Page 34 - ITAtube Journal 1 2019

Technical Papers
tant step. “For this purpose, yeast and sterile air / oxygen is added to the cooled wort. The oxygen serves to activate the yeast cells. This green beer is piped into the fermentation tanks. The yeast attenuates the extract / sugar in alcohol and carbon dioxide, releasing heat”. Furthermore, the typical beer flavour is created in this main fermentation phase.
Regulating excess CO2
It takes around seven days until the extract content is nearly broken down. The green beer is pumped into storage tanks to mature and continue fermenting for three weeks, at a temperature of 0-1°C. “The yeast deposited in the fer- mentationtanksisthenwithdrawn from the coneat the bottom of the container, washed and can beused for a new fermentation process in part,” explains Gemü.
A complex stainless-steel pipeline system is used to feed the wort into the fermentation tank, with- draw the yeast after fermentation, and move the green beer to the maturing tanks. In order to adhere to the operating parameters, various process variables need to be regulated. In particular, the pressure in the fermentation tank which comes into being because of carbon dioxide build-up must be kept. The saturation of the green beer with CO2 and hence the later beer quality is criti- cally dependent on the pressure,” reports Gemü. However, if the pressure is too high, fermentation is slowed down. A controlled dis- charge of excess CO2 is therefore necessary. It can also be fed into a CO2 extraction plant, making it available for other processes.
Butterfly and diaphragm valves
“The feeding of the wort to the fermentation tank, shifting the
green beer and emptying it from the storage tank later can be carried out using commercially available stainless steel butterfly valves,” emphasises Gemü. The company mounts switchboxes directly on the valve actuators, for actuation and monitoring. Next to the pneumatic pilot valves used to control the butterfly valves, they also allow electrical position feedback to a control room.
Pressure in the fermentation tank is regulated using positioners and process controllers. These control- lers are also placed directly on the actuators of the butterfly valves. “They are allocated the specifi- cation of set values ‘W’ from the system control unit’s PLC”. Dia- phragm valves with electrical position indicators can be used in smaller systems for feeding yeast and ventilating wort.
Higher-quality stainless steel and PEEK
Producers of beer manufacturing equipment thus require numer- ous valves for demanding tasks. “Weuse high-alloyed steels and process optimisations to fulfil the requirements,” states Dietmar Pallasch, head of German sales, Mankenberg. This includes new materials like PEEK (Polyeth- eretherketone), higher quality stainless steel and polishing of valves.
Valves made by Mankenberg are mainly used in secondary cycles, for pressure reduction of water, steam and various gases. Further- more, swimmer valves are used. Vent valves are used inwater treat- ment plants. Around 30 percent of Mankenberg’s standard valves initially fulfil the requirements of the beverage industry for second- ary cycles.
Polished valves in demand
According to Dietmar Pallasch, there is “an increase of the wish for polished valves, as the pipes installed already are polished”. Who wants to remain successful in the market, needs to observe certification requirements for new European and international stand- ards, such as EHEDG, ASME BPE, 3 A and FDA. The requirements “will continuously grow. Welive in an increasingly internationalised world industry”.
Furthermore, the beverage indus- try expects high-quality materials such as high-alloy stainless steel, and for “minimal prices, as the lot size of components are already noteworthy,” explains Dietmar Pallasch. Customers also demand speedy delivery, quality and, most of all, delivery reliability, next to standards compliance.
A beer pipeline for Bruges
Much-loved by all, beer needs to flow. Any way possible. A clever idea of a brewery in Bruges, Belgium, created quite a stir. A beer pipeline connects the brewery in the historical center to a filling plant outside of the town core. This was highly liberating, as beer truckshad to press through the narrow, medieval lanes heavily frequented by tourists several times daily. As six million tour- ists a year visit Bruges‘ historical center, this was seen as quite a strain, which was also detrimental to transporting beer. Now 4000 liters an hour flow unhindered to the filling plant – naturally also with the help of valves.
The Wacken Open Air has also taken up on the idea of subterra- nean beer pipelines. Tractors used to transport beer kegs, battering the festival site. This wasn’t a sit- uation the organisers behind the
ITAtube Journal No1/February 2019
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