Candle filtration is a relatively advanced, safe, efficient, and pollution-free filtration method. It features high energy efficiency, airtight sealing, high precision, easy maintenance, safety, reliability, and a high degree of automation. It is widely used in solid-liquid separation filtration in industries such as petroleum, plastics, electroplating, chemicals, ceramics, pharmaceuticals, and sugar production.
Candle filtration has gradually replaced plate and frame, filter press, bag filters, and cartridge filters as the mainstream filtration method. The filter media can be reused multiple times, saving significant amounts of filter consumables. The airtight and secure candle body ensures a leak-free production process. Microcomputer-controlled, fully automated processes not only maintain continuous production but also improve efficiency, save labor, and significantly reduce the risk of production accidents.
Working Principle: The unique plum-petal-shaped candlestick is the core of this filter. This design enhances filtration efficiency while ensuring that the filter cake adheres to the filter element throughout the entire filtration cycle and ensures thorough cake removal. As material passes through the filter cloth, the outflowing clear liquid flows through the candlestick's outer tubes to the bottom of the candlestick, where it converges at the bottom of the central tube and rises to the liquid collecting rod.
As liquid passes through the filter cloth, solid matter in the liquid gradually accumulates on its surface. When this solid matter reaches a certain thickness, it forms a "cake layer." Because the gaps between the particles in the cake layer are very small, they prevent the escape of particulate impurities in the liquid, resulting in a clearer filtrate and achieving the desired filtration effect. (This is why candle filters are also called cake layer filters.)
After a period of normal filtration, when the cake layer exceeds a certain thickness, the rate at which filtrate passes through the cake layer decreases, and filtration efficiency deteriorates, it becomes necessary to remove the "cake layer." At this point, the system initiates a backflush to remove the cake based on signals from the pressure sensor, simultaneously opening the valve at the bottom of the cylinder to remove the residue. A new "cake layer" is then rebuilt, and
a new filtration cycle begins.
Filter Mode:
Direct Filtration
Installing high-performance, precision filter elements enables direct fine filtration, utilizing the filter cake formed by impurity particles for even finer
filtration. The filter cake also offers excellent cake releasability, with a maximum filter resolution of 0.2μm.
Precoat Filtration
The filter element surface is pre-coated with a filter aid such as diatomaceous earth or perlite to form a filter cake layer. Using this filter cake layer as
the filter medium, filtration can achieve clarifying-grade filtration with high filtration precision, significantly improving product clarity, and offering
the advantage of low operating costs.
Filter Cake Recovery
With its large filtration area and excellent cake releasability, it is capable of recovering large quantities of high-value filter cake from high-solids
liquids in one operation. With the addition of a drying system, a drier filter cake with a moisture content of less than 20% can be obtained.
Slurry Concentration
The filter element can be periodically backwashed and regenerated without discharging particles, and filtration can continue, continuously
increasing the concentration of particulate matter within the filter. Once a certain concentration is reached, the slurry can be discharged for reuse.
Filter Cake Washing
Intercepted filter cake can be washed multiple times directly within the filter. A drying system can also be added, integrating filtration, washing,
drying, and unloading operations. This reduces investment, shortens the process, and saves energy.
Note: These functions require different system designs.
