Speed control disc

A, had cell B, speed control for the motor drive C, support bar (a hole in this served as the confining chamber) D, support disc used to secure the load cell to the apparatus. (This initial load on the load cell—i.e., before compression—was regulated by adjusting the tension in these screws.) E, displacement transducer F, motor-driven micrometer screw G, power supplies for the load cell and the displacement transducer H, recorder. 

In these unbs, as with drum fibers, the feed suspenaon is supplied continuousH into trouts, in which the liquor flow is arranged in the same direction as the rotating di s. The latter move at various speeds, in the range 0.5-3.5 ipm. Submeigences up to 50% of the fibering sur ce can be arranged by level control Disc fibers are available in areas fix>m 0.5-300... 

The Ingedrive MVlOO vector control loops and vector modulation techniques allow an accurate speed control with a very low noise and stress in the motor. The drive operates in speed control mode by receiving the speed reference from the hoist automation level through a fieldbus communication interface. A torque bias compensation (feed-forward action) is also applied for the drive during the shaft starting and acceleration process where the torque reference is calculated at the hoist automation level. The synchronized operation between the electrical drive and the hoist brake disc system is done at the hoist automation level too through the torque feed-forward compensation. 

Prohibitions, (i) High speed abrasive disc saws and similar abrasive power equipment shall not be used for work on cadmium or cadmium-containing materials unless they are equipped with appropriate engineering controls to minimize emissions, if the exposure levels are above the PEL. 

Kassner used a rotating disc, for which the hydrodynamic conditions are well defined, to study the dissolution kinetics of Type 304 stainless steel in liquid Bi-Sn eutectic. He established a temperature and velocity dependence of the dissolution rate that was consistent with liquid diffusion control with a transition to reaction control at 860 C when the speed of the disc was increased. The rotating disc technique has also been used to investigate the corrosion stability of both alloy and stainless steels in molten iron sulphide and a copper/65% calcium melt at 1220 C . The dissolution rate of the steels tested was two orders of magnitude higher in the molten sulphide than in the metal melt. 

This research used mechanically agitated tank reactor system shown in Fig. 1. The reactor, 102 mm in diameter and 165 mm in height, was made of transparant pyrex glass and was equipped with four baffles, 120 mm in length and 8 mm in width, and six blades disc turbine impeller 45 mm in diameter and 12 mm in width. The impeller was rotated by electric motor with digital impeller rotation speed indicator. Waterbath thermostatic, equipped with temperature controller was used to stabilize reactor temperature. Gas-liquid mass transfer coefficient kia was determined using dynamic oxygenation method as has been used by Suprapto et al. [11]. 

The dissolution rate of a solid from a rotating disc is governed by the controlled hydrodynamics of the system, and it has been treated theoretically by Levich [104]. This theory considers only forced convection due to rotation and ignores natural convection, which may occur at low speeds of rotation. Figure 16 shows the solvent flow held near the surface of the rotating disc. The apparent thickness, h, of the diffusion layer next to the surface of the disc is given by... 

Paints were prepared from polymers of different composition and composition distribution using a standard copper thiocyanate based formulation similar to that which has been described by Hails and Symonds (11). A rotating disc technique (3) was used to measure the polishing rate (which is a measure of hydrolysis rate) of polymer and paint films. Standard coated panels were attached to a disc (Figure 4) in a radial display and this disc then rotated at a constant speed (1400 rpm) in a thermostatically controlled lank (25°C) of replenished sea water. They hydrolytic stability of the films was assessed by the rate of change of film thickness as measured by a surface profiling technique (Ferranti Surfcom). 

Latex Drying. The stripped latex was dried in a pilot plant NICHOLS/NIRO spray drier using centrifugal disc atomization. Different disc speeds were obtained by changing the atomizer drive pulleys. The disc speeds could be varied between 10,GOO-24, 000 rev/min, (tip speeds 62-150 m/sec) and were measured with a tachometer. The dryer has a 1.22 m inside diameter and is heated by a gas-fired heater. For a given dryer inlet temperature the dryer outlet temperature is controlled by varying the feed rate to the atomizer, e.g. increasing the feed rate lowers the outlet temperature. The dried resin was collected in a cyclone. 

From equations (5.6) and (5.7), it follows that under conditions of diffusion control the dissolution-rate constant should depend linearly on the square root of the angular speed of the disc rotation. As seen in Fig. 5.9, this is indeed the case (see also Refs 197, 300, 301, 303, 304, 307, 308). 

The ISE s available at the present time are neither sensitive enough nor selective enough for direct measurements of [Pb] in most natural systems. No procedure has yet been developed for the direct determination of I]c/Id under well-defined conditions. None of the ASV data published so far have included a determination of S and none have used a well defined rotating disc electrode for which 6 can be calculated as a function of rotation speed (see discussion by Turner and Whitfield (28, 29)). The normal procedure for estimating the fraction of electrochemically available metal involves a standard addition analysis of an untreated sample and is therefore dependent on the kinetics of the reactions controlling the assimilation of the ionic metal spike. In addition, the theory used in the present paper (28, 29) assumes... 

Some rotational viscometers employ a rotating disc, bar, paddle or pin at a constant speed (or series of constant speeds). It is extremely difficult to obtain tme shear stress, and the shear rate usually varies from point to point in the rotating member. In particular, the velocity field of a rotating disc geometry can be considerably distorted in viscoelastic fluids. Nevertheless, because they are simple to operate and give results easily, and their cost is low, they are widely used in the food industry. While they may be useful for quality control purposes, especially Newtonian foods, the reliability of their values should be verified by comparison with data obtained with well defined geometries (capillary/tube, concentric cylinder, and cone-plate). 

---