There are 3 common types of cage based pulse jet systems:
Dirty side “bottom” access tubular style. The bags are often held in place with a hose clamp.
Clean side “top” access tubular style. The bags are fixed in the “cell plate” with a plate, integral bag “snap band” or venturi fixture.
Clean side envelope style (bags can be side or top access).
Generally held in place with a clamp applying pressure to the cage/bag gasket.
Certain industries have developed their own style of filter bag and cage. Variations of the 3 common types are found in Asphalt Facilities, Food and Grain processing to name a few.
European designs tend to be different than North American styles.
Frost fortunately has hands-on experience in many different makes and models from all over the world.
Shaker Style Systems
Mechanical shaker systems have been in service for over 100 years.
The down side of shaker systems often includes large foot print (size) and the need to stop the airflow through the bags to clean them down (intermittent operation).
The good news about shakers is that they do not need compressed air and the media can often be more forgiving than pulse jet filters in some harsh conditions.
We have extensive service and inspection experience in both standard tube and envelope style filter bag shaker systems.
Envelope style filters are commonly used in small transfer or pressure relief vents where room is at a premium and the dust loading is not too heavy.
There are shaker, pulse and reverse air envelope systems. 40 years ago the envelope system was quite common.
Today, the envelope pulse jet system is still being installed as an alternative to cartridge systems where the process demand and head room are a concern. Many of these systems are derived from European manufacturers.
We service many different makes and models.The more popular include:
- AZO, DCE, Reimelt and Torit multi-bag and single envelopes
- Sly Shakers and reverse air envelope Dynaclones
- Pangborn CH shaker and reverse air envelopes.
Pulse Jets - Cartridges
Cartridge dust collection systems are perhaps the most common being presently installed through-out the world in most dust/powder producing facilities.
Cartridge systems are compact and often easy to change the filters in.
The down side of cartridge dust collectors is that they do not function well if:
1. They are overloaded with dust
2. The dust has a high volume of low micron sized particulate
3. There is a high content of moisture in the air stream
Their performance forgiveness level is less than a pulse-jet cage style baghouse.
Large hoppers help with high dust loadings and pre-coating helps with fine particulate to prolong the life of the filter.
It is important when purchasing a cartridge dust collection system that maintenance access to the clean side of the system is easy. Many OEM’s fail to install inspection hatches.
We can provide help with filter change-outs, troubleshooting and the correct selection of media for your system.
Reverse Air Systems
One of the original “continuous cleaning” dust collection systems utilized a chain driven traveling “reverse air” cleaning ring on the outside of the bags. Reverse air simply indicates a “reverse flow high volume – low pressure air” to clean the dust cake off the bag surface. The airflow through the bags is reversed.
Many modern reverse air systems use a rotating blown down mechanism (traveler) on the clean side of the baghouse that blows clean air in to the clean side of the bags. This allows for continuous operation of the dust collector.
Large reverse air dust collectors use a combination of dampers and fans to collapse or back flush the bags.
We understand the different set-up for each of these systems as we service each style on a regular basis.