Nano Fiber

Recently developed polymeric fibers with a diameter of less than 100 nm to produce innovative membranes

Nano Particles

Particles with a diameter less than 100 nm. Many recent innovative products are based on nano particles with their special mechanical and optical properties. Nano particles are characterized by an enormous spec. surface and their properties are influenced mainly by boundary surface effects, i.e. Van-der-Waals forces.

Needle Felt

Filter medium for surface filtration made of a compacted tangled fiber fleece. The fibers of the fleece, bedded horizontally at first, are looped by punching needles vertically through the fleece. Through this felting process the fiber structure receives a greater stability. Needled felts have a random pore structure which can be varied over a wide range as to their retention properties, but exhibit due to their three-dimensional structure a distinct deep-bed behavior, which can lead to irreversible blockage of the pore structure by intruding particles.

Newtonian Flow

In Newtonian fluids a flow sets in immediately when a force is applied: they have no yield point. In laminar flow parallel liquid layers slide along each other which generate a shear stress between the layers. The following linear relationship exists between the shear stress τ, the viscosity η, and the velocity gradient (slope) dv/dy across the layers:

The viscosity of Newtonian fluids is constant at all shear strains in contrast to shear thickening or shear thinning.

Newtonian Fluid

In Newtonian fluids a flow sets in immediately when a force is applied: they have no yield point. In laminar flow parallel liquid layers slide along each other which generate a shear stress between the layers. The following linear relationship exists between the shear stress τ, the viscosity η, and the velocity gradient (slope) dv/dy across the layers:

The viscosity of Newtonian fluids is constant at all shear strains in contrast to shear thickening or shear thinning.

Newtonian Liquid
Newtonian Fluid
Niagara Filter

Discontinuously working leaf filter for overpressure operation. The rectangular filter leafs, usually covered with metal weaves, hang vertically on a common header in a vertical pressure vessel. The filtration pressure normally does not exceed 6 bar. Niagara filters are well suited for both dry and wet discharge of filter cakes. Furthermore, they operate as precoat filters with a precoat layer consisting of filter aids. Niagara filters possess a wide range of application in many industries.

Nominal Filter Fineness
Filter Fineness
Non-Newtonian Fluid

A fluid whose flow properties differ from those of Newtonian fluids. The viscosity of non-Newtonian fluids depends on the applied shear forces and can show a time-independent decrease with decreasing shear forces (shear thinning), a time-independent increase with increasing shear forces (shear thickening) or a time-dependent increase with increasing shear forces (thixotropy)

Nonionic

Molecules that certainly are soluble in liquids, but do not dissociated as negatively charged anions and positively charged cations.

Nozzle Discharge
Nozzle-type Separator
Nozzle-type Separator

Special design of a disc stack separator, named for the solids discharge system. Permanently open nozzles are installed at the largest radius of the double conical separation space with an opening width adjusted for the specific separation task, through which the settled and highly thickened sludge is continuously discharged. The yeast separator used in food processing is a typical example for a nozzle-type separator. In order to safely establish a compression zone and to prevent a loss of the suspension into the sludge discharge, the solids concentration in the feed material must have a certain minimum value. If this cannot be done, a self cleaning separator can be chosen as an alternative.

Number of Revolutions

Number of rotations of a centrifuge drum or a filter element of a rotary filter, generally expressed in rotations per minute (rpm). While the number of revolutions of centrifuges can vary from 100 up to several 10,000 rpm, it lies in the range of 0.1 to 10 rpm for filters.

Nutsche Filter

Simple, discontinuously working apparatus for the cake filtration producing filter cakes of some 10 mm up to 0.9 m from granular, often crystalline substances. A nutsche filter consists in its basic form of a vessel, closed at the bottom by a filter surface that is filled with a suspension for filtration. Depending on design, the suspension will then be filtered either under vacuum or with overpressure of up to 10 bar in the direction of gravity. Agitators are frequently integrated into nutsche filters to improve the separation. The stirring allows a multitude of additional operations, which can entail a chemical reaction, crystallization, as well as washing and drying of the product. Those nutsches are then called filter reactors. The Nutsche Filter type is also popular in the laboratory due to the simple design and is used both as vacuum filter (Buchner funnel) and as pressure filter (BoFilTest). Filtration characteristics derived with these apparatus of only a few cm2 filter area are quite useful for predicting the performance of other filtration equipment, even continuously working ones.

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