Pressure drop optimal range

The quantity of catalyst used for a given plant capacity is related to the Hquid hourly space velocity (LHSV), ie, the volume of Hquid hydrocarbon feed per hour per volume of catalyst. To determine the optimal LHSV for a given design, several factors are considered ethylene conversion, styrene selectivity, temperature, pressure, pressure drop, SHR, and catalyst life and cost. In most cases, the LHSV is ia the range of 0.4—0.5 h/L. It corresponds to a large quantity of catalyst, approximately 120 m or 120—160 t depending on the density of the catalyst, for a plant of 300,000 t/yr capacity. 

Performance criteria for SCR are analogous to those for other catalytic oxidation systems NO conversion, pressure drop, catalyst/system life, cost, and minimum SO2 oxidations to SO. An optimum SCR catalyst is one that meets both the pressure drop and NO conversion targets with the minimum catalyst volume. Because of the interrelationship between cell density, pressure drop, and catalyst volume, a wide range of optional catalyst cell densities are needed for optimizing SCR system performance. 

The upper limit for this technique is 400 nm. Optimization of parameters for fine particulate packing material carried out on special test mixes was found to shorten analysis time without the usual pressure drop. The use of 1.5 pm particles gave faster and more efficient separation for a wide range of analyses, and using non-porous material was found to offer advantages over the usual porous material [56]. An extension of the technique to powders such as cement, flour and chalk has also been described [57]. The packed column consisted of 50 and 250 pm diameter particles. 

Typically, the air-stripper manufacturer will supply liquid flow ranges acceptable for a particular tower. Selecting an air stripper for which the design flow is at the lower end of the tower s rated capacity will produce high contaminant removal rates, but may not optimize power requirements. For large-scale systems where significant operational costs may be incurred by overdesigning the system, the use of pressure-drop curves and calculations such as Eqs. (1)-(13) are required. 

Industrial cyclone separator Two problems maximization of overall collection efficiency while minimizing (a) pressure drop and (b) cost. NSGA Pareto-optimal solutions of the two problems are similar although their ranges are different Ravi et al. (2000)... 

This indicates that a higher cross-flow velocity under turbulent conditions can result in more than proportional increase in the pressure drop requiring larger pump discharge pressure to maintain a specified recirculation rate. This limits the number of modules that may be placed in series to minimize capital costs. Typical range of cross-flow velocity values is 2 to 7 m/s. The choice of pump is critical to obtain efficient fluid recirculation. It is critical to understand the shear sensitivity of the fluid/particle to be processed to determine the optimal cross-flow velocity in situations where shear-sensitive materials are involved. 

Series coupling of normal-length columns (30 cm) to increase efficiency or to optimize the pore-size range for the separation is common practice. Series coupling of columns is facilitated by the low optimum mobile phase velocity and thus lower column pressure drop per unit column length, typical for SEC separations. 

The light-off temperature increased from 150°C at 400 ppm to 190 °C at 4700 ppm. It was significant that these were among the lowest reported for VOC combustion. A range of 230-300 °C is more usual. The main drawback to this reactor configuration is the pressure drop across the membrane. The authors pointed out that increased pressure drop means increased operating cost, and that membrane optimization is needed to obtain the right balance between pressure drop and conversion. 

Qu and Mudawar [19] discussed a comprehensive methodology for optimizing the design of a two-phase microchannel heat sink. In their study, flow rate and pressure drop were key constraints in the design of microchannel heat sinks which often demanded specialized micro-pumps with performances dictated by either flow rate or pressure drop. For a fixed flow rate of Q = 60 ml/min and a device heat flux of qeft" = 500 W/cm, the acceptable range of two-phase operation was confined so that the dissipative heat flux will not exceed the maximum dissipative heat flux of the microchannel heat sink. For two-phase microchannel heat sinks, the minimum dissipative heat and maximum dissipative heat are defined as ... 

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