Centrifugal Spinning System

This system requires a pump with a best effieieney point (BFP) of 94 feet at 300 gallons per minute. If this is a eonventional industrial centrifugal pump with a BFiP of 94 feet, the shut-off head should be approximately 110 feet. And if the motor is a standard NFMA four pole motor spinning at about 1800 rpm, the diameter of the impeller should be approximately 10.5 inehes. If this pump were bought off the shelf from local distributor stock, it would probably be a 3 x 4 x 12 model end-suction centrifugal back pullout pump with the impeller machined to about 10.5 inches before installing the pump into the. system. And that s the way it is done. 

Forced-flow development enables the mobile phase velocity to be optimized without regard to the deficiencies of a capillary controlled flow system [34,35). In rotational planar chromatography, centrifugal force, generated by spinning the sorbent layer about a central axis, is used to drive the solvent... 

The SpinTek technology involves membranes that are bonded to two sides of a disk. Multiple disks are mounted on a hollow shaft that rotates the membranes, and stationary turbulent promoters are mounted near the rotary membranes to create high shear and turbulence. Liquid waste is pumped into the system that hits the spinning disk and spreads across the membrane. Centrifugal force pulls the solid waste outward to the perimeter of the filter disks, where it is removed from the system. By pulling the solids outward, the centrifugal force keeps the filter clear so that the system can run continuously. 

The extra terms appear because in noncartesian coordinate systems the unit-vector derivatives do not all vanish. Only in cartesian coordinates are the components of the substantial derivative of a vector equal to the substantial derivative of the scalar components of the vector. The acceleration in the r direction is seen to involve w2, the circumferential velocity. This term represents the centrifugal acceleration associated with a fluid packet as it moves in an arc defined by the 9 coordinate. There is also a G acceleration caused by a radial velocity. In qualitative terms, one can visualize this term as being related to the circumferential acceleration (spinning rate) that a dancer or skater experiences as she brings her arms closer to her body. 

The disc centrifuge photosedimentometer (DCP) is an instrument used to determine the particle size and size distribution of latices, pigments and other particulates. Separation is based on Stokes Law for the sedimentation of particles in a centrifugal force field. Particles are assumed to be spherical. In the most common mode of operation the separation takes place in a cylindrical cavity of known dimensions and containing a known volume of fluid. A dilute suspension of the particles of Interest is injected onto the surface of the fluid while the disc is spinning and the particles sediment in the centrifugal force field radially outward past a detector system. The appearance time of the particle at the detector, t, in minutes is given by... 

We have made explicit the fact that this term is evaluated in the molecule-fixed axis system (with q = 0). The first term was introduced previously in equation (9.104) but the second term is less familiar it represents a centrifugal distortion correction to the spin-spin interaction but was not, in fact, included in the analysis of the CH spectrum so we shall not discuss it further here. 

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