Latest News

Partners

NETZSCH Pumpen & Systeme GmbH

27-03-18

Pumping Sparkling Wine Without Foaming

27-03-18

Oil-Free Compact Pump Simplifies Efficient Bottling

Due to their sensitivity, wines are considered to be a difficult fluid to pump, while carbonated wines present completely different challenges: Each variety, for example, has a special carbon dioxide overpressure that must be observed. At the same time, the released CO2 increases the tendency of the beverage to foam, which impairs the quality of the goods. A large Upper Italian winery has therefore been using a particularly low-pulsation, hygienically safe rotary lobe pump of German manufacturer NETZSCH Pumpen & Systeme GmbH for years. This T.Sano® pump guarantees not only the desired pressure over the entire pumping distance – and thus the quality of the wine – but also reliably prevents the unwanted development of foam. In this way, more precise dosing and better barrel emptying is achieved. The complete metal design of the pump and a drive without a lubrication system guarantee food safety and a perfect taste experience.

Whether lively or brisk, bubbles in a carbonated, champagne-style sparkling wine, for example, make you tingle. The amount and pressure of the CO2 are therefore not left to chance, but rather each variety has its own characteristic formula. This formula even determines the typification: Only wines with a carbon dioxide overpressure higher than 3 bar at 20°C are fully sparkling wines (spumante), while those from 1 to 2.5 bar are semi-sparkling wines (frizzante). To guarantee the desired amount and pressure of carbon dioxide, the entire production facility of the winery in Piedmont therefore operates under controlled pressure conditions up until the moment of isobaric bottling. Nitrogen is used as an aid to create still wines at 0 bar and particularly fizzy wines at 5 bar according to variety. This protects not only the special composition of the wine, but also prevents undesired foaming, which can make complete batches unusable in extreme cases.

In addition,the company previously used the gas pressure to pump the fluid. This method, however – as gentle as it is on the product – is very expensive, especially as it only allows imprecise dosing and the tanks are not completely emptied in the process. To achieve higher efficiency here, the winery decided to switch to a micro-filtration system for transport and a feed pump for bottling in the summer of 2015. The pump was never to mix the wines, however, and pulsation and the development of foam had to be prevented at all costs. Added to this were the high hygiene requirements of food safety. The winery ultimately chose the T.Sano® pump from NETZSCH, which was specifically developed for hygienically critical applications.

Gentle pumping and precise dosing

The function of the pump is based on two rotary lobes, which counter-rotate, thus transporting the medium from the suction to the pressure side. Since pumping is performed purely according to the positive displacement principle here, there is no possibility of pressure fluctuations or shearing forces. "In actuality, this type of pump does not pressurise the medium but rather only pumps against the existing counter-pressure – 1 to 8 bar in this case," says Alessandro Modenini, the NETZSCH sales representative responsible for the project. In addition, the specially designed internal geometry of the delivery chamber keeps any pulsation at a very low level so that values similar to those of complex spiralled, multiple rotary lobes can be achieved, despite the smooth rotary lobe. In this manner, a gentle, continuous delivery without any turbulence that could lead to foam is guaranteed and the organoleptic characteristics of the respective wine remain reliable.

An additional advantage of this technology is the constant flow rate, which can be precisely monitored in contrast with pumping with gas pressure. The delivery volume does not depend on the viscosity or consistency of the medium and is determined solely by the speed of the rotary lobe. In this way, the product can be dosed precisely using the speed control, which simplifies bottling and minimises production fluctuations. In addition, the rotary lobe pump is self-prim so that storage containers like wine tanks can be emptied almost completely without great effort. Since excess must be disposed of, this improved yield could noticeably increase the production profits of the winery in comparison with the previous method.

Oil-free, robust, compact drive

To meet food safety guidelines in addition to the economic aspects, all components used in the T.Sano® rotary lobe pump that come into contact with the medium are designed in stainless steel. The special drive also helps protect the product and consumer: Instead of the usual, complex synchronisation gearing, a toothed belt transfers the torque from the motor to the rotary lobe while synchronising the rotation of the rotary lobe in this design as in the case of all models of the T2 series from NETZSCH. It runs completely free of oil, which means no extra lubrication and oil change work is required, but also that environmental damage is absolutely excluded. In addition, the belt drive makes the pump very robust and low-maintenance since it is insensitive to breakdowns, and the hard-soft contact between the belt and gear wheels guarantees extremely smooth running. If a defect does actually occur, the belt can be removed by loosening just two screws and exchanged so that the pump is ready to use again within minutes without special tools.

This unusual drive form makes the T2 series very compact since the motor is flanged to the delivery chamber in a space-saving manner. This results in a comparably low weight and extremely small installation depth, due to which the aggregate can be installed into narrow spaces and used portably without a problem. Winery and brewery operations that convey fluids from tanks using only one pump, already use the latter solution.

Easy cleaning and maintenance

Thorough cleaning is required so that nuances of taste do not mix when different varieties are used. To make this as easy as possible, the interior of T.Sano® is designed to be free of dead spaces in a flow-optimised manner. Mechanical seals are evenly flush with the rear side of the rotary lobe. The rotary lobes themselves stand out from the competition due to smooth surfaces on all sides, as they are not screwed into the pump chamber, but rather fixed externally using quick-release components. In this way, product residue has nowhere to adhere and the pump can be flushed completely in a residue-free manner manually or using the CIP method.

For more detailed cleaning or servicing work, the complete front can be removed very easily so that there is free access to the delivery chamber. The rotary lobes can be removed and installed again completely independently of each other in an uncomplicated manner. For correct positioning during assembly, an installation and mounting gauge integrated into the top cover can be used, while seals designed in cartridge construction can also be easily pushed onto the shaft. For this purpose, the pump does not have be removed from the line and all maintenance can thus take place directly in place (full service in place), which saves time and money, as well as keeping necessary interruptions in operation to a minimum.

As a protective measure against overpressure, which cannot be excluded in pressure-based production, the winery expanded the aggregate by a bypass line. Forced ventilation was also integrated for safety reasons to protect the motor against overheating. T Sano® has therefore been running malfunction-free at the Piedmont company for a year and pumping 7 to 10 m³ wine, both semi-sparkling and sparkling wine an hour at low speed. After the company familiarised itself with the new possibilities that their previous pumpless method did not offer, it now reaches bottling throughputs of up to 11,000 bottles an hour – with just the right amount of fizzy bubbles.

 

Champagne-type sparkling wines and semi-sparkling wines require specific carbonation pressures depending on the type and variety. A well-known Piedmont winery thus provides monitored pressure conditions – which should also remain unchanged during bottling – in its entire production facility using nitrogen.