英文参考文献翻译
二零一五年五月
摘自Ullmann's Encyclopedia of Industrial Chemistry Published Online: 15 APR 2009 DOI: .
英文原文：
Filling
After filtration, all operations must be directed to maintain the quality of the beer. Mistakes made at this point are very hard to rectify and will only become noticeable much later (re-infection and aged taste caused by a high oxygen concentration). Furthermore, the beer must be bottled under an appropriate pressure to prevent the release of carbon dioxide. Filling and packaging are subject to various legal regulations, just like he production of beer itself. These regulations pertain to labeling, container capacity, and volume tolerance .
The amount of beer lost depends on the production facilities, and to a certain extent on capacity, and ranges between 3 and 10 %. Examination of beer loss provides an insight into loss of volume, which occurs from casting to the actual process of bottling, and into loss of extract.
Kegging. Barrels are manufactured of oak wood, aluminum alloys, stainless steel, or plastics lined with stainless steel; their size ranges from 10 to 250 L. After the barrel has been thoroughly cleaned, it is purged with carbon dioxide or, less advantageously, with air, and filled under counterpressure (isobarometric). Bowless filling units not only avoid the danger of infection, but they also protect the beer from
extensive contamination with oxygen.
Barrels with a cylindrical edge are called kegsor system barrels; they have a permanently installed fitting for cleaning, sterilization, filling, and tapping. With such a device, the barrel remains sealed and under a pressure of carbon dioxide even after it has been emptied. In this fashion the drying-up of beer remnants is avoided, and cleaning is facilitated. Cleaning and filling under sterile conditions are easily automated. Kegs and fittings are standardized.
Cellar Tanks. For larger distributors stationary draft beer tanks which hold 10 to 30 hL can be installed. The beer is delivered from the brewery in large tank trucks. The cellar tanks are equipped with cooling devices. They are lined with disposable polyethylene bags, which make it possible to store the beer under impeccable sanitary conditions without the need to clean the cellar tank. The excess pressure necessary to dispense the beer is created by gas which is admitted between the inner wall of the tank and the polyethylene bag.
Bottling. Bottles may be made of glass or plastics (PET, PEN). Whereas glass is diffusion proof, not only can carbon dioxide escape from plastic bottles, but also
