摘要:
In a pocket air velocity gauge, in order to expand the controlled, flow-dependent pointer deflection and the measuring scale to an angular range of at least 270.degree., the air flows through an inlet opening (22) on the back of a housing into a ring channel (12) extending around a pointer shaft (6) and over about 360.degree. and leaves it through a lateral outlet opening (13). In so doing, the air moves an air vane (37) fastened to the pointer shaft (6) counter to a restoring spring force in proportion to the velocity of the air. The ring channel (12) is provided with a cross section widening in the flow direction, and the pointer shaft (6) has assigned to it a second restoring spring which becomes active only after a certain angle deflection of the pointer.
摘要:
A process for the preparation of phthalic anhydride (PA) of catalytic oxidation of naphthalene or o-xylene with air, a preheated mixture of air and naphthalene or o-xylene being passed into a reactor charged with the catalyst, and the reaction gas leaving the reactor being passed through a separator in which the PA is separated out as a solid, in which process the air fed to the reactor is preheated, before or after the admixture of naphthalene or of o-xylene, by using it to cool the reaction gas in the PA separator.
摘要:
A method of separation by fractional crystallization from a liquid mixture in which the liquid mixture is repeatedly passed in turbulent flow through an indirectly cooled crystallization zone, which must be kept full. The liquid remaining after deposition of a layer of crystals on the wall of the crystallization zone is removed, whereupon the surface of the layer of crystals is washed and the crystals are melted by passing a melt of similar compositions to that of the layer of crystals through the crystallization zone. During crystallization the melt is maintained at the temperature of crystallization and crystallization is stopped when the frozen fraction is from 70 to 98%.
摘要:
A process for separating, by means of a selective solvent, a mixture of C.sub.4 -hydrocarbons which contains some hydrocarbons which are more soluble in the selective solvent and some which are less soluble therein, in which process the hydrocarbon mixture is separated, in an extractive distillation zone, into a top product which contains the less soluble hydrocarbons and an extract which contains the more soluble hydrocarbons and the selective solvent, the extract, taken off as the bottom product, is subjected to a flash evaporation and the resulting vapor component of the extract is recycled to the extractive distillation zone while the liquid phase remaining after the flash evaporation is fed to a solvent recovery zone, in which the liquid phase obtained from the flash evaporation is separated into a product containing the hydrocarbons and, as the bottom product, the selective solvent which has been freed from the hydrocarbons, the resulting selective solvent is recycled to the extractive distillation zone and the product which is obtained from the solvent recovery zone and contains the hydrocarbons is partially or completely recycled to the extractive distillation zone, after increasing the pressure in a compression zone, in which process the extract taken off the extractive distillation zone is brought, prior to the flash evaporation to a higher pressure than the pressure in the extractive distillation zone and thereafter the extract which is under this higher pressure is heated, in a heat exchange zone, by indirect heat exchange with the selective solvent obtained as the bottom product from the solvent recovery zone, and the heated extract is subsequently let down, in the flash evaporation, to a pressure which is at least equal to the pressure in the extractive distillation zone and is higher than the pressure in the solvent recovery zone.
摘要:
In a process for the removal of mercury by treatment with elementary nickel an external voltage is applied to maintain the potential of the nickel at a value which differs from the potential of the reversible hydrogen electrode in the liquid concerned by not more than from -250 mV to +50 mV. The treatment is carried out at temperatures of from 80.degree. to 230.degree. C.
摘要:
Flexible magnetic recording media consisting essentially of a web-like nonmagnetic substrate, a magnetic layer applied to one main side of the web-like substrate and a backing layer formed on the opposite main side of the substrate from a polymeric binder, at least one filler, at least one auxiliary pigment and a polyolefin having a spherical particle shape.