Why does the Gold Cone work so well? (continued)

Horizontal Cartridges?

Why would anyone want to lay a filter cartridge on its side? The reason was to overcome upward can velocity effects used in traditional baghouses and in the early cartridge collectors. Air would enter the hopper and flow up into the filter housing. The dust could only be cleaned off the filters if the up flowing air was slow enough to allow the dust to fight back down through the air stream. This system works well on heavy dusts, but not on light dusts like weld smoke and fume silica.

This upward air flow created a limitation on the amount of air you could put in a given size cartridge dust collector where the media is packed much tighter than in a baghouse. It was devised that if you laid the filters horizontally, thus moving the clean air plenum to one side of the collector, you could expose the dirty air plenum to the top of the collector and thus bring the air into the top of the dust collector. This resulted in a down flow effect helping overcome the upward can velocity issue. This improved the performance of the cartridge collector over the old hopper entry inlet design.

The down flow style collector, however, presented many limitations in its inherent nature of laying a filter on its side. The biggest problem is that the dust does not get cleaned off the top of the filter. The dust blinds at least 1/3 of the entire filter because it cannot be cleaned off. This increases the air to media ratio in the collector and has caused premature failure of the filters in many instances. Many Operation and Maintenance manuals from horizontal cartridge filter manufactures recommend opening up the collector and rotating the filters monthly to overcome this problem. See Figure 1.

Figure 1 - Filters lying on their side results in top loading of the filter cartridges.

Another major issue with horizontal cartridge collectors is the fact that 100% of the incoming dust is dumped on top of the filters. There is no chance for pre-separation of heavy or abrasive particles from the air stream before coming in contact with the filters. This is also a major problem on spark generating application because any spark entering the collector will wind up on a filter cartridge increasing the risk of a fire.