Basf Aktiengesellschaft

Erfried Voelkl

Gerd Wunsch

Gerhard Pforr

Siegfried Schreiner

Werner Ostertag

Bernd Leutner

Volker Kiener

Max Appl

Hans Stark

Gerhard Peschau

Gerd Duembgen

Hans-Ulrich Schlimper

Eckhard Hetzel

Franz L Ebenhoech

Siegmar Lukas

Rudi Waibel

Guenter Schippmann

Gotthard Scizi

Hartwig Koester

Theodor Mader

A flange coupling for joining multi-layer apparatus sections or pipeline sections, in which corrosive and hot gases are handled, consists of an inner lining of glass which is resistant to thermal shock, or of quartz, which is surrounded by an outer metal jacket, the interspace between the outer jacket and the lining being packed with a heat-insulating material. In the region of the ends of the lining, refractory bricks which surround the lining, support it but do not touch it over the entire surface are provided between the lining and the outer jacket; the lining, at one or both ends, does not terminate flush with the refractory bricks, and the refractory bricks surrounding the lining terminate at least substantially flush with the surrounding outer jacket, the two ends of which each merge into a flange coupling.

Flange coupling

De-dusting of gases is carried out in an apparatus containing a granular-bed filter, the pourable granular filter medium flowing downward through the bed. The apparatus comprises a vessel of rectangular cross-section with a vertical side wall (4) extending from the top to the bottom. A partition (5), arranged parallel to the side wall (4), extends from the upper end of the vessel into the interior of the vessel. The remaining three side walls of the vessel extend - at least starting from a level corresponding to the lower end of the partition (5), taperingly downward to the outlet (9). The partition (5) is supported by the two walls adjacent to the vertical wall and forms, together with these and with the talus (7) of the filter medium, which arises at the lower end of the partition, a chamber (3) into which the inlet (2) for the gas to be purified opens. At the inlet (10) for the filter medium, located at the upper end of the partition, a further talus (12) of the filter medium forms, defining a collecting chamber (16), in which the outlet (17) for the purified gas is located.

Apparatus for de-dusting gases

To destroy phosgene contained in gases, the phosgene is decomposed catalytically in the presence of active carbon by hydrolysis with water vapor, in the absence of liquid water, at above the dew point of water.

Process for destroying phosgene

In a process for the manufacture of sodium dithionite by reacting sulfur dioxide with sodium formate and aqueous sodium hydroxide solution in the presence of methanol, an aqueous methanolic solution of sodium formate is first produced by reacting carbon monoxide with sodium hydroxide solution in an aqueous medium, containing from 1 to 50% by weight of methanol, based on the amount of water, at from 80 to 120.degree. C. under a pressure of from 10 to 40 bars. The resulting aqueous methanolic solution can be reacted directly, in the conventional manner, with sulfur dioxide and aqueous sodium hydroxide solution to give sodium dithionite.

Manufacture of aqueous methanolic solution of sodium formate

Concentrated dithionite solutions are produced by cathodic reduction of an aqueous solution, containing sulfite and/or bisulfite, which is circulated by pumping. The cathode and anode chambers are separated from one another by a permselective cation exchanger membrane. The catholyte must be circulated at least 10 times per hour and the selective catholyte volume outside the cell, defined as

Continuous manufacture of sodium dithionite solutions by cathodic

Finely divided metal oxides produced by combustion of metal carbonyls are separated from the stream of gas by filtration. Before filtration, the stream of gas is subjected to a permanent change of direction in a tubular zone. This change of direction must be sufficient to cause a centrifugal acceleration which is from at least 1,000 to 10,000 times the acceleration due to gravity.

Separation of finely divided metal oxides, produced by combustion of

For the preparation of anhydrous sodium dithionite by the reaction of sulfur dioxide with sodium formate and caustic soda in the presence of organic solvents, sulfur dioxide is passed, together with the formate, into a liquid containing all of the caustic soda required for the reaction. This initial liquid may contain, in addition to the caustic soda, a portion of the sulfur dioxide or formate required for the reaction.

Manufacture of sodium dithionite

Growing community of inventors

Frankenthal, Germany

Erfried Voelkl