Wine growing has a very special meaning for the city of Krems, located on the river Danube in Lower Austria, in the country’s the largest quality wine growing area. Wine has been cultivated in the 1,000-year-old city since ancient times, a testimony to the tradition of viticulture in Austria. The quality of the wine is the result of the particular soil structure, the prehistoric rock terraces and the favourable Pannonian climate with dry, hot days and cool nights. This explains why viticulture is still a major industry in the region today.
And one of Austria’s most modern, state-of-the art wineries, with annual revenues of EUR 14 million (2015) and 13 hectares under cultivation, is also located here. This IFS-certified winery focuses on bottling quality wines in cooperation with local vintners and associations and international wine trading companies.
The winery already uses various Eaton beverage products throughout its operation. Now, it also relies on Eaton technology to help meet the filtration challenges associated with increased bottling productivity.
During bottling, sheet filtration is combined with a fully automated filter cartridge system. The sterile depth filter sheets, which measure 23.6 x 24.2 in / 600 mm x 615 mm (60 units with a flow of 145 gallons per square meter each hour, or 550 litres per square meter each hour), are connected in series to two pre-filter cartridges and a membrane filter cartridge (0.45 microns). This filter combination keeps bottled wine microbiologically stable and meets the winery’s high-quality demands.
To attain cost-effective filtration results, especially in light of the frequent changes between wine types, ensuring the flexibility of the production process and preventing blockages of the membrane filter cartridge are of utmost importance.
A service interruption usually occurs after every five days of constant two-shift operation, once the sheet filter starts to drip heavily. This short period of operation not only limits productivity but also causes wine loss and hygiene problems.
Another challenge for the winery is its limited capacity for switching from red wine to white wine during a given day, further reducing bottling productivity and flexibility.
“To augment productivity and maintain flexibility, we have studied the overall process and examined where we can best position ourselves in an efficient and cost-conscious manner”, says Andreas Zang, Eaton’s area sales manager for wines and sparkling wines in the regions of Franconia, Württemberg and Austria. “As the winery relies on our expertise in this field, we were able to find the right product to satisfy our customer’s high demands.”
Currently, the wine is first clarified using a sheet filtration system and then sent through a pre-filter and a membrane filter cartridge combination. If the filter sheets in the pre-filter stage do not work efficiently, particles and fine colloids can prematurely block the filter cartridges and especially the downstream membrane cartridge. The membrane filter cartridges are the most expensive filter component in this process and must be protected to ensure cost-efficient results. And the best results in the bottle can only be achieved if the process is microbiologically safe.
Eaton’s BECOPAD 115C sterile depth filter sheets are used to protect membrane filter cartridges in multi-stage filtration systems. They have a nominal retention rate of 0.1 to 0.2 microns and are specially designed to retain fine colloids, to extend the operating life of the membrane filter cartridges and thereby to increase productivity. Filtration of white wine after red wine is also possible thanks to the use of cellulose fibres. It is not possible to filter white wine after red if depth filter sheets with mineral components are used, as these have an adsorbent effect and bind anthocyanins, which are difficult to remove from the sheets even during rinsing.
“With the BECOPAD 115C depth filter sheets, sheet drip loss was practically eliminated and the replacement intervals were tripled. The depth filter sheet also increases the service life of the downstream membrane filter cartridges by significantly reducing the fine colloids beforehand", says Andreas Zang. “We were able to address all of the customer’s needs efficiently and cost-effectively, and we also demonstrated that we are a highly reliable and competent partner in both beverage treatment and filtration.”
Eaton’s products have enabled the winery to extend the service life of the depth filter sheets from five days (filtration volume: 264,304 gallons/320,000 litres) to 15 days (filtration volume: 84,535 gallons/1,000,500 litres). Furthermore, by using the BECOPAD depth filter sheets, drip loss has been substantially reduced compared to standard depth filter sheets.
The edge compression in the sheet filter improved from 0.059 in to 0.045 in (1.5 mm to 1.16 mm). The greater degree of compression is the result of the pure cellulose composition of the sheet. As no mineral components permeate the homogeneous cellulose fibre structure, the flexible fibres can be compressed more efficiently, reducing drip loss by up to 99 %.
Another and more important benefit of using the BECOPAD 115C sterile depth filter sheets is the possibility to filter white wine after red, once the proper rinsing and cleaning steps have been taken. The BECOPAD cellulose fibres have almost no adsorbent capacity and can thus be nearly completely rinsed of anthocyanins. By simplifying the process of changing the wine type, Eaton’s filter products have made it possible to optimise bottling schedules, allowing the winery to operate with greater flexibility.
As a result, the Krems winery is able to pursue its mission of modern oenology marked by high standards of durability, hygiene and flexibility. These are challenges that other large wineries and contract bottling companies also face in their processes.
Familiarity with these processes and the ability to see the bigger picture when developing targeted solutions illustrate Eaton’s track record of understanding and meeting the demands of customers and markets.