Candle Filter Systems for High-Clarity, Automated Solid-Liquid Separation
The preferred choice when your process demands high-clarity filtrate, full containment, and minimal operator involvement - across batch, continuous, and hygienic-grade applications.
What Makes Candle Filters Different
Candle filters are a pressure-driven, fully enclosed filtration technology designed for processes where purity, safety, and consistency cannot be compromised.
Enclosed, Pressure-Driven Design
Unlike open filtration systems, candle filters operate as sealed pressure vessels. The process stream never contacts the environment, making them suitable for toxic, volatile, or sensitive materials.
Self-Cleaning Filter Elements
Candle-shaped filter elements build up a uniform cake during filtration and are cleaned by a reverse gas pulse, eliminating the need for manual media replacement and keeping the process running.
Automated Solids Discharge
Once filtration is complete, solids are discharged automatically, either as a dry cake or slurry, without opening the vessel or manual intervention. The system then resets and restarts the next cycle.
How a Candle Filter Works
Feed slurry is pumped into the sealed pressure vessel. Liquid passes from the outside of the candle elements through the filter medium, while solids collect and gradually form a uniform cake on the element surface.
As the cycle continues, clarified liquid passes through the filter medium and flows up through the candle elements to the filtrate registers. A constant pressure differential is maintained across the medium, ensuring consistent filtrate quality throughout.
Once filtration is complete, gas is forced through the cake toward the inside of the filter elements. This displaces remaining liquid from the cake, achieving thorough dewatering before discharge.
A reverse gas flow pressure shock is applied to each filter element. The filter medium expands, vertical cracks form in the cake, and solids are cleanly discharged, from a few millimetres up to several centimetres of cake thickness, in a single cycle.
Candle Filter, Cartridge Filter, or Filter Press?
Three common technologies for solid-liquid separation. Very different trade-offs depending on your solids loading, containment requirements, and automation needs.
Candle Filter
Cartridge Filter
Filter Press
Best for
High-clarity enclosed service with automated cake discharge
Polishing or low-solids filtration
High-solids batch dewatering
Solids Loading
Low to medium
Low
High
Filter media
Reusable candles/elements
Disposable cartridges
Reusable plates with filter cloths
Automation
High
Low to medium
Low to high, depending on the design
Operating cost
Medium
Can be high with frequent cartridge replacement
Medium, often driven by labour and cycle time
Containment
Excellent
Good, depending on housing
Moderate to excellent, depending on enclosure
Your process handles fine or compressible solids
Enclosed, leak-free operation is required
You need consistent, high-clarity filtrate
Minimising operator intervention matters
Your media is hazardous, toxic, or solvent-based
You need slurry or dry-cake discharge built in at the design stage
From Lab Trial to Full-Scale Production
Every DrM candle filter system starts with testing. The same technology that validates your process at bench scale is what runs in your plant.
Laboratory Testing
0.012 to 0.048 m²Bench-top units designed for early-stage feasibility studies and small-volume process development. Manually operated, they allow rapid evaluation of filtration behaviour, cake formation, washing efficiency, and discharge characteristics with minimal product volume required.
Pilot Testing
0.16 to 50 m²Pilot-scale systems mirror the design and operating principles of DrM's industrial filters, enabling cycle optimisation, parameter validation, and process confirmation under real operating conditions. Available for manual or automated operation.
Industrial Scale
Up to 300 m²Available as standalone filter units, semi-skid, or full-skid configurations, industrial systems integrate seamlessly into new or existing process lines. Every unit is built on the same proven principles as the lab and pilot systems, ensuring consistent scale-up with no surprises.
Material Selection
Material options:
Various Metal Alloys
Rubber Lining
Fluoropolymer Lining
Glass Lining
Rotational Lining
FRP Vessels
Selection criteria:
Process chemistry and pH
Temperature and pressure
Product purity requirements
Maintenance and cleaning methods
FUNDABAC® Candle Filter Process Overview
See the full filtration cycle step by step, from slurry feed to automated cake discharge.
BP OIL
"DrM filters have operated reliably and trouble-free, keeping our amine in excellent condition with minimal operator involvement."
Cydsa
"DrM filters have been in long-term operation and remain in excellent condition. We are very pleased with both the filters and the support provided."
Hitech
"DrM filters have been operating trouble- free for many years and remain in excellent condition. We are very satisfied and hope to cooperate again in the future."
GNFC
"We are able to operate our TDI plant at over 100% of its rated capacity with a single DrM filter running for more than 3 months continuously. The performance has been very satisfactory."
Roquette
"DrM filters have been in operation for over a decade and remain in excellent condition. They require little maintenance, and the support from DrM has been excellent."
SKC
"Over the years, we have gradually expanded to seven DrM filters, appreciating their reliability and low maintenance in our operations."
Explore Our Candle Filter Products
Every process is different. Explore our candle filter product range to find the right fit for your application.
FUNDABAC® Candle Filter
Fully automatic batch filtration for demanding separation processes requiring dry cake discharge and closed-system operation.
Discover
CONTIBAC® Semi-Continuous Candle Filter
Semi-continuous candle filtration for high-throughput processes where uninterrupted operation and consistent filtrate quality are critical.
DiscoverResources & Downloads
Access detailed brochure and our application questionnaire to learn more about our filtration systems, accessories, and performance monitoring options, or to help define the right solution for your process.
