Abstract: A multistage arrangement for countercurrent separation of suspended solids, such as crystals, by means of hydro-cyclone groups connected in series and corresponding pumps and pump wells. For operating with relatively small expenditures with respect to apparatus under high pressures and at high temperatures within a certain, limited temperature range, the hydro-cyclone groups, the pump wells with pumps projecting into the pump wells, and the essential parts or regions of the lines are placed in a common pressure-proof and heat-insulated chamber. In addition, for removing coarser crystallizations and solid particles, an upstream classifier also accommodated in the chamber may be provided. The multistage arrangement can be used in a process for the production of terephthalic acid from dimethyl-terephthalate as the intermediate product, and in a process for the hydrogenation of coal.

Abstract: A process and apparatus for separating metallic from nonmetallic components in a mixture are disclosed. The process and apparatus rely upon the combination of prefractionation by sedimentation, preferably centrifugal sedimentation, followed by final concentration in a laminar flow process, preferably employing a spiral separator and one or more vibrating tables, to recover substantially all metal components of the mixture.

Abstract: A multistage arrangement for countercurrent separation of suspended solids, such as crystals, by means of hydro-cyclone groups connected in series and corresponding pumps and pump wells. For operating with relatively small expenditures with respect to apparatus under high pressures and at high temperatures within a certain, limited temperature range, the hydro-cyclone groups, the pump wells with pumps projecting into the pump wells, and the essential parts or regions of the lines are placed in a common pressure-proof and heat-insulated chamber. In addition, for removing coarser crystallizations and solid particles, an upstream classifier also accommodated in the chamber may be provided. The multistage arrangement can be used in a process for the production of terephthalic acid from dimethyl-terephthalate as the intermediate product, and in a process for the hydrogenation of coal.

Abstract: A method and apparatus for continuously regulating the slurry-weight or slurry-concentration of the discharge for wet-mechanical separated solids from suspensions in which a discharge cross-section of a separation is controlled as the slurry is discharged including means for measuring the viscosity of a discharge slurry formed from separated solids for altering the cross-sectional opening of a discharge member the separator by either increasing or decreasing the discharge cross-section in relation to the slurry viscosity and acccordingly the slurry weight is retained constant and at an approximate predetermined value.

Abstract: A method and apparatus for fractionation with hydrocyclones for providing the relative sharp separation between separate meshes being divided, by cumulating a slurry-fill as a regulative bulk measured variable below a lower reject nozzle, and adjusting the clearance between the surface of the slurry-fill and the lower edge of an overflow adjusted to a predetermined length which is reversely proportional to a desired separation mesh by means for changing or retaining constant the fill level of the slurry fill.