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ON-SITE MICROFILTRATION OF WINE There are several processes available for the filtration of wine. DE pressure leaf and pad filtration have dominated the wine filtration industry for the past several decades. Recently microfiltration (known as cross flow filtration) has seen more extensive use in the world wine industry. Based on technology coming out of the water purification industry, the systems have seen several improvements over the initial systems offered for sale to the wine industry. The most popular cross flow systems in operation today are based on polyethersulfone hollow fiber membranes. Other systems include spiral wound membrane systems and ceramic systems. All of these processes require a cross flow velocity of 1.5 - 2m/s to keep the membrane sufficiently free of fouling between runs. Putting this into perspective, a 1 gallon block of wine will need to be pumped and passed across the same membrane 20-40 times prior to exiting the filter system. There are several pros and cons to all of these processes, with the key being membrane life and replacement cost thereof. VA Filtration USA offers our Lo-Cross-Flo mobile microfiltration system. This is a unique technology in that it is not actually a cross flow filter system, but uses predominantly dead-end filtration to filter the wine. This system is currently in operation in Australia and South Africa. Please contact the respective country offices if you are interested in our service. TECHNICAL SPECIFICATIONS ON THE LO-CROSS-FLO SYSTEM
We do not utilise the cross-flow action to keep the membrane clean but rather make use of a considerable increased surface area to compensate for any loss in flow rate. The membranes are the most important factor in the system. With increased surface area we are not only able to feed semi dead-end but have a lower flux rate per m2 with an immediate lower trans membrane pressure. All these factors equate to a less abrasive filtration system for wine.
HOW DID WE ACHIEVE A SEMI-DEAD-END MODE OF FILTRATION? We have managed to reduce the membrane costs, thus increasing the surface area required for a more gentle system. Specifically for the wine industry it is important that wine be handled as little as possible for various reasons. Pumps are mostly utilised to transfer wine and various studies have proven that the wrong pumping procedure can damage the wine. For this reason we only utilise mono-pumps for 90% of the pumping on board our Low-X-Flo machine since they have no "sheer" effect like centrifugal pumps have. Since our system is not a cross-flow system, we do not need the huge centrifugal pumps required by traditional cross-flow systems.
PRICING The pricing of our mobile service for the filtration of wine at your winery is extremely competitive. In fact, you will be amazed at what we actually charge considering we use such advanced technology. Give us a call for pricing information. You will also be amazed at how much you can save on consumables used for filtration.
WHY FILTER USING MICROFILTRATION (Cross-Flow)? A question many have asked and to which the answer is a matter of preference and taste. The benefits of microfiltration are numerous. The more pertinent question however should be "How does it affect the character of my wine?" Due to the level of filtration achieved by a properly functioning microfiltration system (0.2 µm to 0.4 µm to be compared to an average of 0.6 µm during D.E. filtration) it has been said that cross-flow systems strip the wine of certain high end molecular weight compounds. Now this so called "stripping" affect is purely theoretical and actual test work on this "stripping" phenomenon has yet to be published, however many winemakers are of the belief that red wine is affected considerably during a cross-flow filtration. We believe a lot of this "stripping" is due to the excessive use of the wine as a cleaner during the process i.e. 20:1 cross-flow across the membranes in order to achieve longer run times by reducing fouling. We have challenged this belief and we believe that by lowering the cross-flow action through the system, by increasing surface area and running dead-end, we can prevent the so called "stripping" affect. We have thus introduced you to the Lo-Cross-Flo microfiltration system.
BENEFITS OF USING MICROFILTRATION
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