Abstract: A rotary compressor such as a screw-type or a spiral compressor comprises a compressor stator and one or more rotary compression elements, which compressor stator is provided with a suction port, a delivery port and a lubricant inlet, the lubricant being intended for lubricating each compression element, for sealing the gaps between the individual compression elements and between the compression elements and the compressor stator, and for cooling the medium to be compressed during the compression process. The compressor also comprises an inlet for a cooling medium for cooling the lubricant which opens out near or in the delivery port.

Abstract: Apparatus for continuously removing from the mother liquor the crystals contained in a suspension of crystals in the mother liquor and for washing the crystals with a washing liquid, comprising a closed cylindrical chamber, feed devices for the suspension of crystals, discharge devices for removing the disintegrated crystal bed, feed devices for washing liquid, filter devices in the form of a flat ring for extracting mother liquor from the suspension supplied, while retaining crystals, transport devices in the form of rotating blades which are fitted in the cylindrical chamber above the filter devices and stator blades above the rotating blades being able to move backwards and forwards over a certain stroke in the axial direction between the filter devices and the stator blades fitted at a distance above the filter devices.

Abstract: The invention relates to a crystallization process for recovering a pure substance from a liquid mixture, a starting mixture being cooled down in a crystallization zone to form a crystal suspension from which crystals of the pure substance are recovered, wherein a) the crystal suspension is subjected to a crude preliminary separation in a (preliminary) separation zone to form a first mother liquor and a crystal mass containing relatively small particles, b) the crystal mass formed in a) is allowed to develop in a development zone at a temperature which is higher than that of the crystallization zone and lower than the melting point of the substance to be recovered, and is separated into a developed crystal mass and a second mother liquor, and c) the developed crystal mass formed in b) is separated into a third mother liquor and the intended pure substance in a separation zone, as well as to an apparatus suitable for performing said process.

Abstract: Method and apparatus of discharging non-condensable gases from the circuit of a compression refrigeration machine, wherein a part of the circuit through which there is no flow is indirectly cooled by a smaller secondary refrigeration machine in order to condense the condensable refrigerant vapor in that part and thus to lower the content of non-condensable gases to be discharged in that part, whereby the value of the suction pressure of the refrigerant circuit of the secondary refrigerating machine is used for automatically starting and stopping the discharge of non-condensable gases.

Abstract: The process for separating the solid particles in the column is based on the intermittent supply of pressurized suspension to the apparatus which pressure supplies the energy required for feeding the suspension near one end into the column, the squeezing of the suspension liquid out of the suspension under withdrawal of the suspension liquid from the column near that same end of the column, the compaction of the solid particles, the transport of the compacted bed of particles towards the opposite end of the column and the washing of the compacted bed with wash liquid, the bed is mechanically disintegrated, the product of this disintegration is removed in suspended form while maintaining a wash front separating the non washed and washed parts in the compacted bed.

Abstract: Apparatus for separating solid particles from a liquid suspension and/or purification or leaching of solid particles, consisting of a cylindrical column which near one end is provided with a rotatable scraper for the disintegration of a washed compacted bed, an inlet for wash liquid and an outlet for the disintegrated particles, and contains near the opposite end of the column, means for supplying liquid suspension, a non movable screening device, which screening device is only permeable for the suspension liquid and an outlet for the liquid.

Abstract: An apparatus and method for shaping the teeth on a gear wheel to conform in a close sealing fit with the teeth of a globoid worm wherein a gear wheel blank and tool holder are supported for rotation about non-intersecting, mutually perpendicular axes, the tool holder axis lying in a plane which passes between the front and rear faces of the gear wheel blank. A pair of cutting tools are mounted 180.degree. apart on the tool holder and have cutting edges which extend radially out from the tool holder axis, the two edges being axially separated by a distance equal to the width of a gear wheel tooth. The blank and tools are rotated at velocities which are related by the same ratio as the velocities at which the gear wheel and worm are intended to operate and at the same time the tool holder and blank are fed toward one another, whereupon both sides of the gear wheel teeth are machined in one continuous sequence of undirectional rotational movements.

Abstract: A rotary displacement compressor having a driven cylindrical rotor inside a casing provided with spirally-extending grooves, and at least one gear in sealing engagement with the teeth of the rotor in which the axis of rotation of the gear intersects the axis of rotation of the rotor and in which the gas to be compressed is drawn-in through the open ends of the grooves at one end of the rotor and an exhaust port is located in the wall of the casing near the other end including a second port in the wall casing at the same axial height as each exhaust port, the port being in communication with the intake side of the compressor via a return pipe, and a regulating ring to control the size of the return port and the exhaust port.