Filters for powder spraying chambers

The spray chambers in the powder coating line are designed to collect unsettled powder, filter it, send it to the hopper for reuse and clean air supplied to the powder application area.

The entire filtration system is divided into preliminary, main and fine cleaning. All of these steps require different filters. The powder is sifted out with cartridge and belt filters, cyclones.

Cartridge filters

Cartridge collectors are a self-contained device for collecting unsettled paint. They are directly connected to the camera or installed inside the device.

As a rule, cartridge filters are installed in the chamber for preliminary and final cleaning. The first task is to separate the bulk of the paint from the air. The second is to filter out paint particles smaller than 0.3 microns. They are installed horizontally or vertically. Their number is different and depends on the size of the equipment. When the filters become clogged or broken, the equipment shuts down.

Filtration works like this: thanks to the fan, air with powder particles enters the filters. The paint settles on the outside and the air flows through the pores.

If too much powder accumulates on the filter, its effectiveness will decrease. Therefore, it must be regularly cleaned with compressed air. A programmable controller can be installed that cleans the filter as needed. The paint that has settled on the filter is sent to the collector and after to the feeder for reuse.

Cartridge filters are effective when large volumes of paint must be separated from the air. They can separate up to 99% of the powder and send it for reuse.

Cyclones

The principle of operation of the cyclone is in swirling the air with powder particles inside the device. Thus, centrifugal force is created which separates the paint from the air. It works like this: air at high speed enters the top of the cyclone, swirls and descends. The powder settles at the bottom of the device and goes to a special container.

The cyclone itself is a separator, not a filter. This means that it needs additional filtration of the air flow that returns to the room. Final filters will ensure that the cleanest possible air enters the chamber.

The cyclones are connected to the spray chamber by a pipeline. Their effectiveness depends on the diameter of the body, the size of the inlet / outlet and the height of the device. They can remove up to 98% of the ink. Cyclones are best suited for frequent color changes.

Belt filters

In large and medium-sized industries belt filters are the most effective. They are located at the bottom and rotate parallel to the conveyor path. Polluted air passes through them and the powder remains at the top. The air flow is purified further.

The second air stream, which is supplied by the fan, discharges powder from the filter onto a cartridge filter or cyclone.

The efficiency of these filters, as well as the previous ones can reach 98%.

Fine filters

This is a floor filter for a spray chamber or a ceiling filter. They are made of synthetic polyester fiber. And they are impregnated with a special agent that prevents the material from peeling off and dust migrating inside the material. Powder particles do not come off the filters.

They can hold 4-5 micron powder particles. This is several times the thickness of a human hair.

The average life of a ceiling filter for a spray chamber is 62 days of continuous operation.

Filters must be selected based on the characteristics of the spraying chamber, which is installed in production. They must be effective so that the air enters the chamber clean, and the maximum amount of powder is returned to work. It is very important to clean them regularly.