Plate And Frame Diatomaceous Earth Filter For Wine Making

A Plate and Frame Diatomaceous Earth (DE) Filter is a type of filtration equipment commonly used in winemaking to clarify and stabilize wine. It uses diatomaceous earth (also called kieselguhr) as a filtering medium to remove suspended solids, such as yeast, bacteria, wine sediments, and other particles, improving the clarity, stability, and overall appearance of the wine. The filter is particularly effective for coarse filtration and polishing before bottling.

How the Plate and Frame Diatomaceous Earth Filter Works:

1.Filter Construction:

The filter consists of a series of filter plates and frames arranged in a stack. Each filter plate is typically made of stainless steel or plastic and has a perforated surface to allow liquid to pass through. The frames act as spacers between the plates and allow for the introduction of wine to be filtered.

Diatomaceous earth is applied to the surface of the filter plates, forming a filter cake that captures particles from the wine as it flows through.

2.Diatomaceous Earth Coating:

Before filtration begins, diatomaceous earth is spread across the plates to create a fine layer (called a filter cake). The DE powder has tiny, porous particles that trap suspended solids as the wine passes through the filter.

The wine to be filtered is pumped into the filter, where it flows through the stacked plates. The DE filter cake acts as a barrier, allowing the liquid (wine) to pass through while trapping suspended solids in the cake.

3.Filtration Process:

As the wine passes through the DE-coated plates, the fine particles in the wine (such as yeast, bacteria, and sediments) are trapped in the filter cake. The filtered wine then exits through the filter’s outlet.

As filtration proceeds, the filter cake gradually becomes more saturated with particles, so the pressure required to push the wine through the plates increases. Periodically, the filter plates need to be cleaned or the cake replaced to maintain efficient filtration.

4.Cycle and Maintenance:

Once the filter becomes clogged with solids (after processing a certain amount of wine), the cake layer is removed, and the filter is either recharged with fresh DE or cleaned for reuse. The plates may also require cleaning or replacement if they become too fouled or damaged.

Key Components of a Plate and Frame Filter:

• Filter Plates:These plates hold the diatomaceous earth and are designed to filter out solids from the wine. They are perforated and stacked to create the filtration surface.
• Frames:The frames separate the filter plates and provide channels for the wine to flow through. They help direct the wine into and out of the filter stack.
• Feed and Outlet Ports:The wine enters the filter stack through the feed port and exits through the outlet port once it has been filtered.
• Diaphragms/Valves (optional):These allow for controlling the flow of wine and managing pressure during filtration.

Advantages of Plate and Frame Diatomaceous Earth Filters:

1.High Efficiency:

Diatomaceous earth filters provide high efficiency for coarse filtration, especially for removing yeast, bacteria, and large wine solids like pulp, skins, or stems that remain after fermentation.

They are able to clarify the wine quickly, providing clear, stable wine in a short amount of time.

2.Preservation of Wine Characteristics:

The process is gentle on the wine, preserving its aroma, flavor, and color. Diatomaceous earth filtration is less likely to strip essential phenolic compounds or alter the wine’s sensory profile when compared to more aggressive filtration methods.

3.Cost-Effective for Medium-Scale Production:

For wineries that process moderate volumes of wine, plate and frame DE filters offer a cost-effective solution. They are less expensive than advanced filtration systems like crossflow or membrane filters, while still being highly efficient.

4.Ease of Use and Maintenance:

Plate and frame filters are relatively easy to operate, and the components are usually designed for quick cleaning. The filter cake is simple to replace or clean after each use, making maintenance manageable for most wineries.

5.Flexibility:

The system is versatile and can be used for both coarse filtration (removing large solids) and polishing (clarifying the wine). This makes it suitable for use at different stages of the winemaking process, from post-fermentation to pre-bottling.

Disadvantages of Plate and Frame Diatomaceous Earth Filters:

1.Labor-Intensive (for Manual Systems):

Manual or semi-automatic systems can require more labor, especially when it comes to applying diatomaceous earth, changing or cleaning the filter cake, and monitoring the filtration process. Larger operations may find this impractical.

2.Waste Disposal:

The used diatomaceous earth and filter cake must be properly disposed of after each filtration cycle. Some wineries may repurpose the used DE for agricultural or composting purposes, but disposal still needs to be managed carefully.

3.Clogging and Pressure Build-up:

Over time, the filter cake can become too saturated with solids, causing a build-up of pressure within the filter. This can result in slower filtration and the need for frequent maintenance to clean or replace the filter cake.

4.Limited for Fine Filtration:

While effective for coarse filtration, plate and frame DE filters are not ideal for fine filtration or sterile filtration (which is typically done with membrane filtration). They are less effective at removing very fine particles, bacteria, or yeast that may still be present in the wine.

5.Space Requirements:

Large plate-and-frame systems can take up considerable space in the winery, especially in high-capacity operations.

Applications in Winemaking:

1.Clarification: Plate and frame filters are excellent for removing large particles and improving the clarity of the wine after fermentation, prior to bottling.

2.Stabilization: By removing suspended solids that can cause haze or other issues, these filters help stabilize the wine, ensuring it remains clear and stable throughout its shelf life.

3.Polishing: They are often used as a polishing filter for fine-tuning the clarity of the wine before final bottling. They can also help remove residual yeast or other fermentation by-products that might be present in the wine.

4.Pre-Filtration: Before fine or sterile filtration, a plate and frame filter may be used as a pre-filter to remove coarse solids, reducing the load on more sensitive filtration systems.

Conclusion:

A Plate and Frame Diatomaceous Earth Filter is a reliable, cost-effective filtration option for wineries looking to clarify, stabilize, and polish their wine. It is particularly beneficial for medium-scale wineries or for those looking to improve the clarity and appearance of their wines without compromising on flavor and aroma. While it may not be as fine as membrane filtration, it offers an excellent solution for removing larger solids and is a widely-used tool in the winemaking process.