Abstract: A mixture of isomers of the formula C.sub.6 F.sup.12, which contains at least 80% by weight of the trans isomer of perfluoro-4-methyl-2-pentene and at most 3% by weight of perfluoro-2-methyl-2-pentene, is suitable as a cooling and insulating medium and can be used as a substitute 1,1,2-trichloro-1,2,2-trifluoroethane.

Abstract: The invention relates to a method for testing objects by thermal shock in a closed apparatus, comprising the following, preferably repeated steps:a) introducing the object to be tested into the apparatus,b) cooling the object by immersion in a liquid cold bath,c) drying the object above at least one cold trap or in at least one drying chamber,d) heating the object by immersion in a liquid hot bath ande) drying the object above at least one cold trap or in at least one drying chamber,the temperature difference between the hot bath and cold bath being 50 to 500 K., the temperature of the cold trap being 5-30 K. lower than the temperature of the cold bath and the temperature of the drying chamber being 10 to 50.degree. C. higher than the temperature of the hot bath, and the steps b) to e) being carried out in mutually separated parts of the apparatus, which are connected to one another via closable openings. The invention also relates to a device for testing objects by thermal shock.

Abstract: Apparatus for cleaning textiles, leather and furs by means of organic solvents as well as for working up the solvent, which comprises a cleaning drum with casing connected to a solvent cycle and a feed-back of solvent vapor including vapor liquefaction. The solvent cycle of the apparatus is provided with a pump, a filter, the cited distillation vessel and a solvent supply vessel containing a cooling cycle. The solvent vapor feed-back of the apparatus is provided with a sieve, a compressor, a condenser, a feed-back to the cited distillation vessel (drum casing) between compressor and condenser, and a duct from the condenser to the solvent supply vessel via a gas expansion device. The vapor feed-back is provided with a heat exchanger being part of the cooling cycle on the secondary side and a subsequent stop valve. The cooling cycle is provided with a compressor with subsequent heat exchanger being part of the feed-back on the primary side and a condensing coil being part of the solvent supply vessel.