Candle Type Filters

Description

Candle Type Filters operate based on pressure. The system forces the fluid to be filtered through a series of vertical filters (candles). As solids in the fluid accumulate on the filter candles, flow decreases, and pressure builds. Once the pressure reaches a certain point, the system reverses the flow to blow the caked solids off the candles, causing them to fall to the bottom and exit the filter. These candles can be made from various materials, including cloth, ceramic, and metal. Depending on the material used and the type of fluid being filtered, you may need to replace the filters regularly or use filtering aids like Diatomite or Perlite, which are dosed into the system to pre-coat the filters. The system also requires regular cleaning and maintenance.

You must closely monitor these systems to ensure the pressure remains balanced, the cake sticks to the candles and builds up evenly without becoming too heavy, the pressure does not exceed safe limits, the flow rate is properly adjusted, and the filtering aids are applied and working correctly. Therefore, these systems are best suited for environments that operate with consistent solids levels and flow rates or for occasional batch processing. A glass production environment, however, rarely offers such consistency, with machines coming on and off line, various grinding and polishing tasks occurring throughout the day or week, and frequent breaks or shift changes.

Additionally, glass fines are very heavy and compact quickly into a concrete-like material, which can create significant challenges. Due to the weight of the glass fines, the system must generate high in-flow pressure to keep the solids on the candles and form the cake properly. This pressure may exceed the design limits of the system or filtration type. Moreover, once the cake forms, the dense and compact nature of glass fines can make it difficult to blow the solids off the screens. While Candle Type Filters work well in applications with consistent processes and lighter solids, the maintenance requirements and potential issues with glass fines make them less ideal for the glass fabrication industry.