Circulative ratio

There are relationships between the independent size separation device parameters and the dependent size separation efficiencies. For example, the apparent bypass value does not affect the size distribution of the fine stream but does affect the circulation ratio, ie, the ratio of the coarse stream flow rate to the fine stream flow rate. The circulation ratio increases as the apparent bypass increases and the sharpness index decreases. Consequendy, the yield, the inverse of the circulating load (the ratio of the feed stream flow rate to the fine stream flow rate or the circulation ratio plus one), decreases hence the efficiencies decrease. For a device having a sharpness index of 1, the recovery efficiency is equal to (1 — a). 

FIG. 11 91 Effect of circulation ratio on the overall heat-transfer coefficient of an air-cooling coil. 

C = The average boiler circulation ratio at full load, lbs water-steam mixture circulated in a circuit per lb of steam leaving that circuit. (C is average of all the circuits in the boiler.)... 

Which is adequate to maintain a circulation ratio of 3 1, including allowances for the pressure drop across the piping. 

The air temperature of the intermediate cell is assumed to be equal to 15 °C. This intermediate cell is dehumidified by the membrane contactor system placed at the evaporator inlet. The dehumidified air is driven to an air curtain at the top of the door separating the intermediate cell from storage cell. The heat load of the system and the air circulation ratio are assumed to be constant. The temperature of CaCl2 solution at the inlet of the membrane contactor is assumed to be equal to the indoor IC air temperature. The following parameters have been measured ... 

Fig. 24. Influence of solids circulation ratio on separation efficiency for first-stage separation (after Li and Wang, 1992).

No. Refrigerant Chemical Name or Composition (% by mass) Evaporator Condenser Pressure, Pressure, i MPa MPa Refrigerant Compression Net Refrigerating Circulated, Ratio Effect, kJ/kg g/s Specific Volume of Liquid Circulated, Suction Gas, L/s m /kg Compressor Displacement, L/s Power Consumption, kW Coefficient of Performance Comp. Discharge Temp., K... 

It is well known in industrial media that a large catalyst to oil circulation ratio (C/0) enhances the gasoline yield and selectivity, as the coke yield is kept constant. This effect cannot be described by kinetics if we consider that is the same for all reactions. In this case the curve yield versus conversion would remain unaffected by the C/0. To demonstrate the effect of coke on selectivity, a second set of experiments was done where the variations of conversion were obtained by variation of the equilibrium catalyst mass in the MAT (initial c=0). The comparison of the two sets shown on the figure 4, demonstrates unambiguously that the coke drops the gasoline and coke selectivitres and enhances the gas selectivity. This is a direct laboratory representation of the industrial effect of C/O. In industrial plants, the final coke content of the catalyst is inversely proportional to the C/O because the coke yield is maintained constant to equilibrate the thermal balance of the plant. 

Reboiler circuits may set tower elevations. A thermo-syphon reboiler requires enough liquid static head to provide a driving force so that the reboiler will work properly. This head determines the circulation ratio and the amount of vapor returned to the tower, thereby setting the entire tower gradient. Reboiler circuits must be considered with pump NPSH considerations as they set the tower elevation. 

Several solid circulation ratios, temperatures and air to fuel ratios have been tested in a 7-10 kWj CLC prototype. 

The circulation ratio of the isothermal reactor is about ten times that occurring in most conventional multicompartment reactors. The large difference in circulation rate results in uniform temperatures, uniform sulfate concentration, and larger gypsum crystals [18]. Previously known as the Swenson (Gulf) Isothermal Reactor and offered by Badger, it is now offered by Raytheon Engineers and Constructors, U.S.A. 

For the purpose of this study, a contactor column with two theoretical stages and with the feed composition shown in Table 2 was simulated. The concentration of the lean TEG stream was 99.0 weight % TEG, and it was assumed the TEG temperature was the same as the feed gas. The feed gas was saturated with water at feed conditions. For each contactor pressure and temperature, the lean TEG circulation ratio was varied. 

Figure 3. Absorption of BTEX as a function of temperature and circulation ratio (P=300psia=2069kPa)...

In Figure 3, BTEX absorption is plotted as a function of circulation ratio (TEG liquid volume rate per gas standard volume rate) for three temperatures 77,95 and 122 °F (25, 35 and 50 °C) and for pressure of 300 psia (2069 kPa). Absorption increases with decreasing temperature and increasing circulation ratio. Similarly, Figure 4 presents the absorption of BTEX as a function of circulation ratio for three temperatures listed in Figure 3 but at 1000 psia (6897 kPa). Figures 3 and 4 elearly indieate that at eonstant pressure, the absorption decreases with inerease in temperature. 

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