Errors to Avoid When Operating Your VLS TMF Crossflow
Last updated: 6/2021
Applies to: Winemakers and sparkling winemakers using the VLS TMF Crossflow.
Our Equipment, Parts & Service team has created this guide to highlight important ways in which you can avoid errors while operating your VLS TMF Crossflow. This article will detail both general and wine-specific considerations that will make your filtration smoother:
General Considerations
Setup
- Do not use hoses with a diameter greater than that required for the relative rate of flow. This is important as it prevents air bubbles from forming inside the hoses and increasing the oxygen content of the wine.
- Position the hoses connecting the filter to the feed and filtrate collection tanks so as to prevent obstructions. The length of the hoses must be proportional to the distance of the filter from the tanks. Make sure they are not too short (danger of obstructions) or too long (elevated pressure drops and top dead volume).
- Position the hoses so as to leave enough space for the operator to move around the filter and access the tanks..
- It is best to connect the product feed hose to the partial drain valve of the tank containing the product to filter. This is especially important if the product has not been transferred recently and large quantities of solid residues (such as yeasts) may lie at the bottom of the tank. This measure prevents these solids from clogging the pre-filter at the start of the filtration process.
Wine Preparation
The TMF crossflow filter can be used instead of fossil powder filters; they cannot be used to filter lees or must or used instead of rotary vacuum filters. Crossflows are best used to filter wine prior to bottling. Below are some good practices that will make filtration easier and extend the working life of the membrane:
- Decanting/racking and transferring the product before filtering it.
- Centrifuging the product if a centrifuge is available.
- Clarifying pressed musts with clarifying agents such as gelatin and bentonite (at least one transfer after using bentonite is always required).
- Clarifying the pressed must by flotation.
- Checking that there are no solid deposits on the bottom of the feed tank (yeasts, clarifying agents, bitartrate crystals) and eliminating them.
Operation
- Do not filter without the pre-filter fitted.
- Do not use non-conforming detergents.
- Always observe the maximum working temperatures of the filter.
- Do not cause thermal shock to the plant (e.g., cooling the hot filter rapidly after washing).
- Do not use excessively hard water or water containing an elevated content of metal salts.
- Avoid filtering products with excessive content of bentonite, carbon or PVPP.
- Do not store the filter in areas where the temperature may fall below 0°C.
Wine-Specific Considerations
FILTRATION FLOW RATE
The filtration flow rate of a crossflow filter depends on the type of wine, the content of suspended solids and colloids and the temperature. Higher flow rates may dirty the membrane much more quickly than lower flow rates and may lower the volume of filtered product. Do not exceed recommended flow rates otherwise the membranes may become irreversibly dirty.
If your experience suggests that a certain type of wine is difficult to filter with a normal fossil powder filter, the wine will also be difficult for a crossflow filter. Certain wines, such as young wines with an elevated quantity of colloids, may not be suitable for filtration without pre-treatment. Please remember that filtering flow rates are slower when filtering chilled wines. Cold processing always helps precipitate the colloidal substances that can make filtering difficult.
TMF 1 | TMF 3 | TMF 6 | TMF 9 | |
Young white | 400 | 1200 | 2400 | 3600 |
Young red | 300 | 900 | 1800 | 2700 |
Dessert wine | 300 | 900 | 1800 | 2700 |
Sparkling white | 600 | 1800 | 3600 | 5400 |
Sparkling red | 500 | 1500 | 3000 | 4500 |
FILTRATION OF SPARKLING WINES
Sparkling wine can be filtered only in conjunction with a sparkling wine filtration kit. Before starting the filtration cycle, the operator must make an isobaric connection between the feed tank, the filtering plant, the filtrate collection tank and, if necessary, the concentrate collection tank. This is the only way to filter sparkling wine without the wine losing carbon dioxide or the formation of foam inside the filter.