Balling disk

The unsuitable nature of many commercial instruments which are in common use clearly illustrates the confusion prevalent in the field of viscometric measurements. Many instruments measure some combination of properties which depend only partly on the fluid consistency since the flow is not laminar. In others the shear rates are indeterminate and the data cannot be interpreted completely. Examples of such units include rotational viscometers with inserted baffles, as in the modified Stormer instruments in which the fluid flows through an orifice, as in the Saybolt or Engler viscometers instruments in which a ball, disk, or cylinder falls through the fluid, as in the Gardiner mobilometer. Recently even the use of a vibrating reed has been claimed to be useful for measurement of non-Newtonian viscosities (M14, W10), although theoretical studies (R6, W10) show that true physical properties are obviously not obtainable in these instruments for such fluids. These various instru-... 

Figure 109. Photograph showing the classification effect in a balling disk...

The voltage and amperage were recorded as a function of time using a Varian G-2000 dual pen recorder. The amperage circuit was equipped with a ball disk integrator permitting a direct readoff of the coulombic... 

FIGURE 19. Volumetric wear at ball, disk and total wear, determined in Fretting tests with HIPed Si3N4 ball against Si3N4-BASand HIPed Si3N4 disks for comparison ... 

All the friction measurements were performed under a fixed load (3.0 or 20.0 N) and temperature (25 °C) and along the same ball and disk tracks the radii of the ball and disk tracks are 9.5 and 20.7 mm, respectively. The roughness values (Rafl of the ball and disk are 11 and 10 nm respectively. However, different pairs of the ball/ disk tracks were used for the comparison of the friction measurement in the absence versus presence of the polymers in buffer solution, due to significant wear of the tribo-pair in the former case. The calculated maximum contact pressures are 0.86 and 0.46 GPa for 20.0 and 3.0N, respectively (see table 1). 

All the instrumental parts that are expected to be coated with the polymer, including the waveguides for the OWFS and the balls/disks of all tribological instruments, were oxygen-plasma cleaned for ca. 2 min in a Harrick Plasma Cleaner/Sterilizer PDC-32G... 

The ball-disk integrator is capable of excellent results on all but the most exacting analyses. The recorder used with it must be of top quality and in excellent working order to obtain full capability of the integrator. 

Process-control valves cannot tolerate solids, especially abrasives, in the gas or liquid stream. In applications where high concentrations of particulates are present, valves tend to experience chronic leakage or seal problems because the particulate matter prevents the ball, disk, or gate from completely closing against the stationary surface. 

There are many different ways to manipulate the flows of material and energy into or out of a process for example, the speed of a pump drive, screw conveyer, or blower can be varied. However, a simple and widely used method of accomplishing this result with fluids is to use a control valve. The control valve components include the valve body, trim, seat, and actuator. The valve body contains an orifice that allows for the flow of liquids and/or gases. The trim modulates the flow rate and can be a plug, ball, disk, or gate (Borden, 1998). The seat consists of protective material (typically metal... 

Softening point for bitumen (ring and ball method) NF T 66-008 (future NF EN 1427) ASTM D 36 Temperature at which a ball passes through tin asphalt sample disk attached to a ring... 

Crushing and grinding uses mechanical force to break larger particles into smaller ones. A variety of tools are used depending on the particle s size and hardness. Large particles are crushed using jaw crushers capable of reducing particles to diameters of a few millimeters. Ball mills, disk mills, and mortars and pestles are used to further reduce particle size. 

Wear parts Bearings Jet-nozzle coatings Slurry valves Extrusion dies Abrasive pump seals Computer disk coatings Engine parts Medical implants Ball bearings Drawing dies Textile machinery... 

A conventional optical test rig is shown in Fig. 2 [13]. A superfinished steel ball is loaded against the flat surface of a float-glass disk. Both surfaces can be independently driven. Nominally a pure rolling is used as shown in Fig. 2 that the disk is driven by a shaft and the ball is driven by the disk. 

The silica him thickness was determined as a function of the disk radius by an optical interference method using the spectrometer. A steel ball was loaded against the silica surface to obtain an interference pattern of a central, circular Hertzian area with surrounding circular fringes due to the air gap between the deformed ball and flat. The thickness of... 

If the ball contacts the surface of the glass disk without oil, /z = 0, and then the pure phase change of the system can be obtained as follows ... 

Fig. 24—Measuring instrument (a) interference lights of the measuring system (b) the scheme of the experiment system. For applying an external voltage to the oil film, one end of direct current (dc) power keeps contacting with the Cr layer on the glass disk, and the other end contacts a shaft welded on the steel ball through an electric brush. The SI02 layer with a thickness of 300 nm has been coated on the surface of the Cr film.

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