Abstract: Particulate material such as food is heat treated in a cylindrical vessel by only partially filing the vessel under vacuum and agitating the material while injecting steam. The material is then flash cooled and withdrawn under nitrogen pressure.

Abstract: In a plate heat exchanger, a package of heat transferring plates is kept together between two end plates by means of two or more threaded bolts and nuts in threading engagement therewith. A motor is arranged through an endless drive member, such as a tooth belt or the like, simultaneously to rotate all the bolts or all the nuts. The plate heat exchanger thereby may be rapidly, simply and safely opened and restored for operation in connection with inspection and/or cleaning of the heat transferring plates.

Abstract: For improving the keeping qualities of certain food products, especially sliced meat products, it is suggested that the food products immediately after they have been packed are subjected to a heat treatment by means of microwave energy, so that they are maintained at a temperature in the interval 50.degree.-80.degree. C., preferably 50.degree.-70.degree. C., during a time period of 5-60 seconds. The food products (12) are moved by means of an endless belt (9) in a path across an elongated wave guide (15, 21) which has at least one slot (19; 22, 23) extending across the whole food products movement path.

Abstract: An apparatus for the heat treatment of particulate material such as food includes a vessel which may be pressurized or evacuated and a perforated agitator through which steam is furnished to a layer of the material under treatment in the bottom of the vessel while the agitator is oscillated.