Candle Filters comprise a group of columnar filter elements sealed within a pressure vessel. The filter cartridge can be wedge wire or sintered material element.

The candle filter is used for the clarification of liquids with a low solids content. They are typically installed for clarification and recovery applications from liquids with low solids content from 5% to less than 1% solids and even down to trace amounts. 

Candle Filters are best selected in the following instances:
1. When minimum floor space for large filtration areas is required.
2. When the liquids are volatile and may not be subjected to vacuum.
3. When there is a risk of environmental hazard from toxic, flammable, or volatile cakes specially secured discharge mechanisms may be incorporated.
4. When high filtrate clarity is required for polishing applications.
5. When handling saturated brines that require elevated temperatures the tank may be steam jacketed.
6. When the cake may be discharged either dry or as a thickened slurry.

Advantages
1) Completely airtight filtration, no leakage, no environmental pollution
2) The structure of the filter element adopts a duplex structure, and the flow rate is large
3) Pulse gas is used for back blowing and slag discharge, and the filter cake is easy to fall off, suitable for viscous materials
4) The operation process can be fully automated

Disadvantages
1)High headroom is required for dismantling the filtering elements.
2)The emptying of the vessel in between cake filtration, washing and drying requires close monitoring of the pressure inside the vessel to ensure that the cake holds on to the candles.