducing the chance personnel will come in contact with the liquid. Displacement balloons significantly increase personnel safety when the liquids filtered are aggressive.

 

The aforementioned product waste reduction also reduces disposal costs which are often correlate to the weight of the filter bags. When the carry-out liquid is internally drained into the waste lines its reduction may translate into reduced treatment chemicals and discharges which is also a cost savings. Displacement balloons are fully welded and made of stainless steel to be reused for the life of the bag filter housing.

 

Bag Positioners

These are a skeletal structure made of stainless steel and inserted into the center of the filter bag. Their purpose is to ensure the filter bag is fully expanded within its support basket. Some ultra efficient filter bags having an absolute retention (such as ACCUGAF and PROGAF filter bags) require the use of filter bag positioners due to their multi-layered structure. Even nominally rated filter bags benefit from filter bag positioners because it helps maximize the surface area for the liquid to pass through, minimizing differential pressure and frequency of filter bag replacement. #2 size bag filter vessels having filter bag lengths of 32" are difficult to fully extend with the arms of personnel and it can be dangerous for personnel when the liquid is aggressive; filter bag positioners simplify the process significantly.

 

Magnetic Inserts

Powerful rare earth magnetic assemblies can be suspended in specially designed filter bag positioners to create a powerful magnetic field within the flow path of the liquid being filtered. Their purpose is to increase filtration efficiency by attracting ferrous particles and reducing the clogging rate of the filter bag. The magnetic assemblies are easily removed and cleaned with the separated ferrous material concentrated for recycling or disposal. We've written an article about enhancement of filtration using magnetic assemblies.

 

The following accessories can be used with any of our bag filter designs: