Tips for Operating Your VLS TMF Crossflow
Depending on the type of wine you are filtering, there are different steps and protocols to follow before you start using your VLS TMF Crossflow. Our Equipment, Parts & Service team has outlined this step-by-step guide on how to setup, connect, prepare and operate your VLS.
VLS TMF Crossflows are delivered with the membranes already installed for you. This means the membranes might arrive in a preserving solution or be completely dry. Before you get started using your new Crossflow, we recommend you carry out a complete washing cycle the first time the plant is started to ensure any preserving solutions and other liquids are completely flushed out.
A few important things to remember:
- 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.
Serious operating errors
The following plant operating errors must be avoided:
- Filtering without the pre-ﬁlter ﬁtted.
- Using non-conforming detergents.
- Failing to observe the maximum working temperatures of the ﬁlter.
- Causing thermal shock to the plant (e.g., cooling the hot ﬁlter rapidly after washing).
- Using excessively hard water or water containing an elevated content of metal salts.
- Filtering products with excessive content of bentonite, carbon or PVPP.
- Storing the ﬁlter during winter in areas where temperatures may fall below 0°C.
Using the ﬁlter
The TMF crossﬂow ﬁlters can be used instead of fossil powder ﬁlters; they cannot be used to ﬁlter wine scum or must or used instead of rotary vacuum ﬁlters.
This type of ﬁlter obtains a perfectly clear product, ready for bottling in just one step. It is thereby possible to use just one instead two or more ﬁltration processes with fossil powder ﬁnishing with a sheet ﬁlter.
To make this kind of ﬁlter easier to use and to extend the working lifetime of the membrane we strongly recommend:
- Decanting 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.
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.
- Given the particular nature of the filtration system, adjust the filter according to recommended flow rates. Do not exceed them otherwise the membranes may become irreversibly dirty.
NOTE: If the winemaker’s 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.
- Adjusting the filter to over high flow rates may get the membrane dirty much more quickly than when it is adjusted to lower flow rates. The quantity of filtered product obtained in the first case is less than that obtained in the second.
Certain wines, such as young wines with an elevated quantity of colloids, may not be suitable for ﬁltration given the low ﬂow rates that are obtained. In these cases, pre- treatment may be useful to simplify ﬁltration.
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.
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.
Need additional help? Visit our Parts & Service page to order spare parts online or request service with our expert technicians.