Candle Filter Basics Knowledge

Candle filter element is named based on their shape. These filter elements are usually hollow tubes with a cap on the bottom and a threaded connector on top that attaches to a header. The outer face of the tube is usually made of a punch plate, expanded metal, sintered metal, or porous ceramic to provide support for the filter media.

Our candle filter element media is wedge wire, a triangle-shaped wire that offers excellent abrasion resistance.

Candle Filter Operational Sequence

In its simplest setup, a Candle Filter can operate in three stages: Filling, Filtration, and Discharge. Depending on the process, the operation can include all or most of these steps listed below:

Precoating- If your solid is the product, then precoat is likely not for your operation since it mixes filter aid into the cake. If your slurry is sticky or if you need very clear filtrate right at start-up then running diatomaceous earth, perlite, or another filter aid prior to filtration may be a step you should take.

Filling- Slurry enters the vessel from the bottom, compressing the air or gas in the vessel above the candles and headers.

Filtration- Increasing pressure forces filtrate through the filter media on the candles, through the headers, and out the filtrate outlet. Solids are collected on the filter media and form a cake.

Washing- Spray bars near the headers can clean cake down the length of the candles.

Drying- Steam or gas replaces slurry and is forced through the cake and candles until there is no more filtrate to capture

Heel Removal- Air or gas fills the vessel and presses the remaining slurry out a pipe on the bottom and back into the feed tank.

Discharge- Both the slurry inlet and the filtrate outlet are closed. The sludge drain on the bottom of the vessel opens. The condensed air or gas trapped in a bubble above the candles and headers gets forced out of the sludge drain. This backwash breaks the cake off the candles and it is discharged. The unit is now ready to begin filling again.

 We professional desigh and supply the all wedge wire filter element , and our filtration core/strainer can be used in different industries, such as water treatment, coal mining, paper/ plus, food, beer, etc.