Shut-Off-Valves Preserving Aroma Substances in a Better Way

Author / Editor: Seher Sevim* / Wolfgang Ernhofer |

The freeze drying method is a process used in the production of pharmaceutical products, medication, as well as in food, and has proved itself to be very successful. This process is the most expensive and is thus used in the production of valuable substances, sometimes products which are sensitive to temperature. They may be stored at room temperature and may be used immediately if needed. Within the process the shut-off-valves have to be particularly effective.

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Charging valves in the freeze drying have to work reliably.
Charging valves in the freeze drying have to work reliably.
(Picture: Emil Kammerer)

This freeze drying is a method of preserving substances in which the cells keep their original properties and effect making it possible to return to the original substance by dissolving the dried material in a liquid. The quality remains unchanged and stays in its original high-quality-condition. This preservation-method on one or the other properties of pharmaceutical products can mean a life-saving property. The reliable sealing at minus temperature and the transitional range between atmosphere and vacuum make high demands on shut-off valves used in the process: Particularly the sluice systems have to work reliably.

Deutsche Extrakt Kaffee (DEK) in Berlin is part of the Cafea-Holding with its headquarter in Hamburg. The foundation for the Berlin plant was laid in 1969. This reputable coffee-manufacturer, widespread in Germany, has amalgamated to prepare the way for the manufacture of coffee in Germany under the auspices of the manager Mr. Jan Beernd Rothfos. From then on this plant has served as an example for the first coffee manufacturing plant in Germany.


The DEK has specialized in the production of instant coffee offering several variations. This high-quality-coffee is produced in the freeze-drying-plant quasi-continually in a 24-hour-production-operation. The production building is 35 m high and comprises 5 storeys. The production plant has been supplied with the Kammerer-shut-off-solutions in key positions since its infancy.

Freeze-drying is compared to the classic spray drying and the agglomeration method, the best-known method of protecting the product comprising the 800 various aroma products of the taste of the first-class coffee-bean. It is also called lyophilisation or drying by sublimation. The granules, known as instant coffee, are produced within the framework of this method following strict purity requirements — as a rule in four process steps:

1st Step

The raw coffee beans are roasted and ground: Different kinds of raw coffee beans are cleansed and transmitted to drum roasters, in which they are subjected to 200 °C (392 °F) - 230 °C (446 °F). Each coffee bean contains water which condenses during the roasting process. Coffee, which is the basis for the later instant coffee, is due to the water content darker than filter coffee. The roasted coffee is then ground, according to the size of the granules. In this way possible blockage in the following step is avoided.