Optimizing for Power Consumption

The optimum helix angle cp for power consumption can be determined by setting  

To evaluate the first derivative of power consumption Z with respect to helix angle 9, the power consumption has to be written as an explicit function of the helix angle. Using the equation in Section 7.4.1.3 the following expressions can be derived  

The optimum helix angle now has to be found from the following equation  

Optimum helix angle versus channel depth 

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The instrument MIMOS 11 is extremely miniaturized compared to standard laboratory Mossbauer spectrometers and is optimized for low power consumption and high detection efficiency (see Sect. 3.3) and [326, 327, 336-339]. All components were selected to withstand high acceleration forces and shocks, temperature variations over the Martian diurnal cycle, and cosmic ray irradiation. Mossbauer measurements can be done during day and night covering the whole diurnal temperature... 

As mentioned in this review, AMPLEDs are especially attractive for motion picture applications. The Pay-Per-View effect in OLED displays reduces power consumption and extends operation lifetime. Motion picture applications also minimize image retention and optimize display homogeneity. AMOLED has been widely viewed as a promising display technology in competing with AMLCD and plasma displays. The dream of using organic semiconductor films for optoelectronic device applications has become a reality. 

Robust formulations are today an absolute prerequisite. Concerning the production of granules, the granule size distribution should not vary from batch to batch. The key factors are the correct amount and the type of granulating liquid. The interpretation of the power consumption method can be very important for an optimal selection of the type of granulating liquid. The possible variation of the initial particle size distribution of the active substance and/or excipients can be compen-... 

Optimal compressor- types for the various power ranges are plotted in Fig. 4.1-29, which was calculated on the bases of 1 bar intake pressure and an isothermal efficiency of 64% [24]. It can give only approximate reference points for the most favourable area of application, which varies depending on the manufacturer. If the intake pressure is greater than 1 bar, as is the rule, it is necessary to recalculate. For example the compression of ethylene at a flow-rate of 64000 kg/h 51 130 Nm3/h (Standard cubic metre per hour) from 231 to 2151 bar, corresponds to a real intake volume flow-rate at 231 bar of 161 m3/h, and a power consumption of 8200 kW. 

The electrical power consumption of the refrigerator depends only on the separation condition. The pumping mode is optimal for high extraction pressures (more than 150 bar), low extraction temperatures (40 to 80°C), and separation pressure between 45 and 60 bar. 

In a chemical plant the capital investment in process piping is in the range of 25-40% of the total plant investment, and the power consumption for pumping, which depends on the line size, is a substantial fraction of the total cost of utilities. Accordingly, economic optimization of pipe size is a necessary aspect of plant design. As the diameter of a line increases, its cost goes up but is accompanied by decreases in consumption of utilities and costs of pumps and drivers because of reduced friction. Somewhere there is an optimum balance between operating cost and annual capital cost. 

For absorption controlled by diffusion through a gas film, it is necessary to provide a large enough interface area the interface area depends on the liquid to gas flow rate ratio, VL/VG, essentially for a defined dispersity of the absorbent. On the other hand, increasing VJV,c must lead to increased power consumption so it is important to optimize the flow rate ratio.. The experimental results on the influence of VL/VG on the sulfur-removal efficiency are shown in Fig. 7.13. To keep the conditions of atomization essentially the same, all the experiments in this set were carried out at a fixed volumetric liquid flow rate, VL while the gas flow rate, VG, for each run varies according to the required liquid to gas flow rate ratio and, simultaneously, the corresponding concentration of Ca(OH)2 was used to keep the ratio of Ca/S the same as 1.4. 

The optimization of steam turbine systems is well understood and more widely practiced than the power consumption optimization of alternatives such as electric motors and gas turbines. In addition to the initial cost, the major disadvantage of steam turbines is their low tolerance for wet or contaminated steam. Wet steam can cause rapid erosion, and contaminants can cause fouling. Both will reduce the turbine s efficiency and will shorten its life. Steam quality monitoring is therefore important to maintain the reliability and to reduce the operating cost of steam turbines. 

They found that optimal conditions of the position of the stirrer exist in the range of 0.25 < HJd < 0.75 for both turbine and propeller stirrers. Their work suggests that beyond a Reynolds number of 20,000, the power number becomes constant. An increase in solid content increases the power consumption, while an increase in gas velocity reduces the power consumption. Kurten and Zehner (1979) examined the effect of gas velocity on the power consumption for suspension of solids and found that because of simultaneous aeration, a higher power input is required for suspension in the presence of gas. This is mainly due to the reduced liquid circulation velocity in the presence of gas bubbles. Most recently, Albal et al. (1983) evaluated the effect of liquid properties on power consumption for both two- and three-phase systems. They found that power consumption per unit volume increases with solid concentration. The influence of particle size on power consumption increases with the solids concentration. For an unconventional arrangement of a stirrer, they also found different Ne-Re curves for glycerine and CMC solutions. 

Induction furnaces are optimal for the melting operation. Their good temperature control permits accurate adjustment of the degree of oxidation. Since the melt is held in constant turbulent motion by the magnetic field produced in the primary coil, it is well mixed, even for short melt times. In comparison to the most frequently used resistance furnaces, plant cost and power consumption are higher. 

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