Operational Cycle

The operating cycle is seldom less than two hours, and several sets of frames can be operated in rotation. The cake thickness should be more than 3 mm, 9 mm being a typical value. Sluicing of the cake with a jet of compressed air has been used to permit thinner cakes and shorter filtration times. The leaves are spaced sufficiendy far apart that there is always clearance between the finished cakes. 

SoHd carbon dioxide is produced ia blocks by hydrauHc presses. Standard presses produce blocks 25 x 25 x 25 cm, 50 x 25 x 25 cm, or 50 X 50 X 25 cm. A 25-cm cube of dry ice weighs 23 kg, allowiag for about 10% sublimatioa loss duriag storage and shipment (some 27-kg blocks are also produced). Dry ice is about 1.7 times as dense as water ice, whereas its net refrigerating effect on a weight basis is twice that of water ice. Automation and improved operating cycles have iacreased dry-ice press capacities so that one 50 x 50 x 30 cm press can produce more than thirty metric tons of dry-ice blocks per day (42). 

The transfer of supersaturated liquor from the vaporizer (point B, Fig. 18-69) often causes salt buildup in the piping and reduction of the operating cycle in equipment of this type. The rate of buildup can be reduced by circulating a thin suspension of solids through the vaporizing chamber however, the presence of such small seed ciystals tends to rob the supersaturation developed in the vaporizer, thereby lowering the efficiency of the recirculation system. 

By operating cycle. Filtration may be intermittent (batch) or continuous. Batch filters may be operated with constant-pressure driving force, at constant rate, or in cycles that are variable with respect to both pressure and rate. Batch cycle can vary greatly, depending on filter area and sohds loading. 

These methods of classification are not mutually exclusive. Thus filters usually are divided first into the two groups of cake and clarifying equipment, then into groups of machines using the same land of driving force, then further into batch and continuous classes. This is the scheme of classification underlying the discussion of filters of this subsection. Within it, the other aspects of operating cycle, the nature of the sohds, and additional factors (e.g., types and classification of filter media) will be treated explicitly or implicitly. 

For this duty cycle, the abbreviation is followed by the indication of the cyclic duration factor, the number of duty cycles per hour (c/h) and the factor of inertia (Ff). (See Section 3.4 for FI.) Thus, for a 40% CDF with 90 operating cycles per hour and factor of inertia of 2.5, the cycle will be represented by... 

The thermal efficiency of the process (QE) should be compared with a thermodynamically ideal Carnot cycle, which can be done by comparing the respective indicator diagrams. These show the variation of temperamre, volume and pressure in the combustion chamber during the operating cycle. In the Carnot cycle one mole of gas is subjected to alternate isothermal and adiabatic compression or expansion at two temperatures. By die first law of thermodynamics the isothermal work done on (compression) or by the gas (expansion) is accompanied by the absorption or evolution of heat (Figure 2.2). 

Figure 1-7. Operating cycle of a straight-lobe rotary compressor. Modified, courtesy of Ingersoll-Rand)...

The operating cycle of a belt vacuum filter consists of filtration, washing and dewatering stages. The solids suspension in water is separated under the following set of conditions ... 

Figure 14-38B. Example of gas turbine operating cycle. (Used by permission General Electric Company.)...

Figure 3-79. Straight lobe rotary compressor operating cycle [4,23].

Altitude and ambient temperature, as discussed earlier, can have significant effect on the performance of the generator, and fluctuations over the annual operating cycle will similarly influence the power station output. 

Monitoring the operating cycle and, where appropriate, seasonal shutdowns of plant, equipment (e.g. production process, 24-hour duty, etc.). 

Hydrogen-hydroxide cycle Provides the most favorable operating cycle and results in near neutral water of very high quality. The (hydrogen form) cation resin converts silica to silicic acid (H2Si03), which is then retained by the (hydroxide form) anion resin but breaks through first due to its very weak nature. Poor... 

Part of the operating cycle of water filters or softeners. It involves the upward flow of water to lift up the media bed to release and wash away dirt and other unwanted particulate matter and to reclassify the media. 

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