Filter Plates

The lifespan of filter plates is directly determined by usage, operation, handling, and the characteristics of the filter sludge.

Regularly check and clean the drainage grooves on the surface of the plates to prevent clogging or reduced flow through them.

Ensure that the drying and washing pressures are correct, as incorrect pressures can damage the plates.

The inlet hole must be checked and cleaned after each cycle to prevent clogging, which can cause unbalanced pressure on the filter plates.

Overfilling can lead to a clogged inlet hole, resulting in unbalanced pressure and potential damage to the plates.

Filtrate outlets on the plate should be checked regularly, and any trapped sediment must be removed to maintain proper flow.

High filling rates should be avoided. If a faster filling of the press is desired, the filling speed must be increased gradually to prevent damage.

The filtration cycle should not be interrupted by restarting the filtration process, as this can affect performance and plate integrity.

To preserve the maximum lifespan of the plates, thermal shocks should be avoided. Plates should not be exposed to temperature differences greater than 19 degrees Celsius.

A filter plate consists of a sealing edge and the plate web. Small ”pips” on the plate web surface allow filtrate to discharge after passing through the filter cloth.

Filtrate is discharged via filtrate discharge holes and channels to the corner ports, which collect and guide the filtrate out of the filter press.

Stay bosses provide mechanical stability and control flexing of the filter plate during the delivery of the feed slurry.

Regularly inspect and clean the sealing surfaces to remove solids buildup, which can cause leaks and wear. Use non-metallic scrapers for cleaning.

Fully pressure-wash the plates using a 2,500–3,000 psi pressure washer to clean sealing surfaces, web areas, filtrate ports, and discharge ports.

Keeping these areas clean ensures maximum flow across the plate and helps create evenly-formed filter cakes.

Inspect stay bosses for damage and remove any solid buildup using a pressure washer and medium bristle brush. Check for cracks that could lead to plate failure.

Replace plates that are cracked, warped, or broken. Keeping spare plates on hand can help avoid press downtime.

Clean membrane plates as you would recessed chamber plates. For fixed membrane plates, inspect the hinge point for cracks. Ensure replaceable membranes are fully seated to avoid leaks during the squeeze step.

Ensure the hydraulic cylinder has enough throw to properly clamp the plate stack. Removing plates without replacing them shortens the stack length, potentially causing leaks during the feed cycle.

Membrane filter plates offer advantages such as drier filter cakes, faster cycle times, efficient cake washing, and increased production rates.

The most common causes include:

• Out-of-balance pressures
• Clogged inlet or discharge ports
• Using filter cloths with different permeability in the same plate stack
• High feed velocity
• Uneven cake formation

To prevent out-of-balance pressures:

• Use uniform filter cloths across all plates
• Clean feed holes and channels after each cycle
• Maintain steady and gradual filling rates
• Inspect for uneven cake formation

• Recessed chamber plates hold slurry in deep chambers and rely on high-pressure filtration.
• Membrane filter plates have flexible surfaces that expand to squeeze out additional moisture from the filter cake, improving efficiency.

• High-permeability cloths allow faster filtration but may let fine particles pass.
• Low-permeability cloths provide finer filtration but slow down the process.
• Using inconsistent cloths within the same plate stack can cause uneven pressure distribution.

• Maintain clean and uniform filter cloths
• Ensure feed holes are clear and unobstructed
• Keep a steady and controlled feed rate
• Inspect cakes regularly for inconsistencies

• Polypropylene: Lightweight, corrosion-resistant, and durable for most applications.
• Cast iron: Stronger but heavier, used in high-temperature or corrosive environments.
• Stainless steel: Used for specific chemical-resistant applications.

The choice depends on factors such as:

• Required cake dryness
  Type of slurry being processed
• Filtration cycle time
• Chemical compatibility of materials

• Uneven or excessively wet filter cakes
• Leakage between plates
• High pressure drops or erratic pressure fluctuations
• Plates flexing or moving during operation