Abstract: A heat exchanger (10) for indirectly heating, drying and cooling materials comprises a hollow rotor (40) having an inlet (46) of heating and cooling medium and an outlet (47) of the medium or its condensate, a casing mounted on the hollow rotor, a plurality of disc-shaped base boards (20), a plurality of annular ducts (21, 23; 22, 24) projected from both side surfaces (11, 12) of the base boards (20), the duct forming a passage communicating with the inlet (46) and the outlet (47), arranged so as to be partly superposed sequentially on both front and back surfaces (11, 12) of the base board (20) from the inner peripheral edges to the outer peripheral edges of the base boards (20) in such a manner that partition plates for shielding the ducts (21, 23; 22, 24) being provided in the superposed positions.

Abstract: A plant for heat treating animal or vegetable material comprises apparatuses for two-stage or multi-stage heat treatment. A heat medium which is used in a second heat treatment apparatus (2), which follows a first heat treatment apparatus (1), consists of uncontaminated water/steam which is circulated in a closed circuit, that is to say separated from the heat medium of the first apparatus and from the treatment material of the second apparatus. The closed circuit extends from heat exchanger surfaces, which are supplied with heat energy from exhaust gas/exhaust steam from the first apparatus (1), via heat surfaces of the second apparatus (2) back to said heat exchanger surfaces. The closed circuit includes one or more steam compressor(s) (17) in order to bring in a manner known per se the heat medium of the circuit up to the process steam pressure before it is supplied to the heat surfaces of the second apparatus (2).

Abstract: The apparatus for the production of fodder and fat from animal raw materials such as slaughter house waste includes a heating apparatus for heating the raw material, a pressing apparatus for separating the heated material into a solid material phase and a fluid phase, a drier for drying the solid material phase to remove water and an evaporator for evaporating the fluid phase. The evaporator receives waste heat from the drier to carry out the evaporation of the fluid phase.

Abstract: Screw press with one or more screws having a sieve surface. The screw is fabricated to have a reinforced construction by way of a rigid main stem portion disposed radially inwards of a rigid sieve-forming surface portion and reinforcing ribs disposed between these portions. Screw threads of the screw are secured directly to the sieve-forming surface portion while a drainage duct for draining fluid from the latter portion is formed between this portion and the main stem portion.

Abstract: Process for the production of fodder and fat from animal raw materials, such as slaughterhouse waste. The raw material is subjected to heating to a temperature of from about 60.degree. to about 135.degree. and is separated thereafter into a solid material phase and a fluid phase. The solid material phase is subjected to a separate drying step and thereafter steps for the separation of fat and solid material individually. The fluid phase is subjected to separate evaporation the evaporation product being wholly or partially supplied to the solid material phase for separation of fat and solid material individually. Heat energy in the gases emitted from the drying step of the solid material phase is used in an evaporation step for the fluid phase.

Abstract: Screw press arrangement having two or more screw threads arranged side-by-side in a relatively tightly fitting press basket having openings for the drainage of fluid from the material which is fed into the press. At the feeding-in portion the core of the screw element has a relatively small diameter while the screw threads have a large diameter and at the discharge portion the core of the screw elements has a relatively large diameter while the screw threads have a small diameter. Cylindrical sections of the press basket are employed over the largest part of the length of the press and conically tapered sections of the press basket serve as transition and discharge sections respectively. Provision is made for about 20% of the total length of the screw element in the form of the discharge portion to have a uniformly increasing core diameter towards the discharge end and a uniformly decreasing press basket inner diameter.