Candle Filter Sleeves and Bags

Candle filter sleeves are used in candle filters for solid-liquid separation in industries such as chemical processing, pharmaceuticals, food & beverage, and mining. They help retain solid particles while allowing the filtrate to pass through during processes like pressure filtration and cake filtration.

The filter sleeve is mounted onto the filter element using two filter sleeve clamp rings, one at each end. These rings secure the sleeve in place, ensuring a tight fit and preventing bypass. Proper installation is crucial to maintaining efficient filtration and preventing leaks.

Candle filter sleeves are made from a variety of synthetic and metallic fabrics, depending on the application. Common materials include:

• Polypropylene (PP) – Chemical-resistant and widely used in industrial filtration. Up to 90°C (194°F)
• Polyester (PE) – Offers good mechanical strength and durability. 150°C (302°F)
• Nylon (PA) – Flexible with high filtration efficiency. Up to 120°C (248°F)
• PTFE (Teflon) – Excellent for high-temperature and aggressive chemical environments. Up to 260°C (500°F)
• PVDF (Polyvinylidene Fluoride) – Resistant to high temperatures and aggressive chemicals, making it ideal for harsh filtration conditions. Up to 150°C (302°F)

• Filtration rating (micron size) – Determines the particle retention efficiency.
• Chemical compatibility – Ensures resistance to aggressive process fluids.
• Temperature resistance – The sleeve must withstand operating temperatures.
• Cake release properties – Ensures smooth discharge of filter cake.
  Seamless vs. stitched design – Seamless sleeves reduce the risk of bypass and improve performance.

A seamless filter sleeve eliminates weak points where leaks or fiber shedding can occur. This provides:

• More uniform filtration
• Better mechanical strength
• Increased durability
• Lower risk of contamination in sensitive applications like pharmaceuticals and food processing

The lifespan of a candle filter sleeve depends on factors such as:

• Operating conditions
• Filtrate composition
• Cleaning frequency and method

  Typically, they need replacement every few months to several years, depending on wear and clogging.

• Backflushing with air or liquid to remove trapped solids.
• Chemical cleaning using mild detergents or acid/alkali solutions (depending on the sleeve material).
• Steam cleaning for high-temperature sterilization (only for temperature-resistant materials like PTFE or PVDF).

Yes, many candle filter sleeves are reusable after proper cleaning. However, some materials may degrade over time and require replacement.

Candle filters are commonly used in pressure filtration systems, offering:

• High filtration efficiency
• Dryer filter cake
• Compact and fully enclosed operation
• Low maintenance and long service life

During filtration, solids build up on the outer surface of the sleeve, forming a filter cake that improves filtration efficiency. The cake is then removed by backflushing at the end of the cycle.

• Plain weave – Provides uniform filtration and high strength.
• Twill weave – Improves particle retention for finer filtration.
• Dutch weave – Offers very fine filtration with high durability.

Signs of a failing filter sleeve include:

• Increased pressure drop across the filter.
• Reduced filtration efficiency and cloudy filtrate.
• Tears, holes, or visible wear on the sleeve.
• Difficulty in cake discharge due to clogging.

• Regular cleaning and maintenance.
• Proper installation with secure filter sleeve clamp rings.
• Using the correct material for process conditions.
• Avoiding excessive pressure differentials that can damage the sleeve.