摘要:
Process for purifying a stream comprising phosphoric acid and a first amount of impurities, comprising: forming a slurry of phosphoric acid crystals in a water mother liquor; separating the phosphoric acid crystals from the mother liquor by filtration in a wash column comprising a filtering element, while a packed bed of crystals coming from the slurry forms near such filtering element; washing the separated phosphoric acid crystals in the wash column by bringing a washing liquid in countercurrent to the crystals in the bed up to a wash front, where the washing liquid recrystallizes, the bed being subjected to a movement in the direction of such wash front; forming a purified stream comprising phosphoric acid and a reduced amount of impurities by melting at least part of the washed crystals; and extracting the purified stream from the wash column through a product outlet of the wash column; wherein water is introduced into the wash column, between the wash front and the product outlet and/or in a melting circuit producing at least part of the washing liquid, and wherein the introduction of the said water decreases the equilibrium temperature of the contents of the melting circuit.
摘要:
A wash column for processing a suspension of solid particles in a liquid comprising a bed forming chamber in which a packed bed of solid particles can be formed, filtrate extraction means for extracting liquid from the suspension as to form the packed bed of solid particles in the bed forming chamber, and a suspension supply line for supplying the suspension directly to an end of the bed forming chamber, wherein the suspension supply line ends in the bed forming chamber.
摘要:
A rotating knife is disclosed for disintegrating a crystal bed formed in a washing column for processing suspension of solid particles in a liquid. The rotating knife is provided with a spoke support. The spoke support comprises at least two spokes. The relative angle of the spokes is between approximately 20° and approximately 80°.
摘要:
A method for treating a contaminated alkaline amino acid salt solution is provided. First, carbon dioxide is introduced into the amino acid salt solution, with the result that carbonate or carbonate salts is or are precipitated, these being filtered off. The remaining filtrate is then cooled, amino acid or amino acid salts being crystallized out and likewise being filtered off. The amino acid or amino acid salt is then dissolved again, with the result that a treated amino acid salt solution is recovered.
摘要:
A method is provided for automatic preparation of displays containing requirements for compliance with export restrictions for a set of exportable elements. The method includes the steps of: compiling an inventory of the exportable elements with applicable criteria for control identified for each exportable element; obtaining a digital matrix of a plurality of destinations containing control criteria for each destination; and automatically, using a computer, comparing criteria for control for each exportable element with control criteria for a plurality of countries and preparing a display, selected from the group consisting of a display for each country with applicable restrictions for each of the exportable elements for which restrictions apply to that destination, a display for at least one exportable element that includes destination for which restrictions apply, and both of the preceding displays.
摘要:
A tool for use in the fixing of plank cladding where the tool includes a first member (1) and a second member (11) shorter than and spaced from the first member (1) to provide the sides of a plank receiving slot (36) which has a bottom (35), a hook (12) on the second member faces away from the first member (1), a plank retainer (21) extends through the first member (10) and is biassed by a spring (28) to obstruct the slot (36). In use the tool hook (12) is engaged with an already fixed support plank and the next plank to be fixed is supported on the retainer (21). When the next plank is part fixed the retainer (21) is withdrawn from the plank slot (36) to allow the part fixed plank to enter further into the slot (36) as the tool is raised to unhook it from the support plank.